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1.
Three germacrane-type sesquiterpenoids, (+)-germacrone-4,5-epoxide, germacrone and (+)-curdione were biotransformed by Aspergillus niger to give hydroxylated guaiane-type sesquiterpenoids together with allylic alcohols and spirolactone. 相似文献
2.
A method is described for the preparation of enriched populations of ciliated cells from rabbit tracheas. Following protease digestion of tracheal lumen tissue, cells were subjected to centrifugal elutriation. This produced two cell fractions of interest: an 8 µm diameter fraction believed to be composed largely of basal cells, and a 15 µm diameter fraction containing a mixture of ciliated cells and Clara cells. Further treatment of the 15 µm cells with a dextran/polyethylene glycol/phosphate buffer system resulted in separation of a highly enriched ciliated cell fraction (84.3 ± 2.7% ciliated cells with 6.5 ± 1.5% Clara cells) from a fraction containing both ciliated cells (42.0 ± 2.1%) and Clara cells (27.0 ± 3.5%). The yield of cells in the enriched ciliated cell fraction was 0.68 ± 0.09 × 106 cells/ trachea. Analysis of mixed-function oxidase activity in tracheal cells showed 7-ethoxycoumarin deethylase and coumarin hydroxylase activities to be present in the 8 µm cells as well as in ciliated cells and Clara cells. Enzyme activities measured in the ciliated cells (152 ± 66 pmol/ min/ mg protein or 51.2 ± 20.5 pmol/ min/ 106 cells for 7-ethoxycoumarin deethylase and 31.7 ± 15.4 pmol/ min/ mg protein or 10.5 ± 4.8 pmol/ min/ 106 cells for coumarin hydroxylase) were not attributable to contamination with Clara cells.Abbreviations CD
cell digest
- DNase
deoxyribonuclease I
- E-1
first elutriator fraction
- E-2
second elutriator fraction
- E-3
third elutriator fraction
- 7-Ec
7-ethoxycoumarin
- FCS
fetal calf serum
- HEPES
N-2-hydroxy-ethylpiperazine-N-2-ethanesulfonic acid
- HpBS
HEPES-buffered salt solution
- NADH
reduced nicotinamide adenine dinucleotide
- NADPH
reduced nicotinamide adenine dinucleotide phosphate
- NBT
nitro blue tetrazolium
- PEG
Carbowax polyethylene glycol 6000 相似文献
3.
Experiments were conducted to assess the ability of Streptomyces (strain PS1/5) to metabolize twelve herbicides representing several different classes including: acetanilides, triazines, ureas, uracils, and imidazoles. Incubations in aqueous culture with dextrin as carbon source and either ammonium or Casamino acids as nitrogen source resulted in transformations (>50%) of eight of the herbicides tested: alachlor, metolachlor, atrazine, prometryne, ametryne, linuron, tebuthiuron, and bromacil; the remaining four herbicides (cyanazine, diuron, metribuzin, and imazapyr) were also transformed, but to a lesser extent. In most instances, biotransformations occurred concurrently with growth and results were consistent regardless of the nitrogen source (ammonium vs. Casamino acids). However, in some instances there were differences in rates of biotransformation as a consequence of the nitrogen source (e.g. alachlor, metribuzin), suggesting the selective induction of certain metabolic enzymes; in other instances biotransformations were not associated with growth, suggesting secondary metabolism. An experiment was also conducted to assess the ability of Streptomyces (strain PS1/5) to metabolize atrazine contaminated soil. Inoculation of soil amended with 20 g/g of atrazine and 5% chitin as carbon source resulted in ca. 78% removal of atrazine within 28 days. These data suggest that Streptomyces species may be potential candidates for soil inoculation to bioremediate herbicide contaminated soils.The U.S. Government's right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
4.
