聚苯胺-蒙脱土纳米复合材料防腐蚀性能的研究

为提高聚苯胺(PAn)涂料耐强烈的腐蚀介质的性能，运用插层复合的方法用苯胺(An)和蒙脱土(MMT)制备出了PAn-MMT复合材料。经XRD和SEM分析表明，该复合材料中的蒙脱土d001面层间距已完全消失，以纳米数量级片层结构分散在聚苯胺中；在NaCl质量含量为3．5％的腐蚀环境中，用恒电位仪测定以该复合纳米材料作为冷轧钢涂层的腐蚀电流，正交实验表明：当聚合温度为25℃，n(过硫酸铵)：n(苯胺)=l：l、ωMMT=0．5％、掺杂剂为0．03moL／L磺基水杨酸(SSA)时产品的溶解度较大，成膜性较好，其腐蚀电流为2．1μA，明显优于纯聚苯胺作为涂层的18μA和冷轧钢的23μA；在机同的腐蚀环境中电化学阻抗谱(EIS)证明以PAn-MMT复合纳米材料为底漆，环氧树脂为面漆防腐蚀效果较纯环氧树脂好，其中以ωMMT=0．75％制成的PAn-MMT复合纳米材料底漆，防腐蚀效果最好。     

Abnormal autonomic stress responses in obstructive sleep apnoea are reversed by nasal continuous positive airway pressure

Obstructive sleep apnoea (OSA) is associated with abnormalities in autonomic stress tests, which are tests of cardiovascular response in the autonomic nervous system (ANS). The level of abnormality has been related to the level of overnight arterial oxygen saturation (Sa,O2). We have studied ANS function pre- and post-treatment with nasal continuous positive airway pressure (nCPAP) in six males with moderately severe or severe OSA (apnoea/hypopnoea index (AHI) median 51 (range 14-74 events.h-1 of sleep). Tests consisted of heart rate responses to Valsalva manoeuvre, deep breathing, and change of posture from lying to standing. In addition, systolic blood pressure (SBP) response to standing and diastolic blood pressure (DBP) response to handgrip were studied. Each abnormal test (compared to published normal values) scored +1.0 and each marginal test result (90-95% confidence interval for normals) scored +0.5. A total score was calculated for the five tests performed in the evening and morning (maximum score 10 per patient). Patients had been receiving treatment for more than 1 year (median 471 (389-624) days) and objective compliance was monitored by a clock counter in the nCPAP machines. Five of six patients had regularly used nCPAP (mean 7.8 h.night-1) and all showed a normalization in ANS test score: pre-nCPAP 2 (1-4.5), post-nCPAP 0.2 (0-0.5) (p < 0.05, Wilcoxon signed rank test). One poorly compliant subject (No. 6; nCPAP 3 h.night-1) had a deterioration in ANS test score: 1 pre-nCPAP to 1.5 post-nCPAP. The improvement in ANS test score in the five compliant patients was positively correlated with an improvement in mean Sa,O2 during sleep posttreatment. We conclude that successful treatment of obstructive sleep apnoea leads to normalization of impaired autonomic stress responses.     

Upper airway changes in snorers and mild sleep apnea sufferers after uvulopalatopharyngoplasty (UPPP)

OBJECTIVES: We used upper airway (UA) imaging in 20 patients to determine (1) whether an effective enlargement of the UA is obtained after uvulopalatopharyngoplasty (UPPP), and (2) whether UA modifications explain the results of such surgery. METHODS: Cephalometric measurements were made to assess the posterior airway space, the length and width of the soft palate, and the distance between the hyoid bone and the mandibular plane. Pharyngeal CT measured the airway cross-sectional area (CSA) at each 10-mm slice from 10 mm above (-10) to 40 mm below (+40) the hard palate. Polysomnography was performed before and after surgery (10+/-10 [SD] months). Good responders were defined by an apnea-hypopnea index (AHI) of <10 postsurgery or, in patients in whom AHI was initially <10, a reduction of AHI >50% of the initial AHI. RESULTS: Twenty patients (age=45+/-11 years) were studied. For the whole group, the mean body mass index (26+/-4 kg/m2) and AHI (14+/-13 vs 18+/-16/h) were unchanged after UPPP. The results of the surgery were mediocre with 7 good responders (35%) and 13 nonresponders (65%) defined by polysomnographic criteria. The only changes on UA imaging for the group as a whole after UPPP were decrease in length (40+/-6 vs 29+/-5 mm, p< or =0.0006) and increase in width of the soft palate (11.5+/-2.7 vs 13.6+/-3.5 mm, p< or =0.006). The increase or decrease in minimal CSA at the oropharyngeal (OP) level after UPPP was significantly correlated with the change in AHI (r=-0.54, p<0.02). Moreover, the changes in CSA obtained at the OP level were significant only in the patients who responded favorably to UPPP (7 vs 13 nonresponders). CONCLUSIONS: Postoperative OP enlargement is associated with a good outcome of UPPP. Persistent narrowing in nonresponders could be due to the increase in soft palate width after surgery.     

