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1.
Br J Pharmacol ; 2020 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-32037512

RESUMO

BACKGROUND AND PURPOSE: Non-alcoholic fatty liver disease (NAFLD) is a worldwide public health problem with no established pharmacological therapy. Here, we explored the potential benefit of P7C3-A20, a novel aminopropyl carbazole compound with neuroprotective activity, in a NAFLD model, induced in mice by a high-fat diet (HFD). EXPERIMENTAL APPROACH: C57BL/6J mice were given a HFD (42% fat content) for 16 weeks to induce NAFLD. P7C3-A20 (20 mg·kg-1 ·day-1 ) was given by gavage for 2 weeks. Indirect calorimetry, histological analysis, immunoblotting, immunohistochemistry, and biomedical examinations were performed. Gut microbiota were determined using a 16S ribosomal RNA sequencing analysis. KEY RESULTS: P7C3-A20 treatment reduced body weight gain/adiposity, improved insulin resistance, promoted energy expenditure (O2 consumption/CO2 production), inhibited lipid oxidation, suppressed hepatic inflammation (Kupffer cell number and pro-inflammatory factors), decreased necroptosis/apoptosis (receptor-interacting protein kinase 3, cleaved caspase-3, and TUNEL), and alleviated liver fibrosis and injury. Mechanistically, P7C3-A20 stimulated FGF21 and FGF1 via activating liver kinase B1 (LKB1) and AMP-activated protein kinase (AMPK), which further resulted in a reduced nuclear translocation of CREB-regulated transcription coactivator 2 (CRTC2). In AMPKα2 knockout mice, the protection of P7C3-A20 against HFD-induced metabolism abnormalities and fat accumulation, as well as the elevation of blood FGF21 and FGF1, was abolished. P7C3-A20 increased the gut microbiota species richness. Moreover, it enhanced the proportions of Akkermansia, Lactobacillus, and Prevotellaceae, while reducing the proportions of Enterobacteriaceae, Escherichia, and Parasutterella. CONCLUSIONS AND IMPLICATIONS: P7C3-A20 increased levels of NAD+ and alleviated NAFLD through stimulating FGF21 and FGF1 in an LKB1/AMPK/CRTC2-dependent manner and shaping gut microbiota.

2.
Bioresour Technol ; 305: 123010, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32105844

RESUMO

In this study, a new strain of Lactobacillus plantarum (CY.6) was identified and its L-arabinose isomerase (L-AI) encoding gene (araA) was overexpressed in Escherichia coli BL21 for the biosynthesis of D-tagatose from milk whey powders (WP). Whole-cell biotransformation of lactose in WP into D-tagatose was done by three technological approaches, including 100%, 50% and 0% hydrolysis of lactose in WP before biotransformation, where simultaneous saccharification and biotransformation (SSB, 0% prior hydrolysis of lactose) produced maximum amounts of D-tagatose. Two-stage SSB provided 73.6% conversion efficiency (based on D-galactose) and 36.8% (in term of lactose), with 51.5 g/L of D-tagatose after 96 h, while concentration of D-tagatose produced after first stage was 34.4 g/L. Yield and volumetric productivity of D-tagatose after two-stage SSB were found to be 0.26 g/g of WP (0.37 g/g of lactose, 0.74 g/g of D-galactose produced from lactose) and 0.54 g/L/h, respectively.

