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1.
PLoS One ; 16(1): e0246188, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33507995

RESUMO

Osteoarthritis (OA) is one of the major causes of chronic pain in dogs. However, the pathogenesis of OA has not been fully understood in dogs. The objective of this study was to comprehensively investigate the mRNA expression levels of proinflammatory cytokines, inflammatory mediators, nerve growth factor and its receptor, and matrix metalloproteinases in the synovium of dogs with spontaneous OA as well as to elucidate their relationships with the severity of synovitis. Dogs that were diagnosed with stifle OA on the basis of radiographic findings were included, and the degree of synovitis was observed using stifle arthroscopy. The dogs were assigned to two different groups depending on their synovitis scores: the low-grade group (score of 1 or 2; n = 8) and high-grade group (score of 3 to 5; n = 18). The dogs showing no evidence of orthopedic disease were included in the control group (n = 6). Synovial tissue samples were collected from the sites at which synovitis scores were assessed using arthroscopy. Total RNA was extracted from the collected synovial tissue, and cDNA was synthesized. Subsequently, RT-qPCR were performed using canine-specific primer sets for IL1B, IL6, CXCL8, TNF, TGFB1, PTGS2, PTGES, MMP3, MMP13, NGF, NTRK1, and PTGER4. Expression levels of IL1B, IL6, CXCL8, and MMP13 were significantly higher in the high-grade group than in the control group. In addition, expression levels of IL1B, CXCL8, TNF, and PTGS2 were significantly higher in the high-grade group than in the low-grade group. Expression levels of IL1B, IL6, CXCL8, TNF, PTGS2, and PTGER4 showed significant positive correlation with synovitis score. In conclusion, all mRNA expression levels in the synovial membrane varied according to the degree of synovitis in dogs with spontaneous OA. Thus, this study may partially elucidate the pathogenesis of synovitis in dogs with spontaneous OA.

2.
Appl Radiat Isot ; 168: 109553, 2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-33302249

RESUMO

As the commissioning phase of the Nagoya University Accelerator-driven Neutron Source for boron neutron capture therapy, in-phantom thermal neutron flux measurements were conducted using a small 6LiF/Eu:CaF2 scintillator detector and activation foils. The spatial distribution of the measured thermal neutron flux agreed with the Monte Carlo simulation results. Based on this comparison, the free-in-air neutron spectrum, calculated at the exit aperture, was verified and the epithermal neutron flux, at a 0.25 mA proton current, was evaluated as (1.49 ± 0.10) × 107 n/(cm2 s).

3.
Appl Opt ; 59(32): 9937-9943, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33175765

RESUMO

We demonstrate a new design high-contrast optics suitable for use on a stray-light reduction. Two-dimensional distribution of diffracted light was numerically analyzed and confirmed by a laboratory measurement to determine its characteristics. Laboratory measurements confirm stray-light performance with ∼10-8 rejection viewing as close as 1.0° to a bright-light source. The present improvement replaces the conventional normal-edge vane by an edge with microscopic Gaussian-shaped structures. This permits simplified fabrication, provides even more weight reduction, and delivers improved performance for a given size.

