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1.
J Am Chem Soc ; 146(1): 824-832, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38123470

RESUMO

Glucose and its polyhydroxy saccharide analogs are complex molecules that serve as essential structural components in biomacromolecules, natural products, medicines, and agrochemicals. Within the expansive realm of saccharides, a significant area of research revolves around chemically transforming naturally abundant saccharide units to intricate or uncommon molecules such as oligosaccharides or rare sugars. However, partly due to the presence of multiple hydroxyl groups with similar reactivities and the structural complexities arising from stereochemistry, the transformation of unprotected sugars to the desired target molecules remains challenging. One such formidable challenge lies in the efficient and selective activation and modification of the C-O bonds in saccharides. In this study, we disclose a modular 2-fold "tagging-editing" strategy that allows for direct and selective editing of C-O bonds of saccharides, enabling rapid preparation of valuable molecules such as rare sugars and drug derivatives. The first step, referred to as "tagging", involves catalytic site-selective installation of a photoredox active carboxylic ester group to a specific hydroxyl unit of an unprotected sugar. The second step, namely, "editing", features a C-O bond cleavage to form a carbon radical intermediate that undergoes further transformations such as C-H and C-C bond formations. Our strategy constitutes the most effective and shortest route in direct transformation and modification of medicines and other molecules bearing unprotected sugars.


Assuntos
Carboidratos , Açúcares , Glucose , Oligossacarídeos , Radical Hidroxila
2.
Exp Dermatol ; 32(4): 436-446, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36463492

RESUMO

Hydroquinone (HQ) is one of the most effective drugs to treat hyperpigmentary disorders, but often causes skin irritation in clinic. Mast cell plays an important role in contact dermatitis and triggering pseudo-allergic reactions via MRGPRX2. Whether HQ-induced skin irritant reaction through activating mast cells via MRGPRX2 remains unknown. To investigate the role of mast cells in HQ-induced skin irritant reaction and verify whether MRGPRX2 participated in the HQ effect on mast cells which contributed to the pathogenesis of skin irritant reaction, a mouse model of HQ-induced skin irritation was established to observe the local and systemic inflammation associated with mast cell receptor MrgprB2. Human mast cell LAD2 was used to verify the effect of HQ on mast cells via MRGPRX2 by knocking down with siRNA. As a result, mast cells were involved in the development of HQ-induced irritant reaction, and local inflammation is closely related to mast cell receptor MrgprB2. HQ could activate mast cells via MRGPRX2, causing changes in calcium concentration, degranulation and release of inflammatory cytokines which lead to skin irritant reaction. In conclusion, HQ-induced skin irritant reaction could be skin pseudo-allergic reactions achieved by activating mast cells via MRGPRX2.


Assuntos
Dermatite Atópica , Hipersensibilidade , Animais , Camundongos , Humanos , Mastócitos/patologia , Irritantes/toxicidade , Hidroquinonas/efeitos adversos , Receptores Acoplados a Proteínas G/genética , Inflamação/patologia , Dermatite Atópica/patologia , Degranulação Celular , Proteínas do Tecido Nervoso/genética , Receptores de Neuropeptídeos/genética
3.
J Org Chem ; 88(12): 7641-7650, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35960861

RESUMO

A series of compounds featuring a novel bispiro[indanedione-oxindole-cyclopropane] moiety have been synthesized through a squaramide-catalyzed [2+1] cycloaddition reaction. The tandem Michael-alkylation reaction of 2-arylidene-1,3-indanediones with 3-bromooxindoles furnished the cycloadducts in high yields with excellent diastereo- and enantioselectivities. The ammonium ylide in the catalytic process, as a key intermediate, was revealed by the high-resolution mass spectrometry study.


