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1.
Diabetes Obes Metab ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39295089

RESUMO

AIMS: To determine if estimated glucose disposal rate (eGDR) can predict cardiovascular disease mortality risk at different levels of glycaemic tolerance. MATERIALS AND METHODS: The eGDR levels of 11 656 individuals aged 45-79 years from the National Health and Nutrition Examination Survey cycles 1999 to 2010 were analysed. Associations between eGDR levels and all-cause and cardiovascular mortality were examined using Cox proportional hazards and Fine and Gray models, respectively. RESULTS: After a median follow-up of 12.8 years, a total of 2852 participants died, with 777 of those deaths attributed to cardiovascular causes. When comparing participants with eGDR values of ≤4 mg/kg/min to those with eGDR values falling within the ranges of 4-6, 6-8 and >8 mg/kg/min, it was found that the latter groups exhibited lower hazard ratios for both all-cause mortality (0.61 [0.52-0.72], 0.61 [0.52-0.72] and 0.46 [0.39-0.55]) and cardiovascular mortality (0.44 [0.33-0.57], 0.45 [0.34-0.59] and 0.30 [0.23-0.40]). A U-shaped relationship between eGDR and all-cause mortality was observed, with an inflection point at an eGDR of 9.54 mg/kg/min. CONCLUSIONS: In the general population, the association between reduced eGDR and all-cause and cardiovascular mortality was independently significant, contributing to the identification of individuals at high risk for different levels of glucose tolerances.

2.
J Environ Sci (China) ; 123: 235-254, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36521987

RESUMO

Abrupt air pollution accidents can endanger people's health and destroy the local ecological environment. The appropriate emergency response can minimize the harmful effects of accidents and protect people's lives and property. This paper provides an overview of the key emergency response technologies for abrupt air pollution accidents around the globe with emphasis on the major achievements that China has obtained in recent years. With decades of effort, China has made significant progress in emergency monitoring technologies and equipment, source estimation technologies, pollutant dispersion simulation technologies and others. Many effective domestic emergency monitoring instruments (e.g., portable DOAS/FT-IR systems, portable FID/PID systems, portable GC-MS systems, scanning imaging remote sensing systems, and emergency monitoring vehicles) had been developed which can meet the demands for routine emergency response activities. A monitoring layout technique combining air dispersion simulation, fuzzy comprehensive evaluation, and a post-optimality analysis was proposed to identify the optimal monitoring layout scheme under the constraints of limited monitoring resources. Multiple source estimation technologies, including the forward method and the inversion method, have been established and evaluated under various scenarios. Multi-scale dynamic pollution dispersion simulation systems with high temporal and spatial resolution were further developed. A comprehensive emergency response platform integrating database support, source estimation, monitoring schemes, fast monitoring of pollutants, pollution predictions and risk assessment was developed based on the technical idea of "source identification - model simulation - environmental monitoring" dynamic interactive feedback. It is expected that the emergency response capability for abrupt air pollution accidents will gradually improve in China.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Ambientais , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Acidentes , China , Poluentes Atmosféricos/análise
3.
Angew Chem Int Ed Engl ; 62(6): e202217045, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36517419

RESUMO

Chiral boron/nitrogen doped multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters are promising for highly efficient and color-pure circularly polarized organic light-emitting diodes (CP-OLEDs). Herein, we report two pairs of MR-TADF materials (Czp-tBuCzB, Czp-POAB) based on planar chiral paracyclophane with photoluminescence quantum yields of up to 98 %. The enantiomers showed symmetric circularly polarized photoluminescence spectra with dissymmetry factors |gPL | of up to 1.6×10-3 in doped films. Meanwhile, the sky-blue CP-OLEDs with (R/S)-Czp-tBuCzB showed an external quantum efficiency of 32.1 % with the narrowest full-width at half-maximum of 24 nm among the reported CP-OLEDs, while the devices with (R/S)-Czp-POAB displayed the first nearly pure green CP electroluminescence with |gEL | factors at the 10-3 level. These results demonstrate the incorporation of planar chirality into MR-TADF emitter is a reliable strategy for constructing of efficient CP-OLEDs.

4.
J Viral Hepat ; 29(10): 890-898, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35793410

RESUMO

Acute-on-chronic liver failure (ACLF) is a severe clinical syndrome associated with high short-term mortality and reversibility. This study aimed to compare the characteristics of survival and reversibility in hepatitis B virus (HBV)-related ACLF (HBV-ACLF) patients with and without previous decompensation. Overall, 1044 patients who fulfilled the acute hepatic insult criteria of the APASL-ACLF Research Consortium (AARC) definition were enrolled from a prospectively established cohort of HBV-related liver failure patients. These patients were divided into the AARC ACLF group and the non-AARC ACLF group according to prior decompensation. Mortality, reversibility of ACLF syndrome, and predicted factors associated with reversibility were evaluated. Liver transplantation-free mortality of the AARC ACLF group was significantly lower than that of the non-AARC ACLF group (28 days: 28.2% vs. 40.3%, p = .012; 90 days: 41.7% vs. 65.4%, p < .001). The 5-year cumulative reversal rates of ACLF syndrome were 88.0% (374/425) and 66.0% (31/47) in the AARC and non-AARC ACLF groups, respectively, (p = .039). Following reversibility of ACLF syndrome, 340/374 (90.9%) and 21/31 (67.7%) patients in the AARC and non-AARC ACLF groups, respectively, maintained a stable status within 5 years. Although prior decompensation indicated poor reversibility of ACLF syndrome, HBV-infected patients with prior decompensation who fulfilled the acute hepatic insult criteria of the AARC definition showed favourable reversibility and maintained a stable status after receiving nucleoside analogues. The AARC ACLF definition identified HBV-ACLF as a distinct syndrome with good reversibility. HBV-infected patients with prior decompensation could be included in the AARC ACLF management.


Assuntos
Insuficiência Hepática Crônica Agudizada , Transplante de Fígado , Estudos de Coortes , Vírus da Hepatite B , Humanos , Prognóstico
5.
Mol Biol Rep ; 49(9): 8715-8725, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35781603

RESUMO

BACKGROUND: Presently, liver transplantation is the only treatment strategy for liver failure (LF). Although granulocyte-colony stimulating factor (G-CSF) exhibits protective functions in LF, it is not clear whether it directly affects the liver cells. METHODS AND RESULTS: We established an injured liver cell model and observed that G-CSF treatment promoted cell viability and enhanced Ki67 and VEGF-A expression. Thereafter, human umbilical vein endothelial cells (HUVECs) were cultured in a conditioned medium collected from the G-CSF-treated injured liver cells. HUVECs' proliferation and tubule formation were promoted. Furthermore, in an injured liver mouse model, confirmed via haematoxylin-eosin staining, we evaluated serum alanine aminotransferase activity, Ki67 expression, and microvessel density (MVD). G-CSF treatment significantly relieved liver injury, upregulated Ki67 expression, and enhanced MVD in the injured mouse liver tissue. Additionally, AKT and ERK signal targets were explored, and it was demonstrated that the effects of G-CSF on injured liver cells were mediated through the AKT and ERK signalling pathways. CONCLUSIONS: G-CSF promotes injured liver viability and angiogenesis by directly affecting injured liver cells via the AKT and ERK signalling pathways. These findings improve our understanding of the role of G-CSF in recovery from LF.


Assuntos
Fator Estimulador de Colônias de Granulócitos , Proteínas Proto-Oncogênicas c-akt , Animais , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Antígeno Ki-67 , Fígado/metabolismo , Camundongos , Neovascularização Patológica/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo
6.
Angew Chem Int Ed Engl ; 61(45): e202209438, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36102181

RESUMO

Herein, we report the structures of chiral-at-cage carborane derivatives bearing carbazole chromophores that emit circularly polarized luminescence (CPL) and aggregation-induced electrochemiluminescence (AIECL). By adjusting the substituent positions on the carborane derivatives, two chiral luminescent molecules, Cb1 and Cb2, with different properties were obtained. The photoluminescence dissymmetry factors |gPL | of both (R/S)-Cb1 and (R/S)-Cb2 enantiomers in neat films were as high as 6.24×10-3 and 7.38×10-3 , respectively. Cb1 showed a deep blue emission peak at 434 nm in n-pentane. Interestingly, distinct fluorescence and CPL spectra were observed in solvents of different polarities due to the twisted intramolecular charge transfer effect, suggesting its potential use in solvent recognition. Meanwhile, Cb2 exhibited good AIECL property, excellent ECL stability and could be used for determining dopamine concentrations, suggesting its potential applications in biology and diagnosis.


