Today’s diabetes-oriented telemedicine systems can gather and analyze many parameters like blood glucose levels, carbohydrate intake, insulin doses, and physical activity levels (steps). Information collected can be presented to patients in a variety of graphical outputs. Despite the availability of several technical means, a large percentage of patients do not reach the goals established in their diabetes treatment.The objective of the study was to evaluate the benefits of the Diani telemedicine system for the treatment of patients with type 1 diabetes mellitus.1c) and the patient’s body weight were measured, and the patient’s use of the telemedicine system and their daily physical activity level were monitored. All data were sent from the patient’s device to the Diani server using a real-time diabetes diary app. Wilcoxon and Friedman tests and the linear mixed effects method were used for data analysis.Data were collected during a 24-week feasibility study. Patients responded to the World Health Organization Quality of Life – BREF (WHOQOL-BREF) questionnaire and a system evaluation questionnaire. The level of glycated hemoglobin  mmol/mol. The median number of days the patients used the system was 84. After the intervention, the mean HbA1c decreased by 4.35 mmol/mol (P=.01). The patients spent 18.6 (SD 6.8) minutes on average using the app daily. After the intervention, the number of patients who measured their blood glucose level at least 3 times a day increased by 30%. The graphical visualization of the monitored parameters, automatic transmission of measured data from the glucometer, compatibility, and interconnection of individual devices when entering data were positively evaluated by patients.This study involved 10 patients , with a mean age of 47.7 (SD 19.3) years, a mean duration of diabetes of 10.5 (SD 8.6) years, and a mean HbA1c level.The Diani system was found to be beneficial for patients with type 1 diabetes mellitus in terms of managing their disease. Patients perceived it positively; it strengthened their knowledge of diabetes and their understanding of the influences of the measured values on the management of their disease. Its use had a positive effect on the HbA Diabetes mellitus is a major public health problem that is approaching epidemic proportions worldwide . The preThe increase in global health expenditure due to diabetes has been considerable, growing from US $232 billion in 2007 to US $966 billion in 2021 for adults aged 20 to 79 years. Direct costs of diabetes are expected to continue to increase. The International Diabetes Federation estimates that total diabetes-related health expenditure will reach US $1.03 trillion by 2030 and US $1.05 trillion by 2045 [1c) for patients with type 1 diabetes was 66 mmol/mol  [The overall average glycated hemoglobin (HbAp users) .Currently, different technological tools are available for patients with diabetes mellitus that can significantly facilitate their daily life with diabetes and, at the same time, adapt to their individual needs. Telemedicine systems (TSs) have the potential to offer a solution to the sustainability of health care systems, maintaining or increasing the quality and accessibility of health care and managing large amounts of health-related data with limited resources ,9.TSs have been increasingly used in the care of diabetes in the last decade -17. DespHowever, the technologies themselves will not help the patients if they are unable or unwilling to fully use what the given technology offers. It is necessary to ensure frequent interaction with the technology. To find the right motivation for a given patient, it is necessary to know the patient’s involvement in terms of treatment, in situations in which it is difficult to self-manage diabetes mellitus, as well as mental abilities and environment . For lon1c values in patients with type 1 diabetes [Diani is a TS for the management of diabetes mellitus and other chronic diseases, which reports a significant improvement in HbAdiabetes . The fea1c and body weight. Specific objectives were to identify the benefits and limitations of the system from the perspective of patients, namely whether the system contributes to a sense of security, whether patients have educational benefits as a result of using the system, whether they feel more confident in managing diabetes care, what functions the system likes to use and which they have not used, and why. The parallel target was to monitor the patient’s views on the operation and use of the system and to evaluate whether the Diani TS affects their health and quality of life. Furthermore, this study aims to determine how patients have used the system (frequency and duration of using particular sections of the Diani TS and access method).The main objective of the study was to evaluate the Diani TS for the treatment of patients with type 1 diabetes mellitus, especially its effect on HbA1c and the body weight of the patient with diabetes. The study followed the principles of the randomized, crossover intervention study  [The study has been designed as a feasibility study focusing on the evaluation of the Diani TS based on a questionnaire survey of patients with type 1 diabetes mellitus and the use of the Diani TS, which also includes tracking patients’ use of the system. The monitored parameters were HbAd study) ,24. The In a selected internal medicine clinic, which provides comprehensive diagnostic and therapeutic care to both outpatients and hospitalized patients with diabetes mellitus from all over the Czech Republic, 10 patients were recruited and included in this study, with an emphasis on maintaining the highest representativeness.The Diani TS configuration used in the study consisted of a web app (Diani), a mobile app called the Diabetesdagboka (DDB) diabetes diary , a Fora Diamond MINI Bluetooth glucometer (FORA Care Suisse AG), and a Fitbit Flex smart bracelet (Fitbit Inc). A continuous blood glucose monitor  and a smartwatch (Pebble Classic), with the DDB app for the Pebble Smartwatch, were all connected to the system, allowing for an alternative way of entering information into the DDB app . The mon1c values and patient body weight were determined at each of the 3 physician visits during the study . The parameters were collected in a diabetological office, including taking a blood sample, which was evaluated by the internal hospital laboratory. The primary objective was to check whether there was a significant change in these values after the intervention. The secondary objective was to see if there was a change in these values at V3 .HbA1c, at least in the short term, but there was no evidence of a convincing effect on the quality of life [A growing number of studies discuss the influence of digital technologies on the compensation of diabetes mellitus disease ,18-20,27 of life . Telemed of life .To determine the characteristics of the group, patients completed the patient questionnaire at the initial visit (V1). To determine the possible impact of the Diani TS on diabetes self-management, selected questionnaire questions were submitted for completion at subsequent visits (V2 and V3). To study the impact of the Diani TS on the quality of life of patients, patients completed a standardized WHO questionnaire at each visit .Key Instruments section) during a postintervention visit.Another partial objective was to find the frequency of using particular Diani TS features and to register the time needed to enter and collect data. For this, a Matomo analytics application was used with a focus on tracking the patient’s use of the Diani system at the time of the intervention. To evaluate the Diani TS and identify the strengths and weaknesses of the system, which is important for its further innovation, patients completed a product questionnaire  mmol/mol. The median number of days for which patients tested the system was 84.The study involved 10 patients (5 women and 5 men). The mean age of the participants was 47.7 (SD 19.3) years; the mean duration of diabetes was 10.5 (SD 8.6) years; and the mean BMI was 26.9 (SD 3.6). The mean body weight of the patient at the time of study entry was 81.1 (SD 16.9) kg and the mean HbAData for the Diani TS evaluation were obtained within the feasibility study, which had the characteristics of a randomized crossover intervention study. The total duration of the study was 24 weeks . The patThe study included 3 visits to the doctor: the initial visit (V1), then a follow-up visit (V2) after 12 weeks of study, and the third visit (V3) after 24 weeks of study.1c and the patient’s body weight.During V1, the physician evaluated the inclusion and exclusion criteria. The physician asked the patient if they were willing to participate in the project and asked them to sign an informed consent. The patients enrolled in the study received a set of questionnaires , which they completed during V1. If the patient was assigned to group A, a Diani TS monitoring kit was given and they were trained in the use of the system. The patients in group A were supposed to use the Diani TS between V1 and V2, optimally for 12 weeks. The data reported by the physician were obtained from medical records and recorded in the Diani web app. The data included HbA1c and the patient’s body weight.V2 and V3 took place within the usual practice in the clinic at 3 and 6 months after V1. The period between weeks 1 and 12 was referred to as phase 1 and the period between weeks 13 and 24 was designated as phase 2. During V2 and V3, the patient completed an updated patient questionnaire (questions from the Demographic section were omitted) and the WHOQOL-BREF Questionnaire. At the end of the intervention, patients completed the product questionnaire (group A at V2 and group B at V3). At V2, patients in group B received the Diani TS monitoring kit and were trained in how to use the system. Patients in group B used the Diani TS between V2 and V3 (weeks 12-24); patients in group A followed their usual plan of diabetes care during this time, as before the Diani TS intervention (without further intervention). The data reported by the physician were obtained from medical records and recorded in the Diani web application. The data collected were HbAThe patient questionnaire was developed by the research team involved in this particular study to obtain data describing important areas related to insulin therapy and diabetes in general. It focuses on the details of the patients and their technical skills in using conventional computing and smartphones in order to assess their ability to use the Diani TS. The questionnaire consists of 43 questions classified into the following categories: demographic data; self-management of diabetes and health, including patient’s eating habits of the patient; physical activity; questions that determine the level of use of computer technology and smartphones.The WHOQOL-BREF Questionnaire is a standardized questionnaire by the WHO. The questionnaire focuses on determining the quality of life of the patient. It is capable of detecting the current deterioration of health and capturing differences in the living conditions of people with long-term illness or disability ,33. The The product questionnaire is a questionnaire created by this study’s research team and focuses on the evaluation of the Diani TS by an intervention group. It is based on standard product evaluation research -37 and iTo track the patients’ usage of the Diani TS, the open-source analytic framework for web analytics, Matomo, was used. This software monitors the digital visits of patients to the Diani TS and shows reports for further analysis. The objective was to identify how often individual users log into the system, how long they stay there, what sections of the system they use or what activities they perform , and in what way .The intervention consisted of using the Diani TS by patients to self-manage diabetes for a predetermined period of time. Patients had access to the Diani web app, the DDB mobile diabetes diary app, the Fitbit smart bracelet, the Pebble smartwatch with the DDB Companion for the Pebble smartwatch app, and the Diamond Mini glucometer.1c and the patient’s body weight after the intervention and at the end of the study (V3), at the selected significance level of .05. Another objective was, at the same level of significance, to identify a potential change in the patient’s quality of