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71.
72.
73.
Enhanced Levels of the Aroma and Flavor Compound S-Linalool by Metabolic Engineering of the Terpenoid Pathway in Tomato Fruits 总被引:20,自引:0,他引:20
Efraim Lewinsohn Fernond Schalechet Jack Wilkinson Kenji Matsui Yaakov Tadmor Kyoung-Hee Nam Orit Amar Elena Lastochkin Olga Larkov Uzi Ravid William Hiatt Shimon Gepstein Eran Pichersky 《Plant physiology》2001,127(3):1256-1265
The aromas of fruits, vegetables, and flowers are mixtures of volatile metabolites, often present in parts per billion levels or less. We show here that tomato (Lycopersicon esculentum Mill.) plants transgenic for a heterologous Clarkia breweri S-linalool synthase (LIS) gene, under the control of the tomato late-ripening-specific E8 promoter, synthesize and accumulate S-linalool and 8-hydroxylinalool in ripening fruits. Apart from the difference in volatiles, no other phenotypic alterations were noted, including the levels of other terpenoids such as gamma- and alpha-tocopherols, lycopene, beta-carotene, and lutein. Our studies indicate that it is possible to enhance the levels of monoterpenes in ripening fruits by metabolic engineering. 相似文献
74.
Senescence-associated mRNAs that may participate in signal transduction and protein trafficking 总被引:2,自引:0,他引:2
The differential display technique was used to generate cDNA probes in order to identify mRNAs that are up-regulated during senescence of Arabidopsis leaves. Three mRNAs were examined that had not previously been associated with senescence. The steady-state levels of these mRNAs are detectable in small amounts in mature green leaves, but increase considerably as chlorophyll levels begin to decline. This relationship to senescence occurs under natural circumstances as well as when senescence is accelerated by leaf detachment in the dark or by addition of 1-aminocyclopropane-1-carboxylic acid (ACC). Retardation of senescence by benzyladenine slows the increase of the mRNAs. One of these mRNAs appears to code for a protein (Sec 13) that may be involved in vesicle formation at the endoplasmic reticulum. Another mRNA codes for a protein with WD‐repeat motif whose function is as yet unidentified, and the third codes for a putative calcium-dependent protein kinase. A fourth cDNA has also been cloned by subtractive hybridization from senescing Arabidopsis leaves that encodes vacuolar-processing enzyme ( γ VPE). Incubation of detached leaves in darkness also caused an abrupt elevation in the steady-state levels of the γVPE , similar to that of the senescing attached leaves. The possible functions of the gene products and their involvement in cellular and biochemical processes during senescence are discussed. 相似文献
75.
Elli Kohen Cahide Kohen Joseph G. Hirschberg Rene Santus Gregory Grabowski Walter Mangel Shimon Gatt Jeffrey Prince 《Cell biochemistry and function》1993,11(3):167-177
Beta-glucosidase activity was evaluated in situ by means of fluorogenic probes in normal human fibroblasts and fibroblasts from homozygous carriers of the Gaucher trait. Probe internalization, targeting to lysosomes and post-cleavage probe retention were the primary concerns. Internalization and targeting were attempted by in situ photosensitized labilization of lysosomal membranes, lysosomotropic detergents and the use of low density lipid (LDL) or the receptor ligand apolipoprotein E (ApoE). Post-cleavage increase of fluorescence with fluoresceinyl (bis) betaglucopyranoside was appreciably above the rather large pre-cleavage emission. In cells incubated overnight with nonylumbelliferylbetaglucoside (UG9) in the presence of bovine serum albumin and in the absence of ApoE, the probe was dealt with as a cytotoxic agent, accumulating in a paranuclear cap, most likely comprising elements of the endoplasmic reticulum (ER) and Golgi apparatus. Targeting of UG9 to lysosomes occurred within 1 to 3 h of preincubation in the presence of ApoE. There was some evidence of specificity, as Gaucher fibroblasts exhibited weaker cleavage of UG9 (by 50 per cent or more) compared to normal fibroblasts, but in the Gaucher cells there was some residual beta-glucosidase activity. Cleavage of UG9 was nearly totally suppressed in Gaucher cells treated with the beta-glucosidase inhibitor, conduritol B epoxide, for 24 h to 7 days. Suppression in the control fibroblasts was evident but to a lesser degree. The in situ method of fluorogenic assay established for beta-glucosidase deficiency, is in principle applicable to enzyme deficiencies in other lysosomal storage diseases, or to evaluate enhanced enzyme activity following gene therapy. 相似文献
76.
