Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 39
Filter
1.
Phys Rev Lett ; 108(12): 122002, 2012 Mar 23.
Article in English | MEDLINE | ID: mdl-22540573

ABSTRACT

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.
Article in English | MEDLINE | ID: mdl-21797598

ABSTRACT

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.
Article in English | MEDLINE | ID: mdl-20366359

ABSTRACT

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.
Phys Rev Lett ; 102(18): 182001, 2009 May 08.
Article in English | MEDLINE | ID: mdl-19518860

ABSTRACT

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

5.
J Cardiovasc Surg (Torino) ; 49(2): 245-8, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18431345

ABSTRACT

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.


Subject(s)
Aneurysm, Infected , Aneurysm, Ruptured , Listeria monocytogenes , Listeriosis , Popliteal Artery , Aged , Aneurysm, Infected/diagnosis , Aneurysm, Infected/microbiology , Aneurysm, Infected/surgery , Aneurysm, Ruptured/diagnosis , Aneurysm, Ruptured/microbiology , Aneurysm, Ruptured/surgery , Humans , Listeriosis/complications , Listeriosis/diagnosis , Male
6.
Phys Rev Lett ; 100(6): 062301, 2008 Feb 15.
Article in English | MEDLINE | ID: mdl-18352463

ABSTRACT

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

7.
Phys Rev Lett ; 99(8): 082301, 2007 Aug 24.
Article in English | MEDLINE | ID: mdl-17930942

ABSTRACT

We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a deuterium target. The muon angular distributions in the dilepton rest frame have been measured over the kinematic range 4.5

Subject(s)
Mesons , Protons , Deuterium , Elementary Particle Interactions , Models, Theoretical , Motion , Nuclear Physics
8.
Epidemiol Infect ; 135(8): 1231-47, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17445320

ABSTRACT

The purpose of this study was to assess and describe the current spectrum of emerging zoonoses between 2000 and 2006 in European countries. A computerized search of the Medline database from January 1966 to August 2006 for all zoonotic agents in European countries was performed using specific criteria for emergence. Fifteen pathogens were identified as emerging in Europe from 2000 to August 2006: Rickettsiae spp., Anaplasma phagocytophilum, Borrelia burgdorferi, Bartonella spp., Francisella tularensis, Crimean Congo Haemorrhagic Fever Virus, Hantavirus, Toscana virus, Tick-borne encephalitis virus group, West Nile virus, Sindbis virus, Highly Pathogenic Avian influenza, variant Creutzfeldt-Jakob disease, Trichinella spp., and Echinococus multilocularis. Main risk factors included climatic variations, certain human activities as well as movements of animals, people or goods. Multi-disciplinary preventive strategies addressing these pathogens are of public health importance. Uniform harmonized case definitions should be introduced throughout Europe as true prevalence and incidence estimates are otherwise impossible.


Subject(s)
Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/transmission , Disease Vectors , Zoonoses/epidemiology , Zoonoses/transmission , Animals , Europe/epidemiology , Humans , Risk Factors
9.
Vasa ; 35(4): 249-51, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17109369

ABSTRACT

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.


Subject(s)
Angiography, Digital Subtraction , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortography , Blood Vessel Prosthesis Implantation , Kidney/abnormalities , Tomography, X-Ray Computed , Aged , Aortic Aneurysm, Abdominal/surgery , Follow-Up Studies , Humans , Kidney/blood supply , Kidney/diagnostic imaging , Male
10.
Vasa ; 35(2): 106-11, 2006 May.
Article in English | MEDLINE | ID: mdl-16796010

ABSTRACT

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.


Subject(s)
Embolism/surgery , Ischemia/surgery , Mesenteric Vascular Occlusion/surgery , Thrombosis/surgery , Acute Disease , Adult , Aged , Aged, 80 and over , Early Diagnosis , Embolectomy , Embolism/diagnosis , Embolism/diagnostic imaging , Embolism/mortality , Female , Humans , Ischemia/diagnostic imaging , Ischemia/mortality , Male , Medical Records , Mesenteric Artery, Superior/diagnostic imaging , Mesenteric Artery, Superior/surgery , Mesenteric Vascular Occlusion/diagnostic imaging , Mesenteric Vascular Occlusion/mortality , Mesenteric Veins/diagnostic imaging , Mesenteric Veins/surgery , Middle Aged , Radiography , Retrospective Studies , Survival Rate , Thrombectomy , Thrombosis/diagnosis , Thrombosis/diagnostic imaging , Thrombosis/mortality
11.
Vasa ; 35(1): 53-5, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16535972

ABSTRACT

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.


