全文获取类型
收费全文 | 165篇 |
免费 | 11篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 15篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 17篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有176条查询结果,搜索用时 15 毫秒
1.
2.
3.
A rapidly frozen vitrified aqueous suspension of influenza A virus was observed by high resolution electron cryomicroscopy. The influenza particles were grouped into small (diameter < 150 nm) spherical particles with well organized interiors, large spherical ones with less internal organization, and filamentous ones. Envelopes of most of the large virus particles were phospholipid bilayers, and the chromatography fraction containing these large particles was largely devoid of viral activity. The envelopes of most of the filamentous and small spherical virus particles, on the other hand, gave a strange contrast which could be ascribed to a combination of a thin outer lipid monolayer and a 7.2 nm thick protein-containing inner layer. These latter particles represented most of the viral activity in the preparation. Densitometric traces of the near in-focus images confirmed these structural differences. Some viral envelope structures apparently intermediate between these two distinct types of membrane were also detected. A structural model of intact biologically active influenza virus particles was formulated from these results, together with computer simulations. 相似文献
4.
An algal suspension containing protoplasmic detritus [termed, single cell detritus (SCD)] was prepared from freeze-dried fronds
of Ulva and its dietary value to Artemia nauplii was tested after size fractionation. The dissolved fraction (<0.22 μm) ofthe
Ulva suspension contained ca. 48% of theoriginal protein in the Ulva, but had no dietaryvalue to Artemia, which is a suspension
feeder. In contrast, the fraction passing through a 100-μm meshand containing SCD of 2–14 μm in diameter, contributedto the
survival of Artemia. The fraction remaining on the 100 μm mesh was further incubated with and without the bacterium Pseudoalteromonas
espejiana strain AR06 FERM BP-5024. The bacterium degraded
Ulva forming new SCD over 106 mL -1 level as rapidly as by 16 h of incubation. The dietary
value of Ulva for Artemia growth was elevated over four times by the incubation. The protein content of the SCD
was approximately doubled by the attaching of bacteria, suggesting the enhanced Artemia growth is attributable to
the combined effect of the SCD and the bacteria. Development of a hatchery diet from Ulva , a resource with a low
commercial value, is suggested utilizing the degrading and attaching ability of P. espejiana.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
The concept of biological control methods in aquaculture 总被引:10,自引:0,他引:10
Masachika Maeda Kinya Nogami Masaei Kanematsu Kazutsugu Hirayama 《Hydrobiologia》1997,358(1-3):285-290
Microbial techniques of biocontrol using the interaction ofmicroorganisms to repress the growth of deleterious bacteria andviruses were developed. The bacterial strain used in this work alsoimproved the growth of fishes and crustaceans. Using the conceptandprocedures of the biocontrol method described here, the aquacultureproduction became stable and evenincreased. 相似文献
6.
Fine structure of the recB and recC gene region of Escherichia coli 总被引:14,自引:0,他引:14
M Sasaki T Fujiyoshi K Shimada Y Takagi 《Biochemical and biophysical research communications》1982,109(2):414-422
7.
Structure of cloned delta-globin genes from a normal subject and a patient with delta-thalassemia; sequence polymorphisms found in the delta-globin gene region of Japanese individuals. 总被引:3,自引:1,他引:2 下载免费PDF全文
A Kimura E Matsunaga Y Ohta T Fujiyoshi T Matsuo T Nakamura T Imamura T Yanase Y Takagi 《Nucleic acids research》1982,10(19):5725-5732
The delta-globin genes of a normal Japanese and a Japanese patient with homozygous delta-thalassemia were cloned, and the nucleotide sequence of a region including the gene was determined. Comparison of the nucleotide sequences of these two individuals with that of pH delta 1, delta-globin clone from the gene library constructed by Maniatis et al., showed differences in the large intervening sequence (IVS 2), at positions 137, 151, 186, 188, 291, 292 and 540 as one base substitutions, at 339 and 823 as one base additions, at 548 as a one base deletion, and a 9 bp duplication between positions 651 and 659, and differences in the 3'-flanking sequence at 51 and 98 nucleotides 3' to the AATAAA sequence. However, in the region studied, no differences was observed in the nucleotide sequences of the normal subject and the patient with delta-thalassemia. Therefore, these differences may represent polymorphisms of the delta-globin gene present in Japanese individuals. These data suggest that IVS 2 is more divergent than other regions, and that a DNA region(s) other than the globin gene may affect expression of the gene. 相似文献
8.
Mizuki Kobayashi Kenta Watanabe Takehiro Suzuki Naoshi Dohmae Masachika Fujiyoshi Masashi Uchida Takaaki Suzuki Kazuei Igarashi Itsuko Ishii 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2021,1866(1):158809
We have reported that acrolein-conjugated low-density lipoprotein (Acro-LDL) uptake by scavenger receptor class A type 1 (SR-A1) can mediate macrophage foam cell formation. The purpose of this study was to determine which amino acid residues of apoB protein in LDL are conjugated with acrolein. Acro-apoB was prepared by incubation of LDL with acrolein (10 to 60 μM) at 37 °C for 7 days. Identification of acrolein-conjugated amino acid residues in apoB was performed using LC-MS/MS. The levels of acrolein-conjugated amino acid residues of apoB as well as crosslinking apoB increased in proportion to acrolein concentration. The level of LDL uptake by macrophages was parallel with the acrolein-conjugated monomer apoB. Acrolein-conjugated amino acid residues in apoB were C212, K327, K742, K949, K1087, H1923, K2634, K3237 and K3846. The NH2-teriminal four amino acid residues (C212, K327, K742 and K949) were located at the scavenger receptor SR-A1 recognition site, suggesting that these four acrolein-conjugated amino acids are involved in the rapid uptake of Acro-LDL by macrophages. It is proposed that the rapid uptake of LDL by macrophages is dependent on acrolein conjugation of four amino acids residues at the scavenger receptor recognition site of apoB in LDL. 相似文献
9.
Ching-Ju Tsai Kazutoshi Tani Katsumasa Irie Yoko Hiroaki Takushi Shimomura Duncan G. McMillan Gregory M. Cook Gebhard F.X. Schertler Yoshinori Fujiyoshi Xiao-Dan Li 《Journal of molecular biology》2013
Activation and inactivation of voltage-gated sodium channels (Navs) are well studied, yet the molecular mechanisms governing channel gating in the membrane remain unknown. We present two conformations of a Nav from Caldalkalibacillus thermarum reconstituted into lipid bilayers in one crystal at 9 Å resolution based on electron crystallography. Despite a voltage sensor arrangement identical with that in the activated form, we observed two distinct pore domain structures: a prominent form with a relatively open inner gate and a closed inner-gate conformation similar to the first prokaryotic Nav structure. Structural differences, together with mutational and electrophysiological analyses, indicated that widening of the inner gate was dependent on interactions among the S4–S5 linker, the N-terminal part of S5 and its adjoining part in S6, and on interhelical repulsion by a negatively charged C-terminal region subsequent to S6. Our findings suggest that these specific interactions result in two conformational structures. 相似文献
10.
Enzymes participating in glucan synthesis by Streptococcus mutans E49 were separated into two fractions with distinctly different activities by chromatography on DEAE Bio-Gel A. The insoluble glucan (IG) was revealed to be formed by the coupling reaction of these two enzymes, dextransucrase (SGE), which synthesizes soluble glucan from sucrose, and a glucan insolubilizing enzyme (IGE), which forms IG from soluble glucan.Ribocitrin was found to inhibit IG synthesis by inhibiting SGE. 相似文献