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1.
Medicine (Baltimore) ; 100(7): e24832, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33607850

RESUMO

ABSTRACT: MicroRNAs (miRNAs) in tumor and tumor-adjacent tissues can be effective diagnostic and prognostic markers to monitor tumor occurrence and progression. Despite improvements in the diagnosis and treatment of esophageal cancer (EC), the survival rate is <25%; consequently, more effective EC-specific prognostic biomarkers are urgently needed to design effective treatment regimens. In this study, we focused on identifying independent prognostic miRNA signatures in tumor and tumor-adjacent tissues in EC.We screened candidate miRNAs using a genome-wide miRNA transcriptome dataset from The Cancer Genome Atlas (TCGA) database that included 82 patients with esophageal adenocarcinoma (EADC) and 83 patients with esophageal squamous cell carcinoma (ESCC). We validated potential prognostic miRNA markers using a microarray profiling dataset that included information of 32 patients with EADC and 44 patients with ESCC from the Gene Expression Omnibus database. TCGA dataset was additionally used to identify differentially expressed mRNAs (DEMs) between the tumor and tumor-adjacent tissues. Univariate and multivariate Cox analyses were performed to detect the relationship between miRNAs and the overall survival of patients with EC. Kaplan-Meier method was applied to assess the survival differences between groups with differential miRNA expression. Lastly, functional enrichment analysis was conducted using miRWalk 2.0 online database for annotation.Although there was a considerable difference between the DEMs of EADC and ESCC, 73 DEMs were differentially expressed in both EADC and ESCC samples in TCGA dataset. Cox regression and Kaplan-Meier survival analyses showed that a higher expression of hsa-miR-186-5p and hsa-let-7d-5p was independently associated with a poor prognosis of EADC and ESCC, respectively. Furthermore, gene functional enrichment analysis revealed that the target genes of hsa-miR-186-5p and hsa-let-7d-5p participated in various cancer-related pathways, including the MAPK signaling pathway, proteoglycans in cancer, and AGE-RAGE signaling pathway.Our results revealed that hsa-miR-186-5p and hsa-let-7d-5p could be used as independent prognostic biomarkers for EADC and ESCC, respectively.

2.
Chemosphere ; 272: 129453, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33485045

RESUMO

Triclosan (TCS) is an emerging contaminant that threatens the environment and human health. This study was conducted to investigate TCS abatement by a novel electro-oxidation (EO) process, which used a Ti-based nickel and antimony doped tin oxide (NATO/Ti) anode and a carbon nanotubes (CNTs) doped carbon/PTFE (CNTs-C/PTFE) gas diffusion electrode (GDE) for oxygen reduction reaction (ORR). A comparative study was also performed for TCS degradation by using a traditional EO with a nickel foam cathode, termed as HER-EO. The optimal initial TCS concentration, current density and solution pH for TCS degradation during the ORR-EO and HER-EO were investigated. Results showed that ORR-EO removed more than 98% of TCS in 10-60 min under the concentration of 5-50 mg/L. The TCS degradation followed pseudo-first-order kinetics and its main intermediates were observed during the ORR-EO and HER-EO using liquid chromatography combined mass (LC-MS). The results of FED analysis and toxicity prediction by ECOSAR software showed that less intermediates accumulated during the ORR-EO and the residues were less harmful. The ORR-EO degradation mechanism for TCS was attacking on the ether bond and the benzene ring by •OH. This novel ORR-EO process exhibits a great merit in the field of emerging contaminants abatement.

3.
J Nanosci Nanotechnol ; 21(4): 2647-2652, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33500088

RESUMO

In this work, CeO2 nanocrystal-decorated TiO2 nanobelt for forming a CeO2@TiO2 heterostructure. CeO2 plays a dual role in improving photocatalytic activity, not only by promoting the separation and transfer of photogenerated charge carriers, but also by increasing visible light absorption of the photocatalyst as a photosensitizer. The as-prepared CeO2@TiO2 heterostructure demonstrates the performance of organic degradation and H2 production (about 17 µmol/h/g, which is about 2.5 times higher than that of pure TiO2 nanobelts). Our work provides a facile and controllable synthesis method for high performance photocatalyst, which will have potential applications in synthesis clean/solar fuel, and photocatalytic water treatment.

