A Novel AC/DC Converter Based on Stacked Boost Circuit and Dual-Mode LLC Circuit

Tingting Yao,Yueshi Guan,Fang Li,Yijie Wang,Wei Wang,Dianguo Xu 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In this paper, a AC/DC converter based on stacked Boost circuit and dual-mode LLC circuit is proposed. In the Power Factor Correction (PFC) part, two Boost circuits are stacked to reduce switch voltage stress, also sharing one inductor operating in Boundary Conduction Mode (BCM). In the DC/DC part, a dual-mode LLC circuit is adopted based on two stacked half-bridge structure. The input voltage of LLC resonant tank can double or halve by switching between two operating modes. Hence, the voltage gain of LLC converter can be modified without large operating frequency modulation range. The proposed AC/DC converter can be utilized in widely input voltage variation condition. A 50W prototype is proposed in the laboratory and the experimental results verify the feasibility of the proposed converter.

On compressive behavior of large welded hollow spherical joints with both internal and external stiffeners

Tingting Shu,Xian Xu,Yao-Zhi Luo 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.2

Welded hollow spherical joints are commonly used joints in space grid structures. An internal stiffener is generally adopted to strengthen the joints when large hollow spheres are used. To further strengthen it, external stiffeners can be used at the same time. In this study, axial compression tests are conducted on four full-scale 550 mm spherical joints. The failure modes and strengths of the tested joints are investigated. It shows that the external stiffeners are able to increase the strength of the joint up to 25%. A numerical model for large spherical joints with stiffeners is established and verified against the experimental results. Parametric studies are executed considering six main design factors using the verified model. It is found that the strength of the spherical joint increases as the thickness, height and number of the external stiffeners increase, and the hollow sphere’s diameter has a neglectable effect on the enhancement caused by the external stiffeners. Based on the experimental and numerical results, a practical formula for the compressive bearing capacity of large welded hollow spherical joints with both internal and external stiffeners is proposed. The proposed formula gives a conservative prediction on the compressive capacity of large welded hollow spherical joints with both internal and external stiffeners.

The relationship between polymorphism of insulin-like growth factor I gene and susceptibility to type 2 diabetes in Uygur population, Xinjiang, China

Wang Tingting,Maimaitituersun Gulixiati,Shi Haonan,Chen Cheng,Ma Qi,Su Yinxia,Yao Hua,Zhu Jia 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: Type 2 diabetes (T2DM) susceptibility varies among different populations and is affected by gene single nucleotide polymorphism (SNP). Insulin-like growth factor (IGF)-1 gene, which has many SNP loci, is involved in T2DM pathogenesis. However, the relationship of IGF-1 gene polymorphism with T2DM in Uyghur population is less studied. Objective: To investigate the relationship between T2DM susceptibility and polymorphism of IGF-1 gene in Uyghur population of Xinjiang, China. Methods: This study enrolled 220 cases (122 males (55.46%) and 98 females (44.54%); mean age of 53.40 ± 10.94 years) of T2DM patients (T2DM group) and 229 (124 males (54.15%) and 105 females (45.85%); mean age of 51.64 ± 10.48 years) healthy controls (control group). Biochemical indexes were determined. IGF-1 gene polymorphism was analyzed by SNP genotyping. Results: The levels of TG, HDL, LDL, BUN, and Cr were statistically significant between the T2DM group and the control group. In terms of IGF-1 polymorphism, T2DM group had higher frequency of AA genotype (OR = 2.40, 95% CI = 1.19-4.84) and allele A (OR = 1.55, 95% CI = 1.17-2.06) of rs35767 loci, suggesting that rs35767 is related to the occurrence of T2DM. A total of 5 gene interaction models was obtained through analyzing the interaction of 5 SNP loci with the GMDR method. Among them, the two-factor model that included rs35767 locus and rs5742694 locus had statistical difference with a large cross-validation consistency (10/10). The combination of GG/CC, GA/AA, AA/AA, and AA/AC genotype was in high-risk group, whereas the combination of GG/AA, GG/AC, GA/AC and GA/CC genotype was in the low-risk group. The risk of T2DM in the high-risk group was 2.165 times than that of the low-risk group (OR = 2.165, 95% CI = 1.478-3.171). Conclusion: TG, HDL, LDL, BUN, and Cr are influencing factors of T2DM in Uyghur population. The rs35767 locus of IGF-1 gene may be associated with T2DM in Uyghur population. The high-risk group composing of rs35767 locus and rs5742694 locus has a higher risk of T2DM.

Propylthiouracil, Perchlorate, and Thyroid-Stimulating Hormone Modulate High Concentrations of Iodide Instigated Mitochondrial Superoxide Production in the Thyroids of Metallothionein I/II Knockout Mice

Qi Duan,Tingting Wang,Na Zhang,Vern Perera,Xue Liang,Iruni Roshanie Abeysekera,Xiaomei Yao 대한내분비학회 2016 Endocrinology and metabolism Vol.31 No.1

