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Search Results: 1 - 10 of 120296 matches for " Huifang Wang "
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Design and research of measuring system of clamping force of hemostats  [PDF]
Huifang Wang, Shuyi Wang, Ying Zhou, Jie Tan
Journal of Biomedical Science and Engineering (JBiSE) , 2010, DOI: 10.4236/jbise.2010.39123
Abstract: Reliability of medical instruments such as hemostats is extremely important because these instruments are used in patients who are in critical condition. Clamping force of hemostats, as an important parameter of hemostats, should be detected. However, it could not be tested directly. In order to test it, a testing system has been put forward. The system is comprised of sensor, acquisition card, and three-way tap and so on. This system is controlled by a computer. The testing system has been proved to be effective in testing the clamping force of hemostats.
A Brief Analysis of Learning Organization Practice from the Perspective of the Fifth Discipline Model Theories—A Case Study of Jatco (Guangzhou)  [PDF]
Huifang Liu
American Journal of Industrial and Business Management (AJIBM) , 2018, DOI: 10.4236/ajibm.2018.811142
Abstract: Since the 1970s and 1980s, learning organizations have attracted the attention of academic circles and became one of the popular themes of academic research. Based on the theoretical perspective of the Peter M. Senge’s five disciplines models, this paper conducts research on an enterprise with Jatco (Guangzhou), which has a unique talent management system and successfully generates a learning organization. This study analyzes the mystery of the successful construction of learning organizations from the five Disciplines of Personal Mastery, Improving Mental Models, Building Shared Vision, Team Learning, and Systems Thinking. We aim to explore the management method of learning organizations by using the classical learning organization theory with the enterprise case practice, and provide some reference and guidance for the enterprise practice of learning organizations.
Measured body mass index, body weight perception, dissatisfaction and control practices in urban, low-income African American adolescents
Youfa Wang, Huifang Liang, Xiaoli Chen
BMC Public Health , 2009, DOI: 10.1186/1471-2458-9-183
Abstract: Cross-sectional data including measured weight and height and self-reported weight status collected from 448 adolescents in four Chicago Public Schools were used.The prevalence of overweight and obesity (BMI ≥ 85th percentile) was 39.8%, but only 27.2% considered themselves as obese, although 43.4% reported trying to lose weight. Girls were more likely to express weight dissatisfaction than boys, especially those with BMI ≥ 95th percentile (62.9% vs. 25.9%). BMI ≥ 85th percentile girls were more likely to try to lose weight than boys (84.6% vs. 66.7%). Among all adolescents, 27.2% underestimated and 67.2% correctly judged their own weight status. Multinomial logistic models show that those with BMI ≥ 85th percentile, self-perceived as obese, or expressed body dissatisfaction were more likely to try to lose weight; adjusted odds ratios and 95% confidence intervals were 4.52 (2.53–8.08), 18.04 (7.19–45.30), 4.12 (1.64–10.37), respectively. No significant differences were found in diet and physical activity between those trying to lose weight and those not trying, but boys who reported trying to lose weight still spent more television time (P < 0.05).Gender differences in weight perception, body dissatisfaction, and weight control practices exist among African American adolescents. One-third did not appropriately classify their weight status. Weight perception and body dissatisfaction are correlates of weight control practices. Adolescents attempting to lose weight need be empowered to make adequate desirable behavioral changes.Nationally representative survey data show that the prevalence of overweight is about 10% higher in African American adolescent girls than in non-Hispanic white peers but is not higher in African American adolescent boys than in their white counterparts [1]. Adolescent girls and boys may evaluate their bodies differently, e.g., girls tend to view their body primarily as a means of attracting others, while boys perceive theirs as a means of effec
Properties of mercuric reductase from a HgCl2-resistant fungus
Wang Baojun,Li Wenzhong,Yang Huifang
环境科学学报(英文版) , 1995,
Abstract: Mercuric reductase is detected in Cephalosporium tabacinum F2.The enzyme, which is an intracellular one,catalyzes the reduction of mercuric ions to elemental mercury,which requires NADH as an electron donor and added sulfhydryl compound.The optimum temperature and pH of the enzymatic reaction are 30℃ and 7.0- 8. 0,respectively.The enzyme activity is stable in the range of 25- 30℃ for 40min,and stable at pH 7. 0 for 2 hours. Metal ions such as Ag+ ,CO2+), Cu2+,Zh2+, Mn2+,Ni2+ show different degrees of inhibitory effect on the enzyme activity,other compounds such as phenylmercury acetate and potassium ferricyanide also partially inhibit the enzyme activity.
