混气电解加工中两相流音速及阻塞机理研究

着重分析研究气液两相流音速特性及其阻塞机理。通过测量由小药量电雷管爆炸而产生的压力波传播速度，然后修正到音速。试验结果表明，气液两相流音速与气泡率、当地压力及其流型有关。由于气液混合物强烈的压缩性，混气电解加工间隙中易于出现类似可压缩气体的阻塞现象。

中医药治疗慢性阻塞性肺疾病作用机理的研究概况

中医药治疗慢性阻塞性肺疾病机理研究 ,基本与现代医学对本病的发病学研究相同步 ,主要集中在细胞因子、炎性介质、内皮素、免疫调节、病理形态学等方面 ,表明中医药治疗慢阻肺的机理研究已经深入到细胞分子生物学及病理形态学水平 ,目前实验模型基本沿用西医的疾病模型。

具有阻塞影响的柔性制造系统排队网络模型

用有限容量局部库区的开排队网络模拟柔性制造系统，模型中，机床加工工件的时间服从指数分布，运送台车按照静态Ｍａｒｋｏｖ方式运送工件且运送时间服从指数分布，被阻塞的工件按照ＢＡＲ机理被处理，静态Ｍａｒｋｏｖ工件运送方式中的概率值受工件被阻塞的影响．理论分析表明该排队网络模型的平衡状态分布具有乘积形式解．基于该乘积形式解，工件被阻塞的概率可由计算一个固定点问题而获得．关于各加工域的输出率同局部库区容量之间的关系，一个重要的结论被给出．

用频装备带内多频电磁辐射阻塞干扰效应预测方法

为解决用频装备复杂电磁环境效应准确评估的技术难题,从电磁辐射信号耦合传输的基本理论出发,推导揭示了射频前端线性不良和动态范围不足分别是导致用频装备电磁辐射效应对带内多频电磁辐射干扰场强有效值、幅值敏感的本质原因。在此基础上建立了2类用频装备的带内多频连续波电磁辐射效应模型,提出了通过正弦调幅波(调制深度100%)、单频连续波电磁辐射临界干扰场强有效值之比(Eame/Esine)确定受试装备电磁辐射敏感类型的方法。Eame/Esine>0.9时,受试装备对干扰场强有效值敏感,0.612<Eame/Esine<0.9时,受试装备对干扰场强幅值敏感。通信电台带内双频、三频电磁辐射效应试验验证表明:所提建模预测方法的误差小于10%,能够有效预测用频装备带内多频连续波电磁辐射效应。

钢管混凝土研究现状综述

本文通过文献调研和工程调研,介绍了钢管混凝土的节点形式、现阶段的检测技术,总结了自密实混凝土的阻塞机理和理论模型,对钢管混凝土节点性能开展了相关调研,阐述了现阶段钢管混凝土的研究方向和相关成果,结合工程实例,整体表明,钢管混凝土技术在施工中合理运用能满足理论模型。

Pouchitis

While restorative proctocolectomy with ileal pouch-anal anastomosis has significantly improved the quality of life in patients with underlying ulcerative colitis who require surgery,complications can occur.Pouchitis as the most common long-term complication represents a spectrum of disease processes ranging from acute,antibiotic-responsive type to chronic antibiotic-refractory entity.Accurate diagnosis using a combined assessment of symptoms,endoscopy and histology and the stratification of clinical phenotypes is important for treatment and prognosis the disease.The majority of patients respond favorably to antibiotic therapy.However,management of chronic antibiotic-refractory pouchitis remains a challenge.

Self-expandable metallic stents for malignant biliary obstruction:Efficacy on proximal and distal tumors

AIM： To compare the efficacy of self-expandable metallic stents （EMS） in the treatment of distal and proximal stricture of malignant biliary tumors. METHODS： From March 1995 to June 2004, 61 patients （40 males, 21 females） with malignant biliary obstruction who received self-expandable metallic stent implantation were reviewed retrospectively. The stents were inserted by an endoscopic or percutaneous transhepatic method. We tried to place two stents in the biliary system in T or Y configuration in cases of hilar tumors with bilateral hepatic duct obstruction. The end points of the study were stent occlusion or patient death. RESULTS： The mean time of stent patency was 421 ± 67 d in the group of proximal stricture（ group Ⅰ） and 168 ± 18 d in the group of distal stricture （group Ⅱ）. The difference was significant in borderline between the two groups （P = 0.0567）. The mean survival time was 574 ± 76 d in group I and 182 ± 25 d in group II. There was a significant difference between the two groups （P = 0.0005）. CONCLUSION： EMS implantation is a feasible, palliative method for unresectable malignant biliary obstruction. The clinical efficacy of EMS in patients with proximal hilar tumors is better than that in patients with distal tumors.

