全文获取类型
收费全文 | 235篇 |
免费 | 16篇 |
专业分类
251篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 15篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 14篇 |
2014年 | 13篇 |
2013年 | 26篇 |
2012年 | 21篇 |
2011年 | 22篇 |
2010年 | 12篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 13篇 |
2003年 | 3篇 |
2002年 | 8篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1976年 | 1篇 |
1970年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有251条查询结果,搜索用时 15 毫秒
1.
Bile acid metabolism in partially hepatectomized rats 总被引:2,自引:0,他引:2
The bile flow and the bile acid secretion, calculated on liver weight basis, increased 12 H and 24 H after 60-70% hepatectomy and returned to the initial levels thereafter. The biliary phospholipid secretion much more increased than bile acids, but the cholesterol secretion decreased. Bile acid composition changed with an increase of the cholic acid group and a decrease of the chenodeoxycholic acid group in both bile and feces. These changes almost disappeared on Day 14. The pool size of bile acid decreased maximally on Day 4 to about 40% of the initial, but the distribution of bile acids in the enterohepatic circulation was not changed. The fecal cholesterol and coprostanol markedly decreased on Day 2 but gradually returned to the initial levels according to the recovery of diet intake. The fecal bile acids decreased on Day 2, increased on Day 4, and returned to the normal range after Day 7. In conclusion, the regenerating liver secretes more bile, bile acids and phospholipids, and less cholesterol than the normal liver. Cholic acid predominates in the bile acids. These changes restored to the initial levels by about one week after the operation. 相似文献
2.
Isamu Yamaguchi Kotaro Takagi Tomomasa Misato 《Bioscience, biotechnology, and biochemistry》2013,77(10):1719-1727
The sites for degradation of blasticidin S was investigated using radioactive compounds which were biosynthetically prepared by a blasticidin S producing organism, St. griseochromogenes.The antibiotic sprayed was located on the surface of the rice plant and little was diffused or transported into the tissue. From the wound or infected part, however, the compound was incorporated and translocated mainly to upper part. In the plant the antibiotic was decomposed at a slow rate, and a small amount of cytomycin and trace of deaminohydroxyblasticidin S were observed as the products. The compound located at the plant surface was efficiently decomposed by sunlight.A considerable quantity of blasticidin S sprayed fell to the ground and was adsorbed on the soil surface tightly. Microbes such as Pseudomonas marginalis, Ps. ovalis and Fusarium oxysporum, which are usually present in the paddy field, decreased the biological activity of blasticidin S. Especially a fungal strain isolated from soil showed marked inactivation of blasticidin S by converting the antibiotic to deaminohydroxyblasticidin S mainly. 相似文献
3.
Eri Akita Yaxiaer Yalikun Kazunori Okano Yuki Yamasaki Misato Ohtani Yo Tanaka Taku Demura Yoichiroh Hosokawa 《Plant Biotechnology》2020,37(4):417
Atomic force microscopy (AFM) can measure the mechanical properties of plant tissue at the cellular level, but for in situ observations, the sample must be held in place on a rigid support and it is difficult to obtain accurate data for living plants without inhibiting their growth. To investigate the dynamics of root cell stiffness during seedling growth, we circumvented these problems by using an array of glass micropillars as a support to hold an Arabidopsis thaliana root for AFM measurements without inhibiting root growth. The root elongated in the gaps between the pillars and was supported by the pillars. The AFM cantilever could contact the root for repeated measurements over the course of root growth. The elasticity of the root epidermal cells was used as an index of the stiffness. By contrast, we were not able to reliably observe roots on a smooth glass substrate because it was difficult to retain contact between the root and the cantilever without the support of the pillars. Using adhesive to fix the root on the smooth glass plane overcame this issue, but prevented root growth. The glass micropillar support allowed reproducible measurement of the spatial and temporal changes in root cell elasticity, making it possible to perform detailed AFM observations of the dynamics of root cell stiffness. 相似文献
4.
