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1.
ESC Heart Fail ; 8(4): 3002-3013, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33934538

RESUMO

AIMS: It has been reported that congestive heart failure (CHF) readmission has not decreased in the last decade. It is also reported that CHF readmission is likely to occur shortly after discharge. We investigated whether an early follow-up at outpatient care within 2 weeks after discharge affects the long-term readmission rate and prognosis. METHODS AND RESULTS: We reviewed consecutive 1002 patients admitted to our hospital due to CHF. Two-hundred and fifty-nine patients who died in-hospital or were transferred to another hospital or readmitted within 2 weeks were excluded and 743 of discharged patients were analysed. We extracted contributing variables associated with heart failure (HF) readmission and the composite adverse outcome (all cause death or HF readmissions) by univariate and multivariate analysis. Multivariate analysis showed that the early follow-up was independently associated with freedom from HF readmission and the composite outcome. We divided these patients into two groups, with/without early follow-up and performed a propensity score-matching analysis (n = 259 each). HF readmission during 2 year follow-up was significantly less in the early follow-up group [P = 0.02, hazard ratio (HR) = 0.647, 95% confidence interval (CI) = 0.447-0.935] as well as the composite outcome was less in the early follow-up group (P = 0.01, HR = 0.643, 95% CI = 0.456-0.908). Medication adjustments were done in only 33.2% of the patients. Rates of HF readmissions were comparable regardless of whether or not medication adjustment was done at the early follow-up (P = 0.505, HR = 1.208, 95% CI = 0.692-2.106). CONCLUSIONS: The present study demonstrates that an early follow-up approach after discharge in CHF patients may improve the long-term prognosis. These results may not depend on medication adjustment but rather on modifying patient factors early after discharge.


Assuntos
Insuficiência Cardíaca , Alta do Paciente , Assistência Ambulatorial , Seguimentos , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Humanos , Readmissão do Paciente , Prognóstico
2.
Sci Rep ; 11(1): 5636, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33707638

RESUMO

The recent realisations of hydrogen doped LnFeAsO (Ln = Nd and Sm) superconducting epitaxial thin films call for further investigation of their structural and electrical transport properties. Here, we report on the microstructure of a NdFeAs(O,H) epitaxial thin film and its temperature, field, and orientation dependencies of the resistivity and the critical current density Jc. The superconducting transition temperature Tc is comparable to NdFeAs(O,F). Transmission electron microscopy investigation supported that hydrogen is homogenously substituted for oxygen. A high self-field Jc of over 10 MA/cm2 was recorded at 5 K, which is likely to be caused by a short London penetration depth. The anisotropic Ginzburg-Landau scaling for the angle dependence of Jc yielded temperature-dependent scaling parameters γJ that decreased from 1.6 at 30 K to 1.3 at 5 K. This is opposite to the behaviour of NdFeAs(O,F). Additionally, γJ of NdFeAs(O,H) is smaller than that of NdFeAs(O,F). Our results indicate that heavily electron doping by means of hydrogen substitution for oxygen in LnFeAsO is highly beneficial for achieving high Jc with low anisotropy without compromising Tc, which is favourable for high-field magnet applications.

3.
ACS Appl Mater Interfaces ; 11(34): 31169-31175, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31381292

RESUMO

In this study, the effect of the grain boundary density on the transport properties of the Re-substituted higher manganese silicide Mn30.4Re6Si63.6 has been investigated. The efficiency of electrical energy conversion from waste heat, mainly in thermoelectric generators, depends on how the thermal conduction is reduced, while the charge-carrier electrons/holes contribute to possess a large magnitude of both the electrical conductivity σ and Seebeck coefficient S. In this work, we tried to obtain such a condition with a novel approach of merging the energy-filtering effect at the grain boundaries to improve the power factor (PF) = S2σ. The nanostructuring and heavy-element substitution were also employed to greatly scatter the phonon conduction. As a result, enhancement of the PF was observed in the diffused nanostructure of annealed ribbon samples, and the enhancement was correlated with the formation of Schottky barriers at the grain boundary interface. Together with a reduction of the thermal conductivity to very low magnitude 1.27 W m-1 K-1, we obtained a maximum ZT = 1.15 at 873 K for the annealed ribbon samples.

