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1.
Food Chem ; 338: 127988, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32950866

RESUMO

The potential for tristyrylphenol ethoxylates (TSPEOs) residues to contaminate crops or be released into the environment is of increasing concern, as they are toxic to living organisms. This study determined the dissipation of TSPEO homologues in cucumber under field conditions. TSPEOn (n = 6-29) dissipated more rapidly in cucumber than in soil samples, with half-lives of 1.80-4.30 d and 3.73-6.52 d, respectively. Short-chain TSPEOn (n = 6-11) persisted for longer than other oligomers in soil. Concentrations of the final residues (∑TSPEOs) in cucumber and soil were 24.3-1349 µg/kg and 47.3-1337 µg/kg, respectively. TSP15EO or TSP16EO was the dominant oligomer, with concentrations of 2.30-150 µg/kg. The risk assessment showed that the acute and chronic dietary exposure risks of ∑TSPEOs in cucumber were 0.03-0.57% and 0.05-0.39%, respectively, suggesting little or no health risk to Chinese consumers.

2.
Mol Biol Rep ; 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33040266

RESUMO

White clover (Trifolium repens L.) is an important perennial legume forage with high productivity and quality. To strengthen the basic research on the genetic characteristics, fingerprint identification and adaptability of white clover germplasm resources, Simple sequence repeat (SSR) molecular markers were applied to 10 white clover cultivars to assess the genetic diversity and related lines of white clover at the molecular level in order to lay a theoretical foundation for the selection of high-quality seeds and cultivars of white clover. A total of 120 different bands were amplified by 29 pairs of SSR primers with good polymorphism, of which 103 (89.5%) were polymorphic. Meanwhile, the PIC of each primer was 0.181-0.588, with an average of 0.329. Analysis of molecular variance revealed that 57% of the genetic variation occurred within cultivars and 43% occurred among cultivars. The results of cluster analysis and the principal coordinate analysis revealed that the parental relationships of the 10 cultivars, with the 'Purple' cultivar very distantly related to the other 9 cultivars and the closest parental relationship between 'Ladino' and 'Sulky'. The fingerprints constructed by three representative primers (gtrs679, gtrs319, and gtrs678) have a strong identification ability. In summary, the SSR markers had good polymorphism and could be used for DNA fingerprint analysis of white clover cultivars.

3.
Plant Biotechnol J ; 2020 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-33043566

RESUMO

Rice cultivars from japonica and indica lineage possess differential resistance against blast fungus as a result of genetic divergence. Whether different rice cultivars also show distinct metabolomic changes in response to P. oryzae, and their role in host resistance, are poorly understood. Here, we examine the responses of six different rice cultivars from japonica and indica lineage challenged with P. oryzae. Both susceptible and resistant rice cultivars expressed several metabolites exclusively during P. oryzae infection, including the saponin Bayogenin 3-O-cellobioside. Bayogenin 3-O-cellobioside level in infected rice directly correlated with their resistant attributes. These findings reveal, for the first time to our knowledge that besides oat, other grass plants including rice produces protective saponins. Our study provides insight into the role of pathogen-mediated metabolomics-reprogramming in host immunity. The correlation between Bayogenin 3-O-Cellobioside levels and blast resistance suggests that engineering saponin expression in cereal crops represents attractive and sustainable disease management.

4.
Front Immunol ; 11: 2031, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042115

RESUMO

The function of triggering receptor expressed on myeloid cell-like transcript 2 (TLT2) has not been characterized and their role in pulmonary tuberculosis (TB) remains unclear. In this study, we found that surface TLT2 was up-regulated in human monocytes of patients with active TB compared to healthy subjects. In vitro, TLT2 expression was induced in human monocyte cell line THP-1 cells after bacillus Calmette-Guérin (BCG) or Mycobacterium tuberculosis (Mtb) H37Rv infection. Knockdown of TLT2 by siRNA transfection suppressed IL-6 expression, whereas over-expression of TLT2 increased IL-6 production in THP-1 cells infected by H37Rv. TLT2+CD14+ monocytes produced higher level of IL-6 compared to TLT2- subset in active TB patients. Western blot and immunocoprecipitation revealed that TLT2 interacted with kinase JAK1/JAK2/Tyk2 to enhance STAT3 phosphorylation. Moreover, we showed that tyrosine residues 297 and 315 of TLT2 cytoplasmic domain were involved in STAT3 activation. In monocyte/CD4+ T cell co-culture assay, blockage of TLT2 fusion protein facilitated IFN-γ production by CD4+ T cells. Plate count assay showed that monocyte-mediated bacterial killing was promoted by TLT2 fusion protein. In vivo treatment with TLT-2 fusion protein reduced IL-6 production by macrophage but increased IFN-γ production by CD4+ T cell in H37Rv and BCG infected mice. Furthermore, TLT2 fusion protein attenuated inflammation, and reduced bacterial load in lung of infected mice. Together, these findings demonstrate that TLT2 negatively regulates Th1 response against mycobacterial infection, which promotes IL-6 production through JAK/STAT3 signal pathway.

5.
Clin Transl Sci ; 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33045130

RESUMO

Remimazolam is an ultra-short acting benzodiazepine under development for procedural sedation and general anesthesia. Population pharmacokinetic analysis (PopPK) was conducted for remimazolam with arterial and venous samples previously, but results were limited by arterial-venous concentration differences and inaccurate central volume of distribution (V1) estimates. A new model was developed to describe covariate effects after accounting for arterial-venous differences. Arterial and venous plasma concentration-time data from 11 clinical trials were pooled for PopPK. Data from two constant-rate infusion studies were used to account for venous-to-arterial (VtoA) ratio within residual error and to accurately estimate V1. V1 and VtoA ratio from the pilot model were applied to the full dataset, where the optimal fixed/random effects and covariates were assessed. VtoA ratio was described using a maximum effect (Emax ) model during infusion and as a constant postdose. V1 was estimated as 4.83 L for a 70 kg subject and interindividual variability (IIV) on V1 could only be estimated in studies with early concentrations. IIV on clearance was low (22.9%). Covariates included effects of sex on clearance (women 10% > men), and race on clearance and steady-state volume of distribution (African Americans 16% < other races). Arterial-venous concentration differences were best described using an Emax model during infusion with a constant ratio after infusion, resulting in low residual error (20.7%). There are no clinically relevant dose adjustments needed for any covariates based on pharmacokinetic differences.

6.
Nat Commun ; 11(1): 5088, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: covidwho-841957

RESUMO

Early detection of COVID-19 based on chest CT enables timely treatment of patients and helps control the spread of the disease. We proposed an artificial intelligence (AI) system for rapid COVID-19 detection and performed extensive statistical analysis of CTs of COVID-19 based on the AI system. We developed and evaluated our system on a large dataset with more than 10 thousand CT volumes from COVID-19, influenza-A/B, non-viral community acquired pneumonia (CAP) and non-pneumonia subjects. In such a difficult multi-class diagnosis task, our deep convolutional neural network-based system is able to achieve an area under the receiver operating characteristic curve (AUC) of 97.81% for multi-way classification on test cohort of 3,199 scans, AUC of 92.99% and 93.25% on two publicly available datasets, CC-CCII and MosMedData respectively. In a reader study involving five radiologists, the AI system outperforms all of radiologists in more challenging tasks at a speed of two orders of magnitude above them. Diagnosis performance of chest x-ray (CXR) is compared to that of CT. Detailed interpretation of deep network is also performed to relate system outputs with CT presentations. The code is available at https://github.com/ChenWWWeixiang/diagnosis_covid19 .

