In order to overcome the problems existing in traditional teaching of elemental chemistry experiment,a series of reformations including teaching method have been carried out,and good results have been achieved.

The gamma-cyclodextrin-folate (gamma-CD/FA) inclusion-coated CdSe/ZnS quantum dots (QDs) with folate-receptor (FR) targeted were synthesized by simple and convenient sonochemical method. The products were studied using Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), utraviolet-visible spectrometry (UV-vis), fluorescence spectrum and transmission electron micrographs (TEM). The results showed that the gamma-CD/FA-coated CdSe/ZnS QDs not only have good monodispersity and smaller size, but also have good optical performance, such as higher quantum yield (QY) and a long fluorescence lifetime. The cytotoxicity experiments showed that the gamma-CD/FA-coated CdSe/ZnS QDs have lower cytotoxicity and could more effectively enter cancer cells with FR over-expression. The QDs with 4-5 nm in diameter were relatively easy to enter the cell and to be removed through kidneys, so it is more suitable for biomedical applications for bioprobes and bioimaging.

OBJECTIVE:To observe therapeutic efficacy and liver toxicity of chemotherapy combined with bevacizumab in the treatment of colorectal cancer liver metastases (CLMs). METHODS:126 CLMs patients were selected and randomly divided into chemotherapy group(54 cases)and combination group(72 cases). Chemotherapy group received FOLFOXIRI regimen:irinotecan 165 mg/m2+oxaliplatin 85 mg/m2+calcium folinate 200 mg/m2+fluorouracil 2 g. Combination group was additionally given bevaci-zumab 5 mg/kg one day before chemotherapy on the basis of FOLFOXIRI regimen. A treatment course of 2 groups lasted for 2 weeks,and both received 12 courses of treatment. The pathological response,survival rate and toxic reactions caused by chemother-apy were compared between 2 groups. RESULTS:Pathological complete response proportion,tumor remission rating(TRG),the proportion of patients with tumor necrosis rate ≥50% in combination group were significantly higher than chemotherapy group, with statistical significance (P<0.01). The proportion of TRG4-5,TRG 1-3 progression-free survival in combination group were significantly higher than chemotherapy group,with statistical significance (P<0.05). The incidence of liver parenchymal necrosis in combination group was significantlg higher than chemotherapy group,there was statistical significance (P>0.05). CONCLU-SIONS:Chemotherapy combined with bevacizumab can improve pathological response and the incidence of CLMs necrosis and doesn't increase liver toxicity.

In China,there are no standard and good modes for the chemistry courses taught in English for the international medical students.On the basis of the experience achieved in teaching the chemistry courses for overseas students,with the intenti on of the science development,the system of chemistry courses with Chinese characteristic has been programmed.

A series of tacrine-methoxybenzene hybrids (5a-5i) were designed, synthesized and evaluated as inhibitors of cholinesterases (ChEs). All the compounds had better ChEs inhibitory activities than tacrine with IC50 values at the nanomolar range. Compound 5h exhibited the strongest inhibition on acetylcholinesterase (AChE) with an IC50 value of 6.74 nmol x L(-1) and compound 5f showed the most potent inhibition on butyrylcholinesterase with IC50 value of 3.83 nmol x L(-1). Kinetic and molecular modeling studies showed that these hybrids targeted both the catalytic active site and the peripheral anionic site of AChE.

Objective To explore stress response of government employees,businessmen and police officers.Methods A total of1547 government employees,8672 businessmen and1555 police officers were recruited and completed a questionnaire survey concerning psychological stress.t or F test was used for data analysis.Results There were significant differences of stress response among government employees,businessmen and police officers ( P ＜ 0.01).Male or female government employees showed different stress response,physiology,emotion and behavior (all P＜0.01).Government employees from various age group showed difference in emotion and behavior ( both P ＜ 0.01).Businessmen of various gender and age were found difference of stress response at all dimensions ( P ＜ 0.05 ).Police officers of different gender showed different behavior ( P ＜ 0.0l ).ConclusionIt may be necessary to carry out occupation-specific stress management for individuals.

The inclusion compound of amylose and salicylic acid (SA) was prepared by a sealed temperature control method, and the formation of the inclusion compound was confirmed by IR spectrum and powder X-ray diffraction. The kinetic parameters of dissociation of amylose/SA compound were studied by the nonisothermal method which was defined as a relationship between the dissociation ratio and time. The values of activation energy (Ea) and frequency factors (InA) were calculated by a nonlinear least-square method. In this study, the formation of the inclusion compound of amylose/SA was confirmed by IR spectrum powder X-ray diffraction. SA existed in a molecule form in the spiral stouction of amylose. The dissociation of amylose/SA compound was attributed to first order reaction. The values of Ea calculated by the nor-isothermal method were 21.71 and 22.41 kJ x mol(-1) at heating rate 5 and 10 degrees C x h(-1), respectively. The corresponding isothermal method value of Ea was 22.17 kJ x mol(-1); the calculated InA values were 9.32 and 10.08 at heating rate 5 and 10 degrees C x h(-1), respectively. The corresponding isothermal method lnA value was 9.26. The results were in good agreement with Ea values and lnA values by isothermal method. These results indicated that the non-isothermal method described in this study could be adequately used for the stability study of inclusion compound and was a rapid and accurate method for the determination of kinetic parameters.

There are some existing problems in controlling the quality of oxygen. In order to improve quality, efficiency and safety in the use of oxygen, we presented some factors which may give rise to variations in concentration of oxygen and proposed some suggestions based on the investigation and analysis of such problems.
Equipment and Supplies ; Oxygen

Two compositions, a sterol mixture and a pure ceramide, were isolated from the extract of a tunicate,Styela.canopus, collected from the Dayawan Bay, Guangdong. The sterols were detected by gas chromatography/mass spectrometry, and their structure was confimed by spectroscopic analysis. The ceramide was identified by spectroscopic analysis. The contents of sterols and the ceramide in the extract were 12% and 0.3% respectively.This was also the first report about the chemical constituents of Sytela. canopus.

A series of quinoline-polyamine conjugates (8a-8n) were designed, synthesized and evaluated as inhibitors of cholinesterases (ChEs). Some of these compounds had potent ChEs inhibitory activity with IC50 values at micromolar range. Compound 8n exhibited the strongest inhibition on acetylcholinesterase (AChE) with an IC50 value of 8.78 micromol x L(-1), and compound 8i showed the most potent inhibition on butyrylcholinesterase (BChE) with IC50 value of 1.60 micromol x L(-1) which was slightly better than rivastigmine. The structure-activity relationship revealed that the chain length of polyamine and linker played important roles for inhibitory activity. Molecular modeling studies showed that 8i targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of cholinesterases.