Christoph Theurer Hans-Joachim Treumann Thomas Faust Ursula May Wolfgang Kreis 《Plant Cell, Tissue and Organ Culture》1994,38(2-3):327-335
The glycosylation and deglycosylation of cardiac glycosides was investigated using cell suspension cultures and shoot cultures, both established from Digitalis lanata EHRH. plants, as well as isolated enzymes. Shoots were capable of glucosylating digitoxigenin, evatromonoside, digiproside, glucodigitoxigenin and digitoxin. Suspension cultured Digitalis cells glucosylated all the substrates mentioned but digiproside, whereas the UDP-glucosedependent cardinolide glucosyltransferase isolated from that source did not accept digitoxigenin and digiproside as substrates. It is concluded that at least three different glucosyltransferases are involved in cardiac glycoside formation in Digitalis. Similar experiments carried out with glucosylated cardenolides which were administered to cultured cells, shoots and a cardenolide -glucosidase isolated from young leaves revealed that at least two different glucosidases occur in Digitalis lanata, albeit in different tissues or during different phases of development. The biotransformation of glucoevatromonoside was investigated using unlabelled compound and [14C-glucose]-glucoevatromonoside synthesized enzymatically. After 7 d of incubation almost no radioactivity could be recovered from the cardenolide fraction, indicating that the terminal glucose of glucoevatromonoside was now incorporated into volatile, hydrophilic and insoluble compounds. Since, on the other hand, large amounts of cardenolides were found in the experiments with unlabelled glucoevatromonoside it is assumed that steady state or pool size regulation is achieved by the coordinated action of a cardenolide glucosidase and a glucosyltransferase.Abbreviations Acdox
D-acetyldigitoxose
- dgen
digoxigenin
- dox
D-digitoxose
- dten
digitoxigenin
- dtl
D-digitalose
- fuc
D-fucose
- gten
gitoxigenin
- qun
D-quinovose
- CGH
cardenolide 16-O-glucohydrolase
- DFT
UDP-fucose:digitoxigenin 3-O-fucosyltransferase
- DGT
UDP-glucose:Digitoxin 16-O-glucosyltransferase
- DQT
UDP-quinovose:digitoxigenin 3-O-quinovosyltransferase 相似文献
5.
A D Brabban J Littlechild R Wisdom 《Journal of industrial microbiology & biotechnology》1996,16(1):8-14
Twenty five environmental isolates enriched for their ability to grow onN-acetylphenylalanine as sole carbon source were investigated for their hydrolytic action on (+)-lactam (2-azabicyclo[2.2.1]hept-5-en-3-one). Strain CMC 3060, a mucoidal Gram-negative rod identified as a strain ofPseudomonas fluorescens, produced high levels of (+)lactamase, and was subsequently found to produce two distinct intracellular enantiomer-selective, -lactamases, one for each isomer. The (+)lactamase was produced constitutively whereas the (-lactamase was produced only in the presence of the substrate. The (+)lactamase was stable when stored as a frozen cell paste but unstable as a protein solution, losing activity during purification and storage. This enzyme was highly selective for the (+)lactam and showed no activity against a wide range of similar compounds. By use of rapid purification techniques and the inclusion of protease inhibitors and protein stabilisers, the (+)lactamase was purified to homogeneity by FPLC and found to be a monomer of molecular weight 61000 Da. 相似文献
6.
7.
专一转化人参二醇类皂苷Rb1为Rd的真菌菌株的筛选 总被引:2,自引:1,他引:2
于2009年的7-10月间在辽宁省的桓仁,吉林省的集安、靖宇、抚松等药材产区采集人参及人参根际土壤样品45份。通过真菌分离和培养,共获得真菌菌株105株,经形态学鉴定分属于15属48种。通过活性筛选,得到具有转化人参总皂苷活性的菌株25株,其中菌株SR87和SR105对人参皂苷Rb1具有专一转化活性。通过TLC和HPLC检测,其转化产物为人参皂苷Rd。经形态学鉴定,确定阳性菌株SR87为莫勒接霉Zygorhynchus moelleri,SR105为灰绿犁头霉Absidia glauca。这两株真菌均有较高的转化潜力,可以应用于制备人参皂苷Rd。 相似文献
8.
