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Abstract

When above certain temperature limits, lauroyl peroxide is an unstable material. If the thermal source cannot be properly governed during any stage in the preparation, manufacturing process, storage or transport, runaway reactions may inevitably be induced immediately. In this study, the influence of runaway reactions on its basic thermal characteristic was assessed by evaluating thermokinetic parameters, such as activation energy (E a) and frequency factor (A) by thermal activity monitor III (TAM III). This was achieved under five isothermal conditions of 50, 60, 70, 80, and 90 °C. Vent sizing package 2 (VSP2) was employed to determine the maximum pressure (P max), maximum temperature (T max ), maximum self-heating rate ((dT dt −1)max), maximum pressure rise rate ((dP dt −1)max), and isothermal time to maximum rate ((TMR)iso) under the worst case. Results of this study will be provided to relevant plants for adopting best practices in emergency response or accident control.

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Abstract  

In this paper, 3-amino-1-hydroxypropylidene-1,1-bisphosphonate(APB), a amidobisphophonate was synthesized and labeled with the α-emitter 211At by an indirect method using N-succinimidyl 5-(tributylstannyl)-3-pyridinecarboxylate (SPC) as a bi-functional linker, and the conjugated amidobisphophonate (211At-SAPC-APB) was preliminarily evaluated in vitro and in vivo by comparison with free astatide (211At) and 99mTc-MDP. 3-amino-1-hydroxypropylidene-1,1-bisphosphonate(APB) was prepared using β-alanine as the starting material. With SPC bi-functional linker, APB was conjugated with 211At in a labeling yield of 80–90% with radiochemical purity of more than 99%. The conjugated amidobisphophonate (211At-SAPC-APB) exhibited considerable stability in vitro, in that the radiochemical purity of 211At-SAPC-APB was still more than 98% in 0.1 mol/L PBS (pH 7.6) or in fetal calf serum, even stayed for 24 h at room temperature (RT). Biodistribution of 211At-SAPC-APB was investigated in NIH strain mice by I.V injection. The results showed that 211At-SAPC-APB could rapidly locate in shank, with the maximum uptake of 23.70 ± 2.29% I.D/g at 6 h, earlier than that of 99mTc-MDP at 12 h, and stayed in the bone for long time. Moreover, 211At-SAPC-APB uptake in some key organs or tissues, especially in thyriod, stomach, lung and spleen, was much less than that of free astatide (211At), implying that 211At-SAPC-APB was constantly stable in vivo as well as in vitro. These results indicated that 211At-SAPC-APB will be a suitable candidate for the targeted radiotherapy of bone metastases and should be further investigated.

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Abstract  

With 2,3,5,6-tetrafluorophenyl 3-(nodo-carboranyl) propionate (TCP) as a new potential bi-functional linker, bovine serum albumin (BSA) was conjugated with 211At, and the conjugated model protein (211At-TCP-BSA) was preliminarily evaluated in vitro and in vivo by comparison with 211At-SAB-BSA and 211At-SAPC-BSA, which conjugated with 211At via aryl derivatives ATE (N-succinimidyl-3-(tri-n-butylstannyl) benzoate) or SPC (N-succinimidyl 5-(tributylstannyl)-3-pyridinecarboxylate). The radiolabeled intermediate 211At-TCP was coupled to BSA in yields ranging from 35 to 45% with radiochemical purity of more than 98%. The conjugated 211At-TCP-BSA exhibited considerable stability in vitro in 0.1 mol/L PBS (pH 7.6) at room temperature (RT), similar to 211At-SAPC-BSA and 211At-SAB-BSA. Biodistribution of the 211At conjugated protein was investigated in NIH strain mice by I.V injection. The results showed that 211At-TCP-BSA was constantly stable in vivo as well as in vitro, but more stable than 211At-SAPC-BSA and 211At-SAB-BSA. These results implied that radioastatinated carboranes based on B–At bonds are higher stability than radioastatinated aryl derivatives based on C–At to in vivo deastatination. In other word, TCP should be a promising bi-functional linker for 211At conjugation of proteins or antibodies.

