2,068 research outputs found

    The Prevalence and Clinical Correlates of an Auscultatory Gap in Systemic Sclerosis Patients

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    Introduction. Accurate blood pressure (BP) measurement is essential to the diagnosis and management of hypertension in patients with systemic sclerosis (SSc) to help prevent renal and cardiovascular complications. The presence of an auscultatory gap during manual BP measurementā€”the temporary disappearance of the Korotkoff sounds during cuff deflationā€”leads to a potentially important underestimate of systolic BP if undetected. Objectives. Since the presence of an auscultatory gap is frequently associated with increased vascular stiffness, we investigated its presence and correlates in 50 consecutive SSc patients. Methods. For each patient, BP was measured sequentially using three different approaches performed in the same order. Results. Sixteen of 50 patients (32%) had an auscultatory gap which if undetected would have resulted in clinically important underestimates of systolic BP in 4 patients. The presence of an auscultatory gap was statistically associated with the presence of antibodies to RNA polymerase III (P<0.0068) and SSc diagnosis type (P<0.01). Conclusions. Our study demonstrates that auscultatory gaps are relatively common in SSc and correlate with markers for SSc vasculopathy. If undetected auscultatory gaps may result in clinically important underestimation of BP. Thus, electronic oscillometric BP may be preferred in SSc patients

    Radioimmunotherapy of pancreatic ductal adenocarcinoma : a review of the current status of literature

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    Pancreatic ductal adenocarcinoma (PDAC) has long been associated with low survival rates. A lack of accurate diagnostic tests and limited treatment options contribute to the poor prognosis of PDAC. Radioimmunotherapy using Ī±- or Ī²-emitting radionuclides has been identified as a potential treatment for PDAC. By harnessing the cytotoxicity of Ī± or Ī² particles, radioimmunotherapy may overcome the anatomic and physiological factors which traditionally make PDAC resistant to most conventional treatments. Appropriate selection of target receptors and the development of selective and cytotoxic radioimmunoconjugates are needed to achieve the desired results of radioimmunotherapy. The aim of this review is to examine the growing preclinical and clinical trial evidence regarding the application of Ī± and Ī² radioimmunotherapy for the treatment of PDAC. A systematic search of MEDLINEĀ® and Scopus databases was performed to identify 34 relevant studies conducted on Ī± or Ī² radioimmunotherapy of PDAC. Preclinical results demonstrated Ī± and Ī² radioimmunotherapy provided effective tumour control. Clinical studies were limited to investigating Ī² radioimmunotherapy only. Phase I and II trials observed disease control rates of 11.2%ā€“57.9%, with synergistic effects noted for combination therapies. Further developments and optimisation of treatment regimens are needed to improve the clinical relevance of Ī± and Ī² radioimmunotherapy in PDAC

    Opportunities for bio-polymer resource conservation through closed loop recycling

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    Oil-derived plastics have become well established as a packaging material over the past 75 years due to their many technical and commercial advantages. However, the disposal of plastic packaging waste, a large proportion of which still goes to landfill, continues to raise increasing environmental concerns. Meanwhile, the price of oil continues to rise as demand outstrips supply. In response, biodegradable polymers made from renewable resources have risen to greater prominence, with a variety of materials currently being developed from plant starch, cellulose, sugars and proteins. Whilst the polymer science continues apace, the real ecological impacts and benefits of these materials remain uncertain. Although life cycle assessment (LCA) has been used to provide comparisons with oil-derived plastics, published studies are often limited in scope, allowing the validity of their conclusions to be challenged. The literature appears to support the popular assumption that the end-of-life management of these materials requires little consideration, since their biodegradable properties provide inherent ecological benefits. Opportunities for conserving resources through the recycling of biopolymers are rarely addressed. Through a review of current academic, industrial and commercial progress in the field of biopolymers, a number of LCA case studies are proposed which will address this weakness in existing research, related to the recycling of biopolymers. These, or similar, studies are required to provide a more complete picture of the potential effects of a transition from non-renewable to renewable polymers, thus allowing material selection decisions to be made with greater confidence throughout the packaging supply chain

    Temperature control in molecular dynamic simulations of non-equilibrium processes

