In analytical techniques such as ion mobility spectrometry(IMS)and mass spectrometry(MS),the ionization efficiency of target analytes is primarily constrained by the type of ionization source and factors such as the species and number density of the reactant ions.Systematic investigation into the reactivity differences of various reactant ions under varying conditions can not only significantly enhance the detection sensitivity of target compound product ions but also provide a theoretical foundation for establishing efficient detection methods based on ion-molecule reaction mechanisms.In this study,the pressure of a pressure-tunable photoionization tandem ion mobility spectrometry(PI-tandem-IMS)was reduced from ambient pressure(100 kPa)to low pressure(20 kPa)to systematically examine the reactivity differences between two negative reactant ions,CO3-and CO4-,and methyl salicylate(MeSA)under varying pressures.When the pressure decreased,the increased relative signal intensity of CO4-significantly influenced the detection sensitivity of the characteristic product ion[MeSA·O2]-.Based on differences in ion mobility(k0),the delay time for the opening of TPG2 was adjusted to selectively inject CO-3 and CO-4 in the drift region 2.Independent characterization of the reactivity of these reactant ions with MeSA in the reaction region confirmed that CO4-exhibited superior reactivity toward MeSA.The theoretical model revealed an Arrhenius plot for the ion-molecule reaction between CO4-and MeSA,showing a positive correlation between the reaction rate coefficient(k)and temperature,the activation energy Ea was 62.45 kJ/mol.Furthermore,controlling parameters such as pressure or temperature significantly influenced the progression of this ion-molecule reaction,demonstrating the technical advantages of PI-tandem-IMS in mechanistic studies and regulation of ion-molecule reactions.

The resolving power and sensitivity are critical for on-site detection of hazardous chemicals using stand-alone ion mobility spectrometry(IMS).However,improving the sensitivity and resolving power of IMS has long been a prominent research hot spot.In the commonly used IMS based on the Bradbury-Nielsen gate(BNG),the gating voltage difference(GVD)applied between the two sets of grid wires affects the electric field distribution in the ionization region and the drift region.This,in turn,influences the spatial distribution and temporal width of the injected ion swarm,and has an impact on the ion mobility discrimination,sensitivity,and resolving power of the instrument.This study showed that increasing the GVD could induce an ion converging effect,boosting the ion number density in front of the BNG by nearly 300％.To simultaneously utilize temporal compression and ion converging effects,a novel BNG controlling mode was proposed by adding a chopping state to the conventional controlling mode.This chopping state reduced the mobility discrimination effects between ions with mobility differences up to about 0.90 cm2/(V·s)to 1/22 of their original value.When analyzing hazardous chemical mixtures using the novel BNG controlling mode,compared with conventional mode,the signal intensity of low-mobility methyl salicylate ions(MS·O2)-increased by 18-fold while the resolving power maintained around 100,and the detection limit for MS was improved from 3.75 μg/L to 97 ng/L.This novel BNG controlling mode only added a potential wave to the low voltage wires,with no requirement of changing the structure of the drift tube,and was easy to apply to existing commercial instruments.

Ion mobility spectroscopy(IMS)has many advantages such as fast detection speed,high sensitivity,and portability,and thus plays an important role in on-site detection of chemical agents,explosives,drugs,environmental pollutants,and other pollutants.As a key component of IMS,the ion number density and temporal width of the injected ion packets directly determine the IMS detection sensitivity and resolution.In yhis study,the dual-parallel-grid structure of Tyndall-Powell gate(TPG),which could effectively isolate the electric fields within the ionization region,gate region,and drift region,was utilized to develop a dual effect TPG gating method for simultaneously enhancing the mobility discrimination reduction and ion packet temporal width compression,thereby improving the IMS performance.A TPG-IMS platform was thus built up and the effects of parameters such as gate opening pulsed width,gate penetration voltage,and ion injection voltage on the sensitivity and resolving power of IMS were systematically investigated using the dual-effect TPG gating method.The results demonstrated that,when detecting diethyl phosphate(DEP)and diethyl methylphosphate(DEMP)mixture using the dual effect TPG gating method,the peak currents of(DEP)2H+and(DEP·DEMP)H+ions with low K0 values were increased by 18 and 45 times respectively,while maintaining a high resolution of about 90.The limits of detection for DEP and DEMP were decreased from 4 ppb(10-9)to 235 ppt(10-12)and from 5 ppb to 156 ppt,respectively.This gating method only regulated the potential of the TPG grid adjacent to the drift region,without changing the structure of the ion mobility tube,making it convenient to apply on existing commercial instruments.

