The Risk Factors and Outcomes for Radiological Abnormalities in Early Convalescence of COVID-19 Patients Caused by the SARS-CoV-2 Omicron Variant: A Retrospective, Multicenter Follow-up Study

Wang Hong,Yang Qingyuan,Li Fangfei,Wang Huiying,Yu Jing,Ge Xihong,Gao Guangfeng,Xia Shuang,Xing Zhiheng,Shen Wen 대한의학회 2023 Journal of Korean medical science Vol.38 No.8

Background: The emergence of the severe acute respiratory syndrome coronavirus 2 omicron variant has been triggering the new wave of coronavirus disease 2019 (COVID-19) globally. However, the risk factors and outcomes for radiological abnormalities in the early convalescent stage (1 month after diagnosis) of omicron infected patients are still unknown. Methods: Patients were retrospectively enrolled if they were admitted to the hospital due to COVID-19. The chest computed tomography (CT) images and clinical data obtained at baseline (at the time of the first CT image that showed abnormalities after diagnosis) and 1 month after diagnosis were longitudinally analyzed. Uni-/multi-variable logistic regression tests were performed to explore independent risk factors for radiological abnormalities at baseline and residual pulmonary abnormalities after 1 month. Results: We assessed 316 COVID-19 patients, including 47% with radiological abnormalities at baseline and 23% with residual pulmonary abnormalities at 1-month follow-up. In a multivariate regression analysis, age ≥ 50 years, body mass index ≥ 23.87, days after vaccination ≥ 81 days, lymphocyte count ≤ 1.21 × 10-9/L, interleukin-6 (IL-6) ≥ 10.05 pg/mL and IgG ≤ 14.140 S/CO were independent risk factors for CT abnormalities at baseline. The age ≥ 47 years, presence of interlobular septal thickening and IL-6 ≥ 5.85 pg/mL were the independent risk factors for residual pulmonary abnormalities at 1-month follow-up. For residual abnormalities group, the patients with less consolidations and more parenchymal bands at baseline could progress on CT score after 1 month. There were no significant changes in the number of involved lung lobes and total CT score during the early convalescent stage. Conclusion: The higher IL-6 level was a common independent risk factor for CT abnormalities at baseline and residual pulmonary abnormalities at 1-month follow-up. There were no obvious radiographic changes during the early convalescent stage in patients with residual pulmonary abnormalities.

Strength and Constitutive Model of Recycled Concrete under Biaxial Compression

Zhiheng Deng,Jun Sheng,Yumei Wang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2

The mechanical properties of recycled concrete under biaxial compression were tested in this study. Five grades of replacement ratio of recycled coarse aggregate (0%, 30%, 50%, 70%, 100%) and four groups of stress ratio (−0.25:−1, −0.5:−1, −0.75:−1, −1:−1) were designed to evaluate their influence on mechanical properties .The strength and deformation values of concrete specimens were tested by servo-controlled static-dynamic triaxial machine (TAWZ-5000/3000). The result shows that the stress and strain of recycled oncrete under biaxial compression were both higher than the corresponding values that under uniaxial compression. The stress ratio and recycled aggregate ratio have different effects on mechanical properties of concrete. The initial elastic modulus was also affected by the two factors. Based on the analysis of the test data and combined with the stress-strain curve, a constitutive model for recycled concrete under biaxial compressive state was proposed. The comparison between the test results and the fitted curves shows that the proposed model can suitably describe the stress-strain relationship for recycled concrete.

Research on crack behavior of recycled concrete beams under short-term loading

Zhiheng Deng,Yumei Wang,Haifeng Yang,Jian Qian 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.5

An experimental investigation was conducted to study the crack behavior of beams constructed with Recycled Concrete Aggregate(RCA). This experimental program consisted of 16 beams. The test parameters for this study include RCA replacement ratio andlongitudinal reinforcement ratio. The flexural properties and crack behaviors of the beams were evaluated based on present designcodes. It is found that the use of RCA does not cause an observable change in the progression of flexural strength and crack pattern. However, results of these statistical tests show that the RCA beams possess a larger crack width compares with the conventionalbeams.

