Numerical study of near-field writing on a phase-change optical disk

Absorption in the phase-change layer of an optical disk located in the near field of a Fabry-Perot laser diode is studied with a combination of finite-difference time domain (FDTD) analysis and a phenomenological laser model that predicts the operational characteristics of a laser diode. Some numerical simulations are performed and results are presented. In addition, the combined FDTD/laser-simulation model is described briefly.     

Isolation of the third capsule-associated gene, CAP60, required for virulence in Cryptococcus neoformans

A polysaccharide capsule is one of the most important virulence factors for the pathogenic fungus Cryptococcus neoformans. We previously characterized two capsule-associated genes, CAP59 and CAP64. To further dissect the molecular mechanism of capsule synthesis, 16 acapsular mutants induced by 4-nitroquinoline-1-oxide were obtained. The acapsular phenotype of one of these mutants was complemented. The cloned gene was designated CAP60, and deletion of this newly described capsule-associated gene resulted in an acapsular phenotype. The proposed 67-kDa Cap60p contains 592 amino acids and appears to have a putative transmembrane domain close to the N terminus. DNA sequence analysis revealed that CAP60 has similarity to CAP59 at the center portion of its coding regions. Contour-clamped homogeneous electric field blot analysis suggested that these two genes are on the same chromosome. CAP60 and CAP59, however, could not be functionally substituted for each other by direct complementation or by domain swap experiments. In addition, CAP60 is closely linked to a gene which is similar to a cellulose growth-specific gene of Agaricus bisporus, CEL1. Immunogold electron microscopy studies of the epitope-tagged CAP60 gene revealed that Cap60p was primarily localized to the nuclear membrane. Animal model studies indicated that CAP60 is essential for virulence. Thus, CAP60 is required for both capsule formation and virulence.     

POEMS syndrome in a patient with diabetic ketoacidosis: case report and review

This article summarise the main data in the literature on the role of bacteriological contamination of the dialysate fluid in inflammatory reactions in hemodialysis. Pyrogenic substances of small molecular weight from Gram-negative bacteria grown in dialysate can pass across intact dialyzer membrane to stimulate cytokine production by peripheral blood mononuclear cells. Cellulosic hemodialysis membranes are more permeable to endotoxins than synthetic membranes. Polysulfone membranes and polyamide membranes are able to adsorb bacterial toxins on the dialysate side. The diffusive transfer of bacterial products across dialysis membrane from dialysate fluid was demonstrated. Transmembrane passage of cytokine-inducing bacterial products across reprocessed dialyzers is greater than across new dialyzers. Bacteriological contamination of the dialysate fluid is a problem which must be considered with much more care by nephrologists, especially as LAL test is unable to detect all the bacterial products which can contaminate the dialysate fluid.     

Absence of normal activation of the left anterior fusiform gyrus during naming in left temporal lobe epilepsy

Patients with left temporal lobe epilepsy (TLE) often have impaired naming. We studied 13 patients with left TLE and 10 healthy control subjects with [(15)O]H2O PET during visual confrontation naming. Statistical mapping detected multiple regions of significant cerebral blood flow increases within individuals. The left fusiform gyrus was activated in nine healthy subjects, but only in two patients with TLE (a significant difference, p < 0.001). Other activation sites were more variable in healthy subjects and those with TLE. Impaired naming ability may be associated with a lack of increased cerebral blood flow in the left fusiform gyrus in TLE.     

Application of micellar electrokinetic capillary chromatography for the determination of benzoic acid and its esters in liquid formula medicines as preservatives

We described a method for the simultaneous determination of preservatives including benzoic acid, methyl-, ethyl- and propyl-benzoate by micellar electrokinetic capillary chromatography (MECC). The factors affecting the reproducibility in the quantitative analysis of pharmaceuticals by MECC were investigated by varying the running buffer and washing condition in-between runs. Preservatives in liquid formula medicines have been determined by optimum MECC condition using p-hydroxy benzoic acid as an internal standard. The reproducibility of this method was acceptable as a validate method for the quality control of pharmaceuticals (RSD < 2%). Routine quantitative analysis of pharmaceuticals using MECC could be possible with well characterized reproducible procedure.     

