Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
1.
Nat Commun ; 15(1): 2197, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467628

RESUMO

The superconductivity in systems containing dispersionless (flat) bands is seemingly paradoxical, as traditional Bardeen-Cooper-Schrieffer theory requires an infinite enhancement of the carrier masses. However, the combination of flat and steep (dispersive) bands within the multiple band scenario might boost superconducting responses, potentially explaining high-temperature superconductivity in cuprates and metal hydrides. Here, we report on the magnetic penetration depths, the upper critical field, and the specific heat measurements, together with the first-principles calculations for the Mo5Si3-xPx superconducting family. The band structure features a flat band that gradually approaches the Fermi level as a function of phosphorus doping x, reaching the Fermi level at x ≃ 1.3. This leads to an abrupt change in nearly all superconducting quantities. The superfluid density data placed on the 'Uemura plot' results in two separated branches, thus indicating that the emergence of a flat band enhances correlations between conducting electrons.

2.
J Genet Psychol ; : 1-16, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38373089

RESUMO

Strategies for favoring close others, such as friends and in-group members, benefit individuals and society. Although younger and older children apply these sharing strategies, how they integrate these relationships remain understudied. Friendship and group membership sometimes conflict (e.g. a friend from another, even a rival group), driving the question of how children behave in such situations. To address this question, this preregistered study recruited 121 4-6-year-olds and 94 9-12-year-olds from a middle-class community in China. A 2 (friend vs. stranger) by 2 (in vs. out-group) between-subjects design was applied per age group. Participants were asked to share seven objects with a recipient, who was either a stranger, or a previously nominated friend and from an in- or out-group (manipulated in the Minimal Group Paradigm). The results showed that children in both age groups shared more with friends than with strangers. However, only 4-6-year-olds shared more resources with in-group members than with out-group ones. Moreover, 4-6-year-olds did not distinguish between an out-group friend and an in-group stranger, while 9-12-year-olds shared more with an out-group friend relative to an ingroup stranger, indicating that friendship outweighs minimal group membership only among 9-12-year-olds. Furthermore, there was an interaction between age and minimal group membership, implying a decrease in the minimal group effect between 4-6-year-olds and 9-12-year-olds. Accordingly, the implications of friendship and minimal group effects, and their relative influence on sharing during childhood are discussed.

3.
J Phys Condens Matter ; 35(21)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36913736

RESUMO

We report the discovery and detailed investigation of superconductivity in Mo4Ga20As. Mo4Ga20As crystallizes in a space group ofI4/m(No. 87), with the lattice parametersa= 12.86352 Å andc= 5.30031 Å. The resistivity, magnetization, and specific heat data reveal Mo4Ga20As to be a type-II superconductor withTc= 5.6 K. The upper and lower critical fields are estimated to be 2.78 T and 22.0 mT, respectively. In addition, electron-phonon coupling in Mo4Ga20As is possibly stronger than the BCS weak-coupling limit. First-principles calculations suggest the Fermi level being dominated by the Mo-4dand Ga-4porbitals.

4.
IEEE Trans Cybern ; 52(10): 10814-10826, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33878009

RESUMO

As one of the most important topics in image forensics, resampling detection has developed rapidly in recent years. However, the robustness to JPEG compression is still challenging for most classical spectrum-based methods, since JPEG compression severely degrades the image contents and introduces block artifacts in the boundary of the compression grid. In this article, we propose a method to estimate the upscaling factors on double JPEG compressed images in the presence of image upscaling between the two compressions. We first analyze the spectrum of scaled images and give an overall formulation of how the scaling factors along with the parameters of JPEG compression and image contents influence the appearance of tampering artifacts. The expected positions of five kinds of characteristic peaks are analytically derived. Then, we analyze the features of double JPEG compressed images in the block discrete cosine transform (BDCT) domain and present an inverse scaling strategy for the upscaling factor estimation with a detailed proof. Finally, a fusion method is proposed that through frequency-domain analysis, a candidate set of upscaling factors is given, and through analysis in the BDCT domain, the optimal estimation from all candidates is determined. The experimental results demonstrate that the proposed method outperforms other state-of-the-art methods.

