Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 473
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Phys Rev Lett ; 126(23): 236801, 2021 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-34170165

RESUMEN

Spin-charge conversion via spin-orbit interaction is one of the core concepts in the current spintronics research. The efficiency of the interconversion between charge and spin current is estimated based on Berry curvature of Bloch wave function in the linear-response regime. Beyond the linear regime, nonlinear spin-charge conversion in the higher-order electric field terms has recently been demonstrated in noncentrosymmetric materials with nontrivial spin texture in the momentum space. Here, we report the observation of the nonlinear charge-spin conversion in a nominally centrosymmetric oxide material SrIrO_{3} by breaking inversion symmetry at the interface. A large second-order magnetoelectric coefficient is observed at room temperature because of the antisymmetric spin-orbit interaction at the interface of Dirac semimetallic bands, which is subject to the symmetry constraint of the substrates. Our study suggests that nonlinear spin-charge conversion can be induced in many materials with strong spin-orbit interaction at the interface by breaking the local inversion symmetry to give rise to spin splitting in otherwise spin degenerate systems.

2.
Sci Technol Adv Mater ; 22(1): 449-460, 2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34211334

RESUMEN

To realize a sustainable society, 'green technology' with low (or even zero) CO2 emissions is required. A key material in such technology is a permanent magnet because it is utilized for electric-power conversion in several applications including electric vehicles (EVs), hybrid EVs (HEVs), and turbines for wind power generation. To realize highly efficient electric-power conversion, a stronger permanent magnet than Nd-Fe-B is necessary. One potential candidate is a Fe-rich SmFe12-based compound with a ThMn12 structure. In this paper, the phase stability, structure, and intrinsic and extrinsic magnetic properties in both film and bulk forms are reviewed. Based on these results, a possible way to realize a strong SmFe12-based permanent magnet in bulk form is discussed.

3.
Eur J Neurol ; 26(9): 1219-1225, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31002446

RESUMEN

BACKGROUND AND PURPOSE: The association between an increased supraventricular ectopic beat (SVEB) and subclinical cerebrovascular disease remains unclear. Given the emerging concept that an increased SVEB is a marker of atrial cardiomyopathy or atherosclerosis burden, we sought to determine whether excessive supraventricular ectopic activity (ESVEA) is associated with a higher burden of subclinical cerebrovascular disease in the middle-aged to older cohort with neither apparent stroke nor atrial fibrillation. METHODS: We conducted a cross-sectional population-based study of 462 men (mean age, 68.1 years) who underwent 24-h Holter electrocardiography and brain magnetic resonance imaging. ESVEA was defined as the presence of >10 SVEBs/h. Subclinical cerebrovascular diseases were defined as silent brain infarct (SBI), white matter hyperintensity (WMH) and intracranial atherosclerotic stenosis (ICAS). The association of ESVEA with the presence of subclinical cerebrovascular diseases was adjusted for potential confounding covariates. RESULTS: A total of 88 (19.0%) participants had ESVEA and 81 (17.5%), 91 (19.7%) and 109 (23.6%) had SBI, WMH and ICAS, respectively. In multivariable-adjusted Poisson regression with robust error variance, ESVEA was associated with the presence of WMH (relative risk, 1.58; 95% confidence interval, 1.06-2.36) and ICAS (relative risk, 1.49; 95% confidence interval, 1.02-2.18), but not with that of SBI (relative risk, 1.32; 95% confidence interval, 0.86-2.01). These associations were consistent when the graded distributions of subclinical cerebrovascular diseases were applied as outcomes in ordinal logistic regression. CONCLUSIONS: The ESVEA was independently associated with higher burdens of WMH and ICAS. This suggests that increased SVEBs might improve risk stratification of individuals at high risk of subclinical cerebrovascular disease and consequently apparent ischaemic stroke.


