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1.
Inorg Chem ; 60(9): 6191-6200, 2021 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-33853328

RESUMEN

The lack of low-temperature (<200 °C) and easy-to-handle vapor deposition precursors for cadmium has been a limitation for cadmium chalcogenide ALD. Here, the cadmium amidinate system is presented as a scaffold for vapor deposition precursor design because the alkyl groups can be altered to change the properties of the precursor. Thus, the molecular structure affects the precursor stability at elevated temperature, onset of volatility, and reactivity. Cadmium bis-N,N-diisopropylacetamidinate (1) was synthesized and evaluated for its thermal stability, volatility, and reactivity-properties relevant to ALD precursors. Compounds 2, cadmium bis-N,N-diisopropyltertertiarybutylamidinate, and 3, cadmium bis-N,N-diisopropylbutylamidinate, are analogous to 1 and were synthesized by substituting the alkyl group on the bridging carbon during amidinate synthesis. All three compounds are volatile under reduced pressure, and thermal stability studies showed 1 and 3 to be stable at 100 °C in solution for days to weeks, while 2 decomposed at 100 °C within 24 h. Solution phase reactivity studies show 1 to be reactive with thiols at room temperature in a stoichiometric manner. No reactivity with either bis-silyl sulfides or alkyl sulfides was observed up to 110 °C over more than 3 days. Overall, the cadmium amidinate compounds presented here show potential as precursors in ALD/CVD processing, which can contribute to research critical for semiconductor processing.

2.
Phys Chem Chem Phys ; 19(23): 15084-15097, 2017 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-28561078

RESUMEN

Metallic nanoparticles (NPs) with tunable physical, optical and catalytic properties have a wide range of applications including various optoelectronics, sensors and fuel cells. In this paper, we demonstrate the evolution of various physical properties, configurations, size and density of palladium (Pd) nanostructures on sapphire(Al2O3) (0001) by the systematic control of deposition amount (DA) at distinct annealing temperatures. The transformation of the deposited thin films into various Pd NPs is achieved by the dewetting of the thin film by means of surface diffusion, nucleation, Volmer-Weber growth and surface energy minimization mechanism. Depending on the evolution of size, density and configuration, five distinctive regimes of Pd nanostructures are demonstrated: (i) nucleation and evolution of small NPs between 1 and 3 nm, (ii) medium NPs with the dominating vertical growth between 5 and 20 nm, (iii) laterally expanded large NPs between 30 and 40 nm, (iv) irregular coalesced Pd NPs between 50 and 80 nm and (v) voids evolution between 100 and 200 nm. Initial film thickness and annealing temperature play major roles on the dewetting process and the resulting Pd nanostructures are notably distinguished. The fabricated Pd nanostructures influence the lattice vibration modes of sapphire(0001) such as gradual decrement in the intensity and left-shift of the peak position with increased surface coverage. In addition, the optical properties are studied by UV-VIS-NIR (300-1100 nm) reflectance spectra, which shows the reflectance, absorption and scattering over the wavelength and are closely related to the morphology evolution of Pd nanostructures.

3.
Hum Fertil (Camb) ; 27(1): 2288634, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38226584

RESUMEN

Endometriosis is a chronic inflammatory condition in women of reproductive age, which can lead to infertility and pelvic pain. Endometriosis associated infertility is multifactorial in nature adversely affecting each step of the natural reproductive physiology and thereby processes and outcomes of Assisted Reproductive Technology (ART) cycles. These outcomes are further complicated by the subtype of endometriosis, being peritoneal, deep infiltrating and ovarian, which bear negative effects on ovarian reserve, response to stimulation, accessibility for oocyte retrieval, intraoperative safety and endometrial receptivity. There is still a lack of clear guidance about the role of surgery for ovarian endometriosis/endometriomas. This guideline evaluates the evidence of the impact of pelvic endometriosis and endometriomas on the outcome of ART and provides recommendations for management options before and during ART including intra-uterine insemination. Recommendations are made based on the current evidence for the management of patients with endometriosis across each step of ART with the primary aim of improving ART outcomes.


Asunto(s)
Endometriosis , Infertilidad Femenina , Humanos , Femenino , Endometriosis/complicaciones , Endometriosis/cirugía , Infertilidad Femenina/etiología , Infertilidad Femenina/terapia , Fertilidad , Técnicas Reproductivas Asistidas/efectos adversos , Fertilización
4.
J Phys Conf Ser ; 425(9)2013.
Artículo en Inglés | MEDLINE | ID: mdl-24489595

RESUMEN

There are a growing number of high brightness synchrotron sources that require high-frame-rate detectors to provide the time-scales required for performing time-resolved diffraction experiments. We report on the development of a very high frame rate CMOS X-ray detector for time-resolved muscle diffraction and time-resolved solution scattering experiments. The detector is based on a low-afterglow scintillator, provides a megapixel resolution with frame rates of up to 120,000 frames per second, an effective pixel size of 64 µm, and can be adapted for various X-ray energies. The paper describes the detector design and initial results of time-resolved diffraction experiments on a synchrotron beamline.