Biotransformation of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide,a novel potent 5‐HT7 receptor antagonist with antidepressant‐like and anxiolytic properties: In vitro and in silico approach 下载免费PDF全文
Karolina Słoczyńska Katarzyna Wójcik‐Pszczoła Vittorio Canale Paweł Żmudzki Paweł Zajdel Elżbieta Pękala 《Journal of biochemical and molecular toxicology》2018,32(5)
The aim of the study was to investigate the metabolism of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide (PZ‐1150), a novel 5‐HT7 receptor antagonist with antidepressant‐like and anxiolytic properties, by the following three ways: in vitro with microsomes; in vitro employing Cunninghamella echinulata, and in silico using MetaSite. Biotransformation of PZ‐1150 with microsomes resulted in five metabolites, while transformation with C. echinulata afforded two metabolites. In both models, the predominant metabolite occurred due to hydroxylation of benzene ring. In silico data coincide with in vitro experiments, as three MetaSite metabolites matched compounds identified in microsomal samples. In human liver microsomes PZ‐1150 exhibited in vitro half‐life of 64 min, with microsomal intrinsic clearance of 54.1 μL/min/mg and intrinsic clearance of 48.7 mL/min/kg. Therefore, PZ‐1150 is predicted to be a high‐clearance agent. The study demonstrated the applicability of using microsomal model coupled with microbial model to elucidate the metabolic pathways of compounds and comparison with in silico metabolite predictions. 相似文献
9.
Kudo H Ueda H Mochida K Adachi S Hara A Nagasawa H Doi Y Fujimoto S Yamauchi K 《Journal of neurochemistry》1999,72(4):1344-1352
A salmonid olfactory system-specific protein (N24) that has been identified in lacustrine sockeye salmon (Oncorhynchus nerka) was characterized by biochemical and molecular biological techniques. N24 is a homodimer, and the intact molecular mass is estimated as approximately 43.3 kDa by gel filtration. Furthermore, N24 was located only in the cytosolic fraction of the olfactory tissues as determined by subcellular fractionation. cDNA encoding the lacustrine sockeye salmon N24 was isolated and sequenced. This cDNA contained a coding region encoding 216 amino acid residues and the molecular mass of this protein is calculated to be 242,224.77. The protein and nucleotide sequencing demonstrates the existence of a remarkable homology between N24 and glutathione S-transferase (GST; EC 2.5.1.18) class pi enzymes. Northern analysis showed that N24 mRNA with a length of 950 bases is expressed in lacustrine sockeye salmon olfactory epithelium. Olfactory receptor cells showed strong hybridization signals for N24 mRNA in the olfactory epithelium. N24 demonstrated glutathione binding activity in affinity-purified GST column experiments. The present study describes for the first time cDNA cloning of GST in fish olfactory epithelium. 相似文献
10.
《Biocatalysis and Biotransformation》2013,31(4):199-207
AbstractThe fungus Penicillium oxalicum is able to selectively metabolize the 20(S)-protopanaxadiol ginsenosides Rb1, Rb2 and Rc to the bioactive ginsenoside compound K using extracellular glycosidases. In this study, two novel extracellular ginsenoside-hydrolyzing enzymes GH3-1 and GH3-2 were purified and characterized from P. oxalicum culture. Using ginsenosides as substrates, GH3-1 and GH3-2 synergistically catalyzed the hydrolysis of Rb1, Rb2 and Rc to yield the final product Compound K (C-K). The hydrolysis pathways were determined to be: Rb1→Rd→F2→C-K, Rb2→CO→CY→C-K and Rc→Mb→Mc→C-K for GH3-1 and GH3-2, respectively. The two enzymes differ, especially in composition, molecular weight, stability and substrate specificity, from GH1, a glycosidase previously purified from the same fungus. These enzymes could be of interest in glycoside degradation, especially in the production of minor ginsenosides. 相似文献