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441.
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P. C. T. Jones 《Cellular and molecular life sciences : CMLS》1971,27(9):1014-1015
Zusammenfassung Feststellung, dass schlafende Goldhamster einen höheren ATP-Gehalt in Gehirn und Leber besitzen als wache Tiere und dass Zeitgeber, wie Licht und Temperatur, sowohl Zellviskosität als auch ATP-Niveau verändern. 相似文献
443.
Dietary cholesterol, sex and scurvy in guinea-pigs 总被引:1,自引:0,他引:1
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447.
Replacing the complementarity-determining regions in a human antibody with those from a mouse 总被引:26,自引:0,他引:26
The variable domains of an antibody consist of a beta-sheet framework with hypervariable regions (or complementarity-determining regions--CDRs) which fashion the antigen-binding site. Here we attempted to determine whether the antigen-binding site could be transplanted from one framework to another by grafting the CDRs. We substituted the CDRs from the heavy-chain variable region of mouse antibody B1-8, which binds the hapten NP-cap (4-hydroxy-3-nitrophenacetyl caproic acid; KNP-cap = 1.2 microM), for the corresponding CDRs of a human myeloma protein. We report that in combination with the B1-8 mouse light chain, the new antibody has acquired the hapten affinity of the B1-8 antibody (KNP-cap = 1.9 microM). Such 'CDR replacement' may offer a means of constructing human monoclonal antibodies from the corresponding mouse monoclonal antibodies. 相似文献
448.
A continuous-wave Raman silicon laser 总被引:2,自引:0,他引:2
Achieving optical gain and/or lasing in silicon has been one of the most challenging goals in silicon-based photonics because bulk silicon is an indirect bandgap semiconductor and therefore has a very low light emission efficiency. Recently, stimulated Raman scattering has been used to demonstrate light amplification and lasing in silicon. However, because of the nonlinear optical loss associated with two-photon absorption (TPA)-induced free carrier absorption (FCA), until now lasing has been limited to pulsed operation. Here we demonstrate a continuous-wave silicon Raman laser. Specifically, we show that TPA-induced FCA in silicon can be significantly reduced by introducing a reverse-biased p-i-n diode embedded in a silicon waveguide. The laser cavity is formed by coating the facets of the silicon waveguide with multilayer dielectric films. We have demonstrated stable single mode laser output with side-mode suppression of over 55 dB and linewidth of less than 80 MHz. The lasing threshold depends on the p-i-n reverse bias voltage and the laser wavelength can be tuned by adjusting the wavelength of the pump laser. The demonstration of a continuous-wave silicon laser represents a significant milestone for silicon-based optoelectronic devices. 相似文献
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Humphray SJ Oliver K Hunt AR Plumb RW Loveland JE Howe KL Andrews TD Searle S Hunt SE Scott CE Jones MC Ainscough R Almeida JP Ambrose KD Ashwell RI Babbage AK Babbage S Bagguley CL Bailey J Banerjee R Barker DJ Barlow KF Bates K Beasley H Beasley O Bird CP Bray-Allen S Brown AJ Brown JY Burford D Burrill W Burton J Carder C Carter NP Chapman JC Chen Y Clarke G Clark SY Clee CM Clegg S Collier RE Corby N Crosier M Cummings AT Davies J Dhami P Dunn M Dutta I Dyer LW Earthrowl ME Faulkner L 《Nature》2004,429(6990):369-374
Chromosome 9 is highly structurally polymorphic. It contains the largest autosomal block of heterochromatin, which is heteromorphic in 6-8% of humans, whereas pericentric inversions occur in more than 1% of the population. The finished euchromatic sequence of chromosome 9 comprises 109,044,351 base pairs and represents >99.6% of the region. Analysis of the sequence reveals many intra- and interchromosomal duplications, including segmental duplications adjacent to both the centromere and the large heterochromatic block. We have annotated 1,149 genes, including genes implicated in male-to-female sex reversal, cancer and neurodegenerative disease, and 426 pseudogenes. The chromosome contains the largest interferon gene cluster in the human genome. There is also a region of exceptionally high gene and G + C content including genes paralogous to those in the major histocompatibility complex. We have also detected recently duplicated genes that exhibit different rates of sequence divergence, presumably reflecting natural selection. 相似文献