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。     

Influence of the viscosity of the swallowed food bolus on the motility of the pharynx

In 9 young men, healthy volunteers, we studied the effect of dry swallows, liquid and paste swallows on the pharyngeal motility. The viscosities of liquids and past were 200 centipoise (cP), 300 cP and 60000 cP, respectively. The bolus volume was 10 ml. For pharyngeal manometry we used two strain-gauge manometric probes taped together, so that a total of six transducers were staggered at 1.5 cm intervals. After its passage through the nose, the assembly was positioned so that all its transducers faced posteriorly, and manometric activity was recorded from oropharynx, hypopharynx and upper esophageal sphincter (UES). We also recorded infra-hyoid electromiographic activity. The amplitude and duration of the oropharyngeal and hypopharyngeal peristaltic pressure complex were not changed by the different boluses. The velocity of peristaltism propagation between oropharynx and UES was slower for paste than for liquids or dry swallows. The increased of viscosity was associated with longer duration of UES relaxation, and greater intrabolus pressure in hypopharynx and UES. The infra-hyoid electromiographic activity was longer for paste than for liquids or dry swallows. These findings suggest that pharyngeal motility is affected by the characteristics of the swallowed bolus.     

Characterization of the beta-adrenoceptor of the adipose cell of the rat

The dose-response curves of the beta-adrenergic agonists isoprenaline (mixed beta 1 and beta 2), prenalterol (beta 1-selective), noradrenaline (more beta 1 than beta 2) and salbutamol (beta 2-selective) were studied on adipose cells of the rat, in vitro. The observed lipolytic potencies were in the order: isoprenaline greater than noradrenaline greater than salbutamol greater than prenalterol. The effects of beta-adrenergic antagonists betaxolol (beta 1-selective) propranolol (non-selective) and ICI 118551 (beta 2-selective) on lipolysis stimulated by the various beta-adrenergic agonists showed that in each case propranolol was the most potent blocking agent. These observations are not compatible with the concept that regulation of lipolysis in adipose tissue is mediated exclusively either by adrenergic receptors of the classical beta 1 type, or of the classical beta 2 type. We propose therefore, that this beta-adrenergic receptor, because of its non-compliance with the current classification system, be termed a 'beta-3' or beta-hybrid' adrenoceptor. Thus cardio-selective beta-adrenergic blocking agents, like betaxolol, may offer a hitherto unrecognized clinical advantage in obese patients undergoing anti-hypertensive therapy by offering a reduced impediment to hormone-induced utilization of calorie stores in adipose tissue.     

On the explanation of the changes in age of the concentration of the death causes

The high concentration of the diagnoses among the categories of death causes is called the concentration of death causes. The idea of diversity used in statistical ecology is in a sense a contrary concept. Introducing the investigation of diversity indices on epidemiological material, we have shown sexual differences and age characteristics of the latter. In the course of the investigations, there was an opportunity to measure exactly and analyse the high increase of the concentration of death causes at an older age. In this paper we related the changes due to age to the structure of the set of specific death rates and to that of hazard functions. According to our fitting investigations, the majority of the elements of the set of curves could be well approximated by the Gompertz or by the Weibull function. In this case, a mathematical explanation can be given to the increase, then decrease of Hill's diversity indices, that is, to the decrease, than increase of the concentration of death causes. Finally we point briefly to the evolutionary aspects of the discussed changes with age of this concentration.     

A comparison of the count of Opisthorchis in the body of the host and of the eggs eliminated with the feces

The study of the intensity of Opisthorchis infestation by counting the amount of the parasites in the liver of 62 corpses and 12 cats and the quantity of the parasite's eggs per g feces was carried out. Furthermore, the number of the eggs depending on the intensity of the infection was counted. The fact of irregular distribution of eggs in the colon content and the lack of correlation between the quantity of parasites in the liver and egg contents per g was revealed. An increase in egg production in cases with severe pathology independent of its form was observed in spite of low intensity of invasion.     

