BACKGROUND: The rare earth elements (Res) have multiple bio-activities and some extent neurotoxicity, Because of their distinct physical and chemical properties. The studies on neuromuscular junction and sympathet ic ganglia have shown that some Res, such as lanthanum(La), gadolinium (Gd),etc, exert considerable effects on synaptic transmission, but the effects and mechanism of Samarium on synaptic transmission are still unknown.OBJECTIVE: To investigate the effects and impossible mechanism of Samarium Chloride (SmCl3) on the nicotinic transmission in the isolated sympathetic ganglia, superior cervical ganglion (SCG) of rats.DESIGN: Controlled experimental study based on cells.SETTING: Department of Pharmacology, Guangxi Medical University. MATERIALS: Totally 40 adult Wistar rats (weighing 250-300 g) of either sex, provided by the Experimental Animal Center of Guangxi Medical University, were used in this study. SmCl3 was made by the chlorination of Samarium Oxide with purity 99.5% and relative molecule mass 348.7, presented by Professor Liu Da-yuan, Guangxi Medical University. Acetylcholine chloride (Ach) and carbachol (Carb) were purchased from Sigma.METHODS: The experiment was completed at the neuropharmacology lab of the experimental center of Guangxi Medical University from September 2001 to December 2002. After sacrificing animals by acute exsanguination,SCG together with their preganglionic nerve trunks were isolated rapidly,then transferred to the recording chamber, the preganglionic nerve trunk was drawn into a suction electrode for orthodromic stimulation. The ganglia were superfused continuously with a Krebs solution, saturated with 950 mL/L 02 and 5mL/L CO2, pH 7.4±0.05, (34±0.5) ℃.The fiber containing glass microelectrodes filled with 3 mol/L KC1 (30-60 MΩ tip resistance) were used to impaled cells and do intracellular recording. The fast excitatory postsynaptic potentials (FEPSPs) were evoked in SCG neurons by single pulse stimulations (0.2-0.5 Hz, 0.5-1.0 ms, 2-10 V)on preganglionic nerve trunk. The remarkable membrane depolarization would be recorded in SCG neurons by superfusing ganglia with exogenous Ach (0.1 mmol/L) or Carb(0.1 mmol/L) for 30-60 s. The effects of 1×(10-7-10-4) mol/L SmCl3 on FEPSPs, membrane potentials, membrane resistance, exogenous Ach and Carb-induced membrane depolarization of SCG neurons were investigated in this experiment.The effects of SmCl3 on the facilitation of high Ca2+ (10 mmol/L ) on FEPSPs were also be observed, namely, first superfusing the ganglia with high Ca2+ (10 mmol/L)to facilitate FEPSPs, then superfusing the ganglia with Ca2+(10 mmol/L)contained SmCl3. All the drugs were solved in Krebs solution or improved Krebs solution and applied to ganglia by superfusion in known concentration.The bioelectricity difference before and after the drug superfusion were analyzed by paired Student's t test.MAIN OUTCOME MESURES: ①Effects of SmCl3 on FEPSPs.②Effects of SmCl3 on membrane potentials and membrane resistances. ③Effects of SmCl3 on exogenous Ach and Carb-induced membrane depolarization. ④Effects of SmCl3 on the facilitation of high Ca2+ (10 mmol/L ) on FEPSPs.RESULTS: ① 1 ×(10-7-10-4)mol/L SmCl3 could reversibly depressed the FEPSPs of rats SCG neurons [the amplitude inhibitory percentage of FEPSPs of l×10-4, 1×10-5, 1×10-6, 1×107 mol/L SmCl3 was (49.78±13.85)%(n=20),(39.05±4.05)%(n=10),(29.83±9.73)%(n=10)and (16.30±2.16)%(n=10)respectively (P ＜ 0.05-0.01)].1×10-4 mol/L SmCl3 could chang Aps into FEPSPs (n=5).②The membrane depolarization induced by Ach (n=5) and Carb (n=7) were not significantly changed by 1×10-4 mol/L SmCl3(P ＞ 0.05).③The membrane potential and membrane resistance were not significantly altered by 1×(10-7-10-4)mol/L SmCl3(n=67), P ＞ 0.05. ④1×10-4 mol/L SmCl3 could antagonized the facilitation of high Ca2+ (10 mmol/L ) on FEPSPs (n=5), P ＜ 0.01.CONCLUSION: SmCl3 can depresses nicotinic transmission in rats sympathetic ganglia by presynaptic mechanisms, perhaps due to its inhibition on Ca2+ influx.

