A physical organic chemistry experiment is described for second-year college students. Students performed nucleophilic aromatic substitution (NAS) reactions on 5,10,15,20-tetrakis(2,3,4,5,6-pentafluorophenyl)porphyrin (TPPF20) using three different nucleophiles. Substitution occurs preferentially at the 4-position (para) because it is thermodynamically favored, and the 2- and 6- (ortho) positions are kinetically disfavored because of steric interactions with the porphyrin ring. The activation energy depends heavily on the nucleophile. Open-source software (ImageJ from NIH) was used to quantify relative intensities of spots on a TLC plate obtained from different times and varying temperatures. These data were used to generate Arrhenius plots allowing students to determine relative activation energies for three different primary nucleophiles. The experiment was developed by 5 undergraduates and evaluated by 40 organic chemistry II students and 8 students in a physical chemistry laboratory. Students gained a deeper understanding of the relationships between the NAS mechanism, Arrhenius plots, and activation energy.
Background: Cephalic index (CI) also called cranial index is the ratio of maximum breadth to a maximum length of head. The purpose of the study was to study anthropometry of cranial parameters using the computed tomography (CT) scans to establish the CI of the sampled population in North India.Materials and methods: The cross-sectional study was carried on the subjects of age group ranging from 6 to 95 years of either sex (total 1000 subjects; 540 male and 460 female) in the radio-diagnosis department of Era's Medical College Lucknow, UP, India. The measurement of maximum cranial breadth (MCB) and maximum cranial length (MCL) were taken on a CT scan machine and recorded for analysis. When associating the measures of precision for different subgroups, a one-way analysis of variance (ANOVA) was used for modest and efficient errors. Multivariate logistic regression analysis was used to identify factors affecting the CI estimation like age, interzygomatic length (IZL), orbital length (OL), MCB, and MCL.Result: Out of 1000 studied subjects, the majority 234 (23.4%) of the subjects belong to the 21-30 years age group. MCB of heads and MCL of heads in different ages and on applying the one-way ANOVA association was statistically significant and CI was statistically insignificant. Pearson correlation between the CI and other parameters like age, MCB of heads, and MCL of heads, and a statistically significant correlation was seen with each other. Dolichocephalic types of the skull are found more in male subjects, and brachycephalic type of skull is more common in female subjects. Conclusion:The average CI of our study was 76.67±3.18. This shows that northern India's dominant head shape, especially in the Lucknow region, was dolichocephaly. Thus, the CT scan is proven an essential modality in the assessment of cranial parameters in anthropometry.
Introduction: Assessment of renal size is a difficult task in view of the complex shape of kidney. Among different imaging modalities Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) owing to their 3 Dimensional reconstructional ability are quite helpful in assessment of kidney size. A relationship between renal size and anthropometric parameters is an issue of interest. Aim: To assess kidney size in North Indian adult population using CT and to assess its relationship with age, sex and height. Materials and Methods: This was a cross-sectional study done over a period of two years (January 2018 to December 2019) in which a total of 300 adults aged between 20-90 years with normal renal function were enrolled. Age and sex of subjects was noted and their heights were measured. All the subjects underwent computed tomographic assessment for kidney size using 384 Slice Somatom Force, Seimens Corp. Multidetected CT machine. Contrast enhanced abdominal CT was performed to visualise the kidneys. Linear renal dimensions (length, lateral diameter, anteriorposterior diameter) were measured and renal volume was calculated using the ellipsoid volume formula. Data was analysed using Statistical Package for the Social Sciences (SPSS) version 21.0 software. Independent samples t-test, paired t-test, Analysis of Variance (ANOVA) and Pearson coefficient constants were calculated. Results: A total of 300 subjects were included, with the mean age of subjects were 41.12 years. Exactly half (50%) were males. Mean kidney size was 94.62 (95% CI: 90.27-98.97) cm3 for right side and 119.84 (95% CI=113.40-126.29) cm3 for left side. Average kidney size was 107.23 (95% CI=102.66-111.80) cm3. For both the sides, males had significantly larger kidney as compared to that of females (p-value <0.01). With increasing age, a significant decline in kidney size was observed (p-value <0.001). With increasing height, a significant increase in kidney size was observed (p-value <0.001). Height showed a significant positive correlation with both right and left side of kidney size (r=0.588, p-value <0.05). Conclusion: The present study provided the normal range for kidney size among North Indian adults using CT. The findings showed an age, gender and height dependence of kidney size in present study population.
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