Aluminum Melt Degassing Process Evaluation Depending on the Design and the Degree of the FDU Unit Graphite Rotor Wear

One of the most important indicators of casting quality is porosity. The formation of pores is largely conditioned by the presence of hydrogen in the batch and subsequently in the melt. The gasification of the melt is the primary factor increasing the porosity of casts. This paper addresses the issue of reducing the melt gasification by using FDU (Foundry Degassing Unit) unit. The gas content in the melt is evaluated by determining the Dichte Index depending on the geometry and the degree of the FDU unit rotor wear. For experiments performed under the operating conditions, three types of graphite rotors with different geometries are used. The extent of melt gasification and the Dichte Index are monitored during the rotor wear, at a rate of 0%, 25%, 50%, 75% and 100% rotor wear. Secondly, the chemical composition of the melt is monitored depending on the design and wear of the rotor. It is proven that the design and the degree of rotor wear do not have significant effect on the chemical composition of the melt and all evaluated samples fell within the prescribed quality in accordance with EN 1706. With regard to the overall comparison of the geometry and wear of individual rotor types, it has been proven that, in terms of efficiency, the individual rotors are mutually equivalent and meet the requirements for melt degassing throughout the service life.     

Die Einwirkung von E. coli-L-Asparaginase auf den Verlauf einer experimentellen Meerschweinchentuberkulose

In our paper we described the results which we obtained by a 35-day application ofE. coli-l-asparaginase (100 i.u./daily) in guinea pigs experimentally infected with M. tuberculosis H₃₇Rv. As it appears from the results, the concentration quoted above ofl-asparaginase will inhibit development of the process. In combination with Emetinum hydrochloricum, the latter will augment the inhibitory capacity ofl-asparaginase. Intracutaneous tuberculin reaction, carried out with the aid of tuberculin PPD RT₂₃, resulted in a reduction of the infiltrate and erythema in guinea pigs of the experimental groups, as compared with the control-group. The possible mechanism of action byl-asparaginase on tbc is discussed.     

PSA bounce after <Superscript>125</Superscript>I-brachytherapy for prostate cancer as a favorable prognosticator

Background

Permanent low-dose-rate brachytherapy (BT) with iodine 125 is an established curative treatment for localized prostate cancer. After treatment, prostate-specific antigen (PSA) kinetics may show a transient rise (PSA bounce). Our aim was to investigate the association of PSA bounce with biochemical control.

Patients and methods

Patients treated with BT in Switzerland were registered in a prospective database. Only patients with a follow-up of at least 2 years were included in our analysis. Clinical follow-up and PSA measurements were assessed after 1.5, 3, 6, and 12 months, and annually thereafter. If PSA increased, additional follow-up visits were scheduled. Cases of PSA bounce were defined as a rise of at least 0.2 ng/ml above the initial PSA nadir with a subsequent decline to or below the initial nadir without treatment. Biochemical failure was defined as a rise to nadir +?2 ng/ml.

Results

Between March 2001 and November 2010, 713 patients with prostate cancer undergoing BT with at least 2 years of follow-up were registered. Median follow-up time was 41 months. Biochemical failure occurred in 28 patients (3.9?%). PSA bounce occurred in 173 (24.3?%) patients; only three (1.7?%) patients with PSA bounce developed biochemical failure, in contrast to 25 (4.6?%) patients without previous bounce (p?<?0.05). The median time to bounce was 12 months, the median time to biochemical failure was 30 months. The median bounce increase was 0.78 ng/ml. Twenty-eight patients with bounce (16.5?%) had a transient PSA rise of +?2 ng/ml above the nadir.

Conclusion

In most cases, an early increase in PSA after BT indicates PSA bounce and is associated with a lower risk of biochemical failure.

