Search Results
You are looking at 1 - 9 of 9 items for
- Author or Editor: Wang Li-Jian x
- Refine by Access: All Content x
A new AMD instrument made in our laboratory is described in this paper. The main advantages of the instrument are very low cost both of construction and in use. Compared with ascending development in conventional instruments, a laboratory-made horizontal sandwich chamber is used for development, and, with the help of a series of special accessories, no obvious mobile phase remains in the distributor after each step; this saves a large amount of solvent. All the components of the instrument are easy to obtain, so the average worker in a chemical laboratory could construct all the instrument except the control unit. An application of the instrument is described; the results obtained were satisfactory.
Abstract
The synergistic extractions of uranium(VI) from hydrochloric acid solution and sulfuric acid solution with 1-phenyl-3-methyl-4-(2
-chlorobenzoyl)-pyrazolone-5 (PMCBP) together with the neutral extractants: tributyl phosphate(TBP), di-octyl sulfoxide(DOSO) and trioctylphosphine oxide(TOPO) in chloroform have been investigated. A high synergistic extraction effect was found. The formulas of the extracted species have been shown to be UO2A2B (where A=PMCBP, B=neutral extractant). The synergistic extraction power increases as follows: PMCBP-TOPO>PMCBP-DOSO>PMCBP-TBP. The equilibrium constants have been calculated. Models for the extraction mechanism are also discussed.
Abstract
Background and aims
Internet gaming disorder (IGD) in adolescents is a concerning issue. Positive parenting has been found to protect against adolescent IGD, but the underlying mechanisms await further investigation. As such, this study examined the longitudinal association between parental involvement (PI) – a specific type of positive parenting understudied in the literature of adolescent gaming disorder – and IGD. Moreover, this study also tested consideration of future consequences (CFC) as a mediator and peer victimization (PV) as a moderator.
Methods
A two-wave longitudinal research spanning 6 months apart was conducted. Participants were Chinese adolescents (final N = 434; 222 females; M age = 14.44 years, SD = 1.56). They provided ratings on PI, PV, and IGD at Wave 1, and CFC-immediate, CFC-future, and IGD at Wave 2.
Results
Descriptive statistics showed that the prevalence rate of IGD was 10.81% and 9.45% at Waves 1 and 2, respectively. Moreover, results of moderated mediation model found that after controlling for Wave 1 IGD and covariates, Wave 1 PI was associated with Wave 2 IGD via preventing adolescents who had higher levels of PV from developing a tendence of CFC-immediate and via promoting adolescents who had lower levels of PV to develop a tendence of CFC-future.
Discussion and Conclusions
Altogether, these results suggest that facilitative ecological systems (e.g., positive parenting and good relationships with peers) and personal strengths (e.g., positive future orientation) jointly contribute to the mitigation of adolescent IGD.
Our studies explore the changes of blood corticosterone (CORT), adrenocorticotropic hormone (ACTH), interleukin (IL)-1β, IL-2, IL-6 concentrations and the pituitary ACTH expression in rats after water floating in the presence or absence of following high-intensity exercise. The rats were randomly assigned into three groups. Group A served as control; Group B received 180 minutes water floating and psychological (fear) stimulation; Group C received the same treatment as Group B in addition and 120-minutes non-stop running. Compared to Group A, Group B showed a significant increase of IL-2 (19.91 ± 2.52 vs. 13.09 ± 3.13 ng/ml, P < 0.05), and IL-6 (0.18 ± 0.08 vs. 0.12 ± 0.05 ng/ml, P < 0.05); Group C demonstrated a significant increase of CORT (977.22 ± 207.36 ng/ml vs. 434.58 ± 110.45 ng/ml, P <0.01) and IL-1β (0.21 ± 0.04 vs. 0.16 ± 0.06 ng/ml, P < 0.05), IL-2 (20.29 ± 4.23 vs. 13.09 ± 3.13 ng/ml, P < 0.05), and IL-6 (0.19 ± 0.03 vs. 0.12 ± 0.05 ng/ml, P < 0.05) levels, and a significant decrease of ACTH (16.95 ± 5.46 vs. 22.96 ± 7.32 pg/ml, P = 0.03). Immunohistochemical staining showed the decreased number of pituitary ACTH-positive cells in both Groups B and C (P < 0.05) as compared to Group A. These results have lead us to believe that acute psychological stress can activate the pituitary-adrenal axis and lead to elevation of serum IL-2, IL-6 concentrations. Combined with high-intensity exercise, it can result in the increase of serum CORT, IL-1β, IL-2, IL-6 levels, and the suppression of ACTH.
Abstract
The low-temperature molar heat capacity of crystalline Mn3(HEDTA)2·10H2O was measured by temperature-modulated differential scanning calorimetry (TMDSC) for the first time. The thermodynamic parameters such as entropy and enthalpy relative to 298.15 K were calculated based on the above molar heat capacity data. The compound was characterized by powder XRD, FT-IR spectrum. Moreover, the thermal decomposition characteristics of Mn3(HEDTA)2·10H2O were investigated by thermogravimetry–mass spectrometer (TG–MS). The experimental result through TG measurement shows that a three-step mass loss process exists. H2O, CO2, NO, and NO2 were observed as products for oxidative degradation of Mn3(HEDTA)2·10H2O from the MS curves.
Abstract
Systematically complicated technique used for preparing high-intensity (more than 8.0 GBq/cm2)241Am 
-source by a new enamel technique is presented. High intensity241Am -sources with activities ranging from 3.7 to 37 GBq have been made by this new technique. The activity and photon output have been measured. The results were compared with the data reported by the Radiochemical Centre Amersham in their specification. The photon output of241Am -source produced by us meets the technical specification of241Am -sources produced by Amersham. Moreover, the highest intensity can reach 1789 mCi/cm2. The overall utilization ratio of241Am activity (59.5 keV) is 31.2%.
Abstract
The antibacterial effect of Curcumin on Staphylococcus aureus growth was evaluated by microcalorimetry. The heat flow power–time curves and nine quantitative parameters of the S. aureus growth were applied to investigate the inhibitory effect with Curcumin. By analyzing these curves and some quantitative parameters using multivariate analytical methods, similarity analysis and principal component analysis, the antibacterial activity of Curcumin on S. aureus could be accurately evaluated from the change of the two main parameters, the second exponential growth rate constant k 2 and the maximum heat flow power P m 2. The main two thermal parameters played more important role in the evaluation: at low concentration (0–10.5 μg mL−1), Curcumin hardly influence the growth of S. aureus, while at high concentration (10.5–43.4 μg mL−1) it could notably inhibit the growth. All these illustrated that the antibacterial activity of Curcumin on S. aureus was enhanced with the increase of the concentration of this compound. This study might provide an useful method and idea accurately evaluate the antibacterial effects of Curcumin, which provides some useful methods for evaluate the nature antibacterial agents.
Abstract
A novel metal-organic frameworks [Cu2(OH)(2,2′-bpy)2(BTC) · 2H2O]n (CuMOF, BTC = benzene-1,3,5-tricarboxylic acid, 2,2′-bpy = 2,2′-bipyridine) has been synthesized hydrothermally and characterized by single crystal XRD, FT-IR spectra. The low-temperature molar heat capacities were measured by temperature modulated differential scanning calorimetry (TMDSC) for the first time. The thermodynamic parameters such as entropy and enthalpy relative to reference temperature 298.15 K were derived based on the above molar heat capacity data. Moreover, the thermal stability and the decomposition mechanism of CuMOF were investigated by TG-MS (thermogravimetry-mass spectrometer). A four-stage mass loss was observed in the TG curve. MS curve indicated that the gas products for oxidative degradation of CuMOF were H2O, CO2, NO and NO2.
Abstract
Using microcalorimetry, the characteristic metabolic heat flow power-time curves of S. aureus growth affected by Ursodesoxycholic acid and Hyodeoxycholic acid were measured at 37 °C. The thermal-kinetic parameters such as, growth rate constant k, the maximum power output (P m), the time corresponding to the maximum power output (t p), total heat-production Q t , half inhibitory concentration of the drugs (IC 50) were calculated from the growth curves. For both HDCA and UDCA, with the increasing of concentration, k, P m, and Q t decreased, meanwhile, k–c fit a linear equation, t p was prolonged correspondingly. Principle component analysis, the results indicated t p might be the main parameter in evaluating the antibacterial activity of HDCA and UDCA in microcalorimetric method. Combining with t p and IC 50, the results revealed that the differences and trends of antibacterial activity of these bile acid derivatives were: HDCA > UDCA. Structure-activity relationship (SAR) analysis showed that the α-OH at C-3 and C-6 position at equal pace on the steroid nucleus enhanced the hydrophilicity of HDCA, which led to a stronger antibacterial effect than UDCA. In this study, a useful tool was provided to accurately evaluate the antibacterial effects of bile acid derivatives. The thermolysis curve recorded by microcalorimetry could provide a lot of kinetic and thermodynamic information for the study of growth process of living microbial, which could be helpful in the screening of high efficacy antibacterial agents.
