Eggs are among the most nutritious foods in the world, a versatile ingredient in many food applications due to their functional attributes such as foaming, emulsifying, and coloring agents. Many studies have been reported on egg yolk fractionation and characterization in the last decade because of its nutritional and health benefits, especially egg yolk granules. This has led to the development of new food products and packaging materials. However, the influence of their physical characteristics during processing significantly impacts the functionality of yolk granules. In this overview, the egg yolk, the granule fraction’s separation, fractionation, components, and molecular protein structure are first presented. Secondly, recent studies on egg yolk granules published over the past decade are discussed. Furthermore, the application of the granules in different industries and current specific scientific challenges are discussed. Finally, it simplifies the changes in the physical characteristics of the granules during different treatment methods and the impact on the functionalities of the resulting products in the food , pharmaceutical, and health (encapsulation systems and biosensors) sectors. Eggs are recognized worldwide as an important part of the human diet because they are low in calories, inexpensive, and exceptional sources of complete protein. Both the egg white and egg yolk contain an equal distribution of protein yolk ; they prEgg yolk is a natural colloidal dispersion  represenEgg yolk granules are a novel food, possessing many interesting characteristics  which aid their utilization as an ingredient in food applications . The proFor research, freshly laid eggs are usually obtained and manually broken. To separate the albumen from the vitellin membrane, the egg is carefully rolled on a blotting tissue to ensure no egg white proteins were mixed up. The vitellin membrane is then cut with a scalpel blade  or tweezEgg yolk is a natural emulsion made up of water, lipids (such as fats and oils), and proteins. The lipids and proteins are organized into various supramolecular structures within the emulsion, which give egg yolk its unique textural and functional characteristics, in different applications. The lipid component of egg yolk is primarily composed of phospholipids and triglycerides, while the protein component is primarily composed of various types of globular proteins such as ovalbumin, conalbumin, and livetin. These proteins can form complexes with lipids and other proteins, creating a hierarchical structure within the emulsion. Egg yolk constituents are difficult to separate due to their complex nature. Understanding the molecular and structural characteristics of each fraction of the egg yolk has clarified the approaches to be used in fractionating egg yolk . CollectHen egg yolk’s main fractions, granules, and plasma contribute to the formation and stability of dispersed systems like emulsions by constituting an interfacial film. In egg yolk, high-density lipoproteins (HDLs) have a structure like globular proteins; single HDL proteins tend to form submicelles with a loop-like structure, like that of human HDL particles . AdditioRecent models of egg yolk and granule structures are shown in g resulted in excellent separation efficiencies. The study predicted this continuous fractionation process of liquid egg yolk is applicable even on the industrial scale level. Researchers have studied egg yolks and their fractions from different animals including hens, turkeys, ducks, etc. Many of the authors focused their research on exploring different methods of egg yolk fractionation and characterization and evaluating the structure of the protein and fractions using different methods and instruments. Laca et al.  describe2, enzymes, and pH, were investigated while exploring a wide range of centrifugation separation parameters for optimal processing conditions [Some authors investigated changes in the physicochemical, functional, and structural properties of egg yolk fractions as affected by different treatments including NaCl addition, soy lecithin addition, alkali and enzyme treatment, pH modification, phosphorylation, succinylation ,18,19,20nditions ,16,22,23Other researchers investigated the modification of egg yolk granules through the application of hydrostatic pressure. Xie et al.  investigResearch interest in this study field shifted to the application of egg yolk fractions and methods of improving the characteristics of the fractions. Egg yolk granules have found potential as ingredients in products such as Pickering emulsions, wheat dough, and muffins, as a low-cholesterol emulsifying agent in the preparation of mayonnaise , and ediLeftover egg yolk granules (a by-product after phosvitin extraction) can find application in food products, as they had significant protein, rheological, and functional properties . The detFrom the documents studied, this review could recommend some further work to compare the impacts of the destabilization methods of egg yolk granules on their functional properties, mineral composition, protein, folic acid, proteomics, metabolomics, and microstructure. An understanding of the impact of structural modification on the functional properties of ultra-high-pressure homogenization-treated egg yolk granules  has beenMany products in the food and pharmaceutical industries are processed at high temperatures (such as sterilization) and high pressure. There is also a need to further study and clarify the aggregation behavior, composition, structural, textural, and functional characteristics of the egg yolk fractions and their applicable products, as well as their composition and shelf stability as affected by high-heat processing conditions. This might provide some insights into key influencing factors that could cause changes in the properties of the egg yolk fraction and products when heat treatment is induced.Individual components of egg yolk can be further characterized for functionality to find practical applications in various sectors. Egg yolk granules have found usefulness in bakery products (muffins) in replacing up to 50% of egg yolk due to its significantly reduced cholesterol and fat content , withoutFurther research can be carried out on the extraction, characterization, and utilization of value-added components of egg yolk granules as functional ingredients. This could help to efficiently utilize by-products or leftover egg yolk granules. Phosvitin (the major egg yolk protein), high-density lipoproteins, and IgY (egg yolk immunoglobin—an antibody), for example, can find useful applications in improving food and health potential. Furthermore, there is a need to investigate the capacity of egg yolk granules in food models as carriers of health-promoting components and as a delivery system of bioactive compounds in a simulated gastrointestinal tract. The efficiency of the microparticles employed for the encapsulation of polyphenols, probiotics, prebiotics, antioxidants, antimicrobial compounds, bioactive proteins, and peptides for nutraceutical and pharmaceutical uses might be investigated. The heat resistance of the bioactive compounds encapsulated using the egg yolk granules, as well as their stability during processing, dilution, and storage, need to be investigated or improved. The nutrient delivery efficiency of the microparticles, as affected by different chemical crosslinking and polysaccharide addition, can also be examined. The recent findings from the study of Li et al.  on the bThe extraction and purification of egg yolk constituents prove a bit challenging due to their complex composition. However, simple dilution and centrifugation methods have been used in the fractionation of the continuous aqueous phase (plasma) and insoluble denser structures (granules). The granules are the precipitated part of egg yolk after dilution and centrifugation, and the influence of its internal structure, constituents, and particle sizes are significantly affected after passing through different treatments. In the past few years, a variety of methods have been developed for the separation of egg yolk constituents. These methods include the use of organic solvents, which facilitate the extraction of proteins and the removal of lipids from the egg yolk , and enhLei and Wu  combinedg, as it has been reported that it allows for the complete separation of granules and plasma [Contrary to freezing  where the separation of granules is not possible from the egg yolk, the pasteurized and HHP-treated granules allowed a full recovery of the folate in the granules. The pasteurization and centrifugation of the egg yolk at a lower centrifugal force promoted fractionation  but resud plasma . The used plasma  employedd plasma  and prov4)2SO4) before extraction using a magnetic stirrer and ultrasonic-assisted treatment, to change the ionic strength, adjust the pH [g) at a controlled temperature of 4 °C and for long residence times (commonly 45 min). The easy and gentle method of separation of egg yolk fractions has proven to provide high separation efficiencies. Other factors influencing the continuous centrifugal separation of egg yolk granules were described by Strixner and Kulozik [Different studies have employed the pre-mentioned procedure with some modifications in the yolk dilution factor, dilution medium (aside from distilled water), and/or centrifugation conditions. This includes dilution in salt solutions  granules from hen egg yolk was investigated [g enabled complete granule fraction removal. The study of Strixner and Kulozik [stigated . The aut Kulozik  also fouThe microstructure of egg yolk granules has been measured using different techniques, and the conditions at which the granule is prepared  result in changes in the structure of the granules . Strixne5O10P3), ethylenediaminetetraacetic acid disodium (EDTA-2Na), and trisodium citrate (C6H5Na3O7) in dissociating micro-sized granules into nanoparticles with good colloidal stability at pH 7.0. This dissociation did not change the chemical bonds or protein profiles of the granules but improved their functionality and storage stability in an emulsion.Physical treatment of egg yolk granules using calcium chelators is also possible. Fu et al.  reportedEgg yolks have immense potential and have gained much attention in the past decade. This study summarizes the current state of knowledge on the structure, processing, and functionality as well as the changes in the physical characterization of the granules during different treatment methods. As discussed above, methods to destabilize granules have been researched, many of which have some unacceptable effects , energy-intensive effects, and so on. This is why some authors are exploring the use of traditional thermal mechanical treatments or non-thermal emerging technologies to improve the separation, functionality, and stability of egg yolk granules. It has great natural anti-obesity, atheroprotective, and anti-osteoporosis potential in the functional food, food packaging, pharmaceutical, health, mechanical, and sustainable environmental fields. This review could provide an understanding of the content of the research area and a valuable strategy for potential research to characterize the bioactive components of the granules, develop new functional materials such as responsive encapsulation systems or biosensors, and search for applications for them in the food, pharmaceutical, and healthcare sectors. As the future need for nutritious, healthy, safe, and sustainable products is pursued worldwide, improving the functionality of egg yolk granules through physical treatment or processing is a huge step toward expanding this scope.


