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1.
Nat Mater ; 23(6): 768-774, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38243113

RESUMO

The key challenge of spin-orbit torque applications lies in exploring an excellent spin source capable of generating out-of-plane spins while exhibiting high spin Hall conductivity. Here we combine PtTe2 for high spin conductivity and WTe2 for low crystal symmetry to satisfy the above requirements. The PtTe2/WTe2 bilayers exhibit a high in-plane spin Hall conductivity σs,y ≈ 2.32 × 105 × h/2e Ω-1 m-1 and out-of-plane spin Hall conductivity σs,z ≈ 0.25 × 105 × h/2e Ω-1 m-1, where h is the reduced Planck's constant and e is the value of the elementary charge. The out-of-plane spins in PtTe2/WTe2 bilayers enable the deterministic switching of perpendicular magnetization at room temperature without magnetic fields, and the power consumption is 67 times smaller than that of the Pt control case. The high out-of-plane spin Hall conductivity is attributed to the conversion from in-plane spin to out-of-plane spin, induced by the crystal asymmetry of WTe2. Our work establishes a low-power perpendicular magnetization manipulation based on wafer-scale two-dimensional van der Waals heterostructures.

2.
Medicina (Kaunas) ; 60(7)2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-39064458

RESUMO

Background and Objectives: Obstructive sleep apnea (OSA) is common in cardiovascular disease (CVD), although positive airway pressure (PAP) treatment has not been demonstrated to improve the cardiovascular outcome. The objective of this study is to investigate the impact of adherence to PAP therapy on cardiopulmonary exercise testing (CPET) performance in patients with concomitant OSA and CVD. Materials and Methods: This preliminary study involved symptomatic OSA patients requiring PAP treatment who had CVD. All subjects underwent polysomnography, echocardiography, and CPET at baseline. After 6 to 12 months of PAP treatment, CPET performance was re-assessed. The changes in CPET parameters before and after PAP treatment were compared between patients who were adherent to PAP and patients who were not adherent to PAP. Results: A total of 16 OSA patients with an apnea-hypopnea index of 32.0 ± 23.4 were enrolled. Patients were classified into the adherent (n = 9) and non-adherent (n = 7) groups with regard to PAP adherence. After 6 to 12 months of PAP treatment, the PAP-adherent group showed a greater increase in peak VO2 than the PAP-non-adherent group, but the difference between the two groups was not significant (p = 0.581). The decrease in ventilatory equivalent for the carbon dioxide slope (VE/VCO2) was significantly greater in the PAP-adherent group compared to the PAP-non-adherent group (p = 0.030). Conclusions: Adherence to PAP therapy for OSA is associated with an improvement in the VE/VCO2 slope, as an index of the ventilatory response to exercise, in patients with CVD. Screening for sleep apnea in CVD patients may be warranted, and strategies to optimize adherence to PAP in these patients are beneficial. Further evidence is needed to elucidate whether CPET could be routinely used to monitor treatment responses of OSA to PAP therapy in patients with CVD.


Assuntos
Aptidão Cardiorrespiratória , Doenças Cardiovasculares , Teste de Esforço , Polissonografia , Apneia Obstrutiva do Sono , Humanos , Apneia Obstrutiva do Sono/terapia , Apneia Obstrutiva do Sono/fisiopatologia , Apneia Obstrutiva do Sono/complicações , Masculino , Feminino , Pessoa de Meia-Idade , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/complicações , Teste de Esforço/métodos , Aptidão Cardiorrespiratória/fisiologia , Polissonografia/métodos , Pressão Positiva Contínua nas Vias Aéreas/métodos , Idoso , Adulto , Cooperação do Paciente/estatística & dados numéricos
3.
Rev Cardiovasc Med ; 24(2): 42, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39077393

