AbstractObjectiveTo examine the protective effects of appropriate personal protective equipment for frontline healthcare professionals who provided care for patients with coronavirus disease 2019 ...(covid-19).DesignCross sectional study.SettingFour hospitals in Wuhan, China.Participants420 healthcare professionals (116 doctors and 304 nurses) who were deployed to Wuhan by two affiliated hospitals of Sun Yat-sen University and Nanfang Hospital of Southern Medical University for 6-8 weeks from 24 January to 7 April 2020. These study participants were provided with appropriate personal protective equipment to deliver healthcare to patients admitted to hospital with covid-19 and were involved in aerosol generating procedures. 77 healthcare professionals with no exposure history to covid-19 and 80 patients who had recovered from covid-19 were recruited to verify the accuracy of antibody testing.Main outcome measuresCovid-19 related symptoms (fever, cough, and dyspnoea) and evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, defined as a positive test for virus specific nucleic acids in nasopharyngeal swabs, or a positive test for IgM or IgG antibodies in the serum samples.ResultsThe average age of study participants was 35.8 years and 68.1% (286/420) were women. These study participants worked 4-6 hour shifts for an average of 5.4 days a week; they worked an average of 16.2 hours each week in intensive care units. All 420 study participants had direct contact with patients with covid-19 and performed at least one aerosol generating procedure. During the deployment period in Wuhan, none of the study participants reported covid-19 related symptoms. When the participants returned home, they all tested negative for SARS-CoV-2 specific nucleic acids and IgM or IgG antibodies (95% confidence interval 0.0 to 0.7%).ConclusionBefore a safe and effective vaccine becomes available, healthcare professionals remain susceptible to covid-19. Despite being at high risk of exposure, study participants were appropriately protected and did not contract infection or develop protective immunity against SARS-CoV-2. Healthcare systems must give priority to the procurement and distribution of personal protective equipment, and provide adequate training to healthcare professionals in its use.
Polymer electrolytes are considered potential key enablers for lithium‐metal batteries due to their compatibility with the lithium‐metal negative electrode. Herein, cross‐linked self‐standing ...single‐ion conducting polymer electrolytes are obtained via a facile UV‐initiated radical polymerization using pentaerythritol tetraacrylate as the cross‐linker and lithium (3‐methacryloyloxypropylsulfonyl)‐(trifluoromethylsulfonyl)imide as the ionic functional group. Incorporating propylene carbonate as charge‐transport supporting additive allowed for achieving single‐ion conductivities of 0.21 mS cm−1 at 20 °C and 0.40 mS cm−1 at 40 °C, while maintaining a suitable electrochemical stability window for 4 V‐class positive electrodes (cathodes). As a result, this single‐ion polymer electrolyte featured good cycling stability and rate capability in Li||LiFePO4 and Li||LiNi0.6Mn0.2Co0.2O2 cells. These results render this polymer electrolyte as potential alternative to liquid electrolytes for high‐energy lithium‐metal batteries.
This study reports a cross‐linked single‐ion (Li+) conducting polymer electrolyte synthesized via a facile UV‐initiated radical polymerization. After incorporation of propylene carbonate as charge‐transport supporter, Li+ conductivities of 0.21 mS cm−1 at 20 °C and 0.40 mS cm−1 at 40 °C, are achieved. The polymer electrolyte features good cycling stability and rate capability in Li||LiFePO4 and Li||LiNi0.6Mn0.2Co0.2O2 cells.
In recent years, modern spectral analysis techniques, such as ultraviolet–visible (UV-vis) spectroscopy, mid-infrared (MIR) spectroscopy, near-infrared (NIR) spectroscopy, Raman spectroscopy, ...terahertz (THz) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, laser-induced breakdown spectroscopy (LIBS), etc., have experienced rapid development and have been widely applied in various fields such as agricultural, food, pharmaceutical, petroleum, chemical industry, tobacco, environmental protection and medical science. A remarkable feature of all these techniques is to extract useful chemical information from the spectral data as detailed as possible with the aid of chemometric methods with the aim of significantly improving both robustness and accuracy of analytical results. Under the general background of the development in artificial intelligence, big data, cloud computing, and other technologies, the emergence of novel idea, approaches, and strategies endows chemometrics with a new vitality. Chemometrics has become the research focuses and hotspots in various fields, especially in the field of spectral analysis. This article reviewed various chemometric methods applied in modern spectral analysis in recent ten years, especially from the perspective of practicability, including spectral pre-processing, wavelength (variable) selection, data dimension reduction, quantitative calibration, pattern recognition, calibration transfer, calibration maintenance, and multispectral data fusion. More importantly, future trends in chemometric methods in the field of spectral analysis was also prospected in this article. It is sincerely expected that this summary and review could give specialists and scholars in the fields of spectroscopy and chemometrics certain inspiration to accelerate modern spectral analysis techniques booming evolution.
•Chemometric methods in modern spectroscopy are reviewed in the last ten years.•Related issues of chemometric methods in practical applications are discussed.•Future trends in chemometric methods in modern spectroscopy are prospected.
Full‐space manipulation of electromagnetic waves with a thin flat plate is particularly intriguing for large‐angle scanning, functionality integration, and data capacity applications. However, ...majority of the designs to date are confined to linearly‐polarized wave operations; these render the versatile full‐space device operating under circularly‐polarized waves unaddressed due to the critical issue of the geometric phase being hardly decoupled among reflections and transmissions. Herein, a strategy for a helicity‐dependent multifunctional design by sandwiching dual‐layer geometric phase metasurfaces with a bandpass frequency selective surface is reported. The top and bottom metasurfaces are composed of two different types of meta‐structures, split ring resonators (SRRs) and a modified H‐shaped structure, which enable triple‐independent wavefronts at lower and upper frequencies (f1 and f2). At f1, the top and bottom SRRs operate under reflection mode on both sides, and two distinctive wavefronts can be modulated by individually rotating the orientations of SRRs. However, at f2, the modified H‐shaped structure operates in transmission geometry, and additional functionality can be independently modulated by changing their orientations. As a proof of concept, a multifunctional meta‐device is constructed with triple‐versatile functionalities. The approach followed in this study sets up a solid platform for arbitrary helicity‐dependent full‐space integrated devices.
Triple functionalities (F1, F2, F3) of proposed helicity‐dependent full‐space metasurfaces are performed in transmission and reflection modes. Split ring resonators (SRRs) operate under reflection mode on both sides, and two distinctive wavefronts can be modulated by individually rotating the orientations of SRRs. However, the modified H‐shaped structure operates under transmission mode, and additional functionality can be independently modulated by changing their orientations.
AIM：To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials（RCTs）.METHODS：We searched Ovid MEDLINE（from 1946 to October 2011）,Cochrane ...Library（2011）,PubMed for articles on dietary fiber intake and constipation using the terms：constipation,fiber,cellulose,plant extracts,cereals,bran,psyllium,or plantago.References of important articles were searched manually for relevant studies.Articles were eligible for the meta-analysis if they were high-quality RCTs and reported data on stool frequency,stool consistency,treatment success,laxative use and gastrointestinal symptoms.The data were extracted independently by two researchers（Yang J and Wang HP） according to the described selection criteria.Review manager version 5 software was used for analysis and test.Weighted mean difference with 95%CI was used for quantitative data,odds ratio（OR）with 95%CI was used for dichotomous data.Both I2 statistic with a cut-off of ≥ 50% and the χ2 test with a P value 〈 0.10 were used to define a significant degree of heterogeneity.RESULTS：We searched 1322 potential relevant articles,19 of which were retrieved for further assessment,14 studies were excluded for various reasons,five studies were included in the analysis.Dietary fiber showed significant advantage over placebo in stool frequency（OR = 1.19;95%CI：0.58-1.80,P 〈 0.05）.There was no significant difference in stool consistency,treatment success,laxative use and painful defecation between the two groups.Stool frequency were reported by five RCTs,all results showed either a trend or a significant difference in favor of the treatment group,number of stools per week increased in treatment group than in placebo group（OR = 1.19;95%CI：0.58-1.80,P 〈 0.05）,with no significant heterogeneity among studies（I2= 0,P = 0.77）.Four studies evaluated stool consistency,one of them presented outcome in terms of percentage of hard stool,which was different from others,so we included the other three studies for analysis.Two studies reported treatment success.There was significant heterogeneity between the studies（P 〈 0.1,I2 〉 50%）.Three studies reported laxative use,quantitative data was shown in one study,and the pooled analysis of the other two studies showed no significant difference between treatment and placebo groups in laxative use（OR = 1.07;95%CI 0.51-2.25）,and no heterogeneity was found（P = 0.84,I2= 0）.Three studies evaluated painful defecation：one study presented both quantitative and dichotomous data,the other two studies reported quantitative and dichotomous data separately.We used dichotomous data for analysis.CONCLUSION：Dietary fiber intake can obviously increase stool frequency in patients with constipation.It does not obviously improve stool consistency,treatment success,laxative use and painful defecation.
