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1.
Artigo em Inglês | MEDLINE | ID: mdl-32012836

RESUMO

Tourism and transportation have extremely complex interactions. Tourism developments have expanded demand and stimulated transportation development, which has consequently affected the environment of cities striving towards low-carbon sustainable development. Therefore, there has been an increased research focus on the coordinated binary development of the tourism and transportation industries to ensure sustainable low-carbon cities. To this end also this paper first developed a comprehensive evaluation index system with three subsystems, seven aspects, and 31 indicators. Then, entropy weight and gray correlation were combined to determine the index weights and a physics coupling concept employed to build a tourism, transportation and low-carbon city (TTLC) coupling coordination degree model, which was then applied to quantitatively analyze the coupling and evolutionary trends in Chongqing's TTLC efforts from 2008 to 2017. It was found that the overall coupling coordination was volatile and rising, and that industry scale, industry performance, and energy consumption had the most significant impact on the coupled systems, indicating that these key factors must be considered in macro decision-making. In general, it was shown that the combination of the coupling coordination degree model and entropy weight gray correlation was able to effectively evaluate dynamic coupling relationships.

2.
Mol Nutr Food Res ; : e1900876, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050056

RESUMO

SCOPE: This study explored the beneficial effects of dietary supplementation of black rice anthocyanin extract (BRAE) on cholesterol metabolism and gut dysbiosis. METHODS AND RESULTS: C57BL/6J mice were grouped into the normal chow diet group (NCD), the high-fat and cholesterol diet group (HCD), and three treatment groups feeding HCD supplemented with various dosage of BRAE (BAL, BAM, BAH) for 12 weeks. Results revealed that BRAE alleviated the increased body weight, serum triglyceride (TG), total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C) levels, and increased fecal sterols excretion and caecal short-chain fatty acids (SCFAs) concentration in HCD-induced hypercholesterolemic mice. Moreover, BRAE decreased hepatic TC content through elevated hepatic AMPKα, LXRα, CYP7A1 and decreased FXR, SHP, HMGCOA-R mRNA levels. Meanwhile, BRAE depressed NPC1L1, ACAT2, MTTP, and preserved CYP7A1, ABCG5/8 mRNA expression, and the relative abundance of gut microbiota. Additionally, the antibiotic treatment experiment indicated that the beneficial effects of BRAE in reducing hypocholesterolemia risk largely depended on the gut microbiota homeostasis (e.g., Bifidobacterium, Lactobacillus). CONCLUSION: BRAE supplement could be a beneficial treatment option for preventing HCD-induced hypocholesterolemia and related metabolic syndromes. This article is protected by copyright. All rights reserved.

3.
Artigo em Inglês | MEDLINE | ID: mdl-32065363

RESUMO

In the original publication Fig. 10b was erroneously plotted due to the authors' carelessness and unintentional misoperation.

4.
Medicine (Baltimore) ; 99(8): e19207, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32080108

RESUMO

Cigarette smoking is associated with thicker carotid intima-media thickness (IMT), probably partly through inflammatory pathways. However, to what extent does inflammation mediate the smoking-carotid atherosclerosis association is unclear. We investigated the mediating effect of inflammation on the association between cigarette smoking and carotid IMT, and quantified the respective contributions of inflammatory markers to this association.A total of 1752 participants from Guangzhou Biobank Cohort Study-Cardiovascular Disease Sub-cohort (GBCS-CVD) were included. Using causal mediation analysis under the counterfactual framework, we decomposed total effects of cigarette smoking on IMT into indirect effects (through inflammatory response) and direct effects (not through inflammatory response).After adjusting for traditional risk factors, the indirect effects of per 10/L increment in leukocyte and granulocyte, per mg/L increment in high-sensitivity C-reactive protein (hs-CRP), and per mg/dL increment in fibrinogen on carotid IMT was 0.0028 mm (95% confidence interval [CI], 0.0011-0.0047), 0.0019 mm (95% CI, 0.0006-0.0034), 0.0017 mm (95% CI, 0.0006-0.003), and 0.001 mm (95% CI, 0.0001-0.0021), respectively. No evidence for a mediating role of lymphocyte was found. The proportion of the smoking-IMT association mediated by leukocyte, granulocyte, hs-CRP, and fibrinogen was 12.57% (95% CI, 8.50%-22.11%), 8.50% (95% CI, 5.76%-15.09%), 7.64% (95% CI, 5.20%-13.79%), and 4.48% (95% CI, 3.04%-8.03%), respectively. Restricting data analysis to men showed similar results.The effects of cigarette smoking on IMT were partly mediated by leukocyte, hs-CRP, and fibrinogen. The mediating role of leukocyte was likely mainly driven by higher granulocyte.

