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111.
The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized.  相似文献   
112.
The objective of the present study was to evaluate the clinical, radiological, and functional outcomes of a subscapularis transthoracic surgical approach and a posterolateral surgical approach with debridement, bone graft fusion, and internal fixation for the treatment of upper thoracic tuberculosis.There is currently debate over the best surgical approach for the treatment of upper thoracic tuberculosis. Traditionally, the subscapularis transthoracic approach has been preferred; however, the posterolateral approach has gained popularity in the past few years.A prospective, consecutive cohort of 43 upper thoracic tuberculosis patients with a mean age of 39 years (range: 20–52 years) was followed up for a minimum of 12 months (range: 12–60 months). Patients were randomly divided into 2 groups. Group A (n = 21) was treated by the subscapularis transthoracic approach and group B (n = 22) was treated by the posterolateral approach. All cases were evaluated for clinical, radiological, and functional outcomes. Intraoperative blood loss, operative duration, intraoperative and postoperative complications, hospital stay, the cure rate, fusion time, and the Frankel scale were used for clinical and functional evaluation, whereas the kyphosis angle was used for radiological evaluation.Grafted bones were fused by 10 months in all cases. There was no statistically significant difference between groups before surgery in terms of gender, age, segmental tuberculosis, erythrocyte sedimentation rate (ESR), Frankel scale, or Cobb''s angle (P > 0.05). The average operative duration for Group B was lower than that of Group A. There were no significant differences in intraoperative blood loss, intraoperative and postoperative complications, hospital stay, grafted bone fusion time, or cure rate between groups (P > 0.05). The Cobb''s angle correction rate for group B (68.5%) was significantly better than that of group A (30.9%). The neurological score showed significant postoperative improvement in both groups, with no significant difference between the groups.The subscapularis transthoracic approach and the posterolateral approach with debridement, bone graft fusion, and internal fixation are both sufficient and satisfactory for the surgical treatment of upper thoracic tuberculosis. However, the posterolateral approach is superior to the subscapularis transthoracic approach in terms of surgical trauma, operative time, and kyphosis correction.  相似文献   
113.
This meta-analysis examined whether early decompressive craniectomy (DC) can improve control of intracranial pressure (ICP) and mortality in patients with traumatic brain injury (TBI).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until May 14, 2015, using the following terms: traumatic brain injury, refractory intracranial hypertension, high intracranial pressure, craniectomy, standard care, and medical management. Randomized controlled trials in which patients with TBI received DC and non-DC medical treatments were included.Of the 84 articles identified, 8 studies were selected for review, with 3 randomized controlled trials s having a total of 256 patients (123 DCs, 133 non-DCs) included in the meta-analysis. Patients receiving DC had a significantly greater reduction of ICP and shorter hospital stay. They also seemed to have lower odds of death than patients receiving only medical management, but the P value did not reach significance (pooled odds ratio 0.531, 95% confidence interval 0.209–1.350, Z = 1.95, P = 0.183) with respect to the effect on overall mortality; a separate analysis of 3 retrospective studies yielded a similar result.Whereas DC might effectively reduce ICP and shorten hospital stay in patients with TBI, its effect in decreasing mortality has not reached statistical significance.  相似文献   
114.
Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur.The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed.The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient''s height had increased 52 cm, shortening of the affected limb was only 1 cm, and the circumference of the affected limb was 2 cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers.In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and provides good functional recovery.  相似文献   
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116.
