Thermocouple simulator

NERMUT, M. Termočlánkový simulátor. Brno: Vysoké učení technické v Brně, Fakulta elektrotechniky a komunikačních technologií, 2009. 62 s. Pedagogický vedoucí bakalářské práce Ing. Stanislav Klusáček. Konzultant Ing. Miroslav Krupa, - IDC Brno, Honeywell s.r.o. Cílem práce je návrh a konstrukce příručního termočlánkového simulátoru, vhodného do laboratoře i do provozu. Přístroj lze ovládat ručně nebo linkou RS232. Důraz je kladen na všestrannost přístroje, snadné ovládání, bezpečný provoz (galvanické oddělení), řádně provedenou teplotní kompenzaci studeného konce, snadnou kalibraci nelinearity. Zadavatelem práce je IDC Honeywell Brno. Základní prameny: - Katalog firmy OMEGA (Temperature Handbook) - Manuály přístrojů OMEGA (www.omega.com) - Katalogové listy termočlánkových simulátorů jiných výrobců (zdroj: internet) - Isotech Traceable Book – Temperature Calibrabration (www.isotech.co.uk) - BELZA J., Nabíječka Li-ion článků (www.belza.cz) Přílohy: - Návod k použití realizovaného přístroj - Elektrické schéma - Kalibrační data - CD (zdrojový kód)NERMUT, M. Thermocouple simulator. Brno: Brno University of Technology, Faculty of Eletrical Engineering and Communication. 2009. 62 s. Supervisor Ing. Stanislav Klusáček. Consultant Ing. Miroslav Krupa, - IDC Brno, Honeywell s.r.o. The aim of the thesis is design and realization of handheld thermocouple simulator, suitable both for laboratory and plant use. Manual or remote control via RS232 are possible. Special attention is focused on universality, easy and safety use (galvanic isolation), properly cold junction compensation, easy calibration of non-linearity. Sponsor: IDC Honeywell, Brno, Czech Republic Basic literature: - OMEGA Temperature Handbook) - Datasheets of OMEGA instruments (www.omega.com) - Datasheets of other vendor instruments (www) - Isotech Traceable Book – Temperature Calibrabration (www.isotech.co.uk) - BELZA J., Buld-in Li-ion accu charger (www.belza.cz) Appendixs: - User manual - Schematic - Calibration data - CD (source code)

Isolation and identification of a canine coronavirus strain from giant pandas (Ailuropoda melanoleuca)

Two giant pandas (Ailuropoda melanoleuca) died of unknown causes in a Chinese zoo. The clinical disease profile suggested that the pandas may have suffered a viral infection. Therefore, a series of detection including virus isolation, electron microscopy, cytobiological assay, serum neutralization and RT-PCR were used to identify the virus. It was determined that the isolated virus was a canine coronavirus (CCV), on the basis of coronavirus, neutralization by canine anti-CCV serum, and 84.3% to 100% amino acid sequence similarity with CCV. The results suggest that the affected pandas had been infected with CCV

Ultrastructure of a hyaluronic acid matrix

Freeze-etch replicas of a hylauronic acid matrix were visualized by electron microscopy. In water a coarse branching fibrillar network of hyaluronic acid aggregates was seen. The high solvent permeability of this matrix suggests that the spaces observed are relatively devoid of unaggregated polymer. Addition of calcium disordered the matrix, resulting in a more dispersed felt of polymer

3D visualization of HIV virions by cryoelectron tomography.

