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1.
Bioorg Med Chem ; : 117788, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38964974

RESUMO

Ovarian cancer is a common malignant tumor in women, and 70 % of ovarian cancer patients are diagnosed at an advanced stage. Drug chemotherapy is an important method for treating ovarian cancer, but recurrence and chemotherapy resistance often lead to treatment failure. In this study, we screened 10 extracts of Tripterygium wilfordii, a traditional Chinese herb, and found that triptonide had potent anti-ovarian cancer activity and an IC50 of only 3.803 nM against A2780 cell lines. In addition, we determined that triptonide had a better antitumor effect on A2780 cell lines than platinum chemotherapeutic agents in vitro and that triptonide had no significant side effects in vivo. We found that triptonide induced apoptosis in ovarian cancer cells through activation of the p38/p53 pathway and it also induced cell cycle arrest at the S phase. In addition, we demonstrated that triptonide could activate lethal autophagy, which led to growth inhibition and cell death in ovarian cancer cells, resulting in an anti-ovarian cancer effect. Triptonide exerts its anti-ovarian cancer effect through activation of the p38/p53 pathway and induction of autophagy to promote apoptosis, which provides a new candidate drug and strategy for the treatment of ovarian cancer.

2.
Lipids Health Dis ; 23(1): 66, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429790

RESUMO

BACKGROUND AND AIMS: Cardiovascular disease (CVD) is associated with inflammation and abnormal lipid metabolism. However, a single inflammatory index or a single lipid index cannot accurately predict the prognosis of CVD independently because it is prone to be affected by various confounding factors. METHODS: This population-based cohort study included 6,554 participants from the China Health and Retirement Longitudinal Study (CHARLS) to investigate correlations. In the present study, the occurrence of CVD events such as stroke and heart disease was evaluated by considering self-reported diagnoses at the beginning of the study and during wave 4, and a restricted cubic spline model was used to investigate potential nonlinear relationships in addition to multivariate logistic regression models. Stratified analyses were performed to examine how sociodemographic characteristics may influence the results. RESULTS: Seven years of follow-up (2011-2018) revealed that 786 people (11.99%) developed CVD. According to the adjusted model, the high-sensitivity C-reactive protein (hs-CRP)-to-high-density lipoprotein cholesterol (HDL-C) ratio is a contributing factor to CVD risk (OR 1.31, 95% CI 1.05-1.64). In addition, a nonlinear relationship was observed between the hs-CRP/HDL-C ratio and the occurrence of new CVD, stroke, or cardiac issues (Poverall <0.05, Pnonlinear <0.05). Moreover, noteworthy associations between the hs-CRP/HDL-C ratio and age were detected in the stratified analysis (P = 0.048), indicating that younger participants had more negative effects of a high hs-CRP/HDL-C ratio. CONCLUSIONS: According to the present cohort study, a high hs-CRP/HDL-C ratio is a significant risk factor for CVD, new stroke, and heart problems. Early intervention in patients with increased hs-CRP/HDL-C ratios may further reduce the incidence of CVD, in addition to focusing on independent lipid markers or independent inflammatory markers.


Assuntos
Doenças Cardiovasculares , Acidente Vascular Cerebral , Idoso , Pessoa de Meia-Idade , Humanos , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Estudos de Coortes , Estudos Longitudinais , Inflamação
3.
BMC Pediatr ; 24(1): 11, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-38178076