5.
Cardiology ; 145(7): 456-466, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32101865

RESUMO

OBJECTIVE: We aimed to study the effect of cariporide (CP) on protecting the saphenous vein and the role of acetaldehyde dehydrogenase 2 (ALDH2) in coronary artery bypass grafting (CABG). BACKGROUND: The saphenous vein is the main graft material used in CABG. Recent studies suggested that CP is effective in protecting against various cardiovascular diseases. METHODS: Segments of a surgically removed saphenous vein were used to examine the vascular response to CP. The ALDH2 genotype and expression of related proteins were assessed by Western blotting and immunohistochemistry. RESULTS: Among the conditions tested, the University of Wisconsin solution with CP (4°C, 5 min) treatment showed the best protective effect on the saphenous vein. The incidence of major adverse cardiac events was higher in the ALDH2-GA (heterozygous mutant) genotype population after CABG. CONCLUSION: CP plays a role in reducing the production of reactive oxygen species and apoptosis by ALDH2-mediated mitochondrial function improvement. The ALDH2 mutant genotype might be one of the risk factors for coronary atherosclerotic heart disease.


Assuntos
Aldeído-Desidrogenase Mitocondrial/genética , Doença da Artéria Coronariana/genética , Guanidinas/uso terapêutico , Veia Safena/efeitos dos fármacos , Veia Safena/patologia , Sulfonas/uso terapêutico , Adenosina , Adulto , Aldeído-Desidrogenase Mitocondrial/sangue , Alopurinol , Apoptose/efeitos dos fármacos , Ponte de Artéria Coronária/efeitos adversos , Doença da Artéria Coronariana/cirurgia , Feminino , Genótipo , Glutationa , Humanos , Insulina , Masculino , Pessoa de Meia-Idade , Soluções para Preservação de Órgãos , Rafinose , Espécies Reativas de Oxigênio/sangue , Veia Safena/transplante
7.
Math Biosci Eng ; 16(6): 6907-6922, 2019 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-31698595

RESUMO

Recently, fully convolutional network (FCN) has been successfully used to locate spliced regions in synthesized images. However, all the existing FCN-based algorithms use real-valued FCN to process each channel separately. As a consequence, they fail to capture the inherent correlation between color channels and the integrity of three channels. So, in this paper, quaternion fully convolutional network (QFCN) is proposed to generalize FCN to quaternion domain by replacing real-valued conventional blocks in FCN with quaternion conventional blocks. In addition, a new color image splicing localization algorithm is proposed by combining QFCNs and superpixel (SP)-enhanced pairwise conditional random field (CRF). QFCNs consider three different versions (QFCN32, QFCN16, and QFCN8) with different up-sampling layers. The SP-enhanced pairwise CRF is used to refine the results of QFCNs. Experimental results on three publicly available datasets demonstrate that the proposed algorithm outperforms the existing algorithms including some conventional algorithms and some deep learning-based algorithms.

8.
Int Heart J ; 59(6): 1211-1218, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30305585

RESUMO

The enormous majority of previous reports focused on evaluating the safety and efficacy of sequential saphenous vein (SV) coronary bypass grafting; however, no reports to date have revealed concern regarding the impacts of the number of distal anastomoses of sequential SV grafting on graft patency after coronary artery bypass grafting (CABG). This single-center retrospective study aimed to evaluate the impacts of three versus two distal anastomoses per single SV conduit on SV graft patency after off-pump CABG, and to determine the independent risk factors for sequential SV graft failure.From January 2011 to December 2014, 1320 eligible patients were assigned to either a triple group (three distal anastomoses of sequential SV grafting, n = 758) or a double group (two distal anastomoses of sequential SV grafting, n = 562). The primary endpoint was over a 2-year follow-up SV graft failure after off-pump CABG.The triple and double group received a similar total patency rate of sequential SV conduits (86.5% versus 87.1%, P = 0.757). The number of distal anastomoses of sequential SV grafting (three versus two) was not a predictive factor for the follow-up graft failure of sequential SV conduits (HR = 0.91, 95% CI: 0.66-2.29, P = 0.137). Moreover, the two groups received a similar follow-up survival freedom from repeat revascularization (χ2 = 1.881, log-rank P = 0.170).Three versus two distal anastomoses per single SV conduit received a similar SV graft patency. The number of distal anastomoses of sequential SV grafting was not an independent risk factor for graft failure.