4.
Arch Virol ; 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33164116

RESUMO

In this study, we determined the near-complete and partial genome sequences of ten SaV isolates. Phylogenetic analysis based on full-length VP1 and RdRp nucleotide sequences indicated that nine isolates were of GI.1 and one was GII.3. Evolutionary dynamics analysis indicated that GI.1 and GII.3 SaVs evolved at different rates, the latter evolving more rapidly. Cluster analysis indicated that distantly related GI.1 SaVs were more similar in their amino acid compositions than were GII.3 SaVs. The data provided in this study may facilitate studies on SaV genomic diversity and epidemiological patterns in China and worldwide.

5.
Int J Clin Pract ; : e13848, 2020 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-33220144

RESUMO

AIMS OF THE STUDY: Increasing studies suggest a significant association between night shift work and an increased risk of type 2 diabetes, obesity, and other metabolic disorders. However, the available evidence of the association of rotating night shift work with gastroesophageal reflux disease (GERD) is limited. Herein, we hypothesized a link between the GERD risk and rotating night shift work among workers in China. METHODS USED TO CONDUCT THE STUDY: A total of 2027 workers who completed a comprehensive health checkup were included. Logistic regression was used to investigate the link between rotating night shift work and the risk of GERD symptoms. Receiver operating characteristic (ROC) curve analysis was used to assess the multivariable model's diagnostic value for identifying GERD symptoms among workers. RESULTS OF THE STUDY: 556 (27.4%) individuals had GERD symptoms among 2027 workers. Multivariate analysis showed five independent factors for GERD: rotating night shift work (OR=3.66, 95%CI: 2.52-5.40), age (OR=2.53, 95%CI: 1.67-3.78), smoking (OR=3.70, 95%CI: 2.63-5.21), Helicobacter pylori (H.pylori) infection (OR=0.68, 95%CI: 0.48-0.96), and obesity (OR=3.04, 95%CI: 2.43-3.83). A five-variable model based on five independent factors provided an area under a ROC curve (AUROC) of 0.80 (95%CI: 0.78-0.81) for identifying GERD symptoms among workers. CONCLUSIONS DRAWN FROM THE STUDY AND CLINICAL IMPLICATIONS: Rotating night shift work is independently associated with an increased risk of GERD symptoms. Moreover, a five-variable model (rotating night shift work, age, smoking, H.pyori infection, and obesity) can help identify individuals at high risk for GERD symptoms among workers in China.

6.
Biosci Rep ; 40(10)2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33015704

RESUMO

Accumulating evidence has demonstrated that tumor microenvironment (TME) plays a crucial role in stomach adenocarcinoma (STAD) development, progression, prognosis and immunotherapeutic responses. How the genes in TME interact and behave is extremely crucial for tumor investigation. In the present study, we used gene expression data of STAD available from TCGA and GEO datasets to infer tumor purity using ESTIMATE algorithms, and predicted the associations between tumor purity and clinical features and clinical outcomes. Next, we calculated the differentially expressed genes (DEGs) from the comparisons of immune and stromal scores, and postulated key biological processes and pathways that the DEGs mainly involved in. Then, we analyzed the prognostic values of DEGs in TCGA dataset, and validated the results by GEO dataset. Finally, we used CIBERSORT computational algorithm to estimate the 22 tumor infiltrating immune cells (TIICs) subsets in STAD tissues. We found that stromal and immune scores were significantly correlated with STAD subtypes, clinical stages, Helicobacter polyri infection, and stromal scores could predict the clinical outcomes in STAD patients. Moreover, we screened 307 common DEGs in TCGA and GSE51105 datasets. In the prognosis analyses, we only found OGN, JAM2, RERG, OLFML2B, and ADAMTS1 genes were significantly associated with overall survival in TCGA and GSE84437 datasets, and these genes were correlated with the fractions of T cells, B cells, macrophages, monocytes, NK cells and DC cells, respectively. Our comprehensive analyses for transcriptional data not only improved the understanding of characteristics of TME, but also provided the targets for individual therapy in STAD.