Masaki Setoguchi Shin Iimura Yuuichi Sugimoto Yoshiyuki Yoneda Jun Chiba Toshiyuki Watanabe Fumihito Muro Yutaka Iigo Gensuke Takayama Mika Yokoyama Tomoe Taira Misato Aonuma Tohru Takashi Atsushi Nakayama Nobuo Machinaga 《Bioorganic & medicinal chemistry》2013,21(1):42-61
We have carried out the optimization of substituents at the C-3 or the C-5 position on the pyrrolidine ring of VLA-4 antagonist 3 with 2-(phenylamino)-7-fluorobenzoxazolyl moiety for the purpose of improving in vivo efficacy while maintaining good aqueous solubility. As a result, we successfully increased in vitro activity in the presence of 3% human serum albumin and achieved an exquisite lipophilic and hydrophilic balance of compounds suitable for oral administrative regimen. The modification resulted in the identification of zwitterionic compound 7n with (5S)-[methoxy(methyl)amino]methylpyrrolidine, which significantly alleviated bronchial hyper-responsiveness to acetylcholine chloride at 12.5 mg/kg, p.o. in a murine asthma model and showed favorable aqueous solubility (JP1, 89 μg/mL; JP2, 462 μg/mL). Furthermore, this compound showed good oral bioavailability (F = 54%) in monkeys. 相似文献
5.
Taizo Maeda Hiroshi Abe Kazuo Kakiki Tomomasa Misato 《Bioscience, biotechnology, and biochemistry》2013,77(5):700-709
Studies were conducted on the influence of Kitazin analogues on the incorporation of 14C-glucosamine into the mycelial cell wall fraction of Pyricularia oryzae. Compounds of thiolates and phosphates, both having in vitro inhibitory activities toward the mycelial growth, inhibited the incorporation, whereas those of thionates and dithioates, either having no fungitoxicity, did not inhibit the incorporation. Mycelia of P. oryzae treated with Kitazin-P (S-benzyl O,O′-diisopropyl phosphrothioate; IBP) accumulated about twice as much an amino sugar derivative as untreated ones. Mycelia treated with thiono or dithio analogues, which have no fungitoxicity, showed no accumulation. The accumulated substance gave a identical spot with authentic UDP-N-acetyl glucosamine on paper chromatograms developed with four solvent systems. 相似文献
6.
Masahiro Hori Kazuo Kakiki Saburo Suzuki Tomomasa Misato 《Bioscience, biotechnology, and biochemistry》2013,77(8):1280-1291
(1) Chitin-UDP acetylglucosaminyltransferase (E.C. 2.4.1.16., chitin synthetase) in the cell-free system from phytopathogenic fungus Piricularia oryzae, and effects of various polyoxins and related compounds on the enzyme activity were studied. Polyoxins A~M, polyoxin A derivatives, polyoxin C derivatives, 5′-amino-5′-deoxyuridine, uridine and thymidine inhibited equally the incorporation of N-acetylglucosamine (GlcNAc) from UDP-N-acetylglucosamine (UDP-GlcNAc) into chitin. (2) Competition between the above inhibitors and UDP-GlcNAc was observed by kinetic studies. The Km for UDP-GlcNAc was determined to be 3.3 × 10?3 m and the Ki values for polyoxins A~M, except polyoxin C, were found to be in the range of 3.3 × 10?5 m to 3.4 × 10?6 m. For polyoxin C, 5′-amino-5′-deoxyuridine and uridine, the Ki values of 2.7 × 10?3 m, 8.0 × 10?3 m and 3.0 × 10?3 m were given, respectively. The inhibitor constants for other related compounds were also calculated. (3) The values of binding affinity, ?ΔG, for formation of substrate- or inhibitor-enzyme complexes were calculated from the Km or Ki values. In addition, partial binding affinities, ?Δg, for certain moieties or groups of polyoxins were estimated from the ?ΔG. For instance, the ?ΔG values for UDP-GlcNAc and polyoxin L were 5.7 kcal/mole and 9.2 kcal/mole, respectively. And the ?Δg values for the nucleoside moiety (part I), the carbamylpolyoxamic acid moiety (part II) and the carboxyl group at C5′ position of polyoxin L were 5.2, 3.5 and 0.7 kcal/mole, respectively. (4) From the results obtained, the mechanism of action and relation between chemical structure and competitive inhibition of chitin synthetase were discussed. 相似文献
7.
