全文获取类型
收费全文 | 817篇 |
免费 | 41篇 |
出版年
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 16篇 |
2015年 | 20篇 |
2014年 | 13篇 |
2013年 | 49篇 |
2012年 | 46篇 |
2011年 | 50篇 |
2010年 | 34篇 |
2009年 | 41篇 |
2008年 | 50篇 |
2007年 | 47篇 |
2006年 | 47篇 |
2005年 | 51篇 |
2004年 | 53篇 |
2003年 | 71篇 |
2002年 | 67篇 |
2001年 | 9篇 |
2000年 | 17篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 11篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
排序方式: 共有858条查询结果,搜索用时 15 毫秒
131.
Growth of larval and juvenile Diaphus theta (Pisces: Myctophidae) in the transitional waters of the western North Pacific 总被引:1,自引:1,他引:0
Diaphus theta is one of the most common myctophid fish species in the subarctic and transitional waters of the North Pacific. The growth
of larval and juvenile D. theta was investigated using sagittal otolith increment analysis of specimens caught in transitional waters of the western North
Pacific. Samples taken over a 24-h period demonstrated that otoliths exhibited daily growth cycles, allowing accurate determination
of age. Calcification of the incremental zone of otoliths took place only at night, suggesting that the formation cycle of
the increment of juvenile D. theta was different from that of shallow-water fishes and would be related to their diel vertical migration. The relationships
between standard length (SL) and daily growth increment (D) were expressed as linear equations: SL = 2.65 + 0.141D (r
2 = 0.942) for larvae of 5.1–9.6 mm SL and SL = 3.54 + 0.129D (r
2 = 0.933) for juveniles of 13.7–27.6 mm SL. The growth rates were 0.14 mm d−1 in larvae and 0.13 mm d−1 in juveniles; this is slow compared with tropical or subtropical mycto-phid species, in which growth occurs at about twice
these rates. The larval period, including the metamorphic stage, was long compared with species at lower latitudes and was
estimated to be 71 days. The slow growth rate and long period of larval stage of D. theta would be the life history pattern of high-latitudinal species adapted to a low-temperature habitat.
Received: March 23, 2001 / Revised: July 5, 2001 / Accepted: July 19, 2001 相似文献
132.
Kouichi Kawamura Yoshikazu Nagata Hiroyuki Ohtaka Yoshihiko Kanoh Jyun-ichi Kitamura 《Ichthyological Research》2001,48(4):369-378
Comparison of meristic characters (pored lateral line scales, vertebrae, and fin rays), and PCR-RFLP analysis in the D-loop
and ND1 regions of mitochondrial DNA were performed to estimate the genetic diversity in local populations of the Japanese
rosy bitterling, Rhodeus ocellatus kurumeus. In terms of meristic characters, the Fukuoka population was the largest in both range and variance of the number of pored
lateral line scales and vertebrae (abdominal and caudal), and Osaka was the second, whereas the Kagawa population showed the
smallest range and variance in these characters. In PCR-RFLP analysis, 11 haplotypes (3 in Fukuoka, 2 in Okayama, 2 in Kagawa,
and 4 in Osaka) were observed, and nucleotide sequence divergence (NSD) was approximately two times larger in ND1 (mean, 0.61%)
than in D-loop (mean, 0.31%). In the neighbor-joining (NJ) tree, based upon the NSD value in ND1, haplotypes were arranged
into four clades, which corresponded to the locality of each haplotype. The Fukuoka population was conspicuously apart from
the other populations (mean, 0.90% in NSD), but the remaining three showed a similar genetic distance with each other (mean,
0.48%–0.52% in NSD). In haplotype diversity of mtDNA, half the stations in Osaka and all in Kagawa were monomorphic. Especially,
two haplotypes endemic to Kagawa were randomly distributed, irrespective of drainages. Rhodeus o. kurumeus in Fukuoka inhabits small rivers and creeks (open water systems), while that in Kagawa and Osaka lives in small ponds (closed
water systems). Taking the information of morphology, mtDNA, and habitat into consideration, the low genetic diversity in
Kagawa and Osaka populations of R. o. kurumeus is thought to be mainly the result of the isolation of their habitat.