Asunto(s)
Infarto Encefálico/epidemiología , Cardiomiopatías/epidemiología , Arteriosclerosis Intracraneal/epidemiología , Leucoaraiosis/epidemiología , Anciano , Infarto Encefálico/diagnóstico por imagen , Cardiomiopatías/diagnóstico , Comorbilidad , Estudios Transversales , Electrocardiografía Ambulatoria , Humanos , Arteriosclerosis Intracraneal/diagnóstico por imagen , Leucoaraiosis/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/fisiopatología
4.
J Clin Pharm Ther ; 43(5): 675-681, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29679392

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: For analysis of blood concentrations of everolimus, many hospital laboratories use either latex agglutination turbidimetric immunoassay (LTIA) or electrochemiluminescence immunoassay (ECLIA). However, no studies have compared both immunoassay methods under the same conditions. Accordingly, in this study, we compared everolimus blood concentrations obtained by LTIA and ECLIA in renal transplant patients. METHODS: Blood samples (n = 230) from 60 renal transplant patients (19 female and 41 male) were evaluated using both immunoassays. Subsequently, we switched the assay for detection of everolimus blood concentrations from LTIA to ECLIA as a clinical application. Three quality control (QC) samples for LTIA were analysed using ECLIA, and 3 QC samples for ECLIA were analysed using LTIA. RESULTS: The Deming regression of ECLIA versus LTIA generated the following parameters: slope, 1.0067 and intercept, 1.7489 ng/mL, in the analysis of 230 samples. Bland-Altman analysis showed an average positive bias of 1.73 ng/mL between ECLIA and LTIA. When the clinical apparatus was switched from LTIA to ECLIA, the average everolimus blood concentration assayed by LTIA before switching was 3.57 ng/mL, whereas that by ECLIA after switching in the same patients taking the same daily dose (mean: 1.43 mg/day) was 5.85 ng/mL. The QCs assayed using LTIA were lower by an average of 67.3% (range: 55.8%-79.5%) for ECLIA, and in the same 230 samples from patients, the everolimus blood concentrations assayed by LTIA were lower by an average of 67.4% (range: 37.1%-114.5%) of ECLIA. WHAT IS NEW AND CONCLUSION: Analysis of everolimus concentrations by immunoassays with high precision and accuracy is required to ensure long-term survival of transplant recipients. Although the concentrations of QCs and calibrators of everolimus in LTIA were previously corrected to 70% concentration because of cross-reactivity with everolimus metabolites, these adjustments may need to be reviewed.


Asunto(s)
Aglutinación/efectos de los fármacos , Everolimus/sangre , Inmunoensayo/métodos , Inmunosupresores/sangre , Inmunoturbidimetría/métodos , Látex/inmunología , Pruebas Diagnósticas de Rutina/métodos , Monitoreo de Drogas/métodos , Femenino , Humanos , Trasplante de Riñón/métodos , Masculino , Persona de Mediana Edad
5.
Diabet Med ; 33(8): 1094-101, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26605507

RESUMEN

AIMS: To elucidate varicella zoster virus (VZV)-specific cell-mediated immunity and humoral immunogenicity against live attenuated Oka varicella zoster vaccine concurrently vaccinated with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in elderly people with diabetes mellitus. METHODS: This double-blind randomized controlled single-centre study of 60-70-year-old people with diabetes compared immunity and safety profiles 3 months after one dose of varicella zoster vaccine or placebo. PPSV23 was immunized simultaneously. Primary analysis evaluated cell-mediated immunity using the VZV skin test. Secondary analyses were a VZV interferon-γ enzyme-linked immunospot (ELISPOT) assay and immunoadherence haemagglutination test. Adverse experiences were recorded using diary questionnaires. RESULTS: By intent-to-treat analysis, 27 participants with diabetes who had been administered the vaccine were compared with 27 participants who were given a placebo. Changes in skin test scores were 0.41 ± 0.80 and 0.11 ± 0.93 (P = 0.2155), and geometric mean fold rises of the ELISPOT counts were 1.2 [95% confidence interval (CI) 0.2, 7.9] and 1.2 (95% CI 0.2, 7.3) (P = 0.989) in the vaccine and placebo groups, respectively. The geometric mean titre did not increase 3 months after vaccination in either group. No vaccination-related severe adverse experience was reported and no participant developed herpes zoster. DISCUSSION: Our previous results demonstrated that varicella zoster vaccine safely enhanced VZV-specific immunity in elderly people with or without diabetes. The results of this study showed that varicella zoster vaccine can be used safely, but it cannot boost virus-specific immunity in elderly people with diabetes when administered with concurrent PPSV23. Alternative strategies are needed to prevent VZV-associated diseases in this population.


