Structural Changes Research Articles

Chronic Pain-Related Cognitive Deficits: Preclinical Insights into Molecular, Cellular, and Circuit Mechanisms.

Cognitive impairment is a common comorbidity of chronic pain, significantly disrupting patients' quality of life. Despite this comorbidity being clinically recognized, the underlying neuropathological mechanisms remain unclear. Recent preclinical studies have focused on the fundamental mechanisms underlying the coexistence of chronic pain and cognitive decline. Pain chronification is accompanied by structural and functional changes in the neural substrate of cognition. Based on the developments in electrophysiology and optogenetics/chemogenetics, we summarized the relevant neural circuits involved in pain-induced cognitive impairment, as well as changes in connectivity and function in brain regions. We then present the cellular and molecular alternations related to pain-induced cognitive impairment in preclinical studies, mainly including modifications in neuronal excitability and structure, synaptic plasticity, glial cells and cytokines, neurotransmitters and other neurochemicals, and the gut-brain axis. Finally, we also discussed the potential treatment strategies and future research directions.

Dynamic Copper Site Redispersion through Atom Trapping in Zeolite Defects.

Single-site copper-based catalysts have shown remarkable activity and selectivity for a variety of reactions. However, deactivation by sintering in high-temperature reducing environments remains a challenge and often limits their use due to irreversible structural changes to the catalyst. Here, we report zeolite-based copper catalysts in which copper oxide agglomerates formed after reaction can be repeatedly redispersed back to single sites using an oxidative treatment in air at 550 °C. Under different environments, single-site copper in Cu-Zn-Y/deAlBeta undergoes dynamic changes in structure and oxidation state that can be tuned to promote the formation of key active sites while minimizing deactivation through Cu sintering. For example, single-site Cu2+ reduces to Cu1+ after catalyst pretreatment (270 °C, 101 kPa H2) and further to Cu0 nanoparticles under reaction conditions (270-350 °C, 7 kPa EtOH, 94 kPa H2) or accelerated aging (400-450 °C, 101 kPa H2). After regeneration at 550 °C in air, agglomerated CuO was dispersed back to single sites in the presence and absence of Zn and Y, which was verified by imaging, in situ spectroscopy, and catalytic rate measurements. Ab initio molecular dynamics simulations show that solvation of CuO monomers by water facilitates their transport through the zeolite pore, and condensation of the CuO monomer with a fully protonated silanol nest entraps copper and reforms the single-site structure. The capability of silanol nests to trap and stabilize copper single sites under oxidizing conditions could extend the use of single-site copper catalysts to a wider variety of reactions and allows for a simple regeneration strategy for copper single-site catalysts.

Articular cartilage corefucosylation regulates tissue resilience in osteoarthritis.

This study aimed to investigate the glycan structural changes that occur before histological degeneration in osteoarthritis (OA) and to determine the mechanism by which these glycan conformational changes affect cartilage degeneration. An OA model was established in rabbits using mannosidase injection, which reduced high-mannose type N-glycans and led to cartilage degeneration. Further analysis of glycome in human OA cartilage identified specific corefucosylated N-glycan expression patterns. Inhibition of N-glycan corefucosylation in mice resulted in unrecoverable cartilage degeneration, while cartilage-specific blocking of corefucosylation led to accelerated development of aging-associated and instability-induced OA models. We conclude that α1,6 fucosyltransferase is required postnatally to prevent preosteoarthritic deterioration of articular cartilage. These findings provide a novel definition of early OA and identify glyco-phenotypes of OA cartilage, which may distinguish individuals at higher risk of progression.