Assuntos
Reação de Cicloadição , Estereoisomerismo
4.
Org Biomol Chem ; 21(5): 1033-1037, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36625240

RESUMO

A highly efficient metal-free selective 1,4-addition reaction of difluoroenoxysilanes to chromones was developed using the low-cost and readily available HOTf as the catalyst, which is a facile and straightforward method to access valuable C2-difluoroalkylated chroman-4-one derivatives. Interestingly, the products could be readily converted to the difluorinated bioisostere of the natural product (S)-2,6-dimethylchroman-4-one and a difluorinated benzo-seven-membered heterocycle via the Schmidt rearrangement reaction. In addition, the in vitro anti-proliferative activities of these synthesized derivatives against human colon carcinoma cells (HCT116) revealed that compound 3g exhibited potent inhibitory effect on HCT116 cancer cells with an IC50 value of 6.37 µM, representing a novel lead compound for further structural optimization and biological evaluation.


Assuntos
Cromonas , Chumbo , Humanos , Relação Estrutura-Atividade , Cromonas/farmacologia , Cromonas/química , Células HCT116
5.
Europace ; 25(10)2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37712716

RESUMO

AIMS: The clinical correlates and outcomes of asymptomatic atrial fibrillation (AF) in hospitalized patients are largely unknown. We aimed to investigate the clinical correlates and in-hospital outcomes of asymptomatic AF in hospitalized Chinese patients. METHODS AND RESULTS: We conducted a cross-sectional registry study of inpatients with AF enrolled in the Improving Care for Cardiovascular Disease in China-Atrial Fibrillation Project between February 2015 and December 2019. We investigated the clinical characteristics of asymptomatic AF and the association between the clinical correlates and the in-hospital outcomes of asymptomatic AF. Asymptomatic and symptomatic AF were defined according to the European Heart Rhythm Association score. Asymptomatic patients were more commonly males (56.3%) and had more comorbidities such as hypertension (57.4%), diabetes mellitus (18.6%), peripheral artery disease (PAD; 2.3%), coronary artery disease (55.5%), previous history of stroke/transient ischaemic attack (TIA; 17.9%), and myocardial infarction (MI; 5.4%); however, they had less prevalent heart failure (9.6%) or left ventricular ejection fractions ≤40% (7.3%). Asymptomatic patients were more often hospitalized with a non-AF diagnosis as the main diagnosis and were more commonly first diagnosed with AF (23.9%) and long-standing persistent/permanent AF (17.0%). The independent determinants of asymptomatic presentation were male sex, long-standing persistent AF/permanent AF, previous history of stroke/TIA, MI, PAD, and previous treatment with anti-platelet drugs. The incidence of in-hospital clinical events such as all-cause death, ischaemic stroke/TIA, and acute coronary syndrome (ACS) was higher in asymptomatic patients than in symptomatic patients, and asymptomatic clinical status was an independent risk factor for in-hospital all-cause death, ischaemic stroke/TIA, and ACS. CONCLUSION: Asymptomatic AF is common among hospitalized patients with AF. Asymptomatic clinical status is associated with male sex, comorbidities, and a higher risk of in-hospital outcomes. The adoption of effective management strategies for patients with AF should not be solely based on clinical symptoms.


Assuntos
Fibrilação Atrial , Isquemia Encefálica , Doenças Cardiovasculares , Ataque Isquêmico Transitório , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Masculino , Feminino , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/terapia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/terapia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/complicações , Ataque Isquêmico Transitório/epidemiologia , Estudos Transversais , Melhoria de Qualidade , Prognóstico , Fatores de Risco
6.
J Neuroradiol ; 50(5): 492-501, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37142216

