Management of streptococcal pharyngitis

Severe hemobilia after blunt hepatic trauma is one of the limits for a conservative medical treatment. Urgent percutaneous highly selective embolization of the bleeding vessel is the treatment of choice today. Failures of radiological treatment require surgery. Primary direct ligation of the bleeding vessel carries a risk of recurrence and prevents subsequent embolization. Under these conditions, when the surgeon prefers a conservative approach, preoperative embolization using permanent material can be performed as reported in our case study.     

热处理工艺对压力容器钢板组织和性能的影响

近年来,随着我国石油化工行业的快速发展,各种石油化工工艺以及设备都在不断推陈出新,在此过程中,各种气化产品的液化、分离、贮存以及运输也已经成为极为常见的现象。压力容器作为盛装这些低温气化产品的最主要工具,市场需求也变得越来越大。随之也带动了压力容器用钢需求量的激增。但是随着压力容器用途的日益广泛,不同用途中对压力容器用钢的要求也存在差异,这就给压力容器制造企业提出了更高了要求。热处理工艺是压力容器钢板生产过程中最重要的处理工艺之一,只有经过了不同形式的热处理,才能使钢板的组织及性能发生变化,并最终使用于制造压力容器的钢板具备更多更加完善的性能。本研究就是在此基础上,以07系列压力容器钢为例,对其热处理工艺进行了系统研究。经过不同工艺的热处理,分别对不同工艺下的淬火温度及保温时间,以及回火温度等对钢板的组织及性能的影响进行了分析。并最终根据实验结果得出,针对不同厚度的实验钢,应当尽量在淬火实验的温度控制在900℃~920℃之间,而回火温度的设定则主要根据实验钢板的厚度来进行设定,通常需要控制在600℃~650℃之间。通过本次实验研究,以期能对今后压力容器钢实际生产过程中的相关工艺的应用起到指导作用。     

RH-MFB真空处理工艺技术

介绍了攀钢RH－MFB轻处理LCAK钢和车轴钢,自然脱碳和MFB吹拉强制脱碳处理IF钢,本处理重轨钢以及MFB加热钢水和真空室的工艺,分析讨论了真空降压方式、MFB吹拉对脱碳速度,真空度对终点碳含量影响。     

Optimization of the heat treatment of ingots of high-strength vessel steel modified by rare-earth metals

A process is developed for the production of high-strength vessel steel. It includes the application of a microcrystalline REM-containing modifier and an improved regime of preliminary heat treatment of ingots. This process ensures high hot deformability of ingots and a substantial decrease in the time of production of high-strength vessel steel. The quality of the produced steel meets the requirements of the existing technical forms and records.     

The prevention and treatment for restenosis in coronary angioplasty

Since the invention of Gruentzig AR in 1977, percutaneous transluminal coronary angioplasty (PTCA) has become a widely accepted therapeutic modality for the treatment of patients with ischemic heart disease (IHD). Restenosis which occurs within six months is a major problem of PTCA. Several clinical trials of pharmacological regimen have failed to show significant improvements in restenosis. Palmaz-Schatz stent could improve in restenosis. STRESS and BENESTENT DCA also could improve in restenosis when aggressive debulking was succeeded (BOAT and OARS). The recent IVUS studies have demonstrated that vessel remodeling (vessel shrinking) was the major factor of restenosis. Stent contributes to the prevention of the vessel shrinking, which leads to the improvement in restenosis. However, the rapid increase in stent implantation rates with widening indications cancels the beneficial effect of stent.     

Monocyte diapedesis through an in vitro vessel wall construct: inhibition with monoclonal antibodies to thrombospondin

Human peripheral blood monocytes were examined for migration across an endothelial cell monolayer in an in vitro vessel wall construct. Few monocytes invaded in the absence of a chemotactic gradient, despite significant adhesion to the endothelial monolayer. However, the addition of zymosan-activated human plasma to the lower compartment, to create a chemotactic gradient across the vessel wall, resulted in significantly enhanced monocyte migration. Pretreatment of the monocytes with monoclonal antibodies to thrombospondin (TSP) dramatically inhibited monocyte diapedesis into the vessel wall. The same treatment inhibited monocyte adhesion to endothelial cells in two-dimensional monolayer cultures as well as in vessel wall constructs (no chemotactic gradient). Of interest, however, the monoclonal antibodies had no inhibitory effect on monocyte migration into collagen gels devoid of endothelial cells in response to the same chemotactic gradient, suggesting the importance of TSP in monocyte-endothelial cell interactions. Monoclonal antibodies to fibronectin and normal mouse immunoglobulin G did not inhibit migration in this model of a vessel wall. Furthermore, monoclonal antibodies to TSP showed no inhibition of human peripheral blood neutrophil migration. Previous studies have shown that monocytes synthesize TSP and express this moiety on their surface. The present data suggest that monocytes may utilize TSP to interact with endothelial cells lining the vessel wall during diapedesis.     