Assuntos
Luminescência , Medições Luminescentes , Estereoisomerismo
7.
J Mol Cell Cardiol ; 159: 120-129, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34175302

RESUMO

Cardiac hypertrophy is an adaptive response of the heart to increased workload induced by various physiological or pathological stimuli. It is a common pathological process in multiple cardiovascular diseases, and it ultimately leads to heart failure. The development of cardiac hypertrophy is accompanied by gene expression reprogramming, a process that is largely dependent on epigenetic regulation. Histone modifications such as methylation and acetylation are dynamically regulated under cardiac stress. These consequently contribute to the pathogenesis of cardiac hypertrophy via compensatory or maladaptive transcriptome reprogramming. Histone methylation and acetylation modifiers play crucial roles in epigenetic remodeling during the pathogenesis of cardiac hypertrophy. Regulation of histone methylation and acetylation modifiers serves as a bridge between signal transduction and downstream gene reprogramming. Exploring the role of histone modifiers in cardiac hypertrophy provides novel therapeutic strategies to treat cardiac hypertrophy and heart failure. In this review, we summarize the recent advancements in functional histone methylation and acetylation modifiers in cardiac hypertrophy, with an emphasis on the underlying mechanisms and the therapeutic potential.


Assuntos
Cardiomegalia/metabolismo , Metilação de DNA/fisiologia , Histonas/metabolismo , Acetilação , Animais , Humanos , Transdução de Sinais/fisiologia
8.
J Nutr ; 151(8): 2175-2187, 2021 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-33979839

RESUMO

BACKGROUND: Dynamic orchestration of metabolic pathways during continuous fasting remains unclear. OBJECTIVE: We investigated the physiological effects of Bigu-style fasting and underlying metabolic reprogramming in healthy adults. METHODS: We conducted a 5-d Bigu trial in 43 healthy subjects [age 23.2 ± 2.4 y; BMI (in kg/m2) 22.52 ± 1.79]. Physiological indicators and body composition were monitored daily during fasting day 1 (F1D) to F5D and after 10-d refeeding postfasting (R10D) and R30D. Blood samples were collected in the morning. Risk factors associated with inflammation, aging, cardiovascular diseases, malnutrition, and organ dysfunction were evaluated by biochemical measurements. Untargeted plasma metabolomics and gut microbial profiling were performed using plasma and fecal samples. Data were analyzed by repeated measures ANOVA with Greenhouse-Geisser correction. Correlation analyses for metabolite modules and taurine were analyzed by Spearman's rank and Pearson tests, respectively. RESULTS: Heart rate was accelerated throughout the fasting period. Risk factors associated with inflammation and cardiovascular diseases were significantly lowered during or after Bigu (P < 0.05). Body composition measurement detected an overconsumption of fat starting from F3D till 1 mo after refeeding. Metabolomics unveiled a coupling between gluconeogenesis and cholesterol biosynthesis beyond F3D. Plasma taurine significantly increased at F3D by 31%-46% followed by a reduction to basal level at F5D (P < 0.001), a pattern inversely correlated with changes in glucose and de novo synthesized cholesterol (r = -0.407 and -0.296, respectively; P < 0.001). Gut microbial profiling showed an enrichment of taurine-utilizing bacteria at F5D, which was completely recovered at R10D. CONCLUSIONS: Our data demonstrate that 5-d Bigu is potentially beneficial to health in young adults. A starvation threshold of 3-d fasting is necessary for maintaining glucose and cholesterol homeostasis via a taurine-microbiota regulatory loop. Our findings provide novel insights into the physiological and metabolic responses of the human body to continuous Bigu-style fasting. This trial was registered at http://www.chictr.org.cn as ChiCTR1900022917.


