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[en] AIM: To determine factors influencing diagnostic yield in computed tomography (CT)-guided biopsy of lung lesions. MATERIALS AND METHODS: One hundred and ninety-five consecutive CT-guided lung biopsies were performed in 182 patients between August 1995 and September 2000 and either fine-needle aspirate samples for cytology or core biopsy samples for histology were collected. Procedures were divided into a diagnostic group (true-positive and true-negative results) and a non-diagnostic group (false-positive and false-negative results) and the factors affecting diagnostic accuracy assessed. RESULTS: One hundred and fifty-six lesions (86%) were malignant, and 26 (14%) were benign. More than one biopsy was performed for 12 lesions. One hundred and thirty-two biopsies were true-positive, 27 true-negative and 36 false-negative. No false-positive results occurred in the study. Overall diagnostic accuracy was 81.5%. Significantly more core biopsies than fine-needle aspirates were diagnostic: 93 versus 78% (p<0.005). No difference was found in frequency of pneumothorax between these two groups. There was a difference in the average depth from the pleural surface of lesions in the diagnostic and non-diagnostic groups, but this did not attain statistical significance: 9.8 versus 17.2 mm (p=0.054). CONCLUSION: In this study CT-guided lung biopsy core biopsy was a more accurate method of tissue sampling than fine-needle aspiration, and was not associated with an excess of complications
[en] Escherichia coli OmpW belongs to a family of small outer membrane (OM) proteins that are widespread in Gram-negative bacteria. Their functions are unknown, but recent data suggest that they may be involved in the protection of bacteria against various forms of environmental stress. In order to gain insight into the function of these proteins we have determined the crystal structure of Escherichia coli OmpW to 2.7 Angstroms resolution. The structure shows that OmpW forms an eight-stranded beta-barrel with a long and narrow hydrophobic channel that contains a bound LDAO detergent molecule. Single channel conductance experiments show that OmpW functions as an ion channel in planar lipid bilayers. The channel activity can be blocked by the addition of LDAO. Taken together, the data suggest that members of the OmpW family could be involved in the transport of small hydrophobic molecules across the bacterial OM
[en] The purpose of the paper is to assess the accuracy of three-dimensional MR imaging reconstruction in the evaluation of meniscal tears. Thirteen knees (26 menisci) were evaluated with MR imaging using spin-echo pulse sequences. The menisci were evaluated in conventional tow-dimensional film format. Three-dimensional reconstructions were performed and were independently analyzed without knowledge of patient identify, history, or findings at tow-dimensional MR imaging. Observations on imaging studies were correlated with findings at videoarthroscopy. Thirteen meniscal tears were seen with all three techniques (two-and three-dimensional MR imaging and arthroscopy). Eight menisci were normal with all techniques. In 5 cases three-dimensional reformations demonstrated meniscal tears that were confirmed at arthroscopy but missed at conventional two-dimensional MR imaging
[en] Seven men, six suffering from widespread bone metastases of prostatic origin and one with urinary bladder carcinoma, demonstrated minimal or no discernible radioactivity in the kidneys and urinary bladder at the time of bone scanning using /sup 99m/Tc-stannous polyphosphate. The mechanism behind this scan finding is thought to be rapid and enhanced uptake of the radiopharmaceutical by pathologic bone. The significance of the faint or absent kidney sign in bone scanning, particularly in cases where abnormally homogeneous and symmetric radioactivity exists, is discussed. (U.S.)