Low-grade inflammation alters the homeostasis of the organism and favors the onset of many chronic diseases. The global growth in the prevalence of noncommunicable diseases in recent years has been accompanied by an increase in the consumption of ultra-processed foods (UPF). Known to be hyperpalatable, economic and ready-to-eat, increased consumption of UPF has already been recognized as a risk factor for several chronic diseases. Different research groups have tried to investigate whether UPF consumption could promote low-grade inflammation and thus favor the development of noncommunicable diseases. Current evidence highlights the adverse health effects of UPF characteristics, not only due to the nutrients provided by a diet rich in UPF, but also due to the non-nutritive components present in UPF and the effect they may have on gut health. This review aims to summarize the available evidence on the possible relationship between excessive UPF consumption and modulation of low-grade inflammation, as potential promoters of chronic disease. Inflammation is an immunosurveillance response essential for host defense, which serves to repair damaged tissues and eliminate toxic agents . HoweverCurrent evidence highlights diet among the modifiable behavioral risk factors for the development of noncommunicable diseases . In receRecent scientific research has sought to investigate whether UPF consumption could promote low-grade inflammation and thus favor the development of noncommunicable diseases. Emerging evidence attributes the negative effects of UPF consumption not only to the nutrients provided by a diet rich in UPF, but also to the non-nutritive components and the effect they may have on the gut microbiota. This review aims to summarize the available evidence on the possible relationship between excessive UPF consumption and modulation of low-grade inflammation as potential promoters of chronic diseases.The inflammatory response is a defense mechanism of the innate immune system  that proThe presence of low-grade inflammation disrupts the homeostatic balance, altering the crosstalk between immune and metabolic responses and promoting chronic metabolic inflammation. This so-called “metainflammation” is primarily caused by metabolic and nutrient excess and triggers immune cell infiltration and the secretion of inflammatory cytokines into the tissue environment, which may inhibit glucose uptake or alter lipid metabolism ,14. As aAmong the environmental and lifestyle factors that can promote or intensify inflammation, increasing scientific evidence supports the role of diet. Potential nutritional compounds influencing inflammation processes include macro- and micronutrients, bioactive molecules such as polyphenols and specific food components . Overalln-3 PUFAs, vitamin C, vitamin E and carotenoids. In contrast, dietary factors that promote inflammation are oxidized lipids, saturated fatty acids (SFAs) and trans fatty acids, which are present at high levels in Western dietary patterns. Unfortunately, in recent years, the increased availability and variety of foods has led to a change in traditional dietary patterns, favoring a nutritional transition and a globalization of the diet towards a Western dietary pattern [A growing number of studies show that the protective effects of these dietary patterns against inflammation are related to the dietary pattern as a whole, not just to its individual components . All the pattern . This di pattern .To further investigate the role of diet in modulating inflammation, several literature-based indices have been developed. The energy-adjusted dietary inflammatory index (E-DII) analyzes the potential effect of 45 dietary elements on 6 inflammatory markers, both pro-inflammatory -α and CRP) and anti-inflammatory . The Empirical Diet Inflammatory Pattern (EDIP) is based on food group consumption and divides the dietary intake into nine inflammatory and nine anti-inflammatory food groups according to their impact on the CRP, IL-6 and TNF-αR2 biomarkers of inflammation . Using tOne of the cornerstones of the Western diet are UPF, widely available and increasingly consumed in the contemporary society ,37. The UPF are also characterized by the presence of non-nutritive components, such as additives and chemicals. Additives are frequently added to make the final product more palatable, with better sensory qualities and longer shelf life. Commonly used additives in the manufacture of UPF include flavorings, emulsifiers and sweeteners such as aspartame, cyclamate or stevia-derived compounds . As to tAccording to previous studies, all these aspects could explain the reason why the incidence of several chronic noncommunicable diseases is increasing along with UPF consumption . Among aThe number of human studies investigating whether the consumption of UPF could promote low-grade inflammation, so favoring the development of noncommunicable diseases, is still limited. The available studies have focused mainly on two aspects: how excessive UPF consumption may affect the presence of biomarkers of inflammation, and how the nutritional composition or non-nutritional components of UPF may influence the development of chronic inflammation and gut dysbiosis, previously correlated with a pro-inflammatory state .The vast majority of studies that have examined the relationship between UPF consumption and inflammation are observational, either cross-sectional or cohort studies , with onCRP is the most investigated inflammatory biomarker to date in relation to UPF consumption. In the only available clinical trial, subjects assigned to a diet based on unprocessed foods showed a significant reduction in hs-CRP levels, while subjects on a diet rich in UPF did not report significant changes . The autAs to the E-DII score, a cross-sectional study in Brazil found a direct relationship between a higher dietary energy intake from UPF and a higher rate of dietary inflammation in pregnant women . SimilarUPF consumption could contribute to an inflammatory state through several mechanisms. First, it could be the high intake of sugars, salt, saturated fats and trans fatty acids typical of a UPF-rich diet that directly promotes the development of chronic inflammation . When hiUPF also have a high salt content, contributing to a high sodium intake. Several cross-sectional studies associated a higher salt intake with higher CRP levels in adults and elderly people ,71, althAs for the fat content of UPF, their inflammatory potential derives not only from a higher consumed quantity with respect to other foods, but also from a poorer quality. In fact, trans fatty acids resulting from the industrial process are associated with a higher presence of low-grade inflammation. Specifically, they have been related to higher levels of hs-CRP, IL-6 and TNF-α ,75,76. DFinally, consuming large amounts of UPF sometimes results in the replacement of foods that are the basis of a healthy and balanced diet. Examples are fruits and vegetables, which are correlated with an anti-inflammatory effect thanks to the presence of numerous phytocompounds ,79. ReceResults from an Italian cohort study suggested that only part of the proinflammatory effect of a high UPF consumption can be directly attributed to the nutritional components of the diet, while the rest could be attributed to non-nutritional factors that may promote low-grade inflammation . One of Non-nutrient components such as bisphenol or phthalates may also be present in UPF due to the migration of chemical substances that are part of food packaging. In fact, several cross-sectional studies reported higher levels of both substances in the urine of people with a high UPF consumption ,94,95,96A recent meta-analysis investigating the role of different endocrine disruptors on the inflammatory response showed that increased exposure to Bisphenol A (BPA) is significantly associated with higher levels of IL-6 and CRP, while increased exposure to phthalates is associated with higher levels of CRP, IL-6 and IL-10 . AlthougThe human gut microbiota is a dynamic and complex network composed of hundreds of thousands of microorganisms, including bacteria, fungi, archaea, viruses and protozoa . When inIn fact, it has been suggested that a diet rich in fiber can decrease the systemic inflammatory response by improving the intestinal barrier function and modulating the intestinal microbiota . This isSeveral studies have also highlighted additives as possible factors affecting the microbiota. Studies in murine models suggested different mechanisms through which emulsifying additives could contribute to intestinal dysbiosis, increasing intestinal permeability and promoting a proinflammatory state ,118. HowLow-grade inflammation plays a pivotal role in the pathogenesis of noncommunicable diseases, which are becoming increasingly prevalent worldwide. In recent years, diet has been highlighted as one of the main risk factors for these diseases, together with the increased consumption of UPF, which through different mechanisms, may contribute to promote a proinflammatory state. Although the evidence on the association between UPF consumption and inflammation is still limited and, in some cases, the results are discordant, considering the potential impact of their excessive consumption on the health status, as well as their potential role in favoring the presence of chronic inflammation, public policies that limit their consumption are required. These public policies should also include the promotion of traditional diets based on unprocessed or minimally processed foods, in order to modulate low-grade inflammation and improve people’s health status. Future human research evaluating clusters of inflammation markers instead of individual biomarkers may help to better understand the mechanism involved in the modulation of low-grade inflammation by a high consumption of UPF. This information could also be useful in establishing policies that promote the reformulation of UPF to minimize their adverse health effects.