7.
Artigo em Inglês | MEDLINE | ID: covidwho-811809

RESUMO

BACKGROUND AND AIMS: Besides prominent respiratory involvement, gastrointestinal manifestations are commonly reported in Coronavirus Disease 2019 (COVID-19) patients. We compared infection of ex vivo human intestinal tissues by SARS-CoV-2 and SARS-CoV with respect to their replication kinetics and immune activation profile. METHODS: Human intestinal tissues were obtained from patients while undergoing surgical operations at the Queen Mary Hospital, Hong Kong. Upon surgical removal, the tissues were immediately processed and infected with SARS-CoV-2 or SARS-CoV. Replication kinetics were determined with immunohistochemistry, qRT-PCR, and plaque assays. Immune activation in the infected intestinal tissues was assessed by detecting the gene expression of interferons and representative pro-inflammatory cytokines and chemokines. RESULTS: SARS-CoV-2 could infect and productively replicate in the ex vivo human intestinal tissues with the release of infectious virus particles, but not in ex vivo human liver and kidney tissues. Importantly, SARS-CoV-2 replicated less efficiently than SARS-CoV, induced less cytopathology in the human intestinal epithelium, and induced a more robust innate immune response including the activation of both type I and type III interferons, than SARS-CoV in human intestinal tissues. CONCLUSION: Using the ex vivo human intestinal tissues as a physiologically relevant model, our data indicated that SARS-CoV-2 could productively replicate in the human guts, suggesting the gastrointestinal tract might serve as an alternative route of virus dissemination. SARS-CoV-2 replicated less efficiently and induced less cytopathology than SARS-CoV in keeping with the clinical observations reported for SARS-2003 and COVID-19, which might be a result of the more robust immune activation by SARS-CoV-2 than SARS-CoV in the human intestine.

8.
Nat Chem Biol ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082574

RESUMO

Neutralizing agents against SARS-CoV-2 are urgently needed for the treatment and prophylaxis of COVID-19. Here, we present a strategy to rapidly identify and assemble synthetic human variable heavy (VH) domains toward neutralizing epitopes. We constructed a VH-phage library and targeted the angiotensin-converting enzyme 2 (ACE2) binding interface of the SARS-CoV-2 Spike receptor-binding domain (Spike-RBD). Using a masked selection approach, we identified VH binders to two non-overlapping epitopes and further assembled these into multivalent and bi-paratopic formats. These VH constructs showed increased affinity to Spike (up to 600-fold) and neutralization potency (up to 1,400-fold) on pseudotyped SARS-CoV-2 virus when compared to standalone VH domains. The most potent binder, a trivalent VH, neutralized authentic SARS-CoV-2 with a half-maximal inhibitory concentration (IC50) of 4.0 nM (180 ng ml-1). A cryo-EM structure of the trivalent VH bound to Spike shows each VH domain engaging an RBD at the ACE2 binding site, confirming our original design strategy.

9.
J Stroke Cerebrovasc Dis ; 29(12): 105335, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33007680

RESUMO

BACKGROUND AND PURPOSE: Modified Thrombolysis in Cerebral Infarction (mTICI)2b/3 has been considered the criterion for successful reperfusion in endovascular treatment. This study aimed to compare the therapeutic safety and efficacy of mTICI2b and mTICI3 recanalization, and to analyze the factors related to outcomes in everyday clinical practice. MATERIALS AND METHODS: This is a single-center retrospective analysis of 224 patients who underwent successful thrombectomy (achieving a mTICI score ≥2b). The primary outcomes included a modified Rankin score (mRS) of 0-2 at 90-day, mortality, and symptomatic intracranial hemorrhage. RESULTS: A total of 111 patients achieved mTICI2b status (49.6%), and 113 achieved mTICI3 status (50.4%). The comparison between mTICI2b and 3 reperfusions showed no differences in short-term outcomes, 90-day mRS, complications, and mortality. There was a trend toward more passes in mTICI2b patients, although the difference was not significant. The univariate analysis showed that poor outcomes after endovascular treatment were associated with older age, previous history of coronary heart disease, atrial fibrillation, diabetes, tandem occlusions, high National Institutes of Health Stroke Scale (NIHSS) score on admission, and general anesthesia. A previous history of coronary heart disease, a high NIHSS score on admission, and the use of general anesthesia were independent factors that affected the therapeutic effects. CONCLUSION: The superiority (efficacy and safety) of mTICI3 reperfusion was not significant compared with that of mTICI2b reperfusion. Prolonged efforts to achieve mTICI3 after achieving mTICI2b should be considered prudently for those with difficulty achieving 100% reperfusion.