5.
Cell Death Dis ; 11(2): 136, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32075954

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a group of chronic interstitial pulmonary diseases characterized by myofibroblast proliferation and extracellular matrix deposition with limited treatment options. Based on our previous observation, we hypothesized microcystin-leucine arginine (LR), an environmental cyanobacterial toxin, could potentially suppress pulmonary fibrosis. In this study, we first demonstrated that chronic exposure of microcystin-LR by oral for weeks indeed attenuated the pulmonary fibrosis both on bleomycin-induced rat and fluorescein isothiocyanate-induced mouse models. Our data further indicated that treatment with microcystin-LR substantially reduced TGF-ß1/Smad signaling in rat pulmonary tissues. The experiments in vitro found that microcystin-LR was capable of blocking epithelial-mesenchymal transition (EMT) and fibroblast-myofibroblast transition (FMT) through suppressing the differentiation of CD206+ macrophages. Mechanically, microcystin-LR was found to bind to glucose-regulated protein 78 kDa (GRP78) and suppress endoplasmic reticulum unfolded protein response (UPRER) signaling pathways. These events led to the modulation of M2 polarization of macrophages, which eventually contributed to the alleviation of pulmonary fibrosis. Our results revealed a novel mechanism that may account for therapeutic effect of microcystin-LR on IPF.

6.
Drug Metab Dispos ; 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32086297

RESUMO

Recent studies have shown that microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) regulate the expression of drug metabolizing enzymes (DMEs) in human hepatic cells and that a set of DMEs, including UGT2B15, is down-regulated dramatically in liver cells by toxic APAP concentrations. In this study we analyzed mRNA, miRNA, and lncRNA expression profiles in APAP-treated HepaRG cells to explore noncoding RNA-dependent regulation of DME expression. The expression of UGT2B15 and lncRNA LINC00574 was significantly decreased in APAP-treated HepaRG cells. UGT2B15 levels were diminished by LINC00574 suppression using antisense oligonucleotides or small interfering RNA. Furthermore, we found that hsa-miR-129-5p suppressed LINC00574 and decreased UGT2B15 expression via LINC00574 in HepaRG cells. In conclusion, our results indicate that LINC00574 acts as an important regulator of UGT2B15 expression in human hepatic cells, providing experimental evidence and new clues to understand the role of crosstalk between noncoding RNAs. SIGNIFICANCE STATEMENT: We showed a molecular network that displays the crosstalk and consequences among mRNA, miRNA, lncRNA and proteins in APAP-treated HepaRG cells. APAP treatment increased the level of hsa-miR-129-5p and decreased that of LINC00574, ultimately decreasing the production of UGT2B15. The proposed regulatory network suppresses UGT2B15 expression through interaction of hsa-miR-129-5p and LINC00574, which may be achieved potentially by recruiting RNA binding proteins.

7.
Aging (Albany NY) ; 122020 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-32087064

RESUMO

Tumor-associated tertiary lymphoid structures (TLS) play a critical role in the progression of various tumors. However, the dynamics of lymphocyte recruitment during hepatocellular carcinoma (HCC) clinical progression have not been fully elucidated. In the present study, tissue microarrays and hematoxylin-eosin staining were used to evaluate the existence and degree of TLS in HCC patients. Nine immune biomarkers in intratumoral tissues were examined by immunohistochemical staining. A total of 462 patients were recruited for the study. Kaplan-Meier analysis showed that TLS was inversely correlated with the risk of early tumor recurrence (P=0.014), whereas no association was found between TLS and overall survival. Cox regression analysis identified TLS as an independent prognostic factor for early HCC recurrence (P=0.005). In addition, TLS was associated with increased intratumoral CD3+, CD8+, CD20+, and decreased infiltration of Foxp3+ and CD68+ cells. A lower density of PD1+, TIM3+, and LAG3+ were found in TLS+ cases. Sub-analysis revealed the prognostic value of TLS on early-stage HCC (BCLC 0-A, TNM stage I-II) and HCC with solitary nodule. The validation cohort verified the prognostic value of TLS in early-stage HCC patients. These results suggest that TLS-targeted immune-modulating therapies may be a potential strategy for effective immune-mediated tumor suppression.

