Silver-Mediated Synthesis of Heterocycles Álvarez-Corral, Míriam; Muñoz-Dorado, Manuel; Rodríguez-García, Ignacio
Chemical reviews,
08/2008, Letnik:
108, Številka:
8
Journal Article
Recenzirano
Silver-mediated synthesis of heterocycles using silver salts is discussed. The use of silver can enrich several available heterocycles as well as help to develop the application of chiral silver ...complexes.
La profesora María Roca ha reunido una rutilante nómina de juristas para homenajear al insigne Santi Romano y a una de esa obras que marcan época e impronta. Las contribuciones que nos ofrecen cada ...uno de ellos dan forma a un volumen que se caracteriza por desplegar un estudio pormenorizado de las cuestiones pertinentes. La propia profesora escribe un magnífico prólogo a la obra, que cumple no sólo la función de situar al lector ante lo que se va a encontrar, sino que siembra las ganas intelectuales de seguir pasando la página para poder leer cómo razonan esas mentes preclaras.
El texto es una reflexión en voz alta sobre la prohibición de difusión de mensajes terroristas en internet, especialmente al hilo de las normas internacionales y nacionales en la materia. En la ...primera parte se analizan las normas que provienen de la Organización de las Naciones Unidas, la Unión Europea y, especialmente, del Consejo de Europa. En la segunda parte, el asunto se aborda en el marco del derecho fundamental a la libertad de expresión del artículo 20.4 de la Constitución española. En ambos casos se insistirá tanto en la jurisprudencia del Tribunal Europeo de Derechos Humanos como del Tribunal Constitucional español.
Does an individualised luteal phase support (iLPS), according to serum progesterone (P4) level the day prior to euploid frozen embryo transfer (FET), improve pregnancy outcomes when started on the ...day previous to embryo transfer?
Patients with low serum P4 the day prior to euploid FET can benefit from the addition of daily subcutaneous P4 injections (Psc), when started the day prior to FET, and achieve similar reproductive outcomes compared to those with initial adequate P4 levels.
The ratio between FET/IVF has spectacularly increased in the last years mainly thanks to the pursuit of an ovarian hyperstimulation syndrome free clinic and the development of preimplantation genetic testing (PGT). There is currently a big concern regarding the endometrial preparation for FET, especially in relation to serum P4 levels around the time of embryo transfer. Several studies have described impaired pregnancy outcomes in those patients with low P4 levels around the time of FET, considering 10 ng/ml as one of the most accepted reference values. To date, no prospective study has been designed to compare the reproductive outcomes between patients with adequate P4 the day previous to euploid FET and those with low, but restored P4 levels on the transfer day after iLPS through daily Psc started on the day previous to FET.
A prospective observational study was conducted at a university-affiliated fertility centre between November 2018 and January 2020 in patients undergoing PGT for aneuploidies (PGT-A) IVF cycles and a subsequent FET under hormone replacement treatment (HRT). A total of 574 cycles (453 patients) were analysed: 348 cycles (leading to 342 euploid FET) with adequate P4 on the day previous to FET, and 226 cycles (leading to 220 euploid FET) under iLPS after low P4 on the previous day to FET, but restored P4 levels on the transfer day.
Overall we included 574 HRT FET cycles (453 patients). Standard HRT was used for endometrial preparation. P4 levels were measured the day previous to euploid FET. P4 > 10.6 ng/ml was considered as adequate and euploid FET was performed on the following day (FET Group 1). P4 < 10.6 ng/ml was considered as low, iLPS was added in the form of daily Psc injections, and a new P4 analysis was performed on the following day. FET was only performed on the same day when a restored P4 > 10.6 ng/ml was achieved (98.2% of cases) (FET Group 2).
Patient's demographics and cycle parameters were comparable between both euploid FET groups (FET Group 1 and FET Group 2) in terms of age, weight, oestradiol and P4 levels and number of embryos transferred. No statistically significant differences were found in terms of clinical pregnancy rate (56.4% vs 59.1%: rate difference (RD) -2.7%, 95% CI -11.4; 6.0), ongoing pregnancy rate (49.4% vs 53.6%: RD -4.2%, 95% CI -13.1; 4.7) or live birth rate (49.1% vs 52.3%: RD -3.2%, 95% CI -12; 5.7). No significant differences were also found according to miscarriage rate (12.4% vs 9.2%: RD 3.2%, 95% CI -4.3; 10.7).
Only iLPS through daily Psc was evaluated. The time for Psc injection was not stated and no serum P4 determinations were performed once the pregnancy was achieved.