Articular cartilage corefucosylation regulates tissue resilience in osteoarthritis

This study aimed to investigate the glycan structural changes that occur before histological degeneration in osteoarthritis (OA) and to determine the mechanism by which these glycan conformational changes affect cartilage degeneration. An OA model was established in rabbits using mannosidase injection, which reduced high-mannose type N-glycans and led to cartilage degeneration. Further analysis of glycome in human OA cartilage identified specific corefucosylated N-glycan expression patterns. Inhibition of N-glycan corefucosylation in mice resulted in unrecoverable cartilage degeneration, while cartilage-specific blocking of corefucosylation led to accelerated development of aging-associated and instability-induced OA models. We conclude that α1,6 fucosyltransferase is required postnatally to prevent preosteoarthritic deterioration of articular cartilage. These findings provide a novel definition of early OA and identify glyco-phenotypes of OA cartilage, which may distinguish individuals at higher risk of progression.

The effect of changes in morphology and structure of ZnS particle spheres on H2S gas release and cellular uptake behavior

Because preparation circumstances are limited, the relationship between spherical porous zinc sulfide (ZnS) and cells is rarely investigated. Thus, using the hydrothermal approach, four different types of ZnS spheres with consistent size, high dispersion, and stability were created in this research by varying the temperature, duration, solvent ratio, and pH level of the hydrothermal process. Three structures are present in the generated particle spheres: solid, hollow, and mesoporous structures. In addition to causing a significant variation in the particle spheres' specific surface area, porosity, and surface roughness, the distinct architectures also have an impact on ZnS particle spheres' capacity to produce hydrogen sulfide (H2S) gas in an acidic environment. Experiments on hemolysis and cytotoxicity demonstrated that ZnS particle spheres with varying concentrations and shapes exhibited no cytotoxicity and good biocompatibility. According to cellular uptake trials, ZnS particle spheres with a rougher surface structure and a bigger specific surface area are more likely to be absorbed by macrophages and release more H2S gas. This activity of releasing H2S gas by H+ action and MA phagocytosis by employing ZnS as a donor lays the groundwork for later particles to load medicines and carry out biological functions.

Nrf2 pre-recruitment at Enhancer 2 is a hallmark of H2 O2 -induced epigenetic transcriptional memory in the HMOX1 gene in human umbilical artery endothelial cells.

Maternal obesity (MO) is a significant cause of increased cardiometabolic risk in offspring, who present endothelial dysfunction at birth. Alterations in physiologic and cellular redox status are strongly associated with altered gene regulation in arterial endothelium. However, specific mechanisms by which the pro-oxidant fetal environment in MO could modulate the vascular gene expression and function during the offspring's postnatal life are elusive. We tested if oxidative stress could reprogram the antioxidant-coding gene's response to a pro-oxidant challenge through an epigenetic transcriptional memory (ETM) mechanism. A pro-oxidant double-hit protocol was applied to human umbilical artery endothelial cells (HUAECs) and EA.hy 926 endothelial cell lines. The ETM acquisition in the HMOX1 gene was analyzed by RT-qPCR. HMOX1 mRNA decay was evaluated by Actinomycin-D treatment and RT-qPCR. To assess the chromatin accessibility and the enrichment of NRF2, RNAP2, and phosphorylation at serin-5 of RNAP2, at HMOX1 gene regulatory regions, were used DNase HS-qPCR and ChIP-qPCR assays, respectively. The CpG methylation pattern at the HMOX1 core promoter was analyzed by DNA bisulfite conversion and Sanger sequencing. Data were analyzed using two-way ANOVA, and p < 0.05 was statistically significant. Using a pro-oxidant double-hit protocol, we found that the Heme Oxygenase gene (HMOX1) presents an ETM response associated with changes in the chromatin structure at the promoter and gene regulatory regions. The ETM response was characterized by a paused-RNA Polymerase 2 and NRF2 enrichment at the transcription start site and Enhancer 2 of the HMOX1 gene, respectively. Changes in DNA methylation pattern at the HMOX1 promoter were not a hallmark of this oxidative stress-induced ETM. These data suggest that a pro-oxidant milieu could trigger an ETM at the vascular level, indicating a potential epigenetic mechanism involved in the increased cardiovascular risk in the offspring of women with obesity.

