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991.
Kim MH Kim MO Heo JS Kim JS Han HJ 《Apoptosis : an international journal on programmed cell death》2008,13(2):295-304
This study examined the effect of acetylcholine (ACh) on the hypoxia-induced apoptosis of mouse embryonic stem (ES) cells.
Hypoxia (60 h) decreased both the cell viability and level of [3H] thymidine incorporation, which were prevented by a pretreatment with ACh. However, the atropine (ACh receptor [AChR] inhibitor)
treatment blocked the protective effect of ACh. Hypoxia (90 min) increased the intracellular level of reactive oxygen species
(ROS). On the other hand, ACh inhibited the hypoxia-induced increase in ROS, which was blocked by an atropine treatment. Subsequently,
the hypoxia-induced ROS increased the level of p38 mitogen activated protein kinase (MAPK) and Jun-N-terminal kinase (JNK)
phosphorylation, which were inhibited by the ACh pretreatment. Moreover, hypoxic exposure (90 min) increased the level of
nuclear factor-κB (NF-κB) phosphorylation, which was blocked by a pretreatment with SB 203580 (p38 MAPK inhibitor) or SP 600125
(JNK inhibitor). However, hypoxia (60 h) decreased the protein levels of Bcl-2 and c-IAPs (cellular inhibitor of apoptosis
proteins) but increased the level of caspase-3 activation. All these effects were inhibited by a pretreatment with ACh. In
conclusion, ACh prevented the hypoxia-induced apoptosis of mouse ES cells by inhibiting the ROS-mediated p38 MAPK and JNK
activation as well as the regulation of Bcl-2, c-IAPs, and caspase-3.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
992.
Because highly invasive species can rapidly assimilate rare taxa, we questioned whether two Florida endangered Lantana depressa varieties existed 21 years after Sanders documented their widespread hybridization with exotic Lantana strigocamara, and whether morphological traits could accurately discriminate genetic individuals. Stepwise discriminant analysis of morphological
characters discriminated the three taxa, correctly classifying 98, 91, 89% of L. strigocamara, L. depressa var. depressa, and var. floridana. Hybrids blurred taxonomic distinctions of varieties and reduced classification accuracy by 7–17%. Species-specific Random
Fragment Length Polymorphism (RFLP-PCR) confirmed hybridization has occurred. Intersimple Sequence Repeat (ISSR) fingerprints
analyzed with STRUCTURE identified three groups indicating introgression. Morphological traits significantly, but weakly correlated
with q ratios (P = 0.0001; r
2 = 0.45). Although L. strigocamara introgression is widespread and ongoing, wild populations contain individuals that are predominantly L. depressa genome, supporting actions to remove adventive L. strigocamara, prevent its sale, and promote sales of genetically confirmed natives. 相似文献
993.
994.
Rubinstein-Taybi syndrome (RSTS), a developmental disorder comprising abnormalities that include mental retardation, an unusual
facial appearance, broad thumbs and big toes is frequently associated with molecular lesions in the CREB-binding protein gene,
CREBBP. The objective of the present study was to identify and analyse CREBBP mutations in Indian RSTS patients on which there are no data. Direct sequencing of CREBBP performed in 13 RSTS patients identified the three zinc fingers (CH1, CH2, CH3) and HAT domain as mutational hotspots in
which ten novel pathogenic mutations were localized. Functional analysis revealed that three of these mutations affecting
amino acids Glu1459, Leu1668 and Glu1724 were critical for histone acetyltransferase activity. Twenty-eight novel CREBBP single-nucleotide polymorphisms (SNPs) were also identified in the Indian population. Linkage disequilibrium studies revealed
associations between (i) SNP (rs129974/c.3836-206G>C) and mutation (p.Asp1340Ala); (ii) (rs130002) with mutation (p.Asn435Lys) and (iii) SNPs rs129974, rs130002 and SNP (c.3836-206G>C) signifying a disease affection status. In conclusion, the present study reports the highest detection rate of CREBBP mutations (76.9%) in RSTS patients to date, of which ten are predicted to be pathogenic and three critical for histone acetyltransferase
activity. Moreover, identification of the association of CREBBP polymorphisms with disease susceptibility could be an important risk factor for the pathogenesis of RSTS. 相似文献
995.
Recently, the gene coding for a new beta-glucuronidase enzyme has been identified and cloned from Streptococcus equi subsp. zooepidemicus. This is another report of a beta-glucuronidase gene cloned from bacterial species. The ORF Finder analysis of a sequenced
DNA (EMBL, AJ890474) revealed a presence of 1,785 bp large ORF potentially coding for a 594 aa protein. Three protein families
in (Pfam) domains were identified using the Conserved Domain Database (CDD) analysis: Pfam 02836, glycosyl hydrolases family
2, triose phosphate isomerase (TIM) barrel domain; Pfam 02837, glycosyl hydrolases family 2, sugar binding domain; and Pfam
00703, glycosyl hydrolases family 2, immunoglobulin-like beta-sandwich domain. To gain more insight into the enzymatic activity,
the domains were used to generate a bootstrapped unrooted distance tree using ClustalX. The calculated distances for two domains,
TIM barrel domain, and sugar-binding domain were comparable and exhibited similarity pattern based on function and thus being
in accordance with recently published works confirming beta-glucuronidase activity of the enzyme. The calculated distances
and the tree arrangement in the case of centrally positioned immonoglobulin-like beta-sandwich domain were somewhat higher
when compared to other two domains but clustering with other beta-glucuronidases was rather clear. Nine proteins, including
beta-glucuronidases, beta-galactosidase, and mannosidase were selected for multiple alignment and subsequent distance tree
creation. 相似文献
996.