The structure of the human immunodeficiency virus (HIV) and some of its components have been difficult to study in three-dimensions (3D) primarily because of their intrinsic structural variability. Recent advances in cryoelectron tomography (cryo-ET) have provided a new approach for determining the 3D structures of the intact virus, the HIV capsid, and the envelope glycoproteins located on the viral surface. A number of cryo-ET procedures related to specimen preservation, data collection, and image processing are presented in this chapter. The techniques described herein are well suited for determining the ultrastructure of bacterial and viral pathogens and their associated molecular machines in situ at nanometer resolution

Strand Transfer and Elongation of HIV-1 Reverse Transcription Is Facilitated by Cell Factors In Vitro

Recent work suggests a role for multiple host factors in facilitating HIV-1 reverse transcription. Previously, we identified a cellular activity which increases the efficiency of HIV-1 reverse transcription in vitro. Here, we describe aspects of the activity which shed light on its function. The cellular factor did not affect synthesis of strong-stop DNA but did improve downstream DNA synthesis. The stimulatory activity was isolated by gel filtration in a single fraction of the exclusion volume. Velocity-gradient purified HIV-1, which was free of detectable RNase activity, showed poor reverse transcription efficiency but was strongly stimulated by partially purified cell proteins. Hence, the cell factor(s) did not inactivate an RNase activity that might degrade the viral genomic RNA and block completion of reverse transcription. Instead, the cell factor(s) enhanced first strand transfer and synthesis of late reverse transcription suggesting it stabilized the reverse transcription complex. The factor did not affect lysis of HIV-1 by Triton X-100 in the endogenous reverse transcription (ERT) system, and ERT reactions with HIV-1 containing capsid mutations, which varied the biochemical stability of viral core structures and impeded reverse transcription in cells, showed no difference in the ability to be stimulated by the cell factor(s) suggesting a lack of involvement of the capsid in the in vitro assay. In addition, reverse transcription products were found to be resistant to exogenous DNase I activity when the active fraction was present in the ERT assay. These results indicate that the cell factor(s) may improve reverse transcription by facilitating DNA strand transfer and DNA synthesis. It also had a protective function for the reverse transcription products, but it is unclear if this is related to improved DNA synthesis

The Architecture of the Adhesive Apparatus of Cultured Osteoclasts: From Podosome Formation to Sealing Zone Assembly

BACKGROUND: Osteoclasts are bone-degrading cells, which play a central role in physiological bone remodeling. Unbalanced osteoclast activity is largely responsible for pathological conditions such as osteoporosis. Osteoclasts develop specialized adhesion structures, the so-called podosomes, which subsequently undergo dramatic reorganization into sealing zones. These ring-like adhesion structures, which delimit the resorption site, effectively seal the cell to the substrate forming a diffusion barrier. The structural integrity of the sealing zone is essential for the cell ability to degrade bone, yet its structural organization is poorly understood. PRINCIPAL FINDINGS: Combining high-resolution scanning electron microscopy with fluorescence microscopy performed on the same sample, we mapped the molecular architecture of the osteoclast resorptive apparatus from individual podosomes to the sealing zone, at an unprecedented resolution. Podosomes are composed of an actin-bundle core, flanked by a ring containing adhesion proteins connected to the core via dome-like radial actin fibers. The sealing zone, hallmark of bone-resorbing osteoclasts, consists of a dense array of podosomes communicating through a network of actin filaments, parallel to the substrate and anchored to the adhesive plaque domain via radial actin fibers. SIGNIFICANCE: The sealing zone of osteoclasts cultured on bone is made of structural units clearly related to individual podosomes. It differs from individual or clustered podosomes in the higher density and degree of inter-connectivity of its building blocks, thus forming a unique continuous functional structure connecting the cell to its extracellular milieu. Through this continuous structure, signals reporting on the substrate condition may be transmitted to the whole cell, modulating the cell response under physiological and pathological conditions

Absence of mutations in four genes encoding for congenital cataract and expressed in the human brain in Tunisian families with cataract and mental retardation

