Polylactic acid (PLA) and its copolymer are biodegradable polymer materials which are widely used in the medical field because of their excellent mechanical properties, chemical stability, good biocompatibility, and biodegradability. In this paper, research advances in the study on polylactic acid and its application in vascular stent are discussed.

Objective:To observe the therapeutic effect and safety of warfarin on patients with atrial fibrillation. Methods:A total of 126 patients with atrial fibrillation from our hospital during Jun 2012-Jun 2013 were selected. According to hiding number random method,they were divided into aspirin group (n=63)and warfarin group (n=63).Coagulation function,blood lipid levels and end-point events were compared between two groups.Results:Compared with aspirin group,after treatment,there were significant reductions in levels of total cholesterol [(5.8 ±0.5)mmol/L vs.(5.2±0.7)mmol/L],triglyceride [(2.6±0.4)mmol/L vs.(2.4±0.3)mmol/L]and low density lipoprotein cholesterol [(2.7±0.5)mmol/L vs.(2.4±0.3)mmol/L],significant rise in level of high den-sity lipoprotein cholesterol [(1.1±0.2)mmol/L vs.(1.3±0.2)mmol/L],prothrombin time [(28.3±11.7)s vs. (36.9±10.4)s]and it′s international normalized ratio [(1.9±0.4)vs.(2.4±0.5)]in warfarin group,P <0.05 all.Incidence rate of endpoint events such as cerebral infarction and peripheral artery embolism etc.in warfarin group was significantly lower than that of aspirin group (3.17% vs.23.81%,P <0.01).The incidence rates of complications were 23.81% and 26.98% in warfarin group and aspirin group respectively,and they had no signifi-cant difference,P >0.05. Conclusion:For atrial fibrillation,the therapeutic effect and safety of warfarin is better than that of aspirin,is worth extending.

Objective To study the clinical and X-ray findings in mamma virilis devolopment.Methods Clinical and X-ray findings in 11 patients with primary mamma virilis development were presented and analysed retrospectvely.Results X-ray findings were divided into 3 groups:1)mass(n=4):round or oval mass with high density and well-defined border;2)patch(n=4):patch like uneven mass with high density and ill-defined border;3)nodule(n=3):irregular uneven nodules.Conclusion Clinical and X-ray findings of mamma virilis development have some characteristic features,it can be differentiated from mamary cancer and pseudogynecomastia.

Superior mesenteric vein (SMV) thrombosis is a relatively rare disease. Most patients may be successfully treated with anti-coagulation alone. However, bowel stricture may develop due to intestinal ischemia which may require surgical treatment. This report describes a rare case of small bowel stricture occurring one month after successful treatment of SMV thrombosis. After segmental resection of strictured bowel, the patient's post-operative course was uneventful.

Objective Combined with susceptibility weighted imaging (SWI) and proton magnetic resonance spectroscopy (1H-MRS) to study the hippocampus in the first-episode depression patients for exploring the causal relationship.Methods 20 first-episode depression patients and 20 healthy volunteers underwent SWI scanning and hippocampal 1H-MRS image,analysis and comparison the changes between the venous system and metabolism of two groups.Results Proton spectroscopy analysis showed that compared with the control group,bilateral hippocampal NAA/Cr(left hippocampus:depression group 0.95±0.77,control group 1.78±0.82; right hippocampus:depression group 1.12±0.74,control group 1.91 ± 0.80) and Cho/Cr (left hippocampus:depression group 1.08±0.83,control group 1.75±0.73 ; right hippocampus:depression group 0.91±0.68,control group 1.95 ±0.74) in the depression group was significantly lower,the difference was significant(NAA/Cr:t value in left and right were -3.14,-3.49,P＜0.05; Cho/Cr:t value in left and right were-3.25,-3.19,P＜0.05),however MI/Cr had no obvious changes (t value in left and right were 1.24,-1.27,P＞0.05).Magnetic sensitive scan showed depression group compared with the control group was significantly reduced in lateral vein diameter,length and branches (t value were 3.23,4.56,2.66,P＜0.05).Conclusion The SWI sequence and 1H-MRS imaging methods can become a new research idea about the central nucleus,and this idea may explain the causal relationship between the hippocampus in depression patients of vascular abnormalities and hippocampal neuronal metabolic abnormalities.