Experimental liver injury: serial splenoportography and post-mortem angiography by means of Schlesinger''s mass

Out of 222 eyes with diabetic retinopathy, observed during a period of 6-42 months after argon laser photocoagulation, 66 (30%) became worse. The most common complication was a fast increase of previous existing macular oedema due to extensive and heavy macular treatment. Another complication was an increase of the neovascularisation due to the inadequate treatment of avascular zones and heavy-leaking areas and to the growth of the neovascular tuft after the feeder vessel technique without previous peripheral ablation. Retinal and vitreal haemorrhages were frequent in this group. Fibrous tissue formation and vascular pseudopapillitis were less frequent complications. Large coagulations outside the macular area (peripheral ablation) are necessary to destroy the zones of borderline nutritional supply, which probably are closely related to the new vessel formation. The feeder vessel technique must not be used without a peripheral ablation although it may be of great help in destroying prepapillary or large neovascularisation.     

Surgical treatment of coronary artery aneurysm with rupture into the right atrium

Considering the increasing number of patients with chest pain who undergo routine coronary artery arteriography, coronary artery aneurysm may be found more frequently. To know how to manage these aneurysms, we must understand their possible complications. The aneurysms can produce symptoms of angina or acute myocardial infarction by total thrombosis of the aneurysm and vessel, embolism to the distal vessel, or progressive enlargement and encroachment upon the distal vessel until it is occluded. Moreover, the aneurysm may enlarge and rupture into the free pericardium or produce a fistula by eroding into a chamber of the heart. The case described herein may represent the first reported case of a coronary artery aneurysm eroding into a cardiac chamber and causing an arteriovenous fistula. The treatment of choice is resection of the aneurysm, closure of the fistula, and re-establishment of continuity of the distal coronary artery with a saphenous vein bypass graft.     

Sulcus fixated posterior chamber lenses with and without suture in cases lacking capsular support

Although percutaneous transluminal coronary angioplasty (PTCA) has been an effective treatment for primary reperfusion in acute myocardial infarction, patients with thrombolytic ineligibility, thrombolytic failure, cardiogenic shock, and vein graft occlusion remain at high risk for complications with PTCA treatment. The transluminal extraction catheter may be useful for treatment for such patients owing to its ability to aspirate thrombus. At 2 clinical centers, extraction atherectomy was prospectively evaluated in 100 patients (age 62 +/- 10 years). High-risk features included thrombolytic failure in 40%, postinfarct angina in 28%, presence of angiographic thrombus in 66%, presence of cardiogenic shock in 11%, and a saphenous vein graft occlusion in 29%. Procedural success, defined as a final residual stenosis <50% and Thrombolysis in Myocardial Infarction 2 or 3 grade flow, was seen in 94%. Events during the hospitalization included death in 5%, bypass surgery in 4%, and blood transfusion in 18%. In a substudy, patients enrolled at William Beaumont Hospital (n = 65) underwent elective predischarge angiography, which revealed a patent infarct-related vessel in 95%. These patients were also followed for 6 months with angiographic follow-up in 60%. Target vessel revascularization was necessary in 38%, and 6-month mortality was 10%. Although long-term vessel patency was 90%, angiographic restenosis occurred in 68%. Acute myocardial infarction patients can be treated with extraction atherectomy with a high technical success rate and a low incidence of complication. Infarct artery patency at 1 week and 6 months was excellent; however, angiographic restenosis remains a problem. Extraction of thrombus in this high-risk group of patients is associated with low in-hospital mortality and a high rate of vessel patency at 6 months.     

