914 research outputs found
Prothrombin G20210A gene mutation, factor V Leiden and anticardiolipin antibodies do not influence renal graft survival after transplantation
INTRODUCTION: Thromboembolic complications are important risk factors for graft failure and worse renal transplantation outcome. Patients with thrombophilic disorders have a higher risk of thromboembolic complications. The prevalence of thrombophilic disorders and the associated risk for graft failure and for intravascular thrombosis were analyzed in renal transplant recipients. METHODS: This is a cohort study of 388 adult recipients investigated regarding the presence of thrombophilia, through the search for anticardiolipin antibodies (aCL) via ELISA and FV G1691A and PT G20210A gene mutations by multiplex PCR. RESULTS: Thrombophilic disorders were identified in 25.8% of the patients. The 2-year graft survival was similar among patients with and without thrombophilic disorder (94% versus 94%, p = 0.53), and so was the survival free of intravascular thrombosis (97% versus 97%, p = 0.83). The prevalence of intravascular thrombosis was similar in both groups (3% versus 3.5%, p = 0.82). Patients with previous kidney transplantation had a higher risk of graft failure (OR 20.8, p < 0.001) and of intravascular thrombosis (OR 6.8, p = 0.008). CONCLUSIONS: The prevalences of FV G1691A and PT G20210A gene mutations in this cohort of patients were similar to those of the general non-transplanted population. The prevalence of aCL antibodies was higher in this cohort than that observed in healthy individuals. The thrombophilic markers studied did not predict the medium-term survival of renal transplant.INTRODUĂĂO: ComplicaçÔes tromboembĂłlicas sĂŁo importantes fatores de risco para perda do enxerto e pior evolução apĂłs o transplante renal. Pacientes com defeito trombofĂlico apresentam maior risco de complicaçÔes tromboembĂłlicas. Foram analisados, entre receptores de transplante renal, a prevalĂȘncia de defeito trombofĂlico e o risco atribuĂdo a esta condição para a perda do enxerto e para o desenvolvimento de tromboses intravasculares. MĂTODOS: Estudo do tipo coorte incluindo 388 receptores adultos analisados quanto Ă presença de trombofilia de acordo com a pesquisa de anticorpos anticardiolipina (aCL) por ELISA e das mutaçÔes G1691A no gene do fator V (FV) e G20210A no gene da protrombina (PT) por PCR multiplex. RESULTADOS: Defeito trombofĂlico foi identificado em 25,8% dos pacientes. As taxas de sobrevida de 2 anos do enxerto foram semelhantes entre os pacientes com e sem defeito trombofĂlico (94% versus 94%, p = 0,53), bem como a sobrevida dos enxertos livres de tromboses intravasculares (97% versus 97%, p = 0,83). Pacientes com defeito trombofĂlico apresentaram prevalĂȘncia de tromboses intravasculares semelhante Ă do grupo-controle (3% versus 3,5%, p = 0,82). O transplante renal anterior foi associado a maior risco de perda de enxerto (OR 20,8, p < 0,001) e de ocorrĂȘncia de tromboses intravasculares (OR 6,8, p = 0,008). CONCLUSĂES: As prevalĂȘncias das mutaçÔes FV G1691A e PT G20210A na população estudada foram semelhantes Ă s da população geral nĂŁo transplantada, e a prevalĂȘncia de anticorpos aCL superou a observada entre os indivĂduos sadios. NĂŁo houve associação entre os marcadores de trombofilia estudados e a sobrevida em mĂ©dio prazo do transplante renal.UNIFESP Departamento de Medicina, Disciplina de HematologiaUNIFESP Departamento de Medicina, Disciplina de NefrologiaUNIFESP Departameto de Medicina, Disciplina de ReumatologiaUNIFESP Departamento de Medicina Preventiva, Disciplina de BioestatĂsticaUniversidad de Antofagasta Departamento de Tecnologia MedicaUNIFESP, Depto. de Medicina, Disciplina de HematologiaUNIFESP, Depto. de Medicina, Disciplina de NefrologiaUNIFESP, Departameto de Medicina, Disciplina de ReumatologiaUNIFESP, Depto. de Medicina Preventiva, Disciplina de BioestatĂsticaSciEL
