BACKGROUND:At present, researches about attention mainly concentrate on the relationship between attention and other psychological phenomena, but studies concerning different types of attention itself (sustained attention versus selective attention) are few. OBJECTIVE:To investigate the brain mechanisms of sustained and selective attentions which have different roles in the cognitive process. METHODS:Event-related potentials (ERPs) were measured when 18 col ege students’ participants (half male and half female) were performing selective and sustained attention tasks. The program was written in E-Prime and displayed on a computer, and the experimental task was adapted from Karl et al. reported experimental paradigm, including selective attention and sustained attention tasks. The time of fixation point given was 500 ms, and the time of three randomly abreast pictures given was 300 ms. Al the participants were asked to make rapid and accurate response as much as possible. RESULTS AND CONCLUSION:The ERPs elicited by the two attention tasks were different in the aspects of time process, wave crest and latency. The brain regions activated by the sustained attention were wider than those by selective attention. The ERPs elicited by the sustained attention mainly presents as positive waves, whereas those elicited by the selective attention were reflected as both positive and negative waves. The EPRs elicited by the sustained attention were N100 and N250, but in the metaphase, selective attention elicited the P180. These may indicate that event choice appears in the middle stage of the task. Besides, the reversion of EPRs elicited by the two attention tasks in the anterior and posterior scalp is likely to be a generality of al attentions.

Objective To analyse pathogens distribution and antibacterial susceptibility of bacteria isolated from clinical speci‐mens in neurosurgery ,in order to provide laboratory basis for rational use of antibacterial agents .Methods Isolation and culturing of bacteria were carried out in various clinical samples collected in neurosurgery from January 2012 to September 2012 in the First Affiliated Hospital of Xi′an Jiaotong University ,all strains were identified by using automatic microbial analyzer ,and the sensitivi‐ties to antibacterial agents were verified by using instrument method and K‐B method .WHONET5 .6 software was used for data a‐nalysis .Results A total of 1 319 strains of non‐repeating pathogenic bacteria were isolated ,including 482 strains (36 .6% ) of gram‐positive bacteria ,797 strains (60 .4% ) of gram‐negative bacteria ,and 40 strains (3 .0% ) of fungi .Most of pathogenic bacteria were isolated from sputum ,cerebrospinal fluid ,urine and blood specimens ,and the most common isolates were Staphylococcus aureus , Acinetobacter baumannii ,Klebsiella pneumoniae ,Pseudomonas aeruginosa and Escherichia coli .Isolated gram‐positive bacteria and gram‐negative bacteria were resistant to antibacterial agents in different degree .The sensitivity rate was 100 .0% only in linezolid and vancomycin against Staphylococcus aureus .The resistant rates of carbapenems against Acinetobacter baumannii were higher than 80 .0% ,and carbapenems‐resistant Klebsiella pneumoniae strains had also appeared .Carbapenems‐resistant Escherichia coli strains had not yet been found .The sensitive rate of Piperacillin‐Tazobactam against Pseudomonas aeruginosa was above 90 .0% . Conclusion Gram‐negative bacteria is the predominant pathogen infecting patients in neurosurgery ,w hile Staphylococcus aureus are the most common isolates .For the increase of multiple drug‐resistant and pan‐drug‐resistant bacteria ,clinical rational use of antibac‐terial agents for anti‐infection treatment may be very important .

Objective To explore the value of procalcitonin(PCT ) as early predictor of bloodstream infections .Methods Blood culturing and PCT detection were carried out simultaneously in 530 blood specimens collected from the First Affiliated Hospital of Xi′an Jiaotong University from January to December 2014 .All strains were identified by using automatic identification microbial an‐alyzer ,and levels of PCT were analyzed by using automatic enzyme‐linked fluorescent immune system .The diagnostic efficacy of PCT was evaluated by using the receiver operating characteristic(ROC) curve .Results A total of 77 specimens were with negative results of blood culturing ,and a total of 453 specimens were with positive results of culturing .Among those specimens with positive results of blood culturing ,there was 114 strains of gram‐positive bacteria ,306 strains of gram‐negative bacteria ,and 33 strains of fungi .ROC curve analysis showed that the area under the curve of PCT test in all pathogenic bacteria ,gram‐negative bacteria ,gram‐positive bacteria and fungi were 0 .760 ,0 .778 ,0 .741 and 0 .686 ,respectively .In maximum Youden′s indexes ,the cut off values were 0 .453 0 ,0 .683 5 ,0 .457 0 and 0 .399 5 ng/mL respectively ,and 0 .453 0 ng/mL was the threshold in diagnosis of bloodstream infec‐tion .Conclusion PCT is a good indicator for early diagnosing bloodstream infection ,and has better timeliness and higher sensitivity than blood culture .Moreover ,the diagnostic efficacy of PCT for gram‐negative bacteria bloodstream infections was better than that for gram‐positive bacteria and fungi bloodstream infections .