Assuntos
Jejum , Glucose , Adulto , Homeostase , Humanos , Metabolismo dos Lipídeos , Taurina , Adulto Jovem
9.
Hepatology ; 69(6): 2471-2488, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30748020

RESUMO

Nonalcoholic fatty liver disease (NAFLD) has become a worldwide epidemic. A large and growing unmet therapeutic need has inspired numerous studies in the field. Integrating the published genomic data available in the Gene Expression Omnibus (GEO) with NAFLD samples from rodents, we discovered that interferon regulatory factor 6 (IRF6) is significantly downregulated in high-fat diet (HFD)-induced fatty liver. In the current study, we identified IRF6 in hepatocytes as a protective factor in liver steatosis (LS). During HFD challenge, hepatic Irf6 was suppressed by promoter hypermethylation. Severity of HFD-induced LS was exacerbated in hepatocyte-specific Irf6 knockout mice, whereas hepatocyte-specific transgenic mice overexpressing Irf6 (IRF6-HTG) exhibited alleviated steatosis and metabolic disorder in response to HFD feeding. Mechanistic studies in vitro demonstrated that hepatocyte IRF6 directly binds to the promoter of the peroxisome proliferator-activated receptor γ (PPARγ) gene and subsequently halts the transcription of Pparγ and its target genes (e.g., genes that regulate lipogenesis and lipid acid uptake) under physiological conditions. Conclusion: Irf6 is downregulated by promoter hypermethylation upon metabolic stimulus exposure, which fail to inhibit Pparγ and its targets, driving abnormalities of lipid metabolism.


Assuntos
Regulação da Expressão Gênica , Fatores Reguladores de Interferon/genética , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , PPAR gama/genética , Animais , Metilação de DNA/genética , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Regulação para Baixo , Hepatócitos/citologia , Humanos , Fatores Reguladores de Interferon/metabolismo , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Distribuição Aleatória , Sensibilidade e Especificidade
10.
BMC Gastroenterol ; 20(1): 320, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993547

RESUMO

BACKGROUND: Infection is common in acute-on-chronic liver failure (ACLF), which may worsen the clinical condition and prognosis. However, the characteristics of infection and its influence on prognosis in hepatitis B virus related ACLF (HBV-ACLF) as defined by the European Association for the Study of the Liver (EASL) have not been clarified. We aimed to investigate the characteristics of infection and its influence on mortality in patients with HBV-ACLF defined by EASL in China. METHODS: We performed a retrospective cohort study in patients with HBV-ACLF defined by EASL in a single center from January 2015 to December 2017. These patients were divided into two groups with and without infection. The incidence, sites of infection, isolated strains, and risk factors associated with mortality were evaluated. RESULTS: A total of 289 patients were included, among them 185 (64.0%) were diagnosed with an infection. The most common type of infection was pneumonia (55.7%), followed by spontaneous bacterial peritonitis (47.6%) and others. The gram-negative bacteria were the most frequent (58.3%). Patients with one, two, and three or more infection sites had a gradually increasing incidence of sepsis (P < 0.01), septic shock (P < 0.001), and ACLF-3 (P < 0.05). Also, patients with infection isolated one, two, and three or more strains showed a growing incidence of sepsis (P < 0.01) and septic shock (P < 0.001). Patients with infection showed a significantly higher 28-day mortality than those without (P < 0.01), especially in patients with ACLF-3. Infection was identified as an independent risk factor for 28-day mortality in all HBV-ACLF patients. Pneumonia and sepsis were identified as independent predictors of 28-day mortality for patients with infection. CONCLUSIONS: Infection is associated with severe clinical course and high mortality in HBV-ACLF defined by EASL. The increased number of infection sites or isolated strains was associated with the occurrence of sepsis and septic shock. Pneumonia and sepsis were independent predictors for mortality in HBV-ACLF patients with infection.


