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Miranda SG, Wang YJ, Purdie NG, Osborne VR, Coomber BL, Cant JP. Selenomethionine stimulates expression of glutathione peroxidase 1 and 3 and growth of bovine mammary epithelial cells in primary culture. J Dairy Sci 2009; 92:2670-83. [PMID: 19448000 DOI: 10.3168/jds.2008-1901] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This study examined the localization of cellular glutathione peroxidase (GPx1) and extracellular glutathione peroxidase (GPx3) in lactating mammary tissue and in primary cultures of bovine mammary epithelial cells (BMEC). The effect of selenium as selenomethionine (SeMet) on the growth and viability of BMEC and GPx protein expression and activity were also studied. Single mammary epithelial cells were recovered by serial collagenase/hyaluronidase digestion from lactating bovine mammary tissue and cultured in a low-serum collagen gel system enriched with lactogenic hormones and 0, 10, 20, or 50 nM SeMet. Positive immunostaining with anti-cytokeratin and bovine anti-casein confirmed the epithelial nature and differentiated state of BMEC. Addition of SeMet to media facilitated rapid confluence of BMEC and formation of dome structures. Immunohistochemical and immunocytochemical staining revealed that both GPx1 and GPx3 are synthesized by BMEC and localized in the cytoplasm and nucleus. Up to 50 nM SeMet linearly increased BMEC number and viability over 5 d of culture. Bovine mammary epithelial cells cultured in SeMet-supplemented medium also exhibited markedly elevated GPx activity and linear increases in abundance of GPx1 and GPx3 proteins. It is apparent that SeMet degradation to release Se for synthesis of selenoproteins is carried out by BMEC. Results indicate that bovine mammary epithelial cells express GPx1 and GPx3 in vivo and in vitro; SeMet enhances expression of these selenoproteins in vitro and the growth and viability of BMEC.
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Wang YJ, Ko M, Holligan S, McBride BW, Fan MZ, Swanson KC. Effect of dry matter intake on visceral organ mass, cellularity, and the protein expression of ATP synthase, Na+/K+-ATPase, proliferating cell nuclear antigen and ubiquitin in feedlot steers. CANADIAN JOURNAL OF ANIMAL SCIENCE 2009. [DOI: 10.4141/cjas08078] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Twenty-four steers [467 ± 7.2 kg initial body weight (BW)] predominately of Angus breeding were used to determine the effect of dry matter intake (1.25, 1.50, 1.75, and 2.00% of BW) on visceral mass, cellularity, and the protein expression of ATP synthase, Na+/K+-ATPase, proliferating cell nuclear antigen (PCNA) and ubiquitin. There were linear increases (P ≤ 0.05) in weights of total viscera, total digestive tract, liver, kidney, heart, lung, spleen, rumen, and abomasum with increasing dry matter intake (DMI). Protein concentration decreased linearly (P < 0.05) in small intestinal mucosa as DMI increased. PCNA expression increased linearly (P < 0.01) in liver as DMI increased. PCNA expression was affected quadratically (P < 0.05) in pancreas and small intestinal mucosa with an increase when DMI increased from 1.25 to 1.75% of BW, and a decrease when DMI increased from 1.75 to 2% of BW. ATP synthase, Na+/K+-ATPase, and ubiquitin expression in pancreas and ubiquitin expression in small intestinal mucosa increased linearly (P < 0.05) as DMI increased. These results indicate that increasing DMI increases the mass of visceral organs and carcass and influences expression of proteins influencing energy utilization and efficiency in pancreas, small intestine, liver, and sternomandibularis muscle.Key words: Dry matter intake, visceral organ mass, cellular energy metabolism, steer
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Yang LP, Wang YJ, Xu WH, Qin MP, Xiang T. A quantum transfer matrix method for one-dimensional disordered electronic systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:145407. [PMID: 21825338 DOI: 10.1088/0953-8984/21/14/145407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We develop a novel quantum transfer matrix method to study thermodynamic properties of one-dimensional (1D) disordered electronic systems. It is shown that the partition function can be expressed as a product of 2 × 2 local transfer matrices. We demonstrate this method by applying it to the 1D disordered Anderson model. Thermodynamic quantities of this model are calculated and discussed.
