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IAEA activities in fire safety at nuclear power plants

KERNTECHNIK 2000年第2-3期65卷 77-79页

作者： Tezuka, H Int Atom Energy Agcy A-1400 Vienna Austria

The IAEA launched a fire safety programme in 1993 to assist Member States in improving fire safety both in new and existing nuclear power plants (NPPs). Under this programme, the IAEA has published a number of guidance and practical documents related to fire safety in NPPs. Ar the request of Member States, fire safety review missions and training courses have also been conducted. In order to improve the reliability of pre safety assessment and promote advanced techniques in this area, the IAEA has established a data collection and reporting system which includes Sire relevant incidents. The IAEA has also organized various technical meetings on five safety for information exchange. IAEA activities on fire safety at NPPs will be continued However, it is expected that, after the IAEA guidance documents have been completed, ficture efforts will focus on assistance in the application this guidance, i.e. on safety review services and training courses.

关键词： Nuclear powerplants International Atomic Energy Agency Safety programs guidance MEMBERS Fire safety

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Real-time MR imaging-guided passive catheter tracking with use of gadolinium-filled catheters

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JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 2000年第8期11卷 1079-1085页

作者： Omary, RA Unal, O Koscielski, DS Frayne, R Korosec, FR Mistretta, CA Strother, CM Grist, TM Univ Wisconsin Sch Med Dept Radiol Madison WI USA Univ Wisconsin Sch Med Dept Med Phys Madison WI USA

PURPOSE: To test the hypothesis that real-time magnetic resonance (MR) imaging-guided passive catheter tracking is feasible with use of dilute gadolinium (Gd) filled catheters, to determine the optimal Gd concentration required for tracking, and to measure catheter tip tracking accuracy. MATERIALS AND METHODS: The authors tested a seal-time, T1-weighted, two-dimensional, spoiled gradient-recalled echo MR imaging sequence suitable for tracking catheters, In a yogurt phantom, the authors placed 5-F catheters filled with 2%-12% Gd solutions. MR imaging was performed with and without use of a projection dephaser that suppressed background signal, The authors measured signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and enhancement ratio to determine the optimal Cd concentration for catheter depiction, Catheter tip tracking accuracy was measured in an acrylic phantom with use of linear regression analysis, with goodness of fit assessed statistically with the F test. RESULTS: Peak catheter SNR, CNR, and enhancement ratios were obtained with 4%-6% Gd concentrations. Tip tracking accuracy was determined to be +/- 0.41 mm (R-2 = 0.99;P < .0001). MR imaging reconstructions were displayed up to 3.1 frames/sec. CONCLUSIONS: Accurate MR imaging-guided passive catheter tracking was feasible in real-time with use of dilute Gd-filed catheters, This technique may have application in MR imaging-guided endovascular procedures.

关键词： magnetic resonance (MR) vascular studies magnetic resonance (MR) guidance

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The bootstrap procedure in individual bioequivalence

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STATISTICS IN MEDICINE 2000年第20期19卷 2741-2754页

作者： Shao, J Chow, SC Wang, B Univ Wisconsin Dept Stat Madison WI 53706 USA StatPlus Inc Yardley PA 19067 USA Merck & Co Inc Blue Bell PA 19422 USA

A bootstrap-type hypothesis test procedure for assessing individual (or population) bioequivalence between two drug formulations is suggested in a draft guidance from the United States Food and Drug Administration (FDA). The purpose of this article is to study the unknown properties of this test procedure and propose some improved test procedures. We find that: the FDA's bootstrap computation is not correct;the power of the FDA's test can be very low;the use of the REML method suggested in the draft guidance does not have any advantage over the use of simpler methods such as the moment method;and the method of sample size determination in the draft guidance is inappropriate. We study the size and power of different bootstrap test procedures and suggest a method for sample size determination. It is our hope that this article will draw some attention to further research in this area, and eventually a satisfactory statistical method can be implemented for assessing individual (or population) bioequivalence. Copyright (C) 2000 John Wiley & Sons, Ltd.

