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71.
Keiji Tsusaki Hikaru Watanabe Tomoyuki Nishimoto Takuo Yamamoto Michio Kubota Hiroto Chaen Shigeharu Fukuda 《Carbohydrate research》2009,344(16):2151-2156
The bacterial strain PP710, isolated from soil and identified as Paenibacillus species, produced a low-digestibility α-glucan containing a large amylase-resistant portion. This α-glucan was obtained in high yields from maltodextrin (dextrose equivalent 3) by using the condensed culture supernatant of the strain as the enzyme preparation. The water-soluble dietary fiber content of the low-digestibility α-glucan was 80.2%, and showed resistance to a rat intestinal enzyme preparation. The α-glucan was found to be a novel highly branched α-glucan by acid hydrolysis, NMR analysis, gel permeation chromatography, methylation analysis, and enzymatic digestion. 相似文献
72.
Mikihiro Shinohara Shigeharu Kinoshita Enkong Tang Daisuke Funabara Makoto Kakinuma Kaoru Maeyama Kiyohito Nagai Masahiko Awaji Shugo Watabe Shuichi Asakawa 《Marine biotechnology (New York, N.Y.)》2018,20(5):594-602
Color is one of the most important factors determining the commercial value of pearls. Pinctada fucata is a well-known pearl oyster producing high-quality Akoya pearls. Phenotypic variation in amount of yellow pigmentation produces white and yellowish pearls. It has been reported that polymorphism of yellow pigmentation of Akoya pearls is genetically regulated, but the responsible gene(s) has remained unknown. Here, we prepared pearl sac pairs formed in the same recipient oyster but coming from donor oysters that differ in their color. These two pearl sacs produced pearls with different yellowness even in the same recipient oyster. Yellow tone of produced pearls was consistent with shell nacre color of donor oysters from which mantle grafts were prepared, indicating that donor oysters strongly contribute to the yellow coloration of Akoya pearls. We also conducted comparative RNA-seq analysis and retrieved several candidate genes involved in the pearl coloration. Whole gene expression patterns of pair sacs were not grouped by pearl color they produced, but grouped by recipient oysters in which they were grown, suggesting that the number of genes involved in the yellow coloration is quite small, and that recipient oyster affects gene expression of the majority of genes in the pearl sac. 相似文献
73.
Nobuo Moriyama Shigeharu Kurimoto Shigeo Horie Kimio Nasu Teruo Tanaka Kenichi Yano Hiroshi Hirano Gozo Tsujimoto Kazuki Kawabe 《The Histochemical journal》1996,28(4):283-288
Summary Adrenergic stimulation induces contraction of hypertrophied prostatic tissue via the α1 adrenoceptor, and the results of pharmacological studies suggested the existence of adrenoceptor subtypes. Recently three
subtypes (α1a, α1b, and α1d) were cloned. Using probes for these subtypes, we demonstrated their expression in the tissues of ten cases of benign prostatic
hypertrophy, usingin situ hybridization. To determine the ratio between these subtypes, an RNase protection assay was also performed in three cases.
Expression of the α1a and α1d adrenoceptors was diffuse in the smooth muscles of the interstitium, but was absent in glandular epithelial cells. On the
contrary, the α1b adrenoceptor was hardly detectable. The RNase protection assay confirmed the absence of the α1b adrenoceptor, the ratio of α1a and α1d being 4∶1. These results supported the idea that the differences in prostatic contractile response to several adrenergic
drugs are based on the affinities of these drugs for the different subtypes. 相似文献
74.
Summary The ability of the vitelline and fertilization envelopes of rainbow trout eggs to trap toxins was investigated using cholera enterotoxin B and staphylococcal enterotoxin B in cytochemical or immunocytochemical experiments. Extracts from both envelopes were investigated by immunoblot analysis to identify toxin-binding proteins after SDS-PAGE. Binding studies of cholera enterotoxin B to vitelline envelopes and fertilization envelopes revealed a greater reactive intensity in the former. Treatment with neuraminidase enhanced the reactive intensity (or deposit) in the vitelline envelope and fertilization envelope outermost layers, with more conspicuous reactivity in the former. Cytochemical experiments showed that exogenous ganglioside GM1 considerably enhanced cholera enterotoxin B binding to vitelline and fertilization envelopes. This enhancement was shown by an intense reactivity following the occurrence of new binding sites on the vitelline envelope inner surface and the inner wall of the zona radiata, a simultaneous extreme reduction in the reactivity of the vitelline envelope outermost layer, and a striking increase in reactive products in the fertilization envelope outermost layer. The surface region of the vitelline or fertilization envelope outermost layer was the binding site for staphylococcal enterotoxin B, and neuraminidase treatment caused a considerable reduction of reactive products in these areas. Immunoblot analysis of cholera enterotoxin Bor staphylococcal enterotoxin B-binding substances in extracts from the vitelline envelopes or fertilization envelopes demonstrated that the great majority of the binding substances are glycoproteins. The present results suggest that glycoproteins constituting the vitelline envelope or fertilization envelope may contribute to the protection of the egg itself or the embryo by trapping noxious toxins. 相似文献
75.