Asunto(s)
Diabetes Mellitus/inmunología , Vacuna contra el Herpes Zóster/inmunología , Herpes Zóster/inmunología , Inmunidad Celular/inmunología , Inmunogenicidad Vacunal/inmunología , Anciano , Método Doble Ciego , Ensayo de Immunospot Ligado a Enzimas , Femenino , Herpes Zóster/prevención & control , Vacuna contra el Herpes Zóster/uso terapéutico , Herpesvirus Humano 3/inmunología , Humanos , Reacción en el Punto de Inyección/epidemiología , Reacción en el Punto de Inyección/etiología , Ensayos de Liberación de Interferón gamma , Masculino , Persona de Mediana Edad , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/uso terapéutico , Prurito/inducido químicamente , Prurito/epidemiología , Pruebas Cutáneas
6.
Int J Obes (Lond) ; 39(3): 488-94, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25109783

RESUMEN

BACKGROUND/OBJECTIVES: Higher volumes of ectopic cardiovascular fat (ECF) are associated with greater risk of coronary heart disease (CHD). Identifying factors that are associated with ECF volumes may lead to new preventive efforts to reduce risk of CHD. Significant racial/ethnic differences exist for overall and central adiposity measures, which are known to be associated with ECF volumes. Whether racial/ethnic differences also exist for ECF volumes and their associations with these adiposity measures remain unclear. SUBJECTS/METHODS: Body mass index (BMI), computerized tomography-measured ECF volumes (epicardial, pericardial and their summation) and visceral adipose tissue (VAT) were examined in a community-based sample of 1199 middle-aged men (24.2% Caucasians, 7.0% African-Americans, 23.6% Japanese-Americans, 22.0% Japanese, 23.2% Koreans). RESULTS: Significant racial/ethnic differences existed in ECF volumes and their relationships with BMI and VAT. ECF volumes were the highest among Japanese-Americans and the lowest among African-Americans. The associations of BMI and VAT with ECF differed by racial/ethnic groups. Compared with Caucasians, for each 1-unit increase in BMI, African-Americans had lower, whereas Koreans had higher increases in ECF volumes (P-values<0.05 for both). Meanwhile, compared with Caucasians, for each 1-unit increase in log-transformed VAT, African-Americans, Japanese-Americans and Japanese had similar increases, whereas Koreans had a lower increase in ECF volumes (P-value<0.05). CONCLUSIONS: Racial/ethnic groups differed in their propensity to accumulate ECF at increasing level of overall and central adiposity. Future studies should evaluate whether reducing central adiposity or overall weight will decrease ECF volumes more in certain racial/ethnic groups. Evaluating these questions might help in designing race-specific prevention strategy of CHD risk associated with higher ECF.