RESUMO

Background: Periprocedural myocardial infarction (PMI) occurs more frequently in patients with heavily calcified lesion and undergoing rotational atherectomy (RA). However, there are limited studies addressing prognostic impact of PMI in patients requiring RA due to severe coronary artery calcification (CAC). Therefore, the objective of this study was to determine the prognostic impact of PMI in patients who underwent percutaneous coronary intervention (PCI) using RA. Methods: A total of 540 patients (583 lesions) who received PCI using RA were enrolled between January 2010 and October 2019. PMI was defined as elevations of creatine kinase-myocardial band (CK-MB) > 10 times the upper limited normal. Patients were divided into a PMI group and a non-PMI group. Primary endpoint was major adverse cardiovascular and cerebrovascular event (MACCE), a composite of cardiac death, target-vessel myocardial infarction, target-vessel revascularization, and cerebrovascular accident. Results: Although in-hospital events occurred more frequently in the PMI group than in the non-PMI group (15 [3.0%] vs. 6 [13.3%], p = 0.005), the incidence of MACCEs at 1 month, 1-12 months, or 12 months failed to show a significant difference between the two groups (1 month, 10 [2.0%] vs. 1 [2.2%], p > 0.999; 1-12 months, 39 [7.9%] vs. 7 [15.6%], p = 0.091; 12 months, 49 [9.9%] vs. 8 [17.8%], p = 0.123). Conclusions: This study shows that PMI after RA in patients with severe CAC was associated with more frequent in-hospital events and a nonsignificant trend for more events during 1 year follow-up.

4.
Medicina (Kaunas) ; 59(10)2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37893526

RESUMO

Background and Objectives: Although both rotational atherectomy (RA) and atrial fibrillation (AF) have a high thrombotic risk, there have been no previous studies on the prognostic impact of AF in patients who undergo percutaneous coronary intervention (PCI) using RA. Thus, the aim of the present study was to determine the prognostic impact of AF in patients undergoing PCI using RA. Materials and Methods: A total of 540 patients who received PCI using RA were enrolled between January 2010 and October 2019. Patients were divided into AF and sinus rhythm groups according to the presence of AF. The primary endpoint was net adverse clinical events (NACEs) defined as a composite outcome of all-cause death, myocardial infarction, target vessel revascularization, cerebrovascular accident, or total bleeding. Results: Although in-hospital adverse events showed no difference between those with AF and those without AF (in-hospital events, 54 (11.0%) vs. 6 (12.2%), p = 0.791), AF was strongly associated with an increased risk of NACE at 3 years (NACE: hazard ratio, 1.880; 95% confidence interval, 1.096-3.227; p = 0.022). Conclusions: AF in patients who underwent PCI using RA was strongly associated with poor clinical outcomes. Thus, more attention should be paid to thrombotic and bleeding risks.


Assuntos
Aterectomia Coronária , Fibrilação Atrial , Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Humanos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/cirurgia , Aterectomia Coronária/efeitos adversos , Intervenção Coronária Percutânea/efeitos adversos , Fibrilação Atrial/complicações , Prognóstico , Resultado do Tratamento , Estudos Retrospectivos , Fatores de Risco
5.
Catheter Cardiovasc Interv ; 99(2): 219-225, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34787371

RESUMO

OBJECTIVES: We aimed to assess the advantages of using the retrograde approach as an initial strategy rather than as a rescue strategy for complex chronic total occlusions (CTOs). BACKGROUND: Even for complex CTOs where a retrograde approach is deemed necessary, an antegrade approach is frequently used as an initial strategy in real-world practice. METHODS: We evaluated 352 retrograde procedures for CTO conducted at our high-volume center between January 2007 and January 2019. Procedural efficiency and safety was assessed based on the guidewire manipulation time (GWMT) and the occurrence of procedure-related adverse events for the primary retrograde approach (PRA) and the rescue retrograde approach (RRA). RESULTS: PRA and RRA were used in 191 (54.3%) and 161 (45.7%) of the CTO procedures, respectively. The complexity of the CTO lesion was significantly higher in the PRA group than in the RRA group (Japanese-CTO score, 2.62 ± 1.07 vs. 2.38 ± 1.06, p = 0.037). The technical success rate of two groups was similar (p = 0.47). The median GWMT required for PRA was significantly shorter than that for RRA (85 [interquartile range, 55-126] vs. 120 [85-157] min, p < 0.001). The total duration of the procedure and fluoroscopic time were shorter, and the number of guidewires and amount of contrast used during the index procedure were smaller in the PRA group. The incidence of procedure-related adverse events was not significantly different between the two groups. CONCLUSIONS: PRA showed higher procedural efficiency than RRA with comparable safety. Opting for PRA for complex CTOs might be a rational decision to enhance the procedural efficiency.


