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1.
Nature ; 565(7741): 581-586, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30700868

RESUMEN

Focusing laser light onto a very small target can produce the conditions for laboratory-scale nuclear fusion of hydrogen isotopes. The lack of accurate predictive models, which are essential for the design of high-performance laser-fusion experiments, is a major obstacle to achieving thermonuclear ignition. Here we report a statistical approach that was used to design and quantitatively predict the results of implosions of solid deuterium-tritium targets carried out with the 30-kilojoule OMEGA laser system, leading to tripling of the fusion yield to its highest value so far for direct-drive laser fusion. When scaled to the laser energies of the National Ignition Facility (1.9 megajoules), these targets are predicted to produce a fusion energy output of about 500 kilojoules-several times larger than the fusion yields currently achieved at that facility. This approach could guide the exploration of the vast parameter space of thermonuclear ignition conditions and enhance our understanding of laser-fusion physics.

2.
Phys Rev Lett ; 128(19): 195002, 2022 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-35622051

RESUMEN

This Letter presents the first observation on how a strong, 500 kG, externally applied B field increases the mode-two asymmetry in shock-heated inertial fusion implosions. Using a direct-drive implosion with polar illumination and imposed field, we observed that magnetization produces a significant increase in the implosion oblateness (a 2.5× larger P2 amplitude in x-ray self-emission images) compared with reference experiments with identical drive but with no field applied. The implosions produce strongly magnetized electrons (ω_{e}τ_{e}≫1) and ions (ω_{i}τ_{i}>1) that, as shown using simulations, restrict the cross field heat flow necessary for lateral distribution of the laser and shock heating from the implosion pole to the waist, causing the enhanced mode-two shape.

3.
Clin Exp Dermatol ; 47(1): 158-161, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34291468

RESUMEN

Two novel methods of measuring the dimensions of oral lesions are described, which would be of help in deciding relative efficacies of different therapeutic agents when used in clinical trials after larger studies quantitatively assessed for inter/intraobserver variability.


Asunto(s)
Dermatología/métodos , Úlceras Bucales/patología , Colorantes , Humanos , Liquen Plano/patología , Variaciones Dependientes del Observador , Papel , Penfigoide Ampolloso/patología , Pénfigo/patología , Reproducibilidad de los Resultados , Jeringas
4.
J Synchrotron Radiat ; 28(Pt 2): 480-489, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33650560

RESUMEN

The germanium auto-diffusion effects on the inter-atomic distance between the nearest neighbors of the Ga atom in GaP epilayers are investigated using high-resolution X-ray diffraction (HRXRD) and X-ray absorption spectroscopy. The GaP layers grown on Ge (111) are structurally coherent and relaxed but they show the presence of residual strain which is attributed to the auto-diffusion of Ge from the results of secondary ion mass spectrometry and electrochemical capacitance voltage measurements. Subsequently, the inter-atomic distances between the nearest neighbors of Ga atom in GaP are determined from X-ray absorption fine-structure spectra performed at the Ga K-edge. The estimated local bond lengths of Ga with its first and second nearest neighbors show asymmetric variation for the in-plane and out-of-plane direction of GaP/Ge(111). The magnitude and direction of in-plane and out-of-plane microscopic residual strain present in the GaP/Ge are calculated from the difference in bond lengths which explains the presence of macroscopic residual tensile strain estimated from HRXRD. Modified nearest neighbor configurations of Ga in the auto-diffused GaP epilayer are proposed for new possibilities within the GaP/Ge hetero-structure, such as the conversion from indirect to direct band structures and engineering the tensile strain quantum dot structures on (111) surfaces.

5.
Public Health Nutr ; 24(9): 2592-2602, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32611463

RESUMEN

OBJECTIVE: To estimate the total energy and micronutrient intakes of children 9-24 months of age and evaluate the probability of adequacy (PA) of the diet in seven MAL-ED sites. DESIGN: Cohort study. Food intake was registered monthly using 24-h recalls beginning at 9 months. We estimated PA for thirteen nutrients and overall mean PA (MPA) by site and 3-month periods considering estimated breast milk intake. SETTING: Seven sites in Asia, Africa and Latin America. PARTICIPANTS: 1669 children followed from birth to 24 months of age. RESULTS: Median estimated %energy from breast milk ranged from 4 to 70 % at 9-12 months, and declined to 0-39 % at 21-24 months. Iron bioavailability was low for all sites, but many diets were of moderate bioavailability for zinc. PA was optimal for most nutrients in Brazil and South Africa, except for iron and vitamin E (both), calcium and zinc (South Africa). PA for zinc increased only for children consuming a diet with moderate bioavailability. MPA increased 12-24 months as the quantity of complementary foods increased; however, PA for vitamin A remained low in Bangladesh and Tanzania. PA for vitamins D and E and iron was low for most sites and age groups. CONCLUSIONS: MPA increased from 12 to 24 months as children consumed higher quantities of food, while nutrient density remained constant for most nutrients. Ways to increase the consumption of foods containing vitamins D, E and A, and calcium are needed, as are ways to increase the bioavailability of iron and zinc.


