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71.
Improved in vitro anti-tumoral activity, intracellular uptake and apoptotic induction of gemcitabine-loaded pegylated unilamellar liposomes 总被引:1,自引:0,他引:1
Celia C Calvagno MG Paolino D Bulotta S Ventura CA Russo D Fresta M 《Journal of nanoscience and nanotechnology》2008,8(4):2102-2113
Anaplastic thyroid carcinoma is one of the most aggressive and lethal solid carcinomas affecting humans. A major limit of the chemotherapeutic agents is represented by their low therapeutic index. In this work, we investigated the possibility of improving the anti-tumoral activity of gemcitabine by using pegylated unilamellar liposomes. Liposomes were made up of 1,2-dipalmitoyl-sn-glycero-3-phospocholine monohydrate/cholesterol/N-(carbonyl-methoxypolyethylene glycol-2000)-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine (6:3:1 molar ratio) and they were prepared with a pH gradient to improve the gemcitabine loading capacity. The anti-tumoral efficacy of the liposomal formulation was tested in vitro on human anaplastic thyroid carcinoma cells (ARO) in culture, comparing the effects with those of the free drug. Gemcitabine-loaded unilamellar liposomes had a mean size approximately 200 nm with a zeta potential approximately -2 mV. The liposomal carrier noticeably improved the anti-tumoral activity of gemcitabine against ARO cells in terms of both dose-dependent cytotoxic effect and of drug exposition effect. Namely, gemcitabine-loaded liposomes showed a cytotoxic effect (58.2% increase of cell mortality at 1 microM with respect to free drug) after 12 h incubation, while the free drug showed a significant activity only after 72 h incubation. Moreover, a significant effect on the cell mortality appeared at 0.1 microM and 100% mortality was detected at a concentration of 1 microM of gemcitabine-loaded liposomes, while the free drug elicited the same effect at a concentration of 100 microM. The improved anti-tumoral activity of gemcitabine determined by the liposomal carrier was due to a greater intracellular uptake. The intracellular gemcitabine levels as a function of time showed a sinusoidal profile with peaks after 2 h, 6 h and 11 h, related to the cellular cycle of ARO. PARP cleavage and DNA fragmentation analysis provided clear evidence of the apoptosis induction in ARO cells by treatment with liposomally entrapped gemcitabine after 72 h incubation. Thus, gemcitabine-loaded liposomes may have a potential therapeutic relevance for the treatment of anaplastic thyroid carcinoma. 相似文献
72.
In this paper, a hierarchical algorithm, HierarchyScan, is proposed to efficiently locate one-dimensional subsequences within a collection of sequences with arbitrary length. The proposed algorithm performs correlation between the stored sequences and the template pattern in the transformed domain to identify subsequences in a scale- and phase-independent fashion. This is in contrast to those approaches based on the computation of Euclidean distance in the transformed domain. In the proposed hierarchical algorithm, the transformed domain representation of each original sequence is divided into multiple groups of coefficients. The matching is performed hierarchically from the group with the greatest filtering capability to the group with the lowest filtering capability. Only those subsequences whose maximum correlation value is higher than a predefined threshold will be selected for additional screening. This approach is compared to the sequential scanning and an order-of-magnitude speedup is observed. 相似文献
73.
Seyedeh Homa Fasihnia Seyed Hadi Peighambardoust Seyed Jamaleddin Peighambardoust Abdulrasoul Oromiehie Maral Soltanzadeh Donatella Peressini 《Journal of food science》2020,85(8):2317-2328
Polypropylene (PP) based active composite films were prepared by adding butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT), and tertiary butylated hydroquinone (TBHQ) antioxidants using the extrusion molding process. All concentrations of BHT, 2% to 3% BHA, and 3% TBHQ significantly increased the tensile strength (TS) of the composite films compared with control films. Increasing antioxidant concentration decreased TS values for BHT films, whereas an opposite trend was observed for BHA and TBHQ films. BHA at < 2%, BHT at > 2%, and TBHQ at all added concentrations significantly reduced elongation at break (Eb) of the composite films compared to control films. Water vapor permeability (WVP) of 1% BHT film was not significantly different from control. However, other antioxidants especially at increased concentrations significantly increased WVP values. TBHQ films with 300% to 662% increase had the highest WVP and BHT films with 5% to 81% increase had the lowest WVP among composite films. All three antioxidants had a negative effect on the transparency of the films; however the effect of BHA at higher concentrations was greater. The antioxidants did not change the color attributes of the films. Films containing all antioxidants showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, which increased with increase in their concentration, especially for those containing 3 wt.% BHT and TBHQ. Overall, incorporating BHA and BHT into a PP matrix improved mechanical, barrier, antioxidant properties, and film appearance and consequently were proposed for the development of antioxidant active PP films. TBHQ film is not recommended for food packaging because of its weak mechanical properties (lower Eb and TS values, higher WVP, and greater migration). 相似文献
74.
Maria Grazia Tupone Gloria Panella Michele dAngelo Vanessa Castelli Giulia Caioni Mariano Catanesi Elisabetta Benedetti Annamaria Cimini 《International journal of molecular sciences》2021,22(23)
Thanks to their reduced size, great surface area, and capacity to interact with cells and tissues, nanomaterials present some attractive biological and chemical characteristics with potential uses in the field of biomedical applications. In this context, graphene and its chemical derivatives have been extensively used in many biomedical research areas from drug delivery to bioelectronics and tissue engineering. Graphene-based nanomaterials show excellent optical, mechanical, and biological properties. They can be used as a substrate in the field of tissue engineering due to their conductivity, allowing to study, and educate neural connections, and guide neural growth and differentiation; thus, graphene-based nanomaterials represent an emerging aspect in regenerative medicine. Moreover, there is now an urgent need to develop multifunctional and functionalized nanomaterials able to arrive at neuronal cells through the blood-brain barrier, to manage a specific drug delivery system. In this review, we will focus on the recent applications of graphene-based nanomaterials in vitro and in vivo, also combining graphene with other smart materials to achieve the best benefits in the fields of nervous tissue engineering and neural regenerative medicine. We will then highlight the potential use of these graphene-based materials to construct graphene 3D scaffolds able to stimulate neural growth and regeneration in vivo for clinical applications. 相似文献
75.
76.
The antigenic profile of Olea europaea pollen from different Mediterranean cultivars was obtained by MALDI mass spectrometry. A simple procedure of chemical fractionation of the whole antigen extract was developed, whereby less complex, or pure, fractions of antigen candidate were obtained prior to mass spectrometric analysis. Some of the features of protein structure and distribution probably depend on cultivar adaptation to the environment. The profilings of pollen proteins thus obtained allow the distinction of the analyzed cultivars into three distinct groups: (i) those characterized by a low Ole e 1 content; (ii) those over-enriched in Ole e 1 and (iii) that containing Ole e 3 and Ole e 7 only. The latter consists of at least four isoforms differing by the degree of glycosilation. These results demonstrate that the proposed experimental procedure, can supply valuable information on the antigens' micro heterogeneity. 相似文献
77.
G Rocchitta O Secchi MD Alvau R Migheli G Calia G Bazzu D Farina MS Desole RD O'Neill PA Serra 《Analytical chemistry》2012,84(16):7072-7079
Ethanol is one of the most widespread psychotropic agents in western society. While its psychoactive effects are mainly associated with GABAergic and glutamatergic systems, the positive reinforcing properties of ethanol are related to activation of mesolimbic dopaminergic pathways resulting in a release of dopamine in the nucleus accumbens. Given these neurobiological implications, the detection of ethanol in brain extracellular fluid (ECF) is of great importance. In this study, we describe the development and characterization of an implantable biosensor for the amperometric detection of brain ethanol in real time. Ten different designs were characterized in vitro in terms of Michaelis-Menten kinetics (V(MAX) and K(M)), sensitivity (linear region slope, limit of detection (LOD), and limit of quantification (LOQ)), and electroactive interference blocking. The same parameters were monitored in selected designs up to 28 days after fabrication in order to quantify their stability. Finally, the best performing biosensor design was selected for implantation in the nucleus accumbens and coupled with a previously developed telemetric device for the real-time monitoring of ethanol in freely moving, untethered rats. Ethanol was then administered systemically to animals, either alone or in combination with ranitidine (an alcohol dehydrogenase inhibitor) while the biosensor signal was continuously recorded. The implanted biosensor, integrated in the low-cost telemetry system, was demonstrated to be a reliable device for the short-time monitoring of exogenous ethanol in brain ECF and represents a new generation of analytical tools for studying ethanol toxicokinetics and the effect of drugs on brain ethanol levels. 相似文献
78.
Mader A Gruber K Castelli R Hermann BA Seeberger PH Rädler JO Leisner M 《Nano letters》2012,12(1):420-423
Carbohydrate-based sensors, that specifically detect sugar binding molecules or cells, are increasingly important in medical diagnostic and drug screening. Here we demonstrate that cantilever arrays functionalized with different mannosides allow the real-time detection of several Escherichia coli strains in solution. Cantilever deflection is thereby dependent on the bacterial strain studied and the glycan used as the sensing molecule. The cantilevers exhibit specific and reproducible deflection with a sensitivity range over four orders of magnitude. 相似文献
79.
80.
Arosio D Belvisi L Colombo L Colombo M Invernizzi D Manzoni L Potenza D Serra M Castorina M Pisano C Scolastico C 《ChemMedChem》2008,3(10):1589-1603
A small library of cyclic RGD pentapeptide mimics, including benzyl-substituted azabicycloalkane amino acids, was synthesized with the aim of developing active and selective integrin antagonists. In vitro binding assays established one particular compound with affinity for both the alpha(v)beta(3) and the alpha(v)beta(5) integrins. The synthesis in solution and the in vitro screening of these RGD derivatives, as well as the determination of the conformational properties of the integrin ligands by spectroscopic and computational methods are described. 相似文献