Asunto(s)
Adiponectina/sangre , Pueblo Asiatico/estadística & datos numéricos , Asiático/estadística & datos numéricos , Negro o Afroamericano/estadística & datos numéricos , Enfermedad Coronaria/etnología , Obesidad Abdominal/etnología , Población Blanca/estadística & datos numéricos , Índice de Masa Corporal , Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/prevención & control , Humanos , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Tomografía Computarizada Multidetector , Obesidad Abdominal/patología , Factores de Riesgo , Circunferencia de la Cintura
7.
Appl Opt ; 53(12): 2711-9, 2014 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-24787600

RESUMEN

We have developed unique solar concentrators for solar-pumped solid-state lasers to improve both efficiency and laser output power. Natural sunlight is collected by a primary concentrator which is a 2 m×2 m Fresnel lens, and confined by a cone-shaped hybrid concentrator. Such solar power is coupled to a laser rod by a cylinder with coolant surrounding it that is called a liquid light-guide lens (LLGL). Performance of the cylindrical LLGL has been characterized analytically and experimentally. Since a 14 mm diameter LLGL generates efficient and uniform pumping along a Nd:YAG rod that is 6 mm in diameter and 100 mm in length, 120 W cw laser output is achieved with beam quality factor M2 of 137 and overall slope efficiency of 4.3%. The collection efficiency is 30.0 W/m2, which is 1.5 times larger than the previous record. The overall conversion efficiency is more than 3.2%, which can be comparable to a commercial lamp-pumped solid-state laser. The concept of the light-guide lens can be applied for concentrator photovoltaics or other solar energy optics.

8.
Opt Lett ; 37(13): 2670-2, 2012 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-22743490

RESUMEN

We propose a simple and efficient pumping approach for a high-power solar-pumped laser by using a liquid light-guide lens (LLGL) and a hybrid pumping cavity. A 2×2 m Fresnel lens is used as a primary concentrator to collect natural sunlight; 120 W cw laser power and a 4.3% total slope efficiency are achieved with a 6-mm diameter Nd:YAG rod within a 14-mm diameter LLGL. The corresponded collection efficiency is 30.0 W/m(2), which is 1.5 times larger than the previous record. This result is unexpectedly better than that of Cr:Nd:YAG ceramics. It is because the scattering coefficient of Cr:Nd:YAG ceramics is 0.004cm(1), which is 2 times larger than that of the Nd:YAG crystal, although both have similar saturation gains.

9.
Nat Commun ; 13(1): 1817, 2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35361763

RESUMEN

Magnetic refrigeration (MR) is a key technique for hydrogen liquefaction. Although the MR has ideally higher performance than the conventional gas compression technique around the hydrogen liquefaction temperature, the lack of MR materials with high magnetic entropy change in a wide temperature range required for the hydrogen liquefaction is a bottle-neck for practical applications of MR cooling systems. Here, we show a series of materials with a giant magnetocaloric effect (MCE) in magnetic entropy change (-∆Sm > 0.2 J cm-3K-1) in the Er(Ho)Co2-based compounds, suitable for operation in the full temperature range required for hydrogen liquefaction (20-77 K). We also demonstrate that the giant MCE becomes reversible, enabling sustainable use of the MR materials, by eliminating the magneto-structural phase transition that leads to deterioration of the MCE. This discovery can lead to the application of Er(Ho)Co2-based alloys for the hydrogen liquefaction using MR cooling technology for the future green fuel society.

10.
J Clin Pharm Ther ; 36(6): 711-5, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21058968

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: St John's wort (SJW, Hypericum perforatum) is one of the most commonly used herbal antidepressants for treatment of mild to moderate depression. SJW enhances CYP3A4 activity and alters the pharmacokinetics of CYP3A4 substrates. This study investigated the effect of SJW on the pharmacokinetics of zolpidem in healthy subjects. METHODS: A controlled, open-label, non-randomized, fixed-dose schedule design was used. Fourteen healthy male subjects received a single 10 mg oral dose of zolpidem followed by SJW administration (300 mg orally, three times a day) for 14 days; the last dose of SJW was coadministered with a single dose of zolpidem. Blood samples were obtained over a 24-h period after zolpidem administration. Pharmacokinetic data for zolpidem alone and in combination with SJW were analysed by high-performance liquid chromatography. RESULTS: After repeated administration of SJW, the mean values of AUC and C(max) for zolpidem significantly decreased (380.3 ± 181.4 vs. 265.4 ± 134.2 ng h/mL, P = 0.001; 83.1 ± 30.1 vs. 55.1 ± 24.8 ng/mL, P = 0.000 respectively) and the mean value of CL/F for zolpidem significantly increased (38.4 ± 31.5 vs. 56.9 ± 57.2 mL/min, P = 0.040). However, in three subjects, the AUC showed a small increase after SJW treatment. WHAT IS NEW AND CONCLUSION: The effect of SJW on the pharmacokinetics of zolpidem has not previously been reported. Repeated administration of SJW decreases the plasma concentration of zolpidem, probably by enhancing CYP3A4 activity. Given the wide inter-subject variability observed, for personalized medicine, advice on the use of the combination should be individualized, based on the circumstances of the patient.