Clinical application of self-expanding metallic stent in the management of acute left-sided colorectal malignant obstruction

AIM： To summarize our experience with the application of self-expanding metallic stent （SEMS） in the management of acute left-sided colorectal malignant obstruction. METHODS： A retrospective chart review of all patients undergoing placement of SENS between April 2000 and January 2004 was performed. RESULTS： Insertion of SENS was attempted in 26 patients under fluoroscopic guidance with occasional endoscopic assistance. The sites of lesions were located in splenic flexure of two patients, left colon of seven patients, sigmoid colon of eight patients and rectum of nine patients. The intended uses of SENS were for palliation in 7 patients and as a bridge to elective surgery in 19 patients. In the latter group, placement of SENS allowed for preoperative systemic and bowel preparation and the following one-stage anastomosis. Successful stent placement was achieved in 22 （85%） of the 26 patients. The clinical bowel obstruction resolved 24 hours after successful stent placement in 21 （95%） patients. Three SENS-related minor complications occurred, two stents migrated and one caused anal pain. CONCLUSION： SEMS represents an effective and safe tool in the management of acute malignant colorectal obstruction. As a bridge to surgery, SEMS can provide time for systematic support and bowel preparation and obviate the need for fecal diversion or on-table lavage. As a palliative measure, SEMS can eliminate the need for emergent colostomy.

Hepatic venous outflow obstruction after piggyback liver transplantation by an unusual mechanism:Report of a case

Hepatic venous outflow obstruction after piggyback liver transplantation is a very rare complication. An unusual mechanism aggravating it is reported. A 33-year-old man with end-stage hepatitis B liver cirrhosis underwent a piggyback orthotopic liver transplantation using a full-size cadaveric graft. Two months after transplantation, he developed gross ascites refractory to maximal diuretic therapy. Doppler ultrasound showed patent portal and hepatic veins. Serial computed tomography scans revealed a hypoperfused right posterior segment of the liver which subsequently underwent atrophy. Hepatic venography demonstrated a high-grade stenosis with an element of torsion of venous drainage at the anastomosis. The stenosis was successfully treated with repeated percutaneous balloon angioplasty. The patient remained asymptomatic six months afterwards with complete resolution of ascites and peripheral edema. We postulate that liver allograft segmental hypoperfusion and atrophy may aggravate or result in a hepatic venous outflow problem by the mechanism of torsion effect. Percutaneous balloon angioplasty is a safe and effective treatment modality for anastomotic stenosis.

Retroperitoneal fibrosis: A rare cause of both ureteral and small bowel obstruction

Retroperitoneal fibrosis (RPF) is a rare condition of unclear etiology. It can cause ureteral obstruction. We present the unique case of a 54 years old female, who initially presented with spontaneous perforation of the cecum. Upon exploring the abdomen, the classical glistening white, unyielding retroperitoneal fibrosis was encountered. A right hemicolectomy was performed. Subsequently, the patient presented with bilateral ureteral obstruction, and later on with small bowel obstruction. Ureteral obstruction was treated with stents, and small bowel obstruction was treated with bypass. To our knowledge no case of idiopathic RPF presenting with features of both bilateral ureteral and small bowel obstruction has been reported in the literature.