Subject(s)
Arteriovenous Fistula/surgery , Fracture Fixation, Internal , Popliteal Artery/surgery , Postoperative Complications , Aged , Arteriovenous Fistula/diagnostic imaging , Arteriovenous Fistula/etiology , Follow-Up Studies , Humans , Male , Popliteal Artery/diagnostic imaging , Popliteal Artery/injuries , Stents , Ultrasonography , Vascular Patency
12.
Eur J Vasc Endovasc Surg ; 31(5): 509-15, 2006 May.
Article in English | MEDLINE | ID: mdl-16427340

ABSTRACT

BACKGROUND: Our aim was to investigate the association of inflammation and Chlamydia pneumoniae infection with the presence and severity of peripheral arterial disease. METHODS: Twenty-eight patients whose initial claudication distance (ICD) in the traditional constant-load treadmill test was <200 m, underwent femoral endarterectomy as part of their interventional treatment (group A). Group B consisted of 23 patients whose ICD was >200 m and were put on medication and a daily exercise program. The control group consisted of 30 non-vascular patients of the Ophthalmology Department (group C). We measured the levels of C-reactive protein, fibrinogen, vascular cell adhesion molecule-1 and tumor necrosis factor-alpha, and the titers of IgA and IgG antibodies against C. pneumoniae in the serum of all the patients. Finally, the atheromas and vein segments of group A patients, were immunohistochemically (IHC) examined for the presence of C. pneumoniae. RESULTS: Peripheral arterial disease (PAD) patients, had significantly higher CRP (p=0.026) and anti-Cp IgA levels (p=0.001) when compared to control subjects, after a multiple linear regression analysis. The odds ratio for the prevalence of femoral atherosclerosis was 3.16 for IgA seropositive patients (CI 1.15-8.67). When comparing group A and group B patients, CRP (p=0.003) and IgA (p=0.011), were significantly correlated with severe PAD. Group A patients with positive immunohistochemical examination of the plaque, had higher anti-Cp IgA levels (p=0.023) and TNF-alpha values (p=0.031), compared to the IHC negative patients. C. pneumoniae was detected in 50% of the femoral atheromas, but in only 3.6% of the veins. CONCLUSION: This study supports the hypothesis that inflammation (CRP) and chronic C. pneumoniae infection (IgA seropositivity), have an important role in lower limb atherosclerosis and correlate with the severity of the disease.


Subject(s)
Atherosclerosis/blood , Atherosclerosis/microbiology , Chlamydophila pneumoniae/isolation & purification , Inflammation Mediators/blood , Peripheral Vascular Diseases/blood , Peripheral Vascular Diseases/microbiology , Aged , Antibodies, Bacterial/blood , C-Reactive Protein/metabolism , Case-Control Studies , Chlamydophila pneumoniae/immunology , Cross-Sectional Studies , Female , Fibrinogen/metabolism , Humans , Male , Middle Aged , Severity of Illness Index , Tumor Necrosis Factor-alpha/metabolism , Vascular Cell Adhesion Molecule-1/blood
13.
Eur J Vasc Endovasc Surg ; 31(4): 386-93, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16359887

ABSTRACT

PURPOSE: The aim of this article is to discuss the role of inflammation in atherosclerosis. SUMMARY: An initial chemical, mechanical or immunological insult induces endothelial dysfunction. This triggers a cascade of inflammatory reactions, in which monocytes, macrophages, T lymphocytes and vascular smooth muscle cells participate. Leukocyte adhesion molecules, cytokines, growth factors and metalloproteinases participate in all stages of atherogenesis. Almost all of the traditional risk factors for atherosclerosis are associated with and participate in the inflammatory process. Many infectious agents, mainly Chlamydia pneumoniae, have been proposed as potential triggers of the cascade. The immune system has been implicated in plaque formation, through the activation of cellular and humoral immunity against innate or microbial heat shock protein 60. Methods of detection of systemic or local plaque inflammation have been developed and research is being conducted on the potential use of anti-inflammatory and antibiotic drugs in atherosclerosis.


Subject(s)
Atherosclerosis/physiopathology , Inflammation/physiopathology , Atherosclerosis/immunology , Atherosclerosis/microbiology , Bacterial Infections/physiopathology , Endothelium, Vascular/physiopathology , Humans , Inflammation/immunology , Inflammation/microbiology , Risk Factors
14.
Eur J Vasc Endovasc Surg ; 28(2): 142-5, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15234694

