339 research outputs found
Hypophosphatemic Osteomalacia Associated with Tenofovir: a Multidisciplinary Approach is Required.
Tenofovir is widely used as first-line treatment of HIV infection, although its use is sometimes complicated by a reversible proximal renal tubulopathy
Structural, spectroscopic and magnetic investigation of the LiFe1-xMnxPO4 (x = 0 - 0.18) solid solution
Different solid state and sol-gel preparations of undoped and Mn substituted cathode material LiFePO4 are investigated. Li3PO4, Fe2P2O7 and Li4P2O7 are detected and quantified by XRPD only in solid state synthesis. In addition, micro-Raman spectra reveal low amount of different iron oxides clusters. EPR data, combined with the results of magnetization measurements, evidence signals from Fe3+ ions in maghemite nanoclusters, and in Li3Fe2(PO4)3. The solâgel synthesis, showing the lowest amount of impurity phases, seems the most suitable to obtain a promising cathode material. The structural refinement gives new insights into the cation distribution of the Mn doped triphylite structure: (i) about 85% of Mn2+ ions substitutes Fe2+, the remaining 15% being located on the Li site, thus suggesting a structural disorder also confirmed by EPR and micro-Raman results; (ii) Mn ions on the Li site are responsible for the observed slight cell volume expansion
Pulmonary hypertension in autoimmune rheumatic diseases.
Objective. Pulmonary hypertension is a severe and rapidly progressive disease, particularly frequent in patients with rheumatic diseases. The aims of this study were the following: to determine the prevalence of pulmonary hypertension in Italian patients with autoimmune rheumatic diseases, and to evaluate if the presence of a rheumatic disease in general, or of a specific autoimmune rheumatic disease, is a risk factor for the development of pulmonary hypertension. Patients and Methods. One hundred and thirteen Italian patients with connective tissue diseases (105 females, 8 males), aged 19 to 83 yrs, entered the study. Fifty-one had systemic sclerosis (SSc): 49 were females, 2 males, aged 34 to 83 yrs; 41 had limited cutaneous SSc, 8 diffuse cutaneous SSc, and 2 SSc sine scleroderma. Thirty-three patients had systemic lupus erythematosus (SLE): all but one were females, their age ranged from 19 to 82 yrs. Twenty-five had rheumatoid arthritis (RA): 21 females, 4 males, aged 26 to 45 yrs. Three females and one male, 51-77 yrs, had mixed connective tissue disease (MCTD). Systolic pulmonary arterial pressure (SPAP) was assessed by Doppler echocardiography. Results. Twenty three patients had pulmonary hypertension, which was more frequent in MCTD than in SLE (75% vs 6.1%, p=0.0002) or in AR (20%, p=0.0313). Pulmonary hypertension was more frequent in SSc than in SLE (25.5% vs 6.1%, p=0.0028) and in limited than in diffuse SSc(21.6% vs 3.9%). SPAP was significanly related to age (R=0.35, P=0.0275), with patients with pulmonary hypertension older than patients with normal SPAP (66±13 vs 52±16 yrs, p=0.0003). Conclusions. These data show a significant association between pulmonary hypertension and autoimmune rheumatic diseases. Therefore pulmonary hypertension assessment seems mandatory, at least in MCTD and SSc. However, more studies are needed to clarify the relationship between age and pulmonary hypertension and to verify whether the low prevalence of pulmonary hypertension we found in our SLE patients is related or not to their lower age
Pair distribution function analysis and Mössbauer study of defects in microwave-hydrothermal LiFePO 4
Olivine-type LiFePO 4 is nowadays one of the most important cathode materials of choice for high-energy lithium ion batteries. Its intrinsic defectivity, and chiefly the so-called lithium iron anti-site, is one of the most critical issues when envisaging electrochemical applications. This paper reports a combined diffractometric (Synchrotron Radiation XRD with Rietveld and PDF analyses) and spectroscopic (Mössbauer) approach able to give a thorough characterization of the material defectivity. Such analytical procedure has been applied to a sample prepared following an innovative microwave-assisted hydrothermal synthesis route that, in a few minutes, allowed us to obtain a well crystallized material. PDF analysis, which is applied for the first time to this type of battery material, reveals the presence of disorder possibly due to Li/Fe exchange or to a local symmetry lowering. A 5% amount of iron on the lithium site has been detected both by PDF as well as by Mössbauer spectroscopy, which revealed a small percentage of Fe 3+ on the regular sites. © 2012 The Royal Society of Chemistry
Recognition of Morphometric Vertebral Fractures by Artificial Neural Networks: Analysis from GISMO Lombardia Database
