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  • Author or Editor: Min Wei x
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Abstract  

Nanoscience and technology (NST) is a young scientific and technological field that has generated great worldwide interest in the past two decades. Previous bibliometric analyses have unmistakably demonstrated the remarkable growth of the global NST literature. While almost all published research articles in NST are in English, increasingly a larger share of NST publications is published in the Chinese language. Perplexingly, Chinese is the only language — apart from English — that displays an ascendant trend in the NST literature. In this brief note, we explore and evaluate three arguments that could explain this phenomenon: coverage bias, language preference, and community formation.

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Abstract

Objective

The present study was conducted to assess the effects of the GnRH agonist (alarelin) on the expression of GnRHR, FSHR and LHR mRNAs in the pituitary gland and uterine development in female mice.

Methods

Sixty pre-estrus female mice were randomly assigned to 4 groups (n = 15). The mice in experiment group 1 (EG-1), experiment group 2 (EG-2), and experiment group 3 (EG-3) were subcutaneously injected with 0.375 μg/kg, 0.75 μg/kg and 1.5 μg/kg alarelin antigen emulsion, respectively, once a day during 7 consecutive days to enhance immune response. Mice in the control group (CG) were injected with 0.l ml solvent once a day on 7 consecutive days. The samples of blood, pituitary and uterine horns were collected aseptically at day 21 from each mouse. Fluorescence quantitative RT-PCR was implemented to detect gene expression of GnRHR, FSHR and LHR in the pituitary glands. ELISA was used to measure the serum LH and FSH concentrations. The uterine slices were observed under an optical microscope; the images were measured using Motic software.

Results

(1) Compared to CG, the uterine weights in EG-1, EG-2 and EG-3 decreased by 34.43%, 54.10% and 55.74% (P < 0.05), respectively. (2) Uterine wall thickness in EG-1, EG-2 and EG-3 reduced by 8.64%, 8.04% and 14.03% (P < 0.05), respectively. Endometrial epithelium thickness in EG-1, EG-2 and EG-3 reduced by 29.43%, 28.55% and 38.49%, respectively, when compared with that of CG. (3) The 2−ΔΔCt values of GnRHR, FSHR and LHR mRNAs in the pituitary gland of EG-1 (P < 0.05), EG-2 (P < 0.01) and EG-3 (P < 0.01) were lower than that of CG. The uterine cavity in EG-1 slightly decreased. (4) Serum FSH concentrations in EG-1, EG-2 (P < 0.05) and EG-3 (P < 0.01) increased, with the highest increment in EG-3 (79.80%). Serum LH concentrations in the three EGs decreased (P < 0.05). (5) The uterine cavities and glandular lumen volumes in EG-2 and EG-3 narrowed, and the uterine wall became thinner obviously. The number of uterine glands in EG-3 decreased.

Conclusion

Alarelin antigen active immunization can suppress the expression of GnRHR, FSHR and LHR mRNAs in the pituitary gland, impact the secretion of FSH and LH, and obviously inhibit uterine growth and development, especially endometrial epithelial cells (EEC) and uterine gland. The effects were dose dependent.

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Planar electrochromatography in the reversed-phase mode has been performed in a commercially available development chamber, which requires only small modification for this purpose. This report illustrates that good separation quality and good reproducibility can both be obtained by use of this apparatus. Only short migration distances — less than 4.0 cm — were obtained under the conditions used.

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Abstract

Methyl ethyl ketone peroxide (MEKPO), which has highly reactive and exothermically unstable characteristics, has been extensively employed in the chemical industries. It has also caused many thermal explosions and runaway reaction accidents in manufacturing processes during the last three decades in Taiwan, Japan, Korea, and China. The goal of this study was to simulate thermal upset by MEKPO for an emergency response. Vent sizing package 2 (VSP2) was used to determine the thermokinetics of 20 mass% MEKPO. Data of thermokinetics and hazard behaviors were employed to simulate thermal explosion in three types of vessel containing 20 mass% MEKPO under various scenarios at the same volume. To compare and appraise the difference of important parameters, such as maximum temperature (T max), maximum pressure (P max), etc. This was necessary and useful for investigating the emergency response procedure associated with industrial applications.

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Abstract  

A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with aminomethylenediphosphonic acid (AMDP) was synthesized through a multiple-step reaction. HYNIC–AMDP could be labeled easily and efficiently with 99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) as coligand to form the 99mTc–HYNIC–AMDP complex in high yield (> 95%). Its partition coefficient indicated that it was a good hydrophilic complex. The biodistribution studies of 99mTc–HYNIC–AMDP in normal ICR mice showed that this complex had high bone uptake and low or negligible accumulation in non-target organs. As compared with 99mTc–MDP, 99mTc–HYNIC–AMDP had a higher bone uptake and the ratios of bone/blood and bone/muscle at early time after injection, suggesting that it could be potentially useful for bone imaging at an earlier time after injection according to further investigations of the biological behavior of this complex.

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Abstract

With two active O–O peroxide groups, 1,1-bis(tert-butylperoxy)cyclohexane (BTBPC) has a certain degree of thermal instability. It is usually used as an initiator in chemical processes, and therefore reckless operation may result in serious thermal accidents. This study focused on the runaway reactions of BTBPC alone and mixed with various concentrations of nitric acid (1, 2, 4, and 8 N). The essential thermokinetic parameters, such as exothermic onset temperature (T o), activation energy (E a), frequency factor (A), time to maximum rate under adiabatic condition (TMRad) and time to conversion limit (TCL), were evaluated by differential scanning calorimetry at the heating rate of 4 °C min−1, and a kinetics-based curve fitting method was used to assess the thermokinetic parameters. All the results indicated that BTBPC mixed with one more than 4 N nitric acid dramatically increased the degree of thermal hazard in the exothermic peak and became more dangerous. However, it was relatively safe for BTBPC mixed with less than 1 N nitric acid under 34.5 °C.

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Abstract

The decomposition of organic peroxides by their relatively weak oxygen linkage and hydroperoxide radical in the presence of reaction solution is one of the thermal hazards for triggering a runaway reaction. Runaway incidents may occur in oxidation reactors, vacuum condensation reactors, tank lorries, or storage tanks. In NFPA 432 organic peroxides in NFPA 432 are classified as flammable. The exothermic behaviors of solid organic peroxides, dicumene peroxide, benzoyl peroxide, and lauroyl peroxide, were determined by differential scanning calorimetry (DSC), and vent sizing package 2 (VSP2). Relevant data detected by DSC provided thermal stability information, such as exothermic onset temperature (T 0), maximum heat-releasing peak (T max), and heat of decomposition (ΔH d). VSP2 was used to perform the bench scale situation for pushing the expected or unexpected reaction to undergo runaway reaction. Onset temperature, maximum pressure, self-heating rate ((dT dt −1)max), and pressure-release rate ((dP dt −1)max) were therefore obtained and explained. These results are essentially crucial in process design for an inherently safer approach.

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Abstract  

In this work, a simple group separation scheme based on extraction for NAA determination of trace of As, Cd, Hg, Cu and Zn in biological materials is described. For this purpose, zinc-diethyldithiocarbamate, Zn(DDC)2, and methyl isobutyl ketone-iodide have been chosen as reagents. The elements can be extracted successively and quantitatively from strong mineral acids without adjusting pH of the solution, and separated into two groups suitable for gamma-ray spectrometry. Samples of 100–200 mg dry weight were double-sealed into polyethylene bags and irradiated in a swimming pool reactor with a thermal neutron flux of 1013n·cm–2·s–1 for 44 hours. After a cooling period of 1–3 days, the samples were digested with microgram quantities of carrier in concentrated nitric acid and sulfuric acid at 150°C for 3.5 hours in a teflon bomb, then extracted as described above. The reliability of the analytical method was checked using reference materials Horse Kidney IAEA H-8, Human Hair NIES-5 and Tomato Leaves NBS-1573. Most of the results obtained for reference materials agreed with the certified values12. Chinese autopsy samples of hair and liver were presented.

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Planar electrochromatography (PEC) is a mode of planar chromatography in which the mobile phase is driven by electroosmotic flow. The variables that affect the performance of PEC with an aqueous mobile phase on a bonded octadecylsilyl layer are discussed. These include the magnitude of the applied electric field, the concentration of the buffer salt, the pH of the mobile phase, and the concentration of acetonitrile used as the organic modifier. The effect of changing each of these variables is illustrated by model separations of a mixture of four compounds of diverse structure.

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Background and aims

Based on the foundations of Bandura’s social cognitive theory and theory of triadic influence (TTI) theoretical framework, this study was designed to examine the mediating role of positive outcome expectancy of Internet use in the relationship between social influence and Internet addiction (IA) in a large representative sample of senior high-school students in Taiwan.

Methods

Using a cross-sectional design, 1,922 participants were recruited from senior high schools throughout Taiwan using both stratified and cluster sampling, and a comprehensive survey was administered.

Results

Structural equation modeling and bootstrap analyses results showed that IA severity was significantly and positively predicted by social influence, and fully mediated through positive outcome expectancy of Internet use.

Discussion and conclusions

The results not only support Bandura’s social cognitive theory and TTI framework, but can also serve as a reference to help educational agencies and mental health organizations design programs and create policies that will help in the prevention of IA among adolescents.

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