Assuntos
Oclusão Coronária , Intervenção Coronária Percutânea , Doença Crônica , Angiografia Coronária/métodos , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/etiologia , Oclusão Coronária/terapia , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Sistema de Registros , Fatores de Risco , Resultado do Tratamento
6.
Heart Vessels ; 36(11): 1617-1625, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33837813

RESUMO

The aim of this study was to investigate the impact of chronic total occlusion (CTO) on clinical outcomes in patients with calcified coronary lesions receiving rotational atherectomy (RA). This multi-center registry enrolled consecutive patients with calcified coronary artery disease who underwent RA during percutaneous coronary intervention (PCI) from 9 tertiary centers in Korea between January 2010 and October 2019. The primary outcome was target-vessel failure (TVF) which included the composite of cardiac death, target-vessel myocardial infarction (TVMI), and target-vessel revascularization (TVR). A total of 583 lesions were enrolled in this registry and classified as CTO (n = 42 lesions, 7.2%) and non-CTO (n = 541 lesions, 92.8%). The CTO group consisted of younger patients who were more likely to have a history of previous percutaneous coronary intervention or coronary artery bypass graft surgery. The incidence of the primary outcome was 14.1% and 16.7% for the non-CTO group and CTO group, respectively. The primary outcomes observed in the two groups were not significantly different (log-rank p = 0.736). The 18-month clinical outcomes of the CTO group were comparable to those of the non-CTO group in multivariate analysis. About 7% of patients requiring RA have CTO lesions and these patients experience similar clinical outcomes compared with those having non-CTO lesions. Use of RA for CTO lesions was safe despite higher procedural complexity.


Assuntos
Aterectomia Coronária , Doença da Artéria Coronariana , Oclusão Coronária , Intervenção Coronária Percutânea , Aterectomia Coronária/efeitos adversos , Doença Crônica , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/cirurgia , Oclusão Coronária/diagnóstico , Oclusão Coronária/cirurgia , Humanos , Sistema de Registros , Fatores de Risco , Resultado do Tratamento
7.
Medicina (Kaunas) ; 57(7)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34356975

RESUMO

Background and Objectives: Data is still limited regarding clinical outcomes of rotational atherectomy (RA) after percutaneous coronary intervention. We sought to evaluate clinical outcomes of RA. Materials and Methods: This multi-center registry enrolled patients who underwent RA during PCI from nine tertiary centers in Korea between January 2010 and October 2019. The primary endpoint was target-vessel failure (TVF; the composite outcome of cardiac death, target-vessel spontaneous myocardial infarction, or target-vessel revascularization). Results: Of 540 patients (583 lesions), the mean patient age was 71.4 ± 0.4 years, 323 patients (59.8%) were men, and 305 patients (56.5%) had diabetes mellitus. Technical success rate was 96.4%. In-hospital major adverse cerebral and cardiac events occurred in 63 cases (10.8%). At 1.5 years, 72 (16.0%) of TVFs were occurred. We evaluated independent predictors of TVF, which included current smoker (hazard ratio (HR), 1.92; 95% confidence interval (CI), 1.17-3.16; p = 0.01), chronic renal disease (HR, 1.87; 95% CI, 1.14-3.08; p = 0.013), history of cerebrovascular attack (HR, 2.14; 95% CI, 1.24-3.68; p = 0.006), left ventricle ejection fraction (HR, 0.98; 95% CI, 0.97-0.999; p = 0.037), and left main disease (HR, 1.94; 95% CI, 1.11-3.37; p = 0.019). Conclusions: From this registry, we demonstrated acceptable success rates, in-hospital and mid-term clinical outcomes of RA in the DES era.


Assuntos
Aterectomia Coronária , Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Calcificação Vascular , Idoso , Doença da Artéria Coronariana/cirurgia , Humanos , Masculino , Sistema de Registros , República da Coreia/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento
8.
J Chem Phys ; 153(4): 044129, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32752726

RESUMO

We investigate the interplay of reactive interference and crowding effects in the irreversible diffusion-influenced bimolecular reactions of the type A+B→P+B by using the Brownian dynamics simulation method. It is known that the presence of nonreactive crowding agents retards the reaction rate when the volume fraction of the crowding agents is large enough. On the other hand, a high concentration of B is known to increase the reaction rate more than expected from the mass action law, although the B's may also act as crowders. Therefore, it would be interesting to see which effect dominates when the number density of B as well as the number density of the crowders increases. We will present an approximate theory that provides a reasonable account for the Brownian dynamics simulation results.

