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Tripping frequently occurs when an individual climbs the stairs with improper foot clearance. Among older adults, falling down the stairs accounts for over 10% of accidental deaths. This paper proposes an exoskeleton control method that blends human-dominant and exoskeleton-dominant control to prevent tripping. The blending controller not only allows the exoskeleton to track the pilot's movements and provide power assistance during regular walking, but also allows the exoskeleton to help the pilot avoid dangers in some cases. An online path planning method is used to generate a safe trajectory in the exoskeleton-dominant mode to help the pilot correct their running trajectory. The controller provides the pilot with adjustment spaces to adapt to sudden changes in the motion mode and enable active self-regulation. The simulations verified the effectiveness of the proposed blending method. Experiments showed that the robot should be involved in the pilot's movements when the foot clearance exceed the safety threshold to prevent tripping.

Quaoar is a classical Trans-Neptunian Object (TNO) with an area equivalent diameter of 1,100 km and an orbital semi-major axis of 43.3 astronomical units. Based on stellar occultations observed between 2018 and 2021, an inhomogeneous ring (Q1R, Quaoar's first ring) was detected around this body. Aims. A new stellar occultation by Quaoar was observed on August 9th, 2022 aiming to improve Quaoar's shape models and the physical parameters of Q1R while searching for additional material around the body. Methods. The occultation provided nine effective chords across Quaoar, pinning down its size, shape, and astrometric position. Large facilities, such as Gemini North and the Canada-France-Hawaii Telescope (CFHT), were used to obtain high acquisition rates and signal-to-noise ratios. The light curves were also used to characterize the Q1R ring (radial profiles and orbital elements). Results. Quaoar's elliptical fit to the occultation chords yields the limb with an apparent semi-major axis of $579.5\pm4.0$ km, apparent oblateness of $0.12\pm0.01$, and area-equivalent radius of $543\pm2$ km. Quaoar's limb orientation is consistent with Q1R and Weywot orbiting in Quaoar's equatorial plane. The orbital radius of Q1R is refined to a value of $4,057\pm6$ km. The radial opacity profile of the more opaque ring profile follows a Lorentzian shape that extends over 60 km, with a full width at half maximum (FWHM) of $\sim5$ km and a peak normal optical depth of 0.4. Besides the secondary events related to the already reported rings, new secondary events detected during the August 2022 occultation in three different data sets are consistent with another ring around Quaoar with a radius of $2,520\pm20$ km, assuming the ring is circular and co-planar with Q1R. This new ring has a typical width of 10 km and a normal optical depth of $\sim$0.004. Like Q1R, it also lies outside Quaoar's classical Roche limit., Accepted for publication in Astronomy & Astrophysics (17-April-2023). 18 pages, 12 figures

In this work, we present the general procedure for the robotic observations of the Transneptunian Automated Occultation Survey (TAOS II). The project aims to detect small TNOs (Transneptunian Objects) by serendipitous stellar occultations. To do so TAOS II will operate three 1.3 m telescopes equipped with CMOS cameras which are able to read about 10,000 stars in multiple subapertures at a 20 Hz cadence. At such rates, it will be possible to identify diffraction features in the lightcurves, helping us to estimate a distance and object size to each occultation event. TAOS II is installed in the Observatorio Astronómico Nacional in San Pedro Mártir, Ensenada, México (OAN-SPM). The site has good observing conditions, typically with around 260 useful nights per year. Here, we describe the different process to be performed in a typical observing night: system start up and shut down, monitoring observing conditions, acquisition of calibration images, field selection, pointing, camera synchronization, determination of aperture sizes and positions, and high speed image acquisition.

This paper studies the characteristics of the insulation shear belt produced by the fracture of the vents of the gunhead desceptor and the reasons for its formation when the shell is fired. The results show that: During the explosion, the rupture of the degenerator belongs to the ligament fracture, and the insulation shear belt produced at the time of the break plays the role of “prefabricated crack”. The smaller the microstructure and grain of alloy steel, the easier it is to promote the production of insulation shear belt.

