OBJECTIVETo explore the working mechanism and age-related change of the conflict processing system of the frontal cortex.

METHODSFifteen normal elderly people and 15 youth were performed a modified Eriksen flanker paradigm, while event-related potential (ERPs), which include 32 systerm electroencephalography, reaction time and correct rate were recorded.

RESULTSThe elderly group showed a distinct effect of reaction time and effect of conflict in the respond level compared with the youth group. The elderly group had a longer time window of N380 and same amplitude as the youth group. Low resolution brain electromagnetic tomography (LORETA) showed the bilateral temporal lobe and the dorsolateral prefrontal cortex (especially right) were activated in the youth group, while the left temporal lobe, the left dorsolateral prefrontal cortex and left medial frontal gyrus were activated in the elderly group.

CONCLUSIONWhen conflict stimuli existed in the response level, old people showed frontal interference control hypofunction. N380 reflected the activation of the left dorsolateral prefrontal cortex and the left temporal lobe during response selection and executive control processing in older people.

Adolescent ; Aged ; Aging ; Electroencephalography ; Evoked Potentials ; Frontal Lobe ; physiology ; Humans ; Prefrontal Cortex ; physiology ; Reaction Time ; Temporal Lobe ; physiology

Using Vibrio fluvialis Ⅱ as host bacteria, 19 bacteriophages have been isolated from the 76 samples which were collected from Haliotis discus hannai ～growing seawater in Dalian marine culture company Dalian, liaoning province from May in 1996 to August I 1997. Ultrastructure of 19 bacteriophages were observed with electron to Bradley the results showed that of these bacteriophages belonged to Bradley A type, they have hexagonal heads of bacteriophages were identified with VP1,VP2,VP4,VP8 as representatives respectively. The phages remain stable at pH6. 0～10. 0, moreover VP2,VP4 and VP8 are rather stable at basic pHs. Although the characterization of heat inactivation course of VP4 is different from others, four phages are sensitive to heat and inactivated at 80℃ in 5 minutes. One step growth experiment showed that the eclipse period of VP1,VP2,VP4,VP8 are sensitive to heat and the eclipse period of VP1, VP2, VP4, VP8 are 42, 30, 46, 28 minutes. In this experiment we have isolated at least four different types phages, it suggest that in fact there is a population of phages in the seawater environment. The result of this study provided a way to find the potential value of phages as an indicator of pathogenic microorganisms Vibrio fluvilis Ⅱ in marine environment.

Objective To compare the effects of ephedrine and phenylephrine on hemodynamics in the patients undergoing surgery in prone position under general anesthesia.Methods Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients, aged 20-60 yr, with body mass index of 18.5-2:5.0 kg/m2, scheduled for elective posterior lumbar interbody fusion under general anesthesia, were randomized to ephedrine group (group E, n =30) or phenylephrine group (group P, n =30).When hypotension [decrease in systolic blood pressure (SBP) ＞20％ of the baseline value, T0] occurred in supine position, SBP, diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), cardiac index (CI) and central venous pressure (CVP) were recorded, and ephedrine 0.1 mg/kg (group E) or phenylephrine 1 μg/kg (group P) was injected via the central veins.The parameters mentioned above were recorded within 10 min after administration (T1-T10).Results Both ephedrine and phenylephrine could maintain the parameters of hemodynamics at the normal level.Compared with the baseline values at T0 , SBP, DBP, MAP and HR at T1-T10 and CO and CI at T2-T10 were significantly increased, and no significant change was found in CVP at each time point after administration in group E, and SBP and MAP at T1-T6, DBP at T1-T5, CVP at T2 and T3, and CO and CI at T1-T3 were significantly increased, and HR was decreased at T2 and T3 in group P.Compared with group P, SBP was significantly decreased at T1, and increased at T2-T10, DBP and MAP were decreased at T1, and increased at T3-T10, HR was increased at T1-T10, CO and CI were increased at T2-T10, and CVP was decreased at T1-T3 in group E.Conclusion Compared with phenylephrine, although ephedrine provides no significant effect on hemodynamics clinically, it can increase cardiac output to some extent in the patients undergoing surgery in prone position under general anesthesia.

