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1.
Phys Chem Chem Phys ; 25(47): 32452-32459, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37991918

RESUMO

A15-type compound Nb3Sn has attracted much attention due to its relatively high critical temperature and critical field of superconductivity, making it a leading material for superconducting applications. In this study, we investigate the structural instability and superconductivity of Nb3Sn under hydrostatic pressure using first-principles calculations. We determine the electronic properties, phonon dispersion, electron-phonon coupling and the superconducting gap for Nb3Sn at pressures ranging from ambient to 9 GPa. Our results show that a significant electron density is present near the Fermi level due to the van Hove singularity, indicating the strong electron-phonon coupling. The phonon dispersion of Nb3Sn exhibits Kohn anomalies at three different wave vectors at a lower temperature. Moreover, above a pressure of 6 GPa, the charge density wave (CDW) instability disappeared, suggesting that pressure inhibits the CDW phase. The superconducting temperature is predicted to be TC = 18.62 K under ambient conditions, which is well consistent with the experimental results. We find that both the CDW and superconducting orders respond to pressure, with their transition temperatures decreasing as the pressure increases below 6 GPa. Above 6 GPa, the superconducting transition temperature increases slowly with pressure. Our results suggest that the instability in Nb3Sn is driven by the softening of the phonon modes due to the CDW caused by strong electron-phonon coupling. Therefore, the CDW phase and superconducting phase of Nb3Sn coexist at low pressure.

2.
Materials (Basel) ; 15(18)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36143666

RESUMO

Electric upsetting has been widely employed to manufacture the preformed workpiece of large-scale exhaust valves. The temperature field in the electric upsetting process plays an important role in microstructure evolution and defect formation. In order to uncover the temperature evolution in a larger-scale electric upsetting process, the electric-thermal-mechanical multi-field coupling finite element model was developed to simulate the electric upsetting forming process of Ni80A superalloy. The temperature distribution characteristics and their formation mechanisms under different stages were analyzed systematically. Results indicate that at the preheating stage, the billet temperature increases from 20 °C to 516.7 °C, and the higher temperature region firstly appears at the contact surface between billet and anvil due to the combined effects of contact resistance and volume resistance. With increasing preheating time, the higher temperature region is transferred to the interior of the billet because the contact resistance is reduced with increasing temperature. As for the forming process, the billet is gradually deformed into an onion shape. The highest billet temperature increases to 1150 °C and keeps relatively constant. The high temperature region always appears at the neck of the onion due to the relatively higher current density at this place. It enlarges continuously in the primary stage and intermediate stage, and then decreases at the stable deformation stage. The low temperature regions lie in the contact surface and the outer surface of the onion because a lot of heat is lost to the anvil and surroundings through thermal conduction and radiation. Finally, the established finite element model was verified by an actual electric upsetting experiment. The average relative error between simulated temperatures and experimental ones was estimated as 7.54%. The longitudinal and radial errors between simulated onion shape and the experimental one were calculated as 1.38% and 2.70%, respectively.

3.
Cardiovasc Diabetol ; 17(1): 149, 2018 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-30482197

RESUMO

BACKGROUND: Negative coronary artery remodeling is frequent in patients with diabetes, but its mechanism remains unclear. We here evaluated the association of serum levels of glycated albumin (GA) and endogenous secretory receptor for advanced glycation end products (esRAGE) with coronary artery remodeling in type 2 diabetic patients. METHODS: Serum levels of GA and esRAGE were measured and intravascular ultrasound was performed in 136 consecutive diabetic patients with 143 coronary intermediate lesions. The remodeling index (RI) was calculated as the ratio between external elastic membrane (EEM) area at the lesion site and EEM area at the reference segment. Negative remodeling (NR) was defined as an RI < 0.95 and intermediate or positive remodeling as an RI ≥ 0.95. RESULTS: Mean plaque burden at the lesion site was 70.96 ± 9.98%, and RI was 0.96 ± 0.18. Negative coronary arterial remodeling existed in 81 (56.6%) lesions. RI correlated closely with serum esRAGE level (r = 0.236, P = 0.005) and was inversely related to serum GA level (r = - 0.240, P = 0.004) and plasma low-density lipoprotein cholesterol (LDL-C) (r = - 0.206, P = 0.014) and total cholesterol levels (r = - 0.183, P = 0.028). Generalized estimating equations logistic regression analysis identified esRAGE (OR 0.037; 95% CI 0.012-0.564, P = 0.021), GA (OR 1.093; 95% CI 1.013-1.179, P = 0.018) and LDL-C (OR 1.479; 95% CI 1.072-2.835, P = 0.023) as independent predictors for negative remodeling. CONCLUSIONS: In diabetic patients, negative coronary artery remodeling is associated with increased GA and decreased esRAGE levels in serum.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Diabetes Mellitus Tipo 2/sangue , Hemoglobinas Glicadas/metabolismo , Receptor para Produtos Finais de Glicação Avançada/sangue , Ultrassonografia de Intervenção , Remodelação Vascular , Idoso , Biomarcadores/sangue , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/patologia , Vasos Coronários/patologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica , Valor Preditivo dos Testes
4.
Catheter Cardiovasc Interv ; 87 Suppl 1: 616-23, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26864270