life after the intervention. For this purpose, a regression analysis, the linear mixed effects (LME) method, and nonparametric tests (Wilcoxon and Friedman tests) were performed.The primary objective was to identify a potential change in HbAThe secondary objective was to determine how frequently the patients used the Diani TS features and when they used them. As with the analysis of the characteristics of the group, the basic descriptive statistical analysis of the primary data  was used here as well.For nonstandardized questions, a list of individual responses, their categorization, and coding into numerical values were performed. For the free text questions, a thematic evaluation of the answers was performed.All procedures were performed according to the Ethics Committee for Multicenter Clinical Trials of Motol University Hospital and the 2nd Faculty of Medicine, Charles University in Prague, Czech Republic . All participants signed an informed consent form.P=.06).All patients agreed that they had been instructed on lifestyle changes and diabetes care during their treatment. Seven (70%) patients checked their blood glucose values at least 3 times a day before entering the study, and 10 (100%) patients checked their blood glucose at least 3 times a day after the intervention. Of these, 6 (60%) participants tested their blood glucose at least 4 times a day, which was 20% more than at the beginning of the study . Using tWhen asked during V1, 4 (40%) patients said that they suffered from depression. This number of cases may seem high, the likely reason being that the term depression was not specified or defined in the questionnaire and patients could thus explain it in different forms. Three (30%) respondents did not feel like managing their lives due to type 1 diabetes mellitus. Seven (70%) patients said that the behavior change plan would help them better compensate for type 1 diabetes mellitus; 6 (60%) patients would like more information in the field of nutritional therapy and information about type 1 diabetes mellitus disease.Seven (70%) patients reported that they could reduce the risk of health complications resulting from diabetes mellitus. Seven out of 10 participants stated that they had a diet plan, but only 2 participants always followed it and 4 occasionally, while the others only rarely or never. Nine (90%) patients stated that they had bigger problems counting carbohydrates and 4 (40%) of them did not manage this activity at all. At the same time, 6 (60%) patients reported eating the recommended portion sizes of food almost always. Half of the participants felt that it was difficult for them to manage their illness and all of them stated that they were motivated to work on their treatment.At V1, 9 (90%) patients reported targeted, planned, and structured physical activity at least once a week, of which 6 (60%) reported, more than twice a week, mostly walking, gardening, or cycling. This activity usually lasted 30-60 minutes. After the intervention, the type of activities decreased , but theNine (90%) of the patients had no experience with using any mobile diabetes diary application prior to participating in this particular study. One patient stated that he had experience with the DDB mobile app. None of the study participants had participated in any study that dealt with diabetes treatment assistance before entering our study.The return rate of the questionnaires was 80%. For the first separate question on the quality-of-life assessment, 60% (n=6) of the participants rated their quality of life as good or very good at V1. At V2 and V3, 78% (n=7) and 89% (n=8) of the participants chose these answers, respectively. The second separate question focused on the evaluation of satisfaction with the participants’ health. At V1, 30% (n=3) of the patients expressed satisfaction with their health; 44% (n=4) and 50% (n=5) of the participants were satisfied with their health at V2 and V3, respectively.The Friedman test did not show significant differences in quality of life within the group between individual study phases. The Wilcoxon test did not show a change regarding the intervention or nonintervention groups.As part of the system evaluation, all users marked the use of the system as socially discreet. Its use  was rated by 90% (n=9) of the patients as rather easy or easy. Similarly, 90% (n=9) of users reported spending more time thinking about diabetes mellitus as a result of using the system and managing to dose insulin better. For example, based on links to educational resources from the DDB app, there was new information for one of the patients that their insulin bolus could be adjusted by more than 2 units. Seven (70%) users feel safer as a result of using the system. In terms of time, 70% (n=7) of the patients evaluated working with the system to be rather undemanding or not at all demanding.In open questions, users positively evaluated the graphical visualization of measured parameters , automatic transmission of measured data from the glucometer, and compatibility and interconnection of individual devices when entering data. One of the system benefits was also reported to be the simplicity of entering data into the mobile app and the generally simple operation of the system. The possibility of connecting a continuous blood glucose monitor and the smart bracelet, digitizing data, and a possible view from several types of devices (interconnection of the system with the internet) was appreciated. The chronological presentation of the key indicators was also positively assessed. These indicators enable the evaluation, comparison, and search for connections between carbohydrate intake, physical activity, and the size of the insulin dose. Patients acknowledged the opportunity to print the monitored values with the selected data filter and decide the amount of data, for easier perception of the information. In the Diani TS evaluation, users emphasized the power of the system in providing feedback to the user, which makes it easier for them to understand the measured values and information in context and as a result of their behavior, to improve diabetes management in the future.The provided smartwatches were reported to be difficult to control  and negatively evaluated. Users also requested the display of key values in a single graph and the depiction of trends in the development of the measured values (curve fitting). Furthermore, the need to link the Diani TS with Kalorické Tabulky (a Czech food composition database mobile app) was requested, and a requirement to automatically add up the registered values of the received carbohydrate intake over a predefined period was mentioned. Users also described the acquisition and registration of data as time-consuming. Another issue was the overuse of devices (both a smartwatch and a smart bracelet placed on the wrist). During the study, patients reported communication issues with the server. This outage was also described as unsatisfactory. This was mainly due to a poor internet connection on the users’ mobile phone, Bluetooth being turned off in the device, or improperly timed technical maintenance of the server. However, these technical issues were eliminated during the study. During these episodes, all data were stored in the user’s mobile phone and were uploaded to the Diani server after the connection was re-established, which occurred within 5-15 minutes.Suggestions for improving the system included the possibility of adjusting the limit values of the monitored blood sugar level. The need for retrospective control of data transfer (in the form of notification) and access to the application for devices operating on the iOS operating system were also wanted features. Additionally, the need to improve the smartwatch so that it is more user-friendly was also stated. Furthermore, a proposal to reduce a large number of items was mentioned in the web version of the application and to emphasize the monitoring of exceeding carbohydrate intakes was mentioned.Five (50%) users expressed their readiness to pay for the use of the system; 3 (30%) users are not willing to pay for the system; and 2 (20%) are unable to decide. One (10%) user would be willing to spend 5%-10% of their monthly income on the system; 40% (n=4) users would be willing to spend between 1% and 5% of their monthly income; and 20% (n=2) user would be willing to spend less than 1% of their monthly income .1c level was 59.5 (SD 6.7) mmol/mol; after the intervention, the mean HbA1c decreased by −4.35 mmol/mol (P=.01) . The effect comparing monitoring at V2 with V1 was −6.54 mmol/mol (P=.04); the effect comparing the use of the Diani TS at V3 with V1 was −2.16 mmol/mol (P=.45). The mean HbA1c at V2 was 60 (SD 9.8) mmol/mol and at V3 was 61.8 (SD 6.1) mmol/mol in participants who participated in the intervention in phase 1.At V1, the mean HbAP>.05) in patients’ body weight between the intervention or control groups; there was even no effect within one group during the study.The average body weight of participants was 81.4 (SD 16.4) kg at V1, 81.1 (SD 16.9) kg after intervention, and 81.5 (SD 16.9) kg at V3. Statistical analysis did not show a significant difference  hours on average using the DDB app, with a daily average use of 29.7 (SD 22.7) minutes. Of the total time, the daily average of 11.6  minutes was spent on manual physical activity registration, 3.5  minutes on the registered blood glucose level, 2.1  minutes on carbohydrate registration and 1.4  minutes on insulin dose registration. The remaining time includes inactive use of the application—viewing records, launching the application on the smartphone, and communicating with the server. On average, patients visited the DDB application 4.5 (SD 2.3) times a day and performed 31.3 (SD 23.9) activities per day; these activities include: registering items, viewing records, and editing data in the application. The average number of activities per visit was 7.1 (SD 2.9), and 29.4% (SD 13.3%) of the visits left the application immediately after viewing an item. The length of 1 visit lasted 14.2 (SD 11.9) minutes on average. As for the length of app use, the average time of the visit decreased during the intervention. Two users had a minimum number of entries in the DDB and were excluded from the objective evaluation of the system due to misrepresentation of results. A comparison of the average values of the daily number of visits and activities performed per day showed that one-third of patients used the system very actively and, conversely, 20% (n=2) of users used the system below average. Seven (70%) patients with a higher degree of involvement with the Diani TS actively used the system even a year after the study ended.This study was the first clinical trial to evaluate the Diani TS for users with type 1 diabetes mellitus. On the basis of the data obtained, recommendations were subsequently derived, and suggestions for further innovation of the Diani TS were determined.1c level associated with participating in the study and the increase in the frequency of blood glucose measurements during self-management control after using the Diani TS. This increase was observed in 50% of the participants and is interpreted as a positive effect of the system. The reason can be that the system allows the patient both to observe the data more and to display it in the context of activities and might motivate patients to improve the measured data.The most significant result of the evaluation was the decrease in HbAData from the patient questionnaire showed that determining the correct content of carbohydrates in the diet is a major challenge. Most (90%) of the respondents admitted that they had this problem; nevertheless, 60% of patients also stated that they consumed the recommended amount of carbohydrates in their diet. The focus on diet should be approached more actively. In the future, it would be interesting to focus on this topic and think about how to motivate patients to learn from the data they enter into the system and how to educate them to use the data and explain the importance of a well-balanced diet plan to compensate for the challenges of diabetes mellitus. This problem was the reason for the integration of the food composition mobile app Kalorické Tabulky  directlyRegarding the quality-of-life assessment (WHOQOL-BREF questionnaire), the trend curve indicated an increase in the perception of