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Wu G, Paz MD, Chiussi S, Serra J, González P, Wang YJ, Leon B. Excimer laser chemical ammonia patterning on PET film. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20:597-606. [PMID: 18853239 DOI: 10.1007/s10856-008-3600-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Accepted: 09/23/2008] [Indexed: 05/26/2023]
Abstract
Laser is a promising technique used for biopolymer surface modification with micro and/or nano features. In this work, a 193 nm excimer laser was used for poly (ethylene terephthalate) (PET) surfaces chemical patterning. The ablation threshold of the PET film used in the experiments was 62 mJ/cm(2) measured before surface modification. Surface chemical patterning was performed by irradiating PET film in a vacuum chamber filled with ammonia at the flux of 10, 15, 20, 25 ml/min. Roughness of the surface characterized by profilometry showed that there were no significant observed change after modification comparing original film. But the hydrophilicity of the surface increased after patterning and a minimum water contact angle was obtained at the gas flux of 20 ml/min. FT-IR/ATR results showed the distinct amino absorption bands presented at 3352 cm(-1)and 1613 cm(-1) after modification and XPS binding energies of C(1s) at 285.5 eV and N(1s) at 399.0 eV verified the existence of C-N bond formation on the PET film surface. Tof-SIMS ions mapping used to identify the amine containing fragments corroborates that amino grafting mainly happened inside the laser irradiation area of the PET surface. A hypothesized radical reaction mechanism proposes that the collision between radicals in ammonia and on the PET surface caused by the incident laser provokes the grafting of amino groups.
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Chu CJ, Hung TH, Hwang SJ, Wang YJ, Yang CF, Lin HC, Lee FY, Lu RH, Chang CY, Chang FY, Lee SD. Association of insulin resistance with hepatic steatosis and progression of fibrosis in Chinese patients with chronic hepatitis C. HEPATO-GASTROENTEROLOGY 2008; 55:2157-2161. [PMID: 19260496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND/AIMS To investigate the relationships between insulin resistance, hepatic steatosis, and fibrosis in consecutive non-diabetic Chinese CHC patients with biopsy results. METHODOLOGY A total of 192 patients were enrolled. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR). Steatosis was assessed as the percentage of hepatocytes containing macrovesicular fat droplets and degree of hepatic fibrosis was graded by the METAVIR scoring system. RESULTS As compared with no steatosis group, patients with hepatic steatosis had significantly higher BMI (24.5+/-0.4 vs. 22.3+/-0.3 kg/m2, p<0.001) and HOMA-IR value (3.04+/-0.15 vs. 2.41+/-0.13, p=0.002). Patients with F3-F4 fibrosis had significantly lower ALT/AST ratio (1.38+/-0.06 vs. 1.76+/-0.05, p=0.022), lower platelet count (155+/-6 vs. 207+/-5 x 1000/cumm, p<0.001), and higher HOMA-IR value (3.29+/-0.17 vs. 2.50+/-0.12, p<0.001) as compared with F1-F2 fibrosis group. In addition, mean HOMA-IR progressively elevated along with the severity of hepatic fibrosis (F1: 2.04+/-0.15, F2: 2.77+/-0.17, F3: 3.11+/-0.25, F4: 3.46+/-0.23). Multivariate analyses showed platelet count <150,000/cumm (odds ratio: 3.88, 95% C.I.=2.87-12.05, p<0.001) and HOMA-IR >2.5 (odds ratio: 2.46, 95% C.I.=1.24-4.90, p=0.010) as independent factors associated with F3-F4 fibrosis. CONCLUSIONS In Chinese CHC patients, insulin resistance can occur in earlier stage of infection and closely related with hepatic steatosis and fibrosis.
