197 research outputs found
Clinical impact of real-time evaluation of the biological activity and degradation of hepatocyte growth factor
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
Self-Efficacy After Life Skills Training: A Case-Control Study
Background: Nursing students’ self-efficacy is a predictor for their educational progress. Students, who believe that they can be successful in their studies, are more confident. Therefore, many universities have focused on life skills training programs to improve the mental health of their students.
Objectives: This study was conducted to evaluate and compare self-efficacy in two groups of nursing students of Tehran University of Medical Sciences (TUMS). One group of students was trained on life skill programs, and the second group was not trained on the issue.
Materials and Methods: A case-control study was conducted on two groups of nursing students in TUMS in the late 2012. The case group (n = 112) had passed life skills training course, and the control group (n = 139) was not trained on the issue. Data was collected using a questionnaire containing 12 questions about demographic features, and the Sherer’s general self-efficacy questionnaire. Data analysis was performed using independent sample t-test, Chi-square, odds ratio, and Fisher’s exact test.
Results: In the untrained and trained groups, 23% and 8% of the students had very high self-efficacy, respectively. The overall mean scores of self-efficacy were 41.99 ± 9.31 and 38.99 ± 10.48 in the trained and untrained groups, respectively (P = 0.015), and the higher mean score indicates lower level of self-efficacy. A significant difference was also found between the self-efficacy and family income (P = 0.029).
Conclusions: The present study showed that life skills training program did not affect self-efficacy of nursing students. Perhaps, the methods used in education were influencing and then, more effective techniques such as role-play and group discussion should be substituted in life skills training
On the new string theory inspired mechanism of generation of cosmological perturbations
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
Observational Constraints on Theories with a Blue Spectrum of Tensor Modes
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 , , and
respectively.Comment: 12 pages, 1 figure, 2 references added, relationship of this work
with Ref. 20 adde
An evaluation of the effectiveness of a reproductive health education program for nonmedical students in Iran: A quasi-experimental pre-test, post-test research
Background: Young people age 10 - 25 are an important population to evaluate the female youth educational program essential to the prevention of issues related to reproductive health. Objectives: This study evaluated the effectiveness of the education program for improving university student�s reproductive health. Patients and Methods: This quantitative study was conducted in Iran from July 2014 to March 2015. The questionnaire addressed socio-demographic features, knowledge of reproductive problems, and attitudes. Program effectiveness was examined using a quasi-experimental research design with pre-intervention and post-intervention. Data from questionnaires was collected preintervention and post-intervention from 150 female students. Results: In this study, results showed that an intervention and education program had a significant effect on several issues related to reproductive health. Most participants stressed the need to provide reproductive health services for young girls. Conclusions: The results of this study suggest that the reproductive health education program improved the students� knowledge and attitudes about sexuality and decision-making after the program and that these educational programs are important for youths. © 2016, Shiraz University of Medical Sciences
Producing a Scale-Invariant Spectrum of Perturbations in a Hagedorn Phase of String Cosmology
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
Cosmological Perturbations in Non-Commutative Inflation
We compute the spectrum of cosmological perturbations in a scenario in which
inflation is driven by radiation in a non-commutative space-time. In this
scenario, the non-commutativity of space and time leads to a modified
dispersion relation for radiation with two branches, which allows for
inflation. The initial conditions for the cosmological fluctuations are
thermal. This is to be contrasted with the situation in models of inflation in
which the accelerated expansion of space is driven by the potential energy of a
scalar field, and in which the fluctuations are of quantum vacuum type. We find
that, in the limit that the expansion of space is almost exponential, the
spectrum of fluctuations is scale-invariant with a slight red tilt. The
magnitude of the tilt is different from what is obtained in a usual
inflationary model with the same expansion rate during the period of inflation.
The amplitude also differs, and can easily be adjusted to agree with
observations.Comment: 7 pages, 1 figur
Inaccessible Singularities in Toral Cosmology
The familiar Bang/Crunch singularities of classical cosmology have recently
been augmented by new varieties: rips, sudden singularities, and so on. These
tend to be associated with final states. Here we consider an alternative
possibility for the initial state: a singularity which has the novel property
of being inaccessible to physically well-defined probes. These singularities
arise naturally in cosmologies with toral spatial sections.Comment: 10 pages, version to appear in Classical and Quantum Gravit
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