Synthesis of submicron barium carbonate using a high-gravity technique

The purpose of this study was to build a platform for producing fine particles by applying a high-gravity (higee) technique to achieve reactive precipitation. Barium carbonate was chosen as a model compound and was produced in a spinning disk reactor (SDR), which is one type of higee equipment, via a carbonation route and a once-through mode. For size measurement, a suitable dispersion method was developed to obtain reproducible particle size data, using a laser-light analyzer. Several factors that affected the particle size of barium carbonate, including the CO₂ flow rate, the feed rate of Ba(OH)₂ slurry, the rotation speed, and the solid-content of feed slurry, were investigated. A high rotating speed and low feeding rate of slurry yielded small particles. The optimum solid-content of feeding slurry for obtaining small particles was also determined. However, the effect of the CO₂ flow rate on the particle size of the product was not significant.     

The use of transmission spectrophotometry for the evaluation of haem pigments in situ in muscle slices

Summary Haem pigments in thin slices of meat can be differentiated by transmission spectrophotometry. The spectral characteristics of the various forms of haem pigment in this situation have compared well with those exhibited in aqueous solution.[/p]The optimum thickness of slice for the observation of haem pigment is 2.0 mm using a Pye Unicam SP 800 recording spectrophotometer. Detachable cells have been constructed that permit the reconstitution of tissues into slices of this thickness when examining meat products too fragile to section conventionally. In this way, sections representative of areas of superficial discoloration can be assembled for spectrophotometric evaluation of contributing haem pigments.[/p]In many cases, selective changes can be applied to a particular form of haem protein for its evaluation by differential spectrophotometry. Reference systems have also been developed for direct examination of the haem pigments, including those formed during curing. Only small samples of tissue are required, so that localized areas of a meat product(s) can be studied without difficulty.

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Gebrauch von Durchlässigkeitsspektrophotometrie für die Wertung von Hämpigmenten in situ in Muskelschnitten

Zusammenfassung Hämpigmente in dünnen Fleischscheiben können durch Durchlässigkeitsspektrophotometrie unterschieden werden, wobei deren spektrale Verteilungscharakteristik der verschiedenen Hämpigmente sich mit denen in wässriger Lösung gut vergleichen lassen.[/p]Die optimale Scheibendicke zur Ablesung von Hämpigmenten ist 2,0 mm bei Benutzung eines Pye Unicam SP 800 registrierenden und integrierenden Spektralphotometers. Es wurden ablösbare Zellen hergestellt, die die Wiederherstellung der Gewebe in Schnitte dieser Dicke bei der Untersuchung von Fleischprodukten, die zu zart zum Schneiden sind, erlauben. Auf diese Weise können repräsentative Schnitte von oberflächlichen Verfärbungsflächen für die spektrophotometrische Wertung der verantwortlichen Hämpigmente gewonnen werden. In vielen Fällen können selektive Änderungen auf eine besondere Form von Hämpigmenten, für deren Wertung durch Differentialspektrophotometrie, angewandt werden. Bezugssysteme für direkte Untersuchung der Hämpigmente, einschließlich deren, die während des Pökelns entstehen, wurden zusätzlich entwickelt. Da nur kleíne Gewebemuster erforderlich sind, können lokalisierte Fleischproduktflächen mühelos studiert werden.

     

Incidence and pathophysiological changes in chronic two-kidney hypertension in the dog

Unilateral renal artery plication in dogs reduced renal blood flow by 80% and produced a sustained elevation in arterial pressure whereas plasma renin activity increased for only 4 days. Sodium was retained for 3 days after plication, but this response is similar to that after a sham operation. Of seven dogs studied chronically, elevated arterial pressure was sustained for 27 days or longer in six animals. In three dogs hypertension continued for 2 mo before collateral vessels developed and arterial pressure fell; ligation of these collaterals restored hypertension. Arterial pressure was unaffected by an infusion of [1-sarcosine, 8-alanine] angiotensin II in chronic hypertensive dogs on a normal sodium intake. This angiotensin antagonist lowered arterial pressure after sodium depletion, but became ineffective following rapid sodium repletion. Chronic hypertensive dogs showed normal responses to deoxycorticosterone acetate. These findings suggest that the renin-angiotensin system is not critically involved in maintenace of chronic two-kidney renovascular hypertension in the dog. The data also show that the homeostatic role played by the renin-angiotensin system in the maintenance of arterial pressure remained intact in chronic hypertension.     

Self-administered relaxation training and money deposits in the treatment of recurrent anxiety.

Evaluated 2 self-administered relaxation manuals and a money deposit in the treatment of recurrent, nonphobic anxiety in 61 18–44 yr old Ss from a college population. Ss were randomly assigned to a self-monitoring-only control group or 1 of 4 active treatment conditions. Ss in active conditions received a progressive relaxation manual or a manual that called for the client to devise his or her own relaxation method and were assigned to deposit or nondeposit conditions. Improvement did not differ for the 2 relaxation procedures, but relaxation training groups improved significantly more than self-monitoring-only Ss on both self-report questionnaires and self-monitored measures of anxiety. The deposit did not produce greater amounts of relaxation practice or adherence to the program, although Ss in this condition reported being more relaxed in practice sessions and improved more on 2 pre–post measures of anxiety (including the State-Trait Anxiety Inventory). Ss' locus of control scores (Rotter's Internal–External Locus of Control Scale) were significantly related to a number of practice, adherence, and outcome variables, but Ss' ratings of the likelihood that they would practice and benefit from the program proved to be as good predictors. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gastric erosions: radiological and endoscopic aspects

Varioliform gastric erosion is a common lesion which can be reliably diagnosed radiologically. The diagnosis was established in 27 (1.7%) of 1,600 detailed radiological examinations made in 1975. There was a good correlation with gastroscopic findings.     

Radiation therapy of nasopharyngeal carcinoma in East Africa

Results of irradiation, 1 to 3 years after treatment, are presented in 64 cases of nasopharyngeal carcinoma in East Africans. Two types of anatomic point indices are presented. Both correlate well with the results. Prophylactic irradiation of the mediastinum and both axillae was not followed by any evident improvement of the results.     

Analyte and label binding assay read by flow cytometry

A new immunometric two-site sandwich assay is introduced, in which a label-scavenging binding partner is added to the sample in addition to the analyte-binding partner. The scavenger binding partner binds excess label antibody, giving a signal proportional to the amount of excess label antibody in the sample solution. A set of two calibration curves is obtained from the two binding partners simultaneously, and a combination of the two signals gives an unambiguous determination of the analyte concentration, even for high analyte concentrations where the hook effect may occur. Two-particle immunofluorometric assays developed for placental alkaline phosphatase and human chorionic gonadotropin on the basis of this principle and yielding signals measured by flow cytometry gave rapid results (2 h) and had working ranges in excess of 5 and 6 orders of magnitude for the respective analytes.