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










Base de datos
Intervalo de año de publicación
1.
Reprod Biol Endocrinol ; 13: 70, 2015 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-26141379

RESUMEN

BACKGROUND: Successful embryo implantation depends on a well-timed maternal-embryonic crosstalk. Human chorionic gonadotropin (hCG) secreted by the embryo is known to play a key role in this process and to trigger a complex signal transduction cascade allowing the apposition, attachment, and invasion of the embryo into the decidualized uterus. Production of hCG was reported to be dependent on blastocyst quality and several articles suggested that intrauterine hCG injection increases pregnancy and implantation rates in IVF patients. However, no study has as yet analysed birth rates as final outcome. Our objective was to determine whether clinical outcome after blastocyst transfer can be improved by intrauterine injection of hCG and whether this is dependent on blastocyst quality. METHODS: A prospective randomised study was conducted in two settings. In cohort A, hCG application was performed two days before blastocyst transfer. In cohort B, the administration of hCG occurred just prior to embryo transfer on day 5. For both cohorts, patients were randomised to either intrauterine hCG application or to the control group that received culture medium. Clinical outcome was analysed according to blastocyst quality of transferred embryos. RESULTS: The outcome of 182 IVF-cycles (cohort A) and 1004 IVF-cycles (cohort B) was analysed. All patients received a fresh autologous blastocyst transfer on day five. Primary outcomes were pregnancy rates (PR), clinical pregnancy rates (cPR), miscarriage rates (MR), and live birth rates (LBR). No improvement of clinical outcome after intrauterine hCG administration on day 3 (cohort A) or day 5 (cohort B) was found, independently of blastocyst quality transferred. The final outcome in cohort A: LBR after transfer of top blastocysts was 50.0 % with hCG and 53.3 % in the control group. With non-top blastocysts, LBR of 17.1 % (hCG) and 18.2 % (control) were observed (n.s.). In cohort B, LBR with top blastocysts was 53.3 % (hCG) and 48.4 % (control), with non-top blastocysts it came to 28.7 % (hCG) and 35.0 % (control). The differences between the groups were statistically not significant. Furthermore, we investigated a possible benefit of hCG administration in correlation with female age. In both age groups (<38 years and ≥ 38 years) we found similar LBR after treatment with hCG vs. medium. A LBR of 47.1 % vs. 48.7 % was obtained in the younger group and 26.6 % vs. 30.8 % in the older group. CONCLUSIONS: In contrast to previous studies indicating a substantial benefit from intrauterine hCG application in cleavage stage embryo transfers, in our study we could not find any evidence for improvement of clinical outcome in blastocyst transfer cycles, neither with top nor with non-top quality morphology.


Asunto(s)
Blastocisto/efectos de los fármacos , Gonadotropina Coriónica/uso terapéutico , Transferencia de Embrión/métodos , Índice de Embarazo , Adulto , Tasa de Natalidad , Gonadotropina Coriónica/farmacología , Femenino , Humanos , Nacimiento Vivo , Embarazo , Estudios Prospectivos , Resultado del Tratamiento , Adulto Joven
2.
Nanoscale ; 5(20): 9541-5, 2013 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-23986154

RESUMEN

Fast and robust infiltration of anodic TiO2 nanotube layers with a model chalcogenide As3S7 glass via spin-coating is reported for the first time. Effective sensitization leads to a significant visible light photocurrent response. This easy and cheap infiltration method can be extended for deposition of other absorbers into nanotubular layers.

3.
Opt Express ; 21(8): 9584-91, 2013 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-23609669

RESUMEN

We demonstrate, for the first time, time- and cost-effective replication of sub-micrometer features from a soft PDMS mold onto a bulk chalcogenide glass over a large surface area. A periodic array of sub-micrometer lines (diffraction grating) with period 625 nm, amplitude 45 nm and surface roughness 3 nm was imprinted onto the surface of the chalcogenide AsSe(2) bulk glass at temperature 225°C, i.e. 5°C below the softening point of the glass. Sub-micrometer soft lithography into chalcogenide bulk glasses shows good reliability, reproducibility and promise for feasible fabrication of various dispersive optical elements, anti-reflection surfaces, 2D photonic structures and nano-structured surfaces for enhanced photonic properties and chemical sensing.


Asunto(s)
Calcógenos/química , Vidrio/química , Impresión Molecular/métodos , Nanopartículas/química , Nanopartículas/ultraestructura , Calcógenos/efectos de la radiación , Luz , Ensayo de Materiales , Nanopartículas/efectos de la radiación , Tamaño de la Partícula , Propiedades de Superficie/efectos de la radiación
4.
Opt Express ; 21(7): 8101-15, 2013 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-23571900

RESUMEN

Reaction order in Bi-doped oxide glasses depends on the optical basicity of the glass host. Red and NIR photoluminescence (PL) bands result from Bi(2+) and Bin clusters, respectively. Very similar centers are present in Bi- and Pb-doped oxide and chalcogenide glasses. Bi-implanted and Bi melt-doped chalcogenide glasses display new PL bands, indicating that new Bi centers are formed. Bi-related PL bands have been observed in glasses with very similar compositions to those in which carrier-type reversal has been observed, indicating that these phenomena are related to the same Bi centers, which we suggest are interstitial Bi(2+) and Bi clusters.