Patients with thoracic neuroblastoma are at high risk of operative neurologic complications due to iatrogenic lesions of the artery of Adamkiewicz (AKA), reducing the possibilities of gross total resection. Therefore, the role of preoperative spinal angiography in such patients must be defined. This study aimed to investigate the role of spinal angiography in thoracic neuroblastoma and the impact of accurately identifying the AKA on surgical resection and neurological complications.Background: Patients with thoracic neuroblastoma (TNB) are at high risk of postoperative neurologic complications due to iatrogenic lesions of the artery of Adamkiewicz (AKA). The role of performing a preoperative spinal angiography (POSA) in these patients must be clarified. The present study sought to further understand the relationship between POSA and TNB, as well as the effects of identifying the AKA on surgical excision and neurological consequences. Methods: Data from patients with TNB who underwent POSA between November 2015 and February 2022 at our tertiary pediatric center were retrospectively analyzed. Results: Six patients were identified, five of whom (83%) were considered eligible for surgical excision. Gross total resection (GTR) was achieved in three patients (60%), which included two patients with an AKA contralateral to the tumor, and one with an homolateral AKAl. After a median follow-up of 4.1 years from diagnosis, no patients developed neurological complications; five (83%) were alive and well, and one died from refractory recurrence. Conclusions: Among patients with TNB, POSA was useful for identifying the AKA and defining the optimal surgical strategy. POSA should be considered in the preoperative evaluation of TNB to increase the likelihood of GTR and reduce the threats of iatrogenic neurologic sequelae. The most frequent solid extracranial tumor in children is neuroblastoma , which dThis study aimed to investigate the role of POSA in TNB and the impact of identifying the AKA on GTR, neurological complications, and sequelae.This single-center retrospective study included consecutive pediatric patients with TNB who underwent POSA at our center between November 2015 and February 2022. The indication for POSA was based on the diagnosis of TNB extending into the costovertebral junction. Depending on the disease stage, age of the patients, and histological findings, patients underwent preoperative chemotherapy according to the treatment guidelines of the Low and Intermediate Risk Neuroblastoma European Study (LINES) or the European SIOP Neuroblastoma Group (SIOPEN HR-NBL 1).The clinical, radiological, and surgical information, follow-up data, and outcomes were reviewed. The primary outcomes evaluated included periprocedural and perioperative findings and complications, GTR, and long-term neurological sequelae. According to international definitions ,12,13, GA preoperative transfemoral angiography using 4 Fr catheter was performed in all patients included in the study. Selective intercostal left and right digital subtractive angiography was achieved in posterior–anterior projection to visualize and assess the origin of the AKA, usually originating from the ninth left intercostal artery but often presenting with anatomical variants.Ninety-two patients with neuroblastoma were treated between November 2015 and February 2022 in our Institution, but only six met the eligibility criteria . Baseline characteristics and patient diagnoses are summarized in Periprocedural information and the spinal angiography results are summarized in Surgical details, follow-up, and long-term outcomes are summarized in The patients were followed up radiologically and clinically, every 2–4 weeks; the median follow-up was 49 months from diagnosis (range: 31–96 months). Two patients (33%) experienced a distant metastatic relapse and no patients presented neurological sequelae after surgery or during the follow-up. Five patients (83%) were alive and well at the end of the follow-up, while one died after a refractory recurrence.Spinal cord vascular injury due to iatrogenic damage of the AKA is a rare but severe complication of posterior thoracic tumors ,7,8,15, There is some utility for the preoperative identification of the AKA using CT or magnetic resonance imaging (MRI) , with adDue to the risk of severe procedure-related complications , indicatIn fact, even if the vertebral levels T9–T12 are the boundaries in the International Neuroblastoma Risk Group Staging System (INRGSS) for IDRFs concerning infiltration of the costovertebral junction, a recent meta-analysis reported that 7.3% and 6.9% of AKAs arise at T8 and L1, respectively . FurtherIn patients with TNB, defining the anatomy of the AKA plays a crucial role in surgical planning. In fact, the ability to GTR while preserving vascularization of the spinal cord has a favorable impact on local control of the disease and general outcomes in patients with neuroblastoma, including those at high risk ,11,12,13We presented our pilot experience regarding the utility of POSA for GTR of TNB. In the present case series, spinal angiography was safe for experienced surgeons, and no periprocedural complications occurred. POSA effectively identified the origin of the AKA in all patients and helped tailor the surgical approach, thus minimizing neurological complications and their sequelae. In fact, patients in whom the origin of the AKA was found to be contralateral to the mass (2/6) or homolateral but not encased by the tumor (1/6) underwent an aggressive but safe surgical approach, achieving GTR without the risk of spinal cord injury. None of the patients developed neurologic complications or long-term sequelae, both perioperatively and at follow-up.Although all previous studies used catheter-based angiography, where catheterization techniques and the extent of angiography varied, the results of the present study are consistent with those in the recent literature . ChampliAs previously reported , POSA isHowever, no access site- or contrast-induced complications were observed in our cohort. Moreover, the mitigated risk of potentially permanent paresis or paraplegia in the absence of POSA outweighs the risks associated with angiography. Furthermore, a more informed discussion of risks and benefits when assessing treatment options with patients and caregivers is made possible by the information provided by POSA.The study has some obvious limitations due to its single-center retrospective design. The small sample size (a function of the low incidence of TNB) and lack of randomization also limit the generalization of the results. Furthermore, children with TNB represent a small population with peculiar characteristics and we acknowledge that POSA may not be available in developing countries or lower resourced settings, but we strongly believe that the treatment of these patients  can benefit from this radiological technological advancement. Therefore, future prospective, multicenter, randomized studies are warranted to confirm our findings.Among children with TNB, POSA was a safe and effective procedure for identifying the AKA and defining the optimal surgical strategy in an experienced center. Spinal angiography should be considered for the preoperative evaluation of patients with TNB to maximize the possibility of GTR and reduce the risk of iatrogenic damage to the AKA and its neurological consequences.


