2,169 research outputs found
Counting all dyons in N =4 string theory
For dyons in heterotic string theory compactified on a six-torus, with
electric charge vector Q and magnetic charge vector P, the positive integer I =
g.c.d.(Q \wedge P) is an invariant of the U-duality group. We propose the
microscopic theory for computing the spectrum of all dyons for all values of I,
generalizing earlier results that exist only for the simplest case of I=1. Our
derivation uses a combination of arguments from duality, 4d-5d lift, and a
careful analysis of fermionic zero modes. The resulting degeneracy agrees with
the black hole degeneracy for large charges and with the degeneracy of
field-theory dyons for small charges. It naturally satisfies several physical
requirements including integrality and duality invariance. As a byproduct, we
also derive the microscopic (0,4) superconformal field theory relevant for
computing the spectrum of five-dimensional Strominger-Vafa black holes in ALE
backgrounds and count the resulting degeneracies
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Rationale and design of the Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation (ARTESiA) trial.
BACKGROUND: Device-detected subclinical atrial fibrillation (AF) refers to infrequent, short-lasting, asymptomatic AF that is detected only with long-term continuous monitoring. Subclinical AF is common and associated with an increased risk of stroke; however, the risk of stroke with subclinical AF is lower than for clinical AF, and very few patients with subclinical AF alone have been included in large AF anticoagulation trials. The net benefit of anticoagulation in patients with subclinical AF is unknown. DESIGN: ARTESiA is a prospective, multicenter, double-blind, randomized controlled trial, recruiting patients with subclinical AF detected by an implanted pacemaker, defibrillator, or cardiac monitor, and who have additional risk factors for stroke. Patients with clinical AF documented by surface electrocardiogram will be excluded from the study. Participants will be randomized to receive either apixaban (according to standard AF dosing) or aspirin 81mg daily. The primary outcome is the composite of stroke, transient ischemic attack with diffusion-weighted magnetic resonance imaging evidence of cerebral infarction, and systemic embolism. Approximately 4,000 patients will be enrolled from around 230 clinical sites, with an anticipated mean follow-up of 36months until 248 adjudicated primary outcome events have occurred. SUMMARY: ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with subclinical AF and additional risk factors
Apoe variants in an iberian alzheimer cohort detected through an optimized sanger sequencing protocol
The primary genetic risk factor for late onset Alzheimer’s disease (LOAD) is the APOE4 allele of Apolipoprotein E (APOE) gene. The three most common variants of APOE are determined by single nucleotide polymorphisms (SNPs) rs429358 and rs7412. Our aim was to estimate allele and genotype frequencies of APOE variants in an Iberian cohort, thus helping to understand differences in APOE-related LOAD risk observed across populations. We analyzed saliva or buccal swab samples from 229 LOAD patients and 89 healthy elderly controls (=68 years old) from Northern Portugal and Castile and León region, Spain. The genotyping was performed by Sanger sequencing, optimized to overcome GC content drawbacks. Results obtained in our Iberian LOAD and control cohorts are in line with previous large meta-analyses on APOE frequencies in Caucasian populations; however, we found differences in allele frequencies between our Portuguese and Spanish subgroups of AD patients. Moreover, when comparing studies from Iberian and other Caucasian cohorts, differences in APOE2 and APOE4 frequencies and subsequent different APOE-related LOAD risks must be clarified. These results show the importance of studying genetic variation at the APOE gene in different populations (including analyses at a regional level) to increase our knowledge about its clinical significance.This work was supported by ‘European Commission’ and ‘European Regional Development Fund’ (FEDER) under the project “Análisis y correlación entre el genoma completo y la actividad cerebral para la ayuda en el diagnóstico de la enfermedad de Alzheimer” (Project 0378_AD_EEGWA_2_P), (Cooperation Programme INTERREG V-A Spain-Portugal POCTEP 2014– 2020) and the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020. Portuguese funds are supporting this work through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). IG, AML, SM, and NP are funded by FCT: CEECIND/02609/2017, IF/01262/2014, CEECIND/00684/2017, and through the Decreto-Lei n◦ 57/2016 de 29 de Agosto, respectively. Spanish funds are supporting this work through ‘Ministerio de Ciencia e Innovación–Agencia Estatal de Investigación’ and FEDER under project PGC2018-098214-A-I00 and by “CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN)” through “Instituto de Salud Carlos III” co-funded with FEDER funds
ILAE Genetic Literacy Series: Postmorterm Genetic Testing in Sudden Unexpected Death in Epilepsy