RESUMO

PURPOSE: To explore the intrinsic alteration of cerebral 18F-FDG metabolism in acute/subacute seropositive autoimmune encephalitis (AE) and to propose a universal classification model based on 18F-FDG metabolic patterns to predict AE. METHODS: Cerebral 18F-FDG PET images of 42 acute/subacute seropositive AE patients and 45 healthy controls (HCs) were compared using voxelwise and region of interest (ROI)-based schemes. The mean standardized uptake value ratios (SUVRs) of 59 subregions according to a modified Automated Anatomical Labeling (AAL) atlas were compared using a t-test. Subjects were randomly divided into a training set (70%) and a testing set (30%). Logistic regression models were built based on the SUVRs and the models were evaluated by determining their predictive value in the training and testing sets. RESULTS: The 18F-FDG uptake pattern in the AE group was characterized by increased SUVRs in the brainstem, cerebellum, basal ganglia, and temporal lobe, and decreased SUVRs in the occipital, and frontal regions with voxelwise analysis (false discovery rate [FDR] p<0.05). Utilizing ROI-based analysis, we identified 15 subareas that exhibited statistically significant changes in SUVRs among AE patients compared to HC (FDR p<0.05). Further, a logistic regression model incorporating SUVRs from the calcarine cortex, putamen, supramarginal gyrus, cerebelum_10, and hippocampus successfully enhanced the positive predictive value from 0.76 to 0.86 when compared to visual assessments. This model also demonstrated potent predictive ability, with AUC values of 0.94 and 0.91 observed for the training and testing sets, respectively. CONCLUSIONS: During the acute/subacute stages of seropositive AE, alterations in SUVRs appear to be concentrated within physiologically significant regions, ultimately defining the general cerebral metabolic pattern. By incorporating these key regions into a new classification model, we have improved the overall diagnostic efficiency of AE.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Encefalite , Doença de Hashimoto , Humanos , Fluordesoxiglucose F18/metabolismo , Encefalite/diagnóstico por imagem , Doença de Hashimoto/diagnóstico por imagem , Doenças Autoimunes do Sistema Nervoso/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo
7.
J Neuroinflammation ; 19(1): 157, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715809

RESUMO

Multiple sclerosis (MS), as an autoimmune neurological disease with both genetic and environmental contribution, still lacks effective treatment options among progressive patients, highlighting the need to re-evaluate disease innate properties in search for novel therapeutic targets. Fatty acids (FA) and MS bear an interesting intimate connection. FA and FA metabolism are highly associated with autoimmunity, as the diet-derived circulatory and tissue-resident FAs level and composition can modulate immune cells polarization, differentiation and function, suggesting their broad regulatory role as "metabokines". In addition, FAs are indeed protective factors for blood-brain barrier integrity, crucial contributors of central nervous system (CNS) chronic inflammation and progressive degeneration, as well as important materials for remyelination. The remaining area of ambiguity requires further exploration into this arena to validate the existed phenomenon, develop novel therapies, and confirm the safety and efficacy of therapeutic intervention targeting FA metabolism.


Assuntos
Esclerose Múltipla , Remielinização , Sistema Nervoso Central/metabolismo , Ácidos Graxos/metabolismo , Humanos , Inflamação/metabolismo
8.
J Biochem Mol Toxicol ; 36(6): e23039, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35279909

RESUMO

The proinflammatory property of cisplatin is potentially destructive and contributes to the pathogenesis of acute kidney injury (AKI). The role and upstream regulatory mechanism of histone acetyltransferase 1 (HAT1) in acute kidney inflammation are still unknown. We performed RNA sequencing to filter differentially expressed microRNAs (miRNAs) in the kidney tissue of mice with AKI induced by cisplatin and ischemia-reperfusion. Here, we found that miR-486-5p was upregulated and that the expression of HAT1 was reduced in AKI mouse models and injured human renal proximal tubular epithelial cell (HK-2) model induced by cisplatin. miR-486-5p is implicated in cisplatin-induced kidney damage in vivo. Bioinformatics analysis predicted a potential binding site between miR-486-5p and HAT1. The Luciferase reporter assay and Western blot confirmed that miR-486-5p directly targeted the 3'-untranslated region of HAT1 mRNA and inhibited its expression in the cytoplasm of HK-2 cells. In the in vitro study, inhibiting miR-486-5p reduced apoptosis, and the expression of proinflammatory mediators was induced by cisplatin in HK-2 cells. Simultaneously, the downregulation of miR-486-5p inhibited the activation of the toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB). We further found that HAT1 could inhibit apoptosis and the activation of cisplatin on the TLR4/NF-κB pathway and that the upregulation of miR-486-5p reversed this effect. Therefore, the upregulation of miR-486-5p targeting HAT1 promoted the cisplatin-induced apoptosis and acute inflammation response of renal tubular epithelial cells by activating the TLR4/NF-κB pathway, providing a new basis to highlight the potential intervention of regulating the miR-486-5p/HAT1 axis.


