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1.
Chemosphere ; 240: 124846, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550594

RESUMO

Cadmium (Cd) precipitation and dissolution in pore water is associated with dissolved organic carbon (DOC)-induced reduction-oxidation of sulfur (S) under waterlogging and is vital for controlling the bioavailability in paddy soil. A 120-day soil incubation experiment, including application of sulfur (S, 30 mg kg-1) and wheat straw (W, 1.0%) alone or in combination (W + S) into Cd-contaminated paddy soil under waterlogging, was conducted to investigate the dynamic of dissolved Cd and its relationship with DOC, S2-, Fe2+, pH, Eh and pe + pH in soil pore water. The results showed that the lowest dissolved Cd concentration was observed in the W + S-treated soil pore water among all treatments when the soil Eh remained at lower values during the period of 15-60 days of incubation, which could be attributed to CdS precipitation and/or co-precipitation of Cd absorbed by FeS2 because of the reduction in sulfur. The application of S resulted in a Cd rebound in the pore water irrespective of W addition when the Eh began to increase from its lowest values during the period of 45-75 days of incubation, and SOB genera were observed in the S added soil. This could be attributed to re-dissolution of the precipitated Cd in soils under the SOB-driven oxidation of sulfide such as CdS and FeS2. In conclusion, DOC-driven reduction-oxidation of sulfur controls Cd dissolution in the pore water of Cd-contaminated paddy soil under waterlogging conditions. Further studies are required to investigate the interaction of sulfur and SOM-induced DOC on Cd bioavailability in rice-planted paddy soils.

2.
Water Res ; 168: 115142, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31605831

RESUMO

Microbial nitrogen removal mediated by anaerobic ammonium oxidation (anammox) are cost-effective, yet it is time-consuming to accumulate the slow-growing anammox bacteria in conventional wastewater treatment plants (WWTPs). Inoculation of anammox enriched pellets is an effective way to establish anammox and achieve shortcut nitrogen removal in full-scale WWTPs. However, little is known about the complex microbial nitrogen-cycling networks in these anammox-inoculated WWTPs. Here, we applied metagenomic and metatranscriptomic tools to study the microbial nitrogen removal in three conventional WWTPs, which have been inoculated exogenous anammox pellets, representing partial-nitrification anammox (PNA) and nitrification-denitrification nitrogen removal processes. In the PNA system of Bali (BL), ammonia was partially oxidized by ammonia-oxidizing bacteria (AOB) Nitrosomonas and the oxidized nitrite and the remaining ammonium were directly converted to N2 by anammox bacteria Ca. Brocadia and Ca. Kuenenia. In the nitrification-denitrification system of Wenshan (WS), ammonia-oxidizing archaea (AOA) Thaumarchaeota unexpectedly dominated the nitrifying community in the presence of AOB Nitrosomonas. Meanwhile, the biomass yield of Ca. Brocadia was likely inhibited by the high biodegradable organic compound input and limited by substrate competitions from AOA, AOB, complete ammonia oxidizers (comammox) Nitrospira, nitrite-oxidizing bacteria (NOB) Nitrospira, and heterotrophic denitrifiers. Unexpectedly, comammox Nitrospira was the predominant nitrifier in the presence of AOB Nitrosomonas in the organic carbon-rich nitrification-denitrification system of Linkou (LK). These results clearly showed that distinct active groups were working in concert for an effective nitrogen removal in different WWTPs. This study confirmed the feasibility of anammox application in ammonium-rich systems by direct inoculation of the exogenous anammox pellets and improved our understanding of microbial nitrogen cycling in anammox-driven conventional WWTPs from both physiochemical and omics perspectives.


