178 research outputs found
Towards a model-independent constraint of the high-density dependence of the symmetry energy
Neutron-proton elliptic flow difference and ratio have been shown to be
promising observables in the attempt to constrain the density dependence of the
symmetry energy above the saturation point from heavy-ion collision data. Their
dependence on model parameters like microscopic nucleon-nucleon cross-sections,
compressibility of nuclear matter, optical potential, and symmetry energy
parametrization is thoroughly studied. By using a parametrization of the
symmetry energy derived from the momentum dependent Gogny force in conjunction
with the T\"{u}bingen QMD model and comparing with the experimental FOPI/LAND
data for 197Au+197Au collisions at 400 MeV/nucleon, a moderately stiff, x=-1.35
+/- 1.25, symmetry energy is extracted, a result that agrees with that of a
similar study that employed the UrQMD transport model and a momentum
independent power-law parametrization of the symmetry energy. This contrasts
with diverging results extracted from the FOPI ratio
available in the literature.Comment: 18 pages, 3 figures, accepted for publication in Phys. Rev.
Flow probe of symmetry energy in relativistic heavy-ion reactions
Flow observables in heavy-ion reactions at incident energies up to about 1
GeV per nucleon have been shown to be very useful for investigating the
reaction dynamics and for determining the parameters of reaction models based
on transport theory. In particular, the elliptic flow in collisions of
neutron-rich heavy-ion systems emerges as an observable sensitive to the
strength of the symmetry energy at supra-saturation densities. The comparison
of ratios or differences of neutron and proton flows or neutron and hydrogen
flows with predictions of transport models favors an approximately linear
density dependence, consistent with ab-initio nuclear-matter theories.
Extensive parameter searches have shown that the model dependence is comparable
to the uncertainties of existing experimental data. Comprehensive new flow data
of high accuracy, partly also through providing stronger constraints on model
parameters, can thus be expected to improve our knowledge of the equation of
state of asymmetric nuclear matter.Comment: 20 pages, 24 figures, review to appear in EPJA special volume on
nuclear symmetry energ
Search for Bremsstrahlung radiation in quasi-free n p --> n p gamma reactions
Due to the high sensitivity of the N N --> N N gamma reaction to the
nucleon-nucleon potential, Bremsstrahlung radiation is used as a tool to
investigate details of the nucleon-nucleon interaction. Such investigations can
be performed at the cooler synchrotron COSY in the Research Centre Juelich, by
dint of the COSY-11 detection system. The results of the identification of
Bremsstrahlung radiation emitted via the d p --> d p gamma reaction in data
taken with a proton target and a deuteron beam are presented and discussed.Comment: 3 pages; Presented at Meson 2004: 8th International Workshop on Meson
Production, Properties and Interaction, Krakow, Poland, 4-8 June 2004;
Submitted to International Journal of Modern Physics
The ability of lumbar Spine DXA and phalanx QUS to detect previous fractures in young thalassemic patients with hypogonadism, hypothyroidism, diabetes, and hepatitis-B: A 2-year subgroup analysis from the taranto area of Apulia Region
Background: Osteoporosis is a leading cause of morbidity in patients affected by β-thalassemia major or intermediate; we aimed to assess the association between demineralization observed in young thalassemic patients. Methods: A total of 88 patients with β-thalassemia were recruited at Microcitemia Center of Taranto Hospital under the Prevention Osteoporosis and Fractures research project from 2008 to 2010. All the patients were screened with both dual energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS). T score and Z score values were obtained for each subject. Results: The overall prevalence of demineralization was 84% with DXA and 70% with QUS, whereas normality was found in 16% of patients screened with DXA and in 30% of cases with QUS. Hypogonadism, hypothyroidism, diabetes mellitus, hepatitis-B, and the presence of previous fragility fractures were significantly associated with the demineralization status (lower T scores values) both with DXA and QUS. CONCLUSION: Our data confirm that DXA and QUS examinations are both useful for detecting bone demineralization in thalassemic patients. © 2013 Lippincott Williams & Wilkins
The ASY-EOS experiment at GSI: investigating the symmetry energy at supra-saturation densities
The elliptic-flow ratio of neutrons with respect to protons in reactions of
neutron rich heavy-ions systems at intermediate energies has been proposed as
an observable sensitive to the strength of the symmetry term in the nuclear
Equation Of State (EOS) at supra-saturation densities. The recent results
obtained from the existing FOPI/LAND data for Au+Au collisions
at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate
of the symmetry term of the EOS but suffer from a considerable statistical
uncertainty. In order to obtain an improved data set for Au+Au collisions and
to extend the study to other systems, a new experiment was carried out at the
GSI laboratory by the ASY-EOS collaboration in May 2011.Comment: Talk given by P. Russotto at the 11th International Conference on
Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1,
2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference
Series (JPCS
Muscle flaps – an alternative for decortication or resection to solve the residual space in impaired patients
Universitatea de Medicină și Farmacie „Victor Babeș”, Clinica I Chirurgie, Spitalul Clinic Judeţean de Urgenţă „Pius Brinzeu”, Clinica de Chirurgie Toracică, Spitalul Clinic Municipal de Urgenţă, Timișoara, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Decorticările sau rezecțiile pulmonare reprezintă tratamentul chirurgical obişnuit în cazul pacienților cu empiem sau
abcese pulmonare cronice. Pentru un număr redus de pacienți cu comorbidități severe asociate sau disfuncții respiratorii aceste
operații nu sunt indicate. Am analizat eficiența lambourilor musculare pentru a corecta cavitățile reziduale.
Material și metode: Am studiat pacienți cu scor de risc ASA >3, cu FEV si FVC<40, clasa NYHA mai mare sau egală cu II. Am inclus
în studiu pacienți cu empiem (1caz), aspergiliom (8 cazuri), abces pulmonar cronic (1 caz) .Am folosit diverse lambouri musculare
pentru a umple cavitățile. Pentru pacienții cu aspergilom am practicat toracotomie, cavernotomie, excizia micetomului, sutura fistulei.
Am folosit lambouri din pectoralul mare (2), muşchii intercostali (4) şi dorsal mare (2). Pentru pacienții cu supurații cronice pulmonare
am folosit dorsal mare, iar pentru empiem am asociat şi muşchi pectoral mare, trapez şi intercostal cu toracoplastie.
Rezultate: Evoluția imediată a fost favorabilă în toate cazurile cu excepția unuia care a necesitat reintervenție pentru sângerare. Un
pacient a dezvoltat serom. În toate cazurile, viabilitatea lamboului nu a fost afectată. Nu s-au inregistrat decese.
Concluzii: Scopul acestor intervenții a fost sa eliminăm spațiile libere din pleură sau plămân. Pentru pacienții tarați, decorticările
şi rezecțiile sunt operații riscante, această nouă abordare fiind benefică. Evoluția favorabilă, morbiditatea minimă după folosirea
lambourilor musculare justifică deplin acest procedeu. Chiar dacă numărul mic de cazuri în care am practicat acest tip de operație ne
limitează pentru moment spectrul de experiență, rezultatele pozitive sunt încurajatoare.Introduction: The surgical treatment of residual space for patients with empyema or chronic lung abscess is in most cases decortication
or lung resection. For a limited number of patients with severe comorbidities or respiratory dysfunction these procedures are prohibited.
We analyzed the efficiency of muscle flaps to solve the residual cavities these patients.
Material and methods: We studied patients with ASA risk > 3, with FEV and FVC < 40%, NYHA II or more. Patients with empyema
(1 case), aspergilloma (8 cases), chronic lung abscess (1 case) were included in the study. Different types of muscle flaps were used
to fill the cavities. For patients with aspergilloma we performed thoracotomy, cavernotomy, excision of the micetoma, fistulae suture;
muscles used: pectoris major – 2, intercostal – 4 and latissimus dorsi – 2. For the patient with chronic suppuration of the lung we used
latissimus, and for the empyema we associated pectoris major, trapezius and intercostal muscle with thoracoplasty.
Results: The immediate outcome was favorable in all cases except one who required exploration for bleeding. One patient developed
wound seroma. In all cases the viability of the transposed muscle was not affected. We recorded no mortality.