Asunto(s)
Dieta , Micronutrientes , Niño , Estudios de Cohortes , Ingestión de Alimentos , Femenino , Humanos , Lactante , Nutrientes , Probabilidad , Sudáfrica
6.
Phys Rev Lett ; 122(3): 035001, 2019 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-30735406

RESUMEN

Fuel-ion species dynamics in hydrodynamiclike shock-driven DT^{3}He-filled inertial confinement fusion implosion is quantitatively assessed for the first time using simultaneously measured D^{3}He and DT reaction histories. These reaction histories are measured with the particle x-ray temporal diagnostic, which captures the relative timing between different nuclear burns with unprecedented precision (∼10 ps). The observed 50±10 ps earlier D^{3}He reaction history timing (relative to DT) cannot be explained by average-ion hydrodynamic simulations and is attributed to fuel-ion species separation between the D, T, and ^{3}He ions during shock convergence and rebound. At the onset of the shock burn, inferred ^{3}He/T fuel ratio in the burn region using the measured reaction histories is much higher as compared to the initial gas-filled ratio. As T and ^{3}He have the same mass but different charge, these results indicate that the charge-to-mass ratio plays an important role in driving fuel-ion species separation during strong shock propagation even for these hydrodynamiclike plasmas.

7.
Phys Rev Lett ; 119(19): 195001, 2017 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-29219482

RESUMEN

It is shown that inertial confinement fusion targets designed with low implosion velocities can be shock-ignited using laser-plasma interaction generated hot electrons (hot-e's) to obtain high energy gains. These designs are robust to multimode asymmetries and are predicted to ignite even for significantly distorted implosions. Electron shock ignition requires tens of kilojoules of hot-e's which can be produced only at a large laser facility like the National Ignition Facility, with the laser-to-hot-e conversion efficiency greater than 10% at laser intensities ∼10^{16} W/cm^{2}.

8.
J Nanosci Nanotechnol ; 17(2): 1178-184, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29679956

RESUMEN

Citrate based sol­gel method is used to synthesize Gd2O3:RE³âº and GdAlO3:RE³âº (RE = Eu, Dy) phosphors. In the present work, the phosphors are characterized using the techniques like X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). Fluorescence confocal microscopy reveals the potential usage of phosphors in biological medium for biolabeling application. XRD patterns confirm the phase purity of Gd2O3 and GdAlO3. The crystallite size and lattice parameters are estimated from XRD result. FTIR spectra are used to investigate the functional group present in the phosphor. The optical emission properties imply that the emission peak positions on Eu³âº or Dy³âº ion are size and host independent. Finally, RAW 264.7 macrophages cell line is used to test the bioimaging performance of the phosphors.

9.
J Fish Biol ; 90(1): 311-325, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27804136

RESUMEN

In this study, the morphology of sagittal otoliths of the plainfin midshipman fish Porichthys notatus was compared between populations, sexes and male alternative reproductive phenotypes (known as 'type I males or guarders' and 'type II males or sneakers'). Sagitta size increased with P. notatus size and changes in shape were also detected with increasing body size. Porichthys notatus sagittae begin as simple rounded structures, but then elongate as they grow and take on a more triangular and complex shape with several prominent notches and indentations along the dorsal and caudal edges. Moreover, the sagittae of the two geographically and genetically distinct populations of P. notatus (northern and southern) differed in shape. Porichthys notatus from the north possessed taller sagittae with deeper caudal indentations compared to P. notatus from the south. Sagitta shape also differed between females and males of the conventional guarder tactic. Furthermore, guarder males had smaller sagittae for their body size than did sneaker males or females. These differences in sagittal otolith morphology are discussed in relation to ecological and life history differences between the sexes and male tactics of this species. This is the first study to investigate teleost otolith morphology from the perspective of alternative reproductive tactics.


