Effects of dynamic transmission errors and vibration stability in helical gears

Jing Wei,Pan Gao,Xinglong Hu,Wei Sun,Jing Zeng 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6

Transmission error is an important reason for instability in helical gears. A six-degree-of-freedom dynamic model coupled flexional,torsional and axial motion of a helical gear transmission system, which includes time varying mesh stiffness, bearing supporting stiffness,mesh damping and backlash, is developed, after taking into account the dynamic characteristics and vibration responses of helical gear inthree dimensions. Influences of involute contact ratio, bearing supporting stiffness, mesh damping and backlash on the dynamic transmissionerrors and vibration stability of the helical gear system are investigated using numerical simulation technique. The effects on dynamictransmission errors and stabilities by contact ratio, supporting stiffness and mesh damping as well as gear backlash are analyzed. The intrinsic relationship between above parameters and dynamic transmission errors and stabilities for helical gear system are presented. The stable and unstable regions under different parameters are given. The results in this paper can be helpful to the dynamic and stabledesign of a helical gear transmission system.

Effect of different phase levels of medium chain triglycerides on the growth performance, excreta microflora and blood profiles of broilers

Jing Hu,박재홍,Jian Ying Zhang,유종상,정진영,김인호 충남대학교 농업과학연구소 2018 Korean Journal of Agricultural Science Vol.45 No.2

Medium chain triglycerides (MCTs) provide polka dot grouper Chromileptes altevelis with a more readily utilizable source of energy than long-chain fatty acids (LCFAs) and significantly elevate the plasma cholesterol level of chickens. As a possible alternative to feed antibiotics, this study investigated the effect of different phase levels of medium chain triglycerides on the growth performance, excreta microflora and blood profiles in broilers. A total of 450 ROSS 308 mixed-sex broilers with an average initial body weight of 49 ± 0.79 g (1 day of age) were used in this trial. They were randomly assigned to the following 3 treatments (15 birds / 10 replications): CON (Basal diet); MCT1 (Starter, Grower, Finisher: Basal diet + 0.1%, 0.075%, 0.05% of MCT) and MCT2 (Starter, Grower, Finisher: Basal diet + 0.1%, 0.1%, 0.1% of MCT). The results show that supplementing the diets with different phase levels of MCT did not have a significant impact on the body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) during the overall experimental period. Additionally, there were no differences in the blood profiles and excreta microflora among the treatments. However, this study found that the BWG was increased by 2.3%, and the FCR was decreased by 0.6% in the broiler fed MCT1 treatment group during overall experiment phase. Therefore, the results suggest that MCTs could be used as an alternative to growth promoting feed additives. Moreover, further research should be done to evaluate the effect of the different levels of MCTs.

Health Service Utilization and Expenditure of the Elderly in China

Jing Hu,Chien-Chung Huang 한국사회복지학회 2016 Asian Social Work and Policy Review Vol.10 No.2

Using data from the China Health and Retirement Longitudinal Survey, we employed counterfactual propensity score matching to examine the association between income and health service utilization and expenditure of the elderly in China. The results demonstrated that income did not differentiate whether the poor elderly in China visited a doctor when suffering an illness, but their expenditure on medical treatment was significantly associated with income. Subgroup analysis further indicated that the medical demands of female, older, and rural elderly were more likely to be reduced by their income compared with their counterparts.

Development of SSR molecular markers for Allium mongolicum

Jing Hu,Xiaoke Hu,Qian Zhang,Jinhu Zhang,Baoli Fan,Qiushi Yu 한국유전학회 2017 Genes & Genomics Vol.39 No.12

Allium mongolicum is high palatability, nutrient, medicinal value and drought resistance wild plant. However, a lack of molecular markers of this plant results in a series of genetic questions remain largely unknown, including molecular marker data, population genetic structure and accuracy of genetic breeding. In this study, a total of 1,409,706 quality- filtered and trimmed reads were obtained from the normalized genomic DNA of pooled A. mongolicum individuals. These sequences were assembled into 2,093,593 high quality contigs, and a total of 219 simple sequence repeats loci were screened. Sixty of them were selected to validate amplification and to determine the degree of polymorphism in the genomic DNA pools. Fifteen primer pairs successfully amplified DNA fragments and detected significant amounts of polymorphism. The number of alleles in ten geographically diverse A. mongolicum populations ranged from 3 to 8 per locus. The observed and expected heterozygosities ranged from 0.350 to 0.860 and 0.516 to 0.931, respectively. Our results provide a valuable resource for A. mongolicum research.

Excessive Convergence and M&A Integration of Chinese Regional Cloud Computing Industry

Jing Hu,Lili Zhang 보안공학연구지원센터 2014 International Journal of Grid and Distributed Comp Vol.7 No.6

Effects of Gastric Cancer Cells on the Differentiation of Treg Cells

Hu, Jing-Lan,Yang, Zhen,Tang, Jian-Rong,Fu, Xue-Qin,Yao, Lan-Jie Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.8

The aim of this study was evaluated the prevalence of Treg cells in peripheral blood in patients with gastric cancer, and investigate the effect of gastric cancer cells on their differentiation. ELISA was employed to assess the concentrations of TGF-${\beta}$ and IL-10 in gastric cancer patients' serum. Then, mouse gastric cancer cells were co-cultured with T lymphocytes or T lymphocytes + anti-TGF-${\beta}$. Flow cytometric analysis and RT-PCR were then performed to detect Treg cells and TGF-${\beta}$ and IL-10 expression in gastric cancer cells. Our data showed that the expression of TGF-${\beta}$ and IL-10 in the patients with gastric cancer was increased compared to the case with healthy donors. The population of Treg cells and the expression levels of TGF-${\beta}$ and IL-10 in the co-culture group were much higher than in the control group (18.6% vs 9.5%) (P<0.05). Moreover, the population of Treg cells and the expression levels of TGF-${\beta}$ and IL-10 in the co-culture systerm were clearly decreased after addition of anti-TGF-${\beta}$ (7.7% vs 19.6%) (P<0.01). In conclusion, gastric cancer cells may induce Treg cell differentiation through TGF-${\beta}$, and further promote immunosuppression.

