RESUMEN
In situ femtosecond x-ray diffraction measurements and ab initio molecular dynamics simulations were performed to study the liquid structure of tantalum shock released from several hundred gigapascals (GPa) on the nanosecond timescale. The results show that the internal negative pressure applied to the liquid tantalum reached -5.6 (0.8) GPa, suggesting the existence of a liquid-gas mixing state due to cavitation. This is the first direct evidence to prove the classical nucleation theory which predicts that liquids with high surface tension can support GPa regime tensile stress.
RESUMEN
Pressure, density, and temperature data for H2O were obtained up to 260 GPa by using laser-driven shock compression technique. The shock compression technique combined with the diamond anvil cell was used to assess the equation of state models for the P-ρ-T conditions for both the principal Hugoniot and the off-Hugoniot states. The contrast between the models allowed for a clear assessment of the equation of state models. Our P-ρ-T data totally agree with those of the model based on quantum molecular dynamics calculations. These facts indicate that this model is adopted as the standard for modeling interior structures of Neptune, Uranus, and exoplanets in the liquid phase in the multi-Mbar range.
RESUMEN
Water, methane, and ammonia are commonly considered to be the key components of the interiors of Uranus and Neptune. Modelling the planets' internal structure, evolution, and dynamo heavily relies on the properties of the complex mixtures with uncertain exact composition in their deep interiors. Therefore, characterising icy mixtures with varying composition at planetary conditions of several hundred gigapascal and a few thousand Kelvin is crucial to improve our understanding of the ice giants. In this work, pure water, a water-ethanol mixture, and a water-ethanol-ammonia "synthetic planetary mixture" (SPM) have been compressed through laser-driven decaying shocks along their principal Hugoniot curves up to 270, 280, and 260 GPa, respectively. Measured temperatures spanned from 4000 to 25000 K, just above the coldest predicted adiabatic Uranus and Neptune profiles (3000-4000 K) but more similar to those predicted by more recent models including a thermal boundary layer (7000-14000 K). The experiments were performed at the GEKKO XII and LULI2000 laser facilities using standard optical diagnostics (Doppler velocimetry and optical pyrometry) to measure the thermodynamic state and the shock-front reflectivity at two different wavelengths. The results show that water and the mixtures undergo a similar compression path under single shock loading in agreement with Density Functional Theory Molecular Dynamics (DFT-MD) calculations using the Linear Mixing Approximation (LMA). On the contrary, their shock-front reflectivities behave differently by what concerns both the onset pressures and the saturation values, with possible impact on planetary dynamos.
RESUMEN
We measured the dihydropyrimidine dehydrogenase (DPD) activity considered to regulate the sensitivity of pyrimidine fluoride anti-cancer drugs in 50 cases of urothelial cancer (preoperative therapy group 10 cases, non-therapy group 40 cases). The association of DPD activity with pathological factors and TS activity as well as the influence of UFT oral administration on the DPD activity in tumors and blood were studied. The DPD activity in cancer tissue tended to be higher than that in the mucous membranes of the non-tumor region, but the difference was not significant. The DPD activity was high in infiltrative cancer (p < 0.05) but was not associated with atypia. The TS activity and DPD activity were manifested independently. The DPD activity in cancer tissue was significantly higher after UFT administration, with levels of 76.7 +/- 71.0 pmol/mg/min before administration and 220.6 +/- 129.1 pmol/mg/min after (p < 0.05). The DPD activity in peripheral blood was elevated after administration, but no significant difference was found. Since DPD activity is found in urothelial cancer tissue, 5-FU stable to DPD should preferably be used. It is also suggested that using a more potent DPD inhibitor in combination will produce higher anti-tumor effects.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Oxidorreductasas/metabolismo , Neoplasias Urológicas/enzimología , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Dihidrouracilo Deshidrogenasa (NADP) , Femenino , Humanos , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/enzimología , Masculino , Persona de Mediana Edad , Oxidorreductasas/efectos de los fármacos , Tegafur/administración & dosificación , Uracilo/administración & dosificación , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/enzimología , Neoplasias Urológicas/tratamiento farmacológicoRESUMEN
Because of dissolution of lighter elements such as sulfur, carbon, hydrogen, and oxygen, Earth's outer core is about 10 percent less dense than molten iron at the relevant pressure and temperature conditions. To determine whether hydrogen can account for a major part of the density deficit and is therefore an important constituent in the molten iron outer core, the hydrogen concentration in molten iron was measured at 7.5 gigapascals. From these measurements, the metal-silicate melt partitioning coefficient of hydrogen was determined as a function of temperature. If the magma ocean of primordial Earth was hydrous, more than 95 mole percent of H2O in this ocean should have reacted with iron to form FeHx, and about 60 percent of the density deficit is reconciled by adding hydrogen to the core.