4.
PLoS One ; 15(7): e0236795, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735625

RESUMO

Osteoarthritis in cats is more prevalent because cats are living longer with advancement in veterinary medicine. Objective evaluation of behavioral changes in cats with osteoarthritis can facilitate an early diagnosis. The objective of this study was to investigate the utility of a novel activity monitor for analyzing physical activities and sleep quality in cats. First, a novel activity monitor (Plus Cycle®; JARMeC, Kanagawa, Japan), with a built-in three-directional accelerometer and an air pressure sensor specifically designed for cats, was compared to a human activity monitor (Actical®; Philips Respironics, OR, USA) previously used in cats (n = 10). Second, the validity of the measurement accuracy of the amount of physical activity, the number of vibrations, the number of jumps, and the resting and sleeping time was evaluated using Plus Cycle® in healthy cats (n = 6). Finally, the effects of gender and age of cats and time of day on the amount of physical activity, the number of vibrations, the number of jumps, and the resting and sleeping time were investigated in client-owned cats (n = 61). There were strong correlations between Plus Cycle® and Actical® in total activity (p < 0.05) and activity intensity (p < 0.05). When the physical activities were measured using Plus Cycle® in healthy cats, those data were quantified with high accuracy. In addition, it was also found to be very accurate in discriminating the resting and sleeping conditions of cats. In client-owned cats, there were no significant differences with respect to gender in any measured traits. The amount of physical activity and the number of jumps significantly decreased with the age of the cat. In contrast, the resting and sleeping times significantly increased with the age of the cat. In conclusion, Plus Cycle® can accurately and objectively assess physical activities and sleep quality with age of the cat, suggesting that this novel activity monitor can be used to manage the feline musculoskeletal health.


Assuntos
Monitores de Aptidão Física/veterinária , Monitorização Fisiológica/veterinária , Animais , Artrite/veterinária , Doenças do Gato , Gatos , Japão , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Descanso , Sono
5.
Science ; 368(6489): 405-409, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32327594

RESUMO

Venus has a thick atmosphere that rotates 60 times as fast as the surface, a phenomenon known as super-rotation. We use data obtained from the orbiting Akatsuki spacecraft to investigate how the super-rotation is maintained in the cloud layer, where the rotation speed is highest. A thermally induced latitudinal-vertical circulation acts to homogenize the distribution of the angular momentum around the rotational axis. Maintaining the super-rotation requires this to be counteracted by atmospheric waves and turbulence. Among those effects, thermal tides transport the angular momentum, which maintains the rotation peak, near the cloud top at low latitudes. Other planetary-scale waves and large-scale turbulence act in the opposite direction. We suggest that hydrodynamic instabilities adjust the angular-momentum distribution at mid-latitudes.

6.
Int J Syst Evol Microbiol ; 70(2): 1372-1397, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32122458

RESUMO

Fourteen novel lipomycetaceous yeasts species were isolated from soil samples collected from the Hokkaido, Chiba and Okinawa prefectures of Japan. Phylogenetic analyses of the D1/D2 domains of the large subunit rRNAs and translation elongation factor 1 alpha genes (TEF1-α) revealed that five strains of two species from the soil in Furano-shi, Hokkaido were related to Dipodascopsis anomala and 29 strains representing 12 species from soils in Kamogawa-shi, Chiba and Iriomote Island, Okinawa were in the Myxozyma clade. The two species of Dipodascopsis form globose or ellipsoid ascospores in their sac-like ascus and pseudohyphae. Furthermore, these species produce ascospores in their pseudohyphae and do not produce an acicular ascus, which is common among the three species including D. anomala. Therefore, we propose transferring D. anomala to the genus Babjevia and amending Babjevia. Two novel species were described and included in the genus Babjevia: Babjevia hyphoforaminiformans sp. nov. (holotype NBRC 111233; MycoBank no. MB 829051) and Babjevia hyphasca sp. nov. (holotype NBRC 112965; MycoBank no. MB 829053). The 12 species in the Myxozyma clade produce neither ascospores nor pseudohyphae and have different characteristics in assimilating several carbon sources from each other. Thus, we propose that the novel species of Lipomyces be classified as forma asexualis (f.a.). From Kamogawa-shi, Chiba (19 strains representing five species): Lipomyces melibiosiraffinosiphilus f.a., sp. nov. (holotype NBRC 111411; MycoBank no. MB 829034), Lipomyces kiyosumicus f.a., sp. nov. (holotype NBRC 111424; MycoBank no. MB 829035), Lipomyces chibensis f.a., sp. nov. (holotype NBRC 111413; MycoBank no. MB 829036), Lipomyces kamogawensis f.a., sp. nov. (holotype NBRC 112967; MycoBank no. MB 829037), Lipomyces amatsuensis f.a., sp. nov. (holotype NBRC 111420; MycoBank no. MB 829041). From Iriomote island, Okinawa (10 strains representing seven species): Lipomyces taketomicus f.a., sp. nov. (holotype NBRC 112966; MycoBank no. MB 829042), Lipomyces yaeyamensis f.a., sp. nov. (holotype NBRC 110433; MycoBank no. MB 829050), Lipomyces iriomotensis f.a., sp. nov. (holotype NBRC 110436; MycoBank no. MB 829045), Lipomyces haiminakanus f.a., sp. nov. (holotype NBRC 110435; MycoBank no. MB 829046), Lipomyces komiensis f.a., sp. nov. (holotype NBRC 110440; MycoBank no. MB 829047), Lipomyces nakamensis f.a., sp. nov. (holotype NBRC 110434; MycoBank no. MB 829048), Lipomyces sakishimensis f.a., sp. nov. (holotype NBRC 110439; MycoBank no. MB 829049).


