Objective To analyze the current situation and influence factors of ordinary medical college undergraduates' contact with scientific research at early stage in order to provide references for scientific research.Methods Totally 1940 students majoring in clinical medicine,imaging,traditional Chinese medicine and nursing (2008 -2010 grade) in China Three Gorges University were enrolled to do questionnaine and SPSS 17.0 was used to do statistical analysis.Results Totally 1653copies of questionnaires were collected from 1940 students,the recovery rate was 85.21％.Two hundred and nineteen students ( 13.25％ ) participated in scientific research,65.28％ students thought college propaganda to be ordinary,95.43％ students got benefits from scientific research.The main influence factors of scientific research were lack of time (23.73％),insufficient knowledge reserves (22.03％) and researchers' own problems (39.73％).Conclusions Medical school should expand the range of scientific research and strengthen propaganda.Medical students should arrange research time and constantly improve their comprehensive ability so as to achieve good results.

Objective To study the difference of attentional bias towards general negative words between non-mediated obsessive-compulsive disorder (OCD) patients and healthy controls.Methods Event-related potentials (ERPs) were collected from 26 non-mediated OCD patients and 24 normal controls while they performed an emotional Stroop task.Results Compared to healthy controls,OCD patients showed significantly longer reaction time (OCD:(467 ± 14.88) ms,Controls:(409.65 ± 15.49) ms,P＜ 0.01),and had significantly larger P2 and P3 amplitude to all three types of words (P2 amplitude:OCD:(10.41±0.49) μV,Controls:(8.89±0.48) μV,P＜0.05;P3 amplitude:(10.04±0.68) μV,Controls:(7.68±0.67) μV,P＜0.05).In addition,the P2 peak latency of the frontal area in OCD patients was significantly longer than that in healthy controls(OCD:(190.09±4.71) ms,Controls:(179.60±4.72) ms,P＜0.05).Conclusion Current findings suggest that OCD patients are characterized by a general attentional inhibition deficit but not an attentional bias to the negative words.

Objective:To observe the effects of low intensity pulsed ultrasound(LIPUS) on the osteogenic differentiation of rat bone marrow mesenchymal stem cells(BMSCs) on titanium surface.Methods:BMSCs from Wistar rat bone marrow were respectively cultured on the flat titanium surface and the large grain blast acid etched(SLA) titanium surface,and induced by mineralization medium.Then,the cells were interfered by LIPUS and a control condition.Alkaline phosphatase(ALP) were quantitative determinated after 3 and 7 d mineralization induction respectively,ALP staining were observed after 14 d induction.Alizarin red staining were observed after 21 d mineralization induction.Osteogenic related protein and gene expressions were detected after mineralization induction.Results:ALP in culture medium of LIPUS group was higher than that of the control group after 3 d and 7 d mineralization induction(P＜0.05).LIPUS group showed stronger ALP staining and alizarin staining,and more mineralized nodules than control group.The expression of osteogenic related proteins,including Runx2,BMP2,OPN in LIPUS group increased.Osteogenic related genes expression,including ALP,Runx2,BMP2,OPN,OCN and Col-1 of the LIPUS group increased.Conclusion:The osteogenic differentiation of BMSCs on the fiat titanium surface or SLA titanium surface can be promoted by LIPUS.