9.
J Chem Phys ; 152(13): 134102, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32268750

RESUMO

By applying a recently developed solution method for the Fredholm integral equation of the second kind, we obtain an expression for Green's function of the Smoluchowski equation with a reaction sink. The result is applied to obtain accurate analytical expressions for the time-dependent survival probability of a geminate reactant pair and the rate coefficient of the bulk recombination between reactants undergoing diffusive motions under strong Coulomb interactions. The effects of both repulsive and attractive interactions are considered, and the results are compared with the numerical results obtained by solving the equation for the survival probability and the nonequilibrium pair correlation function. It is shown that the solutions are accurate enough for most reasonable parameter values.

10.
Am Heart J ; 218: 9-19, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31655415

RESUMO

BACKGROUND: Acuity of clinical presentation may influence decision making of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease. However, it is undetermined whether clinical indication for myocardial revascularization may affect the relative long-term effect after PCI and CABG. METHODS: In the MAIN-COMPARE study including 2,240 patients with LMCA disease treated with PCI (n = 1102) or CABG (n = 1138), we examined interaction between acuity of clinical presentation (acute coronary syndromes [ACS] or non-ACS) and revascularization strategy on 10-year outcomes. Primary outcome was a composite of all-cause death, Q-wave myocardial infarction, or stroke. Secondary outcomes were all-cause death or target vessel revascularization. RESULTS: In overall patients, 1,603 patients (71.6%) presented with ACS and 637 patients (28.4%) presented with non-ACS. The 10-year adjusted risks for primary composite outcome were similar after PCI and CABG among patients who presented with non-ACS (hazard ratio [HR] 1.07; 95% CI 0.71-1.61) and those who presented with ACS (HR 1.00; 95% CI 0.81-1.24) (P for interaction = .29). The adjusted risks of death were also similar between 2 groups in non-ACS (HR 0.98; 95% CI 0.63-1.51) and ACS (HR 1.02; 95% CI 0.81-1.28) patients (P for interaction = .62). The adjusted risks of target vessel revascularization were consistently higher after PCI in non-ACS (HR 6.38; 95% CI 3.14-12.96) and ACS (HR 3.96; 95% CI 2.80-5.60) patients (P for interaction = .39). CONCLUSIONS: In patients with LMCA disease, we have identified no significant interaction between the acuity of clinical indication and the relative treatment effect of PCI versus CABG on 10-year clinical outcomes.


Assuntos
Doença da Artéria Coronariana/cirurgia , Infarto do Miocárdio/etiologia , Isquemia Miocárdica/cirurgia , Gravidade do Paciente , Complicações Pós-Operatórias/etiologia , Acidente Vascular Cerebral/etiologia , Causas de Morte , Ponte de Artéria Coronária/estatística & dados numéricos , Doença da Artéria Coronariana/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/epidemiologia , Revascularização Miocárdica/estatística & dados numéricos , Intervenção Coronária Percutânea/estatística & dados numéricos , Estudos Prospectivos , Stents/estatística & dados numéricos , Fatores de Tempo , Resultado do Tratamento
11.
Catheter Cardiovasc Interv ; 94(3): 315-322, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724018

RESUMO

BACKGROUND: Little is known about how the relative treatment effect of percutaneous coronary intervention (PCI) and coronary-artery bypass grafting (CABG) on clinical outcomes in ostial or shaft left main coronary artery (LMCA) disease has evolved over time. METHODS: This study included 2,112 patients with ostial or shaft LMCA disease from IRIS-MAIN registry who underwent PCI (n = 1,329) or CABG (n = 783). Patients were stratified by time period based on stent type availability: wave 1 (1995-2002, bare-metal stent [BMS] era); wave 2 (2003-2006, first-generation drug-eluting stent [DES] era); and wave 3 (2007-2014, second-generation DES era). RESULTS: Compared to CABG, PCI has been used more frequently from wave 1 to wave 3. PCI showed substantial improvements over time with respect to death (P for trend = 0.012); the composite of death, myocardial infarction (MI), or stroke (P for trend = 0.047); repeat revascularization (P for trend < 0.001); and major adverse cardiac and cerebrovascular events (MACCE; a composite of death, MI, stroke, or repeat revascularization) (P for trend < 0.001). By contrast, outcomes of CABG remained relatively stable over time. The gap between the treatment effects of CABG vs PCI for MACCE has narrowed over time; the adjusted hazard ratios for CABG compared to PCI during wave 1, 2, and 3 were 0.41 (95% confidence interval [CI]: 0.22-0.76), 0.47 (95% CI: 0.31-0.71), and 0.78 (95% CI: 0.50-1.20), respectively. CONCLUSIONS: In patients with ostial or shaft LMCA disease, significant improvements in PCI outcomes resulted in a progressive decline in the gap between the outcomes of CABG and PCI.