Assuntos
Insuficiência Hepática Crônica Agudizada , Hepatite B , Insuficiência Hepática Crônica Agudizada/epidemiologia , China/epidemiologia , Hepatite B/complicações , Hepatite B/epidemiologia , Vírus da Hepatite B , Humanos , Prognóstico , Estudos Retrospectivos
11.
Clin Sci (Lond) ; 132(11): 1199-1213, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29695588

RESUMO

Mindin, which is a highly conserved extracellular matrix protein, has been documented to play pivotal roles in regulating angiogenesis, inflammatory processes, and immune responses. The aim of the present study was to assess whether mindin contributes to the development of atherosclerosis. A significant up-regulation of Mindin expression was observed in the serum, arteries and atheromatous plaques of ApoE-/- mice after high-fat diet treatment. Mindin-/-ApoE-/- mice and macrophage-specific mindin overexpression in ApoE-/- mice (Lyz2-mindin-TG) were generated to evaluate the effect of mindin on the development of atherosclerosis. The Mindin-/-ApoE-/- mice exhibited significantly ameliorated atherosclerotic burdens in the entire aorta and aortic root and increased atherosclerotic plaque stability. Moreover, bone marrow transplantation further demonstrated that mindin deficiency in macrophages was largely responsible for the alleviated atherogenesis. The Lyz2-mindin-TG mice exhibited the opposite phenotype. Mindin deficiency enhanced foam cell formation by increasing the expression of cholesterol effectors, including ABCA1 and ABCG1. The mechanistic study indicated that mindin ablation promoted LXR-ß expression via a direct interaction. Importantly, LXR-ß inhibition largely reversed the ameliorating effect of mindin deficiency on foam cell formation and ABCA1 and ABCG1 expression. The present study demonstrated that mindin deficiency serves as a novel mediator that protects against foam cell formation and atherosclerosis by directly interacting with LXR-ß.


Assuntos
Aterosclerose/prevenção & controle , Proteínas da Matriz Extracelular/deficiência , Receptores X do Fígado/metabolismo , Macrófagos/metabolismo , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Aterosclerose/metabolismo , Aterosclerose/patologia , Transplante de Medula Óssea , Dieta Hiperlipídica , Proteínas da Matriz Extracelular/biossíntese , Proteínas da Matriz Extracelular/fisiologia , Células Espumosas/patologia , Hiperlipidemias/metabolismo , Mediadores da Inflamação/metabolismo , Receptores X do Fígado/antagonistas & inibidores , Macrófagos/patologia , Masculino , Camundongos Knockout para ApoE , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Regulação para Cima/fisiologia
12.
Molecules ; 23(7)2018 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-29933637

RESUMO

This study evaluated the protective effect of proanthocyanidins (PCs) on reducing apoptosis in the mouse intestinal epithelial cell model MODE-K exposed to zearalenone (ZEA) through inhibition of the endoplasmic reticulum stress (ERS)-induced apoptosis pathway. Our results showed that PCs could reduce the rate of apoptosis in MODE-K cells exposed to ZEA (p < 0.01). PCs significantly increased the ZEA-induced antioxidant protective effects on the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and on the content of GSH. PCs also significantly decreased the ZEA-induced increase in the content of malondialdehyde (MDA). The analysis indicated that ZEA increased both mRNA and protein expression levels of C/EBP homologous protein (CHOP), GRP78, c-Jun N-terminal kinase (JNK), and cysteinyl aspartate specific proteinase 12 (caspase-12) (p < 0.05), which are related to the ERS-induced apoptosis pathway. ZEA decreased levels of the pro-apoptotic related protein Bcl-2 (p < 0.05) and increased the anti-apoptotic related protein Bax (p < 0.05). Co-treatment with PCs was also shown to significantly reverse the expression levels of these proteins in MODE-K cells. The results demonstrated that PCs could protect MODE-K cells from oxidative stress and apoptosis induced by ZEA. The underlying mechanism may be that PCs can alleviate apoptosis in mouse intestinal epithelial cells by inhibition of the ERS-induced apoptosis pathway.


Assuntos
Antioxidantes/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Estrogênios não Esteroides/antagonistas & inibidores , Proantocianidinas/farmacologia , Zearalenona/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Caspase 12/genética , Caspase 12/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Estrogênios não Esteroides/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/agonistas , Glutationa/antagonistas & inibidores , Glutationa/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Intestino Delgado/citologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Malondialdeído/agonistas , Malondialdeído/antagonistas & inibidores , Malondialdeído/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , Zearalenona/farmacologia , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
14.
J Org Chem ; 81(8): 3103-11, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26980724

RESUMO

An efficient synthesis of Z-perfluoroalkyl-substituted enones by a multicomponent reaction strategy has been described. A variety of elusive perfluoroalkylated enones are furnished under mild reaction conditions in good yields with unique chemo- and stereoselectivity. A sequence of radical-mediated Kornblum-DeLaMare reaction, Michael addition, and HF elimination is proposed for the mechanism.

