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41.
Memory and Learning Dysfunction Following Copper Toxicity: Biochemical and Immunohistochemical Basis
Jayantee Kalita Vijay Kumar Usha K. Misra Himangsu K. Bora 《Molecular neurobiology》2018,55(5):3800-3811
The prototype disease of Cu toxicity in human is Wilson disease, and cognitive impairment is the presenting symptom of it. There is no study correlating Cu-induced excitotoxicity, apoptosis, and astrocytic reaction with memory dysfunction. We report excitotoxicity, apoptosis, and astrocytic reaction of the hippocampus and frontal cortex with memory dysfunction in rat model of Cu toxicity. Thirty-six rats were divided into group I (control) and group II (100 mg/kgBwt/day CuSO4 orally). Y-maze was performed for memory and learning at 0, 30, 60, and 90 days. Frontal and hippocampal free Cu concentration, oxidative stress markers [glutathione (GSH), total antioxidant toxicity (TAC), and malondialdehyde (MDA)], and glutamate were measured by atomic absorption spectroscopy, spectrophotometry, and ELISA, respectively. N-methyl-d-aspartate receptors (NMDARs) NR1, NR2A, and NR2B were done by real-time polymerase chain reaction. Immunohistochemistry for caspase-3 and glial fibrillary acidic protein (GFAP) were done and quantified using the ImageJ software. The glutamate level in hippocampus was increased, and NMDAR expression was decreased at 30, 60, and 90 days in group II compared to group I. In the frontal cortex, glutamate was increased at 90 days, but NMDARs were not significantly different in group II compared to group I. Caspase-3 and GFAP expressions were also higher in group II compared to group I, and these changes were more marked in hippocampus than frontal cortex. These changes correlated with respective free tissue Cu, oxidative stress, and Y-maze attention score. Cu toxicity induces apoptosis and astrocytosis of the hippocampus and frontal cortex through direct or glutamate and oxidative stress pathways, and results in impaired memory and learning. 相似文献
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Two distinct classes of dust ion acoustic (DIA) solitary waves based on relativistic ions and electrons, dust charge Z d and ion-to-dust mass ratio Q’ = m i /m d are established in this model of multicomponent plasmas. At the increase of mass ratio Q’ due to increase of relativistic ion mass and accumulation of more negative dust charges into the plasma causing decrease of dust mass, relativistic DIA solitons of negative potentials are abundantly observed. Of course, relativistic compressive DIA solitons are also found to exist simultaneously. Further, the decrease of temperature inherent in the speed of light c causes the nonlinear term to be more active that increases the amplitude of the rarefactive solitons and dampens the growth of compressive solitons for relatively low and high mass ratio Q’, respectively. The impact of higher initial streaming of the massive ions is observed to identify the point of maximum dust density N d to yield rarefactive relativistic solitons of maximum amplitude. 相似文献
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Russian Journal of Marine Biology - The brown endophytic alga Laminariocolax aecidioides (Ectocarpales: Chordariaceae) growing in Undaria pinnatifida was found in Ussuriisky Bay (Peter the Great... 相似文献
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Mrinal Kalita Archana Archana Astha Dimri Prema G. Vasudev Ramesh Ramapanicker 《Journal of peptide science》2019,25(3)
An isolated uncharged hydrogen bond acceptor such as the carbonyl functionality of an aldehyde or a keto group is absent in natural amino acids. Although glutamine and asparagine are known to hydrogen bond through the amide carbonyl group in their side chains, they also possess the amide ? NH2 group, which can act as a hydrogen bond donor. This makes the structural study of peptides containing an oxo residue, with an isolated carbonyl group in the side chain, interesting. Here, we report the synthesis of δ‐ and ε‐oxo amino acids and their incorporation into oligopeptides as the N‐terminal residue. The resultant oxo peptides were extensively studied using X‐ray crystallography to understand the interactions offered by the oxo group in peptide crystals. We find that the oxo groups are capable of providing additional hydrogen bonding opportunities to the peptides, resulting in increased intermolecular interactions in crystals. The study thus offers avenues for the utilization of oxo residues to introduce intermolecular interactions in synthetic peptides. 相似文献
