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411.
Ubiquitous presence of fastidious endophytic bacteria in field shoots and index-negative apparently clean shoot-tip cultures of papaya 总被引:5,自引:0,他引:5
This study establishes the widespread prevalence of fastidious or viable but non-culturable endophytic bacteria in field shoots
and in unsuspicious shoot-tip cultures of papaya (Carica papaya L.) against the norm of asepsis in vitro. A total of 150 shoot-tips (approximately 10 mm) were inoculated on MS-based culture
medium after surface sterilization of field-derived axillary shoots of cv. Surya during November or January (100 and 50, respectively)
when 35–50% cultures showed endophytic microbial growth on culture medium. Indexing of apparently clean cultures using bacteriological
media helped in detecting and removing additional 14–17% stocks with covert bacteria during the first two passages. The rest
of the stocks stayed consistently index-negative during the first eight subculture cycles, but appeared positive in PCR-screening
undertaken thereafter employing universal bacterial 16S rRNA gene primers indicating the association of non-cultivable bacteria.
Direct sequencing of the PCR product yielded overlapping nucleotide data signifying mixed template or the presence of diverse
endophytic microorganisms. This was confirmed by light microscopy of tissue sap revealing viable bacteria in considerable
numbers, which were detected under phase contrast or with negative staining. Planting tissue segments or applying homogenate
from these stocks on diverse bacteriological media did not induce the organisms to grow in vitro. The shoot cultures displayed
variation in growth and rooting potential, the onus of such variation was solely attributable to the associated microorganisms.
The findings were confirmed with additional field shoots and fresh in vitro stocks established subsequently. The observations
have implications in micropropagation and all other applications involving plant cell, tissue, organ, and protoplast culture. 相似文献
412.
413.
Khodayar Mohammad Javad Kalantari Heibatullah Khorsandi Layasadat Ahangar Nematollah Samimi Azin Alidadi Hadis 《Molecular biology reports》2021,48(5):4153-4162
Molecular Biology Reports - Valproic acid (VPA) is known as a common drug in seizure and bipolar disorders treatment. Hepatotoxicity is the most important complication of VPA. Taurine (Tau), an... 相似文献
414.
To explore whether glutathione regulates diapause determination and termina tion in the bivoltine silkworm Bombyx mori, we monitored the changes in glutathione redox cycle in the ovary of both diapanse and nondiapauseegg producers, as well as those in dia pause eggs incubated at different temperatures. The activity ofthioredoxin reductase (TrxR) was detected in ovaries but not in eggs, while neither ovaries nor eggs showed activity of glutathione peroxidase. A lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratio was observed in the ovary of diapauseegg producers, due to weaker reduction of oxidized glutathione (GSSG) to the reduced glutathione (GSH) catalyzed by glutathione reductase (GR) and TrxR. This indicates an oxidative shift in the glutathione redox cy cle during diapause determination. Compared with the 25℃treated diapause eggs, the 5℃treated diapause eggs showed lower GSH/GSSG ratio, a result of stronger oxidation of GSH catalyzed by thioredoxin peroxidase and weaker reduction of GSSG catalyzed by GR. Our study demonstrated the important regulatory role of glutathione in diapause determination and termination of the bivoltine silkworm. 相似文献
415.
Jean-Michel Terme Lluís Millán-Ariño Regina Mayor Neus Luque Andrea Izquierdo-Bouldstridge Alberto Bustillos Cristina Sampaio Jordi Canes Isaura Font Núria Sima Mónica Sancho Laura Torrente Sonia Forcales Alicia Roque Pere Suau Albert Jordan 《FEBS letters》2014
In mammals, the linker histone H1, involved in DNA packaging into chromatin, is represented by a family of variants. H1 tails undergo post-translational modifications (PTMs) that can be detected by mass spectrometry. We developed antibodies to analyze several of these as yet unexplored PTMs including the combination of H1.4 K26 acetylation or trimethylation and S27 phosphorylation. H1.2-T165 phosphorylation was detected at S and G2/M phases of the cell cycle and was dispensable for chromatin binding and cell proliferation; while the H1.4-K26 residue was essential for proper cell cycle progression. We conclude that histone H1 PTMs are dynamic over the cell cycle and that the recognition of modified lysines may be affected by phosphorylation of adjacent residues. 相似文献
416.