one’s quality of life and health. Unfortunately, due to the low return rate of the questionnaires (80%) at the end of the first and second phases of the study, the results cannot be considered entirely reliable.In general, the Diani TS was positively evaluated, in terms of graphics, functionality, and practical use. The system was perceived as user-friendly, well organized, and motivating by most of the participants. The participants appreciated the feedback provided by the Diani TS, especially concerning the complexity and orderliness of the monitored data submitted in real time. Based on comprehensive information, patients reported that they were able to perceive and understand the relationship between particular monitored values , which allowed them to better estimate insulin dose. The system enabled patients to deepen their knowledge in their current understanding of blood glucose variations, in general. As a result of the use of the Diani TS, the patients stated that they felt safer and that it was easier for them to leave their comfort zone, for example, when traveling and sleeping outside their place of residence. Eliminating stressful situations like these can have a positive effect on the patient’s quality of life.The accessories of the system, namely the smartwatch, the use of which did not bring patients a large benefit compared to the efforts made to become familiar with them, were negatively evaluated. Proposals for additional innovations to the system were identified on the basis of subjective evaluation.Based on the system logs, the operation of the system was not very time-consuming for patients. They did not spend more than 18.6 (SD 6.8) minutes a day registering the data, which was why the Diani TS was perceived as easy to use and the patients evaluated its use as discreet and not interfering with daily activities.During the study, there were some technical issues regarding the transfer of information from the glucometer to the Diani server. These issues were resolved during the first phase of the study. In case the problems were caused by users’ lack of knowledge of the system, assistance for solving respective problems was provided by means of a telephone conversation or an electronic conversation. More detailed instructions on using the system or video instructions may be appropriate in the future.Difficulties in recruiting participants have been described in previous studies , and mea1c were confirmed among patients who used the Diani TS. The system also helped strengthen the patient’s position in terms of a positive effect on compensating for type 1 diabetes mellitus. Patients expressed a generally positive perception of the system.Significant effects on the reduction of HbA1c [Similar studies have been conducted, but they differ in their study design, patient variability, and technologies used. These studies have similar results in terms of a positive effect on HbA1c ,9,40,41 The feasibility study was a valuable first step in the evaluation of the Diani TS. It helped identify both the benefits and limitations of the system from the users’ perspective, recorded their views on the operation and use of the system, and assessed whether the Diani TS had an impact on their health and quality of life. Based on the information obtained, new needs and demands of patients for the TS were identified, from which recommendations were derived, and suggestions for further innovation of the Diani system were determined. At the same time, the study was helpful as a real test of the system features. In the future, the methodological findings of the study will be used in the evaluation of the Diani TS extended with other components and functions. The study confirmed both that the Diani TS can be beneficial for patients with type 1 diabetes mellitus in managing their disease and that its use can (at least in the short term) increase interest and motivation to follow medical recommendations. The effectiveness of the TS for managing diabetes is limited by its acceptance of patients. We need more information about what motivates the long-term use of the system by patients with diabetes as well as the degree of influence imposed by personality.


However, in the response to author query 4, Micrographs #4 and #8 were changed in Table 1. While processing the suggested changes based on the eProofing comments, the correction team updated the existing table figures and replaced image #05 with the micrograph of image #08 and image #08 with the micrograph of image #04 in the revised table. As a result, the changes got reverted and images were incorrect and duplicated.


In this study, we investigate the optical absorption of a planar superlattice comprising alternatively arranged two-dimensional Transition Metal DiChalcogenide semiconductors. Within a semi-classical model and using the Dirac-like equation in the presence of light interaction as a perturbation, we obtained the governing Hamiltonian. Using this Hamiltonian, we derived a fully analytical relationship for the absorption coefficient of the structure. By calculating the effective mass for different bands and using the Drude-Lorentz model, our approach is able to determine the oscillator strength and the effective refractive index of the structure. We found that the spin–orbit coupling has important effect on the absorption coefficient and energy bands where it reduces the absorption coefficient of the structure from typical value of  Compared to conventional three-dimensional (3D) photonic materials such as GaAs and Si, 2D ones exhibit many unique properties for some important reasons. Due to quantum confinement in 2D materials, they exhibit new electronic and optical properties, which is completely different from their bulk properties. In addition, the surface of these materials naturally do not have dangling bonds; this feature leads to the possibility of integrating 2D materials with photonic systems. On the other hand, despite the low thickness, most of these materials interact strongly with light, and finally since the 2D materials cover a very wide range of electromagnetic spectrum, they can have a variety of photonics applications.Two-dimensional (2D) materials with atomic thickness such as graphene, transition metal dichalcogenides (TMDCs), boron nitride, phosphorene, etc. are considered as highly promising materials for the next generation of electronics and photonics due to their unique electronic and optical properties7. These materials have the chemical formula MX2, where M represents the transition metal atom  and X represents the chalcogen atom . In addition to having a direct band gap due to the structure inversion asymmetry, TMDCs provide access to a new freedom degree of carrier, i.e., the valley index, which leads to a new branch of physics, called valleytronics. Besides, the strong spin–orbit coupling (SOC) leads to spin–orbit splitting and provides the electron spin control by regulating the excitation energy of the laser photon9. All mentioned properties make these materials to be different from the graphene; so that TMDCs nanomaterials such as MoSe2, MoS2, WSe2 and WS2 are emerging as a new generation of photonic nanomaterials11.One of the most important members of the family of 2D materials is the 2DTMDC semiconductors. These 2D semiconductors represent a new class of materials, which proposed in the field of semiconductor physics and nanoscience as well as electro-optical applications. Studies on monolayer TMDCs (ML-TMDCs) have been inspired and benefited almost from the focused research and development on graphene-based systems. Studies on ML-TMDCs, as part of "beyond graphene research" in order to clarify their essential properties and new potential performance are mostly at the basic research level12. The heterostructures could be used to enhance light absorption and, consequently, the development of photovoltaic systems due to various optical properties11.One of the main challenges in the field of 2D materials is the theoretical and analytical study of their optical properties. Optical absorption in ML-TMDCs with a thickness of less than 1 nm in the visible spectral region (E = 1.590–3.263 eV) and near infrared (E = 0.827–1.590 eV) happens through a direct transition between the valence and conduction bands. Due to the strong light-matter interaction and the desirable band gap of 1 to 2 eV, the optical absorption of these materials is in the order of 5 to 10%, which is greater than the absorption of GaAs and Si13. Recently, different mechanisms have been applied for investigation the optical and electronic properties of TMDC-PSL structures. In 2018, Han and et al. created superlattices, especially the planar ones with nanometer channels consisting of ML-WSe2 and ML-MoS214. In 2D WSe2 and MoS2 crystals, the constituent elements are alternatively arranged in a hexagon configuration to produce a honeycomb pattern. The researchers were able to use a special technique in TMDC planar superlattices (TMDC-PSLs). However, a theoretical explanation of the molecular mechanism and an analytical study of the fundamentals underlying the formation of these nanochannels, promise that their formation can be controlled to provide the possibility of obtaining the electro-optical devices at the atomic scale based on planar heterostructure or superlattice. Zhao et al. studied theoretically the tunable electronic structure of TMDC-PSL made of WSe2 and MoS2 bilayers15, where the tunability of direct and indirect band gaps of the structure has been investigated using superlattice parameters through density functional theory (DFT) simulation method. In addition, the role of SOC on electronic band structure and the absorption coefficient was investigated and the absorption coefficient in the order of 21.The 2D materials, with a few nanometer in size, must eventually defeat the silicon-based devices. Creating the thinnest nanometer channels in 2D materials can be a major step towards the development of sub-nanometer electro-optical devices. However, the production of useful electronic devices requires the integration of several 2D materials into one plane, which is a very difficult challenge. Creating 2D material heterostructures enable us to engineer bands on a 2D plane and open up a new domain in materials science, physical devices and their engineering. On the other hand, a periodic structure composed of two layers with different characteristics (superlattice) has promised improving the performance of these devices, because the periodicity of the superlattice leads to improved electrical charge conduction and its control along the superlattice. Incorporation of these two concepts offer to double the performance of devices, including infrared optical detectors and solar cells, and a way to extend fully 2D transistors. Effective usage of solar energy requires adapting the performance of these structures to solar radiation. In order to enhance the functionality of these structures (absorbers) and reduce their fabrication cost, the thickness of these materials must be reduced. On the other hand, it is clear that the most interesting physical phenomenon take place at the interface of two layers, therefore, the performance of superlattice-based solar cells will be improved. Until 2015, no multiple heterostructures or 2D lateral superlattices of less than 5 nm wide, a regime in which quantum-size effects are appeared, have been reported and leaving a major challenge for 2D material researchIn this work, we perform a comprehensive analytical investigation of the optical properties of the TMDC-PSL based on the effective Hamiltonian approach. The optical absorption coefficient and the photoluminescence intensity of the TMDC-PSL is one of the main directions of this research. In the first part, based on some reported experimental and theoretical works, a model was proposed for Hamiltonian of the TMDC-PSL structures. In the second part, using this Hamiltonian approach, we derived a fully analytical relationship for the absorption coefficient of the structure by considering the freedom degree of the valleys as well as the incident light with different polarizations. In the third part, the optical characteristics of the structure is reported by considering the effective mass, oscillator strength and effective refractive index. The effect of geometrical parameters of the superlattice on its optical absorption in different valleys discussed in details. Finally, we will summarize our main findings.13. We start with the ML-TMDCs Hamiltonian to obtain the band structure and transmission spectrum of TMDC-PSL23 as:In our model, we consider the TMDC-PSL as shown in Fig. 23. The central symmetry breakdown caused by the SOC in ML-TMDCs leads to the valance bands splitting. These separated sub-bands have up- and down-spin characteristics , and the thickness of the structure equals to the thickness of the ML-TMDCs, 23. Figure 38. We found an splitting of 168 meV for TMDC-PSL made of 37. As shown in Fig. In this section we will report our findings with discussions. During the calculations, the incident angle of the light is fixed at entclass1pt{minimaentclass1pt{minimaentclass1pt{minimaentclass1pt{minimaWhen an electron in the valence band is excited to the conduction band, the "oscillator strength" (OS) indicates the probability of transition of a created electrical dipole. We study the OS as a function of the final states energies  in the presence of SOC. As was previously mentioned, the primary effect of SOC is the renormalization of the band structure, which has a notable impact on the valence band. In light of SOC, the effective mass of the electron changes less, while that of the hole changes more Fig. a. This m2 and WSe2. It is observed that by considering the SOC effect, the valence band experiences a few hundred meV blueshift while the conduction band will have slight change. Due to the parabolic band structure at In conclusion, we studied the electronic band structure and optical absorption in a planar TMDC superlattices containing alternatively arranged MoS


