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1.
Phys Rev Lett ; 121(2): 022502, 2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30085703

RESUMO

Lifetimes of the first excited 2^{+} and 4^{+} states in the extremely neutron-deficient nuclide ^{172}Pt have been measured for the first time using the recoil-distance Doppler shift and recoil-decay tagging techniques. An unusually low value of the ratio B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+})=0.55(19) was found, similar to a handful of other such anomalous cases observed in the entire Segré chart. The observation adds to a cluster of a few extremely neutron-deficient nuclides of the heavy transition metals with neutron numbers N≈90-94 featuring the effect. No theoretical model calculations reported to date have been able to explain the anomalously low B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios observed in these cases. Such low values cannot, e.g., be explained within the framework of the geometrical collective model or by algebraic approaches within the interacting boson model framework. It is proposed that the group of B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios in the extremely neutron-deficient even-even W, Os, and Pt nuclei around neutron numbers N≈90-94 reveal a quantum phase transition from a seniority-conserving structure to a collective regime as a function of neutron number. Although a system governed by seniority symmetry is the only theoretical framework for which such an effect may naturally occur, the phenomenon is highly unexpected for these nuclei that are not situated near closed shells.

2.
Eur J Vasc Endovasc Surg ; 54(2): 254-263, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28655506

RESUMO

OBJECTIVE/BACKGROUND: The development of ascending aortic dilatation in patients with bicuspid aortic valve (BAV) is highly variable, and this makes surgical decision strategies particularly challenging. The purpose of this study was to identify new predictors, other than the well established aortic size, that may help to stratify the risk of aortic dilatation in BAV patients. METHODS: Using fluid-structure interaction analysis, both haemodynamic and structural parameters exerted on the ascending aortic wall of patients with either BAV (n = 21) or tricuspid aortic valve (TAV; n = 13) with comparable age and aortic diameter (42.7 ± 5.3 mm for BAV and 45.4 ± 10.0 mm for TAV) were compared. BAV phenotypes were stratified according to the leaflet fusion pattern and aortic shape. RESULTS: Systolic wall shear stress (WSS) of BAV patients was higher than TAV patients at the sinotubular junction (6.8 ± 3.3 N/m2 for BAV and 3.9 ± 1.3 N/m2 for TAV; p = .006) and mid-ascending aorta (9.8 ± 3.3 N/m2 for BAV and 7.1 ± 2.3 N/m2 for TAV; p = .040). A statistically significant difference in BAV versus TAV was also observed for the intramural stress along the ascending aorta (e.g., 2.54 × 105 ± 0.32 × 105 N/m2 for BAV and 2.04 × 105 ± 0.34 × 105 N/m2 for TAV; p < .001) and pressure index (0.329 ± 0.107 for BAV and 0.223 ± 0.139 for TAV; p = .030). Differences in the BAV phenotypes (i.e., BAV type 1 vs. BAV type 2) and aortopathy (i.e., isolated tubular vs. aortic root dilatations) were associated with asymmetric WSS distributions in the right anterior aortic wall and right posterior aortic wall, respectively. CONCLUSION: These findings suggest that valve mediated haemodynamic and structural parameters may be used to identify which regions of aortic wall are at greater stress and enable the development of a personalised approach for the diagnosis and management of aortic dilatation beyond traditional guidelines.


Assuntos
Aorta/fisiopatologia , Aneurisma Aórtico/fisiopatologia , Valva Aórtica/anormalidades , Doenças das Valvas Cardíacas/fisiopatologia , Hemodinâmica , Idoso , Aorta/diagnóstico por imagem , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/etiologia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Aortografia/métodos , Doença da Válvula Aórtica Bicúspide , Velocidade do Fluxo Sanguíneo , Angiografia por Tomografia Computadorizada , Dilatação Patológica , Feminino , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Modelagem Computacional Específica para o Paciente , Fluxo Sanguíneo Regional , Fatores de Risco , Estresse Mecânico
3.
Am J Transplant ; 16(10): 2816-2835, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27273869

RESUMO

The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody-mediated liver allograft rejection at the 11th (Paris, France, June 5-10, 2011), 12th (Comandatuba, Brazil, August 19-23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5-10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody-mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included.


