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Objective@#To investigate the changes of brain gray matter volume (GMV) and brain activity in patients with long-term methamphetamine (MA) abstinence compared with healthy controls.@*Methods@#This study included 44 abstinent MA patients and 40 demographically equivalent healthy controls. Structural magnetic resonance imaging (MRI) and resting-state functional MRI (rs-fMRI) were obtained on Siemens 3.0 T MR. Differences in GMV between abstinent MA group and control group were assessed using voxel-based morphometry (VBM) method. Within each region showed significant differences between two groups, the value of the fractional amplitude of low frequency fluctuation (fALFF) was calculated using the rs-fMRI data. Differences of fALFF between groups were also evaluated. Furthermore, partial correlation coefficients adjusted for age, years of education, smoking and drinking were calculated in the abstinent MA group to assess associations between the mean GMV and fALFF values in significant clusters and variables of MA use and abstinence.@*Results@#Compared with controls, abstinent MA group showed increased GMV in the right cerebellum crus and decreased GMV in the right calcarine. While fALFF values within bilateral cerebellum crus in abstinent MA patients were significantly increased. Moreover, GMV of the left cerebellar crus was positively correlated with the withdrawal time among abstinent MA patients.@*Conclusions@#Both structural and functional abnormalities were found in abstinent MA patients even after long-term abstinence. The positive correlation between GMV of left cerebellum crus and abstinent duration suggested that prolonged abstinence may be beneficial to brain recovery. The fALFF of the right calcarine was increased even with decreased GVM in the abstinent MA group. It indicates that the brain activity of this area is increased, which may imply that drug cue-induced craving is significant among methamphetamine patients even after long-term abstinence.
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Objective To investigate the changes of brain gray matter volume (GMV) and brain activity in patients with long?term methamphetamine (MA) abstinence compared with healthy controls. Methods This study included 44 abstinent MA patients and 40 demographically equivalent healthy controls. Structural magnetic resonance imaging (MRI) and resting?state functional MRI (rs?fMRI) were obtained on Siemens 3.0 T MR. Differences in GMV between abstinent MA group and control group were assessed using voxel?based morphometry (VBM) method. Within each region showed significant differences between two groups, the value of the fractional amplitude of low frequency fluctuation (fALFF) was calculated using the rs?fMRI data. Differences of fALFF between groups were also evaluated. Furthermore, partial correlation coefficients adjusted for age, years of education, smoking and drinking were calculated in the abstinent MA group to assess associations between the mean GMV and fALFF values in significant clusters and variables of MA use and abstinence. Results Compared with controls, abstinent MA group showed increased GMV in the right cerebellum crus and decreased GMV in the right calcarine. While fALFF values within bilateral cerebellum crus in abstinent MA patients were significantly increased. Moreover, GMV of the left cerebellar crus was positively correlated with the withdrawal time among abstinent MA patients. Conclusions Both structural and functional abnormalities were found in abstinent MA patients even after long?term abstinence. The positive correlation between GMV of left cerebellum crus and abstinent duration suggested that prolonged abstinence may be beneficial to brain recovery. The fALFF of the right calcarine was increased even with decreased GVM in the abstinent MA group. It indicates that the brain activity of this area is increased, which may imply that drug cue?induced craving is significant among methamphetamine patients even after long?term abstinence.
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Objective:To explore the academic procrastination (AP) status and related factors in college students. Methods: Totally 828 undergraduates (277 male, 551 female, age 18-25 years) from Sun Yat-Sen University were investigated with a self-made questionnaire for basic information and Undergraduate Academic Procrastination Questionnaire (UAPQ) for AP status. UAPQ included overall learning procrastination (OLP), homework procrastination (HP), exam preparing procrastination (EPP) and self-learning procrastination (SLP). Students who scored more than 3 in OLP, HP, EPP, SLP were regarded as procrastinator. Result: The procrastination rates of OLP, HP, EPP, SLP were 40.7％, 29.7％, 41.5％, and 47.6％. Multiple linear regression analysis results showed that bigger (β = 0.32) and normal (β =0.15) influence for academic by mobile-phone, higher level of computer dependence (β =0.15) were positively related with academic procrastination. Higher (β =-0.27) and normal (β =-0.17) levels of grade satisfaction were negatively correlated with academic procrastination. The seniors' academic procrastination levels were lower than those in other grade (β =-0.12). Conclusion: It suggests that undergraduates procrastinate widely in many academic activities. Bigger and normal influence for academic by mobile-phone, higher level of computer dependence may be risk factors of procrastination, while being satisfied with grades and seniors may be protective factors.