Assuntos
Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Veia Safena/transplante , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos , Fatores de Risco
9.
Sci Rep ; 8(1): 14510, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30266915

RESUMO

Injecting supercritical CO2 into gas reservoir is a novel trial to improve condensate gas recovery and decrease the hydrocarbon liquid dropout. A good understanding of the effect of supercritical CO2 on the phase behavior properties of these hydrocarbons is essential for accurately forecasting the displacing performance and storing process of the reservoirs with numerical simulators. This paper presents novel phase behavior experimental procedures and phase equilibrium evaluation methodology for gas-condensate phase system mixed with supercritical CO2 over a wide range of temperatures and pressures. A unique phase behavior phenomena was also reported. The mass transfer between two vapour phases was also measured. In order to interpret and identify the interface property between condensate gas and supercritical CO2, a multiphase thermodynamic VLV equilibrium model was established. Finally, taken YKL condensate gas in Northwest China as an example, the region where the conditions in terms of pressure, temperature and CO2 concentration can yield VLV equilibrium was found. The calculation results of multiphase thermodynamic model for condensate-CO2 system in this paper are close to the experimental data and can truthfully reflect the phase behavior of interface between CO2 and condensate gas. The research results indicate that it is the existence of the interface between CO2 and condensate gas that makes CO2 possible be an attractive option to successfully displace condensate gas and decrease CO2 emissions.

10.
Artigo em Inglês | MEDLINE | ID: mdl-29994181

RESUMO

During the past twenty years, there has been a great interest in the study of spread spectrum (SS) watermarking. However, it is still a challenging task to design a secure and robust SS watermarking method. In this paper, we first define a family of secure SS watermarking methods, named as spherical watermarking (SW). The watermarked correlation of SW is defined to be uniformly distributed on a spherical surface, and this makes SW be key-secure against the watermarked-only attack. Then, we propose an implementation of SW, called transportation SW (TSW), which is designed to decrease embedding distortion in a recursive manner using the transportation theory, meanwhile keeping the security of SW. Moreover, we present a theoretical analysis of the embedding distortion and robustness of the proposed method. Finally, extensive experiments are conducted on simulated signals and real images. The experimental results show that TSW is more robust than existing secure SS watermarking methods.

11.
Int Heart J ; 59(4): 727-735, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-29794393

RESUMO

Sequential grafting may be an effective way to maximize the benefits of the left internal mammary artery (LIMA) conduit. Despite increasing clinical application, the strategy of sequential LIMA grafting has not been proven its superiority. This single-center retrospective study aimed to evaluate the in-hospital and mid-term outcomes of sequential grafting of in situ skeletonized LIMA to the left coronary system.According to the use of sequential or separate LIMA grafting, 1505 eligible patients were assigned to a sequential group (n = 230) and a control group (n = 1275). According to sequential LIMA graft configurations, patients with sequential LIMA grafting were divided into a DOM subgroup (n = 113) and a DLAD subgroup (n = 117). The clinical outcomes and LIMA graft patency were investigated and compared.Sequential LIMA grafting compared with separate LIMA grafting was not an independent predictor either of in-hospital adverse events or follow-up survival free from repeat revascularization during the follow-up period of 32.4 ± 8.5 months. Sequential LIMA grafting had similar LIMA graft patency with separate LIMA grafting (99.5% of 1st sequential sites and 97.7% of 2nd sites versus 98.2% of LIMA-LAD grafts) at 32.3 ± 8.5 months after coronary artery bypass grafting (CABG) surgery. Additionally, the two subgroups received similar mid-term clinical outcomes and graft patency of LIMA segments.Sequential grafting of in situ skeletonized LIMA to the left coronary system resulted in excellent clinical outcomes and graft patency. The two sequential LIMA graft configurations received similar clinical outcomes and graft patency.


