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This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids.
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Amilose , Ácidos Láuricos , Lecitinas , Amido , Zea mays , Ácidos Láuricos/química , Lecitinas/química , Amido/química , Amilose/química , Zea mays/química , Solanum tuberosum/química , Hidrólise , Difração de Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Varredura Diferencial de CalorimetriaRESUMO
BACKGROUND: Dorcus stag beetles in broad sense are one of the most diverse group in Lucanidae and important saproxylic insects playing a crucial role in nutrient recycling and forest biomonitoring. However, the dazzling morphological differentiations have caused numerous systematic confusion within the big genus, especially the puzzlingly generic taxonomy. So far, there is lack of molecular phylogenetic study to address the chaotic situation. In this study, we undertook mitochondrial genome sequencing of 42 representative species including 18 newly-sequenced ones from Eastern Asia and reconstructed the phylogenetic framework of stag beetles in Dorcus sensu lato for the first time. RESULTS: The mitogenome datasets of Dorcus species have indicated the variable mitogenomic lengths ranged from 15,785 to 19,813 bp. Each mitogenome contained 13 PCGs, 2 rRNAs, 22 tRNAs, and a control region, and all PCGs were under strong purifying selection (Ka/Ks < 1). Notably, we have identified the presence of a substantial intergenic spacer (IGS) between the trnAser (UCN) and NAD1 genes, with varying lengths ranging from 129 bp (in D. hansi) to 158 bp (in D. tityus). The mitogenomic phylogenetic analysis of 42 species showed that Eastern Asia Dorcus was monophyletic, and divided into eight clades with significant genetic distance. Four of them, Clade VIII, VII, VI and I are clustered by the representative species of Serrognathus Motschulsky, Kirchnerius Schenk, Falcicornis Séguy and Dorcus s.s. respectively, which supported their fully generic positions as the previous morphological study presented. The topology also showed the remaining clades were distinctly separated from the species of Dorcus sensu lato, which implied that each of them might demonstrate independent generic status. The Linnaeus nomenclatures were suggested as Eurydorcus Didier stat. res., Eurytrachellelus Didier stat. res., Hemisodorcus Thomson stat. res. and Velutinodorcus Maes stat. res. For Clade V, IV, III and II respectively. CONCLUSION: This study recognized the monophyly of Dorcus stag beetles and provided a framework for the molecular phylogeny of this group for the first time. The newly generated mitogenomic data serves as a valuable resource for future investigations on lucanid beetles. The generic relationship would facilitate the systematics of Dorcus stag beetles and thus be useful for exploring their evolutionary, ecological, and conservation aspects.
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Besouros , Genoma Mitocondrial , Filogenia , Animais , Besouros/genética , Besouros/classificação , Genoma Mitocondrial/genética , Ásia OrientalRESUMO
Contact lenses (CLs) are prone to adhesion and invasion by pollutants and pathogenic bacteria, leading to infection and inflammatory diseases. However, the functionalization of CL (biological functions such as anti-fouling, antibacterial, and anti-inflammatory) and maintaining its transparency still face great challenges. In this work, as a member of the MXenes family, vanadium carbide (V2C) is modified onto CL via a water transfer printing method after the formation of a tightly arranged uniform film at the water surface under the action of the Marangoni effect. The coating interface is stable owing to the electrostatic forces. The V2C-modified CL (V2C@CL) maintains optical clarity while providing good biocompatibility, strong antioxidant properties, and anti-inflammatory activities. In vitro antibacterial experiments indicate that V2C@CL shows excellent performance in bacterial anti-adhesion, sterilization, and anti-biofilm formation. Last, V2C@CL displays notable advantages of bacteria elimination and inflammation removal in infectious keratitis treatment.
