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1.
IEEE Trans Image Process ; 29: 199-213, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31329116

RESUMO

Domain adaptation aims to deal with learning problems in which the labeled training data and unlabeled testing data are differently distributed. Maximum mean discrepancy (MMD), as a distribution distance measure, is minimized in various domain adaptation algorithms for eliminating domain divergence. We analyze empirical MMD from the point of view of graph embedding. It is discovered from the MMD intrinsic graph that, when the empirical MMD is minimized, the compactness within each domain and each class is simultaneously reduced. Therefore, points from different classes may mutually overlap, leading to unsatisfactory classification results. To deal with this issue, we present a graph embedding framework with intrinsic and penalty graphs for MMD-based domain adaptation algorithms. In the framework, we revise the intrinsic graph of MMD-based algorithms such that the within-class scatter is minimized, and thus, the new features are discriminative. Two strategies are proposed. Based on the strategies, we instantiate the framework by exploiting four models. Each model has a penalty graph characterizing certain similarity property that should be avoided. Comprehensive experiments on visual cross-domain benchmark datasets demonstrate that the proposed models can greatly enhance the classification performance compared with the state-of-the-art methods.

2.
J Phys Condens Matter ; 32(1): 015401, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31519010

RESUMO

Low plasticity has been a major issue for the application of Mg alloys. Here, based on the generalized stacking fault energy curves and Arrhenius equation, we systematically study alloying effects on the stacking fault energies and the activation probability of basal and non-basal 〈a〉, and pyramidal 〈c + a〉 slip systems in twenty-one Mg alloys. Our results reveal that activation of 〈c + a〉 slip systems on pyramidal II plane can significantly improve the plasticity. For example, Ca is found to promote the activation probability of this slip system by one order of magnitude and dramatically improve the plasticity of Mg.

3.
J Pharm Biomed Anal ; 177: 112850, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31499430

RESUMO

In the present study, an accurate and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of plasma talazoparib concentration in rats was developed and established. The purpose of chromatographic separation of talazoparib and the internal standard (bosutinib) was achieved on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 µm) column with a flow rate of 0.40 mL/min, using a gradient elution with acetonitrile and 0.1% formic acid in water as the mobile phase. The detection was performed on a XEVO TQ-S triple quadrupole tandem mass spectrometer coupled with electrospray ionization interface under positive-ion multiple reaction monitoring (MRM) mode with the precursor-to-product ion transitions of m/z 381.3 → 285.2 for talazoparib and m/z 530.2 → 141.2 for bosutinib (IS), respectively. The method was linear over the range of 0.5-200 ng/mL for talazoparib. The accuracies and precisions of intra- and inter-day were all within the acceptance limits, and no matrix effect was observed in this method. The validated method was further employed to a pharmacokinetic study of talazoparib after oral treatment with 0.2 mg/kg talazoparib to rats.

4.
Toxicol In Vitro ; 62: 104689, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629902

RESUMO

Titanate nanotubes (TiNTs) have been considered as biocompatible nanomaterials (NMs) for biomedical uses. Hereby, we compared the toxicity of TiNTs and TiO2 nanoparticles (NPs) to human umbilical vein endothelial cells (HUVECs). Our results showed that TiNTs were less effectively internalized into HUVECs compared with TiO2 NPs, but none of the NMs induced cytotoxicity or activation of endoplasmic reticulum (ER) stress biomarkers. In addition, intracellular reactive oxygen species (ROS) was only modestly induced by TiNTs and TiO2 NPs. However, both types of NMs significantly promoted the protein levels of vascular cell adhesion molecule-1 (VCAM-1). TiNTs also promoted the release of soluble (sVCAM-1), but THP-1 monocyte adhesion onto HUVECs was only induced by TiO2 NPs. TiNTs decreased the production of NO, associated with a decrease of protein levels of endothelial NO synthase (eNOS). The transcription factors of eNOS, including kruppel-like factor 2 (KLF2) and KLF4, were more effectively down-regulated by TiNTs compared with TiO2 NPs. In conclusion, our results indicated that TiNTs, albeit not cytotoxic, might impair NO signaling pathway in human endothelial cells leading to the activation of endothelial cells.

