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821.
This work reports confirmation of the experimental assignment of the absolute-handedness chirality of single-walled carbon nanotubes (SWNTs). This was achieved by applying the scanning tunneling microscopy (STM) imaging technique to a supramolecular composite consisting of a metalized porphyrin derivative (nickel-5,15-bisdodecylporphyrin [Ni-BDP]) affixed to the surfaces of chiral-concentrated SWNTs (with right-handed helix P- and left-handed helix M- ). On the basis of the handedness chirality, different chiral supramolecular structures of Ni-BDP were observed on the surfaces of the two SWNT enantiomers. The incorporation of a metal center into the porphyrin ring did not significantly affect the SWNT absolute-handedness chirality assignment, the large pi-system porphyrin ring being the crucial factor. These findings will effectively pave the way towards the clear selective synthesis, separation, chemistry, and applications of SWNT enantiomers. 相似文献
822.
823.
Esraa E. Shalan Said S. Soliman Ahmed A. Mahmoud Jameel M. Al-Khayri Salha M. ALshamrani Fatmah A. Safhi Areej S. Jalal Diaa Abd El-Moneim Abdallah A. Hassanin 《Phyton》2023,92(7):2183-2196
Determination of the somaclonal variation of in vitro-propagated plants is crucial to determine the appropriate
micropropagation protocol and growth regulators for commercial scale multiplication. In this research, nine multiplication media (MM) augmented with different concentrations of 6-benzyl adenine (BA), Kinetin (Kin), and
Thidiazuron (TDZ), Three rooting media (RM) supplemented with three levels of α-naphthalene acetic acid
(NAA) and three types of soil mixtures (v/v); Coco peat/Vermiculite/Sand (CVS), Peat moss/Perlite/Sand
(PPS) and Peat moss/Perlite (PP) were used in the micropropagation protocol of daylily plants. MM2 showed
the maximum shoot length and the number of leaves, while MM9 showed the maximum number of shoots.
The RM1 showed the maximum root length and the number of roots. During acclimatization, CVS, PPS, and
PP soil mixture showed similar performance except the CVS mixture showed lower performance regarding plant
height and diameter. The genetic fidelity of micropropagated plants was evaluated using Start Codon Targeted
(SCoT) Markers. Six SCoT primers amplified 51 scorable bands with an approximate range from 146 bp to
1598 bp size. Thirty one out of 51 loci were presented in the mother plants. 40 loci were polymorphic, 11 were
monomorphic and 7 were unique. The amplification patterns of the micropropagated plants demonstrated genetic integrity to the mother plant ranging from 84.32 to 47.06 and somaclonal variations ranging from 52.94 with
5 mg/l BA pathway to 15.68 with 1mg/l TDZ pathway, thus demonstrating that the homogeneity and the variation of the micropropagated plants affected by the type and the quantity of the plant growth regulator used during
multiplication subcultures. This research can be successfully used for other ornamental and medicinal plants’ bulk
multiplication, germplasm conservation, and future genetic improvement. 相似文献
824.
Rania H. Abd El-Hameed Shahenda Mahgoub Hend M. El-Shanbaky Mosaad S. Mohamed Sahar A. Ali 《Journal of enzyme inhibition and medicinal chemistry》2021,36(1):977
Inflammation is associated with the development of several diseases comprising cancer and cardiovascular disease. Agents that suppress cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, besides chemokines have been suggested to minimise inflammation. Here, a variety of novel heterocyclic and non-heterocyclic compounds were prepared from novel three furanone derivatives. The structures of all synthesised compounds were confirmed by elemental and spectral analysis including mass, IR, and 1H-NMR spectroscopy. Anti-inflammatory activities of these synthesised compounds were examined in vitro against COX enzymes, 15-LOX, and tumour necrosis factor-α (TNF-α), using inhibition screening assays. The majority of these derivatives showed significant to high activities, with three pyridazinone derivatives (5b, 8b, and 8c) being the most promising anti-inflammatory agents with dual COX-2/15-LOX inhibition activities along with high TNF-α inhibition activity. 相似文献
825.
826.
Summary Experiments were made to investigate the influence exerted by calcium, strontium, cobalt and molybdenum on the growth and nitrogen fixation of a local strain of Nostoc commune.Calcium, cobalt and molybdenum at least in micro amounts were found to be required for the achievement of best growth and highest nitrogen fixation.Calcium seems to be irreplaceable by strontium, the latter element exerted a strong inhibitory action on both growth and nitrogen fixation processes. 相似文献
827.
828.
