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81.
82.
Joana Martins Martin L. Saker Cristiana Moreira Martin Welker Jutta Fastner Vitor M. Vasconcelos 《Applied microbiology and biotechnology》2009,82(5):951-961
Strains of the cyanobacterium Microcystis aeruginosa were isolated into pure culture from a variety of lakes, rivers, and reservoirs in Portugal. Samples were tested with matrix-assisted
laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF MS) to investigate the presence of various peptide
groups including aeruginosins, microginins, anabaenopeptins, cyanopeptilins, microcystins, and microviridins and other peptide-like
compounds. Binary data, based on the presence and absence of different peptide groups, were analyzed by phylogenetic inference.
DNA was also extracted from the samples and tested using a range of primers. Those strains that gave positive results for
a Microcystis-specific primer pair were further analyzed for the presence of genes linked to the biosynthesis of microginin and microcystin.
The results showed that a wide range of microcystin forms were produced by the strains among which MC-LR, -FR, -RR, -WR, and
-YR were the most common. The peptide profiles obtained from the MALDI analysis were assessed using cluster analysis which
resulted in the formation of distinct groups or chemotypes. 相似文献
83.
Alessandro K. Jordão Vitor F. Ferreira Emerson S. Lima Maria C.B.V. de Souza Eduardo C.L. Carlos Helena C. Castro Reinaldo B. Geraldo Carlos R. Rodrigues Maria C.B. Almeida Anna C. Cunha 《Bioorganic & medicinal chemistry》2009,17(10):3713-3719
This paper describes the synthesis, antiplatelet and theoretical evaluations of 10 N-substituted-phenylamino-5-methyl-1H-1,2,3-triazole-4-carbohydrazides (2a–j). These compounds were synthesized, characterized and screened for their in vitro antiplatelet profile against human platelet aggregation using arachidonic acid, adrenaline and ADP as agonists. Among NAH derivatives 2a–j, the compounds 2a, 2c, 2e, 2g and 2h were the most promising molecules with significant antiplatelet activity. 相似文献
84.
85.
Ferreira VF Jorqueira A Souza AM da Silva MN de Souza MC Gouvêa RM Rodrigues CR Pinto AV Castro HC Santos DO Araújo HP Bourguignon SC 《Bioorganic & medicinal chemistry》2006,14(16):5459-5466
Starting from alpha- and beta-lapachones, in this work we compared the biological and theoretical profile of several oxyran derivatives of lapachone as potential trypanocidal agents. Our biological results showed that the oxyrans tested act as trypanocidal agents against Trypanosoma cruzi with minimal cytotoxicity in the VERO cell line compared to naphthoquinones. The oxyran derivative of alpha-lapachone (7a) showed to be one of the most potent compounds. In our molecular modeling study, we analyzed the C-ring moiety and the redox center of beta-lapachone molecule as the moieties responsible for the trypanocidal and cytotoxic effects on mammalian cell line. The computational methods used to delineate the structural requirements for the trypanocidal profile pointed out that the transposition of the C-ring moiety of beta-lapachone, combined with its oxyran ring, introduced important molecular requirements for trypanocidal activity in the HOMO energy, HOMO orbital coefficient, LUMO density, electrostatic potential map, dipole moment vector, and calculated logP (clogP) parameter. This study could lead to the development of new antichagasic medicines based on alpha-lapachone analogs. 相似文献
86.
87.
Lactoferrin-derived antimicrobial peptide induces a micellar cubic phase in a model membrane system 总被引:1,自引:0,他引:1
Bastos M Silva T Teixeira V Nazmi K Bolscher JG Funari SS Uhríková D 《Biophysical journal》2011,(3):L20-L22
The observation of a micellar cubic phase is reported for a mixture of an antimicrobial peptide from the Lactoferrin family, LFampin 265-284, and a model membrane system of dimyristoylphosphatidylcholine/dimyristoylphosphatidylglycerol (3:1), as derived from small-angle x-ray diffraction (SAXD) measurements. The system shows remarkable thermotropic polymorphism: the peptide disrupts the lipid bilayer, forming a cubic phase of the space group Pm3n (t < 28°C), and as the temperature increases it shows a complex phase behavior (not fully clarified by SAXD). The onset, volume fraction of each phase, and phase parameters are seen to vary with peptide/lipid ratio and temperature. The obtained SAXD data represent the first experimental evidence, to our knowledge, of a micellar cubic phase in the context of antimicrobial peptide/membrane interaction. We propose that the micellization of the membrane according to the carpet model, for long proposed as a possible mechanism of action, can go through the formation of a cubic micellar phase. 相似文献
88.
Denise A. Souza Eduardo A. Ponzio Alessandro K. Jordão Vitor F. Ferreira Maria G.F. Vaz 《Inorganica chimica acta》2011,370(1):469-473
Two new magnetic copper compounds were obtained using the 4,4,4-trifluoro-1-furoylbutane-1,3-dione (Ftfac) ligand and two nitroxide radicals: 3-pyridyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (NITmPy) and 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-N-oxy (Tempol). The complexes with formula [Cu(Ftfac)2(NITmPy)2] (1) and [Cu(Ftfac)2(Tempol)] (2) were structurally characterized by single-crystal X-ray diffraction. In compound 1, the copper ion has a distorted octahedral environment, bound to two NITmpPy ligands through the nitrogen atom of the pyridine ring. In compound 2, the copper ion has a distorted pyramidal environment in which the apical position is occupied by the oxygen atom of the Tempol hydroxyl group. The temperature dependence of the magnetic susceptibility of the two compounds was investigated. It was found that compound 1 presents ferromagnetic interaction (J = 9.1 cm−1) among copper(II) ions and NITmPy radicals. As a result of the interconnection between molecular moieties through H-bonds, compound 2 presents an unusual magnetic behavior with alternating ferro- and antiferromagnetic interactions. 相似文献
89.
Abreu PA da Silva VA Santos FC Castro HC Riscado CS de Souza MT Ribeiro CP Barbosa JE dos Santos CC Rodrigues CR Lione V Correa BA Cunha AC Ferreira VF de Souza MC Paixão IC 《Current microbiology》2011,62(5):1349-1354
Herpes simplex virus is an important human pathogen responsible for a range of diseases from mild uncomplicated mucocutaneous infections to life-threatening ones. Currently, the emergence of Herpes simplex virus resistant strains increased the need for more effective and less cytotoxic drugs for Herpes treatment. In this work, we synthesized a series of oxoquinoline derivatives and experimentally evaluated the antiviral activity against acyclovir resistant HSV-1 strain as well as their cytotoxity profile. The most active compound (3b), named here as Fluoroxaq-3b, showed a promising profile with a better cytotoxicity profile than acyclovir. The theoretical analysis of the structure-activity relationship of these compounds revealed some stereoelectronic properties such as lower LUMO energy and lipophilicity, besides a higher polar surface area and number of hydrogen bond acceptor groups as important parameters for the antiviral activity. Fluoroxaq-3b showed a good oral theoretical bioavailability, according to Lipinski rule of five, with a promising profile for further in vivo analysis. 相似文献
90.
Silva TM Peloso EF Vitor SC Ribeiro LH Gadelha FR 《Journal of bioenergetics and biomembranes》2011,43(4):409-417
Understanding the energy-transduction pathways employed by Trypanosoma cruzi, the etiological agent of Chagas disease, may lead to the identification of new targets for development of a more effective
therapy. Herein, the contribution of different substrates for O2 consumption rates along T. cruzi epimastigotes (Tulahuen 2 and Y strains) growth curve was evaluated. O2 consumption rates were higher at the late stationary phase not due to an increase on succinate-dehydrogenase activity. Antimycin
A and cyanide did not totally inhibit the mitochondrial respiratory chain (MRC). Malonate at 10 or 25 mM was not a potent
inhibitor of complex II. Comparing complex II and III, the former appears to be the primary site of H2O2 release. An update on T. cruzi MRC is presented that together with our results bring important data towards the understanding of the parasite’s MRC. The
findings mainly at the stationary phase could be relevant for epimastigotes transformation into the metacyclic form, and in
this sense deserves further attention. 相似文献