3,389 research outputs found
Extension of the CJP model to mixed mode I and mode II
The present authors have previously proposed a novel ‘plastic inclusion’ approach for dealing withthe local plasticity which occurs at the tip of a growing fatigue crack. This meso-scale model provides amodified set of crack tip stress intensity factors that include the magnitude of plastic wake-induced crack tipshielding and which have the potential to help resolve some long-standing controversies associated withplasticity-induced closure. The present work extends the CJP model to deal with the case of mixed Mode I andMode II loading and thus opens up enhanced possibilities for testing it on inclined cracks in metallic specimens.This extension requires the addition of only one new force parameter to the model, i.e. an anti-symmetric shearforce on either side of the crack
Nature or nurture BMI and blood pressure at 90. Findings from the Belfast Elderly longitudinal free-living aging study Belfast
Hypertension is a key risk factor for stroke, cardiovascular disease and dementia. Although the link between weight, sodium and hypertension is established in younger people, little is known about their inter-relationship in people beyond 80 years of age. Associations between blood pressure, anthropometric indices and sodium were investigated in 495 apparently healthy, community-living participants (age 90, SD 4.8; range 80–106), from the cross-sectional Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST) study. In age-sex-adjusted logistic regression models, blood pressure =140/90 mmHg significantly associated with body mass index (BMI) [odds ratio (OR)?=?1.28/ kg/m2], with weight (OR?=?1.22/kg) approaching significance (P?=?0.07). In further age-sex-adjusted models, blood pressure above the 120/80 mmHg normotensive reference value significantly associated with BMI (OR?=?1.44/kg/m2), weight (OR?=?1.36/kg), skin-fold-thickness (OR?=?1.33/mm) and serum sodium (OR?=?1.37 mmol/l). In BELFAST participants over 80 years old, blood pressure =140/90 mmHg is associated with BMI, in apparently similar ways to younger groups
Duration, Cost, and Escalation of Care Events for Physical Therapy Management of Low Back Pain in Service Members With Limb Loss
Introduction Physical therapy (PT) is recommended as a primary treatment for low back pain (LBP), a common and impactful musculoskeletal condition after limb loss. The purpose of this brief report is to report the duration and cost of PT care, and subsequent escalation of care events, for LBP in service members with and without limb loss. Materials and Methods This was a retrospective cohort, descriptive study. Service members with and without limb loss (matched) who received PT for LBP at a military treatment facility from 2015 to 2017 were included. Duration of PT care, number of PT visits, and escalation of care events 1 year after PT were extracted from medical records. Escalation of care events was identified as epidural steroid injections, referrals to specialists (e.g., orthopedists, spine surgeons, and pain management), and LBP-related hospitalizations.
LBP-related PT encounters were queried; duration of care, number of visits, and cost of care were quantified. Escalation of care events, including opioid prescription, epidural steroid injections, specialty referrals, and hospitalizations, were identified up to 1 year after PT care.
Results
The average course of PT care for LBP was 12.9 more visits, 48.7 days longer, and $764.50 more expensive in service members with limb loss (n = 16) vs. those without limb loss (n = 48). Higher rates of opioid prescriptions and specialty referrals were observed in service members with limb loss.
