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41.
M. Abdul Maleque Hiroaki T. Ishii Kaoru Maeto Shingo Taniguchi 《Arthropod-Plant Interactions》2007,1(3):175-185
We evaluated the effectiveness of line thinning, a new silvicultural technique, toward restoring diversity of Coleoptera in
overstocked Cryptomeria japonica D. Don plantations in central Japan. We compared the abundance of some common Coleoptera families between line-thinned stands
and adjacent unthinned stands in two plantations: low-elevation Sugi site (4 years since thinning) and high-elevation Kuchiotani
site (6 years since thinning). Many bettle families comprising various functional groups such as plant feeders, wood borers,
rotten wood feeders, root feeders, fungus feeders, dung feeders, and scavengers were more abundant in the line-thinned stands
than in the unthinned stands. Furthermore, some important families were missing from the unthinned stands. There were strong
positive relationships between Coleopteran abundance and understory vegetation. Our results suggest that line thinning may
potentially increase biodiversity in overstocked C. japonica plantations by restoring important ecological processes such as food-web interactions (pollination, predation, herbivory,
decomposition, parasitism, etc.), and habitat conditions. 相似文献
42.
K Sato M Ishiai K Toda S Furukoshi A Osakabe H Tachiwana Y Takizawa W Kagawa H Kitao N Dohmae C Obuse H Kimura M Takata H Kurumizaka 《The EMBO journal》2012,31(17):3524-3536
Fanconi anaemia (FA) is a rare hereditary disorder characterized by genomic instability and cancer susceptibility. A key FA protein, FANCD2, is targeted to chromatin with its partner, FANCI, and plays a critical role in DNA crosslink repair. However, the molecular function of chromatin-bound FANCD2-FANCI is still poorly understood. In the present study, we found that FANCD2 possesses nucleosome-assembly activity in vitro. The mobility of histone H3 was reduced in FANCD2-knockdown cells following treatment with an interstrand DNA crosslinker, mitomycin C. Furthermore, cells harbouring FANCD2 mutations that were defective in nucleosome assembly displayed impaired survival upon cisplatin treatment. Although FANCI by itself lacked nucleosome-assembly activity, it significantly stimulated FANCD2-mediated nucleosome assembly. These observations suggest that FANCD2-FANCI may regulate chromatin dynamics during DNA repair. 相似文献
43.
44.
Temperature-sensitive (ts) mutants of rat 3Y1 fibroblasts representing four separate complementation groups (3Y1tsD123, 3Y1tsF121, 3Y1tsG125, and 3Y1tsH203) are arrested mainly in the G1 phase when cells of randomly proliferating population at 33.8 degrees C are shifted to 39.8 degrees C (temperature arrest). We examined the time lag of the cellular entry into the S phase after release at 33.8 degrees C, both from the temperature arrest and from the arrest at 33.8 degrees C at a confluent cell density (density arrest). In the temperature-arrested cells, as the duration of temperature arrest increased, the time lag of entry into S phase after shift down to 33.8 degrees C was prolonged, in all four mutants. These observations suggest that the four different functional lesions, each causing arrest in the G1 phase, are also responsible for prolongation of the time lag of entry into the S phase in cells arrested in the G1 phase. The prolongation of the time lag in the temperature-arrested cultures was accelerated at a higher cell density, in medium supplemented with a lower concentration of serum, and at a higher restrictive temperature. In the density-arrested cells, as the duration of pre-exposure to 39.8 degrees C was increased, the time lag of entry into S phase at 33.8 degrees C after release from the arrest was drastically prolonged, in all four mutants. In 3Y1tsF121, 3Y1tsG125, and 3Y1tsH203, when the density-arrested cells were prestimulated by serum at 39.8 degrees C for various periods of time, the time lag of entry into S phase after release from the density arrest at 33.8 degrees C was initially shortened, and then, prolonged progressively as the period of prestimulation increased. These findings, taken together with other data, show that all four ts defects affect cells in states ranging from the deeper resting to mid- or late-G1 phase. It is suggested that events represented by these four mutants are required for entry into the S phase and normally operate in parallel but not in sequence in cells in states ranging from the deeper resting to the mid- or late-G1 phases, though they may affect each other. 相似文献
45.