关键词： Models Statistical Therapeutic Equivalency Drugs Generic 模型统计学治疗等效 Sketches Pharmaceutical Preparations bootstrapping METHOD OF MOMENTS Generic Drugs Therapeutic Equivalency Testing Procedures guidance United States Food and Drug Administration

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Interventional MRA and intravascular imaging

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JOURNAL OF MAGNETIC RESONANCE IMAGING 2000年第2期12卷 534-546页

作者： Ladd, ME Quick, HH Debatin, JF Univ Hosp Essen Dept Radiol D-45122 Essen Germany

Several attributes make magnetic resonance imaging (MRI) attractive, for guidance of intravascular therapeutic procedures, including high soft tissue contrast, imaging in arbitrary oblique planes, lack of ionizing radiation, and the ability to provide functional information, such as, flow velocity or flow volume per unit time, in conjunction with morphologic information. For MR guidance of vascular interventions to be safe, the interventionalist must be able to visualize catheters, and guidewires, relative, to the vascular system and surrounding tissues. A number of approaches for rendering instruments visible in an MR environment have been developed, including both passive and active techniques. Passive, techniques depend on contrast agents or susceptibility artifacts that enhance the appearance of the catheter in the image itself, whereas active techniques rely on supplemental hardware built into the catheter, such as a radiofrequency (RF) coil. Additionally, the ability to introduce an RF coil mounted on a catheter presents the opportunity to obtain high-resolution images of the vessel wall. These images can provide the capability various plaque components. to distinguish and identify The additional capabilities of MRI could potentially open up new applications within the purview of vascular interventions beyond those currently performed under X-ray fluoroscopic guidance. (C) 2000 Wiley-Liss, Inc.

关键词： interventions guidance MR angiography intravascular imaging catheters guidewires

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Ordered networks of rat hippocampal neurons attached to silicon oxide surfaces

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JOURNAL OF NEUROSCIENCE METHODS 2000年第1期104卷 65-75页

作者： Scholl, M Sprössler, C Denyer, M Krause, M Nakajima, K Maelicke, A Knoll, W Offenhäusser, A Max Planck Inst Polymer Res D-55128 Mainz Germany Univ Mainz Inst Physiol Chem & Pathobiochem D-55099 Mainz Germany Inst Phys & Chem Res Wako Saitama 3510198 Japan

The control of neuronal cell position and outgrowth is of fundamental interest in the development of applications ranging from cellular biosensors to tissue engineering. We have produced rectangular networks of functional rat hippocampal neurons on silicon oxide surfaces. Attachment and network formation of neurons was guided by a geometrical grid pattern of the adhesion peptide PA22-2 which matches in sequence a part of the A-chain of laminin. PA22-2 was applied by contact printing onto the functionalised silicon oxide surface and was immobilised by hetero-bifunctional cross-linking with sulfo-GMBS. Geometric pattern matching was achieved by microcontact printing using a polydimethylsiloxane (PDMS) stamp. In this way the produced grid pattern ranged from 3 to 20 mum in line width and from 50 to 100 mum in line distances. As shown by atomic force microscopy (AFM), line widths and line distances of the peptide pattern differ less than 0.5 mum from the used PDMS stamp. The height of the layer of immobilised PA22-2 was approximately 3.5 nm implying the layer to be monomolecular. Immobilised PA22-2 was capable of binding anti-PA22-2 antibodies indicating that the function of the peptide was not compromised by immobilisation. Rat hippocampal neurons, cultured at low density in serum-free medium, were applied to the growth matrix of PA22-2-coated substrates and, within 1-3 h of culture, formed a network-like pattern that mure or less matched the printed grid. Reliability and reproducibility of neuronal network formation depended on the geometry, line width and node diameter of the grid pattern. The immobilised neurons showed resting membrane potentials comparable with controls and, already after 1 day of culture, were capable of eliciting action potentials. The suitability of the immobilised neurons fur the study of man-made neural networks and for multi-site recordings from a functional neuronal network is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： microcontact printing guidance pattern cell adhesion hippocampal neurons

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Validity of the examination method of occlusal contact pattern relating to mandibular position

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JOURNAL OF DENTISTRY 2000年第1期28卷 23-29页

作者： Ogawa, T Ogimoto, T Koyano, K Kyushu Univ Fac Dent Dept Removable Prosthodont Fukuoka 812 Japan

