A theoretical model for the magnetic forces on ferromagnetic drug particles in a guiding magnetic field is established with the consideration of the electromagnetic field theory. Our model shows that the ferromagnetic drug particles can concentrate on the targeted area with the guidance of the outside magnetic field. Both the distribution of the intensity of the guiding magnetic field and the forces on ferromagnetic drug particles are studied numerically. The theoretical results are in good agreement with the experimental results reported recently.

Objective To study the relevant factors of malignant change of colorectal adenoma. Methods The clinical data of 276 cases of colorectal adenoma admitted in our hospital in recent 14 years were analyzed retrospectively . Results Malignant change rate of the adenoma in the left colon was significantly higher than that in right colon(P

In the reform of medical microbiology education on medical students of 8-year-education pro-gram, we compared the traditional teaching methods with Problem Based Learning (PBL) method. Through our practice, we have found that the combination of traditional lecture-based learning and PBL seems to better match the students’ way of learning. The lack of basic knowledge of the students hindered their learn-ing effect during the bilateral discussion in the PBL education. We also found that the application of PBL in medical microbiology education is an iterative process and should be promoted step by step. The theoretical level and the innovative ideas of the teachers play a crucial role in the dynamic process of education reform.

Objective To evaluate the double-balloon enteroscopy(DBE) for obscure gastrointestinal bleeding(OGIB) and evaluate the health economics under the guidance of DBE for surgical treatment of obscure gastrointestinal bleeding.Methods A total of 114 patients,whose hemorrhage etiology could not be determined by conventional gastroscopy,enteroscopy and gastroenterography,underwent DBE.With pathological results as diagnostic criteria,the value of double-balloon enteroscopy for obscure gastrointestinal bleeding diagnosis was studied.Results The sensitivity,specificity and accuracy of DBE for OGIB were 85.86％,63.63％,81.57％,respectively.The positive likelihood ratio was 2.36 and the negative likelihood ratio was 0.22.The total days of hospitalization,hospital costs,cost of hospital drugs were lower in the DBE group than in the control group(27.2 ± 11.8 days VS 16.4 ±5.3 days,35 690.2 ±3 466.5 Yuan VS 19 409.3 ± 9 253.2 Yuan,17 805.8 ± 2 145.5 Yuan VS 9 133.0 ± 4 664.9 Yuan) (all P ＜ 0.05).Conclusion DBE plays an important role in diagnosis of OGIB.It has significance in clinic,health economics,and social benefits.

Objective To study the effects of 2,2',4,4'-tetrabromodiphenyl ethers(PBDE-47)single exposed and combined with 2,2',4,4',5,5'-hexachlorobiphenyl(PCB153)on learning and memory ability and the uhrastrncture of hippocampal CA1 region in rats.Methods Neonatal SD rats(CL grade)were randomly divided into groups,9 male and 9 female in each,then were exposed to single PBDE-47 at doses of 1,5,10 mg/kg and combined with PCB153 at dose of 5 mg/kg,through gavage for one time. Soya oil was used as the solvent control.The learning and memory ability and ultrastructure of neurons in hippocampal CA1 region were examined respectively 2 months after treatment.Results In the low dose groups(1 mg/kg PBDE-47 and 1 mg/kg PBDE-47+ 5 mg/kg PCB153 treated group),the ultrastructure of neurons in hippocampal CA1 region were as normal as that in the control group.As the dose increasing,in 5 mg/kg PBDE-47 group,the endoplasmic reticulum appeared swelling,expansion and degranulation.In 5 mg/kg PBDE-47 plus 5 mg/kg PCB153 group,the mitochondria appeared swelling,the ridge ruptured,the periplast puffed,and then the cytoplasm condensed.In the high dose groups(10 mg/kg PBDE-47 group and 10 mg/kg PBDE-47 plus 5 mg/kg PCB153 group),the neurons showed acutely denatured,the periplast puffed,the cell organelle dissolved and the mitochondria vacuolizated.The interaction between PBDE-47 and PCB153 on the latency period and the general pathway was presented in place navigation test(P

Objective To assess the relationship between auditory evoked potential (AAI) index and plasma concentration of propofol administered by target-controlled infusion (TCI) in Chinese.Methods Ten ASA Ⅰ～Ⅱ tumor patients (5 males,5 females) scheduled for elective abdominal surgery under general anesthesia was enrolled in this study.Age ranged from 34 to 61 years,body weight from 52 to 79 kg and height from 155 to 178 cm.Radial artery was cannulated for blood sampling.The patients were premeditated with intravenous injection Midazolam 0.06 mg/L.Anesthesia was induced by fentanyl 2μg/kg,vecuronium 0.1 mg/kg and TCI of propofol which the target plasm concentration was set at 3 mg/L.After intubation,the target plasma concentration of propofol was adjusted at 1.7～2.5 mg/L.Vecuronium was continuous infusions at 2～3mg/h.Anesthesia was maintained with fentanyl-TCI of propofol-vecuronium and inhalation of 0.5 MAC isoflurane.The TCI system was composed of Base Primea company orchestra infusion pump using,the schnider pharmacokinetics model.ECG,Bp,HR,PETCO2,SpO2 and TETISO were monitored during anesthesia.Danmeter company A-line depth of anesthesia monitor recorded AAI index.Blood samples were taken at induction of anesthesia (To baseline),1,3,5,10,15,30,60 min (T1-7) and after cessation of infusion 10 and 20 min (T9-10).Plasma propofol concentration were determinated by fluorescence photometry.Results Compared with target concentrations,the measured concentrations of propofol were significantly lower during TCI(P＜0.05).There was negative correlation between AAI and plasma propofol concentrations(r=-0.818,P＜0.01).Conclusion On base of the Schnider pharmacokinetics model,the target propofol concentrations are not paralleled to plasma propofol concentrations which is descending with time prolongation.From negative correlation between AAI index and plasma propofol concentrations,AAI index will reflect indirectly plasma propofol concentrations.