Emi?Ito Hiroaki?Waki Kozo?Miseki Takashi?Shimada Taka-Aki?Sato Kazuaki?Kakehi Minoru?Suzuki Akemi?SuzukiEmail author 《Glycoconjugate journal》2013,30(9):881-888
Four types of neutral glycosphingolipids (LacCer, Gb3Cer, Gb4Cer, and IV3αGalNAc-Gb4Cer; 10 pmol each) were analyzed using high-performance liquid chromatography (HPLC)-electrospray ionization quadrupole ion trap time-of-flight (ESI-QIT-TOF) mass spectrometry (MS) with a repeated high-speed polarity and MSn switching system. This system can provide six types of mass spectra, including positive and negative ion MS, MS2, and MS3 spectra, within 1 s per cycle. Using HPLC with a normal-phase column, information on the molecular weights of major molecular species of four neutral glycosphingolipids was obtained by detecting [M+Na]+ in the positive ion mode mass spectra and [M?H]? in the negative ion mode mass spectra. Sequences of glycosphingolipid oligosaccharide were obtained in the negative ion MS2 spectra. In addition, information on the ceramide structures was clearly obtained in the negative ion MS3 mass spectra. GlcCer molecular species were analyzed by HPLC-ESI-QIT-TOF MS with a reversed-phase column using 1 pmole of GlcCer. The structures of the seven molecular species of GlcCer, namely, d18:1-C16:0, d18:1-C18:0, d18:1-C20:0, d18:1-C22:0, d18:1-C23:0, d18:1-C24:1, and d18:1-C24:0, were characterized using positive ion MS and negative ion MS, MS2, and MS3. The established HPLC-ESI-QIT-TOF MS with MSn switching and a normal phase column has been successfully applied to the structural characterization of LacCer and Gb4Cer in a crude mixture prepared from human erythrocytes. 相似文献
46.
47.
Miho Suzuki Ichiro Sakata Takafumi Sakai Hiroaki Tomioka Koichi Nishigaki Marc Tramier Maïté Coppey-Moisan 《Analytical biochemistry》2015
Cytometry is a versatile and powerful method applicable to different fields, particularly pharmacology and biomedical studies. Based on the data obtained, cytometric studies are classified into high-throughput (HTP) or high-content screening (HCS) groups. However, assays combining the advantages of both are required to facilitate research. In this study, we developed a high-throughput system to profile cellular populations in terms of time- or dose-dependent responses to apoptotic stimulations because apoptotic inducers are potent anticancer drugs. We previously established assay systems involving protease to monitor live cells for apoptosis using tunable fluorescence resonance energy transfer (FRET)-based bioprobes. These assays can be used for microscopic analyses or fluorescence-activated cell sorting. In this study, we developed FRET-based bioprobes to detect the activity of the apoptotic markers caspase-3 and caspase-9 via changes in bioprobe fluorescence lifetimes using a flow cytometer for direct estimation of FRET efficiencies. Different patterns of changes in the fluorescence lifetimes of these markers during apoptosis were observed, indicating a relationship between discrete steps in the apoptosis process. The findings demonstrate the feasibility of evaluating collective cellular dynamics during apoptosis. 相似文献
48.