Hassan Hosseini Monfared Joaquin Sanchiz Zahra Kalantari 《Inorganica chimica acta》2009,362(10):3791-3886
The in-situ formed hydrazone Schiff base ligand (E)-N′-(2-oxy-3-methoxybenzylidene)benzohydrazide (L2−) reacts with copper(II) acetate to a tetranuclear open cubane [Cu(L)]4 complex which crystallizes as two symmetry-independent (Z′ = 2) S4-symmetrical molecules in different twofold special positions with a homodromic water tetramer. The two independent (A and B) open- or pseudo-cubanes with Cu4O4 cores of 4 + 2 class (Ruiz classification) each have three different magnetic exchange pathways leading to an overall antiferromagnetic coupling with J1B = J2B = −17.2 cm−1, J1A = −36.7 cm−1, J2A = −159 cm−1, J3A = J3B = 33.5 cm−1, g = 2.40 and ρ = 0.0687. The magnetic properties have been analysed using the H = −Σi,jJij(SiSj) spin Hamiltonian. 相似文献
417.
MOTIVATION: High-throughput technologies for rapid measurement of vast numbers of biological variables offer the potential for highly discriminatory diagnosis and prognosis; however, high dimensionality together with small samples creates the need for feature selection, while at the same time making feature-selection algorithms less reliable. Feature selection must typically be carried out from among thousands of gene-expression features and in the context of a small sample (small number of microarrays). Two basic questions arise: (1) Can one expect feature selection to yield a feature set whose error is close to that of an optimal feature set? (2) If a good feature set is not found, should it be expected that good feature sets do not exist? RESULTS: The two questions translate quantitatively into questions concerning conditional expectation. (1) Given the error of an optimal feature set, what is the conditionally expected error of the selected feature set? (2) Given the error of the selected feature set, what is the conditionally expected error of the optimal feature set? We address these questions using three classification rules (linear discriminant analysis, linear support vector machine and k-nearest-neighbor classification) and feature selection via sequential floating forward search and the t-test. We consider three feature-label models and patient data from a study concerning survival prognosis for breast cancer. With regard to the two focus questions, there is similarity across all experiments: (1) One cannot expect to find a feature set whose error is close to optimal, and (2) the inability to find a good feature set should not lead to the conclusion that good feature sets do not exist. In practice, the latter conclusion may be more immediately relevant, since when faced with the common occurrence that a feature set discovered from the data does not give satisfactory results, the experimenter can draw no conclusions regarding the existence or nonexistence of suitable feature sets. AVAILABILITY: http://ee.tamu.edu/~edward/feature_regression/ 相似文献
418.
Lipid droplets are discrete organelles present in most cell types and organisms including bacteria, yeast, plants, insects and animals. Long considered as passive storage deposits, recent cell biology, proteomic and lipidomic analysis show that lipid droplets are dynamic organelles involved in multiple cellular functions. They have a central function in lipid distribution to different membrane-bound organelles and serve not only as main reservoirs of neutral lipids such as triglycerides and cholesterol but in addition, contain structural proteins, proteins involved in lipid synthesis and transmembrane proteins. A detailed model for how transmembrane proteins such as SNARE proteins can exist in lipid droplets is proposed. 相似文献
419.
Endothelial transcytosis in health and disease 总被引:1,自引:0,他引:1
The visionaries predicted the existence of transcytosis in endothelial cells; the cell biologists deciphered its mechanisms
and (in part) the molecules involved in the process; the cell pathologists unravelled the presence of defective transcytosis
in some diseases. The optimistic perspective is that transcytosis, in general, and receptor-mediated transcytosis, in particular,
will be greatly exploited in order to target drugs and genes to exclusive sites in and on endothelial cells (EC) or underlying
cells. The current recognition that plasmalemmal vesicles (caveolae) are the vehicles involved in EC transcytosis has moved
through various phases from intial considerations of caveolae as unmovable sessile non-functional plasmalemma invaginations
to the present identification of a multitude of molecules and a crowd of functions associated with these ubiquitous structures
of endothelial and epithelial cells. Further understanding of the molecular machinery that precisely guides caveolae through
the cells so as to reach the target membrane (fission, docking, and fusion), to avoid lysosomes, or on the contrary, to reach
the lysosomes, and discharge the cargo molecules will assist in the design of pathways that, by manipulating the physiological
route of caveolae, will carry molecules of choice (drugs, genes) at controlled concentrations to precise destinations. 相似文献
420.
Jeannine D. Rinderknecht Simone M. Goldinger Sima Rozati Jivko Kamarashev Katrin Kerl Lars E. French Reinhard Dummer Benedetta Belloni 《PloS one》2013,8(3)