The effectiveness of physical activity interventions on blood pressure in children and adolescents:A systematic review and network meta-analysis

Background:High blood pressure(BP)is a major contributor to mortality and cardiovascular diseases.Despite the known benefits of exercise for reducing BP,it is crucial to identify the most effective physical activity(PA)intervention.This systematic review and network meta-analysis(NMA)aimed to evaluate the available evidence on the effectiveness of various PA interventions for reducing BP and to determine their hierarchy based on their impact on BP.Methods:A search of PubMed,SPORTDiscus,PsycINFO,Web of Science,CINAHL,Cochrane,and Eric databases was conducted up to December 2022 for this systematic review and NMA.Randomized controlled trials and quasi-experimental studies targeting healthy children and adolescents aged 6-12 years old were included in this study.Only studies that compared controlled and intervention groups using PA or exercise as the major influence were included.We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines.Three independent investigators performed the literature screening,data extraction,and risk of bias assessment.We used Bayesian arm-based NMA to synthesize the data.The primary outcomes were systolic BP and diastolic BP.We calculated the mean differences(MDs)in systolic BP and diastolic BP before and after treatment.Mean treatment differences were estimated using NMA and random-effect models.Results:We synthesized 27 studies involving 15,220 children and adolescents.PA combined with nutrition and behavior change was the most effective intervention for reducing both systolic BP and diastolic BP(MD=-8.64,95%credible interval(95%CI):-11.44 to-5.84;MD=-6.75,95%CI:-10.44 to-3.11),followed by interventions with multiple components(MD=-1.39,95%CI:-1.94 to-0.84;MD=-2.54,95%CI:-4.89 to-0.29).Conclusion:Our findings suggest that PA interventions incorporating nutrition and behavior change,followed by interventions with multiple components,are most effective for reducing both systolic BP and diastolic BP in children and adolescents.

Simulation of Two-Phase Flowback Phenomena in Shale Gas Wells

The gas-water two-phaseflow occurring as a result of fracturingfluidflowback phenomena is known to impact significantly the productivity of shale gas well.In this work,this two-phaseflow has been simulated in the framework of a hybrid approach partially relying on the embedded discrete fracture model(EDFM).This model assumes the region outside the stimulated reservoir volume(SRV)as a single-medium while the SRV region itself is described using a double-medium strategy which can account for thefluid exchange between the matrix and the micro-fractures.The shale gas adsorption,desorption,diffusion,gas slippage effect,fracture stress sensitivity,and capillary imbibition have been considered.The shale gas production,pore pressure distribution and water saturation distribution in the reservoir have been simulated.The influences of hydraulic fracture geometry and nonorthogonal hydraulic fractures on gas production have been determined and discussed accordingly.The simulation results show that the daily gas production has an upward and downward trend due to the presence of a large amount of fracturingfluid in the reservoir around the hydraulic fracture.The smaller the angle between the hydraulic fracture and the wellbore,the faster the daily production of shale gas wells decreases,and the lower the cumulative production.Nonplanar fractures can increase the control volume of hydraulic fractures and improve the production of shale gas wells.

Numerical and theoretical investigations of heat transfer characteristics in helium-xenon cooled microreactor core

Helium-xenon cooled microreactors are a vital technological solution for portable nuclear reactor power sources.To exam-ine the convective heat transfer behavior of helium-xenon gas mixtures in a core environment,numerical simulations are conducted on a cylindrical coolant channel and its surrounding solid regions.Validated numerical methods are used to determine the effect and mechanisms of power and its distribution,inlet temperature and velocity,and outlet pressure on the distribution and change trend of the axial Nusselt number.Furthermore,a theoretical framework that can describe the effect of power variation on the evolution of the thermal boundary layer is employed to formulate an axial distribution cor-relation for the Nusselt number of the coolant channel,under the assumption of a cosine distribution for the axial power.Based on the simulation results,the correlation coefficients are determined,and a semi-empirical relationship is identified under the corresponding operating conditions.The correlation derived in this study is consistent with the simulations,with an average relative error of 5.3%under the operating conditions.Finally,to improve the accuracy of the predictions near the entrance,a segmented correlation is developed by combining the Kays correlation with the aforementioned correlation.The new correlation reduces the average relative error to 2.9%and maintains satisfactory accuracy throughout the entire axial range of the channel,thereby demonstrating its applicability to turbulent heat transfer calculations for helium-xenon gas mixtures within the core environment.These findings provide valuable insights into the convective heat transfer behavior of a helium-xenon gas mixture in a core environment.