RESUMO

Community-acquired bacterial meningitis (CABM) is the main cause of morbidity and mortality in children. The epidemiology of CABM is regional and highly dynamic. To clarify the diagnostic status and epidemiological characteristics of children with CABM in this region, and pay attention to the disease burden, so as to provide evidence for the prevention and treatment of CABM. By retrospective case analysis, the clinical data of 918 CABM cases in children aged 0-14 years in Zhejiang Province from January, 2019 to December, 2020 were collected. The etiological diagnosis rate of CABM in children was 23.1%, the annual incidence rate 4.42-6.15/100,000, the annual mortality rate 0.06-0.09/100,000,the cure and improvement rate 94.4%, and the case fatality rate 1.4%. The total incidence of neuroimaging abnormalities was 20.6%. The median length of stay for CABM children was 20(16) days, with an average cost of 21,531(24,835) yuan. In addition, the incidence rate was decreased with age. Escherichia coli(E.coli) and group B Streptococcus agalactiae(GBS) were the principal pathogens in CABM infant<3 months(43.3%, 34.1%), and Streptococcus pneumoniae(S. pneumoniae) was the most common pathogen in children ≥ 3 months(33.9%). In conclusion, the annual incidence and mortality of CABM in children aged 0-14 years in Zhejiang Province are at intermediate and low level. The distribution of CABM incidence and pathogen spectrum are different in age; the incidence of abnormal neuroimaging is high; and the economic burden is heavy.


Assuntos
Meningites Bacterianas , Criança , Lactente , Humanos , Estudos Retrospectivos , Meningites Bacterianas/diagnóstico , Meningites Bacterianas/epidemiologia , Meningites Bacterianas/tratamento farmacológico , Streptococcus pneumoniae , Streptococcus agalactiae , Escherichia coli , Incidência
4.
Heart Fail Rev ; 28(6): 1405-1415, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37414918

RESUMO

Anthracyclines and trastuzumab are widely used to treat breast cancer but increase the risk of cardiomyopathy and heart failure. With the use of trastuzumab and anthracycline-containing medications, this study intends to evaluate the effectiveness and security of current treatments against cardiotoxicity. We conducted a systematic review of randomized controlled trials (RCTs), which used at least one angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), or beta-blocker (BB) to prevent cardiotoxicity of antineoplastic agents for breast cancer, in 4 databases (PubMed, Cochrane Library, EMBASE, Web of Science) from inception to 11 May 2022, without language restrictions. The outcome of interest was left ventricular ejection fraction (LVEF) and adverse events. Stata 15 and R software 4.2.1 were used to perform all statistical analyses. The Cochrane version 2 of the risk of bias tool was used to assess the risk of bias, and the grading of recommendations assessment, development, and evaluation (GRADE) assessment was used to appraise the quality of the evidence. Fifteen randomized clinical studies with a total of 1977 patients were included in the analysis. The included studies demonstrated statistically significant LVEF in the ACEI/ARB and BB treatment groups (χ2 = 184.75, I2 = 88.6%, p = 0.000; SMD 0.556, 95% CI 0.299 to 0.813). In an exploratory subgroup analysis, the benefit of experimental agents on LVEF, whether anthracyclines or trastuzumab, was prominent in patients treated with ACEIs, ARBs, and BBs. Compared to placebo, ACEI/ARB and BB treatments in breast cancer patients protect against cardiotoxicity after trastuzumab and anthracycline-containing medication treatment, indicating a benefit for both.


Assuntos
Antineoplásicos , Neoplasias da Mama , Humanos , Feminino , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Cardiotoxicidade/etiologia , Cardiotoxicidade/prevenção & controle , Antineoplásicos/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Trastuzumab/efeitos adversos , Antagonistas de Receptores de Angiotensina/uso terapêutico , Antibióticos Antineoplásicos/uso terapêutico , Antraciclinas/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Langenbecks Arch Surg ; 408(1): 76, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36729303