3.
Anal Bioanal Chem ; 412(6): 1317-1324, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31927600

RESUMO

Herein, a dual-emission metal-organic framework based ratiometric fluorescence nanoprobe was reported for detecting copper(II) ions. In particular, carbon dots (CDs) and gold nanoclusters (AuNCs) were embedded into ZIF-8 (one of the classical metal-organic frameworks) to form CDs/AuNCs@ZIF-8 nanocomposites, which exhibited dual-emission peaks at UV excitation. In the presence of Cu2+, the fluorescence attributed to AuNCs can be rapidly quenched, while the fluorescence of CDs serves as reference with undetectable changes. Therefore, the CDs/AuNCs@ZIF-8 nanocomposites were utilized as a ratiometric fluorescence nanoprobe for sensitive and selective detection of Cu2+. A good linear relationship between the ratiometric fluorescence signal of CDs/AuNCs@ZIF-8 and Cu2+ concentration was obtained in the range of 10-3-103 µM, and the detection limit was as low as 0.3324 nM. The current ratiometric fluorescence nanoprobe showed promising prospects in cost-effective and rapid determination of Cu2+ ions with good sensitivity and selectivity. Furthermore, this nanoprobe has been successfully applied for the quantitative detection of Cu2+ in serum samples, indicating its value of practical application. Graphical abstract Carbon dots (CDs) and gold nanoclusters (AuNCs) were embedded into metal-organic frameworks (ZIF-8) to form CDs/AuNCs@ZIF-8 nanocomposites, which exhibited dual-emission peaks at 365 nm excitation. In the presence of Cu2+, the fluorescence emission peak at 574 nm can rapidly respond by quenching, while the fluorescence at 462 nm serves as reference with undetectable changes.

4.
Physiol Plant ; 168(1): 98-117, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31017672

RESUMO

WRKY transcription factors play a key role in the tolerance of biotic and abiotic stresses across various crop species, but the function of some WRKY genes, particularly in tomato, remains unexplored. Here, we characterize the roles of a previously unstudied WRKY gene, SlWRKY8, in the resistance to pathogen infection and the tolerance to drought and salt stresses. Expression of SlWRKY8 was up-regulated upon Pseudomonas syringae pv. tomato DC3000 (Pst. DC3000), abiotic stresses such as drought, salt and cold, as well as ABA and SA treatments. The SlWRKY8 protein was localized to the nucleus with no transcription activation in yeast, but it could activate W-box-dependent transcription in plants. The overexpression of SlWRKY8 in tomato conferred a greater resistance to the pathogen Pst. DC3000 and resulted in the increased transcription levels of two pathogen-related genes SlPR1a1 and SlPR7. Moreover, transgenic plants displayed the alleviated wilting or chlorosis phenotype under drought and salt stresses, with higher levels of stress-induced osmotic substances like proline and higher transcript levels of the stress-responsive genes SlAREB, SlDREB2A and SlRD29. Stomatal aperature was smaller under drought stress in transgenic plants, maintaining higher water content in leaves compared with wild-type plants. The oxidative pressure, indicated by the concentration of hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA), was also reduced in transgenic plants, where we also observed higher levels of antioxidant enzyme activities under stress. Overall, our results suggest that SlWRKY8 functions as a positive regulator in plant immunity against pathogen infection as well as in plant responses to drought and salt stresses.

6.
ACS Appl Mater Interfaces ; 11(43): 40034-40042, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31580639

RESUMO

Rational design and construction of effective silicon (Si) electrode structures to relieve large volumetric changes that occur during the charge/discharge process remain significant challenges for the development of robust lithium-ion batteries (LIBs). Herein, we propose an electrically conductive poly[3-(potassium-4-butanoate)thiophene] (PPBT) capping layer on the Si surface (Si@PPBT) to serve as the active material and be used in conjunction with a common polymer binder as an approach to tackle issues emanating from volumetric changes. The PPBT protective shell layer provides the system with tolerance toward variations in active material volume during cycling, improves the dispersion of Si nanoparticles in the binder, enhances the electrolyte uptake rate, and provides a strong adhesion force between the Si/carbon additives/current collector, thereby helping to maintain electrode integrity during the charge/discharge process. The π-conjugated polythiophene backbone structure also allows the Si core to maintain electrical contact with carbon additives and/or polymer binder, enabling the formation of effective electrical transport bridges and stabilizing solid electrolyte interphase layer growth. The integrated Si@PPBT/carboxymethyl cellulose (CMC) anode exhibited high initial Coulombic efficiency (84.9%), enhanced rate capability performance, and long cycling stability with a reversible capacity of 1793 mA h g-1 after 200 cycles, 3.4 times higher than that of pristine Si anodes with the same CMC binder (528 mA h g-1). The results suggest that the Si@PPBT design presents a promising approach to promote the practical use of Si anodes in LIBs, which could be extended to other anode materials exhibiting large volume changes during lithiation/delithiation.

