1,447 research outputs found
Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices
To identify and in the region of GeV/c, a
threshold Cherenkov counter equipped with silica aerogels has been
investigated. Silica aerogels with a low refractive index of 1.013 have been
successfully produced using a new technique. By making use of these aerogels as
radiators, we have constructed a Cherenkov counter and have checked its
properties in a test beam. The obtained results have demonstrated that our
aerogel was transparent enough to make up for loss of the Cherenkov photon
yield due to a low refractive index. Various configurations for the photon
collection system and some types of photomultipliers, such as the fine-mesh
type, for a read out were also tested. From these studies, our design of a
Cherenkov counter dedicated to separation up to a few GeV/c %in the
momentum range of GeV/c with an efficiency greater than \%
was considered.Comment: 21 pages, latex format (article), figures included, to be published
in Nucl. Instrm. Meth.
A new method to establish the rational extent of hepatic resection for advanced gallbladder cancer using dye injection through the cystic artery
BackgroundHepatic resection has been indicated to eliminate cancer at the surgical margin in cases of advanced gallbladder carcinoma, but there is considerable controversy about the reasonable extent of liver resection. A new onâtable dye injection technique has been introduced to determine the venous drainage of the gallbladder and ascertain the amount of liver to remove.MethodsIn four hepatic resections for pT2 gallbladder cancer, indocyanine green solution (25 mg/20 ml) was injected over a period of 30 seconds through the cystic artery. The stained area of the liver surface was completely resected, maintaining a margin of at least 2 cm from the gallbladder.ResultsThe entire serosal surface of the gallbladder takes on a light green stain immediately after dye injection, and then the liver surface around the gallbladder gradually becomes stained with a clear demarcation line. The distance between the demarcation line and the gallbladder ranged from 1.0 to 5.0 cm. The extent of the stained area differed from one individual to another. Histopathological examination of resected liver specimens revealed that one of the four resected livers had micrometastasis in the portal area 27 mm from the gallbladder wall and there were no cancer cells at the surgical margins. No recurrence has been seen in any of our 4 patients at 16â26 months after operation.DiscussionThe dye injection method is useful in determining the appropriate extent of hepatic resection for advanced gallbladder cancer, as it is possible to determine the necessary and sufficient amount of liver parenchyma that should be removed according to the perfusion area of the cystic veins in each individual patient
Prevalence of chronic kidney disease in Asia: A systematic review and analysis
Introduction The burden of chronic kidney disease (CKD) is growing rapidly around the world. However, there is limited information on the overall regional prevalence of CKD, as well as the variations in national prevalence within Asia. We aimed to consolidate available data and quantify estimates of the CKD burden in this region. Methods We systematically searched MEDLINE, Embase and Google Scholar for observational studies and contacted national experts to estimate CKD prevalence in countries of Asia (Eastern, Southern and South Eastern Asia). CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m 2 or the presence of proteinuria. For countries without reported data, we estimated CKD prevalence using agglomerative average-linkage hierarchical clustering, based on country-level risk factors and random effects meta-analysis within clusters. Published CKD prevalence data were obtained for 16 countries (of the 26 countries in the region) and estimates were made for 10 countries. Results There was substantial variation in overall and advanced (eGFR <30 mL/min/1.73 m 2) CKD prevalence (range: 7.0%-34.3% and 0.1%-17.0%, respectively). Up to an estimated 434.3 million (95% CI 350.2 to 519.7) adults have CKD in Asia, including up to 65.6 million (95% CI 42.2 to 94.9) who have advanced CKD. The greatest number of adults living with CKD were in China (up to 159.8 million, 95% CI 146.6 to 174.1) and India (up to 140.2 million, 95% CI 110.7 to 169.7), collectively having 69.1% of the total number of adults with CKD in the region. Conclusion The large number of people with CKD, and the substantial number with advanced CKD, show the need for urgent collaborative action in Asia to prevent and manage CKD and its complications
Fast ignitor research at the Institute of Laser Engineering, Osaka University
Copyright 2001 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 8(5), 2268-2274, 2001 and may be found at http://dx.doi.org/10.1063/1.135259
Magnetoresistivity in a Tilted Magnetic Field in p-Si/SiGe/Si Heterostructures with an Anisotropic g-Factor: Part II
The magnetoresistance components and were measured in
two p-Si/SiGe/Si quantum wells that have an anisotropic g-factor in a tilted
magnetic field as a function of temperature, field and tilt angle. Activation
energy measurements demonstrate the existence of a ferromagnetic-paramagnetic
(F-P) transition for a sample with a hole density of
=2\,cm. This transition is due to crossing of the
0 and 1 Landau levels. However, in another sample, with
=7.2\,cm, the 0 and 1 Landau
levels coincide for angles =0-70. Only for >
70 do the levels start to diverge which, in turn, results in the
energy gap opening.Comment: 5 pages, 6 figure
- âŠ