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81.
82.
Novel oligosaccharide has suppressive activity against human leukemia cell proliferation 总被引:1,自引:0,他引:1
Hosomi O Misawa Y Takeya A Matahira Y Sugahara K Kubohara Y Yamakura F Kudo S 《Glycoconjugate journal》2009,26(2):189-198
Various oligosaccharides containing galactose(s) and one glucosamine (or N-acetylglucosamine) residues with β1–4, α1–6 and β1–6 glycosidic bond were synthesized; Galβ1–4GlcNH2, Galα1–6GlcNH2, Galα1–6GlcNAc, Galβ1–6GlcNH2, Galβ1–4Galβ1–4GlcNH2 and Galβ1–4Galβ1–4GlcNAc. Galα1–6GlcNH2 (MelNH2) and glucosamine (GlcNH2) had a suppressive effect on the proliferation of K562 cells, but none of the other saccharides tested containing GlcNAc
showed this effect. On the other hand, the proliferation of the human normal umbilical cord fibroblast was suppressed by none
of the saccharides other than GlcNH2. Adding Galα1–6GlcNH2 or glucosamine to the culture of K562 cell, the cell number decreased strikingly after 72 h. Staining the remaining cells
with Cellstain Hoechst 33258, chromatin aggregation was found in many cells, indicating the occurrence of cell death. Furthermore,
all of the cells were stained with Galα1–6GlcNH-FITC (MelNH-FITC). Neither the control cells nor the cells incubated with
glucosamine were stained. On the other hand, when GlcNH-FITC was also added to cell cultures, some of them incubated with
Galα1–6GlcNH2 were stained. The difference in the stainability of the K562 cells by Galα1–6GlcNH-FITC and GlcNH-FITC suggests that the
intake of Galα1–6GlcNH2 and the cell death induced by this saccharide is not same as those of glucosamine. The isolation of the Galα1–6GlcNH2 binding protein was performed by affinity chromatography (melibiose-agarose) and LC-MS/MS, and we identified the human heterogeneous
ribonucleoprotein (hnRNP) A1 (34.3 kDa) isoform protein (30.8 kDa). The hnRNP A1 protein was also detected from the eluate(s)
of the MelNH-agarose column by the immunological method (anti-hnRNP-A1 and HRP-labeled anti-mouse IgG (γ) antibodies). 相似文献
83.
Takeyuki Shimizu Chiaki Nishitani Hiroaki Mitsuzawa Shigeru Ariki Motoko Takahashi Katsuki Ohtani Nobutaka Wakamiya Yoshio Kuroki 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009,1790(12):1705-1710
Background
We have previously shown that lung collectins, surfactant protein A (SP-A) and surfactant protein D, interact with Toll-like receptor (TLR) 2, TLR4, or MD-2. Bindings of lung collectins to TLR2 and TLR4/MD-2 result in the alterations of signaling through these receptors, suggesting the immunomodulatory functions of lung collectins. Mannose binding lectin (MBL) is another collectin molecule which has structural homology to SP-A. The interaction between MBL and TLRs has not yet been determined.Methods
We prepared recombinant MBL, and analyzed its bindings to recombinant soluble forms of TLR4 (sTLR4) and MD-2.Results
MBL bound to sTLR4 and MD-2. The interactions were Ca2+-dependent and inhibited by mannose or monoclonal antibody against the carbohydrate-recognition domain of MBL. Treatment of sTLR4 or MD-2 by peptide N-glycosidase F significantly decreased the binding of MBL. SP-A bound to deglycosylated sTLR4, and this property did not change in chimeric molecules of SP-A/MBL in which Glu195–Phe228 or Thr174–Gly194 of SP-A were replaced with the corresponding MBL sequences.General Significance
These results suggested that MBL binds to TLR4 and MD-2 through the carbohydrate-recognition domain, and that oligosaccharide moieties of TLR4 and MD-2 are important for recognition by MBL. Since our previous studies indicated that lung collectins bind to the peptide portions of TLRs, MBL and lung collectins interact with TLRs by different mechanisms. These direct interactions between MBL and TLR4 or MD-2 suggest that MBL may modulate cellular responses by altering signals through TLRs. 相似文献84.
Most in vitro protein synthesis systems require a supply of GTP for the formation of translation initiation complexes, with two GTP molecules per amino acid needed as an energy source for a peptide elongation reaction. In order to optimize protein synthesis reactions in a continuous‐flow wheat embryo cell‐free system, we have examined the influence of adding GTP and found that the system does not require any supply of GTP. We report here the preparation of a wheat embryo extract from which endogenous GTP was removed by gel filtration, and the influence of adding GTP to the system on protein synthesis reactions. Using Green Fluorescent Protein (GFP) as a reporter, higher levels of production were observed at lower concentrations of GTP, with the optimal level of production obtained with no supply of GTP. A HPLC‐based analysis of the extract and the translation mixture containing only ATP as an energy source revealed that GTP was not detectable in the extract, however, 35 μM of GTP was found in the translation mixture. This result suggests that GTP could be generated from other compounds, such as GDP and GMP, using ATP. A similar experiment with a C‐terminally truncated form of human protein tyrosine phosphatase 1B (hPTP1B1‐320) gave almost the same result. The wheat embryo cell‐free translation system worked most efficiently without exogenous GTP, producing 3.5 mg/mL of translation mixture over a 48‐h period at 26°C. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献
85.
