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61.
血脑屏障的存在,导致药物不能有效到达靶部位发挥作用,极大的影响神经系统药物的发展和进步。纳米技术已被证明是用于脑靶向治疗的一种有效工具,尤其在脑肿瘤和神经退行性疾病中应用甚广。功能化纳米粒通过表面修饰等提高药物的顺应性,在药物原来的治疗基础上,达到更加精准的靶向性,高效率在靶部位聚集,起到治疗作用。本文主要综述功能化纳米粒及其功能化策略,总结了影响功能化纳米粒脑靶向运输的因素,同时对功能化的纳米粒在脑部疾病治疗中的优势和应用进行阐述,为其相关研究提供参考。  相似文献   
62.
目的:研究miRNA-30b纳米粒对甲状腺未分化癌细胞株TA-K细胞的生物学特性的影响。方法转染不同浓度的miRNA-30b纳米粒进入TA-K细胞中,通过流式法检测TA-K细胞凋亡情况,后通过生物信息学预测miR-NA-30b的生物学靶点,并通过RT-PCR及Western Blot方法验证。结果发现转染了miRNA-30b纳米粒后,TA-K细胞的凋亡显著增加,而生物信息学显示miRNA-30b可靶向作用于Survivin,后经RT-PCR及Western blot 法证实Sur-vivin确实是miRNA-30b的生物学靶点。结论 miRNA-30b可以通过作用Survivin促进TA-K细胞的凋亡,这一现象也为将来甲状腺未分化癌的临床治疗提供了新的思路。  相似文献   
63.
Siloxanes have been detected in the biogas produced at municipal solid waste landfills and wastewater treatment plants. When oxidized, siloxanes are converted to silicon oxides. The objectives of this study were to evaluate the transformation of siloxanes and potential nanotoxicity of Si-based particles released to the atmosphere from the gas engines which utilize biogas. Data available from nanotoxicity studies were used to assess the potential health risks associated with the inhalation exposure to Si-based nanoparticles. Silicon dioxide formed from siloxanes can range from 5 nm to about 100 nm in diameter depending on the combustion temperature and particle clustering characteristics. In general, silicon dioxide particles formed during from combustion process are typically 40–70 nm in diameter and can be described as fibrous dusts and as carcinogenic, mutagenic, astmagenic or reproductive toxic (CMAR) nanoparticles. Nanoparticles deposit in the upper respiratory system, conducting airways, and the alveoli. Size ranges between 5 and 50 nm show effective deposition in the alveoli where toxic effects are higher. In this study the quantities for the SiO2 formed and release during combustion of biogas were estimated based on biogas utilization characteristics (gas compositions, temperature). The exposure to Si-based particles and potential effects in humans were analyzed in relation to their particle size, release rates and availability in the atmosphere. The analyses showed that about 54.5 and 73 kg/yr of SiO2 can be released during combustion of biogas containing D4 and D5 at 14.1 mg/m3 (1 ppm) and 15.1 mg/m3 (1 ppm), respectively, per MW energy yield.  相似文献   
64.
Convincing evidence suggests that high-surface-activity nano-materials, such as MWCNT, exert two modes of action (MoA), in which one appears to be related to surface activity/area and occurs concurrent with deposition, and the other is related to cumulative lung burden. Pulmonary inflammation induced by the latter mode appears to be dependent on cumulative volumetric lung burden and on whether the accumulated particle displacement volume within the pool of alveolar macrophages is above or below the kinetic lung overload threshold. However, the relative importance and effect of each MoA are still controversial. In addition, the test protocol variables, which may predetermine the leading MoA, have not yet received increased attention. This study compares the respective outcome of previously published repeated-exposure inhalation studies with MWCNT (Nanocyl and Baytube) in rats. Modeling procedures were performed to compare post hoc the equivalence of empirical and modeled outcomes, including critical protocol variables. This comparison provided compelling evidence that the accumulated retained particle displacement volume was the most prominent unifying denominator linking the pulmonary retained volumetric particle dose to inflammogenicity and toxicity. However, conventional study designs may not always be appropriate to unequivocally dissociate the surface area/activity-related acute adversity from the cumulative retention volume-related adversity. Thus, in the absence of adequately designed studies, it may become increasingly challenging to differentiate substance-specific deposition-related acute effects from the more chronic retained cumulative dose-related effects. In summary, this analysis of existing data supports the conclusion that both the deposition and retention-related effects need to be judiciously dissociated to better understand the MoA of heightened concern. This exercise supports the conclusion that hypothesis-based computational study design delivers the highest degree of scientifically important information and may further reduce the number of experimental animals in repeated-exposure inhalation studies with low-toxicity, biopersistent, poorly soluble granular particles.  相似文献   
65.