Objective: This study was based on the hypothesis that conflicting findings and inconclusive consensus regarding the role of occlusal factors in the masticatory system are due to the variations in the definitions and methods used to describe and examine the occlusal factors. The object of this study was to determine whether contact patterns during lateral movement vary with mandibular positions and whether the contact pattern in lateral positions close to the maximum intercuspation has characteristics distinct from those in an edge-to-edge position. Methods: Occlusal contacts of 86 young adults were examined using shim stock in regulated lateral positions: 0.5, 1, 2 and 3 mm from the maximum intercuspation, where the 0.5, 1 and 2 mm positions were defined as lateral positions close to the maximum intercuspation and the 3 mm position as an edge-to-edge position. Results: The occlusal contact pattern in the 0.5 mm position showed a marked prevalence of posterior tooth contacts on the working and the non-working sides, compared with the 1, 2 and 3 mm positions. The occlusal contact pattern in the 3 mm position predicted the presence or absence of the occlusal contact in the 1 and 2 mm positions (sensitivity > 0.7) but not in the 0.5 mm position (sensitivity < 0.6). Conclusion: The occlusal contact patterns during lateral movement varied greatly with mandibular positions. The examination method of the occlusal contact pattern in one unregulated position will be invalid. It is necessary to distinguish the occlusal contact patterns between a position close to the maximum intercuspation and an edge-to-edge position when investigating its role in the masticatory system and in oral disease. (C) 1999 Elsevier Science Ltd. All rights reserved.

关键词： occulusion contact guidance lateral excursion occlusion

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Expression and regulation of chicken fibroblast growth factor homologous factor (FHF)-4 at the base of the developing limbs

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MECHANISMS OF DEVELOPMENT 2000年第1-2期95卷 101-112页

作者： Muñoz-Sanjuán, I Fallon, JF Nathans, J Johns Hopkins Univ Sch Med Dept Mol Biol & Genet Baltimore MD 21205 USA Univ Wisconsin Dept Anat Madison WI 53706 USA Johns Hopkins Univ Sch Med Dept Ophthalmol Baltimore MD 21205 USA Johns Hopkins Univ Sch Med Dept Neurosci Baltimore MD 21205 USA Johns Hopkins Univ Sch Med Howard Hughes Med Inst Baltimore MD 21205 USA

Fibroblast growth factor homologous factors (FHFs) have been implicated in limb and nervous system development. In this paper we describe the expression of the cFHF-4 gene during early chicken development, cFHF-4 is expressed in the paraxial mesoderm, lateral ridge, and, most prominently, in the posterior-dorsal side of the base of each limb bud. The expression pattern of cFHF-4 at the base of the limbs is not altered by tissue grafts containing the zone of polarizing activity (ZPA), by implants of Shh-expressing cells, or by implants of beads containing retinoic acid, nor does it depend on the distal growth of the limb as it is not altered in limb buds that are surgically truncated. In three chicken mutants affecting limb patterning - talpid(2), limbless, and wingless - altered patterns of cFHF-4 expression are correlated with abnormal nerve plexus formation and altered patterns of limb bud innervation. Similarly, ectopic expression of cFHF-4 is correlated with a local induction of limb-like innervation patterns when beads containing FGF-2 are implanted in the flank. In these experiments, both ectopic innervation and ectopic expression of cFHF-4 in the flank were observed regardless of the size of the FGF-2-induced outgrowths. By contrast, ectopic expression of Shh and HoxD13 are seen only in the larger FGF-2-induced outgrowths. Taken together, these data suggest that cFHF-4 regulates or is coregulated with early events related to innervation at the base of the limbs. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.

关键词： fibroblast growth factor homologous factors FGF-2 talpid(2) limbless chicken mutant wingless chicken mutant plexus formation axonal guidance

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CT-guided cutting needle biopsy of lung lesions - Safety and efficacy of an out-patient service

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CLINICAL RADIOLOGY 2000年第12期55卷 964-969页

作者： Charig, MJ Phillips, AJ Wexham Pk Hosp Dept Radiol Slough SL2 4HL Berks England

AIM: To determine the safety and efficacy of CT-guided cutting needle biopsy of lung lesions as an out-patient procedure. MATERIALS AND METHODS: A total of 185 consecutive biopsies were performed under CT guidance on 183 patients between January 1991 and December 1998 using 20-gauge (n = 33), 18-gauge (n = 151) or 14-gauge (n = 1) core biopsy needles. A chest radiograph was taken after observation in the Radiology department for I h and asymptomatic patients were discharged. RESULTS: The histology was malignant in 150 biopsies (81.1%) and benign in 23 (12.4%) with 12 false-negative results (6.5%);there were no false-positive results, The sensitivity was 92.6%;specificity 100%;negative predictive value 65.7%;and overall accuracy 93.5%. Pneumothoraces occurred in 48 patients (25.9%);one required aspiration only and four required insertion of an intercostal drain. One patient developed a pneumothorax after discharge, Small haemoptyses occurred in 13 patients without pneumothorax (7.0%), one of whom was admitted, In-patient treatment was required in 10 patients (5.4%). CONCLUSION: Computed tomography-guided cutting needle biopsy of pulmonary lesions is a safe technique with a diagnostic accuracy and complication rate comparable to reported figures for fine needle aspiration biopsy. It can be safely performed on an out-patient basis, Charig, M. J., Phillips, A. J. (2000). Clinical Radiology 55, 964-969. (C) 2000 The Royal College of Radiologists.