Asunto(s)
Hypericum/química , Hipnóticos y Sedantes/farmacocinética , Extractos Vegetales/farmacología , Piridinas/farmacocinética , Administración Oral , Área Bajo la Curva , Cromatografía Líquida de Alta Presión , Citocromo P-450 CYP3A/efectos de los fármacos , Citocromo P-450 CYP3A/metabolismo , Interacciones Farmacológicas , Humanos , Masculino , Adulto Joven , Zolpidem
11.
Int J Immunopathol Pharmacol ; 23(1): 1-11, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20377990

RESUMEN

To prevent and control disease caused by exposure to various agents, it is necessary to determine the harmful level of intervention and to establish a method for measuring that level. In-air microparticle-induced X-ray emission (in-air micro-PIXE) analysis is based on irradiation of specimens with a proton ion microbeam, and has been modified for biological application. Two-dimensional analysis and quantitative analysis using the system confirmed that asbestos induced apoptosis by upregulating Fas expression and also revealed the accumulation of CD163-expressing macrophages in the lungs of patients with asbestosis. By quantitative comparison of the area of Fas or CD163 expression and the Fas- or CD163-negative area in asbestos lung tissue, the harmful levels which caused the expression of Fas or CD163 could be estimated on Silica, Ferrous iron, and Magnesium (the components of asbestos) deposition. These results indicate that the system could be useful for investigating the pathogenesis of inhaled particle-induced immune reactions and for determining harmful levels of exogenous agents.


Asunto(s)
Antígenos CD/análisis , Antígenos de Diferenciación Mielomonocítica/análisis , Amianto/análisis , Asbestosis/inmunología , Pulmón/química , Receptores de Superficie Celular/análisis , Espectrometría por Rayos X/métodos , Receptor fas/análisis , Anciano , Asbestosis/metabolismo , Asbestosis/patología , Humanos , Inmunohistoquímica , Masculino
12.
J Musculoskelet Neuronal Interact ; 10(4): 281-5, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21116065

RESUMEN

OBJECTIVES: Various forms of adrenocortical insufficiency can cause musculoskeletal symptoms such as muscle pain, tautness of the limbs, arthralgia, and flexion contractures. However, the findings of neurological investigations are inconclusive and have not been well summarized. METHODS: We report the case of a 61-year-old man with isolated adrenocorticotropic hormone deficiency who presented with musculoskeletal symptoms, including flexion contractures. We performed three neurological investigations: nerve conduction studies, electromyography, and muscle biopsy analysis. Further, we reviewed reports of 16 patients with various forms of adrenocortical insufficiency and musculoskeletal symptoms by considering the findings of these three investigations. RESULTS: From the literature review, we found that (a) analysis of muscle biopsy is the most sensitive technique, followed by electromyography and then nerve conduction studies; and (b) the longer the duration of the musculoskeletal symptoms, the greater the incidence of abnormal findings with all three techniques. CONCLUSIONS: Physicians may prioritize neurological investigations, depending on these findings.


