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Abstract  

The dimercaptosuccinic acid metronidazole ester (DMSAMe) was synthesized and radiolabeled with 99mTc to form the 99mTc-DMSAMe complex in high yield. The radiochemical purity of the 99mTc-DMSAMe complex was over 90%, as measured by TLC and by HPLC, without any notable decomposition at room temperature over a period of 6 h. Its partition coefficient indicated that it was a lipophilic complex. The tumor cell experiment and the biodistribution in mice bearing S 180 tumor showed that the 99mTc-DMSAMe complex had a certain hypoxic selectivity and accumulated in the tumor with high uptake and good retention. The tumor/blood and tumor/muscle ratios increased with time, suggesting it would be a possible tumor hypoxia imaging agent.

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Acta Chromatographica
Authors:
Xiaoyan Zhang
,
Jie Liu
,
Wenbo Sun
,
Xiangchun Shen
,
Xiaojian Gong
,
Cong Wang
,
Yan Liang
, and
Wei Zhou

Abstract

Natural hemostatic compounds from Toddalia asiatica (Linn) Lam (T. asiatica) root bark had been investigated by a novel strategy, chemical fingerprint–pharmacokinetic–pharmacodynamic (CF–PK–PD) for the first time in this study. The extract sample of T. asiatica root bark was subdivided into petroleum ether (PE), ethyl acetate (EA) and n-butanol (n-B) sample by reagent extraction, EA sample showed significant hemostatic activity using prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB) as evaluation indexes from rat plasma of PK experiment in hemorrhagic rat model. CF analysis was adopted to assist us to discover six natural compounds from T. asiatica root bark in actual rat plasma after sample treatment by Ultra Performance Liquid Chromatography-Electrospray Ionization (UPLC-ESI) MS, there were only lomatin and 5-methoxy-8-hydroxy psoralen showing significant hemostatic effect (P < 0.05) mainly through endogenous coagulation pathway and fibrinolytic system. In PK–PD study, six compounds in EA sample exhibited relatively rapid absorption and slow elimination characteristics. The mean T max and t 1/2β of isopimpinellin and pimpinellin were 1.74 and 0.59 h, 5.31 and 6.89 h in rats. On the basis of Sigmoid–E max model, PK–PD related curves of FIB in hemorrhagic rat model after treatment of T. asiatica root bark were obtained. Predicted E max, EC 50 and k e0 of FIB under isopimpinellin were 4.87 mg/mL, 1.39 μg/mL and 0.81 1/h; predicted E max, EC 50 and k e0 of FIB under pimpinellin were 4.29 mg/mL, 2.47 μg/mL and 0.77 1/h. In conclusion, hemostatic compounds from T. asiatica root bark had been materialized, there were lomatin, isopimpinellin, pimpinellin and 5-methoxy-8-hydroxy psoralen at least as its main active substances through coagulation pathways and fibrinolytic system. CF–PK–PD method as a promising method was worthy of follow-up opening, application in pharmaceutical research.

Open access
Acta Chromatographica
Authors:
Mei-Xia Zhu
,
Sheng-Nan Li
,
Hai-Dan You
,
Bin Han
,
Zhi-Ping Wang
,
Yan-Xi Hu
,
Jin Li
, and
Yu-Feng Liu

High-performance liquid chromatography coupled with photodiode array detection and evaporative light scattering detection (HPLC—DAD—ELSD) was established to determine paeoniflorin and albiflorin simultaneously in Radix Paeoniae Rubra. The assay was performed on a Diamonsil C18 (4.6 mm × 250 mm, 5 μm) column by a gradient elution program with acetonitrile and aqueous formic acid (0.05% v/v) as mobile phase at a flow rate of 1.0 mL min−1. The detection wavelength of DAD was 230 nm, and the evaporator tube temperature of ELSD was set at 110 °C with the nebulizing gas flow rate of 3 L min−1. The temperature of column was kept at 30 °C. The linear ranges of paeoniflorin and albiflorin were within 0.050–1.510 mg mL−1 and 1.007–5.035 mg mL−1. The recoveries of paeoniflorin and albiflorin were 96.2–102.9% and 95.0–102.4%, respectively, while the relative standard deviation (RSD) of them was 0.2–2.5%. This method was quick, simple, accurate, and specific. It could be used for the quality control of Radix Paeoniae Rubra. The proposed approach was expected as a powerful tool for the quality control of Radix Paeoniae Rubra.

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

Abstract

Background and aims

Internet addiction (IA) is common among young students. This study aimed to examine the influence and mechanisms of IA and susceptible personality traits on the impact of suicidal ideation in adolescent students in China.

Methods

This cross-sectional study (09/2012–09/2015) used stratified cluster sampling with “school type” for stratification; 136,266 students from 63 schools completed the questionnaire. Logistic regression analysis was performed to estimate the effect of IA (Young's Internet Addiction Test) and susceptible personality (Barratt impulsiveness scale, Buss & Perry Aggression Questionnaire; and Eysenck Personality Questionnaire-R Short Scale) on suicidal ideation (Scale of Suicidal Ideation).

Results

Suicidal ideation was observed in 20,218 (14.77%) of the students, and IA was detected in 28,836 (21.16%) subjects. Compared with those without IA, students with IA had a higher prevalence of suicidal ideation (P < 0.0001). No planning impulsiveness had a predictive effect on suicidal ideation in the impulsive personality trait, while in the aggressive personality trait, hostility and self-aggression had a predictive effect on suicidal ideation (all P < 0.0001). High psychoticism and neuroticism were impact factors for suicidal ideation, but extroversion was a protective factor (all P < 0.0001).

