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991.
992.
Nelson?DuránEmail author Priscyla?D?Marcato Oswaldo?L?Alves Gabriel?IH?De Souza Elisa?Esposito 《Journal of nanobiotechnology》2005,3(1):8
Extracellular production of metal nanoparticles by several strains of the fungus Fusarium oxysporum was carried out. It was found that aqueous silver ions when exposed to several Fusarium oxysporum strains are reduced in solution, thereby leading to the formation of silver hydrosol. The silver nanoparticles were in the
range of 20–50 nm in dimensions. The reduction of the metal ions occurs by a nitrate-dependent reductase and a shuttle quinone
extracellular process. The potentialities of this nanotechnological design based in fugal biosynthesis of nanoparticles for
several technical applications are important, including their high potential as antibacterial material. 相似文献
993.
Effect of alpha-tocopherol and N-acetylcysteine on benzoyl peroxide toxicity in human keratinocytes 总被引:2,自引:0,他引:2
Bellei E Rota C Bergamini S Manfredini P Albertazzi A Tomasi A Iannone A 《Journal of biochemical and molecular toxicology》2004,18(2):107-114
Benzoyl peroxide is a free-radical generating compound widely used in the polymer industry and also in pharmaceuticals as antimicrobial agent to treat acne. However, benzoyl peroxide causes irritation and contact dermatitis in about 1% of patients. Concern over the use of this compound is motivated by the demonstration that it can also act as skin tumor promoter in mice. In addition, benzoyl peroxide induces DNA strand breaks in many cells, including keratinocytes. Benzoyl peroxide toxicity is presumably mediated by the formation of reactive free radicals and by the consumption of intracellular antioxidants.In this work we investigated the effect of both the lipophilic antioxidant alpha-tocopherol and the hydrophilic thiol donor N-acetylcysteine (NAC) in human keratinocyte line HaCaT exposed to benzoyl peroxide. A protective effect against benzoyl peroxide cytotoxicity was achieved when cells were grown on a alpha-tocopherol layer. On the contrary, the addition of alpha-tocopherol dissolved in ethanol had a pro-oxidant effect, leading to an enhancement of benzoyl peroxide toxicity. Cytotoxicity was also reduced adding NAC to the culture medium; the presence of both NAC and alpha-tocopherol exerts a synergistic cytoprotection. 相似文献
994.
Predominant expression of the long isoform of GP130-like (GPL) receptor is required for interleukin-31 signaling 总被引:2,自引:0,他引:2
Diveu C Lak-Hal AH Froger J Ravon E Grimaud L Barbier F Hermann J Gascan H Chevalier S 《European cytokine network》2004,15(4):291-302
Gp130-like receptor (GPL) is a newly identified cytokine receptor. A recent study reported the involvement of GPL, together with OSMR, in the formation of the receptor complex for IL-31, a novel immune cytokine with a skin tropism. In the present work, we analyzed the signaling properties of IL-31 in glioblastoma and melanoma tumor cells. We demonstrate that in response to IL-31, its receptor complex recruits Jak1, Jak2, STAT1, -3, -5 signaling pathways, as well as the Pi3 kinase / AKT cascade. SHP-2 and Shc adapter molecules are also recruited and contribute to an increased activation of the MAP kinase pathway in response to IL-31. Different responses were observed depending on the expression of short or long GPL receptor isoform within the studied cell lines. We show that the short form of GPL receptor exerts a profound inhibitory effect on the signaling of IL-31 and behaves as a dominant negative receptor. 相似文献
995.
The Toxoplasma gondii bradyzoite antigens BAG1 and MAG1 induce early humoral and cell-mediated immune responses upon human infection 总被引:3,自引:0,他引:3
Di Cristina M Del Porto P Buffolano W Beghetto E Spadoni A Guglietta S Piccolella E Felici F Gargano N 《Microbes and infection / Institut Pasteur》2004,6(2):164-171
Infection of humans by Toxoplasma gondii leads to an acute systemic phase, in which tachyzoites disseminate throughout the body, followed by a chronic phase characterized by the presence of tissue cysts, containing bradyzoites, in brain, heart and skeletal muscles. This work focused on studying the antigenic regions of bradyzoite-specific proteins involved in human B- and T-cell responses. To this aim, we constructed a phage-display library of DNA fragments derived from the bradyzoite-specific genes BAG1, MAG1, SAG2D, SAG4, BSR4, LDH2, ENO1 and p-ATPase. Challenge of the bradyzoite library with sera of infected individuals led to the identification of antigenic regions within BAG1 and MAG1 gene products. Analysis of the humoral and lymphoproliferative responses to recombinant antigens demonstrated that the BAG1 fragment induced T-cell proliferation in 34% of T. gondii-exposed individuals, while 50% of them had specific IgG. In the same subjects, the MAG1 fragment was recognized by T cells from 17% of the exposed donors and by antibodies from 73% of them. A detailed analysis of the antibody response against BAG1 and MAG1 antigen fragments demonstrated that the immune response against bradyzoites occurs early after infection in humans. Finally, we provide evidence that the T-cell response against BAG1 is associated with the production of interferon-gamma, suggesting that bradyzoite antigens should be considered in the design of potential vaccines in humans. 相似文献
996.
