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The nucleotide sequence of luxD (EMBL accession No. X65611), encoding acyltransferase (ACT), of the lux operon from Photobacterium leiognathi PL741 was determined, and the amino acid (aa) sequence was deduced. ACT is a component of the fatty acid reductase complex, which is responsible for converting fatty acid to aldehyde that serves as the substrate in the luciferase-catalyzed bioluminescent reactions. The protein has a calculated M(r) of 34,384 and comprises 305 aa residues. Alignment and comparison of the ACT of P. leiognathi with that of Vibrio fischeri ATCC7744, V. harveyi B392 and Xenorhabdus luminescens Hm shows that there is 66%, 59% and 61% aa identity, respectively.  相似文献   
73.
Epstein-Barr virus (EBV) is associated with the development of several B cell malignancies including Burkitt's lymphoma (BL), post-transplant lymphoproliferative disease (PTLD), and AIDS-related lymphomas. The latter two diseases result from EBV-driven B cell proliferation in the absence of normal immunosurveillance and as such, represent a heterogenous family of lymphoproliferative disorders. This article reviews studies on EBV gene expression and antibody development in PTLD and introduces recent information on the levels of EBV+ peripheral blood lymphocytes to discuss possible mechanisms of pathogenesis under varying conditions of immunosuppression.  相似文献   
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Comparison of interaction energy between an oligonucleotide and a DNA-binding ligand in the minor and major groove modes was made by use of restrained molecular dynamics. Distortion in DNA was found for the major groove mode whereas less significant changes for both ligand and DNA were detected for the minor groove binding after molecular dynamics simulation. The conformation of the ligand obtained from the major groove modes resembles that computed with the ligand soaked in water. The van der Waals contact energy was found to be as significant as electrostatic energy and more important for difference in binding energy between these two binding modes. The importance of van der Waals force in groove binding was supported by computations on the complex formed by the repressor peptide fragment from the bacteriophage 434 and its operator oligonucleotide.  相似文献   
76.
Ion beam enhanced deposition (IBED) was adopted to synthesize biocompatible titanium oxide film. Structure characteristics of titanium oxide film were investigated by RBS, AES, and XRD. The blood compatibility of the titanium oxide film was studied by measurements of blood clotting time and platelet adhesion. The results show that the anticoagulation property of titanium oxide film is improved significantly. The mechanism of anticoagulation of the titanium oxide film was discussed.  相似文献   
77.
Although screening sigmoidoscopy (SS) reduces colorectal cancer mortality, surveys indicate that fewer than half of primary care physicians routinely recommend SS and less than 10% of eligible patients receive this test. The purpose of this study was to explore barriers to compliance with SS through a cross-sectional survey of general medicine patients. Clinician advice, perceived benefit of the test, and having a family member who has had the test are associated with SS, while perceived pain is a barrier to compliance and can negate the positive effects of clinician advice. These factors can be targeted as part of efforts to improve compliance with SS.  相似文献   
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This article reviews the determinants of myocardial oxygen supply (MVO2) and consumption and revisits the effects of IABC on each. Measurements of MVO2, including diastolic pressure-time index (DPTI), tension-time index (TTI), and endocardial viability ratios (EVR), demonstrate the dramatic effects of balloon deflation and the resulting afterload reduction on MVO2. IABC enhances ventricular outflow, thus decreasing preload; reduces systolic and end-diastolic aortic pressures, causing a decrease in ventricular afterload; magnifies the intrinsic Windkessel effect in the aorta, leading to an increased stroke volume; decreases static work and accordingly, MVO2; and stimulates the baroreceptors, causing a reduction in peripheral vascular resistance. IABC also increase in heart rate. Bedside computers enable the clinician to take a closer look at balloon efficacy via DPTI, TTI, and EVR. New sources of information and understanding may provide opportunities for nurses to ensure optimum patient outcomes.  相似文献   
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