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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Jiaheng He
,
Hu Song
,
Yuan Jian
,
Lin Jiang
,
Wenbin Zhong
,
Xinliang Li
,
Zongping Ma
, and
Guoping Liu

Abstract  

The adsorption of 125I on palladium coated silver wires was studied in this paper. The experimental conditions, e.g., reaction volume, carrier concentration, reaction time, reaction temperature, pH of the reaction mixture, were systematically optimized to obtain quantitative adsorption of 125I on palladium coated silver wires. The experiments were performed using potassium iodide 8–9 μg as carrier in a reaction volume of 100 μL incubated in ~50 °C water bath for ~1 h, and the pH of the reaction system was controlled at 2–2.5. The distribution of activity on palladium coated silver wire was uniform, and the source cores can be easily sealed by laser welding into titanium capsules.

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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%.

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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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Acta Chromatographica
Authors:
Su-su Bao
,
Jian Wen
,
Teng-hui Liu
,
Bo-wen Zhang
,
Chen-chen Wang
, and
Guo-xin Hu

Olmutinib (Olita™) is an oral third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) which is used to treat non-small cell lung cancer (NSCLC). A simple, rapid, and sensitive method based on ultra-performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) has been developed for the determination of olmutinib. Sample preparation was performed following simple one-step protein precipitation with acetonitrile. Olmutinib and internal standard (dasatinib) were separated on an Eclipse Plus C18 RRHD (2.1 × 50 mm, 1.8 μm) column. The mobile phase consisted of acetonitrile–0.1% formic acid in water with gradient elution. A total run time of 1.7 min was achieved. Detection was performed on a positive-ion electrospray ionization mass spectrometer in multiple reaction monitoring (MRM) mode, using transitions of m/z 487.2 → 402.1 for olmutinib and m/z 488.2 → 401 for dasatinib (IS), respectively. The calibration curve (R 2 = 0.999) was linear over the range of 1–500 ng/mL. The recovery of olmutinib ranged from 85.8% to 95.5%. This method can be applied to pharmacokinetic studies of olmutinib.

Open access
Scientometrics
Authors:
Chuanfu Chen
,
Kai Sun
,
Gang Wu
,
Qiong Tang
,
Jian Qin
,
Kuei Chiu
,
Yushuang Fu
,
Xiaofang Wang
, and
Jing Liu

Abstract  

The quality and credibility of Internet resources has been a concern in scholarly communication. This paper reports a quantitative analysis of the use of Internet resources in journal articles and addresses the concerns for the use of Internet resources scholarly journals articles. We collected the references listed in 35,698 articles from 14 journals published during 1996 to 2005, which resulted in 1,000,724 citations. The citation data was divided into two groups: traditional citations and Web citations, and examined based on frequencies of occurrences by domain and type of Web citation sources. The findings included: (1) The number of Web citations in the journals investigated had been increasing steadily, though the quantity was too small to draw an inclusive conclusion on the data about their impact on scientific research; (2) A great disparity existed among different disciplines in terms of using information on the Web. Applied disciplines and interdisciplinary sciences tended to cite more information on the Web, while classical and experimental disciplines cited little of Web information; (3) The frequency of citations was related to the reputation of the author or the institution issuing the information, and not to the domain or webpage types; and (4) The researchers seemed to lack confidence in Internet resources, and Web information was not as frequently cited as reported in some publications before. The paper also discusses the need for developing a guideline system to evaluate Web resources regarding their authority and quality that lies in the core of credibility of Web information.

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Abstract

Background and aims

Compulsivity contributes to the development and maintenance of multiple addictive disorders. However, the relationship between compulsivity-related cognitive features and problematic usage of the internet (PUI), an umbrella term for various internet use disorders/interfering behaviors, remains largely unclear, partly due to the multidimensional nature of compulsivity. This scoping review utilized a four-domain framework of compulsivity to consider this topic and aimed to summarize available evidence on compulsivity-related neuropsychological characteristics in PUI based on this framework.

Methods

A systematic literature search was conducted by applying the combination of search term to the search engines of PubMed, PsycINFO and Web of Science. A four-domain framework of compulsivity, involving cognitive flexibility, set-shifting, attentional bias, and habit learning, was used to consider its complex structure and frequently used tasks. Main findings in related PUI studies were summarized based on this framework. Our secondary aim was to compare compulsivity-related features between different PUI subtypes.

Results

Thirty-four empirical studies were retained, comprising 41 task-results and 35 independent data sets. Overall, individuals with PUI showed more consistent deficits in attentional biases and were relatively intact in set-shifting. Few studies have examined cognitive flexibility and habit learning, and more evidence is thus needed to establish reliable conclusions. Moreover, most studies focused on internet gaming disorder, whereas other PUI sub-types were not sufficiently examined.