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Infecções Bacterianas , Lentes de Contato , Humanos , Antibacterianos/farmacologia , Anti-Inflamatórios , Bactérias , Lentes de Contato/microbiologia , Inflamação , Nitritos , Elementos de Transição , Água , ImpressãoRESUMO
Pregnant women and women of childbearing age were enrolled in our study and their knowledge about the Hepatitis B virus (HBV) and chronic hepatitis B (CHB) was evaluated. A questionnaire was distributed to every woman in the cross-sectional study. The questionnaire was answered by all participants before they received health education and advice about HBV and CHB from the doctors visited. Data collected from all answers were analyzed using the χ2 test and logistic regression models. A total of 206 pregnant women and women of childbearing age with CHB infection were enrolled in the study during their first visit to the Infectious Diseases Clinic of the Third Affiliated Hospital of Guangzhou Medical University. Some women of childbearing age (40.8%) and pregnant women with CHB infection (30.6%) still believed HBV could be transmitted through diet and/or mosquito bites. Some women of childbearing age and pregnant women with CHB infection had limited knowledge of the prevention of HBV transmission (111 of 206, 53.9%). Women with higher levels of education had more knowledge about HBV (senior middle school, P = 0.02; university, P <0.01). The majority of participants were willing to take antiviral medicine to decrease the mother-to-child transmission (MTCT) rate of HBV. Some women of childbearing age and/or pregnant women with CHB infection have relatively limited knowledge about HBV or CHB. This situation contributes to the timeliness, or lack thereof, of these women with CHB to see a doctor and receive antiviral therapy. As a result, the morbidity and mortality of HBV-related complications could increase along with the rate of MTCT of HBV.
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Hepatite B Crônica , Hepatite B , Complicações Infecciosas na Gravidez , Feminino , Gravidez , Humanos , Hepatite B Crônica/epidemiologia , Hepatite B Crônica/prevenção & controle , Gestantes , Estudos Transversais , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Vírus da Hepatite B/genética , China/epidemiologia , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , DNA ViralRESUMO
In this study, we developed dry, flat potato starch noodles with an ideal taste and low digestibility. Peanut oligopeptide and potato starch were combined to form dry, flat potato starch noodles containing different peanut oligopeptide contents using a steam-slice method. Adding 5 % and 10 % peanut oligopeptides maintained the dry, flat starch noodles' quality. Scanning electron microscopy (SEM) analysis showed that dry, flat starch noodles containing peanut oligopeptides had more pores with pore sizes ranging from 0.30 µm to 2.00 µm. X-ray diffraction (XRD) results showed that peanut oligopeptide promoted the recrystallization of amylopectin during the retrogradation process after gelatinization, and the crystallinity of noodles ranged from 4.31 % (control noodles) to 18.24 % (noodles containing 10 % peanut oligopeptides). An in vitro simulated digestion test showed that the slowly digestible starch and resistant starch contents of noodles containing 10 % peanut oligopeptides were 18.24 % and 22.03 %-significantly higher than control starch noodles (14.88 % and 9.9 %, respectively). Therefore, when peanut oligopeptides were added to dry, flat starch noodles, it was a promising material for lowering blood sugar levels after meals.
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Arachis , Solanum tuberosum , Solanum tuberosum/química , Amido/química , Farinha/análise , OligopeptídeosRESUMO
It is widely accepted that circadian rhythm disruption caused short- or long-term adverse effects on health. Although many previous studies have focused on exploration of the molecular mechanisms, there is no rapid, convenient, and non-invasive method to reveal the influence on health after circadian rhythm disruption. Here, we performed a high-resolution mass spectrometry-based data-independent acquisition (DIA) quantitative urinary proteomic approach in order to explore whether urine could reveal stress changes to those brought about by circadian rhythm disruption after sleep deprivation. After sleep deprivation, the subjects showed a significant increase in both systolic and diastolic blood pressure compared with routine sleep. More than 2000 proteins were quantified and they contained specific proteins for various organs throughout the body. And a total of 177 significantly up-regulated proteins and 68 significantly down-regulated proteins were obtained after sleep deprivation. These differentially expressed proteins (DEPs) were associated with multiple organs and pathways, which reflected widespread influences of sleep deprivation. Besides, machine learning identified a panel of five DEPs (CD300A, SCAMP3, TXN2, EFEMP1, and MYH11) that can effectively discriminate circadian rhythm disruption. Taken together, our results validate the value of urinary proteome in predicting and diagnosing the changes by circadian rhythm disruption.