Assuntos
Lipomyces/classificação , Filogenia , Microbiologia do Solo , DNA Fúngico/genética , Genes Fúngicos , Japão , Lipomyces/isolamento & purificação , Técnicas de Tipagem Micológica , Fator 1 de Elongação de Peptídeos/genética , Fenótipo , Saccharomycetales/classificação , Análise de Sequência de DNA , Esporos Fúngicos
7.
Biochem Biophys Res Commun ; 525(4): 1081-1086, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32184016

RESUMO

Cell morphology is related to proliferation and differentiation. We previously reported that cell attachment area of rat mesenchymal stem cells (MSCs) is negatively correlated with their osteogenic differentiation level on osteoconductive hydroxyapatite (HAp) with various microstructures. In this study, the correlation between the cell attachment area and osteogenic differentiation level was investigated on substrates without osteoconductive property using tissue culture polystyrene (TCPS), and 3 mol% yttria-stabilized zirconia (3Y-TZP) with or without surface periodic microstructures. It was found that the osteogenic differentiation level after 3 weeks of culture increased with a decrease in cell attachment area after 3 h of culture. The square of the correlation coefficient between cell attachment area and osteocalcin secretion content was 0.845 among the three types of substrates. Thus, the negative correlation between cell attachment area and differentiation level is confirmed even when cultured on substrates without osteoconductive property. These findings suggest that the correlation between the cell attachment area of rat MSCs and osteogenic differentiation level could also apply to various types of substrate, regardless of osteoconductive property.

8.
ACS Nano ; 13(7): 7705-7715, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31241885

RESUMO

Strengthening the antitumor immune response to surpass the activation energy barrier associated with the immunosuppressive tumor microenvironment is an active area of cancer immunotherapy. Emerging evidence suggests that delivery of immunostimulatory molecules with the aid of a carrier system is essential for cancer immunotherapy. However, the size-dependent effect of the delivery system on immune-targeted sites and anticancer immune responses is yet to be comprehensively understood. Herein, to clarify the size-dependent effect of the delivery system on the underlying anticancer immune mechanism, rod-shaped hydroxyapatite (HA) particles with lengths from 100 nm to 10 µm are designed. HA rods stimulate anticancer immunity in a size-dependent manner. Shorter HA rods with lengths ranging from 100 to 500 nm promote antigen cellular uptake, dendritic cell (DC) maturation, and lymph node targeting antigen. In contrast, longer HA rods with lengths ranging from 500 nm to 10 µm prolong antigen retention and increase DC accumulation. Medium-sized HA rods with a length of 500 nm, taking advantage of both short and long rods, show optimized antigen release and uptake, increased DCs accumulation and maturation, highest CD4+ and CD8+ T cell population, and the best anticancer immunity in vivo. The present study provides a rod-scale design strategy for an immune-targeted delivery system toward cancer immunotherapy in the future.