5.
Hum Fertil (Camb) ; 25(1): 13-23, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32666851

RESUMEN

Intracytoplasmic sperm injection (ICSI) is frequently used to overcome severe deficits in semen quality. Concerns, however, are arising over its increasing use for non-male factor infertility. Moreover, increased risk of cardiovascular disease, congenital abnormalities, aneuploidies and childhood cancers have all been reported in the literature in relation to ICSI and it is possible that the quality of sperm chosen for injection may be an important factor in these unwanted outcomes. Given the wider adoption of ICSI to treat beyond the requirements of male infertility alone, research focussed on alternative methods to diagnose and treat the infertile couple is gaining increasing attention. This review focuses on the information available to date on the use of non-selective phosphodiesterase inhibitors (PDEI), specifically pentoxifylline (PF), caffeine (CF) and theophylline (TP) to stimulate sperm motility, thereby potentially reducing the need for ICSI in certain patient groups who may benefit from either expectant management or from a less stressful, minimally invasive and inexpensive treatment such as intrauterine insemination (IUI). The review focuses firstly on the mechanism of action of PDEI followed by treatment effects on sperm parameters such as motility and hyperactivated motility and sperm DNA integrity. Specific clinical implications are discussed that outline the potential role of PDEI in clinical practice and highlights areas in need of further research.


Asunto(s)
Infertilidad Masculina , Análisis de Semen , Niño , Humanos , Infertilidad Masculina/tratamiento farmacológico , Masculino , Inhibidores de Fosfodiesterasa/farmacología , Inhibidores de Fosfodiesterasa/uso terapéutico , Inyecciones de Esperma Intracitoplasmáticas , Motilidad Espermática , Espermatozoides
6.
Hum Fertil (Camb) ; 25(3): 575-582, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33501856

RESUMEN

A retrospective service evaluation was conducted in a tertiary fertility clinic to assess factors influencing the inclinations of individuals to consent for their information to be used for research (non-contact research) and their willingness to be contacted for future research studies (contact research). Self-reported data on ethnicity and country of birth were obtained from the HFEA registration forms of 18,384 patients undergoing fertility treatment. Socio-economic deprivation was assessed using the Index of Multiple Deprivation (IMD) determined by postcode. Analysis of data indicated that 24% were of non-white ethnicity, 32% had been born overseas and 46% resided in more deprived areas. Non-white patients were significantly less likely to consent to research than white patients (contact research: aOR 0.36, 95% CI 0.33 to 0.39; non-contact research: aOR 0.35, 95% CI 0.32 to 0.38), as were patients born overseas (contact research: aOR 0.86, 95% CI 0.79 to 0.94; non-contact research: aOR 0.89, 95% CI 0.82 to 0.97), and those living in more deprived areas (contact research: aOR 0.85, 95% CI 0.80 to 0.91; non-contact research: aOR 0.79, 95% CI 0.74 to 0.85). The findings indicate that ethnicity, country of birth and socio-economic factors are independently associated with willingness to participate in research.


Asunto(s)
Etnicidad , Fertilidad , Humanos , Estudios Retrospectivos , Factores Socioeconómicos
7.
Hum Fertil (Camb) ; 25(5): 813-837, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33820476

RESUMEN

Recurrent implantation failure (RIF) is defined as the absence of a positive pregnancy test after three consecutive transfers of good quality embryos. There remains significant variation in clinical practice in the management of RIF. This British Fertility Society (BFS) Policy and Practice guideline analyses the evidence for investigations and therapies that are employed in RIF and provides recommendations for clinical practice and for further research. Evidence for investigations of sperm and egg quality, uterine and adnexal factors, immunological factors and thrombophilia, endocrine conditions and genetic factors and for associated therapies have been evaluated. This guideline has been devised to assist reproductive medicine specialists and patients in making shared decisions concerning management of RIF. Finally, suggestions for research towards improving understanding and management of RIF have also been provided.


Asunto(s)
Implantación del Embrión , Semen , Femenino , Embarazo , Humanos , Masculino , Fertilidad , Fertilización In Vitro , Índice de Embarazo
8.
J Hum Reprod Sci ; 9(2): 70-81, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27382230

RESUMEN

Poor ovarian response represents an increasingly common problem. This systematic review was aimed to identify the most effective treatment protocol for poor response. We searched MEDLINE, EMBASE, and The Cochrane Library from 1980 to October 2015. Study quality assessment and meta-analyses were performed according to the Cochrane recommendations. We found 61 trials including 4997 cycles employing 10 management strategies. Most common strategy was the use of gonadotropin-releasing hormone antagonist (GnRHant), and was compared with GnRH agonist protocol (17 trials; n = 1696) for pituitary down-regulation which showed no significant difference in the outcome. Luteinizing hormone supplementation (eight trials, n = 847) showed no difference in the outcome. Growth hormone supplementation (seven trials; n = 251) showed significant improvement in clinical pregnancy rate (CPR) and live birth rate (LBR) with an odds ratio (OR) of 2.13 (95% CI 1.06-4.28) and 2.96 (95% CI 1.17-7.52). Testosterone supplementation (three trials; n = 225) significantly improved CPR (OR 2.4; 95% CI 1.16-5.04) and LBR (OR 2.18; 95% CI 1.01-4.68). Aromatase inhibitors (four trials; n = 223) and dehydroepiandrosterone supplementation (two trials; n = 57) had no effect on outcome.

