ABSTRACT
@#Introduction: Cigarette smoking is showing an increasing prevalence among university students nowadays. Smoking includes the act of smoking cigarette containing tobacco and/or other ingredients or just inhaling the cigarette smoke. Smoking has many known physical side effects that include psychological or cognitive effects. Therefore, the aim of this research is to identify the effect of cigarette smoking on the academic achievement among university students. Methods: A cross-sectional study was conducted among 136 students including 113 male and 23 female aged 18 to 29 years from Management and Science University with 30 non smoker students. The questionnaire included items about the social demographic characteristics, smoking status, the study styles and the academic achievement of the participants. A frequency statistics, descriptive statistics and chi square test were used to analyze the collected data using SPSS version 25. Results: Among the smoker students, 51.5% came to class early, 80.8% attend classes regularly, 49.3% studied on weekends and 39.7% planned sufficient time to study for exam. Mean CGPA for smoker students is 2.6. Conclusion: Smoking is proven to be associated with low academic performance among university student.
ABSTRACT
Objective The inclusion complex of vincamine (VIN) and hydroxypropyl-β-cyclodextrin (HP-β-CD) was prepared and characterized. Molecular simulation method was used to study the formation mechanism of inclusion complex. Methods The inclusion complex of VIN/HP-β-CD was prepared by saturated solution. The preparation technology of VIN/HP-β-CD inclusion complex was optimized by orthogonal design, and taking the drug-loading of the inclusion compound as the index. The stability constant of inclusion complex between VIN and HP-β-CD was studied by UV-Vis spectrometry titration, and the inclusion ratio was determined by Job plots method. The VIN/HP-β-CD inclusion complex was characterized by scanning electron microscope (SEM), X-ray powder diffractometry (XRD), infrared spectroscopy (IR), thermal analysis techniques (TG and DSC), and nuclear magnetic resonance (1H, 2D NMR). The water solubility of the VIN/HP-β-CD inclusion complex was measured and the stability test was conducted in the simulated human gastric juice and intestinal fluid environment. Molecular docking and molecular dynamics were used to study the forming mechanism of supramolecular system of VIN/HP-β-CD. Results Using saturated solution method, the optimum conditions of inclusion were: 1:1 for molar ratio of VIN and HP-β-CD, 40 ℃ for inclusion temperature, 7 h for inclusion time and volume ratio of methanol to water (1:6) as solvent; Job curve and UV-vis spectroscopy showed that inclusion ratio of host-guest inclusion complexes was 1:1; After VIN formed inclusion complexes with HP-β-CD, its solubility increased from 0.04 mg/mL to 16.5 mg/mL, and the thermal decomposition temperature of VIN increased from 240.5 ℃ to 306.1 ℃. 1H-NMR and NOESY spectra indicated that the inclusion complex was formed by the a-ring of VIN entering from the large end of HP-β-CD. Quantum chemical calculation and molecular docking indicated that the optimal inclusion mode was consistent with the results of NMR studies. Molecular dynamics studies showed that VIN can penetrate into the hydrophobic cavity of HP-β-CD in water environment, and the interaction between host and guest was strengthened. The space size of host-guest matched better. Conclusion The solubility and thermal stability were significantly improved after the formation of inclusion complex with VIN and HP-β-CD. Hydrophobicity, hydrogen bonding, and van der Waals forces were the main driving forces for inclusion complex formation.