Assuntos
Ponte de Artéria Coronária/tendências , Doença da Artéria Coronariana/terapia , Stents Farmacológicos/tendências , Intervenção Coronária Percutânea/tendências , Idoso , Ásia , Ponte de Artéria Coronária/efeitos adversos , Ponte de Artéria Coronária/mortalidade , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/mortalidade , Desenho de Prótese , Sistema de Registros , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
12.
Heart Vessels ; 34(7): 1187-1195, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30671642

RESUMO

A prognostic value of right ventricular (RV) systolic function assessed by echocardiography in patients with acute non-massive pulmonary embolism (PE) remains controversial. The hypothesis was RV free wall strain measured using speckle-tracking echocardiography might be a powerful prognostic factor in those patients. We aimed to evaluate the prognostic value of echocardiographic measurements of RV systolic function for clinical outcomes and to assess the correlation between the echocardiographic RV function parameters in patients with acute non-massive PE. Between November 2013 and September 2016, 144 consecutive patients diagnosed as acute non-massive pulmonary embolism were prospectively enrolled and echocardiographic evaluations were performed within 1 week of diagnosis to measure various parameters of RV systolic function. The primary endpoint was in-hospital events, the composite of in-hospital PE-related death, need of additive treatments such as thrombolysis or pulmonary artery thromboembolectomy, and need of inotropics due to unstable vital sign. Among patients (mean age 60.3 ± 14.7 years, 50% female) with acute non-massive PE, the in-hospital event rate was 11.1% (16 of 144 patients). In multivariate logistic regression analysis, after adjustment of confounding factors such as age, gender, and diabetes mellitus, RV free wall strain [odd ratio (OR) 1.12, 95% confidence interval (CI) 1.04-1.21, p = 0.002] and RV global wall strain (OR 1.20, 95% CI 1.07-1.35, p = 0.002) were independent predictors for in-hospital events. The event rates were significantly different between groups classified based on RV free wall strain with cut-off value of - 15.85% (p < 0.001). RV strain assessed with speckle-tracking echocardiography is an independent prognostic marker for in-hospital events in patients with acute non-massive PE. Our results may help identify high-intermediate risk patients who need a closer monitoring.


Assuntos
Ecocardiografia , Interpretação de Imagem Assistida por Computador/métodos , Embolia Pulmonar/diagnóstico por imagem , Disfunção Ventricular Direita/diagnóstico por imagem , Doença Aguda , Adulto , Idoso , Causalidade , Feminino , Mortalidade Hospitalar , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Estudos Prospectivos , Embolia Pulmonar/mortalidade , República da Coreia , Medição de Risco , Sensibilidade e Especificidade , Volume Sistólico , Disfunção Ventricular Direita/mortalidade
13.
Ginekol Pol ; 89(11): 611-617, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30508213

RESUMO

OBJECTIVES: The purpose of this study was to identify clinical risk factors for the recurrence of ovarian endometrioma after ovarian cystectomy in Korean women with long-term postoperative medical therapy. MATERIAL AND METHODS: A total of 134 patients who were surgically treated for endometriotic cysts at Pusan National University Hospital were included in this retrospective study. All patients received long-term postoperative medical treatment for at least 12 months after the first-line conservative surgery. Several epidemiologic variables were analyzed as possible risk factors for recurrence. Endometrioma recurrence was considered when a cystic mass was observed on transvaginal or transrectal sonography. Statistical analysis was performed using independent t-tests for parametric continuous variables. RESULTS: The mean follow-up period for the 134 patients was 56.5 ± 14.3 months (range, 36-120 months) and the mean duration of the medical therapy was 17.9 ± 17.3 months (range, 12-120 months). The overall recurrence rate was 35/134 (26.12%). Our univariate analysis showed statistically significant differences between the recurrent and non-recurrent groups in terms of weight (P = 0.013), body mass index (P = 0.007), age at the time of surgery (P = 0.013), the diameter of the largest cyst (P = 0.001), the presence of dysmenorrhea (P < 0.0001), and postoperative pregnancy (P = 0.016). Multivariate analysis showed that body mass index (OR 1.153, 95% CI 1.003-1.326, P = 0.046), age at the time of surgery (OR 0.924, 95% CI 0.860-0.992, P = 0.029), and presence of dysmenorrhea (OR 12.226, 95% CI 3.543-42.188, P < 0.0001) were significantly correlated with the recurrence of endometrioma. CONCLUSIONS: We found that patients with dysmenorrhea after surgery, and a younger age of the patient at the time of surgery were the highest risk factors associated with the recurrence of endometrioma, despite long-term postoperative medication.