Enhanced friction model for high-speed right-angle gear dynamics

Zhiheng Feng,Shilong Wang,Teik C. Lim,Tao Peng 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.11

The modeling of elastohydrodynamic lubrication friction and the analysis of its dynamic effect on right-angle gears, such as hypoid and spiral bevel types are performed in the present study. Unlike the classically applied empirical constant coefficient of friction at the contacting tooth surfaces, the enhanced physics-based gear mesh friction model is both spatial and time-varying. The underlying formulation assumes mixed elastohydrodynamic lubrication (EHL) condition in which the division and load distribution between the full film and asperity contact zones are determined by the film thickness ratio and load sharing coefficient. In the proposed time-varying friction model, the calculation of friction coefficient is performed at each contact grid inside the instantaneous contact area that is being subjected to mineral oil lubrication. The effective friction coefficient and directional parameters synthesized from the net frictional and normal contact forces are then incorporated into a nonlinear time-varying right-angle gear dynamic model. Using this model, the effect of friction on the gear dynamic response due to the transmission error and mesh excitations is analyzed. Also, parametric studies are performed by varying torque, surface roughness and lubrication properties to understand the salient role of tooth sliding friction in gear dynamics. The simulation results are included. But experimental verification is needed.

Detection of Eccentricity Fault Using Slot Leakage Flux Monitoring

Hanfeng Wang,Xiaohua Bao,Chong Di,Zhiheng Cheng 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Eccentricity is a common fault in the running of electrical machines. Aimed at the problem, a new approach to detect eccentricity fault is presented by monitoring the slot leakage flux of stator in this paper. In order to measure the slot leakage flux, two placements of search coil in the stator slot are applied. Firstly, the theoretical analysis shows the slot leakage flux contains more information about eccentricity fault than the stator current does. Then the submersible motor as a model, the induced voltages of search coil and the stator currents are obtained by finite element simulation under healthy motor, static, dynamic and mixed eccentricity, respectively. And various analysis and comparisons of simulations are made. The results show that monitoring the slot leakage flux is effective and has more advantages than the motor current signature analysis.

Xylazole inhibits NO-cGMP pathway in fetal rat nerve cells

Xinyu Wang,Yue Wu,Lin Liu,Hui Bai,Zhiheng Zhang,Mingchao Zhao,Tianwen Ma,Xiaopeng Song,Lina Jia,Liangyu Lv,Yue Yu,Xinyu Xu,Hong Chen,Li Gao 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: Xylazole (Xyl) is a veterinary anesthetic that is structurally and functionally similar to xylazine. However, the effects of Xyl in vitro remain unknown. Objectives: This study aimed to investigate the anesthetic mechanism of Xyl using fetal rat nerve cells treated with Xyl. Methods: Fetal rat nerve cells cultured for seven days were treated with 10, 20, 30, and 40 μg/ mL Xyl for 0, 5, 10, 15, 20, 25, 30, 45, 60, 90, and 120 min. Variations of amino acid neurotransmitters (AANTs), Nitric oxide-Cyclic GMP (NO-cGMP) signaling pathway, and ATPase were evaluated. Results: Xyl decreased the levels of cGMP and NO in nerve cells. Furthermore, Xyl affected the AANT content and Na+-K+-ATPase and Ca2+-Mg2+-ATPase activity in nerve cells. These findings suggested that Xyl inhibited the NO-cGMP signaling pathway in nerve cells in vitro. Conclusions: This study provided new evidence that the anesthetic and analgesic effects of Xyl are related to the inhibition of the NO-cGMP signaling pathway.

Bond Strength between Recycled Concrete and Rebar under Stirrup Constraint after Freeze-thaw Cycles

Zuohua Li,Zhiheng Deng,Haifeng Yang,Zhiyu Tang,Wei Wang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.2

In cold regions, freeze-thaw (F-T) damage is the main detriment to the durability of reinforced concrete structures, which will reduce the bond performance between concrete and rebar, and then adversely affect the bearing capacity and stiffness of structures. In this study, 21 groups of tests were performed to analyze the effects of the number of F-T cycles, volume stirrup ratio, and replacement percentage of recycled aggregate on the bond performance between recycled aggregate concrete and deformed rebar. The stirrup stress during the pulling process was measured using strain gauges attached to the stirrup surface, and the contribution of the stirrup to the bond strength was analyzed. The results showed that the F-T damage and stirrup constraints could affect the failure mode, the bond strength and the peak slip of pullout specimen. The failure mode of specimen with stirrups could be determined by splitting angle index. The indirect contribution of stirrup accounts for 14 − 25% of the bond strength and increases with the increase in F-T damage. The full bond-slip curve was obtained by fitting four parameters including splitting tensile strength, constraint coefficient, splitting angle index and brittleness index.

