This article summarizes some methods in teaching physical chemistry,such as inspiring students’ interests and improving teacher’s teaching level. Then,how to enhance the teaching quality of physical chemistry is discussed.

Objective To analyze the dose‐effects of different doses of dexmedetomidine for sedation and sleep of the patients under epidural nerve block anesthesia .Methods A total of 82 patients undergoing elective lower limbs surgery(ASA grade Ⅰ - Ⅱ) were randomly divided into 4 different doses of dexmedetomidine groups(group 1 ,n=19 ;group 2 ,n=22 ;group 3 ,n=20;group 4 , n=21) ,under continuous epidural nerve block ,the loading dose of dexmedetomidine 0 .7 ,0 .8 ,0 .9 ,1 .0μg · kg -1 · h-1 was intrave‐nously pumped for 30 min ,then pumped at a rate of 0 .7 ,0 .8 ,0 .9 ,1 .0 μg · kg -1 · h-1 in the group 1 ,2 ,3 and 4 respectively .If any patient in 4 groups fell asleep at less than half an hour ,the loading dose was stopped and the continuous dose was changed to pump , the drug administration was discontinued at wound dressing after operation .Whether the patient falling asleep was recorded ,and the mean arterial blood pressure ,heart rate at 4 time points of 10 ,30 ,60 ,90 min after infusion of dexmedetomidine were also recorded . The 50% effective dose(ED50 ) ,ED95 and 95% confidence interval(CI) were calculated by using the Probit method .Results ED50 and ED95 of dexmedetomidine were 0 .65μg/kg(95% CI:0 .36-0 .73μg/kg)and 1 .00 μg /kg(95% CI:0 .90-1 .74μg/kg) ,which could decrease the heart rate and increase the arterial blood pressure .Conclusion Although dexmedetomidine can decrease the heart rate and increase the arterial blood pressure ,but the patients quietly fall asleep without discomfort and pain occurrence by the intra‐venous administration under continuous epidural nerve block .

Aim To study ethanol-induced changes in the development and neuronal number of visual cortex in C57BL /6 mice. Methods Female mice were fed with ethanol during pregnancy . The neuron density (ND) and cortical thickness (CT) in visual cortex of off spring mice were measured at either P0, P7 and P14 with hematoxylin and eosin (H.E) and Nissl staining. Results Embryonic death and malformationswere found in the ethanol-treated groups. Malformations, such as microcephaly,anencephaly and myeloschisis with spinabifida, etc were found in late-term embryos. The malformation rate was 12%. Compared with control group, the development of visual cortex in ethanol-treated groups was delayed, and its lamination was in disorder. The neuron polarity was disturbed. Neuron loss was found after ethanol exposure. At various ages, the neuron density in ethanol-treated groups was lower than that in control group(P

AIM: To study the neuroprotective effect and possible mechanism of ganglioside GM 1 on neonatal hypoxic-ischemic-encephalopathy(HIE). METHODS: A rat model of neonatal HIE was established, then the pathological changes and expressions of nitric oxide synthase (NOS) in the brain tissues were investigated in different periods after hypoxia-ischemia (HI) and the subseqent changes of the above results after GM 1 administrated. RESULTS: The damage of the brain exposed to HI were alleviated significantly after GM 1 administrated. The levels of NOS expressions in the brain tissue increased after HI. GM 1 could inhibit NOS expressions induced by HI. CONCLUSION: GM 1 may have some protective effects on neonatal HIE, and the possible mechanism is related to the partial inhibition of NOS expression.

The authors have made an investigation on the conditions of the internet access,the platform for network-aided teaching,the teaching resource and the teaching effect for physical chemistry among 127 pharmacy students of 2008 enrollment.Based on the results of the investigation,an analysis on the current situation and problems of network-aided teaching for this course was performed and recommendations were put forward accordingly.

The free membrane of Eudragit L100/S100 which is pH-sensitive, colon-specific was prepared by plane casting films. The film humidity, species and amount of plasticizers, the ratio of membrane material was investigated. The rate of membrane permeability and mechanical properties were used as indicators of orthogonal experiment, and its related properties were studied. The results show that the mechanical properties of the membrane and phragmoid capacity are the best when 30% TEC was used as plasticizer; the ratio of membrane material have little effect on the rate of membrane permeability and mechanical properties. By adjusting the species and amount of plasticizers, the ratio of Eudragit L100/S100, the free membrane which is colon-specific can be obtained.

