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1.
Food Microbiol ; 89: 103452, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32138998

RESUMO

The use of whole genome sequencing (WGS) data generated by short-read sequencing technologies such as the Illumina sequencing platforms has been shown to provide reliable results for Salmonella serotype prediction. Emerging long-read sequencing platforms developed by Oxford Nanopore Technologies (ONT) provide an alternative WGS method to meet the needs of industry for rapid and accurate Salmonella confirmation and serotype classification. Advantages of the ONT sequencing platforms include portability, real-time base-calling and long-read sequencing. To explore whether WGS data generated by an ONT sequencing platform could accurately predict Salmonella serotypes, 38 Salmonella strains representing 34 serotypes were sequenced using R9.4 flow cells on an ONT sequencer for up to 2 h. The downstream bioinformatics analysis was performed using pipelines with different assemblers including Canu, Wdbtg2 combined with Racon, or Miniasm combined with Racon. In silico serotype prediction programs were carried out using both SeqSero2 (raw reads and genome assemblies) and SISTR (genome assemblies). The WGS data of the same strains were also obtained from Illumina Hiseq (200 x depth of coverage per genome) as a benchmark of accurate serotype prediction. Predictions using WGS data generated after 30 min, 45 min, 1 h, and 2 h of ONT sequencing time all matched the prediction results from Illumina WGS data. This study demonstrated the comparable accuracy of WGS-based serotype prediction between ONT and Illumina sequencing platforms. This study also sets a start point for future validation of ONT WGS as a rapid Salmonella confirmation and serotype classification tool for the food industry.

2.
ACS Synth Biol ; 9(3): 494-499, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32149495

RESUMO

Tetrahydrobiopterin-dependent hydroxylation of aromatic amino acids is the first step in the biosynthesis of many neuroactive compounds in humans. A fundamental challenge in building these pathways in Escherichia coli is the provision of the non-native hydroxylase cofactor, tetrahydrobiopterin. To solve this, we designed a genetic selection that relies on the tyrosine synthesis activity of phenylalanine hydroxylase. Using adaptive laboratory evolution, we demonstrate the use of this selection to discover: (1) a minimum set of heterologous enzymes and a host folE (T198I) mutation for achieving this type of hydroxylation chemistry in whole cells, (2) functional complementation of tetrahydrobiopterin by indigenous cofactors, and (3) a tryptophan hydroxylase mutation for improving protein abundance. Thus, the goal of having functional aromatic-amino-acid hydroxylation in E. coli was achieved through directed metabolic pathway evolution.

4.
Nanoscale ; 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32207492

RESUMO

Decreasing the particle size of nanoscaled battery materials will induce amazing enhancement effects on their charging rates, which holds a promise to overcome the common bottleneck of the low charging rates of batteries. However, the fabrication of ultrafine-sized battery materials remains a great challenge. Herein, 3.3 nm-sized anatase TiO2 particles embedded in electrically and ionically conductive carbon spheres have been designed and fabricated via the suppression of Ostwald ripening with the aim to obtain insight into the electrochemical behaviors of ultrafine-sized materials. The pseudocapacitive and diffusion-controlled intercalative characteristics of the 3.3 nm-sized TiO2/carbon hybrid spheres for Li-ion and Na-ion storage have been systematically investigated via a cyclic voltammetry (CV) method combined with a differential capacitance method that is introduced here for the first time to analyze battery materials. CV and galvanostatic voltage profiles demonstrate that pseudocapacitance dominates the charge storage and increases with cycling for both Li-ion and Na-ion storage. Capacitance accounts for >83% of the Li-ion storage. A specific pseudocapacitance of 558 F g-1 with a window voltage of ∼2 V in carbonate electrolyte has been achieved. The reversible capacity is higher than the theoretical capacity of TiO2 after 600 discharge/charge cycles at 2 C and maintains ∼60% of that of TiO2 even at 80 C (45 s for full discharge or charge). For Na-ion storage, a high cycliability of 2500 discharge/charge cycles has been obtained at 2 C. Capacitance accounts for ∼79% of the Na-ion storage with cycling. Ultrafine-sized materials are very promising electrode candidates for constructing pseudocapacitive batteries possessing both high energy and power densities.