Assuntos
Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Isoanticorpos/imunologia , Transplante de Fígado/efeitos adversos , Aloenxertos , Humanos , Relatório de Pesquisa
4.
Acta Physiol (Oxf) ; 215(1): 37-45, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26052867

RESUMO

AIM: To analyse the effects of angiotensin II (Ang II) on the contractility of human sigmoid colon, and to characterize the subtype(s) of receptor(s) involved and the related action mechanism. METHODS: The contractility of sigmoid colon circular muscle strips was recorded isometrically. RT-PCR and immunohistochemistry were used to reveal the eventual existence of a local renin-angiotensin system (RAS) and the distribution of Ang II receptors. RESULTS: Transcripts encoding for the Ang II type 1 (AT1 ) and the Ang II type 2 (AT2 ) receptor subtypes and for the angiotensin-converting enzyme in the whole-thickness muscular wall were observed. Ang II caused a concentration-dependent contractile response, which is antagonized by losartan, AT1 receptor antagonist, but not by PD123319, AT2 receptor antagonist. The joint application of losartan and PD123319 did not produce any additive effect. The contractile response to Ang II was partially reduced by tetrodotoxin, Na(+) voltage-gated neural channel blocker, and to some extent by SR48968, tachykinin NK2 receptor antagonist. However, hexamethonium, nicotinic receptor antagonist, atropine, cholinergic muscarinic receptor antagonist and SR140333, tachykinin NK1 receptor antagonist, were ineffective. Immunohistochemical analysis showed that AT1 receptors were expressed on the smooth muscle layers and myenteric plexus. CONCLUSION: Ang II positively modulates the spontaneous contractile activity of human sigmoid colon via activation of post-junctional and pre-junctional AT1 receptors, the latter located on the enteric nerves that modulate the release of tachykinins. The presence of the components of RAS in the human colon suggests that Ang II can be also locally generated to control colonic motility.


Assuntos
Angiotensina II/farmacologia , Colo Sigmoide/efeitos dos fármacos , Colo Sigmoide/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor Tipo 2 de Angiotensina/metabolismo , Sistema Renina-Angiotensina/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imidazóis/farmacologia , Masculino , Pessoa de Meia-Idade , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Peptidil Dipeptidase A/metabolismo , Piridinas/farmacologia , Sistema Renina-Angiotensina/fisiologia
5.
Transplant Proc ; 45(2): 480-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23498782

RESUMO

Bone marrow-derived mesenchymal stem cells were investigated as prompters of liver regeneration in an experimental model of acute hepatic injury. A model was created in Wistar rats through intraperitoneal injection of carbon tetrachloride (CCl4). Bone marrow-derived mesenchymal stem cells collected from the long bones of 10 Wistar rats were intravenously infused 24 hours after induction of acute liver failure in 16 rats, group A. In group B, the control group, 16 rats received a peritoneal injection of CCl4, and an intravenous infusion of normal saline solution. All rats were sacrificed at 2, 3, 4, and 7 days post-CCl4 injection to examined biochemical markers and pathological appearances. The platelet counts were higher in group A versus group B on post-CCl4 infusion days 2 (P = .02) and 3 (P = .001), as were the transaminase trends in glutamic oxaloacetic (P = .002), and glutamic-pyruvic transaminases (P < .0001). Pathological examination showed a greater grade of hepatocellular necrosis with neutrophilic infiltration in group B (P = .02). In conclusion, infusion of bone marrow-derived mesenchymal stem cell resulted in a less aggressive picture of hepatic damage.


Assuntos
Transplante de Medula Óssea , Doença Hepática Induzida por Substâncias e Drogas/cirurgia , Regeneração Hepática , Fígado/patologia , Transplante de Células-Tronco Mesenquimais , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Animais , Aspartato Aminotransferases/sangue , Biomarcadores/sangue , Tetracloreto de Carbono , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Citometria de Fluxo , Coeficiente Internacional Normatizado , Fígado/enzimologia , Necrose , Infiltração de Neutrófilos , Fenótipo , Contagem de Plaquetas , Ratos , Ratos Wistar , Índice de Gravidade de Doença , Fatores de Tempo
6.
Phys Rev Lett ; 110(24): 242502, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-25165917

RESUMO

In recent experiments at the velocity filter Separator for Heavy Ion reaction Products (SHIP) (GSI, Darmstadt), an extended and improved set of α-decay data for more than 20 of the most neutron-deficient isotopes in the region from lead to thorium was obtained. The combined analysis of this newly available α-decay data, of which the (186)Po decay is reported here, allowed us for the first time to clearly show that crossing the Z = 82 shell to higher proton numbers strongly accelerates the α decay. From the experimental data, the α-particle formation probabilities are deduced following the Universal Decay Law approach. The formation probabilities are discussed in the framework of the pairing force acting among the protons and the neutrons forming the α particle. A striking resemblance between the phenomenological pairing gap deduced from experimental binding energies and the formation probabilities is noted. These findings support the conjecture that both the N = 126 and Z = 82 shell closures strongly influence the α-formation probability.


Assuntos
Partículas alfa , Polônio/química , Nêutrons , Física Nuclear
9.
Nature ; 469(7328): 68-71, 2011 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-21179086

RESUMO

Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing, in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus (92)Pd. Gamma rays emitted following the (58)Ni((36)Ar,2n)(92)Pd fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution γ-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction. We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.