Assuntos
Doença da Artéria Coronariana/cirurgia , Vasos Coronários , Oclusão de Enxerto Vascular , Anastomose de Artéria Torácica Interna-Coronária , Artéria Torácica Interna/cirurgia , Enxerto Vascular , Idoso , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Feminino , Oclusão de Enxerto Vascular/diagnóstico , Oclusão de Enxerto Vascular/etiologia , Humanos , Anastomose de Artéria Torácica Interna-Coronária/efeitos adversos , Anastomose de Artéria Torácica Interna-Coronária/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Enxerto Vascular/efeitos adversos , Enxerto Vascular/métodos , Grau de Desobstrução Vascular
12.
Sensors (Basel) ; 18(4)2018 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-29690629

RESUMO

Computer-generated graphics (CGs) are images generated by computer software. The rapid development of computer graphics technologies has made it easier to generate photorealistic computer graphics, and these graphics are quite difficult to distinguish from natural images (NIs) with the naked eye. In this paper, we propose a method based on sensor pattern noise (SPN) and deep learning to distinguish CGs from NIs. Before being fed into our convolutional neural network (CNN)-based model, these images—CGs and NIs—are clipped into image patches. Furthermore, three high-pass filters (HPFs) are used to remove low-frequency signals, which represent the image content. These filters are also used to reveal the residual signal as well as SPN introduced by the digital camera device. Different from the traditional methods of distinguishing CGs from NIs, the proposed method utilizes a five-layer CNN to classify the input image patches. Based on the classification results of the image patches, we deploy a majority vote scheme to obtain the classification results for the full-size images. The experiments have demonstrated that (1) the proposed method with three HPFs can achieve better results than that with only one HPF or no HPF and that (2) the proposed method with three HPFs achieves 100% accuracy, although the NIs undergo a JPEG compression with a quality factor of 75.

13.
IEEE Trans Cybern ; 48(8): 2307-2320, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28841562

RESUMO

Security analysis is a very important issue for digital watermarking. Several years ago, according to Kerckhoffs' principle, the famous four security levels, namely insecurity, key security, subspace security, and stego-security, were defined for spread-spectrum (SS) embedding schemes in the framework of watermarked-only attack. However, up to now there has been little application of the definition of these security levels to the theoretical analysis of the security of SS embedding schemes, due to the difficulty of the theoretical analysis. In this paper, based on the security definition, we present a theoretical analysis to evaluate the security levels of five typical SS embedding schemes, which are the classical SS, the improved SS (ISS), the circular extension of ISS, the nonrobust and robust natural watermarking, respectively. The theoretical analysis of these typical SS schemes are successfully performed by taking advantage of the convolution of probability distributions to derive the probabilistic models of watermarked signals. Moreover, simulations are conducted to illustrate and validate our theoretical analysis. We believe that the theoretical and practical analysis presented in this paper can bridge the gap between the definition of the four security levels and its application to the theoretical analysis of SS embedding schemes.