9.
J Obstet Gynaecol India ; 65(6): 389-95, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26663998

RESUMEN

OBJECTIVE: The objective of this study was to identify clinical practices worldwide, which would help in recognizing women at risk of excessive bleeding or of developing pelvic infection following trans-vaginal ovum pick-up (TV-OPU), measures taken to minimize risks and their management. METHOD: A prospective, web-based questionnaire with distinct questions related to the practice of TV-OPU. RESULTS: A total of 155 units from 55 countries performing 97,200 IVF cycles annually responded to this web-based survey. A majority (65 %) responded that they would routinely carry out full blood count, while 35 % performed coagulation profile. Less than a third agreed screening women for vaginal infections. About a third used both sterile water and antiseptic to minimize ascending infection, and 52 % used antibiotics for prophylaxis. Doppler ultrasound was routinely used by 20 % of clinicians. 73 % of the clinicians preferred conservative management as their first line management for patients diagnosed with intra-abdominal bleeding. CONCLUSION: The study has identified a wide variation in the practices of minimizing infection and bleeding complications. The dearth of good quality evidence may be responsible for the lack of published guidelines, and therefore a lack of consensus on the optimum practice for minimizing the risk of infection and bleeding during TV-OPU.

10.
BMJ Case Rep ; 20142014 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-25471109

RESUMEN

A 29-year-old woman with known ulcerative colitis developed a right-sided abdominal pain a day after preterm vaginal delivery at 30 weeks. She did not have any nausea, vomiting and had normal bowel movements. The observations were within normal limits and white cell counts were marginally elevated with a normal C reactive protein. A large ovarian vein thrombosis on the left side was an incidental finding on a CT of the abdomen and pelvis undertaken to establish the cause for abdominal pain. The patient was managed by a multidisciplinary team and was treated with anticoagulants for 6 months. This case illustrates that the incidence of pelvic venous thrombosis may be higher in pregnancy and puerperium.


Asunto(s)
Colitis Ulcerosa/diagnóstico , Ovario/irrigación sanguínea , Trastornos Puerperales/etiología , Trombosis/etiología , Dolor Abdominal/etiología , Adulto , Colitis Ulcerosa/complicaciones , Diagnóstico Diferencial , Femenino , Humanos , Embarazo , Trastornos Puerperales/diagnóstico por imagen , Trombosis/diagnóstico por imagen , Tomografía Computarizada por Rayos X
11.
PLoS One ; 8(12): e82582, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24340046

RESUMEN

OBJECTIVES: The mechanisms of obesity associated reproductive complications remain poorly understood. Endometrial mesenchymal stem-cells are critical for cyclic renewal and uterine function. Recently, W5C5(+) cells, with high clonogenicity, capable of producing endometrial stroma in vivo, have been described. We sought to investigate the abundance and cloning efficiency of W5C5(+) and W5C5(-) endometrial cells in relation to Body Mass Index, age and reproductive outcome. DESIGN: W5C5(+) and W5C5(-) cells were purified from mid-luteal endometrial biopsies (n = 54) by magnetic bead separation and subjected to in vitro colony-forming assays. RESULTS: First trimester pregnancy losses were significantly higher in obese subjects (n = 12) compared to overweight (n = 20) and subjects with normal Body Mass Index (n = 22) (P<0.05, P<0.01, respectively). W5C5(+) cells (%) were significantly lower in obese subjects compared to subjects with normal Body Mass Index (P<0.05). W5C5(+) cloning efficiency was significantly lower in obese subjects compared to overweight and subjects with normal Body Mass Index (P<0.05, respectively). W5C5(-) cloning efficiency was significantly lower in obese subjects compared to subjects with normal Body Mass Index (P<0.05). Body Mass Index was significantly negatively correlated with W5C5(+) cloning efficiency and W5C5(-) cloning efficiency (P<0.01, respectively), and positively correlated with first trimester loss (P<0.01). We found no significant results with age (P>0.05). CONCLUSIONS: Our observations suggest that the regenerative capacity and plasticity of the endometrium of obese women is suboptimal, which in turn may account for the increased risk of reproductive complications associated with obesity.


Asunto(s)
Pérdida del Embrión/metabolismo , Endometrio/metabolismo , Células Madre Mesenquimatosas/metabolismo , Obesidad/metabolismo , Adulto , Índice de Masa Corporal , Pérdida del Embrión/patología , Endometrio/patología , Femenino , Humanos , Células Madre Mesenquimatosas/patología , Obesidad/patología , Proyectos Piloto , Embarazo , Primer Trimestre del Embarazo/metabolismo
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