7.
J Pineal Res ; 67(4): e12611, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31541591

RESUMO

Melatonin has been previously shown to prevent nonalcoholic fatty liver disease (NAFLD), yet the underlying mechanisms are poorly understood. Here, we identified a previously unknown regulatory action of melatonin on apoptosis signal-regulating kinase 1 (ASK1) signaling pathway in the pathogenesis and development of NAFLD. Although melatonin administration did not alter food intake, it significantly alleviated fatty liver phenotypes, including the body weight gain, insulin resistance, hepatic lipid accumulation, steatohepatitis, and fibrosis in a high-fat diet (HFD)-induced NAFLD mouse model (in vivo). The protection of melatonin against NAFLD was not affected by inactivation of Kupffer cell in this model. In NAFLD mice liver, ASK1 signal cascade was substantially activated, evidence by the enhancement of total ASK1, phospho-ASK1, phospho-MKK3/6, phospho-p38, phospho-MKK4/7, and phospho-JNK. Melatonin treatment significantly suppressed the ASK1 upregulation and the phosphorylation of ASK1, MKK3/6, MKK4/7, p38, and JNK. Mechanistically, we found that lipid stress triggered the interaction between ASK1 and TNF receptor-associated factors (TRAFs), including TRAF1, TRAF2, and TRAF6, which resulted in ASK1 deubiquitination and thereby increased ASK1 protein stability. Melatonin did not alter ASK1 mRNA level; however, it activated a scaffold protein ß-arrestin-1 and enabled it to bind to ASK1, which antagonized the TRAFs-mediated ASK1 deubiquitination, and thus reduced ASK1 protein stability. Consistent with these findings, knockout of ß-arrestin-1 in mice partly abolished the protection of melatonin against NAFLD. Taken together, our results for the first time demonstrate that melatonin safeguards against NAFLD by eliminating ASK1 activation via inhibiting TRAFs-mediated ASK1 deubiquitination and stabilization in a ß-arrestin-1 dependent manner.

8.
Sci Rep ; 9(1): 12361, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31451745

RESUMO

Understanding the impacts of climate on insect pest population dynamics is crucial in forecasting pest outbreaks and developing a sustainable pest management strategy. The orange wheat blossom midge, Sitodiplosis mosellana (Géhin), is a chronic winter wheat (Triticum aestivum L.) pest in China, and its population density can strongly fluctuate. We analyzed climate factors (temperature and precipitation) associated with population dynamics of S. mosellana in a large-scale field trial in central China from 1984 to 2013 using Generalized linear mixed effects models. We found total precipitation during January-March was significantly positively correlated with population density of S. mosellana, whereas temperature parameters were not correlated with the population levels. Moreover, S. mosellana population size was significantly negative effected by interaction between temperature and precipitation, which showed that high precipitation with low temperature in spring also reduced the population density. This suggests that annual population size of S. mosellana in Central China is determined by soil moisture in early spring. These results provide basic information that will help in forecasting population levels and in developing a sound pest management strategy for S. mosellana.