15.
Org Biomol Chem ; 14(36): 8486-92, 2016 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-27539888

RESUMO

A novel Bu4NI-catalyzed pyrazole formation reaction is well described via sequential [3 + 2] cycloaddition and oxidative dehydrogenation reactions using TBHP as the primary oxidant. In comparison with previous cases toward pyrazoles from alkenes and diazo compounds, alkenes without a pre-organized leaving group were applied in this transformation. In addition, this methodology was distinguished by its broad substrate scope, commercially available inexpensive starting materials, high atom economy and operational simplicity.

16.
BMC Microbiol ; 15: 6, 2015 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-25648185

RESUMO

BACKGROUND: Haemophilus influenzae is one of the main pathogens that cause community-acquired respiratory infections in children. Our previous study showed that H. influenzae is the second most common pathogen causing pneumonia and accounts for 30-50% of bacterial meningitis among Chinese children. H. influenzae carriage in children and its resistance to commonly used antimicrobials varies widely both geographically and over time. RESULTS: Surveys of the nasopharyngeal carriage of H. influenzae in children younger than 5 years of age with acute respiratory tract infection (ARI) were conducted in Beijing Children's Hospital, China in 2000, 2002, 2010, and 2012. The overall annual carriage rates of H. influenzae among children younger than 5 years of age with ARI were 35.5%, 20.6%, 14.4%, and 18.7%, and the percentages of H. influenzae isolates producing ß-lactamase were 4%, 13%, 27.1%, and 31%, respectively. The percentages of susceptibility to ampicillin progressively decreased from 96% (2000) to 87% (2002) to 63% (2010) to 61% (2012). All of the ampicillin-resistant isolates were found to be beta-lactamase producers. The susceptibility to tetracycline increased from 54% (2000) to 60% (2002) to 91.5% (2010) to 94.5% (2012). No statistically significant differences were observed in the susceptibility to cefaclor, cefuroxime, sulfamethoxazole, and chloramphenicol. Amoxicillin/clavulanic acid and ceftriaxone were the most effective antimicrobials for the isolates of H. influenzae across the 10-year period. CONCLUSIONS: This report on the H. influenzae carriage rates in children and the susceptibility of these bacteria to commonly used antibiotics showed that H. influenzae carriage decreased from 2000 to 2012. Additionally, the percentage of ß-lactamase-producing isolates increased while their susceptibility to ampicillin progressively decreased during this time. These results indicate that the appropriate empirical antimicrobial therapy should be changed for pediatric patients in China.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/epidemiologia , Infecções por Haemophilus/epidemiologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/isolamento & purificação , Nasofaringe/microbiologia , Pequim/epidemiologia , Portador Sadio/microbiologia , Pré-Escolar , Feminino , Infecções por Haemophilus/microbiologia , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Prevalência , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Inquéritos e Questionários
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3214-9, 2015 Nov.
Artigo em Zh | MEDLINE | ID: mdl-26978939

RESUMO

The four kinds of the structure characteristics of rotary type interferometer are mainly analyzed from the classical Michelson interferometer structure in the paper. The Optical path difference between the interferometer and the rotation angle is also analyzed. By setting parameters, the four kinds of rotary type optical path difference of the interferometer are simulated based on the optical path difference formula. The rotation velcocity of the four kinds of interferometers is also simulated. By simulation and contrast of the optical path difference, the relationship is intuitively reflect by figure between the optical path difference and the rotation angle. The scope of the rotation angle is discussed within 3% of the velocity errors. It is the very good reference significance to study the structure and properties of the interferometer by analyzing and simulating the optical path difference discussed in the paper.