The determination and the significance of the areas of the ventricular deflections of the electrocardiogram

By measuring the areas of the ventricular deflections of the electrocardiogram it is possible to determine the mean electrical axis of QRS, which gives the direction in which the excitatory process spreads over the average element of ventricular muscle, and the mean electrical axis of T, which gives the inverse of the direction in which the recovery process spreads over the average element of ventricular muscle.If all the ventricular muscle passed through the period of excitation in the same time and in the same way, the area of QRS and the area of T would be equal in absolute magnitude, but opposite in sign, and the area of QRST would be zero. The area of QRST is a measure of the electrical effects produced by local variations in the excitatory process. The mean electrical axis of QRST gives the direction of the line along which these local variations are greatest.The local variations in the excitatory process which determine the mean electrical axis of QRST are dependent upon factors that act upon different parts of the ventricular muscle with different intensities. They are not materially influenced by the course of the excitatory process over the ventricular muscle.     

Recording the electrogram of the sinus node. Effects of the injection of tetrodotoxin into the artery of the sinus]

The cells of the SA node (SAN) are very resistant to the action of tetrodotoxine (TTX), a drug which. paradoxically, blocks depolarisation of the outer myocardial cells. Injection of TTX into the artery of the SAN brings about asystole; bur regular electrical activity, consisting of a slow wave of 200 to 300 ms duration, can still be picked up by an electrode placed on the SAN. This electrical activity, which can only be picked up over the SAN, and is resistant to TTX but blocked by acetylcholine, is interpretated as being the electrogram of the SAN. After the artery has been washed out by normal saline, the effect of TTX becomes progressively less; under these conditions, all degrees of sino-atrial block can be observed. Arising from a study of the phenomena of capture of the SA and AV nodes, of the effect of artrial stimulation, and of the time relationships between the various electrical events recorded, some hypotheses of the electrophysiology of the SAN and the sino-atrial conduction are put forward.     

The characteristics of the circulation of the causative agent of opisthorchiasis in the tributaries of the Ob

Opisthorchiasis morbidity is reviewed in the area of the Vasyugan River, an Ob tributary. Intermediate hosts have been found in 3 settlements situated at various distances from the ostium. The infestation of intermediate and additional hosts with Opisthorchis larvae is investigated. The above data and the results of previous population surveys (establishing infestation and contamination) served the basis for elucidating the nature of helminth circulation on the territory along the Vasyugan River. The role of infected fish migration is discussed as a source of human infection in areas where helminth circulation is altogether absent or is at an extremely low level.     

Preservation of the pylorus and resection of the head of the pancreas

The historical evolution of the pylorus-preservation resection of the head of the pancreas is traced from the first resections early in this century to relative standardization of the operation, to a lowering of the operative mortality, and to an interest in improving nutritional status after resection. There are many theoretical advantages for the function of the upper gastrointestinal tract after pylorus and gastric preservation, such as maintenance of gastric capacitance and equilibration of osmotic pressure in gastric digestants, foodstuff digestion and absorption, and bowel motility. After the pylorus-preserving resection, gastric emptying is normal, pyloric function to prevent duodenal reflux is often normal, and gastric acids and serum levels of duodenal hormones are at normal levels, whereas after standard pancreatoduodenectomy, all of these are often abnormal. No prospective blinded studies have been published comparing nutritional values after the two operative procedures, but evidence is presented of a satisfactory result with regard to gastric capacitance, body weight gain, and lack of postgastrectomy symptoms. An undoubted advantage of the pylorus-preserving feature is a simplification of the operation. These gains are achieved without increase in operative mortality, without increase in the incidence of jejunal ulcer, and without theoretical or actual decrease in value of the procedure as a cancer operation, except in patients with duodenal carcinoma proximal to the ampulla of Vater.     

Studies of the vascular anatomy of the mesorectum support the concept of the total mesorectal excision

The relation between the mesorectal vessels and the mesorectal fascia needs to be clarified, as a total mesorectal excision (TME) probably derives its advantage from the fact that the visceral or mesorectal fascia can be regarded as a “tumor-tight packaging” and does not contain anatomically preformed perforations. The purpose of this investigation was to study both rectal arterial supply and vascular distribution pattern within the mesorectum. The arterial supply to the rectum was studied with the injection technique in 12 porcine and 28 human TME specimens. We stain-marked 12 porcine and 15 human specimens. Thirteen human specimens were angiographed after filling their arterial bed with a radio-opaque substance. The superior rectal artery is the main rectal artery. Terminal branches extend downwards and forward around the rectum to the level of the levator and muscle. The superior rectal artery and vein were found to be enclosed in a fibrous sheath. The main mesorectal vessels do not penetrate the mesorectal fascia. This study supports the hypothesis of bilateral somatic and one central visceral compartment in the pelvis and implies the absolute necessity of tumor removal within an intact mesorectal fascia. Received: 15 August 2000 / Accepted in revised form: 1 October 2000     

Analysis of the differing mechanisms of action of the vagus nerves on the work of the heart

Mechanisms of cardiac acceleration in response to vagal stimulation under some experimental conditions were investigated. The stimulation of one (left or right) or both vagal nerves in pigeons was not shown to produce the acceleration phenomenon either in the presence of atropine effects and stimuli of varying intensity, or with weak and sparse stimulation of intact pigeons.     

