810 research outputs found

    Advances in the Treatment of Patients with Benign Brain Tumors

    Get PDF
    Reliable ICP measurement allows an exact quantitation and management of intracranial pressure. This precise assessment of ICP is a valuable adjunct in the management of anesthesia for brain tumor patients. The proper combination of ICP and anesthesia management enables the surgeon to use the operating microscope to approach previously inaccessible areas of the brain and to perform meticulous surgery with a better prognosis for the brain tumor patient

    TB82: The Potential of Softwood Thinnings and Standing Dead Softwoods as a Source of Wood Pulp

    Get PDF
    This study was made to determine the potential of softwood thinnings and standing dead softwood as a source of wood pulp, employing the kraft process. In the thinning studies examined eastern white pine, eastern hemlock, balsam fir, norway spruce, red pine, eastern larch, and northern white cedar. The stem (wood and bark) and the top (wood, bark, and needles) and the stem and top combined were pulped. When compared with pulp from a commercial-size softwood species, the thinnings provided pulps of good strength that were slightly undercooked and that had significantly lower yields. The stem portion pulps were superior in all cases to those made from the top portion. This is attributed to the foliage and higher bark content of the branches of the top which resulted in relatively low yields. The brief study of the characteristics of standing dead softwood trees, either killed by fire or natural attrition, indicated that they compare favorably with the live thinnings as a source of pulp when yield and physical properties are the criteria. It was concluded from this study that 35-4 0 percent of the thinnings material is available as a good grade of wood pulp.https://digitalcommons.library.umaine.edu/aes_techbulletin/1111/thumbnail.jp

    Probing ISM Structure in Trumpler 14 & Carina I Using The Stratospheric Terahertz Observatory 2

    Get PDF
    We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2 (STO2). The Trumpler 14/Carina I region is in the west part of the Carina Nebula Complex, which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 μ\mum transition of [C\,{\sc ii}] with a spatial resolution of 48′′'' and a velocity resolution of 0.17 km s−1^{-1}. The observations cover a 0.25∘^\circ by 0.28∘^\circ area with central position {\it l} = 297.34∘^\circ, {\it b} = -0.60∘^\circ. The kinematics show that bright [C\,{\sc ii}] structures are spatially and spectrally correlated with the surfaces of CO clouds, tracing the photodissociation region and ionization front of each molecular cloud. Along 7 lines of sight that traverse Tr 14 into the dark ridge to the southwest, we find that the [C\,{\sc ii}] luminosity from the HII region is 3.7 times that from the PDR. In same los we find in the PDRs an average ratio of 1:4.1:5.6 for the mass in atomic gas:dark-CO gas: molecular gas traced by CO. Comparing multiple gas tracers including HI 21cm, [C\,{\sc ii}], CO, and radio recombination lines, we find that the HII regions of the Carina Nebula Complex are well-described as HII regions with one-side freely expanding towards us, consistent with the champagne model of ionized gas evolution. The dispersal of the GMC in this region is dominated by EUV photoevaporation; the dispersal timescale is 20-30 Myr.Comment: ApJ accepte

    Duplex assessment of venous reflux and chronic venous insufficiency: The significance of deep venous reflux

    Get PDF
    AbstractPurpose: This study was undertaken to examine the role of superficial and deep venous reflux, as defined by duplex-derived valve closure times (VCTs), in the pathogenesis of chronic venous insufficiency.Methods: Between January 1992 and November 1995, 320 patients and 500 legs were evaluated with clinical examinations and duplex scans for potential venous reflux. VCTs were obtained with the cuff deflation technique with the patient in the upright position. Imaging was performed at the saphenofemoral junction, the middle segment of the greater saphenous vein, the lesser saphenous vein, the superficial femoral vein, the profunda femoris vein, and the popliteal vein. Not all patients had all segments examined because tests early in the series did not examine the profunda femoris or lesser saphenous vein and because some patients had previous ligation and stripping or venous thrombosis. VCTs were examined for individual segment reflux, grouped into superficial and deep systems, and then correlated with the clinical stage as defined by the SVS/ISCVS original reporting standards in venous disease. Segment reflux was considered present if the VCT was greater than 0.5 seconds, and system reflux was considered present if the sum of the segments was greater than 1.5 seconds. Between-group differences were analyzed with analysis of variance and post hoc tests where appropriate.Results: Sixty-nine limbs studied were in class 0, 149 limbs were in class 1, 168 limbs were in class 2, and 114 limbs were in class 3. VCTs in the superficial veins were significantly lower in class 0 than in the other clinical classes. There was no difference in superficial reflux in the symptomatic limbs (classes 1 to 3). Reflux VCTs in the superficial femoral and popliteal veins increased as the clinical symptoms progressed, with a significant increase in class 3 ulcerated limbs when compared with nonulcerated limbs. The incidence of deep venous reflux was 60% in class 3 limbs, compared with 29% in class 2 limbs, whereas the incidence of superficial venous reflux did not differ among the symptomatic limbs. Isolated superficial femoral and popliteal vein reflux was uncommon, even in class 3 limbs, but combined superficial femoral and popliteal vein reflux was found in 53% of class 3 limbs, compared with 18.5% of class 2 limbs.Conclusions: Reflux in the deep venous system plays a significant role in the progression of chronic venous insufficiency. Deep system reflux increases as clinical changes become more severe, with significant axial reflux contributing to ulcer formation. (J Vasc Surg 1996;24:755-62.

    Training of Instrumentalists and Development of New Technologies on SOFIA

    Full text link
    This white paper is submitted to the Astronomy and Astrophysics 2010 Decadal Survey (Astro2010)1 Committee on the State of the Profession to emphasize the potential of the Stratospheric Observatory for Infrared Astronomy (SOFIA) to contribute to the training of instrumentalists and observers, and to related technology developments. This potential goes beyond the primary mission of SOFIA, which is to carry out unique, high priority astronomical research. SOFIA is a Boeing 747SP aircraft with a 2.5 meter telescope. It will enable astronomical observations anywhere, any time, and at most wavelengths between 0.3 microns and 1.6 mm not accessible from ground-based observatories. These attributes, accruing from the mobility and flight altitude of SOFIA, guarantee a wealth of scientific return. Its instrument teams (nine in the first generation) and guest investigators will do suborbital astronomy in a shirt-sleeve environment. The project will invest $10M per year in science instrument development over a lifetime of 20 years. This, frequent flight opportunities, and operation that enables rapid changes of science instruments and hands-on in-flight access to the instruments, assure a unique and extensive potential - both for training young instrumentalists and for encouraging and deploying nascent technologies. Novel instruments covering optical, infrared, and submillimeter bands can be developed for and tested on SOFIA by their developers (including apprentices) for their own observations and for those of guest observers, to validate technologies and maximize observational effectiveness.Comment: 10 pages, no figures, White Paper for Astro 2010 Survey Committee on State of the Professio
    • …
    corecore