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Objective To investigate the effect of evidence-based scene simulation combined with problem-based learning in clinical teaching of critical care for nursing students. Methods Totally 65 nursing students were randomly divided into the study group (n=33)and the control group(n=32). Conventional teaching model were adopted in clinical teaching of critical care for nursing students in the control group, and evidence-based scene simulation combined with problem-based learning were used in clinical teaching of critical care for nursing students in the study group. The theoretical examination, clinical practice skills and student satisfaction with clinical teaching were measured and compared between two groups. Results Scores of theoretical examination, clinical practice assessment and satisfaction evaluation in the study group were higher than those in the control group (P＜0. 05, respectively). Conclusion The evidence-based simulation combined with problem-based learning is effective to arouse students’ motivation and interest in learning English, deepen the understanding of theoretical knowledge, improve the independent problem-solving ability and enhance the clinical practice skills. (目的 探讨在重症医学科护理实习生带教工作中应用基于循证的情景模拟结合以问题为基础(PBL)教学法的效果。方法 选取2020年9月－2021年8月到医院重症医学科实习的65名护理实习生为研究对象, 采用随机数字表法将实习生分为试验组(n=33)和对照组(n=32)。对照组采用传统临床带教方法, 试验组采用基于循证的情景模拟结合PBL教学法, 对比两组护理实习生理论考核成绩、临床工作能力评分和对临床教学的满意度。结果 试验组理论考核成绩评分床工作能力评分和教学满意度评分均高于对照组, 差异有统计学意义(P＜0. 05)。结论 以循证为基础的情景模拟与PBL教学法相结合, 能够调动护理实习生学习的积极性和主动性, 加深对理论知识的理解, 提升自主解决实际临床问题的能力, 提高实际临床工作能力。)

Ambipolar field-effect transistors (FETs) are a class of transistors that transport holes and electrons simultaneously in the conducting channel, and they has extensive application prospects in various emerging fields such as synaptic, memory and logic devices. Single-component semiconductor materials such as ambipolar organic semiconductors, perovskites, black phosphorus and other materials are used as active layers for an ambipolar FET. However, it is difficult to achieve balanced transport of both holes and electrons using these materials. In this study, we designed and fabricated an ambipolar FET based on the Ph-BTBT-10/PMMA/ZnO structure in the solution process. ZnO acts as an n-type semiconductor for electron transport, and the liquid crystal small molecule Ph-BTBT-10 acts as a p-type semiconductor for hole transport. The insulating polymer PMMA is introduced by the vertical phase separation method for improving the interface of ZnO and Ph-BTBT-10. The ambipolar FET exhibits well-balanced electrical performance with hole and electron mobilities of 0.11 and 0.34 cm2 V−1 s−1. Furthermore, an inverter with a voltage gain of up to 17 V/V is demonstrated by employing two ambipolar FETs. [ABSTRACT FROM AUTHOR]

In this work, chopped carbon fibers (CCFs) with different lengths were added to graphite/polypropylene (PP) composite materials to achieve high conductivity and flexural strength performances, which are required for use in proton exchange membrane fuel cells. The effects of CCF length (2–4 mm), CCF content (0–5 wt.%), graphite type‐natural flake graphite (NFG) and synthetic graphite (SG), and graphite particle size (18–106 µm) on the graphite/PP/CCFs composites are examined. The conductivities of the composites decrease significantly with increasing CCF length above 3 wt.%. CCFs improve the composite's strength, with a maximum strength of 45.8 MPa being achieved with 5 wt.% of 4 mm long CCFs. Composite with NFG exhibits superior conductivity to the one with SG but lacks flexural strength. The NFG particle size significantly affects the conductivity of the composite at high graphite contents, with a particle diameter of 75 µm resulting in maximum conductivity. An optimal composition with 38 µm/82 wt.% NFG and 2 mm/3 wt.% CCF, electrical conductivity, and flexural strength of 189.4 S/cm and 30.2 MPa, respectively, were achieved. Also, this composite exhibited interfacial contact resistance 2.52mΩ·cm2$2.52\;{\rm{m}}\Omega \cdot {\rm{c}}{{\rm{m}}^{\rm{2}}}$ and contact angles of 111°, which showed favorable interfacial conductivity and hydrophobicity performances. [ABSTRACT FROM AUTHOR]

