499 research outputs found
Preliminary report on the rate of apoptosis in human first and third trimester placentae
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Sequential use of letrozole and gonadotrophin in women with poor ovarian reserve: a randomized controlled trial
Sequential use of letrozole and human menopausal gonadotrophin (HMG) was compared with HMG only in poor ovarian responders undergoing IVF. Patients (n=53) with less than four oocytes retrieved in previous IVF cycles or less than five antral follicles were randomized to either letrozole for 5days followed by HMG or HMG alone. The letrozole group had lower dosage of HMG (P<0.001), shorter duration of HMG (P<0.001) and fewer oocytes (P=0.001) when compared with controls. Live-birth rate was comparable with a lower miscarriage rate in the letrozole group (P=0.038). Serum FSH concentrations were comparable in both groups except on day 8, while oestradiol concentrations were all lower in the letrozole group from day 4 (all P<0.001). Follicular fluid concentrations of testosterone, androstenedione, FSH and anti-Mullerian hormone were higher in the letrozole group (P=0.009, P=0.001, P=0.046 and P=0.034, respectively). Compared with HMG alone, sequential use of letrozole and HMG in poor responders resulted in significantly lower total dosage and shorter duration of HMG, a comparable live-birth rate, a significantly lower miscarriage rate and a more favourable hormonal environment of follicular fluid. The management of poor ovarian responders or women with poor ovarian reserve in IVF is controversial. The use of letrozole has been studied; however, results are inconsistent. This randomized trial studied the sequential use of letrozole and gonadotrophin compared with gonadotrophin alone in poor responders undergoing IVF. The sequential use of letrozole and gonadotrophin led to a significantly lower dosage and shorter duration of gonadotrophin use, significantly fewer oocytes, comparable live-birth rate, a significantly lower miscarriage rate and a more favourable hormonal environment at a lower cost.postprin
Mechanisms of Peptide Oxidation by Hydroxyl Radicals: Insight at the Molecular Scale
Molecular dynamics (MD) simulations were performed to provide atomic scale insight in the initial interaction between hydroxyl radicals (OH) and peptide systems in solution. These OH radicals are representative reactive oxygen species produced by cold atmospheric plasmas. The use of plasma for biomedical applications is gaining increasing interest, but the fundamental mechanisms behind the plasma modifications still remain largely elusive. This study helps to gain more insight in the underlying mechanisms of plasma medicine but is also more generally applicable to peptide oxidation, of interest for other applications. Combining both reactive and nonreactive MD simulations, we are able to elucidate the reactivity of the amino acids inside the peptide systems and their effect on their structure up to 1 μs. Additionally, experiments were performed, treating the simulated peptides with a plasma jet. The computational results presented here correlate well with the obtained experimental data and highlight the importance of the chemical environment for the reactivity of the individual amino acids, so that specific amino acids are attacked in higher numbers than expected. Furthermore, the long time scale simulations suggest that a single oxidation has an effect on the 3D conformation due to an increase in hydrophilicity and intra- and intermolecular interactions
Consumption of dried fruit of Crataegus pinnatifida (hawthorn) suppresses high-cholesterol diet-induced hypercholesterolemia in rats
Author name used in this publication: Mabel Yin-Chun YauAuthor name used in this publication: Peter Hoi-Fu Yu2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Evaluation of anti-oxidant capacity of root of Scutellaria baicalensis Georgi, in comparison with roots of polygonum multiflorum thunb and Panax ginseng CA Meyer
Author name used in this publication: Jian-Hong WuAuthor name used in this publication: Alice Lai-Shan AuAuthor name used in this publication: Peter Hoi-Fu Yu2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Handover Scenarios for Mobile WiMAX and Wireless LAN Heterogeneous Network
This paper presents proposed handover scenarios for a heterogeneous network comprising mobile worldwide interoperability for Microwave Access and Wireless Local Area Network segments. Homogenous handover scenarios for a mobile WiMAX network are also considered to allow a comparative analysis. A mobile node supporting voice traffic is analysed, when operating in a half-cell overlap coverage scenario, for both pedestrian and vehicular speeds. All proposed handover scenarios are assessed and validated through system-level Media Independent Handover network simulations. Results for both homogenous and heterogeneous handover show that the handover delay and jitter are within the acceptable values published by the WiMAX Forum. For heterogeneous handover, the packet loss is negligible for all cases; however, there were significant occurrences of packet loss in throughput for homogenous handover at vehicular speeds. This is due to the fact that the implementation of an adaptive channel scanning algorithm to allocate scanning intervals can limit communication disruptions
