325 research outputs found
A risk ranking strategy for network level bridge management
Life-Cycle Civil Engineering - Proceedings of the 1st International Symposium on Life-Cycle Civil Engineering, IALCCE '08 2008, Pages 643-648At present almost all bridge owners and managers, i.e. Network Rail, Highways Agency and local authorities in the UK, carryout bridge inspections at regular intervals to collect information on condition and performance of bridges. Introduction of risk based approaches in the selection of inspection regimes can provide consistent safety levels within the network in a cost effective manner. This paper presents the development of a qualitative risk ranking strategy to characterize a network of bridges into groups with similar risk levels, which can form the basis for developing a risk based inspection regime over the network. There are a multitude of factors that affect risk. These factors are identified and rationally combined to present various attributes of bridges. A qualitative scoring system is then introduced which utilizes the attributes to rank bridges in terms of their relative risk. Sensitivity analysis is performed to quantify the effect of relative weights of the attributes on the risk scores. The methodology is demonstrated through its application on UK's Network Rail bridge stock comprising of about 40,000 bridges. The criteria to classify the severity of the attributes are established for the network. A random sample of bridges is ranked to illustrate the proposed methodology. © 2008 Taylor & Francis Group, London
Age- and Sex-Specific Nomographic CT Quantitative Plaque Data From a Large International Cohort.
With growing adoption of coronary computed tomographic angiography (CTA), there is increasing evidence for and interest in the prognostic importance of atherosclerotic plaque volume. Manual tools for plaque segmentation are cumbersome, and their routine implementation in clinical practice is limited.
The aim of this study was to develop nomographic quantitative plaque values from a large consecutive multicenter cohort using coronary CTA.
Quantitative assessment of total atherosclerotic plaque and plaque subtype volumes was performed in patients undergoing clinically indicated coronary CTA, using an Artificial Intelligence-Enabled Quantitative Coronary Plaque Analysis tool.
A total of 11,808 patients were included in the analysis; their mean age was 62.7 ± 12.2 years, and 5,423 (45.9%) were women. The median total plaque volume was 223 mm <sup>3</sup> (IQR: 29-614 mm <sup>3</sup> ) and was significantly higher in male participants (360 mm <sup>3</sup> ; IQR: 78-805 mm <sup>3</sup> ) compared with female participants (108 mm <sup>3</sup> ; IQR: 10-388 mm <sup>3</sup> ) (P < 0.0001). Total plaque increased with age in both male and female patients. Younger patients exhibited a higher prevalence of noncalcified plaque. The distribution of total plaque volume and its components was reported in every decile by age group and sex.
The authors developed pragmatic age- and sex-stratified percentile nomograms for atherosclerotic plaque measures using findings from coronary CTA. The impact of age and sex on total plaque and its components should be considered in the risk-benefit analysis when treating patients. Artificial Intelligence-Enabled Quantitative Coronary Plaque Analysis work flows could provide context to better interpret coronary computed tomographic angiographic measures and could be integrated into clinical decision making
Common Genetic Variation in GLP1R and Insulin Secretion in Response to Exogenous GLP-1 in Nondiabetic Subjects: A pilot study
OBJECTIVE:
Glucagon-like peptide (GLP)-1 receptor is encoded by GLP1R. The effect of genetic variation at this locus on the response to GLP-1 is unknown. This study assessed the effect of GLP1R polymorphisms on insulin secretion in response to hyperglycemia and to infused GLP-1 in nondiabetic subjects.
RESEARCH DESIGN AND METHODS:
Eighty-eight healthy individuals (aged 26.3 +/- 0.6 years, fasting glucose 4.83 +/- 0.04 mmol/l) were studied using a hyperglycemic clamp. GLP-1 was infused for the last 2 h of the study (0.75 pmol/kg/min over 121-180 min, 1.5 pmol/kg/min over 181-240 min). beta-Cell responsivity (Phi(Total)) was measured using a C-peptide minimal model. The effect of 21 tag single nucleotide polymorphisms (SNPs) in GLP1R on Phi(Total) was examined.
