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101.
A. V. Vasil’ev V. I. Ivakhnenko S. A. Khotimchenko V. V. Korzh 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2008,2(3):306-310
Studies of Km for glutathione peroxidase (GPx) and activities of superoxide dismutase and GPx were carried out in liver and erythrocytes of rats kept on either the normal semisynthetic diet or a high-fat diet with increased content of Cu, Zn, Mn, and Se. The diet containing microelement additions caused the increase in TBH affinity of liver and erythrocyte GPx, as well as the decrease of liver SOD observed on the 14th day of the treatment of rats with the high-fat diet with additional increase of Cu, Zn, Mn, and Se. 相似文献
102.
103.
Cu-induced oxidative damage is associated with cancer, diabetes, neurodegenerative and age related diseases. The quest for Cu-chelators as potential antioxidants spans the past decades. Yet, biocompatible Cu-chelators that do not alter the normal metal-ion homeostasis are still lacking. Here, we explored the potential of natural and synthetic nucleotides and inorganic phosphates as inhibitors of the Cu(I)/(II)-induced ()OH formation via either the Fenton or Haber-Weiss mechanisms. For this purpose, we studied by ESR the modulation of Cu-induced ()OH production, from the decomposition of H(2)O(2), by nucleotides and phosphates. ATP inhibited both Cu(I) and Cu(II) catalyzed reactions (IC(50) 0.11 and 0.04mM, respectively). Likewise, adenosine 5'-beta,gamma-methylene triphosphate (AMP-PCP), adenosine 5'-O-(3-thiotriphosphate) (ATP-gamma-S), ADP and tripolyphosphate were identified as good inhibitors. However, AMP and adenosine were poor inhibitors in the Cu(I)-H(2)O(2) system, IC(50) ca. 1.2mM, and radical enhancers in the Cu(II)-H(2)O(2) system. The best antioxidant was adenosine 5'-[beta,gamma-imino] triphosphate (AMP-PNP) (IC(50) 0.05mM at Cu(I)-H(2)O(2) system) which was 15 times more active than the known antioxidant Trolox. ATP and analogues inhibit Cu-induced ()OH formation through an ion chelation rather than a scavenging mechanism. Two phosphate groups are required for making active Fenton-reaction inhibitors. Nucleotides and phosphates triggered a biphasic modulation of the Haber-Weiss reaction, but a monophasic inhibition of the Fenton reaction. We conclude that nucleotides at sub mM concentrations can prevent Cu-induced OH radical formation from H(2)O(2), and hence may possibly prevent oxidative damage. 相似文献
104.
Kowalik-Jankowska T Biega L Kuczer M Konopińska D 《Journal of inorganic biochemistry》2008,102(8):1615-1622
The stoichiometry, stability constants and solution structure of the complexes formed in the reaction of copper(II) with hexapeptide NPTNLH, i.e. the Neobelliera Bullata Trypsin Modulating Oostatic Factor (Neb-TMOF), and its analogues DPTNLH, Ac-NPTNLH and Ac-DPTNLH have been determined by potentiometric, UV-visible, CD and EPR spectroscopic methods. Upon raising pH for Ac-NPTNLH and Ac-DPTNLH peptides, copper(II) coordination starts from the imidazole nitrogen of the His6; afterwards three deprotonated amide nitrogens are progressively involved in metal ions coordination. In a wide pH range of 4.5-8.5 for the NPTNLH and DPTNLH ligands the CuL complex dominates with the imidazole nitrogen of His6 coordinated to form a macrochelate. The N-terminal amino group of the NPTNLH and DPTNLH peptides takes part in the coordination of the metal ion in the CuL, CuH−1L and CuH−2L complexes. However, at pH above 9 the CuH−3L complex with the {NIm, 3N−} coordination mode is formed. For the CuH−2L complex the spectroscopic data clearly indicate the 4N {NH2, CO or COO−, 2N−, NIm} bonding mode with the axial coordination of the N-terminal amine group to the metal ion. 相似文献
105.
Zinc (Zn) consumption has increased in many populations either due to the increased intake of Zn-fortified foods as in the
USA or in agricultural food stuffs as in some Indian states during the last decade. Its excessive intake has been reported
to induce acute pancreatitis (AP) in many studies due to increase in oxidative stress that was further reported to cause Cu
and Mg deficiencies. This led us to design a modified poultry egg (MEΨ) enriched with Cu and Mg along with other antioxidants, and its efficacy on Zn-induced AP was studied in male Wistar rats.
In one set, the rats were fed on equacaloric semi-synthetic basal diet containing 20 mg Zn/kg diet (control, group I), and
Zn-induced AP-I diet and AP-II diet containing 40 and 80 mg Zn/kg diet (groups II and III) for 180 days, respectively. In
another set, the rats were initially fed on Zn-induced AP-I and AP-II diets for 90 days and then shifted to -mixed Zn-induced AP-I and AP-II diets in groups IIME and IIIME for another 90 days. At the end of the experiment, data displayed
increased serum and urinary Zn, Cu, and Mg levels in groups II and III rats, which were reduced and approached closer to control
group I after feeding in groups IIME and IIIME rats. Transmission electron microscopic studies of acinar cells revealed progressive dilation,
vesicularization, and degeneration of endoplasmic reticulum (ER), and decrease in zymogen granules (ZG) in groups II and III
rats in contrast to their curvilinear or concentric long parallel running cisternal profile of ER in control group I. The
treatment of helped in the restoration of the ER profile and ZG number, approaching closer to the control group I. The degree of recovery
was dependent upon the degree of toxicity caused by the amount of Zn given in the diet. The results of this study suggest
that -mixed diet can protect the acinar cells from the deleterious effects of Zn by decreasing the oxidative stress.
Indian patent application no. 2264/Del/2005. 相似文献
106.
Bai P Cao F Lan X Zhao F Ma Y Zhao C 《Journal of biochemical and biophysical methods》2008,70(6):903-908
Chitosan (CS) gel beads were prepared by using phase inversion and precipitation technique. The gel beads could bind copper (II), by which Cu (II) ion-immobilized chitosan gel beads (CS-Cu2+ gel beads) were prepared, and the amount of the immobilized Cu (II) was about 35 mg/g when the CS gel beads were incubated in 150 ppm cupric sulfate solution. The CS-Cu2+ gel beads could selectively adsorb histidine (His) from the mixed solution containing His and tryptophan (Trp); and the selective coefficient which was defined as the adsorbed amount ratio of His to Trp was about 8.0 at the pH value of 7.4. The effect of the pH value on the amino acid adsorption was also studied. In order to investigate the relationship of the amino acid adsorption and protein adsorption, the adsorbed amounts for IgG and albumin were determined; and the results indicated that the CS-Cu2+ gel beads could adsorb a larger amount of IgG than albumin due to the larger amount of the exposed residual His. The study provided a sorbent and a method to selectively remove His and IgG. 相似文献
107.
We analysed the theory of the coupled equilibria between a metal ion, a metal ion-binding dye and a metal ion-binding protein in order to develop a procedure for estimating the apparent affinity constant of a metal ion:protein complex. This can be done by analysing from measurements of the change in the concentration of the metal ion:dye complex with variation in the concentration of either the metal ion or the protein. Using experimentally determined values for the affinity constant of Cu(II) for the dye, 2-(5-bromo-2-pyridylaxo)-5-(N-propyl-N-sulfopropylamino) aniline (5-Br-PSAA), this procedure was used to estimate the apparent affinity constants for formation of Cu(II):transthyretin, yielding values which were in agreement with literature values. An apparent affinity constant for Cu(II) binding to α-synuclein of ∼1 × 109 M−1 was obtained from measurements of tyrosine fluorescence quenching by Cu(II). This value was in good agreement with that obtained using 5-Br-PSAA. Our analysis and data therefore show that measurement of changes in the equilibria between Cu(II) and 5-Br-PSAA by Cu(II)-binding proteins provides a general procedure for estimating the affinities of proteins for Cu(II). 相似文献
108.
