The Silicon Valley Bank crisis that occurred in March 2023 highlights the importance of studying the risk transmission mechanism underlying monetary policy. To explore this mechanism in the monetary and financial services sector from the perspective of asset-liability management, the relationships between asset- and liability-side risks and the corresponding action direction of those risks were empirically studied based on the risk-taking channel theory of monetary policy using publicly available information on 176 Chinese monetary and financial services companies covering the period of 2000 to 2022. The analysis shows that asset-side risks are transmitted through monetary policy as liability-side risks in the monetary and financial service sectors. If the liability side passively takes on these risks, the action direction of monetary policy to asset-side risks is determined; when the liability side actively takes on these risks, monetary policy exerts opposite effects on both types of risks. This conclusion somewhat deepens our understanding of the risk transmission mechanism of monetary policy, which is helpful in better formulating and implementing monetary policy. Another recent example is Credit Suisse, which ranked 23rd among the global systemically important banks and was acquired by UBS Aktiengesellscharf on March 19, 2023.Since 2023, monetary and financial services companies  across Europe and America have shown certain signs of financial crises, which have primarily been attributed to the failure of asset–liability management  to undergo timely adjustments in accordance with changes in monetary policy. The following exemplifies this point: On March 10, 2023, the Silicon Valley Bank, which ranked 16To control inflation rates, interest rates have been continuously elevated as a result of the current quantitative easing of monetary policy implemented by the government, and the corresponding abnormal inversion status, in which the short-term interest rate was abnormally higher than the long-term interest rate, has led to a significant increase in financing costs for those monetary and financial services companies. However, several such companies have failed to adjust the total quantity and structure of their assets and liabilities following the changes in monetary policy, resulting in losses from distressed investments . TherefoPrevious studies conducted from the perspective of macrosupervision that were focused on the risk transmission mechanism of monetary policy in monetary and financial services have tested several risk transmission mechanisms of monetary policy on the asset side, specifically accounting for the factors of loans, investments, risky assets, impairment reserves, credit capital budgets, and other assets in the monetary and financial services sector , 3. PrevMacro- and regulatory-level studies focus only on the asset-side risk of the macro, monetary and financial services sectors as a whole without distinguishing asset-side risks from liability-side risks at the micro and enterprise levels, and therefore these studies inherently suffer from two problems. First, from the perspective of the risk transmission mechanism of monetary policy, assets and liabilities play different roles in the transmission process. From the perspective of the micro and enterprise levels, monetary policy typically acts on liabilities first and then transfers such action to assets. Considering the fact that asset-side risks and liability-side risks are not completely independent of each other, and given changes in monetary policy, there might be a risk transmission mechanism between the asset and the liability sides . AdditioSome previous studies begin from the micro and enterprise level perspective, exploring the risk transmission mechanism of monetary policy through loans, investments, and the financing behaviors of specific monetary and financial services companies using various models, including panel data regression, the dynamic two-step system generalized moment method, difference-in-difference (DID), the general equilibrium of open economy, real option, and ownership structure. It was found that monetary policy transferred risks through short-term interest rates, target customers, market power, regulatory means, impairment reserves, and liquidity. Additionally, the different characteristics  of each monetary and financial services company leads to different transmission results: those companies that had major clients and operated in lowly innovative industries with a large size, high market power, sufficient capital, strong liquidity, irreversible investments and inflexible operation were, in general, barely influenced by changes in monetary policy –28.Currently, these micro- and enterprise-level studies still suffer from limitations. First, rather than merely focusing on asset-side risks, these studies have expanded the analysis to include the source of financing perspective, such as bond market financing , retaineThere is a growing body of theoretical research regarding the risk-taking channel of monetary policy in the monetary and financial services sectors , but litIn this study, using monetary and financial services companies in China as the research sample, the following two questions are explored: (1) Does monetary policy act upon the liability-side risks of monetary and financial services before transmitting to asset-side risks? (2) Does monetary policy act upon the asset-side risks in the same direction as it does upon the liability-side risks of monetary and financial services? This study contributes to the literature in the following ways. First, the risks faced by monetary and financial services companies are clearly divided into asset-side risks and liability-side risks, and the transmission mechanisms of monetary policy to each of these risk dimensions are analyzed. Additionally, an empirical analysis is performed using panel data from the monetary and financial services company level rather than using time series data to further examine the risk transmission mechanism of monetary policy at a more detailed, micro and enterprise level. Finally, the risk transmission relationships between the liability- and asset-side in the risk transmission mechanism of monetary policy in the monetary and financial services sector are determined on the basis of the risk-taking channel theory of monetary policy, thus actively combining perspectives on both the macro and regulatory levels and the micro and enterprise levels.The remainder of the study is organized as follows: In Section II, the theoretical hypotheses on the risk transmission mechanism of monetary policy in the monetary and financial services industry are proposed by reviewing and analyzing the previous performed studies and literature. In Section III, the corresponding testing models are constructed and the relevant variables and data used are described. In Section IV, the empirical results of relevant models analyzed, and the results for those hypotheses are tested in Section II. Given the hypothesis and test results, Section V conducts a further discussion and analysis from the perspective of asset–liability management. Section VI presents the conclusions, implications, and future developments and expectations.The risk-taking channel theory of monetary policy, in which risk-taking is defined as the extent to which monetary and financial services enterprises monitor their lending was proposed in 2010. In this theory, monetary policy affects risk-taking through two pathways that work in opposite directions: the interest rate transmission effect and the risk transfer effect . The theRisk-taking channel theory can only be used to analyze asset-side risks and do not take into account liability-side risks or the interactions between asset-side risks and liability-side risks. However, it has been observed that monetary and financial services companies respond to changes in monetary policy by adjusting both their asset and their liability structures. Based on this fact, both the asset- and the liability-side of monetary and financial services companies are responsive to the impact of monetary policy, and a transmission relationship may exist between them. Risk-taking on the liability side is divided into active risk-taking and passive risk-taking. Active risk-taking means that when monetary policy changes, monetary and financial services companies actively adjust their risk level to maximize profits, while passive risk-taking means that in case of changes in monetary policy, the monetary and financial services companies do not take the initiative to respond. However, the liability-side risks change spontaneously because the liability side is dominated by deposits from individual and corporate savings, which are subject to fluctuations. When monetary policy is loose/tight, deposits, as a fundamental part of the money supply, increase/decrease accordingly, and as the proportion of deposits increases/decreases, the liability-side risks decrease/increase accordingly.It has been concluded that when monetary policy is stringent, the underlying interest rate benchmark drops, leading to a decrease in the money supply, a decrease in the liability-side deposits of monetary and financial services companies, and an increase in the level of reliance on interbank liability financing for those companies; in contrast, when monetary policy is lax, the underlying interest rate benchmark rises, leading to an increase in the money supply, an increase in the liability-side deposits of monetary and financial services companies, and ultimately causing a decreased reliance on interbank liability financing for those companies . TherefoHypothesis 1: Considering that the liability side of monetary and financial services companies inevitably bears passive risks, the flexibility of monetary policy has an adverse effect on asset-side risks; in other words, a laxer monetary policy reduces asset-side risks, whereas a more stringent monetary policy increases asset-side risks.Two contradictory effects were observed for the risk transmission mechanism between the liability-side and the asset-side of monetary and financial services companies. One of these effects is the risk transfer effect, which suggests that liability-side risks are directly transmitted to the asset side, and the higher risks and higher costs of the liability side are covered by the higher returns of the asset side. Therefore, asset-side risks are positively correlated with liability-side risks; in other words, the higher the risks generated from the liability side are, the higher the risks transferred to the asset side. The other effect is the risk dispersion effect. The risk dispersion effect suggests that when the liability-side risks rise, the monetary and financial services companies tend to withhold any increase in their exposure to risky assets (such as risky investments and risky loans) within their investment portfolio and rather tend to pursue a more stable return in exchange for the higher expected returns associated with increased exposure to risky assets; in other words, the higher that the risks generated from the liability side are, the less risk that is taken on the asset side. However, regardless of the recoverability of loans to external customers, interbank liability financing should always be fully repaid. This stringent, full-payment nature of interbank financing on the liability side, in turn, reinforces the risk dispersion effect and would outweighs the risk transfer effect. Thus, it has been observed that the higher that the risks generated from the liability side are, the lower the risks taken on the asset side . In thisHypothesis 2: The higher that the proportion of nondeposit liabilities of monetary and financial services companies is, the higher the degree of effort required for loan supervision. That is, the risks on the liability side are transmitted to the risks on the asset side, but risks on the liability side have an adverse effect on the risks on the asset side.When monetary policy is lax, the money supply increases, and the deposits on the liability side of monetary and financial services companies increase. As a statutory requirement within the monetary and financial service sectors, deposits obtained from individuals and enterprises are protected by statutory insurance policies. When the recoverability of distressed investments or loans suffers from unexpected turbulences in the general economy, the losses are reduced by the statutory insurance policies, and the net losses suffered by monetary and financial services companies are mitigated accordingly ; therefoHypothesis 3: With an increase in the underlying interest rate benchmark, the nondeposit liabilities born by monetary and financial services companies increase accordingly. That is, a stringent monetary policy increases liability-side risks, whereas a lax monetary policy reduces liability- side risks.According to the risk-taking channel theory of monetary policy, the impact of monetary policy on the asset-side risks of monetary and financial services companies depends on the relative weights of the interest rate transmission effect and the risk transfer effect . In thisHypothesis 4: With an increase in the underlying interest rate benchmark, the efforts required for loan supervision by monetary and financial services companies increase. That is, a stringent monetary policy decreases asset-side risks, whereas a lax monetary policy increases asset-side risks.ARISKi,t indicates the asset-side risks; LRISKi,t denotes the liability-side risks; MPt represents the monetary policy; Ci,t is a control variable; δi is the individual heterogeneous feature; θt is the time-fixed effect; and εi,t, ζi,t, and ϑi,t are error terms.Referring to past practice , 41, theModel (1) was designed to test whether monetary policy had a significant impact on the asset-side risks of monetary and financial services companies. Model (2) was designed to test whether the liability-side risks born by monetary and financial services companies are significantly affected by monetary policy, and Model (3) was used to test whether the liability-side risks born by monetary and financial services companies significantly influence the asset-side risks. Taking Models (1) through (3) as a whole, whether risks were transmitted to the asset side through the liability side for monetary and financial