5.
Carbohydr Polym ; 235: 115944, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122483

RESUMO

Carboxymethyl cellulose (CMC) based novel functional films containing Chinese chives root extract (CRE) at different concentrations (1, 3 and 5 % in w/w) were successfully fabricated. It was revealed by SEM that higher extract concentration triggered the formation of agglomerates within the film. Tensile strength of the films was decreased from 30.91 to 16.48 MPa. Thickness of films was increased from 43 to 84 µm, while decrease in water solubility from 77.51-52.91 %, swelling degree from 55.74 to 40.37 %, and water vapor permeability from 5.76 to 1.17 10-10 gm-1s-1 Pa-1 was observed. DPPH and ABTS radical scavenging ability of CMC-CRE films was increased from 0 to 58 % and 82 %, respectively. CMC-CRE5 film showed the highest biodegradability of 58.14 %. The film prepared by the addition of CRE into CMC also exhibited good antioxidant and antimicrobial activity indicating that it could be developed as a bio-composite food packaging material for the food industry.

6.
J Biochem ; 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32044992

RESUMO

The apoptosis of hepatocytes contributes to the activation of hepatic stellate cells (HSCs), thus promoting the accumulation of extracellular matrix proteins and aggravating liver fibrosis. SIRT1 is an anti-fibrotic protein whose downregulation induces hepatocyte apoptosis. This study aims to identify whether SIRT1 is regulated by long non-coding RNA LINC01093 and explore its underlying mechanisms. Liver fibrosis was induced in mice using CCl4, and the differential expressions of several fibrosis-related lncRNAs were detected in liver tissues. The effect of LINC01093 on cell apoptosis and viability of hepatocytes was investigated after LINC01093 overexpression or knockdown using flow cytometry and MTT assay. The anti-fibrotic effect of LINC01093 overexpression was observed in vivo. LncRNA LINC01093 is downregulated in CCl4-induced liver tissues and TGF-ß1-stimulated hepatocytes. Downregulated LINC01093 promoted cell apoptosis and inhibited cell viability of hepatocytes. The co-culture between LINC01093-knockdown hepatocytes and HSCs increased the expressions of pro-fibrotic proteins. Downregulated LINC01093 promoted hepatocyte apoptosis via promoting degradation and ubiquitination of SIRT1 under TGF-ß1 stimulation. The injection of LINC01093-overexpressing vectors alleviated liver fibrosis in vivo. In liver fibrosis, the downregulated LINC01093 promoted hepatocyte apoptosis, which is mediated by increasing the degradation and ubiquitination of SIRT1.

7.
Int J Urol ; 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32100370

RESUMO

OBJECTIVES: To carry out a comparison of upper urinary tract urothelial carcinoma characteristics and behavior between patients in Taiwan and Japan. METHODS: A Taiwan urinary tract urothelial carcinoma cohort was obtained from Kaohsiung Chang Gung Memorial Hospital, and a Japan urinary tract urothelial carcinoma cohort from Hirosaki University Hospital. The inclusion criteria were urinary tract urothelial carcinoma patients who underwent radical nephroureterectomy. Those who received perioperative chemotherapy were excluded. Finally, 765 patients in the Taiwan cohort and 325 in the Japan cohort were analyzed. The end-point of this study was to study the natural course of urinary tract urothelial carcinoma within 5 years between these two groups. RESULTS: The main finding was that urinary tract urothelial carcinoma patients in Taiwan were younger (P < 0.001), more were women (P < 0.001), with low-stage disease (P < 0.001), with more chronic kidney disease (P < 0.001), with less smoking history (P < 0.001), with more bladder cancer history (P = 0.002), with more multifocal (P < 0.001) and less high-grade disease (P = 0.015), as well as less lymphovascular invasion (P < 0.001) and more squamous differentiation (P < 0.001). However, the multivariate Cox regression analysis showed no racial difference in oncologic outcome, such as intravesical recurrence, systemic recurrence or cancer-specific death in primary and propensity-matched cohorts. Bladder cancer history was found to be the most important factor predicting intravesical recurrences, whereas stage was strongly associated with systemic recurrence and cancer specific mortality. CONCLUSIONS: The clinical characteristics of urinary tract urothelial carcinoma in Taiwan are significantly different from those of urinary tract urothelial carcinoma in Japan. However, there is no racial difference in stage-specific oncologic outcome after standard nephroureterectomy.