A 24-year-old man with non-lesional bitemporal lobe epilepsy since age 16 years was found dead in bed around midday. He was last seen the previous night when he was witnessed to have a tonic–clonic seizure. Before his death, he was experiencing weekly focal impaired awareness seizures and up to two focal-to-bilateral tonic–clonic seizures each year. He had trialed several antiseizure medications and was on levetiracetam 1500 mg/day, lamotrigine 400 mg/day, and clobazam 10 mg/day at the time of death. Other than epilepsy, his medical history was unremarkable. Of note, he had an older brother with a history of febrile seizures and a paternal first cousin with epilepsy. No cause of death was identified following a comprehensive postmortem investigation. The coroner classified the death as “sudden unexpected death in epilepsy” (SUDEP), and it would qualify as “definite SUDEP” using the current definitions.1 This left the family with many questions unanswered; in particular, they wish to know what caused the death and whether it could happen to other family members. Could postmortem genetic testing identify a cause of death, provide closure to the family, and facilitate cascade genetic testing of first-degree family members who may be at risk of sudden death? While grieving family members struggle with uncertainty about the cause of death, we as clinicians also face similar uncertainties about genetic contributions to SUDEP, especially when the literature is sparse, and the utility of genetic testing is still being worked out. We aim to shed some light on this topic, highlighting areas where data is emerging but also areas where uncertainty remains, keeping our case in mind as we examine this clinically important area
Nutritional factors associated with chronic non-communicable diseases - the Bambuí Project: a population-based study
Assessment of a novel, capsid-modified adenovirus with an improved vascular gene transfer profile
<p>Background: Cardiovascular disorders, including coronary artery bypass graft failure and in-stent restenosis remain significant opportunities for the advancement of novel therapeutics that target neointimal hyperplasia, a characteristic of both pathologies. Gene therapy may provide a successful approach to improve the clinical outcome of these conditions, but would benefit from the development of more efficient vectors for vascular gene delivery. The aim of this study was to assess whether a novel genetically engineered Adenovirus could be utilised to produce enhanced levels of vascular gene expression.</p>
<p>Methods: Vascular transduction capacity was assessed in primary human saphenous vein smooth muscle and endothelial cells using vectors expressing the LacZ reporter gene. The therapeutic capacity of the vectors was compared by measuring smooth muscle cell metabolic activity and migration following infection with vectors that over-express the candidate therapeutic gene tissue inhibitor of matrix metalloproteinase-3 (TIMP-3).</p>
<p>Results: Compared to Adenovirus serotype 5 (Ad5), the novel vector Ad5T*F35++ demonstrated improved binding and transduction of human vascular cells. Ad5T*F35++ mediated expression of TIMP-3 reduced smooth muscle cell metabolic activity and migration in vitro. We also demonstrated that in human serum samples pre-existing neutralising antibodies to Ad5T*F35++ were less prevalent than Ad5 neutralising antibodies.</p>
<p>Conclusions: We have developed a novel vector with improved vascular transduction and improved resistance to human serum neutralisation. This may provide a novel vector platform for human vascular gene transfer.</p>
The epidemiology of injuries across the weight-training sports
Background: Weight-training sports, including weightlifting, powerlifting, bodybuilding, strongman, Highland Games, and CrossFit, are weight-training sports that have separate divisions for males and females of a variety of ages, competitive standards, and bodyweight classes. These sports may be considered dangerous because of the heavy loads commonly used in training and competition. Objectives: Our objective was to systematically review the injury epidemiology of these weight-training sports, and, where possible, gain some insight into whether this may be affected by age, sex, competitive standard, and bodyweight class. Methods: We performed an electronic search using PubMed, SPORTDiscus, CINAHL, and Embase for injury epidemiology studies involving competitive athletes in these weight-training sports. Eligible studies included peer-reviewed journal articles only, with no limit placed on date or language of publication. We assessed the risk of bias in all studies using an adaption of the musculoskeletal injury review method. Results: Only five of the 20 eligible studies had a risk of bias score ≥75 %, meaning the risk of bias in these five studies was considered low. While 14 of the studies had sample sizes >100 participants, only four studies utilized a prospective design. Bodybuilding had the lowest injury rates (0.12–0.7 injuries per lifter per year; 0.24–1 injury per 1000 h), with strongman (4.5–6.1 injuries per 1000 h) and Highland Games (7.5 injuries per 1000 h) reporting the highest rates. The shoulder, lower back, knee, elbow, and wrist/hand were generally the most commonly injured anatomical locations; strains, tendinitis, and sprains were the most common injury type. Very few significant differences in any of the injury outcomes were observed as a function of age, sex, competitive standard, or bodyweight class. Conclusion: While the majority of the research we reviewed utilized retrospective designs, the weight-training sports appear to have relatively low rates of injury compared with common team sports. Future weight-training sport injury epidemiology research needs to be improved, particularly in terms of the use of prospective designs, diagnosis of injury, and changes in risk exposure