Four hundred eighty patients with carbon monoxide poisoning were randomly assigned to receive hyperbaric oxygen alone or hyperbaric oxygen plus Nimodipine.Treatment outcomes and the incidence of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP)were observed.We found that the incidence of DEACMP was 14.0％(67/480)in all cases,19.2％(46/67)in hyperbaric oxygen group,and 8.8％(21/67)in hyperbaric oxygen plus Nimodipine group(hyperbaric oxygen group vs hyperbaric oxygen plus Nimodipine group,P＜0.05).These results suggested that hyperbaric oxygen combined with Nimodipine could prevent the development of DEACMP.

Objective To compare clinical Pseudomonas aeruginosa different sources of β-lactamase-resistant phenotype differences,as to provide theoretical basis for guiding clinical rational use of antibiotics.Methods Isolation of 478 strains of Pseudomonas aeruginosa were collected from clinical specimens in the First Affiliated Hospital of Xi'an Jiaotong University from January to December 2015,by VITEK 2 Compact bacteria identification and drug sensitivity analysis of advanced expert system for β-lactamase-resistant phenotype,statistical analysis of drug resistance phenotype and antibiotic resistance.Results 478 strains of Pseudomonas aeruginosa were mainly composed of phenotype 5 and phenotype 3.Sputum,drainage fluid and bile duct bile specimens of Pseudomonas aeruginosa were based on phenotype 5,accounted for 31.08％,34.71％ and 38.46％.Multiple comparison x2 were 3.893,4.071 and 5.595,There was no statistical difference between groups compare significance (P＞0.05).Urine,secretions and whole blood samples of Pseudomonas aeruginosa were phenotype 3,accounted for 34.88 ％,27.78 ％,45.45 ％;Multiple comparison x2 were 6.654,9.956 and 9.852.There was no statistical difference between groups compare significance (P＞0.05).Sputum,drainage of liquid,bile duct bile and urine,secretion,whole blood specimens respectively source of Pseudomonas aeruginosa resistant phenotype distribution of two comparative difference was statistically significant (x2 =15.056～22.050,P＜0.05).Comparing the resistance of different β-lactamase-resistant phenotypes in Pseudomonas aeruginosa isolates from different sources:the sputum specimen source in imipenem,meropenem,piperacillin and piperacillin/tazobactam had significant difference (x2 =22.225～39.025,P＜0.05).There was statistical significance in department of hepatobiliary surgery only ceftazidime and meropenem differences (x2 =21.890～22.872,P＜0.05).Conclusion The phenotypic analysis of β-lactamase-resistant phenotypes of Pseudomonas aeruginosa from different specimens was different,which provided a theoretical basis for guiding the clinical application of antibiotics and the control of nosocomial infection of Pseudomonas aeruginosa.

Objective To explore the influence of age factor on the treatment of cutaneous hemangioma with (90Sr-90Y) applicator.Methods A total of 224 babies and children of different ages with cutaneous hemangioma were treated by using 90Sr-90 Y applicator.Then,the relation between their therapeutic effects and ages were analyzed respectively.Results The differences in the therapeutic effect between group of one month to less than one year and group of one to less than five years,and group of one month to less than one year and group of five to ten years,and between group of one to less than five ages and group of five to ten years (P＜0.05),were statistically significant.With an increase of the age,the recovery rate gradually decreased,but their effective rate,improvement rate and ineffective rate increased.In the 199 well-healed or effective patients,the differences in the distribution of treatment course between group of one month to less than one year and group of one to less than five years,and group of one month to less than one year and group of five to ten years,were statistically significant (P＜0.05); but the difference in the distribution of treatment course between group of one to less than five ages and group of five to ten years was not statistically significant (P＞0.05).The number of treatment course presented an increased tendency with an increase of the age for patients.Conclusions The age of patients is a factor influencing the therapeutic effect on cutaneous hemangioma with 90 Sr-90Y applicator.The younger the patients,the better their therapeutic effects,the shorter their courses of treatment,and the smaller the adverse reaction of beta ray.

AIM: To study the expression of tissue factor (TF) in cerebral microvascular thrombosis and its dynamic changes in rats. METHODS: 50 female SD rats were randomized to control group, 2, 4, 6, and 24 hours after thrombosis groups, 10 rats in each group. The model of cerebral microvascular thrombosis was induced by photo-chemical method. ELISA and immunohistochemistry methods were used to observe the changes of TF contents in blood plasma and the expression of TF in cerebral microvascular in each group. RESULTS: Cerebral thrombosis was induced by photo-chemical method successfully. The TF content in plasma was obviously higher in 4 h and 6 h groups than that in control group (P