Protein phosphatase 2C (PP2C) family is characterized by requirement of metal cation for phosphatase activity. We previously
established that PPM1H is a cancer-associated member of the PP2C family. Here we further characterized the phosphatase activity
of PPM1H, focusing on its dependence on metal cation. PPM1H possesses the potential to dephosphorylate p-nitrophenyl phosphate (pNPP), casein and phosphopeptides. Interestingly, PPM1H shows the metal preference that is varied
depending on the substrate (substrate-dependent metal preference); PPM1H prefers Mn2+ when pNPP or phosphopeptides is used as a substrate. Meanwhile, a preference for Mg2+ is displayed by PPM1H with casein as a substrate. When both cations are added to the reaction, the degree of the effect is
always closer to that with Mn2+ alone, irrespective of the substrate. This preponderance of Mn2+ is explained by its greater affinity for PPM1H than Mg2+. From the literature the substrate-dependent metal preference appears to be shared by other PP2Cs. According to the crystal
structure, a binuclear metal center of PP2C plays an important role for coordinating the substrate and nucleophilic waters
in the active site. Therefore, the differences in the size, preferred geometry and coordination requirements between two metals,
in relation to the substrate, may be responsible for this intriguing property. 相似文献
86.
Issei Tsukamoto Hiroyuki Koshio Masaya Orita Chikashi Saitoh Hiroko Yanai-Inamura Chika Kitada-Nozawa Eisaku Yamamoto Takeyuki Yatsu Shuichi Sakamoto Shin-ichi Tsukamoto 《Bioorganic & medicinal chemistry》2009,17(24):8161-8167
A series of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepine-5-ylidene)acetamide derivatives were optimized to achieve potent agonistic activity, both in vitro and in vivo, for the arginine vasopressin V2 receptor, resulting in the eventual discovery of compound 1g. Molecular modeling of compound 1g with V2 receptor was also examined to evaluate the binding mode of this series of compounds. 相似文献
87.
Akihiro Tazumi Yuki Kakinuma Naoaki Misawa John E Moore Beverley C Millar Motoo Matsuda 《BMC microbiology》2009,9(1):256
Background
Identification and characterization of intervening sequences (IVSs) within 23S rRNA genes from Campylobacter organisms including atypical campylobacters were carried out using two PCR primer pairs, designed to generate helix 25 and 45 regions. 相似文献88.
Background
Fungi from environmental samples are typically identified to species level through DNA sequencing of the nuclear ribosomal internal transcribed spacer (ITS) region for use in BLAST-based similarity searches in the International Nucleotide Sequence Databases. These searches are time-consuming and regularly require a significant amount of manual intervention and complementary analyses. We here present software – in the form of an identification pipeline for large sets of fungal ITS sequences – developed to automate the BLAST process and several additional analysis steps. The performance of the pipeline was evaluated on a dataset of 350 ITS sequences from fungi growing as epiphytes on building material. 相似文献89.
Matsumoto N Kohno T Uchida S Shimizu T Kusumoto H Hirose R Yanada K Kurio W Yamaguchi S Watabe K Fujita T 《Bioorganic & medicinal chemistry》2006,14(12):4182-4192
FTY720 (1) is a novel immunosuppressant (immunomodulator), derived from ISP-I (2: myriocin and thermozymocidin). To clarify the pharmacokinetic properties of 1, antibodies against 1 were prepared and a competitive enzyme immunoassay (EIA) was developed. Two kinds of haptens, 3 and 4, for 1 were synthesized and coupled to ovalbumin (OVA). Rabbits were immunized with 3-OVA or 4-OVA, and corresponding antibodies were obtained. Both antibodies recognized the 2-amino-2-(2-phenylethyl)propane-1,3-diol moiety in 1. Using the anti-3-OVA antibody, a competitive EIA for 1 was developed and evaluated. The range of quantification by the EIA was 0.06-10 ng/mL. The application of the EIA has enabled us to measure the FTY720 concentration in serum after oral administration of 1 (1mg/kg) to rats. 相似文献
90.
Harada H Shindo K Iki K Teraoka A Okamoto S Yu F Hattan J Utsumi R Misawa N 《Applied microbiology and biotechnology》2011,90(2):467-476
Tractable plasmids (pAC-Mv-based plasmids) for Escherichia coli were constructed, which carried a mevalonate-utilizing gene cluster, towards an efficient functional analysis of cytochromes
P450 involved in sesquiterpene biosynthesis. They included genes coding for a series of redox partners that transfer the electrons
from NAD(P)H to a P450 protein. The redox partners used were ferredoxin reductases (CamA and NsRED) and ferredoxins (CamB
and NsFER), which are derived from Pseudomonas putida and cyanobacterium Nostoc sp. strain PCC 7120, respectively, as well as three higher-plant NADPH-P450 reductases, the Arabidopsis thaliana ATR2 and two corresponding enzymes derived from ginger (Zingiber officinale), named ZoRED1 and ZoRED2. We also constructed plasmids for functional analysis of two P450s, α-humulene-8-hydroxylase (CYP71BA1)
from shampoo ginger (Zingiber zerumbet) and germacrene A hydroxylase (P450NS; CYP110C1) from Nostoc sp. PCC 7120, and co-transformed E. coli with each of the pAC-Mv-based plasmids. Production levels of 8-hydroxy-α-humulene with recombinant E. coli cells (for CYP71BA1) were 1.5- to 2.3-fold higher than that of a control strain without the mevalonate-pathway genes. Level
of the P450NS product with the combination of NsRED and NsFER was 2.9-fold higher than that of the CamA and CamB. The predominant
product of P450NS was identified as 1,2,3,5,6,7,8,8a-octahydro-6-isopropenyl-4,8a-dimethylnaphth-1-ol with NMR analyses. 相似文献