关键词： lung biopsy computed tomography guidance pneumothorax

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Path integration in insects

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CURRENT OPINION IN NEUROBIOLOGY 2000年第6期10卷 757-762页

作者： Collett, TS Collett, M Univ Sussex Sch Biol Sci Sussex Ctr Neurosci Brighton BN1 9QG E Sussex England Michigan State Univ Dept Zool E Lansing MI 48824 USA

The most notable advance in our knowledge of path integration in insects is a new understanding of how the honeybee measures the distance that it travels during its foraging trips. Data from two groups show that the bee's odometer records distance in terms of the net amount of image motion over the retina that is accumulated during a flight, Progress has also been made in clarifying the relation between path integration and other navigational strategies. On unfamiliar ground, path integration is the only available means of navigation. In familiar surroundings, however, guidance by landmarks may override guidance by path integration. Path integration then becomes a back-up strategy that is used primarily when landmarks fail.

关键词： Behavior Animal Insects Locomotion 行为动物昆虫行走 guidance Insecta Byways Locomotion landmarks

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CT-guided transthoracic needle biopsy of pulmonary nodules smaller than 20 mm: Results with an automated 20-gauge coaxial cutting needle

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CLINICAL RADIOLOGY 2000年第4期55卷 281-287页

作者： Laurent, F Latrabe, V Vergier, B Montaudon, M Vernejoux, JM Dubrez, J Univ Bordeaux 2 CHU Bordeaux Hosp Haut Leveque Dept Radiol F-33604 Pessac France Univ Bordeaux 2 Dept Pathol Hosp Haut Leveque F-33604 Pessac France Univ Bordeaux 2 Dept Pneumol Hosp Haut Leveque F-33604 Pessac France Univ Bordeaux 2 Dept Thorac Surg Hosp Haut Leveque F-33604 Pessac France

AIMS: To evaluate the efficacy and the complication rate of CT-guided percutaneous lung biopsy of pulmonary nodules smaller than 20 mm in diameter using a 20-gauge coaxial automated biopsy device. MATERIAL AND METHODS: A prospective study was undertaken of 200 patients who underwent 202 consecutive biopsies of pulmonary nodules, performed with a single type of automated biopsy device. Sixty-seven biopsies of nodules smaller than 20 mm in diameter were performed in 66 patients (group A). One hundred and thirty-five biopsies of lesions of 20 mm or greater in size were performed in 134 patients (group B). Patient characteristics, lesion and procedure variables, the accuracy and complication rates were compared. RESULTS: In group A, the final diagnosis of the nodules was malignant in 47 and benign in 19 cases (prevalence of malignancy 71.2%). In group B, there were 111 malignant and 21 benign diagnoses (prevalence of malignancy 82.2%). In group A, the sensitivity and specificity for a diagnosis of malignancy were 89.5 and 100%, respectively (positive predictive value 100%, negative predictive value 76%). A specific diagnosis of benignity was obtained in nine out of 19 (47%) biopsies. The pneumothorax rate was 15% (10 patients) of which two (3%) required drainage. CT signs thought to reflect alveolar haemorrhage were noted in 28 (43%) and haemoptysis occurred in five patients (5.9%). In group B, the sensitivity and specificity for a diagnosis of malignancy were 95.5% and 100%, respectively (positive predictive value 100%, negative predictive value 82.7%). A specific diagnosis of benignity was made in 14 cases (58.3%). Complications included pneumothoraces in 22 cases (16.2%) requiring drainage in one (0.7%). Presumed alveolar haemorrhage was recorded in 19 cases (14.1%) and haemoptysis occurred in seven (5.2%). There were no significant differences between group A and group B, except for alveolar haemorrhage (P < 0.001). CONCLUSION: The accuracy and complication rate of

关键词： biopsy technology computed tomography guidance interventional procedures complications lung biopsy neoplasm diagnosis

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