Objective To summarize the clinical experience of liver transplantation in the treatment of hepatocellular carcinoma(HCC).Methods From June 2004 to March 2007,70 consecutive HCC patients underwent liver transplantation in our hospital,including classic orthotopic liver transplantation in 41 cases,and piggyback liver transplantation in 29 cases.All data of patients were retrospectively analyzed.Results All liver transplantation were successfully conducted.The average warm ischemia duration was 4.5 minutes,and cold ischemia duration was 8 hours.There were 3 cases of postoperative deaths.Surgical complications were intra-abdominal hemorrhage in 2 cases,and biliary anastomotic stricture in 4 cases.Sixty-seven cases were followed up for 12-33(average 21) months,10 cases had recurrence of liver cancer after transplatation and 1 dead.Conclusions Liver transplatation can used on selected patients with HCC.Successful liver transplantation relies on good quality of liver graft,and idealized technique of vascular and bile duct reconstruction are key factors of liver transplantation.Proper postoperative management can effectively reduce the complications of operation.

Objective:To investigate the specific interference of OX40 gene expression induced by RNAi technique in 293T cell lines transfected with rat OX40 gene.Methods:293T cells were transfected with recombined plasmid pEGFP-N1-GFP/OX40,and the positive cell clones were selected by fluorescence protein observation and RT-PCR.One specific dicer siRNA targeted to OX40 mRNA was designed and synthesized,which shared no homology with exons of known human gene.Quantitative real-time PCR was performed to measure the inhibitory rate of target gene expression by comparing OX40 mRNA concentrations before and after siRNA transfection.Results:10 nmol/L siRNA-OX40 elicited the highest level of gene silence in 293T cells which was transfected with siRNA after 48 h (68.3?8.7)%);The time of maximal inhibitory effect was at 48-72 h [(61.7?8.4)%,(39.6?5.6)%].Conclusion:The exogenous OX40 expression can be significantly inhibited by treatment with specific siRNA in a dose and time -dependent manner in 293T cells,which may provide a useful profile for further investigation of inhibition of OX40 protein,and a promising control approach for preventing immune reaction.

Objective To study the effects of propofol used alone and in combined with opioids in gastroscopy,in order to select the more suitable anesthesia protocol.Methods A total of 285 pa-tients undergoing gastroscopy were selected in April ,201 5 in our hospital,including 105 males,180 females,ranging from 18 to 65 years old,weighing 40-90 kg,falling the category of ASA Ⅰ or Ⅱ. According to random number table,subjects were divided into four groups:dezocine group(group D, n =76),fentanyl group (group F,n =87),oxycodone group (group O,n = 71 )and control group (group C,n =5 1).Each group was implemented the corresponding anesthesia.SBP,DBP,HR,SpO 2 in baseline(T0 ),1(T1 ),3(T2 ),5(T3 )min after entering gastroscope were recorded.Choking cough, body movement,extra propofol,awakening time and inspecting time were observed.Results Among four groups,there was no statistical significance in age,gender,weight,blood pressure,heart rate and oxygen saturation and other general information.There were more cases given extra propofol in group C than in the other three groups (P <0.01 ).While for the experimental groups,there were more cases needing extra propofol in group O than in group D and group F (P < 0.01 ).The incidences of body movement and choking cough in group C were higher than those in the other three groups (P <0.01 ).Compared with the group C,dosage of propofol ,awakening time in the three groups,especially in group D,were much lower (P < 0.01 ).Conclusion Propofol in combination with opioids for sedation during painless gastroscopy can alleviate adverse reaction caused by propofol used alone.The more suitable anesthesia protocol is propofol with dezocine.

Objective To investigate the effect of blockading OX40-OX40L co-stimulatory signaling on the survival time of liver allograft in rat.Methods siRNA-expression vectors were constructed to targeting OX40.3～5 minutes before DA to Lewis orthotopic liver transplantation was performed,5×109 pfu of targeting OX40 siRNA plasmid DNA were diluted in 5 ml of phosphate buffered saline(PBS)and inlected intravenously into recipient Lewis rat over a period of 10 seconds.Serum IL-2 and IFN-γ levels were assayed by ELISA,and mix lymphocyte response(MLR)were tested by 3H-thymidine.Results The survival time of recipients in siRNA treatment group(74.0±9.3)was significantly longer than that in control group[(7.3±0.5)days].In experiment group,the inflammatory cell infihration and liver tissue structure destruction were very slight.The concentration of serum IL-2 was much lower in siRNA treatment group[(46±8.4)pg/ml]than that in control group[(286.5±14.6)pg/ml].Meanwhile,the concentration of serum IFN-γ was much lower in siRNA treatment group [(202.7±14.6)pg/ml]than that in control group[(1682.7±87.9)pg/ml].Conclusion Administration of OX40-siRNA can blockade OX40-OX40L co-stimulatory signaling pathway.hence inhibit the rejection of liver allograft.

