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991.
Sommaggio R Cohnen A Watzl C Costa C 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(5):2075-2083
Xenotransplantation of genetically engineered porcine chondrocytes may provide a therapeutic solution for the repair of cartilage defects of various types. However, the mechanisms underlying the humoral and cellular responses that lead to rejection of xenogeneic cartilage are not well understood. In this study, we investigated the interaction between human NK cells and isolated porcine costal chondrocytes (PCC). Our data show that freshly isolated NK cells adhere weakly to PCC. Consequently, PCC were highly resistant to cytolysis mediated by freshly isolated NK cells. However, the presence of human natural Abs in the coculture was often sufficient to trigger cytotoxicity against PCC. Furthermore, IL-2 stimulation of NK cells or activation of PCC with the proinflammatory cytokines TNF-α or IL-1α resulted in increased adhesion, which was paralleled by increased NK cell-mediated lysis of PCC. NK cell adhesion to PCC could be blocked by Abs against human LFA-1 and porcine VCAM-1. NKG2D and NKp44 were involved in triggering cytotoxicity against PCC, which expressed ligands for these activating NK cell receptors. Our data further suggest that NKp30 and NKp46 may contribute to the activation of NK cells by PCC under certain conditions. Finally, comparative studies confirmed that PCC are more resistant than porcine aortic endothelial cells to human NK cell-mediated lysis. Thus, the data demonstrate that human NK cells can kill pig chondrocytes and may therefore contribute to rejection of xenogeneic cartilage. In addition, we identify potential targets for intervention to prevent the NK cell response against pig xenografts. 相似文献
992.
RF Martins V Zina EB Silva MT Rebelo E Figueiredo Z Mendel OS Paulo JC Franco SG Seabra 《Journal of genetics》2012,91(2):e75-e78
993.
Da Shi Su Xu Jaylyn Waddell Susanna Scafidi Steven Roys Rao P. Gullapalli Mary C. McKenna 《Journal of neurochemistry》2012,123(6):971-981
Fragile X syndrome (FXS) is the most common form of inherited mental retardation and is studied in the Fmr1 knockout (KO) mouse, which models both the anatomical and behavioral changes observed in FXS patients. In vitro studies have shown many alterations in synaptic plasticity and increased density of immature dendritic spines in the hippocampus, a region involved in learning and memory. In this study, magnetic resonance imaging (MRI) and 1H magnetic resonance spectroscopy (MRS) were used to determine in vivo longitudinal changes in volume and metabolites in the hippocampus during the critical period of early myelination and synaptogenesis at post‐natal days (PND) 18, 21, and 30 in Fmr1 KO mice compared with wild‐type (WT) controls. MRI demonstrated an increase in volume of the hippocampus in the Fmr1 KO mouse compared with controls. MRS revealed significant developmental changes in the ratios of hippocampal metabolites N‐acetylaspartate (NAA), myo‐inositol (Ins), and taurine to total creatine (tCr) in Fmr1 KO mice compared with WT controls. Ins was decreased at PND 30, and taurine was increased at all ages studied in Fmr1 KO mice compared with controls. An imbalance of brain metabolites in the hippocampus of Fmr1 KO mice during the critical developmental period of synaptogenesis and early myelination could have long‐lasting effects that adversely affect brain development and contribute to ongoing alterations in brain function. 相似文献
994.