7.
Nanoscale ; 12(35): 18305-18312, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32869818

RESUMO

This study examines the osteogenic differentiation promotion effect of micro/nanostructures of raffia on human adipose-derived stem cells to confirm the potential application of plant-derived micro/nanotopographies in tissue regeneration. The results confirm that the nanorod array on the front surface and the honeycomb-like microstructure on the back surface of raffia can not only regulate the adhesion, spreading, and migration of stem cells but also promote the osteogenic differentiation of the stem cells at a subsequent stage of cell culture. The osteocalcin expressions by the 21-day cultured cells on the front and back surfaces of raffia were 55-fold and 36-fold higher compared to the expression on a tissue culture plate. This indicates that plant-derived micro/nanotopographies can significantly promote stem cell differentiation. Furthermore, a general strategy for the application of plant-derived materials to stem-cell differentiation and bone-tissue engineering is suggested.

8.
Int J Syst Evol Microbiol ; 70(8): 4531-4536, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32614764

RESUMO

A Gram-staining-negative bacterium, designated 345S023T, was isolated from a sea water sample from the Indian Ocean. The results of 16S rRNA gene sequence analysis revealed that 345S023T represents a member of the genus Alteromonas, with closely related type strains Alteromonas fortis 1T (98.7 %), Alteromonas hispanica F-32T (98.6 %) and Alteromonas genovensis LMG 24078T (98.6 %). Up-to-date bacterial core gene set analysis revealed that 345S023T formed a phyletic lineage with Alteromonas australica H 17T. The case for 345S023T representing a novel species was supported by genomic results. Pairwise in silico DNA-DNA hybridization and average nucleotide identity values were much lower than the proposed and generally accepted species boundaries. Strain 345S023T contains ubiquinone-8 (Q-8) as the sole isoprenoid quinone, summed featured 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as the dominant cellular fatty acids (>10 %), and phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. The genome of strain 345S023T consisted of a 4.4 Mb chromosome with a DNA G+C content of 44.4 %. On the basis of these genomic, chemotaxonomic and phenotypic characteristics, we propose a novel species: Alteromonas profundi sp. nov. The type strain is 345S023T(=JCM 33893T=MCCC 1K04570T).


Assuntos
Alteromonas/classificação , Filogenia , Água do Mar/microbiologia , Alteromonas/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oceano Índico , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
9.
Int J Syst Evol Microbiol ; 70(6): 3839-3844, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32496184

RESUMO

A Gram-stain-negative bacterium, designated strain 501str8T, was isolated from a sediment sample collected from the East Pacific Ocean. 16S rRNA gene sequence analysis revealed that strain 501str8T belonged to the genus Muricauda, with closely related type strains Muricauda aquimarina SW-63T (98.5 %), Muricauda lutimaris SMK-108T (98.3 %) and Muricauda ruestringensis B1T (97.9 %). Up-to-date bacterial core gene set analysis revealed that strain 501str8T represented one independent lineage with M. aquimarina SW-63T. The average nucleotide identity values of strain 501str8T with M. aquimarina SW-63T and M. lutimaris SMK-108T were 80.2 and 81.3 %, respectively. In silico DNA-DNA hybridization values between strain 501str8T and M. aquimarina SW-63T and M. lutimaris SMK-108T were 22.8 and 32.9 %, respectively. The predominant isoprenoid quinone was menaquinone-6, and iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G were the dominant cellular fatty acids. The G+C content of the genomic DNA was 42.8 mol%. Differential phylogenetic distinctiveness and chemotaxonomic differences, together with the phenotypic properties observed in this study, revealed that strain 501str8T could be differentiated from closely related species. Therefore, we propose that strain 501str8T represents a novel species of the genus Muricauda, for which the name Muricauda oceani sp. nov. is suggested. The type strain is 501str8T (=JCM 33902T=MCCC 1K04567T).