10.
Phys Rev Lett ; 103(7): 072501, 2009 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-19792636

RESUMO

A linear universal decay formula is presented starting from the microscopic mechanism of the charged-particle emission. It relates the half-lives of monopole radioactive decays with the Q values of the outgoing particles as well as the masses and charges of the nuclei involved in the decay. This relation is found to be a generalization of the Geiger-Nuttall law in alpha radioactivity and explains well all known cluster decays. Predictions on the most likely emissions of various clusters are presented.

11.
Urologia ; 75(1): 102-4, 2008.
Artigo em Italiano | MEDLINE | ID: mdl-21086359

RESUMO

OBJECTIVES. There is evidence of a clinical correlation between chronic prostatitis and elevated serum levels of prostate specific antigen (PSA). In the present study a system was developed to stage inflammation in benign prostate hyperplasia (BPH), which correlates with serum PSA. MATERIALS AND METHODS. We retrospectively studied 98 patients undergoing transurethral resection of prostate. In all patients, histological sections of prostate showed BPH and inflammatory cell infiltration, which could be graded as G1, G2 and G3, according to involvement of epithelium. PSA levels were assessed pre- and postoperatively by the Immulite 2000 PSA assay. RESULTS. The difference in mean serum PSA values between groups G1 and G3 was highly significant (G1 = 3.3±2.1; G3 = 7.1±3.9 ng/mL; p<0.05). Mean age, prostatic weight and PSA density were similar in the three groups (p<0.05). CONCLUSIONS. We concluded that in patients with BPH and prostatitis on pathological examination there is an associated PSA elevation when glandular epithelium is disrupted.

12.
Urologia ; 75(1): 20-3, 2008.
Artigo em Italiano | MEDLINE | ID: mdl-21086371

RESUMO

OBJECTIVES. Biomarkers (BTA, NMP22, FDP etc.) have been and continue to be evaluated as adjuncts or substitutes for cystoscopy, which is invasive and uncomfortable for some patients. Nuclear matrix protein-22 (NMP22) is involved in the regulation of nuclear processes. The main objective of the present study is to evaluate the clinical utility of urinary NMP22 as a tumor marker in the follow-up of transitional cell carcinoma (TCC) of the bladder. MATERIALS AND METHODS. The study included 62 patients undergoing follow-up, who had had TCC of bladder but who were disease-free at the beginning of the study, as confirmed by cystoscopy. Urine samples were collected for urinary cytology and NMP22 test before the cystoscopy. All samples were processed according to the instructions provided with the manufacturer's kit instructions. Results. 12 cases of TCC recurrences were detected with biopsy. Cystoscopy was positive in 8 cases, NMP22 test was positive in 11 cases, and in only one case the cytopathology yielded positive results. In 14 cases NMP22 resulted as false positive. CONCLUSIONS. Urinary NMP22 appeared to be a potential tumor marker for detecting TCC of the bladder, which might rise the sensitivity of cystoscopy especially in high-grade cancer surveillance more than cytology might do.

13.
Prostate Cancer Prostatic Dis ; 11(2): 148-52, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17637759

RESUMO

Microscopic foci of prostatitis may induce prostate-specific antigen (PSA) increase. PSA reduction after antibiotics might identify those patients in whom biopsy can be avoided. Ninety-nine patients received ciprofloxacin for 3 weeks, of whom 59 showed PSA reduction. Histology detected small foci of prostatitis in 65% of cases. Carcinoma was found in 40 and 20.3% of patients with unchanged or decreased PSA, respectively (P=0.03). No cancer was detected if PSA decreased below 4 ng/ml or more than 70%. Biopsy can be postponed, with a low risk of missing a cancer, if PSA decreases more than 70% or below 4 ng/ml.


Assuntos
Antibacterianos/uso terapêutico , Biópsia por Agulha , Ciprofloxacina/uso terapêutico , Antígeno Prostático Específico/sangue , Próstata/patologia , Prostatite/tratamento farmacológico , Procedimentos Desnecessários , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Palpação , Seleção de Pacientes , Próstata/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/patologia , Prostatite/sangue , Prostatite/diagnóstico , Risco , Fatores de Tempo , Ultrassonografia de Intervenção
14.
Urologia ; 74(3): 164-72, 2007.
Artigo em Italiano | MEDLINE | ID: mdl-21086396

RESUMO

At present, radical prostatectomy is the standard of care for localized prostate cancer. Several mini-invasive urological procedures have been developed during the last years, such as the laparoscopic radical prostatectomy, which is nowadays an innovative technique for urologists. This procedure shows many benefits in terms of anatomic accuracy, reduction of hospitalization and transurethral catheterization, recovery of urinary continence and sexual potency. In this study we have described the laparoscopic radical prostatectomy technique which is carried out by urologists at the "Hôpital Henry Mondor" - Creteil, Paris, where the first author has worked for six months.