On the transient models of the VITAS code:applications to the C5G7-TD pin-resolved benchmark problem

This article describes the transient models of the neutronics code VITAS that are used for solving time-dependent,pinresolved neutron transport equations.VITAS uses the stiffness confinement method(SCM)for temporal discretization to transform the transient equation into the corresponding transient eigenvalue problem(TEVP).To solve the pin-resolved TEVP,VITAS uses a heterogeneous variational nodal method(VNM).The spatial flux is approximated at each Cartesian node using finite elements in the x-y plane and orthogonal polynomials along the z-axis.Angular discretization utilizes the even-parity integral approach at the nodes and spherical harmonic expansions at the interfaces.To further lower the computational cost,a predictor–corrector quasi-static SCM(PCQ-SCM)was developed.Within the VNM framework,computational models for the adjoint neutron flux and kinetic parameters are presented.The direct-SCM and PCQ-SCM were implemented in VITAS and verified using the two-dimensional(2D)and three-dimensional(3D)exercises on the OECD/NEA C5G7-TD benchmark.In the 2D and 3D problems,the discrepancy between the direct-SCM solver’s results and those reported by MPACT and PANDAS-MOC was under 0.97%and 1.57%,respectively.In addition,numerical studies comparing the PCQ-SCM solver to the direct-SCM solver demonstrated that the PCQ-SCM enabled substantially larger time steps,thereby reducing the computational cost 100-fold,without compromising numerical accuracy.

Pregnancy Outcomes for Day 5 Versus Day 6 Single Frozen-thawed Blastocyst Transfer with Different Qualities of Embryos: A Large Matched-cohort Study

Objective This study aimed to determine whether the day of blastocyst expansion affects pregnancy outcomes in frozen-thawed blastocyst transfer(FBT)cycles.Methods A retrospective match-cohort study was conducted.Patients who underwent blastocyst transfer in frozen-thawed cycles at day 5 or 6 were matched for potential confounding factors.A total of 2207 matched pairs of FBT cycles were included from January 2016 to December 2019 in our Reproductive Medicine Center.Results The clinical pregnancy rate(CPR)and live birth rate(LBR)were significantly increased in day 5 blastocyst transfers when compared to day 6 blastocyst transfers,in terms of the same embryo quality.For FBT cycles with good-quality embryo,the CPR at day 5 and 6 was 61.30%and 57.56%,respectively(P=0.045),and the LBR was 44.79%and 36.16%,respectively(P<0.001).For FBT cycles with poor-quality embryo,the CPR at day 5 and 6 was 48.61%and 40.89%,respectively(P=0.006),and the LBR was 31.71%and 25.74%,respectively(P=0.019).The CPR for FBT cycles with good-quality embryo was statistically higher at day 6 than that at day 5 with poor-quality embryo transferred(57.56%vs.48.61%,P=0.001).Maternal age,anti-Müllerian hormone(AMH),endometrial thickness,embryo quality,and the day of blastocyst expansion were independently correlated with the CPR and LBR.The FBT cycles at day 5 had significantly higher CPR(adjusted odds ratio[OR]=1.246,95%confidence intervals[CI]:1.097–1.415,P=0.001)and LBR(adjusted OR=1.435,95%CI:1.258–1.637,P<0.001)than those at day 6.Conclusion The embryo quality is the primary indicator for FBT cycles.Day 5 blastocysts should be preferred when the quality of embryo at day 5 is the same as that at day 6.

