2,300 research outputs found
Contact allergy to 2-hydroxy-5-tert-butyl benzylalcohol and 2,6-bis(hydroxymethyl)-4-tert-butylphenol, components of a phenolic resin used in marking pens
Strategic Missile Forces in Ukraine: Brief Survey of Past and Present Environmental Problems
Various environmental problems related to the former strategic missile forces located in Ukraine are outlined and analyzed. As the combat units and equipment have been disarmed and mostly utilized according to international agreements, various axiliary units, equipment, parts, stockpiles of the rocket fuel and oxidizer remained in Ukraine outside the agreements
Permeability, porosity, dispersion-, diffusion-, and sorption characteristics of chalk samples from Erslev, Mors, Denmark
Unchanged incidence and increased survival in children with neuroblastoma in Denmark 1981–2000: a population-based study
Treatment results for neuroblastoma in Denmark have been poorer than in other Nordic countries, so we investigated whether a change in incidence, stage distribution and survival had occurred between 1981 and 2000. Clinical data were retrieved from the medical charts of 160 children <15 years of age with extra-cranial neuroblastoma (n=139) or ganglioneuroblastoma (n=21) diagnosed in Denmark between 1981 and 2000. The minimal follow-up time was 52 months. Statistical analyses were performed in STATA. The incidence was 8.55 per million children below 15 years of age (world standard 9.6) and 42.6 per million children below 12 months of age, and it has remained unchanged since 1970. The median age at diagnosis was 27 months. In all, 32% of the children were aged below 12 months at diagnosis, 53% had metastatic disease and in 12% the diagnosis was made incidentally. Prognostic factors such as age, stage and site of primary tumour were the same as in other studies and did not change. During the study period, the mortality rate decreased steadily, and the 5-year survival rate increased from 38% in 1981–1985 to 59% in 1996–2000, corresponding to the level found in other Western countries. Increased survival was also seen in children with metastatic disease. Participation in international studies, better supportive care and possibly postoperative autologous stem cell transplantation may have contributed to the increased survival
Epidemiologic Findings and Management Response During a Bighorn Sheep Die-Off in the Elkhorn Mountains of West-Central Montana
Bighorn sheep (Ovis canadensis) were introduced into the Elkhorn Mountains of west-central Montana in the mid 1990s. The population increased in number to approximately 250 animals until the winter of 2007-2008 when about 84 percent of the population died from a pneumonia related epizootic. Management actions during the die-off were geared toward removing as many sick animals as possible in efforts to reduce overall mortality. Due to the stage of the epizootic removal of sick sheep was not effective in interrupting the die-off. Samples were collected from bighorn sheep, domestic sheep, mule deer (Odocoileus hemionus), elk (Cervus elaphus) and domestic goats utilizing the same winter range. Pasteurella spp, Moraxella ovis and Mycoplasma ovipneumonia were isolated from lung tissue of dead bighorns and pharyngeal swabs collected from domestic sheep occupying similar range during the epizootic. Both the bighorn sheep and domestic sheep also shared similar gastro-intestinal parasites including Nematodirus spp and Eimeria spp. Testing tissues and fecal samples from sympatric mule deer suggested no shared bacterial pathogens and limited shared gastrointestinal parasites. Evaluation of fecal samples from domestic goats and elk also occupying bighorn sheep range identified few shared parasites that may have contributed to the epizootic
GC–MS and GC–NPD Determination of Formaldehyde Dimethylhydrazone in Water Using SPME
Formaldehyde dimethylhydrazone (FADMH) is one of the important transformation products of residual rocket fuel 1,1-dimethylhydrazine (1,1-DMH). Thus, recent studies show that FADMH toxicity is comparable to that of undecomposed 1,1-DMH. In this study, a new method for quantification of FADMH in water based on solid phase microextraction (SPME) in combination with gas chromatography (GC) with mass spectrometric (MS) and nitrogen-phosphorus detection (NPD) is presented. Effects of SPME fiber coating type, extraction and desorption temperatures, extraction time, and pH on analyte recovery were studied. The optimized method used 65 micron polydimethylsiloxane/divinylbenzene fiber coating for 1 min headspace extractions at 30 °C. Preferred pH and desorption temperature from the SPME fiber are >8.5 and 200 °C, respectively. Detection limits were estimated to be 1.5 and 0.5 μg L−1 for MS and NPD, respectively. The method was applied to laboratory-scale experiments to quantify FADMH. Results indicate applicability for in situ sampling and analysis and possible first-time detection of free FADMH in water
Geometrical Optics Formalism to Model Contrast in Dark-Field X-ray Microscopy
Dark-field X-ray microscopy is a new full-field imaging technique that
nondestructively maps the structure and local strain inside deeply embedded
crystalline elements in three dimensions. Placing an objective lens in the
diffracted beam generates a magnified projection image of a local volume. We
provide a general formalism based on geometrical optics for the diffraction
imaging, valid for any crystallographic space group. This allows simulation of
diffraction images based on micro-mechanical models. We present example
simulations with the formalism, demonstrating how it may be used to design new
experiments or interpret existing ones. In particular, we show how
modifications to the experimental design may tailor the reciprocal-space
resolution function to map specific components of the deformation gradient
tensor. The formalism supports multi-length scale experiments, as it enables
DFXM to be interfaced with 3DXRD. The formalism is demonstrated by comparison
to experimental images of the strain field around a straight dislocation
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