Assuntos
Antineoplásicos/farmacologia , Materiais Biocompatíveis/química , Sistemas de Liberação de Medicamentos , Durapatita/imunologia , Imunoterapia , Neoplasias/terapia , Adsorção , Animais , Antígenos de Neoplasias/administração & dosagem , Antígenos de Neoplasias/imunologia , Antineoplásicos/síntese química , Antineoplásicos/química , Materiais Biocompatíveis/síntese química , Células Cultivadas , Durapatita/síntese química , Durapatita/química , Feminino , Injeções Subcutâneas , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/imunologia , Imagem Óptica , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Tamanho da Partícula , Propriedades de Superfície
9.
Vet Comp Orthop Traumatol ; 32(3): 182-191, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30873569

RESUMO

OBJECTIVE: The aim of this study was to investigate detailed functional anatomy of the craniomedial bundle (CrMB) and caudolateral bundle (CdLB) of cranial cruciate ligament (CrCL) for application of intra-articular anatomical reconstruction in dogs. MATERIALS AND METHODS: Twelve stifle joint of 12 Beagle cadavers were used. Anatomical characteristics of femoral attachment regions of the CrCL were determined. Then, the location and area of the footprints of the CrMB and CdLB were objectively measured. Each bundle was equally divided into four fibre bundles, and changes in the fibre arrangement were recorded during stifle range of motion. Additionally, the tension of each fibre bundle at various stifle joint angles was objectively measured. RESULTS: The attachment region of the CrCL clearly differed from that reported in humans. The centre of the CdLB attachment site was located craniodistal to that of the CrMB on the femur and slightly caudal to that of the CrMB on the tibia. The area of the CrMB on the femoral and tibial attachment sites was larger than that of the CdLB. During stifle range of motion, each divided fibre bundle in the CrMB and CdLB was twisted intricately. The tension of the CrMB was higher than that of CdLB. The central part of the CrMB was always tense during stifle range of motion. CLINICAL SIGNIFICANCE: These results may contribute to the application of anatomical reconstruction surgery for CrCL deficient stifle in dogs.


Assuntos
Ligamento Cruzado Anterior/anatomia & histologia , Cães/anatomia & histologia , Joelho de Quadrúpedes/anatomia & histologia , Animais , Feminino , Membro Posterior/anatomia & histologia , Masculino
10.
Colloids Surf B Biointerfaces ; 174: 300-307, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30469051

RESUMO

Recombinant protein-based vaccines generally show limited immunogenicity and need adjuvants to achieve robust immune responses. Herein, to combine the excellent biocompatibility of hydroxyapatite (HA) and exciting adjuvant activity of silica, Si-doped HA nanorods with Si/P molar ratio from 0 to 0.65 were hydrothermally synthesized and evaluated as immunoadjuvants. Si-doping decreases the size and increases the BET surface area of the nanorods. Si-doping in HA nanorods increases the in vitro adjuvant activity, including CD11c+CD86+ expression and cytokine secretion of bone marrow derived dendritic cells (BMDCs). Moreover, Si-doping in HA increases the ex vivo adjuvant activity as shown by the increase in both Th1 and Th2 cytokines secretion. Si-doped HA nanorods are promising as a new immunoadjuvant.


Assuntos
Adjuvantes Imunológicos/química , Durapatita/química , Durapatita/imunologia , Nanotubos/química , Dióxido de Silício/química , Animais , Citocinas/biossíntese , Citocinas/imunologia , Feminino , Linfonodos/química , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Tamanho da Partícula , Dióxido de Silício/imunologia , Propriedades de Superfície
11.
Chem Commun (Camb) ; 54(9): 1057-1060, 2018 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-29323387

RESUMO

Stellated fibrous mesoporous silica nanospheres significantly improve the cellular uptake of cancer antigen and the maturation of bone marrow derived dendritic cells in vitro. Moreover, the combination of poly(I:C) with stellated fibrous MS nanospheres markedly decreases the necessary dose of poly(I:C) for anti-tumor immunity, and thus opens new opportunities for the future clinical application of poly(I:C) in cancer immunotherapy.