Assuntos
Flavobacteriaceae/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/isolamento & purificação , Hibridização de Ácido Nucleico , Oceano Pacífico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
10.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(6): 561-566, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-32571452

RESUMO

OBJECTIVE: To investigate the current status of antibiotic use for very and extremely low birth weight (VLBW/ELBW) infants in neonatal intensive care units (NICUs) of Hunan Province. METHODS: The use of antibiotics was investigated in multiple level 3 NICUs of Hunan Province for VLBW and ELBW infants born between January, 2017 and December, 2017. RESULTS: The clinical data of 1 442 VLBW/ELBW infants were collected from 24 NICUs in 2017. The median antibiotic use duration was 17 days (range: 0-86 days), accounting for 53.0% of the total length of hospital stay. The highest duration of antibiotic use was up to 91.4% of the total length of hospital stay, with the lowest at 14.6%. In 16 out of 24 NICUs, the antibiotic use duration was accounted for more than 50.0% of the hospitalization days. There were 113 cases with positive bacterial culture grown in blood or cerebrospinal fluid, making the positive rate of overall bacterial culture as 7.84%. The positive rate of bacterial culture in different NICUs was significantly different from 0% to 14.9%. The common isolated bacterial pathogens Klebsiella pneumoniae was 29 cases (25.7%); Escherichia coli 12 cases (10.6%); Staphylococcus aureus 3 cases (2.7%). The most commonly used antibiotics were third-generation of cephalosporins, accounting for 41.00% of the total antibiotics, followed by penicillins, accounting for 32.10%, and followed by carbapenems, accounting for 13.15%. The proportion of antibiotic use time was negatively correlated with birth weight Z-score and the change in weight Z-score between birth and hospital discharge (rs=-0.095, -0.151 respectively, P<0.01), positively correlated with death/withdrawal of care (rs=0.196, P<0.01). CONCLUSIONS: Antibiotics used for VLBW/ELBW infants in NICUs of Hunan Province are obviously prolonged in many NICUs. The proportion of routine use of third-generation of cephalosporins and carbapenems antibiotics is high among the NICUs.


Assuntos
Recém-Nascido de Peso Extremamente Baixo ao Nascer , Antibacterianos , Peso ao Nascer , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Inquéritos e Questionários
11.
Materials (Basel) ; 13(11)2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32545381

RESUMO

A comparative study of surge current reliability of 1200 V/5 A 4H-SiC (silicon carbide) MPS (Merged PiN Schottky) diodes with different technologies is presented. The influences of device designs in terms of electrical and thermal aspects on the forward conduction performance and surge current capability were studied. Device forward characteristics were simulated and measured. Standard single-pulse surge current tests and thermal impedance measurements were carried to show their surge capability and thermal design differences. An advanced thermal RC (thermal resistance-capacitance) model, with the consideration of current distribution non-uniformity effects, is proposed to accurately calculate the device junction temperature during surge events. It was found that a thinner substrate and a hexagonal layout design are beneficial to the improvement of the bipolar conduction performance in high current mode, as well as the surge current capability. The thinner substrate design also has advantages on thermal aspects, as it presents the lowest thermal resistance. The calculated failure temperature during the surge tests is consistent with the aluminum melting phenomenon, which is regarded as the failure mechanism. It was demonstrated that, for a SiC MPS diode, higher bipolar conduction performance is conducive to restraining the joule heat, and a lower thermal resistance design is able to accelerate the heat dissipation and limit the junction temperature during surge events. In this way, the MPS diode using a thinner substrate and advanced layout design technology is able to achieve 60% higher surge current density capability compared to the other technologies.

