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91.
Coral Reefs - Shallow water tropical reefs are widely threatened by anthropogenic ocean warming which sometimes exceeds their thermal tolerance limit. The majority of reefs have been currently...  相似文献   
92.
Journal of Plant Growth Regulation - Plants require optimum amounts of nutrients for suitable growth and yield production. Accordingly, the most efficient methods of fertilization, including the...  相似文献   
93.
Coral Reefs - The Arabian Gulf is a natural laboratory to examine how subtropical coral reef ecosystems might change in responding to recurring heating events because of uniquely high water...  相似文献   
94.
95.
Elevated CO2 interactions with other factors affects the plant performance. Regarding the differences between cultivars in response to CO2 concentrations, identifying the cultivars that better respond to such conditions would maximize their potential benefits. Increasing the ability of plants to benefit more from elevated CO2 levels alleviates the adverse effects of photoassimilate accumulation on photosynthesis and increases the productivity of plants. Despite its agronomic importance, there is no information about the interactive effects of elevated CO2 concentration and plant growth regulators (PGRs) on potato (Solanum tuberosum L.) plants. Hence, the physiological response and source-sink relationship of potato plants (cvs. Agria and Fontane) to combined application of CO2 levels (400 vs. 800 µmol mol−1) and plant growth regulators (PGR) [6-benzylaminopurine (BAP) + Abscisic acid (ABA)] were evaluated under a controlled environment. The results revealed a variation between the potato cultivars in response to a combination of PGRs and CO2 levels. Cultivars were different in leaf chlorophyll content; Agria had higher chlorophyll a, b, and total chlorophyll content by 23, 43, and 23%, respectively, compared with Fontane. The net photosynthetic rate was doubled at the elevated compared with the ambient CO2. In Agria, the ratio of leaf intercellular to ambient air CO2 concentrations [Ci:Ca] was declined in elevated-CO2-grown plants, which indicated the stomata would become more conservative at higher CO2 levels. On the other hand, the increased Ci:Ca in Fontane showed a stomatal acclimation to higher CO2 concentration. The higher leaf dark respiration of the elevated CO2-grown and BAP + ABA-treated plants was associated with a higher leaf soluble carbohydrates and starch content. Elevated CO2 and BAP + ABA shifted the dry matter partitioning to the belowground more than the above-media organs. The lower leaf soluble carbohydrate content and greater tuber yield in Fontane might indicate a more efficient photoassimilate translocation than Agria. The results highlighted positive synergic effects of the combined BAP + ABA and elevated CO2 on tuber yield and productivity of the potato plants.  相似文献   
96.
The use of chaotropic reagents is common in biophysical characterization of biomolecules. When the study involves transmembrane protein channels, the stability of the protein channel and supporting bilayer membrane must be considered. In this letter, we show that planar bilayers composed of poly(1,2-butadiene)-b-poly(ethylene oxide) diblock copolymer are stable and leak-free at high guanidinium chloride concentrations, in contrast to diphytanoyl phosphatidylcholine bilayers, which exhibit deleterious leakage under similar conditions. Furthermore, insertion and functional analysis of channels such as α-hemolysin and MspA are straightforward in these polymer membranes. Finally, we demonstrate that α-hemolysin channels maintain their structural integrity at 2 M guanidinium chloride concentrations using blunt DNA hairpins as molecular reporters.  相似文献   
97.
98.
Distinguishing the multiple effects of reactive oxygen species (ROS) on cancer cells is important to understand their role in tumour biology. On one side, ROS can be oncogenic by promoting hypoxic conditions, genomic instability and tumorigenesis. Conversely, elevated levels of ROS‐induced oxidative stress can induce cancer cell death. This is evidenced by the conflicting results of research using antioxidant therapy, which in some cases promoted tumour growth and metastasis. However, some antioxidative or ROS‐mediated oxidative therapies have also yielded beneficial effects. To better define the effects of oxidative stress, in vitro experiments were conducted on 4T1 and splenic mononuclear cells (MNCs) under hypoxic and normoxic conditions. Furthermore, hydrogen peroxide (H2O2; 10–1,000 μM) was used as an ROS source alone or in combination with hyaluronic acid (HA), which is frequently used as drug delivery vehicle. Our result indicated that the treatment of cancer cells with H2O2 + HA was significantly more effective than H2O2 alone. In addition, treatment with H2O2 + HA led to increased apoptosis, decreased proliferation, and multiphase cell cycle arrest in 4T1 cells in a dose‐dependent manner under normoxic or hypoxic conditions. As a result, migratory tendency and the messenger RNA levels of vascular endothelial growth factor, matrix metalloproteinase‐2 (MMP‐2), and MMP‐9 were significantly decreased in 4T1 cells. Of note, HA treatment combined with 100–1,000 μM H2O2 caused more damage to MNCs as compared to treatment with lower concentrations (10–50 μM). Based on these results, we propose to administer high‐dose H2O2 + HA (100–1000 μM) for intratumoural injection and low doses for systemic administration. Intratumoural route could have toxic and inhibitory effects not only on the tumour but also on residential myeloid cells defending it, whereas systemic treatment could stimulate peripheral immune responses against the tumour. More in vivo research is required to confirm this hypothesis.  相似文献   
99.
International Journal of Peptide Research and Therapeutics - Cervical cancer is the second most common leading cause of women's death due to cancer worldwide, about 528,000 patients’...  相似文献   
100.
The antioxidant and mutagenic/antimutagenic activities of the fixed oils from Nigella sativa (NSO) and Nigella damascena (NDO) seeds, obtained by cold press-extraction from the cultivar samples, were comparatively investigated for the first time. The antimutagenicity test was carried out using classical and modified Ames tests. The fatty acid composition of the fixed oils was characterized by gas chromatography–mass spectrometry (GC-MS) while the quantification of thymoquinone in the fixed oils was determined by UPC2. The main components of the NSO and NDO were found to be linoleic acid, oleic acid, and palmitic acid. The results of the Ames test confirmed the safety of NSO and NDO from the viewpoint of mutagenicity. The results of the three antioxidant test methods were correlated with each other, indicating NDO as having a superior antioxidant activity, when compared to the NSO. Both NSO and NDO exhibited a significant protective effect against the mutagenicity induced by aflatoxin B1 in Salmonella typhimurium TA98 and TA100 strains. When microsomal metabolism was terminated after metabolic activation of the mycotoxin, a significant increase in antimutagenic activity was observed, suggesting that the degradation of aflatoxin B1 epoxides by these oils may be a possible antimutagenic mechanism. It is worthy to note that this is the first study to assess the mutagenicity of NSO and NDO according to the OECD 471 guideline and to investigate antimutagenicity of NDO in comparison to NSO against aflatoxin.  相似文献   
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