To investigate the application of totally visceral sac separation (TVS) in the treatment of ventral hernia, to summarize the operation procedure and to analyze its safety and effectiveness. Twenty-one consecutive primary and secondary ventral hernias cases were repaired using the TVS procedure from December 2019 to December 2020. A large mesh should be placed in retrorectus sublay or underlay preperitoneal using the minimally invasive procedure. The indications for this procedure include umbilical, incisional hernia, linea alba hernia, lumbar hernia, and parastomal hernia. All the operations were successful, of which 2 cases were converted to laparotomy because of the failure of anterior peritoneal cavity construction and the difficulty of anterior defect closure. The mean operation time was 140 mins (70-260 min), postoperative pain was mild, and the mean visual analogue scale(VAS) was 2.5 (1-4) on the first postoperative day. There were no recurrent cases during the follow-up for more than 6 months. TVS procedure is safe and highly reproducible. Without expensive anti-adhesion mesh and fixation tacker, the technology of TVS is a good technique for the surgical treatment of ventral hernia.探讨完全内镜下内脏囊分离技术（TVS）在腹壁疝治疗中的应用，总结手术操作流程，分析其安全性和有效性。选取2019年12月至2020年12月在浙江大学附属金华医院接受TVS技术修补21例（男4例，女17例，年龄31~79岁）腹壁疝患者，术中置入大张中量聚丙烯网片加强修复。手术适应证：原发性及继发性腹壁缺损，包括脐疝、中上腹部白线疝、腰疝、切口疝和造口旁疝。TVS的技术细节按照手术规范执行。结果21例手术均获得成功，其中有2例因腹膜前建腔失败和前缺损关闭困难而中转开腹。平均手术时间140（70~260）min。术后伤口疼痛轻，术后第1天平均疼痛视觉模拟评分（VAS）2.5分（1~4分）。术后随访时间6个月以上，未见复发病例。总之，TVS技术在腹壁疝中的应用是安全可行的，创伤少，可重复性高，是治疗腹壁疝的一种很好的技术补充。.

We present a new pipeline based on the Support Vector Machine algorithm to confirm the detection and perform classification of small solar system objects by serendipitous stellar occultations. This pipeline is designed to analyze light curves and to identify the occultation events and the classification of the occulting bodies according to their size, typically from a fraction to a few kilometers, and their distance from the Sun, typically a few tens of astronomical units. The input light curves for this pipeline were obtained from the event simulator for the Trans-Neptunian Automated Occultation Survey (TAOS II). We explore parameters affecting occultation light curves such as spectral type, apparent magnitude and finite angular size of the occulted star, angle from opposition, and readout cadence for the observations; also we assumed a Poisson noise distribution as expected from the TAOS II project. We find that occultation events, especially by trans-Neptunian objects with diameters ≥2 km are detected with 99.99%, 99.53%, and 86% efficiency for stars with a visual apparent magnitude of 12, 14, and 16, respectively at 0.05 s of exposure time. In terms of size and distance classification the overall accuracy is 94%. However, for smaller objects the confirmation and classification depends mostly upon the signal-to-noise ratio.

The Transneptunian Automated Occultation Survey (TAOS II) is a blind occultation survey with the aim of measuring the size distribution of Trans-Neptunian Objects with diameters in the range of 0.3 ≲ D ≲ 30 km. TAOS II will observe as many as 10,000 stars at a cadence of 20 Hz with all three telescopes simultaneously. This will produce up to ∼20 billion photometric measurements per night, and as many as ∼6 trillion measurements per year, corresponding to over 70 million individual light curves. A very fast analysis pipeline for event detection and characterization is needed to handle this massive data set. The pipeline should be capable of real-time detection of events (within 24 hours of observations) for follow-up observations of any occultations by larger TNOs. In addition, the pipeline should be fast and scalable for large simulations where simulated events are added to the observed light curves to measure detection efficiency and biases in event characterization. Finally, the pipeline should provide estimates of the size of and distance to any occulting objects, including those with non-spherical shapes. This paper describes a new data analysis pipeline for the detection and characterization of occultation events.

