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51.
Lorenzo Chiariotti Paola Salvatore Rodolfo Frunzio Carmelo B. Bruni 《Glycoconjugate journal》2002,19(7-9):441-449
In this review we have summarized the more recent studies on the expression of mammalian galectins. One interesting observation that can be made is that in most of microarrays and/or differential display analysis performed in recent years one or more galectins have been picked up. From a critical evaluation of the pertinent studies the main conclusion that can be drawn is that, although it is not yet clear whether the 14 galectins identified so far have functions in common, a striking common feature of all galectins is the strong modulation of their expression during development, differentiation stages and under different physiological or pathological conditions. This suggests that the expression of different galectins is finely tuned and possibly coordinated. In spite of these observations it is rather unexpected that very few studies have been performed on the molecular mechanisms governing the activity of galectin genes. Published in 2004. 相似文献
52.
53.
Avery O. Tatters Harris I. Muhlstein Carmelo R. Tomas 《Journal of applied phycology》2010,22(4):435-442
Blooms of the toxic dinoflagellate, Karenia brevis, occur annually along the Gulf coast of Florida. Other species, like Karenia selliformis, are at times found in association. Hemolytic activity, the ability to lyse red blood cells, of two K. brevis clones (SP3 non-toxic (N-tox) and SP3 super toxic (S-tox)) from the Gulf of Mexico and a single clone of K. selliformis from New Zealand was investigated throughout a growth cycle. Activity is reported as effective concentration (EC50) values, the quantitative measure of hemolysis of human erythrocytes expressed as cell numbers. Both cells and media of K. selliformis cultures consistently produced potent levels of hemolysis (maximum EC50 = 4.88 × 103 cells) from inoculation until the population declined 35 days later. For SP3 N-tox and S-tox, no hemolytic activity was detectable
until day 26 of sampling. The media of both SP3 N-tox and SP3 S-tox cultures consistently contained non-detectable or low
levels of hemolysis compared to K. selliformis. Maximum EC50s for the SP3 clones were 1.80 × 106 and 1.97 × 106 cells, respectively. The experimental EC50 values observed represent ecologically relevant cell densities for K. selliformis, but not for the K. brevis clones. In addition, the hemolytic activity of gymnodimine A and various PbTx derivatives was examined in this study. Our
findings indicate that the hemolytic capability of these dinoflagellates, especially K. selliformis, represents an additional component of toxicity aside from their already recognized toxins and that this activity may play
a larger role than was previously considered. The purpose of this study was to extend the knowledge of the biology and toxicology
of species within the genus Karenia. 相似文献
54.
55.
In order to define the ancestors of the Eurasian genera Axis and Rusa, the representatives of the tribe Pliocervini have been reviewed, with the exclusion of the genus Pliocervus. The fossil remains referred to Pliocervini stored in the Palaeontological Museum of Mechnikov Odessa National University and studied by Khomenko [Khomenko, I., 1913. Meotian fauna of v. Tarakliya of Bendery district. Annuaire géologique et minéralogique de la Russie. 1. The ancestors of modern and fossil Cervinae. 2. Giraffidae and Cavicornia 15, 107-132 (in Russian)] are reappraised: these remains are attributed to Cervavitus novorossiae (Khomenko, 1913). The fossil deer collected from the locality of Novoelizavetovka (Odessa region, Ukraine) and observed in the same Museum of the Odessa National University, is referred to Cervavitus variabilis Alexeev (1915).The fossil material from Shanxi and Honan provinces (China), described by Zdansky [Zdansky, O., 1925. Fossil Hirsche Chinas. Palaeontologia Sinica C 2, 1-94] and Teilhard de Chardin and Trassaert [Teilhard de Chardin, P., Trassaert, M., 1937. The Pliocene Camelidae, Giraffidae and Cervidae of southeastern Shansi.] is referred to Cervavitus shanxius Dong and Hu, 1994. The phylogenetic relationships between Pliocervini from China and the European ones are investigated on the basis of the morphological, biochronological and paleogeographical data. These elements and the suggestions of the more recent genetical and biometrical data may indicate that the origin of the two genera Axis and Rusa could be recognized into the Chinese pliocervines. 相似文献
56.