A Novel Design Strategy for Temperature-Responsive IPN Hydrogels Based on a Copolymer of Acrylamide and N-(1,1-Dimethyl-3-Oxobutyl)-Acrylamide  [PDF]
Yu Wang, Huifang Xia, Jun Zhao, Xiuqin Cai, Shengke Chen, Bengxiu Li
Advances in Chemical Engineering and Science (ACES) , 2018, DOI: 10.4236/aces.2018.84018
Abstract: A methology is described for the synthesis of novel temperature-responsive interpenetrating polymer network (IPN) hydrogels with poly(2-acrylamido- 2-methylpropane sulfonic acid) (PAMPS) as a tightly crosslinked 1st network, temperature-responsive poly(acrylamide-co-N-(1,1-dimethyl-3-oxobutyl)- acrylamide) (P(AM-co-DAAM)) with low cost as a lossely crosslinked 2nd network. The structure and morphology of the IPN hydrogels were characterized by FTIR, TGA and SEM, and the results indicated that PAMPS network introduced P(AM-co-DAAM) hydrogels have large, thermally stable and interconnected porous network. The properties of the IPN hydrogels, which include: swelling capacity, equilibrium swelling/deswelling ratio, temperature- responsive behavior, and the dwelling kinetics as specific temperature, were investigated carefully. Results showed that the obtained IPN hydrogels displayed a controllable equilibrium swelling/deswelling behavior and possessed remarkable thermosensitivity. In addition, the results also indicate that the incorporation of the hydrophobic groups DAAM has a big effect on the LCST of the IPN hydrogels. Consequently, these novel temperature-responsive IPN hydrogels with low cost and slow-releasing performance would be promising for potential applications, such as environmental catalysis, water treatment, and agriculture.
Modeling the Soil Water Retention Curves of Soil-Gravel Mixtures with Regression Method on the Loess Plateau of China
Huifang Wang, Bo Xiao, Mingyu Wang, Ming'an Shao
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0059475
Abstract: Soil water retention parameters are critical to quantify flow and solute transport in vadose zone, while the presence of rock fragments remarkably increases their variability. Therefore a novel method for determining water retention parameters of soil-gravel mixtures is required. The procedure to generate such a model is based firstly on the determination of the quantitative relationship between the content of rock fragments and the effective saturation of soil-gravel mixtures, and then on the integration of this relationship with former analytical equations of water retention curves (WRCs). In order to find such relationships, laboratory experiments were conducted to determine WRCs of soil-gravel mixtures obtained with a clay loam soil mixed with shale clasts or pebbles in three size groups with various gravel contents. Data showed that the effective saturation of the soil-gravel mixtures with the same kind of gravels within one size group had a linear relation with gravel contents, and had a power relation with the bulk density of samples at any pressure head. Revised formulas for water retention properties of the soil-gravel mixtures are proposed to establish the water retention curved surface models of the power-linear functions and power functions. The analysis of the parameters obtained by regression and validation of the empirical models showed that they were acceptable by using either the measured data of separate gravel size group or those of all the three gravel size groups having a large size range. Furthermore, the regression parameters of the curved surfaces for the soil-gravel mixtures with a large range of gravel content could be determined from the water retention data of the soil-gravel mixtures with two representative gravel contents or bulk densities. Such revised water retention models are potentially applicable in regional or large scale field investigations of significantly heterogeneous media, where various gravel sizes and different gravel contents are present.
Activity test and mechanism study of an environmentally friendly wheat seed coating agent  [PDF]
Defang Zeng, Huifang Zhao
Agricultural Sciences (AS) , 2013, DOI: 10.4236/as.2013.47048
Abstract:

This novel environmentally friendly wheat seed coating agent which has been made with natural polymer as the primary material could increase yield by about 9% compared with the conventionally virulent wheat seed coating agent. In the premise of this production, the content of malondialdehyde (MDA) and peroxidase (POD) was determined. The results show that, after treated by the self-made wheat seed coating agent, the contents of the MDA were less than traditional group and the blank control group and POD contents were higher than traditional group and blank control group, this provides a good foundation on the further research of self-control wheat seed coating agent.

