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91.
Timothy S. Robinson Stephen F. Lincoln Edward R.T. Tiekink 《Inorganica chimica acta》2006,359(5):1413-1420
The newly synthesised metal ion activated molecular receptor [Cd{1,4,7,10-tetrakis((R)-(−)-2-hydroxy-3-phenylpropyl)-1,4,7,10-tetraazacyclododecane}](ClO4)2 (hereafter [CdL](ClO4)2) acts as a molecular receptor for acetonitrile. The receptor was characterised by X-ray crystallography in its metal free form, as its Cd(II) complex with no included molecule, as its Cd(II) complex with an included acetonitrile molecule and, for comparative purposes, as its Zn(II) complex with a partially included acetonitrile molecule. These structural studies demonstrated that the Cd(II) complex is eight-coordinate, with the potential to form a well defined hydrophobic cavity that can contain one acetonitrile molecule through four hydrogen-bonds, whereas the Zn(II) complex is six-coordinate, with a less rigidly constituted binding cavity, such that when solvated by acetonitrile the solvating molecule is retained by only a single hydrogen-bond. 相似文献
92.
Shin-ei Matsumoto Makiko Yamashita Yoshinori Katakura Eri Noguchi Yoshihiro Aiba Akira Ichikawa Kiichiro Teruya Sanetaka Shirahata 《Cytotechnology》2006,52(3):227-233
We previously developed an in vitro immunization (IVI) protocol of human peripheral blood mononuclear cells (PBMC) for generating
antigen-specific human antibodies. In order to clarify whether IVI protocolinduces antigen-specific B cell responses in PBMC,
we analyzed family gene usage and sequence of the variable region gene of immunoglobulin heavy chain (VH gene) of the antibody
produced from the in vitro immunized PBMC. Sequence homology analyses of VH gene demonstrated that a larger repertoire of
B cells can be sensitized with mite-extract than with cholera toxin B subunit and rice allergen. Further, antigen-specific
B cells were efficiently expanded by using CpG oligodeoxynucleotide as adjuvant. These results suggest that appropriate combination
of sensitizing antigen and adjuvant is primarily important for expansion of antigen-specific B cells in IVI protocol. 相似文献
93.
Highly accurate photopyroelectric (PPE) investigation, in the thermal-wave-resonator-cavity configuration, was combined with
gas chromatography (GC), in order to detect adulteration of flax oil by mixing with sunflower oil. It was found that the value
of the thermal diffusivity for the investigated mixtures ranges from 8.07 × 108m2/s (pure sunflower oil) to 10.03 × 108m2/s (pure flax oil) and is directly correlated with the total amount of the polyunsaturated fatty acids from oils composition.
The correlation between the PPE signal and the composition of unadulterated and adulterated vegetable oils confirms the data
obtained previously on fresh and spoiled vegetable oils and suggests that the thermal diffusivity may be a suitable parameter
to detect oils' quality and their early spoilage and adulteration. 相似文献
94.
Clode PL 《Journal of structural biology》2006,155(3):505-511
Charge contrast imaging (CCI) is a dynamic phenomenon recently reported in insulating and semiconducting materials imaged with low vacuum or variable pressure scanning electron microscopes (SEM). Data presented in this paper illustrates that CCI can also be applied to biominerals and biological soft-tissues and that useful and unique structural information can be obtained from routine samples. Various resin-embedded samples were considered and example images from several different biomaterials are presented. Due to the diverse nature of samples that appear to exhibit charge contrast, this imaging technique has prospective application in a wide range of biological and biomedical research. This work represents the first application of CCI to biomaterials and in particular, highlights a new method for investigating the formation, structure and growth of biominerals. 相似文献
95.
The complete nucleotide sequence of the SSU rRNA gene from the soil bug, Armadillidium vulgare (Crustacea, Isopoda), was determined. It is 3214 bp long, with a GC content of 56.3%. It is not only the longest SSU rRNA
gene among Crustacea but also longer than any other SSU rRNA gene except that of the strepsipteran insect, Xenos vesparum (3316 bp). The unusually long sequence of this species is explained by the long sequences of variable regions V4 and V7,
which make up more than half of the total length. RT-PCR analysis of these two regions showed that the long sequences also
exist in the mature rRNA and sequence simplicity analysis revealed the presence of slippage motifs in these two regions. The
putative secondary structure of the rRNA is typical for eukaryotes except for the length and shape variations of the V2, V4,
V7, and V9 regions. Each of the V2, V4, and V7 regions was elongated, while the V9 region was shortened. In V2, two bulges,
located between helix 8 and helix 9 and between helix 9 and helix 10, were elongated. In V4, stem E23-3 was dramatically expanded,
with several small branched stems. In V7, stem 43 was branched and expanded. Comparisons with the unusually long SSU rRNAs
of other organisms imply that the increase in total length of SSU rRNA is due mainly to expansion in the V4 and V7 regions.
Received: 2 March 1999 / Accepted: 22 July 1999 相似文献
96.
Lu D Jimenez X Witte L Zhu Z 《Biochemical and biophysical research communications》2004,318(2):507-513
In recent years a variety of recombinant methods have been developed for efficient production of bispecific antibodies (BsAb) in various formats. Bispecific diabody (bDAb), a 55-60 kDa molecule comprising two non-covalently associated cross-over single chain Fv (scFv) polypeptides, represents one of the most promising as well the most straightforward approaches to BsAb production. Here we constructed a bDAb, using two human scFv, 11F8 and A12, directed against the epidermal growth factor receptor (EGFR) and the insulin-like growth factor receptor (IGFR), respectively, as the building blocks. A total of 8 scFv and diabody constructs were prepared comprising the same two variable heavy (V(H)) and variable light (V(L)) chain domains but arranged in different orientations. V(H)/V(L) orientation, i.e., V(H)-linker-V(L) or V(L)-linker-V(H), showed significant effects on the expression and antigen-binding activity of scFv and monospecific diabody of both 11F8 and A12. Further, only 2 out of the 4 possible V(H)/V(L) orientations/arrangements in bDAb construction yielded active products that retain binding activity to both EGFR and IGFR. Both active bDAb preparations retained their original antigen-binding activity after incubation at 37 degrees C in mouse serum for up to 7 days, indicating excellent stability of the constructs. Taken together, our results underscore the importance of identifying/selecting optimal V(H)/V(L) orientation/arrangement for efficient production of active bDAb. 相似文献
97.
Belov K Hellman L 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2003,136(4):811-819
In this paper, we review data on the monotreme immune system focusing on the characterisation of lymphoid tissue and of antibody responses, as well the recent cloning of immunoglobulin genes. It is now known that monotremes utilise immunoglobulin isotypes that are structurally identical to those found in marsupials and eutherians, but which differ to those found in birds and reptiles. Monotremes utilise IgM, IgG, IgA and IgE. They do not use IgY. Their IgG and IgA constant regions contain three domains plus a hinge region. Preliminary analysis of monotreme heavy chain variable region diversity suggests that the platypus primarily uses a single VH clan, while the short-beaked echidna utilises at least 4 distinct VH families which segregate into all three mammalian VH clans. Phylogenetic analysis of the immunoglobulin heavy chain constant region gene sequences provides strong support for the Theria hypothesis. The constant region of IgM has proven to be a useful marker for estimating the time of divergence of mammalian lineages. 相似文献
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