14.
Int Heart J ; 59(1): 35-42, 2018 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-29279526

RESUMO

This study aimed to evaluate the feasibility and the mid-term efficacy of an in situ skeletonized right internal mammary artery (IMA) bypass grafting to a left anterior descending artery (LAD), and to determine risk factors for IMA graft failure in a single-center study.From January 2012 to December 2015, 189 patients (173 males, 50.6 ± 6.0 years old) undergoing first isolated coronary artery bypass grafting surgery with the in situ skeletonized right IMA grafting to the LAD were included in this study. Baseline characteristics, peroperative data, and follow-up outcomes were investigated and analyzed.The length of the in situ skeletonized right IMA grafts was 18.6 ± 1.2 cm (17.0-22.0 cm). Intraoperative graft flow of the in situ skeletonized right IMA grafting to LAD was 42 ± 9 mL/minute (18-72 mL/minute) associated with measured pulsatility index of 0.8-4.3. In-hospital mortality was 0.5%. Postoperative morbidity included acute myocardial infarction (0.5%), stroke (0.5%), and deep sternal wound infections (1.1%). The mid-term survival was 97.2% and the incidence of repeat revascularization was 0.6%. The patency rate of the in situ skeletonized right IMA grafting to the LAD was 97.1% by computed tomography angiography examination during the follow-up period of 23.2 ± 9.7 months. Additionally, logistic regression analysis showed that intraoperative graft flow had an independent influence on the risk of the mid-term right IMA graft failure.The strategy of the in situ skeletonized right IMA grafting to the LAD is feasible and effective. Intraoperative graft flow was an independent risk factor for the mid-term right IMA graft failure.


Assuntos
Ponte de Artéria Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Circulação Coronária , Vasos Coronários/cirurgia , Artéria Torácica Interna/transplante , Grau de Desobstrução Vascular , Adulto , Idoso , China/epidemiologia , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/mortalidade , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Feminino , Seguimentos , Mortalidade Hospitalar/tendências , Humanos , Masculino , Artéria Torácica Interna/diagnóstico por imagem , Artéria Torácica Interna/fisiopatologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
15.
Int J Surg ; 48: 99-104, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29061389

RESUMO

BACKGROUND: Previous studies reported the strategy of in situ skeletonised right internal mammary artery (RIMA) grafting to the left anterior descending artery (LAD). However, few reports have focused on assessing RIMA graft patency rate after grafting to the LAD. This study aimed to assess mid-term graft patency of in situ skeletonised RIMA grafting to the LAD versus in situ skeletonised left internal mammary artery (LIMA) grafting to the LAD in a single-centre propensity-matched study. MATERIALS AND METHODS: After propensity score matching, 185 pairs of patients who received first, scheduled, isolated off-pump coronary artery bypass grafting (OPCAB) surgery were assigned to either a RIMA group (patients who received retrosternal crossover in situ skeletonised RIMA-LAD grafting with additional conduits grafting) or a LIMA group (patients who received in situ skeletonised LIMA-LAD grafting with additional conduits grafting). The primary endpoint was mid-term internal mammary artery (IMA) graft failure after grafting to the LAD and was determined by coronary computed tomography angiography examination. The secondary endpoints were mid-term all-cause mortality and the composite mid-term clinical outcome. RESULTS: The graft patency rate of in situ skeletonised RIMA-LAD graft was not inferior to in situ skeletonised LIMA-LAD graft during a follow-up period of 36.6 ± 12.1 months (97.2% vs. 96.6%, p = 0.752). Kaplan-Meier curves showed a similar cumulative IMA graft failure between the two groups (χ2 = 0.092, Log-rank p = 0.762). And Cox regression analysis revealed that grouping was not an independent factor for follow-up IMA graft failure after grafting to the LAD (HR = 0.93, 95% CI: 0.68-2.13). Additionally, Kaplan-Meier curves showed similar cumulative survival free from adverse events between the two groups (χ2 = 2.365, p = 0.124, respectively). CONCLUSIONS: Revascularisation of the LAD using a skeletonised RIMA resulted in excellent mid-term graft patency and clinical outcomes.