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By bioinformatics analysis, a putative keratinase gene gm2886 (Accession number: KY368946) was discovered in the genome of a feather-degrading strain, Streptomyces albidoflavus Fea-10. gm2886 was ligated into integrative Escherichia coli-Streptomyces shuttle vector pSET152 under the promoter PermE and added with C-terminal His-tag. The expression vector was transformed into Streptomyces pactum ACT12 by conjugal transfer and the recombinant protein GM2886-His6 was detected in fermentation broth. GM2886-His6 was purified and characterized. Its size was nearly 36 kDa. GM2886-His6 showed proteolytic activity towards a variety of substrates and could even degrade insoluble substrates, such as azure keratin and chicken feathers. The optimal pH and temperature of GM2886-His6 for proteolysis of casein was pH 10.0 and 50 ℃, respectively. The enzyme activity was inhibited by PMSF, but not EDTA, indicating that GM2886-His6 was a serine proteinase. Our results laid the foundation for the research of the molecular biological mechanism on feather-degrading and for the further utilization of Fea-10.
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Objective:To examine the characteristics of oculomotor inhibition about children with attention deficit hyperactivity disorder(ADHD).Methods:Twenty-one children with ADHD according to the Diagnostic and Statistical Manual of Mental Disorder,4th edition(DSM-IV) and 21 matched controls were administered with fixation,prosaccade and antisaccade tasks.Results:(1) In the fixation task,the children with ADHD demonstrated significantly more intrusive saccade errors than the controls in either condition with distractors or without distractors[no distractors:(12.67±12.28) vs.(6.38±6.95),P=0.040;distractors:(16.91±10.00) vs.(11.29±5.99),P=0.030].(2) In the prosaccade task,there were no significant differences found between groups in saccadic parameters,in either gap condition or overlap condition.(3) In antisaccade task,the direction error rates of the ADHD group in either gap condition or overlap condition,were both higher than that of the control group[gap:(68.14±17.85) % vs.(54.10±20.22) %,P=0.020;overlap:(62.49±17.54) % vs.(49.27±17.21) %,P=0.020].Conclusion: It suggests that there is an abnormality of the oculomotor inhibition,which may be caused by abnormal structure and/or function of fronto-striatal in ADHD children.
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Objective To explore the specific brain regions involved in Chinese character radicals visualspatial processing,as well as to explore the relationship between visual-spatial identification and Chinese characters radicals identification.To provide an evidence for understanding the underlying neural mechanism of developmental dyslexic.Methods Twelve healthy Chinese fourth and fifth grade children(7 boys and 2 girls,aged from 10 to 11 years old)were chosen from a primary school in Guangzhou.The children were native Chinese speakers and right handed.The subjects participated in two fMRI experiments on a 3.0 T Siemens MR scanner.Two separate block-designed cognitive tasks were devised,one was figure directions judgement task and the other was Chinese characters radical identification task.A single-shot GE-EPI scan sequence were used for fMRI scans.The BOLD fMRI data were collected and were preprocessed and analyzed in SPM2.Results The subjects had longer reaction time during the two experiments tasks than in control states((879±127)ms vs(805±124)ms,P=0.029;(917±144)ms vs(750±101)ms,P＜0.01),and had same response accuracy in both tasks and control states((96±5)% vs(95±8)%,P=0.515;(89±10)% vs(96±6)%,P=0.130).In figure direction judgement experiment,activations were found in bilateral occipital,right superior parietal,right precuneus and right middle frontal cortices.However,different and more extensive regions including left superior parietal,left precuneus,left hippocampus,right thalamus,right caudate cortices and bilateral occipital cortices were involved in identifying the radicals of Chinese characters.Conclusion Right hemisphere was dominant in judging the figure direction,and left hemisphere is dominant in identifying radicals of Chinese characters.These fMRI results show light on underlying partial similar neurophysiological mechanism between judging figure directions and identifying Chinese character radicals.The visual-spatial ability may be essential for Chinese character radical identification.