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1.
Eur J Neurol ; 31(5): e16226, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38323746

RESUMO

BACKGROUND AND PURPOSE: Ischemic stroke, a major contributor to global disability and mortality, is underpinned by intricate pathophysiological mechanisms, notably neuroinflammation and immune cell dynamics. Prior research has identified a nuanced and often paradoxical link between immune cell phenotypes and ischemic stroke susceptibility. The aim of this study was to elucidate the potential causal links between the median fluorescence intensity (MFI) and morphological parameters (MP) of 731 immune cell types and ischemic stroke risk. METHODS: By analyzing extensive genetic datasets, we conducted comprehensive Mendelian randomization (MR) analyses to discern the genetic correlations between diverse immune cell attributes (MFI and MP) and ischemic stroke risk. RESULTS: Our study identified key immune cell signatures linked to ischemic stroke risk. Both B cells and T cells, among other immune cell types, have a bidirectional influence on stroke risk. Notably, the regulatory T-cell phenotype demonstrates significant neuroprotective properties, with all odds ratio (OR) values and confidence intervals (CIs) being less than 1. Furthermore, CD39 phenotype immune cells, particularly CD39+ CD8+ T cells (inverse variance weighting [IVW] OR 0.92, 95% CI 0.87-0.97; p = 0.002) and CD39+ activated CD4 regulatory T cells (IVW OR 0.93, 95% CI 0.90-0.97; p < 0.001), show notable neuroprotection against ischemic stroke. CONCLUSION: This investigation provides new genetic insights into the interplay between various immune cells and ischemic stroke, underscoring the complex role of immune processes in stroke pathogenesis. These findings lay a foundation for future research, which may confirm and expand upon these links, potentially leading to innovative immune-targeted therapies for stroke prevention and management.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Análise da Randomização Mendeliana , Acidente Vascular Cerebral/genética , Linfócitos B , Neuroproteção , Estudo de Associação Genômica Ampla
2.
Epilepsy Behav ; 157: 109896, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38905914

RESUMO

BACKGROUND: Neuroinflammation plays an important pathophysiological role in epilepsy; however, the precise connection between immune cells and epilepsy remains unclear. This study used Mendelian randomization (MR) to analyze the causal relationship between 731 immune cell traits and epilepsy. METHODS: Based on data from a genome-wide association study (GWAS), a bidirectional two-sample MR analysis was conducted to investigate the potential influence of immune cell phenotypes on epilepsy. Five MR methods were used to analyze the results, with the inverse variance weighted (IVW) method as the primary method, and the results were corrected using the false discovery rate (FDR) method. Sensitivity analyses were performed to test for heterogeneity and horizontal pleiotropy. RESULTS: After correction for FDR, four immune traits remained significantly associated with epilepsy risk: CD25 expression on memory (OR = 1.04, 95 % CI = 1.02 âˆ¼ 1.06,P = 2.55 × 10-4), IgD+CD38dim (OR = 1.05, 95 % CI = 1.02 âˆ¼ 1.08, P = 4.73 × 10-4), CD24+CD27+ (OR = 1.04, 95 % CI = 1.02 âˆ¼ 1.06, P = 4.82 × 10-4), and IgD-CD38dim (OR = 1.04, 95 % CI = 1.02 âˆ¼ 1.06, P = 1.04 × 10-3) B cells. The risk of generalized epilepsy was significantly associated with two immune cell traits, whereas that of focal epilepsy was significantly associated with seven immune cell traits. Furthermore, immune cell phenotypes are not affected by genetically predicted epilepsy. CONCLUSION: This MR study affirms the causal connection between circulating immune cells and epilepsy, offering guidance for further understanding of the immune mechanisms that underlie epilepsy and the discovery of novel targets for therapy.