BeiDou Satellite-based Augmentation System (BDSBAS) has come into the trial operation stage since July, 2020. To evaluate the characteristic of the augmentation message in BDSBAS-B1C signal, the effectiveness of the message content was firstly analyzed, and then the validity of the broadcasting strategy was estimated. Finally, the accuracy of the user equivalent ranging error (UERE) and the single frequency positioning error with different correction parameters in BDSBAS-B1C message was evaluated. Based on the above analysis, the effectiveness of the augmentation message was preliminarily verified with the results showing that: (1) the BDSBAS-B1C message type, information content and update interval have basically met the international standard; (2) the accuracy of the UERE obtained with the augmentation message had an obvious improvement in contrast to that of the UERE obtained with the usual navigation message of the GPS satellites, and the ionospheric delay was one of the important factors which affected the accuracy of the UERE; (3) the positioning accuracy obtained with the augmentation message was also improved, and the improvement was more obvious in the service areas with high availability of the ionospheric parameters. It can provide seven kinds of service: basic positioning, navigation, and timing (PNT) service, global short message communication (GSMC) service, international search and rescue (SAR) service, satellite-based augmentation service, ground augmentation service, precise point positioning (PPP) service and regional short-message communication (RSMC) service. Up to now, the satellite-based augmentation service of the BDS-3 is still in trial operation stage.BeiDou navigation satellite system (BDS) has gone through the construction of BDS-1 and BDS-2Since 2010, BDS-2 has been providing augmentation message for users in China and the surrounding areas via the BDS-2 geostationary earth orbit (GEO) satellites. The message includes the equivalent clock correction, grid ionospheric correction and the corresponding integrity parameters. As the format of the BDS-2 is designed as page, it is broadcasted along with the basic navigation message. Therefore, BDS-2 is a system which can provide the basic navigation and satellite-based augmentation service simultaneously. It can significantly improve the service precision of the specific area. In recent years, the supplement parameters, such as the comprehensive partition correction parameters and the orbit correction parameters, are added in the message of the BDS-2 to further improve the service performance. Whereas, the equivalent clock correction parameters contain both the error of satellite clock and orbit and the ionospheric grid is a kind of serried grid. All of the parameters are broadcasted in the B1I, B2I or B3I signal. The constraints of the signal features and message format make it hard to meet the certification requirements of the international civil aviation.2. It designs a new message structure and broadcasted different service message in different signals, in accordance with the International Civil Aviation Organization (ICAO) standards.As the new generation of the BDS, the BDS-3 has stepped further in the integration of the platform, data, technology and terminal, and paid more attention in compatibility and interoperability with other international systems3. Owing to the effect of the ionospheric anomalies, it’s difficult to satisfy the requirements of Category I precision approach (CAT-I). Only WAAS and EGNOS have satisfied the requirements of the localizer performance with vertical guidance at 200 feet decision height4,5. Whether the BDSBAS could gain the identification of the ICAO, extensive testing is required to assess the various indicators, such as PE, alarm time and integrity threat.Currently, the SBASs in service are the USA’s Wide Area Augmentation System (WAAS), EU’s European Geostationary Navigation Overlay System (EGNOS), Japanese Michibiki Satellite-based Augmentation System (MASAS), and Indian GPS-aided GEO augmented navigation system, which are all SF SBASsAs the launching of the last BDS-3 GEO satellite in June, 2020, the BDSBAS-B1C messages has been broadcasted steadily. BDSBAS formally steps into the trial operation stage since July, 2020. By the end of 2022, the BDSBAS is still in the testing stage. To preliminarily analyze the performance of the BDSBAS-B1C message, we researched on the content of the broadcasted message, deduced the broadcasting strategy and evaluated the accuracy of the user equivalent ranging error (UERE) and the SF positioning error (PE) with the support of different correction parameters in BDSBAS-B1C.BDSBAS is an important part of the BDS-3, mainly applied in civil aviation, maritime and railway. As shown in Fig. The space segment consists of three BDS GEO satellites. As showed in Fig. The augmented satellites will include BDS-3 medium orbit earth (MEO), inclined geosynchronous orbit (IGSO) satellites and other GNSS satellites, such as global position system (GPS), Galileo satellite navigation system  and global navigation satellite system (GLONASS) satellites. At present, the augmentation message of the GPS satellites is broadcasted in BDSBAS-B1C signal and BDSBAS-B2a signal, while the augmentation message for BDS-3 satellites is only broadcasted in BDSBAS-B2a signal.The ground segment of the BDSBAS is constructed with the BDS-3 ground segment, including monitoring stations, data processing centers, main control stations and injection stations. The distribution of the stations has not been published.The space–time reference system maintained by the BDSBAS SF service keeps consistent with WAAS. The coordinate system of BDSBAS is WGS-84. The deviation of BDSBAS SF service network time (SNT) to GPS Time (GPST) is within 50 ns.The civil terminal of the BDSBAS mainly includes the airborne terminal and land terminal. The airborne terminals can be applied in commercial aviation, general aviation and unmanned aerial vehicles. The land-based terminals can be used for the low dynamic land-based or maritime equipment.3. How to realize the seamless connection in the overlapping area has become an inevitable issue for the performance improvement of the SBAS services6. The consistency of the signal system and message structure is the basic requirement.The current SBASs are independent and regional operating systems, which mainly provide augmentation service to civil aviation users within the coverage area of their respective systems7.The realization of the BDSBAS-B1C message is depend on the BDS signal-in-space interface control document: satellite based augmentation system service signal BDSBAS-B1C, which strictly follows the Satellite Based Augmentation System (SBAS) Standards and Recommended Practices (SARPs) of ICAO “Convention on International Civil Aviation” Annex 10 Aeronautical Telecommunications Volume I Radio Navigation AidsBased on the signal characteristics and message structure described in the BDSBAS-B1C document, the message content and broadcasted strategy can be analyzed with the actual message.The broadcasted BDSBAS-B1C message mainly includes fast corrections, long-term satellite error corrections, ionospheric corrections and the corresponding integrity parameters. Based on the message broadcasted from Dec 11 to 31, 2020, Table Not all messages defined in the BDSBAS-B1C message were broadcasted, such as the offset parameters of BDSBAS SNT and UTC (MT12) and the fast corrections/long term satellite error corrections (MT24). These messages were also not broadcasted regularly in WAAS. Whereas, EGNOS, a system which could augment GPS and GLONASS, provided not only the MT 12 but also the SBAS service message (MT 27). As the augmented object of the BDSBAS was also the GPS and GLONASS, the MT 12 and MT 27 may also be broadcasted in BDSBAS-B1C signal as EGNOS.The correction parameters and the integrity parameters of the 32 GPS satellites have been broadcasted regularly. When the satellites were not in the BDSBAS service area or an alarm event occurs, the correction information of the corresponding satellites should not be broadcasted or set as a default value. Some alarm events have been monitored, which were mainly caused by the low availability as the satellite got close to the service boundary.As shown in Table The details of the broadcasted messages are further described in the following paragraphs:(3)9 as the low availability of the boundary area. As the development of WAAS, it adopted the Kriging interpolation algorithm to calculate the ionospheric delay, which could greatly reduce the reliance on the monitoring stations and improve the IGPSs availability in the boundary areas10,11. While, the applicability of this algorithm for the BDSBAS should be further demonstrated.The ionospheric corrections of the fixed IGPs were shown in Fig. The positioning and clock correction information on Dec 11, 2020 was shown in Fig. (4)MT28 contained an upper triangular mentclass2pt{minim formula :1\documeNormally, the broadcasted ionospheric grids are fixed. To improve the service performance and ensure the availability of each grid, WAAS has made four major adjustments. Whereas, the availability of the ionospheric grids surrounding the BDSBAS service boundary were rather low. Therefore, BDSBAS may further adjust the ionospheric grids.; In the formula, (5)The broadcasted degradation factors were all constant values in MT7 and MT10. The factors concerning the ionosphere took the same values with SDCM and other factors took the values of WAAS. The rationality of the value should be further verified.(6)The MT9 and MT17 provided the satellite position, velocity, clock time and an accuracy exponent of the BDS GEO satellite. Considering that the BDS GEO satellites did not provide ranging service, the accuracy exponent was set as a fixed value of “15” which indicated that the satellite ranging signal should not be used.Therefore, 12 has constrains the maximum update interval of each type, each SBAS has adopted different broadcasting strategies. Compared with WASS and EGNOS, the update interval of BDSBAS-B1C message was rather fixed. The update interval of the BDSBAS augmentation message was shown in Table Up to now, BDSBAS has not published the broadcasted strategy of the BDSBAS-B1C message, so does WAAS and EGNOS. Though the RTCA DO-229EThe update interval of the MT2–4 was 6 s, and the update cycle could be described as the formula The update interval of the MT1, MT7, M9, M10 and M17 was 120 s, and the update cycle could be described as the formula .5\documeIn the formula, (3)The update interval of the MT18 and MT26 was 240 s, and the update cycle could be described as the formula The update interval of the MT25 and M28 was 120 s, and the number of broadcast groups in each update cycle was relative to the visibility and availability of the satellites.