Associations between obesity and metabolic health with nonalcoholic fatty liver disease in elderly Chinese

Background:Nonalcoholic fatty liver disease(NAFLD)is closely associated with obesity.However,this association could be influenced by the coexisting metabolic abnormalities.This study aimed to investigate the role of obesity and metabolic abnormalities in NAFLD among elderly Chinese.Methods:A cross-sectional study was performed among elderly residents who took their annual health checkups during 2016 in Keqiao District,Shaoxing,China.Results:A total of 3359 elderly adults were retrospectively included in this study.The overall prevalence of NAFLD was 28.7%.The prevalence of NAFLD were 7.14%,27.92%,34.80%,and 61.02%in participants with metabolically healthy normal weight(MHNW),metabolically abnormal normal weight(MANW),metabolically healthy obese(MHO),and metabolically abnormal obese(MAO),respectively.NAFLD patients in MHO group had more unfavorable metabolic profiles than those in MHNW group.Logistic regression analysis showed that sex,body mass index(BMI),fasting blood glucose,and serum uric acid were the risk factors of NAFLD.Conclusions:Both obesity and metabolic health were significantly associated with NAFLD in elderly Chinese.Screening for obesity and other metabolic abnormalities should be routinely performed for early risk stratification of NAFLD.

The association of altered RARβ gene expression with the cervical lesion pathogenesis

Objective:Previous reports have shown that the gene promoter region of retinoic acid receptor β(RARβ) was hypermethylated in cervical carcinoma,implying the inhibition of gene transcription.The aim of this study was to investigate the association of cervical cancer development with the RARβ gene expression at the mRNA and protein level to assess the impact of RARβ as a marker for early detection of the cancer.Methods:We collected 126 cases of formalin fixed and paraffin embedded cervical tissue specimens as well as 37 cases of fresh tissue samples from women with cervicitis,cervical intraepithelial neoplasia(CIN) and cervical squamous cell carcinoma(CSCC).The RARβ mRNA and protein expression was detected by quantitative RT-PCR and immunohistochemistry,respectively.Results:(1) The mRNA expression of RARβ in CIN and cervical cancer was markedly decreased compared to cervicitis with a statistically very significant difference,but no difference was found between CIN and cervical cancer.(2) RARβ protein was normally expressed in the epithelial cells of cervicitis and partially lost in a few cases,but with the development of cervical lesion pathogenesis and cancer,a significant loss of protein expression was detected in CIN(38%) and CSCC(57%) compared to cervicitis(P < 0.01).Conclusion:The downregulation of RARβ transcription or loss of protein expression is an important indicator of cervical cancer and its precursur lesions.The detection of RARβ expression coupled with aberrant methylation of the gene may become a biomarker for the early prognosis or diagnosis of the cancer.

基于飞机观测不同天气条件下北京地区黑碳气溶胶的垂直分布及其混合态特性

利用机载单颗粒黑碳光度计(SP2)针对北京地区不同天气条件下黑碳(BC,black carbon)气溶胶的垂直分布特征进行了10次的飞机探测研究。结果显示,在霾和非霾条件下BC气溶胶的浓度都是随着高度升高而减小,而且浓度变化在1500 m高度存在明显的分界线。在1500 m以下,BC气溶胶浓度变化梯度均较大,霾条件下的BC气溶胶浓度约为非霾条件下的4.3倍,在1500 m以上,BC气溶胶浓度变化梯度均较小,霾条件下的BC气溶胶浓度约为非霾条件下的2.5倍。BC气溶胶粒子谱都呈单峰分布,霾条件下峰值粒径主要要集中在0.16µm在非霾条件下峰值粒径主要集中在0.18µm在近地面,霾条件下的平均内混比远远高于非霾条件下,越往高空两种条件下的BC气溶胶的平均内混比越接近。通过CAMx模拟了不同条件下的BC气溶胶,发现霾污染天气下模拟的结果差异较大,在非霾条件下的模拟结果要优于霾条件下的模拟结果,这主要是由于在大部分模式中,很少考虑黑碳的老化状态。

