We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five ...center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7 fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrts=4.681 GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1) MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0) MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3 σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.
Design of functionally graded material (FGM), in which the mechanical property varies along one direction, is the focus of this study. It is assumed that the microstructure of the FGM is composed of ...a series of base cells in the variation direction and self-repeated in other directions. Bi-directional evolutionary structural optimization technique in the form of inverse homogenization is used for the design of the FGM for specified variation in bulk or shear modulus. Instead of designing a series of base cells simultaneously, the base cells are optimized progressively by considering three base cells at each stage. Thus, the proper connections between adjacent base cells can be achieved with high computational efficiency. Numerical examples demonstrate the effectiveness of the proposed method for designing microstructures of 2D and 3D FGMs with specified variation in bulk or shear modulus. The proposed algorithm can also be easily extended to design FGMs with other functional properties.
We carried out this meta-analysis to demonstrate efficacies of neoadjuvant chemotherapy (NACT) and adjuvant chemotherapy (AC) for nasopharyngeal carcinoma (NPC) patients based on randomized, ...controlled trials (RCTs).
We comprehensively searched electronic databases and manuscripts for RCTs and extracted data from eligible studies for meta-analysis. Overall survival (OS) with hazard ratios (HRs), locoregional recurrence rate (LRR) and distant metastasis rate (DMR) with relative risks (RRs) were concerned using random and/or fixed-effects models. Subgroup and sensitivity analyses were also carried out.
Six trials in NACT group (n = 1418) and five in AC group (n = 1187) were eligible. HR of death for NACT was 0.82 95% confidence interval (CI) 0.69–0.98, P = 0.03, corresponding to an absolute survival gain of 5.13% after 3 years. Significant reduction of DMR (P = 0.0002; RR 0.69, 95% CI 0.56–0.84) was also found from NACT. But no decrease in LRR (P = 0.49; RR 0.90, 95% CI 0.66–1.22) was observed. Patients receiving additional AC had lower LRR (P = 0.03; RR 0.71, 95% CI 0.53–0.96). But no benefit of OS and DMR were seen in AC.
NACT can effectively enhance OS and reduce DMR, not LRR in NPC. And AC only helps to better control locoregional recurrence of NPC.
The chloroplast-localized SIB1 protein was previously identified by its interaction with SIGMA FACTOR 1 (SIG1), a component of the RNA polymerase machinery responsible for transcription of plastid ...genes. The physiological function of SIB1 is little known. We found that expression of SIB1 is induced by infection with Pseudomonas syringae, suggesting its possible involvement in the defence response. The sib1 loss-of-function mutation compromises induction of some defence-related genes triggered by pathogen infection and the treatments with salicylic acid (SA) and jasmonic acid (JA), two key signalling molecules in the defence response. Conversely, constitutive over-expression of SIB1 causes the plants to hyper-activate defence-related genes following pathogen infection or the SA and JA treatments, leading to enhanced resistance to infection by P. syringae. SIB1 is a member of the large plant-specific VQ motif-containing protein family, and might act as a link to connect defence signalling with chloroplast function.
To explore the characteristics of Helicobacter pylori resistance in China and the association between antibiotic resistance and several clinical factors.
H. pylori strains were collected from ...patients in 13 provinces or cities in China between 2010 and 2016. Demographic data including type of disease, geographic area, age, gender and isolation year were collected to analyse their association with antibiotic resistance. Antibiotic resistance was detected using the Etest test and the Kirby-Bauer disc diffusion method.
H. pylori were successfully cultured from 1117 patients. The prevalence of metronidazole, clarithromycin (CLA), azithromycin, levofloxacin (LEV), moxifloxacin, amoxicillin (AMO), tetracycline and rifampicin resistance was 78.2, 22.1, 23.3, 19.2, 17.2, 3.4, 1.9 and 1.5%, respectively. No resistance to furazolidone was observed. The resistance rates to LEV and moxifloxacin were higher in strains isolated from patients with gastritis compared to those with duodenal ulcer and among women. Compared to patients ≥40 years old, younger patients exhibited lower resistance rates to CLA, azithromycin, LEV and moxifloxacin. The resistance rates to CLA and AMO were higher in strains isolated more recently, and we also found that the prevalence of resistance to metronidazole, CLA, azithromycin and AMO were significantly different among different regions of China.
The resistance rates to metronidazole, CLA and LEV were high in China. Patient age, gender, disease and location were associated with the resistance of H. pylori to some antibiotics. Furazolidone, AMO and tetracycline are better choices for H. pylori treatment in China.
•Transition size calculation has been raised, covering the effects of notch and size.•Critical size is not only related to Nf, but also to the stress concentration level.•The novel model can treat ...notch features, as well as other large-scale members.
In order to evaluate notch effects and size effects on fatigue performances, smooth specimens without stress gradient and a group of notched specimens particularly designed are investigated in this paper. From the perspective of probability, the statistical size effect of the latter is worth studying for bodies weakened by notches. A unified model of combination of the improved theory of critical distance (TCD), along with the concept of highly-stressed-volume (CHSV) is established to identify the initiation crack size, evaluate the fatigue strength, and determine the fatigue lifetime of notched members, and even similar large-scale components in high cycle fatigue regime. The predicted results are compared with the experimental data sets taken from literatures. Fortunately, we find that, the novel model not only inherits the generality of existing methods, such as TCD, but also provides necessary support for predictions of characteristic length and fatigue lifetime of components containing any blunt-notch geometries.
•A new tow-scale topology optimization algorithm is proposed based on BESO.•Optimization is carried out for structures and their composites simultaneously.•Homogenization is used for linking the ...analyses at the macro and micro levels.•Various optimal macrostructures and microstructures are reported and discussed.
Different from the independent design of macrostructures or material microstructures, a two-scale topology optimization algorithm is proposed by using the bi-directional evolutionary structural optimization (BESO) method for the concurrent design of the macrostructure and its composite microstructure. It is assumed that the macrostructure is made of composite materials whose effective properties are calculated through the homogenization method. By conducting finite element analysis of both structures and materials, sensitivity numbers at the macro- and micro-scale levels are derived. Then, the BESO method is used to iteratively update the macrostructures and the composite microstructures according to the elemental sensitivity numbers at both scales. Some 2D and 3D numerical examples are presented to demonstrate the effectiveness of the proposed optimization algorithm. A variety of optimal macrostructures and optimal material microstructures have been obtained.
In December 2019, a new type of coronavirus-infected pneumonia broke out in Wuhan and spread rapidly to other parts of the country. The purpose of this study was to investigate the clinical features ...of coronavirus disease 2019 (COVID-19).
A retrospective analysis was performed on the confirmed cases of COVID-19, who were admitted to the North Hospital of Changsha first Hospital (Changsha Public Health treatment Center) from January 17 to February 7, 2020.
The median age of COVID-19 patients was 45 years (range 33.5-57). The male patients accounted for 49.7%, 64.6% of the patients had a history of exposure in Wuhan, and 31.7% had family aggregation. The median days of onset were six, and the incidence of severe illness was 18.6%. Compared with the non-severe group, the severe group showed statistical significance in older age, hypertension, bilateral lung plaque shadow, decrease in lymphocyte count, increase in C-reactive protein (CRP), aspartate aminotransferase (AST), lactate dehydrogenase, and creatine kinase.
Age, combined hypertension, oxygenation index, double lung patch, decreased lymphocyte count, and elevated levels of C-reactive protein, aspartate aminotransferase, lactate dehydrogenase, and creatine kinase can be used as predictors of the disease severity.
Summary
What is known and objective
A series of studies have indicated that valproic acid (VPA) plasma concentration decreased rapidly when used concomitantly with carbapenem antibiotics, including ...meropenem (MEPM), imipenem and panipenem, which may increase the risk of seizure breakthrough. However, the cause for the change in VPA pharmacokinetics is unclear. A retrospective analysis of VPA therapeutic drug monitoring (TDM) records was performed to investigate this VPA pharmacokinetics drug–drug interaction.
Methods
Three hundred and eighty one VPA TDM records from the Department of Neurosurgery of Xiangya Hospital from January 2012 to December 2014 were collected. The VPA TDM records were categorized by VPA and MEPM daily dosages in grams/day (g/day). A comparison of VPA plasma levels among different groups was performed to investigate the change in VPA level in this drug interaction.
Results and discussion
Remarkable decreases in VPA plasma level were observed when the drug was used concomitantly with MEPM in both 1.2 g/d and 1.6 g/d VPA groups (67·3 ± 4·6 μg/mL, n = 21 vs. 15·3 ± 1·9 μg/mL, n = 15, P < 0·001; 67·6 ± 1·2 μg/mL vs. 18·1 ± 2·6 μg/mL, n = 38, P < 0·001). No significant difference in VPA plasma concentrations was observed between the 1·2 g/day VPA + MEPM, 1·6 g/day VPA + MEPM and 2·0 g/day VPA + MEPM groups (15·3 ± 1·9 μg/mL, n = 15 vs. 18·1 ± 2·6 μg/mL, n = 38 vs. 9·0 ± 3·0 μg/mL, n = 7; P = 0·252). The decrease in VPA concentration was independent of MEPM daily dose (14·0 ± 5·1 μg/mL, n = 4 for high MEPM daily dose vs. 16·5 ± 1·9 μg/mL, n = 56 for low MEPM daily dose; P = 0·729). After discontinuation of MEPM for more than 7 days, VPA plasma concentration recovered to a value comparable to that before MPEM initiation (69·7 ± 4·2 μg/mL, n = 21 vs. 51·2 ± 8·1 μg/mL, n = 9; P = 0·48).
What is new and conclusion
This is the first study using a large number of VPA TDM records to investigate the change in VPA levels caused by concomitant use of MEPM. Our results imply that the decrease in drug concentration cannot be reversed by increasing VPA dose. Moreover, MEPM daily dose did not influence the drop in VPA plasma level. At least 7 days are required for the recovery of VPA plasma concentration after discontinuation of MEPM.
The magnitude of decrease in VPA plasma concentration was independent of VPA and MEPM daily dose in this drug‐drug interaction.
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