RESUMO

BACKGROUND: There is increasing interest in percutaneous coronary intervention (PCI) for chronic total occlusions (CTO). Periprocedural myocardial injury (PMI) post CTO PCI is not uncommon, but true incidence and implications of PMI are not well understood. OBJECTIVES: This study aimed to investigate risk factors for PMI post CTO PCI and its implications for the 1-year clinical outcome of a Chinese population. METHODS: Baseline characteristics, procedure features, and major adverse cardiac events (MACE) at 1 year were assessed in 629 consecutive patients who underwent CTO PCI. PMI was diagnosed as an elevation of creatine kinase MB ≥3 times ULN 12-24 hr post procedure. Multivariate analysis was performed to determine the correlates of PMI and MACE at 1-year follow-up. RESULTS: In total, PMI was detected in 115 patients (18.3%). Compared with patients without PMI, those with PMI had a higher percentage of previous coronary artery bypass grafting (CABG), right coronary occlusion and side branch occlusion, and technical success was lower in the PMI group (90.4% vs. 96.7%, P = 0.003). One-year MACE-free survival was reduced in the PMI group (87.8% vs. 95.9%, P = 0.001). The final TIMI flow 0-1 (OR 2.23, 95%CI 1.06-4.87, P = 0.02), side branch occlusion (OR 2.67, 95%CI 1.19-7.11, P = 0.009), retrograde PCI (OR 1.35, 95%CI 1.10-2.74, P = 0.04), and history of prior CABG (OR 2.41, 95%CI 1.38-5.91, P = 0.01) were independent risk factors for the occurrence of PMI. CONCLUSIONS: In this unique Chinese cohort, PMI post CTO PCI was associated with several clinical and angiographic factors and exerts an adverse effect on 1-year clinical outcomes.


Assuntos
Oclusão Coronária/terapia , Cardiopatias/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Idoso , Biomarcadores/sangue , Distribuição de Qui-Quadrado , China , Doença Crônica , Angiografia Coronária , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/mortalidade , Creatina Quinase Forma MB/sangue , Intervalo Livre de Doença , Stents Farmacológicos , Feminino , Cardiopatias/sangue , Cardiopatias/diagnóstico , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/mortalidade , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
5.
Catheter Cardiovasc Interv ; 85 Suppl 1: 762-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25630513

RESUMO

BACKGROUND AND PURPOSE: Patients are at risk of developing periprocedural myonecrosis after percutaneous coronary intervention (PCI). We investigated whether the use of the platelet glycoprotein (GP) IIb/IIIa receptor inhibitor tirofiban could reduce periprocedural myocardial infarction (PMI) in patients with stable coronary artery disease undergoing elective PCI with overlapping stent implantation for long lesions. METHODS: A total of 748 stable angina patients with long lesions (≥ 40 mm in length) treated with overlapping stent implantation were randomly assigned to receive tirofiban (tirofiban group; n = 373) or conventional therapy (control group; n = 375). Intravenous tirofiban was initiated before PCI and maintained for 12 hr after the procedure. The primary endpoint was PMI, defined as an elevation in CK-MB > 3 times the upper limit of normal 12 hr after the index procedure. The secondary endpoint was major adverse cardiac events (MACE), including cardiac death, target vessel revascularization, and recurrent MI (re-MI), at one-year of clinical follow-up. The safety end-points included Thrombolysis in Myocardial Infarction (TIMI) major bleeding and stent thrombosis. RESULTS: Despite comparable angiographic and procedural characteristics, in the intention-to-treatment analysis, the primary endpoint was significantly reduced in the tirofiban group (4.0% vs. 11.5%, P < 0.001). Multivariate analysis revealed that the adjunctive use of tirofiban was the only negative predictor of PMI (OR 0.41, 95% CI 0.28-0.81, P < 0.01). At one-year of clinical follow-up, the overall occurrence of MACE was significantly lower in the tirofiban group (13.4% vs. 22.7%, P = 0.001). The rate of TIMI major bleeding and stent thrombosis did not differ significantly between the two groups. CONCLUSION: Our results show that the adjunctive use of tirofiban reduces the occurrence of PMI and MACE at one year in stable coronary artery disease patients undergoing elective PCI for long lesions with overlapping stent implantation.