12.
Int J Syst Evol Microbiol ; 70(7): 4345-4350, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32584750

RESUMO

A Gram-stain-negative bacterium, designated strain 40Bstr34T, isolated from a sediment sample from the West Pacific Ocean, was taxonomically characterized by using a polyphasic approach. The strain was phylogenetically close to Jiella aquimaris LZB041T and Jiella endophytica CBS5Q-3T, with 16S rRNA gene sequence similarities of 98.5 and 97.1 %, respectively. The genome of strain 40Bstr34T featured a G+C content of 65.7 % for a 5.8 Mb chromosome. Up-to-date bacterial core gene set analysis revealed that strain 40Bstr34T represents one independent lineage with J.aquimaris LZB041T. In silico DNA-DNA hybridization values between strain 40Bstr34T and its phylogenetic neighbours ranged from 30.3-34.2 %, below the cutoff of 70 %. In addition, the corresponding average nucleotide identity values were between 81.8-83.7 %, which are lower than 95 % threshold. The predominant cellular fatty acids of strain 40Bstr34T were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), cyclo-C19 : 0 ω8c and iso-C17 : 0 3-OH, and ubiquinone-10 as the predominant respiratory quinone. The major polar lipids included phosphatidylethanolamine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids and two unidentified lipids. Based on the results of phenotypic, chemotaxonomic and genetic analyses, strain 40Bstr34T is identified as representing a novel species of the genus Jiella for which the name Jiella pacifica sp. nov. is proposed. The type strain is 40Bstr34T (=JCM 33903T=MCCC 1K04569T).


Assuntos
Alphaproteobacteria/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Alphaproteobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
13.
J Nanosci Nanotechnol ; 20(9): 5944-5950, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32331200

RESUMO

Nowadays, antibacterial photocatalytic activity of semiconductors has attracted great attention due to its excellent stability, good biocompatibility and no disinfection byproducts. Herein, a porous few-layer C3N4 was successfully fabricated via a simple and low-cost bottom-up method. The asprepared porous few-layer C3N4 exhibits large specific surface areas, which is about 4.8 times than bulk C3N4. Under the light (<430 nm) irradiation, reactive oxygen species (ROS) (singlet oxygen (1O2), hydroxyl radicals (·OH), and superoxide (O·-2)) can be generated. The porous few-layer C3N4 was used as an antibacterial agent to kill gram-positive bacterium S. Aureus with an anibacterial efficiency up to 99.7%. The log removal rate of the porous few-layer C3N4 is more than 50 times than the bulk C3N4. The material shows a potential application in water purification and antibacterial photocatalytic therapy.

14.
Environ Res ; 183: 109249, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32311906

RESUMO

Leachate concentrates, an effluent produced from nanofiltration and/or reverse osmosis, contains a high amount of salts and dissolved organics especially refractory organics. Thus, the treatment of leachate concentrates would consume high energy or a large amount of chemicals. The present study is to develop an effective treatment method by using coupled electrochemical methods with the least possible energy consumption. The leachate concentrates was pretreated by electrocoagulation (EC), with aluminum or iron electrodes as anodes, to decrease the dissolved organic content. EC with Al electrode was found to be more efficient by consuming 1.25 kWh/m3 energy to remove 70% of total organic carbon (TOC). EC effluent was further subjected to a novel simultaneous electro-oxidation and in-situ peroxone process, which used a Ti-based nickel and antimony doped tin dioxide (NATO) as anode and a carbon nanotube coated carbon-polytetrafluoroethylene (CNT-C/PTFE) as cathode for oxygen reduction reaction (ORR). Compared with a traditional EO with cathode for hydrogen evolution reaction (HER-EO), ORR-EO obtained higher efficiency and an energy consumption of 26.25 kWh/m3, which was much lower than 35.5 kWh/m3 for HER-EO. Results showed that after ORR-EO, a final TOC of 57.3 mg/L was obtained. Thus, EC in tandem with ORR-EO process has an excellent capability and economic merit in the field of treating leachate concentrates.