4.
Nanoscale Adv ; 1(8): 3036-3048, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-36133600

RESUMO

Fe-based superconductors present a large variety of compounds whose physical properties strongly depend on the crystal structure and chemical composition. Among them, the so-called 1111 compounds show the highest critical temperature T c in the bulk form. Here we demonstrate the realization of excellent superconducting properties in NdFeAs(O1-x F x ). We systematically investigated the correlation between the microstructure at the nanoscale and superconductivity in an epitaxial 22 nm NdFeAs(O1-x F x ) thin film on a MgO single crystalline substrate (T c = 44.7 K). Atomic resolution analysis of the microstructure by transmission electron microscopy and atom probe tomography identified several defects and other inhomogeneities at the nanoscale that can act as extrinsic pinning centers. X-Ray diffraction and transmission electron microscopy displayed a broad variation of the a-axis lattice parameter either due to a partially strained layer at the interface to the substrate, high local strain at dislocation arrays, mosaicity, or due to composition variation within the film. The electrical transport properties are substantially affected by intrinsic pinning and a matching field corresponding to the film thickness and associated with the Bean-Livingston surface barrier of the surfaces. The thin film showed a self-field critical current density J c(4.2 K) of ∼7.6 MA cm-2 and a record pinning force density of F p ≈ 1 TN m-3 near 35 T for H‖ab at 4.2 K. These investigations highlight the role of the microstructure in fine-tuning and possibly functionalizing the superconductivity of Fe-based superconductors.

5.
Nano Lett ; 13(5): 1915-9, 2013 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-23614400

RESUMO

We investigate the topological surface state properties at various surface cleaves in the topological insulator Bi2Se3, via first principles calculations and scanning tunneling microscopy/spectroscopy (STM/STS). While the typical surface termination occurs between two quintuple layers, we report the existence of a surface termination within a single quintuple layer where dangling bonds form with giant spin splitting owing to strong spin-orbit coupling. Unlike Rashba split states in a 2D electron gas, these states are constrained by the band topology of the host insulator with topological properties similar to the typical topological surface state, and thereby offer an alternative candidate for spintronics usage. We name these new states "topological dangling-bond states". The degree of the spin polarization of these states is greatly enhanced. Since dangling bonds are more chemically reactive, the observed topological dangling-bond states provide a new avenue for manipulating band dispersions and spin-textures by adsorbed atoms or molecules.

6.
Nat Mater ; 11(7): 585-9, 2012 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-22561901

RESUMO

A complicating factor in unravelling the theory of high-temperature (high-T(c)) superconductivity is the presence of a 'pseudogap' in the density of states, the origin of which has been debated since its discovery. Some believe the pseudogap is a broken symmetry state distinct from superconductivity, whereas others believe it arises from short-range correlations without symmetry breaking. A number of broken symmetries have been imaged and identified with the pseudogap state, but it remains crucial to disentangle any electronic symmetry breaking from the pre-existing structural symmetry of the crystal. We use scanning tunnelling microscopy to observe an orthorhombic structural distortion across the cuprate superconducting Bi(2)Sr(2)Ca(n-1)Cu(n)O(2n+4+x) (BSCCO) family tree, which breaks two-dimensional inversion symmetry in the surface BiO layer. Although this inversion-symmetry-breaking structure can impact electronic measurements, we show from its insensitivity to temperature, magnetic field and doping, that it cannot be the long-sought pseudogap state. To detect this picometre-scale variation in lattice structure, we have implemented a new algorithm that will serve as a powerful tool in the search for broken symmetry electronic states in cuprates, as well as in other materials.

7.
Int J Pharm ; 352(1-2): 202-8, 2008 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-18160237

RESUMO

This study describes application of a newly developed method to the fluidized bed granulation. The method is based on predicting suitable amounts of water to be added to multi-component formulations using the corresponding values of components prior to granulation trials. The range of appropriate amount of water for each component in a model formulation was estimated in our previous studies with a refractive near-infrared (NIR) moisture sensor. Using those values, we calculated the range of suitable amount of water to add for the model pharmaceutical formulation. In this study, we examined the relationship between the amount of water added to the model formulation and the NIR sensor output value. Then, we performed fluidized bed granulation of the model formulation at steady-state moisture content levels under monitoring with NIR sensor, within and beyond the suitable range of added water that was calculated from the corresponding range of each component. For the model formulation, we found that the predicted values for suitable amounts of added water well corresponded to those in the granulation trials, suggesting that this predictive method may be useful in estimating suitable amounts of water to be added to formulations before fluidized bed granulation trials.


