117 research outputs found

    Flat Chern Band From Twisted Bilayer MnBi2_2Te4_4

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    We construct a continuum model for the Moir\'e superlattice of twisted bilayer MnBi2_2Te4_4, and study the band structure of the bilayer in both ferromagnetic (FM) and antiferromagnetic (AFM) phases. We find the system exhibits highly tunable Chern bands with Chern number up to 33. We show that a twist angle of 1∘1^\circ turns the highest valence band into a flat band with Chern number ±1\pm1 that is isolated from all other bands in both FM and AFM phases. This result provides a promising platform for realizing time-reversal breaking correlated topological phases, such as fractional Chern insulator and p+ipp+ip topological superconductor. In addition, our calculation indicates that the twisted stacking facilitates the emergence of quantum anomalous Hall effect in MnBi2_2Te4_4.Comment: 7+6 pages, 3+2 figure

    A Two-phase Simulation of Wave Impact on a Horizontal Deck Based on SPH Method

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    AbstractIn this paper, a two-phase numerical model is developed to study the effect of the gas phase in problems of wave attacking deck. The model is based on weakly compressible smoothed particles hydrodynamics (WCSPH) method, and is implemented in C++ and CUDA language to running on GPUs starting from DualSPHysics. Surface tension is considered by incorporating the surface tension force into the momentum equations. Therefore, the continuum surface force (CSF) model is proposed to eliminating the interphase particle penetrations. To calculate surface tension force at interfaces, a color function is assigned to each particle from different phases. Furthermore, to enhance the robustness of this method, the assigned color function is smoothed by calculating the weighted averaging value of initial color function on its support domain. The simulation results are compared with experiment results. The point pressure from numerical results shows well agreement with experimental ones, and is more accurate than one phase simulation. The reason is lying on its satisfying on the condition of air pressure

    Commercial Chinese polyherbal preparation: current status and future perspectives

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    ObjectiveWith the modernization of traditional Chinese medicine (TCM) industry, the investment in research and development of new commercial Chinese polyherbal preparations (CCPPs) is increasing, and the varieties of CCPPs are growing. CCPPs play an increasingly important role in the TCM industry. This study has comprehensively summarized and analyzed the current situation of CCPPs that has been on the market in China, and provided suggestions for the research and promotion of CCPPs.MethodsThis study took the CCPPs approved for marketing in domestic drug database of the National Medical Products Administration (NMPA) as the research object, and combined with the publication of related randomized controlled trials (RCTs) of CCPPs in 2020–2022 and the sales of CCPPs in domestic chain pharmacies, statistical analysis was carried out on the drug name, pharmaceutical companies, dosage form, number of flavors, CBDs, ICD-11 classification of diseases treated, etc.ResultsCurrently, 58,409 approvals for CCPPs have been issued in China, involving 9,986 varieties of CCPPs, 2,896 pharmaceutical companies and 39 dosage forms. The number of flavors of prescriptions of CCPPs varies from 1 to 90, among which Glycyrrhiza glabra L. [Fabaceae; Glycyrrhizae radix et rhizoma] and Angelica sinensis (Oliv.) Diels [Apiaceae; Angelicae sinensis radix] are the most widely used. The study found that the CCPPs with the most diverse variety is CCPPs for the treatment of respiratory diseases, some CCPPs can treat multiple system diseases. According to the survey, the sales of CCPPs for respiratory diseases in the chain pharmacies account for more than 1/3 of the total sales of the chain pharmacies, while the number of published randomized controlled trials (RCTs) on CCPPs for circulatory diseases was the largest.ConclusionThe approval process of CCPPs should be further standardized, and the transformation of TCM prescriptions into CCPPs should be promoted. In the approval process of CCPPs, it is suggested to strengthen the supervision of drug names to clarify the differences between the CCPPs of same name but different prescriptions. Improve the effectiveness and safety of CCPPs by improving the quality of CBDs. It is suggested to optimize the design of new drug research program of CCPPs to avoid waste of research resources

    Effectiveness of Shuxuening injection in coronary heart disease: a systematic review and meta-analysis

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    Background: Coronary heart disease (CHD) poses a serious threat to public health, and the current medical management still faces significant challenges. Reliable evidence on the efficacy of Shuxuening injection (SXNI) in CHD is still lacking, even though it is widely used in China.Purpose: To evaluate the efficacy of SXNI combination therapy in treating CHD.Methods: A systematic search of eight databases was conducted to identify relevant randomized controlled trials (RCTs) from the inception of each database until June 2023. ROB 2.0, RevMan 5.4, and Stata 15.1 were used for quality evaluation and data analysis. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the quality of evidence.Results: A total of 3,779 participants from 39 studies were included. The results showed SXNI combination therapy increased the clinical efficacy and decreased the frequency and duration of angina. Furthermore, SXNI combination therapy improved cardiac function of patients by decreasing LVEDD, and increased CI, CO, and LVEF. It also improved blood lipid profiles by increasing HDL, decreasing TC, TG, and LDL. The thrombosis factors of patients were also improved by decreasing FIB, PV, HCT, and HS. Moreover, SXNI combination therapy was superior to the conventional treatment in improving CRP levels, increasing ECG efficacy and BNP. However, due to the limited safety information, reliable safety conclusions could not be drawn. Furthermore, the levels of evidence ranged from very low to moderate due to publication bias and heterogeneity.Conclusion: SXNI can effectively improve angina symptoms, clinical efficacy, cardiac function, blood lipid indicators, and thrombosis factors of patients with CHD. However, more multi-center and large-sample studies are needed to confirm the conclusions due to the limitations of this study.Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=399606; Identifier: CRD42023433292

    Ethical conflict in nursing: A concept analysis

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    Aims and Objectives The purpose of this paper was to clarify the concept of ethical conflict in nursing and highlight the importance of tackling this issue. Background Ethical conflict is on the rise in the nursing context. It is associated with the compromise of nurses' well-being and patient care. However, there is no thorough conceptual understanding of this concept. Design Concept analysis. Methods Databases (PubMed, PsycINFO, CINAHL, Scopus, Embase, Web of Science and SocINDEX) were searched for studies between 1984 and 2021. Both quantitative and qualitative studies related to ethical conflict in nursing were included. Walker and Avant's method of concept analysis was used to identify the defining attributes, antecedents and consequences of the concept of ethical conflict in nursing. We followed the PRISMA-ScR checklist to report the study. Results Thirty studies were included for conceptualization. Defining attributes were divided into four categories: (1) emotional responses, (2) incompatible values, (3) competing interests and (4) ambiguous obligations. The antecedents were (1) ethical sensitivity, (2) negative ethical climate, (3) insufficient authority, (4) unrealistic expectations, (5) poor collaboration and (6) inadequate resources. The consequences were identified as (1) moral residue, (2) loss of identity, (3) professional burnout and (4) poor patient care. Conclusions A unified conceptual model of ethical conflict in nursing shed light on the ethical issues nurses might come across in practice. Despite the fact that ethical conflict is inherently negative, we conceptualised this concept as a neutral fact and an opportunity for nursing action. The construct identification provides basis for both the development of practice and the development of staff support and education
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