Conclusion

This systematic review highlights the use of the four-domain framework for advancing understanding of mechanisms underlying compulsivity in PUI. Related therapeutic implications and future directions are discussed.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Lin-Quan Liao
,
Hong-Jian Wei
,
Ji-Zhen Li
,
Xue-Zhong Fan
,
Ya Zheng
,
Yue-Ping Ji
,
Xiao-Long Fu
,
Ya-Jun Zhang
, and
Fang-Li Liu

Abstract

The compatibility of poly(3-nitromethyl-3-methyloxetane) (PNIMMO) with some energetic materials are studied by using pressure DSC method in detail. Cyclotetramethylenetetranitroamine (HMX), cyclotrimethylenetrinitramine (RDX), nitrocellulose (NC), nitroglycerine (NG), N-nitrodihydroxyethylaminedinitrate (DINA), and aluminum powder (Al) are used as common energetic materials, and 3,4-dinitrofurzanfuroxan (DNTF), 1,3,3-trinitroazetidine (TNAZ), hexanitrohexazaisowurtzitane (CL-20), 4,6-dinitro-5,7-diaminobenzenfuroxan (CL-14), 1,1-diamino-2,2-dinitroethylene (DADNE), and 4-amino-5-nitro-1,2,3-triazole (ANTZ) are used as new energetic materials. The results show that the binary systems of PNIMMO with HMX, RDX, NC, NG, DINA, Al, CL-14 and DADNE are compatible, with TNAZ, CL-20 and ANTZ are slightly sensitive, and with DNTF is sensitive.

Open access

Exploring antibiotic resistant mechanism by microcalorimetry II

Determination of thermokinetic parameters of imipenem hydrolysis with metallo-β-lactamase ImiS

Journal of Thermal Analysis and Calorimetry
Authors:
Xia Yang
,
Lei Feng
,
Kang-Zhen Xu
,
Hui-Zhou Gao
,
Chao Jia
,
Cheng-Cheng Liu
,
Jian-Min Xiao
,
Le Zhai
,
Li-Sheng Zhou
, and
Ke-Wu Yang

Abstract

In an effort to understand the reaction of antibiotic hydrolysis with B2 metallo-β-lactamases (MβLs), the thermodynamic parameters of imipenem hydrolysis catalyzed by metallo-β-lactamase ImiS from Aeromonas veronii bv. sobria were determined by microcalorimetric method. The values of activation free energy are 86.400 ± 0.043, 87.543 ± 0.034, 88.772 ± 0.024, and 89.845 ± 0.035 kJ mol−1 at 293.15, 298.15, 303.15, and 308.15 K, respectively, activation enthalpy is 18.586 ± 0.009 kJ mol−1, activation entropy is −231.34 ± 0.12 J mol−1 K−1, apparent activation energy E is 21.084 kJ mol−1, and the reaction order is 1.5. The thermodynamic parameters reveal that the imipenem hydrolysis catalyzed by metallo-β-lactammase ImiS is an exothermic and spontaneous reaction.

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Journal of Behavioral Addictions
Authors:
Shan-Shan Ma
,
Patrick D. Worhunsky
,
Jian-song Xu
,
Sarah W. Yip
,
Nan Zhou
,
Jin-Tao Zhang
,
Lu Liu
,
Ling-Jiao Wang
,
Ben Liu
,
Yuan-Wei Yao
,
Sheng Zhang
, and
Xiao-Yi Fang

Background

Cue-induced brain reactivity has been suggested to be a fundamental and important mechanism explaining the development, maintenance, and relapse of addiction, including Internet gaming disorder (IGD). Altered activity in addiction-related brain regions has been found during cue-reactivity in IGD using functional magnetic resonance imaging (fMRI), but less is known regarding the alterations of coordinated whole brain activity patterns in IGD.

Methods

To investigate the activity of temporally coherent, large-scale functional brain networks (FNs) during cue-reactivity in IGD, independent component analysis was applied to fMRI data from 29 male subjects with IGD and 23 matched healthy controls (HC) performing a cue-reactivity task involving Internet gaming stimuli (i.e., game cues) and general Internet surfing-related stimuli (i.e., control cues).

Results

Four FNs were identified that were related to the response to game cues relative to control cues and that showed altered engagement/disengagement in IGD compared with HC. These FNs included temporo-occipital and temporo-insula networks associated with sensory processing, a frontoparietal network involved in memory and executive functioning, and a dorsal-limbic network implicated in reward and motivation processing. Within IGD, game versus control engagement of the temporo-occipital and frontoparietal networks were positively correlated with IGD severity. Similarly, disengagement of temporo-insula network was negatively correlated with higher game-craving.

Discussion

These findings are consistent with altered cue-reactivity brain regions reported in substance-related addictions, providing evidence that IGD may represent a type of addiction. The identification of the networks might shed light on the mechanisms of the cue-induced craving and addictive Internet gaming behaviors.

Open access