5.
BMC Ophthalmol ; 19(1): 215, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699049

RESUMO

BACKGROUND: To evaluate choroidal vascularity index (CVI) in eyes with internal carotid artery (ICA) stenosis using binarization tool in enhanced depth images scanned by spectral domain optical coherence tomography. METHODS: A retrospective cohort study was conducted in 142 patients with ICA stenosis, and 20 normal control subjects matched with the age, sex, etc. According to the diagnostic criteria, the participants are divided into a normal control group (20 cases), a mild stenosis group (64 cases), a moderate stenosis group (61 cases), and a severe stenosis group (17 cases). Enhanced depth imaging optical coherence tomography (EDIOCT) was performed to scan macular fovea, which was separated into a luminal area and a stromal area using image binarization. The choroidal vascularity index (CVI) is luminal area divided by total choroidal area. RESULTS: There was no statistical difference in age or sex among groups. Subfoveal choroidal thickness (SFCT) in the severe stenosis group was significantly lower than that in the normal group (P < 0.05). Moreover, the CVI in moderate stenosis group and severe stenosis group were significantly lower compared with the normal control group (P < 0.001). When CVI = 65.16% was set as the cut-off value, all 162 subjects could be divided into two groups, CVI ≤ 65.16 (n = 83) and CVI > 65.16% (n = 79). The proportions of mild stenosis, moderate stenosis, and severe stenosis in CVI ≤ 65 .16 group and CVI > 65.16% group were statistically significant (P < 0.001). CONCLUSION: CVI may be a useful indicator for early diagnosis and monitoring of choroidal vascular changes in ICA stenosis.

6.
Microb Cell Fact ; 18(1): 195, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699116

RESUMO

BACKGROUND: The biological synthesis of high value compounds in industry through metabolically engineered microorganism factories has received increasing attention in recent years. Valencene is a high value ingredient in the flavor and fragrance industry, but the low concentration in nature and high cost of extraction limits its application. Saccharomyces cerevisiae, generally recognized as safe, is one of the most commonly used gene expression hosts. Construction of S. cerevisiae cell factory to achieve high production of valencene will be attractive. RESULTS: Valencene was successfully biosynthesized after introducing valencene synthase into S. cerevisiae BJ5464. A significant increase in valencene yield was observed after down-regulation or knock-out of squalene synthesis and other inhibiting factors (such as erg9, rox1) in mevalonate (MVA) pathway using a recyclable CRISPR/Cas9 system constructed in this study through the introduction of Cre/loxP. To increase the supplement of the precursor farnesyl pyrophosphate (FPP), all the genes of FPP upstream in MVA pathway were overexpressed in yeast genome. Furthermore, valencene expression cassettes containing different promoters and terminators were compared, and PHXT7-VS-TTPI1 was found to have excellent performance in valencene production. Finally, after fed-batch fermentation in 3 L bioreactor, valencene production titer reached 539.3 mg/L with about 160-fold improvement compared to the initial titer, which is the highest reported valencene yield. CONCLUSIONS: This study achieved high production of valencene in S. cerevisiae through metabolic engineering and optimization of expression cassette, providing good example of microbial overproduction of valuable chemical products. The construction of recyclable plasmid was useful for multiple gene editing as well.

7.
Medicine (Baltimore) ; 98(44): e17463, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31689750

RESUMO

RATIONALE: Malignant peripheral nerve sheath tumor (MPNST) is a very rare sarcoma of the heart, and few cases have been reported. Herein, we retrospectively reviewed clinical manifestations, imaging features and management of our patient and other reported cases. PATIENT CONCERNS: A 32-year-old woman was referred to the emergency department of our institution with expiratory dyspnea, edema of face for a month. DIAGNOSIS: The patient was initially diagnosed with asthma at a local hospital based on a history of fatigue, cough and expiratory dyspnea, as well as negative electroencephalogram (ECG) and chest radiography. Based on computed tomography (CT) and cardiac magnetic resonance imaging (CMRI) in our hospital, she was found to have a malignant tumor involving right atrium. The tumor was diagnosed as MPNST according to histopathological results. INTERVENTIONS: The tumor was deemed unresectable during the surgery. Then, the patient was referred for chemotherapy and radiotherapy. OUTCOMES: The patient deteriorated and died 4 months later. LESSONS: Cardiac MPNST is very uncommon with nonspecific clinical and imaging characteristics according to limited cased reported. CMR, due to the high tissue resolution and multiple sequence imaging advantages, is useful for the detection, location and evaluation whether there is involvement of adjacent structures, and may help better clinical decision-making.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31757416