Assuntos
Imunoterapia/métodos , Neoplasias/imunologia , Neoplasias/terapia , Poli I-C/imunologia , RNA de Cadeia Dupla/síntese química , RNA de Cadeia Dupla/imunologia , Dióxido de Silício/química , Células Dendríticas/imunologia , Humanos , Tamanho da Partícula , Poli I-C/administração & dosagem , Poli I-C/química , Porosidade , RNA de Cadeia Dupla/química , Propriedades de Superfície
12.
Earth Planets Space ; 70(1): 88, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31007533

RESUMO

The existence of lightning discharges in the Venus atmosphere has been controversial for more than 30 years, with many positive and negative reports published. The lightning and airglow camera (LAC) onboard the Venus orbiter, Akatsuki, was designed to observe the light curve of possible flashes at a sufficiently high sampling rate to discriminate lightning from other sources and can thereby perform a more definitive search for optical emissions. Akatsuki arrived at Venus during December 2016, 5 years following its launch. The initial operations of LAC through November 2016 have included a progressive increase in the high voltage applied to the avalanche photodiode detector. LAC began lightning survey observations in December 2016. It was confirmed that the operational high voltage was achieved and that the triggering system functions correctly. LAC lightning search observations are planned to continue for several years.

13.
Earth Planets Space ; 70(1): 23, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31983883

RESUMO

The ultraviolet imager (UVI) has been developed for the Akatsuki spacecraft (Venus Climate Orbiter mission). The UVI takes ultraviolet (UV) images of the solar radiation reflected by the Venusian clouds with narrow bandpass filters centered at the 283 and 365 nm wavelengths. There are absorption bands of SO2 and unknown absorbers in these wavelength regions. The UV images provide the spatial distribution of SO2 and the unknown absorber around cloud top altitudes. The images also allow us to understand the cloud top morphologies and haze properties. Nominal sequential images with 2-h intervals are used to understand the dynamics of the Venusian atmosphere by estimating the wind vectors at the cloud top altitude, as well as the mass transportation of UV absorbers. The UVI is equipped with off-axial catadioptric optics, two bandpass filters, a diffuser installed in a filter wheel moving with a step motor, and a high sensitivity charge-coupled device with UV coating. The UVI images have spatial resolutions ranging from 200 m to 86 km at sub-spacecraft points. The UVI has been kept in good condition during the extended interplanetary cruise by carefully designed operations that have maintained its temperature maintenance and avoided solar radiation damage. The images have signal-to-noise ratios of over 100 after onboard desmear processing.

14.
Earth Planets Space ; 70(1): 24, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31983884

RESUMO

Since insertion into orbit on December 7, 2015, the Akatsuki orbiter has returned global images of Venus from its four imaging cameras at eleven discrete wavelengths from ultraviolet (283 and 365 nm) and near infrared (0.9-2.3 µm), to the thermal infrared (8-12 µm) from a near-equatorial orbit. The Venus Express and Pioneer Venus Orbiter missions have also monitored the planet for long periods but from polar or near-polar orbits. The wavelength coverage and views of the planet also differ for all three missions. In reflected light, the images reveal features seen near the cloud tops (~ 70 km altitude), whereas in the near-infrared images of the nightside, features seen are at mid- to lower cloud levels (~ 48-60 km altitude). The dayside cloud cover imaged at the ultraviolet wavelengths shows morphologies similar to what was observed from Mariner 10, Pioneer Venus, Galileo, Venus Express and MESSENGER. The daytime images at 0.9 and 2.02 µm also reveal some interesting features which bear similarity to the ultraviolet images. The nighttime images at 1.74, 2.26 and 2.32 µm and at 8-12 µm reveal features not seen before and show new details of the nightside including narrow wavy ribbons, curved string-like features, long-scale waves, long dark streaks, isolated bright spots, sharp boundaries and even mesoscale vortices. Some features previously seen such as circum-equatorial belts (CEBs) and occasional areal brightenings at ultraviolet (seen in Venus Express observations) of the cloud cover at ultraviolet wavelengths have not been observed thus far. Evidence for the hemispheric vortex organization of the global circulation can be seen at all wavelengths on the day- and nightsides. Akatsuki images reveal new and puzzling morphology of the complex nightside cloud cover. The cloud morphologies provide some clues to the processes occurring in the atmosphere and are thus, a key diagnostic tool when quantitative dynamical analysis is not feasible due to insufficient information.

