787 research outputs found
The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment
Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have
been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and
polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum
of the outgoing photon in the photon-proton center of mass frame. The
experiment has been performed with the high resolution spectrometers at the
Mainz Microtron MAMI. From the photon angular distributions, two structure
functions which are a linear combination of the generalized polarizabilities
have been determined for the first time.Comment: 4 pages, 3 figure
Cardio-metabolic risk factors and prehypertension in persons without diabetes, hypertension, and cardiovascular disease
10.1186/1471-2458-13-730BMC Public Health131
Aerosols in the Pre-industrial Atmosphere
Purpose of Review: We assess the current understanding of the state and behaviour of aerosols under pre-industrial conditions and the importance for climate. Recent Findings: Studies show that the magnitude of anthropogenic aerosol radiative forcing over the industrial period calculated by climate models is strongly affected by the abundance and properties of aerosols in the pre-industrial atmosphere. The low concentration of aerosol particles under relatively pristine conditions means that global mean cloud albedo may have been twice as sensitive to changes in natural aerosol emissions under pre-industrial conditions compared to present-day conditions. Consequently, the discovery of new aerosol formation processes and revisions to aerosol emissions have large effects on simulated historical aerosol radiative forcing. Summary: We review what is known about the microphysical, chemical, and radiative properties of aerosols in the pre-industrial atmosphere and the processes that control them. Aerosol properties were controlled by a combination of natural emissions, modification of the natural emissions by human activities such as land-use change, and anthropogenic emissions from biofuel combustion and early industrial processes. Although aerosol concentrations were lower in the pre-industrial atmosphere than today, model simulations show that relatively high aerosol concentrations could have been maintained over continental regions due to biogenically controlled new particle formation and wildfires. Despite the importance of pre-industrial aerosols for historical climate change, the relevant processes and emissions are given relatively little consideration in climate models, and there have been very few attempts to evaluate them. Consequently, we have very low confidence in the ability of models to simulate the aerosol conditions that form the baseline for historical climate simulations. Nevertheless, it is clear that the 1850s should be regarded as an early industrial reference period, and the aerosol forcing calculated from this period is smaller than the forcing since 1750. Improvements in historical reconstructions of natural and early anthropogenic emissions, exploitation of new Earth system models, and a deeper understanding and evaluation of the controlling processes are key aspects to reducing uncertainties in future
Management Strategies and Clinical Outcomes of Acute Myocardial Infarction in Leukemia Patients: Insights from Nationwide United States Hospitalizations.
BACKGROUND: Patients with leukemia are at increased risk of cardiovascular events. There are limited outcomes data for patients with a history of leukemia who present with an acute myocardial infarction (AMI). METHODS: We queried the Nationwide Inpatient Sample (2004-2014) for patients with a primary discharge diagnosis of AMI, and a concomitant diagnosis of leukemia, and further stratified according to the subtype of leukemia. Multivariable logistic regression was conducted to identify the association between leukemia and major acute cardiovascular and cerebrovascular events (MACCE; composite of mortality, stroke and cardiac complications) and bleeding. RESULTS: Out of 6,750,878 AMI admissions, a total of 21,694 patients had a leukemia diagnosis. The leukemia group experienced higher rates of MACCE (11.8% vs. 7.8%), mortality (10.3% vs. 5.8%) and bleeding (5.6% vs. 5.3%). Following adjustments, leukemia was independently associated with increased odds of MACCE (OR 1.26[1.20,1.31]) and mortality (OR 1.43[1.37,1.50]) without an increased risk of bleeding (OR 0.86[0.81,0.92]). Acute myeloid leukemia (AML) was associated with approximately three-fold risk of MACCE (OR 2.81[2.51, 3.13]) and a four-fold risk of mortality (OR 3.75[3.34, 4.22]). Patients with leukemia were less likely to undergo coronary angiography (CA) (48.5% vs. 64.5%) and percutaneous coronary intervention (PCI) (28.2% vs. 42.9%) compared to those without leukemia. CONCLUSION: Patients with leukemia, especially those with AML, are associated with poor clinical outcomes after AMI, and are less likely to receive CA and PCI compared to those without leukemia. A multi-disciplinary approach between cardiologists and hematology oncologists may improve the outcomes of patients with leukemia after AMI
Pituitary-hormone secretion by thyrotropinomas
Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells
Comparison between the NASCET method and subjective visual impression in the evaluation of internal carotid artery stenosis
A Mechanistic View of the Role of E3 in Sumoylation
Sumoylation, the covalent attachment of SUMO (Small Ubiquitin-Like Modifier) to proteins, differs from other Ubl (Ubiquitin-like) pathways. In sumoylation, E2 ligase Ubc9 can function without E3 enzymes, albeit with lower reaction efficiency. Here, we study the mechanism through which E3 ligase RanBP2 triggers target recognition and catalysis by E2 Ubc9. Two mechanisms were proposed for sumoylation. While in both the first step involves Ubc9 conjugation to SUMO, the subsequent sequence of events differs: in the first E2-SUMO forms a complex with the target and E3, followed by SUMO transfer to the target. In the second, Ubc9-SUMO binds to the target and facilitates SUMO transfer without E3. Using dynamic correlations obtained from explicit solvent molecular dynamic simulations we illustrate the key roles played by allostery in both mechanisms. Pre-existence of conformational states explains the experimental observations that sumoylation can occur without E3, even though at a reduced rate. Furthermore, we propose a mechanism for enhancement of sumoylation by E3. Analysis of the conformational ensembles of the complex of E2 conjugated to SUMO illustrates that the E2 enzyme is already largely pre-organized for target binding and catalysis; E3 binding shifts the equilibrium and enhances these pre-existing populations. We further observe that E3 binding regulates allosterically the key residues in E2, Ubc9 Asp100/Lys101 E2, for the target recognition
Chromosome 2p14 Is Linked to Susceptibility to Leprosy
BACKGROUND: A genetic component to the etiology of leprosy is well recognized but the mechanism of inheritance and the genes involved are yet to be fully established. METHODOLOGY: A genome-wide single nucleotide polymorphism (SNP) based linkage analysis was carried out using 23 pedigrees, each with 3 to 7 family members affected by leprosy. Multipoint parametric and non-parametric linkage analyses were performed using MERLIN 1.1.1. PRINCIPAL FINDINGS: Genome-wide significant evidence for linkage was identified on chromosome 2p14 with a heterogeneity logarithm of odds (HLOD) score of 3.51 (rs1106577) under a recessive model of inheritance, while suggestive evidence was identified on chr.4q22 (HLOD 2.92, rs1349350, dominant model), chr. 8q24 (HLOD 2.74, rs1618523, recessive model) and chr.16q24 (HLOD 1.93, rs276990 dominant model). Our study also provided moderate evidence for a linkage locus on chromosome 6q24-26 by non-parametric linkage analysis (rs6570858, LOD 1.54, p = 0.004), overlapping a previously reported linkage region on chromosome 6q25-26. CONCLUSION: A genome-wide linkage analysis has identified a new linkage locus on chromosome 2p14 for leprosy in Pedigrees from China
Development of a nursing intervention to facilitate optimal antiretroviral-treatment taking among people living with HIV
<p>Abstract</p> <p>Background</p> <p>Failure by a large portion of PLHIV to take optimally ARV treatment can have serious repercussions on their health. The absence of a systematic treatment-taking promotion program in Quebec prompted stakeholders to develop jointly a theory- and evidence-based nursing intervention to this end. This article describes the results of a collective effort by researchers, clinicians and PLHIV to share their knowledge and create an appropriate intervention.</p> <p>Methods</p> <p>Intervention mapping was used as the framework for developing the intervention. First, the target population and environmental conditions were analyzed and a literature review conducted to identify predictors of optimal treatment taking. The predictors to emerge were self-efficacy and attitudes. Performance objectives were subsequently defined and crossed-referenced with the predictors to develop a matrix of change objectives. Then, theories of self-efficacy and persuasion (the predictors to emerge from step 1), together with practical strategies derived from these theories, were used to design the intervention. Finally, the sequence and content of the intervention activities were defined and organized, and the documentary material designed.</p> <p>Results</p> <p>The intervention involves an intensive, personalized follow-up over four direct-contact sessions, each lasting 45–75 minutes. Individuals are engaged in a learning process that leads to the development of skills to motivate themselves to follow the therapeutic plan properly, to overcome situations that make taking the antiretroviral medication difficult, to cope with side-effects, to relate to people in their social circle, and to deal with health professionals.</p> <p>Conclusion</p> <p>The intervention was validated by various health professionals and pre-tested with four PLHIV. Preliminary results support the suitability and viability of the intervention. A randomized trial is currently underway to verify the effectiveness of the intervention in promoting optimal antiretroviral treatment taking.</p
Protocol for the evaluation of a digital storytelling approach to address stigma and improve readiness to seek services among veterans
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