Assuntos
Nitrificação , Águas Residuárias , Amônia , Reatores Biológicos , Consórcios Microbianos , Nitritos , Nitrogênio , Ciclo do Nitrogênio , Oxirredução
3.
J Med Virol ; 92(1): 53-61, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31429946

RESUMO

Hepatitis B virus (HBV) DNA is vulnerable to editing by human apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) cytidine deaminases. However, the distribution of APOBEC-induced mutations on HBV DNA is not well characterized. To this end, we obtained the HBV DNA sequence of HBV-infected individuals with and without hepatocellular carcinoma (HCC and non-HCC groups, respectively) from NCBI database and calculated the rapo values of APOBEC-induced TpCpW→TpKpW mutation prevalence in HBV DNA. The results showed that the APOBEC-induced mutations were mainly distributed in the minus strand of non-HCC-derived HBV DNA (rapo = 2.04), while the mutation on the plus-strand was weaker (rapo = 0.99). There were high APOBEC-induced mutation regions in the minus strand of HBV DNA 1 to 1000 nucleotides (nts) region and in the plus-strand of HBV DNA 1000 to 1500 nts region; the mutations in the 1 to 1000 nts region were mainly TpCpW→TpTpW mutation types (total T/G: 111/18) and a number of these were missense mutations (missense/synonymous: 35/94 in P gene, 17/15 in S gene, and 5/10 in X gene). The difference between minus to plus-strand rapo of HCC-derived HBV DNA (1.96) was greater than that of the non-HCC group (1.05). The minus-strand rapo of HCC-derived HBV DNA regions 1000 to1500nts and 1500 to 2000 nts (rapo = 4.2 and 4.2) was also higher than that of the same regions of non-HCC-derived HBV DNA (rapo = 1.2 and 1.1). Finally, the ratio of minus to plus-strand rapo was used to distinguish HCC-derived HBV DNA from non-HCC-derived HBV DNA. This study unraveled the distribution characteristics of APOBEC-induced mutations on double strands of HBV DNA from HCC and non-HCC samples. Our findings would help understand the mechanism of APOBECs on HBV DNA and may provide important insights for the screening of HCC.

4.
Food Chem ; 306: 125625, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31606635

RESUMO

A novel ultrasonic-assisted vacuum drying technique for dehydrating garlic slices to give high quality products was developed. Garlic slices were dried at 60 °C using four methods: ultrasonic-assisted vacuum drying (USVD), vacuum drying (VD), ultrasonic-assisted drying (USD), and convective drying (CD, the control with no vacuum or ultrasonic applied). Drying kinetics, water-content changes, and properties of the garlic slices were assessed. Univariate linear and partial-least-squares regression models were used to predict the properties from low-field nuclear magnetic resonance parameters. USVD gave the shortest drying time (180 min less than CD) and provided a better garlic color and texture, and allicin retention rate than the other methods. Higher correlations between low-field nuclear magnetic resonance parameters and quality properties were found by partial-least-squares regression (PLSR) than by univariate analysis, with the analysis results being credible. Overall, ultrasonic-assisted vacuum drying produced high-quality products with its properties predicted well by low-field nuclear magnetic resonance.

5.
J Nanosci Nanotechnol ; 20(3): 1790-1798, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492344

RESUMO

Tungsten oxide microflowers (WO3 MFs) were fabricated by a simple hydrothermal process through adjusting the pH of the solution by HCl. These MFs possess the outer diameters of about 2 µm and are composed of numerous nanoplates with the average pore size of 10.9 nm. Chemiresistive activity of as-fabricated WO3 MFs sensor was attempted towards oxidizing and reducing target gases, revealing a superior selectivity to NO2 with a maximum response of 22.95 (2 ppm NO2) @105 °C compared to other target gases. One of the key features of as-fabricatedWO3 MFs sensor is the lower detection limit of 125 ppb and operating temperature of 105 °C to NO2 with better reproducibility, signifying commercial prospective of the developed sensor materials. Finally, the gas sensing mechanism of WO3 MFs sensor has been proposed.

