Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38065162

RESUMO

A diagnostic for extreme ultraviolet spectroscopy was fielded on the sheared-flow-stabilized (SFS) fusion Z-pinch experiment (FuZE-Q) for the first time. The spectrometer collected time-gated plasma emission spectra in the 5-40 nm wavelength (30-250 eV) range for impurity identification, radiative power studies, and for plasma temperature and density measurements. The unique implementation of the diagnostic included fast (10 ns risetime) pulsed high voltage electronics and a multi-stage differential pumping system that allowed the vacuum-coupled spectrometer to collect three independently timed spectra per FuZE-Q shot while also protecting sensitive internal components. Analysis of line emission identifies oxygen (N-, C-, B-, Be-, Li-, and He-like O), peaking in intensity shortly after maximum current (>500 kA). This work provides a foundation for future high energy spectroscopy experiments on SFS Z-pinch devices.

2.
Rev Sci Instrum ; 93(4): 043502, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35489931

RESUMO

Plasma density measurements are key to a wide variety of high-energy-density (HED) and laboratory astrophysics experiments. We present a creative application of photonic Doppler velocimetry (PDV) from which time- and spatially resolved electron density measurements can be made. PDV has been implemented for the first time in close proximity, ∼6 cm, to the high-intensity radiation flux produced by a z-pinch dynamic hohlraum on the Z-machine. Multiple PDV probes were incorporated into the photoionized gas cell platform. Two probes, spaced 4 mm apart, were used to assess plasma density and uniformity in the central region of the gas cell during the formation of the plasma. Electron density time histories with subnanosecond resolution were extracted from PDV measurements taken from the gas cells fielded with neon at 15 Torr. As well, a null shot with no gas fill in the cell was fielded. A major achievement was the low noise high-quality measurements made in the harsh environment produced by the mega-joules of x-ray energy emitted at the collapse of the z-pinch implosion. To evaluate time dependent radiation induced effects in the fiber optic system, two PDV noise probes were included on either side of the gas cell. The success of this alternative use of PDV demonstrates that it is a reliable, precise, and affordable new electron density diagnostic for radiation driven experiments and more generally HED experiments.

4.
Pneumologie ; 71(9): 580-586, 2017 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-28449136

RESUMO

Background and objectives Alpha-2 Macroglobulin (A2M) is a plasma protein with proteolytic effects on many proteases. In patients with an inborn alpha-1 antitrypsin deficiency (AATD) the homeostasis between proteases and antiproteases is disturbed. The aim of this study was to compare the levels of AAT and A2 M in patients and controls. We hypothesized that in patients with AATD A2 M levels are elevated. Methods Patients with AATD (polymorphism Pi*ZZ, Pi*SZ, Pi*MZ and rare gene variants) as well as healthy volunteers (Pi*MM) were tested for A2 M and AAT levels. The concentration of the proteins was measured by nephelometry. The polymorphisms Pi*Z and Pi*S were detected by polymerase chain reaction (PCR), the rare genetic variants were identified by sequencing. Results In our study, a total of 291 individuals were included. It could be shown that a significant increase in A2 M levels in the serum could be observed in the presence of a gene polymorphism (Pi*ZZ) and an alpha-1 antitrypsin serum level < 50 mg/dl compared to the healthy volunteers. Conclusions In this study, an inverse correlation between the serum levels of AAT and A2 M was found in the presence of a gene polymorphism (Pi*ZZ). Further studies are necessary to elucidate the clinical significance of increased A2 M serum levels in patients with severe AAT deficiency Pi*ZZ and rare gene variants whose AAT serum level is < 50 mg/dl.