Record Maximum Oscillation Frequency in C-face Epitaxial Graphene Transistors
The maximum oscillation frequency (fmax) quantifies the practical upper bound
for useful circuit operation. We report here an fmax of 70 GHz in transistors
using epitaxial graphene grown on the C-face of SiC. This is a significant
improvement over Si-face epitaxial graphene used in the prior high frequency
transistor studies, exemplifying the superior electronics potential of C-face
epitaxial graphene. Careful transistor design using a high {\kappa} dielectric
T-gate and self-aligned contacts, further contributed to the record-breaking
fmax
Risk factors, biochemical markers, and genetic polymorphisms in early coronary artery disease
OBJECTIVE: To assess the risk factors, lipid and apolipoprotein profile, hemostasis variables, and polymorphisms of the apolipoprotein AI-CIII gene in early coronary artery disease (CAD). METHODS: Case-control study with 112 patients in each group controlled by sex and age. After clinical evaluation and nutritional instruction, blood samples were collected for biochemical assays and genetic study. RESULTS: Familial history of early CAD (64 vs 39%), arterial hypertension (69 vs 36%), diabetes mellitus (25 vs 3%), and previous smoking (71 vs 46%) were more prevalent in the case group (p<0.001). Hypertension and diabetes were independent risk factors. Early CAD was characterized by higher serum levels of total cholesterol (235 ± 6 vs 209 ± 4 mg/dL), of LDL-c (154 ± 5 vs 135 ± 4 mg/dL), triglycerides (205 ± 12 vs 143 ± 9 mg/dL), and apolipoprotein B (129 ± 3 vs 105 ± 3 mg/dL), and lower serum levels of HDL-c (40 ± 1 vs 46 ± 1 mg/dL) and apolipoprotein AI (134 ± 2 vs 146 ± 2mg/dL) [p<0.01], in addition to an elevation in fibrinogen and D-dimer (p<0.02). The simultaneous presence of the rare alleles of the APO AI-CIII genes in early CAD are associated with hypertriglyceridemia (p=0.03). CONCLUSION: Of the classical risk factors, hypertension and diabetes mellitus were independently associated with early CAD. In addition to an unfavorable lipid profile, an increase in the thrombotic risk was identified in this population. An additive effect of the APO AI-CIII genes was observed in triglyceride levels.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMSciEL
Seeing phi meson through the dilepton spectra in heavy-ion collisions
Dilepton spectra from the decay of phi mesons produced in heavy-ion
collisions at SIS/GSI energies ( GeV/nucleon) are studied in the
relativistic transport model. We include phi mesons produced from
baryon-baryon, pion-baryon, and kaon-antikaon collisions. The cross sections
for the first two processes are obtained from an one-boson-exchange model,
while that for the last process is taken to be the Breit-Wigner form through
the phi meson resonance. For dileptons with invariant mass near the phi meson
peak, we also include contributions from neutron-proton bremsstrahlung,
pion-pion annihilation, and the decay of rho and omega mesons produced in
baryon-baryon and meson-baryon collisions. Effects due to medium modifications
of the kaon and vector (rho, omega and phi) meson properties are investigated.