Disease-related biomarkers may serve as indicators of human disease. The clinical diagnosis of diseases may largely benefit from timely and accurate detection of biomarkers, which has been the subject of extensive investigations. Due to the specificity of antibody and antigen recognition, electrochemical immunosensors can accurately detect multiple disease biomarkers, including proteins, antigens, and enzymes. This review deals with the fundamentals and types of electrochemical immunosensors. The electrochemical immunosensors are developed using three different catalysts: redox couples, typical biological enzymes, and nanomimetic enzymes. This review also focuses on the applications of those immunosensors in the detection of cancer, Alzheimer’s disease, novel coronavirus pneumonia and other diseases. Finally, the future trends in electrochemical immunosensors are addressed in terms of achieving lower detection limits, improving electrode modification capabilities and developing composite functional materials. Biomarkers are significant biochemical indications of physiological abilities that are used to predict the onset or progression of diseases . It is pTraditionally, the clinical diagnosis of cancer relies on various medical imaging techniques to detect cancerous tissue . ActuallThe sensor is normally composed of a receptor, a transducer, and a detector . ImmunosIn this review, we supply a summary of the fundamentals and types of immunosensing. The applications of electrochemical immunosensors in the detection of disease biomarkers are reviewed and discussed in detail. In addition, the future prospects of electrochemical immunosensors in clinical diagnostics are presented.Electrochemical devices are effective tools used for delicate measurements in bio-analysis and diagnostics . The immThe high specificity and selectivity resulting from antigen–antibody immune recognition allow these immunosensors to be used in complex biological matrices such as blood, plasma, or urine. The electrochemical Immunosensors have the advantages of rapid detection, reusability, accountability, elevated throughput and the possibility of label-free detection. However, disadvantages such as difficult electrode maintenance, costly protein handling and short sensor lifetime cannot be ignored ,32.Typically, there are two categories of electrochemical immunosensors that are based on the accurate identification of antigen and antibody: competitive immunosensors and noncompetitive immunosensors .Competitive immunoassays are those in which the target analyte  competes recognition site on the surface of an antibody with an antigen that has been labeled with a signal molecule, as shown in Noncompetitive immunoassays involve the immunoconjugation of the chemical to be examined with two antibodies, i.e., the primary antibody and the secondary antibody, as shown in Since noncompetitive immunosensors require primary and secondary antibodies to collectively recognize the target antigen, reducing the nonspecificity of the immune response, this approach has elevated specificity and sensitivity. However, this method is mostly suitable for the detection of biological macromolecules, since small-molecule antigens do not have adequate binding sites to bind two antibodies simultaneously ,43. MeanElectrochemical immunosensors can be classified into redox couples, typical biological enzymes, and nanomimetic enzymes based on different catalytic substances. In the following sections, the catalytic substances are carried out differently, and we will present the applications in immunosensing techniques for the detection of different human disease biomarkers according to the two main categories of competitive immunosensors and noncompetitive immunosensors ,51.Electrochemical immunoassays that have the advantages of high sensitivity, rapidity and economy are currently being investigated for application in the detection of human disease markers. Electrochemical analysis of proteins can be achieved by measuring the electrical signal output from redox-active markers in the immune complex system .32+ . T. T3O4 NPRS-CoV-2 . The magal swabs . The SARNumerous immunosensors were developed for the detection of various diseases, such as cancer, Alzheimer’s disease and novel coronavirus pneumonia. It is clear from the examples listed in the text that the type of immunosensor is related to the size of the target analyte. Noncompetitive immunosensors have a higher sensitivity and are better suited for biomolecular detection since it requires two antibodies to bind to the target. Small-molecule targets are better suited for detection with competing immunosensors. Both types of competitive and noncompetitive immunosensors have undergone substantial research and one cannot exist without the other.Nowadays, various diseases are serious threats to human life, thus early diagnosis of diseases through biomarkers is particularly critical. Electrochemical immuosensors play an essential role in biomarker detection. In this review, we highlight the developments of electrochemical immunosensors in the diagnosis of various disease markers in the last five years. Immunosensors are classified by type into two main classes: competitive and noncompetitive, each with three different catalysts: redox couples, typical biological enzymes, and nanomimetic enzymes. This is complicated by the low levels of disease biomarkers and the short detection times required for their detection. In contrast, electrochemical immuonsensors transform the biological signal of antigen–antibody binding into an electrical signal during the reaction process, combining the high sensitivity, rapid signal response, ability to detect low-abundance samples, ease of use and low cost of electrochemical and immunosensing with outstanding advantages in the detection of biomarkers.Depending on the combination of principle types, competitive methods amplify immunoreactive signals through labeled molecules to obtain electrical signals with high sensitivity and great selectivity, and are suitable for the detection of small molecules or semantigens. Noncompetitive immunosensors are highly sensitive and have low nonspecific adsorption because they use two antibodies to bind the same antigen and are suitable for the detection of biological macromolecules. Direct antigen–antibody binding for noncompetitive immunosensors has the advantage of simplicity and low cost, but the method requires attention to the problem of background interference. Three main classes of catalytic substances, redox small molecules, enzymes and nanomaterials, can convert immunoreactive signals into electrical signals and amplify them, depending on the type of immunosensor.A redox couple is labeled on antigens, antibodies or materials to generate electrical signals. Because of their own catalytic action, biological enzymes are used to catalyze characteristic substrates to generate electrical signals. Due to the costly and difficult to preserve nature of biological enzymes, a variety of nanomimetic enzymes were designed and studied for catalyzing the generation of electrical signals in the construction of sensors.Immunosensors allow for sensitive and rapid detection of biomarkers. However, immunosensors also have drawbacks, such as invalidity at excessive concentrations, a short lifetime, and limitations by electrochemical detection equipment. The following are the key approaches for future development of immunosensors: 1. The goal is to achieve fmol or even lower detection limits in order to shorten analysis times and increase analytical sensitivity. 2. The requirement to create strategies for passivating electrode surfaces to thwart nonspecific adsorption of biological materials at the electrode interface. 3. The creation of composite functional materials, especially when combined with numerous amplification techniques, enhances the analytical capabilities of electrochemical enhancers to enhance the analytical performance of electrochemical immunosensors. In conclusion, we believe that electrochemical sensors have a bright future in disease biomarker detection. Building on existing research, the establishment of original methods for joint detection in the fields of immunology, novel nanomaterials, and electrochemistry will continue to advance research on early diagnosis of diseases, and point-of-care testing for diseases will be realized at an early date.