8.
Nanoscale ; 12(7): 4552-4561, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32040104

RESUMO

Lithium-sulfur batteries are promising candidates for the next generation of energy storage systems owing to their high energy density, low toxicity and abundant reserves of sulfur. However, sulfur has poor conductivity, large volume change during charge/discharge, and more importantly, the intermediate polysulfide (Li2Sn, 3 ≤ n≤8) produced in the cycling process is easily soluble in the electrolyte resulting in the "shuttle effect", which have greatly limited the commercialization of lithium-sulfur batteries. Therefore, it is of great value to develop optimized sulfur cathode materials to improve electrode conductivity, buffer volume change and restrain the diffusion of polysulfide. In this work, we construct a V-MOF (MIL-47) derived V2O3@C hollow microcuboid with a hierarchical lasagna-like structure through hydrothermal synthesis followed by calcination, and employ it as a sulfur host for the first time. The fast anchoring of polysulfide by V2O3 nanoparticles and the high electronic conductivity of the 3D carbon framework can simultaneously inhibit the "shuttle effect" in the charge-discharge process and accelerate the kinetics of the redox process. Moreover, the special lasagna-like structure with appropriate voids generated during calcination not only provides many sites for sulfur loading, but also effectively alleviates the volume expansion problem during the electrochemical reaction. Therefore, the final fabricated sulfur cathode via the melt impregnation method exhibits good cycling stability (62.3% after 1000 cycles at 1C) and rate performance (663 mA h g-1 at 2C) at a relatively high sulfur loading of 3.7 mg cm-2.

9.
Sci Total Environ ; 717: 137184, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32084685

RESUMO

Gambierdiscus spp. can produce the polyketide compound, ciguatoxin (CTX), and are hence responsible for ciguatera fish poisoning (CFP). Studying the molecular mechanism that regulates CTX production is crucial for understanding the environmental trigger of CTX as well as for better informing fishery management. Commonly, polyketide synthases are important for polyketide synthesis; however, no gene has been confirmatively assigned to CTX production. Here, suppression subtractive hybridization (SSH) and transcriptome sequencing (RNA-Seq) were used to compare a CTX-producing strain with a non-CTX-producing strain. Using both methods, a total of 52 polyketide synthase (PKS) genes were identified to be up-regulated in the CTX-producing G. balechii, including transcripts encoding single-domain PKSs as well as transcripts encoding multi-domain PKSs. Using reverse transcription quantitative PCR, the expression of these genes in the CTX-producing strain and in nitrogen-limited cultures of the strain was further documented. These data suggest that PKSs are likely involved in polyketide synthesis and potentially in CTX synthesis in this dinoflagellate species. Our study provides the candidate biomarkers for the detection of CTXs or CFP in waters or any other organisms as well as a valuable genomic resource for the research on Gambierdiscus and other dinoflagellates.

10.
Int J Biol Macromol ; 150: 595-604, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32057859

RESUMO

The objective of the present study was to develop chitosan (CS) based novel functional films containing Chinese chive root extract (CRE) using solution casting method. CRE at different concentrations (1, 3 and 5% in w/w) were incorporated into the film-forming solution. Scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal behavior analysis (DSC & TGA) were performed to investigate the structure, potential interaction and thermal stability of prepared films. It was revealed by SEM that higher extract concentration triggered the formation of agglomerates within the films. Incorporation of CRE into CS resulted in decrease tensile properties of the films from 28.9 to 15.4 MPa, whereas thickness was increased from 0.076 to 0.113 mm. The water solubility, swelling degree and water vapor permeability were significantly decreased from 31.6 to 18.7%, 57.4 to 40.5% and 15.67 to 7.81 × 10-11 g·m-1s-1Pa-1, respectively. DPPH and ABTS radical scavenging ability of CS-CRE films were increased from 6.95 to 47.05% and 11.98 to 57.38%, respectively. CS-CRE5 film showed the highest biodegradability of 47.36%. The films prepared by addition of CRE into CS exhibited good antioxidant and antimicrobial activity indicating that it could be developed as bio-composite food packaging material for food industry.