RESUMEN
Affinity-purified autoantibodies against nuclear ribonucleoprotein (nRNP) antigens were applied to fresh-frozen sections of benign tumors, carcinomas in situ, and carcinomas of the human skin. Using indirect immunofluorescence, the benign lesions showed speckled nuclear staining as seen in the normal epidermis. Invasive tumors such as basal cell epitheliomas and squamous cell carcinomas, in contrast, lacked immunoreactivity for nRNP antigens. Recently, ribonucleoprotein complexes defined by nRNP antigens have been postulated to be involved in the excision of intervening sequences of premessenger ribonucleic acids (RNAs). Our findings provide useful information for the understanding of the pathophysiology of human skin cancers.
Asunto(s)
ARN/metabolismo , Neoplasias Cutáneas/metabolismo , Reacciones Antígeno-Anticuerpo , Autoanticuerpos/inmunología , Núcleo Celular/metabolismo , Técnica del Anticuerpo Fluorescente , Humanos , Inmunoelectroforesis , ARN/inmunologíaRESUMEN
Skin eruptions with features of subacute cutaneous lupus erythematosus occurred in a patient with dermatomyositis who was taking griseofulvin. The patient had antibodies against SSA/Ro and SSB/La antigens. Skin rashes disappeared after discontinuation of griseofulvin and recurred on challenge with the drug. These findings support previous studies that the photoactive drug may be synergistic with anti-SSA/Ro antibody to produce lesions of subacute cutaneous lupus erythematosus.
Asunto(s)
Dermatomiositis/tratamiento farmacológico , Erupciones por Medicamentos/etiología , Griseofulvina/efectos adversos , Lupus Eritematoso Cutáneo/inducido químicamente , Adulto , Biopsia , Dermatomiositis/diagnóstico , Erupciones por Medicamentos/patología , Femenino , Griseofulvina/administración & dosificación , Griseofulvina/uso terapéutico , Humanos , Queratinas , Lupus Eritematoso Cutáneo/inmunología , Piel/patologíaRESUMEN
A 72-year-old woman developed a lichen planus pemphigoides-like eruption following the administration of cinnarizine. The eruption recurred on challenge with the drug. Direct immunofluorescence studies of the lesions demonstrated deposition of IgG, IgM and C3 on colloid bodies and fibrin at the epidermal basement membrane zone. Circulating IgG antibasement membrane zone antibodies were detected at high titres, with no complement-fixing activities. To our knowledge, this is the first report of immunologically defined lichen planus pemphigoides induced by a drug.
Asunto(s)
Cinarizina/efectos adversos , Liquen Plano/inducido químicamente , Piperazinas/efectos adversos , Enfermedades Cutáneas Vesiculoampollosas/inducido químicamente , Anciano , Femenino , Humanos , Liquen Plano/inmunología , Liquen Plano/patología , Piel/inmunología , Piel/patología , Enfermedades Cutáneas Vesiculoampollosas/inmunología , Enfermedades Cutáneas Vesiculoampollosas/patologíaRESUMEN
Rifampicin therapy caused exacerbation of skin lesions, rising serum pemphigus antibody titres, and decreased serum betamethasone levels in a 59-year-old man with pemphigus vulgaris. Exacerbation of pemphigus was confined to the period of rifampicin therapy and seems to be best explained by the effect of rifampicin on the metabolism of betamethasone. Physicians prescribing rifampicin for the treatment of tuberculosis should be aware of its potential to produce such an important adverse reaction.
Asunto(s)
Betametasona/antagonistas & inhibidores , Pénfigo/inducido químicamente , Rifampin/efectos adversos , Betametasona/sangre , Betametasona/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Pénfigo/sangre , Pénfigo/tratamiento farmacológico , Tuberculosis Pulmonar/tratamiento farmacológicoRESUMEN
Systemic sclerosis-like lesions developed in a 14-year-old boy with Wilson's disease who had been treated with D-penicillamine for 11 years. Clinical and laboratory manifestations included proximal scleroderma, pulmonary restrictive defects, positive antinuclear antibodies, and the deposition of C3 at the dermal-epidermal junction of the lesional skin. This is the first case reported in which long-term administration of penicillamine was followed by the development of systemic sclerosis-like lesions.
Asunto(s)
Degeneración Hepatolenticular/tratamiento farmacológico , Penicilamina/efectos adversos , Esclerodermia Sistémica/inducido químicamente , Adolescente , Degeneración Hepatolenticular/patología , Humanos , Masculino , Penicilamina/uso terapéutico , Esclerodermia Sistémica/patologíaRESUMEN
Immunopathologic studies of a patient with clinical and histologic evidence of erythema dyschromicum perstans revealed Ia antigen expression on epidermal keratinocytes, pronounced OKT4 and OKT6 staining of epidermal dendritic cells, and dermal infiltration of T lymphocytes of both helper-inducer (OKT4) and suppressor-cytotoxic (OKT8) phenotypes--a pattern commonly associated with lichen planus. These findings, taken in conjunction with positive IgG staining on colloid bodies, suggest the possibility that erythema dyschromicum perstans and lichen planus have similar disease processes.