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The pandemic of COVID-19 had not only led to healthy-damage behaviors, but also raised people's attention to health and generated health-promoting behaviors. However, little is known about the mechanism underlying how the perception of COVID-19 intensity affects health behaviors. The present study investigated the mediating effect of DBTP between event intensity and health behaviors and the moderating role of gender in this relation. Nine hundred and twenty-four Chinese college students (348 males and 576 females) completed a battery of self-report questionnaires, including COVID-19 Event Intensity Scale, Chinese version of Zimbardo Time Perspective Inventory (ZTPI) and Healthy Lifestyle Scale. Moderated mediation analysis was performed using conditional process analysis. The results showed that COVID-19 intensity had a positive predictive effect on college students' health behaviors. DBTP played a partial mediating role in the relationship between COVID-19 intensity and health behaviors for male and not female. In female group, COVID-19 intensity and DBTP was significantly linked with health behaviour; however, COVID-19 intensity and DBTP were not significantly linked. The findings indicated that COVID-19 intensity perceived by college students could increase their health behaviors, and intervention focus on BTP may contribute to health behaviors only in male. Practical implications were discussed in this academic research.
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Pickering emulsion gels (PKEGs) are being explored as solid fat substitutes and delivery systems due to their semi-solid textures and high stabilities. However, these PKEGs have relatively high-fat content, which is undesirable for nutritional and cost reasons. Therefore, in this study, low-fat PKEGs (10 % oil content) were successfully fabricated using zein/phytic acid (ZPA) complex nanoparticles with zein to phytic acid mass ratio of 1:0.006. These nanoparticles have a mean diameter of around 161 nm and wettability of around 89°. The formation of PKEGs were confirmed by the results of dynamic rheology (G' > Gâ³). Confocal laser scanning microscope showed that the complex nanoparticles formed a dense barrier on the surface of the oil droplets, which prevented the oil droplets against coalescence. The chemical stability of curcumin was greatly improved by encapsulation in the PKEGs. The low-fat PKEGs developed in this study may be effective delivery systems for hydrophobic bioactive substances.
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Curcumina , Substitutos da Gordura , Nanopartículas , Zeína , Zeína/química , Emulsões/química , Ácido Fítico , Curcumina/química , Tamanho da Partícula , Géis/química , Nanopartículas/químicaRESUMO
This study developed a novel method for the facile and efficient preparation of the cellulose nanocrystals (CNCs) by using a simultaneous collaborative process combining sulfuric acid hydrolysis and heat-moisture treatment. In this work, we significantly reduced acid dosage compared to conventional acid solution hydrolysis methods to prepare CNCs. The weight of diluted sulfuric acid is no more than 25% on dry basis weight of microcrystalline cellulose. In a relatively short time (2 h), the yield could reach 93.68%, which is higher than the existing methods. The obtained CNCs displayed a normal rod-like shape (100 nm) and unusual spherical shape (10 nm) and showed high relative crystallinity ranged from 70.92% to 81.13%. The combination of acidolysis and heat-moisture treatment may be an economical and effective method for large-scale production of CNCs and provides a new method for preparing short CNCs, which can be used in membrane strengthening and food packages.