Assuntos
Excipientes/química , Espectroscopia de Luz Próxima ao Infravermelho , Tecnologia Farmacêutica/métodos , Água/química , Química Farmacêutica , Desenho de Equipamento , Modelos Químicos , Pós , Reprodutibilidade dos Testes , Comprimidos , Tecnologia Farmacêutica/instrumentação
8.
J Phys Chem B ; 110(31): 15234-43, 2006 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-16884240

RESUMO

A new ultrasound assisted emulsion (consisting of rapeseed oil and aqueous solution of Zn(2+) and Fe(2+) acetates) and evaporation protocol has been developed for the synthesis of zinc ferrite (ZnFe(2)O(4)) nanoparticles with narrow size distribution. The as-synthesized sample consisted of crystalline zinc ferrite particles with an average diameter of approximately 4 nm, whereas the average size of the heat-treated ferrite particles increases to approximately 12 nm. To remove the small amount of oil present on the surface of the as-synthesized ferrite sample, heat treatment was carried out at 350 degrees C for 3 h. The as-synthesized and heat-treated ferrites were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), TGA/DTA, transmission electron microscopy (TEM), and energy dispersion X-ray spectroscopy (EDS) techniques. Magnetic measurements show that the nanocrystalline ZnFe(2)O(4), prepared through this technique, is either at par with those obtained in other cases or even more improved. Both the as-synthesized and heat-treated samples reveal relaxation of magnetization. Our study also shows that one can tailor the magnetization and relaxation pattern by suitably controlling the particle size of the nanocrystalline ZnFe(2)O(4). The key features of this method are avoiding (a) the cumbersome conditions that exist in the conventional methods, (b) the usage of necessary additive components (stabilizers or surfactants, precipitants), and (c) calcination requirements. In addition, rapeseed oil has replaced organic nonpolar solvents used in earlier studies. As a whole, this simple straightforward sonochemical approach results in a better pure phase system of nanoferrite with improved magnetic properties.


Assuntos
Emulsões/química , Compostos Férricos/química , Magnetismo , Nanopartículas/química , Temperatura , Compostos de Zinco/química , Microscopia Eletrônica de Transmissão/métodos , Tamanho da Partícula , Sensibilidade e Especificidade , Espectrometria por Raios X/métodos , Espectroscopia de Perda de Energia de Elétrons/métodos , Volatilização , Difração de Raios X
9.
J Antibiot (Tokyo) ; 57(8): 518-27, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15515889

RESUMO

The in vitro and in vivo antibacterial activities of tricyclic ketolides (TKs: TE-802, TE-806, TE-935, TE-943) have been compared with those of clarithromycin (CAM), azithromycin (AZM) and rokitamycin (RKM). TKs were active against not only erythromycin (EM)-susceptible organisms; aerobic gram-positive bacteria, some gram-negative bacteria, anaerobic bacteria and Mycoplasma pneumoniae, but also EM-resistant Staphylococcus aureus (inducible macrolide-resistant strains) as well as EM-resistant Streptococcus pneumoniae (efflux-resistant strains). The therapeutic efficacies of TKs against systemic infections and respiratory tract infection (RTI) caused by gram-positive bacteria in mice are superior to those of CAM and AZM. The peak plasma levels (Cmax, p.o.) of TE-802 in mice were equal to that of CAM, but the plasma area under the concentration-time curve (AUC(24 hours)) was 4.7 times that for CAM. The plasma Cmax (p.o.) value for TE-802 in monkey was equal to that of CAM, whereas the AUC(8 hours) value was three-fourths that of CAM. The pharmacokinetics of TE-802 are similar to those of AZM in mice and monkeys, suggesting the potential for once-daily administration in humans.


Assuntos
Antibacterianos/farmacologia , Cetolídeos/farmacologia , Animais , Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Humanos , Concentração de Íons de Hidrogênio , Cetolídeos/farmacocinética , Cetolídeos/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Infecções Respiratórias/tratamento farmacológico
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