Assuntos
Doença da Artéria Coronariana/terapia , Stents Farmacológicos , Intervenção Coronária Percutânea/instrumentação , Inibidores da Agregação Plaquetária/administração & dosagem , Tirosina/análogos & derivados , Idoso , Biomarcadores/sangue , Distribuição de Qui-Quadrado , China , Angiografia Coronária , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/mortalidade , Trombose Coronária/etiologia , Trombose Coronária/prevenção & controle , Creatina Quinase Forma MB/sangue , Feminino , Hemorragia/induzido quimicamente , Humanos , Análise de Intenção de Tratamento , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/prevenção & controle , Razão de Chances , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/mortalidade , Inibidores da Agregação Plaquetária/efeitos adversos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Estudos Prospectivos , Desenho de Prótese , Fatores de Risco , Fatores de Tempo , Tirofibana , Resultado do Tratamento , Tirosina/administração & dosagem , Tirosina/efeitos adversos , Regulação para Cima
6.
Zhongguo Zhong Yao Za Zhi ; 38(15): 2448-52, 2013 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-24228533

RESUMO

OBJECTIVE: To compare effects of integrated treatment traditional Chinese medicine and Western medicine (TCM-WM) and simple western medicine on TCM clincal symptoms in the patient of AIDS with pulmonary inflammation. METHOD: A multicenter randomized controlled trials of 164 subjects evaluated the effects of clinical symptoms of AIDS with pulmonary inflammation of TWO regimens: the TCM-WM group (n = 111) and western medicine treatment group (n = 53), while incidence of TCM symptoms in different time points in two groups were analyzed. RESULT: Twenty eight days after treatment, the cured and markedly effective rate of TCM symptoms in the TCM-WM group significantly exceeding that in the western medicine treatment group (cured and markedly effective rate significant efficiency 44.55% vs 20.00%), while the incidence rate for the TCM symptoms of fever and headache in the TCM-WM group was significantly lower than that in western medicine group. CONCLUSION: The integrated treatment of traditional Chinese medicine and Western medicine helps to alleviate the TCM clinical symptoms of AIDS with pulmonary inflammation.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Medicina Tradicional Chinesa/métodos , Pneumonia/complicações , Pneumonia/tratamento farmacológico , Feminino , Humanos , Masculino , Análise Multivariada , Resultado do Tratamento
7.
Chin Med J (Engl) ; 126(6): 1063-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23506579

RESUMO

BACKGROUND: Transradial access has been increasingly used during primary percutaneous coronary intervention (PCI) for patients with acute ST-segment elevation myocardial infarction (STEMI) in last decade. Clinical benefits of upstream use of tirfiban therapy in STEMI patients treated by primary PCI have been reported. We investigated the merits of transradial vs. transfemoral access in primary PCI for STEMI patients with upstream use of tirofiban. METHODS: Patients with STEMI treated with tirofiban between December 2006 and October 2012 then by primary PCI were compared between transradial (n = 298) and transfemoral (n = 314) access. Baseline demographics, angiographic and PCI features and primary endpoint of major adverse cardiac events (MACE) at 30-day clinical follow-up were recorded. RESULTS: Baseline and procedural characteristics were comparable between the two groups, apart from more patients in transradial group had hypertension and were treated by thrombus aspiration during primary PCI. Significantly fewer MACE occurred in the transradial group (5.4%) compared with the transfemoral group (9.9%) at 30-day clinical follow-up. Major bleeding events at 30-day clinical follow-up were 0 in transradial group and in 2.9% of transfemoral group. Multivariate analysis confirmed transradial approach as an independent negative predictor of 30-day MACE (HR 0.68; 95%CI 0.35 - 0.91; P = 0.03). CONCLUSIONS: Using transradial approach in primary PCI for acute STEMI infarction patients treated with tirofiban was clearly beneficial in reducing bleeding complications and improving 30-day clinical outcomes.


Assuntos
Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/terapia , Intervenção Coronária Percutânea/métodos , Tirosina/análogos & derivados , Idoso , Angioplastia Coronária com Balão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tirofibana , Tirosina/uso terapêutico
8.
EuroIntervention ; 8(7): 848-54, 2012 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-23171804

RESUMO

AIMS: To evaluate the efficacy and safety of a 5-in-6 double catheter (DC) technique during transradial complex PCI compared to a conventional buddy-wire or balloon-anchoring approach. METHODS AND RESULTS: One hundred and eighty-seven patients who failed in stent or balloon delivery after successful wiring of the target vessel were prospectively randomised to further treatment with a 5-in-6 DC technique (DC group, n=94) or by a conventional buddy-wire or balloon-anchoring approach (control group, n=93). Baseline clinical and lesion features were comparable between the two groups. The primary endpoint of technical success was significantly higher in the DC than in the control group (97.9% and 39.8%, p<0.001). Fifty-six patients (60.2%) in the control group with failure of the buddy-wire or balloon-anchoring approach achieved successful PCI with bailout use of a DC technique. Procedural x-ray time (58.2±23.1 min vs. 94.9±18.6 min, p<0.001), patient dose-area product (23,970±8,555 cGy.cm2 vs. 44,475±10,573 cGy.cm2, p<0.001) and contrast consumption (177±33 ml vs. 271±70 ml, p<0.001) were significantly reduced in the DC group. One-year major adverse cardiac event-free survival did not differ between the two groups (89.4% vs. 84.9%, p=0.36). CONCLUSIONS: The use of a 5-in-6 DC technique, especially as a bailout strategy, is a more effective back-up support of the guiding system, subsequently facilitating the success of transradial PCI for complex coronary lesions, than a conventional buddy-wire or balloon-anchoring approach.