9.
ACS Appl Mater Interfaces ; 11(28): 25338-25350, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31265224

RESUMO

Inducing the self-assembly of π-conjugated polymers into semicrystalline aggregates has been a topic of substantial interest in the field of organic electronics and is typically achieved using energy-intensive solution processing or postfilm deposition methods. Here, we demonstrate the ability of bioderived cellulose nanocrystals (CNCs) to act as structure-directing agents for the conjugated semiconducting polymer, poly(3-hexylthiophene) (P3HT). CNCs were grafted with polystyrene, P3HT or poly(N-isopropylacrylamide), and subsequently blended with P3HT in solution to study the effect on conjugated polymer self-assembly. The presence of polymer-grafted CNCs resulted in an increase in P3HT semicrystalline aggregate formation, the degree of which depended on the surface free energy of the grafted polymer. The time-dependent P3HT aggregation was characterized by UV-vis spectroscopy, and the resulting data was fit to the Avrami crystallization model. The surface energies of each additive were calculated via contact angle measurements and were used to elucidate the mechanism of P3HT aggregation in these blended systems. P3HT aggregation was enhanced by unfavorable polymer-polymer interactions at the CNC surface, and spatial confinement effects that were imposed by phase separation. Finally, films were cast from the P3HT/CNC solutions and their electronic performance was characterized by organic field-effect transistor device measurements. Films containing polymer-grafted CNCs exhibited higher charge-carrier mobilities, in some cases, up to a 6-fold increase. These bioderived particles constituted a significant volume fraction of the deposited P3HT thin films with an increase in performance, showing promise as a method for reducing costs and improving the sustainability of organic electronics.

11.
Matern Child Health J ; 23(8): 1140-1145, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209616

RESUMO

OBJECTIVES: This study sought to describe the knowledge and perceptions of pregnant women in Miami-Dade County concerning Zika virus (ZIKV) in their community, to characterize their testing behaviors, and to identify any barriers that would keep them from seeking testing. METHODS: The Florida Department of Health in Miami-Dade County partnered with the Healthy Start Coalition of Miami-Dade to administer an assessment survey in eight OBGYN clinics from June to August 2017. The survey captured past ZIKV testing practices, attitudes towards testing, barriers to testing, risk perception of ZIKV in the participants' community, and ZIKV-related knowledge. Descriptive analyses were performed on variables of interest. Chi squared tests examined associations between categorical variables. RESULTS: A total of 363 participants were included in the analysis. Of these, 203 (55.9%) thought they should be tested for ZIKV, and less than half of the participants reported having been previously tested (152, 41.9%). Participants with some high school education were significantly more likely than those with higher education levels to see ZIKV as a "big problem" in the community (p = 0.0026). There was a significant association (p ≤ 0.0001) between women who thought that they should be tested, and those who perceived ZIKV to be a medium or big problem in their community. CONCLUSIONS FOR PRACTICE: Health interventions that focus on increasing ZIKV knowledge should also place greater emphasis on risk communication when targeting the pregnant population. Having a higher risk perception may be more predictive of testing behaviors than having a lack of barriers or a high level of ZIKV-related knowledge.


Assuntos
Programas de Rastreamento/psicologia , Percepção , Gestantes/psicologia , Risco Ajustado/normas , Infecção por Zika virus/diagnóstico , Adolescente , Adulto , Feminino , Florida , Humanos , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Gravidez , Risco Ajustado/métodos , Medição de Risco/métodos , Inquéritos e Questionários , Zika virus/patogenicidade , Infecção por Zika virus/psicologia
12.
Front Plant Sci ; 10: 699, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31214219

RESUMO

Abscisic acid responsive element binding factors (ABFs) play crucial roles in plant responses to abiotic stress. However, little is known about the roles of ABFs in alpine subnival plants, which can survive under extreme environmental conditions. Here, we cloned and characterized an ABF1 homolog, CbABF1, from the alpine subnival plant Chorispora bungeana. Expression of CbABF1 was induced by cold, drought, and abscisic acid. Subcellular localization analysis revealed that CbABF1 was located in the nucleus. Further, CbABF1 had transactivation activity, which was dependent on the N-terminal region containing 89 residues. A Snf1-related protein kinase, CbSnRK2.6, interacted with CbABF1 in yeast two-hybrid analysis and bimolecular fluorescence complementation assays. Transient expression assay revealed that CbSnRK2.6 enhanced the transactivation of CbABF1 on ABRE cis-element. We further found that heterologous expression of CbABF1 in tobacco improved plant tolerance to freezing and drought stress, in which the survival rates of the transgenic plants increased around 40 and 60%, respectively, compared with wild-type plants. Moreover, the transgenic plants accumulated less reactive oxygen species, accompanied by high activities of antioxidant enzymes and elevated expression of stress-responsive genes. Our results thus suggest that CbABF1 is a transcription factor that plays an important role in cold and drought tolerance and is a candidate gene in molecular breeding of stress-tolerant crops.