This article comprises a literature analysis of 41 river rehabilitation projects to assess the short-term (5 years) ability
of indicator groups to demonstrate progress towards river rehabilitation goals. Positive indications were compared to land-use,
river size, rehabilitation intervention and time. A questionnaire was developed to investigate river manager’s interpretation
of rehabilitation success and to assess their level of adherence to recommendations in the literature with regard to rehabilitation
assessment on a conceptual level. A total of 54 responses were received from respondents based in Germany, The Netherlands
and the United Kingdom. The results indicate that macroinvertebrate indicators, while widely used in assessing river rehabilitation
efforts, exhibited a lower frequency of positive responses than most other indicator types in the short term. Conversely,
terrestrial floodplain indicators exhibited the most frequent level of positive response for all ecological type indicators
leading to recommendations for further investigations into their use for short-term monitoring. Assessment procedures recommended
in literature are largely followed, illustrating the advances that have been made with regard to assessment planning. Indicator
responses are influenced by scale factors, for example, land-use and river size, that are often not considered by rehabilitation
managers. While an emphasis is placed on ecological, hydrological and morphological indicators in monitoring schemes, the
socioeconomic perspective (emphasized in the literature as forming an integral part of the river system) is neglected. 相似文献
997.
998.
John Yeuk-Hon Chan Li Li Ji Miao Dong-Qing Cai Kenneth Ka-Ho Lee Yiu-Loon Chui 《Molecular biology reports》2010,37(1):363-368
Stress-responsive genes play critical roles in many biological functions that includes apoptosis, survival, differentiation
and regeneration. We have identified a novel stress-responsive gene called BRE which interacts with TNF-receptor-1 and blocks the apoptotic effect of TNF-α. BRE enhances tumor growth in vivo and is up-regulated in hepatocellular and esophageal carcinomas. BRE also regulates the ubiquitination of the DNA repair complex BRCC, and the synthesis of steroid hormones. Here, we examined
BRE-mRNA in cells after treatments with UV and ionizing radiation (IR). UV and IR treatment alone suppressed BRE-mRNA levels by more than 90% at 24 h, while hydroxyurea, fluorodeoxyuridine, aphidicolin, known inhibitors of S-phase DNA
synthesis, had no significant effect. BRE protein expression was unaltered in cells treated with TNF-α, Interleukin-1 and Dexamethasone, while a threefold increase
was observed following chorionic gonadotropin exposure. Although BRE plays a regulatory role in many different pathways, yet its expression is apparently under very stringent control. 相似文献
999.
Tiago Collares Vinicius Farias Campos Fabiana Kömmling Seixas Paulo V. Cavalcanti Odir A. Dellagostin Heden Luiz M. Moreira João Carlos Deschamps 《Journal of biosciences》2010,35(1):39-47
The silver catfish (Rhamdia quelen) is an endemic American fish species. The sperm of each species has its own peculiarities and biological characteristics,
which influence the success of mass DNA transfer methods. Our objective in this study was to evaluate different sperm-mediated
gene transfer (SMGT) methods to obtain transgenic silver catfish. Different treatments for the incorporation of a foreign
pEGFP plasmid group were used: (1) dehydrated/rehydrated (DR), (2) dehydrated/rehydrated/electroporated (DRE), (3) electroporated
(E), (4) incubated with seminal plasma (INC); and (5) incubated in the absence of seminal plasma (INCSP). Sperm motility,
time of activity duration (TAD), fertilization rate (FR), hatching rate (HR) and sperm morphology were also evaluated. The
polymerase chain reaction (PCR) positivity rates for the presence of the transgene were: DRE 60%; DR 40%; E 25%; INC 5% and
INCSP 25%. The rates of embryo EGFP expression were: DRE 63%; DR 44%; E 34%; INC 8% and INCSP 38%. The fertilization rate
in the control and DRE treatments groups were higher than in the DR group, but the E, INC and INCSP treatment groups had the
lowest rate. The hatching rates of the DRE, DR and control groups were higher than in the INCSP, INC and E treatment groups
(P>0.05). There were no differences among the DRE and DR, E and DR, E and INCSP groups in expression and PCR positivity rates
of enhanced green fluorescent protein (EGFP) in embryos. Scanning electron microscopy also did not show any change in sperm
morphology among treatment groups. To the best of our knowledge, this is the first report on transgene transmission of exogenous
DNA into silver catfish larvae through SMGT technology. 相似文献
1000.
Anne Oxbrough Tom Gittings Thomas C. Kelly John O’Halloran 《Journal of Insect Conservation》2010,14(2):169-179
Malaise traps are typically used to sample a range of flying insect groups; however non-target taxa such as spiders may also
be collected in large numbers. In this study, spiders were sampled in peatlands and wet grasslands and catches in Malaise
and pitfall traps were compared in order to determine the adequacy of Malaise traps for use in spider biodiversity assessment.
Overall, the number of species and individuals caught in Malaise and pitfall traps were comparable, although more species
were sampled in Malaise traps in locations with a greater structural diversity of the vegetation. The spider fauna sampled
by the Malaise traps differed from that of the pitfall traps, but both methods consistently separated the species assemblages
by biotope. These results demonstrate that Malaise traps are effective at sampling spiders and indicate that they can be used
in biodiversity assessment. In addition the complementary species sampled by each method mean that employing both techniques
will be useful where a full inventory of the species is required. The authors do not suggest that Malaise traps should be
used solely to sample spiders; however, if traps are set to collect insects, identification of the spiders sampled may reduce
the need to employ additional sampling techniques. 相似文献