Mechanical debulking versus balloon angioplasty for the treatment of true bifurcation lesions

OBJECTIVES: The purpose of this study was to compare the immediate angiographic and long-term results of debulking versus balloon angioplasty for treatment of true bifurcation lesions. BACKGROUND: Previous studies have shown true bifurcation lesions to be a high risk morphological subset for percutaneous transluminal coronary angioplasty (PTCA). Although atherectomy devices have been used to treat bifurcation lesions, no studies have compared the outcomes of these alternative treatment modalities. METHODS: Between January 1992 and May 1997, we treated 70 consecutive patients with true bifurcation lesions (defined as a greater than 50% stenosis in both the parent vessel and contiguous side branch) with conventional PTCA (n = 30) or debulking (with rotational or directional atherectomy) plus adjunctive PTCA (n = 40). Paired angiograms were analyzed by quantitative angiography, and clinical follow-up was obtained in all patients. RESULTS: Acute procedural success was 73% in the PTCA group and 97% in the debulking group (p = 0.01). Major in-hospital complications occurred in two patients in the PTCA group and one in the debulking group. Treatment with atherectomy plus PTCA resulted in lower postprocedure residual stenoses than PTCA alone (16+/-15% vs. 33+/-17% in the parent vessel, and 6+/-15% vs. 39+/-22% in the side branch; p < 0.001 for both comparisons). At 1 year follow-up, the incidence of target vessel revascularization (TVR) was 53% in the PTCA group as compared with 28% in the debulking group (p = 0.05). Independent predictors of the need for repeat TVR were side branch diameter >2.3 mm, longer lesion lengths, and treatment with PTCA alone. CONCLUSIONS: For the treatment of true bifurcation lesions, atherectomy with adjunctive PTCA is safe, improves acute angiographic results, and decreases target vessel revascularization compared to PTCA alone. The benefits of debulking for bifurcation lesions were especially seen in lesions involving large side branches.     

热处理工艺对Q370R压力容器板性能的影响

论述了Q370R压力容器板的生产工艺,研究了不同的热处理工艺对Q370R压力容器板性能的影响。     

Revascularization and bypass procedures for cerebral aneurysms

Revascularization and bypass procedures are useful in the treatment of complex aneurysms. Extracranial to intracranial bypass grafts are used to augment the distal circulation as an adjunct to proximal vessel occlusion for aneurysm treatment. Bypass grafts are used also to ensure adequate distal circulation during aneurysm trapping procedures. Recent improvements in vascular exposures at the skull base have allowed the development of vessel replacement or interposition grafts for arteries harboring aneurysms at the skull base. Intracranial interposition grafts are used to reconstruct arteries harboring aneurysms that cannot be occluded directly using clip or coil techniques. These techniques in the treatment of cerebral aneurysms are discussed.     

Vascular effects of photodynamic therapy

Vascular damage and blood flow stasis are consequences of photodynamic therapy (PDT) of solid tumors using many photosensitizers. Microvascular stasis and resulting hypoxia are effective means to produce cytotoxicity and tumor regression. The observation of blood flow stasis after photodynamic therapy results from a combination of damage to sensitive sites within the microvasculature and the resulting physiological responses to this damage. A generalized hypothesis for the mechanisms leading to vessel stasis begins with perturbation and damage to endothelial cells during light treatment of photosensitized tissues. Endothelial cell damage leads to the establishment of thrombogenic sites within the vessel lumen and this initiates a physiological cascade of responses including platelet aggregation, the release of vasoactive molecules, leukocyte adhesion, increases in vascular permeability, and vessel constriction. These effects from damage combine to produce blood flow stasis.     

“全混式—卷入—轴向循环型”搅拌混合反应器的模型研究

本文是在“模型研究KR法的搅拌混合特性”一文的基础上,应用模型研究了“全混式—卷入—轴向循环型”反应器的混合特性、机械能的输入和流体流动状态等。研究结果表明,在KR装置中,若同时使用适宜的导流板结构,则在很大程度上阻碍了水平径向流动,发展了垂直轴向循环流,使之成为“完全导流板型”的搅拌混合反应装置。与“剪切型”的KR法相比,这种反应器提高了混合效率。其工艺效益表现为达到均匀混合所需搅拌桨转数可以减少,即达到均匀混合速度约可提高55％,在达到相同的混合程度时,搅拌桨旋转速度大约降低50％,输入功率约为KR法的70％,则所需功率消耗可降低30％左右。搅拌时,容器中液面不再升高,从而提高了搅拌容器的有效处理容积。     

太钢RH真空处理

太钢RH真空处理属于冷扎硅钢生产线的配套工程。主要包括：钢包运输及顶升系统、真空系统、吹氧和煤气加热系统、合金系统、真空室等。     

Testosterone stimulates angiogenesis and vascular regrowth in the ventral prostate in castrated adult rats

