114 research outputs found
Advanced ultra-light multifunctional metallic-glass wave springs
We show that, using thermo -elastic processing, metallic -glass foils can be shaped, without being embrittled, into linear and annular wave springs. These springs exhibit an undulatory behaviour, unique to metallic -glass foils, in which under compression the number of arcs in the spring increases, increasing the load -bearing capacity and the spring constant. We evaluate the performance limits of the metallic -glass wave springs, and consider how the undulatory behaviour can be exploited. The metallic -glass springs can operate over the same load -ranges as commercially available crystalline wave springs, but have material volumes (and therefore weights) that are one to two orders of magnitude less. Their energy storage per unit material volume is as high as 2600 kJ m – 3 . We suggest that the undulatory behaviour is important in rendering the springs fail -safe in case of overload. We discuss the range of applicability of thermo -elastic processing, the likely working limit of metallic -glass wave springs, and the potential for application of metallic -glass springs in MEMS devices
Resistance of Dynamin-related Protein 1 Oligomers to Disassembly Impairs Mitophagy, Resulting in Myocardial Inflammation and Heart Failure
We have reported previously that a missense mutation in the mitochondrial fission gene Dynamin-related protein 1 (Drp1) underlies the Python mouse model of monogenic dilated cardiomyopathy. The aim of this study was to investigate the consequences of the C452F mutation on Drp1 protein function and to define the cellular sequelae leading to heart failure in the Python monogenic dilated cardiomyopathy model. We found that the C452F mutation increased Drp1 GTPase activity. The mutation also conferred resistance to oligomer disassembly by guanine nucleotides and high ionic strength solutions. In a mouse embryonic fibroblast model, Drp1 C452F cells exhibited abnormal mitochondrial morphology and defective mitophagy. Mitochondria in C452F mouse embryonic fibroblasts were depolarized and had reduced calcium uptake with impaired ATP production by oxidative phosphorylation. In the Python heart, we found a corresponding progressive decline in oxidative phosphorylation with age and activation of sterile inflammation. As a corollary, enhancing autophagy by exposure to a prolonged low-protein diet improved cardiac function in Python mice. In conclusion, failure of Drp1 disassembly impairs mitophagy, leading to a downstream cascade of mitochondrial depolarization, aberrant calcium handling, impaired ATP synthesis, and activation of sterile myocardial inflammation, resulting in heart failure
Pressure-induced amorphous-to-amorphous configuration change in Ca-Al metallic glasses
Pressure-induced amorphous-to-amorphous configuration changes in Ca-Al metallic glasses (MGs) were studied by performing in-situ room-temperature high-pressure x-ray diffraction up to about 40 GPa. Changes in compressibility at about 18 GPa, 15.5 GPa and 7.5 GPa during compression are detected in Ca80Al20, Ca72.7Al27.3, and Ca66.4Al33.6 MGs, respectively, whereas no clear change has been detected in the Ca50Al50 MG. The transfer of s electrons into d orbitals under pressure, reported for the pressure-induced phase transformations in pure polycrystalline Ca, is suggested to explain the observation of an amorphous-to-amorphous configuration change in this Ca-Al MG system. Results presented here show that the pressure induced amorphous-to-amorphous configuration is not limited to f electron-containing MGs
Comparison of Two Diverse Populations, British Columbia, Canada, and Ardabil, Iran, Indicates Several Variables Associated with Gastric and Esophageal Cancer Survival
Antimicrobial resistance monitoring and surveillance in the meat chain: A report from five countries in the European Union and European Economic Area
Background
The emergence of antimicrobial resistance (AMR) in zoonotic foodborne pathogens (Salmonella, Campylobacter) and indicator microorganisms (E. coli, enterococci) is a major public health risk. Zoonotic bacteria, resistant to antimicrobials, are of special concern because they might compromise the effective treatment of infections in humans.
Scope and approach
In this review, the AMR monitoring and surveillance programmes in five selected countries within European Union (EU) and European Economic Area (EEA) are described. The sampling schemes, susceptibility testing for AMR identification, clinical breakpoints (clinical resistance) and epidemiological cut-off values (microbiological resistance) were considered to reflect on the most important variations between and within food-producing animal species, between countries, and to identify the most effective approach to tackle and manage the antimicrobial resistance in the food chain.
