Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting

Distribution of gasses to the cast volume and volume of pores can be maintained within the acceptable limits by means of correct setting of technological parameters of casting and by selection of suitable structure and gating system arrangement. The main idea of this paper solves the issue of suitability of die casting adjustment—i.e., change of technological parameters or change of structural solution of the gating system—with regards to inner soundness of casts produced in die casting process. Parameters which were compared included height of a gate and velocity of a piston. The melt velocity in the gate was used as a correlating factor between the gate height and piston velocity. The evaluated parameter was gas entrapment in the cast at the end of the filling phase of die casting cycle and at the same time percentage of porosity in the samples taken from the main runner. On the basis of the performed experiments it was proved that the change of technological parameters, particularly of pressing velocity of the piston, directly influences distribution of gasses to the cast volume.     

县级以下综合医疗机构医务人员对现代结控知识的认识现状调查

目的本文旨在了解医务人员现代结控知识掌握的现状及培训效果?方法于培训前后进行问卷调查,内容包括:病例发现?结核病诊断及化疗?结果培训前疫情报告和转诊,回答正确者占75.2%?71.7%;对临床表现?查痰和诊断依据,回答正确者占83.5%?42.5%?40.8%;抗痨药物?用药方法?化疗原则?短化方案?短化疗程?治愈标准六项,回答正确者占58%?14.4%?20.8%?9.2%?17%?24.3%?培训后再次调查发现,90%以上医务人员对现代结控基本知识已掌握?结论各级医务人员现代结控知识是很贫乏的,因此,对其进行系统培训是极为必要的,此项工作省时?省力?投入少,可收到事半功倍的效果。     

Weighing the QT Intervals with the Slope or the Amplitude of the T Wave

Objective: The reproducibility of QT interval measurements is low, even for the mean QT interval based on the standard ECG. In this study we analyzed whether the reproducibility of the mean weighed QT interval was better than the simple mean QT interval. The weighing was based on the amplitude of the T wave or the slope of the steepest tangent on the terminal part of the T wave. Material and methods: 12‐lead ECGs of 130 postmyocardial infarction patients were obtained. The QT intervals were measured by the tangent‐method on two occasions by the same observer Mismatch QT intervals were defined as QT intervals that were measured at only one occasion. Sixteen ECGs were rejected. The data were split into 34 and 80 ECGs for optimization and validation of the weighing, respectively. The weighed QT dispersion was calculated as the weighed mean of the three longest minus the weighed mean of the three shortest QT intervals. Results: Weighing with the slope increased the reproducibility by 41% (P = 3 10^‐6), but weighing with the amplitude reduced it by 20% (P = 0.02). However, if measurements with errors above 75 ms were rejected, weighing with the slope or the amplitude increased the reproducibility with 26% and 20% (P = 0.02), respectively. Weighing did not change the reproducibility of the weighed QT dispersion. Conclusion: Weighing with the slope improved the reproducibility of the mean weighed QT interval. However, if measurements with errors above 75 ms were rejected, weighing with the amplitude also increased the reproducibility. Weighing did not change the reproducibility of the weighed QT dispersion. Weighing is particularly efficient at reducing the negative impact of mismatch QT intervals on the reproducibility. A.N.E. 2002;7(1):4–9     

大骨节病病区水,粮实验对动物的骨和软骨中化学元素组成的影响

用质子激发 X 线荧光分析方法(PIXE)测定了大骨节病病区和非病区的水、粮以及用该水粮喂养的大白鼠的肋软骨和硬骨中22种化学元素的含量。结果发现水粮中存在差异的元素反应在用该水粮喂养的大白鼠的骨、软骨中也存在差异,含量都低的元素有 P、Mn、Cu、As、Zn。都高的有铅。其中锌低在水、粮、硬骨和软骨中都完全一致呈非常显著性差异(p<0.01)。提示病区水、粮中化学元素对骨质的影响不是单一元素缺乏或过多所致,而是多种元素的复合因素。     

Assessment of the Soft-Tissue Seal at the Interface between the Base of the Fixed Denture Pontic and the Oral Mucosa

Fixed dentures (bridges) are often selected as a treatment option for a defective prosthesis. In this study, we assess the contact condition between the base of the pontic and oral mucosa, and examine the effect of prosthetic preparation and material biocompatibility. The molars were removed and replaced with experimental implants with a free-end type bridge superstructure after one week. In Experiment 1, we assessed different types of prosthetic pre-treatment: (1) the untreated control group (Con: mucosa recovering from the tooth extraction); (2) the laser irradiation group (Las: mucosa recovering after the damage caused by a CO₂ laser); and (3) the tooth extraction group (Ext: mucosa recovering immediately after the teeth extraction). In Experiment 2, five materials (titanium, zirconia, porcelain, gold-platinum alloy, and self-curing resin) were placed at the base of the bridge pontic. Four weeks after the placement of the bridge, the mucosa adjacent to the pontic base was histologically analyzed. In Experiment 1, the Con and Las groups exhibited no formation of an epithelial sealing structure on the pontic base. In the Ext group, adherent epithelium was observed. In Experiment 2, the sealing properties at the pontic interface were superior for titanium and the zirconia compared with those made of porcelain or gold-platinum alloy. In the resin group, a clear delay in epithelial healing was observed.     

