Objective To prepare active components from extract of Arca subcrenata Lischke and analyze its antioxidative activity.Methods The antioxidative component(P3)from Arca subcrenata Lischke was isolated by chromatography on Superdex-75 column followed by a Sephadex LH-20 column,and antioxidative activities were assayed using potassium ferricyanide and DPPH methods,respectively.The characters of this component were determined by ninhydrin reagent,anthrone reagent,Coomassie Brilliant Blue G250 reagent as well as thin-layer chromatography.Results and Conclusion A component with strong antioxidative activity was isolated and identified as glycosylated peptide.

Objective To develop a high-definition video display system for medical endoscope based on system on chip (SoC),and meet the requirement of high-resolution and real-time video display.Method A CMOS camera was used for video data capture.A SoC chip,integrated with a dual-core ARM Crotex-A9 processor and a field programmable gate array (FPGA),was employed as the kernel of the system.The HPS part of the SoC was used to build an embedded system to realize human-computer interaction,and the FPGA part was used to store and cache video data.The HPS and FPGA part were connected through a high-performance ARM AMBA AXI bus bridge broadband system,so as to achieve encoding of the cached video data and real-time display on screen.Results A high-definition video display system was built based on SoC.This system can achieve capture,processing and realtime display of high-definition video,as well as video freeze function.Conclusions The experimental results indicate that this system is feasible and effective,and possesses the advantages of customizability,multiple-exploitation and high performance of real-time video display.

Objective To study an image display method for portable medical endoscopes using intelligent mobile devices for solving the problem of lacking medical resources in remote areas and carrying inconvenience of endoscopic workstations.Method An high-definition camera was employed for image data acquisition,which was driven by the built-in Video4Linux drive program of a embedded Linux system.A wireless network card was used to establish a point-to-point network,and to build the LAN server.The mobile devices could acquire the collected image data through accessing the local area network,which could realize the real-time display on the LCD screen.Results The resolution of a collected image was 1 024×768 pixels,the bit depth was 24 bits,the frame rate was 30 frame/s,and the actual average transmission speed was about 2 MB/s.Conclusions The proposed method is effective and feasible.The collected image is clear,and the system has advantages of simple structure,low cost and easy to carry,which can save the manufacturing cost and meet the conditions of usage in remote areas.

Objective:To study the effects of down-regulated Smad4 expression on the proliferation and apoptosis of breast carcinoma MCF-7 cells,and to explore their mechanisms.Methods:The human breast carcinoma MCF-7 cells and MDA-MB-231 cells were cultured in vitro.RT-PCR method was used to detect the expression levels of Smad4 mRNA in MCF-7 cells and MDA-MB-231 cells.The Smad4-shRNA plasmid and Scramble-shRNA plasmid were respectively stably transfected into the MCF-7 cells with high expression of Smad4.The experiment was divided into non-transfected MCF-7 cells (normal control) group,Smad4 gene silencing group,Scramble(negative control) group.The proliferation abilities of the cells in various groups were detected by CCK-8 method.The apoptotic rates of the cells in various groups were detected by flow cytometry.Real-time PCR method wasused to detect the mRNA expression levels of the proliferation-related genes CDKN1A,CDK1 and CDK2 and the apoptosisrelated genes Suvivin,bcl-2,caspase 3 and caspase 9.Results:The proliferation abilities of cells had no statistical significance between various groups (P＞0.05).The mRNA expression levels of CDKN1A,CDK1 and CDK2 in the cells had no statistical significance between various groups (P＞0.05).Compared with normal control group and negative control group,the apoptotic rate of the cells in Smad4 gene silencing group was significantly decreased (P＜0.01),the expression levels of Suvivin and bcl-2 mRNA in Smad4 gene silencing group were significantly increased (P＜0.01),and the mRNA expression levels of caspase 3 and caspase 9 in Smad4 gene silencing group were significantly decreased (P＜0.05).Conclusion:Smad4 could induce the apoptosis of MCF-7 cells by downregulating the expressions of Suvivin and bcl-2 and up-regulating the expressions of caspase 3 and caspase 9.