services companies.Referring to past practice , whetherAt the same time, unlike central banks in developed nations, the People’s Bank of China  operates a reserve system, where not all deposits can be used for loan issuance, and a portion of the deposits are in the form of legal reserve deposits, which are made by monetary and financial service enterprises to the central bank. In this study, the legal reserve ratio (RESERVE) was adopted as a proxy variable for monetary policy.Referring to practice , the proDeposits are generally guaranteed by a deposit insurance system, but interbank liability financing is not insured. Interbank liabilities include the interbank borrowing and selling of repurchased financial assets, which are riskier than deposits. Although China’s deposit insurance regulations, which have been in effect since May 1, 2015, provide for the full repayment of all insured deposit accounts of the same depositor at the same insured institution covering the combined amount of principal and interest of the funds within 500,000 CNY, it is argued in this study that the impact of the deposit insurance factor is extremely small. First, from a practical point of view, China had an implicit deposit insurance system in place prior to the establishment of the official system because bank deposits have been covered by the implicit guarantee of national credit since before the establishment of the deposit insurance system in China. Second, following the formal establishment of the deposit insurance system, bank deposits could be covered in full by the vast majority of depositors, which is basically equivalent to full deposit insurance. Considering the facts that deposits are unlikely to be run at the first sign of a crisis and that runs on interbank liabilities have played a key role in the bankruptcy and failure of many financial institutions, many recent studies have adopted and utilized this method of measuring liability-side risk-taking, given that monetary and financial services enterprises with a high proportion of nondeposit liabilities are more susceptible to changes in the level of market liquidity, which makes them riskier. With reference to practice , this stReferring to past practice , the folIn addition, to incorporate qualitative factors such as risk culture and corporate governance, a dummy risk management variable, COMMITTEE, was introduced to control for microlevel factors. If the risk management committee is headed by an independent director, more than half of its members are nonexecutive directors, and it meets more than four times a year, then it is assigned a value of 1 and a value of 0 otherwise.https://www.wind.com.cn/). The banks operating in China from 2000 to 2022 were selected from this database, and those with observations of less than 4 years old were excluded to obtain the final sample of 176 banks. With 176 monetary and financial services companies in China between the years between 2000 and 2022 composing the study sample, all monetary and financial services company variables were subjected to 1% quantile and 99% quantile standardization to mitigate the effect of extreme values. The sample in this study is drawn from the Wind Database  variable takes DRATE for the first two of the three periods and R007 for the last period to better simulate the transmission effect.In general, based on the regression analysis results, all four hypotheses proposed in this study were supported by empirical data through the use of statistical methods, which supports that claim that monetary policy first interacts with the liability-side risks of monetary and financial services companies and then transmits to the asset-side risks. The results are consistent with the conclusions . At the For Period I, which used data between 2000 and 2007, the regression results are presented in Columns (1) through (3) of the From the perspective of the liability side, which mainly consists of deposits, when the monetary policy is stringent, deposits are expected to decrease, and the proportion of nondeposit liabilities passively increases with other factors being equal. In contrast, when the monetary policy is lax, deposits are expected to increase, and nondeposit liabilities passively decrease with other factors being equal. On the other hand, from the perspective of the asset side, the decrease in the underlying deposit interest rate benchmark reduces the liability cost of monetary and financial services companies. If their distressed investments and loans could be even partially recovered, their profits would increase, creating a motive for them to put effort into monitoring the recoverability of investments and loans, which in turn would reduce the risks associated with these investments as well as the asset-side risks. This result supports Hypothesis 1. At the same time, it can be observed that the liability side plays an intermediate role in the transmission mechanism of monetary policy to the asset side in an adverse relationship: the greater the level of risk taken on the liability side is, the lower the level of risk taken on the asset side.For Period II, which used the data between 2008 and 2014, the regression results are presented in Columns (4) through (6) of Additionally, from the results displayed in Columns (5) and (8) of Taking both the MP and LRISK variables into account, the regression results are shown in Columns (6) and (9) in (3) Comparing the regression results displayed in Columns (4), (6), (7) and (9), the coefficients of liability-side risks can be seen to remain negative and significant for asset-side risks, indicating that liability-side risks play an intermediate role in the transmission mechanism of monetary policy to asset-side risks with all other conditions being equal. In other words, monetary policy significantly interacts with the asset- and liability-side risks of monetary and financial services companies, and at the same time, the risk transmission mechanism of monetary policy suggests that monetary policy transmits risks to the asset side by influencing liability-side risks. In addition, a more lax monetary policy decreases the level of liability-side risks, which, in turn, leads to an increase in the level of asset-side risks, and vice versa. Unlike past findings showing that monetary policy transmission becomes weaker with increased market concentration , our finWhen in a lax monetary environment, the deposits of monetary and financial services companies increase. Given that these deposits are subject to fewer fluctuations than other liabilities (such as interbank repurchases) and are protected by statutory deposit insurance, the liability-side risks are reduced. As a source of liability financing that is subject to fewer fluctuations, deposits create a precondition for monetary and financial services companies to be actively exposed to higher levels of risk and thus gain higher returns on the asset side. On the one hand, monetary and financial services companies with high deposits often face an excess of liquidity, which negatively affects their profitability; thus, they are motivated to actively take more risks on the asset side . On the Based on the publicly disclosed data of 176 monetary and financial services companies in China over the years of 2000 to 2022, the risk transmission mechanism of monetary policy has been discussed from the perspective of asset-liability management based on the risk-taking channel theory of monetary policy, and the following findings have been drawn:(1) The influences of monetary policy on the asset- and liability-side risks of monetary and financial services are not independent of each other. The effect of changes in monetary policy is transmitted to asset-side risks through liability-side risks. However, in an adverse relationship between asset- and liability-side risks, an increase in the level of liability-side risks leads to a decrease in the level of asset-side risks.(2) Given that the liability side of monetary and financial services companies bears passive risks, monetary policy exerts a negative effect on asset-side risks: lax monetary policy decreases asset-side risks, while a stringent monetary policy increases asset-side risks.(3) Given that the liability side of monetary and financial services also actively takes on risks, monetary policy has a contradictory effect on asset-side risks and liability-side risks; in other words, a more lax monetary policy increases asset-side risks but decreases liability-side risks, while a more stringent monetary policy decreases asset-side risks but increases liability-side risks.Based on the findings above, the following implications are proposed:(1) For the implementation of monetary policy and related macro supervision activities, standard setting committees and regulatory authorities are encouraged to incorporate new data and new procedures from a regulatory perspective to oversee the compliance and asset- and liability-side risks of monetary and financial services companies. As demonstrated in this study, changes in monetary policy have opposite effects on the asset- and liability-side risks of monetary and financial services companies. Thus, more indicators, such as core liabilities, interbank liabilities, asset allocation and asset quality, are needed to ensure that both asset- and liability-side risks are substantially under control. Especially in the current situation of continuous stringent monetary policy applied in the major developed economies, liability-side risks increase as active risk-taking on the liability side increases (as shown in this study), and regulatory authorities are encouraged to promote the prevention of unnecessary risk exposure given the narrowing interest margin and the pressure to expand profits in the monetary and financial services sectors.(2) Changes in monetary policy exert their own influences on each monetary and financial services company, and such companies are encouraged to consider these factors when formulating their own risk statements. This study confirms that a risk transmission mechanism of monetary policy exists for monetary and financial services companies, and monetary policy also affects the risk preference of monetary and financial services companies at both the individual company and the sector levels. The study showed that changes in monetary policy and any corresponding changes in underlying deposit interest rate benchmarks follow the transmission mechanism and affect the implementation of risk statements. Monetary and financial services companies should create their own risk statements based on the sector consensus. In these risk statements, relevant activities and procedures are presented to illustrate how the monetary and financial services companies aim to achieve such stated risks. Items in the risk statement should include, but are not limited to, risk preference, risk policies, risk limits, management review processes, internal control procedures, and related information systems to support the implementation of such risk statements. The risk statement should also be considered at the strategic, business decision-making and operational levels to ensure its full implementation throughout the company.(3) The financial services sector is encouraged to pursue innovative actions regarding the current asset-liability management theories. This study demonstrates that the liability-side risks of monetary and financial services are transmitted to asset-side risks, indicating that the traditional asset-liability management theory, which assumes that assets and liabilities are two independent portfolios, is flawed when accounting for the risk transmission mechanism. Therefore, as stated above, regulatory authorities are encouraged to incorporate new indicators to oversee the unnecessary risk exposures of each individual monetary and financial service company, and individual monetary and financial service companies are encouraged to take innovative actions to develop their own asset-liability management methods. On the one hand, the use of internal and external pricing and analysis tools to provide recommendations on low-cost sources of liabilities and thus reduce liability-side risks is encouraged. On the other hand, asset-side risks should also be carefully considered as the customer base expands, especially in the areas of improving marketing efficiency, enhancing customer stickiness, enriching product functions and driving transactions.This study extends the research on the risk transmission mechanism of monetary policy in the monetary and financial services sector and applies the risk transmission mechanism to China’s empirical data for the period of 2000 to 2022, which broadened the previous literature into the emerging market of China and incorporates over 20 years of data regarding Chinese monetary and financial services companies. The research findings have important significance for both theoretical researchers and regulatory authorities and for the risk and asset-liability management of the monetary and financial services industry. However, this study still has its own limitations. For example, the data used in this study were mainly taken from the publicly disclosed information of these monetary and financial services companies, and the sample was not large. Only a few control variables were used to describe the characteristics of monetary and financial services companies, and the standardization of the variables might not capture the actual results.The following research directions are suggested for further development: (1) Research on the risk transmission mechanism of monetary policy can be further analyzed in terms of each of the main risk factors for both asset- and liability-side risks in an empirical study. In this study, the overall risk transmission mechanism of monetary policy in monetary and financial services companies was investigated. Such research can be furthered by analyzing the main risk factors on the asset- or liability-side, e.g., the portion or absolute amount of interbank loans. (2) Qualitative factors such as risk culture have not been incorporated into the current research on the risk transmission mechanism of the monetary policy of monetary and financial services companies. The incorporation of qualitative factors such as corporate governance is also a future research direction.S1 Data(XLSX)Click here for additional data file.