RESUMO

PURPOSE: To understand the methodological quality of recent guidelines for laparoscopic surgery and endoscopic management for colon cancer and to analyze the heterogeneity and possible reasons for the main recommendations. METHODS: A systematic and comprehensive search of databases and relevant websites was conducted to collect guidelines for laparoscopic surgery for colon cancer in the last 10 years that met the inclusion criteria. The AGREE II manual was used to evaluate the included guidelines and to assess and analyze the heterogeneity and reasons for key recommendations about the surgery. RESULTS: A total of fifteen guidelines were included in this study. Only two guidelines had an overall score greater than 60% and were recommended for clinical use. Eleven guidelines had an overall score of 30-60%, and two guidelines had an overall score of less than 30%. Further analysis of the reasons for heterogeneity in the guideline recommendations and evidence was performed for nine guidelines. This study found that only 36.1% of the evidence levels recommended in the guidelines were high. Significant heterogeneity exists in the main recommendations, mainly because the relevant content is not mentioned or described in detail. CONCLUSION: The quality of guidelines for laparoscopic colon cancer surgery is variable, and there is significant heterogeneity among key recommendations. And the level of evidence underlying the recommendations was generally not high. Further guideline updates should address the causes of the above heterogeneity.


Assuntos
Neoplasias do Colo , Laparoscopia , Humanos , Neoplasias do Colo/cirurgia , Bases de Dados Factuais
6.
BMC Pediatr ; 23(1): 470, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37723538

RESUMO

BACKGROUND: This multi-center study aimed to identify factors affecting fever and delayed defervescence in bacterial meningitis (BM) patients under 3 years of age because of the variability of fever in this patient population. METHODS: Only BM patients under 3 years treated at 49 centers in China from November 2018 to end-April 2021 were included in the study. Univariate and multivariate logistic regression analyses were performed to determine factors associated with afebrile presentation and fever of delayed defervescence. RESULTS: A total of 863 BM patients under 3 years were included in the study. Coagulase negative staphylococcus was associated with afebrile presentation (OR = 1.176), while septicaemia and ear-nose-throat infections were associated with fever (P < 0.05). The patients with fever were assigned into early and delayed defervescence groups based on defervescence time (less than and more than or equal to one week). Furthermore, Streptococcus agalactiae meningitis (OR = 1.124), concomitant gastrointestinal infection (OR = 1.276), encephalomalacia (or = 1.339), and subdural effusion (OR = 1.454) were independently associated with delayed defervescence (all P < 0.05). CONCLUSIONS: The findings can aid in the efficient utilization of fever in auxiliary diagnosis and evaluating the condition of the disease.


Assuntos
Meningites Bacterianas , Sepse , Infecções Estreptocócicas , Humanos , Criança , Pré-Escolar , Estudos Retrospectivos , Meningites Bacterianas/complicações , Meningites Bacterianas/diagnóstico , China/epidemiologia , Febre/etiologia
7.
Anim Biotechnol ; 34(7): 3085-3098, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36271875

RESUMO

Domestic donkeys (Equus asinus) have been maintained mainly for service purposes in the past. Nowadays, there is an increasing interest in donkey milk and meat production in several countries, including China. Donkey meat is highly consumed because of its nutritional value and unique flavor. However, genomic studies on donkey meat are limited. Therefore, in this study, we aimed to examine the molecular difference of longissimus dorsi muscles of donkey, cow, and goat. RNA sequencing and Proteome sequencing technology were used to analyze the transcriptome and proteome of the longissimus dorsi muscle of donkey, cow, and goat. A total of 1338 and 1780 differentially expressed genes (DEGs) were identified in donkey meat compared with that in cow and goat meat, respectively. Most of the DEGs were involved in biological processes, including small GTPase-mediated signal transduction, protein ubiquitination, protein glycosylation, and MAP kinase tyrosine/serine/threonine phosphatase activity. Additionally, 764 and 1024 differentially expressed proteins (DEPs) were identified in cow vs. donkey, and goat vs. donkey, respectively; these DEPs were mainly involved in metabolism. Genetic variation and regulatory factors can combine as a database to provide more valuable molecular information for further analysis.


