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91.
Investigations carried out in a coastal stream flowing to the Northern Bothnian Sea (Ängerån, 63°35'N, 19°50'E) have shown a high drift rate of mayfly nymphs towards the coastal areas. The nymphal development takes place in the estuaries with low salinity (conductivity between 47 and 9800 μS; salinity between 0 and 4–5%0). After the emergence (May/June) the adults fly from the coastal areas to lay their eggs in the stream biotope in the Ängerån. There thus appears to be a colonization cycle between the coastal stream and adjacent coastal areas. The migration movements of downstream drift and the compensatory upstream directed flight are interpreted as asurvival strategy of the species concerned.  相似文献   
92.
Hypoxia is an important factor in the macrophages microenvironment. Many physiological and pathological processes including solid tumor development are characterized by both low oxygen content and presence of macrophages. Tumor-associated hypoxia causes alternative polarization of macrophages in tumor tissue and transformation of these cells into the allies of a malignant neoplasm. The aim of the work was to investigate the effect of NSC631570, a cancer-selective drug that is known to selectively accumulate in the tumor tissue, on hypoxic macrophage function. Murine peritoneal macrophages (PMs) were subjected to hypoxia (3% O2). Nitrite level was assayed by the Griess reaction. Arginase activity was measured by colorimetric method. ROS generation and phagocytosis was estimated by flow cytometry. O 2 ? generation was assayed by the NBT reduction method. HMGB1 expression was determined by ELISA. 42 h hypoxia caused alternative polarization of murine PMs with significant arginase prevalence. NSC631570 repolarized arginine metabolism of hypoxic macrophages to NOS dominant and activated their pro-inflammatory functions: recovered ROS production and increased alarmin release. Thus, NSC631570 can restore pro-inflammatory functions of macrophages, alternatively polarized by hypoxia.  相似文献   
93.
The results of establishing an in vitro culture, plantlet regeneration, and rooting of Camelina sativa cultivar Peremozhets and cultivar Mirazh are presented. The effective concentrations of sterilizing agents and the duration of plant material treatment were estimated. The phytohormone ratio, the sucrose concentration in the nutrient medium that induced the effective formation of C. sativa shoots, and the NAA concentration for plantlet rooting have been established. A method of Agrobacterium-mediated transformation of Camelina by using binary vector pGH217 carrying the reporter β-glucoronidase (gus) gene driven under the 35S CaMV promoter and nos-terminator, as well as the selective marker hpt gene conferring hygromycin-resistance in transgenic plant, was elaborated.  相似文献   
94.
Rare fungus species: Hericium coralloides, Cortinarius violàñås, and Leccanium percandidu were detected for the first time in the Zubtsov area of the Tver region. We note that, in the search for rare species of fungus, attention should be paid to the type of biocenosis.  相似文献   
95.
The high accumulation of a recombinant protein in rice endosperm causes endoplasmic reticulum (ER) stress and in turn dramatically affects endogenous storage protein expression, protein body morphology and seed phenotype. To elucidate the molecular mechanisms underlying these changes in transgenic rice seeds, we analyzed the expression profiles of endogenous storage proteins, ER stress-related and programmed cell death (PCD)-related genes in transgenic lines with different levels of Oryza sativa recombinant alpha antitrypsin (OsrAAT) expression. The results indicated that OsrAAT expression induced the ER stress and that the strength of the ER stress was dependent on OsrAAT expression levels. It in turn induced upregulation of the expression of the ER stress response genes and downregulation of the expression of the endogenous storage protein genes in rice endosperm. Further experiments showed that the ER stress response upregulated the expression of PCD-related genes to disturb the rice endosperm development and induced pre-mature PCD. As consequence, it resulted in decrease of grain weight and size. The mechanisms for the detriment seed phenotype in transgenic lines with high accumulation of the recombinant protein were elucidated.  相似文献   
96.
97.
A simple and efficient cryopreservation protocol using encapsulation-dehydration was established for in vitro-grown shoot-tips of apple ‘Gala’ (Malus × domestica Borkh.). Shoot-tips, of 2.0 mm in length and with 5–6 leaf primordia, excised from 4-week-old shoot stock cultures, without cold-hardening, were encapsulated into beads, each being about 5 mm in diameter and containing a single shoot-tip. The beads were precultured on MS medium containing 0.5 M sucrose for 7 days. The precultured beads were dehydrated by air-drying to reduce the water content of the beads to about 22–20 % in 5–7 h, followed by a direct immersion in liquid nitrogen for 1 h. Frozen shoot-tips were re-warmed in a water bath at 38 °C for 2 min and post-cultured on a recovery medium for shoot regrowth. This protocol was successfully applied to four Malus species and one hybrid, among which M. micromalus and M. robusta are wild species native to China. The highest and lowest shoot regeneration rates were found in ‘Gala’ (75 %) and ‘Wangshanhong’ (36 %), with a mean shoot regrowth rate of 61 % attained for the seven Malus genotypes tested. Histological studies revealed that shoots could be regenerated in cryopreserved shoot-tips only when many cells in the leaf primordia and most of the cells in the apical dome survived following cryopreservation. Morphologies of the regenerated plantlets were identical to those from the in vitro stock cultures. Therefore, the encapsulation-dehydration procedure developed in the present study should provide a technical support for setting-up Malus cryo-banking in China.  相似文献   
98.