S A Slavin 《Plastic and reconstructive surgery》1989,83(5):925-926
77.
A Molecular Glimpse of Vesicular Monoamine Transporters 总被引:6,自引:1,他引:5
Shimon Schuldiner 《Journal of neurochemistry》1994,62(6):2067-2078
78.
Carney D. Matheson Kim K. Vernon Arlene Lahti Renee Fratpietro Mark Spigelman Shimon Gibson Charles L. Greenblatt Helen D. Donoghue 《PloS one》2009,4(12)
The Tomb of the Shroud is a first-century C.E. tomb discovered in Akeldama, Jerusalem, Israel that had been illegally entered and looted. The investigation of this tomb by an interdisciplinary team of researchers began in 2000. More than twenty stone ossuaries for collecting human bones were found, along with textiles from a burial shroud, hair and skeletal remains. The research presented here focuses on genetic analysis of the bioarchaeological remains from the tomb using mitochondrial DNA to examine familial relationships of the individuals within the tomb and molecular screening for the presence of disease. There are three mitochondrial haplotypes shared between a number of the remains analyzed suggesting a possible family tomb. There were two pathogens genetically detected within the collection of osteological samples, these were Mycobacterium tuberculosis and Mycobacterium leprae. The Tomb of the Shroud is one of very few examples of a preserved shrouded human burial and the only example of a plaster sealed loculus with remains genetically confirmed to have belonged to a shrouded male individual that suffered from tuberculosis and leprosy dating to the first-century C.E. This is the earliest case of leprosy with a confirmed date in which M. leprae DNA was detected. 相似文献
79.
Background
The interaction of Arabidopsis with Alternaria brassicicola provides a model for disease caused by necrotrophs, but a drawback has been the lack of a compatible pathosystem. Infection of most ecotypes, including the widely-studied line Col-0, with this pathogen generally leads to a lesion that does not expand beyond the inoculated area. This study examines an ecotype, Dijon G (DiG), which is considered sensitive to A. brassicicola. 相似文献80.
Shimon Edelman 《Biological cybernetics》1995,72(3):207-220
In human vision, the processes and the representations involved in identifying specific individuals are frequently assumed
to be different from those used for basic level classification, because classification is largely viewpoint-invariant, but
identification is not. This assumption was tested in psychophysical experiments, in which objective similarity between stimuli
(and, consequently, the level of their distinction) varied in a controlled fashion. Subjects were trained to discriminate
between two classes of computer-generated three-dimensional objects, one resembling monkeys and the other, dogs. Both classes
were defined by the same set of 56 parameters, which encoded sizes, shapes, and placement of the limbs, ears, snout, etc.
Interpolation between parameter vectors of the class prototypes yielded shapes that changed smoothly between monkey and dog.
Within-class variation was induced in each trial by randomly perturbing all the parameters. After the subjects reached 90%
correct performance on a fixed canonical view of each object, discrimination performance was tested for novel views that differed
by up to 60° from the training view. In experiment 1 (in which the distribution of parameters in each class was unimodal)
and in experiment 2 (bimodal classes), the stimuli differed only parametrically and consisted of the same geons (parts), yet
were recognized virtually independently of viewpoint in the low-similarity condition. In experiment 3, the prototypes differed
in their arrangement of geons, yet the subjects’ performance depended significantly on viewpoint in the high-similarity condition.
In all three experiments, higher interstimulus similarity was associated with an increase in the mean error rate and, for
misorientation of up to 45°, with an increase in the degree of viewpoint dependence. These results suggest that a geon-level
difference between stimuli is neither strictly necessary nor always sufficient for viewpoint-invariant performance. Thus,
basic and subordinate-level processes in visual recognition may be more closely related than previously thought.
Received: 15 November 1993/Accepted in revised form: 14 July 1994 相似文献