Update of the economic analyses of the use of the colony-stimulating factors

The colony-stimulating factors have been used effectively in a variety of clinical settings to prevent febrile neutropenia and to assist patients receiving dose-intensive chemotherapy with or without stem cell support. Several studies have confirmed the clinical efficacy of the colony-stimulating factors used prophylactically in both solid tumors and the hematologic malignancies. The cost of these agents, along with their large scale clinical use, has prompted a number of economic investigations. Economic analyses based on measures of resource utilization derived from randomized clinical trials have provided febrile neutropenia risk threshold estimates for the cost saving use of prophylactic colony-stimulating factor. A number of important studies concerning the clinical and economic impact of these agents have been reported over the past year. These include a revised cost minimization study based on improved febrile neutropenia cost information and a cost-effectiveness analysis in the adjuvant breast cancer setting based on a clinical prediction model to select patients at high risk for neutropenic complications. Continuing clinical and economic evaluation along with updating of clinical practice guidelines is needed due to rapid technologic and clinical advances in this area.     

Involvement of the ventromedial part of the midbrain in the control of the proestrous surge of gonadotropins and prolactin in the rat

To determine the involvement of the midbrain in the control of the proestrous surge of gonadotropins and prolactin, various transections were acutely placed in proestrous rats. Half-dome shaped transections which interrupted the neural fibers in the ventromedial part of the midbrain (VMM transection), as well as lesions in the ventral tegmental area, blocked ovulation and the proestrous surges of gonadotropins and prolactin whereas sham transections or the other transections, either dorsal or lateral to VMM transections, had no effect on ovulation. VMM transections, however, affected neither the postcastration rise in serum gonadotropins in males nor the secondary rise in serum FSH in estrous females. These results suggest that in the ventromedial part of the midbrain there exists a common neural mechanism which controls the proestrous surges of gonadotropins and prolactin.     

Molecular mechanisms of the effect of neurogenic dystrophy of the kidneys in the rat on the sensitivity of the organ to aldosterone

The effect of reflex and denervated dystrophy of the rat kidneys on the interaction of aldosterone-3H with specific cytoplasmic receptors and nuclei of this organ was investigated in vitro and in vivo experiments. It was found that reflex dystrophy decreases the intensity of hormone binding with cytoplasmic receptors by 36% and aldosterone-3H accumulation in the renal nuclei by 51%. The influence of denervated dystrophy of the organ specific hormone accumulation in the same subcellular fractions was not observed. The more accurate data on the effect of renal reflex dystrophy on aldosterone-3H-receptor interaction were obtained in vivo experiments comparatively to those in vitro.     

Morphometry of the intestine of the pig

Weight measurement of the gastrointestinal organs (GIT) and morphometric measurements of circumsections of the small intestine (SI) have demonstrated profound responses to the level of dietary intake. The average response of pigs (all the same live body weight) gaining weight at a moderate rate (treatment LH) relative to pigs losing weight (HL) were as follows (+ denotes increase): GIT weight, +71.5%; SI weight, +84.8%; tissue fraction of SI mucosa, +16.0%; index of quantity of mucosa per SI circumsection, +64.7%; estimate of the mass of mucosa in the whole SI organ, +108%. Although the composition of circumsections from duodenum, jejunum, and ileum differed substantially and significantly, the effects of treatments were similar at each site. Of the 542-g response (LH vs HL) of the small intestine, estimates calculated from circumsection morphometry data indicate that 55 g, 11 g, and 476 g were from muscle, matrix, and mucosa, respectively. Changes in the size of the circumsection were much greater than changes in composition. The shift in the quantity of mucosa in the circumsection was about fourfold greater than would have been predicted from the tissue fraction of mucosa. The relationship between the morphometric responses and biochemical functions of the mucosa are important to understand digestive-absorptive capacities and nutrient requirements during and immediately after a major shift in food intake.     