Conclusions: The aim of surgery is to eliminate all empty space in the pleura or lung. For impaired patients decortication or resection
are very risky, thus new approach was needed. The good outcome, minimal morbidity after using muscle flaps, fully justify their use.
The low number of patients limits our experience, but the good results are encouraging
Study of dielectron production in C+C collisions at 1 AGeV
The emission of e+e- pairs from C+C collisions at an incident energy of 1 GeV
per nucleon has been investigated. The measured production probabilities,
spanning from the pi0-Dalitz to the rho/omega! invariant-mass region, display a
strong excess above the cocktail of standard hadronic sources. The
bombarding-energy dependence of this excess is found to scale like pion
production, rather than like eta production. The data are in good agreement
with results obtained in the former DLS experiment.Comment: submitted to Physics Letters
Coendangered hard-ticks: threatened or threatening?
The overwhelming majority of animal conservation projects are focused on vertebrates, despite most of the species on Earth being invertebrates. Estimates state that about half of all named species of invertebrates are parasitic in at least one stage of their development. The dilemma of viewing parasites as biodiversity or pest has been discussed by several authors. However, ticks were omitted. The latest taxonomic synopses of non-fossil Ixodidae consider valid 700 species. Though, how many of them are still extant is almost impossible to tell, as many of them are known only from type specimens in museums and were never collected since their original description. Moreover, many hosts are endangered and as part of conservation efforts of threatened vertebrates, a common practice is the removal of, and treatment for external parasites, with devastating impact on tick populations. There are several known cases when the host became extinct with subsequent coextinction of their ectoparasites. For our synoptic approach we have used the IUCN status of the host in order to evaluate the status of specifically associated hard-ticks. As a result, we propose a number of 63 coendangered and one extinct hard-tick species. On the other side of the coin, the most important issue regarding tick-host associations is vectorial transmission of microbial pathogens (i.e. viruses, bacteria, protozoans). Tick-borne diseases of threatened vertebrates are sometimes fatal to their hosts. Mortality associated with pathogens acquired from ticks has been documented in several cases, mostly after translocations. Are ticks a real threat to their coendangered host and should they be eliminated? Up to date, there are no reliable proofs that ticks listed by us as coendangered are competent vectors for pathogens of endangered animals
Cochlear implant programming: a global survey on the state of the art
The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice
Indices of insulin sensitivity and secretion from a standard liquid meal test in subjects with type 2 diabetes, impaired or normal fasting glucose
<p>Abstract</p> <p>Background</p> <p>To provide an initial evaluation of insulin sensitivity and secretion indices derived from a standard liquid meal tolerance test protocol in subjects with normal (NFG), impaired fasting glucose (IFG) or type 2 diabetes mellitus.</p> <p>Methods</p> <p>Areas under the curve (AUC) for glucose, insulin and C-peptide from pre-meal to 120 min after consumption of a liquid meal were calculated, as were homeostasis model assessments of insulin resistance (HOMA2-IR) and the Matsuda index of insulin sensitivity.</p> <p>Results</p> <p>Subjects with NFG (n = 19), IFG (n = 19), and diabetes (n = 35) had mean ± SEM HOMA2-IR values of 1.0 ± 0.1, 1.6 ± 0.2 and 2.5 ± 0.3 and Matsuda insulin sensitivity index values of 15.6 ± 2.0, 8.8 ± 1.2 and 6.0 ± 0.6, respectively. The log-transformed values for these variables were highly correlated overall and within each fasting glucose category (r = -0.91 to -0.94, all p < 0.001). Values for the product of the insulin/glucose AUC ratio and the Matsuda index, an indicator of the ability of the pancreas to match insulin secretion to the degree of insulin resistance, were 995.6 ± 80.7 (NFG), 684.0 ± 57.3 (IFG) and 188.3 ± 16.1 (diabetes) and discriminated significantly between fasting glucose categories (p < 0.001 for each comparison).</p> <p>Conclusion</p> <p>These results provide initial evidence to support the usefulness of a standard liquid meal tolerance test for evaluation of insulin secretion and sensitivity in clinical and population studies.</p
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