Our study provides information regarding an 'opportunity window' for improved ongoing pregnancy rates and miscarriage rates through a daily Psc injection in cases of inadequate P4 levels the day previous to FET (P4 < 10.6 ng/ml) and restored values the day of FET (P4 > 10.6 ng/ml). Only euploid FET under HRT were considered, avoiding one of the main reasons of miscarriage and implantation failure and overcoming confounding factors such as female age, embryo quality or ovarian stimulation protocols.
No external funding was received. B.C. reports personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, IBSA and Gedeon Richter outside the submitted work. N.P. reports grants and personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, Theramex and Besins International and personal fees from IBSA and Gedeon Richter outside the submitted work. The remaining authors have no conflicts of interest to declare.
NCT03740568.
Objective To establish the relationship between the degree of difficulty of ET and pregnancy rate (PR), with a view to proposing an algorithm for the objective assessment of ET. Design Retrospective, ...observational study. Setting In vitro fertilization unit. Patient(s) Women undergoing assisted reproductive technology (ART) with ET after IVF/intracytoplasmic sperm injection, in whom fresh embryo transfer or frozen–thawed embryo transfer was performed. Intervention(s) None. Main Outcome Measure(s) Clinical pregnancy rate (CPR). Result(s) A total of 7,714 ETs were analyzed. The CPR was significantly higher in the cases of easy ET compared with difficult ET (38.2% vs. 27.1%). Each instrumentation needed to successfully deposit the embryos in the fundus involves a progressive reduction in the CPR: use of outer catheter sheath (odds ratio OR 0.89; 95% confidence interval CI 0.79–1.01), use of Wallace stylet (OR 0.71; 95% CI 0.62–0.81), use of tenaculum (OR 0.54; 95% CI 0.36–0.79). Poor ultrasound visualization significantly diminish the CPR. Conclusion(s) The CPR decreases progressively with the use of additional maneuvers during ET. An objective classification of the instrumentation applied during ET is proposed.
El presente texto es una puesta al día de las funciones que la Constitución española de 1978 atribuye al Poder Ejecutivo, uno de los tres poderes clásicos y quizá el que mayor importancia tiene en el ...devenir cotidiano de los asuntos nacionales. A tal fin se hace un breve repaso a la cuestión desde la óptica comparada y desde la historia constitucional patria, para pasar después a analizar cada una de las funciones constitucionales que el Gobierno tiene conferidas, en base a la clásica divisoria entre la función de dirección política, la función de dirigir la Administración civil y militar y el ejercicio de la potestad reglamentaria. Posteriormente se hace una referencia al control de los actos del Gobierno, tanto político como jurídico, así como a la labor de ayuda que le prestan ciertos órganos institucionales, tales como el Consejo de Estado y el Tribunal de Cuentas, para finalizar con una reflexión que sintetiza los hallazgos resultantes.
El presente texto es una aproximación crítica al Derecho del ciberespacio. A tal fin, se estudian en el mismo las normas principales que lo componen, tanto nacionales como internacionales, para ...posteriormente abordar algunos problemas que la comunidad de expertos ha detectado sobre ambos sectores. Finaliza con unas conclusiones que sintetizan los hallazgos resultantes.
What factors determine serum progesterone concentrations the day before cryopreserved embryo transfer in artificially prepared cycles?
Retrospective cohort study at a university-affiliated fertility ...centre including infertile women under 45 years old using own oocytes who underwent a total of 685 single cryopreserved blastocyst transfers under hormonal therapy. Determinants that affected live birth rate (LBR) were analysed using a multivariate logistic regression. Univariate analysis and multivariate linear regression were used to evaluate independent factors that affect serum progesterone concentrations.
Age (odds ratio OR 0.93; 95% confidence interval CI 0.89–0.96), duration of oestradiol (OR 0.96; 95% CI 0.92–0.99), serum progesterone concentrations (OR 1.04; 95% CI 1.01–1.08) and patients who underwent preimplantation genetic testing for aneuploidies (PGT-A) (OR 2.17; 95% CI 1.55–3.03) were independently associated with LBR. After univariate analysis, determinants of progesterone concentrations were: age, weight, history of a previous cryopreserved embryo transfer with serum progesterone concentrations <10 ng/ml, and time of blood extraction. The multivariate linear regression showed that increasing age presented a positive correlation with progesterone concentrations (β = 0.11; 95% CI 0.01–0.20). On the contrary, significant negative correlations with progesterone concentrations were shown for a previous history of serum progesterone value <10 ng/ml (β = –3.13; 95% CI –4.45 to –1.81), higher weight (β = –0.05; 95% CI –0.08 to –0.01) and the time of blood sampling during the day (β = –0.13; 95% CI –0.25 to –0.01).
This study adds more evidence regarding the importance of serum progesterone concentrations before frozen embryo transfer (FET). It also showed that body weight, age, time of blood sampling and a history of low progesterone are determinants associated with progesterone concentrations before blastocyst FET.
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