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1.
Phys Rev E ; 105(5-2): 055202, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35706231

RESUMO

The interaction of relativistic short-pulse lasers with matter produces fast electrons with over megaampere currents, which supposedly heats a solid target isochorically and forms a hot dense plasma. In a picosecond timescale, however, thermal diffusion from hot preformed plasma turns out to be the dominant process of isochoric heating. We describe a heating process, fast thermal diffusion, launched from the preformed plasma heated resistively by the fast electron current. We demonstrate the fast thermal diffusion in the keV range in a solid density plasma by a series of one-dimensional particle-in-cell simulations. A theoretical model of the fast thermal diffusion is developed and we derive the diffusion speed as a function of the laser amplitude and target density. Under continuous laser irradiation, the diffusion front propagates at a constant speed in uniform plasma. Our model can provide a guideline for fast isochoric heating using future kilojoule petawatt lasers.

2.
Ann Med ; 53(1): 1402-1409, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34414832

RESUMO

OBJECTIVES: The purpose of the study was to examine the immediate-term effect of positive-word stimuli via a smartphone application on the multi-directional reach ability in standing position in young adults. METHODS: This study was an immediate-term, assessor-blinded, two-arm, parallel-group, randomized controlled trial among young adults recruited from one university in Japan. Participants were randomly assigned to the experimental group or control group using a computer-based random number-generating programme. Participants of the experimental group used an application on iPhone and watched 3-min videos displaying positive-word stimuli. This application repeatedly displayed positive-word stimuli every 5 s. The participants of the control group used an application on iPhone and watched the same videos as in the experimental group. However, a positive-word stimulus did not appear in the videos. The primary outcome was the multi-directional reach test (MDRT) from baseline to immediately after the intervention protocol. RESULTS: Among the 62 randomized participants (experimental group, n = 31; control group, n = 31), 62 (100%) completed the MDRT immediately after the intervention protocol. There were no differences in mean group change values in MDRT between the experimental and control groups. CONCLUSIONS: Among young adults, positive-word stimuli via a smartphone application did not significantly improve multi-directional reach ability in standing position. These findings do not support the superiority of this intervention among young adults. Trial Registration: Clinicaltrials.gov, NCT03546218. Registered 6 June 2018, https://clinicaltrials.gov/ct2/show/NCT03546218KEY MESSAGESIn our study, among young adults, positive-word stimuli via an SPSRS application did not significantly improve the multi-directional reach ability in the standing position.These findings do not support the superiority of this intervention among young adults.


Assuntos
Aplicativos Móveis , Equilíbrio Postural , Smartphone , Posição Ortostática , Acidentes por Quedas , Feminino , Humanos , Masculino , Adulto Jovem
3.
Phys Rev Lett ; 124(3): 035001, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-32031862

RESUMO

Fast isochoric laser heating is a scheme to heat matter with a relativistic intensity (>10^{18} W/cm^{2}) laser pulse for producing an ultrahigh-energy-density (UHED) state. We have demonstrated an efficient fast isochoric heating of a compressed dense plasma core with a multipicosecond kilojoule-class petawatt laser and an assistance of externally applied kilotesla magnetic fields for guiding fast electrons to the dense plasma. A UHED state of 2.2 PPa is achieved experimentally with 4.6 kJ of total laser energy that is one order of magnitude lower than the energy used in the conventional implosion scheme. A two-dimensional particle-in-cell simulation confirmed that diffusive heating from a laser-plasma interaction zone to the dense plasma plays an essential role to the efficient creation of the UHED state.