高胆红素血症对肿瘤标志物测定的影响探讨

目的探讨高胆红素血症对Ca19-9、Ca24-2和CEA检测的影响.方法对320例胆管、胆囊良恶性疾病病人,15例胆囊炎病人的胆汁和血清以及10例肝硬化、10例黄疸肝炎病人进行Ca19-9、Ca24-2和CEA检测.结果在良性胆管、胆囊疾病中,Ca19-9的假阳性最高;在胆红素增高的良性疾病中,Ca19-9假阳性率达46.7%;15例胆汁和血清以及10例肝硬化和10例黄疸肝炎病人中,Ca19-9的假阳性率分别为93%、20%、80%和80%.结论高胆红素血症对Ca19-9检测影响最明显,胆囊、胆管良恶性疾病鉴别时,以Ca24-2和CEA检测为佳.     

Hepato-pancreato-biliary fat: the good, the bad and the ugly

Obesity has become epidemic in the United States, in Europe, and in many urban areas in the developing world. The globalization of certain 'fast foods' and 'soft drinks' may, in part, be contributing to this epidemic. Diets high in saturated fatty acids and trans fats as well as drinks that have high fructose corn syrup levels may be particularly harmful. Recent research suggests that fat is a dynamic endocrine organ and that visceral fat is associated with the metabolic syndrome. Central obesity leads to organ steatosis and altered serum adipokines including reduced adiponectin and markedly elevated leptin. This abnormal adipokine milieu results in increased tissue infiltration of monocytes and macrophages which produce proinflammatory cytokines that alter organ function. Over many years, the combination of steatosis and local inflammation leads to fibrosis and eventually to cancer. Nonalcoholic fatty liver disease (NAFLD) is a precursor for nonalcoholic steatohepatitis (NASH). NAFLD and NASH (1) lead to cirrhosis and hepatocellular carcinoma, (2) increase the risk of liver resection, and (3) compromise the outcome of liver transplantation. Similarly, in the pancreas nonalcoholic fatty pancreas disease (NAFPD) may lead to nonalcoholic steatopancreatitis (NASP). NAFPD and NASP may (1) promote the development of chronic pancreatitis and pancreatic cancer, (2) exacerbate the severity of acute pancreatitis, and (3) increase the risk of pancreatic surgery. In the gallbladder nonalcoholic fatty gallbladder disease (NAFGBD, cholecystosteatosis) may lead to steatocholecystitis. Cholecystosteatosis may be an explanation for (1) the increased incidence of chronic acalculous cholecystitis and (2) the increased number of cholecystectomies.     

Further Studies on the Noradrenergic and the Renin Angiotensin Systems in the Brain of the Rat

Previous investigations have shown that depletion of brain norepinephrine (NE) induced by chemical sympa thectomy resulted in significant changes in the central renin-angiotensin system. The purpose of the present work was to increase the NE concentration in the central nervous system (CNS) in order to analyze its effect on the peptidergic complex and on the blood pressure (BP) levels. Treated rats were given the following drugs in the drinking water: 1-dopa (12 mg/rat/day), carbidopa (6 mg/rat/day) and pargyline (10 mg/rat/day) during 25 days. BP was determined, blood and cerebrospinal fluid (CSF) samples were obtained. The CNS was dissected into several areas. NE, angiotensinogen (AoC) and renin concentration (RC) were determined in the brain parenchyma; AoC was evaluated in CSF and plasma samples. Pharmaco-logical treatment resulted in an hypotensive effect and, at the same time, an increase of NE in the CNS (about 100 %; pCO .0005). These changes were accompanied by a significant decrease in the peripheral and central AoC. These results add new evidence to the postulated relationship between these two important regulatory systems involved in cardiovascular control.     

慢性氟中毒大鼠肝脏损伤机制及抗氧化中药的拮抗作用

目的 研究实验性氟中毒时肝脏自由基代谢及超微结构的变化，探讨氟中毒时自由基在肝脏损伤机制中的作用。方法 用Wistar大鼠复制出慢性氟中毒模型，每日腹腔注射丹参-绞股蓝中药复方制剂，6个月后处死。用电子自旋共振法及其他常规方法检测肝组织自由基代谢水平，用体视形态学分析肝组织超微结构的变化。结果 染氟大鼠自由基、丙二醛增高；SOD及GSH-Px活性降低；电镜观察线粒体肿大、体积密度和表面积密度增加；而抗氧化治疗组各项指标与正常组无明显差异。结论 氟中毒引起的肝脏损伤可能是通过自由基水平增高诱发脂质过氧化所致损伤。     