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Chen XL, Xia ZF, Fang LS, Wang YJ, Wang CH. Co-graft of acellular dermal matrix and autogenous microskin in a child with extensive burns. ANNALS OF BURNS AND FIRE DISASTERS 2008; 21:102-106. [PMID: 21991120 PMCID: PMC3188161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/22/2007] [Indexed: 05/31/2023]
Abstract
A 6-yr-old boy was the victim of a burns accident in a public bathhouse. The burns involved the face, neck, upper and lower extremities, anterior and posterior trunk, and both buttocks, covering 72% of the total body surface area (TBSA). The lesions in the lower extremities and parts of the right upper extremity were deep partial-thickness, comprising 40% TBSA. On day 5 post-burn, the lesions in both lower extremities were excised to the extent of the fascia under general anaesthesia. Meshed J1 Jayya Acellular Dermis®, a kind of acellular allodermal (ADM) matrix, was then placed on the left knee joint. The right knee joint served as control. The wounds in both lower extremities were then overlaid with microskin autografting. At 19 days post-application, the lesions in both lower extremities had almost completely resurfaced. Follow-up at six months revealed well-healed and stable skin of acellular ADM and microskin autografts on the left knee. However, the skin of the right knee was unstable and there was a chronic residual ulcer. Both legs showed some significant hypertrophic scars. The left knee joint (acellular ADM grafted site) showed mild contractures, while the right knee joint developed a significant contracture. The "skin" of the co-graft covered site appeared thicker and more elastic. The movement range of the left knee joint was much larger than that of the right knee joint. These results suggest that co-graft of acellular dermal matrix and autogenous microskin may be an effective way to repair this functional site in children with extensive burns and to improve the functional and cosmetic results.
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Cao J, Vergara LI, Musfeldt JL, Litvinchuk AP, Wang YJ, Park S, Cheong SW. Spin-lattice interactions mediated by magnetic field. PHYSICAL REVIEW LETTERS 2008; 100:177205. [PMID: 18518332 DOI: 10.1103/physrevlett.100.177205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Indexed: 05/26/2023]
Abstract
Application of a magnetic field offers an incisive opportunity to tune competing interactions in complex materials. Here we probe field-induced changes in the local structure of DyMn2O5 by using magnetoinfrared spectroscopy. The high tunability of the dielectric constant and ferroelectric polarization with field is well documented in the literature, but the lattice response on the microscopic level remains unknown. In this work, we reveal the dynamic nature of the local structural response to field and analyze it in terms of calculated mode displacements and local lattice distortions.
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Swanson KC, Kelly N, Salim H, Wang YJ, Holligan S, Fan MZ, McBride BW. Pancreatic mass, cellularity, and alpha-amylase and trypsin activity in feedlot steers fed diets differing in crude protein concentration. J Anim Sci 2008; 86:909-15. [PMID: 18192547 DOI: 10.2527/jas.2007-0514] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Twenty-four yearling beef steers (initial BW = 510 +/- 4.9 kg) predominantly of Angus breeding were used in a randomized complete block design to determine the effect of dietary CP concentration on pancreatic cellularity, mass, and alpha-amylase and trypsin activities. Treatment diets were formulated to contain 8.8, 11.0, 13.2, and 15.4% CP. Soybean meal and Top Soy (ruminal bypass soybean meal) were used as supplemental protein sources to ensure that MP intake was increased with increasing dietary CP concentrations. Steers were penned in groups of 4 (1 steer per treatment) and individually fed at 2.5x the NE(m) requirement by using Calan gates for 28 d before tissue collection. Four steers (1 pen) were slaughtered per week. Pancreases were weighed, subsampled, frozen in liquid N(2), and stored at -80 degrees C until analyses for DNA, RNA, and protein concentrations, and alpha-amylase and trypsin activities. Pancreatic weight (g and g/kg of BW) did not differ among treatment groups. Pancreatic DNA concentration (mg/g) decreased linearly (P = 0.06) with increasing CP concentration. Pancreatic protein (g/pancreas) increased linearly (P = 0.08) with increasing dietary CP concentration. Pancreatic alpha-amylase activity (U/g, U/mg of DNA, U/g of protein, U/pancreas, and U/kg of BW) increased linearly (P < or = 0.04) with increasing dietary CP concentration. Pancreatic trypsin activity (U/g, U/g of DNA, U/g of protein, U/pancreas, and U/kg of BW) increased linearly (P < or = 0.09) with increasing dietary CP concentration. Pancreatic alpha-amylase and trypsin activities (U/mg of RNA) responded quadratically (P < or = 0.09), with the greatest alpha-amylase activity observed in the 13.2% CP treatment. These data indicate that increasing dietary CP concentration decreases pancreatic cell numbers and also increases the concentration and content of pancreatic alpha-amylase and trypsin activities. Changes in cell number and size may be important factors regulating digestive enzyme production in the pancreas of cattle.
