Modeling Knowledge Sharing and Interemployee Helping From a Perspective of Flow Theory: A Survey of Online Knowledge Works

This study proposes a model based on flow theory by postulating key antecedents as the critical drivers of knowledge sharing and interemployee helping. In the model, knowledge sharing is influenced by flow experience directly and also indirectly via the mediation of interemployee helping. Accordingly, the flow experience is influenced simultaneously by four exogenous factors related to individuals’ perception about their work: work skills, self-fulfillment in challenges, perceived control, and vividness. The empirical findings of this study confirm the applicability of flow theory in business organizations by investigating online knowledge workers from business organizations. This study contributes to the knowledge management literature by extending flow theory to the area of knowledge sharing and interemployee helping, by validating idiosyncratic antecedent drivers of the flow theory, and by performing a practical operationalization of the flow experience. This research also provides managerial implications and limitations

Rapid analysis of triclosan in water samples using an in-tube ultrasonication assisted emulsification microextraction coupled with gas chromatography-electron capture detection

In this study, a new in-tube based ultrasound-assisted emulsification microextraction (IT-USAEME) technique coupled with gas chromatography-micro-electron capture detection (GC-μECD) was developed for the efficient and rapid analysis of triclosan in environmental water samples. In this extraction procedure, the aqueous sample was taken in an indigenously fabricated home-made glass extraction device (an 8 mL glass tube inbuilt with a self-scaled capillary tip) and extraction solvent (low density organic solvent) was added to it followed by ultrasonication. After extraction, the upper extractant layer was narrowed into the self-scaled capillary tip by pushing the plunger plug; thus making the collection and measurement of the upper organic solvent layer simple and convenient. Parameters affecting the extraction efficiency such as selection of extraction solvent, extraction solvent volume, ultrasonication time, pH and ionic strength were thoroughly investigated and optimized. Under optimal conditions, the method showed good linearity in the concentration range from 20–2000 ng L−1 with a correlation coefficient of 0.9982 for the target analyte. The limit of detection was 4 ng L−1 and the enrichment factor obtained was 331. The method was validated with real water samples and the relative recoveries of environmental water samples ranged between 91.2 and 97.3% and relative standard deviations ranged between 2.8 and 5.4%, making the proposed method highly reliable. Moreover, the present approach avoids the usage of chlorinated organic extraction solvents and derivatization processes for triclosan determination. The proposed method provides a simple, rapid, sensitive, low cost, easy to handle (in-tube set-up for USAEME) and eco-friendly procedure to determine triclosan in aqueous samples

Light-Independent Inactivation of Dengue-2 Virus by Carboxyfullerene C3 Isomer

AbstractCarboxyfullerene (C60) is known as a photosensitizer for virus inactivation. Its regioisomer with C3 symmetry, named the C3 isomer, could also inactivate the dengue-2 virus without light when the dose of C3 isomer was increased to 40 μM, indicating the possible involvement of a light-independent mechanism. Further analysis showed that the C3 isomer blocked viral replication at the attachment and penetration stages, suggesting that a direct interaction between the C3 isomer and the virion is required for inactivation. The C3 isomer with a bipolar structure showed better lipid interaction and dengue-2 virus suppression than D3, another isomer that contains evenly distributed hydrophilic side chains. Moreover, the C3 isomer selectively inactivated enveloped viruses (viz., dengue-2 virus and Japanese encephalitis virus) instead of nonenveloped viruses (viz., enterovirus 71 and coxsackievirus B3). Collectively, these findings support the hypothesis that C3 isomer suppression of enveloped viruses is effected through its hydrophobic interaction with the viral lipid envelope. Our report, which demonstrates the light-dependent and -independent mechanisms of C60 on viral inactivation, will aid in the development of novel anti-viral agents for use against enveloped viruses

Lack of association between the GRP78 polymorphisms in the promoter and 3' UTR and susceptibility to chronic HBV infection in a Chinese Han population

<p>Abstract</p> <p>Background</p> <p>Hepatitis B virus (HBV) infection causes large amount of unfolding or false-folding protein accumulation in the endoplasmic reticulum (ER), which in turn induces the expression of glucose-regulated protein 78 (GRP78). The aim in the present study was to analyse the potential association between GRP78 single-nucleotide polymorphisms (SNPs) and the risk of HBV infection.</p> <p>Methods</p> <p>The associations between seven common <it>GRP78 </it>polymorphisms in the promoter (rs391957, rs17840762, rs17840761, rs11355458) and in the 3' untranslated region (UTR) (rs16927997, rs1140763, rs12009) and possible risk of chronic HBV infection were assessed in a case-control study. 496 cases and 539 individually matched healthy controls were genotyped.</p> <p>Results</p> <p>Overall, no associations were observed in genotypic analyses. In addition, haplotypes and diplotypes combining those SNPs in the promoter or in the 3' UTR in high linkage disequilibrium (LD) were also not associated with HBV risk.</p> <p>Conclusion</p> <p>These observations do not support a role for <it>GRP78 </it>polymorphisms in HBV infection in a predominantly Chinese Han population.</p

Antiviral Ability of Kalanchoe gracilis Leaf Extract against Enterovirus 71 and Coxsackievirus A16

Pandemic infection or reemergence of Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) occurs in tropical and subtropical regions, being associated with hand-foot-and-mouth disease, herpangina, aseptic meningitis, brain stem encephalitis, pulmonary edema, and paralysis. However, effective therapeutic drugs against EV71 and CVA16 are rare. Kalanchoe gracilis (L.) DC is used for the treatment of injuries, pain, and inflammation. This study investigated antiviral effects of K. gracilis leaf extract on EV71 and CVA16 replications. HPLC analysis with a C-18 reverse phase column showed fingerprint profiles of K. gracilis leaf extract had 15 chromatographic peaks. UV/vis absorption spectra revealed peaks 5, 12, and 15 as ferulic acid, quercetin, and kaempferol, respectively. K. gracilis leaf extract showed little cytotoxicity, but exhibited concentration-dependent antiviral activities including cytopathic effect, plaque, and virus yield reductions. K. gracilis leaf extract was shown to be more potent in antiviral activity than ferulic acid, quercetin, and kaempferol, significantly inhibiting in vitro replication of EV71 (IC50 = 35.88 μg/mL) and CVA16 (IC50 = 42.91 μg/mL). Moreover, K. gracilis leaf extract is a safe antienteroviral agent with the inactivation of viral 2A protease and reduction of IL-6 and RANTES expressions

Rapid analysis of triclosan in water samples using an in-tube ultrasonication assisted emulsification microextraction coupled with gas chromatography-electron capture detection

In this study, a new in-tube based ultrasound-assisted emulsification microextraction (IT-USAEME) technique coupled with gas chromatography-micro-electron capture detection (GC-mECD) was developed for the efficient and rapid analysis of triclosan in environmental water samples. In this extraction procedure, the aqueous sample was taken in an indigenously fabricated home-made glass extraction device (an 8 mL glass tube inbuilt with a self-scaled capillary tip) and extraction solvent (low density organic solvent) was added to it followed by ultrasonication. After extraction, the upper extractant layer was narrowed into the self-scaled capillary tip by pushing the plunger plug; thus Moreover, the present approach avoids the usage of chlorinated organic extraction solvents and derivatization processes for triclosan determination. The proposed method provides a simple, rapid, sensitive, low cost, easy to handle (in-tube set-up for USAEME) and eco-friendly procedure to determine triclosan in aqueous samples