Assuntos
Eletrocoagulação , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água , Eletrodos , Peróxido de Hidrogênio , Ferro , Oxirredução
15.
Mater Sci Eng C Mater Biol Appl ; 111: 110827, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32279755

RESUMO

Mesenchymal stem cells (MSCs) hold great promise in the field of regenerative medicine, and great effort goes into investigating the mechanisms underlying their therapeutic effects. These investigations necessitate the development of sensitive and reliable methods of tracking stem cells. As the unique physicochemical properties of ß-NaGdF4:Yb/Er upconversion nanoparticles make them highly efficient fluorescent probes, they could be utilized to track stem cells through bio-imaging. However, their biocompatibility constitutes a major challenge to their use in biomedical applications. In this paper, we prepared ligand-free spherical ß- NaGdF4:Yb/Er nanoparticles of two different sizes (~15 and ~30 nm in diameter) and investigated their internalization into rat bone marrow-derived MSCs (rBMSCs), as well as their effects on cell proliferation, osteogenic and adipogenic differentiation. Even though particles of both sizes were efficiently taken up by the cells, the larger particles had a stronger fluorescence intensity but their proliferation was not significantly affected; this makes them superior for cell imaging. Analysis of multiple markers revealed that the nanoparticles, especially the larger ones, promoted the process of osteogenic differentiation. In contrast, adipogenesis was slightly hindered by the larger particles, whereas the smaller ones did not affect the process. As a whole, this study suggests that ligand-free spherical ß-NaGdF4:Yb/Er particles of appropriate size are compatible with stem cell proliferation and differentiation, which makes them promising agents for biomedical applications.

16.
Int J Neurosci ; 130(12): 1230-1236, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32070174

RESUMO

Although there are large differences in clinical and pathological features, age-related neurodegenerative diseases (NDs) share common pathogenetic mechanisms involving aggregation and deposition of misfolded proteins, which leads to progressive dysfunction and death of neurons. Up to now, it seems that apoptosis is one major form of neuronal cell death. This review provides an overview of recent progress in unfolded protein response (UPR) during apoptosis induced by abnormal protein aggregation and emphasizes on the potential role of inositol requiring enzyme 1 alpha (IRE1α)-microRNAs (miRNAs) mediated apoptosis in NDs, which will provide new insights in the pathogenesis of neurodegenerative diseases and novel therapeutic targets for the treatment of NDs.

17.
Int Microbiol ; 23(3): 441-451, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31927642

RESUMO

Improvement of the production of vincamine in endophytic fungus VINI-7 was performed by using the inactivated protoplast fusion method. The preparation conditions of protoplasts were optimized by systematic trials with various parameters, and inactivated protoplast fusion was subsequently performed. The mycelium in logarithmic growth phase was treated with 1500 U/mL lywallzyme, 1500 U/mL lysozyme, 2000 U/mL cellulase, and 1000 U/mL snailase solution for 3 h at 30 °C and had the best conditions, in which the concentration of the protoplast was 3.17 × 107 cells/mL. Protoplasts were inactivated by heat, ultraviolet, microwave, sodium nitrite, and diethyl sulfate, respectively. Subsequently, protoplasts inactivated by different methods were subjected to respective protoplast fusion. The results showed that the yield of vincamine in fusants inactivated by mutagens was generally higher than that of fusants inactivated by heat. The highest yield of vincamine in two fusants (U-U1 and N-N1) was 31.6 and 38.7 mg, which increased to 162.24 and 221.16%, respectively, as compared to the parent strain (12.05 mg). LC-MS/MS analysis showed that U-U1 and N-N1 fusants could produce vincamine. Furthermore, the results of genetic stability experiments indicated that U-U1 and N-N1 were genetically stable.

18.
J Hazard Mater ; 384: 121398, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31635820

RESUMO

Recently, a novel proof-of-concept oxygen reduction reaction (ORR) based electro-oxidation (EO) process has been developed, which was accomplished by integrating anodic electrochemical oxidation coupled with an in situ electro-peroxone process, by harnessing the anodic by-product O3 reacted with ORR cathode generated H2O2. To further enhance EO coupled in situ electro-peroxone, a nickel and antimony doped tin oxide anodic catalyst layer, namely NATO, was fabricated on Ti mesh to improve anodic oxidation and reinforce the generation of O3, thus promoting in situ Electro-peroxone. As a result, O3 generation rate was enhanced by 12.6%. Complete phenol, as a model organic compound, and 95% of TOC removal were achieved, respectively, during ORR-EO. Through kinetics and instrument analysis, results show that the amount of intermediates accumulated during phenol degradation was much less in this Ti/NATO based ORR-EO system than in a traditional EO system. Moreover, 35.7% of the energy consumption was saved for ORR-EO, owing to its reduced applied voltage and the enhanced in situ electro-peroxone process.

