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1.
Bioconjug Chem ; 35(7): 944-953, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38954775

RESUMO

The chemical synthesis of homogeneously ubiquitylated histones is a powerful approach to decipher histone ubiquitylation-dependent epigenetic regulation. Among the various methods, α-halogen ketone-mediated conjugation chemistry has recently been an attractive strategy to generate single-monoubiquitylated histones for biochemical and structural studies. Herein, we report the use of this strategy to prepare not only dual- and even triple-monoubiquitylated histones but also diubiquitin-modified histones. We were surprised to find that the synthetic efficiencies of multi-monoubiquitylated histones were comparable to those of single-monoubiquitylated ones, suggesting that this strategy is highly tolerant to the number of ubiquitin monomers installed onto histones. The facile generation of a series of single-, dual-, and triple-monoubiquitylated H3 proteins enabled us to evaluate the influence of ubiquitylation patterns on the binding of DNA methyltransferase 1 (DNMT1) to nucleosomes. Our study highlights the potential of site-specific conjugation chemistry to generate chemically defined histones for epigenetic studies.


Assuntos
Histonas , Cetonas , Ubiquitinação , Histonas/química , Histonas/metabolismo , Histonas/síntese química , Cetonas/química , Ubiquitina/química , Humanos , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/química , Nucleossomos/química , Nucleossomos/metabolismo
2.
Anal Biochem ; 692: 115572, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38777290

RESUMO

Deoxynivalenol (DON) is a common mycotoxin in food that mainly pollutes grain crops and feeds, such as barley, wheat and corn. DON has caused widespread concern in the field of food and feed safety. In this study, a colorimetric immunoassay was proposed based on the aggregation of gold nanoparticles (AuNPs) due to the decomposition of Mn2+ from gold-coated manganese dioxide (AuNP@MnO2) nanosheets. In this study, 2-(dihydrogen phosphate)-l-ascorbic acid (AAP) was hydrolyzed by alkaline phosphatase (ALP) and converted to ascorbic acid (AA). Then, AuNP@MnO2 was reduced to Mn2+ and AuNPs aggregation occurred. Using the unique optical characteristics of AuNPs and AuNP@MnO2, visible color changes realized simple detection of DON with high sensitivity and portability. With increasing DON content, the color changed more obviously. To quantitatively detect DON, pictures can be taken and the blue value can be read by a smartphone. The detection limit (Ic10) of this method was 0.098 ng mL-1, which was 326 times higher than that of traditional competitive ELISA, and the detection range was 0.177-6.073 ng mL-1. This method exhibited high specificity with no cross-reaction in other structural analogs. The average recovery rate of DON in corn flour samples was 89.1 %-110.2 %, demonstrating the high accuracy and stability of this assay in actual sample detection. Therefore, the colorimetric immunoassay can be used for DON-related food safety monitoring.


Assuntos
Colorimetria , Ouro , Manganês , Nanopartículas Metálicas , Smartphone , Tricotecenos , Colorimetria/métodos , Ouro/química , Tricotecenos/análise , Tricotecenos/química , Nanopartículas Metálicas/química , Imunoensaio/métodos , Manganês/química , Compostos de Manganês/química , Contaminação de Alimentos/análise , Óxidos/química , Limite de Detecção
3.
Molecules ; 29(2)2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38257287

RESUMO

The extensive utilization of fossil fuels has led to a rapid increase in atmospheric CO2 concentration, resulting in various environmental issues. To reduce reliance on fossil fuels and mitigate CO2 emissions, it is important to explore alternative methods of utilizing CO2 and H2 as raw materials to obtain high-value-added chemicals or fuels. One such method is CO2 methanation, which converts CO2 and H2 into methane (CH4), a valuable fuel and raw material for other chemicals. However, CO2 methanation faces challenges in terms of kinetics and thermodynamics. The reaction rate, CO2 conversion, and CH4 yield need to be improved to make the process more efficient. To overcome these challenges, the development of suitable catalysts is essential. Non-noble metal catalysts have gained significant attention due to their high catalytic activity and relatively low cost. In this paper, the thermodynamics and kinetics of the CO2 methanation reaction are discussed. The focus is primarily on reviewing Ni-based, Co-based, and other commonly used catalysts such as Fe-based. The effects of catalyst supports, preparation methods, and promoters on the catalytic performance of the methanation reaction are highlighted. Additionally, the paper summarizes the impact of reaction conditions such as temperature, pressure, space velocity, and H2/CO2 ratio on the catalyst performance. The mechanism of CO2 methanation is also summarized to provide a comprehensive understanding of the process. The objective of this paper is to deepen the understanding of non-noble metal catalysts in CO2 methanation reactions and provide insights for improving catalyst performance. By addressing the limitations of CO2 methanation and exploring the factors influencing catalyst effectiveness, researchers can develop more efficient and cost-effective catalysts for this reaction.