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Abstract

Brookite titania nanomaterials modified with gold nanoparticles (NPs) Au–TiO2 were prepared in this research. The photocatalytic activity of the prepared composite was assessed by the photodegradation of organic pollutants. Rhodamine blue was used as a model organic pollutant. The study determined the optimum loading ratio of Au/Ti, which will result in the best photodegradation efficiency. Also, the photocatalytic activity of gold loaded brookite titania nanomaterials was ascertained under visible light. The hydrothermal method was used to prepare brookite titania whiles, gold NPs were loaded on its surface by consecutive ion adsorption and photoreduction. The results revealed that the sample Au–TiO2 (Au/Ti = 2 % molar ratio) had the best photocatalytic degradation efficiency of 100 % after 2 h of irradiation under visible light and was also higher than commercial P25.

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Abstract  

Laser-induced optical fiber fluorimetry has been first used to analyze uranium(VI) concentration in the kinetic studies on the extraction of uranium(VI) between 0.5 mol/l H3PO4 solution and HDEHP-cyclohexane system with a Lewis cell. The effects of stirring speed, temperature and concentrations of uranium(VI) and HDEHP on the rate of extraction were examined. These data show that the extraction rate of uranium(VI) in this system is controlled by the chemical reaction at the interface. The rate equations and the rate constants of forward and reverse extraction are obtained. The mechanism of the extraction is discussed.

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Journal of Thermal Analysis and Calorimetry
Authors:
Sheng-Hung Wu
,
Chu-Chin Hsieh
,
Chung-Cheng Chiang
,
Jao-Jia Horng
,
Wei-Ping Pan
, and
Chi-Min Shu

Abstract

Volatile organic compounds (VOCs) and greenhouse gases are the main factors involved in pollution control and global warming. Various treatment methods involving incineration, adsorption, etc., have been employed to reduce VOCs and greenhouse gases concentration in the operating environment and atmosphere. Activated carbon, zeolite, silica gel, and alumina have been broadly used to adsorb pollutants in various industrial applications. Based on the promising effect of adsorption, we analyzed and identified the thermal phenomena of home-made zeolite using various instruments. The endothermic reaction under 100 °C of home-made zeolite was identified as steam adsorption, which is an important discovery. The optimal adsorption temperatures of home-made zeolite have been determined at 200–550 °C.

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Journal of Behavioral Addictions
Authors:
Wei-Ran Zhou
,
Min Wang
,
Hao-Hao Dong
,
Zhaojie Zhang
,
Xiaoxia Du
,
Marc N. Potenza
, and
Guang-Heng Dong

Abstract

Background

Internet gaming disorder (IGD) is a type of behavioral addiction characterized by poorly controlled and interfering patterns of game playing. Studies have suggested that the IGD is usually accompanied by increased desire or craving for gaming, suggesting that secondary rewards related to gaming may become more salient than those for primary rewards like food. However, this hypothesis has not been formally tested and potential neural mechanisms remain unclear.

Methods

This is a functional magnetic resonance imaging (fMRI) study. Twenty-one IGD subjects and 23 matched individuals with recreational game use (RGU) were scanned when exposed to gaming (secondary rewards), food (primary rewards) and neutral cues. Group-by-cue-type interaction analyses and subsequent within-group analyses for fMRI data were performed and seed-based functional connectivity (FC) analyses explored further potential neural features.

Results

IGD subjects’ subjective craving responses to gaming cues were higher than to food cues, while the opposite was observed in RGU subjects. Group-by-cue interaction effects implicated the precuneus and precuneus-caudate FC. Simple effect analysis showed that for IGD subjects, gaming-related cues elicited higher FC in precuneus-caudate relationships than did food-related cues. In the RGU subjects, the opposite was observed. Significant correlations were found between brain features and craving scores.

Conclusions

These results support the hypothesis regarding imbalances in sensitivities to different types of reward in IGD, and suggest neural mechanisms by which craving for gaming may make secondary rewards more salient than primary ones, thus promoting participation in addictive patterns of gaming.

Open access

Background and aims

This large-scale study aimed to test (a) associations of problematic Internet use (PIU) and sleep disturbance with suicidal ideation and suicide attempts among Chinese adolescents and (b) whether sleep disturbance mediates the association between PIU and suicidal behavior.

Methods

Data were drawn from the 2017 National School-based Chinese Adolescents Health Survey. A total of 20,895 students’ questionnaires were qualified for analysis. The Young’s Internet Addiction Test was used to assess PIU, and level of sleep disturbance was measured by the Pittsburgh Sleep Quality Index. Multilevel logistic regression models and path models were utilized in analyses.

