Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Opt Lett ; 48(17): 4528-4531, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37656545

RESUMO

For the first time, to the best of our knowledge, we demonstrate highly transient, multiwavelength, single-pass Raman generation with combined frequency shifts on two Raman modes of an SrMoO4 crystal with high total Raman conversion efficiency of up to 48% in conditions of competition with self-phase modulation (SPM). A 58-mm-long SrMoO4 crystal was used as the active medium under pumping by the 1030-nm, 40-µJ laser pulses with controllable dispersive stretching in a range of 0.25-6 ps at negative and positive chirping. The pump pulse chirping was optimized for both high- and low-frequency Raman shifts on the primary (888 cm-1) and secondary (327 cm-1) Raman modes of the crystal. At the optimal conditions, four Stokes components of stimulated Raman scattering (SRS) radiation with high- and low-frequency Raman shifts at the wavelengths of 1066, 1134, 1177, and 1261 nm were efficiently generated.

2.
PLoS Genet ; 9(7): e1003612, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23874215

RESUMO

KLF3 is a Krüppel family zinc finger transcription factor with widespread tissue expression and no previously known role in heart development. In a screen for dominant mutations affecting cardiovascular function in N-ethyl-N-nitrosourea (ENU) mutagenized mice, we identified a missense mutation in the Klf3 gene that caused aortic valvular stenosis and partially penetrant perinatal lethality in heterozygotes. All homozygotes died as embryos. In the first of three zinc fingers, a point mutation changed a highly conserved histidine at amino acid 275 to arginine (Klf3(H275R) ). This change impaired binding of the mutant protein to KLF3's canonical DNA binding sequence. Heterozygous Klf3(H275R) mutants that died as neonates had marked biventricular cardiac hypertrophy with diminished cardiac chambers. Adult survivors exhibited hypotension, cardiac hypertrophy with enlarged cardiac chambers, and aortic valvular stenosis. A dominant negative effect on protein function was inferred by the similarity in phenotype between heterozygous Klf3(H275R) mutants and homozygous Klf3 null mice. However, the existence of divergent traits suggested the involvement of additional interactions. We conclude that KLF3 plays diverse and important roles in cardiovascular development and function in mice, and that amino acid 275 is critical for normal KLF3 protein function. Future exploration of the KLF3 pathway provides a new avenue for investigating causative factors contributing to cardiovascular disorders in humans.


Assuntos
Estenose da Valva Aórtica/genética , Doenças Cardiovasculares/genética , Fatores de Transcrição Kruppel-Like/genética , Mutação de Sentido Incorreto , Animais , Estenose da Valva Aórtica/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Proteínas de Ligação a DNA , Etilnitrosoureia/química , Humanos , Fatores de Transcrição Kruppel-Like/química , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Motivos de Nucleotídeos/genética
3.
Biol Trace Elem Res ; 181(1): 1-9, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28444499

RESUMO

The objective of the present study was to perform comparative analysis of hair trace element content in women with natural and in vitro fertilization (IVF)-induced pregnancy. Hair trace element content in 33 women with IVF-induced pregnancy and 99 age- and body mass index-matched control pregnant women (natural pregnancy) was assessed using inductively coupled plasma mass spectrometry. The results demonstrated that IVF-pregnant women are characterized by significantly lower hair levels of Cu, Fe, Si, Zn, Ca, Mg, and Ba at p < 0.05 or lower. Comparison of the individual levels with the national reference values demonstrated higher incidence of Fe and Cu deficiency in IVF-pregnant women in comparison to that of the controls. IVF pregnancy was also associated with higher hair As levels (p < 0.05). Multiple regression analysis revealed a significant interrelation between IVF pregnancy and hair Cu, Fe, Si, and As content. Hair Cu levels were also influenced by vitamin/mineral supplementation and the number of pregnancies, whereas hair Zn content was dependent on prepregnancy anthropometric parameters. In turn, planning of pregnancy had a significant impact on Mg levels in scalp hair. Generally, the obtained data demonstrate an elevated risk of copper, iron, zinc, calcium, and magnesium deficiency and arsenic overload in women with IVF-induced pregnancy. The obtained data indicate the necessity of regular monitoring of micronutrient status in IVF-pregnant women in order to prevent potential deleterious effects of altered mineral homeostasis.


Assuntos
Fertilização in vitro , Cabelo/química , Oligoelementos/análise , Adulto , Eletrólitos/análise , Feminino , Humanos , Gravidez
4.
Acta Sci Pol Technol Aliment ; 17(1): 83-89, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29514427

RESUMO

BACKGROUND: Trace elements play a significant role in the regulation of human reproduction, while advanced age may have a significant impact on trace element metabolism. The objective of the present study was to assess the impact of lifestyle factors on age-related differences in hair trace element content in pregnant women in the third trimester. METHODS: A total of 124 pregnant women aged 20–29 (n = 72) and 30–39 (n = 52) were ex- amined. Scalp hair trace element content was assessed using inductively coupled plasma mass spectrometry at NexION 300D (Perkin Elmer, USA) after microwave digestion. RESULTS: The results showed that the elder pregnant women had 36% (p = 0.009), 14% (p = 0.045), and 45% (p = 0.044) lower hair Zn, V, and Cd content, and 16% (p = 0.044) higher hair B levels – in comparison to the respective younger group values. Multiple regression analysis demonstrated that the age of the women had a significant influence on hair V and Zn levels. B content was also significantly influenced by age at first intercourse, smoking status, and specific dietary habits. None of the lifestyle factors were associated with hair Cd content in pregnant women. Hair V levels were also affected by following a special diet. Interestingly, alcohol intake did not have a significant impact on hair trace element content. CONCLUSIONS: These data indicate that lifestyle factors have a significant influence on age-related changes in hair trace elements during pregnancy that may impact the outcome of pregnancy.