RESULTS:
Two SNPs (rs6923761 and rs3765467) were nominally associated with altered beta-cell responsivity in response to GLP-1 infusion.
CONCLUSIONS:
Variation in GLP1R may alter insulin secretion in response to exogenous GLP-1. Future studies will determine whether such variation accounts for interindividual differences in response to GLP-1-based therapy
Does Integrating Cognitive and Psychological Interventions Enhance Wellbeing After Acquired Brain Injury? Study Protocol for a Phase II Randomized Controlled Trial of the VaLiANT (Valued Living After Neurological Trauma) Group Program
Background and ObjectivesCognitive and emotional changes affect the majority of individuals with acquired brain injury (ABI) and are associated with poorer outcomes. The evidence for “siloed” rehabilitation approaches targeting cognition and mood separately remains mixed. Valued living (i.e., acting consistently with personal values) is associated with better psychological functioning and participation in work and other productive activities. Rehabilitation interventions that concurrently address cognitive and emotional barriers to valued living may therefore result in improved outcomes. VaLiANT (Valued Living After Neurological Trauma) is an 8-week group intervention developed by our team, which uniquely combines cognitive rehabilitation and psychological therapy to improve wellbeing and meaningful participation (i.e., valued living) following ABI.MethodThis protocol describes the design and implementation of a Phase II parallel-group randomized controlled trial with blinded outcome assessors, to evaluate the potential efficacy of VaLiANT and the feasibility of a Phase III trial. Participants are adults with a history of ABI at least 3 months prior to study entry, who experience cognitive and/or emotional difficulties and associated reduced participation in valued activities. Random allocation to the treatment condition (8-week VaLiANT group program) or a usual care waitlist control condition occurs at a 2:1 treatment: control ratio. The primary outcome is wellbeing, measured by the Warwick-Edinburgh Mental Wellbeing Scale. Secondary outcomes include measures of valued living, mood, cognitive complaints, quality of life, community participation, post-traumatic growth, and self-efficacy. All measures are collected across three time points by blinded assessors (baseline, 8-week follow-up, 16-week follow-up). Trial feasibility will be evaluated against recruitment rates, drop-out rates, intervention acceptability, and treatment fidelity (manual adherence and therapist competence).DiscussionThis trial will extend current knowledge on how to improve long-term outcomes following ABI by evaluating an innovative integrated, multi-domain approach to rehabilitation concurrently addressing cognitive and emotional barriers to participation in meaningful life roles
Dedicated plug based closure for large bore access -The MARVEL prospective registry
Objectives To study safety and performance of the MANTA Vascular closure device (VCD) under real world conditions in 10 centers. Background The MANTA is a novel plug-based device for large bore arteriotomy closure. Methods We included all eligible patients who underwent transfemoral large bore percutaneous procedures. Exclusion criteria were per operator's discretion and included severe calcification or marked tortuosity of the access vessel, presence of marked obesity/cachexia or a systolic blood pressure above 180 mmHg. The primary performance endpoint was time to hemostasis. Primary and secondary safety endpoints were major and minor access site related vascular complications up to 30 days, respectively. Vascular complications were adjudicated by an independent clinical event committee according to VARC-2 criteria. We performed multivariable logistic regression to estimate the effect of baseline and procedural characteristics on any and major vascular complications. Results Between February 2018 and July 2019 500 patients were enrolled undergoing Transcatheter aortic valve replacement (TAVR, N = 496), Balloon aortic valvuloplasty (BAV, N = 2), Mechanical circulatory support (MCS, N = 1) or Endovascular aneurysm repair (EVAR, N = 1). Mean age was 80.8 +/- 6.6 years with a median STS-score of 2.7 [IQR 2.0-4.3] %. MANTA access site complications were major in 20 (4%) and minor in 28 patients (5.6%). Median time to hemostasis was 50 [IQR 20-120] sec. Severe femoral artery calcification, scar presence in groin, longer procedure duration, female gender and history of hypertension were independent predictors for vascular complications. Conclusion In this study, MANTA appeared to be a safe and effective device for large bore access closure under real-world conditions.Peer reviewe