This article reports, for the first time, on the absolute configuration of (+)-9-benzyloxy-α-dihydrotetrabenazine ( 8 ), as determined from the perspective of X-ray crystallography. Compound 8 was prepared by a six-step reaction using 3-benzyloxy-4-methoxybenzaldehyde ( 1 ) as a starting material. The X-ray crystal diffraction structure of two compounds, racemic 9-benzyloxy-tetrabenazine ( 5 ) and the diastereomeric salt of compound 8 , is also described for the first time in this article. The X-ray results and the chiral HPLC helped elucidate that compound 8 has an absolute configuration as 2R,3R,11bR. The crystal structure of racemic compound 5 contains two symmetry- independent molecules in the unit cell. Interestingly, while they are structural isomers, they are enantiomers, too, i.e., in solution, because they are not mirror images of each other in the crystal lattice. In order to elucidate the intermolecular interaction mechanism of the diastereomeric salt of compound 8 , its crystal packing was investigated with regard to the weak interactions, such as salt bridge, OH…O and CH…O hydrogen bonds, and intermolecular CH…π interaction. The results showed that the carbonyl-assisted salt bridges and the OH…O hydrogen bonds formed polar columns in the crystal structure of the diastereomeric salt of compound 8 , resembling butterflies with open wings as viewed along the c-axis. These polar columns were extended to three-dimensional network by intermolecular CH…O hydrogen bonds and intermolecular CH…π interactions. Chirality, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
99.
Satisfactory work ability is sustained and promoted by good physical and mental health and by favorable working conditions. This study examined whether favorable and rewarding work‐related factors increased the work ability among European nurses. The study sample was drawn from the Nurses' Early Exit Study and consisted of 7,516 nursing staff from seven European countries working in state‐owned and private hospitals. In all, 10.8% were day, 4.2% were permanent night, 20.9% were shift without night shift, and 64.1% were shift workers with night shifts. Participants were administered a composite questionnaire at baseline (Time 0) and 1 yr later (Time 1). The Work Ability Index (WAI) at Time 1 was used as the outcome measure, while work schedule, sleep, rewards (esteem and career), satisfaction with pay, work involvement and motivation, and satisfaction with working hours at Time 0 were included as potential determinants of work ability. Univariate and multivariate analyses were conducted after adjusting for a number of confounders (i.e., country, age, sex, type of employment, family status, and other job opportunities in the same area). Work schedule was not related to Time 1 changes in WAI. Higher sleep quality and quantity and more favorable psychosocial factors significantly increased work ability levels. Higher sleep quality and quantity did not mediate the effect of work schedule on work ability. No relevant interaction effects on work ability were observed between work schedule and the other factors considered at Time 0. As a whole, sleep and satisfaction with working time were gradually reduced from day work to permanent night work. However, scores on work involvement, motivation, and satisfaction with pay and rewards were the highest in permanent night workers and the lowest in rotating shift workers that included night shifts.  相似文献   
100.
MazF is an mRNA interferase that cleaves mRNAs at a specific RNA sequence. MazF from E. coli (MazF‐ec) cleaves RNA at A and CA. To date, a large number of MazF homologs that cleave RNA at specific three‐ to seven‐base sequences have been identified from bacteria to archaea. MazF‐ec forms a dimer, in which the interface between the two subunits is known to be the RNA substrate‐binding site. Here, we investigated the role of the two loops in MazF‐ec, which are closely associated with the interface of the MazF‐ec dimer. We examined whether exchanging the loop regions of MazF‐ec with those from other MazF homologs, such as MazF from Myxococcus xanthus (MazF‐mx) and MazF from Mycobacterium tuberculosis (MazF‐mt3), affects RNA cleavage specificity. We found that exchanging loop 2 of MazF‐ec with loop 2 regions from either MazF‐mx or MazF‐mt3 created a new cleavage sequence at (A/U)(A/U)AA and C in addition to the original cleavage site, A and CA, whereas exchanging loop 1 did not alter cleavage specificity. Intriguingly, exchange of loop 2 with 8 or 12 consecutive Gly residues also resulted in a new RNA cleavage site at (A/U)(A/U)AA and C. The present study suggests a method for expanding the RNA cleavage repertoire of mRNA interferases, which is crucial for potential use in the regulation of specific gene expression and for biotechnological applications. Proteins 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
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