RESUMO

Altered aerobic glycolysis is an important feature of cancer cell energy metabolism, known as the Warburg effect. Cervical cancer is one of the most common causes of cancer death in females. However, the roles of aerobic glycolysis in the development of cervical cancer are still poorly defined. Here, we identified a transcription factor (TF), ETS-related gene (ERG), as a new regulator of cancer progression and the glycolysis process in cervical cancer. In this study, we found that ectopic expression of ERG enhanced the capacity of aerobic glycolysis and increased glucose uptake, lactate production, and ATP generation. ERG overexpression increased and ERG knockdown decreased the anchorage independent cell growth and cell invasion in cervical cancer cells. Mechanistically, we propose that ERG regulates the expression of hexokinase 2 (HK2) and phosphoglycerate kinase 1 (PGK1) in the glycolytic pathway by directly binding to their promoters. A gain-of-function study showed that the knockdown or overexpression of HK2 and PGK1 abolished the increased or decreased aerobic glycolysis and cervical cancer progression induced by stable ectopic expression or depletion of ERG, respectively. Taken together, our findings suggest that ERG plays a potential role in the progression of cervical cancer, and could serve as a novel biomarker and potential therapeutic target in cervical cancer.

9.
Toxicol Appl Pharmacol ; 385: 114769, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31697999

RESUMO

Tubulointerstitial fibrosis (TIF) is the main pathologic feature of end-stage renal disease. Epithelial-mesenchymal transition (EMT) of proximal tubular cells (PTCs) is one of the most significant features of TIF. MicroRNAs play critical roles during EMT in TIF. However, whether miRNAs can be used as therapeutic targets in TIF therapy remains undetermined. We found that miR-30e, a member of the miR-30 family, is deregulated in TGF-ß1-induced PTCs, TIF mice and human fibrotic kidney tissues. Moreover, transcription factors that induce EMT, such as snail, slug, and Zeb2, were direct targets of miR-30e. Using a cell-based miR-30e promoter luciferase reporter system, Schisandrin B (Sch B) was selected for the enhancement of miR-30e transcriptional activity. Our results indicate that Sch B can decrease the expression of snail, slug, and Zeb2, thereby attenuating the EMT of PTCs during TIF by upregulating miR-30e, both in vivo and in vitro. This study shows that miR-30e can serve as a therapeutic target in the treatment of patients with TIF and that Sch B may potentially be used in therapy against renal fibrosis.

10.
BMC Cancer ; 19(1): 1047, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694596

RESUMO

BACKGROUND: The application of laparoscopic liver resection (LLR) has expanded rapidly in recent decades. Although multiple authors have reported LLR shows improved safety and efficacy in treating hepatocellular carcinoma (HCC) compared with open liver resection (OLR), laparoscopic (LMLR) and open (OMLR) major liver resections for HCC treatment remain inadequately evaluated. This work aimed to test the hypothesis that LMLR is safer and more effective than OMLR for HCC. METHODS: Comparative cohort and registry studies on LMLR and OMLR, searched in PubMed, the Science Citation Index, EMBASE, and the Cochrane Library, and published before March 31, 2018, were collected systematically and meta-analyzed. Fixed- and random-effects models were employed for generating pooled estimates. Heterogeneity was assessed by the Q-statistic. RESULTS: Nine studies (1173 patients) were included. Although the pooled data showed operation time was markedly increased for LMLR in comparison with OMLR (weighted mean difference [WMD] 74.1, 95% CI 35.1 to 113.1, P = 0.0002), blood loss was reduced (WMD = - 107.4, 95% CI - 179.0 to - 35.7, P = 0.003), postoperative morbidity was lower (odds ratio [OR] 0.47, 95% CI 0.35 to 0.63, P <  0.0001), and hospital stay was shorter (WMD = - 3.27, 95% CI - 4.72 to - 1.81, P <  0.0001) in the LMLR group. Although 1-year disease-free survival (DFS) was increased in patients administered LMLR (OR = 1.55, 95% CI 1.04 to 2.31, P = 0.03), other 1-, 3-, and 5-year survival outcomes (overall survival [OS] and/or DFS) were comparable in both groups. CONCLUSIONS: Compared with OMLR, LMLR has short-term clinical advantages, including reduced blood loss, lower postsurgical morbidity, and shorter hospital stay in HCC, despite its longer operative time. Long-term oncological outcomes were comparable in both groups.

11.
Sci Rep ; 9(1): 17117, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745190

RESUMO

Asymmetric transmission (AT) devices are fundamental elements for optical computing and information processing. We here propose an AT device consisting of a pair of coupled complementary subwavelength gratings. Different from previous works, asymmetric dielectric environment is employed for unidirectional excitation of surface plasmon polaritons (SPPs) and thus asymmetric optical transmission, and near-field coupling effect inherent in the coupled complementary structure is exploited to enhance forward transmission and AT behavior, and determine operation bandwidth as well. The influence of asymmetric dielectric environment, effect of vertical and lateral couplings, interactions of electric- and magnetic-dipole moments and the realization of Kerker conditions, are investigated in depth to unearth the AT mechanism and performance. High-performance AT with large forward transmittance of 0.96 and broad bandwidth of 174 nm is achieved at wavelength 1250 nm. Our work helps people to gain a better understanding of near-filed coupling effect in coupled complementary structures, expand their application fields, and it also offers an alternate way to high-performance AT devices.

12.
Biosens Bioelectron ; 149: 111801, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31726276

RESUMO

An ultrasensitive and rapid detection of trace antibiotics is imperative for food safety and public health. Herein, we present a ratiometric fluorescent sensing strategy based on an aptamer labeled with a fluorescent dye and a highly stable zirconium-porphyrin MOF (PCN-222) as a fluorescence quencher for the high-efficiency detection of chloramphenicol (CAP). PCN-222 exhibits a strong adsorption ability toward the dye-labeled aptamer through π-π stacking, electrostatic, hydrogen bond, and coordination interactions. Experimental and simulation studies confirm that PCN-222 demonstrates a high quenching efficiency via fluorescence resonance energy transfer (FRET) and photoinduced electron transfer (PET) processes. In the presence of CAP, dye-labeled aptamers are released from the PCN-222 surface, resulting in the recovery of fluorescence. This proposed biosensor allows the complete detection of CAP within 26 min. For ratiometric measurement, its detection limit is as low as 0.08 pg mL-1 with a wide detection range from 0.1 pg mL-1 to 10 ng mL-1. It is successfully applied to analyze CAP in milk and shrimp samples, and its results are consistent with those of the commercial ELISA kit. This biosensor not only enables the rapid, ultrasensitive, and highly specific detection of CAP but also reveals excellent universality and multiplexed analysis performance.

13.
Nat Struct Mol Biol ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31740854

RESUMO

Amino acid availability in Gram-positive bacteria is monitored by T-box riboswitches. T-boxes directly bind tRNAs, assess their aminoacylation state, and regulate the transcription or translation of downstream genes to maintain nutritional homeostasis. Here, we report cocrystal and cryo-EM structures of Geobacillus kaustophilus and Bacillus subtilis T-box-tRNA complexes, detailing their multivalent, exquisitely selective interactions. The T-box forms a U-shaped molecular vise that clamps the tRNA, captures its 3' end using an elaborate 'discriminator' structure, and interrogates its aminoacylation state using a steric filter fashioned from a wobble base pair. In the absence of aminoacylation, T-boxes clutch tRNAs and form a continuously stacked central spine, permitting transcriptional readthrough or translation initiation. A modeled aminoacyl disrupts tRNA-T-box stacking, severing the central spine and blocking gene expression. Our data establish a universal mechanism of amino acid sensing on tRNAs and gene regulation by T-box riboswitches and exemplify how higher-order RNA-RNA interactions achieve multivalency and specificity.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31702889