Wheat is a staple crop; its production must achieve both high yield and good quality due to worldwide demands for food security and better quality of life. It has been found that the grain qualities vary greatly within the different layers of wheat kernels. In this paper, the spatial distributions of protein and its components, starch, dietary fiber, and microelements are summarized in detail. The underlying mechanisms regarding the formation of protein and starch, as well as spatial distribution, are discussed from the views of substrate supply and the protein and starch synthesis capacity. The regulating effects of cultivation practices on gradients in composition are identified. Finally, breakthrough solutions for exploring the underlying mechanisms of the spatial gradients of functional components are presented. This paper will provide research perspectives for producing wheat that is both high in yield and of good quality. Wheat is arguably the most important food crop in the world. It is unique for the role it plays in a variety of processes, including the creation of leavened and unleavened breads, pasta, noodles, and pastries . Its funThe wheat kernel comprises endosperm, embryo, and bran, with endosperm accounting for around 82%, embryo accounting for approximately 3%, and bran accounting for approximately 15% of the total ,5,6. StaIt is well known that the protein content in wheat grain can be regulated by nitrogen by up to 2 times . It has A topical overview regarding the study of the spatial distribution of wheat grain quality is provided in Kent analyzed the protein content of milled flour from the sub-aleurone layer and endosperm, respectively, and discovered that the protein content of the sub-aleurone layer was approximately two times higher than that of the endosperm . With ad2 are more abundant in the outer layer of the endosperm, while those that are smaller than 1 μm2 are mostly concentrated in the inner endosperm [The distribution of protein in grains at the filling stage can be more intuitively observed by staining an ultrathin section, coupled with microscopy imaging. Xiong et al. observed the protein body (PB) distribution in 19-DAA caryopsis, revealing that the relative areas of PBs were higher in the ventral than in the dorsal region . Based ondosperm . Tosi etStarch consists of two types of glucose polymers: linear amylose, which is constituted of D-glucose linked by an α- glycosidic bond, and branching amylopectin with a high degree of polymerization, occupying 65–82% of the total starch . SimilarThe mature wheat grain contains primarily A-type (>10 μm) and B-type (<10 μm) starch granules . The twoCell wall polysaccharides (CWPS) are the primary source of dietary fiber in cereal products. Wheat grains contain about 9.2% to 20.0% of total dietary fiber (TDF) . The priCertain trace elements in wheat grains, such as mineral elements, vitamin B , and phytin, impact both human health and the quality of flour processing . Iron anThe heterogeneous spatial distribution of chemical components such as starch and protein in grains inevitably results in spatial variances in the processing quality of flours from different layers. From the outer layer to the inner layer of the endosperm, the concentrations of total starch and amylose and the ratio of A-type starch granules rose significantly, resulting in an upward trend of flour gelatinization parameters including peak viscosity, trough viscosity, breakdown, final viscosity, setback value, and pasting time. In contrast, the gelatinization temperature decreased in the flour from the outer to the inner layers. The spatial variability of the storage protein and its components in different parts of the grain led to considerable changes in the farinograph parameters and gluten quality . For insThe baking quality of flours from the different parts of the grain also showed significant spatial heterogeneity . ProteinWheat grain development can be divided into three stages: the cell differentiation and expansion stage (0–14 days after anthesis), when the structures of different parts of the grain are essentially formed and the synthesis of protein and starch begins; the grain-filling stage (14–28 days after anthesis), when the gluten and starch synthesize rapidly; and the dehydration stage (28 days after anthesis—maturity), when the grain filling rate slows and the water content decreases ,44,45. GUgalde and Jenner utilized microsections to investigate the composition of free amino acids and sugars in wheat grains at 20 days after anthesis. It was found that the gradients of amino acids and sucrose in caryopses did not correspond to the accumulation gradients of protein and starch, suggesting that the supply of heterogeneous substrates for grain protein or starch accumulation was not directly related ,54. NeveThe spatial difference in substrate supply capacity in grain is largely connected to its transport pathway. Wang et al. hypothesized that the substrate delivered by the spikelet vascular bundle is first emptied into the apoplast (endosperm cavity) before being transferred to the endosperm. Two transport pathways have been proposed: one is through the transfer cells surrounding the endosperm cavity, moving directly into the endosperm cells and being transported radially outward (transfer cell pathway); the other is transportation through the transfer cells into the aleurone layer, then transportation inwardly . Currently, the reports regarding these two transport routes are contentious . Chen etStarch synthesis occurs primarily in the amyloplast, using sucrose as the starting point to catalyze the creation of the direct precursor of starch synthesis, ADPG, followed by the coordinated activity of a succession of starch synthases . GliadinThe advancement of laser capture microdissection technology in recent years has enabled the precise collection of trace samples from the various regions of wheat grains. The pearling process described above may separate grains into distinct flour layers such as wheat bran, aleurone layer, outer endosperm, middle endosperm, and inner endosperm; however, it can only be used for mature grains and cannot be used to achieve pearled samples of fresh caryopses during grain filling. The laser capture microdissection technique may be used to monitor and find the target cell using a microscope, then mark the target region using a screen linked to the microscope, and then precisely cut the marked area with a laser to extract the target cell. The laser microdissection technique effectively overcomes the problem of cell heterogeneity by separating pure cell groups or even single cells from the fresh sample tissue . In conjHe et al. observed that the sulfur-poor gliadin concentration responded most substantially to nitrogen fertilizer increase and rose simultaneously in the whole grain. The raising effect of nitrogen fertilizer addition on the HMW-GS fraction of the outer endosperm layer was stronger than that on the inner endosperm layer, whereas the sulfur-rich gliadin showed a virtually inverse trend . SimilarThe timing of nitrogen topdressing also regulated the spatial distribution of the grain’s functional components. Delaying nitrogen topdressing timing from the jointing stage to the booting stage increased the gluten protein content in flour from all layers, but the rise was most pronounced in the aleurone and outer endosperm, and the regulation of the GMP and glutenin subunits was consistent with that of gluten protein. Shifting the timing of nitrogen topdressing from the jointing stage to the greening-up stage decreased the total protein and protein components, with the responses of the outer layer being more apparent . AdditioA cultivation practice of increasing density and decreasing nitrogen affected the spatial gradients of protein in soft wheat grain . The spaThe application of sulfur fertilizer increased the levels of total protein and glutenin in each grain layer, with the impact of the HMW subunit being stronger in the outer endosperm and middle endosperm, and gliadin concentration being higher in the outer endosperm than in the other layers . Li et aIn terms of trace elements, Shi et al. found that nitrogen application may enhance the contents of Fe and Zn in bran, but it was only the level of Zn that rose in terms of total flour . AccordiThe spatial heterogeneity in grain composition affords the opportunity to manufacture specialty flour by optimizing the milling process. The flour from the middle and outer endosperm had a greater HMW-GS content and glutenin/gliadin ratio, as well as better dough strength, elasticity, and reduced viscosity, making it ideal for bread baking that demands a high gluten strength . On the Through the combining of multiple layers of flour based on their different qualitative characteristics, it is also feasible to make high-quality unique flour for specialized wheat products. Based on the flour derived from the middle endosperm and supplemented with flour from the aleurone layer, which is rich in protein and mineral elements, the combined flour exhibited decreased pasting properties and increased mineral element content. In addition, the baked bread became deeper in color, with increased volume, hardness, and chewiness. However, when the adding rate surpassed 20%, the bread’s quality and sensory ratings would fall dramatically. Adding bran layer flour that is based on endosperm flour lowered the combined flour’s pasting parameter, increased the mineral elements, and deepened the color of cooked cookies while decreasing the diameter, extension factor, and sensory score. The nutritional quality and taste of the cookies improved when the second layer of wheat grain flour was blended with the fifth layer of flour at a 2:8 ratio, or when the first layer was blended with the ninth layer at a 1:9 ratio .To summarize, the spatial heterogeneity of key components in wheat grain has generally been obvious; however, research on the mechanism of this spatial heterogeneity is hampered owing to sampling difficulties, tiny caryopses size, the huge wheat genome, and other considerations. Recently, the development of nondestructive imaging tools that observe substrate transport and allocation in grains on the appropriate spatial and temporal scales facilitate transport pathway investigations. For instance, positron emission tomography-computed tomography (PET-CT) has been developed to offer a practical imaging technique that is used to assess the entire plant transport and nutrient allocation by quantifying the distribution of positron-emitting radioisotopes in a plant non-invasively and over time ,82,83. CHvMTP1 in endosperm cells, which successfully enhanced the endosperm zinc concentration and improved zinc transport and transfer from the aleurone layer to the endosperm [Furthermore, the advancement of laser microdissection technology and multi-omics analyses will aid in the investigation of the mechanisms behind spatial heterogeneity formation. In the future, the aforementioned technology can be used to obtain cells from any part of the fresh caryopses in conjunction with multi-omics methods to clarify the key regulatory processes, key regulatory genes, or gene networks responsible for the formation of spatial heterogeneity in the context of grain quality. Tauris et al. employed laser microdissection technology to extract the barley grain aleurone layer, nucellus process, embryo, and endosperm cells, which they then paired with microarray technology to determine the zinc transport pathway in the grain to reveal a key zinc transporter (HvMTP1) regulating zinc distribution in barley grains . After tndosperm . This esGrain protein accumulation responds to nitrogen application differentially, as do the spatial gradients of the functional components in wheat grain ,13,15. C


The migration of polluting enterprises (MPE) is a crucial subject within the fields of Environmental Economic Geography and Enterprise Geography. An analysis was conducted on the temporal-spatial evolution and influencing factors of the MPE by employing the full-sample enterprises data from the "Qichacha" system. The main findings were obtained: (1) The polluting enterprises in the Yangtze River Delta have undergone an evolutionary process of proximity migration, intra-provincial proximity to intra-provincial long distance migration, with intra-provincial migration being the main focus supplemented by inter-provincial migration, and coexisting intra-provincial and inter-provincial migration. (2) The estimation results, based on the panel negative-binomial model, reveal that the variables having a greater impact on the MPE encompass environmental regulation, industrial upgrading policies, cost factors, geographical distance, coastal and inter-provincial boundaries, etc. These influencing factors display time heterogeneity and industry heterogeneity. (3) By taking the Nijiaxiang Group, which was involved in the 321 Explosion Accident in Xiangshui, as an example, it was discovered that insufficient inheritance of environmental protection concepts, corruption of officials, and social governance problems have resulted in shortcomings in the area. This has led to a lowered level of local environmental regulation, transforming the local area into a haven for polluting enterprises such as the Nijiaxiang Group. The contribution of this study lies in observing the MPE from the perspective of "inter-regional association," and within the group enterprises. It addresses the deficiencies of existing research that mainly examines the evolution of industrial geographic patterns and statically observes polluting enterprises' entry and exit behavior. Moreover, this study demonstrates that the Pollution Shelter Hypothesis is not universal and has an impact in the Yangtze River Delta region after 2012. The migration of industries that contribute to pollution has emerged as an issue of critical importance and immediacy. Since the convening of the 18th National Congress of the CPC, the country has taken on an active role in meeting its obligations as a major nation by adhering to its commitments with respect to reducing emissions. The CPC has set forth the overarching objective of promoting "synergies in reducing pollution and carbon emissions", ultimately achieving victory in the war against pollution prevention and control. However, at the local level, the migration of polluting industries has emerged as a key strategy for reducing pollution and carbon emissions in certain areas. This has resulted in the widespread migration and migration of polluting enterprises, particularly with regard to equity investment-based spatial migration, which has largely escaped the attention of academia, local authorities, and the general public.In this context, regions with comparatively lax environmental regulations may become "pollution havens," subjecting their inhabitants to severe risks of pollution exposure and health problems. This has led to the emergence of "cancer villages" in some areas. In the early twenty-first century, a county located in northern Jiangsu famously declared that "it is better to die from poisoning than to die from poverty!" More recently, certain industrial parks in Anhui have expressed their eagerness to "contact" local high-pollution and high-emission enterprises that were eliminated from a chemical industry park situated in Jiangsu. Given the differential development strategies adopted across various regions, the pollution industry has undergone spatial reconfiguration, and pollution enterprises have also pursued distinct pathways for migration.2. This approach, however, has been limited by the absence of actual industrial flow data between regions, leading to the issue of "decreasing in one place, but not necessarily increasing in the other". This has impeded efforts to accurately identify the actual movement patterns of polluting industries between regions. (2) Some scholars have conducted field research and case analysis to examine specific regions, enterprises, or listed enterprises3, yet it remains challenging to analyze the migration trajectories of various polluting enterprises as a whole. (3) Due to the absence of relational data, previous research has divided the migration process of polluting enterprises into their entry and exit behaviors, with a focus on the impact of "regionalism" factors on these behaviors4. However, it is difficult to investigate the flow patterns of enterprises between regions, thereby limiting the exploration of the influence of inter-regional association factors.The migration of polluting enterprises represents a form of migration that has been extensively researched in the field of environmental economic geography and enterprise geography. The extant literature has mainly studied this phenomenon from three perspectives. (1) Scholars have explored the changes in the geographical pattern of pollution industries by analyzing the shifts in the scale and structure of polluting enterprisesFor MPE, the Yangtze River Delta region has a strong representation. The Yangtze River Delta is one of the most densely populated manufacturing regions in contemporary China. Since 2001, the Yangtze River Delta region carried out the preliminary exploration of the policy, and industrial migration became an important measure to promote regional coordinated development. There has been a gradual rise in inter-regional investments made by enterprises. As a result, the migration of polluting industries has become more prevalent. To address this phenomenon, this study focuses on the Yangtze River Delta as a research subject, using the complete sample of enterprise migration data provided by the "Qichacha" database. Employing both quantitative modeling and qualitative analysis, this research aims to explore the spatio-temporal processes and underlying mechanisms of polluting enterprise spatial migration. This study not only meets the practical demand of analyzing the migration path and dynamic mechanisms of polluting enterprises in the new era, but also fulfills the theoretical requirement of promoting the integration of environmental economic geography, enterprise geography, relational economic geography, and other relevant sub-disciplines.6  Fro27, nor have they thoroughly analyzed inter-regional relevance factors. This paper aims to address this gap by exploring the spatio-temporal evolution and influencing factors of the MPE from the perspective of "inter-regional association".In conclusion, the MPE is significantly influenced by both regionalism and inter-regional association. While existing studies have predominantly focused on environmental regulation, they have not provided adequate analysis on regional comprehensive factorswww.qcc.com, henceforth referred to as "Qichacha Database"). The database furnishes details such as the enterprise's denomination, the legal representative's moniker, the consolidated social credit code, the establishment's locale, the inception date, the operational status, the industry classification, the principal commerce, the registered funds, the equity percentage, the shareholder particulars, the counterparty investment enterprise, the investment sum, the ultimate beneficiary, and the intellectual property rights, etc.The source of enterprise directory data and inter-enterprise investment relationship data primarily originates from the information gathered between 2001 and 2018 within the "Qichacha" enterprise credit information inquiry platform 29. Finally, the author collected the data on pairing assistance between cities by referring to the official documents of each region.The statistical data pertaining to economic and social indicators at the city level, such as industrial wastewater and SO2 emissions, gross industrial output value, total exports, per capita wage, average land transfer price, and others, were predominantly obtained from the statistical yearbooks of provinces and cities, China Land Resources Yearbook, EPS Chinese city database, among other credible sources. Moreover, local dialect data were sourced from the Attribution