ABSTRACT

OBJECTIVE: To determine the early and late outcome of percutaneous transluminal angioplasty (PTA) for critical limb ischaemia (CLI) in patients aged 80 years and over. METHODS: Retrospective case note review of all patients aged 80 years and over who underwent attempted PTA for CLI between 1st January 1999 and 31st December 2000. Minimum follow-up was 12 months with a maximum of 42 months. RESULTS: One hundred and twenty-eight PTAs were attempted in 113 severely ischaemic limbs of 98 patients (36 men and 62 women of median age 84, range 80-97, years). Seventy patients had significant co-morbidity. The indication for revascularisation was rest pain in 47 procedures, ulceration in 66 and digital gangrene in 15. The anatomical segments involved were iliac (n=19), superficial femoral (n=92), popliteal (n=91) and infrapopliteal (n=72). The technical success rate was 108 of 128 (84%) procedures. Early technical complications occurred in 24 (19%) procedures: four major, 20 minor. The 30-day operative mortality rate was six of 128 (5%). The median (range) in-hospital stay was two (1-72) days. Early or delayed surgical revascularisation was required in 11 limbs and there were six major limb amputations during the study period. The 24-month patient survival rate was 59%. The 24-month primary and secondary symptomatic patency and secondary limb salvage rates were 52, 69 and 95%, respectively. DISCUSSION: PTA is safe, requires a short hospital stay, and is clinically effective in the majority of very elderly patients with CLI. Although minimally invasive, the relatively high peri-procedural mortality rate and low 24-month survival rate reflect the high co-morbidity of this group of patients.


Subject(s)
Angioplasty, Balloon , Ischemia/therapy , Leg/blood supply , Aged , Aged, 80 and over , Female , Humans , Length of Stay , Male , Vascular Patency
15.
Int Angiol ; 23(1): 14-7, 2004 Mar.
Article in English | MEDLINE | ID: mdl-15156124

ABSTRACT

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.


Subject(s)
Carotid Artery Diseases/blood , Carotid Artery Diseases/physiopathology , Hemostasis , Aged , Female , Humans , Male , Middle Aged , Regression Analysis
16.
Phys Rev Lett ; 91(21): 211801, 2003 Nov 21.
Article in English | MEDLINE | ID: mdl-14683289

ABSTRACT

We present measurements of the polarization of the J/psi produced in 800-GeV proton interactions with a copper target. Polarization of the J/psi is sensitive to the ccmacr; production and hadronization processes. A longitudinal polarization is observed at large x(F), while at small x(F) the state is produced essentially unpolarized or slightly transversely polarized. No significant variation of the polarization is observed versus p(T).

17.
Int Angiol ; 22(3): 322-4, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14612861

ABSTRACT

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.


Subject(s)
Angioplasty, Balloon/methods , Embolism/therapy , Popliteal Artery , Aged , Aged, 80 and over , Female , Humans , Treatment Outcome
19.
Eur J Vasc Endovasc Surg ; 26(3): 293-8, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14509893

ABSTRACT

OBJECTIVES: Elevated intra-abdominal pressure (IAP) may cause widespread organ dysfunction (abdominal compartment syndrome) through effects on the respiratory, cardiac, renal and gastro-intestinal systems. The aim of this study was to document IAP following aneurysm surgery, and to determine the effect of IAH on outcome. DESIGN: Prospective observational study. SETTING: University Hospital. SUBJECTS: The patient cohort comprised 75 patients undergoing infra-renal aneurysm repair (53 non-ruptured [40 conventional--1 death, 13 endovascular] and 22 conventionally repaired ruptured AAA--8 deaths). IAP was quantified by bladder manometry at the termination of the procedure and at 24 h intervals in patients who remained intubated. Physiological indices of organ function were recorded. Statistical analysis utilized the unpaired t-test, Fischer's exact test and Pearson's correlation. RESULTS: IAP was significantly higher at abdominal closure following ruptured aneurysm repair (15.4 mmHg [SE 1.6]) than conventional (10.5 [0.89]) or endovascular elective repair (6.4 [1.0]) of non-ruptured AAA. The sensitivity and specificity of IAP to predict subsequent mortality was analysed using a receiver characteristic operating curve. This analysis demonstrated that a cut off of 15 mmHg was the most useful for indicating patients at risk (sensitivity 0.66, specificity 0.79). Physiological indices of organ dysfunction (pH[P = 0.027], base excess [p = 0.005], peak inspiratory pressure [p = 0.0015], CVP and urine output [p = 0.0029]) were significantly impaired in patients with IAP > or = 15 mmHg, in comparison to patients with lower pressures. IAP correlated significantly with indices of cardiac (CVP p = 0.038), respiratory (PaO2/FiO2, p = 0.026), and renal function (urine output p = 0.046). CONCLUSIONS: These data suggest that the management of IAH may have a role following repair of ruptured AAA. High intra-abdominal pressures rarely complicate elective or endovascular aneurysm repair.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Abdomen , Aged , Female , Humans , Male , Postoperative Complications/mortality , Postoperative Complications/physiopathology , Pressure , Prospective Studies , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...