RESUMO

Here, we report a peak ZT of 1.85 at 873 K for sulfur and Pb codoped polycrystalline SnSe by boosting electrical transport properties while suppressing the lattice thermal conductivity. Compared with single sulfur doped samples, the carrier concentration is improved 1 order of magnitude by Pb incorporation, thereby contributing to improved electrical conductivity and power factor. Moreover, the introduction of sulfur and Pb suppresses the bipolar thermal conductivity by enlarging the band gap. The lattice thermal conductivity significantly decreased as low as 0.13 W m-1 K-1 at 873 K due to the synergic approach involving suppressing bipolar thermal conductivity, large mass fluctuation induced by sulfur incorporation, and nanoprecipitates. We demonstrate that the combination of tailoring band structure, suppressing bipolar thermal conductivity, and introducing large mass fluctuation contributes to the high thermoelectric performance in SnSe. The high performance was achieved through boosting electrical transport properties while maintaining ultralow thermal conductivity. Our findings offer a new strategy for achieving high performance thermoelectric materials.

15.
Zootaxa ; 4568(1): zootaxa.4568.1.9, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-31715876

RESUMO

Two new species of flatworm, collected from a beach at eastern Shenzhen, China, were studied through an integrative approach by combining morphological, histological, histochemical (acetylcholinesterase, AChE), and molecular (18S r- DNA) data. These species belong to two genera of marine triclads, previously unrecorded from China, viz. Nerpa Marcus, 1948 and Paucumara Sluys, 1989.        Nerpa fistulata Wang Chen, sp. nov. is characterized by: transparent body; principally pentamerous intestine with three distinct commissures; two very large, prepharyngeal testis follicles; a semi-circular lens in each eye cup; a penis papilla provided with a chitinized, pointed stylet; lateral bursae communicating with the oviduct and opening ventrally to the exterior via a duct. Phylogenetically N. fistulata groups with one member of the family Bdellouridae. This new, Chinese species of Nerpa introduces a major geographic disjunction, as the type species N. evelinae was described from the bay of Santos, Brazil, so that the genus is now known from both Atlantic as well as Pacific coasts.        The species Paucumara falcata Wang Li, sp. nov. is characterized by: three distinct pale yellow transverse pigmentation bands on its dorsal side, between which some snowflake-like specks are randomly distributed, and a brown transverse band anteriorly to the eyes; 8-11 testicular follicles on either side of the body, the follicles extending from immediately behind the ovaries to half-way along the pharyngeal pocket; a musculo-parenchymatic organ with a sclerotic, curved tip projecting from the anterior wall of the male atrium, ventrally to the root of the penis papilla. Phylogenetically P. falcata groups with its congener P. trigonocephala, with the genus Paucumara forming the sister taxon of the genus Ectoplana. Comparison of the nerve structure of P. falcata, as revealed by AChE histochemistry, with that of eight other species of triclad suggested that the nervous system of marine planarians is simpler than that of species of freshwater planarians, but revealed also that the nerve structure is rather variable among species.        The copulatory position exhibited by two partners in Paucumara falcata is remarkable in that they intertwine, with their heads pointing downwards and the tails pointing upwards, the entire process lasting about 10 min. Such a copulatory position has never before been reported for triclad flatworms.