Evaluation of the prevalence of helminthiasis among the population of the Republic of Tajikistan

Helminthological examinations of 2629 persons of different ages have shown that the prevalence rate of soil-transmitted helminths averages 54.24% of the examinees. There isa high rate of helminthiasis in the examined dwellers from two districts (Vanch and Faizobod) in the foothill and mountain zones (78.23% and 67.5%, respectively) and its low rate in the Murgab district in the high-altitude area. The non-observance of personal hygiene and sanitary standards and the use of water from open contamination-unprotected water sources contribute to intensive invasion of the population with helminthes.     

Evaluation of contractile state of the left ventricle from the peak of the first derivative of the apexcardiogram

Simultaneous records of the electrocardiogram, phonocardiogram, apexcardiogram (ACG), and the first derivative of the apexcardiogram ($\text{dA}\text{dt}$) were obtained in 50 normal subjects and in 38 patients with ischemic heart disease. This allowed us to measure the ratio of peak $\text{dA}\text{dt}$ to total amplitude of the first derivative in percent and the interval from electrical stimulation to peak $\text{dA}\text{dt}$ (R to peak $\text{dA}\text{dt}$). In 16 additional normal subjects the effects of pharmacological agents with positive and negative inotropic action were studied with the above parameters. During isoprenaline infusion the ratio of peak to total amplitude $\text{dA}\text{dt}$ was increased and the interval R to peak $\text{dA}\text{dt}$ was shortened, while after propranolol the ratio of peak $\text{dA}\text{dt}$ diminished and the interval R to peak $\text{dA}\text{dt}$ showed elongation.In normal subjects the ratio of peak $\text{dA}\text{dt}$ averaged 48 ± 14% and it is significantly lower in patients with ischemic heart disease (32 ± 13%, p < 0.001). In controls the interval R to peak $\text{dA}\text{dt}$ was 73 ± 15 msec., whereas in ischemic heart disease it showed elongation (121 ± 15 msec., p < 0.01).It is concluded that the ratio peak $\text{dA}\text{dt}$ and the interval R to peak $\text{dA}\text{dt}$, expressing noninvasively the rate of pressure changes and the duration of the development of maximum tension during isovolumic contraction, provide useful information on left ventricular function.     

Preservation of the pylorus in resection of the head of the pancreas

Pylorus preservation has been advocated to decrease the morbidity associated with the classical or standard pancreaticoduodenectomy. The proposed advantages are decreased incidence of peptic ulceration, dumping syndrome, and nutritional problems. However, after an initial period of enthusiasm for the procedure, it is now being found that marginal ulceration at the duodenojejunal anastomosis is encountered with increasing frequency. Delay in gastric emptying occurs frequently, with an overall incidence of 30%. With the availability of better pancreatic enzyme supplements, the current incidence of nutritional problems and weight loss after the standard Whipple procedure is unknown. Whether there is a difference in long-term survival after the two procedures performed for adenocarcinoma of the head of the pancreas is still debatable. A controlled trial is needed to answer many of these questions, and pylorus-preserving pancreaticoduodenectomy should be used cautiously until further data become available.     

Morphometry of the intestine of the pig

A method and scheme are described to improve precision for quantitation of functional aspects of the intestine by morphometric evaluation of a representative sample hereafter called a circumsection. A circumsection is defined as: all tissue lying within the total circumference of a slice of the intestinal wall transected at a right angle to the long axis of the intestine tube. The quantitative values obtained from these substantial specimens therefore provide a basis for reliable estimations of the organ content of specified cellular masses or of functional surfaces, ie, villi volume, epithelial surface, crypt mass, muscle mass, etc. The volume, mass, or area of specialized cells can be compared with physiological functions and capacities. These comparisons and relationships are important to investigate the causes and effects of digestion-absorption parameters on performance output of healthy animals-growth, development, reproduction, lactation, work output, etc. The data can also describe responses of the digestive organs (tissues) to various inputs-dietary, environmental, chemical, and physical. The method involves analysis of a montage of photomicrographs of the circumsection. The method was successful; the data collected demonstrated that the small intestine of the pig has lateral symmetry (left vs right) but is asymmetrical in the opposite plane (mesenteric vs antimesenteric). The asymmetry is especially clear in the ileum and jejunum where significant differences between opposite halves ranged from 7% to 90% of the mean value.