Asunto(s)
Comunicación Animal , Batrachoidiformes/anatomía & histología , Membrana Otolítica/anatomía & histología , Conducta Sexual Animal , Animales , Batrachoidiformes/fisiología , Femenino , Masculino , Membrana Otolítica/fisiología , Factores Sexuales
11.
Phys Rev Lett ; 117(2): 025001, 2016 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-27447511

RESUMEN

A record fuel hot-spot pressure P_{hs}=56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium-tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility, these implosions achieved a Lawson parameter ∼60% of the value required for ignition [A. Bose et al., Phys. Rev. E 93, 011201(R) (2016)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is approximately 40% lower. Three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

12.
Phys Chem Chem Phys ; 18(47): 32057-32071, 2016 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-27805186

RESUMEN

An optical-fiber based evanescent ammonia vapor sensor was constructed with surface-passivated growth of zinc oxide (ZnO) nanostructures, which was achieved through a three-step wet chemical process. Initially, the ZnO nanostructures were synthesized using a wet-chemical method and subsequently surface-passivated with chalcogenide material compounds namely cadmium sulphide (CdS) and cadmium selenide (CdSe) nanoparticles individually using a citric acid assisted chemical synthesis technique. Finally, surface-passivated ZnO was deposited on the cladding modified optical-fiber using a dip coating process. X-ray diffraction (XRD), tunneling electron microscopy (TEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) analyses confirmed the growth of CdS and CdSe nanoparticles on the surface of ZnO nanoparticles. The atomic composition and the full width at half maximum (FWHM) of the oxygen O 1s oxidation state represented in the X-ray photoelectron spectra were lower and narrower for ZC2 nanostructures implying that the available surface oxygen had reacted well and promoted the uniform shell-like growth of CdSe nanoparticles on the ZnO. The significance of the surface-passivated ZnO was realized from UV-Vis diffuse reflectance spectroscopy (DRS) and a photo-luminescence (PL) study and was implemented in a room temperature optical-fiber based evanescent ammonia vapor sensor. The nano-sized CdS particles decorated on the surface of ZnO demonstrate a high vapor sensing behavior. The sensing enhancement was nearly 3 times larger than the core-shell like ZnO/CdSe (ZC2) nanostructures and was attributed to the effective interaction of the incident light and the sensing media, the change in the refractive index of the modified cladding regime, the rate of vapor adsorption and the effective charge-carrier transport between the so-formed hetero-junction interfaces. The ZC2 shows insignificant ammonia vapor adsorption and sensing due to decreased free carrier density produced within the ZnO host lattice and an increased potential barrier width between the ZnO/CdSe hetero-structures.

13.
Phys Rev Lett ; 114(25): 255003, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-26197131

RESUMEN

Estimating the level of alpha heating and determining the onset of the burning plasma regime is essential to finding the path towards thermonuclear ignition. In a burning plasma, the alpha heating exceeds the external input energy to the plasma. Using a simple model of the implosion, it is shown that a general relation can be derived, connecting the burning plasma regime to the yield enhancement due to alpha heating and to experimentally measurable parameters such as the Lawson ignition parameter. A general alpha-heating curve is found, independent of the target and suitable to assess the performance of all laser fusion experiments whether direct or indirect drive. The onset of the burning plasma regime inside the hot spot of current implosions on the National Ignition Facility requires a fusion yield of about 50 kJ.

14.
Mymensingh Med J ; 24(2): 416-9, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26007277

RESUMEN

Primary hypothyroidism is a common clinical condition but ascites caused by hypothyroidism is rare. Concurrent exudative ascites with heart failure even rarer. So its diagnosis is often delayed and patients frequently receive unnecessary procedures such as liver biopsies and exploratory laparotomies. We report a male person of 55 years with hypothyroidism with ascites and heart failure who responded well with thyroid hormone replacement therapy with complete resolution of ascites. Analyses of ascites from patients in this condition usually shows exudative ascites with high protein (>2.5gm/dl) and SAAG <1.1gm/dl. High index of suspicion is required to reach at such diagnosis. Though it is a rare but prognosis is excellent with replacement therapy.