Received: January 14, 2001 / Revised: June 14, 2001 / Accepted: July 1, 2001 相似文献
133.
Satonori Kurashige Kouichi Kitamura Kiyoto Akama Susumu Mitsuhashi 《Microbiology and immunology》1970,14(1):41-47
An immune ribonucleic acid (RNA) preparation was extracted with phenol from the spleens of guinea pigs immunized with diphtheria toxoid. Antibody-carrying cells were detected by immunocyte adhesion as rosette-forming cells. When germ-free rats, conventional guinea pigs or mice were injected intraperitoneally with this preparation, the rosette-formers were detected in either peritoneal exudate cells or spleen cells, whereas serum antibodies were unable to be detected thus far in such animals. Two injections with this preparation did not cause any remarkable increase in the number of rosette-formers, and serum antibody was also not detectable. By contrast, a high titer of serum antibody was demonstrated and the number of rosette-formers increased shortly after an injection of a small amount of diphtheria toxoid into guinea pigs which had previously received an injection with immune RNA. This reaction indicates a secondary response of antibody formation. However, secondary responses were not induced by injections of immune RNA preparations in guinea pigs primed with either diphtheria toxoid or immune RNA preparation. These facts suggest that immune RNA preparations did not contain antigens or fragments thereof and the immune response induced by RNA preparation is not the same as that induced by stimulation by the antigen itself. These results moreover can be accounted for by the notion that the immune RNA preparation is able to induce “memory” cells capable of responding to a secondary stimulus with an antigen and producing a high titer of serum antibody. 相似文献
134.
Ayumi Fujisawa Takaharu Abe Ikuro Ohsawa Kouichi Kamogawa Yoshikazu Izumi 《FEMS microbiology letters》1993,110(1):1-4
Abstract Potassium-limited cultures of Candida utilis grown with ammonium chloride as the sole nitrogen source attained a higher dry weight than similar cultures grown with sodium nitrate as the sole nitrogen source. This increase depended on the extracellular ammonia concentration and was not due to accumulation of storage polymers. We conclude that in this yeast ammonium ions can fulfill to some extent the physiological role of potassium ions and that the intracellular concentration of ammonium ions is predominantly determined by the ammonia concentration in the culture medium. 相似文献
135.
Yusuke Sasaki Toshiyuki Takagi Keisuke Motone Toshiyuki Shibata Kouichi Kuroda 《Bioscience, biotechnology, and biochemistry》2018,82(8):1459-1462
A co-culture platform for bioethanol production from brown macroalgae was developed, consisting of two types of engineered Saccharomyces cerevisiae strains; alginate- and mannitol-assimilating yeast (AM1), and cellulase-displaying yeast (CDY). When the 5% (w/v) brown macroalgae Ecklonia kurome was used as the sole carbon source for this system, 2.1 g/L of ethanol was produced, along with simultaneous consumption of alginate, mannitol, and glucans. 相似文献
136.
Analysis of Vibrio seventh pandemic island II and novel genomic islands in relation to attachment sequences among a wide variety of Vibrio cholerae strains
下载免费PDF全文
![点击此处可从《Microbiology and immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tuan Hai Nguyen Tho Duc Pham Naomi Higa Hanako Iwashita Taichiro Takemura Makoto Ohnishi Kouichi Morita Tetsu Yamashiro 《Microbiology and immunology》2018,62(3):150-157
137.
Kensuke Miyamoto Yuko Mitani Kouichi Soga Junichi Ueda Kazuyuki Wakabayashi Takayuki Hoson Seiichiro Kamisaka Yoshio Masuda 《Physiologia plantarum》1997,101(1):38-44
When white light irradiation inhibits shoot growth in derooted pea ( Pisum sativum L. cv. Alaska) cuttings, it decreases tissue tension, a driving force for shoot growth, by making the cell wall of the inner tissues mechanically rigid. To elucidate the mechanism by which light affects the mechanical properties of the cell wall in the inner tissues, its effect on the chemical properties of the cell walls was studied by analyzing qualitatively and quantitatively cell wall polysaccharides in the epdidermis and inner tissue of pea epicotyls grown in both dark and light. The amount of polysaccharides per subhook in the cell walls of both tissues increased during a 4-h dark incubation. Light suppressed the increase in hemicellulosic (HC)-II and cellulosic polysaccharides in the inner tissues, while it did not affect the increase in other wall fractions in either the epidermal or subepidermal tissues. No light effect was observed on the neutral sugar compositions of pectin, HC-I or HC-II fractions in either of the tissues. Light increased the mass-average molecular mass of xyloglucan and rhamnoarabinogalactan in HC-II fractions in the inner tissues, while such an effect was not observed in the epidermis. These facts suggest that the light-induced decrease in the tissue tension in pea epicotyls is caused by an increase in the molecular size of xyloglucan, rhamnoarabinogalactan in the HC-II fraction and/or the suppression of the synthesis of HC-II and cellulosic polysaccharides in the inner tissues. 相似文献
138.