This work was aimed at predicting and verifying B-cell epitopes of SARS-CoV-2 E protein through bioinformatics methods,and clarifying the dominant B cell epitopes with mouse polyclonal antibody serum prepared through SARS-CoV-2 re-combinant E protein immunization and human positive serum vaccinated with inactivated SARS-CoV-2 vaccine.The structural and B-cell linear epitopes of SARS-CoV-2 E protein were predicted with SOPMA,Expasy,SWISS-MODEL,IEDB database,and Bepid-2.0 software.Candidate epitopes were expressed as GST-tagged recombinant protein fragments in an E.coli sys-tem,and their immunoreactivity with mouse and human poly-clonal positive serum against SARS-CoV-2 E protein was de-tected by western blotting and indirect ELISA,respectively.The epitope prediction results showed that E protein contained linear B cell epitopes Ser6-Val14 and Tyr57-Pro71,and the conformational epitopes of Glu8-Val12,Leu39-Tyr59,and Ser60-Leu65.The GST tagged recombinant E protein fragments of E1 and E3,containing Ser6-Val14 and Tyr57-Pro71 epitopes,respectively,as well as E2 without an epitope sequence as a control,were expressed in an E.coli expression system and successfully purified with an Ni-NTA column.Western blotting and indirect ELISA analysis indicated that all mouse and human SARS-CoV-2 positive sera positively reacted with only E1 and E3 proteins,but negatively reacted with E2 protein,thus indicating that the corresponding epitope prediction with Ser6-Val14 and Tyr57-Pro71 was correct.This study successfully predicted and preliminarily identified two linear B cell epitopes of SARS-CoV-2 E protein,thus providing a reference for the preparation of new coronavirus vaccines and the analysis of immune response characteristics.

Background: The initiation of sodium-glucose cotransporter-2 inhibitors (SGLT2i) typically leads to a reversible initial dip in estimated glomerular filtration rate (eGFR). The implications of this phenomenon on clinical outcomes are not well-defined. Methods: We searched MEDLINE, Embase, and Cochrane Library from inception to March 23, 2023 to identify randomized controlled trials and cohort studies comparing kidney and cardiovascular outcomes in patients with and without initial eGFR dip after initiating SGLT2i. Pooled estimates were calculated using random-effect meta-analysis. Results: We included seven studies in our analysis, which revealed that an initial eGFR dip following the initiation of SGLT2i was associated with less annual eGFR decline (mean difference, 0.64; 95% confidence interval [CI], 0.437 to 0.843) regardless of baseline eGFR. The risk of major adverse kidney events was similar between the non-dipping and dipping groups but reduced in patients with a ≤10% eGFR dip (hazard ratio [HR], 0.915; 95% CI, 0.865 to 0.967). No significant differences were observed in the composite of hospitalized heart failure and cardiovascular death (HR, 0.824; 95% CI, 0.633 to 1.074), hospitalized heart failure (HR, 1.059; 95% CI, 0.574 to 1.952), or all-cause mortality (HR, 0.83; 95% CI, 0.589 to 1.170). The risk of serious adverse events (AEs), discontinuation of SGLT2i due to AEs, kidney-related AEs, and volume depletion were similar between the two groups. Patients with >10% eGFR dip had increased risk of hyperkalemia compared to the non-dipping group. Conclusion Initial eGFR dip after initiating SGLT2i might be associated with less annual eGFR decline. There were no significant disparities in the risks of adverse cardiovascular outcomes between the dipping and non-dipping groups.

Traditional acute kidney injury (AKI) classifications, which are centered around semi-anatomical lines, can no longer capture the complexity of AKI. By employing strategies to identify predictive and prognostic enrichment targets, experts could gain a deeper comprehension of AKI’s pathophysiology, allowing for the development of treatment-specific targets and enhancing individualized care. Subphenotyping, which is enriched with AKI biomarkers, holds insights into distinct risk profiles and tailored treatment strategies that redefine AKI and contribute to improved clinical management. The utilization of biomarkers such as N-acetyl-β-D-glucosaminidase, tissue inhibitor of metalloprotease-2·insulin-like growth factor-binding protein 7, kidney injury molecule-1, and liver fatty acid-binding protein garnered significant attention as a means to predict subclinical AKI. Novel biomarkers offer promise in predicting persistent AKI, with urinary motif chemokine ligand 14 displaying significant sensitivity and specificity. Furthermore, they serve as predictive markers for weaning patients from acute dialysis and offer valuable insights into distinct AKI subgroups. The proposed management of AKI, which is encapsulated in a structured flowchart, bridges the gap between research and clinical practice. It streamlines the utilization of biomarkers and subphenotyping, promising a future in which AKI is swiftly identified and managed with unprecedented precision. Incorporating kidney biomarkers into strategies for early AKI detection and the initiation of AKI care bundles has proven to be more effective than using care bundles without these novel biomarkers. This comprehensive approach represents a significant stride toward precision medicine, enabling the identification of high-risk subphenotypes in patients with AKI.