Assuntos
Equidae , Transcriptoma , Bovinos/genética , Feminino , Animais , Equidae/genética , Proteoma/genética , Proteoma/metabolismo , Músculo Esquelético/metabolismo , Carne/análise , Cabras/genética
8.
Angew Chem Int Ed Engl ; 62(19): e202301879, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-36872618

RESUMO

Nanozymes aim to mimic the highly evolved active centers of natural enzymes. Despite progress in nanozyme engineering, their catalytic performance is much less favorable compared with natural enzymes. This study shows that precise control over the atomic configuration of the active centers of Co single-atom nanozymes (SAzymes) enables the rational regulation of their catalase-like performance guided by theorical calculations. The constructed Co-N3 PS SAzyme exhibits an excellent catalase-like activity and kinetics, exceeding the representative controls of Co-based SAzymes with different atomic configurations. Moreover, we developed an ordered structure-oriented coordination design strategy for rationally engineering SAzymes and established a correlation between the structure and enzyme-like performance. This work demonstrates that precise control over the active centers of SAzymes is an efficient strategy to mimic the highly evolved active sites of natural enzymes.


Assuntos
Carbono , Carbono/química , Catalase , Catálise , Cobalto/química , Materiais Biomiméticos/química
9.
Small ; 18(15): e2108034, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35419992

RESUMO

Surface oxygen vacancies (Vo ) regulation is an effective strategy to improve the electrochemical CO2  reduction reaction (CO2 RR) performance by lowering the activation energy barrier of CO2 ; however, the lack of precise control over the local atomic structures severely hinders the large-scale application of Vo -activated electrocatalyst for CO2 RR. Herein, an efficient strategy to facilitate CO2  activation is developed by introducing Vo into transition metal nanoparticles (NPs) with a steam-assisted chemical vapor deposition method. With the steam process, abundant surface Vo are introduced into the assembled Ni-Fe bimetallic NPs composite (H-NiFe/NG), which adjust surface Ni/Fe atoms to low-valent coordinatively unsaturated Ni (+1)/Fe (+2) sites, serving as electron-rich centers to adsorb and activate inert CO2  molecules. The as-prepared H-NiFe/NG composite exhibits excellent catalytic performance with a maximum Faradaic efficiency of 94% at -0.80 V (vs RHE) for CO production with remarkable stability. The density function theory calculations corroborate that the Ni atoms around surface Vo significantly lower the energy barrier for COOH* intermediate formation, which gives a low overpotential for reducing CO2  to CO, exhibiting superior CO2 RR performance. This general synthetic strategy provides a new insight to introduce surface Vo on transition metal for efficient CO2  reduction.


Assuntos
Nanocompostos , Vapor , Dióxido de Carbono/química , Catálise , Oxigênio
10.
Crit Rev Food Sci Nutr ; : 1-22, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36469643

RESUMO

Traditional processing methods can no longer meet the demands of consumers for high-quality muscle food. As a green and non-thermal processing technology, ultrasound has the advantage of improving processing efficiency and reducing processing costs. Of these, the positive effect of power ultrasound in the processing of muscle foods is noticeable. Based on the action mechanism of ultrasound, the factors affecting the action of ultrasound are analyzed. On this basis, the effect of ultrasound technology on muscle food quality and its action mechanism and application status in processing operations (freezing-thawing, tenderization, marination, sterilization, drying, and extraction) is discussed. The transient and steady-state effects, mechanical effects, thermal effects, and chemical effects can have an impact on processing operations through complex correlations, such as improving the efficiency of mass and heat transfer. Ultrasound technology has been proven to be valuable in muscle food processing, but inappropriate ultrasound treatment can also have adverse effects on muscle foods. In the future, kinetic models are expected to be an effective tool for investigating the application effects of ultrasound in food processing. Additionally, the combination with other processing technologies can facilitate their intensive application on an industrial level to overcome the disadvantages of using ultrasound technology alone.

