Some blood parameters of water buffalo in different physiological conditions

The Authors have studied the changes of GOT, GPT, ALP, CPK and Se in buffaloes under different physiological conditions (age, diet, different pre and post partum times). 99 adult buffaloes were classified in 8 groups on the basis of different pre, post partum time intervals. Moreover, other 39 animals were divided into 4 groups: A = 60-90 day old animals, fed with reconstituted milk supplemented with Vit E; B = same age, fed with maternal milk; C = 6-8 month old animals; D = 12-18 month old animals. In the various classes of animals blood ALP, GPT, GOT, CPK and Se were monitored. Results showed that the high variability in blood activity of the studied enzymes suggest that in establishing their reference values the physiological condition of the subject and the time interval from the parturition must be taken into account. The fact that Se was not detectable in many pregnant animals suggests that the prevention of myodistrophy in buffalo calves must be effected in prenatal epoch.     

Convective heat-transfer measurements in liquid metals under different fluid flow conditions

In this study an experimental method to measure convective heat transfer characteristics in liquid metals is presented. This method involves the immersion into a metal bath of a solid specimen whose melting point is equal to or lower than that of the metal or alloy in the metal bath, and which will not react chemically with the liquid metal or alloys used. The specimen should have a hollow bore whose opening is held above the surface of the liquid metal; immersion continues until such a time as the liquid metal penetrates the hollow bore. The apparent weight of the specimen is monitored to determine the rate at which the net downward force changes. Experimental results are reported for liquid aluminum, liquid copper, and liquid steel. Those experimental results were conducted under different fluid flow conditions. The applicability of this method to liquid slags is also discussed. Formerly Postdoctoral Research Fellow with the Department of Metallurgy and Materials Science, University of Toronto     

Approximations of open quotient and speed quotient from glottal airflow and EGG waveforms: effects of measurement criteria and sound pressure level

A sample of speech acts in everyday discourse referring to persons or events having to do with the term mental retardation was analyzed in order to investigate the belief that language use both constructs and reflects cultural norms that define the social roles of persons reduced to object status through categorical membership. Speech acts gathered suggest four emergent themes: the discourse of category membership, the dichotomy of normal and abnormal, issues of place and space, and fear. These themes were explicated from a social constructionist perspective, displaying the way speech acts construct mental retardation and subvert individuals with the label into demeaned and ridiculed objects of cultural fear.     

Changes of venous blood flow velocity waveforms in fetuses with supraventricular tachycardia

Studies in the fetal lamb have shown that atrial pacing beyond a rate of 300-320 beats/min may be associated with dramatic changes of venous blood velocity waveforms, an increase of venous pressure by up to 75%, hydrops, polyhydramnios and placental edema. The aim of our study was to determine the 'critical' heart rate frequency in the human fetus. In 11 fetuses (five with and six without hydrops) with supraventricular tachycardia, pulsed wave Doppler analysis of flow velocity waveforms of the inferior vena cava, the ductus venosus and the left hepatic vein were performed before and after drug treatment. In ten cases cardioversion was achieved by in utero antiarrhythmic drug therapy; in one case treated with digoxin and flecainide the supraventricular tachycardia was decreased to 160-190 beats/min with disappearance of hydrops. Before intrauterine treatment of supraventricular tachycardia, pulsatile reversal of blood flow in the inferior vena cava, ductus venosus and left hepatic vein was visible, with monophasic forward flow during systole and reversed flow during diastole in ten of 11 fetuses. One fetus with supraventricular tachycardia of 195 beats/min showed a normal biphasic forward flow pattern. During drug-induced sinus rhythm, a normal biphasic forward venous blood flow pattern was shown in all ten cases. In five cases pulsatile reversal was demonstrated during a drug-induced reduction of the heart rate from 280 to 210 beats/min and a normal biphasic forward flow velocity waveform appeared during supraventricular tachycardia below 210 beats/min.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aluminium scrap melting under different liquid aluminium flow conditions: part-II: two phase flow