Assuntos
Anticoncepcionais Orais Hormonais/uso terapêutico , Dismenorreia/epidemiologia , Endometriose/terapia , Procedimentos Cirúrgicos em Ginecologia , Doenças Ovarianas/terapia , Progestinas/uso terapêutico , Adulto , Fatores Etários , Índice de Massa Corporal , Feminino , Humanos , Análise Multivariada , Razão de Chances , Cuidados Pós-Operatórios , Período Pós-Operatório , Gravidez/estatística & dados numéricos , Recidiva , República da Coreia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
14.
J Chem Phys ; 147(14): 144111, 2017 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-29031266

RESUMO

We consider the effects of external electric field and anisotropic long-range reactivity on the recombination dynamics of a geminate charge pair. A closed-form analytic expression for the ultimate separation probability of the pair is presented. In previous theories, analytic expressions for the separation probability were obtained only for the case where the recombination reaction can be assumed to occur at a contact separation. For this case, Noolandi and Hong obtained an exact solution, but their expression for the separation probability was too complicated to evaluate. Hence an approximate analytic expression proposed by Braun has been widely used. However, Braun's expression overestimates the separation probability when the electric field is large. In this work, we present an approximate analytic expression that is accurate enough for all parameter values. In addition, the expression is also applicable when the interaction between the geminate charge pair is described by screened Coulombic potential, and the recombination reaction has an anisotropic and long-range reactivity. We also provide the expression for the separation probability when the initial separation between the geminate charge pair is larger than the contact distance.

15.
J Reprod Med ; 61(3-4): 133-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27172635

RESUMO

OBJECTIVE: To investigate the usefulness of the endometrial volume and vascular indices in the endometrial region as an effective predictor for pregnancy outcome in frozen-thawed embryo transfer (FET). STUDY DESIGN: We evaluated 131 embryo transfer cycles in 73 infertile women. After controlled ovarian stimulation all embryos were cultured to blastocyst stage, and the blastocysts with good quality were vitrified for elective FET. On the day of FET, endometrial thickness, endometrial volume, pulsatility index (PI), and resistance index of uterine artery and endometrial-subendometrial vessels (ESVs) with zonal discrimination were evaluated by transvaginal ultrasonography in each patient. These variables were compared between pregnant and nonpregnant cycles. RESULTS: The endometrial volume was significantly higher in the pregnant group (2.32 ± 0.86, 1.96 ± 0.62 mL, p = 0.007). Also, PI of ESVs was significantly higher in the pregnant cycle (2.58 ± 1.32 and 2.05 ± 1.08, p = 0.016). The other variables were not different between the 2 groups. CONCLUSION: This study suggested that endometrial volume and the vascular indices measured in endometrial region are useful predictors of pregnancy outcome.


Assuntos
Transferência Embrionária/métodos , Endométrio/diagnóstico por imagem , Resultado da Gravidez , Útero/irrigação sanguínea , Adulto , Técnicas de Cultura Embrionária , Endométrio/irrigação sanguínea , Feminino , Fertilização in vitro , Humanos , Infertilidade Feminina/terapia , Indução da Ovulação , Gravidez , Estudos Prospectivos , Ultrassonografia , Útero/diagnóstico por imagem
16.
Reprod Biol Endocrinol ; 12: 113, 2014 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-25421381