8.
Sci Immunol ; 5(44)2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32086382

RESUMO

Lack of responsiveness to checkpoint inhibitors is a central problem in the modern era of cancer immunotherapy. Tumor neoantigens are critical targets of the host antitumor immune response, and their presence correlates with the efficacy of immunotherapy treatment. Many studies involving assessment of tumor neoantigens principally focus on total neoantigen load, which simplistically treats all neoantigens equally. Neoantigen load has been linked with treatment response and prognosis in some studies but not others. We developed a Cauchy-Schwarz index of Neoantigens (CSiN) score to better account for the degree of concentration of immunogenic neoantigens in truncal mutations. Unlike total neoantigen load determinations, CSiN incorporates the effect of both clonality and MHC binding affinity of neoantigens when characterizing tumor neoantigen profiles. By analyzing the clinical responses in 501 treated patients with cancer (with most receiving checkpoint inhibitors) and the overall survival of 1978 patients with cancer at baseline, we showed that CSiN scores predict treatment response to checkpoint inhibitors and prognosis in patients with melanoma, lung cancer, and kidney cancer. CSiN score substantially outperformed prior genetics-based prediction methods of responsiveness and fills an important gap in research involving assessment of tumor neoantigen burden.

9.
Food Res Int ; 129: 108887, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32036906

RESUMO

In the present study, the action mechanism of ultrasound (US) combined with sodium hypochlorite (SH) against Escherichia coli was illustrated by different analysis, including reduction, particle size distribution, scanning electron microscopy (SEM), transmission electron microscopy (TEM), K+ leakage, confocal laser scanning microscopy (CLSM) and fluorescence spectroscopy of Escherichia coli. The results showed that ultrasound improved the antimicrobial effect of SH in control of E. coli. No significant difference was obtained in reduction of E. coli, CLSM analysis and K+ leakage between US + SH30 (US + 30 ppm SH) and SH50 (50 ppm SH) treatment. Smaller particle size was recorded in US and US + SH30 treatment. The changes of morphology and intracellular organization of E. coli cells as a result of these treatments were confirmed by SEM and TEM analyses. Fluorescence spectroscopy results indicated SH30, US + SH30 and SH50 treatment caused the burial of tyrosine residues and tryptophan residues as well as increase of hydrophobicity. Therefore, the mechanism of US + SH30 treatment against E. coli involved decreased particle size, damaged membrane and changes of intracellular organization and protein conformation.

10.
Colorectal Dis ; 2020 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-32037651

RESUMO

The principles of CME and high ligation have been applied by us during colonic resections for cancer. Laparoscopic transverse colectomy for mid-transverse colon cancer maintains the oncological quality, meanwhile the ileocecal vessels, ileocecal valve and part of the ascending colon are preserved. The aim of this video is to demonstrate the laparoscopic treatment for mid-transverse colon cancer.

11.
Emerg Microbes Infect ; 9(1): 302-312, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32013776

RESUMO

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb) bacteria, is a leading infectious cause of mortality worldwide. The emergence of drug-resistant M. tb has made control of TB more difficult. The selective optimization of side activities (SOSA) approach uses old drugs for new pharmacological targets. In the present study by using SOSA approach, we have successfully identified pyrvinium pamoate (PP) which is capable of inhibiting the growth of mycobacteria, including M. tb H37Rv, Mycobacterium smegmatis, Bacille Calmette-Guérin (BCG), M. tb H37Ra, and drug-resistant M. tb clinical isolates in vitro from 1280 known drugs library. The MIC99 of PP, the minimum inhibitory concentration that inhibits more than 99% of M. tb H37Rv and the drug-resistant M. tb clinical isolates, ranges from 1.55 to 4.8 µg/mL. Importantly, PP could reduce the bacterial colony-forming units (CFUs) in lung, spleen and liver tissues, and effectively inhibit inflammatory response in M. tb H37Rv, multidrug-resistant (MDR) M. tb and extensively drug-resistant (XDR) M.tb-infected mice. Our results clearly show that the PP has the potential application for treatment of TB.