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Temperatura Alta , Nanopartículas , Ácidos , Celulose/química , Hidrólise , Nanopartículas/químicaRESUMO
The properties of nutraceutical-loaded biopolymer nanoparticles fabricated by antisolvent co-precipitation (ASCP) and precipitation (ASP) were compared. Curcumin-loaded zein-tea saponin nanoparticles were fabricated using both methods and then their structural and physicochemical properties were characterized. The diameter of the nanoparticles prepared by ASCP were smaller (120-130 nm) than those prepared by ASP (140-160 nm). The encapsulation efficiency of the ASCP-nanoparticles (80.0%) was higher than the ASP-ones (71.0%) at a zein-to-curcumin mass ratio of 3:1, which was also higher than previous studies. The storage and light stability of curcumin was higher in zein-saponin nanoparticles than in zein nanoparticles. All nanoparticles had good water dispersibility after freeze-drying and rehydration. This study shows that nanoparticles produced by antisolvent co-precipitation have superior properties to those produced by antisolvent precipitation. The co-precipitation method leads to a higher encapsulation efficiency, smaller particle size, and greater storage stability, which may be advantageous for some applications.
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Curcumina , Nanopartículas , Saponinas , Zeína , Curcumina/química , Nanopartículas/química , Tamanho da Partícula , Chá , Zeína/químicaRESUMO
BACKGROUND This single center study, which enrolled 108 patients with chronic hepatitis B virus infection treated with pegylated interferon-alpha (PEG-IFN-alpha), aimed to follow up and monitor off-treatment responses, including virological relapse, and analyze predictors of long-term efficacy of the PEG-IFN-alpha regimen. MATERIAL AND METHODS In total, 108 hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B who had completed the PEG-IFN-alpha regimen and achieved virological suppression were enrolled. The patients were followed up for 5 years to monitor off-treatment responses. Twenty-eight relevant factors, including the history of antiviral therapy and HBeAg seroconversion, were analyzed using the Cox proportional hazards regression model. RESULTS The cumulative rates of virological suppression were 75.70%, 68.68%, 65.25%, 63.91%, and 63.91% at 1, 2, 3, 4, and 5 years of the follow-up period, respectively. Compared with the rates of virological suppression, the cumulative rates of clinical suppression were 88.41%, 79.83%, 78.59%, 75.65%, and 75.65%, respectively, for the 5 years. Alanine aminotransferase (ALT) normalization at 24 weeks after off-therapy (relative risk [RR]=3.430, P=0.013) was a potential predictor for sustained virological suppression, and the history of anti-viral therapy (RR=0.164, P=0.004), quantitative value of hepatitis B virus surface antigen (HBsAg) at 48 weeks of anti-viral therapy (RR=2.697, P=0.039), and ALT normalization at 24 weeks after off-therapy (RR=5.467, P=0.004) were potential predictors for sustained clinical suppression. CONCLUSIONS Our results suggested that increased HBsAg levels at 48 weeks and normalization of ALT at 24 weeks after off-therapy might be predictive factors for long-term treatment efficacy.[color=red] [/color].
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Hepatite B Crônica , Antivirais/farmacologia , Antivirais/uso terapêutico , Seguimentos , Antígenos de Superfície da Hepatite B , Antígenos E da Hepatite B , Vírus da Hepatite B , Hepatite B Crônica/tratamento farmacológico , Humanos , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Recidiva , Resultado do TratamentoRESUMO
Photodynamic therapy (PDT) is an important technique to deal with drug-resistant bacterial infections in the post-antibiotic era. However, the hypoxic environment in intractable infections such as refractory keratitis and periodontitis, makes PDT more difficult. In this work, spontaneous oxygen-producing cyanobacteria were used as the carrier of photosensitizer (Ce6), and ultrasmall Cu5.4O nanoparticles (Cu5.4O USNPs) with catalase activity for infection and inflammation elimination and rapid tissue repair (CeCycn-Cu5.4O). The loading of Ce6 and Cu5.4O USNPs onto cyanobacteria surface were confirmed by transmission electron microscopy, nano particle size analyzer, scanning electron microscopy. In vitro sterilization and biofilm removal experiments demonstrated that the restriction of hypoxic environment to PDT was significantly alleviated due to the oxygen production of cyanobacteria. Under laser irradiation, the close transfer of energy photons to oxygen produced by cyanobacteria reduced more than 90% of Ce6 dosages (660 nm, 200 mW/cm2, 2 min). It is worth mentioning that both rapid sterilization through PDT and long-term oxidized free radicals elimination were achieved by adjusting the ratio of Ce6 and Cu5.4O USNPs. Both periodontitis and refractory keratitis animal models proved the excellent self-oxygenation enhanced antibacterial property and promotion of tissue repair.