Key findings and conclusions
The science-based monitoring of AMR should encompass the whole food chain, supported with public health surveillance and should be conducted in accordance with ‘Zoonoses Directive’ (99/2003/EC). Such approach encompasses the integrated AMR monitoring in food animals, food and humans in the whole food (meat) chain continuum, e.g. pre-harvest (on-farm), harvest (in abattoir) and post-harvest (at retail). The information on AMR in critically important antimicrobials (CIA) for human medicine should be of particular importance
Comparison of breast cancer survival in two populations: Ardabil, Iran and British Columbia, Canada
<p>Abstract</p> <p>Background</p> <p>Patterns in survival can provide information about the burden and severity of cancer, help uncover gaps in systemic policy and program delivery, and support the planning of enhanced cancer control systems. The aim of this paper is to describe the one-year survival rates for breast cancer in two populations using population-based cancer registries: Ardabil, Iran, and British Columbia (BC), Canada.</p> <p>Methods</p> <p>All newly diagnosed cases of female breast cancer were identified in the Ardabil cancer registry from 2003 to 2005 and the BC cancer registry for 2003. The International Classification of Disease for Oncology (ICDO) was used for coding cancer morphology and topography. Survival time was determined from cancer diagnosis to death. Age-specific one-year survival rates, relative survival rates and weighted standard errors were calculated using life-tables for each country.</p> <p>Results</p> <p>Breast cancer patients in BC had greater one-year survival rates than patients in Ardabil overall and for each age group under 60.</p> <p>Conclusion</p> <p>These findings support the need for breast cancer screening programs (including regular clinical breast examinations and mammography), public education and awareness regarding early detection of breast cancer, and education of health care providers.</p
Differential mortality in Iran
Background: Among the available data provided by health information systems, data on mortality are commonly used not only as health indicators but also as socioeconomic development indices. Recognizing that in Iran accurate data on causes of death were not available, the Deputy of Health in the Ministry of Health and Medical Education (MOH&ME) established a new comprehensive system for death registration which started in one province (Bushehr) as a pilot in 1997, and was subsequently expanded to include all other provinces, except Tehran province. These data can be used to investigate the nature and extent of differences in mortality in Iran. The objective of this paper is to estimate provincial differences in the level of mortality using this death registration system. Methods: Data from the death registration system for 2004 for each province were evaluated for data completeness, and life tables were created for provinces after correction for under-enumeration of death registration. For those provinces where it was not possible to adjust the data on adult deaths by using the Brass Growth Balance method, adult mortality was predicted based on adult literacy using information from provinces with reliable data. Results: Child mortality (risk of a newborn dying before age 5, or q) in 2004 varied between 47 per 1000 live births for both sexes in Sistan and Baluchistan province, and 25 per 1000 live births in Tehran and Gilan provinces. For adults, provincial differences in mortality were much greater for males than females. Adult mortality (risk of dying between ages 15 and 60, or 45q15) for females varied between 0.133 in Kerman province and 0.117 in Tehran province; for males the range was from 0.218 in Kerman to 0.149 in Tehran province. Life expectancy for females was highest in Tehran province (73.8 years) and lowest in Sistan and Baluchistan (70.9 years). For males, life expectancy ranged from 65.7 years in Sistan and Baluchistan province to 70.9 years in Tehran. Conclusion: Substantial differences in survival exist among the provinces of Iran. While the completeness of the death registration system operated by the Iranian MOH&ME appears to be acceptable in the majority of provinces, further efforts are needed to improve the quality of data on mortality in Iran, and to expand death registration to Tehran province
A Bioinformatics Filtering Strategy for Identifying Radiation Response Biomarker Candidates
The number of biomarker candidates is often much larger than the number of clinical patient data points available, which motivates the use of a rational candidate variable filtering methodology. The goal of this paper is to apply such a bioinformatics filtering process to isolate a modest number (<10) of key interacting genes and their associated single nucleotide polymorphisms involved in radiation response, and to ultimately serve as a basis for using clinical datasets to identify new biomarkers. In step 1, we surveyed the literature on genetic and protein correlates to radiation response, in vivo or in vitro, across cellular, animal, and human studies. In step 2, we analyzed two publicly available microarray datasets and identified genes in which mRNA expression changed in response to radiation. Combining results from Step 1 and Step 2, we identified 20 genes that were common to all three sources. As a final step, a curated database of protein interactions was used to generate the most statistically reliable protein interaction network among any subset of the 20 genes resulting from Steps 1 and 2, resulting in identification of a small, tightly interacting network with 7 out of 20 input genes. We further ranked the genes in terms of likely importance, based on their location within the network using a graph-based scoring function. The resulting core interacting network provides an attractive set of genes likely to be important to radiation response
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