11.
Int Urol Nephrol ; 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31997062

RESUMO

PURPOSE: Upper urinary tract urothelial carcinoma (UTUC) is a relatively uncommon malignancy in Western countries, affecting more men than women. By contrast, UTUC is relatively common in Taiwan and diagnosed more often in women than in men. Previous studies regarding the gender effect on cancer behaviour with UTUC have been controversial. Investigation of female predominance of UTUC in Taiwan may help improve UTUC management in Taiwan as well as understand the gender effect on urothelial carcinoma. METHODS: Between January 2005 and December 2015, 828 patients with localized UTUC treated with radical nephroureterectomy were enrolled. Cox regression analysis was performed to assess the independent roles of perioperative factors on local recurrence and systemic recurrence. RESULTS: Multivariate analysis revealed the male gender had a trend associated with higher systemic recurrence (P = 0.096) and independently associated with higher bladder recurrence (P = 0.011) and cancer-specific mortality (P = 0.014), even after taking smoking and other established prognostic factors into consideration. Bladder cancer history and multifocal disease are strongly associated with bladder recurrence. CONCLUSION: Compared with female UTUC patients, male UTUC patients in Taiwan were associated with more bladder recurrences and higher cancer-specific mortality and had a trend associated with more systemic recurrences.

12.
Lancet Psychiatry ; 7(2): 135-147, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31974072

RESUMO

BACKGROUND: Psychiatric disorders are established risk factors for self-harm. However, variation in the risk of self-harm by specific psychiatric disorder and stratified by gender and age is rarely examined in population-representative samples. This study aimed to investigate the risk of self-harm following diagnosis of different psychiatric disorders in an Asian population, through a review of inpatient records retrieved from the Hong Kong Clinical Data Analysis and Reporting System (CDARS). METHODS: For this nested case-control study, the inpatient data of people admitted for any reason to Hong Kong public hospitals, between Jan 1, 2000, and Dec 31, 2010, were extracted from CDARS. Cases were people aged 10 years or older who had been admitted to inpatient care with a first-listed record of psychiatric disorder during the study period. The seven psychiatric disorders of interest were: depression, alcohol misuse or dependence, personality disorders, bipolar disorders, anxiety disorders, schizophrenia, and substance misuse or dependence. Two control patients were matched per case from a subsample of all individuals with the same gender, age, and admission time (ie, same calendar year and month), who did not have any record of the psychiatric disorders of interest. Any patients with a history of self-harm diagnosis before, or at the same time as, the first diagnosis of psychiatric disorder (cases) or admission (controls), were excluded. For each diagnostic category, a Cox proportional hazard regression model was fitted to estimate the adjusted hazard ratio (HR; plus 95% CIs) of associated self-harm, adjusting for gender, age, control-matched admission time, 20 districts of residence, physical comorbidities established as risk factors for self-harm (diabetes, asthma, migraine, epilepsy, HIV, and cancer), and presence of the six other psychiatric disorders. We repeated this analysis in subgroups stratified by gender (male and female) and by age (adolescent, 10-24 years; young adult, 25-44 years; middle-aged, 45-64 years; and older people, ≥65 years). FINDINGS: Between 2000 and 2010, we followed up a cohort of 86 353 people with a first-recorded diagnosis of a psychiatric disorder of interest, and 134 857 matched controls. The highest risk of self-harm was observed in patients with substance misuse or dependence (adjusted HR vs matched controls, 9·6 [95% CI 8·4-11·0]), followed by those with personality disorders (3·7 [2·8-4·9]) and alcohol misuse or dependence (3·2 [2·9-3·7]). When stratified by gender and age, the highest risk of self-harm behaviour was found in the substance misuse or dependence group for both genders (for female patients: adjusted HR vs matched controls, 7·7 [6·0-9·8]; and for male patients, 10·5 [8·9-12·4]), and for all age groups (adolescent: 9·6 [7·2-12·7]; young adults: 10·2 [8·4-12·3]; middle-aged: 11·2 [8·0-15·6], and older people: 3·2 [1·7-6·1]). INTERPRETATION: First-recorded diagnoses of psychiatric disorders were significantly associated with an elevated risk of subsequent self-harm. The associations varied considerably by diagnostic categories across gender and age subgroups. Our findings highlight the need to develop more efficient and targeted preventive measures in psychiatric care management, with specific attention to demographic characteristics linked to increased risk within the same diagnostic category. FUNDING: None.