We find that the kaon medium effects lead to a broadening of the dilepton
spectrum as a result of the increase of phi meson decay width. Furthermore, the
dropping of phi meson mass in nuclear medium leads to a shoulder structure in
the dilepton spectrum besides the main peak at the bare phi meson mass. The
experimental measurement of the dilepton spectra from heavy-ion collisions is
expected to provide useful information about the phi meson properties in dense
matter.Comment: RevTeX, 18 pages, including 13 postscript figures, submitted to
Nuclear Physics
65 YEARS OF THE DOUBLE HELIX Genetics informs precision practice in the diagnosis and management of pheochromocytoma
Although the authors of the present review have contributed to genetic discoveries in the field of pheochromocytoma research, we can legitimately ask whether these advances have led to improvements in the diagnosis and management of patients with pheochromocytoma. The answer to this question is an emphatic Yes! In the field of molecular genetics, the well-established axiom that familial (genetic) pheochromocytoma represents 10% of all cases has been overturned, with >35% of cases now attributable to germline disease-causing mutations. Furthermore, genetic pheochromocytoma can now be grouped into five different clinical presentation types in the context of the ten known susceptibility genes for pheochromocytoma-associated syndromes. We now have the tools to diagnose patients with genetic pheochromocytoma, identify germline mutation carriers and to offer gene-informed medical management including enhanced surveillance and prevention. Clinically, we now treat an entire family of tumors of the paraganglia, with the exact phenotype varying by specific gene. In terms of detection and classification, simultaneous advances in biochemical detection and imaging localization have taken place, and the histopathology of the paraganglioma tumor family has been revised by immunohistochemical-genetic classification by gene-specific antibody immunohistochemistry. Treatment options have also been substantially enriched by the application of minimally invasive and adrenal-sparing surgery. Finally and most importantly, it is now widely recognized that patients with genetic pheochromocytoma/paraganglioma syndromes should be treated in specialized centers dedicated to the diagnosis, treatment and surveillance of this rare neoplasm.Peer reviewe
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
New Natural Diterpene-Type Abietane from Tetradenia riparia Essential Oil with Cytotoxic and Antioxidant Activities
Tetradenia riparia (Hochstetter) Codd belongs to the Lamiaceae family and it was introduced in Brazil as an exotic ornamental plant. A previous study showed its antimicrobial, acaricidal and analgesic activities. Two compounds were isolated from essential oil of T. riparia leaves and identified as 9 beta, 13 beta-epoxy-7-abietene (1), a new one, and 6,7-dehydroroyleanone (2), already reported for another plant. The structure of these compounds was determined by spectroscopic analysis and by comparison with literature data. The cytotoxic activities of the essential oil and compounds 1 and 2 were determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and by tumor cells MDA-MB-435 (human breast carcinoma), HCT-8 (human colon), SF-295 (human nervous system) and HL-60 (human promyelocytic leukemia). The essential oil and compound 1 showed high cytotoxic potential of the cell lines SF-295 (78.06% and 94.80%, respectively), HCT-8 (85.00% and 86.54%, respectively) and MDA-MB-435 (59.48% and 45.43%, respectively). Compound 2 had no cytotoxic activity. The antioxidant activity was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), beta-carotene-linoleic acid system and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The inhibitory concentration (IC50 in mu g mL(-1)) for essential oil and compound 2 was, respectively 15.63 and 0.01 for DPPH; 130.1 and 109.6 for beta-carotene-linoleic acid and 1524 and 1024 for ABTS. Compound 1 had no antioxidant activity. By fractioning the oil, it was possible to identify two unpublished compounds: 1 with high cytotoxic potential and 2 with high antioxidant potential
Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
The azimuthal anisotropy of charged particles in PbPb collisions at
nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS
detector at the LHC over an extended transverse momentum (pt) range up to
approximately 60 GeV. The data cover both the low-pt region associated with
hydrodynamic flow phenomena and the high-pt region where the anisotropies may
reflect the path-length dependence of parton energy loss in the created medium.
The anisotropy parameter (v2) of the particles is extracted by correlating
charged tracks with respect to the event-plane reconstructed by using the
energy deposited in forward-angle calorimeters. For the six bins of collision
centrality studied, spanning the range of 0-60% most-central events, the
observed v2 values are found to first increase with pt, reaching a maximum
around pt = 3 GeV, and then to gradually decrease to almost zero, with the
decline persisting up to at least pt = 40 GeV over the full centrality range
measured.Comment: Replaced with published version. Added journal reference and DO
Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy
A search for new physics is performed in events with two same-sign isolated
leptons, hadronic jets, and missing transverse energy in the final state. The
analysis is based on a data sample corresponding to an integrated luminosity of
4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of
7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of
140 increase in integrated luminosity over previously published results. The
observed yields agree with the standard model predictions and thus no evidence
for new physics is found. The observations are used to set upper limits on
possible new physics contributions and to constrain supersymmetric models. To
facilitate the interpretation of the data in a broader range of new physics
scenarios, information on the event selection, detector response, and
efficiencies is provided.Comment: Published in Physical Review Letter
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