Assuntos
Planárias , Animais , Brasil , China , Masculino , Sistema Nervoso , Filogenia
16.
JAMA Intern Med ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31764937

RESUMO

Importance: The working schedules of hospitalists vary widely. Discontinuous schedules, such as 24 hours on and 48 hours off, result in several hospitalists providing care during a patient's hospital stay. Poor continuity of care during hospitalization may be associated with poor patient outcomes. Objective: To determine whether admitted patients receiving care from hospitalists with more discontinuous schedules experience worse outcomes. Design, Setting, and Participants: This retrospective cohort study used conditional models to assess Medicare claims data for 114 777 medical admissions of patients with a 3-day to 6-day length of stay from January 1, 2014, through November 30, 2016, who received all general medical care from hospitalists in 229 hospitals in Texas. Data were analyzed from November 2018 to June 2019. Exposures: For each admission, the weighted mean of schedule continuity for the treating hospitalists, assessed as the percentage of all their working days in that year that were part of a block of 7 or more consecutive working days, was calculated. Main Outcomes and Measures: The primary outcome was patient mortality in the 30 days after discharge. Secondary outcomes were readmission rates and Medicare costs in the 30 days after discharge, and discharge destination. Results: Of the 114 777 patient admissions, the mean (SD) age was 79.9 (8.3) years, and 70 047 (61.0%) were women. For admissions in the lowest quartile for continuity of hospitalist schedules, the hospitalists providing care worked 0% to 30% of their total working days as part of a block of 7 or more consecutive days vs 67% to 100% for hospitalists providing care for patients in the highest quartile for continuity. Patient characteristics were not associated with the continuity of working schedules for the hospitalist(s) providing care. In conditional logistic regression models, admitted patients cared for by hospitalists in the highest quartile of schedule continuity (vs the lowest quartile) had lower 30-day mortality after discharge (adjusted odds ratio [aOR], 0.88; 95% CI, 0.81-0.95), lower readmission rates (aOR, 0.94; 95% CI, 0.90-0.99), higher rates of discharge to the home (aOR, 1.08; 95% CI, 1.03-1.13), and lower 30-day postdischarge costs (-$223; 95% CI, -$441 to -$7). The results were similar across a range of different methods for defining continuity of hospitalist schedules and selecting the cohort. Conclusions and Relevance: Hospitalist schedules vary widely. Admitted patients receiving care from hospitalists with schedules that promote inpatient continuity of care may experience better outcomes of hospitalization.

17.
mSphere ; 4(6)2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748247

RESUMO

The aim of this study was to investigate the occurrence and genomic characteristics of extended-spectrum-ß-lactamase-producing Escherichia coli (ESBL-EC) in fennec fox imported from Sudan to China. We screened 88 fecal samples from fennec fox for ESBL-EC, using cefotaxime- and meropenem-supplemented selective medium. Antimicrobial susceptibility testing was performed by the agar dilution method except for colistin and tigecycline; for colistin and tigecycline, testing was conducted by the broth microdilution method. ESBL-EC bacteria were sequenced, and their genomes were characterized. Plasmid conjugation, S1 nuclease pulsed-field gel electrophoresis (PFGE), and Southern blotting were performed for a MCR-1-producing isolate. The genetic environment of mcr-1 and ESBL genes was also investigated. A total of 29 ESBL-EC bacteria were isolated from 88 fennec fox (32.9%), while no carbapenemase producers were found. The most prevalent genotypes were the bla CTX-M-55 and bla CTX-M-14 genes, followed by bla CTX-M-15 and bla CTX-M-64 We detected nine sequence types among 29 ESBL-EC. Furthermore, the mcr-1 gene was detected in isolate EcFF273. Conjugation analysis confirmed that the mcr-1 gene was transferable. S1 PFGE, Southern blotting, and whole-genome sequencing revealed that mcr-1 and bla CTX-M-64 were both located on a 65-kb IncI2 plasmid. This study reports for the first time the occurrence of ESBL-EC in fennec fox. The high prevalence of ESBL producers and the occurrence of MCR-1 producer in fennec fox imported into China from Sudan are unexpected. In addition, it clearly demonstrated that commensal E. coli strains can be reservoirs of bla CTX-M and mcr-1, potentially contributing to the dissemination and transfer of such genes to pathogenic bacteria among fennec fox. Our results support the implication of fennec fox as a biological vector for ESBL-producing members of the Enterobacteriaceae family.IMPORTANCE The extended-spectrum-ß-lactamase (ESBL)-producing members of the Enterobacteriaceae family are a global concern for both animal and human health. There is some information indicating a high prevalence of ESBL producers in food animals. Moreover, there have been an increasing number of reports on ESBL-producing strains resistant to the last-resort antibiotic colistin with the global dissemination of the plasmid-mediated mcr-1 gene, which is believed to have originated in animal breeding. However, little is known regarding the burden of ESBL-producing Enterobacteriaceae on wild animals. No data were available on the prevalence of antimicrobial resistance (AMR) among wild animals imported into China. This is the first study to investigate the microbiological and genomics surveillance investigation of ESBL colonization among fennec fox (Vulpes zerda) imported from Sudan to China, and we uncovered a high prevalence of ESBL-EC. Furthermore, the underlying mechanism of colistin resistance in an isolate that harbored mcr-1 was also investigated. Results of characterization and analysis of 29 ESBL-producing E. coli may have important implications on our understanding of the transmission dynamics of these bacteria. We emphasize the importance of improved multisectoral surveillance for colistin-resistant E. coli in this region.

