In Vivo Degradation Performance of High-Purity Magnesium Subjected to Quantitative Mechanical Load / 医用生物力学

Objective To study the effects of mechanical load on in vivo degradation performance of high-purity magnesium (HP Mg, 99.99 wt.%) quantitatively. Methods Cylindrical Mg specimens, with a 2 mm diameter and a 14 mm length, were mounted in polyetheretherketone (PEEK) rings to bear compressive stresses ［（6.2±0.6） MPa］, tensile stresses ［（4.6±0.1） MPa］ or no stress (as control). The specimens under different stress states were implanted subcutaneously in dorsal abdominal regions of SD rats for 4 weeks. The mass loss, residual volume and surface morphology of the specimens and staining of surrounding soft tissues were used to analyze the degradation rate of HP Mg. Results Specimens and rings were completely encapsulated by membranous tissues after implantation for 4 weeks. No significant differences in the degradation rates were noted between specimens bearing stress and the control. The corrosion layers of specimens under each stress state were uniform. Conclusions The compressive and tensile stresses (4-6 MPa) could not affect significantly HP Mg degradation performance in vivo. The research findings provide theoretical references for the design and clinical application of Mg-based degradable implants.

Gender differences in recovery consequences among heroin dependent patients after compulsory treatment programs.

Studies on recovery patterns and how baseline factors influence recovery consequences among heroin dependent patients have shown mixed results. This study is aimed at describing the gender differences in long-term recovery patterns and exploring the predictors of negative recovery consequences by gender among heroin dependent patients in Shanghai, China. At baseline, this study recruited 503 heroin dependent patients discharged from Shanghai compulsory rehabilitation facilities in 2007 and 2008. In this cohort study, the baseline data was then linked with participants' 5-year follow-up data from official records. Generalized Estimating Equations (GEE) were used to compare males with females in terms of the presence of negative consequences (incarceration, or readmission to compulsory treatment, or both), in the subsequent 5-years after their discharge from compulsory treatment. Ordinary least squares (OLS) regression was used to explore factors associated to the time length of negative consequences in 5 years after the discharge for males and females separately. Our findings indicate that female heroin dependent patients tend to have less negative recovery outcomes than male patients. Male patients with a life-time history of poly drug use and female patients with borderline personality disorder are especially at risk of incarceration and readmission into compulsory treatment programs.

P300 event-related potential in abstinent methamphetamine-dependent patients.

BACKGROUND: Substance use and abuse are characterized by biases in the attentional processing of substance-related stimuli. There are no event related potential (ERP)-based studies of attentional bias for substance-related cues among methamphetamine (MA) dependent patients. The study aimed to measure changes in P300 event-related potentials elicited by MA-related words in MA-dependent individuals at baseline and after 3 and 6 months of abstinence, examining the relationship of ERP changes to craving. METHOD: 26 MA-dependent patients (14 male) newly enrolled in two compulsory treatment centers in China and 29 healthy controls (15 male) were included in this study. At baseline (2-3 weeks in treatment) and after 3 and 6 months of abstinence from MA use, we obtained ERP data during a Stroop color-matching task using MA-related and neutral words. Self-reported craving was measured by a Visual Analog Scale (VAS). FINDINGS: Increased P300 amplitudes elicited by MA-related words were observed over left-anterior electrode sites. Abnormal P300 amplitudes declined to the normal levels of healthy controls at the end of 3 months of abstinence, and the decrease was maintained up to the end of 6 months of abstinence. The behavioral data did not show similar changes. The positive relationship between the changes of VAS scores for MA craving and the changes of P300 amplitudes over left anterior electrode sites elicited by MA-related words within the first 3 months was significant. CONCLUSION: These findings highlight the potential use of ERP as an objective index to track changes in subjective MA craving among abstinent MA-dependent patients.

An analysis on cue-induced craving and the related factors among heroin dependence / 中华行为医学与脑科学杂志

Objective To understand the cue-induced craving, physiological reactions to heroin-related cues, and to explore the factors that impact the cue-induced craving. Methods 369 abstinent heroin addicts were exposed to videotapes of heroin using and simulacrum after the self relaxation. The craving, abstinent symp-toms were measured before and after cue exposures. The physiological reactions were measured by multi-biofeed-back instrument before, during, and after cue exposure. BIS-Ⅱ questionnaire was used to collect information about their impulsive characteristic. Results After cue exposure, the self-reports scores of craving (t=11.24, P< 0.01), physiological index including heart rate((76.6±11.3) beats/min, F=19.23), skin conduct ((7.48± 4.25)μs, F=53.99), pupil size (t=11.73) had significant change in heroin addicts (P<0.01). Logistic regres-sion results showed that the scores of BIS-Ⅱ were related to cue-reduced craving (P=0.001,95% CI: 1.015～1. 065). Conclusions Exposure to drug-related cues can induces craving and physiological reactions in long term abstinence heroin addicts. High impulsive characteristic is a risk factor to induce drug-related craving. The inter-vention strategies should consider the impulsive characteristic and make a comprehensive intervention program to prevent relapse.

Combination of Biofeedback Therapy and Cue-exposure Therapy Decreased Heroin-related Cue Reactivity in Abstinent Heroin Dependents / 中国心理卫生杂志

Objective:To understand whether or not biofeedback therapy(BT)and cue- exposure therapy(CET)could decrease craving and heroin-related cue reactivity in abstinent heroin dependents.Methods:Adopting stratified sampling means,60 abstinent heroin dependents whose craving increased after cue exposed,were allocated to experiment group(n=36)and control group(n=24).The control group dependents received assistance and education.Beside the assistance and education,the experiment group also received 12 times combination therapies of BT and CET.Results:After therapies,the experiment group dependents' craving,EMG and skin conductance(SC)were all decreased compared with control group before cue exposures and after cue exposures[Before cue exposures,the indexes were:craving(3.06±7.26)mm vs.(22.32±20.26)mm;EMG(8.52±4.23)μV vs.(12.06±5.17)μV,SC(2.14±1.43)μS vs.(4.61±2.24)μS.After cue exposures the indexes were:craving(6.97±10.30)mm vs.(33.14±25.40)mm,MEG(8.72±4.31)μV vs.(14.79±5.86)μV,SC(2.15±1.33)μS vs.(4.49±2.59)μS;Ps≤0.01.Conclusion:The combination of biofeedback therapy and cue-exposure therapy could decrease the dependents' craving and cue reactivity sensitivity.