Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Opt Express ; 21(25): 30674-82, 2013 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-24514643

RESUMEN

Barium copper sulfur fluoride (BaCuSF) is a p-type transparent conductor (p-TC) that, when doped with potassium, exhibits exceptionally high conductivity. The results of a detailed optical and electronic characterization of BaCuSF thin films deposited at a substrate temperature of 100 °C are presented. X-ray diffractometry shows the presence of a cubic BaCuSF phase. Spectroscopic measurements demonstrate that the films transmit from the visible through the mid-infrared with a band gap of 1.8 eV. Hall measurements indicate that the material is a degenerate semiconductor. As deposited, the films exhibit conductivity at room temperature of approximately 260 S/cm - among the highest reported room temperature conductivities for p-TCs. After post-deposition treatment in water, their conductivity increases to as high as 800 S/cm, and their band gap is reduced to 1.5 eV. The potential for low temperature deposition of p-type films with high conductivity and optical transmittance makes BaCuSF promising for several applications including flexible electronics and photovoltaics.

2.
Opt Express ; 19(9): 8954-61, 2011 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-21643148

RESUMEN

Room temperature spasing of surface plasmon polaritons at 1.46 µm wavelength has been demonstrated by sandwiching a gold-film plasmonic waveguide between optically pumped InGaAs quantum-well gain media. The spaser exhibits gain narrowing, the expected transverse-magnetic polarization, and mirror feedback provided by cleaved facets in a 1-mm long cavity fabricated with a flip-chip approach. The 1.06-µm pump-threshold of ~60 kW/cm2 is in good agreement with calculations. The architecture is readily adaptable to all-electrical operation on an integrated microchip.


Asunto(s)
Oro/química , Lentes , Resonancia por Plasmón de Superficie/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Temperatura
3.
Metabol Open ; 4: 100019, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32812928

RESUMEN

BACKGROUND: Physical activity and dietary intake of dairy products are associated with improved metabolic health. Dairy products are rich with branched chain amino acids that are essential for energy production. To gain insight into the mechanisms underlying the benefit of the sub-chronic effects of running and intake of milk protein supplements, we studied Low Capacity Runner rats (LCR), a rodent exercise model with risk for metabolic disorders. We especially focused on the role of Sirtuins, energy level dependent proteins that affect many cellular metabolic processes. METHODS: Forty-seven adult LCR female rats sedentary or running voluntarily in wheels were fed normal chow and given supplements of either whey or milk protein drink (PD)-supplemented water, or water only for 21 weeks. Physiological responses were measured in vivo. Blood lipids were determined from serum. Mitochondrial markers and Sirtuins (Sirt1-7) including downstream targets were measured in plantaris muscle by western blotting. RESULTS: For the first 10 weeks whey-drinking rats ran about 50% less compared to other groups; still, in all runners glucose tolerance improved and triglycerides decreased. Generally, running induced a ∼six-fold increase in running capacity and a ∼8% decrease in % body fat. Together with running, protein supplements increased the relative lean mass of the total body weight by ∼11%. In comparison with sedentary controls, running and whey increased HDL (21%) and whey, with or without running, lowered LDL (-34%). Running increased mitochondrial biogenesis and Sirtuins 3 and 4. When combined with exercise, both whey and milk protein drink induced about a 4-fold increase in Sirt3, compared to runners drinking water only, and about a 2-fold increase compared to the respective sedentary group. Protein supplements, with or without running, enhanced the phosphorylation level of the acetyl-coA-carboxylase, suggesting increased fat oxidation. Both supplemented diets increased Sirt5 and Sirt7 without an additional effect from exercise. Running diminished and PD supplement increased Sirt6. CONCLUSION: We demonstrate in rats new sub-chronic effects of milk proteins on metabolism that involve Sirtuins and their downstream targets in skeletal muscle. The results show that running and milk proteins act on reducing the risk factors of metabolic disorders and suggest that the underlying mechanisms may involve Sirtuins. Notably, we found that milk protein supplements have some favorable effects on metabolism even without running.

