Aims/hypothesis We recently reported associations of some persistent organic pollutants (POPs) with both prevalence of type 2 diabetes and insulin resistance in a US population with background ...exposure to POPs. Restricted to non-diabetic participants, we now investigate the relationship between POPs and the metabolic syndrome, a prediabetic state. Materials and methods Cross-sectional associations were investigated in 721 non-diabetic participants aged >=20 years. Nineteen POPs in five subclasses were selected because they were detectable in >=60% of participants. Results Among five POPs subclasses, organochlorine (OC) pesticides were most strongly and consistently associated with metabolic syndrome: adjusted odds ratios (ORs) of 1.0, 1.5, 2.3 and 5.3 across OC pesticide quartiles (p for trend <0.01). Dioxin-like polychlorinated biphenyls (PCBs) were also positively associated with adjusted ORs of 1.0, 1.1, 2.2 and 2.1 (p for trend = 0.01). However, non-dioxin-like PCBs showed an inverted U-shaped association with adjusted ORs of 1.0, 1.3, 1.8 and 1.0 (p for quadratic term <0.01). Associations of specific POPs varied across five components of the metabolic syndrome. OC pesticides were positively and significantly associated with four of the five components, especially elevated triacylglycerol and high fasting glucose, but not high blood pressure. PCBs were significantly associated with waist circumference, triacylglycerol and impaired fasting glucose. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans showed small but significant associations only with high blood pressure. Conclusions/interpretation This study suggests that the prevalence of a cluster of cardiovascular risk factors relates to background exposure to a mixture of POPs, several of which are also related to the prevalence of diabetes. POPs associated differentially with different components of the metabolic syndrome.
The International Pulsar Timing Array project combines observations of pulsars from both northern and southern hemisphere observatories with the main aim of detecting ultra-low frequency (~ ...10-9--10-8 Hz) gravitational waves. Here we introduce the project, review the methods used to search for gravitational waves emitted from coalescing supermassive binary black-hole systems in the centres of merging galaxies and discuss the status of the project.
Summary
Although low doses of persistent organic pollutants (POPs), strong lipophilic chemicals with long half‐lives, have been linked to various endocrine, immune, nervous and reproductive system ...diseases, few obesity studies have considered adipose tissue as an important POPs exposure source. Because the toxicodynamics of POPs relate directly to the dynamics of adiposity, POPs might explain puzzling findings in obesity research. In two people exposed to the same amounts of environmental POPs, the one having more adipose tissue may be advantaged because POPs storage in adipose tissue can reduce burden on other critical organs. Therefore, adipose tissue can play a protective role against the POPs effects. However, two situations increase the POPs release from adipose tissue into the circulation, thereby increasing the risk that they will reach critical organs: (i) weight loss and (ii) insulin resistance. In contrast, weight gain reduces this possibility. Therefore, avoiding harmful health effects of POPs may mostly contradict conventional judgments about obesity and weight change. These contradictory situations can explain the obesity paradox, the adverse effects of intensive intentional weight loss and the protective effects of obesity against dementia. Future studies should consider that adipose tissue is widely contaminated with POPs in modern society.
B cells are important in the pathogenesis of many, and perhaps all, immune-mediated diseases. Each B cell expresses a single B cell receptor (BCR)
, and the diverse range of BCRs expressed by the ...total B cell population of an individual is termed the 'BCR repertoire'. Our understanding of the BCR repertoire in the context of immune-mediated diseases is incomplete, and defining this could provide new insights into pathogenesis and therapy. Here, we compared the BCR repertoire in systemic lupus erythematosus, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, Crohn's disease, Behçet's disease, eosinophilic granulomatosis with polyangiitis, and immunoglobulin A (IgA) vasculitis by analysing BCR clonality, use of immunoglobulin heavy-chain variable region (IGHV) genes and-in particular-isotype use. An increase in clonality in systemic lupus erythematosus and Crohn's disease that was dominated by the IgA isotype, together with skewed use of the IGHV genes in these and other diseases, suggested a microbial contribution to pathogenesis. Different immunosuppressive treatments had specific and distinct effects on the repertoire; B cells that persisted after treatment with rituximab were predominately isotype-switched and clonally expanded, whereas the inverse was true for B cells that persisted after treatment with mycophenolate mofetil. Our comparative analysis of the BCR repertoire in immune-mediated disease reveals a complex B cell architecture, providing a platform for understanding pathological mechanisms and designing treatment strategies.