The binding of antibiotics (gentamicin, oleandomycin and chloramphenicol) to vitelline and fertilization envelopes and their
extracts was investigated by immunohistochemical and immunocytochemical techniques and immunoblot analysis using mature and
artificially activated eggs of the fish Oncorhynchus masou. Binding of antibiotics was detected in the vitelline and fertilization
envelope outermost layers, the fertilization envelope inner surface and cortical alveolus exudates, with differences in immunoreactive
intensity and deposition. The fertilization envelope outermost layer had the capacity to bind much greater amounts of the
antibiotics than the vitelline envelope outermost layer. The greater capacity was caused by the deposition of cortical alveolus
exudates, which were known to be responsible for functional roles of protection against bacteria, fungi and noxious materials.
Treatment of the vitelline and fertilization envelopes with neuraminidase markedly reduced the binding of gentamicin and chloramphenicol
but slightly increased that of oleandomycin; binding of the latter to the vitelline and fertilization envelope outermost layers
was considerably reduced after treatment with alpha-fucosidase. Treatment of the two envelopes with alpha-mannosidase, beta-galactosidase
or beta-SdD-glucosaminidase did not cause any alteration in immunoreactive intensity or number of immunoreactive deposits.
Immunoblot analysis of the vitelline or fertilization envelope extracts indicated that many of the antibiotic-binding substances
were glycoproteins, and several major bands were bound by all three antibiotics. These results suggest that the vitelline
or fertilization envelopes may have the ability to protect the egg itself, or the embryo, respectively, by trapping antibiotics,
and the trapping may be related to the presence of carbohydrate moieties, such as sialyl or fucosyl residues.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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79.
M Fukumoto D Kudou S Murano T Shiba D Sato T Tamura S Harada K Inagaki 《Bioscience, biotechnology, and biochemistry》2012,76(7):1275-1284
Cys116, Lys240*, and Asp241* (asterisks indicate residues from the second subunit of the active dimer) at the active site of L-methionine γ-lyase of Pseudomonas putida (MGL_Pp) are highly conserved among heterologous MGLs. In a previous study, we found that substitution of Cys116 for His led to a drastic increase in activity toward L-cysteine and a decrease in that toward L-methionine. In this study, we examined some properties of the C116H mutant by kinetic analysis and 3D structural analysis. We assumed that substitution of Cys116 for His broke the original hydrogen-bond network and that this induced a significant effect of Tyr114 as a general acid catalyst, possibly due to the narrow space in the active site. The C116H mutant acquired a novel β-elimination activity and lead a drastic conformation change in the histidine residue at position 116 by binding the substrate, suggesting that this His residue affects the reaction specificity of C116H. Furthermore, we suggest that Lys240* is important for substrate recognition and structural stability and that Asp241* is also involved in substrate specificity in the elimination reaction. Based on this, we suggest that the hydrogen-bond network among Cys116, Lys240*, and Asp241* contributes to substrate specificity that is, to L-methionine recognition at the active site in MGL_Pp. 相似文献
80.
Watanabe H Nishimoto T Sonoda T Kubota M Chaen H Fukuda S 《Carbohydrate research》2006,341(8):957-963
A bacterial strain AM7, isolated from soil and identified as Bacillus circulans, produced two kinds of novel cyclic oligosaccharides. The cyclic oligosaccharides were produced from amylose using a culture supernatant of the strain as the enzyme preparation. The major product was a cyclomaltopentaose cyclized by an alpha-(1-->6)-linkage, cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}. The other minor product was cyclomaltohexaose cyclized by an alpha-(1-->6)-linkage, cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}. We propose the names isocyclomaltopentaose (ICG5) and isocyclomaltohexaose (ICG6) for these novel cyclic maltooligosaccharides having one alpha-(1-->6)-linkage. ICG5 was digested by alpha-amylase derived from Aspergillus oryzae, cyclomaltodextrin glucanotransferase (CGTase) from Bacillus stearothermophilus, and maltogenic alpha-amylase. On the other hand, ICG6 was digested by CGTase from B. stearothermophilus and B. circulans, and maltogenic alpha-amylase. This is the first report of enzymatically produced cyclomaltopentaose and cyclomaltohexaose, which have an alpha-(1-->6)-linkage in their molecules. 相似文献