Assuntos
Injúria Renal Aguda , MicroRNAs , Regiões 3' não Traduzidas , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Animais , Apoptose , Cisplatino/efeitos adversos , Células Epiteliais/metabolismo , Histona Acetiltransferases/genética , Inflamação/induzido quimicamente , Inflamação/genética , Camundongos , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/genética
9.
Exp Cell Res ; 400(1): 112437, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33385414

RESUMO

Neurotoxicity induced by glutamate (Glu) is often used to study the signaling mechanism of neurological disorders. The identification of specific genetic factors that cause Glu-induced neurotoxicity provides evidence for the common pathways of neuronal apoptosis and inflammation. TRIM27 has been found to induce apoptosis and inflammation. Nevertheless, there is little evidence that TRIM27 is associated with Glu-induced neurotoxicity. We found that TRIM27 expression was increased in epilepsy patients and in HT22 cells following Glu treatment. Glu-mediated cell apoptosis, decreased PPARγ expression, and increased levels of cleaved Caspase-3 and IL-1ß expression in HT22 cells were significantly inhibited by TRIM27 knockdown. TRIM27 overexpression significantly induced cell apoptosis and expression of cleaved Caspase-3 and IL-1ß, but inhibited PPARγ expression in HT22 cells, which were reversed by ROZ, suggesting the involvement of PPARγ in TRIM27-mediated cell apoptosis and inflammation in HT22 cells. Mechanically, TRIM27 ubiquitinates and degrades PPARγ, following induces cleaved Caspase-3 and IL-1ß expression. Clinically, increased expression of TRIM27 in epilepsy patients was associated with decreased PPARγ expression. Taken together, our study suggests that TRIM27-mediated ubiquitination of PPARγ promotes Glu-induced HT22 cell apoptosis and IL-1ß release.


Assuntos
Apoptose , Encéfalo/patologia , Proteínas de Ligação a DNA/metabolismo , Epilepsia/patologia , Ácido Glutâmico/efeitos adversos , Inflamação/patologia , Proteínas Nucleares/metabolismo , PPAR gama/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Estudos de Casos e Controles , Proteínas de Ligação a DNA/genética , Epilepsia/induzido quimicamente , Epilepsia/imunologia , Epilepsia/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/metabolismo , Proteínas Nucleares/genética , PPAR gama/genética , Ubiquitinação
10.
Phytother Res ; 36(5): 2197-2206, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35315143

RESUMO

Luteolin is a flavonoid found in many fruits, vegetables, and herbs. The antiinflammatory effects of luteolin have been reported. In this study, the effect of luteolin on allergic diseases and the underlying molecular mechanism were investigated. We found that luteolin inhibits Fc epsilon RΙ (FcεRΙ)- and Mas-related G protein-coupled receptor X2 (MRGPRX2)-mediated mast cells (MCs) activation, including degranulation and release of cytokines in vitro. Moreover, luteolin reduces the degree of swelling and Evans blue exudation of mice paw in a dose-dependent manner. The concentrations of histamine, TNF-α, MCP-1, IL-8, and IL-13 in mice serum are also decreased by luteolin administration. Our study reveals that luteolin can inhibit FcεRΙ- and MRGPRX2-mediated allergic responses in vivo and in vitro, and our results discover luteolin inhibited mast cells mediated anaphylactic reaction by inhibiting the phosphorylation level of PLCγ.


