867 resultados para Slag replacement
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Background Numerous studies demonstrate the generation and short-term survival of adipose tissue; however, long-term persistence remains elusive. This study evaluates long-term survival and transferability of de novo adipose constructs based on a ligated vascular pedicle and tissue engineering chamber combination. Methods Defined adipose tissue flaps were implanted into rats in either intact or perforated domed chambers. In half of the groups, the chambers were removed after 10 weeks and the constructs transferred on their vascular pedicle to a new site, where they were observed for a further 10 weeks. In the remaining groups, the tissue construct was observed for 20 weeks inside the chamber. Tissue volume was assessed using magnetic resonance imaging and histologic measures, and constructs were assessed for stability and necrosis. Sections were assessed histologically and for proliferation using Ki-67. Results At 20 weeks, volume analysis revealed an increase in adipose volume from 0.04 ± 0.001 ml at the time of insertion into the chambers to 0.27 ± 0.004 ml in the closed and 0.44 ± 0.014 ml in the perforated chambers. There was an additional increase of approximately 10 to 15 percent in tissue volume in flaps that remained in chambers for 20 weeks, whereas the volume of the transferred tissue not in chambers remained unaltered. Histomorphometric assessment of the tissues documented no signs of hypertrophy, fat necrosis, or atypical changes of the newly generated tissue. Conclusion This study presents a promising new method of generating significant amounts of mature, vascularized, stable, and transferable adipose tissue for permanent autologous soft-tissue replacement.
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Mortality following hip arthroplasty is affected by a large number of confounding variables each of which must be considered to enable valid interpretation. Relevant variables available from the 2011 NJR data set were included in the Cox model. Mortality rates in hip arthroplasty patients were lower than in the age-matched population across all hip types. Age at surgery, ASA grade, diagnosis, gender, provider type, hip type and lead surgeon grade all had a significant effect on mortality. Schemper's statistic showed that only 18.98% of the variation in mortality was explained by the variables available in the NJR data set. It is inappropriate to use NJR data to study an outcome affected by a multitude of confounding variables when these cannot be adequately accounted for in the available data set.
A smoking cessation intervention for people with chronic Hepatitis C : a randomised controlled trial
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Purpose The purpose of this study was to examine the validity of current practice in smoking cessation for the general population i.e., a telephone counselling and nicotine replacement therapy (NRT) intervention and its applicability to people with chronic hepatitis-C. Methods A randomised controlled trial was conducted over twelve weeks. Following consent, ninety-two smokers (outpatients) with chronic hepatitis-C were recruited by the Nurse Practitioner hepatology, randomly assigned and stratified by number of cigarettes smoked (i.e., 15 and greater; <15) into the intervention group (telephone counselling and NRT) and control group (telephone counselling). Outcomes measured included socio-demographics, nicotine dependence, depression, anxiety and stress and quality of life (QOL). All statistical data were analysed using SPSS. Results After 12 weeks, the intervention group showed a sustained reduction of smoking i.e., 5.8(CI: 2.4,9.3) cigarettes less per day, whereas the control group showed 1.6(CI:-1.9,5.2) cigarette reduction. Although not statistically significantly different (F=2.9, p=0.090) the intervention group on average smoked 4.2 fewer cigarettes compared to the control group. After twelve weeks, seven patients in the intervention group and three patients in the control group reported quitting. Whilst not statistically significant (Fisher’s Exact, p=0.311) this was a clinically significant result. No differences were found for nicotine dependence or depression, anxiety and stress. The intervention group experienced no change in QOL (-0.1,CI:-0.9, 0.6), however, the environmental score for the control group decreased by 1.8(CI:1.0, 2.6,p= 0.001). This was statistically significant. Conclusion A telephone counselling and nicotine replacement therapy intervention from the nurse practitioner, hepatology reduced smoking in patients with chronic hepatitis-C. The intervention group showed a sustained reduction over the 12 weeks. A total of 10 patients quit smoking at the end of the study. QOL deteriorated in the environmental subscale for the control group. These results informed a nurse practitioner model of care for approaches to smoking cessation.