4.
Sci Total Environ ; 262(1-2): 123-36, 2000 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-11059848

RESUMEN

The effect of the emissions from large oil shale fuelled power plants and a cement factory in Estonia on the elemental concentration of atmospheric aerosols, deposition, elemental composition of mosses and ecological effects on mosses, lichens and pine trees in the eastern Gulf of Finland region has been studied. In addition to chemical analysis, fly ash, moss and aerosol samples were analysed by a scanning electron microscope with an energy dispersive X-ray spectrometer (SEM/EDS). The massive particulate calcium emissions, approximately 60 kton/year (1992), is clearly observed in the aerosols, deposition and mosses. The calcium deposition is largest next to the Russian border downwind from the power plants and in south-eastern part of Finland. This deposition has decreased due to the application of dust removal systems at the particulate emission sources. At the Virolahti EMEP station approximately 140 km north from the emission sources, elevated elemental atmospheric aerosol concentrations are observed for Al, Ca, Fe, K and Si and during episodes many trace elements, such as As, Br, Mo, Ni, Pb and V. The acidification of the soil is negligible because of the high content of basic cations in the deposition. Visible symptoms on pine trees are negligible. However, in moss samples close to the power plants, up to 25% of the leaf surface was covered by particles. Many epiphytic lichen species do not tolerate basic stemflow and on the other hand most species are also very sensitive for the SO2 content in air. Consequently a large lichen desert is found in an area of 2500 km2 in the vicinity of the power plants with only one out of the investigated 12 species growing.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Aerosoles , Contaminación del Aire , Bryopsida/efectos de los fármacos , Ecología , Estonia , Finlandia , Líquenes/efectos de los fármacos , Microscopía Electrónica de Rastreo/métodos , Centrales Eléctricas , Análisis Espectral/métodos
5.
Anim Reprod Sci ; 52(4): 317-23, 1998 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-9821505

RESUMEN

In situ hybridization with an X chromosome specific painting probe can be used as a tool for studying the numerical and structural rearrangements of X chromosomes. The commercially available porcine specific X chromosome painting probe is still unable to reliably separate autosomes. However, due to across-species X chromosome homology, the human specific X chromosome painting probe can be used in the identification of X chromosomes in pig metaphases. The commercially available human X chromosome specific painting probe was hybridized to metaphase spreads in a Klinefelter boar with a 2n = 39, XXY karyotype to characterize the X chromosomes. Klinefelter syndrome with its effects on the male reproductive trait such as testicular hypoplasia, is under the genetic control of some sex-linked genes in the extra X chromosome which have escaped the X inactivation process. Chromosome analysis by chromosome painting using fluorescence in situ hybridization may in future be more widely used in veterinary medicine and the selection of breeding animals.


Asunto(s)
Síndrome de Klinefelter/veterinaria , Aberraciones Cromosómicas Sexuales/veterinaria , Enfermedades de los Porcinos/genética , Cromosoma X/genética , Animales , Pintura Cromosómica/veterinaria , ADN/química , Femenino , Hibridación Fluorescente in Situ/veterinaria , Síndrome de Klinefelter/genética , Síndrome de Klinefelter/fisiopatología , Masculino , Fenotipo , Aberraciones Cromosómicas Sexuales/genética , Aberraciones Cromosómicas Sexuales/fisiopatología , Porcinos , Enfermedades de los Porcinos/fisiopatología , Testículo/patología , Cromosoma X/química
6.
Anim Reprod Sci ; 56(3-4): 237-43, 1999 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-10497919

RESUMEN

The low number of piglets per litter was the reason why a Finnish Yorkshire breed boar used for artificial insemination (AI) was taken for cytogenetic study. The boar had a reciprocal translocation between autosomes 8 and 10, resulting in a reduction in its litter size of about 19%. In addition the litter sizes were counted from 16 female offspring of this 2n = 38,XY; rcp(8;10)(p1.1;q1.3) boar.


Asunto(s)
Tamaño de la Camada/genética , Porcinos/genética , Translocación Genética/genética , Animales , Bandeo Cromosómico/veterinaria , Femenino , Inseminación Artificial/efectos adversos , Cariotipificación/veterinaria , Masculino
7.
Hepatogastroenterology ; 46(25): 130-5, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10228777

RESUMEN

BACKGROUND/AIMS: Quantitative cholescintigraphy has been used to evaluate biliary emptying and, by some, as a screening test for sphincter of Oddi dyskinesia in cholecystectomized patients. Our aim was to identify variables that might effect the interpretation of the scintigraphy in asymptomatic cholecystectomized volunteers. METHODOLOGY: Quantitative cholescintigraphy was performed in 37 volunteer. There were 11 males and 26 females with a median age of 49 years (range: 32-82). The time interval from cholecystectomy ranged from 1 month to 30 years (median: 5 years). Eight subjects had also undergone choledocholithotomy during the cholecystectomy operation. RESULTS: From the time of the injection of the radioisotope to the maximum activity in the liver, the percentage of clearance and the hepatic hilum-duodenal transit time were measured to be 45 and 60 min, respectively. The maximum activity obtained in the liver was 17 +/- 10 min (mean +/- SD), and the percentage of clearance at 45 min was 52 +/- 22% and at 60 min 67 +/- 20%. Hilum-duodenal transit time was 12 +/- 11 min. The gender of the volunteer and previous choledocholithotomy did not correlate with the parameters studied. The age of the volunteer and the follow-up time had a positive correlation to the time of maximum activity and negative correlation to percentage of clearance. The follow-up time also had a positive correlation to hilum-duodenal transit time. In the multivariate analysis, the time interval since cholecystectomy was the only independent variable affecting study parameters. CONCLUSIONS: The length of the time interval since cholecystectomy but not the gender, age, or previous choledocholithotomy should be taken into consideration when the results of quantitative cholescintigraphy are interpreted.


Asunto(s)
Sistema Biliar/diagnóstico por imagen , Colecistectomía , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Conductos Biliares/diagnóstico por imagen , Sistema Biliar/fisiología , Duodeno/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Cintigrafía , Factores Sexuales , Factores de Tiempo
8.
Hepatogastroenterology ; 45(23): 1436-41, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9840079

RESUMEN

BACKGROUND/AIMS: Endoscopic sphincterotomy is widely used in treating common bile duct stones, but the long-term effects of destroying the sphincter of Oddi are not known. This study investigated the long-term (15-20 years) effects of transduodenal sphincterotomy on gastrointestinal symptoms and hepatobiliary function in a retrospective controlled study. METHODOLOGY: Between 1974 and 1977, choledocholithotomy was performed in 131 patients either transduodenally (60 patients) or via choledochotomy (71 patients). For the retrospective part of the study, all hospital records, death certificates and autopsy reports were reviewed. Twenty-seven patients who could be reached and volunteered to participate (12 and 15, respectively) were re-examined. In the re-examination part of the study, a standard questionnaire interview, laboratory tests, quantitative cholescintigraphy and ultrasonography were performed. RESULTS: The hospital mortality for the primary operations was 0.8%, 0% for the transduodenal sphinterotomies and 2% for the choledochotomies; the difference was not significant. During the follow-up period, no significant differences could be seen in the death rate or in the causes of death between the study groups. During re-examination, flatulence was found to be more common in the choledochotomy subgroup (7/15 vs 2/12, p<0.05). In the laboratory tests, conjugated bilirubin and serum aspartate amino transferase levels were higher in the transduodenal subgroup than in the choledochotomy subgroup (3.3 umol/L, SD 0.4 vs 2.2 umol/L, SD 0.2, p<0.02; and 25 U/L, SD 12.6 vs 18.6 U/L, SD 5.0, p<0.05, respectively). Furthermore, 6/12 (50%) of the transduodenal subgroup had elevated serum alanine aminotransferase, aspartate aminotransferase or amylase levels, as compared to 1/15 (7%) in the choledochotomy subgroup (p<0.02). In terms of ultrasonography, in the choledochotomy subgroup, the common bile duct diameter was larger than 8 mm in 8/15 (53%) patients, as compared to 1/12 (8%) in the transduodenal subgroup (p<0.02). In terms of quantitative cholescintigraphy, in 9/12 (75%) patients of the transduodenal subgroup, the hilum-duodenum transit time was less than 10 minutes, as compared to 4/12 (47%) of the choledochotomy subgroup. CONCLUSIONS: Transduodenal sphincterotomy results in decreased flatulence and enhanced common bile duct drainage, even in the long-term period, but slightly higher serum liver funtion tests, when compared to supraduodenal choledochotomy.


Asunto(s)
Sistema Biliar/fisiología , Enfermedades Gastrointestinales/etiología , Hígado/fisiología , Esfinterotomía Transduodenal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Sistema Biliar/diagnóstico por imagen , Conducto Colédoco/cirugía , Femenino , Estudios de Seguimiento , Cálculos Biliares/cirugía , Humanos , Masculino , Persona de Mediana Edad , Cintigrafía , Estudios Retrospectivos , Esfinterotomía Transduodenal/efectos adversos , Ultrasonografía
9.
Int Surg ; 80(2): 99-101, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8530244

RESUMEN

Laparoscopic cholecystectomy (LC) has become the most popular method of removing the gallbladder. Because it is an expensive operation requiring special training for the team, LC has been challenged by other methods of minimal-access surgery, e.g. by minilaparotomy (MC). This study was planned to be a single-surgeon prospective random study to compare minilaparotomy cholecystectomy (MC) and laparoscopic cholecystectomy (LC), but was never done over the pilot phase. Twenty-four cholecystectomies were included, eight MC and 16 LC, the patients being comparable between the groups. In the MC group three patients (37%) had complications versus no complications in the LC group (p = 0.028). Postoperative hospital stay was longer in the MC group (median three days) than in the LC group (median one day), even when the patients with complications were excluded. Due to these discouraging experiences the extended random study was never done, and MC was abandoned.


Asunto(s)
Colecistectomía Laparoscópica/métodos , Colelitiasis/cirugía , Laparotomía/métodos , Complicaciones Posoperatorias/etiología , Adulto , Anciano , Femenino , Finlandia , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Resultado del Tratamiento
10.
J Small Anim Pract ; 38(11): 506-12, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9403810

RESUMEN

The results of testicular aspirate cytology taken from clinical patients with a history of infertility were compared with the clinical and histological findings. Azoospermia was the most common and the most rewarding indication for the examination. Samples were also taken from cases with suspected testicular tumours, orchitis, epididymitis, severe oligo- and teratozoospermia, lack of libido and unilateral testicular atrophy. Histological and cytological findings were found to correlate well. Identification of cell types from normal germinal epithelium was relatively easy. No immediate adverse effects of aspiration were noted. Five normospermic dogs were monitored for two to six months after aspiration, and there were no marked deleterious effects on testicular consistency, testicular histology or semen characteristics. Testicular cytology obtained by fine needle aspiration may, at least to some extent, be used to assist clinical diagnosis, especially in azoospermic dogs and dogs with palpable changes of testicular tissue.


Asunto(s)
Biopsia con Aguja/veterinaria , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/patología , Infertilidad Masculina/veterinaria , Testículo/patología , Animales , Atrofia/complicaciones , Atrofia/diagnóstico , Atrofia/veterinaria , Biopsia con Aguja/métodos , Criptorquidismo/complicaciones , Criptorquidismo/diagnóstico , Criptorquidismo/veterinaria , Enfermedades de los Perros/etiología , Perros , Infertilidad Masculina/diagnóstico , Infertilidad Masculina/patología , Masculino , Oligospermia/complicaciones , Oligospermia/diagnóstico , Oligospermia/veterinaria , Orquitis/complicaciones , Orquitis/diagnóstico , Orquitis/veterinaria , Semen/citología , Enfermedades Testiculares/complicaciones , Enfermedades Testiculares/diagnóstico , Enfermedades Testiculares/veterinaria , Neoplasias Testiculares/complicaciones , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/veterinaria , Factores de Tiempo
11.
Rev Sci Instrum ; 84(4): 043111, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23635185

RESUMEN

Optical emission spectroscopy has been for long proposed for monitoring and studying industrial steel making processes. Whereas the radiative decay of thermal excitations is always taking place in high temperatures needed in steel production, one of the most promising environment for such studies are electric arc furnaces, creating plasma in excited electronic states that relax with intense characteristic emission in the optical regime. Unfortunately, large industrial scale electric arc furnaces also present a challenging environment for optical emission studies and application of the method is not straightforward. To study the usability of optical emission spectroscopy in real electric arc furnaces, we have developed a laboratory scale DC electric arc furnace presented in this paper. With the setup, optical emission spectra of Fe, Cr, Cr2O3, Ni, SiO2, Al2O3, CaO, and MgO were recorded in the wavelength range 250-600 nm and the results were analyzed with the help of reference data. The work demonstrates that using characteristic optical emission, obtaining in situ chemical information from oscillating plasma of electric arc furnaces is indeed possible. In spite of complications, the method could possibly be applied to industrial scale steel making process in order to improve its efficiency.

12.
Radiat Prot Dosimetry ; 147(1-2): 233-6, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21816721

RESUMEN

The collective effective doses to the population from X-ray and nuclear medicine (NM) examinations in Finland in 2008 and 2009, respectively, were estimated. The estimated collective effective dose per inhabitant was 0.45 mSv from X-ray examinations and 0.03 mSv from NM examinations. The collective effective doses per inhabitant have not changed substantially during the last 10 y. However, proportional dose due to CT examinations has increased from 50 % in 2005 to 58 % in 2009 of the total collective effective dose from all X-ray examinations and proportional dose of PET examinations from 7 to 13 % of the total collective effective dose from NM examinations. The collective effective dose from conventional plain radiography was over 20 % higher when estimated using the new (ICRP 103) tissue weighting factors than that obtained using the old (ICRP 60) tissue weighting factors.