6.
J Sci Food Agric ; 100(1): 184-192, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472017

RESUMO

BACKGROUND: Slight acidic electrolyzed water (SAEW) has been widely used in cleaning systems of fruit and vegetables. It strongly reduces microbial contamination. However, no information is available on whether SAEW offers the potential for fresh jujube cleaning. The purposes of this study were, first, to compare the effectiveness of SAEW with commercial sanitizers (i.e. sodium hypochlorite (NaClO) or calcium hypochlorite (Ca(ClO)2 )) on 'Jiancui' jujube; second, to determine the response of fruit decay, tissue calcium (Ca) content, and quality attributes to dip application of calcium nitrate (Ca(NO3 )2 ) by concentration; and third, to investigate the effects of SAEW combined with Ca(NO3 )2 or calcium acetate (Ca(OAc)2 )) on fruit Ca uptake, quality attributes, and bioactive compounds. RESULTS: Fruits washed with NaClO, Ca(ClO)2 , or an SAEW solution showed no difference in reduction of decay incidence. In contrast to NaClO treatment, SAEW or Ca(ClO)2 significantly retarded losses in fruit firmness (FF), green color (hue angle), and skin lightness (L*), and maintained intact pericarp tissue structure during storage at 1 °C. Application of Ca(NO3 )2 at 5-10 g L-1 effectively promoted Ca2+ uptake and minimized declines in FF and L* value but had no effect on decay development. Adding 10 g L-1 Ca(NO3 )2 or Ca(OAc)2 to SAEW provided an additional benefit in increasing decay resistance, increasing Ca2+ into fruit and increasing levels of bioactive compounds in jujube fruit. CONCLUSION: SAEW in combination with Ca(NO3 )2 or Ca(OAc)2 has commercial potential for fresh jujube disinfection and improving storage quality as a result of the cleaning processes. © 2019 Society of Chemical Industry.

7.
J Colloid Interface Sci ; 559: 88-95, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610308

RESUMO

In wet magnesia desulfurization, the ultrahigh stable catalysis of sulfite oxidation is a crucial step in byproduct reclaimation. In this study, a robust and efficient catalyst, Co-MOF-74(4), was synthesized through a facile solvothermal method with an optimal Co/ligand ratio of 4:1. The oxidation rate of magnesium sulfite catalyzed by Co-MOF-74(4) was >2.6 times higher than that of previously reported cobalt-based heterogeneous catalysts. Crucially, almost no attenuation of the catalytic activity was observed even after three reuse cycles. The properties of Co-MOF-74(4) before and after the reaction were characterized. Density functional theory calculations demonstrate that the unsaturated cobalt site on the open framework of Co-MOF-74(4) provides greater opportunity for active Co to be attacked by sulfite ions, resulting in the ultra-high catalytic activity of Co-MOF-74(4). In contrast to the conventional impregnated catalysts, the robust combination of active cobalt with ligands prohibits its stripping from the surface of Co-MOF-74(4) particles. The bond length, angle and lattice parameters have only slight changes after sulfite adsorption, which supports the stability of the catalyst in the reaction process.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31688313

RESUMO

OBJECTIVES: In longitudinal studies, serum biomarkers are often measured longitudinally which is valuable to predict the risk of disease progression. Previous risk prediction models for liver cirrhosis restrict data to baseline or baseline and a single follow-up time point, which failed to incorporate the time-dependent marker information. The aim of this study is to develop risk model in patients with chronic hepatitis B for dynamic prediction of cirrhosis by incorporating longitudinal clinical data. METHODS: Data from the hospital-based retrospective cohort at the Third Affiliated Hospital of Sun Yat-sen University, from 2004 to 2016, were analyzed. Using the multilevel logistic regression model, the time-dependent marker information and individual characteristics were taken as input, and the risk of at different time as the output. RESULTS: At the end of follow-up, 8.8% of patients progressed to cirrhosis, the average estimate values of hepatitis B virus DNA and alanine aminotransferase demonstrated a downward trend, the aspartate aminotransferase/alanine aminotransferase ratio showed a flat trend overall. The important predictors were as follows: age, oral antiviral treatment, hepatitis B virus DNA. This risk prediction model had an area under the receiver operator characteristic curve of 0.835 (95% confidence interval: 0.772-0.899) and 0.809 (95% confidence interval: 0.708-0.910) in the derivation and validation sets, respectively. CONCLUSION: Longitudinal prediction model can be used for dynamic prediction of disease progression and identify changing high-risk patients.

