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1.
Anal Sci ; 40(7): 1365-1371, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38573452

RESUMO

Suppressed ion chromatography with perchloric acid deproteinization was developed for the determination of phosphorus in commercially available milk. Although the perchloric acid deproteinization method is widely used in the medical field, it sees limited application in the food industry. Herein, the concentration of perchloric acid and hydrolysis conditions were examined, specifically regarding perchloric acid deproteinization, which was used as a deproteinization method in this study. The calibration curve constructed from the peak area of orthophosphoric acid (monohydrogen phosphate ion: HPO42-) was linear, with a correlation coefficient of 0.999. The relative standard deviation of the peak area of 50 mg/L of HPO42- from six replicates was 0.35%. The detection and quantitative limits of HPO42-, calculated from its signal-to-noise ratio were 0.033 mg/L and 0.100 mg/L, respectively. The proposed method was applied to the analysis of phosphorus in commercially available milk. Perchloric acid deproteinization has proved to be useful in the food industry.


Assuntos
Leite , Percloratos , Fósforo , Leite/química , Fósforo/análise , Fósforo/química , Animais , Percloratos/análise , Percloratos/química , Cromatografia por Troca Iônica/métodos , Limite de Detecção , Hidrólise , Calibragem
2.
Physiol Rep ; 10(5): e15210, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35246949

RESUMO

This study aimed to investigate whether anticipatory cardiorespiratory responses vary depending on the intensity of the subsequent exercise bout, and whether anticipatory cardiorespiratory adjustments contribute importantly to enhancing exercise performance during high-intensity exercise. Eleven healthy men were provided advance notice of the exercise intensity and a countdown to generate anticipation during 10 min prior to exercise at 0, 50, 80 or 95% maximal work-rate (Experiment 1). A different group of subjects (n = 15) performed a time to exhaustion trial with or without anticipatory countdown (Experiment 2). In Experiment 1, heart rate (HR), oxygen uptake (VO2 ) and minute ventilation (VE ) during pre-exercise resting period increased over time and depended on the subsequent exercise intensity. Specifically, there was already a 7.4% increase in HR from more than 5 min prior to the start of exercise at 95% maximal work-rate, followed by progressively augmented increases of 12.5% between 2 and 3 min before exercise, 24.4% between 0 and 1 min before exercise. In Experiment 2, the initial HR for the first 10 s of exercise in the task with anticipation was 11.4% larger compared to without anticipation (p < 0.01), and the difference in HR between the two conditions decreased in a time-dependent manner. In contrast, the initial increases in VO2 and VE were significantly lower in the task with anticipation than that without anticipation. The time to exhaustion during high-intensity exercise was 14.6% longer under anticipation condition compared to no anticipation (135 ± 26 s vs. 119 ± 26 s, p = 0.003). In addition, the enhanced exercise performance correlated positively with increased HR response just before and immediately after exercise onset (p < 0.01). These results showed that anticipatory cardiorespiratory adjustments (feedforward control) via the higher brain that operate before starting exercise may play an important role in minimizing the time delay of circulatory response and enhancing performance after onset of high-intensity exercise in man.


Assuntos
Exercício Físico , Consumo de Oxigênio , Exercício Físico/fisiologia , Teste de Esforço , Frequência Cardíaca/fisiologia , Humanos , Masculino
3.
Nanomaterials (Basel) ; 11(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33375188

RESUMO

Materials that exhibit the photo-induced magnetic-phase transition of titania are receiving significant attention because they can be easily switched between diamagnetism and paramagnetism by UV irradiation. However, it is difficult to store photo-induced titanium (Ti3+) in air because of its easy oxidation upon oxygen exposure. In this study, titania/polycarbonate hybrid films were prepared using linear 1,6-hexanediol (PHMCD), cyclic 1,4-cyclohexanedimethanol (PCHCD), or their copolymerized carbonate oligomers using the sol-gel method. The oxygen permeability of the hybrid film decreased as the ratio of the ring structure increased by a factor of approximately 32 from PHMCD with only the chain structure to PCHCD with only the ring structure. These hybrid films can generate Ti3+ under a UV irradiation of 250 W for 2 h, and the difference in oxygen permeability significantly affected the lifetime of the Ti3+ by a factor of up to 120. In addition, the tensile tests and IR measurements demonstrated that UV irradiation had little effect on the mechanical intensity and matrix chemical structure. Moreover, the magnetic susceptibility of Ti3+ present in PCHCD was confirmed to be 6.2 (10-3 emu/g(titania)) under an external magnetic field of 5 T induced using a superconducting quantum interference device.