15.
Int J Syst Evol Microbiol ; 67(8): 2941-2946, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28820103

RESUMO

Four novel Lipomyces strains were isolated from soil collected in the Okinawa and Yamanashi prefectures, Japan. Based on their morphological and biochemical characteristics, along with sequence typing using the D1/D2 domain of the LSU rRNA, internal transcribed spacer (ITS) region including 5.8S rRNA, and translation elongation factor 1 alpha gene (EF-1α), the four strains were shown to represent two novel species of the genus Lipomyces, described as Lipomyces okinawensis sp. nov. (type strain No.3-a(35)T=NBRC 110620T=CBS 14747T) and Lipomyces yamanashiensis f.a., sp. nov. (type strain No.313T=NBRC 110621T=CBS 14748T).


Assuntos
Lipomyces/classificação , Filogenia , Microbiologia do Solo , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Genes Fúngicos , Japão , Lipomyces/genética , Lipomyces/isolamento & purificação , Técnicas de Tipagem Micológica , Fator 1 de Elongação de Peptídeos/genética , RNA Ribossômico/genética , Análise de Sequência de DNA
16.
Nat Geosci ; 10: 646-651, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29887914

RESUMO

The Venusian atmosphere is in a state of superrotation where prevailing westward winds move much faster than the planet's rotation. Venus is covered with thick clouds that extend from about 45 to 70 km altitude, but thermal radiation emitted from the lower atmosphere and the surface on the planet's night-side escapes to space at narrow spectral windows of near-infrared. The radiation can be used to estimate winds by tracking the silhouettes of clouds in the lower and middle cloud regions below about 57 km in altitude. Estimates of wind speeds have ranged from 50 to 70 m/s at low- to mid-latitudes, either nearly constant across latitudes or with winds peaking at mid-latitudes. Here we report the detection of winds at low latitude exceeding 80 m/s using IR2 camera images from the Akatsuki orbiter taken during July and August 2016. The angular speed around the planetary rotation axis peaks near the equator, which we suggest is consistent with an equatorial jet, a feature that has not been observed previously in the Venusian atmosphere. The mechanism producing the jet remains unclear. Our observations reveal variability in the zonal flow in the lower and middle cloud region that may provide new challenges and clues to the dynamics of Venus's atmospheric superrotation.

17.
Small ; 12(26): 3510-5, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27191183

RESUMO

Hollow and non-hollow mesoporous silica nanospheres are synthesized and used for cancer vaccine adjuvants. The hollow structure of mesoporous silica nanospheres significantly promote cellular uptake of a model cancer antigen by macrophage-like cells in vitro, improve anti-cancer immunity, CD4(+) and CD8(+) T cell populations in splenocytes of mice in vivo.


Assuntos
Adjuvantes Imunológicos/química , Nanosferas/química , Dióxido de Silício/química , Adjuvantes Imunológicos/efeitos adversos , Animais , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/química , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Microscopia Eletroquímica de Varredura , Microscopia Eletrônica de Transmissão , Células NIH 3T3 , Nanosferas/efeitos adversos , Nanosferas/ultraestrutura , Porosidade
18.
Rev Sci Instrum ; 87(2): 02A911, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26931972

RESUMO

A laser ion source that produces shortly bunched ion beam is proposed. In this ion source, ions are extracted immediately after the generation of laser plasma by an ultra-short pulse laser before its diffusion. The ions can be injected into radio frequency (RF) accelerating bucket of a subsequent accelerator. As a proof-of-principle experiment of the ion source, a RF resonator is prepared and H2 gas was ionized by a short pulse laser in the RF electric field in the resonator. As a result, bunched ions with 1.2 mA peak current and 5 ns pulse length were observed at the exit of RF resonator by a probe.