The interactions between power quality in the AC-DC distribution network segments contribute to the distributed propagation of power quality anomalies throughout the entire network. Focusing on the photovoltaic multifunctional grid-connected inverter (PVMFGCI), this study deeply explores a collaborative governance strategy for optimizing regional power quality. Initially, the analysis dissects the DC ripple generation mechanism corresponding to harmonics and asymmetry in AC subnetwork voltages. Subsequently, a strategy is proposed for partitioning comprehensive control regions for AC-side power quality, taking into account photovoltaic governance resources based on insights from photovoltaic control realms and power quality classifications. Further, a collaborative allocation model for governance resources incorporating active optimization potentials of grid-connected converters is established based on the governance capabilities and residual capacities of PVMFGCI. Finally, the effectiveness of the proposed approach is validated through a MATLAB-based example analysis. With the increasing integration of distributed energy resources and demand-side inputs, the traditional unidirectional energy flow paradigm of distribution networks has evolved, giving rise to a dynamic landscape characterized by the coordinated orchestration of diverse energy streams . As a rePresently, the complexity of power quality pollution distribution within AC and DC distribution networks is pronounced, and the consequential interactive effects accentuate the challenges posed to its governance. Notably, a spectrum of issues such as voltage harmonics, voltage deviations, and tripartite imbalances frequently plagues AC distribution networks. Conversely, the preeminent power quality concern in DC distribution networks revolves around the phenomenon of ripple, characterized by multifarious origins and far-reaching ramifications . Within For the power quality problems of AC and DC distribution networks, common solutions include installing active power filters (APF), static var generators (SVG), unified power quality regulators (UPQC), and other compensation devices. Among them, the voltage detection APF takes the node harmonic voltage as the control target, and calculates the APF compensation current according to the detection voltage and the set conductance value to suppress the voltage distortion of its access point ,13; SVG (i)Consider the photovoltaic grid-connected inverters in the distribution network to divide the power quality comprehensive management area of the AC and DC distribution network, which is conducive to the regionalization of power quality management.(ii)Use the remaining capacity of the grid-connected inverter to manage the power quality of the whole network, and realize the reasonable and effective allocation of its governance resources so as to realize the global coordinated management of power quality.According to the existing research, based on the typical grid structure of the AC-DC distribution network, this paper proposes a collaborative governance strategy for the power quality of the AC-DC distribution network based on the coupling characteristics of both sides. Its main potential has two points:Illustrated in In the realm of the AC-DC distribution network, the presence of grid voltage harmonics or asymmetry on the AC side triggers a consequential interplay of unbalanced power components within the AC-DC interconnection power. This intricate interplay gives rise to the propagation of ripples onto the DC side, subsequently inducing fluctuations in voltage and current along the DC bus. The repercussions of these perturbations exert a pronounced impact on the overall power quality of the distribution network. Leveraging the coupling effect interdependence inherent to the power quality dynamics within the AC-DC distribution network, there emerges a compelling impetus to delve deeper into the mechanics underpinning the generation of ripples on the DC side. To address this imperative, the present paper undertakes a meticulous analysis of the mechanism, scrutinizing it through the lens of voltage harmonics and asymmetry embedded within the AC subnetwork .k signifies the harmonic order, while In the presence of harmonic components within the voltage of the AC subnetwork, the voltage and current therein may be characterized as follows:Pa, Pb, and Pc symbolize the three-phase powers of AC subnets A, B, and C, respectively. Meanwhile, Pd denotes the steady-state power quantity, and Subsequently, the three-phase active power of the AC subnetwork can be deduced as follows:DC subnet can be equationed as follows:Rdc signifies the resistance on the DC side, Udc represents the steady-state DC voltage, signifies the fluctuation quantity within the DC voltage, and Cdc denotes the capacitance value pertaining to the DC side.The power within the The steady-state quantity and fluctuation quantity of power on both sides of the AC-DC distribution network are inherently equivalent. Thus, the ripples on the DC side can be calculated by utilizing the fluctuation quantity:With reference to the preceding equation, it is discernible that the presence of a k-order harmonic in the AC subnetwork voltage gives rise to an Im1 and Im2 and Im0 and The imbalanced operation of the AC power distribution system engenders three-phase disparities in the grid voltage. Within the AC-DC distribution network, imbalanced loads on the AC side result in the generation of uneven components of voltage and current. This paper employs the symmetrical component method, wherein the composition of phase A current, comprising diverse sequence components, is expressed as follows:F, Im1, Im2, Im2 obviates any secondary ripple, maintaining a constant DC side current. Conversely, in cases of asymmetrical load, the DC side current encompasses not only the DC current but also twice the power frequency component. The introduction of a negative sequence component within the AC distribution network induces power oscillations, and it is noteworthy that the extent of load imbalance directly corresponds to the amplitude of the ripple on the DC side.Equation (7) reveals a direct correlation between the current and variables In summary, voltage harmonics and three-phase voltage imbalance within the AC subnetwork of the AC-DC distribution network instigate ripples within the DC bus, ultimately compromising the overall power quality and system reliability, particularly under critical conditions. Capitalizing on the DC ripple generation mechanism rooted in the AC-DC coupling characteristics, a collaborative governance strategy for the AC subnet emerges as a potent means to enhance active power stability, augment the quality of current entering the DC subnet, and effectively mitigate DC voltage ripple.Photovoltaic grid-connected inverters exhibit the capacity to concurrently accomplish tasks such as grid-connected power generation, filtering, and reactive power compensation. Within the context of preserving active power generation, the surplus potential inherent in widely dispersed inverters can be effectively channeled towards power quality control. This entails a thoughtful incorporation of distributed photovoltaic management resources, leading to the establishment of distinct control zones. Such an approach fully capitalizes on the power quality management capabilities inherent in inverters within the distribution network.Based on the presence or absence of photovoltaic grid connections at each node within the AC-DC distribution network, two distinct categories of grid nodes emerge: controllable source nodes and load nodes. Notably, controllable source nodes predominantly encompass the PV grid connection points. The prioritized segmentation of controllable source nodes results in each one forming an independent area. Subsequently, the control degree of controllable source nodes over all load nodes across the power grid is calculated, and load nodes exhibiting a substantial degree of control that surpasses the predetermined threshold are allocated to the respective controllable source area. This allocation method determines the control area for each photovoltaic unit, optimizing the influence of controllable source nodes on load nodes and ensuring effective management of photovoltaic units across the region. This study introduces a comprehensive voltage sensitivity model grounded in harmonic, reactive power, and three-phase imbalance sensitivities. Through this model, a partitioning strategy for photovoltaic control areas is devised which aptly considers the three primary power quality indicators.Uh represents the h-order harmonic voltage vector of the distribution network; UXIE.h signifies the h-order harmonic voltage vector originated from the harmonic source; UAPF.h denotes the h-order harmonic compensation voltage vector produced by the photovoltaic grid-connected inverter; Y−1 represents the inverse matrix of the h-order harmonic admittance matrix of the distribution network; and IAPF.h indicates the h-order harmonic compensation current vector generated by the photovoltaic grid-connected inverter.The harmonic voltage at each node in the distribution network is the aggregate of the harmonic voltage produced by individual harmonic sources at that node, alongside the harmonic compensation voltage generated by the photovoltaic grid-connected inverter. This relationship is expressed as follows:j to node i is obtained by determining and superimposing the corresponding weight factors based on the proportion of each harmonic voltage in the node voltage of the distribution network. The equation is expressed as follows:mij represents the harmonic control sensitivity of the photovoltaic grid-connected inverter from node j to node i. The parameter i.The harmonic control sensitivity calculation equation of the photovoltaic grid-connected inverter from node n nodes, comprising m PQ nodes, one balanced node, and n – m − 1 PV nodes. The power equation of the system can be represented in the form of polar coordinates.The reactive power sensitivity involves the partial derivatives of the fundamental voltage amplitude with respect to reactive power. These derivatives can be derived by utilizing the Newton–Raphson power flow calculation method in polar coordinates, as outlined in the reference. Suppose the system encompasses Through linearization, the corrected equation can be expressed as follows:Vi and Qi are the fundamental voltage of node I and the reactive power of node j, respectively.Furthermore, the sensitivity of fundamental voltage to reactive power can be determined as follows:VUFi and i before compensation and after compensation, respectively.Imbalanced loads within low-voltage distribution networks can lead to the generation of negative sequence currents, subsequently resulting in imbalanced three-phase voltages. The sensitivity analysis for three-phase imbalance initially involves evaluating the extent of imbalance in three-phase current or voltage. Subsequently, the sensitivity of the three-phase voltage imbalance to compensation current is computed.ijS, and three-phase imbalance sensitivity Bij. The standardization of each index value is applied to mitigate the impact of varying magnitudes. The comprehensive voltage sensitivity index, denoted as Wij, is established through a weighting method. The expression for this index is presented below:DTHi, DVDi, and DTBi symbolize the total harmonic distortion rate of voltage at node i, the absolute value of voltage deviation, and the absolute value of three-phase voltage imbalance, respectively. The variable i surpass the predetermined limit prior to the distribution network governance intervention.To achieve a comprehensive approach towards addressing harmonic voltage, voltage deviation, and three-phase voltage imbalance, a method is devised based on harmonic sensitivity The fundamental principle of regional power quality management lies in utilizing the correlation between nodes to delineate distinct regions, thereby facilitating comprehensive and decentralized control within intricate networks. The distribution network is segmented into multiple power quality control zones, distinguished by strong interconnectivity between nodes. Owing to the robust interdependence among nodes within each zone, a pivotal control node emerges naturally. By addressing power quality issues at this central node, the mitigation of analogous problems across other nodes within the same region is notably enhanced. This approach enables a more significant impact on regional governance with optimized resource utilization.While Dynamic Time Warping (DTW) provides the capability to align sequences of unequal dimensions, akin to Edit Distance (ED), it does not distinctly depict the interplay between shape attributes and the directional evolution of the sequences. Additionally, it may exhibit a “sick bending” phenomenon characterized by substantial misalignments. This phenomenon pertains to the alignment of sequences with significant disparities. The Dynamic Derivative Time Warping (DDTW) algorithm is introduced to address these limitations and presents itself as a more apt choice for delineating power quality pollution zones compared to the DTW algorithm. The alignment diagrams for both methods are illustrated in DDTW employs the directional change information inherent in the sequences for alignment matching, with the change trend being encapsulated by the first-order derivative. Consequently, within the DDTW matching algorithm, the comparison entails evaluating the squared difference of derivatives between each pair of points . The proTo preprocess the initial time series Normalize the element values After this preprocessing, the transformed sequences The FCM (Fuzzy C-Means) algorithm incorporates the notion of membership, assessing the degree of affiliation of each sample to different categories through the membership matrix. The likelihood of a sample belonging to each category exists within the range of . Consequently, the FCM clustering algorithm represents a form of fuzzy soft clustering. The central concept revolves around iteratively refining the membership matrix and cluster