(5)When there was no valid information generated, the MT0 or MT63 would be broadcast.In the formula, As BDSBAS is still in testing stage, the service boundary has not been published. Assuming the service area of the BDSBAS SF service was within China, some testing terminals were set in the central and boundary areas of China to test the accuracy of the UERE and the SF PE with the different correction parameters in BDSBAS-B1C message.The pseudorange residual error was the difference between the raw pseudorange and the reference range. The reference range could be gain with the true range between the corrected satellite position and the receiver, all the broadcasted corrections, tropospheric delay, receiver clock bias, and multipath. Therefore, the UERE mainly comprised the error in the space segment and the pseudorange residual error in the ground segment. It could be calculated as the formula .8\documeIn the formula, As to UERE of the GPS standard positioning service (SPS), the evaluation equation can be described as the formula .9\documeIn the formula, It could be seen that the difference between the To analyze the UERE of the GPS satellites in different correction modes, four groups of experiments were carried out with the observation data obtained by the known point in Beijing, Sanya, Chengdu, Shantou, Harbin and Urumchi from Dec 11 to 31, 2020. The four specific scenes were constructed as follows: (1) according to the Eq. , the obsCompared with the accuracy of the GPS SPS UERE in the specified area, BDSBAS could effectively improve the accuracy when all or part of the correction parameters applied.The accuracy could not be obviously improved with only the position and clock corrections or the ionospheric corrections applied.As the satellite came in and out the service boundary, the variation range of the It could be seen that:To analyze the SF PE of the GPS satellites with BDSBAS support, four groups of experiments were carried out with the observation data and navigation message obtained from the known points in different service areas from Dec 11 to 31, 2020. The four constructed scenes were the same as the scenes mentioned above. The horizontal positioning error (HPE), vertical positioning error (VPE) and the corresponding PDOP were given in Table Compared with the single point PE of the GPS SPS obtained by the navigation message broadcasted by the GPS satellites, BDSBAS could effectively improve the positioning accuracy with all the correction parameters applied. Whereas, the accuracy could be hardly improved when only the position and clock corrections or the ionospheric corrections were applied.Through the comparison of the different scenes, it could be seen that the positioning accuracy in the vertical direction has more improvements than the accuracy in the horizontal direction. It may benefit from the effective correction of the ionosphere in the vertical direction.The PDOP indicated the availability of the correction parameters for the visible satellite. For the regions with high availability of the ionospheric corrections, such as Beijing and Chengdu, the PDOP was almost the same in different scenes and the PE was mainly affected by the accuracy of the correction parameters. For the boundary area of the BDSBAS service, such as Harbin, there was obvious difference in different scenes. The reason for the lower PDOP in scene2 and scene3 was probably that the ionospheric corrections were applied in scene2 and scene3 and the availability of the ionospheric corrections was low.It could be seen that:The construction and content of the augmentation message broadcasted in the BDSBAS-B1C signal has basically met the requirement of the RTCA DO-229E. Whereas, the offset parameters of BDSBAS SNT and UTC and the SBAS service message have not been broadcasted.BDSBAS has specified a broadcasting strategy of the BDSBAS-B1C message with reference to the standards published by the ICAO, RTCA and other international organizations. Whereas, the fixed timing sequence may be more suitable for the case of no alarm events as the message containing the alert condition should be broadcasted four times in four seconds and relace the fixed message. It should be further verified if it is suitable in the case of alarm.In contrast to the accuracy of the UERE and single point PE obtained by the navigation message of the GPS satellites in the specified area, the BDSBAS could effectively improve the monitoring results. The results showed that the accuracy and availability of the ionospheric parameters was one of the most important factors. To satisfy the requirements of Category I precision approach (CAT-I) as WAAS and EGNOS, more effort should be put into to improve the availability of the ionospheric corrections in the boundary areas.Currently, BDSBAS has realized the broadcasting of the augmentation message with three GEO satellites and constructed along with other BDS-3 services. The conditions for initial operation have been met. Though the above analysis, the basic conclusion could be gain as follows:


What are the incidence and proportion of concussions among National Hockey League (NHL) players following the implementation of Rule 48–Illegal Check to Head?In this cohort study of 688 concussions among NHL players, the incidence following hits to the head from body checks using the shoulder, arm, and glove were similar before and after the implementation of Rule 48. However, the incidence of concussions from hits to the lateral aspect of the head decreased by 0.6/100 games, and the proportion decreased by 18.8 percentage points.These findings suggest that the number of concussions following direct hits to the lateral aspect of head was reduced following the implementation of Rule 48. This cohort study compares the incidence and proportion of concussions among National Hockey League (NHL) players due to a hit to the head before (2006 to 2010) and after (2014 to 2019) the implementation of Rule 48 . A rule prohibiting a direct hit to the lateral side of the head  was introduced in the National Hockey League (NHL) in the 2010-2011 season and refined in the 2011-2012 season to widen the application to include direct contact to all areas of the head.To compare the incidence and proportion of concussions that occurred following hits to the head before and after the implementation of Rule 48.This retrospective cohort study used a before and after design to evaluate concussions among NHL players in regular season games. Data from the 4 seasons preceding the implementation of Rule 48 (2006-2007 to 2009-2010) were compared with data from 5 seasons following its implementation (2014-2015 to 2018-2019). Data were analyzed from October 31, 2021, to November 30, 2022.The incidence and relative proportion of concussion characteristics and mechanisms before and after the introduction of Rule 48.In the analysis of 688 concussions for NHL seasons spanning 2006 to 2010 (n = 231) and 2014 to 2019 (n = 457), there was an overall increase in the incidence of concussion between the 2 time frames, although the incidence of concussions due to hits to the lateral aspect of the head decreased from 1.6/100 games to 1.0/100 games , 0.30/100 games to 0.90/100 games). There was also a reduction of 18.8  percentage points in the proportion of concussions due to hits to the lateral aspect of the head from 80 of 231 concussions (34.6%) to 61 of 457 concussions (13.3%). The incidence of concussions following hits to the head from body checks using the shoulder, arm, and glove was similar before and following the implementation of Rule 48. However, the proportion was reduced 14.7 percentage points from 113 of 231 concussions (48.9%) before to 149 of 457 concussions (32.6%) after implementation of Rule 48 .The findings of this cohort study of NHL players suggest that after the introduction of Rule 48, the incidence rate and proportion of concussions from contact to the lateral aspect of the head decreased, as did the proportion of concussions following direct hits to the head. Some rules have been structural, such as the National Football League (NFL) moving the kicking team forward from the 30- to the 35-yard line for kickoffs to increase touchbacks, while other rules have focused on penalizing players or teams for specific behaviors. For example, Major League Baseball (MLB) implemented a rule to protect athletes from collisions at home plate; the NFL instituted a rule prohibiting a player from lowering his head to initiate helmet contact with an opponent; professional soccer implemented the assessment of a red card  for intentional elbow-head contacts; and professional rugby lowered tackle height. Follow-up observational studies that have examined the effect of these rules6 found varied success at changing behavior or reducing the incidence of concussion and other injuries.It is well known that prevention strategies in certain circumstances can reduce the number and severity of concussions in sports.9 Hutchison et al9 performed video analyses of concussions among National Hockey League (NHL) players over 4 seasons (2006 to 2010). Specifically, they found the most common mechanism of injury was direct contact to the head by the shoulder, elbow, or glove, occurring in 62% of concussions.9 Of these hits to the head, most (67.3%) were initiated by the shoulder.9 Notably, almost half of the hits to the head (46.8%) were classified as a contact to the lateral aspect of the head. Subsequently, Rule 48 was introduced in the 2010-2011 season: “A lateral or blindside hit to an opponent where the head is targeted and/or the principal point of contact is not permitted.”10 Following the initial season when Rule 48 was implemented, in the 2011-2012 season the specific language referring to a “lateral or blindside” hit was removed to broaden the scope of the rule, and was therefore modified to state that the head had to be targeted and the principal point of contact, rather than “and/or.” Language was also added regarding whether the player taking the hit had put himself in a vulnerable position “immediately prior to or simultaneously with the hit” or if head contact with an otherwise legal body check was “unavoidable.”11 However, until now there has not been an evaluation of the sequence of events leading to concussions in NHL players since the introduction of Rule 48.Identifying appropriate policy or rule changes to potentially reduce the risk of concussion appears to differ by sport. Ice hockey is a collision sport played within a confined space, often at high velocities and with rapid direction changes. At the professional level, video analysis has been adopted to improve the documentation and evaluation of the events and mechanisms involved in a concussion.This study aimed to compare the incidence and proportion of concussions among NHL players that occurred due to a hit to the head before (2006-2007 to 2009-2010 seasons) and after (2014-2015 to 2018-2019 seasons) the implementation of Rule 48. We hypothesized that after the implementation of Rule 48, there would be a decrease in both the incidence and proportion of concussions resulting from hits to the head.STROBE) reporting guideline.This retrospective cohort study was approved by the University of Toronto Health Sciences Research Ethics Board and an informed consent waiver was granted because deidentified data were used. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology  were noted in medical records by medical personnel, and the corresponding video records were identified. To the extent that video of an event was available and in line with the event’s description leading to the concussion diagnosis, the events underwent video analysis. A total of 688 of 817 regular season concussions (84.2%) were identified with video documentation for analysis. The remaining events (129 of /817 [15.8%]) were not coded because of poor video quality, lack of adequate camera angles, or occurrence of the suspected concussive event outside of game play . Thus, these 688 events (231 in the 2006-2010 cohort and 457 in the 2014-2019 cohort) were used for the remaining quantitative analyses. Of the 129 events not coded, there was a greater percentage of events with video records in the 2006-2010 cohort (70 of 301 [23.3%]) compared with the 2014-2019 cohort (59 of 516 [11.4%]).Team physicians from the NHL diagnosed concussions using the definition established by the Concussion in Sport Group.8 and are aligned with prior projects examining situational characteristics and mechanism of injury.9 Variables for coding were similar between seasons, although some name changes occurred to variables over the data collection period. The corresponding digital recordings of concussion events included slow motion and multiple viewpoints. The coders (including M.G.H.) who were responsible for interpreting the digital recordings were trained using reliable methods previously used for examining concussions in the NHLData were analyzed from October 31, 2021, to Nvember 30, 2022. The primary objective of this study was to compare the incidence and proportion of concussions that occurred following hits to the head  in the 4 seasons preceding the implementation of Rule 48 (2006-2010 cohort) with the 5 seasons following its implementation (2014-2019 cohort). The 2010-2011 to 2013-2014 seasons were not analyzed because Rule 48 was implemented in 2 phases, and modifications continued to be made after its initial adoption. A difference in proportions (expressed as percentage points [pp]) or incidence (expressed as events/100 games) was estimated from an intercept-only logistic regression; contrasts were created from the posterior intercept estimates corresponding to the 2006-2010 cohort and the 2014-2019 cohort. The inverse logit function was used to transform all parameters from the log-odds scale to the probability scale for results reporting. This modeling approach was also used to compare concussion mechanisms and characteristics. In addition to the estimate of the mean difference between groups, a 90% credible interval (CrI) was also reported. For model formulation, please see the eMethods in Gaussian priors were used to regularize posterior parameter estimates for each intercept (group). Mean (μ) and variance (σ) parameters of the form α ∼ Normal  varied by comparison to establish an a priori skepticism of differences between groups; prior simulations were used to tune prior parameters to expect a mean group difference of 0 pp with a SD of the difference of approximately 10 pp. The priors for the mean proportion of each variable were set to the proportions observed in the 2006-2010 cohort for both groups. For example, if a particular variable comprised 10% of all concussions in the 2006-2010 cohort, the prior was set at 10% for both groups in the logistic regression. This approach served to provide conservative estimates of the difference between groups. For prior sensitivity analyses supporting results for the main outcome—proportion and incidence of lateral hits to the head—please see the eMethods in 13 via R, version 4.1.0,14 and the RStudio integrated development environment, version 1.4.171715 . All models were run across 4 chains at 2000 iterations per change. Convergence was measured using an updated Gelman-Rubin convergence test, with all chains converging to less than 1.01.16 The Rethinking book package, version 2.13,17 was used to interface between RStudio and RStan.18 Plots were created using the ggplot2,19 bayesplot, version 1.8.1,21 and tidybayes, version 3.0.4,22 R packages. Code used to analyze the data can be accessed via GitHub.23All models were fit using the Hamiltonian Monte Carlo engine Stan modeling language, version 2.27,During the 4 regular seasons from 2006-2007 to 2009-2010, 301 concussions were diagnosed in 4920 NHL regular-season games, with an incidence of 6.1/100 games. In the 5 regular seasons from 2014-2015 to 2018-2019, a total of 516 concussions were diagnosed in 6232 NHL regular-season games, resulting in an incidence of 8.3/100 games. This is a mean increase of 2.0 concussions per 100 games  between the 2014-2019 cohort and the 2006-2010 cohort.In the 4 seasons before the implementation of Rule 48 (2006-2010), there were 231 regular season concussions with video data. They occurred equally across open ice and the perimeter , primarily in the defensive zone (106 of 230 [46.1%]) and during the first period of play (117 of 231 [50.6%]). They most often occurred when the injured player was a forward (149 of 231 [64.5%]) and not in possession of the puck ; penalties were not called on most incidents .In the 5-year period following the implementation of Rule 48 (2014-2019), there were 457 concussions with video data. The game-related characteristics were similar to those observed before Rule 48, with a few notable exceptions. First, the perimeter became the predominant location of injury (290 of 455 [63.3%]); the proportion of concussions occurring in open ice decreased by an estimated 9.0 pp . Second, concussions occurring in the first period of play were an estimated 13.4 pp lower following the implementation of Rule 48 . Over the 4-season period prior to the implementation of Rule 48, concussions following hits to the head—defined as a body check where the shoulder, arm, or glove and/or fist makes contact with the opponent’s head—occurred at an incidence rate of 2.3/100 games; these 113 concussions in 4920 games accounted for 48.9% of 231 concussions. In the 5-season period following the implementation of Rule 48, the incidence rate was similar at 2.4/100 games (149 concussions in 6232 games). The difference was 0.1/100 games . However, the proportion of concussions from hits to the head was reduced by 14.7 pp .In addition, concussions following hits to the lateral aspect of the head were reduced after the implementation of Rule 48 . In addition, the proportion of concussions from hits to the lateral aspect of the head reduced by 18.9 pp , from 80 (34.6%) of 231 to 61 (13.3%) of 455 concussions. Concussion prevention remains at the forefront of many contact or collision sports, and rigorous evaluation of the potential sequences of events leading to a diagnosis of concussion is relevant to creating effective prevention strategies. The purpose of this cohort study was to compare the incidence and proportion of concussions that occurred among NHL players following a hit to the head in the seasons before (2006-2007 to 2009-2010) and after (2014-2015 to 2018-2019) the implementation of Rule 48. While the overall incidence of concussions increased during the 2 time frames analyzed, there were notable decreases in the incidence of concussions following hits to the lateral aspect of the head. Also, there was a meaningful reduction in the proportion of concussions following hits to the head overall, particularly direct hits to the lateral aspect of the head.10 Subsequently, in the 2011-2012 season, the language referring to a “lateral or blindside” hit was removed to broaden the scope of the rule where the head is the targeted and principal point of contact.11 Over the most recent study period (2014-2019 cohort), implementation of Rule 48 was associated with a reduction in concussion diagnoses following targeted behaviors .This study provides important insight regarding patterns of concussions and the potential influence of policies targeting health and safety. In the 2010-2011 season, Rule 48 was introduced to address specific behaviors preceding concussion.spearing was prohibited by the NFL to improve the head position of defensive players when tackling. The spearing rule was associated with a dramatic decrease in spinal cord injuries.24 More recently, the ability of these prevention initiatives to demonstrate a reduction in the incidence of concussions have been mixed.6 Although there was an overall increase in the incidence of concussions after the introduction of Rule 48, both the incidence and proportion of concussions from hits to the lateral aspect of the head decreased. While the findings of our study were limited to a professional sport, they underscore the association of policy implementation with behavioral change for the larger medical community. This opens avenues for contemplation among broader injury prevention strategies that harness policies and rules as tools.Historically, there have been successful implementations of prevention strategies in the form of rule changes meant to decrease serious injuries in professional sports. Most notably, in the late 1970s, 26 An enhanced education campaign for all stakeholders on the health risks associated with concussion and the importance of concussion recognition (awareness) and early detection has also been implemented. These targeted initiatives may have resulted in greater awareness and reporting of concussion, thereby likely contributing to the increase in concussion incidence between the 2 periods.Contrary to our hypothesis, the observed increase in concussion incidence was associated with several contributing factors. Importantly, the period following the introduction of Rule 48 coincided with enhanced efforts regarding concussion awareness and identification. This includes the addition of a spotter program whereby certified athletic trainers watch games centrally in an off-site location to identify visible signs of possible concussions. In-arena spotters also watch games live to identify visible signs, including those not captured by video. Assessment tools have improved and data interpretation approaches have been refined for use in the diagnosis of suspected concussion.The identification and prevention of concussion is multifaceted, with Rule 48 serving as one important component of a complex set of variables. Regardless, in recent years, it appears that most concussions occur around the perimeter of the ice rink . Thus, careful examination of the sequence of events and injury characteristics in the perimeter is warranted, particularly regarding the interaction of the playing environment (boards and shielding) and player-to-player contact. Player-to-player body contact remains the primary mechanism preceding concussion diagnosis. Given the inherent nature of collisions—both intentional body checks and incidental collisions—future research should involve a closer examination of the behaviors and mechanisms of concussions following player-to-player contact around the perimeter of the arena . Also, research examining modifiable risk factors that may help to inform future primary prevention strategies may be warranted.9 there were proportionally more events of poor quality or missing video content in the earlier study period (2006-2010); this is likely due to improved quality and/or additional cameras monitoring games in recent seasons. We acknowledge the potential bias, as these events may differ in their characteristics from the concussions with video. Additionally, our study focused exclusively on video events during the regular season and might not offer a complete picture of the new rule’s implications. By not considering events from preseasons and playoffs, we may not have captured the rule’s broader effects across various game scenarios. Last, a limitation of this study relates to the evolution of concussion awareness and evaluation protocols over the study period. This limitation is aligned with the observed increase in the incidence of concussions between the 2006-2010 and 2014-2019 cohorts, underscoring the evolving nature of concussion evaluation standards and awareness.A strength of this study is the large sample size and design: a longitudinal cohort of 688 physician-diagnosed concussions with video footage of the event enabled a careful examination of the sequence of events and mechanisms leading to concussion among NHL players. However, we were limited to events where video content of the event was available. During the study period, we identified and analyzed 84.2% of all reported concussions. While this proportion is similar to those of prior video analysis studies in the NHL,The findings of this cohort study suggest that although the overall incidence of concussions among NHL players increased following the implementation of Rule 48, the incidence and proportion of concussions following direct hits to the lateral aspect of the head was reduced. Collectively, these findings further indicate that the introduction of Rule 48 has coincided with a change in player behavior leading to concussions. Continued efforts to identify meaningful primary prevention are still required, and future efforts should focus on both exploring and evaluating concussion prevention strategies targeting modifiable risk factors.


