14,054 research outputs found
Interpretation of AMS-02 electrons and positrons data
We perform a combined analysis of the recent AMS-02 data on electrons,
positrons, electrons plus positrons and positron fraction, in a self-consistent
framework where we realize a theoretical modeling of all the astrophysical
components that can contribute to the observed fluxes in the whole energy
range. The primary electron contribution is modeled through the sum of an
average flux from distant sources and the fluxes from the local supernova
remnants in the Green catalog. The secondary electron and positron fluxes
originate from interactions on the interstellar medium of primary cosmic rays,
for which we derive a novel determination by using AMS-02 proton and helium
data. Primary positrons and electrons from pulsar wind nebulae in the ATNF
catalog are included and studied in terms of their most significant (while
loosely known) properties and under different assumptions (average contribution
from the whole catalog, single dominant pulsar, a few dominant pulsars). We
obtain a remarkable agreement between our various modeling and the AMS-02 data
for all types of analysis, demonstrating that the whole AMS-02 leptonic data
admit a self-consistent interpretation in terms of astrophysical contributions.Comment: 33 pages, 26 figures and 4 tables, v2: accepted for publication in
JCAP, minor changes relative to v
Antioxidant Supplementation in the Treatment of Aging-Associated Diseases
Oxidative stress is generally considered as the consequence of an imbalance between pro- and antioxidants species, which often results into indiscriminate and global damage at the organismal level. Elderly people are more susceptible to oxidative stress and this depends, almost in part, from a decreased performance of their endogenous antioxidant system. As many studies reported an inverse correlation between systemic levels of antioxidants and several diseases, primarily cardiovascular diseases, but also diabetes and neurological disorders, antioxidant supplementation has been foreseen as an effective preventive and therapeutic intervention for aging-associated pathologies. However, the expectations of this therapeutic approach have often been partially disappointed by clinical trials. The interplay of both endogenous and exogenous antioxidants with the systemic redox system is very complex and represents an issue that is still under debate. In this review a selection of recent clinical studies concerning antioxidants supplementation and the evaluation of their influence in aging-related diseases is analyzed. The controversial outcomes of antioxidants supplementation therapies, which might partially depend from an underestimation of the patient specific metabolic demand and genetic background, are presented
Fertility preservation in ovarian tumours
A considerable number of patients with a cancer diagnosis are of childbearing age and have not satisfied their desire for a family. Despite ovarian cancer (OC) usually occurring in older patients, 3%–14% are diagnosed at a fertile age with the overall 5-year survival rate being 91.2% in women ≤44 years of age when it is found at 1A–B stage. In this scenario, testing the safety and the efficacy of fertility sparing strategies in OC patients is very important overall in terms of quality of life. Unfortunately, the lack of randomised trials to validate conservative approaches does not guarantee the safety of fertility preservation strategies. However, evidence-based data from descriptive series suggest that in selected cases, the preservation of the uterus and at least one part of the ovary does not lead to a high risk of relapse. This conservative surgery helps to maintain organ function, giving patients of childbearing age the possibility to preserve their fertility. We hereby analysed the main evidence from the international literature on this topic in order to highlight the selected criteria for conservative management of OC patients, including healthy BRCA mutations carriers
Local anaesthesia efficacy as postoperative analgesia for open shoulder instability surgery. a prospective randomised controlled study
Background and objectives: The aim of present study was to evaluate for the first time, the clinical effect of local anaesthetic infiltration as postoperative analgesia in open shoulder surgery for anterior-inferior instability. The comparison of the local infiltration and interscalenic brachial plexus block to a control group test the local anaesthetic efficacy in this surgery.
Methods: 78 patients scheduled for open shoulder surgery were enrolled and randomly assigned to one of three groups: local infiltration anaesthesia (LIA), interscalenic brachial plexus block (IBPB) and control (C). All patients received standardized general anaesthesia and all injections were performed with the same dose and volume of anaesthetic. The number boluses delivered by a PCA pump applied at the end of surgery and the visual analogue score (VAS) at 0, 2, 4, 6, 12, 18 and 24 hours after intervention were recorded. A patient satisfaction score was also assessed.
Results: Mean bolus consumption of the rescue analgesic, compared to C, was significantly less both in the LIA and IBPB groups (P<0.05). The IBPB group showed VAS scores that were significantly better than C group at all time points (P<0.05). The VAS scores for LIA group were clinically comparable to IBPB, and only at the 2 and 6 hours, postoperative time points there were no significant differences found in respect to the C group. IBPB and LIA showed comparable patient satisfaction scores.
Conclusion: The local anaesthetic infiltration as postoperative analgesia appears to be a clinically valid alternative, statistically comparable to IBPB, with no clinical meaningful adverse effects
U.S. Philanthropic Commitments For HIV/AIDS
This report produced by the Funders Concerned About AIDS (FCAA) organisation covers 2003 HIV/AIDS grant commitments from 170 grantmaking organisations in all sectors of US philanthropy. The report presents and analyses data on total and top grantmaking, changes in giving pattern, geographic distribution and intended use of HIV/AIDS grants. The appendices list related resources for further reference
THE IMPORTANCE OF DYNAMIC EFFECTS ON THE ENZYME ACTIVITY: X-RAY STRUCTURE AND MOLECULAR DYNAMICS OF ONCONASE MUTANTS.
Onconase (ONC), a member of the RNase A superfamily extracted from oocytes of Rana pipiens, is an effective cancer killer. It is currently used in treatment of various forms of cancer. ONC antitumor properties depend on its ribonucleolytic activity that is low in comparison with other members of the superfamily. The most damaging side effect from Onconase treatment is renal toxicity, which seems to be caused by the unusual stability of the enzyme. Therefore, mutants with reduced thermal stability and/or increased catalytic activity may have significant implications for human cancer chemotherapy. In this context, we have determined the crystal structures of two Onconase mutants (M23L-ONC and C87S,des103-104-ONC) and performed molecular dynamic simulations of ONC and C87S,des103-104-ONC with the aim of explaining on structural grounds the modifications of the activity and thermal stability of the mutants. The results also provide the molecular bases to explain the lower catalytic activity of Onconase compared with RNase A and the unusually high thermal stability of the amphibian enzyme
Evaluating Risk to People and Property for Aircraft Emergency Landing Planning
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143122/1/1.I010513.pd
PHK from phenol hydroxylase of Pseudomonas sp. OX1. Insight into the role of an accessory protein in bacterial multicomponent monooxygenases
Bacterial multicomponent monooxygenases (BMMs) are members of a wide family of diiron enzymes that use molecular oxygen to hydroxylate a variety of aromatic compounds. The presence of genes encoding for accessory proteins not involved in catalysis and whose role is still elusive, is a common feature of the gene clusters of several BMMs, including phenol hydroxylases and several soluble methane monooxygenases. In this study we have expressed, purified, and partially characterized the accessory component PHK of the phenol hydroxylase from Pseudomonas sp. OX1, a bacterium able to degrade several aromatic compounds. The phenol hydroxylase (ph) gene cluster was expressed in Escherichia coli/JM109 cells in the absence and in the presence of the phk gene. The presence of the phk gene lead to an increase in the hydroxylase activity of whole recombinant cells with phenol. PHK was assessed for its ability to interact with the active hydroxylase complex. Our results show that PHK is neither involved in the catalytic activity of the phenol hydroxylase complex nor required for the assembly of apo-hydroxylase. Our results suggest instead that this component may be responsible for enhancing iron incorporation into the active site of the apo-hydroxylase
Increased circulating concentration of interluekin 2 receptor during rejection episodes in heart- or kidney-transplant recipients
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