This experimental research work deals with aluminium (Al) alloy melting in an Al bath. In this liquid metal, nitrogen gas was introduced at specific locations and at different gas flow rates. The samples employed, along with their position in the liquid Al, and the procedure for melting detection, were identical with the ones utilised in Part I. The introduction of gas into liquid Al has different effects on the melting time of the immersed Al 6061 alloy cylinder. For the range of gas flow rates examined, the addition of gas into a stagnant Al bath (i.e. natural convection conditions) produces insignificant changes in melting time. However, when the liquid Al is moving (i.e. forced convection conditions), the gas addition leads to a sizeable reduction in melting time. The melting time reduction ratio is introduced as a way to compare the melting under single and two phase flow liquid Al conditions. It is found that this ratio is affected by the nozzle position and also by the gas flow rate. The concept of an equivalent single phase velocity is also introduced, and defines the single phase velocity of liquid Al which results in the same melting time of the cylinder as under two phase flow conditions. It is found that the equivalent single phase velocity is influenced by both the gas flow rate and the nozzle position. The parameter which most likely contributes to the acceleration of the melting rate in two phase flow is the turbulence intensity, which is expected to increase due to the nitrogen gas injection.     

Aluminium scrap melting under different liquid aluminium flow conditions: part-I: single phase flow

The melting characteristics of aluminium (Al) scrap were studied in a pilot-scale revolving liquid metal tank (RLMT) which sits in a resistance furnace. Commercially pure Al of about 39?kg was melted in the RLMT. Experiments were carried out in a stagnant and in a revolving Al bath at different liquid metal temperatures and speeds. Cylindrical Al 6061 alloy samples were used in this experimental work. Their melting time inside the Al bath was recorded with a specially designed electrical circuit. Upon immersion of a cold cylindrical sample into liquid Al, a shell solidifies around the specimen and subsequently melts back. The time during which the shell exists around the cylinder is called shell period. The free melting period commences when the shell period ends. The thermal contact resistance (TCR) at the Al shell/cylinder interface affects how long the shell lasts. A methodology was developed to estimate this TCR. The convective heat flux from the Al bath to the cylindrical specimen influences the shell and free melting periods, and is a function of liquid Al temperature and speed. The Part I of this research work presents a baseline of Al melting measurements under single phase flow conditions, that will be compared against two phase flow conditions in Part II of this research.

On a étudié les caractéristiques de fusion de rebut d’aluminium (Al) à l’échelle pilote dans une citerne rotative de métal liquide (RLMT), située dans un four à résistance. On a fait fondre dans la RLMT environ 39?kg d’Al commercialement pur. On a effectué les expériences dans un bain stagnant ou dans un bain rotatif d’Al à diverses températures et à diverses vitesses du métal liquide. Dans ce travail expérimental, on a utilisé des échantillons cylindriques d’alliage d’Al 6061. On a enregistré leur temps de fusion dans le bain d’Al au moyen d’un circuit électrique spécialement conçu. Au moment de l’immersion d’un échantillon cylindrique froid dans l’Al liquide, une coquille se solidifie autour de l’échantillon et subséquemment, fond à son tour. La période durant laquelle la coquille existe autour du cylindre s'appelle la période de coquille. La période de fonte libre commence quand la période de coquille se termine. La résistance du contact thermique à l’interface coquille et cylindre d’Al affecte la durée de vie de la coquille. On a développé une méthodologie pour estimer cette résistance du contact thermique. Le flux de chaleur par convection du bain d’Al à l’échantillon cylindrique influence les périodes de coquille et de fonte libre, et il est une fonction de la température et de la vitesse de l’Al liquide. La première partie de ce travail de recherche présente une ligne de base des mesures de fusion de l’Al sous des conditions d’écoulement monophasé, qui sera comparée à des conditions d’écoulement biphasé dans la deuxième partie.     

