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1.
Wang J  Zhou G  Chen C  Yu H  Wang T  Ma Y  Jia G  Gao Y  Li B  Sun J  Li Y  Jiao F  Zhao Y  Chai Z 《Toxicology letters》2007,168(2):176-185
In order to evaluate the toxicity of TiO(2) particles, the acute toxicity of nano-sized TiO(2) particles (25 and 80nm) on adult mice was investigated compared with fine TiO(2) particles (155nm). Due to the low toxicity, a fixed large dose of 5g/kg body weight of TiO(2) suspensions was administrated by a single oral gavage according to the OECD procedure. In 2 weeks, TiO(2) particles showed no obvious acute toxicity. However, the female mice showed high coefficients of liver in the nano-sized (25 and 80nm) groups. The changes of serum biochemical parameters (ALT/AST, LDH) and pathology (hydropic degeneration around the central vein and the spotty necrosis of hepatocytes) of liver indicated that the hepatic injury was induced after exposure to mass different-sized TiO(2) particles. In addition, the nephrotoxicity like increased BUN level and pathology change of kidneys was also observed in the experimental groups. The significant change of serum LDH and alpha-HBDH in 25 and 80nm groups showed the myocardial damage compared with the control group. However, there are no abnormal pathology changes in the heart, lung, testicle (ovary), and spleen tissues. Biodistribution experiment showed that TiO(2) mainly retained in the liver, spleen, kidneys, and lung tissues, which indicated that TiO(2) particles could be transported to other tissues and organs after uptake by gastrointestinal tract.  相似文献
2.
Developments in nanotechnology are leading to a rapid proliferation of new materials that are likely to become a source of engineered nanoparticles (ENPs) to the environment, where their possible ecotoxicological impacts remain unknown. The surface properties of ENPs are of essential importance for their aggregation behavior, and thus for their mobility in aquatic and terrestrial systems and for their interactions with algae, plants and, fungi. Interactions of ENPs with natural organic matter have to be considered as well, as those will alter the ENPs aggregation behavior in surface waters or in soils. Cells of plants, algae, and fungi possess cell walls that constitute a primary site for interaction and a barrier for the entrance of ENPs. Mechanisms allowing ENPs to pass through cell walls and membranes are as yet poorly understood. Inside cells, ENPs might directly provoke alterations of membranes and other cell structures and molecules, as well as protective mechanisms. Indirect effects of ENPs depend on their chemical and physical properties and may include physical restraints (clogging effects), solubilization of toxic ENP compounds, or production of reactive oxygen species. Many questions regarding the bioavailability of ENPs, their uptake by algae, plants, and fungi and the toxicity mechanisms remain to be elucidated.  相似文献
3.
胰岛素肠溶PLGA纳米粒的制备及体内外性质的评价   总被引:8,自引:0,他引:8  
目的制备肠溶胰岛素PLGA纳米粒,并对其理化性质、体外释药以及在正常大鼠体内的降血糖效果进行研究。方法采用改良的乳化溶剂扩散法分别制备了胰岛素PLGA纳米粒和肠溶胰岛素纳米粒(PLGA HP55 NP、PLGA HP50 NP)。通过激光粒度测定仪测定粒径大小,系统考察了肠溶材料HP55的用量及类型对纳米粒性质的影响,以及各种纳米粒在人工胃液、人工肠液中的释药行为和其在正常大鼠体内的降血糖作用,并与PLGA HP50 NP进行了比较。结果制得的最终处方的肠溶纳米粒(PLGA HP55)的粒径为(169±16)nm,胰岛素的载药量为(3.17±0.24)%。肠溶纳米粒在人工胃液中的释药速率明显低于PLGA纳米粒。PLGA纳米粒和肠溶PLGA HP50、PLGA HP55纳米粒均能显著降低正常大鼠的血糖浓度,其在正常大鼠体内24 h相对于皮下注射给药的相对生物利用度分别为(5.46±0.7)%、(6.31±0.64)%和(8.72±0.5)%。结论胰岛素肠溶纳米粒可以有效抑制胰岛素在人工胃液中的释放,与PLGA纳米粒相比显著降低正常大鼠的血糖浓度。其中PLGA HP55纳米粒的降糖作用显著高于PLGA HP50纳米粒。pH值高的纳米粒有望成为胰岛素口服给药的有效载体。  相似文献
4.
The purpose of this study was to construct isotretinoin-loaded SLN (IT-SLN) formulation with skin targeting for topical delivery of isotretinoin. PRECIROL ATO 5 was selected as the lipid of SLN. Tween 80 and soybean lecithin were used as the surfactants to stabilize SLN. The hot homogenization method was performed to prepare the drug-loaded SLN. The various formulations were characterized by photon correlation spectroscopy and all the SLN formulations had low average size between 30 and 50 nm. Transmission electron microscopy studies showed that the IT-SLN formulation had a spherical shape. All the formulations had high entrapment efficiency ranging from 80% to 100%. The penetration of isotretinoin from the IT-SLN formulations through skins and into skins were evaluated in vitro using Franz diffusion cells fitted with rat skins. The in vitro permeation data showed that all the IT-SLN formulations can avoid the systemic uptake of isotretinoin in skins, however the control tincture had a permeation rate of 0.76+/-0.30 microg cm(-2)h(-1) through skins. The IT-SLN consisting of 3.0% PRECIROL ATO 5, 4.0% soybean lecithin and 4.5% Tween 80 could significantly increased the accumulative uptake of isotretinoin in skin and showed a significantly enhanced skin targeting effect. The studied IT-SLN showed a good stability. These results indicate that the studied IT-SLN formulation with skin targeting may be a promising carrier for topical delivery of isotretinoin.  相似文献
5.
壳聚糖纳米粒表面游离氨基与纳米粒特性研究   总被引:7,自引:1,他引:6  
为研究对三聚磷酸钠(TPP)交联的壳聚糖纳米粒的表面游离氨基与纳米粒的性质之间的关联性,采用胶体滴定法测定壳聚糖纳米粒表面氨基游离率,考察表面游离氨基的数量及离解程度对纳米粒粒径、电位、形态及对药物包封率和体外释药特性的影响,并阐述这种变化机制。结果表明,随TPP浓度增加,表面游离氨基逐步减少,在一定TPP浓度范围内,纳米粒粒径减小,表面zeta电位降低,稳定性也随之下降,粒子易聚集,释药速度和程度也随之降低,但药物包封率未受到影响;随着pH升高,表面游离氨基离解程度降低,纳米粒粒径亦随之减小,表面zeta电位降低。酸性介质提高纳米粒的释药速度和程度,在中性和碱性介质中纳米粒的释药速度和程度明显降低。交联程度和pH影响表面游离氨基的数量或离解程度,进而影响纳米粒的体积相转变(溶胀/收缩过程)等重要性质。表面游离氨基与纳米粒性质间有密切的联系。  相似文献
6.
羟基喜树碱半固体脂质纳米粒的制备和体外释药特性   总被引:7,自引:0,他引:7  
目的:制备羟基喜树碱的半固体脂质纳米粒(HCPT-SSLN),初步考察其体外释药规律。方法:采用乳化蒸发-低温固化法制备HCPT-SSLN;用激光粒度仪测定其粒径和ξ电位;考察其混悬液和冻千粉的物理稳定性;用透析法考察其体外释药性质。结果:HCPT-SSLN纳米粒平均粒径为130.5nm,裁药量为2.51%,包封率为79.19%,ξ电位为-33.1mV;室温(25℃)和4℃下放置6个月,纳米粒冻干粉和混悬液外观、粒径及包封率无明显变化;体外释药规律符合Weibull方程lnln[1/(1-Q)]=0.26331nt+0.0509(R^2=0.9485)。结论:制备的HCPT-SSLN包封率高,稳定性好,大小均匀,体外释药具有缓释特点。  相似文献
7.
姜黄素固体脂质纳米粒的制备及表征   总被引:6,自引:0,他引:6  
目的:制备姜黄素(Cur)固体脂质纳米粒(SLN)。方法:用薄膜超声法制备Cur-SLN,以mcur:m单硬脂酸甘油酯、m单硬脂酸甘油酯:m卵磷脂、聚山梨酯-80质量浓度、超声时间为考察因素,以包封率为指标,用正交试验优选处方,并考察其粒径分布、Zeta电位。结果:当mcur:m单硬脂酸甘油酯=1:3、m单硬脂酸甘油酯:m卵磷脂=1:2.5、聚山梨酯-80质量浓度2.5%、超声时间12min时,所制得的Cur-SLN平均粒径为(145.6±5)nm,Zeta电位为(-31.9±1.5)mV,包封率为(97.42±0.39)%,载药量为(7.92±0.05)%。结论:采用薄膜-超声法制备Cur-SLN可行,为开发姜黄素新型给药系统提供试验依据。  相似文献
8.
Magnetic nanoparticles in MR imaging and drug delivery   总被引:6,自引:0,他引:6  
Magnetic nanoparticles (MNPs) possess unique magnetic properties and the ability to function at the cellular and molecular level of biological interactions making them an attractive platform as contrast agents for magnetic resonance imaging (MRI) and as carriers for drug delivery. Recent advances in nanotechnology have improved the ability to specifically tailor the features and properties of MNPs for these biomedical applications. To better address specific clinical needs, MNPs with higher magnetic moments, non-fouling surfaces, and increased functionalities are now being developed for applications in the detection, diagnosis, and treatment of malignant tumors, cardiovascular disease, and neurological disease. Through the incorporation of highly specific targeting agents and other functional ligands, such as fluorophores and permeation enhancers, the applicability and efficacy of these MNPs have greatly increased. This review provides a background on applications of MNPs as MR imaging contrast agents and as carriers for drug delivery and an overview of the recent developments in this area of research.  相似文献
9.
目的:建立葫芦素B人血清白蛋白纳米粒中药物含量的测定方法。方法:采用Diamonsil C18柱(200mm×4.6 mm,5μm);以乙腈-水-磷酸(45∶55∶0.1)作为流动相;流速为1 mL.min-1;检测波长为228 nm;柱温30℃。结果:在本实验条件下蛋白纳米粒中辅料对葫芦素B的测定无干扰,在1.0~20 mg.L-1浓度范围内线性关系良好(r=0.999 9,n=5),葫芦素B平均回收率为100.2%,RSD为0.8%(n=3)。结论:本法准确可靠,简便易行,可用于葫芦素B人血清白蛋白纳米粒中药物含量的测定。  相似文献
10.
黄芩苷固体脂质纳米粒体外释放研究   总被引:5,自引:1,他引:4  
目的:研究黄芩苷固体脂质纳米粒的体外释药规律。方法:采用动态透析技术研究黄芩苷固体脂质纳米粒的体外释药性能,并用高效液相色谱法测定黄芩苷含量,以累积释药百分率进行不同模型的拟合。结果:黄芩苷固体脂质纳米粒的释放曲线符合Hixon-crowell方程,t≈3h。结论:黄芩苷固体脂质纳米粒具有良好的缓释作用。  相似文献
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