503 research outputs found

    Can a Topical Microbicide Prevent Rectal HIV Transmission?

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    Florian Hladik and Charlene Dezzutti discuss a macaque study of whether rectal simian immunodeficiency virus transmission can be prevented by topical pre-exposure application of tenofovir gel

    Fingerprinting redox and ligand states in haemprotein crystal structures using resonance Raman spectroscopy

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    It is crucial to assign the correct redox and ligand states to crystal structures of proteins with an active redox centre to gain valid functional information and prevent the misinterpretation of structures. Single-crystal spectroscopies, particularly when appliedin situat macromolecular crystallography beamlines, allow spectroscopic investigations of redox and ligand states and the identification of reaction intermediates in protein crystals during the collection of structural data. Single-crystal resonance Raman spectroscopy was carried out in combination with macromolecular crystallography on Swiss Light Source beamline X10SA using cytochromec′ fromAlcaligenes xylosoxidans. This allowed the fingerprinting and validation of different redox and ligand states, identification of vibrational modes and identification of intermediates together with monitoring of radiation-induced changes. This combined approach provides a powerful tool to obtain complementary data and correctly assign the true oxidation and ligand state(s) in redox-protein crystals.</jats:p

    Increased strontium uptake in trabecular bone of ovariectomized calcium-deficient rats treated with strontium ranelate or strontium chloride

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    Based on clinical trials showing the efficacy to reduce vertebral and non-vertebral fractures, strontium ranelate (SrR) has been approved in several countries for the treatment of postmenopausal osteoporosis. Hence, it is of special clinical interest to elucidate how the Sr uptake is influenced by dietary Ca deficiency as well as by the formula of Sr administration, SrR versus strontium chloride (SrCl2). Three-month-old ovariectomized rats were treated for 90 days with doses of 25 mg kg-1 d-1 and 150 mg kg-1 d-1 of SrR or SrCl2 at low (0.1% Ca) or normal (1.19% Ca) Ca diet. Vertebral bone tissue was analysed by confocal synchrotron-radiation-induced micro X-ray fluorescence and by backscattered electron imaging. Principal component analysis and k-means clustering of the acquired elemental maps of Ca and Sr revealed that the newly formed bone exhibited the highest Sr fractions and that low Ca diet increased the Sr uptake by a factor of three to four. Furthermore, Sr uptake in bone of the SrCl2-treated animals was generally lower compared with SrR. The study clearly shows that inadequate nutritional calcium intake significantly increases uptake of Sr in serum as well as in trabecular bone matrix. This indicates that nutritional calcium intake as well as serum Ca levels are important regulators of any Sr treatment

    Steam gasification of sewage sludge for synthesis processes

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    The paper presents measurement results of a gasification test run. Municipal sewage sludge from a digestion tower is gasified in an advanced dual fluidized bed reactor system. Steam is used as gasification agent and an olivine-limestone mixture as bed material. The fuel analysis shows a very high ash content and a low heating value of the dried sewage sludge. In addition, a significant amount of nitrogen in the fuel is present, leading to a high ammonia content in the product gas.Sintering effects caused by the high ash content do not occur. Thus, a gasification process without limitation is achieved. The fuel input is located in the lower gasification reactor operating as bubbling fluidized bed, whereas the upper gasification reactor is designed as a column of turbulent fluidized zones for tar cracking. The results show an efficient in-situ tar reduction. With a look on the product gas composition a comparatively high carbon dioxide and a low carbon monoxide content is surprising. It is obvious that an iron oxide reduction of the initial fuel ash occur in the gasification reactor. In addition, it is assumed that the significant iron content in the fuel ash also leads to a transport of oxygen from the combustion reactor to the gasification reactor. Thus, carbon monoxide and hydrogen are oxidized in the gasification reactor by the circulating iron-rich ash particles (chemical looping effect).FFG - Österr. Forschungsförderungs- gesellschaft mbH4351

    Identifying the need for specialized palliative care in adult cancer patients – development and validation of a screening procedure based on proxy assessment by physicians and filter questions