18.
J Environ Sci (China) ; 26(5): 1001-13, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25079630

RESUMO

To understand the further impacts of multiple stressors in freshwater, we investigated the effects of heavy metal (HM, Cu and Zn) and nutrient enrichments (nitrogen and phosphorus, NP) on microbial decomposition of Pterocarya stenoptera litter and the associated extracellular enzyme activities and microbial biomass with microcosms. Results showed that the decomposition rates were slower in the polluted stream waters than those in the unpolluted ones, which corresponded to lower microbial biomass and integrated enzyme activities of cellulose and ß-glucosidase. The decomposition rates were accelerated at low HM level, which was associated with the stimulated enzyme activities of hydrolytic enzymes or was stimulated by both NP levels in polluted stream waters. In particular, the hydrolase enzyme activities of microbial communities in polluted stream waters were stimulated by low HM level, suggesting that low HM level-stimulated litter decomposition may be due to the increased enzymatic activities. When microbial communities were exposed to HM and NP simultaneously, the inhibitory effect (in unpolluted stream waters) or the stimulated effect (in polluted stream waters) of low HM concentration was enhanced and attenuated, respectively, which suggests that the NP antagonistic effect against HM toxicity on litter decomposition may contribute to the litter-associated extracellular enzyme activities. These results suggest that the co-occurrence of HM and NP may have antagonistic effects on stream ecosystem functioning.


Assuntos
Adaptação Fisiológica/fisiologia , Bactérias/efeitos dos fármacos , Folhas de Planta/química , Plantas/química , Poluentes Químicos da Água/farmacologia , Biodegradação Ambiental , Cobre/química , Cobre/farmacologia , Nitrogênio/química , Nitrogênio/farmacologia , Fósforo/química , Fósforo/farmacologia , Rios , Fatores de Tempo , Poluentes Químicos da Água/química , Zinco/química , Zinco/farmacologia
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(3): 587-91, 2014 Mar.
Artigo em Zh | MEDLINE | ID: mdl-25208370

RESUMO

In order to observe two kinds of greenhouse gases, CO2 and CH4, making the biggest contribution to global warming, a ground-based Fourier transform near-infrared spectral remote sensing system was developed to record the perpendicular incidence sun spectra from February 2012 to April 2013 in Hefei continuously. The measured total transmittances in the atmosphere were obtained from perpendicular incidence sun spectra. Methods of line-by-line and low-order polynomial approximation were used to model the total atmospheric transmittances in forward model. The measured transmittance spectra were fitted iteratively using the modeled transmittance spectra in the regions of CO2 6,150-6,270 and CH4 5,970-6,170 cm(-1) in order to obtain their column concentrations. The column-average dry-air mole fractions of CO2 and CH4 were obtained with the internal standard function of O2 column concentrations. CO2 and CH4 daily average values of column-average dry-air mole fractions changed with a larger fluctuation and obvious seasonal periodicity. Their monthly average values were consistent as a whole, although there were different characteristics. Compared with the results reported by Japanese greenhouse-gas satellite in the area of Waliguan, there was a time lag corresponding to peak and trough of CO2 content and the change from peak to trough costed a longtime. CHR content showed variation tendency of unique peak and trough, higher in summer and lower in winter, compared with average values of nationwide CH4 column concentrations based on SCIAMACHY data. The variation characteristics were related to complex factors such as the balance of source and sink, meteorological and climate conditions, and required long-term observation and further study.

20.
Zhongguo Dang Dai Er Ke Za Zhi ; 16(10): 1075-80, 2014 Oct.
Artigo em Zh | MEDLINE | ID: mdl-25344196

RESUMO

Group B Streptococcus (GBS) is responsible for two distinct clinical syndromes in the newborn period categorised as either early- or late-onset GBS disease. Maternal GBS colonization of gastrointestinal tract or vaginal is the major risk factor for GBS diseases. There are two main strategies for identifying women at risk of giving birth to a GBS-infected infant: universal screening strategy and risk-based assessment. In the United States and other countries, the implementation of maternal intrapartum antibiotic prophylaxis policies has significantly reduced the incidence of early-onset neonatal GBS disease, but has little effect on the incidence of late-onset GBS disease. Penicillin is the first choice for antibiotic prophylaxis treatment. GBS strains which are isolated from pregnant women who are allergic to penicillin should undergo antibiotic susceptibility testing. Antibiotic prophylaxis measures have some disadvantages, so researchers should actively develop other precautions to prevent GBS infection.


Assuntos
Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae , Antibioticoprofilaxia , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Gravidez , Complicações Infecciosas na Gravidez , Infecções Estreptocócicas/etiologia
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