Objective To compare the pressor responses to ephedrine during general anesthesia with different drugs.Methods Sixty ASA physical status Ⅰ or Ⅱ patients,scheduled for elective gastrointestinal tumor resection under general anesthesia,aged 20-64 yr,weighing 45-90 kg,were included in this study.The patients were randomized to receive dexmedetomidine + remifentanil + sevoflurane (group Ⅰ,n =20),propofol + remifentanil + sevoflurane (group Ⅱ,n =20),or dexmedetomidine + propofol + remifentanil + sevoflurane (group Ⅲ,n =20) to maintain the depth of anesthesia.Ephedrine 0.1 mg/kg was injected intravenously when the systolic blood pressure (SBP) was decreased to about 90 mm Hg during anesthesia.Blood pressure was monitored and recorded at 1-min intervals for 10 min after the injection.The onset time (TSBP,TDBP,TMAP) for ephedrine to raise the SBP,diastolic blood pressure (DBP) and mean arterial pressure (MAP) and the maximal amplitude (△SBP,△DBP,△MAP) were also recorded.Results Compared with Ⅱ group,TSBP,TDBP and TMAP were significantly shortened,and △SBP,△DBP and △MAP were increased in Ⅰ and Ⅲ groups (P ＜ 0.05).Conclusion Compared with propofol + remifentanil + sevoflurane combined anesthesia,dexmedetomidine + remifentanil + sevoflurane combined anesthesia and dexmedetomidine + propofol + remifentanil + sevoflurane combined anesthesia augment the pressor responses to ephedrine in patients.

Student preparation for laboratory sessions is the first step of conducting laboratory experiments. It makes students maximize use of laboratory time and efficiently perform laboratory exercises in open labs. In view of teaching features and requirements of Microbiology experiment, we designed and developed ‘Online Student Preparation and Management System of Microbiology Experiment’, which integrated func- tions of student preparation for laboratory sessions and teacher management. In the system each experiment consists of six successive parts, viz., learning objectives, principle, materials and equipments, procedure video, manipulation simulation and online quiz. Teaching practices showed that the application of the system enhanced the preparing quality and makes the management of the experiment teaching more normalized and efficient. It was an effective measure in improving experimental teaching of Microbiology.

Objective To compare the dosimetric results of postoperative intensity modulated radiation therapy (IMRT) using single-energy or mixed-energy photons in invasive thymoma patients.Methods Simulation CT images were acquired and clinical target volume (CTV),planning target volume (PTV) and organs at risk (OARs) were defined.Three sets of fixed-field IMRT planning were generated using 6 MV,10 MV and mixed 6/10 MV photons for each case.Monitor Units (MUs) for each plan were recorded after optimization,and parameters of PTV such as conformity index (CI),homogeneity index (HI) and dose to OARs were evaluated on dose-volume histograms.Results Near-Maximal dose (D2％) received by PTV was better in mixed-energy IMRT as compared with 6 MV(t =3.107,P ＜0.05).HI was better in mixed-energy than in 6 MV(t =2.924,P ＜0.05).There were statistically significant differences in CI among three IMRT plans.MU was higher in 6 MV than in both 10 MV and mixed-energy IMRT.The percentages of lung volumes receiving 5 Gy (V5),10 Gy(V10),20 Gy (V20),30 Gy (V30) and the mean lung dose (D) were also significantly different in most plans.V30 and V40 of the heart were comparable between 6 MV and mixed energy plans but better than in 10 MV plan.Conclusions If the reasonable choice of beam angles and number,and capability of energy selection according to beam directions,with combined advantages of low and high energy photons,mixed IMRT plans can improve the quality of IMRT plans in general and has clinical potential for postoperative radiotherapy of invasive thymomas.