Objective:To investigate clinical efficacy of conformal sphincter preservation operation (CSPO) versus intersphincteric resection (ISR) in the treatment of low rectal cancer.Methods:The retrospective cohort study was conducted. The clinicopathological data of 183 patients with low rectal cancer who were admitted to two medical centers (117 in the Changhai Hospital of Naval Medical University and 66 in the Huashan Hospital of Fudan University) from August 2011 to April 2020 were collected. There were 110 males and 73 females, aged (57±11)years. Of 183 patients, 117 cases undergoing CSPO were allocated into CSPO group, and 66 cases undergoing ISR were allocated into ISR group, respectively. Observation indicators: (1) surgical situations of patients with low rectal cancer in the two groups; (2) postoperative complications of patients with low rectal cancer in the two groups; (3) follow-up; (4) influencing factors for prognosis of patients with low rectal cancer; (5) influencing factors for satisfaction with the anal function of patients with low rectal cancer. Follow-up was conducted using outpatient examination, questionnaire and telephone interview to determine local recurrence, distal metastasis, survival, stomal closure, satisfaction with the anal function of patients. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was analyzed using the t test. Measurement data with skewed distribution were represented as M (range). Count data were described as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test. Comparison of ordinal data was analyzed using the rank sum test.The Kaplan-Meier method was used to draw survival curves, and life table method was used to calculate survival rates. Log-rank test was used for survival analysis. Univariate analysis was performed using the linear regression. Variables with P<0.10 in the univariate linear regression analysis were included for multivariate analysis. Multivariate analysis was performed using the COX stepwise regression model and linear regression analysis. Results:(1) Surgical situations of patients with low rectal cancer in the two groups: cases with laparoscopic surgery, operation time, volume of intraoperative blood loss, distance from tumor to distal margin, cases with postoperative chemotherapy, duration of postoperative hospital stay were 44, (165±54)minutes, (142±101)mL, (0.6±0.4)cm, 76, (6.6±2.5)days for the CSPO group, respectively, versus 55, (268±101)minutes, (91±85)mL, (1.9±0.6)cm, 9, (7.9±4.7)days for the ISR group, showing significant differences between the two groups ( χ2=35.531, t=8.995, -3.437, -3.088, χ2=44.681, t=2.267, P<0.05). (2) Postoperative complications of patients with low rectal cancer in the two groups: 19 patients in the CSPO group had complications. There were 6 cases with grade Ⅰ complications, 12 cases with grade Ⅱ complications, 1 case with grade Ⅲb complication. Fourteen patients in the ISR group had complications. There were 4 cases with grade Ⅰ complications, 7 cases with grade Ⅱ complications, 1 case with grade Ⅲa complication, 2 cases with grade Ⅲb complications. There was no significant difference in the postoperative complications between the two groups ( χ2=0.706, P>0.05). Patients with complications in the two groups were improved after symptomatic and supportive treatment. There was no perioperative death in the postoperative 30 days of the two groups. (3) Follow-up: 183 patients received follow-up. Patients of the CSPO group and ISR group were followed up for (41±27)months and (37±19)months, respectively, showing no significant difference between the two groups ( t=-1.104, P>0.05). There were 2 cases with local recurrence and 9 cases with distal metastasis of the CSPO group, respectively, versus 3 cases and 4 cases of the ISR group, showing no significant difference between the two groups ( χ2=1.277, 0.170, P>0.05). The 3-year disease-free survival rate and 3-year total survival rate were 84.0% and 99.0% for the CSPO group, versus 88.6% and 92.8% for the ISR group, showing no significant difference between the two groups ( χ2=0.218, 0.002, P>0.05). The stomal closure rate was 92.16%(94/102) and 96.97%(64/66) for 102 patients of CSPO group and 66 patients of ISR group up to postoperative 12 months,respectively, showing no significant difference between the two groups ( χ2=1.658, P>0.05). Of the 8 cases without stomal closure in the CSPO group, 2 cases refused due to advanced age, 4 cases subjectively refused, and 2 cases were irreducible due to scar caused by radiotherapy. Two cases in the ISR group had no stomal closure including 1 case of postoperative liver metastasis and 1 case of subjective refusal. There were 92 and 61 patients followed up to 12 months after stomal closure, of which 75 cases and 38 cases completed questionnaires of satisfaction with the anal function. The satisfaction score with the anal function was 6.8±2.8 and 5.4±3.0 for CSPO group and ISR group, respectively, showing a significant difference between the two groups ( t=-2.542, P<0.05). Fifty-four cases in the CSPO group and 21 cases in the ISR group had satisfaction score with the anal function >5, showing no significant difference between the two groups ( χ2=3.165, P>0.05). (4) Influencing factors for prognosis of patients with low rectal cancer: results of COX stepwise regression analysis showed that gender and pT staging were independent influencing factors for disease-free survival rate of patients with low rectal cancer ( hazard ratio=2.883, 1.963, 95% confidence interval as 1.090 to 7.622, 1.129 to 3.413, P<0.05). Gender and pT staging were independent influencing factors for total survival rate of patients with low rectal cancer ( hazard ratio=10.963,3.187, 95% confidence interval as 1.292 to 93.063, 1.240 to 8.188, P<0.05). (5) Influencing factors for satisfaction with the anal function of patients with low rectal cancer: results of univariate analysis showed that surgical method and tumor differentiation degree were related factors for satisfaction with the anal function of patients with low rectal cancer (partial regression coefficient=1.464, -1.580, 95% confidence interval as 0.323 to 2.605, -2.950 to -0.209, P<0.05). Results of multivariate analysis showed that surgical method, tumor differentiation degree and preoperative radiotherapy were independent influencing factors for satisfaction with the anal function of patients with low rectal cancer (partial regression coefficient=1.637, -1.456, -1.668, 95% confidence interval as 0.485 to 2.788, -2.796 to -0.116, -2.888 to -0.447, P<0.05). Conclusion:Compared with ISR, CSPO can safely preserve the anus in the treatment of low rectal cancer, without increasing the incidence of postoperative complications, which can also guarantee the oncological safety and improve the postoperative anal function.