Preparation and characterization of three-dimensionally ordered macroporous polystyrene via atom-transfer radical polymerization
Xu Zhang,WeiDong Yan,HuiFang Yang,BaiQuan Wang
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-008-0541-9
Abstract: Three-dimensionally ordered macroporous polystyrene (3DOM PS) with pore size of 350 nm was fabricated using Cp2Co/ Ethyl 2-bromoisobutyrate (EBiB) catalytic system by ATRP. The resulting polymers were detected by FT-IR, 1H-NMR, SEM, and GPC. The microstructure of 3DOM PS was confirmed by FT-IR and 1H-NMR. SEM micrographs show that both silica spheres within the templates and pores in the 3DOM polystyrene are arranged in highly ordered fashion, and the shrinkage of the pores in the 3DOM PS is 24%. GPC curves show that the 3DOM PS possesses slightly lower M n and narrow MWD compared with bulk one. This result indicats that living polymerization is different from non-living polymerizationin in the confined space.
Se-Bearing Colloidal Particles Produced by Sulfate-Reducing Bacteria and Sulfide-Oxidizing Bacteria: TEM Study  [PDF]
Huifang Xu, Larry L. Barton
Advances in Microbiology (AiM) , 2013, DOI: 10.4236/aim.2013.32031
Abstract:

As determined by transmission electron microscopy (TEM), the reduction of selenate and selenite by Desulfovibrio desulfuricans, a sulfate-reducing bacterium, produces spherical (Se, S) sub-micro particles outside the cell. The particles are crystalline or amorphous, depending on medium composition. Amorphous-like Se-rich spherical particles may also occur inside the bacterial cells. The bacteria are more active in the reduction of selenite than selenate. The Desulfovibrio desulfuricans bacterium is able to extract S in the (S, Se) solid solution particles and transform S-rich particles into Se-rich and Se crystals. Photoautotrophs, such as Chromatium spp., are able to oxidize sulfide (S2-). When the bacteria grow in sulfide- and selenide-bearing environments, they produce amorphous-like (S, Se) globules inside the cells. TEM results show that compositional zonation in the (S, Se) globules occur in Chromatium spp. collected from a top sediment layer of a Se-contaminated pond. S2- may be from the products of sulfate-reducing bacteria. Both the sulfate-reducing bacteria and photosynthetic Chromatium metabolize S preferentially over Se. It is proposed that the S-rich zones are formed during photosynthesis (day) period, and the Se-rich zones are formed during respiration active (night) period. The results indicate that both Desulfovibrio desulfuricans and Chromatium spp. are able to immobilize the oxidized selenium (selenate and/or selenite) in the forms of elemental selenium and (Se, S) solid solutions. The bacteria reduce S in the (Se, S) particles and further enrich Se in the crystalline particles. The reduced S combines with Fe2+ to form amorphous FeS.

Phosphodiesterases Inhibition by Bacilli Calmette-Guérin Contributes to Decrease Asthma in Allergic Rats
Yajuan Wang1,Yali Jiang1,Huifang Tang,Xuefeng Wang
Iranian Journal Of Allergy, Asthma and Immunology , 2011,
Abstract: Phosphodiesterases (PDE) hydrolyse intracellular cAMP and cGMP to inactive 5' monophosphates. Decreased level of cAMP is involved in the pathogenesis of asthma. We and others have shown that phosphodiesterases were upregulated in the lung of allergic rats, and Bacilli Calmette-Guérin (BCG) induced the production of cAMP in vitro. However, it is unclear how BCG's effect asthma and whether it is related to PDEs.In this study, BCG was intraperitoneally injected into male Sprague-Dawley rats sensitized and later the rats were challenged with ovabumin/pertusis. The inflammation in lungs was measured. Airway hyperresponsiveness was determined using MedLab software after intravenous methacholine challenge. Furthermore, cAMP level and adenylate cyclase activity in lungs were analyzed by ELISA, phosphodiesterases activities were analyzed by HPLC, while PDEs mRNA levels in lungs was analyzed by reverse transcription-polymerase chain reaction. Administration of BCG significantly attenuated allergen-induced lung inflammatory response and hyper responsiveness as compared with vehicle treatment. Furthermore, the levels of cAMP in lungs were significantly increased in BCG-treated allergic rats. Interestingly, administration of BCG decreased the activity of cAMP-PDE, but not adenylyl cyclase (AC), activity in lungs of animals. Furthermore, pretreatment with BCG significantly decreased the mRNA levels of PDE4A, 4C, 5 and 8, which were induced in lungs of allergic rats. BCG administration attenuated airway inflammatory response and bronchial hyper responsiveness in rats, which are the most important symptoms in asthma. The decreased PDEs mRNA and inhibited cAMP-PDE activities by BCG contribute, at least in part, prevention of allergen-induced airway inflammation and asthma in rats.
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