The applicable value of respiratory impedance for the stage 0 of chronic obstructive pulmonary disease

Objective ：To evaluate the applicable value of respiratory impedance for the stage 0 of chronic obstructive pulmonary disease （COPD）. Methods：Respiratory impedance was measured by impulse oscillometry （lOS） in 41 cases at stage 0 of COPD （NHLBI/WHO, 2001 Standard） and their conventional pulmonary function values were compared with 42 healthy subjects. Both groups had no significant deviation in age, stature and avoirdupois, etc. Master-Screen pulmonary function test system （Jaeger Co, Germany） were used to determine IOS parameters including viscous resistance of 5Hz, 20 Hz and 35Hz （R5, R20, R35）, reactance of 5Hz, 35 Hz （X3, X35）, resonant frequency （Fres） ,total respiratory impedance （Zrs） and routine pulmonary function values including forced expiratory volume in one second to predicted value （FEV1 % ）, forced expiratory volume in one second to forced vital capacity ratio（ FEV1/ FVC% ）, maximal mid expiratory flow （MMEF%）,V23% and V50%. Results：Both groups had no significant deviation in FEV1%, FEV1/FVC% and X35（P〉0.05）. It was increased significantly in viscous resistance of 5Hz, 20 Hz and 35Hz （R5, R20, R35） in COPD group than that in healthy group （P〈0.01）. So were Fres and Zrs （P〈0.01）. MMEF%,V25%,V50% and reactance of 5Hz （X5） in COPD group were marked lower than that in healthy group （P〈0.01）. The sensitivity of MMEF%, V25%,V50% was higher than others, but its specificity was lower. In parameters of IOS, Fres was the most sensitive index for diagnosis of the small airway function and its specificity was higher than that of MMEF%, V25% ,V50%. Conclusion：In the risk case at the stage 0 of COPD, MMEF%, V25% and V50% could be decreased, but Fres, R5 ,R5-20 could be increased in spite of FEV1% and FEV1/FVC% in normal range.

Xanthogranulomatous cholangitis causing obstructive jaundice:A case report

This article reports the case of a 34-year-old woman with xanthogranulomatous cholangitis who developed obstructive jaundice. Microscopically, the bile duct was surrounded and narrowed by a xanthogranulomatous lesion, but no xanthogranulomatous cholecystitis was seen. Although percutaneous cholangiograms done via the transhepatic biliary drainage showed smooth narrowing of the upper to middle bile duct, the cytology of bile was diagnosed as class V adenocarcinoma. Therefore, right extended hepatectomy and extrahepatic bile duct resection were performed. The differentiation of benign and malignant strictures at the hepatic hilum is often difficult. Xanthogranulomatous cholangitis is one possible diagnosis of a bile duct stricture. Precise review of all the preoperative information is required to make a correct diagnosis.

Electric Wheelchair Control System Using Brain-Computer Interface Based on Alpha-Wave Blocking

A brain-computer interface(BCI)-based electric wheelchair control system was developed, which enables the users to move the wheelchair forward or backward, and turn left or right without any pre-learning. This control system makes use of the amplitude enhancement of alpha-wave blocking in electroencephalogram(EEG) when eyes close for more than 1 s to constitute a BCI for the switch control of wheelchair movements. The system was formed by BCI control panel, data acquisition, signal processing unit and interface control circuit. Eight volunteers participated in the wheelchair control experiments according to the preset routes. The experimental results show that the mean success control rate of all the subjects was 81.3%, with the highest reaching 93.7%. When one subject's triggering time was 2.8 s, i.e., the flashing time of each cycle light was 2.8 s, the average information transfer rate was 8.10 bit/min, with the highest reaching 12.54 bit/min.

MANAGEMENT OF AE-CB/COPD: A SURVEY OF RESPIRATORY PHYSICIANS IN SOME REGIONS OF CHINA

Objective To investigate the bacteria spectrum isolated from AE-CB/ COPD and the manner of management of AE-CB/COPD in respiratory or internal medicine department in some regions of China. Methods Respiratory physicians received questionnaire at randomization just after they managed a patient presenting to outpatient department with AE-CB/ COPD, on general conditions and symptoms of patients, type of examinations, diagnosis, type of antibiotics used and mode of administration. Results of sputum bacteria culture were followed up. Results Amang the1583 AE-CB/COPD, 63. 04% were male and 35.19% were female. 54.6% of them were older than 60 years. 81.87% of the patients produced sputum. Sputum bacteria culture, chest X-ray and chest CT were carried out to 21.3%, 66. 3% and 11. 1% patients, respectively. 355 strains were isolated from patients whose sputum bacteria culture was positive. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella ca- tarrhalis were the three most isolates. 84. 7% of the 1583 AE-CB/COPD received 1692 times of antibiotic prescribing. The most frequently prescribed antibiotic were B-lactams （51.36% of all antibiotic prescribing）, macrolides （14. 01% ） and quinolones （31.03%）. Much more macrolides were prescribed in the area where mare patients pay the medicines at his own expense than those in the area where more patients share public health service. Conclusion In China, respiratory physicians can reasonably select antibiotics to manage acute exacerbation of chronic bronchitis/ chronic obstructive pulmonary disease in pulmonary outpatient department. Sputum culture is done in part of the patients, but susceptibility tests are missing. One issue revealed by the survey is that the list of prescribing medications laid down by government have great influence on antibiotic use.