12.
Infect Dis Poverty ; 9(1): 13, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005290

RESUMO

BACKGROUND: China is facing challenges of the shifting presentation of tuberculosis (TB) from younger to elderly due to an ageing population, longer life expectancy and reactivation disease. However, the burden of elderly TB and influence factors are not yet clear. To fill the gap, we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China. METHODS: In this cohort established in 2013 through a prevalence survey conducted in selected sites, a total of 34 076 elderlies without TB were enrolled into two-year follow-up. We used both active and passive case findings to find out all TB patients among them. The person-year (PY) incidence rates for both bacteriologically positive TB and active TB were calculated. Cox proportional regression model was performed to test effect of risk factors, and the population attributable fraction (PAF) of each risk factor contributing to incident TB among elderlies was calculated. RESULTS: Over the two-year follow-up period, a total of 215 incident active TB were identified, 62 of which were bacteriologically positive. The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100 000 PY (95% CI: 417.4-546.2 per 100 000 PY) and 138.9 per 100 000 PY (95% CI: 104.4-173.5 per 100 000 PY), respectively. Incident cases detected by active case finding were significantly higher (P < 0.001). Male, non-Han nationality, previously treated TB, ex/current smoker and body mass index (BMI) < 18.5 presented as independent predictors for developing TB disease. For developing bacteriologically positive TB, the biggest contribution was from self-reported ex or current smoker (18.06%). And, for developing active TB, the biggest contribution was from non-Han nationality (35.40%), followed by male (26.80%) and age at 75 years and above (10.85%). CONCLUSIONS: Ageing population in China had a high TB incidence rate and risk to develop TB disease, implying that National TB Program (NTP) needs to prioritize for elderly. Active case finding should be applied capture more active TB cases among this particular population, especially for male, non-Han nationality, and those with identified risk factors.

13.
Med Sci Monit ; 26: e918382, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32004259

RESUMO

BACKGROUND The coatomer protein complex subunit beta 2 (COPB2) gene is upregulated and promotes cell proliferation in some cancer cells. This study aimed to investigate the role of microRNA (miRNA) targeting by COPB2 gene expression in human lung adenocarcinoma cell lines, including NCI-H1975 cells. MATERIAL AND METHODS COPB2 expression in normal human bronchial epithelial cells and lung adenocarcinoma cells was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. NCI-H1975 human lung adenocarcinoma cells were transfected with short-interfering COPB2 (siCOPB2). Cell apoptosis and cell proliferation were evaluated by flow cytometry and Cell Counting Kit-8 (CCK-8) assays, respectively. The transwell assay evaluated cell migration. Targeting of miR-335-3p by COPB2 was predicted using TargetScan 7.2 and verified using a dual-luciferase reporter assay in NCI-H1975 cells. MiR-335-3p mimics were transfected into NCI-H1975 cells. The further functional analysis included detection of protein expression for cyclin D1, tissue inhibitor matrix metalloproteinase-1 (TIMP-1), matrix metallopeptidase 9 (MMP9), Bcl-2, and Bax, to verify the role of miR-335-3p targeting by COPB2 in lung adenocarcinoma cells. RESULTS COPB2 was upregulated in lung adenocarcinoma cells and was a direct target of miR-335-3p mimics. COPB2 knockdown promoted cell apoptosis, inhibited cell migration and proliferation in NCI-H1975 cells. The effects of COPB2 knockdown on NCI-H1975 cells were increased by miR-335-3p mimics, which also further reduced the expression levels of cyclin D1, MMP9, and Bcl-2 and further increased TIMP-1 and Bax by siCOPB2. CONCLUSIONS This study showed that COPB2 was the functional target of miR-335-3p in NCI-H1975 human adenocarcinoma cells.