Linlin Zhao Matthew G. Pence Plamen P. Christov Zdzislaw Wawrzak Jeong-Yun Choi Carmelo J. Rizzo Martin Egli F. Peter Guengerich 《The Journal of biological chemistry》2012,287(42):35516-35526
N2,3-Ethenoguanine (N2,3-ϵG) is one of the exocyclic DNA adducts produced by endogenous processes (e.g. lipid peroxidation) and exposure to bioactivated vinyl monomers such as vinyl chloride, which is a known human carcinogen. Existing studies exploring the miscoding potential of this lesion are quite indirect because of the lability of the glycosidic bond. We utilized a 2′-fluoro isostere approach to stabilize this lesion and synthesized oligonucleotides containing 2′-fluoro-N2,3-ϵ-2′-deoxyarabinoguanosine to investigate the miscoding potential of N2,3-ϵG by Y-family human DNA polymerases (pols). In primer extension assays, pol η and pol κ replicated through N2,3-ϵG, whereas pol ι and REV1 yielded only 1-base incorporation. Steady-state kinetics revealed that dCTP incorporation is preferred opposite N2,3-ϵG with relative efficiencies in the order of pol κ > REV1 > pol η ≈ pol ι, and dTTP misincorporation is the major miscoding event by all four Y-family human DNA pols. Pol ι had the highest dTTP misincorporation frequency (0.71) followed by pol η (0.63). REV1 misincorporated dTTP and dGTP with much lower frequencies. Crystal structures of pol ι with N2,3-ϵG paired to dCTP and dTTP revealed Hoogsteen-like base pairing mechanisms. Two hydrogen bonds were observed in the N2,3-ϵG:dCTP base pair, whereas only one appears to be present in the case of the N2,3-ϵG:dTTP pair. Base pairing mechanisms derived from the crystal structures explain the slightly favored dCTP insertion for pol ι in steady-state kinetic analysis. Taken together, these results provide a basis for the mutagenic potential of N2,3-ϵG. 相似文献
57.
Researchers have warned that causal illusions are at the root of many superstitious beliefs and fuel many people’s faith in pseudoscience, thus generating significant suffering in modern society. Therefore, it is critical that we understand the mechanisms by which these illusions develop and persist. A vast amount of research in psychology has investigated these mechanisms, but little work has been done on the extent to which it is possible to debias individuals against causal illusions. We present an intervention in which a sample of adolescents was introduced to the concept of experimental control, focusing on the need to consider the base rate of the outcome variable in order to determine if a causal relationship exists. The effectiveness of the intervention was measured using a standard contingency learning task that involved fake medicines that typically produce causal illusions. Half of the participants performed the contingency learning task before participating in the educational intervention (the control group), and the other half performed the task after they had completed the intervention (the experimental group). The participants in the experimental group made more realistic causal judgments than did those in the control group, which served as a baseline. To the best of our knowledge, this is the first evidence-based educational intervention that could be easily implemented to reduce causal illusions and the many problems associated with them, such as superstitions and belief in pseudoscience. 相似文献
58.
Szekely J Wang H Peplowski KM Knutson CG Marnett LJ Rizzo CJ 《Nucleosides, nucleotides & nucleic acids》2008,27(2):103-109
Short, "one-pot" syntheses of malondialdehyde adducts of deoxyguanosine, deoxyadenosine, and deoxycytidine are described. These syntheses proceed in improved yield and easier purification than previous syntheses and are well suited for the preparation of isotopically labeled nucleoside adducts for biomarker and metabolic studies. 相似文献
59.
Due to slow rates of molecular evolution, DNA sequences used to identify and build phylogenies of algal species involved in harmful algal blooms (HABs) are generally invariant at the intraspecific level. This means that it is unknown whether HAB events result from the growth of a single clone, a few dominant clones, or multiple clones. This is true despite the fact that several physiological and demographic traits, as well as toxicity, are known to vary across clones. We generated AFLP fingerprints from a set of 6 clonal isolates, taken from a bloom of Prymnesium parvum at a striped bass mariculture facility. This new haptophyte bloom was recently implicated in fish kills at several sites in the United States. The AFLP fragments were highly reproducible and showed that all isolates were distinguishable due to abundant AFLPs unique to single isolates. These results demonstrate that blooms can be genetically diverse outbreaks and indicate that AFLP can be a powerful molecular tool for characterizing and monitoring this diversity. 相似文献
60.
Kallie M. Stavros Edward K. Hawkins Carmelo J. Rizzo Michael P. Stone 《Nucleic acids research》2014,42(5):3450-3463
2-Amino-3-methylimidazo[4,5-f]quinolone (IQ), a heterocyclic amine found in cooked meats, undergoes bioactivation to a nitrenium ion, which alkylates guanines at both the C8-dG and N2-dG positions. The conformation of a site-specific N2-dG-IQ adduct in an oligodeoxynucleotide duplex containing the iterated CG repeat restriction site of the NarI endonuclease has been determined. The IQ moiety intercalates, with the IQ H4a and CH3 protons facing the minor groove, and the IQ H7a, H8a and H9a protons facing the major groove. The adducted dG maintains the anti-conformation about the glycosyl bond. The complementary dC is extruded into the major groove. The duplex maintains its thermal stability, which is attributed to stacking between the IQ moiety and the 5′- and 3′-neighboring base pairs. This conformation is compared to that of the C8-dG-IQ adduct in the same sequence, which also formed a ‘base-displaced intercalated’ conformation. However, the C8-dG-IQ adopted the syn conformation placing the Watson−Crick edge of the modified dG into the major groove. In addition, the C8-dG-IQ adduct was oriented with the IQ CH3 group and H4a and H5a facing the major groove. These differences may lead to differential processing during DNA repair and replication. 相似文献