Excessive Zn but normal Cu and Mg in the staple food consumed by the people of Chandigarh (Union territory and capital of
Punjab and Haryana States of India) has been considered to be the major risk factor for the prevalence of obesity (33.15%)
and obesity-related diseases in this region. Therefore, in the present investigations, in obesity-related diseases, the status
of these minerals was estimated in their tissues, including hair, nails, and blood serum and urine, and compared with those
of normal subjects. They were grouped as: normal subjects in control Group A, middle-aged diabetics in Group DM, older diabetics in Group DO, and diabetics with osteoarthritis in Group D+ OA, osteoarthritis in Group OA and rheumatoid arthritis in Group RA, respectively.
The results evaluated in the order as: hair Zn, group D+OA>DM>OA>A (control)>RA>DO (p < 0.001); hair Cu, group A (control)>DM>OA>D+OA>DO>RA (p < 0.001); hair Mg, group A (control)>DM>OA>D+OA>RA>DO (p < 0.001, 0.01); hair Mn, group A (control)>RA>OA>D-OA>DM>DO (p < 0.001); nail Zn, group DM>D+OA>OA>A (control)>RA>DO (p < 0.001, 0.05); nail Cu, group A (control)>OA>DM>D+OA>RA>DO (p < 0.001); nail Mg, group A (control)>OA>DM>DO>D+OA >RA (p < 0.001); nail Mn, group A (control) >RA>OA>D+OA>DM>DO (p < 0.01); urine Zn, group DO>DM>D+OA>A (control)>RA>OA (p < 0.01); urine Cu, group RA>D+OA>DO>OA> DM>A (control) (p<0.001); urine Mg, group RA>OA>D+OA>DO>DM>A (control; p < 0.001); urine Mn, group DO>DM>OA>D+OA>RA>A (control; p < 0.001), respectively. The analysis of the mineral status in serum of diabetics further showed their highly significant
rise from lower mean age subgroup to higher mean age subgroup than their control counter parts (p < 0.001, 0.01, and 0.05) with coincident deficiencies of Cu, Mg, and Mn in their tissues. This study would be helpful considering
the status of minerals in these obesity-related diseases depending on the choice of the food consumed to improve the quality
of life and prognosis for the diseases. 相似文献
109.
Joanna Chwiej Dariusz Adamek Magdalena Szczerbowska-Boruchowska Anna Krygowska-Wajs Sylvain Bohic Marek Lankosz 《Journal of trace elements in medicine and biology》2008,22(3):183-188
Parkinson's disease (PD) is referred to as idiopathic disorder, which means that its causes have not been found yet. However, a few processes such as oxidative stress, protein aggregation and mitochondrial dysfunction are suspected to lead to the atrophy and death of substantia nigra (SN) neurons in case of this neurodegenerative disorder. Cu is a trace element whose role in the pathogenesis of PD is widely discussed. The investigation of Cu oxidation state inside single nerve cells from SN of PD and control cases may shed some new light on the role of this element in PD. The differences in Cu chemical state were investigated with the use of X-ray absorption near edge structure (XANES) spectroscopy. The least-square fitting method was applied for the analysis of XANES spectra. The comparison of the positions of white line, multiple scattering and pre-edge peak maximum at the energy scale did not reveal the existence of differences in Cu chemical state between PD and control samples. However, it was found that most of the Cu inside SN neurons occurs in tetrahedral environment and probably as Cu(II). 相似文献
110.
Ghatak H. Mukhopadhyay S.K. Jana T.K. Sen B.K. Sen S. 《Wetlands Ecology and Management》2004,12(3):145-155
Humic (HA) and fulvic (FA) acids isolated from mangrove sediments of Sundarban, the largest delta on earth in the estuarine phase of the river Ganges, were studied and attempts were made to characterize their binding sites by quenching of Synchronous fluorescence (SyF) bands with Fe (III) and Cu (II). A modified Stern-Volmer relationship applicable for static quenching was applied for the determination of conditional stability constants and the data were compared with those determined by potentiometric titration. In the excited state HA and FA showed different acidity constant compared to the ground state. Values of the conditional stability constant (log Kc) for Fe (III) and Cu (II) indicated that binding sites were bidentate in nature. FA were better chelators than the HA fractions. High energy binding sites of both FA & HA were occupied by Fe(III) and the low energy binding sites, mainly responsible for mobilization and immobilization of metal, were occupied by Cu(II). 相似文献