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Protein corona (PC) usually changes the physicochemical properties of nanoparticles (NPs) and determines their ultimate fate in the physiological environment. As NPs are widely used in food, it is important to obtain a deep understanding of PC formation in the gastrointestinal fluid. Herein, we explored the adsorption of pepsin to chitin nanowhiskers (CNWs) and their interactions in simulated gastric fluid. Results suggest that the binding of pepsin reduced the surface potential of CNWs from 22.4 ± 0.15 to 12.9 ± 0.51 mV and caused their aggregation. CNWs quenched the fluorescence of pepsin and induced slightly changes in its secondary structure containing a reduction in the ß-sheet content (â¼ 3%) and an increase in the random coils (â¼ 2%). The isothermal titration calorimetry (ITC) data suggested that the interaction forces between CNWs and pepsin were mainly hydrogen bonds and van der Waals forces.
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Nanopartículas , Coroa de Proteína , Calorimetria , Quitina/química , Nanopartículas/química , Pepsina A/metabolismo , Coroa de Proteína/químicaRESUMO
The impact of lutein-loaded nanoemulsions and excipient nanoemulsions mixed with lutein-based dietary supplements (capsules and soft gels) on the bioaccessibility of lutein was explored using a simulated gastrointestinal tract (GIT). The particle size, particle size distribution, ζ-potential, microstructure, lipid digestibility, and lutein bioaccessibility of all the samples were measured after they were exposed to different environments (stomach and small intestine environments) within a simulated GIT. As expected, the bioaccessibility of lutein from the capsules (1.5%) and soft gels (3.2%) was relatively low when they were administered alone. However, the co-administration of excipient nanoemulsions significantly increased the bioaccessibility of lutein from both the capsules (35.2%) and soft gels (28.7%). This phenomenon was attributed to the fast digestion of the small oil droplets in the excipient nanoemulsions and the further formation of mixed micelles to solubilize any lutein molecules released from the supplements. The lutein-loaded nanoemulsions exhibited a much higher lutein bioaccessibility (86.8%) than any of the supplements, which was attributed to the rapid release and solubilization of lutein when the lipid droplets were rapidly and extensively digested within the small intestine. This study indicates that the bioaccessibility of lutein is much higher in nanoemulsion droplets than that in dietary supplements. However, consuming dietary supplements in the presence of nanoemulsion droplets can greatly increase lutein bioavailability. The results of this study have important guiding significance for the design of more effective lutein supplements.
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Excipientes , Luteína , Disponibilidade Biológica , Suplementos Nutricionais/análise , Digestão , Emulsões , Tamanho da PartículaRESUMO
The objective of this work was to develop a simple and efficient method to prepare waxy maize starch nanoparticles (SNPs) by hydrochloric acid (HCl) vapor hydrolysis combined with ultrasonication treatment. The size, morphology, thermal property, and crystal structure of the SNPs were systematically studied. HCl treatment introduces a smaller particle diameter of starch particles from 13.73 ± 0.93 µm to 1.52 ± 0.01-8.32 ± 0.63 µm. Further ultrasonication treatment formed SNPs that displayed desirable uniformity and near-perfect spherical and ellipsoidal shapes with a diameter of 150.65 ± 1.91-292.85 ± 0.07 nm. The highest yield of SNPs was 80.5%. Compared with the native starch, the gelatinization enthalpy changes of SNPs significantly decreased from 14.65 ± 1.58 J/g to 7.40 ± 1.27 J/g. Interestingly, the SNPs showed a wider melting temperature range of 22.77 ± 2.35 °C than native starch (10.94 ± 0.87 °C). The relative crystallinity of SNPs decreased to 29.65%, while long-time ultrasonication resulted in amorphization. HCl vapor hydrolysis combined with ultrasonication treatment can be an affordable and accessible method for the efficient large-scale production of SNPs. The SNPs developed by this method will have potential applications in the food, materials, and medicine industries.
