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1.
Phys Rev Lett ; 108(12): 122002, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22540573

RESUMO

The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d(Δ)- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d(Δ)- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A(γ)-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A(γ)-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V(ud)/V(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.

2.
Phys Rev Lett ; 107(2): 022501, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21797598

RESUMO

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasielastic scattering on the deuteron, at backward angles (lab scattering angle of 108°) for Q² = 0.22 GeV²/c² and 0.63 GeV²/c² at beam energies of 362 and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single-photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (πN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasistatic deuterium approximation, and is also in agreement with theory.

3.
Phys Rev Lett ; 104(1): 012001, 2010 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-20366359

RESUMO

We have measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q2=0.22 and 0.63 GeV2. They are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of approximately < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial-vector current at these four-momentum transfers.

4.
J Cardiovasc Surg (Torino) ; 49(2): 245-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18431345

RESUMO

We describe a case of a voluminous infected aneurysm of the popliteal artery, with Listeria monocytogenes (LM) associated with rupture, in a 72-year old man. After radical resection of the aneurysm a reconstruction was not necessary, because of the sufficient blood supply, due to the pre-existent good development of collateral circulation. The patient was discharged on the 12th postoperative day with primary healing of the wound and viable leg. Adequate antibiotic treatment was continued for 4 weeks. In the following 18 months the serial clinical examinations, laboratory tests and ultrasound scans have shown no evidence of reinfection.


Assuntos
Aneurisma Infectado , Aneurisma Roto , Listeria monocytogenes , Listeriose , Artéria Poplítea , Idoso , Aneurisma Infectado/diagnóstico , Aneurisma Infectado/microbiologia , Aneurisma Infectado/cirurgia , Aneurisma Roto/diagnóstico , Aneurisma Roto/microbiologia , Aneurisma Roto/cirurgia , Humanos , Listeriose/complicações , Listeriose/diagnóstico , Masculino
5.
Vasa ; 35(2): 106-11, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16796010

RESUMO

BACKGROUND: Acute mesenteric ischaemia remains a serious condition requiring emergency, surgical management. The mortality rate still remains high, due to the unspecific and delayed diagnosis and ranges from 59% to 100%. Purpose of our study is to present our experience in the management of the disease. PATIENTS AND METHODS: This is a retrospective study of 61 patients treated surgically for acute mesenteric ischaemia, between 1988 and 2004. All patients underwent a laparotomy. 75% of the patients were operated within the first 24 hours and the rest within 48 hours. RESULTS: Superior mesenteric artery embolism occurred in 36 (59%), thrombosis in 21 (34%) and superior mesenteric vein thrombosis in 4 (7%) cases. In 49 (80%) cases, embolectomy or thrombectomy of the superior mesenteric artery with resection of the necrotic segment of the bowel was performed. Twelve cases (20%) were considered inoperable because of massive bowel necrosis. According to our study mortality and morbidity rate amounts to 75% and 80% respectively. No significant difference in the mortality rate between patients with embolism (75%) and thrombosis (76%) was found. However a significant increase of mortality rate was observed when the surgical intervention became afterwards the first 24-hour period. (72% versus 87%). Patients who underwent embolectomy or thrombectomy with bowel resection presented an improved survival rate compared with patients that underwent only bowel resection. (p = 0.019) CONCLUSIONS: Acute mesenteric ischaemia has the characteristics of a highly lethal condition and only early recognition and appropriate treatment can reduce the potential for a devastating outcome. The reduction of time interval from the beginning of symptoms up to the treatment remains the main critical important factor.


Assuntos
Embolia/cirurgia , Isquemia/cirurgia , Oclusão Vascular Mesentérica/cirurgia , Trombose/cirurgia , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Precoce , Embolectomia , Embolia/diagnóstico , Embolia/diagnóstico por imagem , Embolia/mortalidade , Feminino , Humanos , Isquemia/diagnóstico por imagem , Isquemia/mortalidade , Masculino , Prontuários Médicos , Artéria Mesentérica Superior/diagnóstico por imagem , Artéria Mesentérica Superior/cirurgia , Oclusão Vascular Mesentérica/diagnóstico por imagem , Oclusão Vascular Mesentérica/mortalidade , Veias Mesentéricas/diagnóstico por imagem , Veias Mesentéricas/cirurgia , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Taxa de Sobrevida , Trombectomia , Trombose/diagnóstico , Trombose/diagnóstico por imagem , Trombose/mortalidade
6.
Vasa ; 35(4): 249-51, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17109369

RESUMO

We report the preoperative diagnosis and surgical treatment of an abdominal aortic aneurysm (AAA) in association with a horseshoe kidney (HSK) in a 70-year-old man. Through a median laparotomy a vascular tube graft was successfully used for repair the AAA. The extensive parenchymal isthmus overlying the aneurysm remained intact.


Assuntos
Angiografia Digital , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aortografia , Implante de Prótese Vascular , Rim/anormalidades , Tomografia Computadorizada por Raios X , Idoso , Aneurisma da Aorta Abdominal/cirurgia , Seguimentos , Humanos , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Masculino
7.
Vasa ; 35(1): 53-5, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16535972

RESUMO

We report a case of an arteriovenous fistula (AVF) following osteosynthetic treatment of a fracture of the lower limb 13 years ago. A stent-graft technique had been used to close a high flow traumatic AVF between the popliteal artery and the popliteal vein. The failure to properly evaluate traumatic AVF may sometimes lead to remarkable delay in diagnosis with devastating consequences including edema, ischaemia, ulceration and high output heart failure. Endovascular treatment of these lesions is promising but long-term follow-up will be required to determine the durable patency and the onset of potential complications.