Carvalho Barbosa Rde C Menezes DC Freire TF Sales DC Alencar VH Rabenhorst SH 《Molecular biology reports》2012,39(4):4899-4907
Polymorphisms in genes involved in folate metabolism have been shown to be implicated in breast cancer risk but with contradictory
results. In this case–control study, we investigated the association between MTHFR C677T and A1298C, TYMS 5′-UTR, MTR A2756G and cSHMT C1420T and also the folate carrier (RFC1 G80A) and breast cancer risk in a northeastern Brazilian population. The study included 183 women diagnosed with breast cancer
and 183 controls volunteers without any history of cancer. Also a significant number of healthy individuals were included
for allelic frequency in the population studied. Risk of breast cancer was estimated by conditional logistic regression. An
association with risk was found for women carrying the MTR A2756G polymorphic allele (AG, P = 0.0036; AG/GG, P = 0.0040), and a protective effect in carriers of the RFC1 G80A polymorphic allele (GA, P = 0.0015; AA, P = 0.0042). Stratifying the data by age (cutoff point of 50 years old), different distributions were observed for breast cancer
risk. For women ≤50 years, the risk observed in the presence of the polymorphic allele MTR 2756 (AG/GG) in the general analysis was, restricted to this age group (P = 0.0118). Conversely, for women over 50, the risk of breast cancer development was statistically associated with the MTHFR 677CT genotype, but especially significant was risk associated with the presence of the polymorphic allele of cSHMT C1420T (P = 0.0120) and the protective effect associated with the RFC1 G80A polymorphism allele (P = 0.0021), was restrict to this age group. These data indicate that the cutoff age used (50 years old) was appropriate, since
it was able to discriminate risk in each age group in the population studied and also to point to the importance of age in
the analyses of cancer-associated polymorphisms. 相似文献
995.
996.
dos Reis SP Tavares Lde S Costa Cde N Brígida AB de Souza CR 《Molecular biology reports》2012,39(6):6513-6519
Cassava (Manihot esculenta Crantz) is one of the world’s most important food crops. It is cultivated mainly in developing countries of tropics, since
its root is a major source of calories for low-income people due to its high productivity and resistance to many abiotic and
biotic factors. A previous study has identified a partial cDNA sequence coding for a putative RING zinc finger in cassava
storage root. The RING zinc finger protein is a specialized type of zinc finger protein found in many organisms. Here, we
isolated the full-length cDNA sequence coding for M. esculenta RZF (MeRZF) protein by a combination of 5′ and 3′ RACE assays. BLAST analysis showed that its deduced amino acid sequence
has a high level of similarity to plant proteins of RZF family. MeRZF protein contains a signature sequence motif for a RING
zinc finger at its C-terminal region. In addition, this protein showed a histidine residue at the fifth coordination site,
likely belonging to the RING-H2 subgroup, as confirmed by our phylogenetic analysis. There is also a transmembrane domain
in its N-terminal region. Finally, semi-quantitative RT-PCR assays showed that MeRZF expression is increased in detached leaves
treated with sodium chloride. Here, we report the first evidence of a RING zinc finger gene of cassava showing potential role
in response to salt stress. 相似文献
997.
Zhang WB Qiu PC Jiang HW Liu CY Xin da W Li CD Hu GH Chen QS 《Molecular biology reports》2012,39(5):6087-6094
Northeast of China is the main soybean production area, drought and low-temperature tolerance are both main factors involved
in reducing soybean yield and limiting planting regions, the most effective way to solve this problem is to breed cultivars
with drought and low-temperature tolerance. A set of the BC2F3 lines was constructed with Hongfeng 11 as recurrent parent and Harosoy as donor parent, and screened in drought and low-temperature
condition at the germination stage. Related QTLs were obtained by Chi-test and ANOVA analysis with genotypic and phenotypic
data. Eighteen QTLs of drought tolerance and 23 QTLs of low-temperature tolerance were detected. Among them, 12 QTLs were
correlated with both drought and low-temperature tolerance, which showed a partial genetic overlap between drought and low-temperature
tolerance at the germination stage in soybean. Among the 12 genetic overlap QTLs, Satt253, Satt513, Satt693, Satt240, Satt323,
and Satt255 were detected by at least one method for both drought and low-temperature tolerance. Satt557, Satt452, Sat_331,
Satt338, Satt271, and Satt588 were detected by only one analysis method. The QTLs detected above were significant loci for
drought or low-temperature tolerance in soybean. This will play an important role in MAS for development of both drought and
low-temperature tolerance variety. 相似文献
998.