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SUMMARY: Recently, the use of the pharmacological agent strontium ranelate has come to prominence for the treatment of osteoporosis. While much investigation is focused on preventing disease progression, here we fabricate strontium-containing scaffolds and show that they enhance bone defect healing in the femurs of rats induced by ovariectomy. INTRODUCTION: Recently, the use of the pharmacological agent strontium ranelate has come to prominence for the treatment of osteoporosis due to its ability to prevent bone loss in osteoporotic patients. Although much emphasis has been placed on using pharmacological agents for the prevention of disease, much less attention has been placed on the construction of biomaterials following osteoporotic-related fracture. The aim of the present study was to incorporate bioactive strontium (Sr) trace element into mesoporous bioactive glass (MBG) scaffolds and to investigate their in vivo efficacy for bone defect healing in the femurs of rats induced by ovariectomy. METHODS: In total, 30 animals were divided into five groups as follows: (1) empty defect (control), (2) empty defects with estrogen replacement therapy, (3) defects filled with MBG scaffolds alone, (4) defects filled with MBG + estrogen replacement therapy, and (5) defects filled with strontium-incorporated mesopore-bioglass (Sr-MBG) scaffolds. RESULTS: The two groups demonstrating the highest levels of new bone formation were the defects treated with MBG + estrogen replacement therapy and the defects receiving Sr-MBG scaffolds as assessed by μ-CT and histological analysis. Furthermore, Sr scaffolds had a reduced number of tartrate-resistant acid phosphatase-positive cells when compared to other modalities. CONCLUSION: The results from the present study demonstrate that the local release of Sr from bone scaffolds may improve fracture repair. Future large animal models are necessary to investigate the future relationship of Sr incorporation into biomaterials.
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Background Research has identified associations between serum 25(OH)D and a range of clinical outcomes in chronic kidney disease and wider populations. The present study aimed to investigate vitamin D deficiency/insufficiency in dialysis patients and the relationship with vitamin D intake and sun exposure. Methods A cross-sectional study was used. Participants included 30 peritoneal dialysis (PD) (43.3% male; 56.87 ± 16.16 years) and 26 haemodialysis (HD) (80.8% male; 63.58 ± 15.09 years) patients attending a department of renal medicine. Explanatory variables were usual vitamin D intake from diet/supplements (IU day−1) and sun exposure (min day−1). Vitamin D intake, sun exposure and ethnic background were assessed by questionnaire. Weight, malnutrition status and routine biochemistry were also assessed. Data were collected during usual department visits. The main outcome measure was serum 25(OH)D (nm). Results Prevalence of inadequate/insufficient vitamin D intake differed between dialysis modality, with 31% and 43% found to be insufficient (<50 nm) and 4% and 33% found to be deficient (<25 nm) in HD and PD patients, respectively (P < 0.001). In HD patients, there was a correlation between diet and supplemental vitamin D intake and 25(OH)D (ρ = 0.84, P < 0.001) and average sun exposure and 25(OH)D (ρ = 0.50, P < 0.02). There were no associations in PD patients. The results remained significant for vitamin D intake after multiple regression, adjusting for age, gender and sun exposure. Conclusions The results highlight a strong association between vitamin D intake and 25(OH)D in HD but not PD patients, with implications for replacement recommendations. The findings indicate that, even in a sunny climate, many dialysis patients are vitamin D deficient, highlighting the need for exploration of determinants and consequences.
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A novel solution processable donor-acceptor (D-A) based low band gap polymer semiconductor poly{3,6-difuran-2-yl-2,5-di(2-octyldodecyl)-pyrrolo[3,4- c]pyrrole-1,4-dione-alt-thienylenevinylene} (PDPPF-TVT), was designed and synthesized by a Pd-catalyzed Stille coupling route. An electron deficient furan based diketopyrrolopyrrole (DPP) block and electron rich thienylenevinylene (TVT) donor moiety were attached alternately in the polymer backbone. The polymer exhibited good solubility, film forming ability and thermal stability. The polymer exhibits wide absorption bands from 400 nm to 950 nm (UV-vis-NIR region) with absorption maximum centered at 782 nm in thin film. The optical band gap (Eoptg) calculated from the polymer film absorption onset is around 1.37 eV. The π-energy band level (ionization potential) calculated by photoelectron spectroscopy in air (PESA) for PDPPF-TVT is around 5.22 eV. AFM and TEM analyses of the polymer reveal nodular terrace morphology with optimized crystallinity after 200 °C thermal annealing. This polymer exhibits p-channel charge transport characteristics when used as the active semiconductor in organic thin-film transistor (OTFT) devices. The highest hole mobility of 0.13 cm 2 V -1 s -1 is achieved in bottom gate and top-contact OTFT devices with on/off ratios in the range of 10 6-10 7. This work reveals that the replacement of thiophene by furan in DPP copolymers exhibits such a high mobility, which makes DPP furan a promising block for making a wide range of promising polymer semiconductors for broad applications in organic electronics.
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The environmental performance of a listed firm could affect its level of investment in pollution prevention and its access to financial markets. Previous studies using Tobin's q that explore market response to environmental performance do not distinguish between the impact of performance on investment and market response, which may mislead conclusions. To overcome this problem, we simultaneously estimate the functions of the intangible asset, the replacement cost, and the toxic chemical risk. We find that the Japanese financial market does not value risk associated with toxic chemical releases. Nevertheless, even without market valuation, firms increase investment to reduce pollution. © 2010 by the Board of Regents of the University of Wisconsin System.