14.
Curr Drug Targets ; 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32056522

RESUMO

Preserving of articular cartilage is an effective way to protect synovial joints from becoming osteoarthritic (OA) joints. Understanding of the molecular basis of articular cartilage degeneration will provide valuable information in the effort to develop cartilage preserving drugs. There are currently no disease-modifying OA drugs (DMOADs) available to prevent articular cartilage destruction during the development of OA. Current drug treatments for OA focus on the reduction of joint pain, swelling, and inflammation at advanced stages of the disease. However, based on discoveries from several independent research laboratories and our laboratory in the past 15 to 20 years, we believe that we have a functional molecular understanding of articular cartilage degeneration. In this review article, we present and discuss experimental evidence to demonstrate a sequential chain of the molecular events underlying articular cartilage degeneration, which consists of transforming growth factor beta 1, high-temperature requirement A1 (a serine protease), discoidin domain receptor 2 (a cell surface receptor tyrosine kinase for native fibrillar collagens), and matrix metalloproteinase 13 (an extracellular-matrix degrading enzyme). If, as we strongly suspect, this molecular pathway is responsible for the initiation and acceleration of articular cartilage degeneration, which eventually leads to progressive joint failure, then these molecules may be ideal therapeutic targets for the development of DMOADs.

15.
Sci Rep ; 10(1): 1924, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024868

RESUMO

Previous studies on Chinese showed mixed results describing the relationship between obesity and mortality. The optimum levels of body mass index (BMI) and waist circumference (WC) are inconsistent. In the Guangzhou Biobank Cohort Study, after excluding ever smokers and those with poor health, 19,405 Chinese (50+ years) recruited from 2003 to 2008 were followed-up until 2017. During an average follow-up of 11.5 (standard deviation = 2.3) years, 1,757 deaths were recorded. All-cause mortality showed a J-shaped association with BMI, with the lowest mortality risks at 22.5 kg/m2 for both men and women. In those with BMI ≥ 22.5 kg/m2, an increase of 5 kg/m2 was associated with 29% higher all-cause mortality (hazard ratio (HR) = 1.29, 95% confidence interval (CI) 1.15-1.46), 30% higher cancer mortality (1.30, 95% CI 1.08-1.57), and 37% higher cardiovascular disease (CVD) mortality (1.37, 95% CI 1.13-1.67) after adjustment for potential confounders. In this first cohort study in one of the most economically developed cities in China, the lowest all-cause mortality was observed for a BMI of 22.5 kg/m2 in all participants, and a WC of 78 cm in men and 72 cm in women.

16.
Artigo em Inglês | MEDLINE | ID: mdl-32073709

RESUMO

Here we introduce the use of di(2-pyridyl)ketone in subcomponent self-assembly. When combined with a flexible triamine and zinc bis(trifluoromethylsulfon)imide, this ketone formed a new Zn 4 L 4 tetrahedron 1 bearing twelve uncoordinated pyridyl units around its metal-ion vertices. The acid stability of 1 was found to be greater than that of the analogous tetrahedron 2 built from 2-formylpyridine. Intriguingly, the peripheral presence of additional pyridine rings in 1 resulted in distinct guest binding behavior from that of 2 , affecting guest scope as well as binding affinities. The different stabilities and guest affinities of capsules 1 and 2 enabled the design of systems whereby different cargoes could be moved between cages using acid and base as chemical stimuli.

17.
Nature ; 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32015508

RESUMO

Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health1-3. Despite intense research efforts, how, when and where new diseases appear are still the source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to Wuhan Central Hospital on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing4 of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here 'WH-Human 1' coronavirus (and has also been referred to as '2019-nCoV'). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China5. This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans.

