Authors:Zhijia Fang, Song Wang, Xiuxiu Du, Ping Shi and Zhiwei Huang
Phosphatidate phosphatase-1 (PAP1) enzymes (yeast Pah1p/Smp2p, mammalian lipin1-3) have a key role in lipid homeostasis by controlling the relative proportions of its substrate phosphatidate (PA) and its product diacylglycerol (DAG). Recent investigation shows that mammalian lipin-1 complements phenotypes exhibited by yeast pah1Δ mutant cells, which indicates the functions of PAP1 enzymes are evolutionarily conserved. The observation was confirmed after transformation of human LPIN1 into PAH1-defective yeast, which resulted in human LPIN1-induced accumulation of triacylglycerol (TAG )and lipid droplet formation. In double mutants lacking Tgl3p and Tgl4p, overexpression of PAH1 or LPIN1 induced TAG accumulation and excessive obesity. Furthermore, the obese yeast was used as a model to study the anti-obesity effects of PAP1 activity inhibitors, including propranolol and clenbuterol. The data showed that the inhibitors significantly suppressed TAG accumulation and lipid droplets formation. These findings demonstrate that LPIN1 plays a functional role in lipid synthesis and storage, a role which is highly conserved from human to yeast. Inhibition of TAG synthesis will become an efficacious treatment strategy for obesity and our excessive obesity model will provide a very useful tool for discovery of new anti-obesity drugs in the future.
Authors:Ping Shi, Xiao-Xin Li, Wei Zhu, Hong Yang, Chi Dong and Xiao-Ming Li
C-reactive protein (CRP) is an established marker of inflammation and has been proposed to play a proinflammatory role in pathologies of several diseases. CRP is primarily produced by the liver and released into circulation as a pentameric molecule composed of five identical subunits. It has been suggested that the activation of the proinflammatory actions of CRP requires sequential conformational changes triggered by local inflammatory conditions. These include the dissociation into the subunit form (monomeric CRP, mCRP) and further reduction of the intra-subunit disulfide bond of mCRP. This model predicts that mCRP is the primary isoform present in inflamed but not healthy tissues, however the supporting evidence is lacking. Herein, we stained tissue samples across multiple anatomical locations from several types of human diseases with highly selective monoclonal antibodies that can differentiate CRP and mCRP. The results indicated that mCRP is the predominant form existing in the lesions. Further immunoblotting of the patient tissue samples revealed the potential presence of reduced mCRP. Together, we conclude that mCRP but not CRP is the major isoform present in local inflammatory lesions, supporting the so-called cascading model of CRP function and regulation.
Authors:Tsing-Hai Wang, Wen-Chun Yeh, Shih-Chin Tsai, Yi-Lin Jan and Shi-Ping Teng
We have examined the working diameter of capillary columns with diameter of 5, 7, 10 and 20 mm. These modified capillary columns
were carefully filled with local Taiwan laterite (LTL). The porosity and density of these packed columns was 0.51±0.02 g/g
and 1.27±0.05 g/cm3, respectively. The diffusion experiments were then carried out in synthetic groundwater with Cs loading of 0.1mM at room
temperature. Experimental results have shown that the diffusion profiles of modified capillary columns fit Fick’s second law
very well. This result revealed that the working diameter of a capillary column can be expanded to at least to 20 mm without
affecting the validity of the derived diffusion coefficients. Among these columns, the ones with 5 mm diameter show the most
consistent results of the derived Kd, apparent and effective diffusion coefficients. Although the derived distribution and effective diffusion coefficients slightly
decrease as the diameter of these columns increases due to the increase of the solid/liquid ratio. These values are still
informative of the Cs diffusion in local Taiwan laterite. Moreover, our results clearly demonstrate the potential of using
“modified capillary method” to study the diffusion behaviors of concerned radionuclide because columns with large diameter
enable the filling with more versatile geological substances.
Authors:Ping Zhang, Huisheng Shi, Ruan Xiuxiu, Qian Guangren and Ray L. Frost
Hydrocalumite (CaAl-Cl-LDH) has the similar structure to layered double hydroxide (LDH). The effects of Na-dodecylsulfate (SDS) on the structure, morphology, and thermal property of CaAl-Cl-LDH have been investigated. Through ion exchange, CaAl-Cl-LDH had been modified with SDS at two concentrations: 0.005 mol L−1 and 0.2 mol L−1. Two different adsorption behaviors were observed through Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) patterns. When the SDS concentration was 0.005 mol L−1, surface anion exchange was the major process. When the SDS concentration was 0.2 mol L−1, anion exchange intercalation occurs, with the interlayer distance expanded to 3.25 nm, and the particle morphology from regular hexagons to irregular platelets. The thermal analysis (TG–DTA) showed that dehydration and dehydroxylation occur at a lower temperature when hydrocalumite was intercalated with dodecylsulfate. All these observations revealed that the property of CaAl-Cl-LDH has been changed by SDS modification.
Authors:Ping Shi, Zhi Qin, Xiaorong Tan, Zhiwei Huang, Fuli Zeng and Ruwen Deng
Multitracer technique was used to study the uptake and distribution of some relatively long half-life radionuclides Be, Na, Mn, Co, Sc to growing cucumber (Cucumis Sativus L.) with two different treatments. In Hoagland solution, only 54Mn and 60Co accumulated in the every part of plants. 54Mn, 60Co and other radionuclides were absorbed in distilled water. The results indicate that there were major differences in the accumulation of trace elements between the two different treatments.
Authors:Shan Li, Zhi Qin, Zhenghu Shen, Xiaorong Tan, Ping Shi, Yafu Wang and Ruolan Dai
A convenient procedure for preparing a multitracer solution from irradiated silver foils by 80 MeV/nucleon 20Ne ions was developed. The carrier-free and salt-free solution containing 19 essential elements or trace elements for plant growth were prepared, and had been applied to study the regulation effect of metal ions on somatic embryogenesis of Lycium barbarum L.
Authors:Chuan-Pin Lee, Shih-Chin Tsai, Yuan-Yaw Wei, Shi-Ping Teng and Chun-Nan Hsu
This study focused on sorption mechanism of Cs and Se in mudrock by batch techniques. Batch kinetics tests have been conducted
with carriers 10−4M CsCl and SeO2 by using individual and coupling radiotracers of 137Cs and 75Se. The distribution coefficients (Kd) of Cs in synthetic groundwater (GW) and seawater (SW) showed that there is no interference between individual and coupling
value (13 and 6 ml/g). Moreover, individual and coupling Kd) (80 and 40 ml/g) of Se in GW and SW are in agreement with Cs. It is quite clear that the sorption mechanisms of Cs and Se
on mudrock are independent and different by using radiotracer’s technique.
Authors:Shih-Chin Tsai, Tsing-Hai Wang, Yi-Lin Jan, Yuan-Yaw Wei and Shi-Ping Teng
Retardation factor (Rf) is the most frequently used indicator to describe the transport of radionuclides through geological substances. In this
work, we compare the Rf values determined by four methods including direct experimental data, model fitting curve, integration technique and modeling
at two relative concentration (C/C0) 0.5 and 1.0 in a case study of Cs transport through crushed granite. A simple Q-test indicated all Rf values are valid at 96% confidence level. Meanwhile, the T-test demonstrated that the precision of Rf value is 4.21±0.39 at 90% and ±0.45 at 95% confidence level, which is about 9.3% and 10.7% of the average value of the Rf value. An uncertainty window of 10% is recommended in Rf value determination.
Authors:Chuan-Pin Lee, Yi-Lin Jan, Pei-Lun Lan, Yuan-Yaw Wei, Shi-Ping Teng and Chun-Nan Hsu
This study is focused on sorption and determination of distribution ratios (Rd) of cesium and selenium on mudrock, which is the potential host rock for waste disposal in Taiwan. Batch tests including
sorption kinetic and isotherms tests have been performed in synthetic groundwater at aerobic and anaerobic conditions which
might be found in the deep geologic environment. It is found that Rd for sorption of cesium did not have an obvious difference in both conditions with various contact time. However, Rd in anaerobic condition for sorption of selenium was greater than that in aerobic condition. Selenium is a redox sensitive
element and its solubility in reducing conditions is controlled by the formation of metallic or precipitable selenium. It
demonstrated variation of Rd with time in both conditions for Se sorption kinetic experiments was equal (10 ml/g) and indicated a part formation (10%)
of precipitable selenium (Se0, FeSe or FeSe2) in the solution. Moreover, it was not enough to form precipitable selenium completely in reducing condition as to insufficient
experimental period (2 weeks) and in the presence of Fe2+. The Freundlich and Langmuir isotherm for the concentration ranges (i.e., 10−3–10−7M) conducted in both conditions seem to be adequate to quantitatively describe the sorption of cesium and selenium, respectively.