71 research outputs found

    Preconception Care and Treatment with Assisted Reproductive Technologies

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    Couples with fertility problems seeking treatment with assisted reproductive technologies (ART) such as in vitro fertilization should receive preconception counseling on all factors that are provided when counseling patients without fertility problems. Additional counseling should address success rates and possible risks from ART therapies. Success rates from ART are improving, with the highest live birth rates averaging about 40% per cycle among women less than 35 years old. A woman’s age lowers the chance of achieving a live birth, as do smoking, obesity, and infertility diagnoses such as hydrosalpinx, uterine leiomyoma, or male factor infertility. Singletons conceived with ART may have lower birth weights. Animal studies suggest that genetic imprinting disorders may be induced by certain embryo culture conditions. The major risk from ovarian stimulation is multiple gestation. About one-third of live-birth deliveries from ART have more than one infant, and twins represent 85% of these multiple-birth children. There are more complications in multiple gestation pregnancies, infants are more likely to be born preterm and with other health problems, and families caring for multiples experience more stress. Transferring fewer embryos per cycle reduces the multiple birth rate from ART, but the patient may have to pay for additional cycles of ART because of a lower likelihood of pregnancy

    The quest for the solar g modes

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    Solar gravity modes (or g modes) -- oscillations of the solar interior for which buoyancy acts as the restoring force -- have the potential to provide unprecedented inference on the structure and dynamics of the solar core, inference that is not possible with the well observed acoustic modes (or p modes). The high amplitude of the g-mode eigenfunctions in the core and the evanesence of the modes in the convection zone make the modes particularly sensitive to the physical and dynamical conditions in the core. Owing to the existence of the convection zone, the g modes have very low amplitudes at photospheric levels, which makes the modes extremely hard to detect. In this paper, we review the current state of play regarding attempts to detect g modes. We review the theory of g modes, including theoretical estimation of the g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the techniques that have been used to try to detect g modes. We review results in the literature, and finish by looking to the future, and the potential advances that can be made -- from both data and data-analysis perspectives -- to give unambiguous detections of individual g modes. The review ends by concluding that, at the time of writing, there is indeed a consensus amongst the authors that there is currently no undisputed detection of solar g modes.Comment: 71 pages, 18 figures, accepted by Astronomy and Astrophysics Revie

    Angiogenesis inhibitors in clinical development; where are we now and where are we going?

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    Angiogenesis is crucial for tumour growth and the formation of metastases. Various classes of angiogenesis inhibitors that are each able to inhibit one of the various steps of this complex process can be distinguished. Results from clinical studies with these agents are summarised. In general, it has been shown that most angiogenesis inhibitors can be safely administered, but that tumour regressions are rare. Combining angiogenesis inhibitors with cytotoxic chemotherapy can enhance anticancer activity. Recently, some promising data with regard to clinical efficacy have been presented. While performing clinical studies with angiogenesis inhibitors, defining biological activity is crucial, but thus far no validated techniques are available. It is conceivable that in the near future various classes of angiogenesis inhibitors will be combined in an attempt to further improve antiangiogenic and anticancer activity

    Participants’ perspectives on mindfulnessbased cognitive therapy for inflammatory bowel disease: a qualitative study nested within a pilot randomised controlled trial

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    Background: Mindfulness-based interventions have shown to improve depression and anxiety symptoms as well as quality of life in patients with inflammatory bowel disease (IBD). However, little is known about the experiences of this group of patients participating in mindfulness interventions. This paper sets out to explore the perspectives of patients with IBD recruited to a pilot randomised controlled trial (RCT) of mindfulness-based cognitive therapy (MBCT) about the intervention. Methods: In a qualitative study nested within a parallel two-arm pilot RCT of mindfulness-based cognitive therapy for patients with IBD, two focus group interviews (using the same schedule) and a free text postal survey were conducted. Data from both were analysed using thematic analysis. Data and investigator triangulation was performed to enhance confidence in the ensuing findings. Forty-four patients with IBD were recruited to the pilot RCT from gastroenterology outpatient clinics from two Scottish NHS boards. Eighteen of these patients (ten from mindfulness intervention and eight from control group) also completed a postal survey and participated in two focus groups after completing post intervention assessments. Results: The major themes that emerged from the data were the following: perceived benefits of MBCT for IBD, barriers to attending MBCT and expectations about MBCT. Participants identified MBCT as a therapeutic, educational and an inclusive process as key benefits of the intervention. Key barriers included time and travel constraints. Conclusions: This qualitative study has demonstrated the acceptability of MBCT in a group of patients with IBD. Participants saw MBCT as a therapeutic and educational initiative that transformed their relationship with the illness. The inclusive process and shared experience of MBCT alleviated the sense of social isolation commonly associated with IBD. However, time commitment and travel were recognised as a barrier to MBCT which could potentially influence the degree of therapeutic gain from MBCT for some participants. Keywords: Inflammatory bowel disease, Mindfulness, MBCT, Focus groups, Qualitative stud

    Limits on active to sterile neutrino oscillations from disappearance searches in the MINOS, Daya Bay, and bugey-3 experiments

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    Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^2 2θμe are set over 6 orders of magnitude in the sterile mass-squared splitting Δm^2 41. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm^2 41 < 0.8 eV^2 at 95% CLs

    Modelling the Cryopreservation Process of a Suspension of Cells: The Effect of a Size-Distributed Cell Population

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    Cryopreservation of biological material is a crucial step of tissue engineering, but biological material can be damaged by the cryopreservation process itself. Depending on some bio-physical properties that change from cell to cell lineages, an optimum cryopreservation protocol needs to be identified for any cell type to maximise post-thaw cell viability. Since a prohibitively large set of operating conditions has to be determined to avoid the principal origins of cell damage (i.e., ice formation and solution injuries), mathematical modelling represents a valuable alternative to experimental optimisation. The theoretical analysis traditionally adopted for the cryopreservation of a cell suspension addresses only a single, average cell size and ascribes the experimental evidence of different ice formation temperatures to statistical variations. In this chapter our efforts to develop a novel mathematical model based on the population balance approach that comprehensively takes into account the size distribution of a cell population are reviewed. According to this novel approach, a sound explanation for the experimental evidence of different ice formation temperatures may now be given by adopting a fully deterministic criterion based on the size distribution of the cell population. In this regard, the proposed model represents a clear novelty for the cryopreservation field and provides an original perspective to interpret system behaviour as experimentally measured so far. First our efforts to successfully validate the proposed model by comparison with suitable experimental data taken from the literature are reported. Then, in absence of suitable experimental data, the model is used to theoretically investigate system behaviour at various operating conditions. This is done both in absence or presence of a cryo-protectant agent, as well as when the extra-cellular ice is assumed to form under thermodynamic equilibrium or its dynamics is taken into account consistently by means of an additional population balance. More specifically, the effect of the cell size distribution on system behaviour when varying cooling rate and cryo-protectant content within practicable values for a standard cryopreservation protocol is investigated. It is demonstrated that, cell survival due to intra-cellular ice formation depends on the initial cell size distribution and its osmotic parameters. At practicable operating conditions in terms of cooling rate and cryo-protectant concentration, intra-cellular ice formation may be lethal for the fraction of larger size classes of the cell population whilst it may not reach a dangerous level for the intermediate size class cells and it will not even take place for the smaller ones
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