In this case, the most effective approach is the use of composite membranes. However, to obtain these, it is necessary to take into account the chemical and morphological resistance of membrane supports to long-term exposure to amine absorbents and their oxidative degradation products. In this work, we studied the chemical and morphological stability of a number of commercial porous polymeric membranes exposed to various types of alkanolamines with the addition of heat-stable salt anions as a model of real industrial CO2 amine solvents. The results of the physicochemical analysis of the chemical and morphological stability of porous polymer membranes after exposure to alkanolamines, their oxidative degradation products, and oxygen scavengers were presented. According to the results of studies by FTIR spectroscopy and AFM, a significant destruction of porous membranes based on polypropylene (PP), polyvinylidenefluoride (PVDF), polyethersulfone (PES) and polyamide  was revealed. At the same time, the polytetrafluoroethylene (PTFE) membranes had relatively high stability. On the basis of these results, composite membranes with porous supports that are stable in amine solvents can be successfully obtained to create liquid–liquid and gas–liquid membrane contactors for membrane deoxygenation.Membrane gas–liquid contactors have great potential to meet the challenges of amine CO The desire to limit the impact of these emissions led to the signing of the Paris Agreement [2 capture is amine purification, an absorption process using various alkanolamines [According to global statistics, COgreement , a progrgreement . In addigreement  and oil greement  fields. olamines . This teolamines .(a)2 absorption from gas mixtures using aqueous solutions of amines: The overwhelming majority of work in this area is devoted to precisely this stage of the process [Direct CO process ,8;(b)2 desorption/stripping: In the last decade, this direction of membrane contactor application has been intensively studied [2 from amines at elevated temperatures;Membrane CO studied ,10, and (c)Membrane deoxygenation of amine solvents: This is a relatively new field of the application of gas–liquid or liquid–liquid membrane contactors. The promise of this approach was first demonstrated by TNO using the Dissolved Oxygen Removal Apparatus (DORA) at TRL6 . The relMembrane contactors can be used for various aspects of amine absorption technology: Both porous membranes made of hydrophobic polymers and composite membranes with thin permeable layers can be used in membrane contactors. The use of composite membranes prevents the penetration and wetting of the porous membrane structure by the absorbent. However, the selective layers of the composite membranes are permeable to solvent vapors ,27. AminIn all the above cases (a–c), the membranes used in the contactors are exposed to amines at elevated temperatures (60–100 °C), often with the presence of oxidative degradation products . Accordi2S and CO2. On the other side, despite the alkaline environment, even after six months of exposure, the membranes almost did not degrade. In [The stability of various polymeric membranes is being studied by researchers for many applications. For example, in a number of works ,30,31,322 solvents, the works devoted to the analysis of membrane stability in amine solvents are of significant interest. In particular, the stability of the hollow PP fiber membranes Celgard X40-200 and Celgard X50-215 in diethanolamine (DEA) was considered in [2. The results showed a decrease in membrane degradation in solutions with a high content of CO2. However, in this case, there was also a decrease in the performance of the membrane contactor. According to [Within the framework of works on amine COdered in . Furtherrding to , the degrding to . In thisrding to ,37,38, lrding to ,40, and rding to ,42. In prding to ,44,45, s2 absorption, it may be of interest to study changes in the structure of membrane materials after their contact with solutions of inorganic salts. The authors of [2 solution for 72 h. It was shown that the porosity and pore size of membranes increased after 72 h of interaction with water due to the penetration of a non-wetting liquid into the pores with their subsequent expansion. On the other hand, in the case of using a CaCl2 solution, no significant changes in the morphology of the membrane surface were observed. This could be associated with a less intense penetration of the CaCl2 solution due to a higher surface tension [Since aqueous solutions of alkanolamines containing oxidative degradation products are used for COthors of  compared tension . Similar tension  studied Additionally, one of the solutions to the problem of the oxidative degradation of amine absorbents is the introduction of oxygen scavengers, such as sodium/potassium sulfite or bisulfite, into the solvent composition ,47. Such2, the maximum temperature of the carbon-dioxide-filled solvent can be up to 100–120 °C (the temperature of regeneration of absorbents). Membrane contactors can also be used under these conditions to implement such a process [Accordingly, the effect of amine solvents containing oxidative degradation products, as well as oxygen scavengers, on the structure and morphology of various polymeric membranes is of interest. This issue is especially interesting for their use as composite membrane supports in membrane contactors operating in an absorbent medium. Thus, within the framework of this work, it was proposed to study the stability of a number of commercial porous polymer membranes  in various types of alkanolamines at elevated temperatures with the addition of HSS ions, which simulates the composition of real industrial solutions. The study of membrane stability at elevated temperatures is due to their potential use in membrane contactors. During amine purification from CO process ,49. An aIn this work, five commercial porous polymer membranes (commonly used as porous supports for composite membranes) were studied: fluoropolymer, polyolefin, polyethersulfone, and polyamide membranes. Some information about the investigated membranes can be found in We used commercial flat membranes made of polypropylene , polyvinylidenefluoride PVDF-022, polytetrafluoroethylene MFF4-020, polyethersulfone PES-020, and polyamide MMK-010 .Within the framework of this work, four industrially used amines were studied. In addition to the model solutions, a real industrial degraded absorbent was also applied. 2SO3 (50 g/L) was used with the addition of a catalyst Co(NO3)2 ) as a model oxygen scavenger.Monoethanolamine ), N-methyldiethanolamine (MDEA) manufactured by GC Sintez OKA , 2-Amino-2-methylpropane-1-ol (AMP) and piperazine (PZ) manufactured by Sigma-Aldrich  were used for the preparation of the model amine solvents. An aqueous solution of NaThe following anions in the form of the corresponding acids were added to the model solutions of MEA, MDEA, AMP, and PZ to simulate the presence of absorbent degradation products (HSSs). Acid concentrations were taken on the basis of the data presented in ,51 Tabl.The solution was prepared using distilled water  and a set of acids: formic acid, oxalic acid, acetic acid, nitric acid, sulfuric acid, and hydrochloric acid . 2 solvents MEA, MDEA, AMP, PZ containing HSS anions, industrial DEA solution, and a solution of a model oxygen scavenger Na2SO3). The closed containers with solutions and membranes were placed in an oven  at 100 °C and kept for at least 14 days. After that, membranes were removed from the solutions, kept at room temperature in ethanol (2 h) and water (2 h) to remove residual absorbents, air-dried, and examined by a number of physicochemical methods of analysis. It should be noted that all the applied methods of analysis were also used to study the properties of the initial membranes before exposure to amine solvents.To assess resistance to long-term exposure to various compounds, samples of porous polymeric membranes (~2 × 3 cm) were placed in different liquids . Mathematical processing of the spectra  was carried out using the OPUS-7.0 software package . The wavenumber  was set as the abscissa axis of all the presented spectra, and the dimensionless intensity value, optical density (D), was set as the ordinate axis.The possible changes in the chemical structure of polymeric membranes that were not destroyed after exposure to selected liquids were studied by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectra of the membranes were recorded by the reflection method on an IFS-66v/s IR Fourier spectrometer  using an attenuated total reflection (ATR) attachment . AFM was used to quantitatively analyze the morphology of the selective layer of the hollow fiber. A Horiba Smart SPM scanning probe microscope  was used with the semi-contact mode of atomic force microscopy. We used probes from Nanoandmore  with parameters F = 330 kHz, C = 42 N/m, L = 125 µm, and R ≤ 10 nm. The porosity and surface roughness of the test samples were calculated using the Gwyddion software  from their AFM images. To calculate the porosity of the membrane samples, the area of the AFM images was analyzed using the Gwyddion software (version 2.62). The porosity of the sample was determined as a percentage of the area of the pores to the total area of the image.aR (Formula (2)) and the root-mean-square roughness qR (Formula (2)).rl is the length of the baseline and z(x) is the deviation from the baseline. The roughness was determined based on the automatically determined depth of dots on the image by two parameters: the average roughness max) and the diameter of the smallest pore (dmin), as well as the mean flow pore size dMFP. The mean flow pore size value is defined as the pore size at which 50% of the flux penetrates through the larger pores and 50% of the flux