[目的]研究真武汤合苓桂术甘汤对心肾综合征大鼠模型水钠潴留的作用机制。[方法]将60只雄性SD大鼠随机分为两组,即空白组与手术组,空白组大鼠常规饲养,手术组大鼠经5/6肾切除联合异丙肾上腺素皮下注射制备心肾综合征模型,剔除死亡大鼠后,将手术组剩余成模大鼠按体质量分层随机分为空白组、中药组、常规治疗组。中药组给予真武汤合苓桂术甘汤灌胃,给药量为7.29 g生药/(kg·d);常规治疗组给予贝那普利(0.45 mg/kg)+呋塞米(1.8m g/kg);空白组予以等容积生理盐水灌胃,每日1次,连续6周。观察实验过程中各组大鼠的精神状态、活动情况、灵敏度、毛发情况、食欲、大小便等一般情况及死亡情况,比较各组灌胃前、灌胃6周后的血清脑钠肽(BNP)、血肌酐(Scr)、血尿素氮(BUN)、尿水通道蛋白2(AQP2)的前后差值情况。[结果]灌胃6周后,中药组大鼠一般情况较灌胃前改善、喘息不明显,常规治疗组一般情况同样较灌胃前改善。通过比较治疗前后各组大鼠实验室指标差值发现,中药组与常规治疗组BNP均下降,中药改善大鼠心力衰竭情况接近常规治疗组水平,两组下降水平无统计学差异(P0.05);中药组Scr水平较前下降,常规治疗组Scr水平升高;中药组尿AQP2水平较前略增高,与空白组尿AQP2水平无统计学差异(P0.05),常规治疗组尿AQP2水平较前明显升高。[结论]心肾综合征大鼠尿AQP2的表达主要由肾脏调控,AQP2可作为心肾综合征水钠潴留状态的参考指标,真武汤合苓桂术甘汤改善心肾综合征大鼠水钠潴留状态的作用机制可能是通过抑制大鼠肾脏AQP2过度表达,减少水的重吸收,改善了水钠潴留状态。  相似文献   
117.
历代医家一直重视脏腑相关问题,本文从中医发展之初对脏腑问题的两种视角(联系视角与解剖视角)开始思考,基于《脉经》前后的经典文献梳理《脉经》文本,得出《脉经》脏腑讨论的初步认识,即王叔和讨论了传统藏象视角认识下的脏腑生理、病理、诊断与经脉腧穴的联系,而各种古代文献的重组、编排、归纳则提示藏象理论的系统构建在此时发生,并且已经纳入经脉的相关内容;《脉经》卷六集中体现了王叔和对“脏腑-经脉一体化”的理论构建和临床观察,《脉经》对于脏腑病候进行了仔细梳理,并注重病候、诊脉、脏腑与腧穴的联系。  相似文献   
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Immune dysregulation is a cardinal feature of autoimmune diseases and chronic microbial infections. In particular, regulatory T cells are downregulated in autoimmune diseases while upregulated in chronic microbial infections. FOXP3 is the master regulator of Treg development. Treg-specific demethylated region (TSDR) is a highly conserved locus on the FOXP3 gene that is fully demethylated in natural Tregs but methylated in effector T cells. In our study, we used high resolution melt-polymerase chain reaction (HRM-PCR) to determine the FOXP3 TSDR methylation status in autoimmune diseases and chronic microbial infections. We found that FOXP3 TSDR to have the highest mean melting temperature (highly methylated) in active SLE patients compared to all the other groups (p?<?0.001). The psoriasis group also had a significantly high mean melting temperature (78.62?±?0.20) when compared with the inactive SLE group (78.49?±?0.29, p?<?0.05) and control group (78.44?±?0.25, p?<?0.01). There was no significant difference in melting temperature between inactive SLE and healthy controls. Disease activity in SLE was directly associated with methylation of the FOXP3 TSDR. On the other hand, patients with chronic microbial infections had significantly lower FOXP3 TSDR mean melting temperature (demethylated) when compared with healthy controls (78.28?±?0.21 vs 78.44?±?0.25, p?<?0.05). Our results suggest that the use of HRM-PCR to detect FOXP3 TSDR methylation status is a reliable and easy method to predict natural regulatory T cell levels in peripheral blood in different disease conditions. Determining FOXP3 TSDR methylation status can be a useful tool in diagnosis, and monitoring the severity of autoimmune diseases and chronic microbial infections.  相似文献   
120.
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