Restricted cubic spline Cox proportional hazard regression model analysis is an important method of epidemiological multivariate survival analysis. By comparing the typical Cox regression model and the restricted cubic spline Cox regression model, this study expounds the limitations of the typical Cox regression model, and explains the basic principles and implementation process of the restricted cubic spline Cox proportional hazard regression model. When the follow-up data does not meet the application conditions of the typical Cox regression model, this method can be used to realize the correlation analysis between continuous exposure and outcomes.限制性立方样条Cox比例风险回归模型分析是流行病学多因素生存分析的重要方法。本研究通过对典型Cox比例风险回归模型和限制性立方样条Cox比例风险回归模型比较，阐述了典型Cox比例风险回归模型的局限性，以及限制性立方样条Cox比例风险回归模型基本原理与实现过程。在随访数据不满足典型Cox比例风险回归模型应用条件时，可采用该方法实现连续性暴露与结局之间的关联分析。.

To summarize the current practice and potential strategy in diagnosing coronavirus disease 2019 (COVID-19).PubMed, Web of Science were systematically searched using terms including "COVID-19", "SARS-CoV-2" and "2019-nCoV". After removing duplicates, we then identified articles, letters and commentaries regarding diagnosing COVID-19.Here we summarized relatively mature diagnostic methods like nuclear acid test and computed tomography. Besides, new aspects regarding these detection methods like suitable specimens for nuclear acid test, possible use of 18F-FDG PET/CT were also reported. Especially, we also presented several novel techniques for diagnosing COVID-19 like lung ultrasound.Chinese Clinical Guidance for COVID-19 Pneumonia Diagnosis and Treatment (7th edition) by National Health Commission is recommended to follow as it provides detailed diagnostic procedures using currently available tools. We suggest clinicians further explore the saliva's utility as a specimen for nuclear acid test and the use of lung ultrasound.

The purpose of this study was to investigate the effect of Casitas b-lineage lymphoma b (Cblb) on the regulation of T follicular helper (Tfh) in the development of lupus nephritis.The Tfh (CD4+CXCR5+PD-1+) cells in peripheral blood were analyzed by flow cytometry. Forty mice were divided into 4 groups (10/group), WT, lpr, Cblb-/- and lpr.Cblb-/-. Urine protein, serum creatinine, blood urea nitrogen (BUN), dsDNA, and antinuclear antibody (ANA) titer of mice were monitored once every four weeks. Peripheral blood mononuclear cells (PBMCs) from mice were collected to assess circulating Tfh. The expressions of Cblb in Tfh cells were regulated by transfecting siRNA and overexpression plasmid approach in vitro.The patients with lupus nephritis (LN) had abnormal renal clinical manifestations compared with healthy volunteers. The peripheral Tfh cells were increased and the expression of Cblb were downregulated in patients with LN (p0.05). Both lpr mice and lpr.Cblb-/- mice had LN symptoms. LN symptoms were more serious in lpr.Cblb-/- mice compared with that in lpr mice (p0.05). The number of Tfh cells in peripheral blood from lpr.Cblb-/- mice was significantly higher than that from lpr mice (p0.05). Overexpression of Cblb in Tfh cells led to reduction of IgG expression, while the knockdown of Cblb in Tfh cells was accompanied by increased expression of immunoglobulin (IgG) (p0.05).Cblb showed a negative regulatory effect on Tfh. The deletion of Cblb may be a key factor in progression of renal injury.

Osteogenic differentiation of bone marrow stromal stem cells (BMSCs) is beneficial to the treatment of osteoarthritis (OA). Lnc-RNA BLACAT1 involves in occurrence and development of various diseases. However, the role of Lnc-RNA BLACAT1 in BMSCs differentiation under inflammation remains unclear.Rat BMSCs were isolated and randomly divided into control group and inflammation group (addition of IL-6). The inflammation group was further divided into BLACAT1 siRNA group and BLACAT1 siRNA+miR-142-5p inhibitor group, followed by analysis of Lnc-RNA BLACAT1 expression by real time PCR, BMSCs proliferation, Caspase 3 activity, ALP activity, expression of Runx2, OC and PPARγ2 by real time PCR, and secretion of TNF-α and IL-1β by enzyme-linked immunosorbent assay (ELISA). The bioinformatics software and the Luciferase reporter system analyze the targeted relationship between BLACAT1 and miR-142-5p.In inflammation group, Lnc-BLACAT1 expression was increased, along with inhibited BMSCs proliferation, increased Caspase 3 activity, decreased ALP activity, and expression of Runx2 and OC, increased PPARγ2 expression and secretion of TNF-α and IL-1β. The difference was statistically significant compared with control group (p0.05). MiR-142-5p is the target miRNA of Lnc-RNA BLACAT1. BLACAT1 siRNA down-regulated BLACAT1 expression, promoted cell proliferation, inhibited Caspase 3 activity, increased ALP activity and Runx2 and OC expression, decreased PPARγ2 expression and TNF-α and IL-1β secretion. Compared with inflammation group, the difference was statistically significant (p0.05). Of note, BLACAT1 siRNA+miR-142-5p inhibitor group reversed the effect of siRNA-mediated knockdown of BLACAT1.Lnc-RNA BLACAT1 expression was increased in inflammatory BMSCs, and knockdown of BLACAT1 promoted proliferation and osteogenic differentiation of BMSCs targeting miR-142-5p.

The two preparation methods of amorphous composite TEM samples, electrolytic double spray thinning and ion thinning, are studied. In addition, an improved ion thinning method is used to successfully prepare a metastable brittle amorphous composite TEM sample. The TEM sample prepared by the ion thinning method has a large thin area near the interfaces in composites, which lays a solid foundation for further research on the interface principle of composite materials, and also provides reliable data support for optimizing the preparation process of the composite materials.

TAOS II is a next-generation occultation survey with the goal of measuring the size distribution of the small end of the Kuiper Belt (objects with diameters 0.5–30 km). Such objects have magnitudes r > 30, and are thus undetectable by direct imaging. The project will operate three telescopes at San Pedro Mártir Observatory in Baja California, México. Each telescope will be equipped with a custom-built camera comprised of a focal-plane array of CMOS imagers. The cameras will be capable of reading out image data from 10,000 stars at a cadence of 20 Hz. The telescopes will monitor the same set of stars simultaneously to search for coincident occultation detections, thus minimising the false-positive rate. This talk described the project, and reported on the progress of the development of the survey infrastructure.

Metal prostheses of artificial joints undergo wear, producing numerous metal particles and ions, such as Cr3+. Cr3+ is considered a key factor leading to aseptic loosening. Many studies focus on the effect of Cr3+ on osteoblasts; however, little is known about the effect of Cr3+ on the B cell maturation antigen in the osteoblasts. In this study, we first demonstrated the B cell maturation antigen expressed in human SaOS-2 osteoblasts through reverse transcriptase-polymerase chain reaction, western blot and immunocytochemical analyses. Cr3+ decreased alkaline phosphatase, osteocalcin, cell mineralization, and collagen type I mRNA and protein expression. Moreover, Cr3+ has an inhibitive effect on the expression of the B cell maturation antigen in human SaOS-2 osteoblasts. However, after we up-regulated the expression of the B cell maturation antigen, alkaline phosphatase, osteocalcin, cell mineralization, and collagen type I mRNA and protein expression were increased. Overall, this study demonstrates that the B cell maturation antigen is involved in human SaOS-2 osteoblast osteogenetic metabolism and plays a regulatory role on the toxic effect of chromium ions on human SaOS-2 osteoblasts. This article is protected by copyright. All rights reserved