<p>Abstract</p> <p>Background</p> <p>To identify the genetic defect associated with autosomal recessive congenital cataract (ARCC), mental retardation (MR) and ARCC, MR and microcephaly present in most patients in four Tunisian consanguineous families.</p> <p>Methods</p> <p>We screened four genes implicated in congenital cataract by direct sequencing in two groups of patients; those affected by ARCC associated to MR and those who presented also microcephaly. Among its three genes <it>PAX6</it>, <it>PITX3 </it>and <it>HSF4 </it>are expressed in human brain and one gene <it>LIM2 </it>encodes for the protein MP20 that interact with the protein galectin-3 expressed in human brain and plays a crucial role in its development. All genes were screened by direct sequencing in two groups of patients; those affected by ARCC associated to MR and those who presented also microcephaly.</p> <p>Results</p> <p>We report no mutation in the four genes of congenital cataract and its flanking regions. Only variations that did not segregate with the studied phenotypes (ARCC associated to MR, ARCC associated with MR and microcephaly) are reported. We detected three intronic variations in <it>PAX6 </it>gene: IVS4 -274insG (intron 4), IVS12 -174G>A (intron12) in the four studied families and IVS4 -195G>A (intron 4) in two families. Two substitutions polymorphisms in <it>PITX3 </it>gene: c.439 C>T (exon 3) and c.930 C>A (exon4) in one family. One intronic variation in <it>HSF4 </it>gene: IVS7 +93C>T (intron 7) identified in one family. And three intronic substitutions in <it>LIM2 </it>gene identified in all four studied families: IVS2 -24A>G (intron 2), IVS4 +32C>T (intron 4) and c.*15A>C (3'-downstream sequence).</p> <p>Conclusion</p> <p>Although the role of the four studied genes: <it>PAX6</it>, <it>PITX3</it>, <it>HSF4 </it>and <it>LIM2 </it>in both ocular and central nervous system development, we report the absence of mutations in all studied genes in four families with phenotypes associating cataract, MR and microcephaly.</p

Substrate Adhesion Regulates Sealing Zone Architecture and Dynamics in Cultured Osteoclasts

The bone-degrading activity of osteoclasts depends on the formation of a cytoskeletal-adhesive super-structure known as the sealing zone (SZ). The SZ is a dynamic structure, consisting of a condensed array of podosomes, the elementary adhesion-mediating structures of osteoclasts, interconnected by F-actin filaments. The molecular composition and structure of the SZ were extensively investigated, yet despite its major importance for bone formation and remodelling, the mechanisms underlying its assembly and dynamics are still poorly understood. Here we determine the relations between matrix adhesiveness and the formation, stability and expansion of the SZ. By growing differentiated osteoclasts on micro-patterned glass substrates, where adhesive areas are separated by non-adhesive PLL-g-PEG barriers, we show that SZ growth and fusion strictly depend on the continuity of substrate adhesiveness, at the micrometer scale. We present a possible model for the role of mechanical forces in SZ formation and reorganization, inspired by the current data

HIV-1 Protease and Reverse Transcriptase Control the Architecture of Their Nucleocapsid Partner

The HIV-1 nucleocapsid is formed during protease (PR)-directed viral maturation, and is transformed into pre-integration complexes following reverse transcription in the cytoplasm of the infected cell. Here, we report a detailed transmission electron microscopy analysis of the impact of HIV-1 PR and reverse transcriptase (RT) on nucleocapsid plasticity, using in vitro reconstitutions. After binding to nucleic acids, NCp15, a proteolytic intermediate of nucleocapsid protein (NC), was processed at its C-terminus by PR, yielding premature NC (NCp9) followed by mature NC (NCp7), through the consecutive removal of p6 and p1. This allowed NC co-aggregation with its single-stranded nucleic-acid substrate. Examination of these co-aggregates for the ability of RT to catalyse reverse transcription showed an effective synthesis of double-stranded DNA that, remarkably, escaped from the aggregates more efficiently with NCp7 than with NCp9. These data offer a compelling explanation for results from previous virological studies that focused on i) Gag processing leading to nucleocapsid condensation, and ii) the disappearance of NCp7 from the HIV-1 pre-integration complexes. We propose that HIV-1 PR and RT, by controlling the nucleocapsid architecture during the steps of condensation and dismantling, engage in a successive nucleoprotein-remodelling process that spatiotemporally coordinates the pre-integration steps of HIV-1. Finally we suggest that nucleoprotein remodelling mechanisms are common features developed by mobile genetic elements to ensure successful replication