19.
Acta Biomater ; 25: 347-55, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26232621

RESUMO

UNLABELLED: A potential standard method for measuring the relative dissolution rate to estimate the resorbability of calcium-phosphate-based ceramics is proposed. Tricalcium phosphate (TCP), magnesium-substituted TCP (MgTCP) and zinc-substituted TCP (ZnTCP) were dissolved in a buffer solution free of calcium and phosphate ions at pH 4.0, 5.5 or 7.3 at nine research centers. Relative values of the initial dissolution rate (relative dissolution rates) were in good agreement among the centers. The relative dissolution rate coincided with the relative volume of resorption pits of ZnTCP in vitro. The relative dissolution rate coincided with the relative resorbed volume in vivo in the case of comparison between microporous MgTCPs with different Mg contents and similar porosity. However, the relative dissolution rate was in poor agreement with the relative resorbed volume in vivo in the case of comparison between microporous TCP and MgTCP due to the superimposition of the Mg-mediated decrease in TCP solubility on the Mg-mediated increase in the amount of resorption. An unambiguous conclusion could not be made as to whether the relative dissolution rate is predictive of the relative resorbed volume in vivo in the case of comparison between TCPs with different porosity. The relative dissolution rate may be useful for predicting the relative amount of resorption for calcium-phosphate-based ceramics having different solubility under the condition that the differences in the materials compared have little impact on the resorption process such as the number and activity of resorbing cells. STATEMENT OF SIGNIFICANCE: The evaluation and subsequent optimization of the resorbability of calcium phosphate are crucial in the use of resorbable calcium phosphates. Although the resorbability of calcium phosphates has usually been evaluated in vivo, establishment of a standard in vitro method that can predict in vivo resorption is beneficial for accelerating development and commercialization of new resorbable calcium phosphate materials as well as reducing use of animals. However, there are only a few studies to propose such an in vitro method within which direct comparison was carried out between in vitro and in vivo resorption. We propose here an in vitro method based on measuring dissolution rate. The efficacy and limitations of the method were evaluated by international round-robin tests as well as comparison with in vivo resorption studies for future standardization. This study was carried out as one of Versailles Projects on Advanced Materials and Standards (VAMAS).


Assuntos
Reabsorção Óssea/patologia , Fosfatos de Cálcio/farmacologia , Cerâmica/farmacologia , Teste de Materiais/métodos , Fosfatase Ácida/metabolismo , Animais , Concentração de Íons de Hidrogênio , Isoenzimas/metabolismo , Porosidade , Coelhos , Fosfatase Ácida Resistente a Tartarato
20.
Int J Mol Sci ; 16(4): 8294-309, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25874757

RESUMO

Surface-mediated gene transfer systems using biocompatible calcium phosphate (CaP)-based composite layers have attracted attention as a tool for controlling cell behaviors. In the present study we aimed to demonstrate the potential of CaP-based composite layers to mediate area-specific dual gene transfer and to stimulate cells on an area-by-area basis in the same well. For this purpose we prepared two pairs of DNA-fibronectin-apatite composite (DF-Ap) layers using a pair of reporter genes and pair of differentiation factor genes. The results of the area-specific dual gene transfer successfully demonstrated that the cells cultured on a pair of DF-Ap layers that were adjacently placed in the same well showed specific gene expression patterns depending on the gene that was immobilized in the underlying layer. Moreover, preliminary real-time PCR results indicated that multipotential C3H10T1/2 cells may have a potential to change into different types of cells depending on the differentiation factor gene that was immobilized in the underlying layer, even in the same well. Because DF-Ap layers have a potential to mediate area-specific cell stimulation on their surfaces, they could be useful in tissue engineering applications.


Assuntos
Apatitas/química , Transfecção/métodos , Animais , Células CHO , Diferenciação Celular , Cricetinae , Cricetulus , DNA/química , Fibronectinas/química , Genes Reporter , Luciferases de Vaga-Lume/biossíntese , Luciferases de Vaga-Lume/genética , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Camundongos , Propriedades de Superfície
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