centroids until the objective function achieves its minimum, ultimately yielding the definitive cluster centers.n signifies the total count of sample data, and j represents the subscript associated with each sample datum.Consider a sample dataset denoted as c represents the total number of cluster categories, i represents the subscript of the cluster category; j-th sample data belonging to the i-th class; m = 2; i-th class.The objective function of the FCM clustering algorithm is expressed as follows:P [P signifies a more favorable outcome in terms of clustering effectiveness, reflecting improved data separation and quality of categorization.j-th sample data that belong to the k-th class. The numerator in the expression represents the inter-class distance, while the denominator signifies the intra-class distance. Upon reaching its maximum value, the clustering validity index P aids in determining the optimal number of clusters, denoted as c, for the given sample data set.The relationship linking the Euclidean distance between individual elements and the cluster center to the membership degree matrix is established through the utilization of Lagrange multiplication. This relationship, in turn, facilitates the derivation of an iterative link between the membership degree matrix and the cluster center. FCM, classified as an unsupervised algorithm, operates on sample data for which categorization is typically unknown. For effective application of the FCM algorithm, a specific cluster count c must be designated to segment the sample data set into c distinct categories. The foundational principle governing clustering algorithms underscores the goal of minimizing intra-class distances while concurrently maximizing inter-class distances. Within this principle, the number of clusters denoted by c holds significant influence. Thus, a function that employs the number of clusters c as an independent variable is essential to characterize clustering performance. This function is aptly termed the clustering validity function. This function serves to evaluate the efficacy of clustering by considering the ratio of inter-class distance to intra-class distance, quantified through the functional evaluation index P . NotablyBuilding upon the foundation laid out in Equations (16) and (17), the tripartite power quality indices encompassing harmonics, voltage deviation, and three-phase imbalance are meticulously weighted and amalgamated for every node situated within the expansive AC and DC distribution network. This intricate synthesis yields a unified power quality time series, which emerges as a potent tool for crafting an AC regional division strategy. This strategy, rooted in the fusion of power quality data, becomes the linchpin for orchestrating a comprehensive approach to managing power quality within subnetworks, ensuring their harmonious and effective operation.(i)A comprehensive voltage sensitivity model is equationed by integrating harmonic sensitivity, reactive power sensitivity, and three-phase imbalance sensitivity. This model takes into consideration the presence of distributed photovoltaic governance resources within the distribution network. It delineates photovoltaic control areas that effectively address the three primary power quality indicators.(ii)The DDTW-FCM clustering and partitioning algorithm is harnessed to analyze time series data. This approach determines the optimal number of clusters through the maximization of the clustering validity function. Subsequently, it assigns nodes to respective classes, thereby facilitating the delineation of power quality areas. Each area’s central node, closest to the cluster center, is identified as the pilot node for regional governance.(iii)The comprehensive management area of power quality is defined based on the spatial relationship between the two types of areas through the following methods: if the photovoltaic control area is entirely encompassed within the power quality area, the comprehensive management area is set to be the extent of the photovoltaic control area. In cases where the regions overlap, the approach involves amalgamating the PV control region with the corresponding power quality region of the predominant node it encompasses.This paper presents a comprehensive regional division strategy for managing power quality in AC and DC distribution networks. The process is illustrated in In the low-voltage distribution network of my country, the prevalent power supply method often employs three-phase four-wire configurations ,27. The The control loop of the Photovoltaic Grid-Connected Inverter (PVMFGCI) continuously monitors the load current within the distribution network. It extracts harmonic, reactive power, and imbalanced current components, subsequently generating a reference value for compensation current. This compensation current reference is then integrated with the active current from photovoltaic power generation to establish the final grid-connected command current. This approach ensures cohesive regulation of power generation and active filtering functions during grid connection. The present study places emphasis on the synergistic utilization of photovoltaic grid connection and parallel-connected Active Power Filters (APF). This integrated approach is particularly effective in addressing power-related issues such as grid imbalances, all the while contributing active power to the grid. Due to the scope of this paper, detailed discussion on the Maximum Power Point Tracking (MPPT) technique is not provided.SN. Among this capacity, a portion is allocated to DG grid connection, represented as SDG, leaving the remaining capacity designated as SRE.U is the distribution network voltage, and I1 is the active current output by the inverter.The Photovoltaic Grid-Connected Inverter (PVMFGCI) has a total capacity denoted as Sh, Sq, and S2 represent the capacities of the DG grid-connected inverter for harmonic control, reactive power compensation, and three-phase imbalance control, respectively.The interplay between the harmonic control and reactive power compensation capacity of the photovoltaic grid-connected inverter and its remaining capacity can be equationed as follows:Taking into account the geographical placement and capacity of distributed generation (DG) grid-connected inverters within the distribution network, a prudent allocation of residual inverter capacity can yield tailored governance outcomes, thereby differentially influencing power quality across distinct distribution network regions. Through the meticulous optimization of compensation strategies, the efficacy of the photovoltaic multifunctional grid inverter (PVMFGCI) in mitigating harmonics, reactive power, and three-phase imbalances can be rendered more cost-effective and logically coherent. This approach fosters an efficient distribution of governance resources, thereby achieving a heightened level of power quality enhancement across various sectors of the network, as elucidated in reference .I1, Ih, Iq, and I0 represent the fundamental current, harmonic current, reactive current, and three-phase imbalanced current on the grid side, respectively.Building upon the allocated capacity of PVMFGCI, a mathematical framework is devised to determine the optimal compensation coefficients for harmonics, reactive power, and three-phase imbalances using its residual capacity. The subsequent equations serve to articulate these coefficients individually:Suppose the coefficients for harmonic control, reactive power compensation, and three-phase imbalance control of the remaining capacity of PVMFGCI are represented as Ip1, Iph, Ipq, and Ip2 are PVMFGCI output active current, harmonic wave control, reactive power compensation, and three-phase imbalance control current, respectively.Developing a comprehensive evaluation model for power quality under various operating scenarios involves solving for PVMFGCI .(28)minλ represent the Lagrangian multiplier, and equation the Lagrangian function as follows:Considering the simplicity of the Lagrange multiplier method, this study employs this approach to solve the optimal coefficient problem related to the comprehensive power quality control of the remaining capacity of PVMFGCI . Let λ rCompute using the Lagrange multiplier method in order to solve:(i)A comprehensive voltage sensitivity model is equationed by integrating harmonic sensitivity, reactive power sensitivity, and three-phase imbalance sensitivity. This model takes into consideration the presence of distributed photovoltaic governance resources within the distribution network. It delineates photovoltaic control areas that effectively address the three primary power quality indicators.(ii)SRE ≥ QN0, and satisfiesIf The comprehensive management strategy of power quality of PVMFGCI remaining capacity is as follows:(iii)SRE ≤ QN0, and satisfy, then no compensation will be invested.If Subsequently, full compensation can be executed directly when the value of To validate the efficacy of the zoning management approach outlined in this study, we employ the AC/DC distribution network depicted in Adhering to the harmonic standards applicable in my country, this section establishes a permissible upper threshold of 4% for the Total Harmonic Distortion Rate of harmonic voltage. The harmonic distribution among the system nodes, pertinent to the calculation example, is outlined in Utilizing the comprehensive voltage sensitivity model, it becomes possible to delineate photovoltaic control areas within the AC subnet, factoring in the three power quality indicators. These areas are established for each of the four photovoltaic sources, with their corresponding controllable source nodes and the nodes under their control outlined in As observed in the table, the four controllable source nodes align with distinct photovoltaic control areas. Given that power quality compensation takes the form of current, each control area predominantly encompasses nodes situated along the same branch. Under the function of photovoltaic power quality management, enhancements in power quality can be anticipated within the photovoltaic control area. Fundamentally, the compensation processes for harmonics, reactive power, and imbalance within the system all revolve around controlling the current waveform. The application of uniform compensation results in a system current that is both symmetrical and sinusoidal in nature.The power quality time series data from the 16 nodes undergo dimension reduction, followed by the application of the DDTW-FCM method for power quality partitioning. Within each partition, the node nearest to the cluster center is designated as the dominant node. The achieved clustering effectiveness is depicted in From the clustering validity function, it is evident that the optimal division of regions is achieved when the number of regions is four. At this point, the power quality coupling between regions is minimized, while the coupling within each region is maximized. Referring to the table, the dominant control nodes for regions I, II, IV, and V are identified as 3, 7, 15, and 11, respectively. Based on this regional division strategy for comprehensive power quality management in the AC and DC distribution network, a refined power quality division on the AC side, considering distributed photovoltaic management resources, can be further established.Drawing upon the spatial relationship between these two area types, the comprehensive power quality control areas are precisely delineated. Specifically, the AC subnetwork of the AC-DC distribution network is partitioned into four comprehensive power quality control areas, as illustrated in Derived from the power quality optimization strategy involving the adaptable capacity of the photovoltaic grid-connected system, the optimal coefficients for compensating harmonics, reactive power, and three-phase imbalance are deduced. The resulting capacity allocation and compensation coefficients are illustrated in As indicated in From the figure, it is evident that following the comprehensive treatment of the AC subnet, the harmonics at each node are consistently below 2%. Moreover, the degree of three-phase imbalance experiences a noticeable reduction, and the calculated ripple coefficient of the DC bus decreases from 1.75% to 0.5%. The implementation of power quality control measures within the AC subnet proves effective in diminishing the introduced ripple, enhancing the power quality of the DC subnet, and ensuring the stable operation of the DC subnet.In order to improve the power quality of the AC-DC distribution network and give full play to the advantages of flexible and controllable output power of photovoltaic power generation, this paper proposes a collaborative governance strategy for the power quality of the AC-DC distribution network based on the coupling characteristics of both sides, and comprehensively considers the coupling characteristics of power quality, rationally allocates photovoltaic governance resources, and realizes the comprehensive optimization of power quality.(i)In the problem of power quality on both sides of AC and DC, the DC ripple generation mechanism corresponding to the harmonics and asymmetry of the AC subnetwork voltage is derived and analyzed. With the help of the inverter’s fast response and high-precision adjustment capabilities, it can quickly identify and respond to current distortions and imbalances and achieve effective control.(ii)Based on the comprehensive voltage sensitivity model to determine the photovoltaic control area, the DDTW-FCM cluster partition algorithm is used to divide the power quality area and its dominant node, and four comprehensive power quality control areas of the AC and DC distribution network are determined.(iii)Considering the power quality management function of PVMFGCI, the optimal compensation coefficients of power quality indicators in the four regions are solved based on its remaining capacity, which effectively improves the harmonics, reactive power, and imbalance of the AC side, and reduces the ripple of the DC bus wave, to achieve a more reasonable and economical AC and DC distribution network power quality collaborative governance.


The behavioral variant of frontotemporal dementia (bvFTD) has a devastating effect on multiple domains of daily living. The purpose of this PRISMA-compliant systematic review is to summarize the most important factors associated with functional impairment in this clinical group by critically analyzing the existing literature spanning the period from 2000 to 2023. To be included in the review, a study had to investigate any kind of correlates of functional status in bvFTD patients, using a previously validated instrument of functional assessment. Out of 40 articles assessed for eligibility, 18 met the inclusion criteria. The anatomical pattern of cerebral atrophy at baseline appeared to be the strongest predictor of the rate of functional decline over time, with the frontal-dominant anatomical subtype being associated with a faster rate of functional impairment. Additionally, executive dysfunction as well as apathy appeared to contribute significantly to functional disability in bvFTD patients. A comparative examination of bvFTD in relation to other clinical subtypes of FTD and other types of dementia in general suggests that it is the predominant atrophy of the frontal lobes along with the subsequent unique combination of cognitive and neuropsychiatric manifestations that account for the pronounced functional limitations observed in these individuals, even from the early stages of the disease. Behavioral variant frontotemporal dementia (bvFTD) is the most common FTD clinical subtype and is characterized by progressive changes in behavior, personality, and emotional and interpersonal functioning, as well as by pronounced executive dysfunction ,2. TheseBvFTD progresses rapidly and has a devastating effect on multiple domains of daily living ,8,9. TheThe primary objective of this systematic review is to comprehensively investigate and analyze the factors associated with functional impairment in individuals diagnosed with bvFTD. The varying rate of functional decline among bvFTD patients poses significant challenges in disease prognosis , necessiThis systematic review represents a novel contribution, as no similar review or meta-analysis has been conducted in this area to date. By synthesizing and analyzing the findings from the included studies, we aim to provide a comprehensive overview of the factors that contribute to the functional decline exhibited by bvFTD patients. This systematic review aims to fill the existing research gap and provide valuable insights for researchers, clinicians, and caregivers, facilitating a better understanding of disease progression and potentially informing the development of targeted interventions and management strategies for bvFTD patients.The systematic review was conducted in accordance with the criteria of the PRISMA  guidelines for the reporting of systematic reviews and meta-analyses . The rev)) AND  AND (“predict*” OR “contribut*” OR “role” OR “correlates” OR “drivers”).To be considered eligible for inclusion in the review, studies had to investigate any kind of correlates or predictors of functional status in patients with a diagnosis of bvFTD, using a previously validated instrument of functional assessment. Only studies published in English between 1 January 2000 and 20 June 2023, with the full text available online, were considered. The inclusion of English-language studies aimed to ensure effective comprehension and analysis, while the specified publication date range sought to capture research spanning from the beginning of the millennium to the present. Reviews, meta-analyses, editorials, and books were excluded to focus on primary research studies providing original data and analysis. Two independent reviewers assessed the eligibility of the full-text articles of all citations selected in the screening process, with any disagreements or uncertainties resolved through discussion and consensus. A third reviewer was involved when necessary.The initial search of the online databases yielded a total of 82 studies. After removing duplicates, a screening process was conducted on the remaining 47 records. Out of these, 6 studies were excluded as systematic reviews, 1 study was excluded as a book chapter, and 22 studies were excluded as they did not align with the specific research topic of interest. Ultimately, 18 studies met the eligibility criteria and were included in the review.We conducted a qualitative synthesis of the findings of the included studies. In order to enhance the clarity of the findings, the results of the systematic review were categorized based on the types of predictive factors associated with functional decline in patients with bvFTD. Through a comprehensive analysis of the included studies, a classification of predictive factors emerged, indicating a well-defined structure in the data. By organizing the findings according to these distinct categories, the results not only offer a comprehensive overview of the factors predicting functional decline in bvFTD, but also provide valuable insights into the multidimensional nature of this clinical syndrome.This review identified a total of 18 studies examining factors associated with functional decline in bvFTD patients ,27,28,29The studies identified through the literature search commenced from 2007 onwards. All retrieved articles were written in English. Notably, a limited number of the eligible studies encompassed substantial sample sizes of bvFTD patients. In addition, only six of the selected studies employed a longitudinal research design to investigate predictors of functional decline in bvFTD, while the remaining studies followed a cross-sectional design.The assessment of everyday functioning across the included studies involved the utilization of various psychometric instruments. At this juncture, it is worth mentioning that everyday functioning pertains to an individual’s ability to effectively engage in and manage various everyday tasks, and it is commonly evaluated through the assessment of two overarching categories of activities of daily living (ADLs), namely, basic ADLs and instrumental ADLs . Basic AA variety of rating scales were employed across the included studies for the evaluation of everyday functioning in bvFTD patients. Specifically, the “Disability Assessment for Dementia” (DAD)  was emplThe selected studies investigated a wide range of factors associated with functional status in bvFTD, encompassing demographic, clinical, genetic, neural, motor, cognitive, and behavioral variables. In the following paragraphs, we present a detailed overview of the results derived from the included studies, following a qualitative data synthesis approach.With regard to demographic correlates of functional status in bvFTD, Mioshi et al. (2007)  found thDevenney et al. (2015)  found thIn terms of genetic correlates, Josephs et al. (2011)  found thFindings based on MRI measuresWith respect to neural correlates, Kipps et al. (2007) , based o2.Findings based on TMS measuresBenussi et al. (2020)  showed t3.Findings based on blood-related measuresSteinacker et al. (2018)  found thDe Silva et al. 2016) [16 [20] iStudies that investigated cognitive correlates of functional status in patients with bvFTD showed relative homogeneity in their results. Almost all of them showed that greater cognitive deficits predict faster functional decline. More specifically, Josephs et al. (2011)  showed tIn terms of correlates related to social cognition, Kipps et al. (2009)  showed tIn relation to the behavioral correlates of functional status in bvFTD, Kipps et al. (2009)  found a As outlined in the Materials and Methods section of the review, our inclusion criteria focused solely on primary research studies that offer original data and analysis. Within this framework, during the screening phase, a total of six studies were identified and subsequently excluded due to their classification as systematic reviews ,43,44,45The current systematic review provided a comprehensive summary of the research conducted since the start of the millennium until the present, focusing on the key predictive factors associated with functional decline in individuals diagnosed with bvFTD. A comparative analysis alongside other reviews within the field demonstrates that our systematic review represents a novel contribution. It effectively addresses a critical gap in the existing literature by offering a comprehensive synthesis of the available evidence, an endeavor not previously undertaken. The presentation of the findings derived from the 18 eligible studies was systematically structured