Assuntos
Transtornos de Ansiedade/epidemiologia , Transtorno Bipolar/epidemiologia , Transtorno Depressivo/epidemiologia , Transtornos da Personalidade/epidemiologia , Esquizofrenia/epidemiologia , Comportamento Autodestrutivo/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Estudos de Casos e Controles , Criança , Feminino , Seguimentos , Hong Kong/epidemiologia , Hospitais Públicos/estatística & dados numéricos , Humanos , Pacientes Internados/estatística & dados numéricos , Masculino , Sistemas Computadorizados de Registros Médicos/estatística & dados numéricos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Risco , Fatores Sexuais , Adulto Jovem
13.
Artigo em Inglês | MEDLINE | ID: mdl-31974552

RESUMO

BACKGROUND: To investigate the current use status of official WeChat accounts for the Centers for Disease Control and Prevention in public health education and relevant factors that can impact the effectiveness of message delivery. METHODS: A retrospective survey was conducted to evaluate the effectiveness of official WeChat accounts. About 531 official WeChat accounts and 50 939 articles were analyzed using a cluster sampling survey design. The Kruskal-Wallis test and multivariate logistic regression were used to explore factors associated with the usefulness of the number of views and "Likes" of the articles. RESULTS: The study identified a total of 531 public WeChat accounts, including 19 province-level accounts, 179 municipal-level accounts and 333 county-level accounts. In the univariable analysis, the administrative level of the account, article order, time segment, article originality and thematic category were associated with the number of views and "Likes." Province-level accounts, first articles, the 5:00-6:00 time segment, original articles and theme 3 (emergencies) had higher numbers of views and "Likes" than the others (P < 0.05). CONCLUSIONS: Promoting health education through Official WeChat account is an effective, sustainable and feasible strategy. Potential indicators of the impact of public health education suggest that administrators should effectively use official WeChat accounts for public health education.

14.
Environ Res ; 183: 109141, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31999999

RESUMO

BACKGROUND: Ozone is currently one of the most important air pollutants. Volatile organic compounds (VOCs) can easily react with atmospheric radicals to form ozone. In-field measurement of VOCs may help in estimating the local VOC photochemical pollution level. METHOD: This study examined the spatial and temporal distribution characteristics of VOCs during winter at three typical sites of varying classification in China; industrial (Guangzhou Economic and Technological Development District (GETDD)), urban (Guangzhou higher education mega center (HEMC)), and rural (Pingyuan county (PYC)), using Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS). RESULTS: The concentrations of total VOCs (TVOCs) at the GETDD, HEMC and PYC sites were 352.5, 129.2 and 75.1 ppb, respectively. The dominant category of VOCs is nitrogen-containing VOCs (NVOCs, accounting for 43.3% of TVOCs) at GETDD, of which C4H11N (m/z+ = 74.10, butyl amine) was the predominant chemical species (80.5%). In contrast, oxygenated VOCs (OVOCs) were the most abundant at HEMC and PYC, accounting for 60.2% and 64.1% of the total VOCs, respectively; here, CH4O (m/z+ = 33.026, methanol) was the major compound, accounting for 40.5% of the VOCs at HEMC and 50.9% at PYC. The ratios of toluene to benzene (T/B) were calculated for different measured sites, as the ratios of T/B can reveal source resolution of aromatic VOCs. The average contributions to total ozone formation potentials (OFP) of the total measured VOCs in each area were 604.9, 315.9 and 111.7 µg/m3 at GETDD, HEMC and PYC, respectively; the highest OFP contributors of the identified VOCs were aliphatic hydrocarbons (AlHs) at GETDD, aromatic hydrocarbons (AHs) at HEMC, and OVOCs at PYC. CONCLUSIONS: OFP assessment indicated that the photochemical pollution caused by VOCs at GETDD was serious, and was also significant in the HEMC region. The dominant VOC OFP groups (AlHs and AHs) should be prioritized for control, in order to help reduce these effects.