13.
Bioresour Technol ; 284: 188-196, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30933827

RESUMO

The aim of this work was to study the random mutagenesis of Clostridium butyricum strain. A high 1,3-PD tolerant mutant strain, designated as C. butyricum YP855, was developed from the wild strain C. butyricum XYB11, using combined chemical (NTG, N-methyl-N'-nitro-N-nitrosoguanidine,) and plasma-based mutagenesis (ARTP, atmospheric and room temperature plasma). The YP855 showed a maximum tolerance of 85 g/L to 1,3-PD (up to 30.8% increase) when compared with the tolerance exhibited by the wild strain. Under the optimum conditions as established by the response surface methodology (RSM), the mutant strain produced 37.20 g/L of 1,3-PD, which is 29.48% higher than the concentration obtained from the wild strain (28.73 g/L). This research would offer information for further development of the biosynthesis of 1,3-PD by the mutant strain of C. butyricum.


Assuntos
Clostridium butyricum/metabolismo , Propilenoglicóis/metabolismo , Clostridium butyricum/genética , Fermentação , Mutagênese
14.
Disaster Med Public Health Prep ; 13(1): 94-96, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30012229

RESUMO

OBJECTIVE: The Florida Department of Health in Miami-Dade County (DOH-Miami-Dade) investigated 106 reported carbon monoxide (CO) exposures over a 9-day timeframe after Hurricane Irma. This report evaluates risk factors for CO poisoning and the importance of heightened surveillance following natural disasters. METHODS: Data on CO poisoning cases from September 9 to 18, 2017 were extracted from Merlin, the Florida Department of Health Surveillance System. Medical records were obtained and follow-up interviews were conducted to collect data on the confirmed CO poisoning cases. Data were analyzed using SAS v9.4. RESULTS: Ninety-one of the 106 people exposed to CO met the case definition for CO poisoning: 64 confirmed, 7 probable, and 20 suspect cases. Eighty-eight percent of the affected individuals were evaluated in emergency departments and 11.7% received hyperbaric oxygen treatment. The most frequently reported symptoms included headache (53.3%), dizziness (50.7%), and nausea (46.7%). Three patients expired due to their exposure to CO. CONCLUSIONS: Post Hurricane Irma, the DOH-Miami-Dade investigated numerous cases for CO exposure. By understanding who is most likely to be impacted by CO and the impact of generators' location on people's health, education efforts can be tailored to the population most at risk and further CO exposures and related mortalities following natural disasters can be reduced. (Disaster Med Public Health Preparedness. 2019;13:94-96).


Assuntos
Intoxicação por Monóxido de Carbono/complicações , Intoxicação por Monóxido de Carbono/terapia , Tempestades Ciclônicas/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Monóxido de Carbono/efeitos adversos , Intoxicação por Monóxido de Carbono/epidemiologia , Criança , Pré-Escolar , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Florida/epidemiologia , Humanos , Oxigenação Hiperbárica/estatística & dados numéricos , Lactente , Masculino , Pessoa de Meia-Idade
15.
Clin Infect Dis ; 69(6): 949-955, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30452604