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Electrocatalysis: Bifunctional Electrocatalytic Activity of Boron‐Doped Graphene Derived from Boron Carbide (Adv. Energy Mater. 17/2015) 下载免费PDF全文
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Cancers are characterized by unrestricted cell division and independency of growth factor and other external signal responsiveness. Eukaryotic parental cells of tumors, on the other hand, constitute tissues and other higher structures like organs and systems and are capable of performing various functions in a highly co-ordinated fashion. Hence, cancer cells may be considered as entities capable of incessant growth and cell division but lacking any evolutionarily advanced intracellular or intercellular regulation. Since receptor tyrosine kinases are highly altered and exist in deregulated/constitutively active forms in cancer cells - achieved through various epigenetic mechanisms - we hypothesize the functional RTKs in cancer cells to resemble their counterparts in more primitive species. Analysis of RTK sequences of various species and of cancer is, therefore, expected to prove this hypothesis. Association rule in data mining can reveal the hidden biological information. This study utilizes the Boolean association rule to mine the occurrence pattern of glycine, arginine and alanine in receptor tyrosine kinases (RTKs) of invertebrates, vertebrates and cancer related vertebrate RTKs based on protein sequence informations. The results reveal that vertebrate cancer RTKs resembles prokaryotes and invertebrate RTKs showing an increasing trend of glycine, alanine and decreasing trend in arginine composition. The aminoacid compositions of vertebrates: invertebrates: prokaryotes: vertebrate cancer with respect to Glycine (>=6.1) were 42.86: 50.0: 85.71: 100%, Alanine (>=6.2) were 10.72: 66.67: 85.71: 100%, whereas Arginine (>=5.9) were 21.43: 16.67: 14.29: 0%, respectively. In conclusion, results from this study supports our hypothesis that cancer cells may resemble lower organisms since functionally cancer cells are unresponsive to external signals and various regulatory mechanisms typically found in higher eukaryotes are largely absent. 相似文献
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Pairwise comparisons of Genista tinctoria (dyer’s weed) rhizobium nodA, nodC, and nodZ gene sequences to those available in databanks revealed their highest sequence identities to nodulation loci of Bradyrhizobium sp. (Lupinus) strains and rhizobia from other genistoid legumes. On phylogenetic trees, genistoid microsymbionts were grouped together in monophyletic clusters, which suggested that their nodulation genes evolved from a common ancestor. G. tinctoria nodulators formed symbioses not only with the native host, but also with other plants of Genisteae tribe such as: Lupinus luteus, Sarothamnus scoparius, and Chamaecytisus ratisbonensis, and they were classified as the genistoid cross-inoculation group. The dyer’s weed root nodules were designated as indeterminate with apical meristem consisting of infected and uninfected cells.The GenBank accession numbers for the sequences reported in this paper are as follows: nodC, DQ139776–DQ139781; nodA, DQ135897, Q135898; nodZ, DQ135899–DQ135903. 相似文献
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Jason R. Neale Natali B. Richter Kevyn E. Merten K. Grant Taylor Sujan Singh Leonard C. Waite Nicole K. Emery Ned B. Smith Jian Cai William M. Pierce 《Bioorganic & medicinal chemistry letters》2009,19(3):680-683
In this study a novel bone-targeting agent containing elements of the tricarbonylmethane system of ring A of tetracycline was developed and was shown to bind to the mineral constituent of bone, hydroxyapatite. Conjugation of this bone-targeting agent to estradiol resulted in a bone-targeted estrogen (BTE2-A1) with an enhanced ability to bind to hydroxyapatite. In an ovariectomized rat model of osteoporosis a partial separation of the skeletal effects of estradiol from the uterine effects was observed following subcutaneous administration of BTE2-A1. This novel bone-targeting estradiol delivery system has the potential to improve the safety profile of estradiol in the treatment of osteoporosis. 相似文献