Objective To clone,express and characterize a tegument protein gene of Schistosoma japonicum(Sj29),and investigate the immune protection of the recombinant protein against S.japonicum in mice.Methods The gene coding for Sj29 protein was amplified by PCR,and the sequence was analyzed by bioinformatics tools.Partial fragment of Sj29 gene was subcloned into the prokaryotic expression vector pET28c(+).The recombinant plasmid was transformed into E.coli BL21(DE3) and induced the recombinant with IPTG.The recombinant protein(rSj29) was purified by His-binding-resin affinity chromatography and characterized by Western blotting.Three groups each with 10 BALB/c mice were immunized subcutaneously three times(two weeks interval) respectively with 100 ?l recombinant rSj29(0.1 mg/ml),adjuvant or PBS.At the 15th day after the final inoculation,each mouse was challenged by 40 ?2 cercariae of S.japonicum.At the 53th day after infection,the mice were sacrificed to obtain the number of adult worms,number of eggs in liver and feces.Serum samples were collected at pre-immunization and certain time after immuniza-tion,and were analyzed for IgG by ELISA.The localization of rSj29 in worms of different developmental stages was demonstrated by immunofluorescent technique.mRNA expression level of Sj29 gene in worms of different developmental stages and three groups after infection was detected by quantitative real-time PCR.Results A 576 bp Sj29 gene fragment was obtained.The recombinant protein rSj29 with Mr 22 900 was expressed in the form of inclusion body.The recombinant rSj29 can be recognized by sera of mice immunized with rSj29 and sera of infected mice.The number of adult worms(15.4?5.9),number of hepatic eggs(40 143.3?2 995.9) and number of fecal eggs(3 803.9?110.9) in re-combinant protein group were significantly higher than those of PBS control group(20?3.4,49 318.1?6 648.3,5 238.1? 303.5,respectively)(P

Intraoperative radiotherapy (IORT) is a radiotherapy method that uses a radiotherapy device to provide a brachytherapy with single high-dose radiation to a target tissue (primary tumor beds,residual tumors,and lymphatic drainage areas) during surgery,which includes intraoperative electron beam radiotherapy and high-dose-rate intraluminal brachytherapy.Nowadays,the implementation of precise radiation dose is an important part of multidisciplinary,individualized treatment of tumors.IORT achieves precise treatment by maximizing the radiation dose to the target volume and protecting surrounding normal tissues as much as possible.This article describes the recent research on IORT.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and current therapeutic strategies are limited in their effectiveness.The expressions of Rab5 and the M2 tumor-associated macrophage marker CD163 in tissues were detected by Western blot. The migration and invasion of cells were determined using a Transwell assay. The expressions of the exosome markers were evaluated by Western blot. The polarization of human macrophages (THP-1) was determined by incubation of THP-1 cells with conditioned medium or exosomes collected from MDA-MB-231 cells with indicated transfections or by a coculture system of THP-1 and MDA-MB-231 cells. The M1 and M2 macrophage markers were evaluated by qRT-PCR. The expression of Rab5 in TNBC was significantly higher than that in normal breast tissue. Rab5 expressions in triple-negative and luminal A breast cancer were higher than those in other molecular subtypes. Higher CD163 expression was observed in triple-negative breast cancer and in triple-negative and luminal B subtypes. Rab5 knockdown suppressed but Rab5 overexpression promoted the migration and invasion capacity of MDA-MB-231 cells. The levels of CD63 and CD9 in the medium of Rab5 knockdown cells were lower than those in control cells, whereas higher levels of CD63 and CD9 were observed in Rab5 overexpression cells. Rab5 knockdown decreased the excretion but did not alter the diameter of the exosomes. Knockdown of Rab5 facilitated the anti-tumor polarization of macrophages, which was partially reversed by Rab5 overexpression. Therefore, Rab5 is expected to be a potential therapeutic target for triple-negative breast cancer.

The ethyl acetate extract of Euphorbia lunulata Bge was separated and researched on anticancer activity about it with in vitro cell experiments,in order to provide a theoretical basis for the exploit and utilization of E.lunulata and more options to develop natural anticancer drugs.Quercetin and Gallic Acid in ethyl acetate were extracted by HPLC,which the ethyl acetate extract of E.lunulata was separated and extracted by solvent system.The MTT was used to measure the inhibition of each component with different concentration from ethyl acetate extract to the 2R-75-30 breast cancer cell.The results showed that Quercetin and Galic Acid of ethyl acetate extract were 19.99％ and 55.04％,respectively.There were 17 component from the ethyl acetate extract,and finally merged into six fractions.Each component (the concentration of 50 μg/ml-150 μg/ml range) from ethyl acetate extract of E.lunulata could inhibit the growth of ZR-75-30 breast cancer cell.And a certain gradient relationship with the drug concentration increased with the inhibition rate enhancement on the 2R-75-30 breast cancer cell's growth.The 2nd fraction showed the highest activity.It was concluded that there were flavonoids and phenolic acids in ethyl acetate extract.Each component from the extract showed inhibition on the growth of breast cancer cell if it was further separated.This study was designed to provide a theoretical basis to exploit the anticancer drugs from E.lunulata.