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Ren NQ, Chua H, Chan SY, Tsang YF, Wang YJ, Sin N. Assessing optimal fermentation type for bio-hydrogen production in continuous-flow acidogenic reactors. BIORESOURCE TECHNOLOGY 2007; 98:1774-80. [PMID: 16935495 DOI: 10.1016/j.biortech.2006.07.026] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 07/03/2006] [Accepted: 07/03/2006] [Indexed: 05/11/2023]
Abstract
In this study, the optimal fermentation type and the operating conditions of anaerobic process in continuous-flow acidogenic reactors was investigated for the maximization of bio-hydrogen production using mixed cultures. Butyric acid type fermentation occurred at pH>6, propionic acid type fermentation occurred at pH about 5.5 with E(h) (redox potential) >-278mV, and ethanol-type fermentation occurred at pH<4.5. The representative strains of these fermentations were Clostridium sp., Propionibacterium sp. and Bacteriodes sp., respectively. Ethanol fermentation was optimal type by comparing the operating stabilities and hydrogen production capacities between the fermentation types, which remained stable when the organic loading rate (OLR) reached the highest OLR at 86.1kgCOD/m(3)d. The maximum hydrogen production reached up to 14.99L/d.
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Wang YJ, Hua FL, Tsang YF, Chan SY, Sin SN, Chua H, Yu PHF, Ren NQ. Synthesis of PHAs from waster under various C:N ratios. BIORESOURCE TECHNOLOGY 2007; 98:1690-3. [PMID: 16844370 DOI: 10.1016/j.biortech.2006.05.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 05/26/2006] [Accepted: 05/26/2006] [Indexed: 05/10/2023]
Abstract
Polyhydroxyalkanoates (PHAs) production was carried out under various C:N ratios. A ratio of 100 resulted best polymer yield. C-source was an important factor in synthesis. For example, as the ratio of valeric acid (C5) to butyric acid (C4) in N-free medium was increased, the mole fraction of HV in the copolymer increased. When soy waste was used as a C-source a copolymer, a high HV mole fraction (HB:HV, 75:25) was produced while when malt waste was used, a much lower HV mole fraction (HB:HV, 90:10) was generated. It was concluded that activated sludge bacteria could be induced to produce PHAs using food wastes as C-sources and this could be the basis for production of biodegradable plastics.
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Chu CJ, Wang YJ, Hwang SJ, Lu RH, Chang FY, Chang CY, Yang YC, Lee SD. Kinetics of hepatitis C virus RNA load during pegylated interferon plus ribavirin therapy in Treatment-naive Chinese patients. HEPATO-GASTROENTEROLOGY 2007; 54:866-70. [PMID: 17591081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND/AIMS To investigate the viral kinetics of Chinese CHC patients received pegylated interferon plus ribavirin and examine the impact of HCV genotypes and severity of liver disease. METHODOLOGY 65 treatment-naove CHC patients who finished a 24-week therapy with peginterferon (alpha-2b (1.5 mcg/kg/week) plus ribavirin (1000-1200 mg /day) and 24 weeks of follow-up were enrolled. Hepatic fibrosis was graded by the METAVIR scoring system. Serum quantitative HCV RNA was determined by Versant HCV RNA 3.0 assay (Bayer Inc.). RESULTS Genotype non-1 patients responded quickly and a higher percentage of them achieved undetectable HCV RNA (< 615 IU/mL) at week 4 compared with genotype 1 patients (93% vs. 69%, p = 0.018). Degree of hepatic fibrosis significantly affected end-of-treatment and sustained response (SVR). For patients who did not achieve early virological response (EVR), the negative predictive value for SVR was 100%. In genotype 1 patients, undetectable HCV RNA by week 4 was a good marker to predict treatment response, with a positive predictive value of 84% and a negative predictive value of 82%. CONCLUSIONS EVR can be applied to Chinese patients as an early stopping rule. A 24-week duration of pegylated IFN/ribavirin might be adequate for genotype 1 patients who rapidly responded to therapy.