Asunto(s)
Medicina Nuclear , Dosis de Radiación , Protección Radiológica , Radiografía/normas , Finlandia/epidemiología , Humanos , Radiografía/efectos adversos , Rayos X
18.
Res Commun Chem Pathol Pharmacol ; 17(1): 115-24, 1977 May.
Artículo en Inglés | MEDLINE | ID: mdl-877398

RESUMEN

Adult female mice, male rats, female hamsters and male guinea pigs received various doses of styrene (150-1000 mg/kg of body weight) and acrylonitrile (20-80 mg/kg of body weight) intraperitoneally. Both styrene and acrylonitrile caused a depression of the hepatic nonprotein sulfhydryl content. Mouse was the most vulnerable and rat the most resistant species to the effect of both of these two important plastic monomers.


Asunto(s)
Acrilonitrilo/farmacología , Hígado/metabolismo , Nitrilos/farmacología , Estirenos/farmacología , Compuestos de Sulfhidrilo/metabolismo , Animales , Cricetinae , Depresión Química , Femenino , Cobayas , Hígado/efectos de los fármacos , Masculino , Mesocricetus , Ratones , Ratas , Especificidad de la Especie , Factores de Tiempo
19.
Ann Chir Gynaecol ; 82(4): 241-4, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8122871

RESUMEN

One hundred and seventy two consecutive patients of 70 years or older undergoing cholecystectomy at laparotomy for gallbladder stone disease during a five-year period in Tampere University Hospital were studied to evaluate the present safety of "conventional" cholecystectomy in the elderly. One hundred and six (62%) underwent emergency or urgent cholecystectomy for acute cholecystitis and 66 (33%) elective cholecystectomy. The mortality was zero per cent in elective operations as compared to 5% in emergency/urgent operations (P < 0.001). The complication rate was 8% in elective operations compared to 25% in emergency/urgent operations (P < 0.001). These results suggest that conventional cholecystectomy is a very safe operation in the elderly, when performed electively. The development of new methods to treat gallbladder stone disease, such as laparoscopic cholecystectomy, must be undertaken from this background.


Asunto(s)
Colecistectomía , Factores de Edad , Anciano , Anciano de 80 o más Años , Colecistectomía/mortalidad , Femenino , Humanos , Masculino , Complicaciones Posoperatorias
20.
J Biol Chem ; 264(21): 12148-57, 1989 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-2545699

RESUMEN

The modification of avian phosphoenolpyruvate carboxykinase by a variety of sulfhydryl reagents leads to inhibition. The inhibition is related to the loss of 1 highly reactive cysteine residue of the 13 cysteines present in the enzyme. Inhibition by reagents which yield a mixed disulfide was rapidly reversed by thiols. Reagents specific for vicinal sulfhydryl configurations were not potent inhibitors. The cysteine-modified enzyme continues to bind Mn2+ with the same stoichiometry and dissociation constant as the native enzyme. All of the substrates also bind to thiol-modified inactive enzyme. The modification of the reactive cysteine with the spin-labeled iodoacetate derivative leads to inactive enzyme with spin label stoichiometrically incorporated. The EPR spectrum showed an immobilized spin label on the enzyme. EPR studies of the perturbation of the phosphoenolpyruvate carboxykinase-bound spin label by bound Mn2+ showed a dipolar interaction between the two spins, estimated to be 10 A apart. The perturbation of the 1/T1 and 1/T2 values of the 31P resonances of ITP by spin-labeled enzyme indicates that this portion of the nucleotide binds 8-10 A from the spin label. These results indicate that the reactive cysteine is close to but not at the active site of the enzyme. The thiol group must be free and in its reduced form for the enzyme to be active. Perhaps modification of this group prevents conformational change(s) upon ligand binding necessary for the catalytic process.


Asunto(s)
Cisteína , Hígado/enzimología , Fosfoenolpiruvato Carboxiquinasa (GTP)/metabolismo , Animales , Sitios de Unión , Pollos , Espectroscopía de Resonancia por Spin del Electrón , Yodoacetatos/metabolismo , Ácido Yodoacético , Cinética , Manganeso/metabolismo , Unión Proteica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA