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871.
Peter Lazar Dean Konjević Uwe Kierdorf Vera Njemirovskij Jan Čurlík Marijan Grubešić 《European Journal of Wildlife Research》2009,55(1):85-89
The paper presents the skull of a male gray wolf shot in the region of Snina, eastern Slovakia. Age at death of the wolf was
estimated at 6 years. The skull was characterized by the almost-complete absence of the alveolar processes of the incisive
bones and multiple dental abnormalities that were attributed to a severe trauma. All maxillary incisors and both maxillary
first premolars were missing. In addition, both maxillary canines were fractured with only tooth fragments being left. The
pulp exposure associated with the crown fractures of the maxillary canines had caused pulp necrosis and periapical lesions,
as evidenced on radiographs. The right P2, P3, and P4 were fractured, with only the remaining tooth structure of the second and third premolars being left. In the right P4 and the left M1, periapical bone resorption was diagnosed radiologically. In the mandibular dentition, the right I2 and left P1 had been lost in life. The mandibular canines exhibited distinct wear facets that were caused by contact with the maxillary
third incisors, which were subsequently lost. The fact that all fractured teeth showed signs of wear indicates that the trauma
had occurred some time before the wolf was shot. 相似文献
872.
Saša N. Malkov Miodrag V. Živković Miloš V. Beljanski Srđan Đ. Stojanović Snežana D. Zarić 《The protein journal》2009,28(2):74-86
Using the data from Protein Data Bank the correlations of primary and secondary structures of proteins were analyzed. The
correlation values of the amino acids and the eight secondary structure types were calculated, where the position of the amino
acid and the position in sequence with the particular secondary structure differ at most 25. The diagrams describing these
results indicate that correlations are significant at distances between −9 and 10. The results show that the substituents
on Cβ or Cγ atoms of amino acid play major role in their preference for particular secondary structure at the same position
in the sequence, while the polarity of amino acid has significant influence on α-helices and strands at some distance in the
sequence. The diagrams corresponding to polar amino acids are noticeably asymmetric. The diagrams point out the exchangeability
of residues in the proteins; the amino acids with similar diagrams have similar local folding requirements.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
873.
Cultivated and wild Allium species were investigated in order to compare the antioxidant capacity of their leaves and bulbs. Leaf and bulb anti-oxidative
enzymes and scavenger activities, along with quantities of non-enzymic antioxidants, malonyl-dialdehyde and OH radicals were
determined. Results obtained suggest that leaves possess higher anti-oxidant and scavenging activities than bulbs in the majority
of cultivated and wild Allium species examined. Cultivation of some wild species such as A. flavum L., A. schoenoprasum L. and A. ursinum L. could be conducted in the future in order to produce Allium species with high antioxidant capacity in leaves and bulbs. 相似文献
874.
Popsavin M Spaić S Svircev M Kojić V Bogdanović G Popsavin V 《Bioorganic & medicinal chemistry letters》2006,16(20):5317-5320
A new tiazofurin analogue, 2-(3-amino-3-deoxy-beta-d-xylofuranosyl)thiazole-4-carboxamide (3), was synthesized starting from d-glucose and evaluated for its in vitro antiproliferative activity against a panel of human tumour cell lines. Compound 3 exhibited the most powerful cytotoxicity against K562 cells, being approximately 100-fold more potent than tiazofurin. This analogue was also active against Jurkat, HT-29 and HeLa malignant cells, with respective IC(50) values being ca. 2-, 27- and 17-fold lower than those observed for tiazofurin. Remarkably, compound 3 did not exhibit any significant cytotoxicity towards normal foetal lung MRC-5 cell line. 相似文献
875.
Todorović N Phuong NT Langer P Weisz K 《Bioorganic & medicinal chemistry letters》2006,16(6):1647-1650
A delta-carboline derivative was covalently coupled to a 7 mer oligonucleotide at its 5'- or 3'-end. The stability of triplexes formed from the conjugates and a double-helical target was studied by UV melting experiments. Compared to the unmodified control triple helices, triplexes with the conjugate exhibit a significantly higher stability. However, the degree of stabilization depends on the particular triplex structure formed. 相似文献
876.
Glycation of biomolecules, such as proteins, peptide hormones, nucleic acids, and lipids, may be a major contributor to the pathological manifestations of aging and diabetes mellitus. These nonenzymatic reactions, also termed the Maillard reaction, alter the biological and chemical properties of biomolecules. In order to investigate the effect of various reducing sugars on the products formed from small bioactive peptides (Tyr-Gly-Gly-Phe-Leu, Tyr-Gly-Gly-Phe-Leu-NH2, Tyr-Gly-Gly-Phe-Leu-OMe, Tyr-Gly-Gly-Phe, and Tyr-Gly-Gly), model systems were prepared with glucose, mannose or galactose. Peptide-sugar mixtures were incubated at 37 or 50 degrees C in phosphate-buffered saline, pH 7.4, or in methanol. The extent of glycation was determined periodically by RP HPLC. All sugar-peptide mixtures generated two different types of glycation products: N-(1-deoxy-ketos-1-yl)-peptide (Amadori compound) and the imidazolidinone compound substituted by sugar pentitol and peptide residue. The amount and distribution of peptide glycation products depended on the structure of the reactants, and increased in both concentration- and time-dependent manner in relation to exposure to sugar. Additionally, the rate of hydrolysis of glucose-derived imidazolidinone compounds, obtained either from leucine-enkephalin (1) or its shorter N-terminal fragments 2 and 3, was determined by incubation at 37 degrees C in human serum. These results revealed that imidazolidinones obtained from glucose and small peptides are almost completely protected from the action of enzymes in serum, the predominant route of degradation being spontaneous hydrolysis to initial sugar and peptide compound. 相似文献
877.
Jarak I Kralj M Piantanida I Suman L Zinić M Pavelić K Karminski-Zamola G 《Bioorganic & medicinal chemistry》2006,14(8):2859-2868
A series of cyano- and amidino-substituted derivatives of thieno[2,3-b]- and thieno[3,2-b]thiophene-2-carboxanilides and their 'cyclic' derivatives (quinolones) were synthesized. 'Cyclic' compounds displayed a rather strong and differential antiproliferative effect on various cell lines, while the 'acyclic' amidino-substituted compounds were much more active, but showing mostly non-differential cytotoxicity, whereas cyano-substituted compounds (2a,b) produced a strikingly strong effect selectively on HeLa and Hep-2 cell lines. Antiproliferative activity of 'cyclic' derivatives is very likely caused by intercalation into DNA, while their 'acyclic' analogues use other target(s) and/or mechanisms of action. 相似文献
878.
Characterization of the archaeal thermophile Sulfolobus turreted icosahedral virus validates an evolutionary link among double-stranded DNA viruses from all domains of life 下载免费PDF全文
Maaty WS Ortmann AC Dlakić M Schulstad K Hilmer JK Liepold L Weidenheft B Khayat R Douglas T Young MJ Bothner B 《Journal of virology》2006,80(15):7625-7635
Icosahedral nontailed double-stranded DNA (dsDNA) viruses are present in all three domains of life, leading to speculation about a common viral ancestor that predates the divergence of Eukarya, Bacteria, and Archaea. This suggestion is supported by the shared general architecture of this group of viruses and the common fold of their major capsid protein. However, limited information on the diversity and replication of archaeal viruses, in general, has hampered further analysis. Sulfolobus turreted icosahedral virus (STIV), isolated from a hot spring in Yellowstone National Park, was the first icosahedral virus with an archaeal host to be described. Here we present a detailed characterization of the components forming this unusual virus. Using a proteomics-based approach, we identified nine viral and two host proteins from purified STIV particles. Interestingly, one of the viral proteins originates from a reading frame lacking a consensus start site. The major capsid protein (B345) was found to be glycosylated, implying a strong similarity to proteins from other dsDNA viruses. Sequence analysis and structural predication of virion-associated viral proteins suggest that they may have roles in DNA packaging, penton formation, and protein-protein interaction. The presence of an internal lipid layer containing acidic tetraether lipids has also been confirmed. The previously presented structural models in conjunction with the protein, lipid, and carbohydrate information reported here reveal that STIV is strikingly similar to viruses associated with the Bacteria and Eukarya domains of life, further strengthening the hypothesis for a common ancestor of this group of dsDNA viruses from all domains of life. 相似文献
879.
Influence of sorbitol on protein production and glycosylation and cell wall formation in Trichoderma reesei 总被引:1,自引:0,他引:1
Górka-Nieć W Perlińska-Lenart U Zembek P Palamarczyk G Kruszewska JS 《Fungal biology》2010,114(10):855-862
Sorbitol is often used at 1 mol/liter as an osmotic stabilizer for cultivation of fungi with a fragile cell wall phenotype. On the other hand, at this concentration sorbitol causes an osmotic stress in fungal cells resulting in intensive production of intracellular glycerol. The highly increased consumption of glucose for glycerol synthesis may lead to changes in processes requiring carbohydrate residues. This study provides new information on the consequences of osmotic stress to the cell wall composition, protein production and glycosylation, and cell morphology of Trichoderma reesei. We observed that high osmolarity conditions enhanced biomass production and strongly limited synthesis of cell wall glucans and chitin. Moreover, in these conditions the amount of secreted protein decreased nearly ten-fold and expression of cbh1 and cbh2 genes coding for cellobiohydrolase I and cellobiohydrolase II, the main secretory proteins in T. reesei, was inhibited resulting in a lack of the proteins in the cell and cultivation medium. The activity of DPM synthase, enzyme engaged in both N- and O-glycosylation pathways, was reduced two-fold, suggesting an overall inhibition of protein glycosylation. However, the two modes of glycosylation were affected divergently: O-glycosylation of secreted proteins decreased in the early stages of growth while N-glycosylation significantly increased in the stationary phase. 相似文献
880.