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This study compared proximal femoral morphology in patients living in soft and hard water regions. The proximal femoral morphology of two groups of 70 patients living in hard and soft water regions with a mean age of 72.3 (range 50 to 87 years) were measured using an antero-posterior radiograph of the non-operated hip with magnification adjusted. The medullary canal diameter at the level of the lesser trochanter (LT) was significantly wider in patients living in the hard water region (mean width 1.9 mm wider; p= 0.003). No statistical significant difference was found in the medullary canal width at 10 cm below the level of LT, Dorr index, or Canal Bone Ratio (CBR). In conclusion, the proximal femoral morphology does differ in patients living in soft and hard water areas. These results may have an important clinical bearing in patients undergoing total hip replacement surgery. Further research is needed to determine whether implant survivorship is affected in patients living in hard and soft water regions.
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A method for calculating visual odometry for ground vehicles with car-like kinematic motion constraints similar to Ackerman's steering model is presented. By taking advantage of this non-holonomic driving constraint we show a simple and practical solution to the odometry calculation by clever placement of a single camera. The method has been implemented successfully on a large industrial forklift and a Toyota Prado SUV. Results from our industrial test site is presented demonstrating the applicability of this method as a replacement for wheel encoder-based odometry for these vehicles.
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Young males are over-represented in road crashes. Part of the problem is their proneness to boredom, a hardwired personality factor that can lead to risky driving. This paper presents a theoretical understanding of boredom in the driving context and demonstrates convincing arguments to investigate the role of boredom further. Specifically, this paper calls for the design of innovative technologies and applications that make safe driving more pleasurable and stimulating for young males, e.g., by applying gamification techniques. We propose two design concepts through the following questions: A. Can the simulation of risky driving reduce actual risky driving? B. Can the replacement of risky driving stimuli with alternative stimuli reduce risky driving? We argue that considering these questions in the future design of automotive user-interfaces and personal ubiquitous computing devices could effectively reduce risky driving behaviours among young males.
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Genetically diverse RNA viruses like dengue viruses (DENVs)segregate into multiple, genetically distinct, lineages that temporally arise and disappear on a regular basis. Lineage turnover may occur through multiple processes such as, stochastic or due to variations in fitness. To determine the variation of fitness, we measured the distribution of fitness within DENV populations and correlated it with lineage extinction and replacement. The fitness of most members within a population proved lower than the aggregate fitness of populations from which they were drawn, but lineage replacement events were not associated with changes in the distribution of fitness. These data provide insights into variations in fitness of DENV populations, extending our understanding of the complexity between members of individual populations.
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Background Chronic kidney disease is a global public health problem of increasing prevalence. There are five stages of kidney disease, with Stage 5 indicating end stage kidney disease (ESKD) requiring dialysis or death will eventually occur. Over the last two decades there have been increasing numbers of people commencing dialysis. A majority of this increase has occurred in the population of people who are 65 years and over. With the older population it is difficult to determine at times whether dialysis will provide any benefit over non-dialysis management. The poor prognosis for the population over 65 years raises issues around management of ESKD in this population. It is therefore important to review any research that has been undertaken in this area which compares outcomes of the older ESKD population who have commenced dialysis with those who have received non-dialysis management. Objective The primary objective was to assess the effect of dialysis compared with non-dialysis management for the population of 65 years and over with ESKD. Inclusion criteria Types of participants This review considered studies that included participants who were 65 years and older. These participants needed to have been diagnosed with ESKD for greater than three months and also be either receiving renal replacement therapy (RRT) (hemodialysis [HD] or peritoneal dialysis [PD]) or non-dialysis management. The settings for the studies included the home, self-care centre, satellite centre, hospital, hospice or nursing home. Types of intervention(s)/phenomena of interest This review considered studies where the intervention was RRT (HD or PD) for the participants with ESKD. There was no restriction on frequency of RRT or length of time the participant received RRT. The comparator was participants who were not undergoing RRT. Types of studies This review considered both experimental and epidemiological study designs including randomized controlled trials, non-randomized controlled trials, quasi-experimental, before and after studies, prospective and retrospective cohort studies, case control studies and analytical cross sectional studies. This review also considered descriptive epidemiological study designs including case series, individual case reports and descriptive cross sectional studies for inclusion. This review included any of the following primary and secondary outcome measures: •Primary outcome – survival measures •Secondary outcomes – functional performance score (e.g. Karnofsky Performance score) •Symptoms and severity of end stage kidney disease •Hospital admissions •Health related quality of life (e.g. KDQOL, SF36 and HRQOL) •Comorbidities (e.g. Charlson Comorbidity index).