15.
J Viral Hepat ; 27(3): 323-328, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31667945

RESUMO

We examined whether the hepatitis B virus (HBV) pregenomic RNA (pgRNA) status after nucleos(t)ide (NA) treatment can predict the long-time prognoses of chronic hepatitis B patients. Patients with chronic hepatitis B (98) who were treatment-naïve and had begun a 7-year NA therapy regimen were enrolled in this study. Biochemical indicators and serological markers of HBV infection were performed during therapy. HBV pgRNA was quantified by real-time quantitative PCR with specific primers. During treatment, HBV DNA undetectable rates increased. The aminotransferase (ALT) normalization (ALT < 50 IU/L) and HBeAg-negative rates also increased. After 48 weeks' NA treatment, 48.28% (28/58) of HBV DNA undetectable patients still had HBV pgRNA-positive. After 7 years of treatment, more HBV pgRNA-negative patients (n = 35) achieved HBeAg clearance than the patients who were HBV pgRNA-positive (n = 63) (19/23 vs 19/56, P < .00). HBV pgRNA-positive patients also had an increased risk of failing to achieve HBeAg clearance (OR = 9.25, 95% CI: 2.75-31.08). The median time to HBeAg clearance in the HBV pgRNA-positive patients was longer than that of the HBV pgRNA-negative patients (152 weeks vs 72 weeks). The HBV pgRNA-positive patients also required more time to achieve HBV DNA undetectable (124 weeks, 95% CI: 103.33-144.67 vs 48 weeks, 95% CI: 34.80-61.20). The HBV pgRNA status after NA treatment can predict the long-term prognoses of patients with chronic HBV. Patients who remain HBV pgRNA-positive after 48 weeks of NA treatment have an increased risk of not achieving HBeAg clearance, need more time to achieve HBeAg clearance and undetectable HBV DNA load.

16.
J Hazard Mater ; 384: 121460, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31690502

RESUMO

Phase-selective organogelators (PSOGs) have drawn wide attention due to their potential applications in recovery of leaked aromatics and spilled oils. However, powder form PSOGs with fast gelling abilities and broad applicabilities are still limited. Herein, we developed three D-gluconic acetal-based gelators with different alkyl chains, all of which show excellent gel properties for hydrocarbon solvents. The spectroscopic and X-ray results revealed that the gel formation was the synergy of hydrogen bonding, π-π stacking and van der Waals forces. Surprisingly, the powder form gelator A with a cis double bond in the alkyl chain could instantly and selectively gel aromatic hydrocarbons, and also rapidly solidify crude oils with widely ranging viscosities from seawater at room temperature within minutes. Further research revealed that A powder exhibited porous amorphous morphology because the cis double bonds broke the crystalline chain-chain interdigitation between the assemblies. Therefore, the fast dispersion and recombination of fibers under the action of oil molecules lead to the fast room temperature gel process. Overall, a non-toxic and low-cost powder form PSOG with rapid room temperature phase selective gelation ability for a wide range of oils makes it promising for the emergency treatment of oil spill and aromatics leakage.

17.
Genes Genomics ; 42(2): 155-164, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31797312

RESUMO

BACKGROUND: The evolution of male pregnancy is the most distinctive characteristic of syngnathids, and they were recognized as flagship species for marine conservation. Genus Halicampus is an important branch of syngnathid fishes that has not received the attention it deserves. OBJECTIVE: To sequence the mitochondrial genome of Halicampus grayi, and investage the genetic structure of its populations. METHODS: Degenerate primers were designed to amplify the entire mitochondrial genome of H. grayi. The phylogenetic relationship between H. grayi and other syngnathids were conducted using maximum-likelihood method. Population genetic structure of three geographic population of H. grayi were determined using median-joining haplotype network based on COI and Cytb sequences. RESULTS: The complete mitochondrial genome of Halicampus grayi was assembled into a 17,059 bp circular sequence, which contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 D-loop region. The overall base composition of H. grayi is 29.93% A, 29.31% T, 16.23% G and 24.54% C, with a slight A + T rich feature (59.24%). Phylogenetic analysis indicated that H. grayi has a close relationship with Trachyrhamphus serratus. Population genetic analysis revealed a relatively high genetic diversity across different geographic populations of H. grayi, and the results of median-joining haplotype network indicated a lack of structure in populations of H. grayi. CONCLUSION: The mitogenome of H. grayi will provided important information about the origin and evolution issues of syngnathid fishes, and the high-level genetic diversity detected in their populations will provide insight into the gene flow pattern of marine fishes.