Assuntos
Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Vasos Coronários/cirurgia , Artéria Torácica Interna/patologia , Transplantes/patologia , Idoso , Angiografia por Tomografia Computadorizada , Ponte de Artéria Coronária sem Circulação Extracorpórea/mortalidade , Feminino , Sobrevivência de Enxerto , Humanos , Estimativa de Kaplan-Meier , Masculino , Artéria Torácica Interna/diagnóstico por imagem , Artéria Torácica Interna/transplante , Pessoa de Meia-Idade , Pontuação de Propensão , Modelos de Riscos Proporcionais , Análise de Regressão , Transplantes/diagnóstico por imagem , Resultado do Tratamento
16.
Circ J ; 82(1): 102-109, 2017 12 25.
Artigo em Inglês | MEDLINE | ID: mdl-28794353

RESUMO

BACKGROUND: To evaluate in-hospital and mid-term outcomes of sequential vs. separate grafting of in situ skeletonized left internal mammary artery (LIMA) to the left coronary system in a single-center, propensity-matched study.Methods and Results:After propensity score-matching, 120 pairs of patients undergoing first scheduled isolated coronary artery bypass grafting (CABG) with in situ skeletonized LIMA grafting to the left anterior descending artery (LAD) territory were entered into a sequential group (sequential grafting of LIMA to the diagonal artery and then to the LAD) or a control group (separate grafting of LIMA to the LAD). The in-hospital and follow-up clinical outcomes and follow-up LIMA graft patency were compared. Both propensity score-matched groups had similar in-hospital and follow-up clinical outcomes. Sequential LIMA grafting was not found to be an independent predictor of adverse events. During a follow-up period of 27.0±7.3 months, 99.1% patency for the diagonal site and 98.3% for the LAD site were determined by coronary computed tomographic angiography after sequential LIMA grafting, both of which were similar with graft patency of separate grafting of in situ skeletonized LIMA to the LAD. CONCLUSIONS: Revascularization of the left coronary system using a skeletonized LIMA resulted in excellent in-hospital and mid-term clinical outcomes and graft patency using sequential grafting.


Assuntos
Ponte de Artéria Coronária/métodos , Vasos Coronários/cirurgia , Artéria Torácica Interna/cirurgia , Revascularização Miocárdica/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Resultado do Tratamento , Grau de Desobstrução Vascular
17.
J Cardiothorac Surg ; 12(1): 11, 2017 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-28231841

RESUMO

BACKGROUND: Limited experiences of applying an on-pump beating-heart technique for surgical revascularization in patients with severe left ventricular dysfunction have been reported. Which strategy, either off-pump coronary artery bypass grafting (CABG) or on-pump beating-heart CABG surgery, is the best strategy for surgical revascularization in patients with severe left ventricular dysfunction is still controversial. This single-center study aimed to evaluate the impacts of an on-pump beating-heart versus an off-pump technique for surgical revascularization on the early clinical outcomes in patients with a left ventricular ejection fraction (LVEF) of 35% or less to explore which technique would be more suitable for surgical revascularization in patients with severe left ventricular dysfunction. METHODS: A total of 216 consecutive patients with an echocardiographic estimated LVEF of 35% or less who underwent non-emergency, primary, isolated CABG from January 2010 to December 2014 were included in this study and were divided into either an ONBEAT group (patients who received on-pump beating-heart CABG surgery, n = 88) or an OFF group (patients who received off-pump CABG surgery, n = 128). The early clinical outcomes were investigated and compared. RESULTS: Patients in the ONBEAT group compared to the OFF group had a significant higher early postoperative LVEF (35.6 ± 2.9 vs. 34.8 ± 3.3%, p = 0.034) but shared a similar baseline LVEF (31.0 ± 2.8 vs. 31.0 ± 2.9%, p = 0.930). Patients in the ONBEAT group compared to the OFF group received a greater number of grafts and an increased amount of drainage during the first 24 h (3.7 ± 0.8 vs. 2.8 ± 0.6, p <0.001; 715 ± 187 ml vs. 520 ± 148 ml, p <0.001, respectively), without evidence of worse in-hospital mortality or major postoperative morbidity. Additionally, logistic regression analysis showed that surgical technique (on-pump beating-heart CABG vs. off-pump CABG) had no independent influence on in-hospital mortality or major postoperative morbidity in patients with preoperative LVEF of 35% or less. CONCLUSIONS: The on-pump beating-heart technique may be an acceptable alternative to the off-pump technique for surgical revascularization in patients with an estimated LVEF of 35% or less.


