191 research outputs found

    Clinical impact of real-time evaluation of the biological activity and degradation of hepatocyte growth factor

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    Hepatocyte growth factor (HGF) is essential for injury repair. Despite high HGF levels in chronic ulcers, up-regulation of HGF receptor in ulcer tissue and decreased biological activity of HGF in ulcer secretions have been observed. With a surface plasmon resonance-based method, we assessed the binding of HGF to antibodies, receptors, and the basement membrane and identified binding interactions that are indispensable for the biological activity of HGF. Recombinant HGF (rHGF) lots were tested for activity, structural integrity, and degradation, and the results were verified in an in vitro model of cell injury. Biologically active rHGF, as well as plasma from healthy volunteers, bound to heparan sulphate proteoglycan (HSPG) and to anti-HGF antibodies. Decreased binding to HSPG was the first event in rHGF degradation. This study established the feasibility of identifying patients with chronic inflammation who need exogenous HGF and of using ligand-binding assessment to evaluate rHGF lots for biological activity

    On the new string theory inspired mechanism of generation of cosmological perturbations

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    Recently a non-inflationary mechanism of generation of scale-free cosmological perturbations of metric was proposed by Brandenberger, Nayeri, and Vafa in the context of the string gas cosmology. We discuss various problems of their model and argue that the cosmological perturbations of metric produced in this model have blue spectrum with a spectral index n = 5, which strongly disagrees with observations. We conclude that this model in its present form is not a viable alternative to inflationary cosmology.Comment: 11 pages, 1 figur

    The social well-being of nurses shows a thirst for a holistic support: A qualitative study

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    Introduction: Social well-being is one of the important aspects of health. In fact, this is a reflection of experience in a social environment, indicating how social challenges are determined. In other words, social well-being is an explanation of people's perception and experience of being in a good situation, satisfaction with the structure, and social interaction. This qualitative study intended to explore nurses' experience of social well-being. Methods: Qualitative content analysis was used to conduct the study. Through purposive sampling, a total of 18 nurses with various clinical experiences participated in semi-structured interviews. The data were analysed using the five-step, qualitative content analysis introduced by Graneheim and Lundman. Results: The main theme extracted from the data analysis was "thirst for a holistic support" in nurses. It consisted of two subthemes including internal support (family's support, colleague's support, and organizational support) and external support (society's support and media's support). Conclusions and discussion: Nurses' experiences in shaping their social well-being show that nurses need support in order to rebuild their social well-being. It is supported in partnership with the media, the community, health-related organizations, and by nurses and family. This improves job satisfaction, hope, motivation, commitment, and confidence so as to ultimately facilitate improvement of social well-being of nurses. © 2015 N. Mozaffari et al

    Closed String Thermodynamics and a Blue Tensor Spectrum

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    The BICEP-2 team has recently reported the positive detection of cosmic microwave background Bmode polarization. Although uncertainties due to galactic dust foregrounds remain, it is a constructive exercise to work out the implications of presuming some part of the detected B-mode signal to be due to primordial gravitational waves. Were a positive detection of a tensor-to-scalar ratio larger than r greater than or similar to O(10(-2)) confirmed, detecting a tilt in the tensor spectrum comparable to that observed for the scalar power spectrum becomes in principle possible. We wish to explore in this brief paper the possibility of there being a blue tilt to the primordial gravitational-wave spectrum. Such a tilt would be incompatible with standard inflationary models, although it was predicted some years ago in the context of a mechanism that thermally generates the primordial perturbations through a Hagedorn phase of string cosmology. By scrutinizing the data with priors informed by a model that is immediately falsifiable, but which predicts features that may be favored by the data-namely a blue tensor tilt with an induced and complementary red tilt to the scalar spectrum, with a naturally large tensor-to-scalar ratio that relates to both-we offer a useful straw model against which to test the predictions of single-field inflation

    Observational Constraints on Theories with a Blue Spectrum of Tensor Modes

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    Motivated by the string gas cosmological model, which predicts a blue tilt of the primordial gravitational wave spectrum, we examine the constraints imposed by current and planned observations on a blue tilted tensor spectrum. Starting from an expression for the primordial gravitational wave spectrum normalized using cosmic microwave background observations, pulsar timing, direct detection and nucleosynthesis bounds are examined. If we assume a tensor to scalar ratio on scales of the CMB which equals the current observational upper bound, we obtain from these current observations constraints on the tensor spectral index of nT0.79n_{T} \lesssim 0.79, nT0.53n_{T} \lesssim 0.53, and nT0.15n_{T} \lesssim 0.15 respectively.Comment: 12 pages, 1 figure, 2 references added, relationship of this work with Ref. 20 adde

    Determining the Effectiveness of Microbial Protease on Production Variables in Lactating Holstein Cows

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    Lactating Holstein cows were assigned to a control diet or a diet containing a blend of supplemental protease enzymes (Rumagentin™, Feed Sources LLC, Alta Loma CA) at the Iowa State University Dairy farm. Study objectives were to examine the effects of proteases on milk yield, milk composition, feed intake and feed efficiency in lactating Holstein cows. Our results indicate that protease enzymes enhanced feed conversion efficiency and nitrogen utilization of dairy cows

    Producing a Scale-Invariant Spectrum of Perturbations in a Hagedorn Phase of String Cosmology

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    We study the generation of cosmological perturbations during the Hagedorn phase of string gas cosmology. Using tools of string thermodynamics we provide indications that it may be possible to obtain a nearly scale-invariant spectrum of cosmological fluctuations on scales which are of cosmological interest today. In our cosmological scenario, the early Hagedorn phase of string gas cosmology goes over smoothly into the radiation-dominated phase of standard cosmology, without having a period of cosmological inflation.Comment: 4 pages, 1 figur
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