Effect of dehydroepiandrosterone sulfate on uterine artery flow velocity waveforms in term pregnancy

OBJECTIVE: To investigate the interrelation between estrogen synthesis by the fetoplacental unit and uteroplacental hemodynamics in term pregnancy. METHODS: Transvaginal color Doppler flow imaging and pulsed Doppler ultrasonographic assessments were made on ten normal full-term pregnant women before and 3, 5, 10, 30, and 60 minutes after the administration of a 200-mg intravenous dose of dehydroepiandrosterone sulfate (DHAS) in 20 mL of 5% dextrose. Ten normal full-term pregnant women received 20 mL of 5% dextrose as controls. The pulsatility index (PI) values for the uterine artery, heart rate, and mean arterial pressure were recorded. Plasma estradiol (E2) was measured before and 10 minutes after the infusion. RESULTS: In the DHAS group, uterine artery PI decreased from baseline by 26% (P < .05) after 5 minutes, and the mean reduction was 36% (P < .05) after 10 minutes and 15% (P < .05) after 30 minutes. The PI returned to the baseline value 60 minutes later. In the control group, there was no change in uterine artery PI. No change was found in heart rate or mean arterial blood pressure in the control or DHAS groups. The mean plasma E2 increased from 22.3 +/- 6.6 to 56.2 +/- 24.1 ng/mL (P < .05) 10 minutes after the infusion in DHAS subjects, whereas there was no significant change in plasma E2 in the controls. CONCLUSION: Dehydroepiandrosterone sulfate induces a significant decrease in the uterine artery PI, which suggests a possible decrease in uterine vascular impedance in term pregnancy.     

Parameterization of the voice source by combining spectral decay and amplitude features of the glottal flow

A new method is presented for the parameterization of glottal volume velocity waveforms that have been estimated by inverse filtering acoustic speech pressure signals. The new technique, Parameter for Spectral and Amplitude Features of the Glottal Flow (PSA), combines two features of voice production, the AC value and the spectral decay of the glottal flow, both of which contribute to changes in vocal loudness. PSA yields a single parameter that characterizes the glottal flow in different loudness conditions. By analyzing voices of 8 speakers it was shown that the new parameter correlates strongly with the sound pressure level of speech.     

Quantitative changes in pharmacodynamic parameters of noradrenaline in different rat aorta preparations: influence of endogenous EDRF

The adaptive nature of taste discrimination has been questioned on the basis that marked differences in taste thresholds for soluble sugars across mammals may not correspond to distinct dietary tendencies and further imply inaccurate prediction of the energetic value of food. Appropriate models of the evolution of taste, however, require not only consideration of adaptations to diet but also recognition of phylogenetic and allometric effects. Here, we analyse these factors in primates exhibiting various diets and covering a wide range of body weights. Taste thresholds for sucrose and fructose are negatively related to body weight overall but are commonly similar in closely related species irrespective of dietary specialisations. By contrast, major interspecific differences in the discrimination of quinine hydrochloride are observed in the absence of any allometric effect. We propose that this asymmetrical differentiation of sweet and bitter taste discrimination reflects divergent evolutionary trends for meeting energy requirements and for avoiding noxious substances.     

Effect of antenatal administration of thyrotrophin releasing hormone on fetal flow velocity waveforms

AIM: To determine whether antenatal administration of thyrotrophin releasing hormone (TRH), to promote lung maturation, alters blood flow through the fetal middle cerebral, umbilical artery, or ductus arteriosus and through the maternal uterine arteries. METHODS: The effect of transplacentally administered TRH on the fetal circulation was prospectively evaluated in 30 patients between 24 and 34 weeks' gestation. TRH (400 micrograms) was given to the mother intravenously either as a bolus or an infusion. Fetal effects were determined by measuring the maximum velocity and pulsatility index (PI) in middle cerebral artery, ductus arteriosus, uterine artery and umbilical artery Doppler waveforms. Measurements were made immediately before, and 10 and 60 minutes after maternal TRH administration. RESULTS: Intravenous injection of TRH had no significant effect on PI in the uterine, umbilical, or middle cerebral artery and the ductus arteriosus within 60 minutes of administration in either group. CONCLUSION: The antenatal use of TRH in conjunction with steroids for fetal lung maturity does not affect utero-placental or fetal haemodynamic variables, as measured by Doppler. These findings, therefore, do not support the suggestion that antenatal intravenous administration of TRH either as bolus or infusion may have immediate adverse vascular effects in the fetus.     