Assuntos
Epilepsia , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Fenótipo , Humanos , Epilepsia/genética , Epilepsia/imunologia , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único
3.
Mol Divers ; 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38609691

RESUMO

4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27; HPPD) is one of the important target enzymes in the development of herbicides. To discover novel HPPD inhibitors with unique molecular, 39 cyclohexanedione derivations containing pyrazole and pyridine groups were designed and synthesized. The preliminary herbicidal activity test results showed that some compounds had obvious inhibitory effects on monocotyledon and dicotyledonous weeds. The herbicidal spectrums of the highly active compounds were further determined, and the compound G31 exhibited the best inhibitory rate over 90% against Plantago depressa Willd and Capsella bursa-pastoris at the dosages of 75.0 and 37.5 g ai/ha, which is comparable to the control herbicide mesotrione. Moreover, compound G31 showed excellent crop safety, with less than or equal to 10% injury rates to corn, sorghum, soybean and cotton at a dosage of 225 g ai/ha. Molecular docking and molecular dynamics simulation analysis revealed that the compound G31 could stably bind to Arabidopsis thaliana HPPD (AtHPPD). This study indicated that the compound G31 could be used as a lead molecular structure for the development of novel HPPD inhibitors, which provided an idea for the design of new herbicides with unique molecular scaffold.

4.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(6): 708-714, 2024 Jun 10.
Artigo em Chinês | MEDLINE | ID: mdl-38818555

RESUMO

OBJECTIVE: To explore the distribution and hematological characteristics of rare thalassemia-associated mutations in Chenzhou region of Hunan Province with an aim to provide a basis for genetic counseling and effective prevention. METHODS: A total of 37 370 individuals enrolled from January 2015 to December 2021 were screened by routine blood test and hemoglobin electrophoresis. The genotypes were determined with high-throughput sequencing. RESULTS: A total of 8 455 thalassemia mutations (including 185 rare ones) were detected, which had involved 27 mutational types. Rare type α-Thalassemia --THAI and CD31 (AGG>AAG) have the typical microcytic hypochromic hematological features, whilst SEA-HPFH, CD14 (CTG>-TG), CD37 (TGG>TAG), -90(C>T), Codon 15 (G>A), IVS-I-128 (T>G), CD86 (GCC>GC-) and Chinese Gγ+(Aγδß)0 had typical microcytic hypochromic and ß-thalassemia-associated hematological features of elevated HbA2 or HbF. In addition, the -50(G>A)heterozygotes of ß-thalassemia had normal or slightly decreased MCV and MCH without an increase in HbA2. CONCLUSION: Various forms of thalassemia-associated mutations have been identified in the Chenzhou region of Hunan Province. Above finding has facilitated development of preventive and control strategies for thalassemia as well as birth health programs.


Assuntos
Mutação , Humanos , China , Feminino , Masculino , Adulto , Talassemia/genética , Talassemia/sangue , Talassemia alfa/genética , Adulto Jovem , Adolescente , Criança , Genótipo , Talassemia beta/genética , Talassemia beta/sangue , Pré-Escolar , Pessoa de Meia-Idade
5.
Tob Induc Dis ; 222024.
Artigo em Inglês | MEDLINE | ID: mdl-38550907

RESUMO

INTRODUCTION: This study analyzes the impact of active smoking and secondhand smoke on the ischemic stroke burden of Pakistan, 1990-2019. METHODS: We used data from the Global Burden of Disease (GBD) database to conduct a comprehensive evaluation of ischemic stroke-related indicators in Pakistan, including the number of deaths, mortality rates, disability-adjusted life years (DALYs), DALY rates, and the estimated annual percentage change (EAPC). Joinpoint analysis was applied to assess sex-specific temporal trends in the burden of active smoking and secondhand smoke in Pakistan and regions of Pakistan. These assessments incorporated the Socio-Demographic Index (SDI) and we have made comparative analyses of epidemiological differences between active smoking and secondhand smoke exposure. RESULTS: The burden of ischemic stroke related to tobacco use is presented in terms of the age-standardized mortality rate (ASMR) and the age-standardized disability-adjusted life year rate (ASDR) per 100000 population. The results (ASMR/ASDR) for Pakistan were 6.04/130.81, in the middle SDI region 7.69/176.54, and low-middle SDI region 5.64/124.22. Pakistan's ASMR is higher than the global average of 5.85, while ASDR is lower than the global average of 140.23. From 1990 to 2019, a downward trend in both ASMR and ASDR was observed, indicating progress in controlling tobacco-related stroke burdens. Individuals aged ≥70 years experienced the highest rates of stroke (ASMR: 66.31; ASDR: 1091.20). Gender disparities were evident: men were more affected by active smoking (ASMR: 3.08; ASDR: 78.47) than women (ASMR: 0.79; ASDR: 20.76), while women faced a higher burden from secondhand smoke (ASMR: 0.66; ASDR: 16.33) compared to men (ASMR: 0.79; ASDR: 9.93). Regional differences within Pakistan show fluctuating death and DALY rates. Notably, an increasing trend in female ASDR due to secondhand smoke in the Khyber Pakhtunkhwa Region (annual percentage change, APC=0.17 from 2010 to 2019) calls for focused health interventions. CONCLUSIONS: The study finds ASMR for tobacco-related ischemic stroke in Pakistan exceeds global averages, with significant gender and age disparities in exposure to smoke, highlighting the need for targeted health interventions.