RESUMO

BACKGROUND: Many studies have proposed that putative ovarian stem cells (OSCs) derived from the ovarian surface epithelium (OSE) layer of adult mammalian ovaries can produce oocytes. Few studies have reported that ovaries of aged mammalian females including mice and women possess rare premeiotic germ cells that can generate oocytes. However, no studies have reported the changes of OSCs according to the age of the female. Therefore, this study evaluated pluripotent and germ cell marker expression in the intact ovary, scraped OSE, and postcultured OSE according to age in female mice. METHODS: C57BL/6 female mice of 2 age groups (6-8 and 28-31 weeks) were superovulated by injection with 5 IU equine chorionic gonadotropin (eCG). Both ovaries were removed after 48 hours and scrapped to obtain OSE. Gene expressions of pluripotent (Oct-4, Sox-2, Nanog) and germ cell markers (c-Kit, GDF-9, and VASA) were evaluated by RT-PCR. VASA and GDF-9 were immune-localized in oocyte-like structures. RESULTS: Expressions of germ cell markers in the intact ovary were significantly decreased in aged females, whereas expressions of pluripotent markers were not detected, regardless of age. Scraped OSE expression of all pluripotent and germ cell markers, except for c-Kit, was similar between both age groups. Three weeks postcultured OSE had significantly decreased expression of GDF-9 and VASA , but not c-Kit, in old mice, as compared to young mice; however there was no difference in the expression of other genes. The number of positively stained Oct-4 by immunohistochemistry in postcultured OSE was 2.5 times higher in young mice than aged mice. Oocyte-like structure was spontaneously produced in postcultured OSE. However, while that of young mice revealed a prominent nucleus, zona pellucida-like structure and cytoplasmic organelles, these features were not observed in old mice. CONCLUSIONS: These results show that aged female mice have putative OSCs in OSE, but their differentiation potential, as well as the number of OSCs differs from those of young mice.


Assuntos
Envelhecimento/genética , Células Epiteliais/metabolismo , Oócitos/metabolismo , Células-Tronco Pluripotentes/metabolismo , Transcriptoma , Fatores Etários , Animais , Núcleo Celular/metabolismo , Células Cultivadas , Gonadotropina Coriônica/farmacologia , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Feminino , Fator 9 de Diferenciação de Crescimento/genética , Fator 9 de Diferenciação de Crescimento/metabolismo , Proteínas de Homeodomínio/genética , Cavalos , Imuno-Histoquímica , Camundongos Endogâmicos C57BL , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Oócitos/citologia , Ovário/citologia , Ovário/efeitos dos fármacos , Células-Tronco Pluripotentes/citologia , Proteínas Proto-Oncogênicas c-kit/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXB1/genética , Superovulação/efeitos dos fármacos
17.
Nat Commun ; 15(1): 4046, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744961

RESUMO

The ability to electrically manipulate antiferromagnetic magnons, essential for extending the operating speed of spintronic devices into the terahertz regime, remains a major challenge. This is because antiferromagnetic magnetism is challenging to perturb using traditional methods such as magnetic fields. Recent developments in spin-orbit torques have opened a possibility of accessing antiferromagnetic magnetic order parameters and controlling terahertz magnons, which has not been experimentally realised yet. Here, we demonstrate the electrical manipulation of sub-terahertz magnons in the α-Fe2O3/Pt antiferromagnetic heterostructure. By applying the spin-orbit torques in the heterostructure, we can modify the magnon dispersion and decrease the magnon frequency in α-Fe2O3, as detected by time-resolved magneto-optical techniques. We have found that optimal tuning occurs when the Néel vector is perpendicular to the injected spin polarisation. Our results represent a significant step towards the development of electrically tunable terahertz spintronic devices.

18.
Sci Rep ; 14(1): 365, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429290

RESUMO

Body mass index (BMI), as an important risk factor related to metabolic disease. However, in some studies higher BMI was emphasized as a beneficial factor in the clinical course of patients after acute myocardial infarction (AMI) in a concept known as the "BMI paradox." The purpose of this study was to investigate how clinical outcomes of patients treated for AMI differed according to BMI levels. A total of 10,566 patients in the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) from May 2010 to June 2015 were divided into three BMI groups (group 1: BMI < 22 kg/m2, group 2: ≥ 22 and < 26 kg/m2, and group 3: ≥ 26 kg/m2). The primary outcome was major adverse cardiac and cerebrovascular event (MACCE) at 3 years of follow-up. At 1 year of follow-up, the incidence of MACCE in group 1 was 10.1% of that in group 3, with a hazard ratio (HR) of 2.27, and 6.5% in group 2, with an HR of 1.415. This tendency continued up to 3 years of follow-up. The study demonstrated that lower incidence of MACCE in the high BMI group of Asians during the 3-year follow-up period compared to the low BMI group. The results implied higher BMI could exert a positive effect on the long-term clinical outcomes of patients with AMI undergoing percutaneous coronary intervention (PCI).