Loss of viability during freeze-thaw of intact and adherent human embryonic stem cells with conventional slow-cooling protocols is predominantly due to apoptosis rather than cellular necrosis
10.1007/s11373-005-9051-9Journal of Biomedical Science133433-44
Impact of Rheumatic Musculoskeletal Disease on Psychological Development in Adolescents and Young Adults
Adolescents and young adults (AYAs) undergo significant physiological and psychological transformations. When developmental milestones are combined with additional challenges of growing up with a chronic rheumatic musculoskeletal disease (RMD), it can increase AYA's susceptibility to psychological problems. Emotional issues in adolescence can often persist into adulthood and negatively impact future health, social, and work outcomes. This chapter summarises psychological challenges for AYAs and recommends ways for healthcare professionals (HCPs) to promote mental wellbeing in AYAs with RMD
Paternal effect on genomic activation, clinical pregnancy and live birth rate after ICSI with cryopreserved epididymal versus testicular spermatozoa
<p>Abstract</p> <p>Background</p> <p>This study takes an in depth look at embryonic development, implantation, pregnancy and live birth rates with frozen epididymal and testicular sperm from obstructed (OA) and non-obstructed (NOA) patients.</p> <p>Methods</p> <p>Paternal effect of sperm source on zygote formation, embryonic cleavage, and genomic activation were examined. Additional outcome parameters monitored were clinical pregnancy rate (CPR), implantation rate (IR) and live birth rate.</p> <p>Results</p> <p>In this report, we retrospectively analyzed 156 ICSI cycles using cryopreserved epididymal sperm (ES; n = 77) or testicular sperm (TESE; n = 79). The developmental potential of embryos did not appear to be influenced by the type of surgically retrieved sperm. The average number of blastomeres observed on Day 3 was not different among different groups; 7.5 +/- 1.7 (ES), 7.6 +/- 2.1 (TESE-OA) and 6.5 +/- 2.3 (TESE-NOA). Compaction and blastulation rates, both indicators of paternal genomic activation, were similar in embryos derived from ICSI with ES or TESE from OA as well as NOA men. The only parameter significantly affected in NOA-TESE cases was the fertilization rate. CPR and IR with cryopreserved TESE (TESE-OA 59%, 34%, and TESE-NOA 37%, 20%) were also not statistically different, from that achieved with cryopreserved ES (61% and 39%). Live birth rates also appeared to be independent of sperm type. The 87 clinical pregnancies established using cryopreserved TESE and ES, resulted in the birth of 115 healthy infants. No congenital anomalies were noted.</p> <p>Conclusion</p> <p>Zygotic activation seems to be independent of sperm origin and type of azoospermia.</p
Age-Associated Metabolic and Morphologic Changes in Mitochondria of Individual Mouse and Hamster Oocytes
Background: In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus) and mouse (Mus musculus) ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte.
Methodology/Principal Findings: Individual metaphase II oocytes from a total of 25 young and old mice and hamsters were collected from ovarian follicles after hormone stimulation and prepared for biochemical or structural analysis. Adenosine triphosphate levels and mitochondrial DNA number were determined within individual oocytes from young and old animals. In aged hamsters, oocyte adenosine triphosphate levels and mitochondrial DNA molecules were reduced 35.4% and 51.8%, respectively. Reductions of 38.4% and 44% in adenosine triphosphate and mitochondrial genomes, respectively, were also seen in aged mouse oocytes. Transmission electron microscopic (TEM) analysis showed that aged rodent oocytes had significant alterations in mitochondrial and cytoplasmic lamellae structure.
Conclusions/Significance: In both mice and hamsters, decreased adenosine triphosphate in aged oocytes is correlated with a similar decrease in mtDNA molecules and number of mitochondria. Mitochondria in mice and hamsters undergo significant morphological change with aging including mitochondrial vacuolization, cristae alterations, and changes in cytoplasmic lamellae
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