Objective To investigate the effect of prior statin use on outcome after intravenous thrombolysis in patients with acute ischemic stroke. Methods Consecutive patients with acute ischemic stroke treated with intravenous thrombolysis at the Department of Neurology, the Third People's Hospital of Chengdu from July 2014 to August 2017 were enrolled, and divided into the statin use group and nonstatin use group according to prior statin use. Symptomatic intracranial hemorrhage and the outcome at 90 days after onset (good outcome and poor outcome were defined as the modified Rankin Scale score 0-2 and > 2, respectively) in the two groups were compared, and multivariate logistic regression analysis was used to identify the effect of prior statin use on the outcome. Results A total of 327 patients were enrolled, including 68 (20. 80％ ) in the statin use group, and 59 (79. 20％ ) in the nonstatin use group. There were no significant differences in the incidence symptomatic intracranial hemorrhage (7. 35％ vs. 10. 04％; χ2 = 0. 453, P = 0. 501), good outcome rate at 90 days (69. 12％ vs. 66. 02％; χ2 = 0. 232, P = 0. 630), and mortality rate (7. 35％ vs. 7. 34％; P = 1. 000) between the statin use group and the nonstatin use group. Multivariable logistic regression analysis showed that prior statin use were not an independent risk factor for symptomatic intracranial hemorrhage (odds ratio 0. 658, 95％ confidence interval 0. 233-1. 857; P = 0. 429) and poor outcome at 90 dafter onset (odds ratio 0. 848, 95％ confidence interval 0. 424-1. 696; P = 0. 641) in patients treated with intravenous thrombolysis. Conclusion Prior statin use is not associated with symptomatic intracranial hemorrhage and outcome after intravenous thrombolysis in patients with acute ischemic stroke.

Objective To investigate the influences of atrial fibrillation (AF) on clinical outcome and hemorrhagic transformation (HT) after intravenous thrombolysis for acute ischemic stroke.Methods The patients with acute ischemic stroke treated with intravenous recombinant tissue plasminogen activator thrombolysis were enrolled retrospectively.The modified Rankin Scale score 0-2 at 90 d was defined as a good outcome.Multivariate logistic regression analysis was used to determine the correlation between AF and clinical outcomes after intravenous thrombolvsis.Results A total of 160 patients with acute ischemic stroke treated with intravenous recombinant tissue plasminogen activator thrombolysis were enrolled,including 67 (41.88％) with AF.Compared with the non-AF group,the age was older (median [interquartile range] 77 [71-83] years vs.69 [59-78] years;Z=4.142,P＜ 0.001),baseline National Institutes of Health Stroke Scale (NHISS) score was higher (11.0[6.0-17.0] vs.7.0[4.0-14.0];Z=2.623,P=0.009)in the AF group.There were no significant differences in the NIHSS score reduction and the proportion of patients with good outcomes at 24 h (3.0 [1.0-4.5] vs.2.0 [0-6.0];Z=-0.312,P=0.775) and7d(4.0 [2.0-5.0] vs.5.0[2.0-8.0];Z=l.574,P=0.115) after thrombolysis and the proportion of patients with good outcome at 90 d (38.81％ vs.25.82％;x2 =3.063,P =0.080) between the AF group and the non-AF group,however,the proportions of HT within 24 h (14.93％ vs.5.38％;x2 =4.179,P =0.041) and death within 90 days (16.42％ vs.6.45％;x2 =4.073,P =0.044) in the AF group were significantly higher than those in the non-AF group.Multivariate logistic regression analysis showed that AF was not independent correlation with the clinical outcomes at 90 d (odds ratio [OR] 0.950,95％ confidence interval [CI]0.381-2.366;P =0.912),HT within 24 h (OR 1.992,95％ CI0.580-6.369;P =0.285),and death within 90 d (OR 2.483,95％ CI 0.727-8.586;P=0.146).Conclusion AF is not the independent risk factor that influences on clinical outcome at 90 d and-HT within 24 h after intravenous thrombolysis in patients with acute ischemic stroke.