of Dialects in China's Counties30. To identify polluting enterprises, a commonly adopted approach involves first defining the polluting industry and subsequently designating all enterprises belonging to said industry as polluting enterprises.The polluting enterprise is broadly defined as an enterprise that generates a considerable amount of pollutants directly or indirectly during production processes. Such pollution poses a threat to human beings, animals, plants, and overall environmental degradation if not managed and controlled appropriately32; (2) the total amount or intensity method sets a pollution emission threshold to select polluting industries based on either their total amount or intensity of pollution34; (3) the cost method selects polluting industries based on the proportion of pollution control costs in the total cost35. This study has identified 23 industrial categories as polluting industries based on the aforementioned methods. These industries include: coal mining and washing industry, petroleum and natural gas mining industry, ferrous metal ore mining industry, non-ferrous metal ore mining industry, non-metallic ore mining industry, mining professional and auxiliary activities, other mining industry, agricultural and sideline food processing industry, food manufacturing industry, wine, beverage and refined tea manufacturing industry, textile industry, leather, fur, feathers and their products and footwear industry, paper and paper products industry, petroleum, coal and other fuel processing industry, manufacturing of chemical raw materials and chemical products, pharmaceutical manufacturing, chemical fiber manufacturing, rubber and plastic products industry, non-metallic mineral products industry, ferrous metal smelting and rolling processing industry, non-ferrous metal smelting and rolling processing industry, metal products industry, and electric power and thermal production industry.At present, the methods for defining industries that are responsible for polluting the environment include various approaches: (1) The legal approach, which relies on official documents issued by the state and relevant ministries to identify polluting industries. Examples of such documents include the Notice on Environmental Protection Verification for Listed Enterprises Applying for Listing and Listed Enterprises Applying for Refinancings issued by the Ministry of Environmental Protection, the Environmental Information Disclosure Guide for Listed Enterprises, and the First National Pollution Source Census Plan issued by The State CouncilA list of enterprises operating within 23 polluting industries located in the Yangtze River Delta region was compiled from the Qichacha database.Information regarding foreign holding investments, with a share ratio greater than 50%, as well as subsidiary information for each of the aforementioned enterprises was collected. It is noteworthy that each polluting enterprise may establish multiple holding subsidiaries and branches across different regions.This study transformed the aforementioned "one-to-many" investment relationships into a "one-to-one" migration relationship for polluting enterprises. As a result, a total of 5,840 migration sample were identified in this study.The paper summarized the "relationship pairs" of the aforementioned enterprises and transformed them into "relationship pairs" of cities with districts. This allowed for the creation of a directed correlation network comprised of 41 cities with districts as nodes, where the frequency of polluting enterprise migration between cities with districts was used as the weight for the network.In this paper, the establishment of cross-regional subsidiary companies based on green field investment, mergers and acquisitions is regarded as the enterprise migration behavior. The steps for the identification of this behavior are specified as follows:This study focuses on the impact of inter-regional association factors on the MPE. In the region of the Yangtze River Delta, a relationship matrix among the districted cities was established. The explained variable was the frequency of the MPE between cities, while explanatory variables included urban attributes and various relational variables between cities. It is necessary to adopt a counting model because the explained variables are integers. Poisson model and negative binomial model are both common counting models. One of the original assumptions of the Poisson model is that the expectation of the explained variable is equal to the variance. However, after conducting calculations, it was found that the variance of the sample utilized in this study is approximately three times that of the mean value , indicating that the explained variables exhibit the phenomenon of "excessive dispersion". Results from the negative binomial regression model reveal that the confidence interval of alpha is , and at the significance level of 1%, it is possible to reject the null hypothesis of an overly dispersed parameter "alpha = 0". As a result, this study adopts the negative binomial regression model.i indicates an assistance pair, t is the year, MPE is the dependent variable, X represents a series of explanatory variables, μt is the time attribute, εi,t is a random error term, β0 is a constant term, and β1 is coefficients of X.A matrix of the assistance pairs among cities in the Yangtze River Delta region was formulated, and the assistance pairs as the study samples. Regression analysis was conducted through a negative binomial model, in which the frequency of the MPE between cities were dependent variable , and various variables of the relationship between cities were used as the explanatory variables. The baseline model is as follows:Premised on the aforementioned theoretical analysis, this paper primarily examines the impact of policy and official factors, industrial development environment, and geographical location on the MPE. Table 37, the level of environmental regulation is measured by the reciprocal of the comprehensive emission coefficient of pollutants. The specific calculation steps are as follows:In this study, linear standardization of industrial wastewater and industrial sulfur dioxide emissions per unit of output value for each city was conducted. This paper mainly calculated as follows: .PEij is the pollutant discharge per unit output value of j pollutants in city i, max(PEj) and min(PEj) are the maximum and minimum values of each indicator in all cities, and j pollutant emissions per unit output value during the sample period.To account for the variations in pollutant characteristics arising from the dissimilarities in emission types across different cities, an adjustment coefficient was employed. Specifically, the adjustment coefficient is Calculate the combined emission coefficient at the city level:Factoring in relevant studiesThe provinces such as Jiangsu, Zhejiang, and Shanghai have witnessed a substantial increase in investments in "village enterprises", "township enterprises", and "hot development zones" after 1978. Since 2001, the policy of regional coordinated development has become an important part of China's regional development strategy. The Yangtze River Delta region carried out the preliminary exploration of the policy, and industrial migration became an important measure to promote regional coordinated development. There has been a gradual rise in inter-regional investments made by enterprises. As a result, the migration of polluting industries has become more prevalent. In addition, the Covid-19 pandemic broke out at the end of 2019, and the impact mechanism behind the MPE is more complex after this time. Therefore, this study analyzes the MPE from 2001 to 2018.This study provides a summary and analysis of the historical context and spatial–temporal evolution of polluting enterprises' migration in the Yangtze River Delta region after the year 2000. To facilitate a comprehensive analysis, the region comprising Jiangsu, Zhejiang, and Anhui provinces has been further divided into sub-regions, namely Southern Jiangsu, Central Jiangsu, Northern Jiangsu, Eastern Zhejiang, Northern Zhejiang, Southwest Zhejiang, Southern Anhui, Central Anhui, and Northern Anhui , Shanghai's primary migration occurred in southern Jiangsu and northern Zhejiang before 2005. However, in the later period, there was a rapid increase in the number of polluters expanding towards northern Jiangsu, central Jiangsu, eastern Zhejiang, and northern Anhui. After 2005, the primary migration flow of the Yangtze River Delta shifted from southern Jiangsu to northern Jiangsu. Additionally, the migration of southern Jiangsu towards southern and northern Anhui witnessed a gradual increase after 2010. Anhui province has experienced intra-provincial migration for a prolonged duration, with the primary flow being from central Anhui to northern Anhui. As for Zhejiang enterprises, they mainly operate in northern Zhejiang and expand towards Jiaxing, Huzhou, and other areas from Hangzhou. After 2010, they expanded their operations to Wenzhou, Ningbo, Lishui, and other areas in eastern and southwestern Zhejiang.Regarding policy background, the migration trajectory of polluting enterprises exhibits a strong correlation with policies aimed at industrial upgrading, environmental regulation, and matching assistance. ① Industrial upgrading policy. Jiangsu has put forward "Jiangsu Traditional Industry Upgrading Plan", "South Jiangsu National Independent Innovation Demonstration Zone" and other policies to encourage enterprises in South Jiangsu to accelerate the "north–south industrial gradient transfer" by relocating and transforming their operations. Similarly, Zhejiang has implemented policies such as the "Return of Zhejiang Businessmen" and the "Huzhou Provincial Industrial Transfer Demonstration Zone." Moreover, Shanghai has announced its "Key Work Arrangement of Industrial Structure Adjustment," which aims to restructure its industrial landscape. In general, the MPE in Shanghai, southern Jiangsu, and northern Zhejiang is chiefly