461 research outputs found
Equilibrium of a Brownian particle with coordinate dependent diffusivity and damping: Generalized Boltzmann distribution
Fick's law for coordinate dependent diffusivity is derived. Corresponding
diffusion current in the presence of coordinate dependent diffusivity is
consistent with the form as given by Kramers-Moyal expansion. We have obtained
the equilibrium solution of the corresponding Smoluchowski equation. The
equilibrium distribution is a generalization of the Boltzmann distribution.
This generalized Boltzmann distribution involves an effective potential which
is a function of coordinate dependent diffusivity. We discuss various
implications of the existence of this generalized Boltzmann distribution for
equilibrium of systems with coordinate dependent diffusivity and damping.Comment: 11 pages, 1 figur
Comparative trial with highly purified natural ACTH, synthetic ACTH 1—24 peptide and synthetic ACTH 1—39 peptide
Peer Reviewe
House dust mite induced allergic airway disease is attenuated in CD11ccreIL-4Rα−/l°x mice
Abstract The precise mechanisms leading to development of T helper type (Th)2-driven allergic responses are unknown. We aimed to determine how IL-4 receptor alpha (IL-4Rα) signaling on CD11c+ cells influences allergen-induced Th2 responses in mice. CD11ccreIL-4Rα−/l°x mice, deficient in IL-4Rα on dendritic cells and alveolar macrophages, were compared to IL-4Rα−/l°x littermate controls in models of allergic airway disease induced by OVA/alum, OVA alone or house dust mite. Cytokine responses, eosinophil and neutrophil infiltration into the lungs, airway hyperreactivity and mucus hypersecretion were evaluated after allergen challenge. In the OVA/alum model, CD11ccreIL-4Rα−/lox mice had similar airway hyperreactivity, eosinophil infiltration, Th2-type cytokine production and mucus hypersecretion to littermate controls. When alum was omitted during sensitization, CD11ccreIL-4Rα−/lox mice had similar airway hyperreactivity and mucus secretion but reduced Th2-type cytokine production and eosinophils, suggesting alum overrides the requirement for IL-4Rα signaling on CD11c+ cells in enhancing Th2-type responses. In the house dust mite model, CD11ccreIL-4Rα−/lox mice showed similar mucus secretion, but reduced Th2 responses, eosinophils, neutrophils and airway hyperreactivity, unlike previously tested LysMcreIL-4Rα−/lox mice, which lack IL-4Rα on alveolar macrophages but not on dendritic cells. Therefore, our results indicate that IL-4Rα signaling on dendritic cells promotes allergen-induced Th2 responses and eosinophil infiltration into the lung
Who uses running apps and sports watches? : determinants and consumer profiles of event runners' usage of running-related smartphone applications and sports watches.
Individual and unorganized sports with a health-related focus, such as recreational running, have grown extensively in the last decade. Consistent with this development, there has been an exponential increase in the availability and use of electronic monitoring devices such as smartphone applications (apps) and sports watches. These electronic devices could provide support and monitoring for unorganized runners, who have no access to professional trainers and coaches. The purpose of this paper is to gain insight into the characteristics of event runners who use running-related apps and sports watches. This knowledge is useful from research, design, and marketing perspectives to adequately address unorganized runners' needs, and to support them in healthy and sustainable running through personalized technology. Data used in this study are drawn from the standardized online Eindhoven Running Survey 2014 (ERS14). In total, 2,172 participants in the Half Marathon Eindhoven 2014 completed the questionnaire (a response rate of 40.0%). Binary logistic regressions were used to analyze the impact of socio-demographic variables, running- related variables, and psychographic characteristics on the use of running-related apps and sports watches. Next, consumer profiles were identified. The results indicate that the use of monitoring devices is affected by socio-demographics as well as sports-related and psychographic variables, and this relationship depends on the type of monitoring device. Therefore, distinctive consumer profiles have been developed to provide a tool for designers and manufacturers of electronic running-related devices to better target (unorganized) runners' needs through personalized and differentiated approaches. Apps are more likely to be used by younger, less experienced and involved runners. Hence, apps have the potential to target this group of novice, less trained, and unorganized runners. In contrast, sports watches are more likely to be used by a different group of runners, older and more experienced runners with higher involvement. Although apps and sports watches may potentially promote and stimulate sports participation, these electronic devices do require a more differentiated approach to target specific needs of runners. Considerable efforts in terms of personalization and tailoring have to be made to develop the full potential of these electronic devices as drivers for healthy and sustainable sports participation.</p
IL-13 Signals Independent of IL-4 Receptor-Alpha Chain to Drive Ovalbumin-Induced Dermatitis
