PROCESSING HIGH EFFICIENCY CdTe SOLAR CELLS

High efficiency solar cells can be fabricated on CdTe films prepared by a wide variety of deposition techniques. Most of these methods yield CdTe layers that need to be subjected to post-deposition treatments before they can be utilized in high efficiency device fabrication. In some cases these treatments can be made an integral part of the film growth process so that a post-deposition step is not needed. This paper discusses the procedures that are commonly used in high efficiency CdTe solar cell fabrication and reports on a newly emerging technique that holds the promise of becoming a high-throughput industrial process for thin film photovoltaic module production.     

Factors influencing reduction in blood pressure and left ventricular mass in hypertensive type-1 diabetic patients using captopril or doxazosin for 6 months

The effect of doxazosin versus captopril on blood pressure, albuminuria, and left ventricular mass was studied in 33 hypertensive type-1 diabetic patients randomized to 6 months treatment with captopril (17 patients, mean daily dose 100 mg) or doxazosin (16 patients, mean daily dose 9 mg). Casual and 24-h ambulatory blood pressure (24hBP) were reduced from 163/95 to 144/83 mm Hg and 152/86 to 145/81 mm Hg, respectively, in the captopril group, and from 160/93 to 145/86 mm Hg and 156/86 to 147/79 mm Hg in the doxazosin group (all P < .05). The achieved 24hBP on treatment was positively associated with pretreatment levels of glycosylated hemoglobin (HbA1c) and plasma atrial natriuretic peptide (r = 0.53 and 0.59, respectively, both P < .01). Albuminuria did not change significantly in either group. Left ventricular hypertrophy was present in 13 patients (7 in the captopril and 6 in the doxazosin group). Left ventricular mass was reduced by an average of 27% and 23%, respectively, in these patients (both P < .01), but did not change significantly in patients without left ventricular hypertrophy. The reduction in left ventricular mass was positively associated with the presence of baseline left ventricular hypertrophy and inversely with dietary sodium intake and achieved casual blood pressure on treatment (R2 = 0.59, P < .001). We conclude that doxazosin and captopril used for 6 months are equally effective in reducing blood pressure and left ventricular hypertrophy in hypertensive type-1 diabetic patients; the antihypertensive effect is closely related to glycemic control; and dietary sodium intake and achieved casual blood pressure after treatment are independent determinants of the reduction in left ventricular mass seen in these patients.     

cis-Elements in the 5''-region of the Oct-1 gene. Possibilities of autoregulation

The anti-diuretic hormone vasopressin (AVP) regulates water excretion from the kidney by increasing the water permeability of the collecting duct. AVP binds to V2-receptors and induces the translocation of aquaporin-2 water channels (AQP-2) into the apical plasma membrane of principal cells. By this mechanism AVP controls water reabsorption in the kidney. The effects of AVP on the endolymphatic sac (ES) of the inner ear, which is thought to mediate reabsorption of endolymph, were investigated. Both the V2-receptor and the AQP-2 water channel were found to be expressed in the ES epithelium. In the ES AVP binds to receptors most probably of the V2-subtype. Application of AVP to organotypically cultured ES inhibits membrane turnover in ribosomal-rich cells of the ES epithelia, which is thought to mediate translocation of AQP-2 into the surface membrane. This suggests that AVP has contrasting effects in the inner ear and kidney, which may be physiologically useful for maintaining endolymphatic pressure during severe hypovolemia. Animal experiments show that AVP causes endolymphatic hydrops after systemic application to guinea-pigs, which suggests a causal role for the increased AVP levels found in humans suffering from Ménière's disease.     

Tumor necrosis factor-induced release of endogenous fatty acids analyzed by a highly sensitive high-performance liquid chromatography method