Discussion

These results highlight the importance of assessing personality traits and reducing IA as a possible means of lessening suicidal ideation. Susceptible personality (such as high psychoticism, high neuroticism, and low extroversion) play a prominent role in influencing the probability of having suicidal behavior among those recently exposed to IA.

Conclusions

IA and susceptible personality traits were significantly correlated with suicidal and self-harm ideation among adolescent students.

Open access

Abstract  

The fractional cumulative yields (FCY) of133mTe and133gTe in the spontaneous fission of252Cf were measured for the first time by a radiochemical method. The values ofFCY are 0.533±0.014 and 0.291±0.042 for133mTe and133gTe, respectively. The isomeric state to ground state fractional independent yield (FIY) ratio of133Te,R, was found to be 3.5. The root-mean-square angular momentum of the primary fragment corresponding to the fission product133Te, Jr.m.s.=8.8h, was estimated according to a simple one-parameter statistical model. The fractional cumulative yields from this work together with other literature data in the mass region A=131–141 are compared with the normal yields given by the empiricalZ p model by Whhl. It suggests that both theN=82 neutrons shell and nucleus pairing effects are not apparent for the spontaneous fission of252Cf.

Restricted access
Acta Chromatographica
Authors:
Chen Cheng
,
Nie Cun-Xi
,
Liang Jing
,
Wang Yong-Qiang
,
Liu Yan-Feng
,
Ge Wen-Xia
, and
Zhang Wen-Ju

A validated high-performance liquid chromatography (HPLC) method has been developed to analyze the (±)-gossypol in the selection of strains of Candida tropicalis culture. Since gossypol was easily degraded and oxidized, the addition of antioxidant NADPH-Na4 and acetone extraction was chosen to prevent gossypol degradation and gradient elution assay was applied to obtain gossypol resolution. Concentrations of gossypol in C. tropicalis ZD-3 culture 20 μg/mL were determined, and concentration–time profiles were observed. Linearity of the gossypol standard curve by HPLC area method was ranged from 0.1 to 20 μg/mL with Y = 26.954 × X − 29.547, R 2 = 0.9991, and n = 3, with limit of detection (LOD) of 50 ng/mL and lower limit of quantification (LLOQ) of 500 ng/mL. The recovery rate is dose-dependent and ranged from 85.3% to 103.5%. It is a rapid and reliable HPLC method for gossypol quantization in microorganism culture which could be applied in solid fermentation in the feed industry.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Kang-Zhen Xu
,
Xian-Gang Zuo
,
Hang Zhang
,
Biao Yan
,
Jie Huang
,
Hai-Xia Ma
,
Bo-Zhou Wang
, and
Feng-Qi Zhao

Abstract

A new high-energy organic potassium salt, 1-amino-1-hydrazino-2,2-dinitroethylene potassium salt [K(AHDNE)], was synthesized by reacting of 1-amino-1-hydrazino-2,2-dinitroethylene (AHDNE) and potassium hydroxide in methanol aqueous solution. The thermal behavior of K(AHDNE) was studied using DSC and TG/DTG methods and can be divided into three obvious exothermic decomposition processes. The decomposition enthalpy, apparent activation energy and pre-exponential factor of the first decomposition process were −2662.5 J g−1, 185.2 kJ mol−1 and 1019.63 s−1, respectively. The critical temperature of thermal explosion of K(AHDNE) is 171.38 °C. The specific heat capacity of K(AHDNE) was determined using a micro-DSC method, and the molar heat capacity is 208.57 J mol−1 K−1 at 298.15 K. Adiabatic time-to-explosion of K(AHDNE) was also calculated. K(AHDNE) presents higher thermal stability than AHDNE.

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Journal of Thermal Analysis and Calorimetry
Authors:
Lingli Peng
,
Xiangyu Xu
,
Zhi Lv
,
Jiaqing Song
,
Mingyuan He
,
Qian Wang
,
Lijun Yan
,
Yang Li
, and
Zhaofei Li

Abstract

The boehmite nanofibers were prepared by using NaAlO2 and Al2(SO4)3 as the starting materials without any surfactant. The phase transitions of the boehmite nanofibres against different temperature were studied and various phases were derived from well-crystallized boehmite nanofibers. All these phases had the same morphology even after high temperature calcination. In addition, the retention of specific surface area of the samples were very high because of the limited aggregation occurred in calcinations for each sample. For instance, the γ-Al2O3 obtained at 500 °C had the specific surface area (208.56 m2/g) with an average pore diameter of 6.0 nm. With the further increase of the calcination temperature, the nanofibers became shorter and coarsening, which resulted in the decrease of the specific surface area. It is worthwhile to notice that the BET surface areas (40.97 m2/g) and the pore volume (0.27 cm3/g) of the fibrous structures obtained after 1200 °C calcination are substantially higher than that of the non-fibrous alumina because of the morphology maintenance.

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Journal of Thermal Analysis and Calorimetry
Authors:
Xingfeng Li
,
Cheng Jin
,
Wei Liu
,
Jian Zhou
,
Weijun Kong
,
Bing Dai
,
Jiabo Wang
,
Dan Yan
,
Yanling Zhao
,
Yun Luo
, and
Xiaohe Xiao

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, kc 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.

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