Assuntos
Anafilaxia , Sinalização do Cálcio , Anafilaxia/tratamento farmacológico , Animais , Cálcio/metabolismo , Degranulação Celular , Linhagem Celular , Luteolina/farmacologia , Mastócitos , Camundongos , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/metabolismo
11.
Epilepsia ; 62(12): 3058-3067, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34595752

RESUMO

OBJECTIVE: Cognitive impairment is common in patients with chronic drug-resistant temporal lobe epilepsy (TLE). Hyperphosphorylated tau (pTau) and amyloid-ß (Aß) plaques, pathological hallmarks of Alzheimer disease, have been hypothesized to play a mechanistic role. We investigated Aß plaques and pTau prevalence in TLE patients who underwent resective surgery and correlated their presence with preoperative psychometric test scores and clinical factors. METHODS: Patients were retrospectively selected from the epilepsy surgery register of the Royal Melbourne Hospital, Australia. Sections from the resected temporal lobe were immunostained for pTau and Aß plaques (antibodies: AT8, 1E8). The presence and severity of pathology were correlated with clinical characteristics, and verbal and visual learning functions as measured by the Verbal Pair Associates (VPA) test and Rey Complex Figure Test. RESULTS: Fifty-six patients (55% female) aged 20-68 years (median = 34 years) at surgery were included. Aß plaques were detected in four patients (7%), all at the moderate level. There was no difference in duration, age at onset of epilepsy, or side of resection between patients with and without Aß plaques. Sparse pTau was found in two patients (3.5%). Both had moderate Aß plaques and were >50 years of age. Patients with Aß plaques had a lower median score for the VPA hard assessment compared to those without (0 vs. 4; p = .02). There was otherwise no correlation between pathology and psychometric test scores. SIGNIFICANCE: Aß plaques and pTau were uncommon in the resected brain tissue of patients who have undergone temporal lobectomy, and did not correlate with clinical characteristics or preoperative psychometric test scores, except for a lower VPA median score in patients with Aß plaques. Therefore, considering the low prevalence of Aß plaques and pTau herein observed, it is unlikely that cognitive impairment in TLE is driven by the same mechanisms as in Alzheimer disease.


Assuntos
Doença de Alzheimer , Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Adulto , Idoso , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Epilepsia Resistente a Medicamentos/epidemiologia , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia do Lobo Temporal/epidemiologia , Epilepsia do Lobo Temporal/patologia , Epilepsia do Lobo Temporal/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Lobo Temporal/patologia , Adulto Jovem , Proteínas tau/metabolismo
12.
BMC Cardiovasc Disord ; 21(1): 109, 2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33622241

RESUMO

BACKGROUND: Observational studies suggest that early menopause is associated with increased risk of death and cardiovascular disease (CVD); however, the results of these studies have been inconsistently. We aimed to assess the association of menopause with death and CVD and whether this association was modified by cardiovascular risk factors. METHODS: The study population was women age 35-64 years living in two communities of Beijing who were enrolled in the Chinese Multi-provincial Cohort Study in 1992. Participants were followed until first cardiovascular event, death, or the end of follow-up (2018). Self-reported age at menopause was recorded. Multivariate Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of death and CVD after adjusting for baseline covariates of age, family history of CVD, and white blood cell count, as well as time-varying covariates of menopause, use of oral estrogen, and conventional risk factors. Additionally, we assessed the combined effect of age at menopause and risk factors on the primary endpoint. RESULTS: Of 2104 eligible women, 124 died and 196 had a first CVD event (33 fatal CVD and 163 non-fatal CVD). Compared with women who experienced menopause at age 50-51 years, the risk of death was higher in women with menopause at age 45-49 years (HR 1.99, 95% CI 1.24-3.21; P = 0.005), and the risk of ischemic stroke was higher in women with menopause at age < 45 years (HR 2.16, 95% CI 1.04-4.51; P = 0.04) and at age 45-49 years (HR 2.05, 95% CI 1.15-3.63; P = 0.01). Women who had menopause before age 50 years and at least one elevated risk factor at baseline had a higher risk of death (HR 11.10, 95% CI 1.51-81.41; P = 0.02), CVD (HR 3.98, 95% CI 1.58-10.01; P = 0.003), ischemic CVD (HR 4.53, 95% CI 1.63-12.62; P = 0.004), coronary heart disease (HR 8.63, 95% CI 1.15-64.50; P = 0.04), and stroke (HR 2.92, 95% CI 1.03-8.29; P = 0.04) than those with menopause at age 50-51 years and optimal levels of all risk factors. CONCLUSIONS: Earlier menopause may predict death and ischemic stroke. Furthermore, there is a combined effect of earlier menopause and elevated risk factors on death and CVD.