Background: Increased oxidative stress has been suggested as one of the underlying mechanisms in iodide excess-induced thy roid disease. Metallothioneins (MTs) are regarded as scavengers of reactive oxygen species (ROS) in oxidative stress. Our aim is to investigate the effects of propylthiouracil (PTU), a thyroid peroxidase inhibitor, perchlorate (KClO4), a competitive inhibitor of iodide transport, and thyroid stimulating hormone (TSH) on mitochondrial superoxide production instigated by high concentra tions of iodide in the thyroids of MT-I/II knockout (MT-I/II KO) mice. Methods: Eight-week-old 129S7/SvEvBrd-Mt1 tm1Bri Mt2tm1Bri/J (MT-I/II KO) mice and background-matched wild type (WT) mice were used. Results: By using a mitochondrial superoxide indicator (MitoSOX Red), lactate dehydrogenase (LDH) release, and methyl thia zolyl tetrazolium (MTT) assay, we demonstrated that the decreased relative viability and increased LDH release and mitochon drial superoxide production induced by potassium iodide (100 μM) can be relieved by 300 μM PTU, 30 μM KClO4, or 10 U/L TSH in the thyroid cell suspensions of both MT-I/II KO and WT mice (P<0.05). Compared to the WT mice, a significant de crease in the relative viability along with a significant increase in LDH release and mitochondrial superoxide production were de tected in MT-I/II KO mice (P<0.05). Conclusion: We concluded that PTU, KClO4, or TSH relieved the mitochondrial oxidative stress induced by high concentrations of iodide in the thyroids of both MT-I/II KO and WT mice. MT-I/II showed antioxidant effects against high concentrations of io dide-induced mitochondrial superoxide production in the thyroid.

A Novel Two-Step Tensegrity Topology-Finding Method Based on Mixed Integer Programming and Nonlinear Programming

Xian Xu,Shaoxiong Huang,Tingting Shu,Yafeng Wang,Yao-Zhi Luo 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.4

A two-step topology-fi nding method based on mixed integer programming and nonlinear programming is proposed for tensegrity structures. In the fi rst step, feasible and symmetric strut connectivities are obtained through a ground structure method combined with mixed integer programming; in the second step, the cable connectivities are optimized through nonlinear programming to obtain a feasible tensegrity structure. The same ground structure used in the fi rst step is adopted in the second step, which is benefi cial to fi nd a more symmetric cable layout. The independent continuous mapping method is used in the second step to convert the 0–1 binary variables of cable connectivities to continuous variables to transform the combinatorial optimization problem into a nonlinear programming problem. The number of strut lengths is adopted as a control parameter and a symmetry objective function is proposed to generate a variety of regular and symmetric tensegrity structures. A multi-stage computation scheme is proposed to improve the computational effi ciency. Typical examples are carried out to validate the proposed method. The computational effi ciency of the method is benchmarked with existing methods fully based on mixed integer programming. Results demonstrate that the computational effi ciency of the proposed method is signifi cantly improved compared to the existing methods.

Hypolipidemic effect of soluble dietary fibers prepared from Asparagus officinalis and their effects on the modulation of intestinal microbiota

Miansong Zhang,Mengke Yao,Airong Jia,Yaping Shi,Xinfeng Bai,Xue Liu,Tingting Cui,Xin Liu,Changheng Liu 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.13

The soluble dietary fiber from Asparagus officinalis(ASDF) was successively prepared using enzymolysiscombined with spray-drying technology. Highperformanceliquid chromatography analysis showed thatASDF contained two polysaccharide fractions with theaverage molecular weight of 2.77 9 105 and6.44 9 103 Da, and was composed of mannose, rhamnose,galacturonic acid, glucose, galactose, and arabinose with amolecular ratio of 19.93:1.02:1.94:32.17:1.00:1.91,respectively. ASDF showed potential in vitro antioxidantactivities. The oral administration of ASDF significantlyreduced the levels of total cholesterol, triglyceride, andlow-density lipoprotein cholesterol in HD-induced miceserum. Furthermore, 16S rRNA gene sequencing analysisshowed that ASDF significantly affected the compositionof intestinal microbiota, especially reducing the Firmicutes/Bacteroidotetes ratio and the relative abundances ofDesulfobacterota, Proteobacteria, Actinobacteriota andincreasing that of Muribaculaceae, Bacteroides, and Alloprevotella. These results demonstrated that the intake ofASDF could regulate intestinal microbiota and serum lipidlevels in hyperlipidemic conditions.

Underlying mechanisms of phosphodiesterase 10A and glutamate-ammonia ligase genes that regulate inosine monophosphate deposition and thereby affect muscle tenderness in Jingyuan chickens

Wang, Weizhen,Zhang, Juan,Hu, Honghong,Yu, Baojun,He, Jintong,Yao, Tingting,Gu, Yaling,Cai, Zhengyun,Xin, Guosheng Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.11

Objective: Inosine monophosphate (IMP) is a key factor that imparts of meat flavor. Differences in the IMP content in the muscles were evaluated to improve chicken meat quality. Methods: For this study, the IMP content was detected by high performance liquid chromatography. The gene expression profiles of Jingyuan chickens with different feeding patterns and different sexes were analyzed by RNA-sequencing (RNA-seq). Results: Breast muscle IMP content in free-range chickens was extremely significantly higher than that of caged chickens (p<0.01). Breast muscle IMP content in hens was also higher than that of cocks, but the difference was not significant. Correlation analysis showed that the breast muscle IMP content in caged hens and cocks was negatively correlated with the shear force, and the breast muscle IMP content in free-range hens was significantly negatively correlated with the shear force (p<0.05). The two key genes associated with IMP synthesis in chickens with different feeding patterns were glutamate-ammonia ligase (GLUL) and phosphodiesterase 10A (PDE10A). Bioinformatics analysis revealed that the GLUL and PDE10A genes are involved in glutamine biosynthesis and purine salvage pathways respectively. In addition, GLUL expression was positively correlated with the IMP content in caged and free-range chickens, and PDE10A expression was significantly positively correlated with the IMP content in caged and free-range chickens (p<0.05). Conclusion: These findings will facilitate the comprehension of the deposition of IMP in the muscles and thereby aid the process of selection and breeding of good quality local chickens.