4.
Phys Rev Lett ; 123(11): 113603, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31573242

RESUMO

We experimentally demonstrate storage and on-demand release of phase-sensitive, photon-number superposition states of the form α|0⟩+ße^{iθ}|1⟩ for an optical quantized oscillator mode. For this purpose, we newly developed a phase-probing mechanism compatible with a storage system composed of two concatenated optical cavities, which was previously employed for storage of phase-insensitive single-photon states [Phys. Rev. X 3, 041028 (2013)PRXHAE2160-330810.1103/PhysRevX.3.041028]. This is the first demonstration of all-optically storing highly nonclassical and phase-sensitive quantum states of light. The strong nonclassicality of the states after storage becomes manifest as a negative region in the corresponding Wigner function shifted away from the origin in phase space. This negativity is otherwise, without the phase information of the memory system, unobtainable. While our scheme includes the possibility of optical storage, on-demand release and synchronization of arbitrary single-rail qubit states, it is not limited to such states. In fact, our technique is extendible to more general phase-sensitive states such as multiphoton superposition or entangled states, and thus it represents a significant step toward advanced optical quantum information processing, where highly nonclassical states are utilized as resources.

5.
Microsc Microanal ; 25(2): 356-366, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30712527

RESUMO

We summarize the findings from an interlaboratory study conducted between ten international research groups and investigate the use of the commonly used maximum separation distance and local concentration thresholding methods for solute clustering quantification. The study objectives are: to bring clarity to the range of applicability of the methods; identify existing and/or needed modifications; and interpretation of past published data. Participants collected experimental data from a proton-irradiated 304 stainless steel and analyzed Cu-rich and Ni-Si rich clusters. The datasets were also analyzed by one researcher to clarify variability originating from different operators. The Cu distribution fulfills the ideal requirements of the maximum separation method (MSM), namely a dilute matrix Cu concentration and concentrated Cu clusters. This enabled a relatively tight distribution of the cluster number density among the participants. By contrast, the group analysis of the Ni-Si rich clusters by the MSM was complicated by a high Ni matrix concentration and by the presence of Si-decorated dislocations, leading to larger variability among researchers. While local concentration filtering could, in principle, tighten the results, the cluster identification step inevitably maintained a high scatter. Recommendations regarding reporting, selection of analysis method, and expected variability when interpreting published data are discussed.

6.
Materials (Basel) ; 10(12)2017 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-29232914

RESUMO

We performed thin carbonate-containing apatite (CA) coating on titanium (Ti) by an aqueous spray coating (ASC) method that consisted of a Ca-CO3-PO4 complex. Two different CA coatings were produced by two different spray amounts and were heat-treated after spraying. We evaluated three-dimensional structures, adhesiveness to Ti, and durability of the CA film. In addition, we performed immersion experiments in simulated body fluid (SBF), and bone responses were evaluated after implantation into a femoral bone defect in rats. The bonding ability of ASC-coated implant into the bone was examined by push-in tests. Unique network structures with small particles were identified on CA coatings. Although heat treatment produced no significant difference in surface morphology, scratch tests revealed that heat treatment improved the adhesion of CA coatings to Ti. Crystal formation progressed on CA-coated specimens, and the sample placement direction influenced crystal formation and growth in SBF immersion. Animal implantation experiments revealed significantly greater bone-to-implant contact ratio and bone mass in both cortical and bone marrow, respectively, four weeks after implantation. Push-in tests suggested that the bonding of the CA coating to Ti is clinically acceptable. Therefore, we conclude that CA coating to Ti by the ASC method would be possible for clinical applications, including dentistry.

7.
Microscopy (Oxf) ; 66(2): 120-130, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28100661

RESUMO

To evaluate dislocations induced by neutron irradiation, we developed a weak-beam scanning transmission electron microscopy (WB-STEM) system by installing a novel beam selector, an annular detector, a high-speed CCD camera and an imaging filter in the camera chamber of a spherical aberration-corrected transmission electron microscope. The capabilities of the WB-STEM with respect to wide-view imaging, real-time diffraction monitoring and multi-contrast imaging are demonstrated using typical reactor pressure vessel steel that had been used in an European nuclear reactor for 30 years as a surveillance test piece with a fluence of 1.09 × 1020 neutrons cm-2. The quantitatively measured size distribution (average loop size = 3.6 ± 2.1 nm), number density of the dislocation loops (3.6 × 1022 m-3) and dislocation density (7.8 × 1013 m m-3) were carefully compared with the values obtained via conventional weak-beam transmission electron microscopy studies. In addition, cluster analysis using atom probe tomography (APT) further demonstrated the potential of the WB-STEM for correlative electron tomography/APT experiments.