RESUMO

BACKGROUND: On 29 April 2015, the Florida Department of Health in Miami-Dade County (DOH Miami-Dade) was notified by a local dermatologist of 3 patients with suspected nontuberculous mycobacterial (NTM) infection after receiving tattoos at a local tattoo studio. METHODS: DOH Miami-Dade conducted interviews and offered testing, described below, to tattoo studio clients reporting rashes. Culture of clinical isolates and identification were performed at the Florida Bureau of Public Health Laboratories. Characterization of NTM was performed by the Centers for Disease Control and Prevention and the US Food and Drug Administration (FDA), respectively. Whole-genome sequencing (WGS) and single-nucleotide polymorphism (SNP) analyses were used to construct a phylogeny among 21 Mycobacterium isolates at the FDA. RESULTS: Thirty-eight of 226 interviewed clients were identified as outbreak-associated cases. Multivariate logistic regression revealed that individuals who reported gray tattoo ink in their tattoos were 8.2 times as likely to report a rash (95% confidence interval, 3.1-22.1). Multiple NTM species were identified in clinical and environmental specimens. Phylogenetic results from environmental samples and skin biopsies indicated that 2 Mycobacterium fortuitum isolates (graywash ink and a skin biopsy) and 11 Mycobacterium abscessus isolates (5 from the implicated bottle of graywash tattoo ink, 2 from tap water, and 4 from skin biopsies) were indistinguishable. In addition, Mycobacterium chelonae was isolated from 5 unopened bottles of graywash ink provided by 2 other tattoo studios in Miami-Dade County. CONCLUSIONS: WGS and SNP analyses identified the tap water and the bottle of graywash tattoo ink as the sources of the NTM infections.

16.
Angew Chem Int Ed Engl ; 58(9): 2638-2643, 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30577090

RESUMO

Porous organic cages (POCs) are individual soluble, porous molecules. When fabricated into mixed-matrix membranes (MMMs), the soluble POC molecules have the potential to exhibit intimate molecular-level mixing with the polymer matrix. POCs have only recently been incorporated into mixed matrix membrane materials, but this process has not yet resulted in significant improvements of membrane performance. Now, vertex-functionalized amorphous scrambled porous organic cages (ASPOCs) have been utilized as membrane performance enhancers and the amorphous ASPOC mixtures are observed to distribute throughout the matrix without any indication of particle formation or agglomeration, creating unique, molecularly mixed composite membranes. Overall, the molecularly mixed composite membrane provide significant increases in both membrane permeability and selectivity, offering new avenues for creation of membranes with unique properties in industrially relevant separations.

17.
Mol Med Rep ; 18(5): 4733-4738, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30221721

RESUMO

The aim of the present study was to investigate the acute effect and mechanism of tumor necrosis factor (TNF) on basolateral 50 pS K channels in the thick ascending limb (TAL) of the rat kidney. The TAL tubules were isolated from the rat kidney, and the activity of the 50 pS K channels was recorded using the patch­clamp technique. The results indicated that the application of TNF (10 nM) significantly activated the 50 pS K channels and the TNF effect was concentration­dependent. Inhibition of protein kinase A, phospholipase A2 and protein tyrosine kinase using pathway inhibitors (H89, AACOCF3 and Herbimycin A, respectively) did not abolish the stimulatory effect of TNF, indicating that none of these pathways mediated the TNF effect. By contrast, the phenylarsine oxide inhibitor against protein tyrosine phosphatase (PTP) decreased the activity of the 50 pS K channels and blocked the stimulatory effect of TNF on these channels. Furthermore, western blot analysis demonstrated that the application of TNF (10 nM) in the TAL increased the phosphorylation of PTP, an indication of PTP activity stimulation. Thus, it was concluded that the acute application of TNF may stimulate the basolateral 50 pS K channel in the TAL and the stimulatory effect of TNF may be mediated by the PTP­dependent pathway.