The castration-induced regression and testosterone stimulated regrowth of the vasculature in the rat ventral prostate lobe were studied using stereological techniques. Seven days after castration, the endothelial cell proliferation rate (bromodeoxyuridine labeling index); the total weights of blood vessel walls, blood vessel lumina, endothelial cells, glandular epithelial cells; and total organ weight were all decreased. Within 2 days after sc treatment with testosterone, the total weights of blood vessel walls, endothelial cells, and vascular lumina, as well as the endothelial cell proliferation rate, were all normalized. In contrast to the rapid response of the vasculature, the total weight of glandular epithelium and total organ weight were not normalized during the 4 days of testosterone treatment. Growth of the vasculature apparently precedes growth of the glandular epithelium. The testosterone- dependent factors stimulating the vasculature are unknown, but factors derived from epithelial cells, mast cells (which accumulate in the prostate during the first day of testosterone treatment), and tissue macrophages could all be involved. Castration-induced regression and testosterone-stimulated regrowth of the prostatic vasculature can be used as an experimental model to study factors regulating angiogenesis and organ growth in the prostate.     

RH真空室更换方式及其选择

真空室更换方式的选择是确定RH工艺布置的必然步骤,针对RH真空室更换的不同方式,进行了对比分析。总结了RH真空室更换方式选择时应遵循的基本原则：国内新建RH通常采用真空室平移式;RH单工位通常配置双室平移更换式,或选用双工位布置;适用于双工位布置的准双室平移式是一种较好折中的更换方式;空室顶部单室平移式优于本体单室平移式;改扩建RH需综合多种因素,创造性地灵活选用。该分析有助于深化对RH工序的理解,为钢铁企业在设计选型时提供依据。     

09MnNiDR钢焊接临界粗晶区冲击脆断行为及焊后热处理工艺

用Gleeble-3800热模拟试验机模拟了09MnNiDR低温压力容器钢焊接临界粗晶区(intercritically reheated coarse-grained heat-affected zone),并对其进行了焊后热处理(post-welding heat treatment)工艺研究。采用力学性能检测及结构表征方法研究了热处理前后焊接临界粗晶区的力学性能及影响机制。试验分析表明,尺寸较大的MA岛(martensite-austenite island)是材料受力时裂纹的启裂源,是引起试验钢焊接临界粗晶区冲击韧性较差的主要原因。经过焊后热处理,临界粗晶区的冲击韧性明显改善,并且热处理温度工艺窗口(560~640℃)较宽。热处理后M-A岛的分解、碳化物的球化及大角度晶界对裂纹扩展的阻碍作用是韧性提高的主要原因。     

Protection of the renal artery in nephron-sparing surgery. I. Pathomorphological study

It is necessary to clamp the renal artery for some time in renal surgery to preserve the organ. Not only the renal parenchyma but also the wall of the clamped renal artery may be damaged due to known ischaemic-reperfusion causes. Regional venous renal hypothermia induced by intracellular solutions (Sacks II, Euro-Collins) could provide protection against damage of the vessel wall caused by reperfusion or clamping in our experiments, in cases of clamping for 30 minutes, probably because it also ensured the cooling of the surface of the vessel wall. Similar vasoprotective effect could be achieved by systematic antioxidant treatment (MTDQ-DS) and regional renal hypothermia given in combination. Harmful effects of 45-minute clamping could be best avoided by applying antioxidant treatment alone. While there were no significant morphological changes in the renal arteries the persistent endothelial damage may trigger further complications like renal ischaemic condition.     

Minimally invasive interventions in heart surgery

Recently a number of minimally invasive surgical techniques have been developed in order to reduce surgical trauma especially to avoid median sternotomy and cardio-pulmonary bypass (CPB). In March 1996 we started successfully a clinical trial with the Port Access technique at our institution for the first time in Europe for the treatment of coronary artery single vessel disease. In addition mitral valve disease, aortic valve disease and ASD were treated successfully with minimally invasive surgical techniques. We developed a new minimally invasive surgical technique (Dresden technique) for the treatment of coronary artery multi vessel disease at our institution. Besides we used several minimally invasive surgical techniques without CPB. Our results indicate that minimally invasive surgical techniques routinely used will decrease the morbidity and time of convalescence after cardiac surgery. These techniques can be applied for a variety of cardiac diseases.