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    Thermostats are often used in various condensed matter problems, e.g. when a biological molecule undergoes a transformation in a solution, a crystal surface is irradiated with energetic particles, a crack propagates in a solid upon applied stress, two surfaces slide with respect to each other, an excited local phonon dissipates its energy into a crystal bulk, and so on. In all of these problems, as well as in many others, there is an energy transfer between different local parts of the entire system kept at a constant temperature. Very often, when modelling such processes using molecular dynamics simulations, thermostatting is done using strictly equilibrium approaches serving to describe the NV T ensemble. In this paper we critically discuss the applicability of such approaches to non-equilibrium problems, including those mentioned above, and stress that the correct temperature control can only be achieved if the method is based on the generalized Langevin equation (GLE). Specifically, we emphasize that a meaningful compromise between computational efficiency and a physically appropriate implementation of the NV T thermostat can be achieved, at least for solid state and surface problems, if the so-called stochastic boundary conditions (SBC), recently derived from the GLE (Kantorovich and Rompotis 2008 Phys. Rev. B 78 094305), are used. For SBC, the Langevin thermostat is only applied to the outer part of the simulated fragment of the entire system which borders the surrounding environment (not considered explicitly) serving as a heat bath. This point is illustrated by comparing the performance of the SBC and some of the equilibrium thermostats in two problems: (i) irradiation of the Si(001) surface with an energetic CaF2 molecule using an ab initio density functional theory based method, and (ii) the tribology of two amorphous SiO2 surfaces coated with self-assembled monolayers of methyl-terminated hydrocarbon alkoxylsilane molecules using a classical atomistic force field. We discuss the differences in behaviour of these systems due to applied thermostatting, and show that in some cases a qualitatively different physical behaviour of the simulated system can be obtained if an equilibrium thermostat is used

    Improving Function in Age-related Macular Degeneration: A Randomized Clinical Trial.

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    PURPOSE: To compare the efficacy of problem-solving therapy (PST) with supportive therapy (ST) to improve targeted vision function (TVF) in age-related macular degeneration (AMD). DESIGN: Single-masked, attention-controlled, randomized clinical trial with outcome assessments at 3 months (main trial endpoint) and 6 months (maintenance effects). PARTICIPANTS: Patients with AMD (n = 241) attending retina practices. INTERVENTIONS: Whereas PST uses a structured problem-solving approach to reduce vision-related task difficulty, ST is a standardized attention-control treatment. MAIN OUTCOME MEASURES: We assessed TVF, the 25-item National Eye Institute Vision Function Questionnaire plus Supplement (NEI VFQ), the Activities Inventory (AI), and vision-related quality of life (QoL). RESULTS: There were no between-group differences in TVF scores at 3 (P = 0.47) or 6 (P = 0.62) months. For PST subjects, mean Ā± standard deviation TVF scores improved from 2.71Ā±0.52 at baseline to 2.18Ā±0.88 at 3 months (P = 0.001) and were 2.18Ā±0.95 at 6 months (change from 3 to 6 months, P = 0.74). For ST subjects, TVF scores improved from 2.73Ā±0.52 at baseline to 2.14Ā±0.96 at 3 months (P = 0.001) and were 2.15Ā±0.96 at 6 months (change from 3 to 6 months, P = 0.85). Similar proportions of PST and ST subjects had less difficulty performing a TVF goal at 3 months (77.4% vs 78.6%, respectively; P = 0.83) and 6 months (76.2% vs 79.1%, respectively; P = 0.61). There were no changes in the NEI VFQ or AI. Vision-related QoL improved for PST relative to ST subjects at 3 months (F(4, 192) = 2.46; P = 0.05) and at 6 months (F(4, 178) = 2.55; P = 0.05). The PST subjects also developed more adaptive coping strategies than ST subjects. CONCLUSIONS: We found that PST was not superior to ST at improving vision function in patients with AMD, but that PST improved their vision-related QoL. Despite the benefits of anti-vascular endothelial growth factor treatments, AMD remains associated with disability, depression, and diminished QoL. This clinical reality necessitates new rehabilitative interventions to improve the vision function and QoL of older persons with AMD. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article
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