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951.
Miguel Martorell Ana Pérez-Vallés Francisco Gozalbo Jose Angel Garcia-Garcia Jair Gutierrez John Gaona 《Diagnostic pathology》2007,2(1):19
Background
Extrapleural Solitary Fibrous tumors (SFTs) have been increasingly reported. The retroperitoneum, deep soft tissues of proximal extremities, abdominal cavity, trunk, head and neck are the most common extraserosal locations reported. Microscopically they show a wide range of morphological features, and so the differential diagnosis is extensive. Immunohistochemically, they commonly express CD34, vimentin, bcl-2 and CD99. Epithelial membrane antigen (EMA) and smooth muscle actin (SMA) may occasionally be expressed. Epithelioid morphology in extrapleural SFT has only very occasionally been described (five cases reported), some of them with biphasic pattern and others with malignant characteristics.Case presentation
A SFT of the thigh with epithelioid areas in a 63 year old woman is reported. Microscopically the tumor showed areas hypo and hipercellular. At the periphery of the hipercellular areas there were nodules composed of epithelioid cells. Immunohistochemically both the spindle and epithelioid cells were positive for CD34, vimentin, bcl-2 and CD99. Epithelial, neural and muscular markers were negative. Molecular study was done and ruled out a synovial sarcoma.Conclusion
Ten cases of SFT of the thigh have been reported but to our knowledge this is the first case with epithelioid morphology affecting the extremities. Identification of this pattern of SFT is of importance, to avoid misdiagnosis with other more aggressive conditions in soft tissue.952.
953.
Peter Nyhuis Tobias Heinen Michael Brieke 《Flexible Services and Manufacturing Journal》2007,19(3):286-307
Objective-oriented factory planning is a prerequisite for the economic operation of a factory. As intensive discussions in the literature as well as practical findings in factories over the years show, transformability and logistics are among the key objectives of a factory. It is striking, however, that both objectives have not so far been related to each other. Based on these findings, a method for evaluating the actual as well as the target transformability of a factory has been developed. It allows the user to assess whether the factory possesses adequate and economic transformability. In order to make the method more manageable for users in practice, a software tool is presented, and a benchmarking has been derived from the data collected by evaluating factory transformability. In addition, it has been found that transformability can influence logistics. A procedure will be presented that allows major means of adjustment to be found that improve the logistics objectives of a factory by using transformability. Finally, the outlook for future developments is discussed. 相似文献
954.
Suzanne de Treville Samuel Bendahan Annelies Vanderhaeghe 《Flexible Services and Manufacturing Journal》2007,19(4):334-357
How firms scan and interpret their environments has implications for the flexibility strategy that they choose, as well as for the performance of that strategy. We extend Daft and Weick’s (Acad Manage Rev 9(2):284–295, 1984) model of firms as interpretation systems into a theoretical model of flexibility performance through extended iterations between observations of a failed flexibility initiative and relevant literature. We test the model using well-known teaching cases. We argue that the use of an iterative process that involves cases and theory both stimulates creativity in integrating theory and lays an initial foundation for evidence-based practice. 相似文献
955.
Mechanistic analysis on the effects of salt concentration and pH on protein adsorption onto a mixed-mode adsorbent with cation ligand 总被引:1,自引:0,他引:1
Gao D Lin DQ Yao SJ 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,859(1):16-23
Streamline Direct HST is a new kind of mixed-mode adsorbent with cation exchange ligand, especially developed for the expanded bed adsorption process, which can capture target protein directly from the moderate ionic strength feedstock without the need of dilution or other additives. In this study, the isotherm adsorption behaviors and the isocratic retention factors of bovine serum albumin (BSA) on Streamline Direct HST were measured, and the corresponding adsorption mechanisms were also described. The results indicated that Streamline Direct HST shows the typical property of salt-independent adsorption and the maximum binding capacity of BSA occurs near the isoelectric point of BSA. When there are some amounts of electrostatic repulsion protein-adsorbent interactions, the multilayer adsorption could be found, and high salt concentration does not favor the adsorption of protein. A patch-controlled adsorption process and an oriented adsorption model are proposed for describing the adsorption behaviors under electrostatic repulsion condition. 相似文献
956.