OBJECTIVES: Liver cancer is the sixth most common malignant tumor in the world. Hepatocellular carcinoma (HCC) accounts for 85%-90% of all patients with liver cancer. It possesses the characteristics of insidious onset, rapid progression, early recurrence, easy drug resistance, and poor prognosis. NIMA related kinase 2 (NEK2) is a cell cycle regulating kinases, which regulates cell cycle in mitosis. Cellular senescence is a complex heterogeneous process, and is a stable form of cell cycle arrest that limits the proliferative potential of cells. This study aims to investigate the relationship between the expression level of NEK2 and the senescence in hepatoma cells, and to explore the effect of NEK2 expression on hepatoma cell senescence and the underlying molecular mechanism. METHODS: A total of 581 senescence-relevant genes were obtained from the GenAge website. The gene expression data of tumor tissues of 370 HCC patients were downloaded from the Cancer Genome Atlas database. The co-expression of NEK2 and aging-related genes was analyzed by R-package. KEGG was used to analyze the significant gene enrichment pathway of differentially expressed genes in NEK2 overexpression HEK293. The stable transfected cell lines with overexpression and knockdown of NEK2 were constructed in hepatoma cell line SMMC-7721 and HepG2, and senescence-associated β-galactosidase (SA-β-gal) staining was used to detect senescence, the cell proliferation was detected by CCK-8 method and clone formation experiment, the cell cycle was analyzed by flow cytometry, and the expression of proteins related to p53/p21, p16/Rb, and phosphatase and tensin homolog deleted on chromosome ten (PTEN)/Akt signal transduction pathway was detected by Western blotting. RESULTS: There were 320 senescence related genes co-expressed with NEK2. KEGG analysis showed that the senescence signaling pathway was significantly enriched in HEK293 cells with overexpression of NEK2.Compared with SMMC-7721 or HepG2 without knockdown of NEK2, the senescent cells of SMMC-7721 and HepG2 with knockdown of NEK2 were increased, cell proliferation and clone formation were decreased significantly, the percentage of cells in G₀/G₁ phase was increased, the expression levels of phospho-Akt (p-Akt) and phospho-Rb (p-Rb) protein were decreased significantly, and the expression level of p16 protein was increased significantly (all P<0.05). Compared with SMMC-7721 or HepG2 transfected with blank plasmid, the senescent cells of SMMC-7721 and HepG2 overexpressing NEK2 were decreased, the cell proliferation and clone formation were increased significantly, the percentage of cells in G₀/G₁ phase were decreased, the expression levels of p-Akt and p-Rb protein were increased significantly, and the expression level of p16 protein was decreased significantly (all P<0.05). CONCLUSIONS NEK2 may mediate the anti-aging effect of hepatoma cells through p16/Rb and PTEN/Akt signal transduction pathways, which provides a new theoretical basis for NEK2 to promote the progress of liver cancer and a new idea for the targeting treatment for liver cancer.
Carcinoma, Hepatocellular/pathology* ; Cell Line, Tumor ; Cell Proliferation/physiology* ; Cellular Senescence/genetics* ; HEK293 Cells ; Humans ; Liver Neoplasms/pathology* ; NIMA-Related Kinases/genetics* ; Proto-Oncogene Proteins c-akt/metabolism*