Limited Efficacy of Aspirin in Patients with Peripheral Arterial Occlusive Disease

Antiplatelet drugs represent one of the basic options for management of patients with different atherosclerotic diseases. Aspirin is the oldest and most often prescribed antiplatelet drug. It seems that it is most effective in coronary patients with clinically unstable disease, less effective in prevention of cerebrovascular incidents, and its efficacy is uncertain in peripheral artery disease （PAD） patients. One of the first meta-analysis indicated that antiplatelet drugs also significantly reduce cardiovascular events in patients with PAD. However, latest meta-analysis of randomized control trials of aspirin therapy involving patients with diabetes and PAD demonstrated no benefit of aspirin in reducing cardiovascular events. Also in patients with preclinical PAD aspirin did not result in a significant reduction of vascular events. The new anti-platelet drugs prasugrel, ticagrelol, picotamide seem to be more effective than aspirin in PAD patients, particularly in diabetic patients with PAD. However, evidence based data are scanty. New studies on PAD patients are necessary to better define the role of anti-platelet agents in these patient and one of the promising ways of access to anti-platelet treatment would be personalized anti-platelet therapy.

FACTORS ASSOCIATED WITH QUALITY OF LIFE IN ACUTE EXACERBATION OF COPD

Objective To measure the QOL in patients with AECOPD and the frequency of potential risk factors, and to evaluate the association of risk factors with poor QOL in patients with AECOPD. Methods A study sample of 196 patients with moderate to severe COPD admitted for acute exacerbations to two large general hospitals were studied. The St George QOL (SGQOL) scale, socio-demographic, clinical and patient care characteristics, including depression and spirometry were ascertained in the stable state before discharge and at one-month post discharge. Results There was a high prevalence of current or ex-heavy smokers, depression and consumption of psychotropic drugs, and low prevalence of care giver support, pulmonary rehabilitation and vaccination. The mean scores for the different domains were 55.9 for Symptoms; 65.1 for Activity; 32.9 for Impact; and the mean of overall Total scores was 46.5. Multiple regression analysis showed that CMH, male, depression, previous frequent hospital readmissions and poor therapy compliance were independently related to worse Symptoms Scores. Previous frequent readmissions, depression, severe dyspnea and older age (>72 years) were related to worse Activity Scores of SGQOL. Depression, previous frequent readmissions, severe dyspnea, long COPD duration(≥5years) and severe smoking were related to worse Impact Scores of SGQOL. Depression, previous frequent readmissions, severe dyspnea and long COPD duration(≥5years) were independently related to worse Total Scores of SGQOL. Conclusion Poor QOL in patients with COPD exacerbation was associated with disease severity, psychosocial and health care factors which are modifiable.

颗粒型防砂工艺设计施工的最新进展及其性能评价

防砂作业,尤其是那些使用粒状滤料的作业,如砾石充填和压裂充填正在被越来越多地使用,并且作业环境更为苛刻。设备、作业液及施工方面的改进一直在持续。防砂滤料的设计连续地以有限数量的离散储层样品为基础。这些样品被认为能够完全代表整个产油层的真实粒径。要想明确伤害的原因及位置通常比较困难,除非使用诸如生产测井仪之类昂贵的评价工具。本文给出了研究工作的结果,成功研制出一个分析工具和一个容许改进防砂作业设计及评价的全新颗粒体系。在逐步进阶的基础上,建立了一个确定颗粒尺寸的体系,并且逐步认识了孔隙阻塞的机理。此外.设计出了粒状滤料,从而使颗粒运移导致的渗透率伤害能够逆转。给出的结果以"多孔介质内的固体颗粒流动"原理为基础。主要工作包括室内对各种砾石所做的试验及其结果。开展了现场验证,取得了激光衍射分析数据及一口海上斜井的数据。