208 research outputs found
Evaluation of ozone difluoride as a liquid propellant additive Final report
Ozone difluoride evaluated as liquid propellant additiv
Superstring-Inspired E_6 Unification, Shadow Theta-Particles and Cosmology
We construct a new cosmological model considering the superstring-inspired
E_6 unification in the 4-dimensional space at the early stage of the Universe.
We develop a concept of parallel existence in Nature of the ordinary and shadow
worlds with different cosmological evolutions.Comment: 7 page
Hepatic pathology in mice after continuous inhalation exposure to 1,1,1-trichloroethane
Mice exposed to either 250ppm or 1,000ppm 1,1,1-trichloroethane in air continuously for 14 weeks demonstrated significant changes in the centrilobular hepatocytes for the 1,000ppm group. Moderate liver triglyceride accumulation was evident in the 1,000ppm group and peaked at 40mg/gm of tissue after 7 weeks of exposure. Focal hepatocyte necrosis occurred in 40% of the mice exposed to 1,000ppm for 12 weeks. This necrosis was associated with an acute inflammatory infiltrate and hypertrophy of Kupffer cells. These findings indicate that the pathological alternations observed with 1,1,1-trichloroethane are similar to those observed with dichloromethane except for different time courses of the effects and different degrees of recovery. The toxic effects of 1,1,1-trichloroethane are of a similar type to those produced by carbon tetrachloride but appear much less severe
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On Visible Homelessness and the Micro-Aesthetics of Public Space
In this article, we investigate the circumstances that have produced the current municipal regulatory approach to homelessness in the City of Melbourne, Victoria, and the ways in which visibly homeless people are policed through a micro-aesthetics of their presence in public space, which involves the monitoring of their bodily demeanour and their physical possessions. Our study contributes to and draws from a range of debates, including studies of the governmental conjunction of poverty and crime, analysis of the co-implication of law and spatiality, research on the criminalisation of homelessness and homeless people, and the burgeoning criminological interest in the significance of the visual field for our understandings of crime and criminality. This article recounts how homelessness, public space and questions of aesthetics have recently coalesced in debates about the regulation of homelessness in the public space of Melbourne’s city centre. It approaches the issues through comparative consideration of genres of municipal management frameworks in other jurisdictions, detailed textual consideration of the Protocol on Homelessness in the City of Melbourne and an empirical study of visible homelessness in the public places of central Melbourne
Efficiency of Collisionally-activated dissociation and 193-nm photodissociation of peptide ions in fourier transform mass spectrometry
AbstractFor tandem mass spectrometry, the Fourier transform instrument exhibits advantages for the use of collisionally-activated dissociation (CAD). The CAD energy deposited in larger ions can be greatly increased by extending the collision time to as much as 120 s, and the efficiency of trapping and measuring CAD product ions in many times greater than the found for triple-quadrupole or magnetic sector instruments, although the increased pressure from the collision gas is an offsetting disadvantage. A novel system that uses the same laser for photodesorption of ions and their subsequent photodissociation can produce complete dissociation of larger oligopeptide ions and unusually abundant fragment ions. In comparison to CAD, much more internal energy can be deposited in the primary ions using 193-nm photons, sufficient to dissociate peptide ions of m/z > 2000. Mass spectra closely resembling ion photodissociation spectra can also be obtained by neutral photodissociation (193-nm laser irradiation of the sample) followed by ion photodesorption
Randomized controlled trial of live lactobacillus acidophilus plus bifidobacterium bifidum in prophylaxis of diarrhea during radiotherapy in cervical cancer patients
<p>Abstract</p> <p>Background</p> <p>Radiation-induced diarrhea is frequently observed during pelvic radiotherapy. This study was performed to determine the ability of a probiotic containing live lactobacillus acidophilus plus bifidobacterium bifidum to reduce the incidence of radiation-induced diarrhea in locally advanced cervical cancer patients.</p> <p>Methods</p> <p>Patients who were undergoing pelvic radiotherapy concurrent with weekly cisplatin were randomly assigned to a study drug or placebo, in a double-blind study. Diarrhea was graded weekly according the Common Toxicity Criteria (CTC) system. Stool consistency and white and red blood cell count in stool were also assessed. The primary endpoint was to reduce the incidence of diarrhea, defined by a CTC grade 2 or more, and the need for anti-diarrheal medication.</p> <p>Results</p> <p>A total of 63 patients were enrolled. Grade 2 -3 diarrhea was observed in 45% of the placebo group (n = 31) and 9% of the study drug group (n = 32) (p = 0.002). Anti-diarrheal medication use was significantly reduced in the placebo group (p = 0.03). The patients in the study drug group had a significantly improved stool consistency (p < 0.001).</p> <p>Conclusions</p> <p>Live lactobacillus acidophilus plus bifidobacterium bifidum reduced the incidence of radiation-induced diarrhea and the need for anti-diarrheal medication and had a significant benefits on stool consistency.</p
Fourier transform ion cyclotron resonance mass spectrometric detection of small Ca2+-induced conformational changes in the regulatory domain of human cardiac troponin C
AbstractTroponin C (TnC), a calcium-binding protein of the thin filament of muscle, plays a regulatory role in skeletal and cardiac muscle contraction. NMR reveals a small conformational change in the cardiac regulatory N-terminal domain of TnC (cNTnC) on binding of Ca2+ such that the total exposed hydrophobic surface area increases very slightly from 3090 ± 86 Å2 for apo-cNTnC to 3108 ± 71 Å2 for Ca2+-cNTnC. Here, we show that measurement of solvent accessibility for backbone amide protons by means of solution-phase hydrogen/deuterium (H/D) exchange followed by pepsin digestion, high-performance liquid chromatography, and electrospray ionization high-field (9.4 T) Fourier transform Ion cyclotron resonance mass spectrometry is sufficiently sensitive to detect such small ligand binding-induced conformational changes of that protein. The extent of deuterium incorporation increases significantly on binding of Ca2+ for each of four proteolytic segments derived from pepsin digestion of the apo- and Ca2+-saturated forms of cNTnC. The present results demonstrate that H/D exchange monitored by mass spectrometry can be sufficiently sensitive to detect and identify even very small conformational changes in proteins, and should therefore be especially informative for proteins too large (or too insoluble or otherwise intractable) for NMR analysis
How many human proteoforms are there?
Despite decades of accumulated knowledge about proteins and their post-translational modifications (PTMs), numerous questions remain regarding their molecular composition and biological function. One of the most fundamental queries is the extent to which the combinations of DNA-, RNA- and PTM-level variations explode the complexity of the human proteome. Here, we outline what we know from current databases and measurement strategies including mass spectrometry-based proteomics. In doing so, we examine prevailing notions about the number of modifications displayed on human proteins and how they combine to generate the protein diversity underlying health and disease. We frame central issues regarding determination of protein-level variation and PTMs, including some paradoxes present in the field today. We use this framework to assess existing data and to ask the question, "How many distinct primary structures of proteins (proteoforms) are created from the 20,300 human genes?" We also explore prospects for improving measurements to better regularize protein-level biology and efficiently associate PTMs to function and phenotype
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