4.
Chemistry ; 29(37): e202300414, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37080930

RESUMO

Ufmylation is involved in various cellular processes and associated with many human diseases. The understanding of this modification relies on the use of customized UFM1-derived probes for activity-based profiling of its related enzymes. This study presents a highly optimized total chemical synthesis for the generation of diverse UFM1-derived probes including UFM1-PA, Biotin-UFM1-PA and UFM1-AMC, in which a UFM1 C-terminal valine hydrazide was readily prepared by hydrazide-based ligation and used as a versatile handle for the installation of enzyme-sensitive warheads and fluorescent reporters. The resulting probes display high reactivity and selectivity for UFM1-specific enzymes in cell lysates. This strategy facilitates the generation and diversity of the UFM1-derived toolkit that can be employed to profile UFM1-specific enzymes, thereby shining insights into the dynamics of ufmylation.


Assuntos
Enzimas Ativadoras de Ubiquitina , Ubiquitina-Proteína Ligases , Humanos , Proteínas
5.
Langenbecks Arch Surg ; 408(1): 119, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36918430

RESUMO

PURPOSE: Although radiofrequency ablation (RFA) has been proven to provide a good survival benefit for small hepatocellular carcinoma (HCC), there is limited information about RFA for combined hepatocellular-cholangiocarcinoma (cHCC-CC). The purpose of this study was to explore the clinicopathological features of cHCC-CC and the curative effect of RFA in small cHCC-CC without distant metastases compared with liver resection (LR) and liver transplantation (LT). METHODS: Patients with cHCC-CC, intrahepatic cholangiocarcinoma, or HCC were identified in the Surveillance, Epidemiology, and End Results database. RESULTS: cHCC-CC had the highest rate of poor pathological grade and the lowest rate of bone metastases compared with intrahepatic cholangiocarcinoma and HCC (all P < 0.05). In patients with cHCC-CC after surgery, multivariate analysis showed that compared with RFA, LR and LT were independent protective factors for survival (all P < 0.05). But in cHCC-CC stratified by tumor size, for tumor size ≤ 3.0 cm, there was no significant difference among RFA, LR, and LT in univariate survival analysis (P = 0.285). For tumor size 3.0-5.0 cm, multivariate analysis showed that RFA for cHCC-CC yielded worse survival outcomes in comparison with that of LR (hazard ratio [HR]: 7.51, 95% confidence interval [CI]: 2.09-26.94, P = 0.002) and LT (HR: 4.48, 95% CI: 1.20-16.64, P = 0.025). CONCLUSIONS: In patients with cHCC-CC without distant metastases, for tumor size ≤ 3.0 cm, there was no significant survival difference among RFA, LR, and LT. However, for tumor size 3.0-5.0 cm, RFA may provide a worse survival benefit than LT and LR.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Neoplasias Hepáticas , Transplante de Fígado , Ablação por Radiofrequência , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/patologia , Ductos Biliares Intra-Hepáticos , Estudos Retrospectivos
6.
Metab Brain Dis ; 38(3): 1013-1024, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36580191

RESUMO

Diabetes-related cognitive impairment has been shown in diverse epidemiological investigations and lab-based studies, although the underlying pathological mechanisms remain unclear. Unbalanced protein homeostasis may contribute to cognitive decline by inducing abnormal protein aggregation in the diabetic brain. This study aimed to determine possible changes in the proteasome, which is an important pathway involved in abnormal protein degradation. To this end, we examined potential alterations of proteasomal subunits and hydrolytic activity in the brain of diabetic rats fed with high-fat diet combined with small doses of streptozotocin (STZ). Furthermore, lactacystin were used to inhibit proteasomal activity in vivo and typical Alzheimer's disease (AD)-like pathologies were detected, including amyloid-beta, tau phosphorylation, and oxidative protein changes. Our results showed that proteasomal activity increased in the brains of diabetic rats compared to age-matched control rats. After proteasome inhibition, the levels of tau phosphorylation and protein oxidative modification significantly increased; however, no changes were detected in the pathway involved in amyloid production. These results indicated that changes in protein homeostasis balance in diabetes play a role in some typical AD-like changes, especially in oxidative protein degradation, providing evidence that prevention of diabetes-induced protein imbalance may be a potential therapeutic target.


Assuntos
Doença de Alzheimer , Diabetes Mellitus Experimental , Ratos , Animais , Doença de Alzheimer/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Estreptozocina , Diabetes Mellitus Experimental/metabolismo , Proteínas tau/metabolismo , Encéfalo/metabolismo
7.
Int J Mol Sci ; 24(5)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36902108

RESUMO

We explored the antimicrobial activity of sertraline on Listeria monocytogenes and further investigated the effects of sertraline on biofilm formation and the virulence gene expression of L. monocytogenes. The minimum inhibitory concentration and minimum bactericidal concentration for sertraline against L. monocytogenes were in the range of 16-32 µg/mL and 64 µg/mL, respectively. Sertraline-dependent damage of the cell membrane and a decrease in intracellular ATP and pHin in L. monocytogenes were observed. In addition, sertraline reduced the biofilm formation efficiency of the L. monocytogenes strains. Importantly, low concentrations (0.1 µg/mL and 1 µg/mL) of sertraline significantly down-regulated the expression levels of various L. monocytogens virulence genes (prfA, actA, degU, flaA, sigB, ltrC and sufS). These results collectively suggest a role of sertraline for the control of L. monocytogenes in the food industry.


Assuntos
Anti-Infecciosos , Proteínas de Bactérias , Listeria monocytogenes , Sertralina , Fatores de Virulência , Anti-Infecciosos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/genética , Listeria monocytogenes/patogenicidade , Sertralina/farmacologia , Virulência/efeitos dos fármacos , Virulência/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
8.
World J Microbiol Biotechnol ; 39(8): 196, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37183209

RESUMO

The antagonistic Bacillus amyloliquefaciens HY2-1 was a marine microbiology that was isolated previously from the seabed silt of Beibu Gulf in China by dual culture with Penicillium digitatum. As a continuous study, the present work focused on evaluating the antimicrobial activity, identifying the produced active components, and revealing the fermentation characteristics of B. amyloliquefaciens HY2-1, respectively. It was found that B. amyloliquefaciens HY2-1 exhibited a broad-spectrum antimicrobial activity against the tested seven phytopathogenic fungi and five pathogenic bacteria by producing Bacillus lipopeptides such as fengycin A (C14 to C19 homologues) and surfactin (C14 and C15 homologues). Morphological observation of P. digitatum under light microscope, scanning electron microscopy, transmission electron microscopy, and fluorescence microscope inferred that B. amyloliquefaciens exerted the antagonistic activity by damaging the fungal cell membrane, thus inhibiting the mycelium growth and sporification of phytopathogenic fungi. As a marine microbiology, our results showed that B. amyloliquefaciens could survive and metabolize even at the culture condition with 110 g/L of NaCl concentration, and the produced antimicrobial compounds exhibited excellent thermostability and acid-alkali tolerance. The dynamic models were further constructed to theoretically analyze the fermentation process of B. amyloliquefaciens HY2-1, suggesting that the synthesis of antimicrobial compounds was coupled with both cell growth and cell biomass. In conclusion, the marine lipopeptides-producing B. amyloliquefaciens HY2-1 showed a promising prospect to be explored as a biocontrol agent for plant disease control of crops and postharvest preservation of fruits and vegetables, especially due to its outstanding stress resistance and the broad-spectrum and effective antagonist on various phytopathogenic fungi.


Assuntos
Anti-Infecciosos , Bacillus amyloliquefaciens , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Bacillus amyloliquefaciens/metabolismo , Fermentação , Cinética , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Lipopeptídeos/metabolismo
9.
Angew Chem Int Ed Engl ; 62(40): e202309572, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37581950

RESUMO

Catalytic acylation of organohalides with aldehydes is an ideal strategy for the direct synthesis of ketones. However, the utilization of unactivated alkyl halides in such a transformation remains a formidable challenge. In this study, we developed a cross-coupling reaction of aldehydes with unactivated alkyl halides through N-heterocyclic carbene catalysis. With this protocol, various ketones could be rapidly synthesized from readily available starting materials under mild conditions. This organocatalytic system was successfully applied in the late-stage functionalization of pharmaceutical derivatives. Mechanistic investigations suggest a closed-shell nucleophilic substitution mechanism for this reaction.

10.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(4): 381-387, 2023 Apr 15.
Artigo em Zh | MEDLINE | ID: mdl-37073843

RESUMO

OBJECTIVES: To study the clinical and bronchoscopic characteristics of tracheobronchial tuberculosis (TBTB) in children and to identify factors influencing residual airway obstruction or stenosis. METHODS: The clinical data of children with TBTB were retrospectively collected. The children were divided into two groups based on the last bronchoscopic result within one year of follow-up: a group with residual airway obstruction or stenosis (n=34) and a group without residual airway obstruction or stenosis (n=58). A multivariate logistic regression analysis was used to identify the factors influencing residual airway obstruction or stenosis in children with TBTB. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of the factors influencing residual airway obstruction or stenosis in children with TBTB. RESULTS: A total of 92 children with TBTB were included, and the main symptoms were cough (90%) and fever (68%). In children under 1 year old, the incidence rates of dyspnea and wheezing were significantly higher than in other age groups (P<0.008). Chest CT findings included mediastinal or hilar lymph node enlargement (90%) and tracheobronchial stenosis or obstruction (61%). The lymphatic fistula type was the main type of TBTB observed bronchoscopically (77%). All children received interventional treatment, and the effective rate was 84%. During one year of follow-up, 34 children had residual airway obstruction or stenosis. The TBTB diagnostic time and the initiation of interventional treatment were significantly delayed in the group with residual airway obstruction or stenosis compared with the group without residual airway obstruction or stenosis (P<0.05). The multivariate logistic regression analysis showed that the TBTB diagnostic time was closely related to residual airway obstruction or stenosis in children (P<0.05). ROC curve analysis showed that at the cut-off value of 92 days of TBTB diagnostic time, the area under the curve for predicting residual airway obstruction or stenosis in children with TBTB was 0.707, with a sensitivity of 58.8% and a specificity of 75.9%. CONCLUSIONS: The clinical manifestations of TBTB are nonspecific, and symptoms are more severe in children under 1 year old. TBTB should be suspected in children with tuberculosis and chest imaging indicating airway involvement. Delayed diagnosis of TBTB is associated with the development of residual airway obstruction or stenosis.


Assuntos
Obstrução das Vias Respiratórias , Broncopatias , Tuberculose , Lactente , Criança , Humanos , Broncoscopia/métodos , Constrição Patológica/complicações , Broncopatias/diagnóstico , Broncopatias/complicações , Broncopatias/terapia , Estudos Retrospectivos , Tuberculose/diagnóstico , Obstrução das Vias Respiratórias/etiologia , Obstrução das Vias Respiratórias/terapia
11.
Fish Shellfish Immunol ; 131: 662-671, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36341870

RESUMO

The Japanese eel (Anguilla japonica) experiences dramatic internal and external environmental changes during its transoceanic reproductive migrations. Here, we assess immune function changes in the primary and secondary immune organs (head kidney and spleen) of A. japonica during artificial ovarian maturation at the previtellogenic (PV), midvitellogenic (MV), and ovulating (OV) stages by transcriptome analyses. Stress responses were also assessed by determining the serum concentrations of lysozyme, alkaline phosphatase, acid phosphatase, total antioxidant capacity, and superoxide dismutase. Our results showed that together with increased serum 17ß-estrogen and testosterone, lysozyme activity and antioxidant capacity were suppressed during artificial ovarian maturation. Comparisons across these developmental stages identified 60 (head kidney) and 36 (spleen) differentially expressed genes associated with the immune system. Genes related to the key activation markers of innate immune function, such as CXCL10, CXCL11, CCL20, HSP90B, MMP9, and MMP13, were upregulated and significantly enriched in the interleukin-17 signaling pathway. Adaptive immune function-related genes (IGM and MHC1) were upregulated in the head kidney from PV to MV, and their levels increased thereafter in the spleen. Moreover, a correlation between Pax5 expression and IGM expression in the spleen of MV (IGM+/Pax5+) and OV (IGM++/Pax5-) stage suggests that adaptive immune function was enhanced during ovarian maturation. To our knowledge, the present study is the first to describe transcriptome profiling of immune organs during ovarian maturation in teleost. Our findings suggest that the interleukin-17 pathway and IgM may play important roles in spawning.


Assuntos
Anguilla , Animais , Anguilla/genética , Anguilla/metabolismo , Interleucina-17/genética , Muramidase/metabolismo , Antioxidantes/metabolismo , Perfilação da Expressão Gênica/veterinária , Imunidade , Imunoglobulina M/genética
12.
Environ Sci Technol ; 56(17): 12635-12644, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35976700

RESUMO

During the pyrite oxidation process, aqueous ferrous/ferric ions (Fe2+/Fe3+), as well as surface-adsorbed Fe2+/Fe3+, have been widely recognized to dominate hydroxyl radical (•OH) generation, while this study reveals that the secondary solid iron species also play non-negligible roles. Based on the different forms and the presence of sites, the secondary solid iron species were classified as Fecoat (iron-containing coating on the pyrite surface) and Fedep (ex situ-deposited iron (oxyhydr)oxide that is not in contact with pyrite). Instead of participating in building a stubborn passivation layer on the pyrite surface, Fecoat is easy to fall off from the pyrite surface as the oxidation of pyrite deepens, while large fractions of Fedep and Fecoat are found to be extractable with nitrilotriacetic acid (NTA). Achieved by cyclically oxidizing pyrite within different NTA levels (0/0.1/10 mM), Fecoat and Fedep were proved to have distinct redox behavior during the pyrite oxidation process. Amorphous Fedep, originated from the hydrolyzation of dissolved Fe3+, accelerates the nonradical decay of hydrogen peroxide (H2O2); as a result, the accumulation of Fedep always decreases the •OH production during the pyrite oxidation process. However, part of Fedep adsorbs on the pyrite surface through electrostatic attraction and converts into Fecoat. The electron conduction between Fecoat and pyrite was verified, which accelerates the oxidative dissolution of pyrite, produces reactive Fe(II), and therefore favors •OH generation. This study improves our understanding of the redox behavior of pyrite in complex media such as natural processes and practical engineering systems.


Assuntos
Peróxido de Hidrogênio , Radical Hidroxila , Compostos Férricos , Ferro , Oxirredução , Sulfetos
13.
J Pept Sci ; 28(5): e3381, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34811838

RESUMO

The reversible and dynamic post-translational modifications (PTMs) of histones in eukaryotic chromatin are intimately connected to cell development and gene function, and abnormal regulation of PTMs can result in cancer and neurodegenerative diseases. Specific combinations of these modifications are mediated by a series of chromatin proteins that write, erase, and read the "histone codes," but mechanistic studies of the precise biochemical and structural relationships between different sets of modifications and their effects on chromatin function constitute a unique challenge to canonical biochemical approaches. In the past decade, the development and application of chemical methods for investigating histone PTM crosstalks has received considerable attention in the field of chemical biology. In this review, taking the functional crosstalk between H2B ubiquitylation at Lys120 (H2BK120ub) and H3 methylation at Lys79 (H3K79me) as a typical example, we survey recent developments of different chemical methods, in particular, protein synthetic chemistry and protein-based chemical probes, for studying the mechanism of the functional crosstalks of histone PTMs.


Assuntos
Histonas , Processamento de Proteína Pós-Traducional , Cromatina/genética , Histonas/química , Metilação , Ubiquitinação
14.
Eur J Pediatr ; 181(5): 2135-2146, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35192051

RESUMO

The purpose of this systematic review is to evaluate the efficacy and safety of using potential drugs: remdesivir and glucocorticoid in treating children and adolescents with COVID-19 and intravenous immunoglobulin (IVIG) in treating MIS-C. We searched seven databases, three preprint platform, ClinicalTrials.gov, and Google from December 1, 2019, to August 5, 2021, to collect evidence of remdesivir, glucocorticoid, and IVIG which were used in children and adolescents with COVID-19 or MIS-C. A total of nine cohort studies and one case series study were included in this systematic review. In terms of remdesivir, the meta-analysis of single-arm cohort studies have shown that after the treatment, 54.7% (95%CI, 10.3 to 99.1%) experienced adverse events, 5.6% (95%CI, 1.2 to 10.1%) died, and 27.0% (95%CI, 0 to 73.0%) needed extracorporeal membrane oxygenation or invasive mechanical ventilation. As for glucocorticoids, the results of the meta-analysis showed that the fixed-effect summary odds ratio for the association with mortality was 2.79 (95%CI, 0.13 to 60.87), and the mechanical ventilation rate was 3.12 (95%CI, 0.80 to 12.08) for glucocorticoids compared with the control group. In terms of IVIG, most of the included cohort studies showed that for MIS-C patients with more severe clinical symptoms, IVIG combined with methylprednisolone could achieve better clinical efficacy than IVIG alone. CONCLUSIONS: Overall, the current evidence in the included studies is insignificant and of low quality. It is recommended to conduct high-quality randomized controlled trials of remdesivir, glucocorticoids, and IVIG in children and adolescents with COVID-19 or MIS-C to provide substantial evidence for the development of guidelines. WHAT IS KNOWN: • The efficacy and safety of using potential drugs such as remdesivir, glucocorticoid, and intravenous immunoglobulin (IVIG) in treating children and adolescents with COVID-19/MIS-C are unclear. WHAT IS NEW: • Overall, the current evidence cannot adequately demonstrate the effectiveness and safety of using remdesivir, glucocorticoids, and IVIG in treating children and adolescents with COVID-19 or MIS-C. • We are calling for the publication of high-quality clinical trials and provide substantial evidence for the development of guidelines.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Adolescente , COVID-19/complicações , Criança , Glucocorticoides/uso terapêutico , Humanos , Imunoglobulinas Intravenosas/efeitos adversos , Respiração Artificial , Síndrome de Resposta Inflamatória Sistêmica
15.
Mar Drugs ; 20(3)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35323477

RESUMO

One new depsidone derivative, aspergillusidone H (3), along with seven known biosynthetically related chlorinated polyketides, were obtained from the Beibu Gulf coral-derived fungus Aspergillus unguis GXIMD 02505. Their structures were determined by comprehensive physicochemical and spectroscopic data interpretation. Notably, the X-ray crystal structure of 2 and the previously unknown absolute configuration of 8, assigned by ECD calculations, are described here for the first time. Compounds 1-5, 7 and 8 exhibited inhibition of lipopolysaccharide (LPS)-induced NF-κB in RAW 264.7 macrophages at 20 µM. In addition, the two potent inhibitors (2 and 7) dose-dependently suppressed RANKL-induced osteoclast differentiation without any evidence of cytotoxicity in bone marrow macrophages cells (BMMs). This is the first report of osteoclastogenesis inhibitory activity for the metabolites of these kinds. Besides, compounds 1, 2, 4, and 6-8 showed inhibitory activity against marine biofilm-forming bacteria, methicillin-resistant Staphylococcus aureus, Microbulbifer variabilis, Marinobacterium jannaschii, and Vibrio pelagius, with their MIC values ranging from 2 to 64 µg/mL. These findings provide a basis for further development of chlorinated polyketides as potential inhibitors of osteoclast differentiation and/or for use as anti-fouling agents.


Assuntos
Antozoários/microbiologia , Antibacterianos , Aspergillus/química , Produtos Biológicos , Osteogênese/efeitos dos fármacos , Policetídeos , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Células Cultivadas , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Molecular , NF-kappa B/metabolismo , Oceanos e Mares , Policetídeos/química , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Ligante RANK
16.
BMC Med Educ ; 22(1): 154, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35255878

RESUMO

BACKGROUND: Undergraduate medical (UM) students faced the difficulties inherent in medical careers due to the coronavirus (COVID-19) outbreak. Thus, imperative containment measures might affect UM students' career intentions. Information on the factors that may be associated with these students' career change intentions is limited. METHODS: We conducted a cross-sectional survey in August 2020 to investigate the impact of the COVID-19 pandemic on career intention and the associated factors in UM students. Univariate analyses and logistic regression analysis were performed to identify said factors. RESULTS: A total of 2040 medical students from the Hubei University of Medicine were surveyed. Univariate analyses showed that grade, attitude towards healthcare, and the degree of the COVID-19 pandemic's impact on the students' lives were associated with changes in career choice (P<0.05). Logistic regression analysis showed that Grade 2, Grade 5, attitude towards a medical career, and having relatives with a medical background were associated with changes in career choice. The degree of the COVID-19 pandemic's impact was a common and significant factor associated with career preference, career perspective, and ideal workplace. CONCLUSIONS: Changes in career intentions were particularly influenced by grade, attitude towards being a health worker, and the degree of COVID-19's impact on the participants' lives. Treating large-scale public health emergencies rationally, setting up correct views of occupation choice, and building reasonable career planning may reduce the loss of medical talent.


Assuntos
COVID-19 , Estudantes de Medicina , COVID-19/epidemiologia , Escolha da Profissão , Estudos Transversais , Humanos , Intenção , Ocupações , Pandemias , SARS-CoV-2 , Inquéritos e Questionários
17.
World J Microbiol Biotechnol ; 38(12): 243, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36280649

RESUMO

Exopolysaccharides (EPSs) can be used as effective exogenous substances to alleviate the toxic effect of cadmium (Cd) on rice and other crops, thus improving plant growth characteristics under stress conditions, and reducing the accumulation of Cd in grains, but the underlying mechanism is still unclear. In the present work, the effects of EPSs from Lactobacillus plantarum on the efficiency of Cd absorption and distribution in rice seedlings under Cd stress were investigated. The results revealed that growth of rice seedlings was severely inhibited by exposure to Cd, resulting in the decrease of plant height, leaf length and biomass. This inhibition phenomenon was alleviated by the addition of EPSs from L. plantarum LPC-1. The underlying mechanism might be that EPSs could facilitate the accumulation efficiency of Cd in rice roots and reduce the transportation rate of Cd from root to leaves, therefore decreasing the Cd content in leaves. Further research showed that Cd contents in the cell wall fraction of the rice seedling root were increased by the addition of EPSs, while the proportions of Cd in the cell organelle and cell soluble component were reduced. Application of EPSs promotes the proportion of pectate- and protein- integrated Cd in rice roots. While the content of water-soluble Cd, which is more toxic to plants, decreased continuously both in roots and leaves. Our study clearly confirmed the positive effects of EPSs on alleviating Cd toxicity and decreasing Cd translocation in rice above-ground parts. Furthermore, the subcellular distribution and chemical forms of Cd in different rice seedlings parts were also affected by the addition of EPSs, which might be an important potential mechanism for EPSs in respect of alleviating Cd toxicity for rice. These findings provided a foundation for the application of exogenous substances on improving the growth performance of crops under heavy metal stress.


Assuntos
Lactobacillus plantarum , Oryza , Plântula , Cádmio/análise , Raízes de Plantas , Água
18.
Environ Monit Assess ; 194(6): 412, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35534593

RESUMO

This study uses the daily product data of the concentration of ozone in the atmospheric column (ozone column concentration) collected by the Aura satellite's Ozone Monitoring Instrument (OMI), to evaluate the ozone pollution status of the Fenwei Plain in east-central China, by employing pixel-based spatial analysis, an θslope trend index, a Hurst index, and grey correlation. The following results were found. (1) The spatial distribution of ozone in the atmosphere of the Fenwei Plain was higher in the north and lower in the south, with high values appearing in Jinzhong, Lvliang, and other cities. (2) The changes in ozone column concentration periodically and seasonally in the Fenwei Plain. Seasonally, the ozone column concentration was highest in spring, followed by summer, winter, and autumn. (3) The pixel-based trend change of the ozone slope (θslope) indicated that the ozone concentration in the region was in a downward trend, while the long-term correlation of the time series trend Hurst index found that the region should expect to see a weak rebound in the ozone column concentration in the future, so that routine monitoring should be strengthened. (4) The present study on the factors influencing the ozone concentration found that the concentration is relatively closely related to temperature, air pressure, humidity, grain sowing area, highway mileage, and secondary industry.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Cidades , Monitoramento Ambiental/métodos , Ozônio/análise , Tecnologia de Sensoriamento Remoto , Estações do Ano
19.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 53(1): 166-170, 2022 Jan.
Artigo em Zh | MEDLINE | ID: mdl-35048619

RESUMO

OBJECTIVE: To explore the effects of interventional therapy with bronchoscopy in children with acquired subglottic stenosis (SGS). METHODS: The clinical data of ten pediatric inpatients with acquired SGS who were admitted to Children's Hospital of Chongqing Medical University, as well as their follow-up information obtained 1 week, 1 month, 3 months and 6 months after the procedure was done.were retrospectively analyzed to examine the effect of interventional bronchoscopic therapies, including balloon dilatation, holmium laser, and cryotherapy, in pediatric patients with acquired SGS. RESULTS: Among the 10 patients with acquired SGS, there were 5 boys and 5 girls aged between 1 month and 6 years and 5 months, with a median age of 11 months and 1 day. Among the 5 patients with acute acquired SGS, two were treated with balloon dilatation only, with one cured and one showing clinical improvement, while three received comprehensive interventional therapy combining balloon dilatation, holmium laser, and cryotherapy, with two cured and one showing improvement. Among the 5 patients with chronic acquired SGS, four cases were cured with comprehensive interventional therapy, while one case suffered from aggravated upper airway obstruction 4 + hours after balloon dilatation. The patient was subsequently put on invasive mechanical ventilation for 4 days, but was unable to be extubated. The parents signed do-not-resuscitate order and the patient died afterwards. Bronchoscopy performed 1 week, 1 month and 3 months after the procedure was done showed that the SGS was improved to varying degrees. CONCLUSION: Bronchoscopy intervention is an effective therapy for acquired SGS in children.


Assuntos
Laringoestenose , Broncoscopia , Criança , Endoscopia , Feminino , Humanos , Lactente , Laringoestenose/etiologia , Laringoestenose/terapia , Masculino , Estudos Retrospectivos , Resultado do Tratamento
20.
Environ Sci Technol ; 55(19): 13286-13296, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34529405

RESUMO

The stack configuration in flow-electrode capacitive deionization (FCDI) has been verified to be an attractive and feasible strategy for scaling up the desalination process. However, challenges still exist when attempting to simultaneously improve the desalination scale and the cell configuration. Here, we describe a novel stack FCDI configuration (termed a gradient FCDI system) based on a membrane-current collector assembly, in which the charge neutralization enables the in situ regeneration of the flow electrodes in the single cycle operation, thereby realizing a considerable increase in the desalinating performance. By evaluating standardized metrics such as the salt rejection, productivity (P), average salt removal rate (ASRR), energy-normalized removed salt (ENRS), and TEE, the results indicated that the gradient FCDI system could be a performance-stable and energy-efficient alternative for scale-up desalination. Under optimal operating conditions (carbon content = 10 wt %, feed salinity = 3000 mg L-1, cell voltage = 1.2 V, and productivity = 56.7 L m-2 h-1), the robust desalination performance (ASRR = 1.07 µmol cm-2 min-1) and energy consumption (ENRS = 7.8 µmol J-1) of the FCDI system with a desalination unit number of four were verified at long-term operation. In summary, the stacked gradient FCDI system and its operation mode described here may be an innovative and promising strategy capable of enlarging the scale of desalination while realizing performance improvement and device simplification.


Assuntos
Purificação da Água , Adsorção , Eletrodos , Salinidade , Cloreto de Sódio
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