Conclusions
This study suggests that service members with limb loss and LBP received higher quantities and longer durations of PT than those without limb loss, yielding a nearly 4 times higher cost of PT
Modeling the transboundary risk of feed ingredients contaminated with porcine epidemic diarrhea virus
Citation: Dee, S., Neill, C., Singrey, A., Clement, T., Cochrane, R., Jones, C., . . . Nelson, E. (2016). Modeling the transboundary risk of feed ingredients contaminated with porcine epidemic diarrhea virus. Bmc Veterinary Research, 12, 12. doi:10.1186/s12917-016-0674-zBackground: This study describes a model developed to evaluate the transboundary risk of PEDV-contaminated swine feed ingredients and the effect of two mitigation strategies during a simulated transport event from China to the US. Results: Ingredients imported to the USA from China, including organic & conventional soybeans and meal, lysine hydrochloride, D-L methionine, tryptophan, Vitamins A, D & E, choline, carriers (rice hulls, corn cobs) and feed grade tetracycline, were inoculated with PEDV. Control ingredients, and treatments (ingredients plus a liquid antimicrobial (SalCURB, Kemin Industries (LA) or a 2 % custom medium chain fatty acid blend (MCFA)) were tested. The model ran for 37 days, simulating transport of cargo from Beijing, China to Des Moines, IA, US from December 23, 2012 to January 28, 2013. To mimic conditions on land and sea, historical temperature and percent relative humidity (% RH) data were programmed into an environmental chamber which stored all containers. To evaluate PEDV viability over time, ingredients were organized into 1 of 4 batches of samples, each batch representing a specific segment of transport. Batch 1 (segment 1) simulated transport of contaminated ingredients from manufacturing plants in Beijing (day 1 post-contamination (PC)). Batch 2 (segments 1 and 2) simulated manufacturing and delivery to Shanghai, including time in Anquing terminal awaiting shipment (days 1-8 PC). Batch 3 (segments 1, 2 and 3) represented time in China, the crossing of the Pacific and entry to the US at the San Francisco, CA terminal (day 1-27 PC). Batch 4 (segments 1-4) represented the previous events, including transport to Des Moines, IA (days 1-37 PC). Across control (non-treated) ingredients, viable PEDV was detected in soybean meal (organic and conventional), Vitamin D, lysine hydrochloride and choline chloride. In contrast, viable PEDV was not detected in any samples treated with LA or MCFA. Conclusions: These results demonstrate the ability of PEDV to survive in a subset of feed ingredients using a model simulating shipment from China to the US. This is proof of concept suggesting that contaminated feed ingredients could serve as transboundary risk factors for PEDV, along with the identification of effective mitigation options
Ybp1 and Gpx3 signaling in Candida albicans govern hydrogen peroxide-induced oxidation of the Cap1 transcription factor and macrophage escape
Peer reviewedPublisher PD
Sulfur monoxide thermal release from an anthracene-based precursor, spectroscopic identification, and transfer reactivity
Sulfur monoxide (SO) is a highly reactive molecule and thus, eludes bulk isolation. We report here on synthesis and reactivity of a molecular precursor for SO generation, namely 7-sulfin-ylamino-7-azadibenzonorbornadiene (1). This compound has been shown to fragment readily driven by dinitrogen expulsion and anthracene formation on heating in the solid state and in solution, releasing SO at mild temperatures (<100 ◦C). The generated SO was detected in the gas phase by MS and rotational spectroscopy. In solution, 1 allows for SO transfer to organic molecules as well as transition metal complexes. Keywords: microwave spectroscopy; reactive intermediate; molecular precursor; astrochemistry; sulfur monoxid
Growth of inclined fatigue cracks using the biaxial CJP model
The CJP model of crack tip stresses is a modified version of the Williams crack tip stress field which takes account of simplified stress distributions that arise from the presence of a zone of plastic deformation associated with the crack flanks and crack tip, and that act on the elastic field responsible for driving crack growth. The elastic stress field responsible for crack growth is therefore controlled by the applied loading and by the induced boundary stresses at the interface with the plastic zone. This meso-scale model of crack tip stresses leads to a modified set of crack tip stress intensity factors that include the resultant influence of plastic wake-induced crack tip shielding, and which therefore have the potential to help resolve some longstanding controversies associated with plasticity-induced closure. A full-field approach has now been developed for stress using photoelasticity and also for displacement using digital image correlation. This paper considers the characterisation of crack growth rate data with the biaxial CJP model, using compact tension specimens that contain inclined cracks at the notch tip with initial angles of 30°, 45° and 60° to the horizontal axis. Significant experimental difficulties are experienced in growing cracks in a biaxial field under uniaxial tensile loading, as the natural tendency of the crack is to turn so that it becomes perpendicular to the maximum principal stress direction. However, crack angle is not an issue in the CJP model which calculates the stress field parallel with, and perpendicular to, the crack plane. These stress components can be rotated into directions comparable with the usual KI and KII directions and used to calculate stress intensity parameters that should be directly comparable with the standard stress intensity formulations. Another difficulty arises, however, in finding published expressions for KI and KII for CT specimens with curved or kinked cracks. The CJP model has been successful in achieving a sensible rationalisation of crack growth rate data for the specimens considered in this work, although some observations are not easily explained. Nonetheless, considering the complexity of characterising crack growth rates for cracks with an initial orientation of 30°, 45° or 60° to the horizontal and which subsequently change angle during growth, the results found so far indicate that there is value in further pursuing the CJP approach. The paper introduces future research directions for the CJP model
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