Asunto(s)
Insuficiencia Cardíaca , Hipotiroidismo , Ascitis , Biopsia , Humanos , Masculino , Persona de Mediana Edad , Pronóstico
15.
Phys Chem Chem Phys ; 15(35): 14761-9, 2013 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-23903020

RESUMEN

A detailed study on visible light photocatalytic degradation of methylene blue (MB) has been investigated in aqueous heterogeneous media containing hexagonal phase molybdenum oxide (h-MoO3) nanocrystals (NCs) which was identified as a new material for visible light driven photocatalysis. A simple and template-free solution based chemical precipitation method was employed to synthesize h-MoO3 NCs by reacting ammonium heptamolybdate tetrahydrate (AHM) with nitric acid. The formation and growth mechanism of h-MoO3 microstructures was explained. In addition, by annealing the h-MoO3 sample, the phase stability of hexagonal was retained up to 410 °C and showed an irreversible phase transition from hexagonal (h-MoO3) to highly stable orthorhombic phase (α-MoO3). Finally, the photocatalytic activities of h-MoO3 and α-MoO3 samples were evaluated using the degradation of MB, representing an organic pollutant of dye wastewater. The effects of various experimental parameters such as catalyst loading, initial dye concentration, light intensity, and operating temperature were analyzed for the degradation of MB. The results demonstrated that the efficiency of visible light assisted MB degradation using h-MoO3 NCs can be effectively enhanced by catalyst loading, light intensity, and operating temperature. However, the efficiency declined with the increase in initial dye concentration. Optimum conditions for higher photocatalytic performance were recognized as a catalyst loading of 100 mg L(-1), a dye concentration of 12 mg L(-1), a light intensity of 350 mW cm(-2), and an operating temperature of 45 °C.


Asunto(s)
Azul de Metileno/aislamiento & purificación , Molibdeno/química , Nanopartículas/química , Óxidos/química , Fotólisis , Aguas Residuales/análisis , Contaminantes Químicos del Agua/aislamiento & purificación , Catálisis , Luz , Purificación del Agua/métodos
16.
Antimicrob Agents Chemother ; 56(10): 5149-56, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22825118

RESUMEN

Type III phosphatidylinositol-4-kinase beta (PI4KIIIß) was previously implicated in hepatitis C virus (HCV) replication by small interfering RNA (siRNA) depletion and was therefore proposed as a novel cellular target for the treatment of hepatitis C. Medicinal chemistry efforts identified highly selective PI4KIIIß inhibitors that potently inhibited the replication of genotype 1a and 1b HCV replicons and genotype 2a virus in vitro. Replicon cells required more than 5 weeks to reach low levels of 3- to 5-fold resistance, suggesting a high resistance barrier to these cellular targets. Extensive in vitro profiling of the compounds revealed a role of PI4KIIIß in lymphocyte proliferation. Previously proposed functions of PI4KIIIß in insulin secretion and the regulation of several ion channels were not perturbed with these inhibitors. Moreover, PI4KIIIß inhibitors were not generally cytotoxic as demonstrated across hundreds of cell lines and primary cells. However, an unexpected antiproliferative effect in lymphocytes precluded their further development for the treatment of hepatitis C.


Asunto(s)
1-Fosfatidilinositol 4-Quinasa/antagonistas & inhibidores , Antivirales/farmacología , Hepacivirus/efectos de los fármacos , Animales , Antivirales/efectos adversos , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Humanos , Masculino , Ratones , Ratas , Ratas Sprague-Dawley
17.
J Nanosci Nanotechnol ; 12(1): 75-83, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22523948

RESUMEN

In this report, hydrothermal synthesis and the absorption properties of the cubic shaped zinc oxide nanostructures doped with different amount of yttrium (Y) metal cation (0 to 15 at.%) are demonstrated. The structural and optical properties of chemically synthesized pure and Y doped ZnO powders are investigated by using powder X-ray diffraction (XRD), field emission scanning electron spectroscopy (FESEM) and transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorbance, photoluminescence (PL), and Fourier transform infra-red spectroscopy (FT-IR). It is found that the dopant ions stabilize in wurtzite hexagonal phase of ZnO upto the concentration of less than 6 at.%, which is mainly due to the fact that the ZnO lattice expands and the optical bandgap energy decreases at this level. Increasing the dopant concentration to greater than 6 at.% leads to a contraction of the lattice, which in turn produces a significant structural disorder evidenced by shift in the XRD peaks due to additional interstitial incorporation of Y. The vibrational modes of the metal oxide groups have been identified from the IR transmission spectra. The optical absorption results show that the optical bandgap energy of Y:ZnO nanocrystals is much less as compared to that of the pure bulk ZnO particles. Doping ZnO with trivalent Y produces excess number of electrons in the conduction band and thus, shifts the absorption edge and narrows down to 80 meV approximately. PL spectra are used to study the dependence of doping on the deep-level emission, which show an enhanced blue emission after Y doping. The existence of near band edge (NBE) emission and blue emission, related to zinc interstitials are observed in the luminescence spectra of Zn(1-x)Y(x)O nanostructures.