Blasticidin S deaminase (EC 3.5.4.23) was purified by affinity chromatography using a column of Sepharose 4B coupled with pyrimidinoblasticidin S as a ligand. The Michaelis constant Km and the maximum velocity Fmax varied with pH, which suggests that enzyme ionization is important either for substrate binding or for catalytic activity. The inflection point at pH 8.6 ~ 8.9 in the plot of pKm versus pH was attributed to an enzyme amino group which corresponded to the carboxyl group of substrates, and an inflection at pH 5.3 in the log Vmax-pH plot was assigned to the imidazole group of histidine, which appeared to be critical for catalytic deaminohydroxylation. The binding of substrates by the enzyme was inferred to be promoted thermodynamically, and activation of the substrate-enzyme complex was presumed to proceed endothermically. From the results obtained, a hypothetical mode of reaction for blasticidin S deaminase is proposed. 相似文献
8.
Masahiro Hori Kazuo Kakiki Tomomasa Misato 《Bioscience, biotechnology, and biochemistry》2013,77(4):691-698
As a part of studies on the mechanism of action of antibiotics polyoxins, effects of various N-aminoacyl derivatives of polyoxin C and other polyoxins on chitin-UDP acetylglucosaminyl-transferase (EC 2.4.1.16, chitin synthetase) prepared from phytopathogenic fungus Piricularia oryzae were investigated. It was found that they inhibited the enzyme in competition with the substrate UDP-N-acetylglucosamine, Inhibitor constants, Ki, for these polyoxins were determined and the values of binding affinity, ?ΔGbind of the inhibitors to the enzyme were calculated from the Ki values. In addition, by using these ?ΔGbind values the values of partial binding affinity, ?Δg for the several atoms and atomic groups or the several moieties contained in the polyoxin J molecule were estimated. From the results obtained, it was concluded that the carbamoylpolyoxamic acid moiety of polyoxins helps to stabilize the polyoxin-enzyme complex through the contributions of its oxygen atom at C?1″, amino group at C?2″, hydroxyl groups at C?3″ and C?4″, aliphatic carbon chain and terminal carbamoyloxy group.The results obtained by the kinetic investigation using various nucleotides and nucleotide sugars suggested that there was a specific binding site on the enzyme corresponding to the uridine moiety of UDP-N-acetylglucosamine, and that the pyrimidine nucleoside moiety of polyoxins was also bound to this site. 相似文献
9.
10.
Quantitative and antioxidative behavior of Trolox in rats’ blood and brain by HPLC‐UV and SMFIA‐CL methods
下载免费PDF全文
![点击此处可从《Luminescence》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mitsuhiro Wada Misato Wada Rie Ikeda Yuki Fuchigami Hironari Koyama Susumu Ohkawara Shigeru Kawakami Naotaka Kuroda Kenichiro Nakashima 《Luminescence》2016,31(2):414-418
Trolox, a water‐soluble vitamin E analogue has been used as a positive control in Trolox equivalent antioxidant capacity and oxygen radical antioxidant capacity assays due to its high antioxidative effect. In this study, the ex vivo antioxidative effects of Trolox and its concentration in blood and brain microdialysates from rat after administration were evaluated by newly established semi‐microflow injection analysis, chemiluminescence detection and HPLC‐UV. In the administration test, the antioxidative effect of Trolox in blood and brain microdialysates after a single administration of 200 mg/kg of Trolox to rats could be monitored. The antioxidative effects in blood (12.0 ± 2.1) and brain (8.4 ± 2.1, × 103 antioxidative effect % × min) also increased. Additionally, the areas under the curve (AUC)s0–360 (n = 3) for blood and brain calculated with quantitative data were 10.5 ± 1.2 and 9.7 ± 2.5 mg/mL × min, respectively. This result indicates that Trolox transferability through the blood–brain barrier is high. The increase in the antioxidative effects caused by Trolox in the blood and brain could be confirmed because good correlations between concentration and antioxidative effects (r ≥ 0.702) were obtained. The fact that Trolox can produce an antioxidative effect in rat brain was clarified. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献