Synthesis and Characterization of Novel Radiopaque Polycarbonate.

Polymeric materials implanted in the human body are usually invisible under X-ray, and the mixing of heavy metal salts into polymeric materials by physical compounding often poses compatibility problems. A new iodine-containing cyclic carbonate monomer, 4-iodo-N-(2-oxo-1,3-dioxan-5-yl)benzamide (IBTMC), is synthesized, which has a degradable carbonate group as its basic structural unit and iodine atoms attached to the side chain in the form of covalent bonds. The ring-opening polymerization of IBTMC is achieved at room temperature under the catalysis of the solid superbase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD). The structure and X-ray developing ability of the synthesized polycarbonate are characterized by 1 H-NMR, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), Gel Permeation Chromatography (GPC), and micro-computed tomography (Micro-CT). The iodine atoms remain bound to the polymer as covalent bonds after a series of reactions and exhibit a high level of X-ray opacity. In vitro degradation experiments of the polymer prove that the polymer is degradable.

[Study on the use of benzodiazepine among middle school students in Wuhan City].

OBJECTIVE: In order to understand the status of benzodiazepine (BZD) use in middleschool students from Wuhan city. METHODS: In the Wuhan city zone, twenty-eight middle-schools were chosen randomly to the even numbers, with students from grade 8 to 12 had been studied. Altogether, 258 classes were investigated with 12 345 questionnaires were filled in by the subjects anonymously. SPSS 10.0 was used for data analysis. RESULTS: Rate of BZD use in Wuhan middle school students was 4.0% with the rate of dependence as 4.1per thousand. There were differences in gender and grade: male students tend to be higher than females (P< 0.01), and senior higher than junior's (P < 0.01). More commonly used drugs would include Diazepam (59%) and Surazepam (29.7%). Among students who used drugs, 43.3% used for 1-7 day and 8.2% of them used 6 tablets or more. 57.6% used 1 tablet once a day (46.2%) before bed time (40.8%). The major reason for using drug was insomnia (43%), followed by pressure from school. The reasons for BZD abuse were: relief of anxiety (14.1%), curiosity (13.3%), peer pressure (10.8%), and fun seeking (9.85%), etc. The source of drugs was from their families (29%). By Multinomial logistic regression, the risk factors of abuse BZD were: ignorance of drug prescription, sex, regular alcohol intake, knowing that BZD use can bring amusement regular, smoking cigarettes, relationship with parents, mother's way of providing education, schooling of fathers, relationship between parents. CONCLUSION: Difference was seen in the use of BZD between gender and age of the students. Multiple factors showed that: personal, family and social factors were related to the use of BZD.