Jonny E. Scherwinski-Pereira Elequisandra da C. Araruna Lima Tatiane L. da Silva Antonio G. Gomes Mesquita Simone de A. Maciel Frederico H. da Silva Costa 《Plant Cell, Tissue and Organ Culture》2012,109(2):263-269
We have developed an efficient and simplified method for shoot proliferation of the pineapple (Ananas comosus L.), using a Double-Phase Culture System (DPS) (semi-solid medium with a layer of liquid medium on the top). Under these
conditions, up to 430 microshoots were produced from 5 initial shoots within 5 months, and without shoot manipulation. Thus,
>50% shoots proliferated as compared to that on agar-solidified medium. Shoots taken from DPS were rooted within 4 weeks at
a frequency of up to 100%, in full-strength or half-strength Murashige and Skoog medium containing 0.5–2.5 μM indole-3-butyric
acid. The plantlets were then transferred into soil, and they survived acclimatization with 100% success. Thus, DPS could
be useful for large-scale micropropagation of a range of pineapple cultivars, with high production of plantlets at the end
of process, and reduced labor costs during the subcultures. 相似文献
999.
Saraiva DG Fournier GF Martins TF Leal KP Vieira FN Câmara EM Costa CG Onofrio VC Barros-Battesti DM Guglielmone AA Labruna MB 《Experimental & applied acarology》2012,58(2):159-166
From June 2005 to November 2010, 43 small mammals encompassing 6 species of Didelphimorphia, 8 species of Rodentia, and 1 species of Lagomorpha were found parasitized by ticks in the state of Minas Gerais, southeastern Brazil. Nine tick species, in total 186 specimens, were identified as follows: Amblyomma cajennense (larvae and nymphs) on opossums and rodents; Amblyomma ovale (nymphs) on rodents; Amblyomma parvum (nymphs) on rodents; Amblyomma coelebs (nymphs) on opossums; Amblyomma dubitatum (nymph) on opossums; Ixodes amarali (females, nymphs, and larvae) on opossums and rodents; Ixodes loricatus (male, females, nymph) on opossums; Ixodes schulzei (female) on rodents; and Haemaphysalis leporispalustris (female) on rabbits. Most of the tick-host associations found in the present study have never been recorded in the literature; those include three new host records for I. amarali, four for A. cajennense, one for A. dubitatum, two for A. ovale, and one for A. coelebs. In addition, we provide the first record of A. coelebs in the state of Minas Gerais. 相似文献
1000.
Costa H Distéfano AJ Marino-Buslje C Hidalgo A Berenguer J Biscoglio de Jiménez Bonino M Ferrarotti SA 《Applied microbiology and biotechnology》2012,94(1):123-130
Cyclodextrin glycosyltransferases (CGTases) are important enzymes in biotechnology because of their ability to produce cyclodextrin
(CD) mixtures from starch whose relative composition depends on enzyme source. A multiple alignment of 46 CGTases and Shannon
entropy analysis allowed us to find differences and similarities that could be related to product specificity. Interestingly,
position 179 has Gly in all the CGTases except in that from Bacillus circulans DF 9R which possesses Gln. The absence of a side chain at that position has been considered as a strong requirement for substrate
binding and cyclization process. Therefore, we constructed two mutants of this enzyme, Q179L and Q179G. The activity and kinetic
parameters of Q179G remained unchanged while the Q179L mutant showed a different CDs ratio, a lower catalytic efficiency,
and a decreased ability to convert starch into CDs. We show that position 179 is involved in CGTase product specificity and
must be occupied by Gly—without a side chain—or by amino acid residues able to interact with the substrate through hydrogen
bonds in a way that the cyclization process occurs efficiently. These findings are also explained on the basis of a structural
model. 相似文献