BACKGROUND: It is known that bone mineral density (BMD) predicts the fracture's risk only partially and the severity and number of vertebral fractures are predictive of subsequent osteoporotic fractures (OF). Spinal deformity index (SDI) integrates the severity and number of morphometric vertebral fractures. Nowadays, there is interest in developing algorithms that use traditional statistics for predicting OF. Some studies suggest their poor sensitivity. Artificial Neural Networks (ANNs) could represent an alternative. So far, no study investigated ANNs ability in predicting OF and SDI. The aim of the present study is to compare ANNs and Logistic Regression (LR) in recognising, on the basis of osteoporotic risk-factors and other clinical information, patients with SDIâ„1 and SDIâ„5 from those with SDIâ=â0. METHODOLOGY: We compared ANNs prognostic performance with that of LR in identifying SDIâ„1/SDIâ„5 in 372 women with postmenopausal-osteoporosis (SDIâ„1, nâ=â176; SDIâ=â0, nâ=â196; SDIâ„5, nâ=â51), using 45 variables (44 clinical parameters plus BMD). ANNs were allowed to choose relevant input data automatically (TWIST-system-Semeion). Among 45 variables, 17 and 25 were selected by TWIST-system-Semeion, in SDIâ„1 vs SDIâ=â0 (first) and SDIâ„5 vs SDIâ=â0 (second) analysis. In the first analysis sensitivity of LR and ANNs was 35.8% and 72.5%, specificity 76.5% and 78.5% and accuracy 56.2% and 75.5%, respectively. In the second analysis, sensitivity of LR and ANNs was 37.3% and 74.8%, specificity 90.3% and 87.8%, and accuracy 63.8% and 81.3%, respectively. CONCLUSIONS: ANNs showed a better performance in identifying both SDIâ„1 and SDIâ„5, with a higher sensitivity, suggesting its promising role in the development of algorithm for predicting OF
Metastatic gastric cancer presenting with shoulder-hand syndrome: a case report
<p>Abstract</p> <p>Introduction</p> <p>Shoulder-hand syndrome is a relatively rare clinical entity classified as a complex regional pain syndrome type 1 and consisting essentially of a painful 'frozen shoulder' with disability, swelling, vasomotor or dystrophic changes in the homolateral hand. The pathophysiology is not completely clear but a predominant 'sympathetic' factor affecting the neural and vascular supply to the affected parts seems to be involved. Shoulder-hand syndrome has been related to many surgical, orthopedic, neurological and medical conditions; it is more often seen after myocardial infarction, hemiplegia and painful conditions of neck and shoulder, such as trauma, tumors, cervical discogenic or intraforaminal diseases and shoulder calcific tendinopathy, but has also been associated with herpetic infections, brain and lung tumors, thoracoplasty and drugs including phenobarbitone and isoniazid. The diagnosis of shoulder-hand syndrome is primarily clinical, but imaging studies, particularly bone scintigraphy, may be useful to exclude other disorders.</p> <p>Case presentation</p> <p>We report the case of a 67-year-old woman who presented with shoulder-hand syndrome as the initial manifestation of gastric cancer which had metastasized to bone.</p> <p>Conclusion</p> <p>Wider investigations are advisable in patients with atypical shoulder-hand syndrome. To the best of the authors' knowledge this is the first case of shoulder-hand syndrome associated with metastatic gastric cancer.</p
Polymorphism of the Fractalkine Receptor CX3CR1 and Systemic Sclerosis-associated Pulmonary Arterial Hypertension
Fractalkine (FKN) and its receptor CX3CR1 are critical mediators in the
vascular and tissue damage of several chronic diseases, including systemic
sclerosis (SSc) and pulmonary arterial hypertension (PAH). Interestingly, the V249I
and T280M genetic polymorphisms influence CX3CR1 expression and function. We
investigated whether these polymorphisms are associated with PAH secondary to
SSc. CX3CR1 genotypes were analyzed by PCR and sequencing in 76 patients with
limited SSc and 204 healthy controls. PAH was defined by colorDoppler echocardiography.
Homozygosity for 249II as well as the combined presence of 249II and 280MM were
significantly more frequent in patients with SSc compared to controls (17 vs 6%,
p = 0.0034 and 5 vs 1%, p = 0.0027, respectively). The 249I and 280M alleles were
associated with PAH (odd ratio [OR] 2.2, 95% confidence interval [CI] 1.01-4.75,
p = 0.028 and OR 7.37, 95%CI: 2.45-24.60, p = 0.0001, respectively). In conclusion,
the increased frequencies of 249I and 280M CX3CR1 alleles in a subgroup of
patients with SSc-associated PAH suggest a role for the fractalkine system in
the pathogenesis of this
condition. Further, the 249I allele might be associated with susceptibility to SSc
Search for heavy neutral lepton production in K+ decays
A search for heavy neutral lepton production in K + decays using a data sample collected with a minimum
bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the 10â7 to 10â6 level
are established on the elements of the extended neutrino mixing matrix |Ue4|
2 and |UΌ4|
2 for heavy
neutral lepton mass in the ranges 170â448 MeV/c2 and 250â373 MeV/c2, respectively. This improves on
the previous limits from HNL production searches over the whole mass range considered for |Ue4|2 and
above 300 MeV/c2 for |UΌ4|2
Model-independent search for the presence of new physics in events including H â γγ with = 13 TeV pp data recorded by the ATLAS detector at the LHC
Abstract
A model-independent search for new physics leading to final states containing a Higgs boson, with a mass of 125.09 GeV, decaying to a pair of photons is performed with 139 fbâ1 of
s
= 13 TeV pp collision data recorded by the ATLAS detector at the Large Hadron Collider at CERN. This search examines 22 final states categorized by the objects that are produced in association with the Higgs boson. These objects include isolated electrons or muons, hadronically decaying Ï-leptons, additional photons, missing transverse momentum, and hadronic jets, as well as jets that are tagged as containing a b-hadron. No significant excesses above Standard Model expectations are observed and limits on the production cross section at 95% confidence level are set. Detector efficiencies are reported for all 22 signal regions, which can be used to convert detector-level cross-section limits reported in this paper to particle-level cross-section constraints
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