Objective To acquaint the condition of learning burnout of medical students and to explore the relationship of learning burnout with professional commitment and social support. Methods 610 medical students were evaluated with Learning Burnout Scale, professional commitment scale and social support scale. Results ①In general, learning burnout index of medical students was 2.84±0.49; in terms of gender difference, male students [(2.83±0.65) and (3.08±0.61)] were higher than females[(2.70±0.63) and (2.96±0.60)] at the level of emotional turndown and behavioral unsuitableness, the difference was statistically significant( P <0.05); in terms of grades, medical students'learning burnout of different grades was significant( F =4.244,P <0.01); there was no difference in profession. ②Learning burnout was significantly negative correlation with professional commitment and social support( P <0.01). ③Multiple regression analysis showed that affective commitment and family support had significant predications on learning burnout of medical students( P <0.01). Conclusion Medical students'learning burnout level is comparatively high, learning burnout closely relates to professional commitment and social support.

Histocytological Preparation Techniques ; methods ; Microtomy ; methods ; Tissue Embedding

Food Contamination ; Humans ; Infant ; Triazines ; toxicity ; Urinary Calculi ; diagnosis ; etiology ; therapy

In modern hospital outpatient management, patients should be paid more attention to than hospital management and economic management. Automatic and paperless management is also important. So, the software and hardware all should be updated to gain great social and economic benefit.

Objective:To investigate the effects of extracts of aqueous joint during CIA development on the HUVEC proliferation in vitro and expression of VEGF Methods: 3H TaR incorporation was used to estimate the HUVEC proliferation by extracts of aqueous joint and VEGF, and was used cultured in an absolutely serum free medium Results:Extracts of aqueqous joint during CIA development stimulated proliferation of HUVEC and this proliferation was inhibited by the anti VEGF neutralizing antibody Conclusion:The expression of VEGF in the extracts of the aqueous joint during an early stage of CIA development increased and expressed biologically active

Objective: To compare the difference of self-concept between children of complete and divorced family. Methods: 42 subjects in divorced family and 45 controls were tested by Piers-Harris Self-concept Scale for Children. Rusults: The students in divorced family reported significantly lower scores on self-concept than the controls on behavior,anxiety, gregariousness, satisfaction and total score. Conclusion: The self-concept of divorced family students is lower than that of the control group.

Objectives:To detect the altered expression of SOCS-3 and GHR gene in intraabdominal infection and its relationship to growth hormone resistance.Methods:Liver expression of SOCS-3,GHR and IGF-I mRNA were detected by RT-PCR in control and intraabdominal infected rats,serum growth hormone levels were measured by RIA in two groups.Results:Serum concentrations of growth hormone were elevated more obviously in infected rats than controls,they were (0.843±0.17)ng/ml and (0.614±0.138)ng/ml respectively,the difference was significant (P<0.05).Liver GHR mRNA levels were decreased by 57.2% in infected rats compared with control rats.SOCS-3 mRNA was weakly expressed in control rats,however,it was strongly expressed in infected rats and had a 312.8 % increase.Liver IGF-I mRNA levels were reduced by 45.3% in infected rats compared with control rats.Conclusions:The elevated SOCS-3 and reduced GHR mRNA expression may contribute to the growth hormone resistance in intraabdominal infection.

Objective To establish a gas chromatography method for the determination of hydrogen sulfide in waste gas. Methods Hydrogen sulfide was collected with 100 ml glass injector,then the sample was separated with the column of GDX-104, and it was detected by gas chromatography with the flame-photometric detector.Results The linear range was 0.000 5-0.85 mg/m~3, the linear equation was y=33.532 89+1.921 81x(r=0.999 86),RSD was 2.54%-3.89%,the lowest detected concentration was 0.000 5 mg/m~3.Conclusion This method is rapid,sensitive,accurate,stable and applicable to the determination of hydrogen sulfide in waste gas.

Phenols are organic pollutants of high priority concerns because of their toxicity and possible accumulation in the environment. It is important to treat and recover phenols from wastewater economically and effectively. In this paper,the source and harm of phenolic wastewater were introduced. The situation and progress in treatment process of phenolic wastewater,including absorption,extraction,oxidation process,and biological treatment are also summarized. The characteristics,main problems ,area and further application of each treatment process are pointed out. The developing trend on combination treatment of phenolic wastewater is further described.