Yukinori Yamada Tomoharu Yokooji Naoki Ninomiya Takanori Taogoshi Eishin Morita Hiroaki Matsuo 《Biochemistry and Biophysics Reports》2019
We previously developed Hokushin wheat line as a hypoallergenic wheat lacking ω5-gliadin (1BS-18), a major allergen for wheat-dependent exercise-induced anaphylaxis. However, the allergenicity of 1BS-18 has not been understood completely. In this study, we evaluated the allergenicity of 1BS-18 such as anaphylactic elicitation ability and sensitization ability using rats sensitized with ω5-gliadin or glutens prepared from Hokushin (Hokushin gluten) or 1BS-18 (1BS-18 gluten). Rats were sensitized by intraperitoneal administration of ω5-gliadin, Hokushin gluten or 1BS-18 gluten. Immunoglobulin E-mediated systemic anaphylaxis was evaluated by measuring changes in rectal temperature for 30 min after intravenous challenge with ω5-gliadin or the test glutens in unsensitized rats or rats sensitized with ω5-gliadin or the test glutens. In ω5-gliadin-sensitized rats, intravenous challenge with ω5-gliadin or Hokushin gluten significantly decreased the rectal temperature at 30 min after challenge while challenge with 1BS-18 gluten did not reduce the rectal temperature. Furthermore, intravenous challenge with ω5-gliadin significantly decreased the rectal temperature in rats sensitized with Hokushin gluten or 1BS-18 gluten. However, the reduced degree observed in 1BS-18 gluten-sensitized rats was smaller than that in Hokushin gluten-sensitized rats. In conclusion, 1BS-18 elicited no allergic reaction in ω5-gliadin-sensitized rats and had less sensitization ability for ω5-gliadin than that of Hokushin wheat. 相似文献
49.
Ozaki TJ Sato N Kitajo K Someya Y Anami K Mizuhara H Ogawa S Yamaguchi Y 《Cognitive neurodynamics》2012,6(2):185-198
An ambiguous figure such as the Necker cube causes spontaneous perceptual switching (SPS). The mechanism of SPS in multistable
perception has not yet been determined. Although early psychological studies suggested that SPS may be caused by fatigue or
satiation of orientation, the neural mechanism of SPS is still unknown. Functional magnetic resonance imaging (fMRI) has shown
that the dorsal attention network (DAN), which mainly controls voluntary attention, is involved in bistable perception of
the Necker cube. To determine whether neural dynamics along the DAN cause SPS, we performed simultaneous electroencephalography
(EEG) and fMRI during an SPS task with the Necker cube, with every SPS reported by pressing a button. This EEG–fMRI integrated
analysis showed that (a) 3–4 Hz spectral EEG power modulation at fronto-central, parietal, and centro-parietal electrode sites
sequentially appeared from 750 to 350 ms prior to the button press; and (b) activations correlating with the EEG modulation
traveled along the DAN from the frontal to the parietal regions. These findings suggest that slow oscillation initiates SPS
through global dynamics along the attentional system such as the DAN. 相似文献
50.
The Yersinia enterocolitica effector YopP inhibits host cell signalling by inactivating the protein kinase TAK1 in the IL-1 signalling pathway 总被引:1,自引:0,他引:1 下载免费PDF全文
Thiefes A Wolf A Doerrie A Grassl GA Matsumoto K Autenrieth I Bohn E Sakurai H Niedenthal R Resch K Kracht M 《EMBO reports》2006,7(8):838-844
The mechanism by which YopP simultaneously inhibits mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB pathways has been elusive. Ectopic expression of YopP inhibits the activity and ubiquitination of a complex consisting of overexpressed TGF-beta-activated kinase 1 (TAK1) and its subunit TAK1-binding protein (TAB)1, but not of MEK kinase 1. YopP, but not the catalytically inactive mutant YopP(C172A), also suppresses basal and interleukin-1-inducible activation of endogenous TAK1, TAB1 and TAB2. YopP does not affect the interaction of TAK1, TAB1 and TAB2 but inhibits autophosphorylation of TAK1 at Thr 187 and phosphorylation of TAB1 at Ser 438. Glutathione S-transferase-tagged YopP (GST-YopP) binds to MAPK kinase (MAPKK)4 and TAB1 but not to TAK1 or TAB2 in vitro. Furthermore, YopP in synergy with a previously described negative regulatory feedback loop inhibits TAK1 by MAPKK6-p38-mediated TAB1 phosphorylation. Taken together, these data strongly suggest that YopP binds to TAB1 and directly inhibits TAK1 activity by affecting constitutive TAK1 and TAB1 ubiquitination that is required for autoactivation of TAK1. 相似文献