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2.
NPJ Microgravity ; 9(1): 33, 2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37120425

RESUMEN

We conducted a charge-charge clustering experiment of positively and negatively charged colloidal particles in aqueous media under a microgravity environment at the International Space Station. A special setup was used to mix the colloid particles in microgravity and then these structures were immobilized in gel cured using ultraviolet (UV) light. The samples returned to the ground were observed by optical microscopy. The space sample of polystyrene particles with a specific gravity ρ (=1.05) close to the medium had an average association number of ~50% larger than the ground control and better structural symmetry. The effect of electrostatic interactions on the clustering was also confirmed for titania particles (ρ ~ 3), whose association structures were only possible in the microgravity environment without any sedimentation they generally suffer on the ground. This study suggests that even slight sedimentation and convection on the ground significantly affect the structure formation of colloids. Knowledge from this study will help us to develop a model which will be used to design photonic materials and better drugs.

3.
iScience ; 25(7): 104569, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35784793

RESUMEN

This paper presents an investigation of the heat transfer processes in miniature thermomagnetic generators (TMGs) that are based on the recently developed concept of resonant self-actuation of a cantilever enabling efficient conversion of thermal into electrical energy. A lumped element model (LEM) is introduced to describe the dynamics of heat intake during mechanical contact between a thermomagnetic (TM) film and heat source, and of heat dissipation. The key parameters governing heat intake and dissipation are the heat transfer coefficient at contact and the thermal resistance R b of the bonding layer between TM film and cantilever, respectively. The effects of these parameters on the performance metrics are investigated for different heat source temperatures above the Curie temperature of the TM film. LEM simulations reveal critical values of κ and R b , above which stable performance of energy generation occurs characterized by large stroke and frequency resulting in large power.

4.
Materials (Basel) ; 14(5)2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33807906

RESUMEN

This paper presents a lumped element model (LEM) to describe the coupled dynamic properties of thermomagnetic generators (TMGs) based on magnetic shape memory alloy (MSMA) films. The TMG generators make use of the concept of resonant self-actuation of a freely movable cantilever, caused by a large abrupt temperature-dependent change of magnetization and rapid heat transfer inherent to the MSMA films. The LEM is validated for the case of a Ni-Mn-Ga film with Curie temperature TC of 375 K. For a heat source temperature of 443 K, the maximum power generated is 3.1 µW corresponding to a power density with respect to the active material's volume of 80 mW/cm3. Corresponding LEM simulations allow for a detailed study of the time-resolved temperature change of the MSMA film, the change of magnetic field at the position of the film and of the corresponding film magnetization. Resonant self-actuation is observed at 114 Hz, while rapid temperature changes of about 10 K occur within 1 ms during mechanical contact between heat source and Ni-Mn-Ga film. The LEM is used to estimate the effect of decreasing TC on the lower limit of heat source temperature in order to predict possible routes towards waste heat recovery near room temperature.

5.
Materials (Basel) ; 12(4)2019 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-30769820

RESUMEN

We report a numerical study of the field assisted sintering of silicon germanium alloys by a finite element method, which takes into account contact resistances, thermal expansion and the thermoelectric effect. The distribution of electrical and thermal fields was analyzed numerically, based on the experimental data collected from spark plasma sintering (SPS) apparatus. The thermoelectric properties of Si-Ge used within the simulation were considered as the function of density and the sintering temperature. Quantitative estimation of the temperature distribution during the sintering pointed to a significant, up to 60 °C, temperature difference within the specimen volume for the case of the sintering temperature at 1150 °C.

6.
Clin Neuropharmacol ; 41(5): 151-155, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30234616

RESUMEN

AIM: Up to 60% of depressed patients do not obtain sufficient relief from a course of antidepressant therapy, and these treatment-resistant major depressive disorder (TRD) patients are at increased risk for relapse, chronicity, persistent psychosocial impairments, and suicide. Probiotics actively participate in treatment of neuropsychiatric disorders. However, the role of gut microbiota in brain disorders and depression remains unclear. We performed a prospective study to evaluate the effects of Clostridium butyricum MIYAIRI 588 (CBM588). METHODS: This was an 8-week open-label study to evaluate the efficacy and safety of CBM588 in combination with antidepressants in adult patients diagnosed with TRD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Forty antidepressant-treated inpatients were included. Patients were randomized to adjuvant treatment with CBM588 (n = 20) or control (n = 20). The primary endpoint was the change in the 17-item Hamilton Depression Rating Scale score from baseline to week 8. Secondary end points were changes in the Beck Depression Inventory and the Beck Anxiety Inventory scale scores from baseline to week 8. The Systematic Assessment of Treatment Emergent Events-General Inquiry was used to assess adverse effects. RESULTS: CBM588 (60 mg/d) in combination with antidepressants (flvoxamine, paroxetine, escitalopram, duroxetine, and sertraline) provided significant improvement in depression. All patients completed the trial, and 70% responded to treatment; the remission rate was 35.0%. No serious adverse events occurred. CONCLUSIONS: These preliminary data suggest that CBM588 in combination with antidepressants is effective and well tolerated in the treatment of TRD. Further studies using a larger, double-blind, parallel-group design are warranted to confirm these findings.