Results

Of the total sample, 2,864 (13.7%) reported having suicidal ideation, and 537 (2.6%) reported having suicide attempts. After adjusting for control variables and sleep disturbance, PIU was associated with an increased risk of suicidal ideation (AOR = 1.04, 95% CI = 1.03−1.04) and suicide attempts (AOR = 1.03, 95% CI = 1.02−1.04). Findings of the path models showed that the standardized indirect effects of PIU on suicidal ideation (standardized β estimate = 0.092, 95% CI = 0.082−0.102) and on suicide attempts (standardized β estimate = 0.082, 95% CI = 0.068−0.096) through sleep disturbance were significant. Conversely, sleep disturbance significantly mediated the association of suicidal behavior on PIU.

Discussion and conclusions

There may be a complex transactional association between PIU, sleep disturbance, and suicidal behavior. The estimates of the mediator role of sleep disturbance provide evidence for the current understanding of the mechanism of the association between PIU and suicidal behavior. Possible concomitant treatment services for PIU, sleep disturbance, and suicidal behavior were recommended.

Open access
Acta Physiologica Hungarica
Authors:
Jin-Song Wei
,
Zhe-Bin Jin
,
Zhi-Qiang Yin
,
Qiang-Min Xie
,
Ji-Qiang Chen
,
Zi-Gang Li
, and
Hui-Fang Tang

In order to determine whether local anesthetics directly affect the propagation and strength of myometrial contractions, we compared the effects of bupivacaine, ropivacaine, lidocaine and tetracaine on the contractions of myometrium isolated from pregnant and non-pregnant rats. Full-thickness myometrial strips were obtained from 18- to 21-day pregnant and non-pregnant Sprague-Dawley rats and incubated in an organ bath. When spontaneous contractions became regular, strips were exposed to cumulative concentrations of the four local anesthetics ranging from 0.01 to 300 μmol/L and the amplitude and frequency of contraction were recorded. All four compounds caused a concentration-dependent inhibition of the contractility of pregnant and non-pregnant uterine muscle. In pregnant myometrium, the concentration that caused 50% inhibition (IC50) was 100 μmol/L for bupivacaine, 157 μmol/L for ropivacaine, > 1000 μmol/L for lidocaine, and 26.3 μmol/L for tetracaine. In non-pregnant myometrium, the IC50 was 26.9 μmol/L for bupivacaine, 40 μmol/L for ropivacaine, 384 μmol/L for lidocaine, and 7.4 μmol/L for tetracaine. These results suggested that local anesthetics do inhibit myometrial contractions in pregnant and non-pregnant rats in a concentration-dependent manner.

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Journal of Behavioral Addictions
Authors:
Qian Zhao
,
Yongjun Zhang
,
Min Wang
,
Jiecheng Ren
,
Yijun Chen
,
Xueli Chen
,
Zhengde Wei
,
Jingwu Sun
, and
Xiaochu Zhang

Abstract

Background and aims

Internet gaming disorder (IGD) leads to serious impairments in cognitive functions, and lacks of effective treatments. Cue-induced craving is a hallmark feature of this disease and is associated with addictive memory elements. Memory retrieval-extinction manipulations could interfere with addictive memories and attenuate addictive syndromes, which might be a promising intervention for IGD. The aims of this study were to explore the effect of a memory retrieval-extinction manipulation on gaming cue-induced craving and reward processing in individuals with IGD.

Methods

A total of 49 individuals (mean age: 20.52 ± 1.58) with IGD underwent a memory retrieval-extinction training (RET) with a 10-min interval (R-10min-E, n = 24) or a RET with a 6-h interval (R-6h-E, n = 25) for two consecutive days. We assessed cue-induced craving pre- and post-RET, and at the 1- and 3-month follow-ups. The neural activities during reward processing were also assessed pre- and post-RET.

Results

Compared with the R-6h-E group, gaming cravings in individuals with IGD were significantly reduced after R-10min-E training at the 3-month follow-up (P < 0.05). Moreover, neural activities in the individuals with IGD were also altered after R-10min-E training, which was corroborated by enhanced reward processing, such as faster responses (P < 0.05) and stronger frontoparietal functional connectivity to monetary reward cues, while the R-6h-E training had no effects.

Discussion and Conclusions

The two-day R-10min-E training reduced addicts’ craving for Internet games, restored monetary reward processing in IGD individuals, and maintained long-term efficacy.

Open access