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991.
The investigation of the antioxidative properties of the novel synthetic organoselenium compounds in some rat tissues 总被引:1,自引:0,他引:1
Selamoglu Talas Z Ozdemir I Yilmaz I Gok Y Orun I 《Experimental biology and medicine (Maywood, N.J.)》2008,233(5):575-579
DMBA (7,12-dimethylbenz[a]anthracene) is a polycyclic aromatic hydrocarbon (PAH) known to cause tumors in rats. Selenium is an essential element with physiological non-enzymatic antioxidant properties. Because of the health problems induced by many environmental pollutants, many efforts have been undertaken in evaluating the relative antioxidant potential of selenium and synthetic organoselenium compounds. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (1-isopropyl-3-methylbenzimidazole-2-selenone [SeI] and 1,3-di-p-methoxybenzylpyrimidine-2-selenone [SeII]) in the determined doses. The protective effects of novel synthetic organoselenium compounds (SeI and SeII) against DMBA-induced changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities and total glutathione (GSH) and malone-dialdehyde (MDA) levels of rat heart and brain were investigated. It was determined that SeI and SeII fully or partially restored enzyme activity. It was also found that lipid peroxidation was also decreased in SeI and SeII treated groups. Consequently, it was determined that novel synthetic organoselenium compounds (SeI and SeII) provided protection of antioxidant activity, and protection against lipid peroxidation measured as MDA in SeI and SeII treated groups was provided by novel synthesized organoselenium compounds. The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rats was rationalized. 相似文献
992.
Nabil A. Yassin Samar A. Muwakkit Ahmad O. Ibrahim Imad M. Kayim Mohammad-Zohair M. Habbal Nabil M. Chamseddine Khaled M. Musallam Ali I. Shamseddine 《Journal of applied genetics》2008,49(4):421-424
Gaucher disease (GD) is an autosomal recessive inborn error of metabolism, resulting from a deficiency of the enzyme glucocerebrosidase,
causing an accumulation of the glycolipid glucocerebroside within lysosomes of macrophages in the reticuloendothelial system.
Three major clinical forms have been assigned and more than 200 gene mutations have been identified. We herein report a Lebanese
boy born with a novel combined mutation L371V/Rec-NciI, who presented with moderate-severe type 1 GD. An overview of the clinical
and biomarker improvement following enzyme replacement therapy with imiglucerase is described in a follow-up of 30 months.
Imiglucerase seems to be efficacious in decreasing the severity of the disease associated with this mutation. However, a high
dose may be required to achieve optimal growth, platelet count, and hemoglobin level. 相似文献
993.
El-Bestawy E El-Sokkary I Hussein H Keela AF 《Journal of industrial microbiology & biotechnology》2008,35(11):1517-1529
The main objective of the present study was to improve the quality of pulp and paper industrial wastewater of two local mills
RAKTA and El-Ahlia, Alexandria, Egypt, and to bring their pollutant contents to safe discharge levels. Quality improvement
was carried out using integrated chemical and biological treatment approaches after their optimization. Chemical treatment
(alum, lime, and ferric chloride) was followed by oxidation using hydrogen peroxide and finally biological treatment using
activated sludge (90 min for RAKTA and 60 min for El-Ahlia effluents). Chemical coagulation produced low-quality effluents,
while pH adjustment during coagulation treatment did not enhance the quality of the effluents. Maximum removal of the tested
pollutants was achieved using the integrated treatment and the pollutants recorded residual concentrations (RCs) of 34.67,
17.33, 0.13, and 0.43 mg/l and 15.0, 11.0, 0.0, and 0.13 mg/l for chemical oxygen demand (COD), biochemical oxygen demand
(BOD5), tannin and lignin, and silica in RAKTA and El-Ahlia effluents, respectively, all of which were below their maximum permissible
limits (MPLs) for the safe discharge into water courses. Specific oxygen uptake rate (SOUR) and sludge volume index (SVI)
values reflect good conditions and healthy activated sludge. Based on the previous results, optimized conditions were applied
as bench scale on the raw effluents of RAKTA and El-Ahlia via the batch chemical and the biological treatment sequences proposed.
For RAKTA effluents, the sequence was as follows: (1) coagulation with 375 mg/l FeCl3, (2) oxidation with 50 mg/l hydrogen peroxide, and (3) biological treatment using activated sludge with 2,000 mg/l initial
concentration and 90 min hydraulic retention time (HRT), while for El-Ahlia raw effluents, the sequence was (1) coagulation
with 250 mg/l FeCl3, (2) oxidation with 45 mg/l hydrogen peroxide, and (3) biological treatment using activated sludge with 2,000 mg/l initial
concentration and 60 min HRT. In conclusion, results confirmed that the application of the proposed sequential treatments
removed almost all COD, BOD5, high molecular weight compounds, and silica from RAKTA and El-Ahlia influents and produced high-quality effluents, thus
achieving the main objective of this study. 相似文献
994.
The public markets aren't what they used to be and venture capitalists are seeking investments with shorter timelines. But the good news is several new sources of financing are becoming available. 相似文献
995.
Martine Albert Mohamed Hassen Chelli Nathalie Sermondade Ibrahim Hammoud Marianne Bergerel François Vialard Jacqueline Selva 《Andrologie》2008,18(1):26-34
Motile Sperm Organelle Morphology Examination (MSOME) constitutes a real improvement in ART management and outcome, as it allows detection of specific sperm anomalies on living cells, which cannot be detected by routine analysis. MSOME applied to the selection of sperm injected into the oocyte is called IMSI (Intracytoplasmic Morphologically Selected sperm Injection) and is associated with a considerable improvement of implantation, clinical pregnancy and delivery rates. A high-power microscope (X 2,000 to X 10,000) and video enhancement system are necessary and technical limitations are related to cryptozoospermia and/or severe teratozoospermia. Compared to routine sperm morphology assessment, MSOME allows the detection of subtle cephalic anomalies, such as vacuoles. These vacuoles seem to have a deleterious effect on fertilization and embryo developmentin vitro. These observations have led to a detailed classification of anomalies and this morphological diagnosis on living sperm demonstrates that most sperm selected for conventional ICSI at X 400 are actually abnormal on MSOME at X 6,000 or more. In addition to the very good results obtained in IMSI, this new approach opens up interesting prospects concerning the relationship between the phenotype of the injected sperm and its fertilization capacity and embryo development. In terms of diagnosis, MSOME could be used to select and study homogeneous groups of normal sperm or homogeneous groups of sperm exhibiting the same well defined anomaly. Such studies, associated with fine analysis of injected sperm and follow-up of each oocyte and each embryo, should provide more information about the relationship between sperm structure and function and should help to define the relevant indications for IMSI and the choice of spermatozoa to be injected. 相似文献
996.
Polymerization of 20% neutralized acrylic acid (Na form), AA, in presence of Karaya gum, KG, or tamarind seed gum, TG, at AA/gum weight ratio of 1/1 and 2/1 results in PAA/KG1, PAA/KG2, PAA/TG1 and PAA/TG2 adducts, respectively (where the suffix 1 or 2 stands for AA/gum ratios of 1/1 or 2/1). Infra red spectra of adducts are examined. Aqueous pastes of adducts, native gums and GG are of non-Newtonian thixotropic flow within a shear rate range of 4–40 s−1. Adduct pastes (7.5% w/v) are of higher apparent viscosities (η) than their native gums or GG, and pastes of TG adducts are of higher η than KG adducts. Except for PAA/TG2 adduct, the power law does not correlate well to the other pastes. Preliminary trials showed that adducts are excellent thickeners for reactive and acid printing on wool, silk and nylon 6. Prints by adducts are of higher color strength than those by native gums or GG. GG paste was completely destroyed after storing for 7 days, whereas η of pastes of adducts and native gums were noticeably decreased upon storing. 相似文献
997.
Razagui IB 《Biological trace element research》2008,123(1-3):47-57
A comparative evaluation of three washing methods for removing exogenous elemental contamination from fetal scalp hair is described. A total of 12 samples, including 6 from normal pregnancies and 6 from abruptio placentae (AP) cases, were used. Each was divided into four subsamples, with one left unwashed for comparison, while three were subjected to one of the three washing methods. The first consisted of agitating hair for 5 min in sequential and equal measures (30 ml) of acetone and water, followed by rinsing with acetone, and the process repeated twice. In the second and third, hair was agitated for 30 min in aqueous solutions of sodium lauryl sulfate (0.5%, w/v), and Triton X-100 (0.5%, v/v), respectively, followed by sequential rinsing with deionized water and acetone. After drying and microwave-assisted digestion in concentrated nitric acid, the subsamples' concentrations of zinc, copper, cadmium, lead, mercury and selenium were determined using inductively coupled mass spectrometry. All washed subsamples, irrespective of washing method used, had lower elemental concentrations than the corresponding, unwashed subsamples. These differences, taken as presumptive indicators of exogenous contamination, showed only small variations (<5%) between the three washing methods, irrespective of element, mode of delivery, and obstetric outcome. However, the contamination levels elicited by each of the three methods varied in magnitude according to individual elements, with those of copper being highest, followed by those of zinc, cadmium, mercury, selenium, and lead. They also varied according to obstetric outcome, being highest in the AP subsamples, while in the normal pregnancy group, copper and zinc contamination levels in the subsamples from neonates delivered by elective caesarean section were higher than in those from normal-delivery neonates. The data from this study suggest that the three washing methods used have comparable efficacies in removing exogenous elemental contamination from fetal hair, further inferring that it is probably a simple biological matrix to decontaminate. Possible contributory factors are discussed and contrasted with those affecting adult hair. 相似文献
998.
Wheat flavone O-methyltransferase catalyzes three sequential methylations of the flavone tricetin. Like other flavonoid O-methyltransferases, the protein is a homodimer. We demonstrate, using analytical ultracentrifugation, that perchlorate dissociates the dimer into monomers. The resulting monomers retain all their catalytic capacity, including the ability to catalyze the three successive methylations. We show, using isothermal titration calorimetry, that the binding constant for S-adenosyl-L-methionine does not change significantly as the protein dissociates. The second substrate, tricetin, binds to the dimers but could not be tested with the monomers. CD, UV and fluorescence spectroscopy show that there are substantial changes in the structure of the protein as it dissociates. The fact that there are differences between the monomers and dimers even as the monomers maintain activity may be the result of the very low catalytic capacity of this enzyme. Maximal turnover numbers for the dimers and monomers are only about 6-7 per minute. Even though the binding pockets for S-adenosyl-L-methionine, tricetin, selgin and tricin are intact, selection of a catalytically competent structure may be a very slow step during catalysis. 相似文献
999.
Background
The Mitotic Spindle Assembly Checkpoint (MSAC) is an evolutionary conserved mechanism that ensures the correct segregation of chromosomes by restraining cell cycle progression from entering anaphase until all chromosomes have made proper bipolar attachments to the mitotic spindle. Its malfunction can lead to cancer.Principle Findings
We have constructed and validated for the human MSAC mechanism an in silico dynamical model, integrating 11 proteins and complexes. The model incorporates the perspectives of three central control pathways, namely Mad1/Mad2 induced Cdc20 sequestering based on the Template Model, MCC formation, and APC inhibition. Originating from the biochemical reactions for the underlying molecular processes, non-linear ordinary differential equations for the concentrations of 11 proteins and complexes of the MSAC are derived. Most of the kinetic constants are taken from literature, the remaining four unknown parameters are derived by an evolutionary optimization procedure for an objective function describing the dynamics of the APC:Cdc20 complex. MCC:APC dissociation is described by two alternatives, namely the “Dissociation” and the “Convey” model variants. The attachment of the kinetochore to microtubuli is simulated by a switching parameter silencing those reactions which are stopped by the attachment. For both, the Dissociation and the Convey variants, we compare two different scenarios concerning the microtubule attachment dependent control of the dissociation reaction. Our model is validated by simulation of ten perturbation experiments.Conclusion
Only in the controlled case, our models show MSAC behaviour at meta- to anaphase transition in agreement with experimental observations. Our simulations revealed that for MSAC activation, Cdc20 is not fully sequestered; instead APC is inhibited by MCC binding. 相似文献1000.
Steinauer ML Mwangi IN Maina GM Kinuthia JM Mutuku MW Agola EL Mungai B Mkoji GM Loker ES 《PLoS neglected tropical diseases》2008,2(4):e222