Wind-induced fragility assessment of urban trees with structural uncertainties

Yongbo Peng,Zhiheng Wang,Xiaoqiu Ai 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.26 No.1

Wind damage of urban trees arises to be a serious issue especially in the typhoon-prone areas. As a family of tree species widely-planted in Southeast China, the structural behaviors of Plane tree is investigated. In order to accommodate the complexities of tree morphology, a fractal theory based finite element modeling method is proposed. On-site measurement of Plane trees is performed for physical definition of structural parameters. It is revealed that modal frequencies of Plane trees distribute in a manner of grouped dense-frequencies; bending is the main mode of structural failure. In conjunction with the probability density evolution method, the fragility assessment of urban trees subjected to wind excitations is then proceeded. Numerical results indicate that small-size segments such as secondary branches feature a relatively higher failure risk in a low wind level, and a relatively lower failure risk in a high wind level owing to windward shrinks. Besides, the trunk of Plane tree is the segment most likely to be damaged than other segments in case of high winds. The failure position tends to occur at the connection between trunk and primary branches, where the logical protections and reinforcement measures can be implemented for mitigating the wind damage.

Wind-induced fragility assessment of urban trees with structural uncertainties

Peng, Yongbo,Wang, Zhiheng,Ai, Xiaoqiu Techno-Press 2018 Wind and Structures, An International Journal (WAS Vol.26 No.1

Wind damage of urban trees arises to be a serious issue especially in the typhoon-prone areas. As a family of tree species widely-planted in Southeast China, the structural behaviors of Plane tree is investigated. In order to accommodate the complexities of tree morphology, a fractal theory based finite element modeling method is proposed. On-site measurement of Plane trees is performed for physical definition of structural parameters. It is revealed that modal frequencies of Plane trees distribute in a manner of grouped dense-frequencies; bending is the main mode of structural failure. In conjunction with the probability density evolution method, the fragility assessment of urban trees subjected to wind excitations is then proceeded. Numerical results indicate that small-size segments such as secondary branches feature a relatively higher failure risk in a low wind level, and a relatively lower failure risk in a high wind level owing to windward shrinks. Besides, the trunk of Plane tree is the segment most likely to be damaged than other segments in case of high winds. The failure position tends to occur at the connection between trunk and primary branches, where the logical protections and reinforcement measures can be implemented for mitigating the wind damage.

CRISPR/Cas9-mediated knockout of the Vanin-1 gene in the Leghorn Male Hepatoma cell line and its effects on lipid metabolism

Xu Lu,Wang Zhongliang,Liu Shihao,Wei Zhiheng,Yu Jianfeng,Li Jun,Li Jie,Yao Wen,Gu Zhiliang 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.3

Objective: Vanin-1 (VNN1) is a pantetheinase that catalyses the hydrolysis of pantetheine to produce pantothenic acid and cysteamine. Our previous studies have shown that the VNN1 is specifically expressed in chicken liver which negatively regulated by microRNA-122. However, the functions of the VNN1 in lipid metabolism in chicken liver haven’t been elucidated. Methods: First, we detected the VNN1 mRNA expression in 4-week chickens which were fasted 24 hours. Next, knocked out VNN1 via CRISPR/Cas9 system in the chicken Leghorn Male Hepatoma cell line. Detected the lipid deposition via oil red staining and analysis the content of triglycerides (TG), low-density lipoprotein-C (LDL-C), and highdensity lipoprotein-C (HDL-C) after VNN1 knockout in Leghorn Male Hepatoma cell line. Then we captured various differentially expressed genes (DEGs) between VNN1- modified LMH cells and original LMH cells by RNA-seq. Results: Firstly, fasting-induced expression of VNN1. Meanwhile, we successfully used the CRISPR/Cas9 system to achieve targeted mutations of the VNN1 in the chicken LMH cell line. Moreover, the expression level of VNN1 mRNA in LMH-KO-VNN1 cells decreased compared with that in the wild-type LMH cells (p<0.0001). Compared with control, lipid deposition was decreased after knockout VNN1 via oil red staining, meanwhile, the contents of TG and LDL-C were significantly reduced, and the content of HDL-C was increased in LMH-KO-VNN1 cells. Transcriptome sequencing showed that there were 1,335 DEGs between LMH-KO-VNN1 cells and original LMH cells. Of these DEGs, 431 were upregulated, and 904 were downregulated. Gene ontology analyses of all DEGs showed that the lipid metabolism-related pathways, such as fatty acid biosynthesis and long-chain fatty acid biosynthesis, were enriched. KEGG pathway analyses showed that “lipid metabolism pathway”, “energy metabolism”, and “carbohydrate metabolism” were enriched. A total of 76 DEGs were involved in these pathways, of which 29 genes were upregulated (such as cytochrome P450 family 7 subfamily A member 1, ELOVL fatty acid elongase 2, and apolipoprotein A4) and 47 genes were downregulated (such as phosphoenolpyruvate carboxykinase 1) by VNN1 knockout in the LMH cells. Conclusion: These results suggest that VNN1 plays an important role in coordinating lipid metabolism in the chicken liver.