Asunto(s)
Bismuto/química , Calcógenos/química , Vidrio/química , Plomo/química , Mediciones Luminiscentes/métodos , Modelos Químicos , Simulación por Computador , Ensayo de Materiales
5.
J Colloid Interface Sci ; 353(2): 454-8, 2011 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-21035816

RESUMEN

Chalcogenide opal and inverse opal photonic crystals were successfully fabricated by low-cost and low-temperature solution-based process, which is well developed in polymer films processing. Highly ordered silica colloidal crystal films were successfully infilled with nano-colloidal solution of the high refractive index As(30)S(70) chalcogenide glass by using spin-coating method. The silica/As-S opal film was etched in HF acid to dissolve the silica opal template and fabricate the inverse opal As-S photonic crystal. Both, the infilled silica/As-S opal film (Δn ~ 0.84 near λ=770 nm) and the inverse opal As-S photonic structure (Δn ~ 1.26 near λ=660 nm) had significantly enhanced reflectivity values and wider photonic bandgaps in comparison with the silica opal film template (Δn ~ 0.434 near λ=600 nm). The key aspects of opal film preparation by spin-coating of nano-colloidal chalcogenide glass solution are discussed. The solution fabricated "inorganic polymer" opal and the inverse opal structures exceed photonic properties of silica or any organic polymer opal film. The fabricated photonic structures are proposed for designing novel flexible colloidal crystal laser devices, photonic waveguides and chemical sensors.

6.
Opt Lett ; 34(8): 1234-6, 2009 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-19370128

RESUMEN

Single-mode optical rib waveguides operating at telecommunication wavelengths are successfully patterned via a hot embossing technique in a thermally evaporated chalcogenide glass thin film on a chalcogenide glass substrate. Ellipsometry is used to measure the refractive index dispersion of the pressed film (As(40)Se(60)) and substrate (Ge(17)As(18)Se(65)).

7.
Dev Dyn ; 237(9): 2496-505, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18729229

RESUMEN

Protocadherin-1 (Pcdh1) is a member of the delta-protocadherin subgroup of non-clustered protocadherins. We studied the expression of Pcdh1 from the early embryonic to the adult stage of mouse development by semi-quantitative RT-PCR and in situ hybridization. Pcdh1 can be detected as early as embryonic day 9.5. In early embryogenesis, expression is especially prominent in blood vessels. During later development and in the adult mouse, organs derived from the embryonic gut, such as the esophagus, intestines, liver, lung, and submandibular gland, contain epithelia and other types of tissues that are Pcdh1-positive. Other positive organs include the brain, spinal cord, retina, peripheral ganglia, the inner ear, hair follicles, kidney, vagina, uterus, placenta, testis, prostate, and the seminal gland. The tight spatial and temporal regulation of Pcdh1 expression suggests that this protocadherin plays multiple roles not only during development but also in mature tissues and organs in the mouse.


Asunto(s)
Cadherinas/genética , Regulación del Desarrollo de la Expresión Génica , Sistema Nervioso/metabolismo , Animales , Sistema Cardiovascular/embriología , Sistema Cardiovascular/metabolismo , Embrión de Mamíferos/metabolismo , Femenino , Tracto Gastrointestinal/embriología , Tracto Gastrointestinal/metabolismo , Hibridación in Situ , Riñón/embriología , Riñón/metabolismo , Ratones , Sistema Nervioso/embriología , Embarazo , Isoformas de Proteínas/genética , Protocadherinas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Vejiga Urinaria/embriología , Vejiga Urinaria/metabolismo
8.
Opt Express ; 16(3): 1466-74, 2008 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-18542221

RESUMEN

We report the kinetics of below band-gap light induced photodarkening in (80-x)GeS(2)-20Ga(2)S(3)-xAgI (x = 0 and 20 mol %) bulk chalcogenide glasses by measuring the time evolution of transmission spectra at every 10 milliseconds. The results prove clearly the enhancement of photosensivity upon doping of AgI compound in glasses. It is interesting to find that PD observed in AgI-doped glass totally disappears two hours later after the laser exposing even at room temperature. In significant contrast to 80GeS(2)-20Ga(2)S(3) glass that the metastable part of PD remains for a long time. We expect such a fast auto-recovery property in AgI-doped glass can be utilized for optical signal processing.


Asunto(s)
Calcógenos/química , Vidrio/química , Halógenos/química , Modelos Químicos , Fotoquímica/métodos , Simulación por Computador , Iones , Luz , Ensayo de Materiales , Dispersión de Radiación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA