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81.
Electrochemical Signal Tracing by Glucose Oxidase and Ferrocene Dually Functionalized Gold Nanoprobe for Ultrasensitive Immunoassay 下载免费PDF全文
A glucose oxidase (GOD) and ferrocene (Fc) dually functionalized gold nanoprobe was simply prepared for electrochemical immunoassay. By combination with sandwich immunoreaction at a carbon nanotube (CNT)‐based immunosensor and signal tracing of the nanoprobe through the Fc‐mediated GOD‐catalytic reaction, a new electrochemical immunoassay method was successfully developed. Both the multi‐enzyme signal amplification of the nanoprobe and the electron transfer promotion of the CNTs modified on the immunosensor greatly enhanced the signal response. Thus this method showed excellent analytical performance including ultrahigh sensitivity, wide linear range as well as good specificity, reproducibility, stability and reliability for human IgG measurement. 相似文献
82.
Dungchai W Siangproh W Lin JM Chailapakul O Lin S Ying X 《Analytical and bioanalytical chemistry》2007,387(6):1965-1971
A micro-magnetic chemiluminescence (CL) enzyme immunoassay with high sensitivity, selectivity, and reproducibility was developed
for the determination of the tumor marker, carcinoembryonic antigen (CEA) in human serum. A sandwich scheme assay has been
utilized with fluorescein isothiocyanate antibody (FITC)-labeled anti-CEA antibody and alkaline phosphate (ALP)-labeled anti-CEA
antibody being used in the CL detection. The CL signal produced by the emission of photons from 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2′-adamantane)
(AMPPD) was directly proportional to the amount of analyte present in a sample solution. The influences of the reaction time
of antigen with antibody, the reaction time of substrate with label, the dilution ratio of ALP-labeled anti-CEA antibody,
the concentration of FITC-labeled anti-CEA antibody, and other relevant variables upon the CL signal were examined and optimized.
The CL responses depended linearly on the CEA concentration over the range from 2 to 162 ng mL−1 in a logarithmic plot. Assay sensitivity as low as 0.69 ng mL−1 was achieved. A coefficient of variance of less than 13% was obtained for intra- and inter-assay precision. This method has
been successfully applied to the analysis of CEA in human serum. According to the procedure based on spiked standards, the
recoveries obtained were 80–110%. Comparison experiments were carried out with the commercially available CEA chemiluminescence
immunoassay. Satisfactory results were obtained according to a paired t-test method (t value < t
critical at the 95% confidence level). 相似文献
83.
Kolosova AY De Saeger S Eremin SA Van Peteghem C 《Analytical and bioanalytical chemistry》2007,387(3):1095-1104
Rapid-response analytical tests that can be performed at the point of sampling are based on a visual detection system. The
influence of different factors on the signal generation in a membrane-based enzyme immunoassay was investigated. The research
was applied to a flow-through immunoassay for the detection of ochratoxin A (OTA). This assay format is a very convenient,
simple and fast qualitative screening tool. Conjugates of OTA with horseradish peroxidase (HRP) and alkaline phosphatase (AP)
were used as enzyme tracers. A new conjugate OTA-AP has been synthesized in our laboratory and its performance in the assay
was compared with that of OTA-HRP. Different substrate systems for HRP and AP were compared. Several reagents, including polymers
and surfactants, were tested for their possible effect on signal generation with the use of OTA-HRP conjugate. Polymers such
as poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG) 6000 exerted a favourable effect on signal amplification, whereas
surfactants negatively affected assay performance. The highest signal amplification (30–70% compared to the standard assay
procedure) was achieved using 0.5% PVA in tetramethylbenzidine (TMB) Colorburst substrate solution and phosphate-buffered
saline (PBS) for the washing step. It allowed more reliable visual estimation of the results from OTA-HRP assay. Exclusion
of the detergent (Tween 20) from the washing solution exerted a favourable effect on assay performance using both enzyme tracers.
The assay using OTA-HRP was more susceptible to matrix interferences than the assay with OTA-AP. Signal development in the
matrix was better for the OTA-AP assay and visual estimation of the results was easier to perform in this case. For the analysis
of spiked wheat samples, OTA-AP conjugate gave a more sensitive, stable and reproducible assay with a cut-off level of 4 μg
kg−1 for OTA. The application of the new OTA-AP conjugate resulted in improved assay performance for the food samples. 相似文献
84.
电化学发光法测定发光标记试剂ABEI 总被引:1,自引:0,他引:1
ABEI-[N-(4-氨基丁基)-N-乙基]-氯基-2,3-二氢吩噻嗪-1,4-二酮是化学发光免疫分析法(简称LIA)中最常用的发光标记试剂,但有关电化学发光免疫分析目前尚未见报道。本文利用自制的电化学发光仪,对ABEI和ABEI标记兔抗HCG的电化学发光行为进行了研究。提出了利用电化学发光进行免疫分析的新途径。 相似文献
85.
设计了一种化学发光免疫分析试剂吖啶酯的合成新路线,以二苯胺为原料合成吖啶-9-羧酸,经酰氯化后与3-(4-羟基苯基)-丙酸-N-羟基琥珀酰亚胺酯反应得4-(2-琥珀酰亚胺基氧羰基乙基)苯基-9-吖啶羧酸酯,最后与氟磺酸甲酯反应即得4-(2-琥珀酰亚胺基氧羰基)苯基-10-甲基吖啶-9-羧酸酯氟磺酸盐(俗称吖啶酯). 相似文献
86.
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88.
TAN Wenjia SUN Zhixia XUAN Lili LI Junling XIE Wenbing HE Chengyan PAN Lihua 《高等学校化学研究》2018,34(1):24-27
The effect of the chelating agent 4,7-bis(chlorosulfophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BCPDA) labeled hepatitis B surface antibodies(HBsAb) on time-resolved fluoroimmunoassays(TRFIA) was investigated. The labeling detection method was established. The biotin-streptavidin(BAS) system was introduced, and the multi-stage amplification effect of the BAS system was analyzed. It is found that the BCPDA-Eu3+-HBsAb-BAS fluorescent marker can emit strong fluorescence. Compared to BCPDA-Eu3+-HBsAb, BCPDA-Eu3+-HBsAb-BAS demonstrates an enhanced fluorescence intensity by over 10 times. This study provides a guidance for the next gene- ration non-radio immunoassays in clinical diagnosis. 相似文献
89.
Filiz Ibraimi Kirstin Kriz Henrik Merin 《Journal of magnetism and magnetic materials》2009,321(10):1632-1634
We describe an one-step 11-min magnetic permeability based two-site immunoassay for C-reactive protein (CRP) utilizing polyclonal anti-canine CRP antibody conjugated dextran iron oxide nanoparticles (79 nm) as superparamagnetic labels and polyclonal anti-canine CRP conjugated silica microparticles (15 to 40 μm) as carriers. An inductance based magnetic permeability reader was used to detect the target analyte, CRP, in 10 μL whole blood samples, by measuring the magnetic permeability increase of the silica microparticle sediment due to immuno complex superparamagnetic nanoparticles. Measurements on standards showed a linear response between 0 and 17.5 mg/L CRP. Measurements performed on 16 whole blood samples from mixed breeds showed good correlation with a commercially available ELISA assay. 相似文献
90.
Luc Lenglet 《Journal of magnetism and magnetic materials》2009,321(10):1639-1643
A powerful route to utilizing magnetic nanoparticles as labels in magnetic immunoassays is to exploit their non-linear response when they are exposed to a multi-frequency alternating magnetic field. We have upgraded this non-linear method allowing for the detection, discrimination and quantification of particles of two kinds when mixed together, with no need for spatial resolution. Each kind of particle is characterized by a specific magnetic signature based on d2B(H)/dH2. Appropriate data processing of the signature measured on a mixture of both particles allows for obtaining the amount of each particle. This will enable utilizing magnetic labels for multiparametric magnetic immunoassays. 相似文献