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Wang YJ, Xu SJ, Zhao DG, Zhu JJ, Yang H, Shan XD, Yu DP. Non-exponential photoluminescence decay dynamics of localized carriers in disordered InGaN/GaN quantum wells: the role of localization length. OPTICS EXPRESS 2006; 14:13151-13157. [PMID: 19532212 DOI: 10.1364/oe.14.013151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this article, we report a combined experimental and theoretical study on the luminescence dynamics of localized carriers in disordered InGaN/GaN quantum wells. The luminescence intensity of localized carriers is found to exhibit an unusual non-exponential decay. Adopting a new model taking the radiative recombination and phonon-assisted hopping transition between different localized states into account, which was recently developed by Rubel et al., the non-exponential decay behavior of the carriers can be quantitatively interpreted. Combining with precise structure characterization, the theoretical simulations show that the localization length of localized carriers is a key parameter governing their luminescence decay dynamics.
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Ning CY, Wang YJ, Lu WW, Qiu QX, Lam RWM, Chen XF, Chiu KY, Ye JD, Wu G, Wu ZH, Chow SP. Nano-structural bioactive gradient coating fabricated by computer controlled plasma-spraying technology. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2006; 17:875-84. [PMID: 16977384 DOI: 10.1007/s10856-006-0176-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Accepted: 08/23/2005] [Indexed: 05/11/2023]
Abstract
The poor mechanical property of hydroxyapatite was the major problem for load bearing and implant coating in clinical applications. To overcome this weakness, a bioactive gradient coating with a special design composition of hydroxyapatite (HA), ZrO2, Ti, bioglass was developed. This 120 microm coating with an upper layer of 30-50 microm porous HA produced by computer controlled plasma spraying which maintained energy level of the plasma which ensure proper melting of powder. The crystal size of the coating was 18.6-26.2 nm. Transformation of t-ZrO2 to m-ZrO2 reduced the thermal stress that weakened the coating and lowered down interfacial strength of the coating and metal substrate. Thermal stress of sprayed coating was 16.4 MPa which was much smaller than the sample without thermal treatment of 67.1 MPa. Interfacial strength between the coating and metal substrate was 53 MPa which is much higher than conventional Hydroxyapatite coating. Based on XRD analysis crystallinity of HA approached 98%. Therefore, high temperature treatment improved long term stability of the coating through improved crystallinity of hydroxyapatite and reduced other impure calcium phosphate phase.
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Xu JH, Li SW, Tan J, Wang YJ, Luo GS. Controllable preparation of monodisperse O/W and W/O emulsions in the same microfluidic device. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:7943-6. [PMID: 16952223 DOI: 10.1021/la0605743] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This letter presents a simple way to prepare monodisperse O/W and W/O emulsions in the same T-junction microfluidic device just by changing the wetting properties of the microchannel wall with different surfactants. Highly uniform droplets ranging from 50 to 400 mum with a polydispersity index (sigma) value of less than 2% were successfully prepared. With the change in surfactants and surfactant concentrations, the interfacial tension and the wetting properties varied, and disordered or ordered two-phase flow patterns could be controllable. Monodisperse O/W and W/O emulsions were prepared under the action of a cross-flowing shear force or a perpendicular shear force by using an oil solution with 0.1-2.0 wt % Span 80 and an aqueous solution with 0.1-2.0 wt % Tween 20 as a continuous-phase flow, respectively. It gives a controllable method of preparing O/W and W/O emulsions in the same microfluidic device.