Objective:To analyze the research status, development trend and frontier hotspots of midwifery education in China in recent 20 years.Methods:Based on the topic of "midwifery education" or "midwifery teaching", this paper searched the periodical literatures from 2001 to 2021 on CNKI database, and used CiteSpace5.7R5 software to analyze them visually and generate knowledge map.Results:A total of 548 Chinese papers were included in this study, and the annual number of published papers showed an overall upward trend. The research field of midwifery education in China formed an obvious core team, and there was few cooperation among core author groups. Health Vocational Education, Chinese Nursing Education and Chinese Higher Medical Education were the top three journals. The six topics with the highest frequency were midwifery specialty, midwifery personnel, midwifery education, practice teaching, delivery mode and teaching mode, forming 10 clusters of midwifery education. In recent three years, the research of midwifery education in China has gradually changed into simulation teaching, flipped classroom, postpartum rehabilitation and so on. Conclusion:The research scope of midwifery education in China is wide and has formed an obvious core team, but the correlation is weak and there is less communication and cooperation among the research teams. The research in the field of high-level midwifery education is insufficient. Midwifery educators and researchers should pay enough attention to carry out in-depth research on relevant aspects.

Objective: To examine the effect of functional sports training on the development of spatial awareness in children aged 6-8 years old,to provide a reference to improve children s ability of spatial sense. Methods: A class of 125 children aged 6-8 years from first, second, and third grades of an elementary school in Zhengzhou City were conveniently selected by stratified random sampling, who were divided into the experimental group ( n =62) and the control group ( n =63) by random number tables. The experimental group received functional sports intervention for 8 weeks,3 times a week,20 min each time, and the control group received traditional sports game program. Results: After the intervention,the error values of depth perception, orientation perception, and space perception in the experimertal group of 6 and 7 year old children reduced by 1.98 cm, 2.88°, and 22.00 cm (6 year old children) and 1.61 cm, 2.34°, and 17.99 cm (7 year old children) compared with the control group, respectively. Compared with those in the control group of 8 year old after the intervention, and the differences were of statistical signifiance( t =-3.07, -2.94, -3.07 ; -3.25, -3.29, -3.15, P <0.01). There was no significant difference in the error values of depth perception, orientation perception and space perception between the experimental group and the control group after intervention ( P >0.05). In the experimental group, the error values of depth perception, orientation perception and space perception reduced by 2.30 cm, 3.88°, 28.05 cm (6 year old children), 2.16 cm, 2.15°, 17.45 cm (7 year old children) and 1.16 cm, 1.81°, 9.10 cm (8 year old children) in children aged 6-8 years after intervention, significant improvement were observed compared with before intervention ( t = 8.50 , 9.04, 7.35; 7.39, 10.30, 11.05; 4.67, 4.46, 14.14, P <0.01). Compared with before the intervention, children aged 6-8 in the control group only had significant differences in space perception( t =4.13, 6.71, 8.93, P <0.01). Conclusion Functional sports games can improve depth perception, orientation perception and spatial perception for children aged 6-8 years. It can be integrated into children s daily activities to play a positive role in promoting the healthy growth of children.

Two new labdane diterpenoids were isolated from 95% ethanol extract of the leaves of Callicarpa formosana Rolfe by using silica gel column, MCI column, ODS column and HPLC. Their structures were elucidated by HR-ESI-MS, NMR and ECD spectral data. All of them are new compounds, named 13E-6β-hydroxylabda-8(17),13-dien-15-oic acid (1) and 13E-7α-hydroxylabda-8(17),13-dien-15-oic acid (2). Compounds 1 and 2 were tested for antioxidant activity, and none of them had obvious activity.

Objective:To solve the problem of leg shaking caused by the sudden change of angular acceleration at the joint of periodic motion during circular gait training of lower limb rehabilitation robot. Methods:A kind of quasi-circular gait was proposed, which divided the periodic motion into three phases: start phase, middle phase and end phase. The time was equal in the start phase and the end phase, and could be adjusted with the parameter ratio. The joint trajectories of the two phases were planned by quintic polynomial, and the middle phase was still the circular gait joint trajectory. The trajectory of the proposed quasi-circular gait was simulated. Results:The angular velocity was continuously differentiable and 0, the angular acceleration was continuous and 0, and the end-effector trajectory became flat with the increase of ratio. The results on the physical prototype of the lower limb rehabilitation robot were principally consistent with the simulation, and the machine worked smoothly. Conclusion:The proposed variable quasi-circular gait had smooth angular acceleration at the junction of periodic motions, which effectively solved the jitter problem when using circular gait for lower limb rehabilitation training and avoided secondary injury to the patients.