Improved photoetching fabrication method

Photoetching method producing well-defined lines with minimum undercutting was developed for etching coolant passages in nickel sheet. Phosphate coating is applied over conventional silver plate maskant and phosphoric acid solution is used to remove silver maskant. Phosphoric acid prevents etching of silver edges and mask has sharply-defined lines

Clostridium septicum aortitis with synchronous ascending colon and rectal adenocarcinoma.

Clostridium septicum (C. septicum) aortitis is a rare condition frequently associated with colon adenocarcinoma and carries a poor prognosis. We report the case of a 66-year-old man who presented with abdominal pain, blood in the stool, fever and chills. Laboratory tests were significant for leukocytosis and microcytic anemia. Abdominal imaging revealed a right colon mass and aortitis. Colonoscopy confirmed the right colon mass and also discovered a rectal mass, both adenocarcinomas. Treatment consisted of antibiotics, aortic repair, right hemi-colectomy and later trans-anal excision of the rectal mass. Blood cultures and the aortic specimen grew C. septicum. The patient improved and was doing well in follow up

RFX2 is a candidate downstream amplifier of A-MYB regulation in mouse spermatogenesis

<p>Abstract</p> <p>Background</p> <p>Mammalian spermatogenesis involves formation of haploid cells from the male germline and then a complex morphological transformation to generate motile sperm. Focusing on meiotic prophase, some tissue-specific transcription factors are known (A-MYB) or suspected (RFX2) to play important roles in modulating gene expression in pachytene spermatocytes. The current work was initiated to identify both downstream and upstream regulatory connections for <it>Rfx2</it>.</p> <p>Results</p> <p>Searches of pachytene up-regulated genes identified high affinity RFX binding sites (X boxes) in promoter regions of several new genes: <it>Adam5</it>, <it>Pdcl2</it>, and <it>Spag6</it>. We confirmed a strong promoter-region X-box for <it>Alf</it>, a germ cell-specific variant of general transcription factor TFIIA. Using <it>Alf </it>as an example of a target gene, we showed that its promoter is stimulated by RFX2 in transfected cells and used ChIP analysis to show that the promoter is occupied by RFX2 in vivo. Turning to upstream regulation of the <it>Rfx2 </it>promoter, we identified a cluster of three binding sites (MBS) for the MYB family of transcription factors. Because testis is one of the few sites of <it>A-myb </it>expression, and because spermatogenesis arrests in pachytene in <it>A-myb </it>knockout mice, the MBS cluster implicates <it>Rfx2 </it>as an <it>A-myb </it>target. Electrophoretic gel-shift, ChIP, and co-transfection assays all support a role for these MYB sites in <it>Rfx2 </it>expression. Further, <it>Rfx2 </it>expression was virtually eliminated in <it>A-myb </it>knockout testes. Immunohistology on testis sections showed that A-MYB expression is up-regulated only after pachytene spermatocytes have clearly moved away from the tubule wall, which correlates with onset of RFX2 expression, whereas B-MYB expression, by contrast, is prevalent only in earlier spermatocytes and spermatogonia.</p> <p>Conclusion</p> <p>With an expanding list of likely target genes, RFX2 is potentially an important transcriptional regulator in pachytene spermatocytes. <it>Rfx2 </it>itself is a good candidate to be regulated by A-MYB, which is essential for meiotic progression. If <it>Alf </it>is a genuine RFX2 target, then <it>A-myb</it>, <it>Rfx2</it>, and <it>Alf </it>may form part of a transcriptional network that is vital for completion of meiosis and preparation for post-meiotic differentiation.</p

Review of world experience and properties of materials for encapsulation of terrestrial photovoltaic arrays

Published and unpublished information relating to encapsulation systems and materials properties was collected by searching the literature and appropriate data bases (over 1,300 documents were selected and reviewed) and by personal contacts including site and company visits. A data tabulation summarizing world experience with terrestrial photovoltaic arrays (50 installations) is presented in the report. Based on criteria of properties, processability, availability, and cost, candidate materials were identified which have potential for use in encapsulation systems for arrays with a lifetime of over 20 years high reliability, an efficiency greater than 10 percent, a total price less than $500/kW, and a production capacity of 500,000 kW/yr. The recommended materials (all commercially available) include, depending upon the device design, various borosilicate and soda-lime glasses and numerous polymerics suitable for specific encapsulation system functions

Methodology for designing accelerated aging tests for predicting life of photovoltaic arrays

A methodology for designing aging tests in which life prediction was paramount was developed. The methodology builds upon experience with regard to aging behavior in those material classes which are expected to be utilized as encapsulant elements, viz., glasses and polymers, and upon experience with the design of aging tests. The experiences were reviewed, and results are discussed in detail

A Survey About Nothing: Monitoring a Million Supergiants for Failed Supernovae

Extragalactic transient searches have historically been limited to looking for the appearance of new sources such as supernovae. It is now possible to carry out a new kind of survey that will do the opposite, that is, search for the disappearance of massive stars. This will entail the systematic observation of galaxies within a distance of 10 Mpc in order to watch ~10^6 supergiants. Reaching this critical number ensures that something will occur yearly, since these massive stars must end their lives with a core collapse within ~10^6 years. Using deep imaging and image subtraction it is possible to determine the fates of these stars whether they end with a bang (supernova) or a whimper (fall out of sight). Such a survey would place completely new limits on the total rate of all core collapses, which is critical for determining the validity of supernova models. It would also determine the properties of supernova progenitors, better characterize poorly understood optical transients, such as eta Carina-like mass ejections, find and characterize large numbers of Cepheids, luminous blue variables and eclipsing binaries, and allow the discovery of any new phenomena that inhabit this relatively unexplored parameter space.Comment: final version, 7 pages, 5 figures, ApJ in pres

Evaluation of nonmetallic thermal protection materials for the manned space shuttle. Volume 1, task 1: Assessment of technical risks associated with utilization of nonmetallic thermal protection system

Technical problems of design and flight qualification of the proposed classes of surface insulation materials and leading edge materials were reviewed. A screening test plan, a preliminary design data test plan and a design data test plan were outlined. This program defined the apparent critical differences between the surface insulators and the leading edge materials, structuring specialized screening test plans for each of these two classes of materials. Unique testing techniques were shown to be important in evaluating the structural interaction aspects of the surface insulators and a separate task was defined to validate the test plan. In addition, a compilation was made of available information on proposed material (including metallic TPS), previous shuttle programs, pertinent test procedures, and other national programs of merit. This material was collected and summarized in an informally structured workbook