10.
Theriogenology ; 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31711699

RESUMO

Reproductive traits are important factors in sheep production. The Booroola fecundity (FecB) gene-the first major gene for prolificacy identified in sheep-has a positive effect on ovulation rates and litter size under natural reproductive conditions. However, the effect of the FecB gene on reproductive performance under assisted reproduction, which uses many artificial hormones, remains unclear. In the present study, we evaluated the effect of FecB (BMPR-1B mutation) on reproductive performance under assisted reproduction, and examined offspring body weight at birth and weaning and survival rate at weaning. There were no differences among three genotype groups (homozygous carrier, BB; heterozygous carrier, B+; non-carrier, ++) in terms of estrus detection rate, time to estrus onset, or estrus duration following estrus synchronization (P > 0.05). The pregnancy rates at 60 d were similar among three genotype groups after artificial insemination (P > 0.05). However, the B allele had an additive effect on litter size (one copy resulted in an increase of 0.88 lambs and two copies produced an additional 0.41 lambs; P < 0.01), and increased lambing and fecundity rates (P < 0.01). After multiple ovulation, the average numbers of recovered embryos per ewe were 9.16 ±â€¯0.79, 8.20 ±â€¯0.77, and 8.44 ±â€¯0.61 in the BB, B+, and ++ ewes, respectively (P > 0.05). There were no differences in the fertilization rate or numbers of grade 1-2 embryos among different groups (P > 0.05). The birth and weaning weights of lambs from BB and B+ ewes were lower than those of lambs born from ++ ewes (P < 0.01) owing to the high fecundity. The survival rate of lambs at weaning did not differ among groups (P > 0.05). Our results indicated that the presence of the B allele had an additive effect on litter size after artificial insemination, but it did not influence the parameters of estrus synchronization and multiple ovulation. Furthermore, the higher prolificacy in ewes carrying the B allele was associated with a reduction in offspring body weight at birth and weaning.

11.
Bioresour Technol ; 296: 122319, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31689612

RESUMO

A kind of reduced graphene oxide decorated with titanium-based (RGO/TiO2) composites are successfully synthesized and employed in this current study as a novel nonprecious metal catalyst for enhancing bioelectricity generation and cathodic oxygen reduction reaction (ORR) in single chamber microbial fuel cells (MFCs). Compared with commercial Pt/C, RGO/TiO2 shows obviously enhanced oxygen reduction reaction activity due to the appropriately-permeated, large electrochemical active area, enough exposure of electrocatalytic active sites of RGO/TiO2. The air-cathode MFC with RGO/TiO2-1 cathode achieves 1786.7 mW m-3 of power density, 86.7% ±â€¯1.2% of COD removal and 31.6% ±â€¯1.1% of CE, which are higher than commercial Pt/C. Moreover, RGO/TiO2-1 cathode exhibits high-effective electrocatalytic activity, and the power density of RGO/TiO2-1 can keep a stable level and only has a minor decline (5.35%) during 30-cycles operation. These results indicate that RGO/TiO2-1 is a potential cathode catalyst, markedly enhancing cathode ORR, wastewater treatment efficiency, and bioelectricity generation of MFC.