Assuntos
Doenças Cardiovasculares/epidemiologia , Menopausa , Adulto , Fatores Etários , Pequim/epidemiologia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/mortalidade , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Incidência , AVC Isquêmico/diagnóstico , AVC Isquêmico/epidemiologia , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores Sexuais , Fatores de Tempo
13.
Pharmacopsychiatry ; 54(3): 131-141, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33634460

RESUMO

BACKGROUND: Metabolism disturbances are common in patients with depression. The drug metformin has been reported to exhibit antidepressant activity. The purpose of this study was to investigate metabolism disturbances induced by corticosterone (CORT) and determine if metformin can reverse these effects and their accompanying depression-like behaviors. METHODS: Rats were exposed to corticosterone with or without metformin administration. Depression-like behaviors were tested. Gene expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis. In addition, the metabolites were quantified by LC-MS/MS analysis. RESULTS: Metformin attenuated the depression-like behaviors induced by CORT. Furthermore, metformin reversed disturbances in body weight, serum glucose, and triglyceride levels, as well as hepatic TG levels induced by CORT. Metformin normalized the alterations in the expression of glucose metabolism-related genes (PGC-1α, G6pc, Pepck, Gck, PYGL, Gys2, PKLR, GLUT4) and insulin resistance-related genes (AdipoR1, AdipoR2) in the muscles and livers of rats induced by CORT. Metabolomic analysis showed that metformin reversed the effects of CORT on 11 metabolites involved in the pathways of the tricarboxylic acid cycle, glycolysis, and gluconeogenesis (3-phospho-D-glycerate, ß-D-fructose 6-phosphate, D-glucose 6-phosphate, and pyruvate). CONCLUSION: Our findings suggest that metformin can attenuate metabolism disturbances and depression-like behaviors induced by CORT mediating the glucose metabolism pathway.


Assuntos
Corticosterona , Metformina , Animais , Cromatografia Líquida , Depressão/induzido quimicamente , Depressão/tratamento farmacológico , Glucose , Humanos , Metformina/farmacologia , Ratos , Espectrometria de Massas em Tandem
14.
Chem Soc Rev ; 49(24): 9154-9196, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33140778

RESUMO

Recent years have witnessed an upsurge in the development of non-precious catalysts (NPCs) for alkaline water electrolysis (AWE), especially with the strides made in experimental and computational techniques. In this contribution, the most recent advances in NPCs for AWE were systematically reviewed, emphasizing the application of in situ/operando experimental methods and density functional theory (DFT) calculations in their understanding and development. First, we briefly introduced the fundamentals of the anode and cathode reaction for AWE, i.e., the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), respectively. Next, the most popular in situ/operando approaches for characterizing AWE catalysts, including hard and soft XAS, ambient-pressure XPS, liquid and identical location TEM, electrochemical mass spectrometry, and Raman spectroscopy were thoroughly summarized. Subsequently, we carefully discussed the principles, computational methods, applications, and combinations of DFT with machine learning for modeling NPCs and predicting the alkaline OER and HER. With the improved understanding of the structure-property-performance relationship of NPCs for AWE, we proceeded to overview their current development, summarising state-of-the-art design strategies to boost their activity. In addition, advances in various extensively investigated NPCs for AWE were evaluated. By conveying these methods, progress, insights, and perspectives, this review will contribute to a better understanding and rational development of non-precious AWE electrocatalysts for hydrogen production.