6.
Int J Mol Med ; 53(3)2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38299236

RESUMO

Stroke, a debilitating cerebrovascular ailment, poses significant threats to human life and health. The intricate interplay between the gut­brain­microbiota axis (GBMA) and cerebral ischemia­reperfusion has increasingly become a focal point of scientific exploration, emerging as a pivotal research avenue in stroke pathophysiology. In the present review, the authors delved into the nexus between the GBMA and neuroinflammation observed post­stroke. The analysis underscored the pivotal roles of histone deacetylase 3 and neutrophil extracellular traps subsequent to stroke incidents. The influence of gut microbial compositions and their metabolites, notably short­chain fatty acids and trimethylamine N­oxide, on neuroinflammatory processes, was further elucidated. The involvement of immune cells, especially regulatory T­cells, and the intricate signaling cascades including cyclic GMP­AMP synthase/stimulator of interferon genes/Toll­like receptor, further emphasized the complex regulatory mechanisms of GBMA in cerebral ischemia/reperfusion injury (CI/RI). Collectively, the present review offered a comprehensive perspective on the metabolic, immune and inflammatory modulations orchestrated by GBMA, augmenting the understanding of its role in neuroinflammation following CI/RI.


Assuntos
Isquemia Encefálica , Traumatismo por Reperfusão , Acidente Vascular Cerebral , Humanos , Doenças Neuroinflamatórias , Eixo Encéfalo-Intestino , Isquemia Encefálica/metabolismo , Acidente Vascular Cerebral/metabolismo , Traumatismo por Reperfusão/metabolismo
7.
Cell Signal ; 122: 111331, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39094671

RESUMO

Endoplasmic reticulum stress (ERS) and ferroptosis are linked to cerebral ischemia reperfusion injury (CIRI). The neuroprotective properties of 1α, 25-dihydroxyvitamin D3 (VitD3 or 1,25-D3) have been well established; however, the mechanism by which VitD3 treats CIRI through ERS and ferroptosis has not been examined. Hence, we developed middle cerebral artery occlusion/reperfusion (MCAO/R) model in SD rats to ascertain if VitD3 preconditioning mediates ERS and ferroptosis involving of p53 signaling. In this study, we observed that VitD3 can reduce infarction volume and cerebral edema, which leads to the improvement of nerve function. HE, Nissl and Tunel staining showed that VitD3 treatment significantly improved the morphology of neuronal cells and reduced their death. The expression and activation of Vitamin D receptor (VDR), PKR-like ER kinase (PERK), C/EBP-homologous protein (CHOP), p53, nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and reactive oxygen species (ROS) in the ischemic penumbral area were detected by real-time qPCR, Western-blotting and Elisa. The results showed that after VitD3 treatment, VDR increased, ERS-related indices (PERK, CHOP) significantly decreased and ferroptosis-related indices (Nrf2, GPX4) increased. As a VDRs antagonist, pyridoxal-5-phosphate (P5P) can partially block the neuroprotective effects of VitD3. Therefore, CIRI can induce ERS and ferroptosis in the ischemic penumbra area and VitD3 may ameliorate nerve damage in CIRI rats by up-regulating VDR, alleviating p53-associated ERS and ferroptosis.