12.
Cells ; 8(11)2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31689969

RESUMO

MicroRNAs (miRNAs) are important negative regulators of genes involved in physiological and pathological processes in plants and animals. It is worth exploring whether plant miRNAs play a cross-kingdom regulatory role in animals. Herein, we found that plant MIR167e-5p regulates the proliferation of enterocytes in vitro. A porcine jejunum epithelial cell line (IPEC-J2) and a human colon carcinoma cell line (Caco-2) were treated with 0, 10, 20, and 40 pmol of synthetic 2'-O-methylated plant MIR167e-5p, followed by a treatment with 20 pmol of MIR167e-5p for 0, 24, 48, and 72 h. The cells were counted, and IPEC-J2 cell viability was determined by the MTT and EdU assays at different time points. The results showed that MIR167e-5p significantly inhibited the proliferation of enterocytes in a dose- and time-dependent manner. Bioinformatics prediction and a luciferase reporter assay indicated that MIR167e-5p targets ß-catenin. In IPEC-J2 and Caco-2 cells, MIR167e-5p suppressed proliferation by downregulating ß-catenin mRNA and protein levels. MIR167e-5p relieved this inhibition. Similar results were achieved for the ß-catenin downstream target gene c-Myc and the proliferation-associated gene PCNA. This research demonstrates that plant MIR167e-5p can inhibit enterocyte proliferation by targeting the ß-catenin pathway. More importantly, plant miRNAs may be a new class of bioactive molecules for epigenetic regulation in humans and animals.

13.
J Cosmet Dermatol ; 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31692232

RESUMO

OBJECTIVE: We conducted this meta-analysis to assess the efficacy and safety of imiquimod in comparison with other treatments in patients with BCC. METHODS: A comprehensive literature search was performed in the database of PubMed, Embase, and Web of Science. Outcomes of interest included histological/composite clearance rate, success rate, complete response rate, tumor free survival, and adverse events. Pooled risk ratio (RR) with 95% confidence intervals (CIs) using a fixed-effects or random-effects model were determined for each outcome. RESULTS: A total of 13 studies involving 4256 patients were identified. Imiquimod was associated with significantly higher histological clearance rate (RR = 9.28, 95%CI: 5.56, 15.49; P < .001) and composite clearance rate (RR = 34.24, 95%CI: 21.29, 55.06; P = .001). Moreover, imiquimod also significantly increased complete response rate (RR = 3.15, 95%CI: 1.55, 6.38; P = .001) but had no effect in the success rate (RR = 0.98, 95%CI: 0.89, 1.08; P = .727) and probability of tumor-free survival (RR = 1.15, 95%CI: 0.98, 1.35; P = .088), as compared with other treatments. There were more patients in imiquimod group who developed adverse events than in other treatment group (RR = 2.00, 95%CI: 1.39, 2.88; P < .001). CONCLUSION: This study indicated the effects of imiquimod in improving the histological/composite clearance rates as compared with other treatments. However, its treatment-related adverse events also should be noticed. Our findings supported that, imiquimod could be used as the first-choice treatment for BCC.

14.
Drug Des Devel Ther ; 13: 2957-2968, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31686779

RESUMO

Drug discovery for complex diseases can be viewed as a challenging problem in which the influence of compounds on dynamic features of disease system should be considered, especially the strategies escaping from the disease attractors. Moreover, escaping from the disease-related attractors has been proved to be a cue for the treatment of the complex diseases. The drug discovery methodology based on the attractor theory indicates new solutions for target identification, drug discovery and drug combination design. The methodology is based on the holism level of the organism and the features of system dynamics, so it has advantages for the classification of complex diseases and drug discovery. Currently, research results of this method have increased, which expand the insight scope for drug discovery. This article introduces the major drug discovery methods in the history of pharmacy development and their characteristics, so as to illustrate the reasons and inevitability of the appearance of attractor method, its position in the history of pharmacy development, and its advantages for drug discovery and design, thereby to prove that the attractor method can indeed become the next major drug development method. In addition, it provides a comprehensive description about the concept of attractor, the pipeline of attractor analysis, the common methods of each process and its research progress, so as to provide a macroscopic framework and optional methods and tools for the follow-up researchers.