Assuntos
Ponte de Artéria Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Disfunção Ventricular Esquerda/etiologia , Idoso , Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Masculino , Período Pós-Operatório , Estudos Retrospectivos , Resultado do Tratamento , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/cirurgia , Função Ventricular Esquerda
18.
J Med Chem ; 60(3): 913-927, 2017 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-28072531

RESUMO

The design and synthesis of a new series of potent non-prostanoid IP receptor agonists that showed oral efficacy in the rat monocrotaline model of pulmonary arterial hypertension (PAH) are described. Detailed profiling of a number of analogues resulted in the identification of 5c (ralinepag) that has good selectivity in both binding and functional assays with respect to most members of the prostanoid receptor family and a more modest 30- to 50-fold selectivity over the EP3 receptor. In our hands, its potency and efficacy are comparable or superior to MRE269 (the active metabolite of the clinical compound NS-304) with respect to in vitro IP receptor dependent cAMP accumulation assays. 5c had an excellent PK profile across species. Enterohepatic recirculation most probably contributes to a concentration-time profile after oral administration in the cynomolgus monkey that showed a very low peak-to-trough ratio. Following the identification of an acceptable solid form, 5c was selected for further development for the treatment of PAH.


Assuntos
Acetatos/uso terapêutico , Carbamatos/uso terapêutico , Hipertensão Pulmonar/tratamento farmacológico , Receptores de Prostaglandina/agonistas , Acetatos/farmacocinética , Administração Oral , Animais , Disponibilidade Biológica , Carbamatos/farmacocinética , Descoberta de Drogas , Ratos , Relação Estrutura-Atividade
19.
IEEE Trans Cybern ; 47(2): 315-326, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26829812

RESUMO

Histogram shifting (HS) embedding as a typical reversible data hiding scheme is widely investigated due to its high quality of stego-image. For HS-based embedding, the selected side information, i.e., peak and zero bins, usually greatly affects the rate and distortion performance of the stego-image. Due to the massive solution space and burden in distortion computation, conventional HS-based schemes utilize some empirical criterion to determine those side information, which generally could not lead to a globally optimal solution for reversible embedding. In this paper, based on the developed rate and distortion model, the problem of HS-based multiple embedding is formulated as the one of rate and distortion optimization. Two key propositions are then derived to facilitate the fast computation of distortion due to multiple shifting and narrow down the solution space, respectively. Finally, an evolutionary optimization algorithm, i.e., genetic algorithm is employed to search the nearly optimal zero and peak bins. For a given data payload, the proposed scheme could not only adaptively determine the proper number of peak and zero bin pairs but also their corresponding values for HS-based multiple reversible embedding. Compared with previous approaches, experimental results demonstrate the superiority of the proposed scheme in the terms of embedding capacity and stego-image quality.

20.
IEEE Trans Image Process ; 25(6): 2647-56, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27093626

RESUMO

The local variance of image intensity is a typical measure of image smoothness. It has been extensively used, for example, to measure the visual saliency or to adjust the filtering strength in image processing and analysis. However, to the best of our knowledge, no analytical work has been reported about the effect of JPEG compression on image local variance. In this paper, a theoretical analysis on the variation of local variance caused by JPEG compression is presented. First, the expectation of intensity variance of 8×8 non-overlapping blocks in a JPEG image is derived. The expectation is determined by the Laplacian parameters of the discrete cosine transform coefficient distributions of the original image and the quantization step sizes used in the JPEG compression. Second, some interesting properties that describe the behavior of the local variance under different degrees of JPEG compression are discussed. Finally, both the simulation and the experiments are performed to verify our derivation and discussion. The theoretical analysis presented in this paper provides some new insights into the behavior of local variance under JPEG compression. Moreover, it has the potential to be used in some areas of image processing and analysis, such as image enhancement, image quality assessment, and image filtering.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...