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Although long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) was reported to be associated with acute lung injury (ALI), its specific mechanism has not been well studied. Mouse and cell ALI models were constructed by lipopolysaccharide (LPS). Cell viability was evaluated by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide assay. Cell death was evaluated by lactate dehydrogenase release (LDH) detection kit and flow cytometry. The levels of cytokines in lung tissues lysates were detected by quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The expression of apoptosis-related markers was detected by Western blot. The relationship between NEAT1, miR-98-5p, and toll-like receptor 4 (TLR4) was determined by bioinformatics prediction, luciferase reporter assay, and RNA immunoprecipitation (RIP) assay. Rescue experiments were performed to determine the role of NEAT1/miR-98-5p/TLR4 in ALI. NEAT1 was significantly upregulated during ALI both in vitro and in vivo. NEAT1 knockdown efficiently attenuated LPS-induced ALI and reduced LPS-induced elevation of cytokines both in vitro and in vivo. NEAT1 negatively regulated miR-98-5p by directly sponging it, and TLR4 was a target of miR-98-5p. MiR-98-5p inhibition or TLR4 overexpression could obviously attenuate the protective effects of NEAT1 knockdown in LPS-treated A549 cells. Our study demonstrated that NEAT1 knockdown alleviated LPS-induced ALI by targeting the miR-98-5p/TLR4 axis.
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Lesão Pulmonar Aguda/induzido quimicamente , Lipopolissacarídeos/toxicidade , MicroRNAs/metabolismo , RNA Longo não Codificante/fisiologia , Receptor 4 Toll-Like/metabolismo , Células A549 , Lesão Pulmonar Aguda/metabolismo , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Técnicas de Silenciamento de Genes , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Longo não Codificante/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
BACKGROUND: Severe COVID-19 caused by SARS-CoV-2 should closely be cared because of the relatively high mortality rate. If SARS-CoV-2 could be cleared as soon as possible, the mortality rate might lower. In the present study, we analyzed factors which might be related to the clearance of SARS-CoV-2. METHODS: One hundred and twenty-eight severe COVID-19 cases were enrolled. All of them had been isolated and treated at Shenzhen Third People's Hospital because they were positive for nucleic acid of SARS-CoV-2 tested by qRT-PCR. Their baseline clinical characteristics and antiviral regimens were collected and analyzed, respectively. RESULTS: Of the 128 enrolled severe COVID-19 cases, unfortunately 3 died. The mean viral duration of all patients was 23.5 (range 17-32) days. All patients achieved viral clearance during 9 weeks. 13.4% of patients achieved viral clearance within 2 weeks, and 63.0% of patients achieved viral clearance within 4 weeks. The combined regimens of three or more antiviral drugs, the use of invasive mechanical ventilation, and late admission might be related to the delay of viral clearance within 2 weeks. The use of arbidol, the use of invasive mechanical ventilation, and late admission might be related to the delay of viral clearance within 4 weeks. Patients often had a prolonged course of COVID-19 and hospitalization, and were more likely transferred to intensive care unit (ICU) for treatment, if they could not clear SARS-CoV-2 during 23 days. CONCLUSION: Severe COVID-19 cases should be admitted to hospital as soon as possible. The combined regimens of three or more antiviral drugs might not be useful for viral clearance, and should be performed carefully and cautiously.