Assuntos
Angioplastia Coronária com Balão/instrumentação , Cateteres Cardíacos , Doença da Artéria Coronariana/terapia , Stents Farmacológicos , Artéria Radial , Idoso , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/mortalidade , Distribuição de Qui-Quadrado , China , Meios de Contraste , Angiografia Coronária , Ponte de Artéria Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Intervalo Livre de Doença , Desenho de Equipamento , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Estudos Prospectivos , Desenho de Prótese , Artéria Radial/diagnóstico por imagem , Doses de Radiação , Retratamento , Fatores de Tempo , Resultado do Tratamento
9.
Int J Cardiovasc Imaging ; 28(7): 1653-62, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22222382

RESUMO

This study aimed to evaluate the impact of vascular response assessed by intravascular ultrasound (IVUS) imaging on clinical outcomes in elderly patients (≥ 75 years) undergoing percutaneous coronary intervention (PCI) for de novo lesions with sirolimus-eluting stent (SES) implantation. Repeat coronary angiography with IVUS was performed 1 year after SES-based PCI for de novo lesions in 136 elderly patients (≥ 75 years) and 427 younger counterparts (< 75 years) (219 lesions and 635 lesions, respectively). Major adverse cardiac events (MACE) including cardiac death, non-fatal myocardial infarction, and target lesion revascularization (TLR) during 2-year follow-up were recorded. Despite similar angiographic in-stent restenosis and TLR and IVUS-detected incomplete stent apposition (ISA), absolute intimal hyperplasia and percentage of volumetric obstruction were lower in elderly than in younger patients. At 2-year follow-up, cumulative survival freedom from composite death and myocardial infarction or MACE was significantly reduced in elderly patients, but very late stent thrombosis was similar in the two groups. Cox proportional hazards model identified age, diabetes, left ventricular ejection fraction, lesion length,minimal stent cross-sectional area and plaque progression as independent predictors of non-fatal myocardial infarction or mortality. In elderly patients undergoing SES-based PCI, despite similar TLR, neointimal hyperplasia was significantly lower than in younger patients. IVUS measurements except for minimal stent cross-sectional area did not correlate with stent thrombosis and clinical outcomes at 2 years.


Assuntos
Fármacos Cardiovasculares/administração & dosagem , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/diagnóstico por imagem , Stents Farmacológicos , Intervenção Coronária Percutânea/instrumentação , Sirolimo/administração & dosagem , Ultrassonografia de Intervenção , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Angiografia Coronária , Doença da Artéria Coronariana/mortalidade , Trombose Coronária/diagnóstico por imagem , Trombose Coronária/etiologia , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/etiologia , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/mortalidade , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
10.
Zhonghua Yi Xue Za Zhi ; 91(29): 2055-9, 2011 Aug 09.
Artigo em Chinês | MEDLINE | ID: mdl-22093935

RESUMO

OBJECTIVE: To analyze the magnetic resonance imaging (MRI) findings of lesions in the limbic system related structures in general paresis of insane (GPI) patients so as to explore its pathogenesis and provide a new MRI diagnostic method. METHODS: The clinical data and MRI findings of lesions in the limbic system related structures were retrospectively analyzed for a total of 31 GPI patients. The parameters were volume and signal abnormality. RESULTS: On MRI, structural abnormalities were found in amygdaloid body (n = 29), hippocampus (n = 28), insular lobe (n = 24), parahippocampal gyrus (n = 23), lenticular nucleus (n = 23), corpus callosum (n = 20), caudate nucleus (n = 11), hypothalamus (n = 10), anterior nucleus of thalamus (n = 10), cingulate gyrus (n = 8) and thalamus (n = 2). The frequent manifestations were atrophy, swelling, T2 hyperintensity in various structures and T2 hypointensity in lenticular nucleus. CONCLUSION: A frequent involvement of limbic system structures in GPI patients may be related with dementia and other psychiatric symptoms. Swelling and T2 hyperintensity of involved structures may be the characteristic MRI manifestations of GPI.