Objective To explore the cell metabolism of the bilateral hippocampus effected by the inflammatory factor of blood serum in the development of the depression.Methods Using Proton magnetic resonance spectroscopy 1 H-MRS technology to detect multiple metabolic indices of the bilateral hippocampus of 20 first episode depression patients and 20 healthy persons,and detecting the levels of IL-6,IL-2,IL-10 in blood serum were detected.Finally the correlation between them was analyzed.Results Compared with the healthy group,the values of Glx/Cr and NAA/ Cr were reduced in left hippocampus (Glx/Cr: (0.82±0.48),t=2.69,P＜0.05 ; NAA/Cr: (1.12 ±0.44),t =2.81,P＜ 0.05) and the value of Cho/ Cr was increased in left hippocampus ((2.49± 0.78),t =2.36,P＜0.05),but only the value of Glx/ Cr were reduced in right hippocampus ((0.84 ± 0.47),t =2.43,P＜ 0.05),and the other metabolic indices changed unobvious.The depressive group had the significantly higher levels of IL-6,IL-2 in blood serum(IL-6: (12.47±3.19) ng/L,t=4.53,P＜0.05 ; IL-2: (29.44±5.72) ng/L,t=2.44,P＜0.05),but no significant difference was found in the IL-10 level in blood serum.The Glx/ Cr of bilateral hippocampus level was negatively correlated to the IL-6 and IL-2 level in blood serum(left:(IL-6: r=-0.555,P＜0.05;IL-2: r=-0.624,P＜0.05) ;right:(IL-6: r=-0.575,P＜0.05; IL-2: r=-0.523,P＜0.05)).The NAA/ Cr of left hippocampus level was negatively correlated to the IL-6 and IL-2 level in blood serum(IL-6: r=-0.582,P＜0.05;IL-2: r=-0.607,P＜0.05).The Cho/Cr of left hippocampus level was negatively correlated to the IL-6 and IL-2 level in blood serum(IL-6: r=0.601,P＜0.05; IL-2: r=0.552,P＜0.05).Conclusion The abnormal of glutamic acid system in bilateral hippocampus maybe the important performance and the potential originating link,the changes of the inflammatory cytokines level maybe the factor of these abnormal changes.

Objective To investigate the feasibility and safety of laparoscopic aortobifemoral bypass (LABF) for diffuse aortoiliac occlusive diseases.Methods Clinical data of 18 cases who underwent LABF were retrospectively analyzed.The intraoperative procedures and postoperative outcome were evaluated.Results LABF was performed successfully in 17 of 18 patients.The mean operation time was (280 ±57) minutes,with a mean aortic cross-clamp time of (117 ±32) minutes.Estimated blood loss was(524 ±45) ml.Mean ICU stay was ( 1.0 ± 1.2) days.The mean postoperative hospital stay was ( 10 ±5) days.Mean time to resume diet was (3 ± 3 ) days.Postoperative myocardial infarction developed in 1 case,lung infection in 2 cases.There was no perioperative mortality.Graft thrombosis developed in 1 case and embolectomy surgery was successfully performed.All patients were followed up from 3 to 27 months,with mean follow-up of (18 ± 8) months,grafts were all patent.Conclusions Laparoscopic aortic bypass is feasible and miniinvasive in patients with diffuse aortoiliac occlusive disease.Short-term outcomes are comparable to those with open conventional aortic bypass.

Objective To explore the sensibility of the encephalic region affected by the inflammatory factor of cerebrospinal fluid(CSF) and the role of the inflammatory factor in the development of the depression.Methods Based on the evaluation of ethology,forty SD rats were randomly and equally divided into control group and model group which was exposed to chronic unpredictable mild stress for 4 weeks.Using analyzing technology 1 H-MRS to detect prefrontal cortex and hippocampus of each group and detecting the levels of interlukin 6(IL-6),interlukin 2 (IL-2),interlukin 10 (IL-10) in CSF at the beginning and 4 weeks later,and the correlation was analyzed between them.Results Compared with the control group,the values of Glx/ Cr and NAA/ Cr in bilateral prefrontal cortex were reduced which did not reach statistically significance (P ＞ 0.05),and the value of Cho/ Cr had no significant difference.The values of Glx/Cr and NAA/Cr in left hippocampus reduced significantly(Glx/Cr:(1.16 ±0.07),t =2.50,P＜0.05 ;NAA/Cr:(1.30 ±0.09),t=5.94,P＜0.01),and the value of Cho/Cr was increased which did not reach statistically significance(P＞ 0.05).The values of Glx/Cr and NAA/Cr were reduced and the value of Cho/Cr was increased in right hippocampus which did not reach statistical significance(P＞0.05).The depressive group had the significantly higher levels of IL-6,IL-2 in CSF(IL-6:(32.41 ± 3.52),t =11.46,P ＜ 0.01 ; IL-2:(18.89 ± 2.56),t =7.42,P ＜ 0.01),but no significant difference was found in the IL-10 level in CSF.The Glx/Cr of left hippocampus level was negatively correlated to the IL-6 and IL-2 level in CSF (IL-6:r =-0.555,P＜ 0.05 ; IL-2:r=-0.582,P＜ 0.05) ; the NAA/Cr of left hippocampus level was negatively correlated to the IL-6 and IL-2 level in CSF(IL-6:r=-0.582,P＜0.05;IL-2:r=-0.607,P＜0.05).Conclusion The development of inchoate depression has a correlation with the high sensibility of the left hippocampus affected by the inflammatory factor levels.The metabolism of never cells has changed,which maybe constitutes the physiopathology basis of the depression.