As a member of photosynthetic bacteria

The glucose transporter 4 (GLUT4) translocation is a vital link of insulin-induced glucose uptake in adipose tissue and skeletal muscle. It is an important topic in anti-diabetic research to explore novel agents to facilitate the role of insulin. The aim of this study was to verify the hypothesis that neuropeptide galanin may enhance insulin-induced GLUT4 translocation to increase glucose uptake in adipose tissue of type 2 diabetic models. Insulin and/or galanin were injected respectively or cooperatively into type 2 diabetic rats once a day for fifteen days. The results showed that administration of galanin significantly enhanced insulin-induced GLUT4 and vesicle-associated membrane protein 2 (VAMP2) translocation, Akt phosphorylation and glucose uptake, but not GLUT4 mRNA and protein expression levels in adipose cells. The beneficial roles of galanin on insulin-induced events may be blocked by MK-2206, an Akt inhibitor, indicating that the Akt phosphorylation is essential for promoting impact of galanin on the insulin-induced events. These results suggest that galanin may benefit insulin-induced GLUT4 and VAMP2 translocation, and subsequent glucose uptake via the activated Akt-VAMP2-GLUT4 pathway in adipose cells. These findings deepen our understanding of the anti-diabetic effect of galanin and its mechanism.

研究传染性单核细胞增多症（IM）的发病机制、临床特征、病理形态学特点、免疫表型和鉴别诊断，以提高对IM的认识和诊断水平。采用苏木精-伊红（HE）染色、免疫组织化学及原位杂交技术，结合临床资料、病理变化、免疫表型和EB病毒感染的情况，对IM进行分期。结合IM的临床病理变化、免疫表型和EB病毒编码的小RNA表达情况，把IM分为前期、中期、后期及末期，并总结各个时期的病理形态学特征、鉴别诊断。.

We present a new occultation event simulator for the Trans-Neptunian Automated Occultation Survey (TAOS II). We have developed a method to compute occultation shadows by small objects with non-circular apparent shapes (as may result from an intrinsic morphology or from the projection of a contact binary). The new simulator calculates diffraction features in the occultation shadows, as well as resulting light curves as would be measured by the TAOS II survey system. We include effects such as the spectral type and finite angular size of the occulted star. We find that occultation events, especially by Trans-Neptunian Objects with diameters ~3 km may be misidentified or mischaracterized when not taking non-spherical shapes into account.

We analyzed the project results of preventive medicine from the National Natural Science Foundation of China (NSFC) finished in 2017 based on the project-ending reports and data on science fund sharing service network. A total of 406 projects in this field were completed in 2017. A total of 3 122 published articles supported by these projects, including 1 789 articles in science citation index (SCI) journals and 525 articles in Chinese core journals. In addition, there were 224 patent application/software copyright and 589 trained postgraduates. The top three sub-disciplines of project were non-communicable disease epidemiology, human nutrition and hygienic toxicology, accounting for 45.32% of the total number of completed projects. There were 12 institutions which had more than 10 finished projects, accounting for 41.87%. During the recent 5 years, the number of SCI articles and patents/software copyrights per project showed a general uptrend. It should be noted that the number of articles in Chinese core journals and postgraduates decreased in recent two years. Our analyses demonstrated that the project results should be guided by the new era policy of science fund to promote sustainable development of scientific research.以国家自然科学基金委员会预防医学相关领域2017年度项目结题报告作为研究对象，并从科学基金共享服务网检索结题项目相关数据，分析该年度的结题项目成果。2017年度结题项目数为406项，发表期刊论文3 122篇，其中SCI期刊论文1 789篇，中文核心期刊论文525篇，申请专利/软件著作权224项，培养研究生589名。结题项目数前3位的分支学科是非传染病流行病学、人类营养和卫生毒理，占结题项目总数的45.32%。12家依托单位的结题项目多于10项，占总数的41.87%，是主要的科研项目承担单位。比较近5年结题项目成果，项均SCI论文数、专利/软件著作权呈上升趋势。但近两年来发表中文核心期刊论文以及培养研究生数量降低，需要引起重视。建议以新时代科学基金的资助导向为方针做好项目结题工作，促进科学研究的可持续发展。.

Microstructure and corrosion behavior of the Ti-6Al-4V- x Zr ( x = 0, 10, 20, 30, 50 wt.%) alloys were investigated. Zr additions in the Ti-6Al–4V alloy promote the formation of martensitic phase. The width of α lamellae decreases and the β phase content increases with the increase of Zr content. The corrosion behavior of the alloys with various Zr content are significantly different. The passivation ability of Ti-6Al-4V- x Zr alloys increases with increasing Zr content. For the Ti-6Al-4V-30Zr and Ti-6Al-4V-50Zr alloys, a sudden increase in the current density occurred, which is caused by pitting corrosion.

A new downy mildew resistance gene, Pl 19 , was identified from wild Helianthus annuus accession PI 435414, introduced to confection sunflower, and genetically mapped to linkage group 4 of the sunflower genome. Wild Helianthus annuus accession PI 435414 exhibited resistance to downy mildew, which is one of the most destructive diseases to sunflower production globally. Evaluation of the 140 BC1F2:3 families derived from the cross of CMS CONFSCLB1 and PI 435414 against Plasmopara halstedii race 734 revealed that a single dominant gene controls downy mildew resistance in the population. Bulked segregant analysis conducted in the BC1F2 population with 860 simple sequence repeat (SSR) markers indicated that the resistance derived from wild H. annuus was associated with SSR markers located on linkage group (LG) 4 of the sunflower genome. To map and tag this resistance locus, designated Pl 19 , 140 BC1F2 individuals were used to construct a linkage map of the gene region. Two SSR markers, ORS963 and HT298, were linked to Pl 19 within a distance of 4.7 cM. After screening 27 additional single nucleotide polymorphism (SNP) markers previously mapped to this region, two flanking SNP markers, NSA_003564 and NSA_006089, were identified as surrounding the Pl 19 gene at a distance of 0.6 cM from each side. Genetic analysis indicated that Pl 19 is different from Pl 17 , which had previously been mapped to LG4, but is closely linked to Pl 17 . This new gene is highly effective against the most predominant and virulent races of P. halstedii currently identified in North America and is the first downy mildew resistance gene that has been transferred to confection sunflower. The selected resistant germplasm derived from homozygous BC2F3 progeny provides a novel gene for use in confection sunflower breeding programs.

SUMMARYThe objective of the present study was to evaluate the effects of isovalerate supplementation on growth performance and ruminal fermentation in pre- and post-weaning dairy calves. Forty-eight Chinese Holstein male calves at 15 days of age and 45·1 ± 0·36 kg body weight (BW) were assigned randomly to four groups. The treatments were: control, low-isovalerate, moderate-isovalerate (MIV) and high-isovalerate (HIV) with 0, 3, 6 and 9 g isovalerate per calf per day, respectively. Isovalerate was hand-mixed into milk in pre-weaning calves and the concentrate portion in post-weaning calves. The study lasted 75 days, including a 15-day adaptation period followed by a 60-day sampling period. Weaning was conducted when calves were 60 days old. Six calves were chosen from each treatment at random and slaughtered at 30 and 90 days of age. Average daily weight gain increased linearly whether during pre-weaning or post-weaning period with increasing isovalerate supplementation. Dry matter intake linearly increased at 90 days of age with increasing isovalerate supplementation. During weaning, ruminal pH and ammonia nitrogen (N) decreased linearly, whereas total ruminal volatile fatty acid concentration increased linearly with increasing isovalerate supplementation. The ratio of acetate to propionate increased linearly with increasing isovalerate supplementation due to increased acetate concentration and the unchanged propionate concentration. Activities of caboxymethyl-cellulase, cellobiase, xylanase and pectinase linearly increased at 90 days of age, α-amylase and β-amylase activities linearly increased at 30 and 90 days of age. Relative quantities of Butyrivibrio fibrisolvens, Ruminococcus albus, Fibrobacter succinogenes and Ruminococcus flavefaciens increased linearly with increasing isovalerate supplementation. Ruminal fermentation, enzyme activities and cellulolytic bacteria were higher for HIV and MIV than for the control. The present results indicate that isovalerate accelerated growth of calves by improving ruminal fermentation, microbial enzyme activities and cellulolytic bacteria growth during weaning. In the experimental conditions of the current trial, the optimum isovalerate dose was about 6·0 g isovalerate per calf per day.