18.
ACS Nano ; 14(1): 175-184, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31789497

RESUMO

Structural asymmetry of materials plays a crucial role in developing multipurpose devices. Layered metallic transition metal dichalcogenides (MTMDCs) have been proposed as promising materials in electronics. However, they are still subject to native surface oxidation, limiting their practical applications. Combination of surface protection and native surface oxidation of MTMDCs will create asymmetric structures for devices but has yet to be explored. Here, we report a bifunctional NbS2-based vertical heterostructure derived from epitaxially grown NbS2 on MoS2 followed by a natural oxidation (MoS2-NbS2-NbOx), which simultaneously exhibits both high-efficiency tunneling conductive and memristive surfaces. With the tunneling conductive surface, the heterostructure functions as nearly ohmic contact electrodes with a two-dimensional (2D) channel in lateral transistors, delivering an enhanced mobility ∼140 times higher than that of the exfoliated NbS2-contacted device. With the memristive surface, the heterostructure can be used to build high-performance lateral or vertical memristors with low working voltages and synaptic functions. By combining both types of surfaces, a memristor array for nonvolatile memory is further developed. Moreover, the memristors show a good endurance for 2000 cycles of bending as flexible devices. The bifunctional heterostructure based on NbS2 offers a strategy toward the future applications of layered metallic materials.

19.
Sci Total Environ ; 708: 134998, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31810667

RESUMO

The change of land use and land coverage (LULC) has a direct impact on the underlying surface of the drainage basin, hence alters the rainfall-runoff processes. This study described the procedure to use the CA-Markov model to predict the future distributed land use in the Qinhuai River basin in 2028 based on the historical evolution. The hydrological model HEC-HMS was then utilized to examine the impact of land use change on the hydrological responses of the drainage basin. The major findings were as follows: (1) from 2001 to 2010, major changes detected in land use were substantial conversion of paddy fields, forest land and dryland into urban land (increased by 56.81%), following the trend recognized by CA-Markov model, urban land and dry land were predicted to increase by 17.47% and 14.05% by 2028. (2) the projected land use in 2028 resulted in various degrees of increase in flood peak and volume according to the severity of the floods characterized by flood volumes, the smaller floods were predicted to result in more significant increase with 3.5% increase in flood peak and 2.9% increase in flood volume while these values decreased to 0.4% and 1.1% for a big scale flood; (3) greater increase in urbanization leads to greater change of the flood peak and volume change. For small scale floods, when the proportion of urban land use increases by 30% to 60% hypothetically, the relative increment in flood peaks increase from 4.7% to 8.1% with 4% to 6.6% increase in the flood volume; (4) on the sub-basin scale, the trend of change in urban land use and the flood peak and volume were consistent. The methods and conclusions may shed light on urban land development and management and design of flood control measures in a large river basin.

20.
Invest New Drugs ; 38(1): 148-159, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31399906

RESUMO

Background The 5-year survival rate for extensive-disease small-cell lung carcinoma (ED-SCLC) is only 1%. Recently, apatinib exerted promising effects on cancer patients after failure of first-line chemotherapy. Methods This study enrolled 24 ED-SCLC patients to study the efficacy and toxicity of apatinib in combination with chemotherapy and maintenance therapy. The primary endpoints were overall survival (OS) and progression-free survival (PFS). The secondary endpoints included toxicity and safety. Apatinib was given 250 mg/day during the chemotherapy interval, and as maintenance therapy after 4-6 cycles until the patient progressed, died, or was intolerant to drug toxicity. The study further evaluated the cytotoxicity, cell-cycle arrest and apoptotic induction of apatinib in A549 and H446 cells. Results There was no difference in short-term efficacy between combined and chemotherapy groups. Long-term efficacy showed that the median PFS was 7.8 months and 4.9 months in combination and chemotherapy groups, respectively [p = 0.002, HR(95%CI): 0.18(0.06-0.60)]. The median OS was 12.1 months and 8.2 months in combination and chemotherapy groups, respectively [p = 0.023, HR(95%CI): 0.38 (0.16-0.90)]. Multivariate Cox regression analysis showed that apatinib combined with chemotherapy was an independent prognostic factor for OS and PFS. The ECOG score was an independent prognostic factor affecting OS. In vitro analysis showed that apatinib inhibited cell proliferation and caused cell-cycle arrest and apoptosis. Conclusion Apatinib combination/maintenance therapy showed promising efficacy and safety to extend OS/PFS in ED-SCLC and will be a potent therapeutic option in future practice. Although the scale of this study is small, further research on large sample sizes is needed.

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