19.
Nanotechnology ; 31(14): 145101, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31846954

RESUMO

Recently, the wide application of upconversion nanoparticles (UCNPs) in the field of bioimaging has raised the requirement of biocompatibility. Current cytocompatibility studies on UCNPs mainly focus on cancer cells; however, their potential effects on normal cells are rarely addressed. Herein, the cellular effects of a trace amount of ligand-free NaYF4:Yb/Er nanocrystals on the differentiation of rat bone mesenchymal stem cells (rBMSCs) were investigated. First, due to their excellent upconversion fluorescent properties, the cellular uptake of ligand-free NaYF4:Yb/Er nanocrystals was confirmed by confocal laser scanning microscopy, and a homogeneous cytoplasmic distribution was imaged. Second, the viability of the rBMSCs cultured with a series of concentrations of nanoparticles (0, 30, 300, and 3000 ng ml-1) was evaluated, and a dose threshold was determined. Third, the effects of ligand-free NaYF4:Yb/Er nanocrystals on the osteogenesis of the rBMSCs were intensively characterized. The alkaline phosphatase activity assay, quantitative real time polymerase chain reaction for related osteogenic genes, and immunofluorescence staining of specific biomarkers and mineral deposits demonstrated that the ligand-free NaYF4:Yb/Er nanocrystals at a proper concentration can enhance osteogenic differentiation. Finally, intracytoplasmic lipid detection showed that the adipogenic differentiation of rBMSCs might be inhibited in the presence of ligand-free NaYF4:Yb/Er nanocrystals. Meanwhile, these results showed that the effects of ligand-free NaYF4:Yb/Er nanocrystals on rBMSCs were concentration-dependent and reciprocal between osteogenic and adipogenic differentiation. This work provides new insights into the exploring the biocompatibility of UCNPs and will benefit the research community engaged in nanotechnology and biomedicine.


Assuntos
Adipogenia/efeitos dos fármacos , Érbio/química , Fluoretos/farmacologia , Células-Tronco Mesenquimais/citologia , Osteogênese/efeitos dos fármacos , Itérbio/química , Ítrio/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Fluoretos/química , Células HeLa , Humanos , Ligantes , Células-Tronco Mesenquimais/efeitos dos fármacos , Microscopia Confocal , Nanopartículas , Ratos , Coloração e Rotulagem , Ítrio/química
20.
Micromachines (Basel) ; 11(1)2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31861314

RESUMO

In this work, a 1200V/200A full-SiC half-bridge power module was fabricated for high-power high-frequency application, and the characteristics of gate-source voltage (vgs) at turn-on transient under different output power was investigated via experiments, modeling, and simulation. Also, the comparison of the vgs characteristics between the upper-side and lower-side was conducted. From experiments, the vgs characteristics show negative spike issue and it becomes severe under higher output power conditions. On the other hand, the upper-side and lower-side show different characteristics, namely, the vgs spike of upper-side is superimposed by a 83.3MHz high frequency oscillation during the process of vgs being pulled down, while the vgs spike of lower-side contains no oscillation. The mechanisms behind the influence of output power on the vgs spike characteristics and their difference between the upper-side and lower-side were studied via modeling and simulation. Equivalent RLC (resistance-inductance-capacitance) circuit models were proposed and established for the gate driver loops of the upper-side and lower-side based on the internal structure of the power module. With the help of the proposed models, vgs characteristics of the upper-side and lower-side were simulated and compared with the experimental results. The trend of changes in the vgs pulling-down and oscillation amplitude along with the increasing output power from simulation are consistent with that of the experimental results. In addition, different conditions of gate resistance for the SiC power module are compared. Through the comparison between the experiments and simulations, the validity of the proposed equivalent RLC circuit model and the rationality of the analysis about the mechanisms behind the vgs characteristics at turn-on transient for SiC half-bridge power module are confirmed.

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