15.
Women Health ; 61(9): 902-913, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34693883

RESUMO

The purpose of the study was to investigate whether premenopausal body mass index (BMI) and waist circumference (WC) influence age at menopause. A total of 2116 women aged 35-64 years from two communities of the CMCS Beijing cohort were recruited in 1992 and followed up to 2018. Of 1439 premenopausal women at baseline, 6 women data were missing. Finally, 1433 women were included for analysis. Overweight was defined as BMI 24-27.99 kg/m2. Central obesity was defined as WC ≥80 cm. Age at menopause was categorized as <45 years, 45-49 years, 50-51 years (reference), and >51 years. Multinomial logistic regression models were used to estimate relative odds ratios (RORs) and 95% confidence intervals (CIs). Compared to women with normal weight and normal WC, overweight women with normal WC had higher risk of menopause at >51 years (ROR 1.64, 95% CI 1.10-2.45; P = .01); and overweight women with central obesity had higher risk of menopause at not only >51 years (ROR 1.82, 95% CI 1.13-2.93; P = .01) but also <45 years (ROR 3.13, 95% CI 1.20-8.43; P = .02) and 45-49 years (ROR 2.76, 95% CI 1.71-4.46; P < .001). When overweight women combine with central obesity, the risk of early menopause will increase in some of them.


Assuntos
Menopausa , Índice de Massa Corporal , China/epidemiologia , Estudos de Coortes , Feminino , Humanos , Fatores de Risco , Circunferência da Cintura
16.
Molecules ; 25(4)2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32102412

RESUMO

We propose a flexible, binder-free and free-standing carbonaceous paper fabricated via electrostatic spray deposition using reduced graphene oxide/carbon nanotube (rGO/CNT) as a promising electrode material for flexible sodium-ion batteries (NIBs). The as-prepared rGO/CNT paper exhibits a three-dimensional (3D) layered structure by employing rGO as conductive frameworks to provide sodium-storage active sites and CNT as spacer to increase rGO interlayer distance and benefit the diffusion kinetics of sodium ions. Consequently, the rGO/CNT paper delivers an enhanced sodium ion storage capacity of 166.8 mAh g-1 at 50 mA g-1, retaining an average capacity of 101.4 mAh g-1 when current density sets back 100 mA g-1 after cycling at various current rates. An average capacity of 50 mAh g-1 at 200 mA g-1 was stabilized when cycling up to 300 cycles. The well-maintained electrochemical performance of free-standing rGO/CNT paper is due to the well-established hybrid 3D nanostructures, which demonstrates our carbon based material fabricated by a facile approach can be applied as one of the high-performance and low-cost electrode materials for applications in flexible energy storage devices.


Assuntos
Fontes de Energia Elétrica , Elétrons , Grafite/química , Nanotubos de Carbono/química , Sódio/química , Cátions Monovalentes , Eletricidade , Técnicas Eletroquímicas , Eletrodos , Humanos , Papel
17.
Zhonghua Nan Ke Xue ; 26(3): 210-214, 2020 Mar.
Artigo em Zh | MEDLINE | ID: mdl-33346958

RESUMO

The outbreak of coronavirus disease 2019 (COVID-19) caused by 2019 novel coronavirus has become a global public health challenge. In addition to the typical respiratory symptoms, COVID-19 can induce damage to testicular spermatogenesis. This study focuses on the possible causes and follow-up monitoring of testicular injury induced by COVID-19.