based on the nature of the examined variables in relation to functional status.According to the results of the included studies, it can be concluded that among the investigated predictive variables, the occurrence of GRN genetic mutation or C9orf72 expansion, the predominance of frontal and frontotemporal anatomic patterns of atrophy, the presence of elevated serum neurofilament light chain (NfL) levels, the magnitude of dysfunction of inhibitory and facilitatory intracortical circuits, as well as the severity of executive deficits and apathy emerge as robust correlates of functional impairment in individuals diagnosed with bvFTD. Furthermore, the results derived from the included longitudinal studies provide evidence that bvFTD patients who present with these specific characteristics or combinations thereof at baseline are significantly more likely to demonstrate a faster rate of disease progression and functional deterioration.Initially, in relation to GRN genetic mutation, it appears that individuals with bvFTD carrying GRN mutations demonstrate a faster rate of whole brain atrophy, suggesting a more rapid disease progression, compared to patients carrying other genetic variations, such as MAPT ,47. AddiThe C9orf72 mutation has also been identified as one of the most prevalent genetic causes of familial bvFTD, and it has demonstrated associations with disease progression, as well as with cognitive and functional deterioration . The proStudies focusing on the neural underpinnings of functional impairment in bvFTD have revealed that certain biomarkers hold potential as prognostic indicators. Specifically, based on MRI measures, the presence of predominantly frontal and frontotemporal patterns of atrophy at the early stage of the disease has been shown to predict decreased levels of everyday functioning and an accelerated trajectory of functional decline among individuals diagnosed with bvFTD ,22. It aOn the contrary, bvFTD patients with temporal dominant and temporofrontoparietal patterns of atrophy at baseline tend to demonstrate a slower rate of functional impairment over time . First, It is also worth mentioning that the included studies that investigated the neural substrates of functional decline in bvFTD indicated that a normal brain scan or a scan showing limited brain atrophy, even in the presence of pronounced behavioral and cognitive symptomatology, is associated with a more favorable functional prognosis . These fMoreover, studies examining the neurophysiological correlates of functional status in bvFTD showed that the examination of serum neurofilament light chain (NfL) levels, a marker of axonal damage, can offer valuable insights into the degree of functional disability demonstrated by bvFTD patients throughout the course of the disease . Indeed,In addition to the markers previously discussed, the included literature indicates that the assessment of inhibitory and facilitatory intracortical circuits, as evaluated through TMS measures, holds significant prognostic value, predicting the longitudinal functional decline in individuals with bvFTD . LongituAccording to the results of the included studies, motor symptoms do not appear to contribute to the functional impairment observed in bvFTD patients, potentially due to the relatively scarce presentation of motor symptoms in this clinical population . ConversThe specific mechanisms through which executive functions influence everyday functioning have not been fully identified yet and require further investigation. Nevertheless, it is evident that many everyday activities rely on cognitive processes that involve executive components . More spWhen examining social cognition, the included studies have focused mainly on the role of emotion recognition ability to functional status in bvFTD and have produced conflicting results ,29. DefiFinally, the included literature highlights the crucial role of behavioral symptoms in predicting the functional status of individuals with bvFTD ,26,28,29In conclusion, a comparative examination of bvFTD in relation to other clinical subtypes of FTD and other types of dementia in general  suggests that it is the predominant atrophy of the frontal lobes along with the subsequent distinctive combination of cognitive and neuropsychiatric manifestations that account for the pronounced functional deficits and the malignant course of everyday functioning observed in bvFTD patients. The executive dysfunction as well as the apathy arising from the disorganization of the underlying frontal networks appear to be the key factors contributing to the notable functional limitations in these individuals, even from the early stages of the disorder.At this juncture, it is worth mentioning that, after a thorough review of the existing literature, we recognized the importance of considering some supplementary studies that were not captured by our initial database search, as they fell beyond the purview of our predefined keyword-based criteria. These studies shed light on some additional neuroimaging and neuroinflammatory parameters that can contribute to a more comprehensive perspective on the factors associated with functional decline in bvFTD.Advanced neuroimaging techniques have undoubtedly emerged as a pivotal tool for unraveling the complexities regarding disease trajectory in bvFTD. A study employing brain single-photon emission computed tomography (SPECT) scans to explore the connection between regional cerebral blood flow (rCBF) and disease severity in bvFTD found that clinical measures of functional status were correlated with perfusion patterns in both the left and right frontal cortices . More spIn another recent study investigating the prognostic value of in vivo neuroimaging techniques, researchers examined the role of microglial activation in predicting the rate of cognitive decline and disease progression among FTD patients . By emplFurthermore, the prognostic potential of two key biomarkers, namely, plasma glial fibrillary acidic protein (pGFAP) and plasma neurofilament light chain (pNfL), has garnered attention within the context of FTD. A recent relevant study uncovered significant correlations between pGFAP concentrations and various critical factors, such as cognition, levels of cerebrospinal fluid (CSF), cortical thickness, and levels of plasma NfL, among individuals with FTD . NotablyFinally, in addition to the abovementioned neuroimaging and biomarker evidence, recent research has also uncovered notable insights into the relationship between peripheral inflammation and disease progression in bvFTD. A relevant study revealed that plasma levels of peripheral inflammatory markers, such as BAFF/TNFSF13B, IL-4, IL-6, IL-17A, and TNF-α, exhibited associations with patterns of brain atrophy, brain hypometabolism, and clinical measures of disease severity and functional status in bvFTD . These fAs evidenced by the present review, a considerable body of research has been undertaken thus far within the realm of predictive variables concerning the functional status of individuals affected by bvFTD. However, it is recommended that further research is needed in the future in this particular research field, ideally adopting longitudinal research designs, including larger sample sizes, and incorporating additional predictive variables in designs . By adopting such an expanded approach, a more comprehensive understanding of the multifaceted nature of functional decline in bvFTD can be achieved.BvFTD displays variable rates of progression throughout the course of the disease. Therefore, when confronted with a diagnosis of bvFTD, it is strongly advised that clinicians undertake a comprehensive assessment encompassing detailed clinical, neurologic, genetic, neuroimaging, cognitive, and behavioral evaluations. Such an extensive assessment aids in identifying crucial predictive characteristics associated with the progression of the disease. Therefore, the adoption of such a holistic approach enables clinicians to enhance their ability to prognosticate and make more precise predictions concerning the trajectory of the disease, which is still speculative in daily clinical practice.The identification of key predictive features related to the functional status in bvFTD may provide novel insights into the etiopathology of the disease, allow improved prognostic estimates in a syndrome that predominantly affects the middle-aged population, and indicate new avenues for the development of therapeutic interventions tailored to the unique characteristics of this specific clinical group.