15.
Environ Microbiol ; 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31691434

RESUMO

Thermoprofundales (Marine Benthic Group D archaea, MBG-D) is a newly proposed archaeal order and widely distributed in global marine sediment, and the members in the order may play a vital role in carbon cycling. However, the lack of pure cultures of these oeganisms has hampered the recognition of their catabolic roles. Here, by constructing high-quality metagenome-assembled genomes (MAGs) of two new subgroups of Thermoprofundales from hydrothermal sediment and predicting their catabolic pathways, we here provide genomic evidences that Thermoprofundales are capable of degrading aromatics via the phenylacetic acid (PAA) pathway. Then, the gene sequences of phenylacetyl-CoA ligase (PCL), a key enzyme for the PAA pathway, were searched in reference genomes. The widespread distribution of PCL genes among 14.9% of archaea and 75.9% of Thermoprofundales further supports the importance of the PAA pathway in archaea, particularly in Thermoprofundales where no ring-cleavage dioxygenases were found. Two PCLs from Thermoprofundales MAGs, PCLM8-3 and PCLM10-15 , were able to convert PAA to phenylacetyl-CoA (PA-CoA) in vitro, demonstrating the involvement of Thermoprofundales in aromatics degradation through PAA via CoA activation. Their acid tolerance (pH 5-7), high-optimum temperatures (60°C and 80°C), thermostability (stable at 60°C and 50°C for 48 h) and broad substrate spectra imply that Thermoprofundales are capable of transforming aromatics under extreme conditions. Together with the evidence of in situ transcriptional activities for most genes related to the aromatics pathway in Thermoprofundales, these genomic, and biochemical evidences highlight the essential role of this ubiquitous and abundant archaeal order in the carbon cycle of marine sediments.

16.
EBioMedicine ; 49: 354-363, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31685443

RESUMO

BACKGROUND: Mothers are the primary source of bacteria for newborns, but it is unclear whether mother-to-newborn transmission occurs prior to, during or after birth. Similarly, the effect of the delivery mode on neonatal microorganisms has been the focus of controversy. METHODS: Healthy maternal and neonatal pairs that underwent vaginal birth and caesarean section were enrolled in this study. Meconium, placenta, membrane and amniotic fluid samples for newborns and vaginal, rectal and oral samples for mothers were collected. All samples were amplified and sequenced by a 16S rRNA gene primer set targeting bacteria and archaea. FINDINGS: A total of 550 samples from 36 mother-neonate pairs with vaginal births and 42 mother-neonate pairs with caesarean sections were included in this study. The negative controls showed that the data analysis in this study was not affected by contamination. There was a high diversity of microbial communities in the pregnancy environment of the foetus. Meconium samples could be divided into three distinct types that were not influenced by the delivery method. INTERPRETATION: The distribution patterns of bacterial communities in the meconium, placenta, and foetal membranes were highly similar and had nothing to do with the mode of delivery. For approximately half of the placental microorganisms, the same sequence could be found in the vaginal, rectal, and oral samples of the mother.

17.
Artigo em Inglês | MEDLINE | ID: mdl-31736292

RESUMO

We report a previously unknown monolayer borophene allotrope and we call it super-B with a flat structure based on the ab initio calculations. It has good thermal, dynamical, and mechanical stability compared with many other typical borophenes. We find that super-B has a fascinating chemical bond environment consisting of standard sp, sp2 hybridizations and delocalized five-center three-electron π bond, called π(5c-3e). This particular electronic structure plays a pivotal role in stabilizing the super-B chemically. By extra doping, super-B can be transformed into a Dirac material from pristine metal. Like graphene, it can also sustain tensile strain smaller than 24%, indicating superior flexibility. Moreover, due to the small atomic mass and large density of states at the Fermi level, super-B has the highest critical temperature Tc of 20.8 K in single-element superconductors at ambient condition. We attribute this high Tc of super-B to the giant anharmonicity of two linear acoustic phonon branches and an unusually low optic phonon mode. These predictions provide new insight into the chemical nature of low dimensional boron nanostructures and highlight the potential applications of designing flexible devices and high Tc superconductor.