Assuntos
Fístula Arteriovenosa/cirurgia , Fixação Interna de Fraturas , Artéria Poplítea/cirurgia , Complicações Pós-Operatórias , Idoso , Fístula Arteriovenosa/diagnóstico por imagem , Fístula Arteriovenosa/etiologia , Seguimentos , Humanos , Masculino , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/lesões , Stents , Ultrassonografia , Grau de Desobstrução Vascular
8.
Phys Rev Lett ; 84(15): 3256-60, 2000 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-11019064

RESUMO

Measurements of the suppression of the yield per nucleon of J/psi and psi(') production for 800 GeV/ c protons incident on heavy nuclear targets, relative to light nuclear targets, have been made with very broad coverage in x(F) and p(T). The observed suppression is smallest at x(F) values of 0.25 and below, and increases at larger values of x(F). It is also strongest at small p(T). Substantial differences between psi(') and J/psi production are observed for the first time in p-A collisions. The suppression for psi(') production is stronger than that for J/psi for x(F) near zero, but becomes comparable to that for J/psi for x(F)>0.6.

9.
J Cardiovasc Surg (Torino) ; 43(3): 399-401, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12055573

RESUMO

Adventitial cystic disease of the popliteal artery (ACDPA) is an unusual cause of a unilateral progressive intermittent claudication in young or middle-aged men. In the case described here, ultrasound (US) examination provided the preoperative diagnosis. The lesion was dealt with by simple evacuation of the cyst and excision of the wall. This simple treatment is all that is required in the majority of cases and provides good long-term results.


Assuntos
Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/cirurgia , Claudicação Intermitente/diagnóstico por imagem , Claudicação Intermitente/cirurgia , Artéria Poplítea , Adulto , Humanos , Masculino , Ultrassonografia
10.
Int Angiol ; 22(3): 322-4, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14612861

RESUMO

We present a modification of a previously reported endovascular technique where a large embolus was "pushed and parked" into a diseased artery. A saddle embolus at the bifurcation of the popliteal artery, which occurred as a complication after a percutaneous subintimal recanalization, was pushed and parked into the tibio-peroneal trunk. This was achieved using 2 balloon catheters, one to disengage the embolus from the anterior tibial artery, and the other to push the embolus into the tibio-peroneal trunk, thus establishing flow into the anterior tibial artery. Pushing and parking an embolus into a less useful vessel when all attempts at catheter embolectomy have failed is a simple and quick method which should be borne in mind by all vascular interventionalists.


Assuntos
Angioplastia com Balão/métodos , Embolia/terapia , Artéria Poplítea , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Resultado do Tratamento
11.
Int Angiol ; 23(1): 14-7, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15156124

RESUMO

AIM: Since conventional risk factors predict less than one half of future cardiovascular events, other factors that contribute to atherogenesis need to be evaluated. The aim of this study was to investigate whether clotting factors are associated with carotid artery disease. Furthermore, we tried to determine whether clotting factors could be used to predict the risk of cerebrovascular events in patients with internal carotid artery stenosis. METHODS: Twenty-six patients with high-grade (>70%) internal carotid artery stenosis and 43 age-matched controls were evaluated for atherogenic risk factors and hemostatic function. Laboratory tests included plasma assays of fibrinogen, tissue plasminogen activator (TPA), D-dimer, plasminogen activator inhibitor 1 (PAI-1), plasminogen and factor VII:c. Nineteen (72%) patients had history of stroke or transient ischemic attack, while the remaining 7 (28%) were asymptomatic. Statistical analysis was performed using multiple linear regression analysis. RESULTS: Carotid artery stenosis was associated with high levels of TPA (p<0.001), D-dimer (p=0.019) and PAI-1 (p<0.001). No statistically significant correlation was found between the presence of carotid artery disease and the levels of fibrinogen (p=0.28), plasminogen (p=0.96) or factor VII:c (p=0.19). As regards the clinical manifestations, none of the studied clotting factors was correlated with the history of cerebrovascular events in the patients with carotid stenosis. CONCLUSION: The results of this study show that the hemostatic system may play a role in the development of carotid artery atherosclerotic disease, while it does not seem to affect the development of symptoms in patients with carotid stenosis.


Assuntos
Doenças das Artérias Carótidas/sangue , Doenças das Artérias Carótidas/fisiopatologia , Hemostasia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão
13.
Vasa ; 29(1): 87-8, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10731897

RESUMO

Aneurysms of the distal branches of the external carotid artery are rare and usually traumatic in origin. We present two cases which were treated in our clinic. The first case is about a traumatic aneurysm of the left superficial temporal artery (STA) in a young boy 8 years old. The young patient developed a pulsatile mass above his left eyebrow ten days after a bite by a boy of the same age. The second case is referred in a 36-year old woman with a pulsatile mass behind the right ear, which was an aneurysm of the posterior auricular artery. The treatment was ligation and resection under local anesthesia in the first case and under general anesthesia in the latter. Surgeons' familiarity with this entity is important for diagnosis and treatment.


Assuntos
Aneurisma/diagnóstico , Doenças das Artérias Carótidas/diagnóstico , Orelha Externa/irrigação sanguínea , Artérias Temporais , Adulto , Angiografia Digital , Artéria Carótida Externa , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino
19.
Phys Rev Lett ; 102(18): 182001, 2009 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-19518860

RESUMO

We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5

20.
Phys Rev Lett ; 100(6): 062301, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18352463

RESUMO

We report a high statistics measurement of Upsilon production with an 800 GeV/c proton beam on hydrogen and deuterium targets. The dominance of the gluon-gluon fusion process for Upsilon production at this energy implies that the cross section ratio, sigma(p+d-->Upsilon)/2sigma(p+p-->Upsilon), is sensitive to the gluon content in the neutron relative to that in the proton. Over the kinematic region 0

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