BACKGROUND:Osteogenesis is closely integrated with angiogenesis in bone formation and repair process, and hypoxia-inducible factor 1 alpha (HIF-1α) is considered to be the most important core transcription factor promoting angiogenesis gene regulation, which may promote the formation of blood vessels at hypoxia portion, and thus contribute to bone formation.
OBJECTIVE:To construct the Lenti-HIF-1α-IRES-EGFP (wild type) and Lenti-HIF-1α-IRES-EGFP (point mutant type) lentiviral eukaryotic expression vectors and to detect their impact on the osteogenic gene expression of rabbit bone marrow mesenchymal stem cells.
METHODS:The Lenti-HIF-1α-IRES-EGFP (wild type) and Lenti-HIF-1α-IRES-EGFP (point mutant type) lentiviral eukaryotic expression vectors were constructed according to the wild type human HIF-1αgene sequence and the determined restriction sites of human HIF-1αpoint mutant sequence. Rabbit bone marrow mesenchymal stem cells were transfected with the prepared Lenti-HIF-1α-IRES-EGFP (wild type) and Lenti-HIF-1α-IRES-EGFP (point mutant type) virus solution.
RESULTS AND CONCLUSION:Immunofluorescence microscopy observations indicated that the cells of Lenti-HIF-1α-IRES-EGFP (wild type) group and Lenti-HIF-1α-IRES-EGFP (point mutant type) group showed no obvious fluorescence on transfected 7 days, and two groups of cells showed a more obvious green fluorescent after transfection 14 days. Quantitative PCR analysis results showed that there were obvious HIF-1αand bonemorphogenetic protein 2 gene expressions on days 7 after transfection and the two genes stil showed highly expression levels after transfection 14 days. The two lentiviral eukaryotic expression vectors of Lenti-HIF-1α-IRES-EGFP (wild type) and Lenti-HIF-1α-IRES-EGFP (point mutant type) could be constructed according to the wild type human HIF-1αgene sequence and the determined restriction sites of human HIF-1αpoint mutant sequence;HIF-1αgene can promote the osteogenic gene expression of lentivirus-transfected rabbit bone marrow mesenchymal stem cells.

Thiamin pyrophosphate (TPP) is a thiamine (vitamin B1) derivative and an essential cofactor in oxidative metabolism of the sugars,fatty acids and amino acids in living cells.By now,numerous TPP-dependent artificial riboswitch systems have been developed to regulate target gene expression but limited in bacteria,fungi or plant cells.Herein,the activating (switch-on) and inhibiting (switch-off) TPP-depended hammerhead ribozyme switches,which are from previous reported structures of prokaryotes screening,were investigated in mammalian cells.These ribozyme switches were inserted into the 3'UTR of the enhanced green fluorescence protein (EGFP) gene to construct the efficient ribozyme-based artificial switches through overlap extension PCR cloning.The HEK293 cells were transfected with the engineered ribozyme switches at increasing concentration of TPP.The EGFP gene-regulatory ability was analyzed with fluorescent microscope and flow cytometry.These TPP-inducible gene regulation devices showed the obvious ligand dose-dependency and excellent specificity.Two switch-on and one switch-off constructs demonstrated 3.1-fold or 1.9-fold increment and 2.3-fold reduction of EGFP level respectively with 150 μ mol/L TPP.The ligand-responsive ribozyme switches,by tuning the change of TPP concentration into the visual reporter genetic expression in cells,enable an efficient development of label-free,noninvasive and high-specific biosensors in living mammalian cells.

Objective To investigate the therapy effect of fermented cordyceps powder on diabetic cardiomyopathy, and the effect on expressions of NLRP3, Caspase-1 and interleukin (IL)-1βin myocardium of diabetic rats. Methods A total of 45 male SD rats were randomly divided into normal control group (group CON), diabetes group (group DM) and fermented cordyceps powder administration group (group CS, 1 g · kg-1 · d-1). Diabetes rat model was induced by tail vein injection with streptozotocin (45 mg/kg) in group DM and group CS. The rats in group CS were given fermented cordyceps powder solution by gavage at a single dose of 1 g·kg-1·d-1 for 18 weeks. Rats of group CON and group DM were given 0.9%NaCl in the same way. All rats were sacrificed after 18 weeks. The pathological changes in myocardium were observed by HE staining and electron microscope. The expression of NLRP3 in myocardium was detected by Western blotting. The expression levels of NLRP3, Caspase-1 and IL-1βin myocardium were detected by immunohistochemistry. Results (1) Myocardial necrosis and fibrosis and mitochondrial damages were observed under electron microscope in group DM. The above-mentioned pathological changes were improved in the group CS. (2) The result of Western blotting showed that the expression of NLRP3 in myocardium was significantly increased in group DM and group CS than that in group CON, and the expression of NLRP3 was significantly lower in group CS than that in group DM. (3) The result of immunohistochemistry showed that, compared with the group CON, the expressions of NLRP3, Caspase-1 and IL-1β in myocardium were significantly increased in group DM and group CS, and which were significantly lower in group CS than those in group DM. Conclusion Fermented cordyceps powder can improve diabetic cardiomyopathy through decreasing the expressions of NLRP3, Caspase-1 and IL-1βin myocardium.