Investigation of the degradation mechanisms of poly(malic acid) esters in vitro and their related cytotoxicities on J774 macrophages 总被引:1,自引:0,他引:1
Poly(beta-malic acid) hydrophobic derivatives are promising polymers for biomedical and pharmaceutical applications. The objectives of the present work were to study the in vitro degradation profile of three PMLA hydrophobic derivatives and to evaluate their cytotoxicity before and after degradation. For this purpose, nanoparticles from poly(benzyl-malate) (PMLABe), poly(hexyl-malate) (PMLAHe), and poly(malic acid-co-benzyl-malate) (PMLAH/He) were prepared for degradation studies on standardized materials. Size exclusion chromatography (SEC) and 1H NMR indicated that degradation occurred by random hydrolysis of the polymer main chain for all three polymer derivatives. The presence of carboxyl groups on the side chain and their esterification with different alcohols varying hydrophilicities could affect the degradation rate. It was postulated that the degradation depended on the rate of diffusion of water into the core of the particles. The cytotoxicity of the polymer nanospheres as well as their degradation products were evaluated in vitro with J774 A1 murine macrophage-like cell line. The cytotoxicity depended on the degradation rate of the polymers and the amount of degradation products of low molecular weight produced. 相似文献
997.
Inactivation of Drosophila tumor suppressor genes can cause excessive proliferation and, in some cases, neoplastic growth. Neoplastic growth in Drosophila tissues can also be followed by metastasis upon transplantation into hosts or in vivo. Recently, we have shown that metastatic tumors of Drosophila can provide a model in which to identify genes that are involved in the metastatic process. 相似文献
998.
Merello E De Marco P Moroni A Raso A Calevo MG Consalez GG Cama A Capra V 《Birth defects research. Part A, Clinical and molecular teratology》2004,70(11):885-888
BACKGROUND: Neural tube defects (NTDs) are complex embryological malformations, affecting 1 in 1,000 live births. Antisense studies have implicated murine Mab21 genes as having an important role in neural tube development. We investigated whether MAB21L1/L2 genes could be involved in the aetiology of NTDs. METHODS: Denaturing HPLC (DHPLC) analysis of MAB21 genes was performed in 116 NTD cases. A case-control approach was used to test if the two single nucleotide polymorphisms (SNPs) of the MAB21L1 gene might be associated with increased NTD risk. RESULTS: No pathological variants of MAB21L1/L2 genes were identified by DHPLC analysis. Case-control studies demonstrated that the two SNPs (CAG triplets in 5'UTR; A-->C in 3'UTR) in the MAB21L1 gene are unlikely to be directly responsible for myelomeningocele. CONCLUSIONS: We suggest that MAB21 genes are unlikely to have substantial impact on NTDs. These preliminary findings will need to be investigated in larger samples before firm conclusions can be made. 相似文献
999.
Ferreira EN Pires LC Parmigiani RB Bettoni F Puga RD Pinheiro DG Andrade LE Cruz LO Degaki TL Faria M Festa F Giannella-Neto D Giorgi RR Goldman GH Granja F Gruber A Hackel C Henrique-Silva F Malnic B Manzini CV Marie SK Martinez-Rossi NM Oba-Shinjo SM Pardini MI Rahal P Rainho CA Rogatto SR Romano CM Rodrigues V Sales MM Savoldi M da Silva ID da Silva NP de Souza SJ Tajara EH Silva WA Simpson AJ Sogayar MC Camargo AA Carraro DM 《Genetics and molecular research : GMR》2004,3(4):493-511
1000.
Solana ME Celentano AM Tekiel V Jones M González Cappa SM 《The Journal of parasitology》2002,88(1):102-106
C3H/HeN female mice infected with distinct Trypanosoma cruzi subpopulations (RA strain [pantropic/reticulotropic] and K98 clone of the CA-I strain [myotropic]) show differences both in inflammatory compromise of the genital tract and in the outcome of pregnancy. The group of mice infected with the K98 clone show lymphomononuclear infiltrates in pelvian fat and in uterus interstitium, coexisting with the presence of T. cruzi DNA, and show moderate oophoritis, perioophoritis, and vasculitis. However, neither parasite DNA nor inflammatory foci were detected in the uterus, and only mild oophoritis was observed among RA-infected mice at mating time. Independently from the parasite subpopulation, females developed estrous 30 days postinoculation (PI), and at the same time, parasite counts were similar for K98 and for RA-infected mice. However, fertility was significantly diminished in K98-infected females. On day 14 of gestation, fetal resorptions increased in this group and cannot be attributed to hormonal disbalance because similar serum progesterone levels were found in all groups. At this time (44 days PI), parasitemia was higher in K98- than in RA-infected mice. However, resorptions were not triggered by massive infection because polymerase chain reaction failed to prove parasite DNA in resorbing fetuses. In contrast with K98 females, RA-infected mice delivered T. cruzi-infected newborns. 相似文献