4,139 research outputs found
Large Dimension and Low-Cost Fe-SMA Rods
The effects on sample size on abnormal grain growth in inexpensive FeMnAlNi shape memory alloy (SMAs) wires and rod were investigated. It was shown that repeated heat treatments between single phase (bcc) and two phase (bcc + fcc) region resulted in abnormal grains with bamboo structure both in small sized wires and large diameter rods. Microstructural features were investigated using electron backscatter diffraction (EBSD) and it was found that 0.5 mm wires possess strong [011] texture whereas, large diameter rods have random texture after grain growth heat treatments
Concealed concern: Fathers' experience of having a child with Juvenile Idiopathic Arthritis
Despite increased research into families of chronically ill children, more needs to be known about the father’s experience. We address this issue through asking: ‘What is it like to be the father of a child with juvenile idiopathic arthritis?’ (JIA). Four members of eight families with an adolescent diagnosed with JIA, including seven fathers, were interviewed and transcripts analyzed using grounded theory. This study suggests that fathers of children with JIA experience several severe losses which are exacerbated through comparisons they make between their own situation and that of fathers of healthy children. In addition, the fathers faced several constraints which reduced their opportunities to communicate with their ill child through shared activities. Fathers appeared to conceal their distress by adopting strategies of denial and distraction however their adjustment was facilitated, to some extent, by social support. They could also develop greater acceptance of their situation over time as the care of their ill child became assimilated into family life and constraints upon their life gradually reduced through the increased maturity of their son or daughter with JIA. These findings have implications for healthcare professionals and voluntary organizations
Average Heating Rate of Hot Atmospheres in Distant Clusters by Radio AGN: Evidence for Continuous AGN Heating
We examine atmospheric heating by radio active galactic nuclei (AGN) in
distant X-ray clusters by cross correlating clusters selected from the 400
Square Degree (400SD) X-ray Cluster survey with radio sources in the NRAO VLA
Sky Survey. Roughly 30% of the clusters show radio emission above a flux
threshold of 3 mJy within a projected radius of 250 kpc. The radio emission is
presumably associated with the brightest cluster galaxy. The mechanical jet
power for each radio source was determined using scaling relations between
radio power and cavity (mechanical) power determined for nearby clusters,
groups, and galaxies with hot atmospheres containing X-ray cavities. The
average jet power of the central radio AGN is approximately \ergs. We find no significant correlation between radio power, hence
mechanical jet power, and the X-ray luminosities of clusters in the redshift
range 0.1 -- 0.6. This implies that the mechanical heating rate per particle is
higher in lower mass, lower X-ray luminosity clusters. The jet power averaged
over the sample corresponds to an atmospheric heating of approximately 0.2 keV
per particle within R. Assuming the current AGN heating rate does not
evolve but remains constant to redshifts of 2, the heating rate per particle
would rise by a factor of two. We find that the energy injected from radio AGN
contribute substantially to the excess entropy in hot atmospheres needed to
break self-similarity in cluster scaling relations. The detection frequency of
radio AGN is inconsistent with the presence of strong cooling flows in 400SD
clusters, but does not exclude weak cooling flows. It is unclear whether
central AGN in 400SD clusters are maintained by feedback at the base of a
cooling flow. Atmospheric heating by radio AGN may retard the development of
strong cooling flows at early epochs.Comment: ApJ in pres
Integrated Health Monitoring of Transportation Structures with Magnetic Fe-SMA Wires
In this work, the magnetization response of FeMnAlNi superelastic shape memory alloys (SMAs) is investigated under stress. Wires with a diameter of 0.5 mm were subjected to repeated abnormal grain growth heat treatments in order to obtain bamboo structured oligocrystalline grains that are necessary for superelasticity. Solution heat treated wires were aged at 200ºC for 3 h to strengthen the austenite matrix. Tensile cyclic tests were performed at room temperature until failure, while the magnetization response of the wires was monitored using a hall sensor during loading and unloading in each cycle. It is observed that after each cycle, overall magnetization of the alloy decreases once the irrecoverable strain is introduced after large deformations and magnetization of the sample is inversely correlated with the irrecoverable strain. The findings of this work show that the magnetic shift in Fe-SMAs under deformation can be used a health monitoring tool in next generation structures to detect large deformations and cracks
Post-streptococcal reactive arthritis in children: a distinct entity from acute rheumatic fever
There is a debate whether post-streptococcal reactive arthritis (PSRA) is a separate entity or a condition on the spectrum of acute rheumatic fever (ARF). We believe that PSRA is a distinct entity and in this paper we review the substantial differences between PSRA and ARF. We show how the demographic, clinical, genetic and treatment characteristics of PSRA differ from ARF. We review diagnostic criteria and regression formulas that attempt to classify patients with PSRA as opposed to ARF. The important implication of these findings may relate to the issue of prophylactic antibiotics after PSRA. However, future trials will be necessary to conclusively answer that question
A survey of healthcare providers’ knowledge and attitudes regarding pain relief in labor for women in Ethiopia
BACKGROUND: To explore healthcare providers' knowledge and attitudes to the need for pain relief for women in labor.