Abstact Polar organisms should have mechanisms to survive the extremely cold environment. Four genes encoding cold-shock proteins,
which are small, cold-induced bacterial proteins, have been cloned from the Antarctic bacterium Streptomyces sp. AA8321. Since the specific functions of any polar bacterial or Streptomyces cold-shock proteins have not yet been determined, we examined the role of cold-shock protein A from Streptomyces sp. AA8321 (CspASt). Gel filtration chromatography showed that purified CspASt exists as a homodimer under physiological conditions, and gel shift assays showed that it binds to single-stranded, but not
double-stranded, DNA. Overexpression of CspASt in Escherichia coli severely impaired the ability of the host cells to form colonies, and the cells developed an elongated morphology. Incorporation
of a deoxynucleoside analogue, 5-bromo-2′-deoxyuridine, into newly synthesized DNA was also drastically diminished in CspASt-overexpressing cells. These results suggest that CspASt play a role in inhibition of DNA replication during cold-adaptation. 相似文献
957.
The GrpE protein from E. coli is a homodimer with an unusual structure of two long paired α-helices from each monomer interacting in a parallel arrangement
to form a “tail” at the N-terminal end. Using site-directed mutagenesis, we show that there is a key electrostatic interaction
involving R57 (mediated by a water molecule) that provides thermal stability to this “tail” region. The R57A mutant showed
a drop in T
m of 8.5°C and a smaller ΔH
u (unfolding) compared to wild-type for the first unfolding transition, but no significant decrease in dimer stability as shown
through equilibrium analytical ultracentrifugation studies. Another mutant (E94A) at the dimer interface showed a decrease
in ΔH
u but no drop in T
m for the second unfolding transition and a slight increase in dimer stability. 相似文献
958.
The issue of amino acid depth in proteins gives important insights to our understanding of protein’s three-dimensional structure.
There has already been much research done in mathematical and statistical sciences regarding the general definitions, properties
and algorithms describing the particle depth of spatially extended systems. We constructed a method of calculating the amino
acids depths and applied it to a set of 527 protein structures. We propose the introduction of amino acid depth tendency factors
for three-dimensional structures of proteins. The depth tendency factors relate not only to the hydrophobicity indices but
also to the electrostatic charge. We found a relationship between the protein size and the number of residues using the distance
between the deepest residue and surface residues. We made a prediction regarding the number of residues on the surface of
a protein, the deepest amino acid, and the average depth, all of which are fitted well to a linear functional relationship
with the length of the protein. Finally, we have predicted the depths of multiple peptides in protein’s three-dimension structure.
Electronic supplementary material The online version of this article () contains supplementary material, which is available to authorized users. 相似文献
959.
Typical physico-chemical studies of metal binding proteins are usually aimed at determination of the metal binding constant
K for a native protein (K
n), while the significance of the K value for the thermally denatured protein (K
u) is usually underestimated. Meanwhile, metal binding induced shift of thermal denaturation transition of a single site metal
binding protein is defined by K
n to K
u ratio, implying that knowledge of both K values is required for full characterization of the system. In the present work, the most universal approach to the studies
of single site metal binding proteins, namely construction of a protein “phase diagram” in coordinates of free metal ion concentration
– temperature, is considered in detail. The detailed algorithm of construction of the phase diagrams along with underlying
mathematic procedures developed here may be of use for studies of other simple protein-target type systems, where target represents
low molecular weight ligand. Analysis of the simplest protein-ligand system reveals that thermodynamic properties of apo-protein
dictate the maximal possible increase of its affinity to any simple ligand upon thermal denaturation of the protein. Experimental
and general problems coupled with the use of the phase diagrams are discussed. 相似文献
960.
The polypeptides integrating amaranth globulin-p and 11S-globulin were characterized by two-dimensional electrophoresis, ion-exchange
chromatography and RP-HPLC. All polypeptides exhibited charge and hydrophobic heterogeneity. Almost all acid (A, pI 5–7) and
basic (B, pI 9–10) polypeptides were present in both globulins, and the same happened with the unprocessed M polypeptides
with pI in the range of 7–7.5 which fits well with a sequence containing both the A and B polypeptides. There were other polypeptides
only present in 11S-globulin, like some of 41 and 16 kDa, which might come from another precursor or be the products of a
different processing of the propolypeptide. These results suggested that, although amaranth subunits from different subfamilies
are interchangeable in different oligomers, some structural differences between them might affect the assembly of globulin
molecules. Structural differences arising from this behavior could account for the different physicochemical properties of
globulin molecules. 相似文献