[en] Strong quantum confinement in InP is observed to significantly reduce the separation between the direct and indirect conduction band states. The effects of three-dimensional confinement are investigated by tailoring the initial separation between conduction band states using quantum dots (QDs) of different sizes and hydrostatic pressure. Analyses of the QD emission spectra show that the X1c states are lowest in energy at pressures of ∼6 GPa , much lower than in the bulk. The transition to the X1c states can be explained by either a sequence of Γ-L and L-X crossings, or by the crossover between strongly coupled Γ and X states. (c) 2000 The American Physical Society
[en] Recently the authors introduced a new technique of intravenous (IV) radionuclide total-body arteriography. The major arterial system, multiple organs of the whole body, and cardiac function can be evaluated with one small IV injection in the arm. After analyzing more than 1000 cases, they have found that many pathologies can be detected and/or confirmed in this procedure. This new technique may be used as a general whole-body screening test for those patients at high risk for disease
[en] The identification of non-ideal flows in a continuous-flow mixing of non-Newtonian fluids is a challenging task for various chemical industries: plastic manufacturing, water and wastewater treatment, and pulp and paper manufacturing. Non-ideal flows such as channelling, recirculation, and dead zones significantly affect the performance of continuous-flow mixing systems. Therefore, the main objective of this paper was to develop an identification protocol to measure non-ideal flows in the continuous-flow mixing system. The extent of non-ideal flows was quantified using a dynamic model that incorporated channelling, recirculation, and dead volume in the mixing vessel. To estimate the dynamic model parameters, the system was excited using a frequency-modulated random binary input by injecting the saline solution (as a tracer) into the fresh feed stream prior to being pumped into the mixing vessel. The injection of the tracer was controlled by a computer-controlled on-off solenoid valve. Using the trace technique, the extent of channelling and the effective mixed volume were successfully determined and used as mixing quality criteria. Such identification procedures can be applied at various areas of chemical engineering in order to improve the mixing quality. (authors)
[en] Highlights: • Details of status monitoring instrumentation are presented. • Protection instrumentation details are presented. • Instrumentation installation details, signal conditioning and DAQ system details and the results during SST-1 operation are presented. - Abstract: Superconducting magnets of SST-1 are extensively instrumented to continuously monitor the health of magnets during machine cool-down, plasma experiments and also during the machine warm-up phase. These instrumentations include temperature sensors, flow meters, hall probes, strain gages, displacement sensors, pressure sensors and voltage taps. The number of sensors and their locations has been optimized to systematically monitor all important magnet parameters to ensure its safety. In-house developed modular signal conditioning cards have been developed for these instrumentations. The data is acquired on a Versa Module Europa bus based data acquisition system (VME DAQ). This paper gives an overview of selection, installation, laboratory scale validations, and distribution logics of these instrumentations. Results during plasma campaigns and the up-gradation aspects of these instrumentations are also discussed in this paper.
[en] Highlights: • Design of Venturi meter for SST-1 magnet system. • Details of Helium mass flow measurement system used in SST-1. • Instruments and measurement techniques for flow measurement. • VME based data acquisition system details and flow calculation and results from SST-1 campaigns. - Abstract: Superconducting Magnet System (SCMS) of Steady State Superconducting Tokamak – 1 (SST-1) is forced-flow cooled by a closed cycle 1.3 kW (at 4.5 K) class Helium Refrigerator cum Liquefier (HRL) system. An accurate measurement of helium mass flow rate in different coils is required to ensure the uniform cooling of the cold mass in the entire range of operating temperature (300 K to 4.5 K) and pressure (0.9–0.4 MPa). To meet this requirement, indigenously designed and fabricated venturi meters are installed on 27 different coils of SST-1 SCMS. A VME based Data Acquisition System (DAS) has been developed and used to acquire the flow measurement data from different flowmeters. The details of the design of venturi meter, its different measurement and signal conditioning components, the data acquisition system and the mass flow rate calculation method are described in this paper. The mass flow rate measurement data from cryogenic acceptance and SST-1 magnet commissioning experiments are also presented and discussed in this paper.
[en] Highlights: • Prototype of bridge type joints fabricated and validated successfully. • Bridge type joints fabricated and validated on one of the SST-1 PF#3T coil successfully. • Joint resistance was measured with precision nano volt meter and PXI based data acquisition system. • Leak tightness of joint box was better than 3 × 10−6 Pa m3 s−1. • The measured joint resistance of bridge type joint was ∼1.6 nano ohm. - Abstract: A novel concept of bridge joint for Poloidal field (PF) magnet of SST-1 with damaged winding pack has been realized. This joint has been fabricated on 5th and 6th layers of PF#3T coil winding pack (WP) after validation at 10 kA at liquid helium temperature of 4.2 K in current lead test chamber. The joint resistance of bridge joint was measured ∼1.6 nΩ at flat top DC current of 10 kA. This type of joint could be economically useful for revival of a shorted and damaged WP superconducting PF magnets of Tokamaks. In this paper, details of bridge joint design, fabrication and validations are discussed