Assuntos
COVID-19/complicações , Espermatogênese , Testículo/fisiopatologia , Causalidade , Surtos de Doenças , Seguimentos , Humanos , Masculino , Testículo/virologia
18.
Zhonghua Nan Ke Xue ; 26(2): 111-117, 2020 Feb.
Artigo em Zh | MEDLINE | ID: mdl-33346412

RESUMO

OBJECTIVE: To study the effect of different levels of autophagy in the testis on the apoptosis of spermatogenic cells in the rat model of varicocele (VC). METHODS: We randomly divided 54 SD male rats into six groups, blank control (n = 6), rapamycin control (n = 6), chloroquine control (n = 6), VC model control (n = 12), VC + rapamycin (n = 12), and VC + chloroquine (n = 12). We observed the histomorphological changes of the testis and epididymis by HE staining, obtained the scores on spermatogenesis in the testis and epididymis, calculated the apoptosis index (AI) of the testicular spermatogenic cells by TUNEL, and determined the expressions of LC3-Ⅱ, LC3-Ⅰ, p62, Bax and Bcl-2 proteins in the testis tissue by Western blot. RESULTS: There were no significant morphological changes in the testis and epididymis of the rats in the blank control, rapamycin control and chloroquine control groups, or significant differences in the scores on testicular and epididymal spermatogenesis and AI of the testicular spermatogenic cells (P>0.05). The animals in the VC model control group exhibited significant pathological damage in the testicular and epididymal tissues, with remarkably decreased scores on spermatogenesis (P<0.01) and increased AI (P<0.01), which were markedly improved in the VC + rapamycin group and slightly aggravated in the VC + chloroquine group compared with the VC model controls. In comparison with the rats in the blank control group, those in the VC model control group showed significantly up-regulated expressions of the autophagy-related protein LC3 (including the LC3-Ⅱ/LC3-Ⅰ ratio) and the pro-apoptotic protein Bax in testicular tissue (P<0.01) but down-regulated expression of the anti-apoptotic protein Bcl-2 (P<0.01). The expressions of LC3 and Bcl-2 in the testis tissue were significantly higher in the VC + rapamycin (P<0.01) but lower in the VC + chloroquine group (P<0.01), while those of p62 and Bax remarkably lower in the VC + rapamycin (P<0.01) but higher in the VC + chloroquine group than in the VC model controls (P<0.01). CONCLUSIONS: Varicocele induces autophagy in the testis and apoptosis of spermatogenic cells in rats. Up-regulating autophagy can inhibit while blocking autophagy can promote the apoptosis of spermatogenic cells.


Assuntos
Autofagia , Células Germinativas/citologia , Espermatogênese , Testículo/citologia , Varicocele/fisiopatologia , Animais , Apoptose , Masculino , Ratos , Ratos Sprague-Dawley , Testículo/efeitos dos fármacos
20.
Int J Syst Evol Microbiol ; 69(12): 3885-3890, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31490112

RESUMO

A Gram-stain-negative, aerobic, non-motile, rod-shaped, cold-tolerant bacterium, designated F01003T, was isolated from soil sampled near Happiness Bay on the west coast of Antarctica. Strain F01003T was found to grow at 4-30 °C (optimum, 25 °C), pH 5.5-8.0 (pH 6.5-7.0) and in the presence of 0-1 % NaCl (0 %, w/v). Cells were oxidase-positive and catalase-positive. Strain F01003T contained menaquinone 7 (MK-7) as the predominant respiratory quinone. The main cellular fatty acids included summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and iso-C15 : 0. Phosphatidylethanolamine and an unidentified aminolipid were identified as the major polar lipids. The DNA G+C content of strain F01003T was 44.8 mol%. Phylogenetic analysis of the nearly full-length 16S rRNA gene sequence revealed that strain F01003T was most closely related to the genus Mucilaginibacter and exhibited the highest sequence similarity to Mucilaginibacter phyllosphaerae LMG 29118T (97.3 %). On the basis of the evidence presented in this polyphasic taxonomic study, strain F01003T is considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibactergilvus sp. nov. is proposed. The type strain is F01003T (=KCTC 62991T=CCTCC AB 2019023T).


Assuntos
Bacteroidetes/classificação , Filogenia , Microbiologia do Solo , Regiões Antárticas , Técnicas de Tipagem Bacteriana , Bacteroidetes/isolamento & purificação , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfatidiletanolaminas/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
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