The growing awareness of the consequences of climate change has prompted the formulation of policies and regulations to foster sustainability. This global concern has had a far-reaching impact, influencing change and innovation in various sectors, including the plastics industry . ResearcIn the field of plastics, the development of new polymer materials and methods that address environmental and sustainability concerns is being promoted. Novel materials are engineered to be more environmentally friendly, but their stabilization and tendency to degrade require careful assessment of their performance in various environmental conditions, including exposure to factors such as UV radiation, microorganisms, increased humidity, and temperature stress . PlasticGiven these challenges and ongoing research, the Special Issue “Degradation and Stabilization of Polymer Materials” presents ten articles by experts addressing various aspects and challenges related to (bio)plastic materials and their interaction with the environment. The articles explore research and development progress in the realm of (bio)polymers, encompassing their stabilization and degradation, as well as the formation and decomposition of microplastics and their environmental impact. The contributions are underpinned by significant innovations in characterization methods and techniques, offering a comprehensive perspective on this important field. A summary of the articles is provided below.Some polymers are susceptible to biodegradation in the natural environment by microorganisms such as bacteria and fungi or small organisms  such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) and with a hyperbranched structure of more peripheral alkyl chains. More terminal cations and higher positive charge density facilitate the attraction and lysis of bacteria. Polymeric quaternary ammonium salts are considered to be one of the most promising materials for antibacterial efficacy, and therefore, they will be the object of further research.The authors of contribution 2 also dealt with environmentally friendly polymers. Two water-soluble antibacterial agents were synthesized by starting the polymerization of isonitrile monomers with linear and star palladium catalysts, respectively, followed by quaternization with N,N-dimethyloctylamine. They presented an efficient strategy for the synthesis of polyisocyanide quaternary ammonium salts with a novel star-shaped structure. Due to the new structure, increased cation density, and improved water solubility, the prepared quaternary ammonium salts of star polyisocyanide show excellent antibacterial properties against A promising material is also the polymeric film from the article “Degradation of P(3HB-co-4HB) Films in Simulated Body Fluids” (contribution 3) where the authors considered the stability of polymer films from a completely different, biomedical point of view. A new model for the preparation of biodegradable PHA copolymer films was used and the biodegradability of various PHA copolymers was evaluated and their biomedical applicability discussed. Two copolymers of 3-hydroxybutyrate and 4-hydroxybutyrate were prepared by growing thermophilic plants—P(3HB-co-36 mol.% 4HB) and P(3HB-co-66 mol.% 4HB)—the bacterial strain Aneurinibacillus sp. H1, and investigated degradability in simulated body fluids. Both showed faster weight loss in synthetic gastric juice and artificial intestinal fluid than the simple P3HB homopolymer. Synthetic gastric juice proved to be the most aggressive environment due to its low pH, resulting in the greatest weight loss of both copolymers. Most likely, this weight loss cannot be attributed to enzymatic hydrolysis. The authors state that the rate of biodegradation and concomitant biocompatibility are key factors in the selection of in vivo intestinal applications. Regarding the degradation rate of the copolymer, these materials appear to be very promising substitutes for other investigated materials such as PLA or PCL ,15. The 2 produced by PLA, which can maintain the acid–base balance in sandy soil and is beneficial to plant growth. Therefore, the degradation of COF-PLA does not cause pollution, making it a promising sand-control material that will continue to gain interest.Yang, Du, and Liu also worked on a biodegradable polymer material, polylactic acid (PLA), and developed a novel environmentally friendly covalent organic framework/PLA composite material (contribution 4). A new high-strength, thermally stable, and degradable covalent organic framework (COF)-modified polylactic acid fiber (PLA) material (COF-PLA) was constructed for reinforcing the PLA material for environmentally friendly sand barriers. The micrographs, structure, thermal stability, and photodegradation products of COF-PLA were investigated. The results of this study indicated that the COF material was compatible with PLA and that the COF-PLA material took on the advantages of the COF by having a more regular arrangement, smoother surface, and smaller size, and it was more thermostable than PLA alone. After photodegradation, the COF-PLA material can produce melamine molecules that can neutralize the lactic acid and CO2/MDOS), where the pristine and weathered polyethylene (PE) and tire wear particles (TWPs) were used. The weathering of MPs was performed in an accelerated weathering chamber. The chemical properties and morphology of the Fe@SiO2/MDOS, PE, and TWPs were confirmed via FTIR and SEM, respectively, and the thermal properties were evaluated using TGA. Using 1.00 mg of Fe@SiO2/MDOS nanocomposite, 2.00 mg of pristine and weathered PE were extracted from freshwater, whereas using the same amount of the nanocomposite, 7.92 mg of pristine TWPs and 6.87 mg of weathered TWPs were extracted. With this work, they provided a feasible strategy for the magnetic extraction of pristine and weathered PE and TWPs from freshwater using an iron-silane-based Fe@SiO2/MDOS nanocomposite. The magnetic separation technique can be used to remove MPs from the environment, which is simple, economical, and less time-consuming. Further work in magnetic separation toward large-scale applications could be made possible by the construction of a novel, inexpensive magnetic carrier media and separation devices.In order to minimize microplastic pollution, the group of Budhiraja et al. presented the magnetic extraction of tire wear (contribution 5). This work offers a rapid and low-cost solution for the separation of microplastics (MPs), whereby magnets are used to separate MPs from complex environmental matrices by magnetizing the hydrophobic surface of the MP. In this scientific research, they synthesized a hydrophobic Fe-silane-based nanocomposite . They determined the adsorption of organic pollutants onto weathered polyethylene MPs and their interaction, and demonstrated a change in the behavior of degraded MPs in the environment, i.e., their adsorption, degradation, toxicity, etc. In this study, a laboratory-accelerated weathering experiment was carried out with a virgin PE film and an oxidative degradable PE (OXO-PE) film, i.e., PE modified by the addition of a pro-oxidant catalyst. The differences caused by the degradation of PE and OXO-PE were assessed through FTIR spectroscopy, and the hydrophilic nature of the weathered samples was confirmed via contact angle measurements, TGA thermal analysis, and SEM morphology studies. Also, the adsorption of two model organic pollutants, triclosan and methylparaben (MeP), onto weathered and virgin PE was analyzed with GC-PID. The results also clearly show that OXO degradable plastics represent a fast route to MP degradation and may lead to the increased adsorption of pollutants. Both the effect of weathering on the adsorption of organic pollutants and the interaction between organic pollutants adsorbing onto MPs are highly relevant to actual MP pollution in the environment, where MPs are exposed to weathering conditions and mixtures of organic pollutants. Further research is suggested to study the combined toxic effect of weathered MPs (containing additives) and multiple coexisting pollutants on marine organisms.2+ in fillers reacted with the carboxylic acids produced by the degradation of the epoxy resin ester bond to form carboxylates, which destroyed the resin–filler interface and increased the material hydrophilicity. The authors proposed the application of ATR-FTIR spectroscopy to easily monitor the degradation of the epoxy composite system of electrical insulation.Exposure to high temperatures can cause the degradation of polymers. This may result in chain scission, cross-linking, or the release of volatile compounds . ThermalThe choice of preparation and stabilization methods and additives used depends on the type of polymer, its intended use, and the environmental conditions it will encounter. Appropriate testing and quality control are also essential to ensure that the stabilization methods chosen effectively protect the polymer material during its intended lifetime, and to monitor the environmental impact of the (bio-based) plastic thus prepared. The three articles in this Special Issue deal with the development of methods for tracking/determining the stability and degradation of polymer materials. Al Khulaifi et al. have investigated the thermal depolymerization of a polymer in real-time (contribution 8), while Beiras et al. and Kuznetsova et al. have presented tools and methods to assess the degradability of plastics in seawater (contributions 9 and 10). In contribution 8, the isothermal decomposition of poly(methyl methacrylate) (PMMA) synthesized by the radical route of methyl methacrylate in the presence of azobisisobutyronitrile as the initiator was carried out and monitored with the DART-Tof-MS technique at different temperatures. For better understanding, they also used NMR, TGA, MS analysis, and size-exclusion chromatography analysis. DART mass spectrometry was successfully applied to study the isothermal decomposition of PMMA. It was found that the non-isothermal decomposition of PMMA studied with TGA shows two steps of weight loss. The isothermal decomposition of the polymer with the DART-Tof-MS method revealed only one weight loss stage. However, DART mass spectrometry was successfully applied to study the isothermal decomposition of PMMA.Also of great importance is contribution 9, in which a practical tool for the assessment of polymer biodegradability in marine environments was presented, which can guide the development of truly biodegradable plastics. The alternative plastics labeled as compostable are replacing polyolefins. By fitting experimental data to a non-linear logistic model, the ultimate biodegradability can be calculated without taking into account