A highly sensitive method to determine agonist-induced release of endogenous fatty acids from cells in culture was developed using high-performance liquid chromatography and fluorescence detection. Fatty acids were selectively derivatized with 1-pyrenyldiazomethane and separated on a LC18 reversed phase column using an acetonitrile-water gradient. The detection limit was approx. 20 fmol and the recovery of the complete method using oleic acid was 93-98%. Tumor necrosis factor alpha (TNF-alpha) increased the extracellular release of endogenous arachidonic acid (20:4n-6) from 21 to 153 pmol/well per 4 h using 2.7 x 10(6) WEHI fibrosarcoma cells. In cells preincubated with 50 microM 20:4n-6, the corresponding figures were 463 and 3379 pmol 20:4n-6/well. Simultaneously, nearly equimolar amounts of 22:4n-6 were released together with slightly lower amounts of 24:4n-6, 16:0, 16:1n-9, and 18:1n-9. Analysis of cell lipid fatty acids showed that phosphatidylcholine was the major source of the released fatty acids. TNF-alpha increased the intracellular concentration of unesterified 20:4n-6 and 22:4n-6 by 368% and 451%, respectively. This suggests that released 20:4n-6 is rapidly chain elongated to 22:4n-6. The results indicate that the present method facilitates studies on agonist-induced release of endogenous fatty acids, and that TNF-induced fatty acid release seems to be less selective for 20:4n-6 than previously reported.     

Psychiatric correlates of MR deep white matter lesions in probable Alzheimer's disease

The authors examined the relationship between psychiatric symptoms and the presence of of MR deep white matter lesions (DWMLs) in 28 probable Alzheimer's disease (AD) patients with mild to moderate dementia. The difference in frequency of psychiatric symptoms between patients with and without DWMLs was not statistically significant. However, MR global scores of severity correlated with the presence of ideational disturbances (such as low self-esteem and suicidal ideation). Analysis of specific cerebral regions indicated that the highest correlation occurred in the frontal white matter. Thus, DWMLs are correlated with specific symptoms of depression in AD. Whether DWMLs are etiologically related to these symptoms remains to be determined.     

On Enumerating Minimal Dicuts and Strongly Connected Subgraphs

We consider the problems of enumerating all minimal strongly connected subgraphs and all minimal dicuts of a given strongly connected directed graph G=(V,E). We show that the first of these problems can be solved in incremental polynomial time, while the second problem is NP-hard: given a collection of minimal dicuts for G, it is NP-hard to tell whether it can be extended. The latter result implies, in particular, that for a given set of points , it is NP-hard to generate all maximal subsets of contained in a closed half-space through the origin. We also discuss the enumeration of all minimal subsets of whose convex hull contains the origin as an interior point, and show that this problem includes as a special case the well-known hypergraph transversal problem. This research was supported by the National Science Foundation (Grant IIS-0118635). The third and fourth authors are also grateful for the partial support by DIMACS, the National Science Foundation’s Center for Discrete Mathematics and Theoretical Computer Science. Our friend and co-author, Leonid Khachiyan tragically passed away on April 29, 2005.     

Cytogenetic patterns in synapsis of meiotic chromosomes in animals and plants

Chromosome synapsis in meiosis is performed through the formation of a synaptonemal complex (SC). The SC aggregates homologues until the diplotene stage, when the function of physical binding is carried out by a chiasmata. SC formation is controlled by specific genes. Regularities of SC formation in animals and plants are being studied at the Laboratory of Cytogenetics, Vavilov Institute of General Genetics, the Russian Academy of Sciences. It was shown that, in Drosophila melanogaster, the presence or absence of SC in meiosis is determined by balance between autosomes and sex chromosomes. i.e., SC is formed according to regularities in sex determination. The dose of the 8C-11A segment of X chromosome plays a key role in this process. Eight mutations in synaptic genes that affect SC formation were studied in rye Secale cereale. SC variants occurring in heteromorphic sex chromosomes were analyzed in the Ellobius genera and in B-chromosomes of Apodemus peninsulae. It was shown that, in addition to homologous synapsis, non-homologous synapsis of aberrant chromosomes occurs in rye and mouse heterozygotes at chromosome rearrangements. Twice as many heterozygous chromosome rearrangements were revealed, when the SC was studied at pachytene instead of diakinesis and metaphase I. Simple methods of SC investigations extended the capabilities of cytogenetic analysis of meiosis and provided new perspectives for studying the action of meiotic gen.     

Acute appendicitis secondary to non-0 group I Vibrio cholerae

Acute appendicitis is the most common abdominal surgical condition and is usually associated with colonic flora. The patient described had acute appendicitis associated with an uncommon microorganism. This report underscores the importance of obtaining an adequate occupational, travel, and dietary history.