penetrates through the smaller pores of the membrane.The pore size was measured by liquid–liquid displacement porosimetry using the porometer POROLIQ 1000 ML . Membrane pore size analysis was performed by the liquid–liquid displacement method using water-saturated isobutanol and isobutanol-saturated water as a solvent pair. The size was calculated according to the procedure described in detail in . The porTo study changes in the transport and separation characteristics of porous polymeric membranes, gas permeance was measured according to the volumetric method described in  using th2SO3 solution. The FTIR spectra of PP, PES, and PA membrane samples are found in To analyze changes in the chemical structure of the polymeric materials of the studied membranes under the influence of amine solvents, an analysis was carried out by FTIR spectroscopy. For example, −1 from PVDF do not appear. The technique for recording spectra using a ZnSe crystal makes it possible to record the spectrum of a membrane surface with a thickness of up to 1.4 μm. Consequently, it can be concluded that HSSs covered the PVDF–MEA sample with a layer no less than 1.4 µm-thick. In the FTIR spectrum of the PVDF-AMP sample, the bands from HSSs (1500–1700 cm−1) also have a high intensity, but at the same time, all the characteristic bands corresponding to PVDF also appear. In the spectra of PVDF–DEA, PVDF–AMP–MDEA, PVDF–Na2SO3, the HSS intensity of the bands is 10 times lower, and in the PVDF–Na2SO3 sample, the salt content does not exceed 0.05 mol.%.In the FTIR spectrum of the PVDF membranes, the presence of ammonium cations and carbamate anions is manifested in almost all the samples, with many of them on the surface of the PVDF membrane after exposure to AMP (PVDF–AMP) and MEA (PVDF–MEA). In the case of the PVDF–MEA sample, the formed salts completely covered the membrane surface in such a way that no bands of the polymeric material of the membrane (PVDF) appear in the spectrum. Therefore, even very intense bands of C-F bonds in the region of 1200 cm−1, ammonium cations at 1620 cm−1, and C-H bonds in the region of 2840–2960 cm−1 appear. However, in the PTFE–DEA sample, the content of these impurities does not exceed 0.02 mol.%, and in the PTFE–MEA sample, their content is approximately 3 times less.In the FTIR spectra of the PTFE samples b, there 2SO3 > MDEA > AMP > PZ. At the same time, in the PP–MEA sample, the salt content does not exceed 0.1 mol.% relative to PP.The FTIR spectra of the PP samples  show wea2 and the CH3) groups or the stretching vibrations of C−H bonds in the region of 2840–2960 cm−1. However, the spectra of all the samples aged in amines contain weak bands in this region. At the same time, in the case of the PES–MDEA sample, the characteristic peaks of MDEA are more pronounced. Thus, amines were present in small amounts (less than 0.02 mol.%) on the polymer surface.In the PES FTIR spectra , there a−1), shifted to the region of long waves. At the same time, the bands corresponding to the C=O bond in the PA spectrum are also shifted to the long-wavelength region: 1633 cm−1 (amide I) and 1538 cm−1 (amide II). After the amine solvents, water practically does not appear on the surface of the samples. It is almost impossible to identify salts of ammonium cations and carbamate ions in the region of 1700–1550 cm−1 on the FTIR spectra due to very intense bands of the PA amide group in this region. However, in all the studied spectra of PA membranes exposed to amines, new bands appear in the region of 1100–950 cm−1, which may correspond to C−OH bonds. The spectrum of the PA–Na2SO3 sample shows the presence of the most intense bands in this region (peak at 1016 cm−1), which are not characteristic of sulfite ions (in the region of 1100 cm−1). This may be due to the more intensive processes of oxidation of amide units in Na2SO3 with the formation of C−OH groups.In the FTIR spectrum of the original PA membrane , there aChanges in the morphology of the porous polymeric membranes as a result of exposure to model solutions of amine solvents were studied by the AFM method. For example, 2SO3 solution. Statistical quantities (minimum and maximum heights of points on the image), porosity , and roughness (defined as root-mean-square qR and average aR roughness) were chosen as the parameters for analysis. The PVDF membrane samples underwent morphological changes in all the studied liquids . DespiteAs described in The morphology of the PES membranes also underwent changes under the influence of the model solutions used. Contact of the PES membrane with the solvents led to an increase in the surface porosity. At the same time, in the environment of primary alkanolamines , there was also a narrowing of the initial pores, which is illustrated by the images in The PA membrane samples were morphologically unstable in the solvents used. Contact with amines apparently led to partial ‘etching’ of the surface with an increase in roughness and the adsorption of amine molecules on the membrane surface, which is most noticeable for the samples of PA–MDEA . 2 capacity were significantly reduced within 30 days of hollow-fiber operation in a membrane absorption process using a 1M MEA solution as an absorbent. At the same time, PVDF membranes turned out to be less stable than PP ones [According to the results obtained, the absence of chemical and morphological stability of the samples of porous polymeric membranes from PP, PVDF, PES and PA (nylon) in the environment of model degraded absorbents based on alkanolamines at elevated temperature was revealed. The conclusions drawn on the stability of the studied membranes are in good agreement with the literature data. The authors of  noted th PP ones . It is i PP ones . HoweverMoreover, the PTFE membranes demonstrated a sufficiently high chemical stability with certain changes in the surface morphology, which is also consistent with the results of ,42. The 2 by MEA was performed using PTFE and PVDF membranes. The PTFE membranes were able to maintain their performance after 60 h of process, while the PVDF membranes were degraded. The increase in resistance to mass transfer in membranes increased due to wetting [Accordingly, the results obtained in the field regarding changes in the morphology of the membranes can be associated with different levels of wettability and penetration into the pores of the solvents of various compositions and viscosities ,54,55,56To study the effect of membrane wettability on the change in morphology, we also measured the water contact angles before and after exposure to the model solvent . ContactThe data obtained are consistent with the data in The membrane samples were investigated in more detail using liquid–liquid displacement porosimetry to establish changes in the porous structure. min pore size area; dMFP remained practically unchanged for all the amine solvents used. This phenomenon may confirm the assumption that contact with liquids leads to the ‘etching’ of the surface, which was inferred based on AFM images. The porous structure of the PTFE membranes underwent the greatest changes in the d2, O2, and CO2, as well as the calculated values of the ideal selectivities for CO2/N2 and CO2/O2 gas pairs. 2/N2 gas pair selectivities of the studied membranes, respectively. The permeance values of all membranes studied for N2, O2, and CO2 and ideal selectivities for CO2/N2 and CO2/O2 gas pairs are presented in the The PTFE membranes were further investigated in terms of their gas transport characteristics. The absence or presence of performance changes can additionally confirm the results of the study of the stability of porous polymer membranes in amine solvents. Changes in membrane transport and membrane separation characteristics were evaluated in terms of the permeance of individual gases NMFP remained practically unchanged after exposure to amine solvents; min. These results also provide additional evidence for the resistance of porous polymeric PTFE membranes to amine solvents. The membrane permeance measurements were consistent with the changes in their chemical and morphological structure. The average porosity and pore size mainly determine the gas permeance of the membranes. Thus, in the case of the PTFE membranes, the gas permeance changed slightly. This phenomenon is a result of the minor variation of transport porosity (d3(STP)∙(m2∙h∙bar)−1 , nitrogen permeance significantly decreased from 430 to 340 mh∙bar)−1 , which m 0.01 μm  after ex2SO3). Commercial membranes made from fluoropolymers , polypropylene (PP), polyethersulfone (PES) and polyamide  were studied by FTIR spectroscopy, atomic force microscopy and liquid–liquid porosimetry to establish changes in the chemical structure and morphology of the membranes. This study showed that the commercial porous polymeric membranes presented are not sufficiently chemically and morphologically stable in amine CO2 solvents containing HSS anion media. The porous polymeric PTFE membranes turned out to be the most stable, which makes them promising for use as porous supports for composite membranes. The results of the measurement of the pore size and the permeance of these membranes for N2, CO2, and O2 are consistent with changes in their chemical and morphological structure, and indicate a resistance to amine solvents. Based on the results obtained, liquid–liquid and gas–liquid membrane contactors with amine solvent polymeric membranes that are stable in CO2 can also be successfully created for use in membrane deoxygenation.Within the framework of this work, we analyzed the chemical and morphological stability of porous polymeric membranes during long-term exposure at elevated temperatures to model amine solvents containing degradation products, a real industrial amine solvent, and a model solution of the oxygen scavenger (Na