Assuntos
Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Índice de Massa Corporal , Intervenção Coronária Percutânea/efeitos adversos , Infarto do Miocárdio/etiologia , Fatores de Risco , Sistema de Registros , Resultado do Tratamento
19.
J Stroke ; 26(2): 242-251, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38836271

RESUMO

BACKGROUND AND PURPOSE: In young patients (aged 18-60 years) with patent foramen ovale (PFO)-associated stroke, percutaneous closure has been found to be useful for preventing recurrent ischemic stroke or transient ischemic attack (TIA). However, it remains unknown whether PFO closure is also beneficial in older patients. METHODS: Patients aged ≥60 years who had a cryptogenic stroke and PFO from ten hospitals in South Korea were included. The effect of PFO closure plus medical therapy over medical therapy alone was assessed by a propensity-score matching method in the overall cohort and in those with a high-risk PFO, characterized by the presence of an atrial septal aneurysm or a large shunt. RESULTS: Out of the 437 patients (mean age, 68.1), 303 (69%) had a high-risk PFO and 161 (37%) patients underwent PFO closure. Over a median follow-up of 3.9 years, recurrent ischemic stroke or TIA developed in 64 (14.6%) patients. In the propensity score-matched cohort of the overall patients (130 pairs), PFO closure was associated with a significantly lower risk of a composite of ischemic stroke or TIA (hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.24-0.84; P=0.012), but not for ischemic stroke. In a subgroup analysis of confined to the high-risk PFO patients (116 pairs), PFO closure was associated with significantly lower risks of both the composite of ischemic stroke or TIA (HR: 0.40; 95% CI: 0.21-0.77; P=0.006) and ischemic stroke (HR: 0.47; 95% CI: 0.23-0.95; P=0.035). CONCLUSION: Elderly patients with cryptogenic stroke and PFO have a high recurrence rate of ischemic stroke or TIA, which may be significantly reduced by device closure.

20.
PLoS One ; 18(6): e0286670, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37267287

RESUMO

BACKGROUND: Although statins are an effective strategy for the secondary prevention of atherosclerotic cardiovascular disease (ASCVD) in the general population, the benefits for dialysis patients are controversial. We sought to assess trends of statin use and evaluate outcomes of statin therapy in dialysis patients with different types of ASCVD. METHODS: This nationwide retrospective population-based cohort study using data from the Korean National Health Insurance Service included adult patients (aged ≥ 18 years) undergoing chronic dialysis who had an initial ASCVD event in the time period of 2013 to 2018. Annual trends of statin use according to age, sex, and ASCVD types were analyzed. The association between 1-year mortality and statin use was examined using multivariable Cox proportional hazards regression analyses. RESULTS: Among 17,242 subjects, 9,611(55.7%) patients were statin users. The overall prevalence of statin use increased from 52.9% in 2013 to 57.7% in 2018; the majority (77%) of dialysis patients were prescribed moderate-intensity statins. The proportions of low- or moderate-intensity statin use were similar, but high-intensity statin use increased from 5.7% in 2013 to 10.5% in 2018. The use of the statin/ezetimibe combination has gradually increased since 2016. Statin use was independently associated with the reduced 1-year all-cause mortality after adjusting for confounding factors (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.80-0.96, P = 0.004). CONCLUSION: The prevalence of statin prescriptions in dialysis patients after ASCVD event increased from 2013 to 2018. Most patients received moderate-intensity statin. However, high-intensity statin and statin/ezetimibe combination therapy has remarkably increased. Statin use was associated with decreased 1-year all-cause mortality in dialysis patients with ASCVD.


Assuntos
Aterosclerose , Doenças Cardiovasculares , Inibidores de Hidroximetilglutaril-CoA Redutases , Adulto , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/epidemiologia , Estudos Retrospectivos , Estudos de Coortes , Diálise Renal , Aterosclerose/tratamento farmacológico , Aterosclerose/epidemiologia , Aterosclerose/prevenção & controle , Ezetimiba
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