Effects of contact shape on ballistic phonon transport in semiconductor nanowires

Jing-Jing Yao,Wei-Qing Huang,Gui-Fang Huang,Yuan Chen,Ling-Ling Wang,Wangyu Hu,Anlian Pan 한국물리학회 2012 Current Applied Physics Vol.12 No.2

We study the effects of contact shape on ballistic phonon transport in semiconductor nanowires at low temperatures using an approximative scalar model of continuum elasticity. Five different contacts connected to two semiconductor nanowires with different transverse widths are discussed. Numerical results show that the contact shape acts as an ‘acoustic impedance adaptor’, playing a crucial role on the ballistic phonon transmission and thermal conductance. The phonon coupling in the contacts with certain length facilitates ballistic phonon transmission compared to the abrupt interface, in which the phonon scattering is the strongest. It is found that the more the contact is abrupt, the smaller the thermal conductance is. The catenoidal contact rather than the abrupt interface is also the competitive candidate to obtain bigger thermal conductance. These results indicate that choosing an appropriate contact shape is one of the most critical factors to accurately measure the thermal conductance with a very high precision and reliability in different temperature ranges at low temperatures.

Preparation and Evaluation of Pectin-based Colon-specific Pulsatile Capsule In Vitro and In Vivo

Jing Liu,Liang-ke Zhang,Yuntao Jia,Wenjing Hu,Jing-qing Zhang,Huiming Jiang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.11

The purpose of this study was to develop and evaluate a colon-specific, pulsatile drug delivery system, which consists of an impermeable capsule body filled with a 5-aminosalicylic acid rapid-disintegrating tablet and a pectin-based erodible plug placed in the opening of the capsule body. To obtain an appropriate gel-forming ability and suitable lag time for the colon-specific drug delivery, high-methoxy pectin (HM-pectin) was formulated with lactose and lowmethoxy pectin (LM-pectin) with HPMC to prepare the plug tablet. In order to evaluate the lag time, prior to the rapid drug release, both the formulation of the plug tablet and in vitro release medium were studied. The lag time prior to the rapid drug release was mainly determined by the HM-pectin/lactose or LM-pectin/HPMC ratio. The addition of pectinase or rat cecal content into the release medium shortened the lag time significantly, which predicted the probable enzyme sensitivity of pectin plug tablet. In vivo studies showed that the plasma concentration of drug can only be detected 6 h after oral administration of the pulsatile capsule, which indirectly proved the colon-specific characteristics. These results show that the pulsatile capsule may have the therapeutic action for colon-specific drug delivery.

An Automatic Spring-back Compensation Method in Die Design Based on a Genetic Algorithm

Jing Hu,정관수,Xiao-Xing Li,박태준,Guo-Feng Zhou,Rao Yao 대한금속·재료학회 2011 METALS AND MATERIALS International Vol.17 No.3

In the present work, a die shape design method to compensate spring-back in the sheet metal forming process is developed based on a finite element analysis and a genetic algorithm. The proposed method is robust and automated enough for industrial applications. Using a simple stretch bending process as an example,it was demonstrated that the new method optimizes the die profile effectively. The good performance of the die profile optimized utilizing the new method was also verified experimentally, confirming that the new method is likely to be more cost-effective than common design practices in practical applications.

Resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates

Yi-Jing Wang,Pan Zhao,Bing-Dong Sui,Nu Liu,Cheng-Hu Hu,Ji Chen,Chen-Xi Zheng,An-Qi Liu,Kun Xuan,Ya-Ping Pan,Yan Jin 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Mesenchymal stem cell (MSC)-based regeneration, specifically cell aggregate or cell sheet engineering, is a promising approach for tissue reconstruction. Considering the advantages of ease of harvest and lack of immune rejection, the application of autologous MSCs (i.e., patients’ own MSCs) in regenerative medicine has developed considerable interest. However, the impaired cell viability and regenerative potential following MSCs impacted by disease remain a major challenge. Resveratrol (RSV) exhibits reliable and extensive rejuvenative activities that have received increasing clinical attention. Here, we uncovered that resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates. Periodontal ligament MSCs (PDLSCs) from normal control subjects (N-PDLSCs) and periodontitis patients (P-PDLSCs) were investigated. Compared to N-PDLSCs, P-PDLSCs were less capable of forming cell aggregates, and P-PDLSC aggregates showed impaired osteogenesis and regeneration. These functional declines could be mimicked in N-PDLSCs by tumor necrosis factor alpha (TNF-α) treatment. Notably, a TNF-α-induced functional decline in N-PDLSC aggregates was rescued by RSV application. More importantly, in both N-PDLSCs and P-PDLSCs, RSV promoted cell aggregate formation and improved their osteogenic potential. Furthermore, as proven ectopically in vivo, the tissue regenerative capability of P-PDLSC aggregates was also enhanced after RSV treatment during aggregate formation in vitro. Finally, in a rat in situ regeneration model, we successfully applied both N-PDLSC aggregates and P-PDLSC aggregates to repair periodontal defects upon long-term functional improvements by RSV preconditioning. Together, our data unravel a novel methodology for using pharmacology (i.e., RSV)-based cell aggregate engineering to improve the functionality and facilitate the regeneration of MSCs from both healthy and inflammatory microenvironments, shedding light on improving the application of autologous MSC-mediated regenerative medicine.