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81.
Alemu EA Sjøttem E Outzen H Larsen KB Holm T Bjørkøy G Johansen T 《Cellular and molecular life sciences : CMLS》2011,68(11):1953-1968
The protein kinase C (PKC) family of serine/threonine kinases consists of ten different isoforms grouped into three subfamilies,
denoted classical, novel and atypical PKCs (aPKCs). The aPKCs, PKCι/λ and PKCζ serve important roles during development and
in processes subverted in cancer such as cell and tissue polarity, cell proliferation, differentiation and apoptosis. In an
effort to identify novel interaction partners for aPKCs, we performed a yeast two-hybrid screen with the regulatory domain
of PKCι/λ as bait and identified the Krüppel-like factors family protein TIEG1 as a putative interaction partner for PKCι/λ.
We confirmed the interaction of both aPKCs with TIEG1 in vitro and in cells, and found that both aPKCs phosphorylate the DNA-binding
domain of TIEG1 on two critical residues. Interestingly, the aPKC-mediated phosphorylation of TIEG1 affected its DNA-binding
activity, subnuclear localization and transactivation potential. 相似文献
82.
The apicomplexan plastid and its evolution 总被引:1,自引:0,他引:1
Sato S 《Cellular and molecular life sciences : CMLS》2011,68(8):1285-1296
Protistan species belonging to the phylum Apicomplexa have a non-photosynthetic secondary plastid—the apicoplast. Although
its tiny genome and even the entire nuclear genome has been sequenced for several organisms bearing the organelle, the reason
for its existence remains largely obscure. Some of the functions of the apicoplast, including housekeeping ones, are significantly
different from those of other plastids, possibly due to the organelle’s unique symbiotic origin. 相似文献
83.
In eukaryotes, cellular energy in the form of ATP is produced in the cytosol via glycolysis or in the mitochondria via oxidative
phosphorylation and, in photosynthetic organisms, in the chloroplast via photophosphorylation. Transport of adenine nucleotides
among cell compartments is essential and is performed mainly by members of the mitochondrial carrier family, among which the
ADP/ATP carriers are the best known. This work reviews the carriers that transport adenine nucleotides into the organelles
of eukaryotic cells together with their possible functions. We focus on novel mechanisms of adenine nucleotide transport,
including mitochondrial carriers found in organelles such as peroxisomes, plastids, or endoplasmic reticulum and also mitochondrial
carriers found in the mitochondrial remnants of many eukaryotic parasites of interest. The extensive repertoire of adenine
nucleotide carriers highlights an amazing variety of new possible functions of adenine nucleotide transport across eukaryotic
organelles. 相似文献
84.
Pan Q Qiao F Gao C Norman B Optican L Zelenka PS 《Cellular and molecular life sciences : CMLS》2011,68(20):3425-3436
The non-receptor tyrosine kinase Src is a critical regulator of cytoskeletal contraction, cell adhesion, and migration. In
normal cells, Src activity is stringently controlled by Csk-dependent phosphorylation of Src(Y530), and by Cullin-5-dependent
ubiquitinylation, which affects active Src(pY419) exclusively, leading to its degradation by the proteosome. Previous work
has shown that Src activity is also limited by Cdk5, a proline-directed kinase, which has been shown to phosphorylate Src(S75).
Here we show that this phosphorylation promotes the ubiquitin-dependent degradation of Src, thus restricting the availability
of active Src. We demonstrate that Src(S75) phosphorylation occurs in vivo in epithelial cells, and like ubiquitinylation,
is associated only with active Src. Preventing Cdk5-dependent phosphorylation of Src(S75), by site-specific mutation of S75
or by Cdk5 inhibition or suppression, increases Src(Y419) phosphorylation and kinase activity, resulting in Src-dependent
cytoskeletal changes. In transfected cells, ubiquitinylation of Src(S75A) is about 35% that of wild-type Src-V5, and its half-life
is approximately 2.5-fold greater. Cdk5 suppression leads to a comparable decrease in the ubiquitinylation of endogenous Src
and a similar increase in Src stability. Together, these findings demonstrate that Cdk5-dependent phosphorylation of Src(S75)
is a physiologically significant mechanism of regulating intracellular Src activity. 相似文献
85.
86.
Inflammasomes: current understanding and open questions 总被引:2,自引:2,他引:0
Bauernfeind F Ablasser A Bartok E Kim S Schmid-Burgk J Cavlar T Hornung V 《Cellular and molecular life sciences : CMLS》2011,68(5):765-783
The innate immune system relies on its capability to detect invading microbes, tissue damage, or stress via evolutionarily
conserved receptors. The nucleotide-binding domain leucine-rich repeat (NLR)-containing family of pattern recognition receptors
includes several proteins that drive inflammation in response to a wide variety of molecular patterns. In particular, the
NLRs that participate in the formation of a molecular scaffold termed the “inflammasome” have been intensively studied in
past years. Inflammasome activation by multiple types of tissue damage or by pathogen-associated signatures results in the
autocatalytic cleavage of caspase-1 and ultimately leads to the processing and thus secretion of pro-inflammatory cytokines,
most importantly interleukin (IL)-1β and IL-18. Here, we review the current knowledge of mechanisms leading to the activation
of inflammasomes. In particular, we focus on the controversial molecular mechanisms that regulate NLRP3 signaling and highlight
recent advancements in DNA sensing by the inflammasome receptor AIM2. 相似文献
87.
Hosseinkhani S 《Cellular and molecular life sciences : CMLS》2011,68(7):1167-1182
Firefly luciferase-catalyzed reaction proceeds via the initial formation of an enzyme-bound luciferyl adenylate intermediate.
The chemical origin of the color modulation in firefly bioluminescence has not been understood until recently. The presence
of the same luciferin molecule, in combination with various mutated forms of luciferase, can emit light at slightly different
wavelengths, ranging from red to yellow to green. A historical perspective of development in understanding of color emission
mechanism is presented. To explain the variation in the color of the bioluminescence, different factors have been discussed
and five hypotheses proposed for firefly bioluminescence color. On the basis of recent results, light-color modulation mechanism
of firefly luciferase propose that the light emitter is the excited singlet state of OL− [1(OL−)*], and light emission from 1(OL−)* is modulated by the polarity of the active-site environment at the phenol/phenolate terminal of the benzothiazole fragment
in oxyluciferin. 相似文献
88.
89.
90.
Rodríguez-Muñoz M Sánchez-Blázquez P Vicente-Sánchez A Bailón C Martín-Aznar B Garzón J 《Cellular and molecular life sciences : CMLS》2011,68(17):2933-2949
A series of pharmacological and physiological studies have demonstrated the functional cross-regulation between MOR and NMDAR.
These receptors coexist at postsynaptic sites in midbrain periaqueductal grey (PAG) neurons, an area implicated in the analgesic
effects of opioids like morphine. In this study, we found that the MOR-associated histidine triad nucleotide-binding protein
1 (HINT1) is essential for maintaining the connection between the NMDAR and MOR. Morphine-induced analgesic tolerance is prevented
and even rescued by inhibiting PKC or by antagonizing NMDAR. However, in the absence of HINT1, the MOR becomes supersensitive
to morphine before suffering a profound and lasting desensitization that is refractory to PKC inhibition or NMDAR antagonism.
Thus, HINT1 emerges as a key protein that is critical for sustaining NMDAR-mediated regulation of MOR signaling strength.
Thus, HINT1 deficiency may contribute to opioid-intractable pain syndromes by causing long-term MOR desensitization via mechanisms
independent of NMDAR. 相似文献