Failed Neuroprotection of Combined Inhibition of L-Type and ASIC1a Calcium Channels with Nimodipine and Amiloride

Effective pharmacological neuroprotection is one of the most desired aims in modern medicine. We postulated that a combination of two clinically used drugs—nimodipine (L-Type voltage-gated calcium channel blocker) and amiloride (acid-sensing ion channel inhibitor)—might act synergistically in an experimental model of ischaemia, targeting the intracellular rise in calcium as a pathway in neuronal cell death. We used organotypic hippocampal slices of mice pups and a well-established regimen of oxygen-glucose deprivation (OGD) to assess a possible neuroprotective effect. Neither nimodipine (at 10 or 20 µM) alone or in combination with amiloride (at 100 µM) showed any amelioration. Dissolved at 2.0 Vol.% dimethyl-sulfoxide (DMSO), the combination of both components even increased cell damage (p = 0.0001), an effect not observed with amiloride alone. We conclude that neither amiloride nor nimodipine do offer neuroprotection in an in vitro ischaemia model. On a technical note, the use of DMSO should be carefully evaluated in neuroprotective experiments, since it possibly alters cell damage.     

亚波长光栅用于实现宽光谱消色散1/4波片的研究

基于严格耦合波理论 ,分析了共振区域矩形位相光栅的衍射特性 :位相延迟与光栅周期、占空比、槽深的关系 ,并设计出在 40 0～ 80 0nm范围内的消色散 1/4波片光栅 ,可以实现较为平坦的衍射效率和位相延迟曲线 ,其中位相延迟可保持在 90°左右 ,最大偏差小于 9% ,达到甚至优于普通二元复合消色散波片。通过对加工及安装误差的讨论 ,得到了影响消色散波片光栅性能的主要加工误差是槽深误差和占空比误差。     

理论、实践经验和实践能力

掌握了理论知识并不等于有了实战经验,更不等于有实战能力。从理论到有实战能力的飞跃,只有亲临生产线,在不断解决问题过程中实现。     

测厚仪的维护保养与检修排故

本文简单介绍了差动变压器式测厚仪的日常维护要点及常见故障排除方法。     

Topical use of aprotinin in open heart operations

Among various pharmacological agents used to reduce bleeding after open-heart operations, high-dose aprotinin therapy seems most promising. However, its long-term effects are still obscure; there is almost always possibility of bypass graft occlusions produced by the hypercoagulable state induced by aprotinin in coronary bypass operations. Topical application of aprotinin into the pericardial cavity could prevent the adverse effects. Fifty patients were prospectively studied to evaluate the effects of topical aprotinin. One million KIU of aprotinin was poured into the pericardial cavity before closure of the sternotomy in group 1 (n = 25). Patients in group 2 (n = 25) served as controls. Total postoperative bleeding was significantly reduced in group 1 when compared with that of group 2 (722.7 +/- 230.8 versus 1,282.6 +/- 225.7 mL; p < 0.01). The use of banked donor blood products was significantly less in group 1 than in group 2 (0.33 +/- 0.67 versus 1.36 +/- 0.86 units; p < 0.01). These results show that topical use of aprotinin reduces post-operative blood loss and need for transfusion. It seems promising and warrants further studies to be done.     

黄坛口水电站溢洪道弧形闸门的安全检测与更新改造设计

黄坛口水电站建于50年代,设计和施工时在总体布置上没有考虑弧形闸门的检修条件,使闸门一直处于挡水状态,存在相当多的隐患。通过对弧形闸门和启闭机的安全检测,分析了弧形闸门和启闭机存在的缺陷,提出了更新改造设计方案。     

Swenson's operation for neonatal Hirschsprung's disease

OBJECTIVE: To describe our experience with Swenson's operation for Hirschsprung's disease done during the neonatal period. DESIGN: Retrospective study. SETTING: University department of paediatric surgery. SUBJECTS: 10 Neonates with Hirschsprung's disease. INTERVENTIONS: Rectosigmoidectomy and pull through (Swenson's operation), with covering transverse colostomy. MAIN OUTCOME MEASURES: Mortality, morbidity, and continence. RESULTS: The median age at definitive operation was 25 days (range 15-35). There was one late death three weeks after discharge from hospital of respiratory and cardiac failure. Two patients presented with caecal perforation and two with intestinal obstruction; in all four Hirschsprung's disease was diagnosed on frozen section, a transverse colostomy was done, and the Swenson's operation was done electively. The other six were diagnosed by barium enema examination and biopsy, and underwent total bowel irrigation followed by Swenson's operation and transverse colostomy. The colostomies were closed three to four weeks later. There were no postoperative complications. All nine surviving patients were continent (3-4 stools/day), at a mean (SD) follow up of 21 (5) months. CONCLUSION: With the current high standards of anaesthesia and neonatal intensive care, and an experienced surgeon, Swenson's operation for neonatal Hirschsprung's disease is safe and the procedure of choice for this condition.     

Heat-integration retrofit study of a petroleum refinery

The operation of a petroleum refinery at TÜPRA . Tütünçiftlik was assessed using the pinch-design method. By making use of heat integration in the heat-exchange network, appreciable amounts of energy can be saved as a result of a capital investment having a pay-back period of about 6·5 months.