Assuntos
Sistema Límbico/patologia , Imageamento por Ressonância Magnética , Neurossífilis/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
Circ Cardiovasc Qual Outcomes ; 4(3): 355-62, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21521833

RESUMO

BACKGROUND: Traditional reperfusion options for patients with acute ST-segment elevation myocardial infarction (STEMI) presenting to non-primary percutaneous coronary intervention (PPCI)-capable hospitals generally include onsite fibrinolytics or emergency transfer for PPCI. A third option, involving interventionalist transfer, was examined in the REVERSE-STEMI study. METHODS AND RESULTS: A total of 334 patients with acute STEMI who presented to 5 referral hospitals with angiographic facilities but without interventionalists qualified for PPCI were randomized to receive PPCI with either an interventionalist- (n=165) or a patient-transfer (n=169) strategy. The primary end point of door-to-balloon (D2B) time and secondary end points of left ventricular ejection fraction and major adverse cardiac events (MACE) at 1-year clinical follow-up were compared between the 2 groups. Compared with the patient-transfer strategy, the interventionalist-transfer strategy resulted in a significantly shortened D2B time (median, 92 minutes versus 141 minutes; P<0.0001), with more patients having first balloon angioplasty within 90 minutes (21.2% versus 7.7%, P<0.001). This treatment strategy also was associated with higher left ventricular ejection fraction (0.60±0.07 versus 0.57±0.09, P<0.001) and improved 1-year MACE-free survival (84.8% versus 74.6%, P=0.019). Multivariate Cox proportional hazards modeling revealed that the interventionalist-transfer strategy was an independent factor for reduced risk of composite MACE (hazard ratio, 0.63; 95% CI, 0.45 to 0.88; P=0.003). CONCLUSIONS: The interventionalist-transfer strategy for PPCI may be effective in improving the care of patients with STEMI presenting to a non-PPCI-capable hospital, particularly in a congested cosmopolitan region where patient transfers could be prolonged.


Assuntos
Angioplastia Coronária com Balão , Eletrocardiografia , Relações Hospital-Médico , Infarto do Miocárdio/terapia , Transferência de Pacientes , Transferência de Tecnologia , Idoso , China , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Avaliação de Resultados em Cuidados de Saúde , Prática Profissional , Modelos de Riscos Proporcionais , Estudos Prospectivos , Estudos Retrospectivos , Volume Sistólico/fisiologia , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
12.
Clin Imaging ; 35(3): 193-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21513855

RESUMO

PURPOSE: To compare image quality and patient radiation dose in a group of patients who underwent 320-detector computed tomography coronary angiography performed with prospective electrocardiogram (ECG) gating with image quality and radiation dose in a group of patients matched for clinical features who underwent 320-detector computed tomographic (CT) coronary angiography performed with retrospective ECG gating. MATERIALS AND METHODS: This study was approved by our institutional human research committee. All patients had clinical indications for coronary computed tomography angiography (CTA). Two independent reviewers separately scored coronary artery segment image quality for 480 cardiac CT studies in prospective group and retrospective group (240 in each group). Reviewer variability was calculated. Estimated effective radiation dose was compared for prospective versus retrospective ECG gating. RESULTS: The two groups matched well for clinical characteristics and CT parameters. There was good agreement for coronary artery segment image quality scores between the independent reviewers (k=0.73). Of the 6408 coronary artery segments scored, there were no coronary artery segments that could not be evaluated in each group. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 76.50% lower for prospective gating (4.2 mSv) than for retrospective gating (18.1 mSv) (P<.01). CONCLUSION: Use of 320-detector CT coronary angiography performed with prospective ECG gating has similar subjective image quality scores but 76.50% lower patient radiation dose when compared with use of retrospective ECG gating.


Assuntos
Técnicas de Imagem de Sincronização Cardíaca/métodos , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Doses de Radiação , Proteção Radiológica/métodos , Tomografia Computadorizada por Raios X/métodos , Eletrocardiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiometria , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
13.
Zhonghua Nei Ke Za Zhi ; 50(1): 59-62, 2011 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-21418892

RESUMO

OBJECTIVE: To evaluate the therapeutic effect of highly active anti-retroviral therapy (HAART) in treatment-naïve Chinese patients with AIDS, to provide evidences for standardizing HAART. METHODS: Seventy-four treatment-naive AIDS patients were initiated with HAART and followed up regularly for 3 years. The clinical and laboratory data, side effects and drug resistance were observed and analyzed during the follow-up period. RESULTS: Of the 74 patients, 46 were males and 28 were females, with the average age being 42 years. The mean HIV viral load was (2.2 ± 2.0) × 10(5) copies/ml and the baseline mean CD(4)(+)T lymphocyte count was (62 ± 71) cells/µl before treatment. After treatment for 3, 6, 12, 18, 24, 30 and 36 months, the percentage of undetectable HIV viral road (less than 50 copies/ml) was 71.6%, 83.8%, 75.7%, 77.0%, 82.4%, 81.1% and 79.7% respectively, and CD(4)(+)T lymphocyte count ascended to (167 ± 105), (177 ± 129), (238 ± 137), (290 ± 158), (304 ± 191), (331 ± 175) and (352 ± 202) cells/µl. The increase in amplitude of CD(4)(+)T lymphocyte count in different periods examined was different, with the period of 0-3 months post-treatment demonstrating the most obvious augmentation (P < 0.01). The most common adverse reactions were liver function injury (52/74, 70.3%), hyperlipemia (52/74, 70.3%), hematopoietic inhibition of the bone marrow (33/74, 44.6%), peripheral neuritis (32/74, 43.2%) and lipoatrophy (26/74, 35.1%). Clinical drug resistance were found in nine patients and HIV gene mutations were detected in these patients. CONCLUSIONS: Chinese treatment-naive AIDS patients have achieved good virological and immunological response to generic-drug-predominant HAART regimes with low drug resistance, but relatively more side effects.