8.
Sci Adv ; 2(5): e1501772, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27386536

RESUMO

A fundamental element of quantum information processing with photonic qubits is the nonclassical quantum interference between two photons when they bunch together via the Hong-Ou-Mandel (HOM) effect. Ultimately, many such photons must be processed in complex interferometric networks. For this purpose, it is essential to synchronize the arrival times of the flying photons and to keep their purities high. On the basis of the recent experimental success of single-photon storage with high purity, we demonstrate for the first time the HOM interference of two heralded, nearly pure optical photons synchronized through two independent quantum memories. Controlled storage times of up to 1.8 µs for about 90 events per second were achieved with purities that were sufficiently high for a negative Wigner function confirmed with homodyne measurements.


Assuntos
Modelos Teóricos , Fótons , Teoria Quântica , Humanos
9.
Mater Sci Eng C Mater Biol Appl ; 62: 283-92, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26952425

RESUMO

The initial adhesion of cells to biomaterials is critical in the regulation of subsequent cell behaviors. The purpose of this study was to investigate a mechanism through which the surface wettability of biomaterials can be improved and determine the effects of biomaterial surface characteristics on cellular behaviors. We investigated the surface characteristics of various types of hydroxyapatite after sintering in different atmospheres and examined the effects of various surface characteristics on cell adhesion to study cell-biomaterial interactions. Sintering atmosphere affects the polarization capacity of hydroxyapatite by changing hydroxide ion content and grain size. Compared with hydroxyapatite sintered in air, hydroxyapatite sintered in saturated water vapor had a higher polarization capacity that increased surface free energy and improved wettability, which in turn accelerated cell adhesion. We determined the optimal conditions of hydroxyapatite polarization for the improvement of surface wettability and acceleration of cell adhesion.


Assuntos
Durapatita/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Durapatita/farmacologia , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Temperatura , Termodinâmica , Molhabilidade , Difração de Raios X
10.
J Biomed Mater Res A ; 104(6): 1500-9, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26860353

RESUMO

DNA coating on dental titanium (Ti) implants is attracting attention due to its osteogenic properties. The aim of the present study was to evaluate in vitro and in vivo bioactivities of a multilayered DNA/protamine (D/P) coating on Ti implant by simulated body fluid (SBF) immersion experiments and implantation experiments into extracted sockets of rat molars. Two types of DNA, 300 base pair (bp) and 7000 bp fragments, were used. Protamine was initially immobilized onto Ti implants using a tresyl chloride-activated method and DNA and protamine were then alternatively deposited after the immobilization of protamine by a layer-by-layer technique. A multilayered D/P-coating was confirmed by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy measurements. The deposition of apatite progressed more on the surfaces of multilayered D/P-coated Ti implants than on those of nontreated Ti implants in SBF immersion experiments. Animal implantation experiments showed that multilayered D/P-coated Ti implants provided a significantly higher bone-to-implant (BIC) contact ratio 3 weeks after implantation. No significant difference was observed in the BIC ratio 9 weeks after implantation. The results of the present study demonstrated that a multilayered D/P-coating promoted new bone formation at the early stages of the bone healing process. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1500-1509, 2016.


Assuntos
Osso e Ossos/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , DNA/farmacologia , Protaminas/farmacologia , Titânio/farmacologia , Animais , Cristalização , DNA/química , Eletrólitos/química , Corantes Fluorescentes/química , Masculino , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Ratos Wistar , Salmão , Propriedades de Superfície , Difração de Raios X
11.
Microsc Microanal ; 21(6): 1373-1378, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26373477

RESUMO

Elemental distributions in a magnetic multilayer system with the structure Si substrate/Ta/NiFe/Ru/CoFeB/Ru/NiFe were studied using atom probe tomography (APT) along different analysis directions. The distributions of Ru and B atoms, which require a high evaporation field, were strongly influenced by the APT analysis direction. In particular, B in the CoFeB layer appeared near the interface with the lower Ru layer when the analysis was anti-parallel to the film growth direction, while B atoms were observed at the other side of the CoFeB layer when the analysis was parallel to the film growth direction. Moreover, when the analysis was perpendicular to the film growth direction, a homogenous distribution of B atoms was found within the CoFeB layer. Owing to this B behavior, the underlying Ru layer was affected in both of these analysis directions. In APT measurements of such a multilayer system composed of a stack of different evaporation field materials, evaluation of the elemental distribution around interfaces should be performed from more than one analysis direction.