Assuntos
Túbulos Renais/metabolismo , Rim/metabolismo , Canais de Potássio/genética , Fator de Necrose Tumoral alfa/metabolismo , Animais , Ácidos Araquidônicos/administração & dosagem , Arsenicais/administração & dosagem , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Isoquinolinas/administração & dosagem , Rim/efeitos dos fármacos , Rim/patologia , Túbulos Renais/efeitos dos fármacos , Alça do Néfron/efeitos dos fármacos , Alça do Néfron/metabolismo , Masculino , Técnicas de Patch-Clamp , Inibidores de Fosfolipase A2/administração & dosagem , Fosfolipases A2/genética , Canais de Potássio/metabolismo , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Rifabutina/administração & dosagem , Rifabutina/análogos & derivados , Sulfonamidas/administração & dosagem , Fator de Necrose Tumoral alfa/administração & dosagem
18.
Bioresour Technol ; 247: 838-843, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30060420

RESUMO

In this study, a newly strain named Clostridium butyricum YJH-09 were isolated from the sample of pond soil and identified through physiological, biochemical and 16S rDNA analysis. Then, the dhaT gene encoding a novel 1,3-propanediol dehydrogenase (PDOR) was cloned from this strain and expressed in Escherichia coli BL21(DE3). Subsequently, the recombinant PDOR was purified and the optimal pH and temperature, specific activities and kinetic parameter were investigated. Furthermore, the whole cells of Clostridium butyricum YJH-09 mixed with BL21-dhaT were used to produce 1,3-PD through co-biotransformation. As results, 25.88g/L of 1,3-PD was generated with 0.54g/g yield from 50g/L glycerol in 30h, and the 1,3-PD production was increased more than 2-fold compared with wild type strain alone. This research would offer useful information for further development of the biosynthesis of 1,3-PD.


Assuntos
Álcool Desidrogenase , Clostridium butyricum/metabolismo , Propilenoglicóis , Biotransformação , DNA Bacteriano , Fermentação , Glicerol
19.
Sheng Wu Gong Cheng Xue Bao ; 34(7): 1069-1080, 2018 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-30058306

RESUMO

Crude glycerol is the main by-product of biodiesel production. A few microorganisms can transfer crude glycerol to 1,3-propanediol (1,3-PD) that is an important chemical material. There exist many limitations such as substrate inhibition, product inhibition when wild strains are used in 1,3-PD biosynthesis. In this review, based on the microbial transformation of 1,3-propanediol from glycerol and its limitations, some strategies using genetic engineering such as knockout or gene overexpression were summarized. The latest research progresses in biosynthesis of 1,3-propanediol from glycerol by genetically engineered strains are discussed.


Assuntos
Biocombustíveis , Glicerol/metabolismo , Microbiologia Industrial , Microrganismos Geneticamente Modificados , Propilenoglicóis/metabolismo , Fermentação
20.
J Theor Biol ; 455: 342-356, 2018 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-30053386

RESUMO

Chikungunya, dengue, and Zika viruses are all transmitted by Aedes aegypti and Aedes albopictus mosquito species, had been imported to Florida and caused local outbreaks. We propose a deterministic model to study the importation and local transmission of these mosquito-borne diseases. The purpose is to model and mimic the importation of these viruses to Florida via travelers, local infections in domestic mosquitoes by imported travelers, and finally non-travel related transmissions to local humans by infected local mosquitoes. As a case study, the model will be used to simulate the accumulative Zika cases in Florida. Since the disease system is driven by a continuing input of infections from outside sources, orthodox analytic methods based on the calculation of the basic reproduction number are inadequate to describe and predict their behavior. Via steady-state analysis and sensitivity analysis, effective control and prevention measures for these mosquito-borne diseases are tested.


Assuntos
Aedes/virologia , Surtos de Doenças , Modelos Biológicos , Mosquitos Vetores/virologia , Infecção por Zika virus , Zika virus , Animais , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/transmissão , Vírus Chikungunya , Dengue/epidemiologia , Dengue/transmissão , Vírus da Dengue , Florida/epidemiologia , Humanos , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão
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