Objective To explore the effect of Fas/FasL pathway on fluoride.induced apoptosis in hurnan neumbla8toma SH-SY5Y cells.Methods The cell survival rate,percentage of apoptosis,and mRNA expression levels of Fas and FasL were measured respectively after the SH-SY5Y cells were exposed to O(control),20,40,80 mg/L sodium nuoride(NaF)for 24 hours/n vitro.Furthermore,the changes of the percentage of apoptosis and mRNA expression levels of Fas and FasL in 40 mg/L NaF-treated groups incubated with activaling or neutralizing anti-Fas antibody(CH11 or ZB4)also observed respectively.Results Compared with the control group(100.00%), the cell surval rates in 40,80 mg/L NaF-treated groups[(84.63±2.57)%,(69.04±5.63)%]were significandy lower(P<0.01).The percentage of apoptosis in 40,80 mg/L NaF.treated groups[(8.54±1.95)%.(17.94±2.71)%]were higher(P<0.05)than thal in the control group[(3.32±1.33)%],and increased with the dose of NaF.NaF could up-regulate Fas and FasL mRNA expression,and increased the Fas/β-actin [40 ms/L group (0.94±0.51),80 mg/L group(0.99±0.12)]and FasL/β-actin[40 mg/L group(0.96±0.42),80 mg/L group(0.99±0.24)] ratio,compared with the control[Eas/β-actin(0.50±0.33),FasL/β-actin(0.58±0.23)],both the difference had 8tatistical significances (P<0.05).NaF and CH I 1 had a synergisfic effect on apoptosis and mRNA expression levels of Fas and FasLL(F=32.89,18.46,.14.69,P<0.01)while NaF and ZB4 had an antagonistic effect (F=5.73,24.26,10.17,P<0.05 or<0.01).Conclusion NaF exposure can cause apoptosis in SH-Y5Y cells,and the Fas/FasL pmhway may play an important role in NaF-induced apoptosis.

Objective To investigate the dynamic changes of serum insulin-like growth factor-1 (IGF-1) in acute traumatic brain injury (TBI) as well as their correlations with the initial severity of TBI and prognosis.Methods A total of 229 patients with acute TBI admitted from September 2014 to June 2016 were retrospectively studied.Patients were further classified as mild TBI group (GCS 13-15 points),moderate TBI group (GCS 9-12 points) and severe TBI group (GCS 3-8 points) according to Glasgow coma score (GCS).The control group consisted of 30 healthy subjects.The prognosis was evaluated by using Glasgow outcome scale (GOS) at 6 months after TBI.The IGF-1 levels were further tested at days 1,3,5,7 and 14 and their correlations with the initial GCS and GOS at 6 months after injury were evaluated.Results (1) The serum IGF-1 levels of mild,moderate and severe TBI group at all time points were significantly lower than those of the control group (P ＜ 0.05);the serum IGF-1 levels of severe and moderate TBI groups at all time points after injury were significantly lower than those of the mild TBI group (P ＜0.05);the serum IGF-1 levels of the severe group at days 1,3,5 and 7 d after injury were lower than those of the moderate TBI group (P＜0.05).(2) IGF-1 levels were significantly different between the two groups (P ＜ 0.05) at different time points during the follow-up of 6 months.(3)IGF-1 levels were positively correlated with both GCS and GOS at the acute stage of TBI and sub-acute stage following TBI (P ＜ 0.05).Conclusion The dynamic changes of serum IGF-1 levels in patients with acute TBI are related to both initial severity of TBI and the neurological outcomes and can be used as a reliable biomarker for early severity assessment and prognostic prediction of TBI.

Objective To study the efficacy and mechanism of compound Tripterygium hypoglaucum Hutch (THH) on photoallergic contact dermatitis in mice. Methods The photoallergic animal model of BALB/c mice was established by using photosensitizer chlorpromazine and UVA irradiation. The therepeutic efficacy was determined by measuring the thickness and the weight of the swelling ear and the number of infiltrated mononuclear cells in the ear tissue. Immunohistochemical technique was used to detect the ICAM-1 expression on keratinocytes, fibroblasts and vascular endothelial cells. The serum level of INF-? was measured by ELISA. The tested animals were divided into 3 groups: compound THH, THH alone and normal saline. Results The difference of the thickness of left ear before and after challenge, the differences of the thickness and the weight of ear tissue, the difference of the number of infiltrated mononuclear cells of left and right ear after challenge were significantly less in the compound THH group than those in the THH alone group (P

Objective To evaluate short-term curative effect of endovascular abdominal aortic aneurysm repair. Methods Twelve cases of infra-renal abdominal aortic aneurysms were checked. Results The av-erage bleeding in the operation was 245 millimeter, the avenage hospitalization time was 8.6 days, and the average abrosia time was 1.5 days. White blood cell, hemoglobin, thrombocyte, hepatic function, and renal function were in the normal limits. Prothrombin time and activated partial thromboplastin time were post-poned after operation, and recovered normally within one week. Complications of operations were as follows:1 case of pulmonary infection, 2 cases of abdominal distention, and 1 case of intraoperafive endoleak. The former two kinds of complications alleviated after conventional treatment, and the latter disappeared naturally after 3 months. Conclusion Endovascular abdominal aortic aneurysm repair is safe, mini-invasive, and has little disturbance for body internal environment.