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    Background One challenge in caring for cancer patients with incurable disease is the adequate identification of those in need for specialized palliative care (SPC). The study’s aim was to validate an easy to use phenomenological screening tool. Methods The German tool is based on the National Comprehensive Cancer Network (NCCN) Palliative Care guidelines and contains ten items in five domains that focus e.g. on diagnosis, functional status, complications, comorbidities, and palliative care relevant problems such as symptom management, distress, and support of family and team members. Sum score ranges from 0 to 14 (no need to great need). Assessment to identify SPC needs was done in university hospital wards between 1 and 08/2017 by health care professionals on admission of the patient if the disease was incurable and expected prognosis < 12 months. The Integrated Palliative Outcome Scale (IPOS, staff version), an outcome assessment instrument for palliative care that consists of ten items, served as external criterion; in sub samples inter-rater/test-retest were performed. Results Data from 208 patients with incurable disease and life expectancy < 12 months (54.8% female; average age 63.5 years, range 21–96) were assessed using the tool. The tool has good convergent validity; the correlation between the sum scores of IPOS and our tool showed a significant and substantial effect. The sum score was independent of the patient’s age, gender and primary diagnosis. Patients who already were in contact with SPC had significantly higher screening scores than patients without. With a cut point of  ≥ 5, 80.8% of the screened patients were in need for SPC. Cronbach’s alpha was α = .600. Rater agreement (inter-rater, test-retest) varied between single items. Correlation coefficients showed significant substantial effects. Conclusions This is the first validation of a screening procedure in German language identifying SPC needs of adult patients with advanced cancer and the first using filter questions as a pre-screening. Proxy assessment of SPC needs by physicians in cancer care settings is feasible and the suggested tool presents a valid instrument to trigger a PC consultation. Trial registration The study was not registered

    Tidal Volume Single Breath Washout of Two Tracer Gases - A Practical and Promising Lung Function Test

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    Small airway disease frequently occurs in chronic lung diseases and may cause ventilation inhomogeneity (VI), which can be assessed by washout tests of inert tracer gas. Using two tracer gases with unequal molar mass (MM) and diffusivity increases specificity for VI in different lung zones. Currently washout tests are underutilised due to the time and effort required for measurements. The aim of this study was to develop and validate a simple technique for a new tidal single breath washout test (SBW) of sulfur hexafluoride (SF(6)) and helium (He) using an ultrasonic flowmeter (USFM)

    A Realistic Validation Study of a New Nitrogen Multiple-Breath Washout System

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    Background For reliable assessment of ventilation inhomogeneity, multiple-breath washout (MBW) systems should be realistically validated. We describe a new lung model for in vitro validation under physiological conditions and the assessment of a new nitrogen (N2)MBW system. Methods The N2MBW setup indirectly measures the N2 fraction (FN2) from main-stream carbon dioxide (CO2) and side-stream oxygen (O2) signals: FN2 = 1−FO2−FCO2−FArgon. For in vitro N2MBW, a double chamber plastic lung model was filled with water, heated to 37°C, and ventilated at various lung volumes, respiratory rates, and FCO2. In vivo N2MBW was undertaken in triplets on two occasions in 30 healthy adults. Primary N2MBW outcome was functional residual capacity (FRC). We assessed in vitro error (√[difference]2) between measured and model FRC (100–4174 mL), and error between tests of in vivo FRC, lung clearance index (LCI), and normalized phase III slope indices (Sacin and Scond). Results The model generated 145 FRCs under BTPS conditions and various breathing patterns. Mean (SD) error was 2.3 (1.7)%. In 500 to 4174 mL FRCs, 121 (98%) of FRCs were within 5%. In 100 to 400 mL FRCs, the error was better than 7%. In vivo FRC error between tests was 10.1 (8.2)%. LCI was the most reproducible ventilation inhomogeneity index. Conclusion The lung model generates lung volumes under the conditions encountered during clinical MBW testing and enables realistic validation of MBW systems. The new N2MBW system reliably measures lung volumes and delivers reproducible LCI values

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

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    Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model
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