4D打印技术的研究进展

3D打印技术具有能够方便廉价地实现从3D虚拟模型到实体化的优点,在产品设计、快速成型、先进材料等领域得到了广泛的应用。近年来,"4D打印"概念的提出引起了社会和学术界广泛的关注。4D打印技术是在3D打印的基础上引入时间维度,在一定外界刺激的作用下,4D打印刺激响应材料的形状、结构和功能能够随着时间的推移而不断变化。文中对4D打印进行了概述,着重介绍了4D打印材料及其形状记忆效应,总结了4D打印技术在各个领域的应用前景,并结合4D打印研究现状探讨了4D打印技术的发展趋势。

Long non-coding RNA GAS5 promotes PC12 cells differentiation into Tuj1-positive neuron-like cells and induces cell cycle arrest

Growth arrest-specific 5 (GAS5) is an anti-oncogene that has been extensively studied in tumors. However, research on GAS5 in the context of nervous system disease is rare at present. This study aimed to investigate the role of the long non-coding RNA GAS5 in rat pheochromocytoma cells (PC12 cells). GAS5-overexpressing lentivirus was transfected into PC12 cells, and expression levels of GAS5 and C-myc were detected by real-time PCR. Ratios of cells in S phase were detected by 5-ethynyl-2′-deoxyuridine. Immunohistochemical staining was used to detect the immunoreactivity of neuron microtubule markers Tuj1, doublecortin, and microtubule-associated protein 2. Apoptosis was detected by flow cytometry, while expression of acetylcholine in cells was detected by western blot assay. We found that GAS5 can promote PC12 cells to differentiate into Tuj1-positive neuron-like cells with longer processes. In addition, cell proliferation and cell cycle were significantly suppressed by GAS5, whereas it had no effect on apoptosis of PC12 cells. Our results indicate that GAS5 could increase the expression of choline acetyltransferase and acetylcholine release. Thus, we speculate that GAS5 is beneficial to the recovery of neurons and the cholinergic nervous system.

miR-103-3p targets Ndel1 to regulate neural stem cell proliferation and differentiation

The regulation of adult neural stem cells(NSCs) is critical for lifelong neurogenesis. MicroRNAs(miRNAs) are a type of small, endogenous RNAs that regulate gene expression post-transcriptionally and influence signaling networks responsible for several cellular processes. In this study, mi R-103-3 p was transfected into neural stem cells derived from embryonic hippocampal neural stem cells. The results showed that mi R-103-3 p suppressed neural stem cell proliferation and differentiation, and promoted apoptosis. In addition, mi R-103-3 p negatively regulated Nud E neurodevelopment protein 1-like 1(Ndel1) expression by binding to the 3′ untranslated region of Ndel1. Transduction of neural stem cells with a lentiviral vector overexpressing Ndel1 significantly increased cell proliferation and differentiation, decreased neural stem cell apoptosis, and decreased protein expression levels of Wnt3 a, β-catenin, phosphor-GSK-3β, LEF1, c-myc, c-Jun, and cyclin D1, all members of the Wnt/β-catenin signaling pathway. These findings suggest that Ndel1 is a novel mi R-103-3 p target and that mi R-103-3 p acts by suppressing neural stem cell proliferation and promoting apoptosis and differentiation. This study was approved by the Animal Ethics Committee of Nantong University, China(approval No. 20200826-003) on August 26, 2020.

1085例手术切除浸润性肺腺癌淋巴结转移的相关因素分析及诺模图模型的建立

目的:探究浸润性肺腺癌淋巴结转移与肺腺癌病理亚型等相关因素之间的关系。方法:收集1085例浸润性肺腺癌患者的相关临床病理资料,对其淋巴结转移情况与年龄、性别、病理亚型、肿瘤部位、肿瘤最大径、胸膜侵犯6项因素之间的关系进行分析。将单因素分析中有意义的变量纳入多因素Logistic回归模型中,以此为基础构建诺模图,并用一致性指数(C-index)、校正模型、受试者工作特征(ROC)曲线等对该模型进行评价。结果:多因素非条件Logistic回归分析结果显示,年龄≤67岁(OR=1.599,P=0.036)、病理亚型(OR=1.337,P<0.001)、肿瘤部位(OR=1.162,P=0.027)、肿瘤最大径(OR=1.765,P<0.001)、胸膜侵犯(OR=2.179,P<0.001)为肺癌淋巴结转移的独立风险因素。应用上述因素构建诺模图,对该诺模图模型进行验证,C-index为0.860(95%CI:0.834~0.885),校正曲线有较好的一致性,ROC曲线下面积(AUC)为0.829(95%CI:0.799~0.858)。结论:年龄≤67岁、病理亚型、肿瘤部位、肿瘤最大径及胸膜侵犯为肺腺癌淋巴结转移的风险因素,对淋巴结转移具有重要预测意义。本研究构建的诺模图预测模型预测能力较好。