Value and limits of complementary investigations in cases of toxoplasmosis seroconversion during pregnancy. A case report and review of the literature]

We report a case of acute toxoplasmosis during the first trimester of pregnancy in which antenatal diagnosis was negative. Except for non-specific signs of liver failure, assessment by repeated ultrasound scans, testing of fetal blood for toxoplasmic specific antibodies and competitive PCR to isolate the parasite, had ruled out fetal infection. In spite of early treatment with spiramycin, and although the infant was assumed to be non-contaminated, severe hydrocephalus was noted at 3 and half months of life, arising soon after therapy had been stopped. This case focuses attention on the problem of the shortcomings of the diagnostic techniques currently used, and leads us to question our practical course of action. Several questions are thus raised: how reliable are indirect signs of fetal compromise, what is the real sensitivity of the PCR test and how useful are repeated amniocentesis and inoculation of the amniotic fluid to mice.     

改良溶栓方案治疗静脉窦血栓形成

目的探讨改良溶栓方案（最低静脉窦内微量持续泵点尿激酶１０万u／２４h）治疗脑静脉窦血栓形成的疗效和安全性。方法对２１例患者（合并出血性梗死５例,其中病史超过１个月２例,超过３个月１例）进行机械性破栓、静脉窦内留置微导管行最低量尿激酶１０万u／２４h静脉窦直接泵点滴４８～９６h治疗。术后积极治疗原发病,抗凝治疗６个月。术后随访６～１２个月,平均１０个月。结果２１例脑静脉窦血栓形成患者,脑静脉窦均获得再通（其中１２例患者应用尿激酶１０万u／２４h效果良好,９例患者在应用尿激酶１０万u／２４h,４８h复查后增量至２５万u／２４h）,无一例并发或加重脑出血,预后良好。结论改良溶栓方案可有效治疗脑静脉窦血栓形成,有效规避了大量应用溶栓药物的问题,在达到同样疗效情况下更为安全。     

机械辅助动脉内溶栓治疗急性缺血性脑卒中

【摘要】 目的 评估机械辅助动脉内尿激酶溶栓治疗缺血性脑卒中的临床疗效及安全性。方法 2007年1月至2010年10月对28例急性缺血性脑卒中患者,于发病时间在90 ~ 450 min行机械辅助动脉内尿激酶溶栓治疗。采用的机械辅助方法有导丝碎栓、导管抽吸取栓及支架应用等,术后统计血管再通率、出血并发症及3个月后改良Rankin量表（mRS）评分。 结果 28例患者应用机械辅助溶栓成功再通血管23例,血管再通率为82.1%,平均血管再通时间为65.22 min,3个月后mRS评分均≤ 3分;5例血管再通无效者中2例死亡,1例mRS评分4分,2例mRS评分≤ 3分。血管再通组中,机械辅助溶栓并未增加出血并发症率。结论 机械辅助溶栓治疗急性缺血性脑卒中安全有效,能减少尿激酶用量及血管再通时间,提高再通率。
     

Replication of liner collapse phenomenon observed in hyperbaric type IV hydrogen storage vessel by explosive decompression experiments

An experimental design based on representative sample is described in order to reproduce the detachment and deformation of the inner polymer layer (called liner) of hyperbaric hydrogen storage vessels during the emptying step. It is the first step of a better understanding of the mechanisms involved in the creation of a liner collapse. Results showed that a hydraulic testing machine fitted with a pressure hydrogen chamber enables to create a liner collapse on small samples by explosive decompression experiments. Tomographic observations have revealed that the collapse appears at the polymer liner/composite interface in areas that are not sufficiently bonded, nor consistently. Determination of liner collapse amplitudes, assessed by tomography, has underlined that, under some specific conditions, the deformation of the liner is permanent even when hydrogen has completely desorbed from the sample. In addition to liner collapses, composite cracks were also highlighted.     

锆与铪分离技术的研究现状及应用前景

锆铪分离技术大体分为火法分离和湿法分离,着重介绍了湿法分离的溶剂萃取法中甲基异丁酮－硫氰酸法,三辛胺法,磷酸三丁酯法和改进的N235－H2SO4法,锆铪主要在核能工业上应用,锆铪工业的发展与核能工业紧密关联,加强锆与铪分离工艺的研究,对发展锆铪材料的生产和促进我国核电和国防工业的发展具有重要的战略意义。