On the track to the beta-cell

Abstract The imaging and quantification of the endocrine pancreas by a non-invasive procedure remains a challenge. In the prolongation of prior work on selected succinic acid esters and monosaccharide esters, it is proposed that d-mannoheptulose, which might be transported across the plasma membrane at the intervention of GLUT-2, could be used to label preferentially the endocrine moiety of the pancreatic gland. This heptose is taken up more efficiently by hepatocytes and islet cells, than by erythrocytes, parotid cells, acinar pancreatic cells or tumoural islet cells of either the RINm5F or INS-1 line. Likewise, d-mannoheptulose only inhibits d-glucose metabolism in hepatocytes and isolated islets. Its hexaacetate ester, however, inhibits the catabolism of the hexose in all cell types. The uptake of d-mannoheptulose represents a carrier-mediated process. Human islets behave like rat islets in terms of D-mannoheptulose uptake and inhibition by the heptose of both D-glucose metabolism and insulinotropic action. The use of radiolabelled analogs of D-mannoheptulose suitable for imaging of the endocrine pancreas is discussed. In the same perspective, it is proposed that advantage could be taken of the much greater accumulation of glycogen in insulin-producing cells, as compared to other pancreatic cell types, in situations of sustained hyperglycaemia. [Diabetologia (2001) 44: 393–406]     

特应性与非特应性哮喘的发病机制研究

目的研究炎症细胞及其相关细胞因子、炎性介质在哮喘发病中的作用及相互关系，探讨特应性与非特应性哮喘的发病机制。方法对36例哮喘患者和12例健康者（对照组）进行痰液诱导，对其痰液中的中性粒细胞、嗜酸粒细胞数及白介素4（IL-4）、IL-5、IL-8、髓过氧物酶（MPO）进行检测。结果哮喘组中重度患者痰液中嗜酸粒细胞和中性粒细胞数均高于轻度患者及对照组。IL-4和IL-8水平除缓解期患者与对照组比较无统计学差异外，其余均有统计学意义（P〈0．05）。哮喘组中重度患者MPO与其余比较有统计学差异；哮喘组轻度患者与对照组比较统计学差异显著（P〈0．01）。结论特应性哮喘的发病机制与诱导痰中嗜酸粒细胞数相关；非特应性哮喘与中性粒细胞数相关。     

On the Role of the Septal Area in the Development of Doca-Salt Hypertension in the Rat

The extensive destruction of forebrain noradrenergic nerve terminals by the intraventricular injection of 250 μg of 6-hydroxy-dopamine prevents the subsequent development of DOCA-salt experimental hypertension in rats while the lesser destruction of noradrenergic nerve terminals produced by 90 μg of 6-hydroxydopa does not. The greatest difference in brain part noradrenaline levels between these two neurotoxins was in the septal area where noradrenaline was less than 15% of controls after 6-hydroxydopamine but was the same as controls after 6-hydroxydopa. The non-specific destruction of the lateral septal area by radiofrequency lesions prevented the subsequent development of DOCA-salt hypertension. The relatively selective destruction of catecholamine nerve terminals in the lateral septal area by the injection of 1 μg 6-hydroxydopamine in 1 μl vehicle also prevented the development of DOCA-salt hypertension. These data suggest that the lateral septal area may be the location of the forebrain catecholaminergic neural activity that is necessary for the development of DOCA-salt experimental hypertension in rats.     

Echocardiography in the Emergency Department: From the Perspective of the Emergency Physician and the Cardiologist

Echocardiography performed in the emergency department must adapt to this new setting for noninvasive diagnostic testing. Emergency physicians require echocardiography to provide rapid diagnosis in life-threatening emergencies. New initiatives are being proposed by emergency physicians in the delivery of this test. Cardiologists now use echocardiography in the emergency-department to make the diagnosis of heart disease earlier and with greater accuracy.     

Letting the Inmates Run the Asylum

No abstract available for this article.     

Tracing the protectors path from the germ line to the genome

One of the basic principles that nature uses in evolution is to recycle successful concepts and create new functions by modifying existing units. This conservatism in evolution has resulted in an astonishingly high sequence identity of genes, even between evolutionarily distant species such as the nematode Caenorhabditis elegans and Homo sapiens. The recycling of successful concepts in conjunction with gene duplication events has also led to the existence of highly homologous proteins within the genome of many species. Often, these homologous proteins show similar, yet distinct functions that, in combination with their individual tissue distribution, define their specific physiological role. One prominent example is the p53 protein family, which consists of p53, p63, and p73. Recent advances in understanding the specific biological functions of these members have shed some light onto the evolution of this crucial protein family, from a germ line-specific quality-control factor to a somatic tumor suppressor. Furthermore, structures of the oligomerization domains of the mammalian paralogs, p53 and p73, and invertebrate orthologs, CEP-1 and DMP53, have delineated evolutionary changes and revealed that the oligomerization domain of p53 lacks additional stabilizing structural elements present in all other p53 family members. This suggests that p53 is the most recent evolutionary member of this protein family and predicts a mechanism for p53 activation.