     

Molecular heterosis in metamphetamine abusers

Objective. The aim of our study was to assess whether the catechol-O-methyltransferase (COMT) genetic background of patients dependent on metamphetamine is related to their non-abstinence in a 1-year follow-up. Methods. We examined COMT gene Val158Met polymorphism and 1-year abstinence in a group of 31 (women N=8) Czech Caucasian metamphetamine abusers (average age, 23.8±4.0years). Results. Non-abstinence was significantly (P=0.046, Fisher's exact test) associated with the heterozygous Val/Met genotype. Conclusion. The case where subjects heterozygous for a specific genetic polymorphism show a significantly greater or lesser effect for a phenotypic trait than subjects homozygous for either allele is described as molecular heterosis in the literature. We discuss several explanations and recommendations for further research.     

Split or slip – passive generation of monodisperse double emulsions with cores of varying viscosity in microfluidic tandem step emulsification system

We investigate the role of viscosities on the formation of double emulsion in a microfluidic step emulsification system. Aqueous droplets of various viscosities and sizes were engulfed in fluorocarbon oil and subsequently transformed into double droplets in the microfluidic step emulsifying device. We identify two distinct regimes of double droplet formation: (i) core droplets split into multiple smaller droplets, or (ii) cores slip whole into the forming oil shell. We show that the viscosity ratio of the core and shell phases plays a crucial role in determining the mode of formation of the double emulsions. Finally, we demonstrate that high viscosity of the core droplet allows for generation of double emulsions with constant shell thickness for cores of various sizes.

We investigate the role of fluid viscosities on formation of double emulsion in a microfluidic step emulsification system. The ratio of fluid viscosities controls double droplet formation, leading to splitting of the core for low core-to-shell viscosity ratio.     

Prevalence of eating disorders in a swiss family planning clinic: A pilot study

Abstract

The present and past prevalence of eating disorders was estimated in women attending a family planning clinic. This is the first study to systematically assess the prevalence of eating disorders in a non-student-based population in Switzerland. Of 122 consecutive clinic attenders, two women in the high-risk group had bulimia nervosa, giving an estimated prevalence of 1.7%, and five women had a partial syndrome, giving an estimated prevalence of 4.1%. One woman in the low-risk group had a partial syndrome as well. The study shows an internationally comparable prevalence of eating disorders and disturbances.     

Surgical treatment of lumbar spondylodiscitis: a comparison of two methods

Purpose

This study evaluates two basic hypotheses: (1) the risk of an isolated dorsal approach to ventral lumbar spondylodiscitis based on clinical and radiographic results and (2) the risk of anterior radical debridement due to using a titanium implant in the site of bone infection.

Methods

Group A consisting of 23 patients was treated only by a dorsal transmuscular approach and group B consisting of eight patients was treated by two-stage posteroanterior surgery. Both evaluated groups were assessed before surgery, six weeks and one year after surgery with the Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) and Kirkaldy-Willis functional criteria. To evaluate the sagittal balance restoration, measurement by the Cobb modified angle of the affected segment was performed.

Results

Differences (p < 0.001) in group A were found between JOA values before surgery (average 9.30) and at six weeks after surgery (average 11.82) and 12 months after surgery (13.27) and VAS differences before surgery (average 7.39), six weeks after surgery (average 3.82) and 12 months after surgery (average 2.36) in group A. According to the Kirkaldy-Willis functional criteria, 11 patients were evaluated as excellent, nine patients as good and two patients as poor. The values of the JOA score in group B showed an improvement compared with the JOA values before surgery (average 9.38) at six weeks after surgery (average 11.75) and 12 months after surgery (average 13.63), and the VAS score before surgery (average 7.38) was found to have improved six weeks after surgery (average 4.63) and 12 months after surgery (average 2.25). The functional evaluation according to the Kirkaldy-Willis functional criteria assessed three patients as excellent, four patients as good and one patient as fair. Radiographic examinations of group A revealed the following findings before surgery (average 1.75), six months after surgery (average −3.73) and 12 months after surgery (average −0.79) and in group B before surgery (average 3.71), six weeks after surgery (average −8.21) and 12 months after surgery (average −6.45).

Conclusions

The results demonstrate the minimum serious surgical complications and greater loss of sagittal balance without clinical correlation in group A. We did not find any relapse or persistence of the infection in the post-operative period in group B.