High‐Temperature X‐Ray Imaging with Transparent Ceramics Scintillators

AbstractScintillators with high spatial‐resolution and high‐stability are highly desirable for X‐ray imaging applications at unpredictable environments. To challenge state‐of‐the‐art technology, it is necessary to design high thermal stable scintillators with high‐resolution and high light yield. In this work, the zero‐thermal‐quenching Lu3Al5O12:Ce3+ (LuAG: Ce3+) transparent ceramics (TCs) is synthesized with high optical transparency. The thermoluminescence (TL) curves of the as‐obtained TCs demonstrate that the formation of the oxygen vacancies, acting as the trapping centers, can capture the carriers and then contribute to the enhancement of its thermals stability via the thermal compensation effect. The exceptional thermal‐stability of the TCs scintillator endows the monitoring of the dynamic changes of the internal structure of the objective samples without any ghosting effects during heating. In addition, given the ultra‐high uniform, transparency, and fast light decay of the TCs scintillator, the excellent spatial resolution (≈112 lp mm−1) of the X‐ray microscopic imaging is realized. These results undeniably demonstrate that the as‐obtained LuAG: Ce3+ TCs have great prospects for advancement in X‐ray detectors.

Late-adolescent onset of prefrontal endocannabinoid control of hippocampal and amygdalar inputs and its impact on trace-fear conditioning behavior.

Prefrontal cortex (PFC) maturation during adolescence is characterized by structural and functional changes, which involve the remodeling of GABA and glutamatergic synapses, as well as changes in the endocannabinoid system. Yet, the way PFC endocannabinoid signaling interacts with local GABA and glutamatergic function to impact its processing of afferent transmission during the adolescent transition to adulthood remains unknown. Here we combined PFC local field potential recordings with local manipulations of 2-AG and anandamide levels to assess how PFC endocannabinoid signaling is recruited to modulate ventral hippocampal and basolateral amygdalar inputs in vivo in adolescent and adult male rats. We found that the PFC endocannabinoid signaling does not fully emerge until late-adolescence/young adulthood. Once present, both 2-AG and anandamide can be recruited in the PFC to limit the impact of hippocampal drive through a CB1R-mediated mechanism whereas basolateral amygdalar inputs are only inhibited by 2-AG. Similarly, the behavioral effects of increasing 2-AG and anandamide in the PFC do not emerge until late-adolescence/young adulthood. Using a trace fear conditioning paradigm, we found that elevating PFC 2-AG levels preferentially reduced freezing behavior during acquisition without affecting its extinction. In contrast, increasing anandamide levels in the PFC selectively disrupted the extinction of trace fear memory without affecting its acquisition. Collectively, these results indicate a protracted recruitment of PFC endocannabinoid signaling, which becomes online in late adolescence/young adulthood as revealed by its impact on hippocampal and amygdalar-evoked local field potential responses and trace fear memory behavior.

Transition to a weaker Sun: Changes in the solar atmosphere during the decay of the Modern Maximum