Alpha radiolysis of nitric acid aqueous solution irradiated by 238Pu source

Alpha radiolysis of nitric acid aqueous solution by a ^(238)Pu source is investigated experimentally and theoretically.The time dependence of the nitrous acid yield on dose rate,nitric acid concentration,and nitrate ion concentration is studied.A novel kinetic model for the α-radiolysis of nitric acid aqueous solution is established,by considering the direct and indirect effects.The simulation results agree well with the experimental data,indicating the validity of our model to treat the reaction paths for generation and consumption of nitrous acid.It is shown that the redox reactions involving Pu cannot be neglected in theα-radiolysis of the solution.The results provide a better understanding of the α-ray radiolysis of aqueous nitric acid.

SP3-coupled global variance reduction method based on RMC code

A global variance reduction(GVR)method based on the SPN method is proposed.First,the global multi-group cross-sections are obtained by Monte Carlo(MC)global homogenization.Then,the SP3 equation is solved to obtain the global flux distribution.Finally,the global weight windows are approximated by the global flux distribution,and the GVR simulation is performed.This GVR method is implemented as an automatic process in the RMC code.The SP3-coupled GVR method was tested on a modified version of C5 G7 benchmark with a thickened water shield.The results show that the SP3-coupled GVR method can improve the efficiency of MC criticality calculation.

Mesoscale Numerical Simulation Study of Warm Fog Dissipation by Salt Particles Seeding

Based on the dynamic framework of WRF and Morrison 2-moment explicit cloud scheme, a salt-seeding scheme was developed and used to simulate the dissipation of a warm fog event during 6–7 November 2009 in the Beijing and Tianjin area. The seeding effect and its physical mechanism were studied. The results indicate that when seeding fog with salt particles sized 80 μm and at a quantity of 6 gm^（-2） at the fog top, the seeding effect near the ground surface layer is negative in the beginning period, and then a positive seeding effect begins to appear at 18 min, with the best effect appearing at 21 min after seeding operation. The positive effect can last about 35 min. The microphysical mechanism of the warm fog dissipation is because of the evaporation due to the water vapor condensation on the salt particles and coalescence with salt particles.The process of fog water coalescence with salt particles contributed mostly to this warm fog dissipation. Furthermore, two series of sensitivity experiments were performed to study the seeding effect under different seeding amounts and salt particles sizes. The results show that seeding fog with salt particles sized of 80 μm can have the best seeding effect, and the seeding effect is negative when the salt particle size is less than 10 μm. For salt particles sized 80 μm, the best seeding effect, with corresponding visibility of 380 m, can be achieved when the seeding amount is 30 g m^（-2）.

γ-Ray radiolysis of acetohydroxamic acid in HNO_3 and its radiolytic product

Acetohydroxamic acid(AHA) is a novel saltfree reagent used for the separation of Pu and Np from U in the advanced Purex process. This paper reports the c-ray damage of AHA in HNO_3 and its radiolytic product. For 0.2 mol L^(-1) AHA in 0.2–2.0 mol L^(-1) HNO_3 irradiated at a dose of 5–25 kGy, the radiolytic rate of AHA is6.63–77.5%, and it increases with the HNO_3 concentration and absorbed dose. The main radiolytic gases are N_2O and H_2, with volume fractions of(0.500–16.2) 9 10^(-2) and(1.30–11.8) 9 10^(-3), respectively, and they increase with the absorbed dose; the H_2 volume fraction decreases with increasing HNO_3 concentration. The main liquid radiolytic products are CH_3 COOH and HNO_2, and their concentrations are(3.40–19.7) 9 10^(-2) and(0.200–4.80) 9 10^(-3)-mol L^(-1), respectively, which increase with the HNO_3 concentration. Since a significant concentration of HNO_2 is present in the irradiated AHA-HNO_3 solution, a holding reductant must be used to destroy HNO_2 and stabilize Pu(Ⅲ) and Np(Ⅴ) when AHA is applied for the separation of Pu and Np from U.