Asunto(s)
Enfermedad de Addison/complicaciones , Enfermedades Musculoesqueléticas/diagnóstico , Enfermedades Musculoesqueléticas/etiología , Enfermedad de Addison/diagnóstico , Enfermedad de Addison/fisiopatología , Adulto , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Enfermedades Musculoesqueléticas/fisiopatología
13.
Rev Sci Instrum ; 91(4): 043304, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32357747

RESUMEN

The energy spreads of ion beams generated from a penning ionization gauge-type ion source with electromagnets were measured using a parallel electrostatic analyzer. The ion source was developed to be installed in a mega-electron volt (MeV) compact ion microbeam system. A gaseous ion beam of expectedly high brightness and narrow energy spread was generated from the ion source to form a microbeam. To produce such an ion beam, a high-density plasma with a small volume was generated using a strong magnetic field in the ion source. The beam energy spread width was of particular importance because it forms an ion microbeam by reducing the chromatic aberration at a focusing lens. In this report, the energy spread was investigated by changing the parameters of the ion source, e.g., extraction voltage, excitation current of electromagnets, vacuum, and anode voltage. The investigation showed that spread widths are influenced by the extraction voltage, vacuum, and anode voltage. The minimum width of ∼5.0 ± 0.1 eV was obtained at a beam energy of 200 eV. This value is acceptable for the MeV compact ion microbeam system.

14.
Sci Rep ; 10(1): 19191, 2020 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-33154530

RESUMEN

Orexins are originally characterized as orexigenic hypothalamic neuropeptides in mammals. Subsequent studies found orexin to be expressed and perform pleiotropic functions in multiple tissues in mammals. In avian (non-mammalian) species, however, orexin seemed to not affect feeding behavior and its physiological roles are poorly understood. Here, we provide evidence that orexin and its related receptors are expressed in chicken hepatocytes. Double immunofluorescence staining showed that orexin is localized in the ER, Golgi, and in the lysosomes in LMH cells. Brefeldin A treatment reduced orexin levels in the culture media, but increased it in the cell lysates. Administration of recombinant orexins upregulated the expression of orexin system in the liver of 9-day old chicks, but did not affect feed intake. Recombinant orexins increased fatty acid synthase (FASN) protein levels in chicken liver, activated acetyl-CoA carboxylase (ACCα), and increased FASN, ATP citrate lyase(ACLY), and malic enzyme (ME) protein expression in LMH cells. Blockade ERK1/2 activation by PD98059 attenuated these stimulating effects of orexin on lipogenic factors. Overexpression of ERK1/2 increased the expression of lipogenic genes, and orexin treatment induced the phosphorylated levels of ERK1/2Thr202/Tyr204, but not that of p38 Thr180/Tyr182 or JNK1/2 Thr183/Tyr185 in chicken liver and LMH cells. Taken together, this is the first report evidencing that orexin is expressed and secreted from chicken hepatocytes, and that orexin induced hepatic lipogenesis via activation of ERK1/2 signaling pathway.


Asunto(s)
Lipogénesis/fisiología , Hígado/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Orexinas/metabolismo , Acetil-CoA Carboxilasa/metabolismo , Animales , Brefeldino A/farmacología , Pollos , Ingestión de Alimentos/fisiología , Ácido Graso Sintasas/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Lipogénesis/efectos de los fármacos , Hígado/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Malato Deshidrogenasa/metabolismo , Orexinas/genética , Fosforilación/efectos de los fármacos , Inhibidores de la Síntesis de la Proteína/farmacología , Regulación hacia Arriba/efectos de los fármacos
15.
Ultramicroscopy ; 109(5): 644-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19162400

RESUMEN

The distribution of Mn in a Ga(0.963)Mn(0.037)As ferromagnetic semiconductor film has been characterized by the three-dimensional atom probe (3DAP) technique. Atom probe specimens were directly prepared from the (Ga,Mn)As film grown epitaxially on a p-type GaAs substrate by the lift-out technique using a scanning electron microscope/focused ion beam system. The atom probe elemental map revealed that the Mn atoms in the Ga(0.963)Mn(0.037)As are uniformly dissolved without forming any nanometer-sized clusters.

