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11.
Theodore M. Liszczak Ph.D. Lorraine Foley Peter McL. Black 《Cell and tissue research》1986,246(2):379-385
Summary The experiments described herein use an in vitro preparation of choroid plexus to demonstrate that it is a vasopressin-responsive organ by morphologic criteria. Choroid plexus from rats was incubated for one hour in graded concentrations of arginine vasopressin (AVP). Within physiologic range of molar concentration, incubation in vasopressin induced a decrease in basal and lateral spaces in choroid plexus epithelial cells as well as an increase in number of dark cells. The number of cells with basal spaces decreased significantly from 82.7±9.2 in control tissue to 19±18 in tissue incubated in 10-12 M AVP; similarly, the number with lateral cellular spaces decreased from 20±8.8 to 7.6±2.2 cells in 10-10 M AVP. Dark cells increased in number from 3.8±2.6 in control conditions to 49±4 with 10-9 M vasopressin. These data suggest important effects of arginine vasopressin in cerebrospinal fluid (CSF) on choroid plexus, compatible with enhanced fluid transport across choroid epithelial cells. 相似文献
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Mary Taub Milton H. Saier Lorraine Chuman Sue Hiller 《Journal of cellular physiology》1983,114(2):153-161
Prostaglandin E1(PGE1), one of the components in the hormone-supplemented, serum-free medium for Madin Darby Canine Kidney (MDCK) cells (Medium K-1), is required for both long-term growth and for dome formation. Variant cells have been isolated from MDCK populations, which lack the PGE1, requirement for long-term growth in Medium K-1. These variants will be useful in identifying the molecular events initiated by PGE1 which are necessary for the growth response to be observed. The growth and functional properties of five independently isolated PGE1 independent clones have been examined. Normal MDCK cells grew at an equivalent rate in Medium K-1 and in serum-supplemented medium; the growth rate was lower in Medium K-1 lacking PGE1. In contrast, PGE1 independent clone 1 grew at an equivalent rate in Medium K-1 minus PGE1, and in serum-supplemented medium. When PGE1 was added to K-1 minus PGE1, less growth of PGE1 independent clone 1 was observed. A similar observation was made with one other PGE1 independent clone which was studied. A hormone deletion study indicated that PGE1 independent clone 1 still retained growth responses to the other four supplements in Medium K-1 (insulin, transferrin, T3, and hydrocortisone). The molecular alterations associated with loss of the PGE1 requirement for long-term growth were examined. At confluency, all of the PGE1 independent clones studied had higher intracellular cyclic AMP levels following PGE1 treatment, as compared with normal MDCK cells. The increased cyclic AMP levels in the variant cells could result from a number of different types of defects, including reduced cyclic adenylic acid (cyclic AMP) efflux, an increased affinity of PGE2 for the PGE1 receptor, or a defect in cyclic AMP metabolism. However, in all of the variant clones studied a decreased rate of cyclic AMP degradation by cyclic AMP phosphodiesterase was observed. Thus, the increased cyclic AMP levels in the PGE1 independent variants may result from alterations which affect cyclic AMP metabolism. The effect of PGE1 on dome formation by the variant cells was also examined. The frequency of dome formation by PGE1 independent clone 1 was enhanced in a dosage-dependent manner, like normal MDCK cells. This observation suggests that PGE1 affects MDCK cell growth and dome formation by different mechanisms. 相似文献
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Jan Klein Christophe Benoist Chella S. David Peter Demant Kirsten Fischer Lindahl Lorraine Flaherty Richard A. Flavell Ulrich Hämmerling Leroy E. Hood Stephen W. Hunt III Patricia P. Jones Philippe Kourilsky Hugh O. McDevitt Daniel Meruelo Donal B. Murphy Stanley G. Nathenson David H. Sachs Michael Steinmetz Susumu Tonegawa Edward K. Wakeland Elizabeth H. Weiss 《Immunogenetics》1990,32(3):147-149
15.
Jeff Reeve Lorraine H. Kligman Robert Anderson 《Applied microbiology and biotechnology》1990,33(2):161-166
Summary Isolated lipids from Deinococcus radiodurans were reconstituted at final concentrations of 1 mg/ml into dioleoyl phosphatidyl choline (DOPC) vesicles and assayed for the ability to protect cells of Escherichia coli against killing by UV light (254 nm). Values of D37 (UV dose required to reduce the number of surviving cells to 37% of the original number) were calculated from killing curves. E. coli was afforded the greatest protection with an individual lipid, identified as vitamin MK8 (D37=310 J//m2, compared to D37=67 J/m2 for E. coli irradiated in the presence of DOPC alone). Liposome-mediated protection was dependent on UV254 absorbance and not on turbidity-related light-scattering. BOth vitamin MK8 from D. radiodurans and vitamin K1, which is available commercially, showed a similar degree of UV254-protection for E. coli. The UV-protective properties of vitamin K1 were also investigated on mammalian cells in comparison with other natural lipids and known sunscreens. Survival curves were obtained for mouse fibroblast (L) cells irradiated at UV254 in the absence or presence of DOPC liposomes into which were incorporated various natural lipids or standard sunscreen ingredients, all at final concentrations of 1 mg/ml. Experimentally determined values of D37 were as follows: Vitamin K1, 73 J/m2; \-carotene, 44 J/m2; -tocopherol, 20 J/m2; sulisobenzone, 156 J/m2; p-aminobenzoic acid (PABA), 113 J/m2; benzophenone, 80 J/m2; oxybenzone, 61 J/m2 and DOPC alone. 23 J/m2. Vitamin K1, the most protective lipid tested, was also compared with PABA and oxybenzone (all at concentrations of 20 mg/ml; applied topicall) for its ability to protec Skh-hairless mice from UV254-induced erythema, yielding a UV254 protection factor of 3.5. In addition, vitamin K1 (at 100 mg/ml) was able to provide hairless mice with a small degree of UVB protection, as indicated by an experimentally determined Solar Protection Factor of 1.5–2.0. Although it is concluded that vitamin K is not likely to account for the extraordinarily high degree of UV-resistance of D. radiodurans, vitamin K does show characteristics worthy of its consideration as a UV-screening agent.
Offprint requests to: R. Anderson 相似文献
16.
T. C. Hsu Edward J. Shillitoe Lorraine M. Cherry Qi Lin Stimson P. Schantz Cynthia Furlong 《In vitro cellular & developmental biology. Plant》1990,26(1):80-84
Summary Forty lymphoblastoid (lymphoid) lines were established from 42 volunteer blood donors, including healthy individuals and patients
with head and neck carcinomas. Each peripheral blood sample was split into two portions, one for the establishment of a lymphoid
line and the other for short-term culture, which was used to estimate bleomycin sensitivity by cytogenetic procedures. Twenty
lymphoid lines were selected at random to compare bleomycin sensitivity with data obtained from short-term lymphocyte cultures.
In each set, bleomycin sensitivity of lymphoid cells was similar to that of the lymphocytes. The lymphoid lines, which can
be propagated for an unlimited supply of relatively homogeneous cellular material, will be useful for a variety of future
investigations.
This investigation was supported by grants from the John S. Dunn Foundation, Houston, TX, the Esther Knispel Fund administered
by The University of Texas M. D. Anderson Cancer Center, Houston, TX, and Department of Health and Human Services PHS grant
DE 07007. 相似文献
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