Assuntos
Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Terapia Antirretroviral de Alta Atividade , Síndrome da Imunodeficiência Adquirida/virologia , Adolescente , Adulto , Idoso , Contagem de Linfócito CD4 , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Carga Viral , Adulto Jovem
14.
Histol Histopathol ; 26(1): 23-35, 2011 01.
Artigo em Inglês | MEDLINE | ID: mdl-21117024

RESUMO

A remarkable feature of HBV-associated HCC is male predominance. The cooperation of hepatitis B virus X protein (HBx) with androgen receptor (AR) signaling pathway has been documented to contribute to this dominance. HBx, a multifunctional viral regulator, has been documented to induce promoter hypermethylation and low expression of tumor suppressor genes via activation of DNA methyl-transferase (DNMT) in hepatocarcinogenesis. In prostate cancer, hypermethylation of AR promoter is associated with loss of AR expression. However, the relationship among HBx, DNMTs, the methylation status of AR and AR expression in HBV-associated HCC is still unknown. In this report, we found that HBx correlated with high levels of AR in HCC cases and induced AR expression by stimulating its transcription in liver cell lines. HBx correlated with high expression of DNMTs in HCC cases too. Both in vivo and in vitro, however, the expression of AR was not associated with its promoter methylation status, and the methylation status of AR was not regulated by DNMTs. AR expression is higher in peritumoral tissues than in tumors, as well as being higher in HBV-associated HCC than in HBV-negative cases. Therefore, HBx-induced high expression of AR plays a role during hepatocarcinogenesis, but is not involved with its promoter methylation or DNMTs. HBx-mediated DNMT deregulation is gene-specific, and the expression and methylated regulation of AR is tissue-specific.


Assuntos
Carcinoma Hepatocelular/etiologia , Hepatite B/complicações , Neoplasias Hepáticas/etiologia , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Transativadores/metabolismo , Adulto , Idoso , Sequência de Bases , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , Primers do DNA/genética , Feminino , Hepatite B/genética , Hepatite B/metabolismo , Hepatite B/virologia , Vírus da Hepatite B/metabolismo , Vírus da Hepatite B/patogenicidade , Humanos , Técnicas In Vitro , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Transdução de Sinais , Proteínas Virais Reguladoras e Acessórias
15.
Zhong Yao Cai ; 33(2): 210-3, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20575411

RESUMO

OBJECTIVE: To study the alkaloids from Corydalis impatiens. METHODS: The alkaloids were isolated and purified by chromatography and their structures were identified by spectral data and others methods. RESULTS: Seven alkaloids were isolated and identified as bicuculline(1), ochotensine(2), ochotensimine(3), ochrobirine(4), tetrahydrothalifendine(5), norochotensimine(6), N-methylactinodaphnine(7). CONCLUSION: All these compounds are isolated from this plant for the first time.


Assuntos
Alcaloides/isolamento & purificação , Corydalis/química , Dioxolanos/isolamento & purificação , Plantas Medicinais/química , Alcaloides/química , Bicuculina/química , Bicuculina/isolamento & purificação , Cromatografia em Camada Fina , Dioxolanos/química , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/química
16.
Zhonghua Gan Zang Bing Za Zhi ; 18(4): 292-6, 2010 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-20460051

RESUMO

OBJECTIVE: To evaluate the clinical significance of 320-slice CT hepatic artery images in patients with liver transplantation. METHODS: A total of 58 patients underwent CT scanning by 320-slice scanner after liver transplantation. They were divided into 2 groups according to the concentration of contrast media as follows: Group A (27 cases, 350 mgI/ml iopromide), Group B (31 cases, 370 mgI/ml iopromide). Contrast medium was infused at 6 ml/s, with a total dose of 50 ml. Images were generated by dynamic volume scanning and were processed by 4D digital subtraction angiography (DSA) imaging software. The time-density curve (TDC) of the hepatic artery was delineated. The time to peak, peak contrast enhancement were recorded. The physiological parameters such as body weight and height were analyzed. RESULTS: (1) There were no differences in clinical parameters such as age, sex, height, weight, or BMI between groups. The time to peak of hepatic artery of group A and B was (19.71+/-3.11) s and (20.06+/-3.67) s, and had no significant difference. The maximum peak enhancement of hepatic artery in groups B was higher than that group A (P < 0.05). (2) 4D DSA revealed hepatic artery pseudo-aneurysm (n = 2), and hepatic artery mild stenosis (n = 13), moderate stenosis (n = 5), severe stenosis (n = 9) and occlusion (n = 1), segmental moderate and severe stenosis (n = 4), and compensatory circulation with hepatic artery severe stenosis and occlusion (n = 6). hepatoportal arteriovenous fistulas (HPAVF, n = 12), donor-recipient hepatic artery mismatch (n = 3). Hepatic arterial branch are decreased and opened in 15 cases and 8 cases. CONCLUSION: 320-slice CT hepatic artery images is safe, noninvasive, and accurate technique to evaluate hepatic arterial complications after liver transplantation.