Fault Attribute Reduction of Oil Immersed Transformer Based on Improved Imperialist Competitive Algorithm

The original fault data of oil immersed transformer often contains a large number of unnecessary attributes,which greatly increases the elapsed time of the algorithm and reduces the classification accuracy,leading to the rise of the diagnosis error rate.Therefore,in order to obtain high quality oil immersed transformer fault attribute data sets,an improved imperialist competitive algorithm was proposed to optimize the rough set to discretize the original fault data set and the attribute reduction.The feasibility of the proposed algorithm was verified by experiments and compared with other intelligent algorithms.Results show that the algorithm was stable at the 27th iteration with a reduction rate of 56.25%and a reduction accuracy of 98%.By using BP neural network to classify the reduction results,the accuracy was 86.25%,and the overall effect was better than those of the original data and other algorithms.Hence,the proposed method is effective for fault attribute reduction of oil immersed transformer.

规模化养猪场非洲猪瘟防疫策略

中国人的肉食结构中猪肉占比超过八成,形成为中华民族一种特有的文化现象。2018年以来非洲猪瘟疫情导致了生猪养殖量急剧减少,为了保障猪肉产品的供给,规模化养猪场的生猪复养势在必行。文章提出了规模化生猪养殖场的全面防疫策略,包括猪场全面消毒、增强生物安全意识、争取政策补贴、坚持自繁自养和分区分级管理、规范化工作流程等防疫策略,以供同行借鉴参考。

Bioinspired zinc-mediated umpolung thiolation of alkyl electrophiles: reaction development, scope and mechanism

Zinc-promoted umpolung thiolation of alkyl electrophiles with masked sulfur transfer reagents in the absence of nickel or copper catalysis is described. This protocol proceeds via a SET process of Zn to electrophilic sulfur reagent followed by insertion of Zn into disulfide and nucleophilic thiolation, providing straightforward access to a wide range of alkyl sulfides with broad substrate scope. A neutral TMEDA-ligated four-coordinated zinc thiolate with tetrahedra geometry was synthesized, isolated and fully characterized by NMR, IR and X-ray analysis. More importantly, the chemical reactivity of this active intermediate has been investigated, enabling the construction of C-Se, C-Te, Sb-S and Bi-S bonds to prepare valuable sulfur-containing molecules and beyond.

FMSA:a meta-learning framework-based fast model stealing attack technique against intelligent network intrusion detection systems

Intrusion detection systems are increasingly using machine learning.While machine learning has shown excellent performance in identifying malicious traffic,it may increase the risk of privacy leakage.This paper focuses on imple-menting a model stealing attack on intrusion detection systems.Existing model stealing attacks are hard to imple-ment in practical network environments,as they either need private data of the victim dataset or frequent access to the victim model.In this paper,we propose a novel solution called Fast Model Stealing Attack(FMSA)to address the problem in the field of model stealing attacks.We also highlight the risks of using ML-NIDS in network security.First,meta-learning frameworks are introduced into the model stealing algorithm to clone the victim model in a black-box state.Then,the number of accesses to the target model is used as an optimization term,resulting in minimal queries to achieve model stealing.Finally,adversarial training is used to simulate the data distribution of the target model and achieve the recovery of privacy data.Through experiments on multiple public datasets,compared to existing state-of-the-art algorithms,FMSA reduces the number of accesses to the target model and improves the accuracy of the clone model on the test dataset to 88.9%and the similarity with the target model to 90.1%.We can demonstrate the successful execution of model stealing attacks on the ML-NIDS system even with protective measures in place to limit the number of anomalous queries.