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301.
An efficient algorithm is presented that solves a generalization of the Longest Common Subsequence problem, in which one of the two input strings contains sets of symbols which may be permuted. This problem arises from a music application. 相似文献
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304.
DL Hirschberg G Moalem J He F Mor IR Cohen M Schwartz 《Canadian Metallurgical Quarterly》1998,89(1-2):88-96
The central nervous system (CNS) enjoys a unique relationship with the immune system. Under non-pathological conditions, T cells move through the CNS but do not accumulate there. CNS trauma has been shown to trigger a response to CNS self-antigens such as myelin basic protein (MBP). Here, we examined whether the injured CNS tissue undergoes changes that permit T cell accumulation. We found that injury to CNS white matter, such as the optic nerve, led to a transiently increased accumulation of T cells (between days 3 and 21). In Lewis rats with unilaterally injured optic nerves, systemic administration of passively transferred T cells recognizing either self-antigen (MBP) or non-self-antigen (ovalbumin) resulted in accumulation of the T cells in injured optic nerve, irrespective of their antigenic specificity. The effect of the T cells on the damaged nerve, the lack of selectivity in T cell accumulation and the mechanism underlying non-selective accumulation are discussed. 相似文献
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In this paper we construct approximate algorithms for the following problems: integer multiple-choice knapsack problem, binary multiple-choice knapsack problem and multi-dimensional knapsack problem. The main result can be described as follows: for every ε 0 one can construct a polynomial-time algorithm for each of the above problems such that the ratio of the value of the objective function by this algorithm and the optimal value is bounded below by 1 - ε. 相似文献
307.
W.J. Minkowycz Ping Cheng Robert N. Hirschberg 《International Communications in Heat and Mass Transfer》1984,11(2):127-141
An analysis has been performed for the study of the buoyancy effects in the parallel and stagnation forced flows in a porous medium adjacent to a heated surface with wall temperature being a power function of distance, i.e., . Local non-similarity methods were used to obtain approximate solutions for the problem. Numerical solutions were carried out to the third level of truncation for parallel aiding flow over a heated horizontal surface with for a wide range of buoyancy parameters. For wall temperature with λ < 0.5, it is found that the differences between the first and the third level of truncations are very small. The difference is more marked for λ > 0.5, and it accentuates as the value of the buoyancy parameter or λ is increased. 相似文献
308.
Svetlana V. Demyanenko Maria A. Pitinova Yulia N. Kalyuzhnaya Andrey M. Khaitin Svetlana A. Batalshchikova Natalya M. Dobaeva Yulia A. Shevtsova Kirill V. Goryunov Egor Y. Plotnikov Svetlana G. Pashkevich Gennady T. Sukhikh Denis N. Silachev 《International journal of molecular sciences》2022,23(15)
Peripheral nerve injury remains a serious problem for medicine, with no effective method of treatment at the moment. The most prominent example of this problem is neonatal brachial plexus palsy, which results from the stretching of the brachial plexus nerves in the birth or perinatal period. Multipotent mesenchymal cells (MSCs) and the extracellular vesicles (EVs) they produce are known to have a marked neuroprotective effect in central nervous system injuries. We suggested that the use of MSCs-derived EVs may be an effective approach to the regeneration of peripheral nerves after injury. Sciatic nerve injury was modeled in rats via crushing, and then a gel containing MSCs–EVs was applied to the injured area. After 15 and 30 days, a histological, physiological, and functional assessment of nerve, dorsal root ganglia (DRG), and innervated muscles’ recovery was performed. Transplantation of EVs to the area of sciatic nerve injury significantly reduced muscle atrophy as compared to the control group. Functional recovery of the innervated muscles, as measured by the extensor postural thrust test, was revealed 30 days after the surgery. We associate the obtained results with EVs-induced neuroprotective mechanisms, which were expressed in a decrease in apoptotic neuronal death and an increase in regeneration-associated proteins NF-200 and GAP-43, as well as in DRG and damaged nerve. We suggest that the therapeutic scheme we used is efficient for the treatment of acute peripheral nervous system injuries and can be transferred to the clinics. However, additional studies are required for a more detailed analysis of neuroprotection mechanisms. 相似文献
309.
I. Vancs-Szmercsnyi E. Szab-Rthy P. Hirschberg 《Advanced Synthesis \u0026amp; Catalysis》1971,313(3):502-510
The overall rate of polyesterification depends on the rate of the forward and reverse reaction. It is the purpose of this paper to establish relationships between these two reactions, depending on the structure of the monomers used, by comparing the rate constants of catalytic hydrolysis, polyesterification and equilibrium condensation. The differences in the rate of polyesterification observed on using different dicarboxylic acids are known to be caused by proton catalysis of the reaction. In our investigations the reverse reaction was found to be also affected by the acidity. The rate of acid hydrolysis increases with increasing acid strength of the dicarboxylic acid component in the polyester. Summarily, the results of extensive investigations prove the acid strength of the dicarboxylic acid to affect the equilibrium rate of polyesterification and hydrolysis in the same way. 相似文献
310.
Pentaferometer: a solid Sagnac interferometer 总被引:4,自引:0,他引:4
A solid two-beam Sagnac-type interferometer is described that is especially adapted for use with a microscope for Fourier excitation and emission fluorescence spectroscopy. Its advantages are its compactness and stability, and because it is an integral optical element, the need for eliminating vibration and for shielding from air currents is greatly reduced. 相似文献