Objective:To analyze the wall thickness of C-shaped canals in permanent mandibular second molars.Methods:40 ex-tracted permanent mandibular second molars with C-shaped root were collected from native Chinese and were scanned by micro-CT scan-ner.The specimens were reconstructed three-dimensionally by software Mimics 10.01.The roots were sliced from cemento-enamel junc-tion (CEJ)to apex with 1 mm intervals.The cross-sectional root canal configurations were classified into 5 types according to the Fan's Classification.The minimum buccal wall thickness (MBWT),minimum lingual wall thickness(MLWT)and their locations,as well as the wall thickness at the mesial and distal reference sites were detected.Two-way ANOVA and post hoc LSD-t tests were used to com-pare the mean thickness at 4 sides.Results:Among 370 cross-sections of 40 C-shaped roots,C1,C2 and C3 canals were observed on 126(34.1%),46 (12.4%)and 160 (43.2%)sections respectively.Except at the 10 mm level,the mean MLWT was always lower than MBWT;and the MLWT and MBWT were always lower than the wall thickness at the mesial and distal reference sites.The differ-ence was statistically significant (P <0.05)along the root length above the 12 mm level.The MBWT of the C2 and C3 canals was more likely located at the mesial region,and the MBWT of the C1 and the MLWT of C1,C2 and C3 was more frequently located at the center region.Conclusion:The lingual wall of C-shaped canal in mandibualr second molars was the thinnest zone among four sides,and care should be taken during root canal instrumentation and post space preparation to avoid perforation.

Objective To investigate the variation of middle cerebral arteries of rats in depression model by using 3D-TOF sequence on 3.0T MR.Methods Forty SD rats were randomly divided into control group and depressive group with 20 in each.Compared with control group,depressive group were handled according to the demand of rat depression model.Rats were scanned by 3.0T MR on 0th,4th,6th,8th week respectively.Using Mimics software,the variation of middle cerebral arteries were described and analysed.Results Compared with the control group,the middle cerebral arteries of depressive group rats changed along with the increase of time.On the 4th week,the diameter of the middle cerebral arteries of rats decreased significantly (the diameter of left middle cerebral arteries:control group (0.31 ±0.05) mm,depressive group (0.28±0.04) mm,t=2.76,P＜0.05 ; the diameter of right middle cerebral arteries:control group (0.30 ± 0.05) mm,depressive group (0.27± 0.03) mm,t =2.61,P＜ 0.05).On the 6th week,the length of the middle cerebral arteries of rats decreased significantly (the length of left middle cerebral arteries:control group (5.6± 0.77) mm,depressive group (4.9 ± 0.73) mm,t =2.84,P＜ 0.05 ; the length of right middle cerebral arteries:control group(5.5±0.76) mm,depressive group(4.8±0.72) mm,t=3.11,P ＜0.05).On the 8th week,the diameter and length of the middle cerebral arteries of rats decreased more significantly (the diameter of left middle cerebral arteries:control group (0.31 ±0.05) mm,depressive group (0.22±0.02) mm,t =5.50,P＜ 0.01 ; the diameter of right middle cerebral arteries:control group (0.30 ± 0.04) mm,depressive group (0.21 ±0.02) mm,t=5.57,P＜0.01 ; the length of left middle cerebral arteries:control group (5.6±0.78) mm,depressive group (4.3±0.70)mm,t=5.49,P＜0.01 ;the length of right middle cerebral arteries:control group (5.5 ± 0.79) mm,depressive group (4.2±0.71)mm,t=5.45,P＜0.01).Conclusion The variation of middle cerebral arteries of depressive rats reveals the relationship between brain vessels and depression in a certain extent.