Effect of dehydroepiandrosterone sulfate on fetal middle cerebral artery flow velocity waveforms in term pregnancy

OBJECTIVE: To investigate whether bolus injection of dehydroepiandrosterone sulfate (DHAS) is associated with changes in fetal middle cerebral artery flow velocity waveforms in term pregnancy. METHODS: Ten normal full-term pregnant women received the administration of a 200-mg intravenous dose of DHAS in 20 ml of 5% dextrose. Ten normal full term pregnant women received 20 ml 5% dextrose as controls. Color Doppler flow imaging and pulsed Doppler ultrasonographic assessments were made on fetuses in each group before and 10 min, 30 min, 60 min, 90 min. and 120 min after DHAS or dextrose administration. The pulsatility index (PI) values for the middle cerebral artery, and umbilical artery, and fetal heart rate were recorded. RESULTS: In the DHAS group, middle cerebral artery PI decreased from baseline by 24% (p<.05) after 10 min, and the mean reduction was 22% (p<.05) after 30 min. The PI returned to the baseline value 60 min later. In the control group, there was no change in middle cerebral artery PI. No change was found in umbilical artery PI or fetal heart rate in the control or DHAS group. CONCLUSION: DHAS induces a significant decrease in the fetal middle cerebral artery PI, which suggests a possible decrease in fetal cerebral vascular impedance in term pregnancy.     

A computer-based statistical pattern recognition for Doppler spectral waveforms of intracranial blood flow

The effects of 2 months treatment with simvastatin (40 mg, 20 mg p.o. daily) or placebo on erythrocyte membrane cholesterol content and acyl chain composition have been studied in 36 patients with a clinical history of atherosclerosis enrolled in the Oxford Cholesterol Study. All patients received advice corresponding to a standard phase 1 cholesterol-lowering diet. As expected the mean serum total cholesterol fell substantially (-26.5%, 20 mg simvastatin, P < 0.05; -32.7%, 40 mg simvastatin, P < 0.05) compared to placebo (-6.3%, ns). However, mean erythrocyte cholesterol content did not change significantly in any group (2 months therapy: 20 mg simvastatin, -0.62%; 40 mg simvastatin, +2.2%; placebo, -4.2%). Erythrocyte cholesterol was also unaltered after 5 months of therapy. Erythrocyte osmotic fragility was unchanged in the treatment and placebo groups. In the placebo group dietary advice alone was associated with a significant increase in the linoleic acid content of erythrocytes from 9.4 mole% of total acyl chains to 11.8 mole% (P < 0.05). Treatment with simvastatin was associated with an increase in the arachidonic acid content of the erythrocyte membrane from 12.2 to 15.3 mole% (P < 0.05). Treatment with simvastatin does not alter erythrocyte cholesterol content, but does alter acyl chain distribution. These results suggest that the chemical potential of cholesterol in serum is not markedly altered by HMG-CoA reductase inhibition.     

Doppler flow velocity waveforms of the umbilical arteries correlate with intravillous blood volume

OBJECTIVE: My purpose was to measure the volume of the fetoplacental vessel tree and to relate findings to Doppler flow patterns of the umbilical arteries. STUDY DESIGN: One hundred sixty placentas were examined by means of standardized random block placental histomorphometry after delivery and the results were compared with antenatal Doppler findings. RESULTS: There was a high correlation (r = -0.703) between the intravillous blood volume obtained from measurements of intermediate and terminal villi and the Doppler flow velocity waveforms detected within the last week before delivery. Moreover, the reduced size of a vessel tree less than 85 mL is highly predictive of perinatal complications, such as fetal growth restriction, low umbilical artery pH values after birth, reduced Apgar scores, and cesarean section for fetal distress. CONCLUSION: These data suggest that reduced end-diastolic flow velocities in the umbilical arteries are associated with elevated fetoplacental impedance owing to reduced vascularization of intermediate and terminal villi.     