the incubation time. Whereas the commercial products show negligible or very low marine biodegradability, one of the novel materials exceeds the 20% biodegradation threshold relative to fully marine biodegradable PHB after 28 days. Because of its short duration and environmental relevancy, this presented method is useful to classify commercial plastic products according to their potential biodegradability in marine conditions and to guide the development of novel polymeric materials intended to rapidly degrade in the sea. In most trials, the experimental data fitted the non-linear logistic model well. It was found that for the evaluation of thin films, micronization pretreatment is not always necessary, whereas for the evaluation of more compact materials, micronization is essential to reduce the particle size to at least less than 1 mm. Furthermore, it has been proven that below 250 µm, different fractions behave similarly and do not accelerate the rate of biodegradation with decreasing size. Further research could yield interesting results where the test could be further accelerated by increasing the density of marine heterotrophic microorganisms in the incubation vessels.Kuznetsova, Shtykov, and Timerbaev (contribution 10) assessed the behavior of plastics in seawater using mass spectrometry which enables us to use reliable analytical tools to unravel the transformations of primary plastics exposed to the marine environment. The authors evaluated the performance of the isotope ratio mass spectrometry (IRMS) technique for identifying the origin of polymers and monitoring the compositional alterations due to its chemical degradation. The carbon and hydrogen isotope measurements in natural abundance have revealed that biopolymers incline to substantial chemical transformation upon prolonged exposure to seawater and sunlight irradiation. To assess the seawater-mediated aging that leads to the release of micro/nano fragments from plastic products, they propose the use of microfiltration as a front end to IRMS. The fragmentation of plastics was recorded, and it was found that the rate and extent of disintegration varied significantly for different classes of polymers. Another impact of plastics on the environment is that toxic metals are adsorbed on their surface from the seashore water. They addressed this issue by using inductively coupled mass spectrometry after nitric acid leaching. IRMS proved useful as a ‘one-stone-three-birds’ tool for the characterization of plastic polymers in a seawater environment. The method was shown to be capable of (i) acquiring reliable IR data that help with the identification of polymer debris contaminating seawater, (ii) differentiating between petroleum- and plant-derived polymers, and (iii) monitoring their compositional alterations due to chemical degradation in seawater. This study measured the degradation degree of different types of polymers in seawater, filling a knowledge gap on plastic pollution and providing a useful methodology and important reference data for future research. Forthcoming research will be directed towards revealing the structural changes in plastics during degradation as well as the structure of disintegrated fragments.This Special Issue covers the crucial topics of polymeric material degradation and stabilization, both of which are paramount in the polymer industry as well as for the preservation of our environment. The continuous emergence of new polymeric materials that are intended for end-users and may enter the environment as waste after use makes it essential to understand how they are affected by different environmental conditions.Following the presentation of the collected articles, it is evident that the Special Issue “Degradation and Stabilization of Polymer Materials” comprehensively encompasses the multidisciplinary nature of the field. The ten articles featured in the issue span a wide spectrum, including the development of novel materials, innovative testing and analytical methods, applications in biomedicine and electronics, as well as their implications in both marine and terrestrial environments. This multidisciplinary approach has the potential to significantly influence the plastics industry and its environmental footprint.We are grateful for the contributions in the form of original articles in the Special Issue, as they have greatly enriched our understanding of these critical subjects.


Editorial on the Research TopicAdvancements and challenges in cost and resource allocation: 20221.Frontiers in Health Services editorial team, with a view to collecting a variety of studies from 2022 that fall within the scope of our Section. The resulting Research Topic demonstrates the breadth of methods and topics that are relevant to Cost and Resource Allocation.The efficient use of healthcare resources and assessments of cost-effectiveness are paramount in decision-making for health services. We launched a Research Topic exclusively for publications authored by members of the This editorial synthesises the collection of articles which delve into various facets of cost and resource allocation in healthcare. With meticulous research and analysis, the articles illuminate cost-effectiveness, capacity development needs, and barriers to accessing care across different healthcare interventions and services. Such research is a necessary input to effective evidence-based decision-making and health policy and seeks to influence a diverse set of stakeholders. The aim of this editorial is to provide a high-level summary of the key findings from these articles, underscoring their importance in enhancing our understanding of efficient resource allocation in healthcare.2.King et al. performed a cost-effectiveness analysis of heart rate characteristics (HRC) monitoring in very low birth weight (VLBW) infants, using data from a clinical trial. The study concluded that HRC monitoring was cost-effective in enhancing survival outcomes, saving lives with efficient use of resources. It is notable that the researchers use data from a trial published over a decade ago. The findings from this study have practical implications for healthcare providers and policymakers in contexts where HRC monitoring is already adopted, as well as those settings where decision-makers may be considering its adoption.Part of this Research Topic reports on economic evaluations, the principle tool in determining the cost-effectiveness and efficiency of healthcare interventions. Pace et al. examined the cost-effectiveness of a tele-resuscitation intervention in pediatric emergency departments. The study found the intervention to be cost-effective, indicating its potential to optimise healthcare delivery and resource allocation. The research employed interviews to understand the broader cost implications of healthcare, including out-of-pocket payments and productivity losses, which are important considerations in the evaluation of telehealth interventions. These findings underscore the importance of considering telemedicine interventions as possible solutions to enhance access to specialised care while managing costs effectively.In a similar vein, 3.Hanney et al. explored the perceived barriers to accessing physical therapy services among individuals with low back pain in Florida. The study identified factors such as proximity to physical therapy clinics, availability of childcare, session duration, session frequency, and individual activity levels as significant barriers. These findings have important policy implications, suggesting that addressing these barriers through targeted interventions and policy changes can enhance access to physical therapy services, reduce healthcare disparities, and optimise resource allocation.Access to care and capacity development are vital components of resource allocation in healthcare. Two studies in this Research Topic provide valuable insights into these areas. Ward et al. investigated the capacity development needs of a national prostate cancer service in Scotland. The study identified several barriers to capacity development, including a lack of shared understanding of the quality of care between policymakers and healthcare professionals, a lack of leadership of service developments at national and regional levels, and difficulties in drawing on other capacities to support the service. The study also highlighted the need for cohesive working and efficient training for nurse specialists to develop capacity. These findings underscore the importance of addressing these barriers and facilitating capacity development to enhance the ability of healthcare services to meet demand, improve the quality of care, and optimise resource allocation.4.It is important for research to characterise the link between economic evaluation and access to healthcare. Economic evaluations provide crucial information on the cost-effectiveness of interventions, enabling policymakers to make informed decisions regarding resource allocation. By identifying interventions that are not only clinically effective but also cost-effective, policymakers can prioritise the allocation of resources to maximise health outcomes within the available budget. Robust evidence on cost-effectiveness can support buy-in from stakeholders that help to ensure access to care.Hanney et al., can prevent individuals from receiving necessary care, even when the intervention is deemed cost-effective. Therefore, it is essential to address these barriers in conjunction with economic evidence. Policymakers should focus on developing strategies that enhance access to cost-effective interventions, ensuring that all individuals, regardless of their socioeconomic background, have equal opportunities to benefit from them.However, cost-effectiveness alone does not ensure equitable access to healthcare services. Barriers to access, as identified in the study by The collection of articles in this editorial offers valuable insights into cost and resource allocation in healthcare, with a focus on economic evaluations and access to care. The findings have practical implications for healthcare providers, policymakers, and stakeholders, guiding decision-making processes and promoting efficient allocation of resources. By integrating cost-effectiveness considerations and addressing barriers to access, healthcare systems can enhance the delivery of cost-effective interventions and ensure equitable access to care. Future opportunities lie in exploring long-term cost-effectiveness, refining financing mechanisms, and leveraging technology to optimise resource allocation. Continued research and collaboration in this field will contribute to building sustainable healthcare systems that deliver high-quality care to all.