10.
Artigo em Inglês | MEDLINE | ID: mdl-33010495

RESUMO

BACKGROUND AND AIMS: Besides prominent respiratory involvement, gastrointestinal manifestations are commonly reported in Coronavirus Disease 2019 (COVID-19) patients. We compared infection of ex vivo human intestinal tissues by SARS-CoV-2 and SARS-CoV with respect to their replication kinetics and immune activation profile. METHODS: Human intestinal tissues were obtained from patients while undergoing surgical operations at the Queen Mary Hospital, Hong Kong. Upon surgical removal, the tissues were immediately processed and infected with SARS-CoV-2 or SARS-CoV. Replication kinetics were determined with immunohistochemistry, qRT-PCR, and plaque assays. Immune activation in the infected intestinal tissues was assessed by detecting the gene expression of interferons and representative pro-inflammatory cytokines and chemokines. RESULTS: SARS-CoV-2 could infect and productively replicate in the ex vivo human intestinal tissues with the release of infectious virus particles, but not in ex vivo human liver and kidney tissues. Importantly, SARS-CoV-2 replicated less efficiently than SARS-CoV, induced less cytopathology in the human intestinal epithelium, and induced a more robust innate immune response including the activation of both type I and type III interferons, than SARS-CoV in human intestinal tissues. CONCLUSION: Using the ex vivo human intestinal tissues as a physiologically relevant model, our data indicated that SARS-CoV-2 could productively replicate in the human guts, suggesting the gastrointestinal tract might serve as an alternative route of virus dissemination. SARS-CoV-2 replicated less efficiently and induced less cytopathology than SARS-CoV in keeping with the clinical observations reported for SARS-2003 and COVID-19, which might be a result of the more robust immune activation by SARS-CoV-2 than SARS-CoV in the human intestine.

11.
Nat Commun ; 11(1): 5088, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33037212

RESUMO

Early detection of COVID-19 based on chest CT enables timely treatment of patients and helps control the spread of the disease. We proposed an artificial intelligence (AI) system for rapid COVID-19 detection and performed extensive statistical analysis of CTs of COVID-19 based on the AI system. We developed and evaluated our system on a large dataset with more than 10 thousand CT volumes from COVID-19, influenza-A/B, non-viral community acquired pneumonia (CAP) and non-pneumonia subjects. In such a difficult multi-class diagnosis task, our deep convolutional neural network-based system is able to achieve an area under the receiver operating characteristic curve (AUC) of 97.81% for multi-way classification on test cohort of 3,199 scans, AUC of 92.99% and 93.25% on two publicly available datasets, CC-CCII and MosMedData respectively. In a reader study involving five radiologists, the AI system outperforms all of radiologists in more challenging tasks at a speed of two orders of magnitude above them. Diagnosis performance of chest x-ray (CXR) is compared to that of CT. Detailed interpretation of deep network is also performed to relate system outputs with CT presentations. The code is available at https://github.com/ChenWWWeixiang/diagnosis_covid19 .

12.
Chemosphere ; 264(Pt 2): 128557, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33049504

RESUMO

Capacitive deionization (CDI) is a promising method to remove metal contaminants in water. Herein, we report on the preparation of activated carbon from cation-exchange resin by introducing ZnCl2 via ion exchange followed by heat treatment and CO2 activation, which is evaluated for removal of Cu2+ in water via CDI technology. The results have shown that both the heat treatment and the CO2 activation are helpful to tune the pore structure of the activated carbons in terms of ions adsorption and transportation. The activated carbon prepared by heat treatment at 600 °C and CO2 activation at 750 °C, named as AC-600-750, has the highest specific surface area of 1162 m2 g-1 and a specific capacitance of 247.4 F g-1 at 50 mV-1, with a Cu2+ adsorption capacity of 77.8 mg g-1 at 1.2 V in 50 mg L-1 CuCl2 solution that is much higher than that of the commercial activated carbon. The electrosorption of Cu2+ ions over activated carbon follows a monolayer adsorption scheme, of which the kinetic can be well explained by pseudo-first-order kinetic model. The resin-based activated carbons are of potential as an electrode material for efficient removal of heavy metal from contaminated water by CDI process.

13.
J Am Chem Soc ; 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33048529

RESUMO

All atomically laminated MAB phases (M = transition metal, A = A-group element, and B = boron) exhibit orthorhombic or tetragonal symmetry, with the only exception being hexagonal Ti2InB2. Inspired by the recent discovery of chemically ordered hexagonal carbides, i-MAX phases, we perform an extensive first-principles study to explore chemical ordering upon metal alloying of M2AlB2 (M from groups 3 to 9) in orthorhombic and hexagonal symmetry. Fifteen stable novel phases with in-plane chemical ordering are identified, coined i-MAB, along with 16 disordered stable alloys. The predictions are verified through the powder synthesis of Mo4/3Y2/3AlB2 and Mo4/3Sc2/3AlB2 of space group R3̅m (no. 166), displaying the characteristic in-plane chemical order of Mo and Y/Sc and Kagomé ordering of the Al atoms, as evident from X-ray diffraction and electron microscopy. The discovery of i-MAB phases expands the elemental space of these borides with M = Sc, Y, Zr, Hf, and Nb, realizing an increased property tuning potential of these phases as well as their suggested potential two-dimensional derivatives.

14.
Anesth Analg ; 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33048913

RESUMO

Maternal-fetal surgery is a rapidly evolving specialty, and significant progress has been made over the last 3 decades. A wide range of maternal-fetal interventions are being performed at different stages of pregnancy across multiple fetal therapy centers worldwide, and the anesthetic technique has evolved over the years. The American Society of Anesthesiologists (ASA) recognizes the important role of the anesthesiologist in the multidisciplinary approach to these maternal-fetal interventions and convened a collaborative workgroup with representatives from the ASA Committees of Obstetric and Pediatric Anesthesia and the Board of Directors of the North American Fetal Therapy Network. This consensus statement describes the comprehensive preoperative evaluation, intraoperative anesthetic management, and postoperative care for the different types of maternal-fetal interventions.

15.
BMC Pregnancy Childbirth ; 20(1): 596, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028253

RESUMO

BACKGROUND: The correlation between stage of labor and adverse delivery outcomes has been widely studied. Most of studies focused on nulliparous women, it was not very clear what impact the stage of labor duration had on multiparous women. METHODS: A retrospective cohort study was conducted among all the multiparous women of cephalic, term, singleton births, who planned vaginal delivery. The total stage of labor covered the first stage and the second stage in this study, and they were divided into subgroups. Adverse maternal outcomes were defined as referral cesarean delivery, instrumental delivery, postpartum hemorrhage, perineal laceration (III and IV degree), hospitalization stay ≥90th, and adverse neonatal outcomes as NICU, shoulder dystocia, Apgar score ≤ 7(5 min), neonatal resuscitation, assisted ventilation required immediately after delivery. RESULTS: There were 7109 parturients included in this study. The duration of first stage was 6.2(3.6-10.0) hours, the second stage was 0.3(0.2-0.7) hour, the total stage was 6.9(4.1-10.7) hours in multiparous women. At the first stage, the rates of overall adverse outcome were 21, 23.4, 28.8, 35.5, 38.4% in subgroups < 6 h, 6-11.9 h, 12-17.9 h, 18-23.9 h, ≥24 h, which increased significantly (X2 = 57.64, P < 0.001), and ARR (95% CI) were 1.10 (0.92,1.31), 1.33 (1.04,1.70), 1.80 (1.21,2.68), 2.57 (1.60,4.15) compared with subgroup < 6 h (ARR = 1); At the second stage, the rates of overall adverse outcome were 20.0, 30.7, 38.5, 61.2, 69.6% in subgroups < 1 h, 1-1.9 h, 2-2.9 h, 3-3.9 h, ≥4 h (X2 = 349.70, P < 0.001), and ARR (95% CI) were 1.89 (1.50, 2.39), 2.22 (1.55, 3.18), 10.64 (6.09, 18.59), 11.75 (6.55, 21.08) compared with subgroup < 1 h (ARR = 1)). At the total stage, the rates of overall adverse outcome were 21.5, 30.8, 42.4% in subgroups < 12 h, 12-23.9 h, ≥24 h (X2 = 84.90, P < 0.001), and ARR (95% CI) were 1.41 (1.16,1.72), 3.17 (2.10,4.80) compared with subgroup < 12 h (ARR = 1). CONCLUSIONS: The prolonged stage of labor may lead to increased adverse outcomes in multiparous women, it was an independent risk factor of adverse maternal and neonatal outcomes.

16.
Artigo em Inglês | MEDLINE | ID: covidwho-808973

RESUMO

BACKGROUND AND AIMS: Besides prominent respiratory involvement, gastrointestinal manifestations are commonly reported in Coronavirus Disease 2019 (COVID-19) patients. We compared infection of ex vivo human intestinal tissues by SARS-CoV-2 and SARS-CoV with respect to their replication kinetics and immune activation profile. METHODS: Human intestinal tissues were obtained from patients while undergoing surgical operations at the Queen Mary Hospital, Hong Kong. Upon surgical removal, the tissues were immediately processed and infected with SARS-CoV-2 or SARS-CoV. Replication kinetics were determined with immunohistochemistry, qRT-PCR, and plaque assays. Immune activation in the infected intestinal tissues was assessed by detecting the gene expression of interferons and representative pro-inflammatory cytokines and chemokines. RESULTS: SARS-CoV-2 could infect and productively replicate in the ex vivo human intestinal tissues with the release of infectious virus particles, but not in ex vivo human liver and kidney tissues. Importantly, SARS-CoV-2 replicated less efficiently than SARS-CoV, induced less cytopathology in the human intestinal epithelium, and induced a more robust innate immune response including the activation of both type I and type III interferons, than SARS-CoV in human intestinal tissues. CONCLUSION: Using the ex vivo human intestinal tissues as a physiologically relevant model, our data indicated that SARS-CoV-2 could productively replicate in the human guts, suggesting the gastrointestinal tract might serve as an alternative route of virus dissemination. SARS-CoV-2 replicated less efficiently and induced less cytopathology than SARS-CoV in keeping with the clinical observations reported for SARS-2003 and COVID-19, which might be a result of the more robust immune activation by SARS-CoV-2 than SARS-CoV in the human intestine.

17.
BMC Infect Dis ; 20(1): 779, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33081702

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become a public health emergency of international concern. SARS-CoV-2 RNA detection is the diagnostic criterion for coronavirus disease 2019 (COVID-19). Nevertheless, RNA detection has many limitations, such as being time-consuming and cost-prohibitive, and it must be performed in specialized laboratories. Virus antibody detection is a routine method for screening for multiple viruses, but data about SARS-CoV-2 antibody detection are limited. METHOD: Throat swabs and blood were collected from 67 suspected SARS-CoV-2 infection patients at the Affiliated Hospital of Zunyi Medical University and Zunyi Fourth People's Hospital isolated observation departments. Throat swab samples were subjected to SARS-CoV-2 RNA detection by real-time PCR. Blood was used subjected to SARS-CoV-2 IgG/IgM detection by an enzyme-linked immunosorbent assay (ELISA) and gold immunochromatography assay (GICA). Blood underwent C-reactive protein detection by immunoturbidimetry, and white blood cells, neutrophil percentages and lymphocyte percentages were counted and calculated, respectively. Clinical symptoms, age and lifestyle habits (smoking and drinking) in all patients were recorded. Data were analysed using SPSS version 19. The results were confirmed by T and χ2 tests; correlations with detection results were analysed by kappa coefficients. Odds ratio (OR) and corrected OR values were analysed by logistic regression. P < 0.05 was considered statistically significant. RESULTS: Of the 67 patients included in this study, 26 were SARS-CoV-2 RNA-positive. GICA IgM sensitivity was 50.9% (13/26), and specificity was 90.2% (37/41). ELISA IgM sensitivity was 76.9% (20/26), and specificity was 90.2% (37/41). ELISA IgG sensitivity was 76.9% (20/26), and specificity was 95.1% (39/41). The kappa coefficients between RNA detection and ELISA IgG, ELISA IgM, and GICA IgM results were 0.741 (P < 0.01), 0.681 (P < 0.01) and 0.430 (P < 0.01), respectively. CONCLUSION: Among the candidate blood indicators, serum IgG and IgM detected by ELISA had the best consistency and validity when compared with standard RNA detection; these indicators can be used as potential preliminary screening tools to identify those who should undergo nucleic acid detection in laboratories without RNA detection abilities or as a supplement to RNA detection.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33095713

RESUMO

Heatmap regression (HR) has become one of the mainstream approaches for face alignment and has obtained promising results under constrained environments. However, when a face image suffers from large pose variations, heavy occlusions and complicated illuminations, the performances of HR methods degrade greatly due to the low resolutions of the generated landmark heatmaps and the exclusion of important high-order information that can be used to learn more discriminative features. To address the alignment problem for faces with extremely large poses and heavy occlusions, this paper proposes a heatmap subpixel regression (HSR) method and a multi-order cross geometry-aware (MCG) model, which are seamlessly integrated into a novel multi-order high-precision hourglass network (MHHN). The HSR method is proposed to achieve high-precision landmark detection by a well-designed subpixel detection loss (SDL) and subpixel detection technology (SDT). At the same time, the MCG model is able to use the proposed multi-order cross information to learn more discriminative representations for enhancing facial geometric constraints and context information. To the best of our knowledge, this is the first study to explore heatmap subpixel regression for robust and high-precision face alignment. The experimental results from challenging benchmark datasets demonstrate that our approach outperforms state-of-the-art methods in the literature.

19.
Epidemics ; 33: 100406, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33096342

RESUMO

When analysing in vitro data, growth kinetics of influenza virus strains are often compared by computing their growth rates, which are sometimes used as proxies for fitness. However, analogous to mathematical models for epidemics, the growth rate can be defined as a function of mechanistic traits: the basic reproduction number (the average number of cells each infected cell infects) and the mean generation time (the average length of a replication cycle). Fitting a model to previously published and newly generated data from experiments in human lung cells, we compared estimates of growth rate, reproduction number and generation time for six influenza A strains. Of four strains in previously published data, A/Canada/RV733/2003 (seasonal H1N1) had the lowest basic reproduction number, followed by A/Mexico/INDRE4487/2009 (pandemic H1N1), then A/Indonesia/05/2005 (spill-over H5N1) and A/Anhui/1/2013 (spill-over H7N9). This ordering of strains was preserved for both generation time and growth rate, suggesting a positive biological correlation between these quantities which have not been previously observed. We further investigated these potential correlations using data from reassortant viruses with different internal proteins (from A/England/195/2009 (pandemic H1N1) and A/Turkey/05/2005 (H5N1)), and the same surface proteins (from A/Puerto Rico/8/34 (lab-adapted H1N1)). Similar correlations between traits were observed for these viruses, confirming our initial findings and suggesting that these patterns were related to the degree of human adaptation of internal genes. Also, the model predicted that strains with a smaller basic reproduction number, shorter generation time and slower growth rate underwent more replication cycles by the time of peak viral load, potentially accumulating mutations more quickly. These results illustrate the utility of mathematical models in inferring traits driving observed differences in in vitro growth of influenza strains.

20.
RNA ; 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33008838

RESUMO

A recent crystal structure of a ribosome complex undergoing partial translocation in the absence of elongation factor EF-G showed disruption of codon-anticodon pairing and slippage of the reading frame by -1, directly implicating EF-G in preservation of the translational reading frame. Among mutations identified in a random screen for dominant-lethal mutations of EF-G were a cluster of 6 that map to the tip of domain IV, which has been shown to contact the codon-anticodon duplex in trapped translocation intermediates. In vitro synthesis of a full-length protein using these mutant EF-Gs revealed dramatically increased -1 frameshifting, providing new evidence for a role for domain IV of EF-G in maintaining the reading frame. These mutations also caused decreased rates of mRNA translocation and rotational movement of the head and body domains of the 30S ribosomal subunit during translocation. Our results are in general agreement with recent findings from Rodnina and co-workers based on in vitro translation of an oligopeptide using EF-Gs containing mutations at two positions in domain IV, who found an inverse correlation between the degree of frameshifting and rates of translocation. Four of our six mutations are substitutions at positions that interact with the translocating tRNA, in each case contacting the RNA backbone of the anticodon loop. We suggest that EF-G helps to preserve the translational reading frame by preventing uncoupled movement of the tRNA through these contacts; a further possibility is that these interactions may stabilize a conformation of the anticodon that favors base-pairing with its codon.

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