Sounding the stratosphere and mesosphere by infrared limb scanning from space   总被引：1，自引：0，他引：1  

Gille JC  Bailey PL  Craig RA  House FB  Anderson GP 《Science (New York, N.Y.)》1980,208(4442):397-399

Inversion of the measurements obtained by the infrared limb scanner on the Nimbus 6 satellite has demonstrated that the stratospheric and mesospheric temperatures and ozone concentrations may be obtained remotely from space with accuracy and precision comparable to in situ methods. Such global data have many applications in middle atmospheric research and operational temperature sounding.  相似文献   

Nicotine in breast fluid of nonlactating women   总被引：2，自引：0，他引：2  

N L Petrakis  L D Gruenke  T C Beelen  N Castagnoli  J C Craig 《Science (New York, N.Y.)》1978,199(4326):303-305

Using a combination of gas chromatography, mass spectrometry, and selected ion recording techniques, we have identified nicotine and its major metabolite, continine, in the breast fluid of nonlactating women smokers. As little as 25 picograms could be measured by using the deuterated variants, [5',5'-2H]nicotine and [3,3-2H]cotinine, both as internal standards and as carriers in an inverse isotope dilution method.  相似文献   

Multilineage potential of adult human mesenchymal stem cells   总被引：7，自引：0，他引：7  

Pittenger MF  Mackay AM  Beck SC  Jaiswal RK  Douglas R  Mosca JD  Moorman MA  Simonetti DW  Craig S  Marshak DR 《Science (New York, N.Y.)》1999,284(5411):143-147

Human mesenchymal stem cells are thought to be multipotent cells, which are present in adult marrow, that can replicate as undifferentiated cells and that have the potential to differentiate to lineages of mesenchymal tissues, including bone, cartilage, fat, tendon, muscle, and marrow stroma. Cells that have the characteristics of human mesenchymal stem cells were isolated from marrow aspirates of volunteer donors. These cells displayed a stable phenotype and remained as a monolayer in vitro. These adult stem cells could be induced to differentiate exclusively into the adipocytic, chondrocytic, or osteocytic lineages. Individual stem cells were identified that, when expanded to colonies, retained their multilineage potential.  相似文献   

INFLUENCE OF DEUTERIUM OXIDE ON PHOTOCHEMICAL AND DARK REACTIONS OF PHOTOSYNTHESIS     

Pratt R  Craig FN  Trelease SF 《Science (New York, N.Y.)》1937,85(2202):271-273

  相似文献   

Systemic RNAi in C. elegans requires the putative transmembrane protein SID-1   总被引：1，自引：0，他引：1  

Winston WM  Molodowitch C  Hunter CP 《Science (New York, N.Y.)》2002,295(5564):2456-2459

Double-stranded RNA-mediated gene interference (RNAi) in Caenorhabditis elegans systemically inhibits gene expression throughout the organism. To investigate how gene-specific silencing information is transmitted between cells, we constructed a strain that permits visualization of systemic RNAi. We used this strain to identify systemic RNA interference-deficient (sid) loci required to spread gene-silencing information between tissues but not to initiate or maintain an RNAi response. One of these loci, sid-1, encodes a conserved protein with predicted transmembrane domains. SID-1 is expressed in cells sensitive to RNAi, is localized to the cell periphery, and is required cell-autonomously for systemic RNAi.  相似文献   

Rational design of peptide-based HIV proteinase inhibitors   总被引：48，自引：0，他引：48  

N A Roberts  J A Martin  D Kinchington  A V Broadhurst  J C Craig  I B Duncan  S A Galpin  B K Handa  J Kay  A Kr?hn 《Science (New York, N.Y.)》1990,248(4953):358-361

A series of peptide derivatives based on the transition-state mimetic concept has been designed that inhibit the proteinase from the human immunodeficiency virus (HIV). The more active compounds inhibit both HIV-1 and HIV-2 proteinases in the nanomolar range with little effect at 10 micromolar against the structurally related human aspartic proteinases. Proteolytic cleavage of the HIV-1 gag polyprotein (p55) to the viral structural protein p24 was inhibited in chronically infected CEM cells. Antiviral activity was observed in the nanomolar range (with one compound active below 10 nanomolar) in three different cell systems, as assessed by p24 antigen and syncytium formation. Cytotoxicity was not detected at 10 and 5 micromolar in C8166 and JM cells, respectively, indicating a high therapeutic index for this new class of HIV proteinase inhibitors.  相似文献   

Paleoindian seafaring, maritime technologies, and coastal foraging on California's Channel Islands     

Erlandson JM  Rick TC  Braje TJ  Casperson M  Culleton B  Fulfrost B  Garcia T  Guthrie DA  Jew N  Kennett DJ  Moss ML  Reeder L  Skinner C  Watts J  Willis L 《Science (New York, N.Y.)》2011,331(6021):1181-1185

Three archaeological sites on California's Channel Islands show that Paleoindians relied heavily on marine resources. The Paleocoastal sites, dated between ~12,200 and 11,200 years ago, contain numerous stemmed projectile points and crescents associated with a variety of marine and aquatic faunal remains. At site CA-SRI-512 on Santa Rosa Island, Paleocoastal peoples used such tools to capture geese, cormorants, and other birds, along with marine mammals and finfish. At Cardwell Bluffs on San Miguel Island, Paleocoastal peoples collected local chert cobbles, worked them into bifaces and projectile points, and discarded thousands of marine shells. With bifacial technologies similar to those seen in Western Pluvial Lakes Tradition assemblages of western North America, the sites provide evidence for seafaring and island colonization by Paleoindians with a diversified maritime economy.  相似文献   

Function of rhodopsin in temperature discrimination in Drosophila     

Shen WL  Kwon Y  Adegbola AA  Luo J  Chess A  Montell C 《Science (New York, N.Y.)》2011,331(6022):1333-1336

Many animals, including the fruit fly, are sensitive to small differences in ambient temperature. The ability of Drosophila larvae to choose their ideal temperature (18°C) over other comfortable temperatures (19° to 24°C) depends on a thermosensory signaling pathway that includes a heterotrimeric guanine nucleotide-binding protein (G protein), a phospholipase C, and the transient receptor potential TRPA1 channel. We report that mutation of the gene (ninaE) encoding a classical G protein-coupled receptor (GPCR), Drosophila rhodopsin, eliminates thermotactic discrimination in the comfortable temperature range. This role for rhodopsin in thermotaxis toward 18°C was light-independent. Introduction of mouse melanopsin restored normal thermotactic behavior in ninaE mutant larvae. We propose that rhodopsins represent a class of evolutionarily conserved GPCRs that are required for initiating thermosensory signaling cascades.  相似文献   

Genetics. FDA races in wrong direction     

Haga SB  Venter JC 《Science (New York, N.Y.)》2003,301(5632):466

Despite recent genetic evidence and the promise of individualized medicine, there is a continuing interest in using self-identified categories of race and ethnicity as variables in scientific and medical research. The U.S. Food and Drug Administration recently proposed a standardized approach for the collection of race and ethnicity data in clinical trials. We believe that this move fails to acknowledge new scientific data and recommend that relevant data from individuals be collected and used rather than broad group statistics. We also encourage that increased funding be committed to this important issue.  相似文献   

An ethical affirmation for scientists     

Craig CR  Cather A  Culberson J 《Science (New York, N.Y.)》2003,299(5615):1982-1983

  相似文献