Assuntos
Fatores Etários , Cabelo/química , Estilo de Vida , Terceiro Trimestre da Gravidez , Oligoelementos/análise , Adulto , Feminino , Humanos , Gravidez , Fatores Socioeconômicos , Adulto Jovem
5.
Clin Interv Aging ; 12: 343-349, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28260868

RESUMO

BACKGROUND: Delirium, a common problem among hospitalized elderly patients, is not usually diagnosed by doctors for various reasons. The primary aim of this study was to evaluate the effect of a short training course on the identification of delirium and the diagnostic rate of delirium among hospitalized patients aged ≥65 years. The secondary aim was to identify the risk factors for delirium. METHODS: A prospective study was conducted in an acute-care hospital in Moscow, Russia. Six doctors underwent a short training course on delirium. Data collected included assessment by the confusion assessment method for the intensive care units, sociodemographic data, functional state before hospitalization, comorbidity, and hospitalization indices (indication for hospitalization, stay in intensive care unit, results of laboratory tests, length of hospitalization, and in-hospital mortality). RESULTS: Delirium was diagnosed in 13 of 181 patients (7.2%) who underwent assessment. Cognitive impairment was diagnosed more among patients with delirium (30.0% vs 6.1%, P=0.029); Charlson comorbidity index was higher (3.6±2.4 vs 2.3±1.8, P=0.013); and Barthel index was lower (43.5±34.5 vs 94.1±17.0, P=0.000). The length of hospitalization was longer for patients with delirium at 13.9±7.3 vs 8.8±4.6 days (P=0.0001), and two of the 13 patients with delirium died during hospitalization compared with none of the 168 patients without delirium (P=0.0001). CONCLUSION: Although the rate of delirium was relatively low compared with studies from the West, this study proves that an educational intervention among doctors can bring about a significant change in the diagnosis of the condition.


Assuntos
Delírio/diagnóstico , Delírio/epidemiologia , Hospitalização/estatística & dados numéricos , Unidades de Terapia Intensiva/organização & administração , Unidades de Terapia Intensiva/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Comorbidade , Feminino , Nível de Saúde , Mortalidade Hospitalar/tendências , Humanos , Masculino , Moscou/epidemiologia , Estudos Prospectivos , Fatores de Risco , Fatores Socioeconômicos
6.
Opt Lett ; 34(7): 1102-4, 2009 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19340233

RESUMO

Passively Q-switched self-Raman laser oscillations in the SrMoO4:Nd3+ crystal optically pumped by a laser diode (LD) at 804 nm are demonstrated for the first time to our knowledge. Output parameters of LD-pumped SrMoO4:Nd3+ laser were investigated in free-running, passively Q-switched, and self-Raman regimes of laser operation, over a wide range of pulse repetition rates (8.5-85 kHz). A pulse energy of 21 microJ was measured in the self-Raman regime at 1163 nm (first Stokes) wavelength, which is 6 times higher than that for the GdVO4:Nd3+ self-Raman laser of similar design.

7.
Development ; 132(19): 4375-86, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16155213

RESUMO

Oculodentodigital dysplasia (ODDD) is an autosomal dominant disorder characterized by pleiotropic developmental anomalies of the limbs, teeth, face and eyes that was shown recently to be caused by mutations in the gap junction protein alpha 1 gene (GJA1), encoding connexin 43 (Cx43). In the course of performing an N-ethyl-N-nitrosourea mutagenesis screen, we identified a dominant mouse mutation that exhibits many classic symptoms of ODDD, including syndactyly, enamel hypoplasia, craniofacial anomalies and cardiac dysfunction. Positional cloning revealed that these mice carry a point mutation in Gja1 leading to the substitution of a highly conserved amino acid (G60S) in Cx43. In vivo and in vitro studies revealed that the mutant Cx43 protein acts in a dominant-negative fashion to disrupt gap junction assembly and function. In addition to the classic features of ODDD, these mutant mice also showed decreased bone mass and mechanical strength, as well as altered hematopoietic stem cell and progenitor populations. Thus, these mice represent an experimental model with which to explore the clinical manifestations of ODDD and to evaluate potential intervention strategies.


Assuntos
Anormalidades Múltiplas/genética , Conexina 43/genética , Modelos Animais de Doenças , Mutação Puntual , Animais , Fenômenos Biomecânicos , Densidade Óssea , Osso e Ossos/anormalidades , Osso e Ossos/fisiopatologia , Conexina 43/metabolismo , Anormalidades Craniofaciais/genética , Hipoplasia do Esmalte Dentário/genética , Etilnitrosoureia , Anormalidades do Olho/genética , Junções Comunicantes/fisiologia , Junções Comunicantes/ultraestrutura , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/fisiopatologia , Humanos , Camundongos , Penetrância , Células-Tronco/patologia , Sindactilia/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa