Objective To evaluate the effect of sevoflurane preconditioning on the expression of heat shock protein 70 (HSP70) during renal ischemia-reperfusion in rats.Methods Twenty-four pathogen-free healthy adult male Sprague-Dawley rats,weighing 250-300 g,aged 2-3 months,were divided into 3 groups (n=8 each) using a random number table:sham operation group (group S),renal I/R group (group I/R) and sevoflurane preconditioning group (group SP).The animals were anesthetized with 2％ pentobarbital sodium 50 mg/kg.After the right kidney was removed,the left renal artery was clamped for 45 min followed by 2 h reperfusion to establish the model of renal I/R injury.In group SP,2.2％ sevoflurane was inhaled for 1 h followed by 10-min washout before the model was established.The animals were sacrificed at the end of rcpcrfusion,and kidneys were then removed for determination of the expression of HSP70 (by immunohistochemistry) and malondialdehyde (MDA) content in renal tissues (by thiobarbituric acid colorimetric method).Results Compared with group S,the expression of HSP70 in renal tissues was significantly up-regulated,and the MDA content in renal tissues was increased in t/R and SP groups (P＜0.05).Compared with group I/R,the expression of HSP70 in renal tissues was significantly up-regulated,and the MDA content in renal tissues was decreased in group SP (P＜0.05).Conclusion The mechanism by which sevoflurane preconditioning reduces renal I/R injury is related to up-regulation of HSP70 expression in rats.

ObjectiveTo investigate the neural mechanism of processing the salient target during the visual search task with spatiotemporal patterns of event-related potential(ERP).MethodsSixteen subjects were asked to judge the existence of a low or high salient target from 4 items,in which one distractor might be also salient or not.A two-way repeated-measure ANOVA was carried out for behavioral performance and ERP data( distractor saliency:YES,NO)*( target:none,low salient,high salient).ResultsSignificant interaction was found between target and distractor for the reaction time (F( 1.99,29.79) =21.56,P=0.00).For the low salient target,significant difference of reaction time was found between the YES (552.57 ± 82.32 ms) and NO (540.47 ± 75.68 ms)of distractor saliency( t (15) =- 2.489,P =0.025 ).However,such difference of reaction time was not significant for the high salient target.The statistical parametric mapping of F-value of ERP suggested the effect of the distractor saliency revealed in the right fronto-parietal-temporal areas related to stimulus novelty and the effect of the target saliency appeared in the parietal-occipital regions related to visual processing during the same stage ( 350 ～ 450ms ).The significant interaction occurred in the left temporal regions (450 ～ 600 ms ) related to stimulus familiarity and its classification.ConclusionDue to both mechanisms of the parallel processing for the target and the distractor during the perceptual stage and the effective classification of the familiar network within left hemisphere during the stage of pattern classification,the salient target can be processed quickly in spite of the interference from the salient distractor.

Objective To investigate the effects of sevoflurane preconditioning on renal ischemia-reperfusion(I/R)injury in rats.Methods Twenty-four adult male SD rats weighing 250-300 g were randomly divided into 3 groups(n=8 each):sham operation group (group S);I/R group; sevoflurane preconditioning group (group SP). After the rats underwent right nephrectomy, renal I/R was produced by occlusion of left renal artery for 45 min followed by reperfusion in I/R and SP groups.In group SP, the rats inhaled 2.2% sevoflurane for 1 h, then the inhalation was stopped and renal ischemia was performed 10 min later. Venous blood samples were collected at 2 h of reperfusion to determine the concentrations of serum creatinine(Cr), urea nitrogen (BUN), cystatin C (Cys C) . The renal tissues were obtained for microscopic examination, and Paller's score was recorded. Results Compared with group S, there was no significant difference in the serum Cr and BUN concentrations (P＞0.05), while the serum Cys C concentration and Paller's score for acute renal tubular injury were significantly increased in group I/R(P＜0.05). The serum Cys C concentration and Paller's score were significantly lower in group SP than in group I/R(P＜0.05).I/R-induced renal injury was significantly reduced in group SP compared with group I/R. Conclusion Preconditioning with sevoflurane can provide significant protection against renal I/R injury.

Objective To investigate the neural mechanism of the reduction of switch cost induced by short presentation of the task cue.Methods The event-related potentials (ERP) was recorded from 19 subjects while they performed a Chinese Stroop switching task.The factorial design of repeated-measures was adopted with the cue presentation time (100/1000 ms) and the type of succeeding task (repeat/switch).Results For the switch cost of reaction time (the switch subtracts the repeat),the difference between the long cue group (15.0 ± 33.3 ms) and the short group (0.80 -±40.7 ms) had the significantly tendency( t (18) =- 1.77,P=0.09).During the stage of cue processing,the ERP effects of cue reveal in the frontal-occipital areas ( 100 ～ 200 ms),frontoparietal and tempo-occipital regions (200 ～500 ms),frontoparietal network and centro-occipital regions (500 ～900ms).During the stage of task execution,the ERP effects of the cue were observed from the left fronto-occipital areas ( 300 ～ 400 ms) to parieto-occipital areas (400 ～ 900 ms).The ERP effects of the task started from the right hemisphere (500 ～600 ms ) and extended to bilateral prefrontal and centro-parietal area (600 ～900 ms ).Conclusion The short cue presentation can not only start up the preparation of frontoparietal network earlier during cue processing stage but also enhance its retrieval in the left dorsal lateral frontal cortex during task executive stage.

OBJECTIVETo investigate the effects of task probability on context processing using AX-type continuous performance test (AX-CPT) and event-related potential (ERP).

METHODSWe set 3 groups of complementary probabilities (AX/AY: 0.55/0.15, 0.35/0.35, and 0.15/0.55) for AX task and AY task and kept the probability 0.15 for both BX and BY tasks. Eighteen subjects were asked to press the button only when the go-probe (X: green "<" or ">") followed the go-cue (A: blue "ooo") and withdraw response when the go-probe or a nogo-probe (Y: red "<" or ">") followed the nogo-cue (B: blue "xxx").

RESULTSAs the task probability increased, the reaction time of AX task was shortened and the rate of false alarm of BX task increased significantly. The probability effects of ERP revealed by statistical parametric mapping occurred in many regions during both cue and probe stages: cue A in the parietal central (300-350 ms) and the left occipital area (450-500 ms); cue B in the right frontal pole (350-500 ms) and the left frontal pole (750-950 ms); AX probe in the right frontoparietal area (200-250 ms), the left frontal pole, the right dorsal prefrontal and bilateral parietal region (300-400 ms), and the bilateral occipital area and parietal region (400-650 ms); AY probe in the fronto-central area (350-500 ms) - the P3 effect; BX probe in the right temporal and the left occipital areas (300-350 ms); BY probe in the left temporal area (150-250 ms).

CONCLUSIONThe task probability not only influences both the encoding of go-cue and expectancy of nogo-cue but also modulates the neural assemblies of probe processing differentially.

Objective:To explore the value of cardiovascular MR (CMR) T 1 mapping in evaluating myocardial injury in patients recovered from COVID-19. Methods:The clinical and image data of 15 patients with COVID-19 (9 with moderate clinical manifestation, 6 with severe clinical manifestation) who underwent CMR screening at 3 months after being discharged from the Second People′s Hospital of Fuyang City during May 2020 to June 2020 were prospective collected. Fifteen COVID-19 patients were selected as case group, and another 11 healthy volunteers were selected as control group. A standardized CMR protocol included cine, native and enhanced T 1 mapping, late gadolinium enhancement (LGE). Cardiac functional parameters, native T 1 value of left ventricular and extracellular volume fraction (ECV) were measured. One way ANOVA was used to assess the difference between CMR parameters among moderate and severe manifestation groups and control group, and LSD- t was used to assess the difference between the three groups. Results:LGE value was negative in all subjects. ECV values were higher in recovered COVID-19 patients with either moderate (27.9%±2.7%) or severe manifestation (30.0%±3.7%) than control group (23.2±1.9%) ( P<0.05); there was no significant difference of ECV values between recovered COVID-19 patients with moderate and severe manifestation ( P=0.100). There was no difference of native T 1 values and other functional and morphologic parameters of left ventricular and right ventricular among recovered COVID-19 patients with moderate and severe manifestation and control group ( P>0.05). Conclusion:CMR myocardial tissue ECV increase in patients who recovered from COVID-19, suggesting subclinical myocardial injury.

Xi'an Jiaotong University has proposed the concept of "less teaching and more learning, interaction between guiding and learning" in medical education, based on its sedimentary deposits, and carried out reform for all clinical medical students since 2001. After more than ten years of educational reform, we have built brand new management framework, and established integrated organ system-based curriculum and PBL teaching pattern. This pattern involves eight aspects of comprehensive reform, including training program, curriculum model, textbook, teaching method, learning style, assessment and evaluation, teaching organization, teaching conditions and guarantee. It will provide paradigm for the integrated curriculum reform in peer colleges, and will be a milestone in the history of medical education in China.