8.
Front Aging Neurosci ; 16: 1394738, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38737586

RESUMO

Background: An increasing body of research has demonstrated a robust correlation between circulating inflammatory proteins and neuromyelitis optica spectrum disorders (NMOSD). However, whether this association is causal or whether immune cells act as mediators currently remains unclear. Methods: We employed bidirectional two-sample Mendelian randomization (TSMR) analysis to examine the potential causal association between circulating inflammatory proteins, immune cells, and NMOSD using data from genome-wide association studies (GWAS). Five different methods for Mendelian randomization analyses were applied, with the inverse variance-weighted (IVW) method being the primary approach. Sensitivity analyses were further performed to assess the presence of horizontal pleiotropy and heterogeneity in the results. Finally, a two-step Mendelian randomization (MR) design was employed to examine the potential mediating effects of immune cells. Results: A notable causal relationship was observed between three circulating inflammatory proteins (CSF-1, IL-24, and TNFRSF9) and genetically predicted NMOSD. Furthermore, two immune cell phenotypes, genetically predicted CD8 on naive CD8+ T cells, and Hematopoietic Stem Cell Absolute Count were negatively and positively associated with genetically predicted NMOSD, respectively, although they did not appear to function as mediators. Conclusion: Circulating inflammatory proteins and immune cells are causally associated with NMOSD. Immune cells do not appear to mediate the pathway linking circulating inflammatory proteins to NMOSD.

9.
Neural Regen Res ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38993125

RESUMO

ABSTRACT: The cGAS-STING pathway plays an important role In Ischemla/reperfuslon Injury In the heart, liver, brain, and kidney, but its role and mechanisms in cerebral ischemia/reperfusion injury have not been systematically reviewed. Here, we outline the components of the cGAS-STING pathway and then analyze its role in autophagy, ferroptosis, cellular pyroptosis, disequilibrium of calcium homeostasis, inflammatory responses, disruption of the blood-brain barrier, microglia transformation, and complement system activation following cerebral ischemia/reperfusion injury. We further analyze the value of cGAS- STING pathway inhibitors in the treatment of cerebral ischemia/reperfusion injury and conclude that the pathway can regulate cerebral ischemia/reperfusion injury through multiple mechanisms. Inhibition of the cGAS-STING pathway may be helpful in the treatment of cerebral ischemia/reperfusion injury.

10.
JPRAS Open ; 41: 25-32, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38868740

RESUMO

Background: Atrophic scarring is a severe form-disfiguring sequela of acne, which can lead to negative effect on patients' life. Fractional microplasma radiofrequency (RF) has emerged as a promising modality, leveraging dermal fibroblast remodeling to enhance aesthetic results for scars and hyperpigmentation. This study evaluates the efficacy and safety of high-power fractional microplasma RF for atrophic acne scars, considering patient tolerance to procedural discomfort. Methods: In this prospective study, 95 Chinese patients with atrophic facial acne scars underwent three sessions of fractional microplasma RF treatment, with assessments at 1, 3, and 6 months post-treatment. Patients were categorized based on treatment power: Group A (50-70 W) and Group B (70-85 W). Efficacy was determined by three independent dermatologists using digital photographs and Echelle d'Evaluation Clinique des Cicatrices d'Acné (ECCA) scores, and patient-reported outcomes gauged satisfaction levels. Results: Eighty-six patients completed the study. Significant improvements were observed, with a reduction in ECCA scores from 107.21 to 42.27 (P<0.05), demonstrating notable scar amelioration across both groups, albeit with a superior outcome in Group B. All patients experienced transient side effects such as pain, erythema, and edema, deemed tolerable with no long-term adverse effects reported. The treatment was well-received, with high satisfaction rates, underscoring its efficacy and acceptable safety profile. Conclusion: Fractional microplasma RF therapy, particularly at higher power settings, is an effective and safe option for treating atrophic acne scars, offering significant aesthetic improvement with manageable discomfort. This modality presents a valuable addition to acne scar management strategies, especially for patients with darker skin tones seeking minimal downtime and reduced risk of hyperpigmentation.