Keemun, Assam, Darjeeling and Ceylon black teas are honored as the world's four most famous black teas, and their excellent aroma qualities are well received by people around the world. In this ...study, aroma components in these four types of teas were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) and gas chromatography-olfactometry (GC-O) technologies. A total of 42 aroma-active compounds were ultimately identified, especially benzeneacetaldehyde, geraniol, (Z)-3-hexen-1-yl hexanoate, trans-β-ionone, cis-linalool oxide (pyranoid), hotrienol, and methyl salicylate presented the strongest aroma strengths with pleasant scents in all tested teas. The quantification results indicated that 19 compounds including (Z)-3-hexenol, 1-octen-3-ol, linalool, phenylethyl alcohol, hexanal, benzeneacetaldehyde, limonene, heptanoic acid, (Z)-3-hexen-1-ol, acetate, benzyl alcohol, trans-linalool oxide (furanoid), hotrienol, 1-octen-3-one, 2-nonanone, (E)-2-octenal, nonanal, β-myrcene, 2-pentylfuran, and methylpyrazine were identified as the key compounds with odor activity values (OAVs) higher than 1.0 in the world's four most famous black teas. Notably, the comparison of GC-O and OAV calculation results showed that methyl salicylate (Ceylon), (E)-2-octenal (Assam), benzeneacetaldehyde (Keemun) and linalool and trans-linalool oxide (furanoid) (Darjeeling) might be the most definitive odorants in the corresponding tea categories.
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•Key odorants in world's four most famous black teas were identified and quantified.•Methyl salicylate, 1-octen-3-ol, linalool etc. were key odorants of Ceylon teas.•(E)-2-Octenal, benzeneacetaldehyde, linalool etc. were key odorants of Assam teas.•Benzeneacetaldehyde, hotrienol, nonanal etc. were key odorants of Keemun teas.•Linalool, trans-linalool oxide (furanoid) etc. were key odorants of Darjeeling teas.
Enveloped virus usually utilizes the receptor-mediated multiple endocytic routes to enter permissive host cells for successful infection. Cellular receptors are cell surface molecules, either by ...helping viral attachment to cell surface followed by internalization or by triggering antiviral immunity, participate in the viral-host interaction. White spot syndrome virus (WSSV), the most lethally viral pathogen with envelope and double strand DNA genome in crustacean farming, including shrimp and crayfish, has been recently found to recruit various endocytic routes for cellular entry into host cells. Meanwhile, other than the typical pattern recognition receptors for recognition of WSSV, more and more putative cellular receptors have lately been characterized to facilitate or inhibit WSSV entry. In this review, recent findings on the endocytosis-dependent WSSV entry, viral entry mediated by putative cellular receptors, the molecular interplay between WSSV and cellular receptors, and the following anti-WSSV immunity are summarized and discussed, which may provide us a better understanding of the WSSV pathogenesis and further possible antiviral control of white spot disease in crustacean farming.
•Recent findings on the putative cellular receptors-mediated recognition and entry of WSSVare summarized.•Advances in cellular receptors-mediated sensing of WSSV and triggering of anti-WSSV immunity are discussed.•IgSF receptors, Integrin, Laminin receptor, Chitin-binding protein and glucose transporter 1 mediate WSSV entry.•Toll-like receptors, C-type lectins and Scavenger receptors sense WSSV and trigger antiviral immunity.
Abstract Background Large cohort studies provide conflicting evidence regarding the potential for oral macrolide antibiotics to increase the risk of serious cardiac events. Objectives This study ...performed a meta-analysis to examine the link between macrolides and risk of sudden cardiac death (SCD) or ventricular tachyarrhythmias (VTA), cardiovascular death, and death from any cause. Methods We performed a search of published reports by using MEDLINE (January 1, 1966, to April 30, 2015) and EMBASE (January 1, 1980, to April 30, 2015) with no restrictions. Studies that reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the associations of interest were included. Results Thirty-three studies involving 20,779,963 participants were identified. Patients taking macrolides, compared with those who took no macrolides, experienced an increased risk of developing SCD or VTA (RR: 2.42; 95% CI: 1.61 to 3.63), SCD (RR: 2.52; 95% CI: 1.91 to 3.31), and cardiovascular death (RR: 1.31; 95% CI: 1.06 to 1.62). No association was found between macrolides use and all-cause death or any cardiovascular events. The RRs associated with SCD or VTA were 3.40 for azithromycin, 2.16 for clarithromycin, and 3.61 for erythromycin, respectively. RRs for cardiovascular death were 1.54 for azithromycin and 1.48 for clarithromycin. No association was noted between roxithromycin and adverse cardiac outcomes. Treatment with macrolides is associated with an absolute risk increase of 118.1 additional SCDs or VTA, and 38.2 additional cardiovascular deaths per 1 million treatment courses. Conclusions Administration of macrolide antibiotics is associated with increased risk for SCD or VTA and cardiovascular death but not increased all-cause mortality.
Background
We previously found that autoantibodies against a panel of six tumor-associated antigens (p53, NY-ESO-1, MMP-7, Hsp70, PRDX6 and Bmi-1) may aid in early detection of esophageal squamous ...cell carcinoma. Here we aimed to evaluate the diagnostic value of this autoantibody panel in esophagogastric junction adenocarcinoma (EJA) patients.
Methods
Serum autoantibody levels were measured by enzyme-linked immunosorbent assay in a training cohort and a validation cohort. We used receiver-operating characteristics (ROC) to calculate diagnostic accuracy.
Results
We recruited 169 normal controls and 122 EJA patients to the training cohort, and 80 normal controls and 70 EJA patients to the validation cohort. Detection of the autoantibody panel demonstrated an area under the curve (AUC) of 0.818, sensitivity 59.0% and specificity 90.5% in training cohort, and AUC 0.815, sensitivity 61.4% and specificity 90.0% in validation cohort in the diagnosis of EJA. Measurement of the autoantibody panel could distinguish early stage EJA patients from normal controls (AUC 0.786 and 0.786, sensitivity 50.0% and 56.0%, and specificity 90.5% and 90.0%, for training and validation cohorts, respectively). Moreover, a restricted panel consisting of autoantibodies against p53, NY-ESO-1 and Bmi-1 exhibited similar diagnostic performance for EJA (AUC 0.814 and 0.823, sensitivity 53.5% and 60.0%, and specificity 90.5% and 93.7%, for training and validation cohorts, respectively) and early stage EJA (AUC 0.744 and 0.773, sensitivity 55.6% and 52.0%, and specificity 90.5% and 93.7%, for training and validation cohorts, respectively).
Conclusions
Autoantibodies against an optimized TAA panel as serum biomarkers appear to help identify the present of early stage EJA.
Manipulating the polarization states of electromagnetic (EM) waves, a fundamental issue in optics, attracted intensive attention recently. However, most of the devices realized so far are either too ...bulky in size, and/or are passive with only specific functionalities. Here we combine theory and experiment to demonstrate that, a tunable metasurface incorporating diodes as active elements can dynamically control the reflection phase of EM waves, and thus exhibits unprecedented capabilities to manipulate the helicity of incident circular-polarized (CP) EM wave. By controlling the bias voltages imparted on the embedded diodes, we demonstrate that the device can work in two distinct states. Whereas in the "On" state, the metasurface functions as a helicity convertor and a helicity hybridizer within two separate frequency bands, it behaves as a helicity keeper within an ultra-wide frequency band in the "Off" state. Our findings pave the way to realize functionality-switchable devices related to phase control, such as frequency-tunable subwavelength cavities, anomalous reflectors and even holograms.
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