Assuntos
alfa 2-Macroglobulinas Associadas à Gravidez/metabolismo , Deficiência de alfa 1-Antitripsina/sangue , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Variação Genética/genética , Homeostase/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/genética , Valores de Referência , alfa 1-Antitripsina/sangue , Deficiência de alfa 1-Antitripsina/genética
5.
Internist (Berl) ; 55(4): 401-14, 2014 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-24577341

RESUMO

Chronic obstructive pulmonary disease (COPD) is a very common chronic disease with increasing prevalence. Inhaled particles and gases (in particular tobacco smoke) induce chronic inflammation of the airways accompanied by a not fully reversible airflow limitation. Destruction of lung tissue and deterioration of gas exchange may follow. In parallel, several comorbidities can be observed. The COPD assessment was revised and now takes into account lung function, the patients' symptoms, and history of exacerbations. More recently, several new long-acting bronchodilators received approval. Combination products, consisting of long-acting ß2-agonists and long-acting anticholinergics, and a new combination of a long-acting ß-agonist and an inhaled corticosteroid will follow in the near future. Smoking cessation is of central importance.


Assuntos
Broncodilatadores/uso terapêutico , Aprovação de Drogas , Drogas em Investigação/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Administração por Inalação , Corticosteroides/uso terapêutico , Agonistas Adrenérgicos beta/uso terapêutico , Resistência das Vias Respiratórias/efeitos dos fármacos , Antagonistas Colinérgicos/uso terapêutico , Preparações de Ação Retardada , Combinação de Medicamentos , Alemanha , Humanos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Testes de Função Respiratória , Abandono do Hábito de Fumar
6.
Artigo em Inglês | MEDLINE | ID: mdl-11137438

RESUMO

Despite advances characterizing mammalian angiotensin receptors, the phylogeny of fish angiotensin receptors remains unclear. Three aspects of receptor function: (1) the nature of the ligand; (2) the second messenger system activated by it; and (3) the pharmacological profile of specific antagonists, are examined to provide insight into the fish receptor. (1) The octapeptide sequences of fish and mammalian angiotensin II (ANG II) are nearly homologous, differing only at the first and fifth residues. Both peptides are almost equally efficacious and equipotent in heterologous systems and both contain key agonist switches Tyr(4) and Phe(8) necessary to activate mammalian AT(1)-type receptors. (2) ANG II increases inositol trisphosphate production, and elevates intracellular calcium in fish tissues consistent with activation of the AT(1) receptor. (3) However, the specific mammalian sartan-type AT(1) antagonists, e.g. losartan, produce inconsistent results in fish often acting as partial agonists, or inhibiting only at elevated concentrations. Because sartans and ANG II act at distinct sites on the AT(1) receptor, we propose that the teleost receptor is an AT(1)-type receptor that is fairly well conserved with respect to both the ANG binding site and coupling to the second messenger system, whereas the sartan binding site has been poorly conserved. The evidence for non-AT(1) type ANG II receptors in teleosts is limited. Mammalian AT(2) receptor antagonists are generally ineffective but may block at elevated, non-specific doses. Truncated ANG II fragments, ANG III and ANG IV, are often less potent than ANG II, however, their receptors have not been examined. Preliminary studies in trout indicate that angiotensin 1-7 may have a mild vasodilatory effect; additional work is needed to determine if non-AT(1)-type receptors are involved.


Assuntos
Angiotensinas/fisiologia , Peixes/fisiologia , Receptores de Angiotensina/fisiologia , Sequência de Aminoácidos , Angiotensinas/genética , Animais , Fenômenos Fisiológicos Cardiovasculares , Sistema Nervoso Central/fisiologia , Ingestão de Líquidos/fisiologia , Peixes/genética , Brânquias/fisiologia , Humanos , Intestinos/fisiologia , Rim/fisiologia , Fígado/fisiologia , Mamíferos , Receptores de Angiotensina/classificação , Receptores de Angiotensina/genética , Homologia de Sequência , Transdução de Sinais
7.
Can Vet J ; 22(6): 189-91, 1981 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7284951

RESUMO

Serum samples were obtained from 26 beef cows with uterine prolapse and from 15 with minor dystocia (controls). The serum of animals with uterine prolapse had significantly lower calcium concentration (mean +/- S.D. = 8,22 +/- 0,69 mg/dL, P

Assuntos
Doenças dos Bovinos/etiologia , Prolapso Uterino/veterinária , Animais , Bovinos , Distocia/complicações , Distocia/veterinária , Feminino , Hipocalcemia/complicações , Hipocalcemia/veterinária , Gravidez , Prolapso Uterino/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...