driven by industrial upgrading policy. ② Environmental regulation policy. After the "Taihu cyanobacteria incident," Jiangsu Province has ramped up efforts to clean up polluting enterprises in southern Jiangsu. Zhejiang Province has similarly implemented policies such as the "263 Special Environmental Remediation Action" and the "811" Environmental Pollution Control Action. Moreover, Shanghai has introduced its "Clean Air Action Plan" to curb air pollution. ③Pair assistance policies. Jiangsu, Zhejiang, and Anhui provinces have successively introduced provincial pair assistance policies, such as Jiangsu Province's "north–south link assistance" policy, Zhejiang Province's "Mountain and Sea Cooperation" plan, Anhui Province's "cooperative construction of a modern industrial park in northern Anhui". These policies are designed to promote coordinated regional development, but they have also resulted in the MPE from developed areas to less developed areas, such as northern Jiangsu and northern Anhui. Therefore, policymakers need to pay close attention to and optimize these policies to ensure a sustainable and balanced regional development.From 2001 to 2018, the migration trajectory of polluting enterprises in the Yangtze River Delta underwent an evolutionary process characterized by the evolution process of: "adjacent migration—intra-provincial adjacent migration to intra-provincial long-distance migration—emphasizing intra-provincial migration, supplemented by inter-provincial migration—parallel intra-provincial and inter-provincial migration."15, this study focuses on the dynamic changes of environmental regulatory factors. However, after 2012, highly incentive-oriented officials in the destination area will promote the settlement of polluting enterprises, which needs to be carefully monitored. Under the overall improvement of environmental regulations, less developed areas will have more opportunities to attract polluting enterprises, which may become a means for officials in those areas to be promoted. Additionally, paired assistance policies were found to be statistically significant at the 5% level in promoting the MPE. This is related to the corresponding counterparts in Jiangsu and Zhejiang provinces, who provide support to the MPE' spatial presence.Policy and official factors. Industrial upgrading policy exhibited consistently high significance level differences across regions. The difference in the intensity of environmental regulation indicates that the "pollution haven effect" is not universal, and only became statistically significant after 2012. Highly incentivizing officials in the source area are more likely to promote the MPE. Compared with the existing studies, which mainly observed the environmental regulatory factors driving MPE staticallyIndustrial development environment. Prior to 2012, the urban development intensity was identified as the primary driver of such migration. However, a shift in the migration patterns of polluting enterprises occurred after 2012, which was predominantly influenced by profitability and cost factors. Specifically, the migration decisions were shaped by considerations of land cost, labor costs, and industrial agglomeration. These findings indicate that the MPE was previously impeded by constraints related to land resources, while post-2012, the migration decisions were predominantly driven by the profit and cost considerations of the enterprises.Geographical location. Prior to 2012, inter-provincial boundary cities had a greater tendency to acquire larger areas, which corresponded with the findings of previous studies on the "boundary effect". However, after 2012, two distinct variables, namely geographic distance and Port advantage, emerged as significant predictors of the migration patterns of polluting enterprises. Port cities were found to possess substantial advantages in terms of import and export activities, as well as greater convenience for pollutant discharge, thus emerging as a vital alternative location for such enterprises.The regression analysis on the entire sample was conducted in Model (1). It was found that several variables had a significant impact on the migration of heavily polluting enterprises. Among them, variables with high statistical and economic significance included environmental regulation factors, industrial upgrading policies, the presence of strong incentive officials in the source area, average land price, urban development intensity, geographical distance, and terrain factors such as difference and the location advantage of coastal and interprovincial borders Table . It is wIn conclusion, the location determinants of the spatial distribution of polluting enterprises have evolved from a primary focus on the scarcity of land resources to a more nuanced consideration of profitability factors such as land prices, labor costs, and industrial agglomeration. In addition, with respect to the geographical location aspect, there is a clear shift in preference towards coastal port cities as opposed to peripheral regions within a province.In light of the intercorrelation between various industries, the manufacturing sectors of chemical raw materials, chemical products, rubber and plastic products, as well as pharmaceuticals, were integrated into a singular entity known as the "pharmaceutical and chemical industry". To further investigate this amalgamated industry, sub-sample estimation was carried out Table .Table 4AAmong various policy and official factors, it is found that environmental regulation policies have a greater impact on industries involved in power, thermal and food production industries. In addition, it has been observed that highly motivated officials in the country of origin can exert considerable pressure on enterprises operating in the power and thermal industries, leading them to withdraw from their local operations.In the context of industrial development, regions with higher overall industrial output values are more appealing to the power and thermal generation industry, as such regions require the provision of power and thermal support for their local industrial enterprises. On the other hand, industries such as metal products, pharmaceuticals, and chemicals are more drawn to less developed regions with lower levels of industrial development. The impact of other industries' development environments varies across these four categories of industries. While the electric power and thermal generation enterprises are affected by various factors, the food manufacturing industry is primarily attracted by the advantage of lower labor costs. Meanwhile, the metal products, pharmaceutical, and chemical industries exhibit similar preferences, being attracted to areas with lower land costs. In terms of geographical location factors, it is mainly observed that the power and thermal industries are drawn to areas with port advantages.http://www.neegroup.cn)]. It has established a holding subsidiary in Xiangshui County Jiangsu Tianjiayi Chemical Co., LTD. (referred to as Tianjiayi Company). In 2019, the company was hit by a catastrophic explosion known as the "March 21" incident, prompting the State Council to form an investigative team that disclosed a wealth of information about the group and the local government. This information facilitated an in-depth analysis of the factors that influenced Nijiaxiang Group's decision to invest in Tianjiayi Company, from Wuxi to Yancheng.Jiangsu Nijiaxiang Group Co., LTD. (referred to as "Nijiaxiang Group"), located in Jiangyin City, Wuxi City, is a group enterprise involved in textile, printing and dyeing, fiber, chemical industry, trade logistics and other industries [Company Profile of Jiangsu Nijiaxiang Group Co., LTD. Can be obtained from its official website  We found that there are differences in environmental regulation policies in the Yangtze River Delta region, which can affect MPE. Therefore, policymakers should establish an environmental regulation system that focuses on fairness and justice, thereby preventing polluting enterprises from relocating due to differences in environmental regulations. (2) The environmental monitoring mechanism of pair assistance policies should be improved, as polluters are expanding into less developed areas under these policies. Jiangsu Province and Zhejiang Province in the Yangtze River Delta region are among the earliest in China to carry out the exploration of pair assistance policies. Pair assistance policies, which were originally designed to enhance economic and social development in underdeveloped regions, have now become transmission channels for pollutants and polluting enterprises, necessitating special attention. Therefore, it is essential to strengthen the environmental monitoring mechanism when formulating and implementing pair assistance policies. (3) The source of polluting enterprises should be considered as one of the bases for ecological compensation and technological compensation. A lifelong environmental tracking and monitoring system is expected to be established for polluting enterprises and their stakeholders, based on the Superfund Act of the United States and the "Dark Green" revolution of the four Nordic countries.This paper is not without limitations that necessitate further elaboration in future research efforts. Firstly, the analysis of both the comprehensive MPE and the internal migration of cities divided into districts requires further attention. Secondly, the extant research pertaining to the identification of polluting enterprises primarily rests on the scrutiny of 2-digit industry categories, thus lacking in granularity. Given the disparities in technological advancement within industries, particularly in the context of the value chain division of labor, there may be significant variation in pollution emission levels despite belonging to the same industry classification. Accordingly, forthcoming research will leverage enterprise-level pollution emission data to explore the degree of pollution emission intensity among different value chain links.