Assuntos
Artéria Hepática/diagnóstico por imagem , Hepatopatias/diagnóstico por imagem , Transplante de Fígado/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Hepatopatias/etiologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Zhonghua Xin Xue Guan Bing Za Zhi ; 38(2): 121-5, 2010 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-20398556

RESUMO

OBJECTIVE: Intravascular ultrasound (IVUS) was used to compare the effects on neointimal hyperplasia inhibition between national made Firebird stents and Cypher stents in patients with coronary artery disease. METHODS: From May 2003 to March 2007, 215 patients with 317 native lesions received either Firebird stent (147 lesions of 108 patients, Firebird group) or Cypher stent implantation (138 lesions of 107 patients, Cypher group). Quantitative coronary angiography (QCA) and IVUS were performed at one-year follow-up. RESULTS: The baseline clinical and angiographic characteristics between the two groups were similar, but post procedural minimal lumen diameter was significantly larger in Firebird group than that in Cypher group [(2.88 +/- 0.43) mm vs. (2.78 +/- 0.33) mm, P < 0.05]. follow-up QCA results showed that in-stent late loss [(0.17 +/- 0.29) mm vs. (0.16 +/- 0.27) mm, P > 0.05] and in-segment late loss [(0.18 +/- 0.36) mm vs. (0.20 +/- 0.32) mm, P > 0.05] was similar between Firebird group and Cypher group, while stent cross sectional area (CSA) [(6.99 +/- 2.25) mm(2) vs. (6.46 +/- 1.71) mm(2), P < 0.05], lumen CSA [(6.89 +/- 2.30) mm(2) vs. (6.36 +/- 1.73) mm(2), P < 0.05], stent volume [(162.5 +/- 68.9) m(3) vs. (140.8 +/- 57.9) mm(3), P < 0.01], lumen volume [(160.4 +/- 69.5) mm(3) vs. (138.6 +/- 57.6) mm(3), P < 0.01] and minimal stent CSA [(5.40 +/- 1.85) mm(2) vs. (4.92 +/- 1.43) mm(2), P < 0.05] were larger in Firebird group than those in Cypher group. IVUS analysis showed that there was no significant difference in neointimal hyperplasia volume [(2.09 +/- 5.46) mm(3) vs. (2.23 +/- 6.50) mm(3), P > 0.05] and percentage of volume obstruction [(1.68 +/- 5.84)% vs. (1.59 +/- 4.10)%, P > 0.05] between the two groups. CONCLUSION: Implantation of Firebird stent was associated with low restenosis rate and both Firebird and Cypher stents equally and effectively inhibited neointimal hyperplasia.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Sirolimo/administração & dosagem , Ultrassonografia de Intervenção , Idoso , Stents Farmacológicos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Sirolimo/uso terapêutico
18.
Zhonghua Yi Xue Za Zhi ; 90(3): 165-8, 2010 Jan 19.
Artigo em Chinês | MEDLINE | ID: mdl-20356550

RESUMO

OBJECTIVE: To evaluate the value of low-dose contrast-enhanced 4D DSA acquired from 320-detector row CT on the diagnosis of the hepatic artery complications after liver transplantation. METHODS: 320-detector row CT were performed in fifth patients with liver dynamic enhanced using volume CT body-perfusion protocol, hepatic artery phase images obtained after intravenous injection of 50 ml of contrast at a rate of 6 ml/s were acquired based on 4D DSA. The time-density curve (TDC) of the hepatic artery was delineated. The time to peak, peak contrast enhancement were recorded. The data of artery phase were sent to workstation to reconstruct the hepatic artery with VR, MIP and MPR. RESULTS: The delay mean time and the peak CT value of hepatic artery was 20 (10.0 - 24.2) s and 373 (310 - 440) HU; 4D DSA revealed hepatic artery pseudo-aneurysm (n = 2), and hepatic artery mild stenosis (n = 3), moderate stenosis (n = 4), severe stenosis (n = 1) and occlusion (n = 1). Compensatory circulation was seen in 2 cases. 4 patients were appeared segmental stenosis and hepatoportal arteriovenous fistulas (HPAVF). Hepatic arterial branch are decreased and opened in 9 cases and 4 cases. 4D DSA also displayed other signs including hepatic hemangioma and the splenic artery aneurysms (SAA) and ectasi (n = 1), donor-recipient hepatic artery mismatch (n = 3). CONCLUSION: 4D DSA provided a safe, noninvasive and accurate method for guiding the diagnosis of hepatic artery complication and play an effective role after liver transplantation.