Memory Metamaterials Driscoll, T; Kim, Hyun-Tak; Chae, Byung-Gyu ...
Science (American Association for the Advancement of Science),
09/2009, Letnik:
325, Številka:
5947
Journal Article
Recenzirano
Odprti dostop
The resonant elements that grant metamaterials their distinct properties have the fundamental limitation of restricting their useable frequency bandwidth. The development of frequency-agile ...metamaterials has helped to alleviate these bandwidth restrictions by allowing real-time tuning of the metamaterial frequency response. We demonstrate electrically controlled persistent frequency tuning of a metamaterial, which allows the lasting modification of its response by using a transient stimulus. This work demonstrates a form of memory capacitance that interfaces metamaterials with a class of devices known collectively as memory devices.
In October-November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air ...sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4-27.9% of non-methane organic compounds (NMOCs) and ~ 21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3 ), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in the first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13-195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~ 20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The δHCN/δCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also support an earlier finding that C3 -C4 alkynes may be of use as biomass burning indicators on the time-scale of hours to a day. It was possible to measure the downwind chemical evolution of the plume on four of the fires and significant O3 formation (δO3 /δCO from 10-90%) occurred in all of these plumes within two hours. The slowest O3 production was observed on a cloudy day with low co-emission of NOx . The fastest O3 production was observed on a sunny day when the downwind plume almost certainly incorporated significant additional NOx by passing over the Columbia, SC metropolitan area. Due to rapid plume dilution, it was only possible to acquire high-quality downwind data for two other trace gas species (formaldehyde and methanol) during two of the fires. In all four of these cases, significant increases in formaldehyde and methanol were observed in <2 h. This is likely the first direct observation of post-emission methanol production in biomass burning plumes. Post-emission production of methanol does not always happen in young biomass burning plumes, and its occurrence in this study could have involved terpene precursors to a significant extent.
In ferromagnetic thin films, broken inversion symmetry and spin-orbit coupling give rise to interfacial Dzyaloshinskii-Moriya interactions. Analytic expressions for spin-wave properties show that the ...interfacial Dzyaloshinskii-Moriya interaction leads to nonreciprocal spin-wave propagation, i.e., different properties for spin waves propagating in opposite directions. In favorable situations, it can increase the spin-wave attenuation length. Comparing measured spin-wave properties in ferromagnet/normal metal bilayers and other artificial layered structures with these calculations could provide a useful characterization of the interfacial Dzyaloshinskii-Moriya interactions.
Matter with a high energy density (>10(5) joules per cm(3)) is prevalent throughout the Universe, being present in all types of stars and towards the centre of the giant planets; it is also relevant ...for inertial confinement fusion. Its thermodynamic and transport properties are challenging to measure, requiring the creation of sufficiently long-lived samples at homogeneous temperatures and densities. With the advent of the Linac Coherent Light Source (LCLS) X-ray laser, high-intensity radiation (>10(17) watts per cm(2), previously the domain of optical lasers) can be produced at X-ray wavelengths. The interaction of single atoms with such intense X-rays has recently been investigated. An understanding of the contrasting case of intense X-ray interaction with dense systems is important from a fundamental viewpoint and for applications. Here we report the experimental creation of a solid-density plasma at temperatures in excess of 10(6) kelvin on inertial-confinement timescales using an X-ray free-electron laser. We discuss the pertinent physics of the intense X-ray-matter interactions, and illustrate the importance of electron-ion collisions. Detailed simulations of the interaction process conducted with a radiative-collisional code show good qualitative agreement with the experimental results. We obtain insights into the evolution of the charge state distribution of the system, the electron density and temperature, and the timescales of collisional processes. Our results should inform future high-intensity X-ray experiments involving dense samples, such as X-ray diffractive imaging of biological systems, material science investigations, and the study of matter in extreme conditions.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We apply a quantum diamond microscope for detection and imaging of immunomagnetically labeled cells. This instrument uses nitrogen-vacancy (NV) centers in diamond for correlated magnetic and ...fluorescence imaging. Our device provides single-cell resolution and a field of view (∼1 mm(2)) two orders of magnitude larger than that of previous NV imaging technologies, enabling practical applications. To illustrate, we quantified cancer biomarkers expressed by rare tumor cells in a large population of healthy cells.
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