11.
J Affect Disord ; 363: 292-299, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39029686

RESUMO

BACKGROUND: Depression is a significant public health issue, closely associated with epilepsy and oxidative stress (OS). This study aims to explore the level of OS in patients with epilepsy and its relationship with moderate to severe depression (MSD). METHODS: This cross-sectional study includes 10,819 participants aged 20-80 from the National Health and Nutrition Examination Survey (NHANES) database (2013-2020 pre-pandemic). Depression symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), and epilepsy was diagnosed based on antiepileptic drug use in the past 30 days. The oxidative balance score (OBS) was calculated from dietary recall and lifestyle habits over the previous 24 h. RESULTS: Compared to non-epileptic subjects, epileptic patients have a significantly higher prevalence of depression. Epileptic patients exhibit lower OBS and Dietary Oxidative Balance Scores (DOBS), while there is no significant difference in Lifestyle Oxidative Balance Scores (LOBS). Depressed patients show lower OBS, DOBS, and LOBS. The mediation model indicates that DOBS mediates 3.44 % of epilepsy-related MSD. CONCLUSIONS: Epileptic patients exhibit significantly higher levels of OS and consume more pro-oxidant foods compared to the general population. However, their lifestyle habits do not differ significantly from those of the control group. Additionally, epileptic patients are at a higher risk of developing MSD. Although a pro-oxidant diet may be associated with epilepsy-mediated MSD, its mediating effect is relatively weak.


Assuntos
Epilepsia , Inquéritos Nutricionais , Estresse Oxidativo , Humanos , Feminino , Masculino , Adulto , Epilepsia/epidemiologia , Pessoa de Meia-Idade , Estudos Transversais , Idoso , Estresse Oxidativo/fisiologia , Adulto Jovem , Idoso de 80 Anos ou mais , Depressão/epidemiologia , Estilo de Vida , Índice de Gravidade de Doença , Prevalência , Dieta , Estados Unidos/epidemiologia
12.
Plants (Basel) ; 13(15)2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39124202

RESUMO

The combination of no-till farming and green manure is key to nourishing the soil and increasing crop yields. However, it remains unclear how to enhance the efficiency of green manure under no-till conditions. We conducted a two-factor field trial of silage maize rotated with hairy vetch to test the effects of tillage methods and returning. Factor 1 is the type of tillage, which is divided into conventional ploughing and no-tillage; factor 2 is the different ways of returning hairy vetch as green manure, which were also compared: no return (NM), stubble return (H), mulching (HM), turnover (HR, for CT only), and live coverage (LM, for NT only). Our findings indicate that different methods of returning hairy vetch to the field will improve maize yield and quality. The best results were obtained in CT and NT in HM and LM, respectively. Specifically, HM resulted in the highest dry matter quality and yield, with improvements of 35.4% and 31.9% over NM under CT, respectively. It also demonstrated the best economic and net energy performance. However, other treatments had no significant effect on the beneficial utilization and return of nutrients. The LM improved yields under NT by boosting soil enzyme activity, promoting nitrogen transformation and accumulation, and increasing nitrogen use efficiency for better kernel development. Overall, NTLM is best at utilizing and distributing soil nutrients and increasing silage maize yield. This finding supports the eco-efficient cultivation approach in silage maize production in the region.

13.
Materials (Basel) ; 17(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38591471

RESUMO

A new type of poly-diamond plate without a catalyst was produced via the high-pressure high-temperature (HPHT) compression of diamond powders. The densification of diamond powders and sp3 to sp2 carbon on the surface under HPHT compression was investigated through the characterization of the microstructure, Raman spectroscopy analysis and electrical resistance measurement. The densification and sp3-sp2 transformation on the surface are mainly affected by the pressure, temperature and particle size. The quantitative analysis of the diamond sp3 and sp2 carbon amount was performed through the peak fitting of Raman spectra. It was found that finer diamond particles under a higher temperature and a lower pressure tend to produce more sp2 carbon; otherwise, they produce less. In addition, it is interesting to note that the local residual stresses measured using Raman spectra increase with the diamond particle size. The suspected reason is that the increased particle size reduces the number of contact points, resulting in a higher localized pressure at each contact point. The hypothesis was supported by finite element calculation. This study provides detailed and quantitative data about the densification of diamond powders and sp3 to sp2 transformation on the surface under HPHT treatment, which is valuable for the sintering of polycrystalline diamonds (PCDs) and the HPHT treatment of diamonds.

14.
J Agric Food Chem ; 72(20): 11308-11320, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38720452

RESUMO

The dearomatization at the hydrophobic tail of the boscalid was carried out to construct a series of novel pyrazole-4-carboxamide derivatives containing an oxime ether fragment. By using fungicide-likeness analyses and virtual screening, 24 target compounds with theoretical strong inhibitory effects against fungal succinate dehydrogenase (SDH) were designed and synthesized. Antifungal bioassays showed that the target compound E1 could selectively inhibit the in vitro growth of R. solani, with the EC50 value of 1.1 µg/mL that was superior to that of the agricultural fungicide boscalid (2.2 µg/mL). The observations by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that E1 could reduce mycelial density and significantly increase the mitochondrial number in mycelia cytoplasm, which was similar to the phenomenon treated with boscalid. Enzyme activity assay showed that the E1 had the significant inhibitory effect against the SDH from R. solani, with the IC50 value of 3.3 µM that was superior to that of boscalid (7.9 µM). The mode of action of the target compound E1 with SDH was further analyzed by molecular docking and molecular dynamics simulation studies. Among them, the number of hydrogen bonds was significantly more in the SDH-E1 complex than that in the SDH-boscalid complex. This research on the dearomatization strategy of the benzene ring for constructing pyrazole-4-carboxamides containing an oxime ether fragment provides a unique thought to design new antifungal drugs targeting SDH.


Assuntos
Desenho de Fármacos , Inibidores Enzimáticos , Fungicidas Industriais , Oximas , Pirazóis , Succinato Desidrogenase , Succinato Desidrogenase/antagonistas & inibidores , Succinato Desidrogenase/química , Succinato Desidrogenase/metabolismo , Pirazóis/química , Pirazóis/farmacologia , Pirazóis/síntese química , Fungicidas Industriais/farmacologia , Fungicidas Industriais/química , Fungicidas Industriais/síntese química , Relação Estrutura-Atividade , Oximas/química , Oximas/farmacologia , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Proteínas Fúngicas/química , Proteínas Fúngicas/antagonistas & inibidores , Proteínas Fúngicas/metabolismo , Simulação de Acoplamento Molecular , Rhizoctonia/efeitos dos fármacos , Éteres/química , Éteres/farmacologia , Estrutura Molecular
15.
Front Neurol ; 14: 1336348, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38274886

RESUMO

Blepharospasm is a focal dystonia characterized by involuntary tetanic contractions of the orbicularis oculi muscle, which can lead to functional blindness and loss of independent living ability in severe cases. It usually occurs in adults, with a higher incidence rate in women than in men. The etiology and pathogenesis of this disease have not been elucidated to date, but it is traditionally believed to be related to the basal ganglia. Studies have also shown that this is related to the decreased activity of inhibitory neurons in the cerebral cortex caused by environmental factors and genetic predisposition. Increasingly, studies have focused on the imbalance in the regulation of neurotransmitters, including dopamine, serotonin, and acetylcholine, in blepharospasm. The onset of the disease is insidious, and the misdiagnosis rate is high based on history and clinical manifestations. This article reviews the etiology, epidemiological features, and pathogenesis of blepharospasm, to improve understanding of the disease by neurologists and ophthalmologists.

16.
Polymers (Basel) ; 16(1)2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38201711

RESUMO

To achieve exceptional recyclable DC cable insulation material using thermoplastic polypropylene (PP), we have introduced the organic polar molecule styrene-maleic anhydride copolymer (SMA) into PP-based insulation materials following the principles of deep trap modification. PP, PP/SMA, PP/ethylene-octene copolymer (POE), and PP/POE/SMA insulating samples were prepared, and their meso-morphology, crystalline morphology, and molecular structure were comprehensively characterized. The results indicate that SMA can be uniformly dispersed in PP with minimal impact on the crystalline morphology of PP. The DC electrical properties of the materials were tested at temperatures of 30, 50, and 70 °C. The findings demonstrate that the introduction of SMA can improve the DC properties of the material in both PP and PP/POE. The thermal stimulated depolarization current results reveal that SMA can introduce deep traps into the material, thereby improving its DC properties, which is in agreement with the quantum chemical calculation results. Subsequently, a bipolar carrier transport model was employed for coaxial cables to simulate the space charge distribution in the insulation layer of the four sets of insulation samples as well as the actual cable in service. The results highlight that SMA can significantly suppress space charge in PP and PP/POE systems, and it exhibits excellent electric field distortion resistance. In summary, the results illustrate that SMA is expected to be used as an organic deep trap modifier in PP-based cable insulation materials.

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