Although, several health benefits were associated with green tea, these effects may be beneficial up to a certain dose. Higher doses of green tea may cause several adverse effects. So, there is a need to test the potential negative effects of green tea during pregnancy. This study was designated to evaluate the effect of prenatal exposure of green tea extract on the development of the central nervous system of 20-day old rat fetuses. The pregnant rats were divided into 4 groups; the control group (received distal water) and the other 3 groups received green tea extract at different doses (200, 600 & 1000 mg/kg/day, respectively) from the 6th to 15th day of gestation i.e., during the organogenesis phase of development. Cerebral cortex, cerebellum and spinal cord specimens were subjected to histological, immunohistochemical and ultrastructure investigations. The body weight of both mothers and fetuses was significantly decreased in the groups that received 600 and 1000 mg green tea extract. Also, the neuronal tissues displayed various signs of degeneration which were evident with the 600 and 1000 mg doses. Green tea extract also increases the glial fibrillary acidic protein (GFAP) and decreases the proliferating cell nuclear antigen (PCNA) which were directly proportional with increasing the dose. Administration of green tea extract during rat organogenesis period induced various histological, immunohistochemical and ultrastructural degenerative changes in the cerebral cortex, cerebellum and spinal cord of 20-day old rat fetuses. These deleterious changes were directly proportional to increasing the green tea extract dose. Thus, it should be stressed that the effect of green tea is dose-dependent and therefore it can be either beneficial or adverse. 相似文献
829.
Resinous beehive product propolis has many biological activities. It contains various aromatic substances that have great differences in their chemical composition depending on the natural flora. Thus, chemical characterization and biological properties of propolis samples is an important subject for the pharmaceutical industry. In this study, the propolis samples collected from three cities in Turkey were prepared as methanol (MEP), ethanol (EEP), chloroform (ChlEP), hexane (HxEP), and ethyl acetate (EAEP) extracts using an ultrasonic assisted technique. The antioxidant capacities of the samples were evaluated by free radical scavenging activity (DPPH), cation radical scavenging activity (ABTS), and reducing activity (CUPRAC) and (FRAP). The strongest biological activities were detected in ethanol and methanol extracts. Enzyme inhibition of the propolis samples were determined against the human glutathione S-transferase (GST) and angiotensin converting enzyme (ACE). IC50 values of MEP1, MEP2, and MEP3 samples against the ACE were found as 13.9 μg/mL, 14.8 μg/mL, and 12.8 μg/mL, while against the GST IC50 values of MEP1, MEP2, and MEP3 samples were as 5.92 μg/mL, 9.49 μg/mL, and 5.72 μg/mL. To know the possible causes of the biological test results advanced LC/MS/MS method was applied. trans-ferulic acid, kaempferol, and chrysin were found as the most abundant phenolic compounds in each sample. The propolis extracts obtained using the proper solvent have a good potential to be used in pharmaceuticals to treat the diseases related to oxidative damage, hypertension, and inflammation. Finally, the interactions between chrysin, trans-ferulic acid and kaempferol molecules with ACE and GST receptors were analyzed using molecular docking study. Selected molecules interact with active residues by binding to the active site of the receptors. 相似文献
830.
S. Abdel Fattah A. A. E.-E. Rizk A. G. Motawie T. I. Abd El-Galil M. El Sebaie 《Biotechnic & histochemistry》2019,94(4):234-243
Although the risks of smoking are well known, the effects of exposure to nicotine on endocrine functions remain unclear. We investigated the deleterious effects of nicotine on the adrenal gland and the mechanisms of these changes in rats. The role of melatonin in ameliorating pathological changes also was investigated. We used 24 rats divided into four groups of six: group 1, control; group 2, nicotine treated; group 3, nicotine and melatonin treated; group 4, melatonin treated. We used histology; immunohistochemistry of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and tyrosine hydroxylase (TH); measured oxidative and antioxidative markers, malondialdehyde (MDA) and glutathione (GSH); and performed real-time PCR for NF-κB 65, IL1-B and IL6. We also performed histomorphometric analysis. Indentation and lamellar separation of the adrenal capsule, vacuolated degenerated cells and lymphocytic infiltration were observed in group 2. Vacuolated cells and cells with pyknotic nuclei also were detected in the zona reticularis and medulla of the same group. We observed improved shape and cellular lining of the gland in groups 3 and 4. Widespread expression of iNOS, VEGF and TH, increased area percent collagen, decreased GSH (56%) and increased MDA, NF-κB, IL1-B and IL-6 were observed in group 2. All parameters were ameliorated in groups 3 and 4. The effects of nicotine on the adrenal gland can be attributed to oxidative and inflammatory stress; melatonin ameliorates these effects. 相似文献