Assuntos
Meios de Contraste , Artéria Hepática/diagnóstico por imagem , Transplante de Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Adulto Jovem
19.
Coron Artery Dis ; 21(3): 175-81, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20305549

RESUMO

OBJECTIVES: This study aimed to evaluate the impact of angiographic and intravascular ultrasound (IVUS) features on clinical outcome in nondiabetic and type 2 diabetic patients after percutaneous coronary intervention (PCI) with sirolimus-eluting stent (SES) implantation. METHODS: Repeat coronary angiography with IVUS imaging was performed after SES-based PCI for de-novo lesions in 128 diabetic and 327 nondiabetic patients (189 lesions and 504 lesions, respectively). The rate of major adverse cardiac events including cardiac death, non fatal myocardial infarction (MI), and target lesion revascularization during clinical follow-up was recorded. RESULTS: In-stent and in-segment late loss, intimal hyperplasia volume, and percentage volumetric obstruction were similar, but stented external elastic membrane cross-sectional area and reference/stented segment ratio were lower in diabetic than in nondiabetic patients. Incomplete stent apposition (ISA) was less frequent, but occurrence of new coronary lesions was higher in diabetic than in nondiabetic patients. Despite similar target lesion revascularization, cumulative survival rates freedom from composite cardiac death and nonfatal MI or major adverse cardiac events were reduced in diabetic patients. Cox proportional hazards model identified diabetes, left ventricular ejection fraction, minimal stent CSA, maximal ISA area, atherosclerotic progression and lesion length as independent predictors of non fatal MI or mortality at follow-up. CONCLUSION: In diabetic patients, PCI with SES implantation neutralizes the excess risk of intimal hyperplasia and decreases occurrence of ISA, but could not modify the propensity of increased adverse clinical outcomes at follow-up.


Assuntos
Angioplastia Coronária com Balão/instrumentação , Fármacos Cardiovasculares/administração & dosagem , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/terapia , Diabetes Mellitus Tipo 2/complicações , Stents Farmacológicos , Sirolimo/administração & dosagem , Ultrassonografia de Intervenção , Idoso , Angioplastia Coronária com Balão/efeitos adversos , Distribuição de Qui-Quadrado , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/mortalidade , Reestenose Coronária/diagnóstico , Reestenose Coronária/etiologia , Vasos Coronários/patologia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/mortalidade , Diabetes Mellitus Tipo 2/terapia , Feminino , Cardiopatias/diagnóstico , Cardiopatias/etiologia , Cardiopatias/mortalidade , Humanos , Hiperplasia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/etiologia , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
20.
Zhonghua Yi Xue Za Zhi ; 90(41): 2911-5, 2010 Nov 09.
Artigo em Chinês | MEDLINE | ID: mdl-21211396

RESUMO

OBJECTIVE: The objective of this study was to evaluate the performance of 320-row multi-detector CT (MDCT) in the detection and grading of esophageal varices and to evaluate the ability of MDCT in predicting the risk of hemorrhage in comparison with upper endoscopy in patients with portal hypertension. METHODS: A total of 69 patients, with clinically confirmed portal hypertension, underwent epigastric triphasic enhancement scans using 320-row MDCT 1 weeks or less before upper endoscopies were performed. Two blinded abdominal imagers retrospectively interpreted all CT images to detect the presence of esophageal varices and divided EV into large EV (≥ 5 mm) and small EV (< 5 mm). The correlation between CT measurements and endoscopic grading was assessed by kappa values. With endoscopy as standard, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the two radiologists in detection of EV were calculated. Correlations between CT measurements of varix size and red color sign were assessed by correlation analysis. RESULTS: Of the total of 69 patients, 56 patients had esophageal varices, 41 had large EV, and 15 had small EV according to the endoscopic findings. MDCT showed an excellent interobserver reliability with regard to the diagnosis of the EV (k = 0.94). Agreement between CT and endoscopy with regard to the grading of EV were excellent (k = 0.77). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of radiologist 1 in the detection of EV was 95%, 69%, 87%, 93% and 75% respectively; the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of radiologist 2 in the detection of EV was 93%, 77%, 87%, 95% and 71%, respectively. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the two radiologists in the detection of large EV was 95%, 100%, 97%, 100% and 93%, respectively. CT variceal grading showed a strong correlation with endoscopic grading for both observers (P < 0.01). Correlations between CT measurements of varix size and red color sign were significant in both radiologists with a correlation coefficient r of 0.731 for radiologist 1 (P < 0.01) and 0.718 for radiologist 2 (P < 0.01). CONCLUSION: 320-row MDCT is useful for the detection and grading of EV, and it is useful in evaluation of EV for predicting a risk of hemorrhage.


Assuntos
Varizes Esofágicas e Gástricas/diagnóstico por imagem , Hemorragia/prevenção & controle , Hipertensão Portal/diagnóstico por imagem , Adulto , Idoso , Varizes Esofágicas e Gástricas/patologia , Feminino , Hemorragia/diagnóstico por imagem , Humanos , Hipertensão Portal/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
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