Building Information Modeling Education for Quantity Surveyors in Hong Kong: Current States, Education Gaps, and Challenges
Rapid developments in building information modeling (BIM) are escalating the architecture, engineering, and construction (AEC) industry toward digital transformation. However, the lack of skilled BIM professionals is a critical issue slowing this transformation. Currently, few educational institutions include BIM topics in their curricula, especially those developed for quantity surveying (QS) programs. Moreover, the learning outcomes of BIM curricula may not meet the current industrial requirements. Thus, this study investigated the current states, gaps, and challenges of BIM education for QS practices in Hong Kong. This study conducted surveys to determine industrial requirements and a case study to examine the BIM curricula currently offered at Hong Kong educational institutions. The results suggest that the current BIM education for QS practices is in line with the pace of BIM development in the AEC industry. However, some advanced topics are not covered in BIM education. Additionally, the non-standardized BIM competencies to be attained by students lead to uncertainty and challenges in BIM education for quantity surveyors.Publishe
The regulation of pulmonary vascular tone by neuropeptides and the implications for pulmonary hypertension
© 2018 Lo, Moosavi and Bubb. Pulmonary hypertension (PH) is an incurable, chronic disease of small pulmonary vessels. Progressive remodeling of the pulmonary vasculature results in increased pulmonary vascular resistance (PVR). This causes secondary right heart failure. PVR is tightly regulated by a range of pulmonary vasodilators and constrictors. Endothelium-derived substances form the basis of most current PH treatments. This is particularly the case for pulmonary arterial hypertension. The major limitation of current treatments is their inability to reverse morphological changes. Thus, there is an unmet need for novel therapies to reduce the morbidity and mortality in PH. Microvessels in the lungs are highly innervated by sensory C fibers. Substance P and calcitonin gene-related peptide (CGRP) are released from C-fiber nerve endings. These neuropeptides can directly regulate vascular tone. Substance P tends to act as a vasoconstrictor in the pulmonary circulation and it increases in the lungs during experimental PH. The receptor for substance P, neurokinin 1 (NK1R), mediates increased pulmonary pressure. Deactivation of NK1R with antagonists, or depletion of substance P prevents PH development. CGRP is a potent pulmonary vasodilator. CGRP receptor antagonists cause elevated pulmonary pressure. Thus, the balance of these peptides is crucial within the pulmonary circulation (Graphical Abstract). Limited progress has been made in understanding their impact on pulmonary pathophysiology. This is an intriguing area of investigation to pursue. It may lead to promising new candidate therapies to combat this fatal disease. This review provides a summary of the current knowledge in this area. It also explores possible future directions for neuropeptides in PH
When do myopia genes have their effect? Comparison of genetic risks between children and adults
Previous studies have identified many genetic loci for refractive error and myopia. We aimed to investigate the effect of these loci on ocular biometry as a function of age in children, adolescents, and adults. The study population consisted of three age groups identified from the international CREAM consortium: 5,490 individuals aged 25 years. All participants had undergone standard ophthalmic examination including measurements of axial length (AL) and corneal radius (CR). We examined the lead SNP at all 39 currently known genetic loci for refractive error identified from genome-wide association studies (GWAS), as well as a combined genetic risk score (GRS). The beta coefficient for association between SNP genotype or GRS versus AL/CR was compared across the three age groups, adjusting for age, sex, and principal components. Analyses were Bonferroni-corrected. In the age group <10 years, three loci (GJD2, CHRNG, ZIC2) were associated with AL/CR. In the age group 10–25 years, four loci (BMP2, KCNQ5, A2BP1, CACNA1D) were associated; and in adults 20 loci were associated. Association with GRS increased with age; β = 0.0016 per risk allele (P = 2 × 10–8) in <10 years, 0.0033 (P = 5 × 10–15) in 10- to 25-year-olds, and 0.0048 (P = 1 × 10–72) in adults. Genes with strongest effects (LAMA2, GJD2) had an early effect that increased with age. Our results provide insights on the age span during which myopia genes exert their effect. These insights form the basis for understanding the mechanisms underlying high and pathological myopia
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