The 3D-QSAR method comparative molecular field analysis (CoMFA) involves the estimation of atomic partial charges as part of the process of calculating molecular electrostatic fields. Using 30 data sets from the literature the effect of using different common partial charge calculation methods on the predictivity (cross-validated R2) of CoMFA was studied. The partial charge methods ranged from the popular Gasteiger and the newer MMFF94 electronegativity equalization methods, to the more complex and computationally expensive semiempirical charges AM1, MNDO, and PM3. The MMFF94 and semiempirical MNDO, AM1, and PM3 methods for computing charges were found to result in statistically significantly more predictive CoMFA models than the Gasteiger charges. Although there was a trend toward the semiempirical charges performing better than the MMFF94 charges, the difference was not statistically significant. Thus, semiempirical partial charge calculation methods are suggested for the most predictive CoMFA models, but the MMFF94 charge calculation method is a very good alternative if semiempirical methods are not available or faster calculation speed is important.
2D and 3D QSAR techniques are widely used in lead optimization-like processes. A compilation of 40 diverse data sets is described. It is proposed that these can be used as a common benchmark sample for comparisons of QSAR methodologies, primarily in terms of predictive ability. Use of this benchmark set will be useful for both assessment of new methods and for optimization of existing methods.
India is amongst the fastest growing markets for smartphones in the world which are driven by a young population. This study seeks to understand the intention to use mobile news applications by students in India. To address this broad objective, an extended technology adoption model has been proposed with the inclusion of news motivation and perceived hedonic value and tested on 384 students at a university in India. Structural equation modeling results reveal that student mobile news app adoption intention is not dependent on the perceived hedonic value; however, this relationship is mediated by attitude. News motivation predicts adoption intention, which indicates that news app adoption is largely seen as utilitarian, this is also proven by the fact that perceived usefulness significantly predicts adoption intention.
Background: Cyclic vomiting syndrome is an increasingly recognized disorder with sudden, repeated episodes of severe nausea, vomiting, and physical exhaustion that occur with no apparent cause. It is more common in children than adults. However, we don’t often see a diagnosis of cyclic vomiting syndrome being made. Hereby we report 7 cases of cyclical vomiting.Methods: This is a retrospective study. Medical records of 5 years were review and consecutive paediatric patients discharged with a diagnosis of cyclic vomiting syndrome were identified, data collected and analysed.Results: Total of 7 cases were found, all of which were adolescents. The mean age was 13.28. 57.14% (4) were females and 42.86% (3) were boys. 42.86% (3) presented with complications. 14.28% (1) had an association with menstrual cycles and 14.28% (1) had an association with psychological stress.Conclusions: Cyclic vomiting syndrome should be kept in mind when a child presents with multiple episodes of vomiting, especially when repeated admissions have been made for the same. Early diagnosis and treatment can improve the quality of life.
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