18.
J Phys Chem Lett ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31769691

RESUMO

Two dimensional InSe possesses good electrical conductivity, intrinsic and structural flexibility, high chemical stability and tunable band gap, enabling it to be a promising candidate for flexible and wearable solar cells. Here we construct a lateral p-n junction by partially doping molybdenum trioxide (MoO3) at the surface of InSe monolayer. Our density-functional theory calculations reveal that, the strong hybridization between MoO3 and InSe induces a lateral built-in electric field in the partially doped substrate and promotes the effective separation of carriers. Under a large range of external stains, the doped InSe can maintain the direct band gap and the lateral-structure device exhibits the power conversional efficiencies over 5% and high carrier mobility around 1000 cm2 V-1 s-1. In particular, a power conversional efficiency of 20.7% was achieved with 10% compressive strain.

19.
Environ Toxicol ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31738477

RESUMO

Cadmium (Cd) is one of the major contaminants in aquatic ecosystem. Stearoyl-coenzyme A desaturase 1 (Scd1) has been implicated in adaptive responses to environmental stressors. The objectives of this study are (a) to characterize scd1 mRNA from silver pomfret (Pampus argenteus); (b) to investigate the expression and activity of Scd1 in silver pomfret exposed to Cd; and (c) to investigate how Cd modifies scd1 gene transcription in silver pomfret. Results indicated that Scd1 was generally conserved across fish species and scd1 mRNA level was higher by far in the brain and liver, followed by the kidney and intestine. Exposure to Cd led to significant changes of the expression and activity of Scd1 in in the liver and intestine. The liver mRNA abundance of scd1 was significantly lower in the Cd-treated groups than in the control group. The 10 days treatment with 1 mg/L Cd significantly upregulated the intestinal scd1 mRNA level, an approximately 9-fold higher in the 1 mg/L Cd-treated group as compared with the control group. Accordingly, Scd1 activity indices (18:1n-9/18:0) in the liver were significantly decreased in the 0.5 mg/L group compared with the control group, while Scd1 activity indices in the intestine were significantly increased in the 1 mg/L group compared with the control group. Moreover, overexpression of sterol regulatory element binding transcription factor 1 (Srebp1) and peroxisome proliferator-activated receptor γ (Pparγ )in HEK 293T cells produced a 2-fold increment in the activity of the scd1 promoter. Furthermore, srebp1 had a similar expression pattern to scd1 in the liver and intestine of silver pomfret exposed to Cd. These results indicated that Cd could regulate scd1 expression, possibly through the transcriptional factor Srebp1.

20.
Fitoterapia ; 139: 104411, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31705951

RESUMO

Eleven sesquiterpenoids including four new eudesmane sesquiterpenoids, solanoids A-D (1-4), and seven known compounds (5-11) were isolated from the herbs of Solanum lyratum. By analyzing the UV, MS and NMR data, the gross structures of all isolates were established. The absolute configurations of these new compounds were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The in vitro cytotoxicity of all isolates against the hepatocellular carcinoma Hep3B and HepG2 cell lines was evaluated. Among them, compounds 7 and 11 exhibited moderate cytotoxicity against two cell lines.

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