Study design and baseline characteristics of patients on dialysis in the ASCEND-D trial
BACKGROUND: The Anemia Studies in chronic kidney disease (CKD): Erythropoiesis via a Novel prolyl hydroxylase inhibitor (PHI) Daprodustat-Dialysis (ASCEND-D) trial will test the hypothesis that daprodustat is non-inferior to comparator epoetin alfa or darbepoetin alfa for two co-primary endpoints: haemoglobin efficacy and cardiovascular safety. METHODS: We report the trial design, key demographic, clinical, and laboratory findings, and baseline therapies of 2964 patients randomised in the open-label (sponsor-blinded) active-controlled, parallel-group, randomised ASCEND-D clinical trial. We also compare baseline characteristics of ASCEND-D patients with patients who are on dialysis (CKD G5D) enrolled in other large cardiovascular outcome trials (CVOTs) and in the most relevant registries. RESULTS: The median age of patients was 58 years, 43% were female; 67% were white and 16% were black. The median haemoglobin at baseline was 10.4 g/dL. Among randomised patients, 89% were receiving haemodialysis and 11% peritoneal dialysis. Among key co-morbidities, 42% reported a history of diabetes mellitus, and 45% a history of cardiovascular disease. Median blood pressure was 134/74 mmHg. The median weekly dose of epoetin was 5751 units. Intravenous and oral iron use was noted in 64% and 11% of patients, respectively. Baseline demographics were similar to patients with CKD G5D enrolled in other CVOTs and renal patient registries. CONCLUSION: ASCEND-D will evaluate the efficacy and safety of daprodustat compared with epoetin alfa or darbepoetin alfa in the treatment of patients with anaemia with CKD G5D
Pregnancy-Associated Venous Thromboembolism: Insights from GARFIELD-VTE.
Introduction The risk of venous thromboembolism (VTE) increases during pregnancy and the puerperium such that VTE is a leading cause of maternal mortality. Methods We describe the clinical characteristics, diagnostic strategies, treatment patterns, and outcomes of women with pregnancy-associated VTE (PA-VTE) enrolled in the Global Anticoagulant Registry in the FIELD (GARFIELD)-VTE. Women of childbearing age (<45 years) were stratified into those with PA-VTE ( n = 183), which included pregnant patients and those within the puerperium, and those with nonpregnancy associated VTE (NPA-VTE; n = 1,187). Patients with PA-VTE were not stratified based upon the stage of pregnancy or puerperium. Results Women with PA-VTE were younger (30.5 vs. 34.8 years), less likely to have pulmonary embolism (PE) (19.7 vs. 32.3%) and more likely to have left-sided deep vein thrombosis (DVT) (73.9 vs. 54.8%) compared with those with NPA-VTE. The most common risk factors in PA-VTE patients were hospitalization (10.4%), previous surgery (10.4%), and family history of VTE (9.3%). DVT was typically diagnosed by compression ultrasonography (98.7%) and PE by chest computed tomography (75.0%). PA-VTE patients more often received parenteral (43.2 vs. 15.1%) or vitamin K antagonists (VKA) (9.3 vs. 7.6%) therapy alone. NPA-VTE patients more often received a DOAC alone (30.2 vs. 13.7%). The risk (hazard ratio [95% confidence interval]) of all-cause mortality (0.59 [0.18-1.98]), recurrent VTE (0.82 [0.34-1.94]), and major bleeding (1.13 [0.33-3.90]) were comparable between PA-VTE and NPA-VTE patients. Uterine bleeding was the most common complication in both groups. Conclusion VKAs or DOACs are widely used for treatment of PA-VTE despite limited evidence for their use in this population. Rates of clinical outcomes were comparable between groups
Saturn satellites as seen by Cassini Mission
In this paper we will summarize some of the most important results of the
Cassini mission concerning the satellites of Saturn. Given the long duration of
the mission, the complexity of the payload onboard the Cassini Orbiter and the
amount of data gathered on the satellites of Saturn, it would be impossible to
describe all the new discoveries made, therefore we will describe only some
selected, paramount examples showing how Cassini's data confirmed and extended
ground-based observations. In particular we will describe the achievements
obtained for the satellites Phoebe, Enceladus and Titan. We will also put these
examples in the perspective of the overall evolution of the system, stressing
out why the selected satellites are representative of the overall evolution of
the Saturn system.Comment: 34 pages, 10 figures, to appear on the special issue of Earth, Moon
and Planets for the Elba worksho
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