16.
Ultramicroscopy ; 109(5): 467-71, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19232830

RESUMEN

Influence of femtosecond laser pulse condition on the performance of an energy-compensated optical tomographic atom probe has been investigated. The unstable oscillator makes the mass peaks significantly broadened. Double 80fs pulse train with 10ns interval makes the mass peaks slightly shifted to the higher mass side. The mass peak shift corresponds to the fight time of ions triggered by laser pulsing. Chirping ratio for the laser pulses ranging from 80fs to 10ps is controlled by the pulse compressor for the fragile specimens such as oxide dispersion strengthen steel or insulator materials. A first-principle calculation for optical dielectric breakdown in diamond has been successfully demonstrated. It is shown that effective conductive increase has appeared at the laser intensity around 10(13)W/cm(2).

17.
J Clin Pharm Ther ; 34(6): 683-92, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20175802

RESUMEN

OBJECTIVE: The aim of this study was to elucidate the effect of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activating angiotensin receptor blocker (ARB) telmisartan and the non-PPAR-gamma activating ARB valsartan and candesartan on mycophenolic acid (MPA) pharmacokinetics in renal transplant recipients. METHODS: Recipients (n = 10 each group) were randomly given either 40 mg of telmisartan, 80 mg of valsartan or 8 mg of candesartan cilexetil for at least 6 months, and no ARB. Blood was sampled a year after transplantation. RESULTS: Dose-adjusted maximum and trough plasma concentration of MPA co-administered with telmisartan were the lowest in all groups. The mean dose-adjusted area under the concentration curve from 0 to 12 h (AUC(0-12)) and AUC(0-6) of MPA co-administered with telmisartan were significantly lower than that without ARB (98 vs. 138 ng x h/mL/mg, P = 0.0353 and 63 vs. 96 ng x h/mL/mg, P = 0.0305). Coadministration of valsartan and candesartan did not alter MPA pharmacokinetics. The AUC ratio of MPA glucuronide (MPAG)/MPA co-administered with telmisartan was higher than that without ARBs, but not significantly (14.2 vs. 9.1). The mean maximum and minimum plasma concentrations of telmisartan (40 mg) after oral administration were 84 and 15 ng/mL, respectively, and that of valsartan (80 mg) 2220 and 441 ng/mL, respectively. Plasma concentrations of candesartan in most transplant patients were not observed 19 h after oral administration of candesartan cilexeil (8 mg). CONCLUSIONS: The degree of drug interaction between MPA and telmisartan was significantly greater than that between MPA and valsartan or candesartan. Uridine diphosphate-glucuronosyltransferase (UGT) 1A9 has been identified as a PPAR-gamma target gene. UGT induction by telmisartan might stimulate MPA glucuronidation. A combination of telmisartan and mycophenolate mofetil might require periodic monitoring of MPA.


Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Bencimidazoles/farmacología , Benzoatos/farmacología , Inmunosupresores/farmacocinética , Trasplante de Riñón , Ácido Micofenólico/análogos & derivados , Tetrazoles/farmacología , Valina/análogos & derivados , Adulto , Área Bajo la Curva , Bencimidazoles/farmacocinética , Benzoatos/farmacocinética , Compuestos de Bifenilo , Interacciones Farmacológicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ácido Micofenólico/farmacocinética , Telmisartán , Tetrazoles/farmacocinética , Valina/farmacocinética , Valina/farmacología , Valsartán
18.
Kyobu Geka ; 62(13): 1132-5, 2009 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-19999089

RESUMEN

A severely calcified, so-called, "porcelain" aorta may complicate aortic valve replacement (AVR). We report a case of successful AVR with an extensively calcified aortic root, involving the right coronary ostium. A 73-year-old female presented with a stenotic aortic valve with the pressure gradient of 60 mmHg. Computed tomography demonstrated extensive calcification of the ascending aortic root. Coronary angiogram showed 90% right coronary artery ostial stenosis. We endarterectomized the ascending aorta, the Valsalva sinus and the right coronary ostium, which enabled AVR with a 19 mm CarboMedics valve. These procedures might be a favorable option for the treatment of porcelain aorta and calcified aortic valve.