Fragment productions in spallation reactions and projectile fragmentation reactions are important topics in nuclear reaction both theoretically and experimentally, which find important applications in fundamental nuclear physics, radioactive ion beam facilities, nuclear waste disposal, medical isotopes production, etc. Besides the many models to predict the fragment productions, such as the transport model, empirical parametrizations or formula, machine learning models have been constructed to predict fragment cross-sections in proton induced spallation reactions and projectile fragmentation reactions. In this paper, the recently proposed models using Bayesian neural network (BNN) models were introduced for precise prediction of fragments, especially for extreme rare isotopes with large isospins in nuclear spallation and projectile fragmentation reactions. Two types of models were introduced, i.e., the BNN models which were constructed based on massive learning to experimental data, and the physical model guided BNN+ models which were constructed based on massive learning to the differences between measured data and physical model predictions. The simplified EPAX (sEPAX) formula and the FRACS formulas were adopted as the physical model to guide the BNN+ model for spallation reaction (BNN+sEPAX) and projectile fragmentation reaction (BNN+FRACS), respectively. The BNN and BNN+ models have the structure of one input layer with key parameters related to the reaction, one hidden layer with optimized numbers of neural nodes and one output layer. For the numbers of learning data set, it was 15 370 measured fragments in the proton induced nuclear spallation reactions and 6 393 measured fragments in the projectile fragmentation reactions. It is found that the machine learning models provide new type of predictive models for nuclear reactions besides the physical models. The BNN model needs sufficient information to achieve good prediction ability, while the BNN+ model can inherit the advantage of the physical model and make up for the defects of the physical model, which makes it achieve good predictive ability when known data are insufficient. The predicted results show that the BNN and BNN+ models have high predictions to fragments cross-sections in spallation reactions smaller than 136Xe within an incident energy range from tens of MeV/u to a few GeV/u, and projectile fragmentation reactions for projectile from 40Ar to 208Pb within the range of incident energy from tens of MeV/u to 1 GeV/u. Particularly, the BNN model for projectile fragmentation reaction predicts a 0.46 fb compared to the experimental estimation 0.5 fb for 39Na isotope in the 345 MeV/u 48Ca+9Be reaction, indicating it is capable for high quality prediction to near drip-line isotopes.

Listeria monocytogenes is a widespread foodborne pathogen contaminating foods during their production or processing stages. Fresh meat is susceptible to such contamination if it is not properly preserved. Our study was conducted to reveal the level of contamination and prevalence of Listeria spp. present in livestock and poultry meat from Gansu province. A total of 1,387 samples were collected from five cities in Gansu Province according to standard sampling procedures, of which 174 samples (12.5%) were positive for Listeria species. Among them, 14 isolates of L. monocytogenes (1.0%), 150 isolates of Listeria innocua (10.8%), and ten isolates of Listeria welshimeri (0.7%) were identified by conventional bacteriological and molecular identification methods. All isolates were subjected to serological assays, antimicrobial susceptibility tests, growth curve assays, determination of biofilm-forming capacity, and cluster analysis of the 16S rRNA gene sequences. Four predominant serotypes of L. monocytogenes were identified, including 1/2a (35.7%, 5/14), 1/2b (14.3%, 2/14), 1/2c (42.9%, 6/14), and 4b (7.1%, 1/14). All L. monocytogenes isolates were resistant to tetracycline and cefoxitin. Most L. innocua isolates (63.6%, 14/22) and L. welshimeri (40%, 4/10) were resistant to tetracycline. The high biofilm-forming ability was observed among 1/2c and 1/2a serotype isolates. The cluster analysis of the 16S rRNA gene sequences revealed a close genetic relationship between the three Listeria species. This study fills the gap in the knowledge of livestock and poultry meat that carry Listeria in slaughterhouses and markets in Gansu Province.

BackgroundNeutral beam injection heating is a very effective auxiliary heating method in magnetic confinement fusion experiment. The built 5 MW neutral beam injection plays an important role in the H-mode operation with 1 MA plasma current of HL-3 tokamak. In order to achieve the H-mode operation with 2.5 MA, three neutral beam injection heating systems will be constructed with a total heating power of 20 MW.PurposeThis study aims to investigate the transmission efficiency of 7 MW neutral beam injector designed for HL-3 tokamak.MethodsThe beam transmission efficiency was studied from two aspects of neutralization efficiency and power deposition. The initial target thickness of the neutralizer under two beam parameters was analyzed based on Monte Carlo method. The optimal neutralization efficiency was achieved by adding neutralizer gas supply, and the target thickness required for the optimal neutralization efficiency was given. Finally, power deposition method was employed to analyze the transmission performance of the two neutral beams with different parameters at different beam divergence angles.ResultsThe results show that the optimal neutralizer efficiency is achieved when the neutralizer gas supply is 0.6 Pa∙m3∙s-1 and 1.1 Pa∙m3∙s-1, respectively. The neutral beam power obtained under two beam parameters with a divergence angle of 1.2° is 7.2 MW and 6.8 MW, respectively, and the corresponding transmission efficiency is 0.4 and 0.35, respectively.ConclusionsThe new neutral beam injector of HL-3 tokamak will be built according to the design of this study, with optimized parameter of 100 kV/45 A, while still retaining the ability to deliver a 120 keV deuterium beam.

BackgroundIn neutral beam injectors (NBIs) of Tokamak device, the calorimetric target is one of the most important water-cooled components, responsible for receiving and measuring beam power. In addition, by using a built-in thermocouple array, the temperature rise at different positions of the target plate can be monitored in real-time, thereby obtaining the power density distribution of the extracted ion beam or neutral beam.PurposeThis study aims to develop a calorimetric target for the neutral beam injector in the HL-3 device, which can meet the requirements of target plate lifting and thermal load absorption.MethodsA linear push rod mechanism was applied to the design of the calorimetry target to achieve lifting and lowering, and a "W" - shaped target plate structure was adopted to achieve absorption of neutral beam energy. According to the design parameters, the fluid calculation module of Ansys Workbench was employed to simulate the temperature distribution of the calorimetry target under full power operation.ResultsCalculation results show that the maximum temperature rise of the calorimetry target is 526.4 ºC when the deflecting magnet is opened under full power operating conditions, and the temperature can be lowered to room temperature within 30 s, satisfying the requirements for the use of the beam line.ConclusionsThe successfully developed calorimetric target of this study meets application requirements on second neutral beam injection beamline of HL-3 device, providing references for further engineering design of calorimetric targets in other NBIs.

Aims/Introduction: The purpose of the present study was to observe the relationship between serum α‐klotho (KL) protein level and diabetic retinopathy (DR), and to further examine the effects of KL protein on apoptosis induced by palmitic acid (PA) in human retinal endothelial cells. Materials and Methods: A total of 17 healthy people and 60 type 2 diabetes patients were included. According to the results from fundus fluorescein angiography, the diabetes patients were divided into three subgroups: without DR, non‐proliferative DR and proliferative DR. Serum KL level was measured by enzyme‐linked immunosorbent assay. In vitro, human retinal endothelial cells were exposed to PA with or without KL protein. Apoptosis rates were analyzed by flow cytometry analysis. Apoptotic‐related protein expressions were detected by western blotting analysis. Results: Serum KL level was lower in diabetes patients than that in healthy participants (P = 0.007), and was gradually decreased among the without DR, non‐proliferative DR and proliferative DR subgroups (P = 0.045). A logistic regression analysis showed that after adjusting for the other confounding factors, serum KL level was independently and negatively related with DR (P = 0.049). Furthermore, the increased apoptosis rates induced by PA were inhibited with the addition of KL protein. Consistently, KL protein reversed the expression levels of the increased pro‐apoptotic protein Bax and the decreased anti‐apoptotic protein Bcl‐2 induced by PA. However, the anti‐apoptotic effect of KL protein was attenuated by LY294002 through the phosphatidylinositol 3 kinase‐serine∕threonine kinase pathway. Conclusions: The data suggested that KL protein was probably a potential protective factor against retinopathy in type 2 diabetes patients. [ABSTRACT FROM AUTHOR]

In order to clarified characteristics and function of internalin G (inlG) in Listeria monocytogenes ATCC®19111 (1/2a) (LM), the immune protection of the inlG was evaluated in mice, the homologous recombination was used to construct inlG deletion strains, and their biological characteristics were studied by the transcriptomics analysis. As a result, the immunization of mice with the purified protein achieved a protective effect against bacterial infection. The deletion strain LM-AinlG was successfully constructed with genetic stability. The mouse infection test showed that the virulence of LM was decreased after the deletion of the inlG gene. The deletion strain showed enhanced adhesion to and invasion of Caco-2 cells. Compared to the wild strain, 18 genes were up-regulated, and 24 genes were down-regulated in the LM-AinlG. This study has laid a foundation for further research on the function of inlG and the pathogenesis of LM.

The selection of photoactive materials and the design of device structures are critical to the photoelectronic performance of photodetectors. This study reports on a vertically structured photodetector device with rapid, stable, and efficient photoelectric performance across the UV-visible broadband range based on the Si ++ /SiO 2 /Au/single-layer graphene/CsPbI 3 quantum dots (QDs) configuration. In this specific device structure, a relatively high conductivity Si ++ /SiO 2 wafer was used as the substrate, a CsPbI 3 QD film with high light absorption was used as the photoactive layer, and a monolayer graphene with high conductivity was inserted between the substrate and the CsPbI 3 QD film to form a heterojunction with the QD film. Based on the Frenkel-Poole emission effect arising from the high trap state density within the SiO 2 layer, the device exhibited excellent photoelectric performances. Especially at a wavelength of 365 nm, a photocurrent responsivity of 2319 A/W, a specific detectivity of 1.15 × 10 14 Jones, an external quantum efficiency of 7883%, and an on/off time of 39/36 ms at a Si ++ terminal voltage of -80 V and an optical power density of 84.03 nW/cm 2 can be achieved.