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991.
Trimethylaminuria, also called fish-odour syndrome, is an inherited disorder caused by deficient N-oxidation and increased excretion of trimethylamine. This study reports on two unrelated and otherwise healthy children with transient trimethylaminuria, a hitherto unknown abnormality, without N-oxidation deficiency. This demonstrates that a diagnosis of fish-odour syndrome should include the analysis of urinary excretion not only of trimethylamine but also of trimethylamine-N-oxide. Since transient trimethylaminuria may be a common condition and no cause for it can presently be recognized, such patients will require careful follow-up.  相似文献   
992.
993.
Improvement of power supply EMC by chaos   总被引:12,自引:0,他引:12  
The authors demonstrate the feasibility of using chaos to depress the spectral peaks of the interference from a switched mode power supply. A boost converter is used to show experimentally that the spectrum of the input current is spread, its peaks are reduced and EMC is improved, compared to the case when the circuit is operating periodically  相似文献   
994.
A. A. Bochvar All-Union Scientific-Research Institute of Standardization in Machine Engineering. Moscow Engineering Physics Institute. Translated from Atomnaya énergiya, Vol. 77, No. 2, pp. 123–129, August, 1994.  相似文献   
995.
This paper describes a verified compiler for PreScheme, the implementation language for thevlisp run-time system. The compiler and proof were divided into three parts: A transformational front end that translates source text into a core language, a syntax-directed compiler that translates the core language into a combinator-based tree-manipulation language, and a linearizer that translates combinator code into code for an abstract stored-program machine with linear memory for both data and code. This factorization enabled different proof techniques to be used for the different phases of the compiler, and also allowed the generation of good code. Finally, the whole process was made possible by carefully defining the semantics ofvlisp PreScheme rather than just adopting Scheme's. We believe that the architecture of the compiler and its correctness proof can easily be applied to compilers for languages other than PreScheme.This work was supported by Rome Laboratory of the United States Air Force, contract No. F19628-89-C-0001, through the MITRE Corporation, and by NSF and DARPA under NSF grants CCR-9002253 and CCR-9014603. Author's current address: Department of Computer Science and Engineering, Oregon Graduate Institute, P.O. Box 91000, Portland, OR 97291-1000.The work reported here was supported by Rome Laboratory of the United States Air Force, contract No. F19628-89-C-0001. Preparation of this paper was generously supported by The MITRE Corporation.This work was supported by Rome Laboratory of the United States Air Force, contract No. F19628-89-C-0001, through the MITRE Corporation, and by NSF and DARPA under NSF grants CCR-9002253 and CCR-9014603.  相似文献   
996.
997.
An overview of MOSFET modeling for circuit simulation is presented. After discussing some of the implications of analog and low-power applications, the history of the MOS models commonly used in SPICE-like circuit simulators is presented, followed by a discussion of the evolution of strategies for modeling the geometry dependence of MOSFET characteristics. The growth of complexity and requirements for future MOS models are also considered  相似文献   
998.
We investigated the effect of c-myb antisense phosphorothioate oligodeoxynucleotides [(S)ODNs] and cisplatin (CDDP) combination on the human colon carcinoma cell line LoVo Dx both in vitro and in nude mice bearing LoVo Dx solid tumour. We show that antisense (S)ODN treatment decreases c-myb mRNA and protein expression, induces growth arrest in the G1 phase of the cell cycle, and inhibits cell proliferation. In vivo treatment with c-myb antisense (S)ODNs results in a reduction in tumour growth. A greater inhibition of cell proliferation in vitro and a higher increase of tumour growth inhibition and growth delay in vivo were obtained with the combination of (S)ODNs and CDDP than when the two agents were administered separately. This comparative study, using the same tumour cell line in vitro and in vivo, suggests that c-myb antisense (S)ODNs might be useful in the therapy of colon cancer in combination with antineoplastic drugs.  相似文献   
999.
Methylation is one of the many post-translational modifications that modulate protein function. Although asymmetric NG,NG-dimethylation of arginine residues in glycine-arginine-rich domains of eucaryotic proteins, catalyzed by type I protein arginine N-methyltransferases (PRMT), has been known for some time, members of this enzyme class have only recently been cloned. The first example of this type of enzyme, designated PRMT1, cloned because of its ability to interact with the mammalian TIS21 immediate-early protein, was then shown to have protein arginine methyltransferase activity. We have now isolated rat and human cDNA orthologues that encode proteins with substantial sequence similarity to PRMT1. A recombinant glutathione S-transferase (GST) fusion product of this new rat protein, named PRMT3, asymmetrically dimethylates arginine residues present both in the designed substrate GST-GAR and in substrate proteins present in hypomethylated extracts of a yeast rmt1 mutant that lacks type I arginine methyltransferase activity; PRMT3 is thus a functional type I protein arginine N-methyltransferase. However, rat PRMT1 and PRMT3 glutathione S-transferase fusion proteins have distinct enzyme specificities for substrates present in both hypomethylated rmt1 yeast extract and hypomethylated RAT1 embryo cell extract. TIS21 protein modulates the enzymatic activity of recombinant GST-PRMT1 fusion protein but not the activity of GST-PRMT3. Western blot analysis of gel filtration fractions suggests that PRMT3 is present as a monomer in RAT1 cell extracts. In contrast, PRMT1 is present in an oligomeric complex. Immunofluorescence analysis localized PRMT1 predominantly to the nucleus of RAT1 cells. In contrast, PRMT3 is predominantly cytoplasmic.  相似文献   
1000.
Analogies with interferometers using a light source with low temporal coherence are used to analyze the principles of the construction of laser interferometers with averaging over the photodetector aperture, whose sensitivity to the position of an object being monitored at the maximum of the output signal is as good as that of low-coherence interferometry and tomography. Pis’ma Zh. Tekh. Fiz. 24, 19–24 (February 26, 1998)  相似文献   
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