12.
Biomed Mater ; 10(1): 011001, 2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25585714

RESUMO

The surface modification of ceramic biomaterials used for medical devices is expected to improve osteoconductivity through control of the interfaces between the materials and living tissues. Polarisation treatment induced surface charges on hydroxyapatite, ß-tricalcium phosphate, carbonate-substituted hydroxyapatite and yttria-stabilized zirconia regardless of the differences in the carrier ions participating in the polarisation. Characterization of the surfaces revealed that the wettability of the polarised ceramic biomaterials was improved through the increase in the surface free energies compared with conventional ceramic surfaces.


Assuntos
Materiais Biocompatíveis/química , Cerâmica/química , Osso e Ossos/química , Fosfatos de Cálcio/química , Carbonatos/química , Durapatita/química , Propriedades de Superfície , Molhabilidade , Difração de Raios X , Ítrio/química , Zircônio/química
13.
J Biomed Mater Res B Appl Biomater ; 102(6): 1277-88, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24449291

RESUMO

Thin carbonate-containing hydroxyapatite (CA) films coating partially stabilized zirconia (Y-TZP) were prepared (CA-Y-TZP) to establish a metal-free implant system. CA was coated using a molecular precursor method. The CA film was deposited on the surface of Y-TZP using a precursor solution, which was a mixture of a calcium-ethylenediaminetetraacetic acid (EDTA) complex and phosphate compounds. The deposited CA film was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy measurements. A focus ion beam system technique revealed that the thickness of the CA film was less than 1.0 µm. Biological evaluations of CA-Y-TZP were performed by immersion experiments in simulated body fluid (SBF) and implantation experiments in the tibiae and femoral condyles of rabbits. In the SBF immersion experiment, apatite deposition progressed more on CA-Y-TZP at the early stage of immersion than on Y-TZP without the CA coating. Animal experiments revealed that bone formation on CA-Y-TZP was similar with than on Y-TZP. Histomorphometrical evaluations showed a significantly higher bone-to-implant contact ratio and bone mass on CA-Y-TZP after implantation into the femoral trabecular bone of rabbits. Therefore, CA-Y-TZP appears to be applicable as a metal-free implant.


Assuntos
Substitutos Ósseos , Carbonatos , Materiais Revestidos Biocompatíveis , Durapatita , Osteogênese/efeitos dos fármacos , Zircônio , Animais , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Carbonatos/química , Carbonatos/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/química , Durapatita/farmacologia , Feminino , Teste de Materiais/métodos , Coelhos , Zircônio/química , Zircônio/farmacologia
14.
Acta Biomater ; 8(2): 860-5, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21971419

RESUMO

The use of micro-arc oxidation titania (MAO TiO2) coatings to modify titanium surfaces improves the biocompatibility of implant surfaces. To obtain hydrophilic MAO TiO2 coating surfaces electric polarization, which induces surface electric fields in the materials and produces surface charges, was performed in this study. Electric polarization of the MAO TiO2 coatings was confirmed by measuring the thermally stimulated depolarization current. After electric polarization treatment the MAO TiO2 coatings did not exhibit any obvious changes in surface roughness, morphology, or phase components. X-ray photoelectron spectroscopy results indicated that electric polarization resulted in oxidation of the cathodic-faced surfaces and reduction of the anodic-faced surfaces. This result suggests that the existence of a concentration gradient of oxide ions/oxygen vacancies produced the stored space charge in the coatings. Reduction of the deionized water contact angle on the polarized MAO TiO2 surfaces was maintained for longer periods compared with the non-polarized surface. Our study demonstrated that metastable electric fields across the MAO TiO2 coating produced by electric polarization made it durably wettable by reducing the interfacial surface tension between the material and water.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Eletricidade , Interações Hidrofóbicas e Hidrofílicas/efeitos dos fármacos , Titânio/farmacologia , Temperatura Alta , Microscopia Eletrônica de Varredura , Oxirredução/efeitos dos fármacos , Espectroscopia Fotoeletrônica , Propriedades de Superfície/efeitos dos fármacos , Água/química , Difração de Raios X
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