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COVID-19 , Antivirais/uso terapêutico , Hospitalização , Humanos , Respiração Artificial , SARS-CoV-2RESUMO
Urban scene modeling is a challenging task for the photogrammetry and computer vision community due to its large scale, structural complexity, and topological delicacy. This paper presents an efficient multistep modeling framework for large-scale urban scenes from aerial images. It takes aerial images and a textured 3D mesh model generated by an image-based modeling system as the input and outputs compact polygon models with semantics at different levels of detail (LODs). Based on the key observation that urban buildings usually have piecewise planar rooftops and vertical walls, we propose a segment-based modeling method, which consists of three major stages: scene segmentation, roof contour extraction, and building modeling. By combining the deep neural network predictions with geometric constraints of the 3D mesh, the scene is first segmented into three classes. Then, for each building mesh, the 2D line segments are detected and used to slice the ground into polygon cells, followed by assigning each cell a roof plane via a MRF optimization. Finally, the LOD model is obtained by extruding cells to their corresponding planes. Compared with direct modeling in 3D space, we transform the mesh into a uniform 2D image grid representation and most of the modeling work is performed in 2D space, which has the advantages of low computational complexity and high robustness. In addition, our method doesn't require any global prior, such as the Manhattan or Atlanta world assumption, making it flexible to model scenes with different characteristics and complexity. Experiments on both single buildings and large-scale urban scenes demonstrate that by combining 2D photometric with 3D geometric information, the proposed algorithm is robust and efficient in urban scene LOD vectorized modeling compared with the state-of-the-art approaches.
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The pandemic of corona virus disease 2019 (COVID-19) caused by SARS-CoV-2 is ravaging the world. Diagnosis and isolation of persons who are infected with SARS-CoV-2 is very important medical emergency to contain the epidemic of COVID-19. To date, the diagnosis of COVID-19 is mainly depending on positive quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) results for SARS-CoV-2. In the present study, we reported that two cases with uncommon symptoms from a family cluster were ultimately diagnosed as COVID-19 after more than twice of collecting samples and qRT-PCR tests were done. It is easily to miss diagnosis of COVID-19 especially for patients with uncommon symptoms. More attention should be paid to observe the clinical characteristics of it and invent more accurate and convenient methods to detect SARS-CoV-2 as soon as possible.
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COVID-19 , SARS-CoV-2 , Técnicas de Laboratório Clínico , Reações Falso-Negativas , Humanos , Pandemias , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The establishment of comprehensive drought index is a fundamental task for the analysis of drought hazard system evolution. To fully explore the characteristics of drought variation process, the cloud uncertainty reasoning method was applied to construct comprehensive drought index integrating precipitation with soil moisture indicators. The application results of the proposed drought index in Anhui Province, China revealed that, (1) The overall drought evolution presented significant intensifying trend with the drought occurrence frequency increasing from 32% to 41% from south to north in Anhui Province, and the primary drought type in the northern area was moderate-level drought events and above, while the drought type in the central and southern region was dominated by light-level drought events. (2) Autumn drought was the dominant type from 1960 to 2007 in Anhui Province, with the average drought occurrence frequency of 40%. In addition, the evolution of spring and autumn drought all presented intensifying trends from 1960 to 2007, while the summer and winter drought evolution trends were opposite. (3) The Mann-Kendall trend test results revealed that the drought evolution presented evidently intensifying trend from August 1967 to February 1969, but slight declining trend from May 1974 to August 1978, July 1989 to August 2001 and February 2003 to December 2007, and the mutation of drought evolution occurred in November 1972, February 1978 and August 1998, etc. The above results were basically consistent with the historical statistics, indicating that the proposed comprehensive drought index and its construction framework were reliable, which can be further applied in the related research field of regional drought risk management.