Validation of volume flow measurements with cine phase-contrast MR imaging for peripheral arterial waveforms

Shock wave lithotripsy (SWL) has made a revolution in the treatment of urolithiasis. Recent reports suggesting that stone features for SWL have changed during the last years have forced us to compare our initial and last 250 patients treated at our ESWL unit in terms of stone and patient characteristics. We found that the number of ureteric stones and small calyceal stones have increased significantly with time whereas the number of larger stones undergoing SWL has decreased significantly. We believe that this change in stone features is caused by the changing trends in the treatment of stone disease by incorporating other therapeutic options and modifying the SWL indications according to patient characteristics We also believe that prophylactic lithotripsy for asymptomatic calyceal stones still remains to be a debatable issue.     

Design and calculation of gas property parameters for constant area lance under conditions of friction flow with heating

Abstract

Formulae for calculating the outlet property parameters of gas heating and friction streams in tubular and annular type lances with constant area (tuyeres) are given, and have been applied to the case of an annular type used for an AOD (argon–oxygen decarburisation) vessel of 18 t capacity. The distributions of both the inner wall temperatures of the tuyere and the gas stagnation temperatures along its length have been more reasonably fixed. The friction factors for the gas flows through the main and subtuyeres during blowing refining have been determined by comparison of the practically measured P–Q relationships with the results from trial calculations. The outlet parameters of the gas streams for the central tube (main tuyere) and annular slit pipe (subtuyere) of the tuyere have been calculated. The influences of the gas supply pressure, the length and diameter of the tuyere, and the type and composition of the gases, as well as the heating effect, on the gas outlet parameters have been considered. The results obtained may be expected to offer useful information and a reliable basis for tuyere design and determination, control, and optimisation of the gas blowing parameters and technology, as well as for the investigation of hydraulic modelling of the blowing processes.     

Effects of oophorectomy and hormone replacement therapy on ophthalmic artery blood flow velocity waveforms

Our objective was to compare ophthalmic artery flow velocity waveforms in unilateral oophorectomized patients not on hormone replacement therapy with findings in bilateral oophorectomized patients on hormone replacement therapy. Ten patients who underwent hysterectomy and unilateral oophorectomy and 10 women treated by hysterectomy and bilateral oophorectomy were studied using color and pulsed Doppler ultrasonography 1 day before and on days 7 and 28 after surgery. Serum estradiol levels were measured serially. Bilateral oophorectomy patients were given hormone replacement therapy (conjugated estrogen, 0.625 mg/day, and medroxyprogesterone acetate, 2.5 mg/day) orally starting on day 8 after surgery. The pulsatility index values of the ophthalmic artery in unilateral oophorectomy patients were 1.93 +/- 0.41, 2.10 +/- 0.26, and 1.68 +/- 0.27 for 1 day before and on days 7 and 28 after surgery, respectively. The pulsatility index values of the ophthalmic artery in bilateral oophorectomy patients were 1.99 +/- 0.39, 2.17 +/- 0.47, and 1.75 +/- 0.32 for 1 day before and on days 7 and 28 after surgery, respectively. No significant differences were found between pulsatility index values in the unilateral and bilateral oophorectomy patients in each time period. The pulsatility index values on day 28 decreased significantly compared with the findings on day 7 in both groups (P < 0.05). The serum estradiol levels were significantly reduced from 1 day before to day 7 day after surgery and were significantly elevated by day 28 after surgery (P < 0.05) in both groups of patients. No significant differences were found between the serum estradiol levels in the unilateral and bilateral oophorectomy patients in each time period. Vascular tone in the ophthalmic artery seems to change according to serum estradiol levels, a finding that may help explain some of the beneficial effects of hormone replacement therapy for bilateral oophorectomized patients.