The Sun experienced a period of unprecedented activity during the 20th century, now called the Modern Maximum (MM). The decay of the MM after its maximum in cycle 19 has changed the Sun, the heliosphere, and the planetary environments in many ways. However, studies disagree on whether this decay has proceeded synchronously in different solar parameters or not. One of the related key issues is if the relation between two long parameters of solar activity, the sunspot number and the solar 10.7\,cm radio flux, has remained the same during this decay. A recent study argues that there is an inhomogeneity in the 10.7\,cm radio flux in 1980, which leads to a step-like jump ("1980 jump") in this relation. If true, this result would reduce the versatility of possible long-term studies of the Sun during the MM. Here we aim to show that the relation between sunspot number and 10.7\,cm radio flux does indeed vary in time, not due to an inhomogeneous radio flux but due to physical changes in the solar atmosphere. We used radio flux measurements made in Japan at four different wavelengths, and studied their long-term relation with the sunspot number and the 10.7\,cm radio flux during the decay of MM. We also used two other solar parameters, the MgII index and the number of solar active regions, in order to study the nature of the observed long-term changes in more detail. We find that the 1980 jump is only the first of a series of 1-2-year "humps" that mainly occur during solar maxima. All five radio fluxes depict an increasing trend with respect to the sunspot number from the 1970s to 2010s. These results exclude the interpretation of the 1980 jump as an inhomogeneity in the 10.7\,cm flux, and reestablish the 10.7\,cm flux as a homogeneous measure of solar activity. The fluxes of the longer radio waves are found to increase with respect to the shorter waves, which suggests a long-term change in the solar radio spectrum. We also find that the MgII index of solar UV irradiance and the number of active regions also increased with respect to the sunspot number, further verifying the difference in the long-term evolution in chromospheric and photospheric parameters. Our results provide evidence for important structural changes in solar magnetic fields and the solar atmosphere during the decay of the MM, which have not been reliably documented so far. We also emphasize that the changing relation between the different (e.g., photospheric and chromospheric) solar parameters should be taken into account when using the sunspot number or any single parameter in long-term studies of solar activity.

Double‐Helical Carbon Nanotube‐Wrapped Elastomeric Mandrel for Electrical Shortage‐Free, One‐Body Multifunctional Fiber Systems

AbstractSoft and elastic fiber‐based electronic devices exhibiting high electromechanical stability are highly desirable for sustainable and continuous utilization in various applications. However, effectively assembling the cathode and anode in a single body without unwanted interconnections and realizing an intimate contact interface between the electrode and substrate remain challenging. Here, an electrical shortage‐free one‐body fiber system with double‐helix buckle electrodes created by torsion‐ and strain‐mismatch between carbon nanotube (CNT) ribbons and a rubber substrate is reported. The as‐used CNT ribbons serve as the strain‐insensitive electrode, while the rubber mandrel‐core fiber acts as the key matrix in the following three aspects: as an elastic substrate that ensures reversible structural changes during mechanical deformations; as a dielectric layer for capacitive strain sensing; and as an electrothermal expansion element for tensile contraction. Moreover, because of the mismatch‐induced torque‐balance structure, the helically wrapped CNT buckle electrodes can effectively absorb the applied stresses without noticeable delamination and electrical conductance loss. Consequently, the double‐helix buckle fiber system can reliably provide multiple functions, viz. detection of various deformations (e.g., stretching, twisting, and pressing), electrochemical energy storage with excellent strain tolerance, and reversible electrothermal tensile actuation.

Penerapan Algoritma K-Medoids Dalam Menentukan Cluster Kabupaten/Kota Berdasarkan Migrasi Penduduk Jawa Barat

One of the three main factors influencing population dynamics is migration, along with births and deaths. Changes in population structure will definitely be influenced by migration. If in-migration is more than out-migration, the population will increase, but if out-migration is less than in-migration, the population will decrease. Therefore, it is necessary to know the grouping of regions based on population migration levels. To carry out this grouping, it is necessary to use Data mining methods. In this research, the Data mining used is Clustering using the K-Medoids algorithm. This method divides each district into predetermined groups. The K-Medoids method was chosen because it uses physical data that is not abstract and clear, which is suitable for the problem of grouping population migration data. By grouping migration levels based on districts/cities in West Java, it will be known which districts/cities in West Java have high levels of incoming migration, medium migration and high outmigration. Then recommendations can be given to the local government according to the migration level category.

Right Ventricular Structure and Function in Adolescent Athletes: A 3D Echocardiographic Study.

