Molecular biology. When a part is as good as the whole     

deHaseth PL  Nilsen TW 《Science (New York, N.Y.)》2004,303(5662):1307-1308

  相似文献   

Vibrational energy transfer across a reverse micelle surfactant layer     

Deàk JC  Pang Y  Sechler TD  Wang Z  Dlott DD 《Science (New York, N.Y.)》2004,306(5695):473-476

In a suspension of reverse micelles, in which the surfactant sodium dioctyl sulfosuccinate (AOT) separates a water nanodroplet from a bulk nonpolar CCl4 phase, ultrafast vibrational spectroscopy was used to study vibrational energy transfer from the nanodroplet through the AOT interfacial monolayer to the surrounding CCl4. Most of the vibrational energy from the nanodroplet was transferred to the polar AOT head group within 1.8 picoseconds and then out to the CCl4 within 10 picoseconds. Vibrational energy pumped directly into the AOT tail resulted in a slower 20- to 40-picosecond transfer of energy to the CCl4.  相似文献   

Freedom and rules: the acquisition and reprogramming of a bird's learned song     

Gardner TJ  Naef F  Nottebohm F 《Science (New York, N.Y.)》2005,308(5724):1046-1049

Canary song is hierarchically structured: Short stereotyped syllables are repeated to form phrases, which in turn are arranged to form songs. This structure occurs even in the songs of young isolates, which suggests that innate rules govern canary song development. However, juveniles that had never heard normal song imitated abnormal synthetic songs with great accuracy, even when the tutor songs lacked phrasing. As the birds matured, imitated songs were reprogrammed to form typical canary phrasing. Thus, imitation and innate song constraints are separate processes that can be segregated in time: freedom in youth, rules in adulthood.  相似文献   

Recombination of human mitochondrial DNA   总被引：1，自引：0，他引：1  

Kraytsberg Y  Schwartz M  Brown TA  Ebralidse K  Kunz WS  Clayton DA  Vissing J  Khrapko K 《Science (New York, N.Y.)》2004,304(5673):981

  相似文献   

Another unmet public health need     

Baker SP  Baker TD 《Science (New York, N.Y.)》2002,296(5571):1237

  相似文献   

Conservation. Caffeine and conservation     

O'Brien TG  Kinnaird MF 《Science (New York, N.Y.)》2003,300(5619):587

  相似文献   

Malaria eradication in India: a failure?     

Baker TD 《Science (New York, N.Y.)》2008,319(5870):1616

  相似文献   

Medicine. The future of personal genomics     

McGuire AL  Cho MK  McGuire SE  Caulfield T 《Science (New York, N.Y.)》2007,317(5845):1687

  相似文献   

Epoxide-opening cascades promoted by water     

Vilotijevic I  Jamison TF 《Science (New York, N.Y.)》2007,317(5842):1189-1192

Selectivity rules in organic chemistry have been inferred largely from nonaqueous environments. In contrast, enzymes operate in water, and the chemical effect of the medium change remains only partially understood. Structural characterization of the "ladder" polyether marine natural products raised a puzzle that persisted for 20 years: Although the stereochemistry of adjacent tetrahydropyran (THP) cycles would seem to arise from a biosynthetic cascade of epoxide-opening reactions, experience in organic solvents argued consistently that such a pathway would be kinetically disfavored. We report that neutral water acts as an optimal promoter for the requisite ring-opening selectivity, once a single templating THP is appended to a chain of epoxides. This strategy offers a high-yielding route to the naturally occurring ladder core and highlights the likely importance of aqueous-medium effects in underpinning certain noteworthy enzymatic selectivities.  相似文献   

Prevention of organ allograft rejection by a specific Janus kinase 3 inhibitor     

Changelian PS  Flanagan ME  Ball DJ  Kent CR  Magnuson KS  Martin WH  Rizzuti BJ  Sawyer PS  Perry BD  Brissette WH  McCurdy SP  Kudlacz EM  Conklyn MJ  Elliott EA  Koslov ER  Fisher MB  Strelevitz TJ  Yoon K  Whipple DA  Sun J  Munchhof MJ  Doty JL  Casavant JM  Blumenkopf TA  Hines M  Brown MF  Lillie BM  Subramanyam C  Shang-Poa C  Milici AJ  Beckius GE  Moyer JD  Su C  Woodworth TG  Gaweco AS  Beals CR  Littman BH  Fisher DA  Smith JF  Zagouras P  Magna HA  Saltarelli MJ  Johnson KS  Nelms LF  Des Etages SG  Hayes LS  Kawabata TT 《Science (New York, N.Y.)》2003,302(5646):875-878

Because of its requirement for signaling by multiple cytokines, Janus kinase 3 (JAK3) is an excellent target for clinical immunosuppression. We report the development of a specific, orally active inhibitor of JAK3, CP-690,550, that significantly prolonged survival in a murine model of heart transplantation and in cynomolgus monkeys receiving kidney transplants. CP-690,550 treatment was not associated with hypertension, hyperlipidemia, or lymphoproliferative disease. On the basis of these preclinical results, we believe JAK3 blockade by CP-690,550 has potential for therapeutically desirable immunosuppression in human organ transplantation and in other clinical settings.  相似文献