Atopic dermatitis (AD) is an allergic skin condition that can result from intrinsic genetic factors or repetitive occupational damage. Disruption of the skin barrier leads to sensitization to allergens followed by local inflammation (Leung et al., 2004, Pigatto et al., 1992). Strong evidence has shown that the T helper-2 (Th2) cytokine, IL-13, is the dominant disease-causing factor in the pathogenesis of AD in mice (Nieuwenhuizen et al., 2009, Sivaprasad et al., 2010, Tazawa et al., 2004). Hence, it is possible that patients with AD would benefit from treatments specifically targeting IL-13 signaling pathways. However, current treatment strategies are limited to broader therapies, such as emollients, topical glucocorticoids, and calcineurin inhibitors (Beck et al., 2014, De Benedetto et al., 2012, Gittler et al., 2012). A recent study by Beck et al. (2014), which used the monoclonal antibody dupilumab to block IL-4 receptor-alpha (IL-4Rα) signaling, showed promise in targeting specific immunological pathways. Until recently, IL-13 was thought to signal only through the IL-4Rα/IL-13Rα1 complex; however, recent data suggest that IL-13 may also signal via IL-13Rα2, previously known as a decoy receptor. In AD, the signaling pathway of IL-13 remains to be defined. In this study we addressed this problem by using a combination of IL-4Rα–deficient mice that lacked or overexpressed IL-13 to determine if IL-13 can signal independently of the IL-4Rα chain to mediate AD. Our results may have potential implications for therapeutic strategies, such as using IL-4Rα–antagonists to treat the disease.National Research Foundation (South Africa
Electronic Excitations in Complex Molecular Environments: Many-Body Green's Functions Theory in VOTCA-XTP
Many-body Green's functions theory within the GW approximation and the
Bethe-Salpeter Equation (BSE) is implemented in the open-source VOTCA-XTP
software, aiming at the calculation of electronically excited states in complex
molecular environments. Based on Gaussian-type atomic orbitals and making use
of resolution of identify techniques, the code is designed specifically for
non-periodic systems. Application to the small molecule reference set
successfully validates the methodology and its implementation for a variety of
excitation types covering an energy range from 2-8 eV in single molecules.
Further, embedding each GW-BSE calculation into an atomistically resolved
surrounding, typically obtained from Molecular Dynamics, accounts for effects
originating from local fields and polarization. Using aqueous DNA as a
prototypical system, different levels of electrostatic coupling between the
regions in this GW-BSE/MM setup are demonstrated. Particular attention is paid
to charge-transfer (CT) excitations in adenine base pairs. It is found that
their energy is extremely sensitive to the specific environment and to
polarization effects. The calculated redshift of the CT excitation energy
compared to a nucelobase dimer treated in vacuum is of the order of 1 eV, which
matches expectations from experimental data. Predicted lowest CT energies are
below that of a single nucleobase excitation, indicating the possibility of an
initial (fast) decay of such an UV excited state into a bi-nucleobase CT
exciton. The results show that VOTCA-XTP's GW-BSE/MM is a powerful tool to
study a wide range of types of electronic excitations in complex molecular
environments
Determination of Tissue Iron and Ferritin in Liver Pathology. Comparison of Histochemical and Biochemical Results
Peer Reviewe
Use of chromogenic peptide substrates in the determination of clotting factors II, VII, IX and X in normal plasma and in plasma of patients treated with oral anticoagulants
Spectrophotometric methods were used to assay the clotting factors II, VII, IX and X in plasma of 33 subjectively healthy human donors and in plasma of 98 patients receiving long-term oral anticoagulant therapy. In 33 normal subjects the interindividual variations in the plasma activities of the clotting factors II, VII, IX and X are respectively 12.2, 21.4, 11.0 and 15.0%. After correction for the assay variations the remaining biological variations are respectively 11.7, 21.2, 9.7 and 14.8%. Plasma from 98 patients receiving long-term anticoagulant therapy was assayed with ‘Thrombotest’, a clotting test in whole blood introduced by Owren and in these plasmas the activity of each of the vitamin K-dependent factors was assayed with spectrophotometric methods. For the clotting factors IX and VII, novel spectrophotometric methods were applied and the plasma activities thus measured were compared to results obtained with factor IX and VII clotting assays. Chromogenic activities of the different factors were correlated among each other and with 1/Thrombotest values. When the therapeutic range for Thrombotest values is set between 5 and 12.5% the corresponding therapeutic ranges for the activity of the factors II, VII, IX and X are respectively 12.6–36.1, 27.0–52.3, 23.1–49.3 and 18.9–36.2% (expressed as a percentage of the activity in normal pool plasma). The chromogenic assays for the factors II, VII, IX and X provide the same information on the therapeutic state of the patients in respectively 86.7, 78.6, 81.6 and 89.8% of the cases. Finally we discuss the suitability of the different assays to monitor oral anticoagulant therapy
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