11.
Anim Genet ; 53(4): 487-497, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35535569

RESUMO

Donkeys are widely distributed labour animals in the world. During the process of the domestication and artificial selection of domestic donkeys, body sizes show significant differences among different breeds of donkeys. Based on the genome resequencing data of 103 Chinese indigenous donkeys from 11 breeds (Biyang, Dezhou, Guangling, Hetian, Jiami, Kulun, Qingyang, Turfan, Tibetan, Xinjiang, and Yunnan), seven Spanish donkeys from two breeds (Zamorano~Leonés and Andalusian), and three wild donkeys, we investigated the population structures of Chinese domestic donkeys with different body sizes. We used FST and XP-EHH analyses to explore the selected regions related to body sizes. The results showed that Chinese indigenous donkeys have a closer relationship with African wild donkeys than with Asian wild donkeys. LCORL/NCAPG, FAM184B, TBX3, and IHH were identified as genes with strong signals in analysis of selection signature (FST and XP-EHH) in large and small donkeys. The seven identified variants can be served as candidate loci affecting the body size of Chinese donkeys. Five of seven loci were located in intron 9 of FAM184B and were in a haplotype block, and one of the identified variants (Chr03:112664848) located in the CDS region of the LCORL gene was found to cause stop-loss. These candidate genes and variants shed new light on the molecular basis of donkey body size and will facilitate the breeding activities of donkeys.


Assuntos
Equidae , Genoma , Animais , China , Equidae/genética , Sequenciamento de Nucleotídeos em Larga Escala , Polimorfismo de Nucleotídeo Único , Seleção Genética , Análise de Sequência de DNA
12.
Anim Genet ; 53(3): 368-379, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35307856

RESUMO

The aim of the present study was to analyze the main factors that have a significant impact on skin thickness, and to further identify the genes and signaling pathways regulating skin growth by RNA-seq in Dezhou donkeys. Skin samples from different body regions of 15 slaughtered donkeys were obtained to study variations in skin thickness over the bodies. Skin thickness data for another 514 donkeys was obtained by minimally invasive skin sampling from the back, and measurements of the donkeys' body size traits and pedigree data were also collected. These data were used to analyze changes in skin thickness and estimate genetic parameters. In addition, transcriptomic analysis was conducted on the skin tissues of individuals from two groups with significant differences in skin thickness. Our results showed that skin thickness over the bodies ranged from 1.08 to 4.36 mm. The skin from the back was the thickest and had the highest correlation with that of other regions of the body. The skin thickness decreased from the back to the side of the ventral abdomen, and the skin thickness on the limbs increased from the proximal end to the distal end. The results also showed that the skin from the same body regions of jacks was thicker than that of jennies in the same age group. The skin thickness of jennies increased from birth to the age of 2 and then clearly decreased after 2 years of age. The estimated heritability of skin thickness was 0.15, and the genetic correlations between skin thickness and body size traits were negligible. Transcriptome analysis showed that the thick-skin group had 65 up-regulated genes and 38 down-regulated genes compared with the thin-skin group. The differentially expressed genes were highly enriched in epidermal development and cell adhesion molecule signaling pathways. We identified the candidate genes responsible for variations in skin thickness in the Dezhou donkey, including KRT10, KRT1, CLDN9, MHCII and MMP28. These results contribute to a better understanding of the growth and development of donkey skin, reveal the molecular mechanism responsible for donkey skin thickness and suggest directions for genetic selection in the Dezhou donkey population.


Assuntos
Equidae , Animais , Tamanho Corporal/genética , Equidae/genética , Feminino , Fenótipo , RNA-Seq
13.
Compr Rev Food Sci Food Saf ; 21(6): 4812-4846, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36201389