Asunto(s)
Antidepresivos/uso terapéutico , Clostridium butyricum/fisiología , Trastorno Depresivo Mayor/terapia , Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológico , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Inhibidores de Captación de Serotonina y Norepinefrina/uso terapéutico , Adulto , Terapia Combinada , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/microbiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Escalas de Valoración Psiquiátrica , Resultado del Tratamiento
7.
Medicine (Baltimore) ; 95(19): e3594, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27175663

RESUMEN

Aceruloplasminemia is an autosomal recessive disorder of iron metabolism caused by mutations in the ceruloplasmin gene. Its prevalence is 1 in 2,000,000 people in Japan. This is a disorder of neurodegeneration with iron accumulation in the brain revealed by MRI. The iron overload induces oxidative stress and generation of reactive oxygen species, which triggers a cascade of pathological events that lead to neuronal death. Intravenous administration of an iron chelator, deferoxamine has been proposed as a method of inhibiting the accumulation of iron.The patient was a 46-year-old Japanese woman. She was diagnosed at the age of 33 years. Deferoxamine was administrated for 6 months but was discontinued due to adverse effects. On admission at the age of 46, psychomotor excitement was acute in onset. The extrapyramidal symptoms reflected iron deposition in the basal ganglia and substantia nigra in the midbrain. Ataxia and a wide-based gate reflected iron deposition in the dentate nuclei of the cerebellum. An antibiotic, minocycline at 150 mg/day successfully ameliorated the clinical symptoms.Minocycline, a second generation tetracycline, has a direct radical scavenging property due to its chemical structure. It has been reported that minocycline is similar to deferoxamine in its ability to chelate iron. Minocycline is also involved in preventing the upregulation of proinflammatory cytokines. The iron-chelating, antioxidant, and anti-inflammatory effects of minocycline were involved in this case.


Asunto(s)
Antibacterianos/administración & dosificación , Ceruloplasmina/deficiencia , Trastornos del Metabolismo del Hierro/tratamiento farmacológico , Minociclina/administración & dosificación , Enfermedades Neurodegenerativas/tratamiento farmacológico , Agitación Psicomotora/tratamiento farmacológico , Femenino , Humanos , Trastornos del Metabolismo del Hierro/complicaciones , Japón , Persona de Mediana Edad , Enfermedades Neurodegenerativas/complicaciones , Agitación Psicomotora/genética
8.
J Pharmacol Sci ; 100(4): 243-61, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16565579

RESUMEN

Benidipine is a dihydropyridine-derived calcium channel blocker developed in Japan, with several unique mechanisms of action, that is, triple calcium channels (L, N, and T) blocking action with a membrane approach. Benidipine has relatively high vascular selectivity and is expected to show protective effects on vascular endothelial cells. Renal protective effects of benidipine also have been shown in several basic and clinical studies. Moreover, anti-oxidative action and enhancing nitric oxide production have been noted with this drug, following its cardio-protective effects in patients with ischemic heart diseases. In fact, benidipine exerted a better prognostic effect than other calcium channel blockers in the therapy for patients with vasospastic angina. In addition, benidipine showed reliable antihypertensive, renoprotective effects if used in combination with angiotensin II type 1 receptor blockers (ARBs) when adequate anti-hypertensive effects are not achieved by ARBs alone, indicating that benidipine is an useful calcium channel blocker in combination therapy for hypertension. Benidipine was launched on the Japanese market 14 years ago, but few severe side effects have been reported, suggesting that this is a drug with established safety and long-acting pharmacological effects.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Bloqueadores de los Canales de Calcio/farmacología , Dihidropiridinas/farmacología , Vasodilatadores/farmacología , Angina de Pecho/tratamiento farmacológico , Animales , Bloqueadores de los Canales de Calcio/farmacocinética , Bloqueadores de los Canales de Calcio/uso terapéutico , Canales de Calcio Tipo L/efectos de los fármacos , Canales de Calcio Tipo N/efectos de los fármacos , Canales de Calcio Tipo T/efectos de los fármacos , Ensayos Clínicos como Asunto , Nefropatías Diabéticas/tratamiento farmacológico , Dihidropiridinas/farmacocinética , Dihidropiridinas/uso terapéutico , Evaluación Preclínica de Medicamentos , Células Endoteliales/efectos de los fármacos , Corazón/efectos de los fármacos , Humanos , Hipertensión/tratamiento farmacológico , Riñón/irrigación sanguínea , Riñón/efectos de los fármacos , Circulación Renal , Vasodilatadores/farmacocinética , Vasodilatadores/uso terapéutico
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