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111.
We have developed an optical delivery device (catheter) capable of transmitting broadband infrared light (IR wavelengths from 2 to 10 microm) for both diagnostic and therapeutic applications. The catheter is 1.68 mm in outer diameter and 1 m in length. It consists of two hollow glass waveguides coupled to a high-refractive-index optic tip. The IR light interacts with the tissue at the optic-tissue interface to measure the spectral signatures and perform therapy on the tissue at this interface. Fourier-transform IR spectrophotometer light is used to obtain the spectral signatures, and an IR free-electron laser (FEL) is used to study the therapeutic interaction of evanescent waves with the tissue. We present our catheter design; preliminary IR spectroscopy of aorta, blood, fatty tissue, and muscle; and IR FEL therapy on atheroslerotic aorta. 相似文献
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An optimal probabilistic neural network (PNN) as a core classifier for fault detection and status indication of a power transformer has been presented. In this scheme, various operating conditions of a transformer are distinguished using signatures of the differential currents. The proposed differential protection scheme is implemented through two different structures of PNN, that is, one having one output and the other having five outputs. The developed algorithm is found to be stable against external fault, magnetising inrush, sympathetic inrush and over-excitation conditions for which relay operation is not required. For the test data of fault, it is found to operate successfully. The performance of proposed PNN and classical artificial neural network (ANN) has been compared. For evaluation of the developed algorithm, relaying signals for various operating conditions of a transformer are obtained by modelling the transformer in PSCAD/EMTDC. The algorithms are implemented using MATLAB. The results show the capability of PNN in terms of classification accuracy and speed in comparison to classical ANNs. 相似文献
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Rous sarcoma virus (RSV) and murine leukemia virus (MLV) are examples of distantly related retroviruses that normally do not encounter one another in nature. Their Gag proteins direct particle assembly at the plasma membrane but possess very little sequence similarity. As expected, coexpression of these two Gag proteins did not result in particles that contain both. However, when the N-terminal membrane-binding domain of each molecule was replaced with that of the Src oncoprotein, which is also targeted to the cytoplasmic face of the plasma membrane, efficient copackaging was observed in genetic complementation and coimmunoprecipitation assays. We hypothesize that the RSV and MLV Gag proteins normally use distinct locations on the plasma membrane for particle assembly but otherwise have assembly domains that are sufficiently similar in function (but not sequence) to allow heterologous interactions when these proteins are redirected to a common membrane location. 相似文献
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M Delgado C Martinez D Pozo JR Calvo J Leceta D Ganea RP Gomariz 《Canadian Metallurgical Quarterly》1999,162(2):1200-1205
The neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) down-regulate cytokine production. Because human septic shock involves excessive cytokine production, the effect of VIP/PACAP was investigated in a high endotoxemia murine model. Both peptides protect against endotoxin-induced lethality and prevent septic shock-associated histopathological alterations. VIP/PACAP reduce serum and peritoneal TNF-alpha and IL-6, suggesting that the protective effect is exerted by inhibiting the production of endogenous TNF-alpha/IL-6. Consistent with this mechanism, VIP does not protect against septic shock induced by exogenous TNF-alpha. The immunomodulatory role of VIP in vivo is supported by the appearance of high levels of VIP in serum and peritoneal fluid following LPS administration. Thus, the neuropeptides VIP/PACAP protect from the lethal effect of high endotoxemia, presumably by down-regulating TNF-alpha and IL-6 production, and may offer an alternative in the treatment of human septic shock syndrome. 相似文献
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Neuromuscular block (NMB) at the larynx has been assessed by measuring the cuff pressure (CP) in an endotracheal tube (ETT) placed between the vocal cords. In this study, we evaluated the decrease in resting cuff pressure (RCP) after the administration of rocuronium and the effect of this decrease on the assessment of NMB, and we compared CP measurement with an alternative technique, video imaging (VI). In 20 patients, NMB was determined at the hand by mechanomyography and at the larynx initially by CP and subsequently by VI, recording images using a fiberoptic bronchoscope via a laryngeal mask. Train-of-four stimuli were applied at both sites. After baseline measurements, the ETT was replaced, and rocuronium was infused to achieve a steady-state 50% (n = 10) or 75% (n = 10) block at the hand. CP measurements were recorded before and after restoration of RCP to prerocuronium pressure, followed by further VI measurements. The mean RCP decreased from 21 +/- 4 to 12 +/- 5 mm Hg after rocuronium. At 50% block at the hand, the CP estimate of block at the larynx with reduced RCP was 62% +/- 18%, and that after restoring RCP was 29% +/- 13%; VI estimated 27% +/- 14% block. At 75% block at the hand, CP and VI estimated 52% +/- 11% and 46% +/- 9% block, respectively (RCP maintained). We conclude that RCP decreases after the administration of rocuronium, that restoring RCP significantly alters CP estimates of NMB, and that VI is in agreement with CP measurement if RCP is maintained at prerelaxant values. Implications: In this study, we show that a muscle relaxant-induced decrease in resting tension at the larynx may confound the assessment of neuromuscular block by cuff pressure measurement. The preliminary data suggest that video imaging may provide a suitable alternative to cuff pressure measurement to assess neuromuscular block at the larynx. 相似文献
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Anil Maheshwari 《Information Systems Management》1999,16(2):85-88
Securing databases requires IS managers to have the utmost attention paid to all kinds of breaches of security, within and outside the organizations. Dynamic page generation and cookies are two of the newer issues that cause IS managers to be forever open to new ways of solving security problems. 相似文献