Asunto(s)
Enfermedades de la Aorta/cirugía , Válvula Aórtica/cirugía , Calcinosis/cirugía , Endarterectomía , Prótesis Valvulares Cardíacas , Anciano , Estenosis de la Válvula Aórtica/etiología , Estenosis de la Válvula Aórtica/cirugía , Femenino , Humanos
19.
J Hum Hypertens ; 22(3): 197-204, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18172452

RESUMEN

The usefulness of self-measurements of blood pressure (BP) at home (home BP measurements) in hypertensive patients has been reported by many studies. Several national guidelines recommend the use of home BP measurements to achieve better hypertension control. The objective of this study was to clarify the association between home BP measurements and hypertension treatment among 2363 essential hypertensive patients taking antihypertensive drugs. Compared to the 543 (23.0%) patients who had not taken home BP measurements, the 1820 (77.0%) patients who had taken home BP measurements were significantly older, included a higher proportion of males, included a higher proportion with a family history of hypertension, took a greater number of antihypertensive drugs and alpha blockers and took antihypertensive drugs more often in the evening. Home BP measurements were associated with significantly better control of home and office BP levels. Compared to patients who had not taken home BP measurements, the adjusted odds ratios for good control of morning home BPs, evening home BPs and office BPs in patients who had taken home BP measurements were 1.46 (95% confidential interval (CI) 1.33-1.57), 1.35 (95% CI 1.21-1.47) and 1.23 (95% CI 1.06-1.37), respectively. Home BP measurements were associated with good hypertensive management. Our findings suggest that it is important that physicians recommend home BP measurements to their patients.


Asunto(s)
Monitoreo Ambulatorio de la Presión Arterial/métodos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Anciano , Antihipertensivos/uso terapéutico , Distribución de Chi-Cuadrado , Estudios Transversales , Femenino , Humanos , Japón , Modelos Logísticos , Masculino , Persona de Mediana Edad , Factores de Riesgo
20.
Int J Immunopathol Pharmacol ; 21(3): 567-76, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18831923

RESUMEN

Inhalation of asbestos increases the risk of lung cancer and pulmonary fibrosis. It is difficult to directly assess the distribution and content of inhaled particles in lung tissue sections. The purpose of this study is to employ an in-air micro particle induced X-ray emission (in-air micro-PIXE) system for assessment of the spatial distribution and content of asbestos and other metals in lung tissue. A proton ion-microbeam from this system was applied to irradiate lung tissue of patients with or without asbestosis, tumor tissue from both groups, and asbestos fibers (in vitro). The content of each element composing asbestos and those of other metals were calculated and their distribution was assessed from the characteristic X-ray pattern for each element obtained after irradiation. This in-air micro-PIXE system could identify the location of asbestos bodies composed of Si, Mg, and Fe in lung tissue sections. Macrophage and lymphocytes accumulated in that area. This new system also revealed deposits of titanium, nickel, and cobalt in the lung tissues, in addition to asbestos bodies. The Si and Fe content were higher in lungs with asbestosis than in lungs without asbestosis or in tumor tissue. Analysis of asbestos fibers composed of chrysotile, crocidolite, and amosite showed that the ratios of Si, Fe, and Mg corresponded with those for the chemical structures. In-air micro-PIXE analysis is useful for assessing the distribution and quantities of asbestos bodies and also other metals in lung tissue comparing to immune-related cell localizations, and is also useful for analysis of standard asbestos fibers.


Asunto(s)
Amianto/análisis , Pulmón/química , Metales/análisis , Espectrometría por Rayos X/métodos , Anciano , Humanos , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA