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411.
Can Liu Andrew J. Martins William W. Lau Nicholas Rachmaninoff Jinguo Chen Luisa Imberti Darius Mostaghimi Danielle L. Fink Peter D. Burbelo Kerry Dobbs Ottavia M. Delmonte Neha Bansal Laura Failla Alessandra Sottini Eugenia Quiros-Roldan Kyu Lee Han Brian A. Sellers Foo Cheung John S. Tsang 《Cell》2021,184(7):1836-1857.e22
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412.
J P van Netten R L Racca J B Armstrong M L Brigden A R Sellers P Coy C Fletcher I G Thornton 《Analytical cellular pathology》1989,2(1):59-62
An apparatus has been designed to retain the spatial orientation of breast biopsies throughout surgery, transport and processing in the pathology laboratory. It does not interfere with regular surgical procedures and simplifies the surgeon's task of marking the orientation of a specimen. As the use of the apparatus does not involve either chemical or physical substances it is an appropriate handling procedure for those specimens requiring sensitive testing procedures such as cell culture. 相似文献
413.
A H Sellers 《CMAJ》1984,131(2):103-104
414.
Because of an increasing incidence of poisoning with the newer organophosphorus anticholinesterase insecticides, these compounds have been reviewed in terms of their history and pharmacology, relationship with other drugs, factors affecting toxicity, mechanism of action, toxic signs and treatment. The modern organophosphorus pesticide requires metabolic conversion before toxicity develops. Insects have a greater propensity for this conversion than humans. Nevertheless, this conversion does occur in humans and can be potentiated by other drugs. Toxicity also varies with age, sex, route and frequency of administration, and previous exposure. The mechanism of toxicity is inhibition of acetylcholinesterase, causing an intoxicating build-up of acetylcholine. Signs and symptoms consist of the clinical manifestations of unopposed parasympathetic and central activity. Treatment must be initiated early. Respiration must be maintained and the effects of acetylcholine must be counteracted by massive doses of atropine. Metaraminol enhances the antagonistic action of atropine against acetylcholine and may also be given. Once acetylcholinesterase is inactivated, restoration is slow. Recovery can be accelerated by enzyme reactivators like the oxime compounds. Pyridine aldoxime (Pralidoxime, Protopam, P2S and 2-PAM) can be given in combination with atropine and metaraminol (AMP therapy) and may be the treatment of choice. 相似文献
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PAWEŁ JAŁOSZYŃSKI 《Systematic Entomology》2012,37(2):346-359
A new extinct species of the ant‐like stone beetle supertribe Mastigitae, Euroleptochromus sabathi gen. & sp.n. is described from Eocene Baltic amber. A phylogenetic analysis of Clidicini, with representatives of Leptomastacini and Mastigini as out‐group taxa, provided strong support for a sister‐group relationship between the Neotropical Leptochromus and the new genus. The monophyly of Clidicini is questioned because of an alternative placement of Nearctic Papusus as a sister taxon to Leptomastacini + [Clidicus + (Palaeoleptochromus + (Euroleptochromus + Leptochromus))]. A dispersal‐vicariance analysis provided three alternative scenarios for the evolution of Mastigitae; with Laurasia as the ancestral area of the supertribe, major branching events occurring within either Eurasia or Laurentia and two trans‐Beringia dispersals in Late Cretaceous and Eocene. Euroleptochromus, Palaeoleptochromus and Leptochromus share highly derived structures on postgenae and maxillary palps, probably as part of a specialised feeding or prey capture mechanism. The formation of these modifications in Clidicini is demonstrated to involve a process (traced back to the Campanian, 79 Ma) of elongation and narrowing of maxillary palps and forming a cuticular setal projection from a broadened insertion site of sensory setae. 相似文献
418.
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Preparation and characterization of heavy meromyosin and subfragment 1 from vertebrate cytoplasmic myosins 总被引:5,自引:0,他引:5
The soluble fragments of myosin, heavy meromyosin (HMM), and subfragment 1 (S-1) have been instrumental in elucidating the kinetic mechanisms of the actin-activated MgATPase activity of both skeletal and smooth muscle myosin. To date, relatively little has been published on these fragments from vertebrate cytoplasmic myosins. We now describe the preparation and steady-state kinetic characterization of S-1 and HMM from human platelet and avian intestinal epithelial brush border myosin. The HMM prepared from each of these tissues was similar both in their SDS-polyacrylamide gel pattern and in their steady-state kinetic properties. The Vmax of the actin-activated MgATPase activity varied between 0.8 and 2.5 s-1, and the KATPase (the apparent dissociation constant derived from a double-reciprocal plot of the MgATPase activity) was about 1-2 microM. This low value for the apparent dissociation constant was similar to the dissociation constant of HMM for actin directly measured under similar conditions and is about 40 times lower than that determined with avian smooth muscle HMM. The KATPase of the cytoplasmic HMM was only slightly increased when the ionic strength was raised from 12 to 112 mM. 相似文献
420.