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Wang YJ, Zheng YG, Zheng RC, Shen YC. Stability study on the nitrile hydratase of Nocardia sp. 108: from resting cell to crude enzyme preparation. PRIKLADNAIA BIOKHIMIIA I MIKROBIOLOGIIA 2006; 42:434-7. [PMID: 17022452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In recent years, nitrile hydratases (NHases) have drawn increasing attentions due to their critical roles in organic synthesis. In present paper, extensive investigation on the stability and activity of the NHase from Nocardia sp. 108, which is succeed in the industrial application in China, were conducted by the bioconversion of acrylonitrile to acrylamide in a batch manner. Cultivation study demonstrated that biosynthesis of NHase changed significantly with culture time, and the optimal NHase biosynthesis phase was 45 h after inoculation with NHase activity of 1209.8 U/g of biomass. Stability study indicated that crude enzyme preparation both exhibit a good stability when exposed to the pH 7.2 tris-HCl buffer at 4 degrees C for 4 h.
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Yang LM, Wang YJ, Sun YW, Luo GS, Dai YY. Synthesis of micrometer-sized hard silica spheres with uniform mesopore size and textural pores. J Colloid Interface Sci 2006; 299:823-30. [PMID: 16616179 DOI: 10.1016/j.jcis.2006.02.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 02/18/2006] [Accepted: 02/21/2006] [Indexed: 11/28/2022]
Abstract
Micrometer-sized silica spheres were prepared using a new pH-induced rapid colloid aggregation method in water-in-oil (W/O) emulsion separately with F127 and the mixture of Pluronic triblock copolymer (F127, P123, or P105) and PEG20000 as templates. All the mesoporous silica spheres exhibited high surface areas (657-1145 m2/g) and large pore volumes (0.46-2.16 ml/g). Through optimizing the synthetic conditions, hard silica spheres with narrow particle size distribution, uniform pore size, and textural pores were obtained. Finally, the mechanism of this synthetic route is discussed.
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Wang YJ, Tsui OKC. Unconventional spinodal surface fluctuations on polymer films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:1959-63. [PMID: 16489774 DOI: 10.1021/la052750y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We study the temporal growth pattern of surface fluctuations on a series of spinodally unstable polymer films where the instability can be adjusted with the film thickness, h0. For the most unstable film studied (whose /(h0 - h(sp))/h(sp)/ = 0.988; h(sp) is the thickness where the second derivative of the interfacial potential of the film equals zero), the growth rate function of the surface modes as a function of the wavevector fits well to the mean-field theory. When the film thickness is increased such that /(h0 - h(sp))/h(sp)/ < or = 0.977, the mean-field theory demonstrates marked disagreement with experiment, notwithstanding the provision of the known corrections from nonlinear effects and thermal noise. We show that the deviations arise from large-amplitude fluctuations induced by homogeneous nucleation, which are not considered in the conventional treatments.
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Dordevic SV, Beach KSD, Takeda N, Wang YJ, Maple MB, Basov DN. Heavy fermion fluid in high magnetic fields: an infrared study of CeRu4Sb12. PHYSICAL REVIEW LETTERS 2006; 96:017403. [PMID: 16486514 DOI: 10.1103/physrevlett.96.017403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2004] [Indexed: 05/06/2023]
Abstract
We report a comprehensive infrared magnetospectroscopy study of a CeRu4Sb12 compound revealing quasiparticles with a heavy effective mass m*, with a detailed analysis of optical constants in fields up to 17 T. We find that the applied magnetic field strongly affects the low-energy excitations in the system. In particular, the magnitude of m* approximately = 70 m(b) (m(b) is the quasiparticle band mass) at 10 K is suppressed by as much as 25% at 17 T. This effect is in quantitative agreement with the mean-field solution of the periodic Anderson model augmented with a Zeeman term.
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Liu N, Zhang T, Wang YJ, Huang YP, Ou JH, Shen P. A heat inducible tyrosinase with distinct properties from Bacillus thuringiensis. Lett Appl Microbiol 2004; 39:407-12. [PMID: 15482430 DOI: 10.1111/j.1472-765x.2004.01599.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
AIMS The objective of this work was to purify the tyrosinase from Bacillusthuringiensis subsp. kurstaki (Bt) (CCTCC AB 90010) and study its enzymatic properties. METHODS AND RESULTS A 'one-step' purification method was used in this work, which was an easy, high-yield purification method. Tyrosinase activity of this purity was measured under different conditions to study its kinetic characterizations. The optimum pH and thermal stability of this enzyme were also determined. The results revealed that the tyrosinase from Bt has distinct properties compared with those from other sources. CONCLUSIONS A heat-inducible tyrosinase of a wild strain of Bt was identified and partially characterized. SIGNIFICANCE AND IMPACT OF THE STUDY The distinct properties of Bt tyrosinase are important to the application of Bt as a biology pesticide.
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Sawant MS, Zhang SC, Wang QY, Wang YJ. Production of interspecies chimeras by transplanting rosy barb (Puntius conchonius) embryonic cells to zebrafish (Danio rerio) embryos. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2004; 42:830-6. [PMID: 15573536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Establishment of a cell-mediated gene transfer system has potential as a new breeding technique for commercially valuable fishes. As an important step toward developing an inter-species chimera, cells from blastula-stage embryos of rosy barb (Puntius conchonius) were transplanted into zebrafish (Danio rerio) blastula-stage embryos to observe the development of the recipient. From the total of 473 transplants obtained only a fraction of 13 chimeras appeared perfectly normal after one month. Over two in normal 13 chimeras showed some characters from the donor cells with scarce pigmentation. This is the first successful inter-species study on zebrafish by using blastula cell transplants from rosy barb both belonging to the same family cyprinidae.
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Guo W, Luo GS, Wang YJ. A new emulsion method to synthesize well-defined mesoporous particles. J Colloid Interface Sci 2004; 271:400-6. [PMID: 14972618 DOI: 10.1016/j.jcis.2003.08.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2003] [Accepted: 08/16/2003] [Indexed: 11/19/2022]
Abstract
A new emulsion method for preparing ordered mesoporous materials with polymer PEG as the swelling agent has been explored in the present work. The synthesis conditions including the chain length and the PEG concentration, the duration of aging, the kind of emulsion, and the time when the swelling agents were added to the reaction system are discussed. The results show that with the advantage of the emulsion method, the nucleation and growth were controlled very well. The nicely spherical particles produced by the emulsion method were more uniform and less prone to agglomerate than those produced through the hydrothermal method. When different MW PEG were added as swelling agents, the pore size changed little: it was centered around 4 nm and had a narrow distribution. When different concentrations of PEG were applied, BET surface area, pore size, and pore volume changed. To summarize, in the formation of mesoporous materials, polymers such as PEG can not only control the pore size from 3 to 70 nm through variation of concentration, but also regulate the structures and improve the morphology of particles by the chain length of polymers. By adjusting the time of addition of the swelling agents, a poroshell mesoporous material was prepared. This method is particularly important for those applications that strictly require particle uniformity, such as chromatography separation.
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Tsui OKC, Wang YJ, Zhao H, Du B. Some views about the controversial dewetting morphology of polystyrene films. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2003; 12:417-425. [PMID: 15007769 DOI: 10.1140/epje/e2004-00010-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Huang HC, Huang YS, Wu JC, Tsay SH, Huo TI, Wang YJ, Lo JC, Chen CY, Li CP, Chang FY, Lee SD. Characteristics of autoimmune hepatitis in Taiwan: the 11 years' experiences of a medical center. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 2002; 65:563-9. [PMID: 12636201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
BACKGROUND Unlike in Western countries, autoimmune hepatitis (AIH) is an infrequent diagnosis in Taiwan. The clinical characteristics of AIH in this area are unclear. The aim of this study was to elucidate the clinical features of AIH in Taiwan. METHODS All the medical records of in-patients with the diagnosis of chronic hepatitis in our hospital from 1990 to 2001 were reviewed for the possibility of AIH. The clinical features, biochemical data, immunological presentations, treatments and survival of the patients were evaluated. RESULTS Twenty-two patients (15 females and 7 males) were diagnosed as having AIH within 11 years. The median age at onset was 64 years (range: 17-77 years). Compared with female patients, male patients had older age (p = 0.001), shorter duration from initial presentation of symptoms to diagnosis (p = 0.015), lower serum levels of alkaline phosphatase (ALK-P, p = 0.022) and albumin (p = 0.043). Five (23%) patients presented with cirrhosis upon diagnosis. Compared with non-cirrhotic patients, cirrhotic patients had lower serum levels of alanine aminotransferase (p = 0.002), aspartate aminotransferase (p = 0.015), gamma-glutamyl transferase (G-GT, p = 0.002), albumin (p = 0.14), white cell counts (p = 0.009) and platelet counts (p = 0.002). Thirteen (59%) patients had concomitant clinico-pathological features of cholestatic liver disease (ALK-P > or = 2 times of upper normal limit or pathologic evidence of cholangiopathy). They had higher serum levels of ALK-P (p < 0.001) and G-GT (p = 0.004) than 9 non-cholestatic patients. There were no significant differences in survival between these groups. The prescribed initial and maintained prednisolone dosages for our patients to control disease activity were 19 +/- 15 mg and 8 +/- 1 mg, respectively, which were lower than those recommended in Western countries. The remission rate to steroid treatment and relapse rate after discontinuing corticosteroids were 87.5% and 50%, respectively. CONCLUSIONS Compared with Western AIH patients, the AIH patients in Taiwan are older and more likely to develop cholestasis, and need a relatively lower dose of steroid for treatment. Owing to one quarter of the patients already having liver cirrhosis on diagnosis, AIH should be suspected in any Taiwanese patient with cryptogenic hepatitis or cirrhosis.
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Luo JC, Hwang SJ, Chang FY, Chu CW, Lai CR, Wang YJ, Lee PC, Tsay SH, Lee SD. Simple blood tests can predict compensated liver cirrhosis in patients with chronic hepatitis C. HEPATO-GASTROENTEROLOGY 2002; 49:478-81. [PMID: 11995477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
BACKGROUND/AIMS Twenty to fifty percent of patients with chronic hepatitis C virus infection will insidiously progress to cirrhosis after 10-20 years' follow-up. The aim of this study is to retrospectively evaluate the role of simple non-invasive blood tests in detecting the presence of compensated liver cirrhosis in Chinese patients with chronic hepatitis C. METHODOLOGY One hundred and eleven biopsy-proven chronic hepatitis C patients were enrolled, 23 (20.7%) patients showed cirrhosis with class A in Child-Pugh's classification and were all asymptomatic. Liver biochemistry, complete blood count, and serum N-terminal propeptide of type III procollagen were determined and then compared between chronic hepatitis C patients with compensated cirrhosis and without cirrhosis. Multivariate logistic regression analysis was used to predict factors associated with compensated cirrhosis. RESULTS Multivariate logistic regression analysis showed platelet count < or = 140,000/mm3 (odds ratio: 23.44, P < 0.001), globulin/albumin ratio > or = 1 (odds ratio: 31.47, P = 0.008), and AST/ALT ratio > or = (odds ratio: 6.58, P = 0.035) were significant predictors associated with hepatitis C virus-related compensated cirrhosis. Platelet count < or = 140,000/mm3 had 83% sensitivity and 85% specificity in detecting liver cirrhosis. Globulin/albumin ratio > or = 1 had 43% sensitivity, 98% specificity and AST/ALT ratio > or = 1 had 39% sensitivity, 92% specificity in detecting liver cirrhosis. Combined tests with AST/ALT > or = 1 and globulin/albumin > or = 1, platelet count < or = 140,000/mm3 and globulin/albumin > or = 1 had 100% specificity, 100% positive predictive value but lower sensitivity (22% and 39% respectively), lower negative predictive value (83% and 86%, respectively) in detecting hepatitis C virus-related compensated liver cirrhosis. CONCLUSIONS Simple blood tests with platelet count < or = 140,000/mm3, globulin/albumin ratio > or = 1, and AST/ALT ratio > or = 1 can indicate liver cirrhosis in follow-up patients with chronic hepatitis C.
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Dong AG, Wang YJ, Tang Y, Ren N, Yang WL, Gao Z. Fabrication of compact silver nanoshells on polystyrene spheres through electrostatic attraction. Chem Commun (Camb) 2002:350-1. [PMID: 12120069 DOI: 10.1039/b110164c] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nanoshells composed of close-packed silver nanocrystals have been fabricated on polystyrene spheres via direct electrostatic attraction at appropriate pH; the thickness and roughness of the shell can be readily controlled through a layer-by-layer technique.
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