Asunto(s)
Cristalización/métodos , Nanoestructuras/química , Nanoestructuras/ultraestructura , Óxido de Zinc/química , Conductividad Eléctrica , Ensayo de Materiales , Tamaño de la Partícula , Refractometría , Propiedades de Superficie
18.
Plant Biol (Stuttg) ; 24(7): 1146-1156, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34939277

RESUMEN

By killing or weakening trees, drought could change the partitioning of growth between tree sizes or species, thereby altering stand structure. Growth partitioning, often quantified using the growth dominance coefficient (DC) or the shape of tree size versus growth relationships (SGR), indicates the relative contribution of differently sized trees to the total stand growth. Changes in growth partitioning due to droughts are rarely examined but provide valuable information that links tree- and stand-level responses to droughts. The objective of this study was to test whether the 2018 European megadrought altered the growth partitioning among tree sizes and species. For this purpose, we first evaluated whether DC or SGR can be calculated from small sample sizes of trees typical of individual forest inventory plots. DC, and particularly SGR, were sensitive to sample size, forest type (even-aged and uneven-aged), target variable (tree diameter, basal area or stem mass) and range of tree sizes within the sample. SGR could therefore not be used for our analyses. We found no differences in DC prior to and during the 2018 drought. However, when considering only beech (Fagus sylvatica)-dominated stands, DC was lower during post-drought years than during the 2018 drought. The growth of larger trees, especially beech, was more negatively affected during post-drought years. Therefore, an extreme drought event can indeed alter the growth partitioning within forest stands. The DC indicates such changes in partitioning and, hence, which trees can be selected for commercial thinning, or released from competition, to minimize potential impacts of droughts.


Asunto(s)
Fagus , Árboles , Suiza , Sequías , Bosques , Cambio Climático
19.
J Tradit Complement Med ; 11(3): 228-237, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34012869

RESUMEN

BACKGROUND AND AIM: Balarista is a fermented ayurvedic liquid preparation recommended as a good therapy for the treatment of rheumatoid arthritis. In the present investigation, the anti-arthritic activity of in-house Balarista formulation and marketed M1, M2, M3 and M4 Balarista formulations at the dose of 2.31 ml/kg were studied on Complete Freund's adjuvant-induced arthritic rat model. EXPERIMENTAL PROCEDURE: Measurement of paw diameter, arthritic index, arthritic score, and body weight were made to assess the anti-arthritic activity. Alterations in hematological and biochemical parameters were carried out to ascertain the disease progression. The inflammatory mediators (TNF-α, IL-1ß, and IL-6) were measured by the ELISA method. The oxidative stress parameters were evaluated in tissues of joint, liver, spleen and kidney. The histological and radiological changes in the ankle joint of rats were also studied. RESULTS AND CONCLUSION: Administration of in-house and marketed formulations exhibited significant anti-arthritic activity by reducing all the arthritic parameters. The anomalous alterations in hematological and biochemical parameters were remarkably restored. The expression level of serum pro-inflammatory cytokines was significantly suppressed in treated animals. The oxidative stress, indicated by an increase in lipid peroxidation, decreased in antioxidant enzyme i.e. superoxide dismutase and catalase along with non-enzymatic reduced glutathione in tissues, were strongly counteracted by the formulation. Abnormal changes in arthritic ankle joints shown by X-ray and histological examination were significantly protected by the formulation. The present study suggests that the administration of in-house and marketed Balarista formulations have produced a significant anti-arthritic effect by inhibiting free radicals and inflammatory cytokines.

20.
Rev Sci Instrum ; 92(6): 063502, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243553

RESUMEN

We report on the design and implementation of a new system used to characterize the energy-dependent x-ray transmission curve, Θ(E), through filters used in high-energy density physics diagnostics. Using an Amptek X-123-CdTe x-ray spectrometer together with a partially depleted silicon surface barrier detector, both the energy spectrum and total emission of an x-ray source have been accurately measured. By coupling these detectors with a custom PROTO-XRD x-ray source with interchangeable cathodes, accurate characterizations of Θ(E) for filters of varying materials and thicknesses have been obtained. The validity of the technique has been confirmed by accurately reproducing areal densities for high-purity filters with known x-ray transmission properties. In this paper, the experimental setup is described and the results of absorption calibrations performed on a variety of different filters are presented.

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