Objective To summarize the experience of adjuvant therapy for primary hepatocellular carcinoma. Methods 316 cases of operable hepatocellular carcinoma were divided into three groups. Only hepatectomy were performed in group one (21 8cases).Preopemtive adjuvant TACE were done in group two (52 cases). Preoperative adjuvant TACE and postoperative trans-portal vein chemotherapy were done in group three (46 cases), which was named hepatectomy sequencing two vessel therapy. Results 1, 3 and 5 year survival rote were 51.2 %, 30.0 % and 20.5 % respectively in group one, 57.2 %, 43.0 % and 31.5 % in group two, 84.0 %, 62.5 % and 51.0 % in group three. The postoperative disease-free survival rate in group three was significantly higher than that in group one and group two (P ＜0.05). Conclusion Hepatectomy sequencing two vessels therapy in perioperative period might improve the survival rate, which can prevent and delay the incidence of recurrence and may improve the effect of liver resection.

· AIM: To explore the dynamic expression and correlation among telomerase catalytic subunit (TERT), proliferating cell nuclear antigen ( PCNA) and antiapoptosis protein Bd-2 which relate to cell proliferation in epiretinal membrane of rat traumatic proliferative vitreoretinopathy(PVR).· METHODS: S-P technique was applied for immunohistochemical staining of epiretinal membrane of traumatic PVR with TERT, PCNA and Bcl-2 antibody. HE staining was also carried out. The staining results were analyzed with image analysis system.· RESULTS: The positive rate and average A of PCNA protein were upregulated at first and then down-regulated, with the peak value in 14d Group, which was significantly different from those in 7d Group and 28d Group.The positive rate and average A of TERT and Bcl-2 were also upregulated at first and then down-regulated, with the peak value in 14d Group and 21d Group, which were significantly different from those in 7d Group. There was significant correlation among PCNA, Bcl-2 and TERT protein expression (P≤0.01).· CONCLUSTON: TERT and Bcl-2 take part in the regulation of proliferative cells in epiretinal membrane of traumatic proliferative PVR, with high correlation with the dynamic changes of cell proliferation.

Objective To investigate the content of cadmium in shellfish in Guangdong Province and make dietary exposure assessment of cadmium in shellfish.Methods The shellfish samples were collected from Pearl River Delta,Eastern and Western Guangdong Province using random sampling method.Point assessment method was used to evaluate the exposure of dietary cadmium intake from shellfish.The risk of dietary cadmium exposure from shellfish were evaluated.Results Three hundred and seven samples were included in the analysis.The median concentration of cadmium in shellfish was 0.630 mg/kg and the exceeding standard rate was 23.8％ (73/307).The exceeding standard rates in Eastern Guangdong,Western Guangdong and Pearl River Delta were 19.4％ (13/67),23.5％ (16/68),and 25.6％ (44/172),respectively.The corresponding median concentration of cadmium were 0.530,0.806 and 0.853 mg/kg,and the difference was not statistically significant (x2 =0.94,P ＞ 0.05).The average (P50) and high level (P97.5) daily intake of cadmium from shellfish by the total survey population was 0.957 μg/d,and 4.511 μg/d,respectively.The monthly intake of cadmium associated with shellfish calculated from average and P97.5 exposure doses accounted for 1.91％ and 9.02％ of PTMI,respectively.Conclusion The cadmium content of some shellfish in Guangdong Province exceeded the standard.However,the cadmium intake from shellfish by the survey population was not high.

Objective To investigate the mechanism and suppression effect of human cytomegalovirus (HCMV) on proliferation of megakaryocyte progenitors(CFU-Mk)in vitro.Methods Colony forming unit-assay was applied to observe the effect of HCMV-AD 169 strain on CFU-Mk of cord blood. The technique of PCR was used to demonstrate the existence of HCMV-AD 169 DNA in the colony cells of cultured CFU-Mk.Results 1.The number of CFU-Mk colonies in HCMV-infected groups decreased significantly compared with that of control group. The CFU-Mk formation was inhibited significantly after HCMV-AD 169 strain infection.The suppression effect showed a dose-dependent fashion: 46.7 % inhibition with 10 -1of HCMV, 29.7 % with 10 -2 and 14.5 % with 10 -3 in the CFU-Mix assay. The peak of CFU-Mk colonies (d16-18) was not significantly different between control group and experimental groups, but the duration of the CFU-Mk colonies in infected groups was significantly shorter than that in control group.2. HCMV-DNA was positively detected in the colony cells of viral infected group by PCR, while negative in control group.Conclusions HCMV-AD 169 strain may inhibit the differentiation and proliferation of CFU-Mk by infecting the hematopoietic progenitors. HCMV may cause the suppression of hematopoiesis by direct infection, which may be the main reason for HCMV infection associated with thrombocytopenia.