RESUMO

Freezing can prolong the shelf life of muscle foods and is widely used in their preservation. However, inevitable quality deterioration can occur during freezing, frozen storage, and thawing. This review explores the eating quality deterioration characteristics (color, water holding capacity, tenderness, and flavor) and mechanisms (irregular ice crystals, oxidation, and hydrolysis of lipids and proteins) of frozen muscle foods. It also summarizes and classifies the novel physical-field-assisted-freezing technologies (high-pressure, ultrasound, and electromagnetic) and bioactive antifreeze (ice nucleation proteins, antifreeze proteins, natural deep eutectic solvents, carbohydrate, polyphenol, phosphate, and protein hydrolysates), regulating the dynamic process from water to ice. Moreover, some novel thermal and nonthermal thawing technologies to resolve the loss of water and nutrients caused by traditional thawing methods were also reviewed. We concluded that the physical damage caused by ice crystals was the primary reason for the deterioration in eating quality, and these novel techniques promoted the eating quality of frozen muscle foods under proper conditions, including appropriate parameters (power, time, and intermittent mode mentioned in ultrasound-assisted techniques; pressure involved in high-pressure-assisted techniques; and field strength involved in electromagnetic-assisted techniques) and the amounts of bioactive antifreeze. To obtain better quality frozen muscle foods, more efficient technologies and substances must be developed. The synergy of novel freezing/thawing technology may be more effective than individual applications. This knowledge may help improve the eating quality of frozen muscle foods.


Assuntos
Conservação de Alimentos , Gelo , Gelo/análise , Conservação de Alimentos/métodos , Água/química , Músculos/química , Tecnologia
14.
J Am Chem Soc ; 143(20): 7819-7827, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33983725

RESUMO

Product selectivity in multielectron electrocatalytic reactions is crucial to energy conversion efficiency and chemical production. However, a present practical drawback is the limited understanding of actual catalytic active sites. Here, using as a prototype single-atom catalysts (SACs) in acidic oxygen reduction reaction (ORR), we report the structure-property relationship of catalysts and show for the first time that molecular-level local structure, including first and second coordination spheres (CSs), rather than individual active atoms, synergistically determines the electrocatalytic response. ORR selectivity on Co-SACs can be tailored from a four-electron to a two-electron pathway by modifying first (N or/and O coordination) and second (C-O-C groups) CSs. Using combined theoretical predictions and experiments, including X-ray absorption fine structure analyses and in situ infrared spectroscopy, we confirm that the unique selectivity change originates from the structure-dependent shift of active sites from the center Co atom to the O-adjacent C atom. We show this optimizes the electronic structure and *OOH adsorption behavior on active sites to give the present "best" activity and selectivity of >95% for acidic H2O2 electrosynthesis.

15.
J Am Chem Soc ; 143(44): 18643-18651, 2021 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-34726407

RESUMO

Although great progress has been made in artificial enzyme engineering, their catalytic performance is far from satisfactory as alternatives of natural enzymes. Here, we report a novel and efficient strategy to access high-performance nanozymes via direct atomization of platinum nanoparticles (Pt NPs) into single atoms by reversing the thermal sintering process. Atomization of Pt NPs into single atoms makes metal catalytic sites fully exposed and results in engineerable structural and electronic properties, thereby leading to dramatically enhanced enzymatic performance. As expected, the as-prepared thermally stable Pt single-atom nanozyme (PtTS-SAzyme) exhibited remarkable peroxidase-like catalytic activity and kinetics, far exceeding the Pt nanoparticle nanozyme. The following density functional theory calculations revealed that the engineered P and S atoms not only promote the atomization process from Pt NPs into PtTS-SAzyme but also endow single-atom Pt catalytic sites with a unique electronic structure owing to the electron donation of P atoms, as well as the electron acceptance of N and S atoms, which simultaneously contribute to the substantial enhancement of the enzyme-like catalytic performance of PtTS-SAzyme. This work demonstrates that thermal atomization of the metal nanoparticle-based nanozymes into single-atom nanozymes is an effective strategy for engineering high-performance nanozymes, which opens up a new way to rationally design and optimize artificial enzymes to mimic natural enzymes.