18.
Artigo em Inglês | MEDLINE | ID: mdl-32028764

RESUMO

A rechargeable aqueous zinc-ion battery (ZIB) is one of the attractive candidates for large-scale energy storage. Its further application relies on the exploitation of a high-capacity cathode and the understanding of an intrinsic energy storage mechanism. Herein, we report a novel layered K2V3O8 cathode material for the ZIB, adopting a strategy of charging first to extract part of K-ions from vanadate in initial few cycles, which creates more electrochemically active sites and lowers charge-transfer resistance of the ZIB system. As a result, a considerable specific capacity of 302.8 mA h g-1 at 0.1 A g-1, as well as a remarkable cycling stability (92.3% capacity retention at 4 A g-1 for 2000 cycles) and good rate capability, are achieved. Besides, the energy storage mechanism was studied by in situ X-ray diffraction, in situ Raman spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma mass spectroscopy. An irreversible K-ion deintercalation in the first charge process is proved. It is believed that this novel cathode material for the rechargeable aqueous ZIB and the optimizing strategy will shed light on developing next-generation large-scale energy storage devices.

19.
J Virol ; 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32075934

RESUMO

Polyomaviruses (PyVs) are small DNA viruses carried by diverse vertebrates. The evolutionary relationships of viruses and hosts remain largely unclear due to very limited surveillance in sympatric communities. In order to investigate whether PyVs can transmit among different mammalian species and to identify host-switching events in the field we conducted a systematic study of a large collection of bats (n=1,083) from 29 sympatric communities across China which contained multiple species with frequent contact. PyVs were detected in 21 bat communities with 192 PyVs identified in 186 bats from 15 species within 6 families representing at least 28 newly-described PyVs. Surveillance results and phylogenetic analyses surprisingly revealed three inter-family PyV host-switching events in these sympatric bat communities: two distinct PyVs were identified in two bat species in restricted geographical locations, while another PyV clustered phylogenetically with PyVs carried by bats from a different host family. Virus-host relationships of all discovered PyVs were also evaluated and no additional host-switching events were found. PyVs were identified in different horseshoe bat species in sympatric communities without observation of host-switching events, showed high genomic identities, clustered with each other. This suggested that even for PyVs with high genomic identities in closely-related host species, the potential for host-switching is low. In summary, our findings revealed that PyV host-switching in sympatric bat communities can occur but is limited, and host-switching events of bat-borne PyVs are relatively rare on the predominantly evolutionary background of co-divergence with their hosts.ImportanceSince the discovery of murine polyomavirus in the 1950s, polyomaviruses (PyVs) have been considered highly host-restricted in mammals. Sympatric bat communities commonly contain several different bat species in an ecological niche facilitating viral transmission, and therefore represent a model to identify host-switching events of PyVs. In this study, we screened PyVs in a large number of bats in sympatric communities from diverse habitats across China. We provide evidence that cross-species bat-borne PyV transmission exists, though is limited and that host-switching events appear relatively rare during the evolutionary history of these viruses. PyVs with close genomic identities were also identified in different bat species without host-switching events. Based on these findings, we propose an evolutionary scheme for bat-borne PyVs in which limited host-switching events occur on the background of co-divergence and lineage duplication generating the viral genetic diversity in bats.

20.
Anal Chim Acta ; 1098: 164-169, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31948580

RESUMO

Detecting molecular biomarkers in high sensitivity plays an important role in the diagnosis of various diseases at the early stage. Here, by combining the target-induced polymerization nicking reaction (TIPNR) with the loop-mediated isothermal amplification (LAMP), we describe an ultrasensitive and label-free aptamer-based sensing method for detecting low levels of proteins in human serum by using thrombin as the model target analyte. The target thrombin binds and causes spontaneous assembly of two distinct aptamer probes to form the templates for the polymerization nicking reaction recycling amplification to produce many forward inner primer sequences. Subsequently, downstream LAMP reactions are initiated by these sequences for the generation of tremendous DNA hairpins with various lengths via automated cyclic strand displacement reactions. The SYBR Green I organic dye further binds the many hairpins to show drastically amplified fluorescence for ultrasensitive detection of thrombin down to 3.6 fM in the linear range from 0.01 pM to 10 nM. Such a sensing method based on aptamers has high discrimination capability for the target molecules against other non-specific proteins and is applicable for diluted serum samples. With the successful demonstration of the substantial signal amplification ability and simplicity feature of this assay approach, highly sensitive and convenient detection of other disease biomarkers with this method can be envisioned in the near future.

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