18.
Plasmid ; : 102476, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31758959

RESUMO

Corynebacterium glutamicum is an important industrial strain used for the production of amino acids and vitamins. Most tools developed for overexpression of genes in C. glutamicum are based on the inducible promoter regulated by the lacIq gene or contain an antibiotic resistance gene as a selection marker. These vectors are essential for rapid identification of recombinant strains and detailed study of gene functions, but, as a considerable disadvantage, these vectors are not suitable for large-scale industrial production due to the need for the addition of isopropyl-ß-D-thiogalactopyranoside (IPTG) and antibiotics. In this study, the novel Escherichia coli-C. glutamicum shuttle expression vector pLY-4, derived from the expression vector pXMJ19, was constructed. The constitutive vector pLY-4 contains a large multiple cloning site, the strong promoter tacM and two selective markers: the original chloramphenicol resistance gene cat is used for molecular cloning operations, and the auxotrophy complementation marker alr, which can be stably replicated in the auxotrophic host strain without antibiotic selection pressure, is used for industrial fermentation. Heterologous expression of the gapC gene using the vector pLY-4 in C. glutamicum for L-methionine production indicated the potential application of pLY-4 in the development of C. glutamicum strain engineering and industrial fermentation.

19.
Biomed Pharmacother ; 121: 109583, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31706106

RESUMO

BACKGROUND: Perihilar cholangiocarcinoma (PHCCA) is the most common type of human cholangiocarcinoma with a very dismal prognosis. Tumor markers and target drugs of PHCCA are desperately needed. Protein phosphatase N3 (PTPN3) has dual roles in the progression of human cancers, but its expression and functions in PHCCA have not been elucidated. MATERIALS AND METHODS: The expression of PTPN3 in PHCCA was detected with western blotting, qRT-PCR and immunohistochemistry. The clinical significance of PTPN3 was identified by analyzing the correlations between its expression and the clinicopathological variables, and the prognostic value was evaluated by univariate and multivariate analyses. The functions of PTPN3 in the progression of PHCCA were estimated with both in vitro and in vivo experiments. RESULTS: PTPN3 expression was down-regulated in PHCCA compared with normal bile duct. Low PTPN3 expression was markedly associated with large tumor size and unfavorable prognosis. After knocking down PTPN3, the percentages of G2/S phase of PHCCA cells were elevated, and the proliferation increased significantly. Moreover, we demonstrated that the phosphorylation of AKT was elevated by PTPN3 knockdown, and it was required in PTPN3-involved proliferation of PHCCA. Within vivo experiments, PTPN3 and AKT inhibitor MK-2206 were demonstrated to suppress tumor size of PHCCA. CONCLUSION: PTPN3 was a favorable prognostic biomarker of PHCCA. PTPN3 suppressed the proliferation of PHCCA by inhibiting AKT phosphorylation and arresting cell cycle. Our results suggested thatpost-operative detection of PTPN3 would be a helpful approach to stratify the PHCCA patients with high-risk.

20.
Mikrochim Acta ; 186(11): 738, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676959

RESUMO

The peroxidase-like activity of hollow Prussian Blue nanocubes (hPBNCs) is used, in combination with the enzyme alcohol oxidase (AOx), in a colorimetric ethanol assay. Different from other nanozymes, the large cavity structure of the hPBNCs provides a larger surface and more binding sites for AOx to be bound on their surface or in the pores. This extremely enhances the sensitivity of the assay system. In the presence of ethanol, AOx is capable of catalyzing the oxidation of alcohols to aldehydes, accompanied by the generation of hydrogen peroxide (H2O2). The hPBNCs act as peroxidase mimics and then can catalyze the oxidation of 3,3'5,5'-tetramethylbenzidine (TMB) by H2O2, resulting in a color change of the solution from colorless to blue with a strong absorption at 652 nm. The lower detection limit for ethanol is 1.41 µg∙mL-1. Due to the high catalytic activity of hPBNCs in weakly acidic and neutral solutions, the system was successfully applied to the determination of ethanol in mice blood. This is critically important for studying the alcohol consumption and monitoring the ethanol toxicokinetics. Graphical abstract Schematic representation of hollow Prussian Blue nanocubes (hPBNCs) used as both a peroxidase mimetic and as a carrier for alcohol oxidase. Utilizing hPBNCs along with the ethanol conversion enzyme, a sensitive colorimetric assay for ethanol was developed and applied to blood samples with satisfactory results.

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