Kentaro Ooume Kouichi Soga Kazuyuki Wakabayashi Takayuki Hoson 《Biological Sciences in Space》2004,18(3):158-159
Water immersion has been used as a simulator of microgravity for analyzing gravity responses in semiaquatic plants such as rice. To examine whether or not water immersion for a short experimental period is a useful microgravity simulator even in terrestrial plants, we analyzed effects of water immersion on the cell wall rigidity and metabolisms of its constituents in azuki bean epicotyls. The cell wall rigidity of epicotyls grown underwater was significantly lower than that in the control. Water immersion also caused a decrease in molecular mass of xyloglucans as well as the thinning of the cell wall. Such changes in the mechanical and chemical properties of the cell wall underwater were similar to those observed in microgravity conditions in space. These results suggest that water immersion for a short period is a useful system for analyzing gravity resistance responses even in terrestrial plants. 相似文献
139.
Kazuyuki Wakabayashi Kouichi Soga Seiichiro Kamisaka Takayuki Hoson 《Biological Sciences in Space》2003,17(3):228-229
Cell wall structure of wheat coleoptiles grown under continuous hypergravity (300 g) conditions was investigated. Length of coleoptiles exposed to hypergravity for 2-4 days from germination stage was 60-70% of that of 1 g control. The amounts of cell wall polysaccharides substantially increased during the incubation period both in 1 g control and hypergravity-treated coleoptiles. As a results, the levels of cell wall polysaccharides per unit length of coleoptile, which mean the thickness of cell walls, largely increased under hypergravity conditions. The major sugar components of the hemicellulose fraction, a polymer fraction extracted from cell walls with strong alkali, were arabinose (Ara), xylose (Xyl) and glucose (Glc). The molar ratios of Ara and Xyl to Glc in hypergravity-treated coleoptiles were higher than those in control coleoptiles. Furthermore, the fractionation of hemicellulosic polymers into the neutral and acidic polymers by the anion-exchange column showed that the levels of acidic polymers in cell walls of hypergravity-treated coleoptiles were higher than those of control coleoptiles. These results suggest that hypergravity stimuli bias the synthesis of hemicellulosic polysaccharides and increase the proportion of acidic polymers, such as arabinoxylans, in cell walls of wheat coleoptiles. These structural changes in cell walls may contribute to plant resistance to hypergravity stimuli. 相似文献
140.
Yuko Takahashi Shyuichi Ohwada Kouichi Watanabe Yan Ropert-Coudert † Ryoko Zenitani ‡ Yasuhiko Naito § Takahiro Yamaguchi 《Marine Mammal Science》2006,22(4):819-830
The corpora albicantia (CAs) from the ovaries of 39 common dolphins ( Delphinus delphis ) caught in driving fisheries were used, and histologically and immunohistochemically examined. The area of each corpus albicans (CA) and the proportion of that area occupied by elastin were measured using NIH-image software. In all CAs, elastoid material (EM) was apparent although EM area varied in each CA. CAs increased in number with dolphin age. Smaller CAs contained a higher proportion of EM. EM was completely digested by elastase, but not by collagenase. Furthermore, EM was immunostained with anti-α-elastin antibody. These results demonstrated that EM was elastin. The present study is the first to describe the presence of elastin in cetacean CAs. The higher proportion of elastin in small-sized CAs of common dolphins is suggested as the likely cause of the persistence of CA. 相似文献