Computer support for learning in collaborative contexts: prompted hypothesis testing in physics

An enormous amount of work has been carried out into the ways in which computers can support collaboration in the service of learning. Less attention has been paid to computer support for learning when collaboration is non-problematic, yet this is arguably of equal significance. Recognizing this, the present paper reports software which was developed to help collaborating pupils test hypotheses, an activity thought by many to be relevant to conceptual learning. The software addressed hypotheses relating to: (a) the factors which influence the pressure of water; and (b) the factors which influence the formation of shadows. It required collaborating pupils to formulate hypotheses about such factors, decide which factors must be manipulated to check correctness, formulate predictions about outcomes prior to testing, observe the results of tests, and draw conclusions across test series. Pupils were asked to input their decisions at key points as they used the software, and they received prompts to the extent that their decisions were inappropriate. The prompts became increasingly explicit as inappropriate decisions persisted. The paper describes the use of the software by 9–14-year-old pupils, comparing their activity with that of similarly aged pupils who worked with otherwise equivalent software which lacked any prompts. Evidence is presented for the value of prompting, with implications not simply for the use of hypothesis testing as an instructional strategy but also for the design of computer-based support for other complex and co-ordinated activities.     

Agonist-induced phosphorylation of the angiotensin AT1a receptor is localized to a serine/threonine-rich region of its cytoplasmic tail

Autosomal recessive juvenile parkinsonism (AR-JP) is a distinct clinical and genetic entity characterized by selective degeneration of nigral dopaminergic neurons and young-onset parkinsonism with remarkable response to levodopa. Recently, we mapped the gene locus for AR-JP to chromosome 6q25.2-q27 by linkage analysis and we identified a novel large gene, Parkin, consisting of 12 exons from this region; mutations of this gene were found to be the cause of AR-JP in two families. Now we report results of extensive molecular analysis on 34 affected individuals from 18 unrelated families with AR-JP. We found four different homozygous intragenic deletional mutations, involving exons 3 to 4, exon 3, exon 4, and exon 5 in 10 families (17 affected individuals). In addition to the exonic deletions, we identified a novel one-base deletion involving exon 5 in two families (2 affected individuals). All mutations so far found were deletional types in which large exonic deletion accounted for 50% (17 of 34) and the one-base deletion accounted for 6% (2/34); in the remaining, no homozygous mutations were found in the coding regions. Our findings indicate that loss of function of the Parkin protein results in the clinical phenotype of AR-JP and that subregions between introns 2 and 5 of the Parkin gene are mutational hot spots.     

In utero diagnosis of intrapericardial teratoma: a case for in utero open fetal surgery

We present a case of intrapericardial teratoma diagnosed by ultrasound at 26 weeks of gestation presenting as a large tumour mass and rapid development of hydrops fetalis. The fetus died in utero one day before scheduled open fetal surgery.     

Nutritional intervention and growth in children with chronic renal failure

During fifties there were at most few tens of persons in this country who believed in the future of computers and cybernetics. One group of such enthusiasts, headed by Antonín Svoboda, was working at a construction of the first Czech computer SAPO. The other group tried to analyse, anticipate, and prepare in advance various applications for the new systemic conceptions and for the information processing machines. Members of both groups met for discussions which opened prospects to the future and influenced many of other activities for a long time. At the early sixties, the Czechoslovak Cybernetic Society was established at the Czechoslovak Academy of Sciences and in 1962 the Main Problem Committee for the Medical Cybernetics was founded at the Department of Health. It coordinated majority of the research programmes in the medical cybernetics and informatics. In 1967-1969 the Committee prepared an extensive project of a medical information system (ZIS), but its accomplishment was finally blocked by the then authorities. However, interests for that topics kept growing and the new working places equipped with available computer technology were formed at the health and clinical centres. The first tentative lectures in medical cybernetics and biocybernetics at our faculty were introduced into the students curricula in the late sixties. Thematically, medical cybernetics subsequently differentiated into the medical informatics, simulations of biological and medical systems, and the biosignal analysis. The growing interest enabled to hold conferences since the middle of seventies, some of which were held periodically, sometimes with international participation. It is not possible in brevity to include the whole spectrum to those goal-directed activities nor to appraise adequately their future significance.