4.
Biol Pharm Bull ; 42(6): 877-885, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31155587

RESUMO

Orthovanadate (OVA), a protein tyrosine phosphatase inhibitor, induces contraction in endothelium-denuded mouse thoracic aortas. OVA-induced contraction was significantly (vs. control rings) suppressed by Rho kinase (Y-27632, 10 µM), extracellular signal-regulated kinase 1 and 2 (Erk1/2, FR180204, 10 µM), Erk1/2 kinase (MEK, PD98059, 10 µM), epidermal growth factor receptor (EGFR, AG1478, 10 µM), and Src inhibitors, and was partially suppressed by c-Jun N-terminal kinase (JNK, AS601245, 10 µM) and p38 (SB203580, 10 µM) inhibitors. However, a myosin light chain kinase inhibitor (ML-7, 10 µM) and a metalloproteinase inhibitor (TAPI-0, 10 µM) had no effect on OVA-induced contraction in mouse thoracic aortas. Phosphorylation of myosin phosphatase target subunit 1 (MYPT1) was abolished by inhibitors of Src, EGFR, MEK, Erk1/2, and Rho kinase, but not by inhibitors of JNK and p38. Erk1/2 phosphorylation by OVA was blocked by inhibitors of EGFR, Src, MEK, and Erk1/2, but not by Rho kinase inhibition. Src phosphorylation at Tyr-416 was abrogated by only Src inhibitor. EGFR phosphorylation at Tyr-1173 was suppressed by a Src inhibitor. These findings suggest that OVA induces contraction via activation of Src, EGFR, MEK, Erk1/2, and Rho kinase, leading to inactivation of myosin light chain phosphatase via MYPT1 phosphorylation.


Assuntos
Aorta Torácica/efeitos dos fármacos , Proteínas Quinases/fisiologia , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Vanadatos/farmacologia , Animais , Aorta Torácica/fisiologia , Masculino , Camundongos , Vasoconstrição/efeitos dos fármacos
5.
Shokuhin Eiseigaku Zasshi ; 47(6): 284-7, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17228794

RESUMO

The preventive effects of acidic xylooligosaccharide prepared from xylan of corncobs and related sugars on stress-induced gastric inflammation in mice were investigated. Oral administration of acidic xylooligosaccharide and hydrocortisone at doses of 100 and 200 mg/kg body weight significantly reduced the number of bleeding points in the gastric mucosa of mice loaded with cold-restraint stress. Acidic xylooligosaccharide showed concentration-dependent superoxide anion radical-scavenging activity at concentrations of 3.3-4.3 mg/mL and its IC50 was 3.5 mg/mL, although this value is approximately six times that of quercetin. The antioxidant activity of acidic xylooligosaccharide could contribute, in part, to its suppressive activities on stress-induced mouse gastritis. Xylose, xylobiose, xylan, and glucuronic acid showed no significant suppressive activities on mouse gastric inflammation at a dose of 100 mg/kg body weight. These results suggest that an appropriate degree of polymerization of xylan (larger than trimer) is necessary for the activities of acidic xylooligosaccharide.


Assuntos
Gastrite/etiologia , Gastrite/prevenção & controle , Oligossacarídeos/uso terapêutico , Estresse Fisiológico/complicações , Xilanos/uso terapêutico , Animais , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres , Masculino , Camundongos , Camundongos Endogâmicos , Oligossacarídeos/administração & dosagem , Oligossacarídeos/farmacologia , Polímeros , Relação Estrutura-Atividade , Xilanos/administração & dosagem , Xilanos/farmacologia , Zea mays/química
6.
Clin Nucl Med ; 28(8): 704-8, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12897669

RESUMO

I-123 iodoamphetamine (IMP) and Ga-67 scintigraphy of malignant melanoma were performed to compare the accumulation of these tracers regarding tumor diameter to determine the site of I-123 IMP accumulation and to evaluate the use of I-123 IMP and Ga-67 in postoperative follow-up. The studies involved 44 patients with a definite diagnosis of malignant melanoma during a 10-year period from April 1991 through March 2001. In this study a very high detection rate of 90.9% was obtained for primary foci with I-123 IMP. With Ga-67, the primary site detection rate was 25%. The results suggest that I-123 IMP is superior to Ga-67 with respect to the detection rate of primary site.


Assuntos
Citratos , Gálio , Iofetamina , Melanoma/diagnóstico por imagem , Idoso , Citratos/farmacocinética , Feminino , Gálio/farmacocinética , Humanos , Iofetamina/farmacocinética , Masculino , Melanoma/metabolismo , Melanoma/secundário , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Valor Preditivo dos Testes , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética
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