Assuntos
Engenharia Química/métodos , Enzimas/síntese química , Enzimas/metabolismo , Nanopartículas Metálicas/química , Platina/química , Catálise
16.
Philos Trans A Math Phys Eng Sci ; 379(2208): 20200398, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34455839

RESUMO

A model based on the Lattice Boltzmann method is developed to study the flow of reactive electro-kinetic fluids in porous media. The momentum, concentration and electric/potential fields are simulated via the Navier-Stokes, advection-diffusion/Nernst-Planck and Poisson equations, respectively. With this model, the total density and velocity fields, the concentration of reactants and reaction products, including neutral and ionized species, the electric potential and the interaction forces between the fields can be studied, and thus we provide an insight into the interplay between chemistry, flow and the geometry of the porous medium. The results show that the conversion efficiency of the reaction can be strongly influenced by the fluid velocity, reactant concentration and by porosity of the porous medium. The fluid velocity determines how long the reactants stay in the reaction areas, the reactant concentration controls the amount of the reaction material and with different dielectric constant, the porous medium can distort the electric field differently. All these factors make the reaction conversion efficiency display a non-trivial and non-monotonic behaviour as a function of the flow and reaction parameters. To better illustrate the dependence of the reaction conversion efficiency on the control parameters, based on the input from a number of numerical investigations, we developed a phenomenological model of the reactor. This model is capable of capturing the main features of the causal relationship between the performance of the reactor and the main test parameters. Using this model, one could optimize the choice of reaction and flow parameters in order to improve the performance of the reactor and achieve higher production rates. This article is part of the theme issue 'Progress in mesoscale methods for fluid dynamics simulation'.

17.
Proc Natl Acad Sci U S A ; 115(18): E4151-E4158, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29678829

RESUMO

Tea, one of the world's most important beverage crops, provides numerous secondary metabolites that account for its rich taste and health benefits. Here we present a high-quality sequence of the genome of tea, Camellia sinensis var. sinensis (CSS), using both Illumina and PacBio sequencing technologies. At least 64% of the 3.1-Gb genome assembly consists of repetitive sequences, and the rest yields 33,932 high-confidence predictions of encoded proteins. Divergence between two major lineages, CSS and Camellia sinensis var. assamica (CSA), is calculated to ∼0.38 to 1.54 million years ago (Mya). Analysis of genic collinearity reveals that the tea genome is the product of two rounds of whole-genome duplications (WGDs) that occurred ∼30 to 40 and ∼90 to 100 Mya. We provide evidence that these WGD events, and subsequent paralogous duplications, had major impacts on the copy numbers of secondary metabolite genes, particularly genes critical to producing three key quality compounds: catechins, theanine, and caffeine. Analyses of transcriptome and phytochemistry data show that amplification and transcriptional divergence of genes encoding a large acyltransferase family and leucoanthocyanidin reductases are associated with the characteristic young leaf accumulation of monomeric galloylated catechins in tea, while functional divergence of a single member of the glutamine synthetase gene family yielded theanine synthetase. This genome sequence will facilitate understanding of tea genome evolution and tea metabolite pathways, and will promote germplasm utilization for breeding improved tea varieties.


Assuntos
Camellia sinensis/genética , Evolução Molecular , Duplicação Gênica , Genoma de Planta , Chá , Camellia sinensis/metabolismo
18.
Angew Chem Int Ed Engl ; 60(6): 3212-3221, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33124719

RESUMO

Demonstrated here is the correlation between atomic configuration induced electronic density of single-atom Co active sites and oxygen reduction reaction (ORR) performance by combining density-functional theory (DFT) calculations and electrochemical analysis. Guided by DFT calculations, a MOF-derived Co single-atom catalyst with the optimal Co1 -N3 PS active moiety incorporated in a hollow carbon polyhedron (Co1 -N3 PS/HC) was designed and synthesized. Co1 -N3 PS/HC exhibits outstanding alkaline ORR activity with a half-wave potential of 0.920 V and superior ORR kinetics with record-level kinetic current density and an ultralow Tafel slope of 31 mV dec-1 , exceeding that of Pt/C and almost all non-precious ORR electrocatalysts. In acidic media the ORR kinetics of Co1 -N3 PS/HC still surpasses that of Pt/C. This work offers atomic-level insight into the relationship between electronic density of the active site and catalytic properties, promoting rational design of efficient catalysts.

19.
Philos Trans A Math Phys Eng Sci ; 378(2175): 20190396, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32564723

RESUMO

A lattice Boltzmann (LB) model is developed, validated and used to study simplified plasma/flow problems in complex geometries. This approach solves a combined set of equations, namely the Navier-Stokes equations for the momentum field, the advection-diffusion and the Nernst-Planck equations for electrokinetic and the Poisson equation for the electric field. This model allows us to study the dynamical interaction of the fluid/plasma density, velocity, concentration and electric field. In this work, we discuss several test cases for our numerical model and use it to study a simplified plasma fluid flowing and reacting inside a packed bed reactor. Inside the packed bed, electric breakdown reactions take place due to the electric field, making neutral species ionize. The presence of the packed beads can help enhance the reaction efficiency by locally increasing the electric field, and the size of packed beads and the pressure drop of the packed bed do influence the outflux. Hence trade-offs exist between reaction efficiency and packing porosity, the size of packing beads and the pressure drop of the packed bed. Our model may be used as a guidance to achieve higher reaction efficiencies by optimizing the relevant parameters. This article is part of the theme issue 'Fluid dynamics, soft matter and complex systems: recent results and new methods'.

20.
BMC Vet Res ; 16(1): 338, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933535

RESUMO

BACKGROUND: This study aims to determine the effects of transportation on the nasal microbiota of healthy donkeys using 16S rRNA sequencing. RESULTS: Deep nasal swabs and blood were sampled from 14 donkeys before and after 21 hours' long-distance transportation. The values of the plasma hormone (cortisol (Cor), adrenocorticotrophic hormone (ACTH)), biochemical indicators (total protein (TP), albumin (ALB), creatinine (CREA), lactic dehydrogenase (LDH), aspartate transaminase (AST), creatine kinase (CK), blood urea (UREA), plasma glucose (GLU)) and blood routine indices (white blood cell (WBC), lymphocyte (LYM), neutrophil (NEU), red blood cell (RBC), hemoglobin (HGB)) were measured. 16S rRNA sequencing was used to assess the nasal microbiota, including alpha diversity, beta diversity, and phylogenetic structures. Results showed that levels of Cor, ACTH, and heat-shock protein 90 (HSP90) were significantly increased (p < 0.05) after long-distance transportation. Several biochemical indicators (AST, CK) and blood routine indices (Neu, RBC, and HGB) increased markedly (p < 0.05), but the LYM decreased significantly (p < 0.05). Nine families and eight genera had a mean relative abundance over 1%. The predominant phyla in nasal microbiota after and before transportation were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Transportation stress induced significant changes in terms of nasal microbiota structure compared with those before transportation based on principal coordinate analysis (PCoA) coupled with analysis of similarities (ANOSIM) (p < 0.05). Among these changes, a notably gain in Proteobacteria and loss in Firmicutes at the phylum level was observed. CONCLUSIONS: These results suggest transportation can cause stress to donkeys and change the richness and diversity of nasal microbiota. Further studies are required to understand the potential effect of these microbiota changes on the development of donkey respiratory diseases.


Assuntos
Equidae/sangue , Equidae/microbiologia , Nariz/microbiologia , Meios de Transporte , Animais , Aspartato Aminotransferases/sangue , Bactérias/classificação , Bactérias/genética , Contagem de Células Sanguíneas/veterinária , China , Creatina Quinase/sangue , Equidae/fisiologia , Masculino , Microbiota , RNA Ribossômico 16S/genética , Estresse Fisiológico
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