METHODS: A structured questionnaire (n = 200) distributed to healthcare providers working in the obstetric departments, including theatres, of three public hospitals in different settings (rural, peri-urban and urban) in Ethiopia. Descriptive analysis was performed using Excel 2013 and SPSS version 22 for associations.
RESULTS: The response rate was 81.5% with 164 questionnaires completed. The majority, 79% of respondents, understood that women can feel moderate to severe pain in labor and 77% were of the opinion that labor pain should be relieved. However, common practices included only supportive measures such as breathing and relaxation exercises, back massage and support from family. The general attitude of healthcare providers is that labor is a natural process, women should be able to cope and that pain relief is not a priority for women in labor. More than half, 52% of healthcare providers had safety concerns with using pharmacological methods to relieve pain in labor.
CONCLUSION: The majority of healthcare providers understand that women suffer significant pain during labor. However, providing effective pain relief is currently not provided as part of routine intra-partum care in Ethiopia
The effect of radio-adaptive doses on HT29 and GM637 cells
<p>Abstract</p> <p>Background</p> <p>The shape of the dose-response curve at low doses differs from the linear quadratic model. The effect of a radio-adaptive response is the centre of many studies and well known inspite that the clinical applications are still rarely considered.</p> <p>Methods</p> <p>We studied the effect of a low-dose pre-irradiation (0.03 Gy – 0.1 Gy) alone or followed by a 2.0 Gy challenging dose 4 h later on the survival of the HT29 cell line (human colorectal cancer cells) and on the GM637 cell line (human fibroblasts).</p> <p>Results</p> <p>0.03 Gy given alone did not have a significant effect on both cell lines, the other low doses alone significantly reduced the cell survival. Applied 4 h before the 2.0 Gy fraction, 0.03 Gy led to a significant induced radioresistance in GM637 cells, but not in HT29 cells, and 0.05 Gy led to a significant hyperradiosensitivity in HT29 cells, but not in GM637 cells.</p> <p>Conclusion</p> <p>A pre-irradiation with 0.03 Gy can protect normal fibroblasts, but not colorectal cancer cells, from damage induced by an irradiation of 2.0 Gy and the application of 0.05 Gy prior to the 2.0 Gy fraction can enhance the cell killing of colorectal cancer cells while not additionally damaging normal fibroblasts. If these findings prove to be true in vivo as well this may optimize the balance between local tumour control and injury to normal tissue in modern radiotherapy.</p
Emerging Use of Gene Expression Microarrays in Plant Physiology
Microarrays have become an important technology for the global analysis of gene expression in humans, animals, plants, and microbes. Implemented in the context
of a well-designed experiment, cDNA and oligonucleotide arrays can provide highthroughput,
simultaneous analysis of transcript abundance for hundreds, if not
thousands, of genes. However, despite widespread acceptance, the use of microarrays
as a tool to better understand processes of interest to the plant physiologist is still
being explored. To help illustrate current uses of microarrays in the plant sciences,
several case studies that we believe demonstrate the emerging application of gene
expression arrays in plant physiology were selected from among the many posters
and presentations at the 2003 Plant and Animal Genome XI Conference. Based
on this survey, microarrays are being used to assess gene expression in plants
exposed to the experimental manipulation of air temperature, soil water content and
aluminium concentration in the root zone. Analysis often includes characterizing
transcript profiles for multiple post-treatment sampling periods and categorizing
genes with common patterns of response using hierarchical clustering techniques.
In addition, microarrays are also providing insights into developmental changes
in gene expression associated with fibre and root elongation in cotton and maize,
respectively. Technical and analytical limitations of microarrays are discussed and
projects attempting to advance areas of microarray design and data analysis are
highlighted. Finally, although much work remains, we conclude that microarrays
are a valuable tool for the plant physiologist interested in the characterization and
identification of individual genes and gene families with potential application in the
fields of agriculture, horticulture and forestry
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