The aim of this study was to characterize the right ventricular (RV) contraction pattern and its associations with exercise capacity in a large cohort of adolescent athletes using resting three-dimensional echocardiography (3DE). We enrolled 215 adolescent athletes (16±1 years, 169 males, 12±6 hours of training/week) and compared them to 38 age and sex-matched healthy, sedentary adolescents. We measured the 3DE-derived biventricular ejection fractions (EF). We also determined the relative contributions of longitudinal EF (LEF/RVEF) and radial EF (REF/RVEF) to the RVEF. Same-day cardiopulmonary exercise testing was performed to calculate VO2/kg. Both LV and RVEFs were significantly lower (athletes vs. controls; LVEF: 57±4 vs 61±3, RVEF: 55±5 vs 60±5%, p<0.001). Interestingly, while the relative contribution of radial shortening to the global RV EF was also reduced (REF/RVEF: 0.40±0.10 vs 0.49±0.06, p<0.001), the contribution of the longitudinal contraction was significantly higher in athletes (LEF/RVEF: 0.45±0.08 vs 0.40±0.07, p<0.01). The supernormal longitudinal shortening correlated weakly with a higher VO2/kg (r=0.138, P=0.044). Similarly to the adult athlete's heart, the cardiac adaptation of adolescent athletes comprises higher biventricular volumes and lower resting functional measures with supernormal RV longitudinal shortening. Characteristic exercise-induced structural and functional cardiac changes are already present in adolescence.

The Limitation of Unproductive Binding of Cellulases to Lignin by Ozone Pretreatment

The limitation of enzymatic saccharification of lignocellulose is attributed to the nonproductive adsorption between lignin and cellulase. This study aims to investigate the effects of ozone pretreatment on the physical structure and chemical properties of milled wood lignin (MWL). The objective is to reduce the non-productive adsorption of cellulase on lignin. The structure–activity relationship between the physical structure of MWL and the occurrence of nonproductive adsorption was analysed using two-dimensional heteronuclear single quantum coherence–nuclear magnetic resonance (HSQC-NMR) and phosphorus-31 nuclear magnetic resonance spectrum (31P-NMR), etc. The results indicate that ozone pretreatment resulted in a decrease in the phenolic hydroxyl content and S/G ratio, an increase in the carboxyl content, and a negative zeta potential of MWL. The maximum adsorption capacity decreased from 25.77 mg/g to 10.09 mg/g, the Langmuir constant decreased from 13.86 mL/mg to 10.11 mL/mg, and the binding strength decreased from 357.14 mL/g to 102.04 mL/g, as determined by Langmuir isothermal adsorption. This suggests that ozone pretreatment resulted in a reduction in the hydrophobicity of lignin and a weakening of the electrostatic attraction between lignin and cellulase, thereby effectively reducing the non-productive adsorption of cellulase on lignin. This study provides an environmentally friendly pretreatment technique and comprehensively analyses the structural changes of ozone-treated MWL. These findings contribute to a deeper understanding of the interaction between lignin and cellulase.

Corpus callosum and cerebellum participate in semantic dysfunction of Parkinson's disease: a diffusion tensor imaging-based cross-sectional study.

Language dysfunction is common in Parkinson's disease (PD) patients, among which, the decline of semantic fluency is usually observed. This study aims to explore the relationship between white matter (WM) alterations and semantic fluency changes in PD patients. 127 PD patients from the Parkinson's Progression Markers Initiative cohort who received diffusion tensor imaging scanning, clinical assessment and semantic fluency test (SFT) were included. Tract-based special statistics, automated fiber quantification, graph-theoretical and network-based analyses were performed to analyze the correlation between WM structural changes, brain network features and semantic fluency in PD patients. Fractional anisotropy of corpus callosum, anterior thalamic radiation, inferior front-occipital fasciculus, and uncinate fasciculus, were positively correlated with SFT scores, while a negative correlation was identified between radial diffusion of the corpus callosum, inferior longitudinal fasciculus, and SFT scores. Automatic fiber quantification identified similar alterations with more details in these WM tracts. Brain network analysis positively correlated SFT scores with nodal efficiency of cerebellar lobule VIII, and nodal local efficiency of cerebellar lobule X. WM integrity and myelin integrity in the corpus callosum and several other language-related WM tracts may influence the semantic function in PD patients. Damage to the cerebellum lobule VIII and lobule X may also be involved in semantic dysfunction in PD patients.

Analyzing the energy metabolism of the automotive industry to study the differences found in this sector across EU countries

The automotive industry plays a key economic and political role in developed countries due to its contribution to exports, employment and revenues. Fragmentation of production and offshoring have distributed manufacturing stages among EU national automotive industries. An energy metabolic perspective allows us to explain differences in performance determined by the expression of different functions and the weight within the national economy. This paper analyses the Motor vehicles industry (MVI) and its sub-sectors in 8 EU countries in 2018 visualizing data in end-use matrixes, a Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) tool. We study the relation over energy carriers (electricity, and thermal energy), GHG emissions, working time, and value added at three different scales: the whole national economy, the MVI sector, and the subsectors within MVI. Through this multi-scale and multi-dimensional characterisation, we cluster the countries according to their functional specialization in (i) manufacturing intermediate parts and modules, (ii) final assembly of vehicles, and (iii) management and engineering design. This representation provides an integrated overview of this industry in relation to its core-periphery dynamics in the spatial division of labour. Additionaly, we provide new insights to labor productivity, efficiency, decoupling and structural changes for sustainability.

Operando Combined SAXS/XRD/XAFS Measurements of Lithium Conversion Battery

AbstractMany chemical reactions are accompanied by concerted phenomena, such as variance transition, structural changes, and particle formation. Various measurement techniques are employed to understand the whole picture of such concerted phenomena. A combination of small‐angle X‐ray scattering (SAXS), X‐ray diffraction (XRD), and X‐ray absorption fine structure (XAFS) is useful for studying concerted phenomena that occur, for example, inside rechargeable batteries. This combination can cover large lengths from 1 Å to several hundred nm. Operando measurements using this combination of methods can follow reactions during the charging and discharging of a rechargeable battery in a single experimental run. Fixed‐exit optics enable irradiation at the same point in a wide energy range. By employing 2D detectors for XRD and SAXS and using a quick XAFS technique, one can make the interval of each measurement sufficiently short to track various phenomena during charging and discharging. Here, an application of the system for alternating SAXS/XRD/XAFS measurements constructed in BL28XU, SPring‐8, Japan to the study of rechargeable batteries, is presented.

Real-Time Automated Geosteering Interpretation Combining Log Interpretation and 3D Horizon Tracking

Existing methods for estimating formation boundaries from well-log data only analyze the formation along the wellbore, failing to capture changes in the 3D formation structure around it. This paper presents a method for real-time 3D formation boundary interpretation using readily available well logs and seismic image data. In the proposed workflow, the mean formation boundary is estimated as a curve following the well path. 3D surfaces are then fitted through this boundary curve, aligning with the slopes and features in the seismic image data. The proposed method is tested on both synthetic and field datasets and illustrates the capabilities of accurate boundary estimation near the well path and precise representation of boundary shape changes further away from the well trajectory. With this fully automated geological interpretation workflow, human bias and interpretation uncertainty can be minimized. Subsurface conditions can be continually updated while drilling to optimize drilling decisions and further automate the geosteering process.

Effect of serum concentrations of IL-6 and TNF-α on brain structure in anorexia nervosa: a combined cross-sectional and longitudinal study.

Previous studies of brain structure in anorexia nervosa (AN) have reported reduced gray matter in underweight patients, which largely normalizes upon weight gain. One underlying biological mechanism may be glial cell alterations related to low-grade inflammation. Here, we investigated relationships between brain structure as measured by magnetic resonance imaging and serum concentrations of two pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) cross-sectionally in 82 underweight adolescent and young adult female patients (mean age 16.8 years; 59 of whom were observed longitudinally after short-term weight restoration; mean duration 2.8 months), 20 individuals long-term weight-recovered from AN (mean age 22.7 years) and 105 healthy control (HC) participants (mean age 17.2 years). We measured cortical thickness, subcortical volumes and local gyrification index, a measure of cortical folding. In contrast to most previous studies of cytokine concentrations in AN, we found no cross-sectional group differences (interleukin-6: p = 0.193, tumor necrosis factor alpha: p = 0.057) or longitudinal changes following weight restoration (interleukin-6: p = 0.201, tumor necrosis factor alpha: p = 0.772). As expected, widespread gray matter reductions (cortical thickness, subcortical volumes, cortical folding) were observed in underweight patients with AN compared to HC. However, we found no evidence of associations between cytokine concentrations and structural brain measures in any participant group. Furthermore, longitudinal changes in cytokine concentrations were unrelated to changes in gray matter. In conclusion, we did not identify any association between (sub-)inflammatory processes and structural brain changes in AN. Future studies are needed to elucidate which other factors besides nutritional status may contribute to brain morphological alterations.

The structural change and determinants of global carbon footprint network embodied in international migration: A social network analysis

The carbon footprint embodied in international population mobility has a complex spatial correlation, which exacerbates the difficulty of global climate governance. However, the features, changing trends, and determinants of the carbon footprint flow embodied in global population migration are poorly understood. This study employed social network analysis and the exponential random graph model (ERGM) to investigate the structural changes and drivers of the carbon footprint network embodied in global migration from 1995 to 2015. The results showed that approximately 50% of carbon footprint flow embodied in international migration flowed from developing to developed countries. The spatial connections between countries in the network were becoming increasingly close, displaying a typical small-world structure, and showing low reciprocity and negative assortativity. Moreover, centrality analysis highlighted the United States and the European Union as being at the core of the network, whereas some emerging economies (e.g., China, India, and South Africa) were shown as having an increasing influence on the network. The determinants of network formation were divided into three effects. For node attribute effect, countries with developed economy, high proportion of industrial value added, urbanization and openness were becoming the destinations of carbon inflows from immigrants, while countries with high consumption of renewable energy and energy intensity had a trend of carbon outflows with emigrants over periods. As for exogenous network effect, the significance of economic integration on the formation of the network was strengthening, while that of geographical proximity and cultural similarity was declining. Additionally, the positive impact of self-organizational effect on the network was decreasing. This study provided guidance for countries to formulate policies to reduce the carbon emissions embodied in international migration.

Optical coherence tomography angiography for the assessment of retinal microvasculature characteristics in preterm-born children: A systematic review and meta-analysis.

This study aimed to evaluate the usefulness of optical coherence tomography angiography (OCTA) in assessing retinal microvascular structural changes in preterm-born children and compare them with those in term-born children. The Web of Science Library, Cochrane Library, PubMed, Embase, CNKI, Wanfang, VIP, and Sino Med databases were searched systematically to extract studies published till April 25, 2023. Two independent reviewers searched all the literature and completed the data extraction and quality assessment. Mean differences (MDs) with 95% confidence intervals (CIs) were used to assess the continuous estimates. STATA software (v15.1; StataCorp, College Station, TX) was used to analyze the data. Twelve published studies were eligible for inclusion in this study. The meta-analysis revealed that the foveal avascular zone (FAZ) area of preterm-born children was remarkably smaller than that of term-born children, with the laser photocoagulation (LP)-ROP group showing the most pronounced reduction. The foveal superficial capillary plexus vessel density (SCP-VD) and deep capillary plexus vessel density (DCP-VD) were remarkably higher in the preterm-born group than in the control group, with variations in subgroups (LP-ROP, anti-VEGF-ROP, SR-ROP, and Pre-T-ROP). The parafoveal SCP-VD was remarkably lower in preterm-born children compared to that of the controls, while no significant difference was identified in the parafoveal DCP-VD. Preterm-born children had a smaller FAZ area, higher foveal SCP-VD and DCP-VD, and lower parafoveal SCP-VD compared to their term-born counterparts. The parafoveal DCP-VD did not differ substantially between preterm- and term-born children. OCTA is an effective modality for assessing alterations in the retinal microvasculature in preterm children.