15.
Urologia ; 74(2): 113-7, 2007.
Artigo em Italiano | MEDLINE | ID: mdl-21086409

RESUMO

OBJECTIVES. Nowadays endorectal probes for Magnetic Resonance Imaging (MRI) have better resolutions, which allows to acquire high-level images of prostate and to improve the MRI sensitivity and specificity to determine the cancer volume and the extraprostatic extension. The objective of the present study is to evaluate the sensitivity and diagnostic accuracy of endorectal MRI for identifying the local extension of prostate carcinoma compared to transrectal sonography (TRUS) of prostate. MATERIALS AND METHODS. The study included 81 patients with clinical suspect of cancer and/or elevated values of serum prostate specific antigen (PSA), who underwent endorectal MRI with 1.5 T endorectal probe before transrectal biopsy. Patients with localized prostate cancer underwent radical surgery. The results of endorectal MRI were compared to those of TRUS and histopathological examination outcomes. RESULTS. 15 of the 81 enrolled patients had extraprostatic localization of cancer, which was assessed through TRUS in 4 cases only (26%), and through MRI in 7 cases (46%). A seminal vesicle involvement was present in 10 patients, detected by MRI in 5 cases and in no cases by TRUS. DISCUSSION AND CONCLUSIONS. Data are similar to the findings collected by several Authors. The endorectal MRI has a better accuracy in staging prostate cancer compared to TRUS. Nevertheless, this procedure has some limits: little availability of equipment in hospitals, physicians' little experience, and higher costs compared to TRUS.

16.
Phys Rev Lett ; 96(7): 072501, 2006 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-16606078

RESUMO

A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angular momentum of the outgoing proton. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.

17.
Phys Rev Lett ; 89(4): 042501, 2002 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-12144477

RESUMO

A formalism to evaluate the resonant states produced by two particles moving outside a closed shell core is presented. It is found that long lived two-body states (including bound states) are mostly determined by either bound single-particle states or by narrow single-particle resonances. However, they can be significantly affected by the continuum part of the spectrum.

18.
J Appl Behav Anal ; 15(3): 469-73, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-16795662

RESUMO

Each year, thousands of pedestrians are killed or injured while crossing streets in the United States. Pedestrians who jaywalk across busy intersections increase their risk of being injured by an automobile. The present series of studies investigated pedestrian jaywalking behaviors under temporal conditions which appeared to control noncompliance and compliance with pedestrian walk signs. An intersection involving three major streets was the target site of the studies. The timing of walk and no-walk light sequences was different in the clockwise and counterclockwise direction and produced differential delays. In three separate studies, significantly more pedestrians jaywalked when walking in the long-delay as opposed to short-delay direction. Traffic planners might use these findings to establish safer pedestrian signal systems.

19.
J Appl Behav Anal ; 15(4): 573-7, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-7153192

RESUMO

Passive smoking has been shown to be hazardous to the health of nonsmokers. Given this documented link between exposure to smoke-filled environments and deleterious health consequences, there is a need to develop effective procedures that establish and maintain no-smoking areas in various public settings. The present study focused on decreasing cigarette smoking in a section of a university cafeteria. Posting of no-smoking signs was found to decrease levels of smoking only minimally. However, when smokers were verbally prompted not to smoke, in the presence of the signs, marked decreases in smoking occurred in the target area.


Assuntos
Terapia Comportamental/métodos , Restaurantes , Prevenção do Hábito de Fumar , Estudantes , Poluição por Fumaça de Tabaco/prevenção & controle , Adulto , Ingestão de Alimentos , Humanos
20.
Science ; 206(4422): 1029-34, 1979 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-17787468

RESUMO

More fundamental knowledge of coal (knowledge of its structure and its behavior during conversion processes) is essential before we can generate new technologies necessary for the efficient use of coal in the future. Herein are suggested specific basic research opportunities in the areas of coal characterization, gasification, combustion, and liquefaction, along with an assessment of the impact such research programs could have. Critical characterization needs include qualitative and quantitative determination of the chemical forms of carbon, oxygen, nitrogen, and sulfur and reliable methods for the measurement of surface area, pore volume, and weight-average molecular weights. Mechanistic studies aimed at increasing understanding of the thermal breakdown of the functionalities in coal, the behavior of coal in the presence of molecular and donor hydrogen environments, and carbon gasification and hydrocarbon synthesis reactions starting from carbon monoxide and hydrogen will lay the scientific foundation for the development of new processes for converting coal into clean usable fuels and chemicals.

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