Drug delivery by inhalation is a noninvasive means of administration that has following advantages for local treatment for airway diseases: reaching the epithelium directly, circumventing first pass metabolism and avoiding systemic toxicity. Moreover, from the physiological point of view, the lung provides advantages for systemic delivery of drugs including its large surface area, a thin alveolar epithelium and extensive vasculature which allow rapid and effective drug absorption. Therefore, pulmonary application is considered frequently for both, the local and the systemic delivery of drugs. Lipid nanoparticles – Solid Lipid Nanoparticles and Nanostructured Lipid Carriers – are nanosized carrier systems in which solid particles consisting of a lipid matrix are stabilized by surfactants in an aqueous phase. Advantages of lipid nanoparticles for the pulmonary application are the possibility of a deep lung deposition as they can be incorporated into respirables carriers due to their small size, prolonged release and low toxicity. This paper will give an overview of the existing literature about lipid nanoparticles for pulmonary application. Moreover, it will provide the reader with some background information for pulmonary drug delivery, i.e., anatomy and physiology of the respiratory system, formulation requirements, application forms, clearance from the lung, pharmacological benefits and nanotoxicity.  相似文献   
66.
目的:研究人肝癌细胞株HepG2对同时包载齐墩果酸(OA)和香豆素6的乳酸羟基乙酸共聚物纳米粒(OCPN)和乳酸羟基乙酸共聚物-水溶性维生素E纳米粒(OCPTN)的体外摄取情况。方法:以超声乳化-溶剂挥发法制备OCPTN和OCPN,其中香豆素6为荧光标记物;采用高效液相色谱法测定两种纳米粒中香豆素6的载药量,体外测定HepG2细胞对分别含100、200、400μg/ml(低、中、高质量浓度)香豆素6的OCPTN、OCPN混悬液的摄取率,显微镜观察HepG2细胞对OCPTN的摄取情况。结果:OCPTN和OPTN中香豆素6的载药量分别为7.6%、6.3%;低、中、高质量浓度OCPTN的细胞摄取率为(62.1±1.2)%、(53.6±1.3)%、(40.9±1.5)%,分别是相同质量浓度OCPN的细胞摄取率[(36.8±1.5)%、(31.2±1.9)%、(22.4±1.3)%]的1.69、1.72、1.83倍;镜下观察OCPTN被HepG2细胞摄取,处于细胞核周围。结论:OCPN和OCPTN均能被HepG2细胞摄取,且OCPTN的被摄取性更强。  相似文献   
67.
透明质酸(hyaluronic acid, HA)因其良好的理化性质和肿瘤靶向性,已作为药物载体或者靶向因子应用于肿瘤治疗的新型给药系统中,并成为肿瘤治疗研究的热点。本文主要对HA在新型给药系统的应用进行介绍。  相似文献   
68.
摘 要 目的:星点设计 效应面法优化姜黄素牛血清白蛋白纳米粒(CUR BSA NPs)的制备工艺,考察其外观粒径分布及体外释放特性。 方法: 以牛血清白蛋白为载体材料,姜黄素作为模型药物,采用去溶剂法制备CUR BSA NPs,通过星点设计 效应面法优化其制备工艺,并对CUR BSA NPs的外观形态、粒径分布、包封率、载药量及体外释放进行研究。 结果: CUR BSA NPs制备的最佳工艺条件为牛血清白蛋白浓度10 mg·ml-1,乙醇体积7.79 ml,搅拌速度915 r·min-1。根据优化处方工艺制备的CUR BSA NPs外观呈圆形或类圆形,平均粒径(203.93±83.10) nm,Zeta电位-40~-50 mV;包封率为86.53%,载药量为3.89%。 结论: 最优工艺条件下制备的CUR BSA NPs包封率和载药量高,粒径分布较为均匀,体外释放试验表明与姜黄素原料药相比制备的CUR BSA NPs有良好的缓释特性。  相似文献   
69.
Baricitinib is a recently approved anti-rheumatic drug having very poor aqueous solubility and hence its performance suffers from low or inconsistent oral bioavailability. The purpose of the study was to develop and evaluate poly lactic-co-glycolic acid (PLGA) nanoparticles of baricitinib in order to enhance in vitro dissolution and performance. Nano-suspension of baricitinib with or without PLGA, a biodegradable, FDA approved semi-synthetic polymer, was developed by nanoprecipitation method. Research methodology employed a quantitative research utilizing experimental design wherein effect of independent variables such as amount of polymer, drug: polymer ratio, types of solvent, and solvent: anti-solvent ratio were evaluated over the size and size distribution of nanoparticles along with entrapment efficiencies. Among the several organic phases evaluated, acetone was found to be suitable solvent for drug and polymer. The aqueous phase (anti-solvent) was deionized water containing 1% w/v pluronic 127 as the stabilizer of nanoparticle suspension. The optimized nanoparticles had particle size less than 100 nm (91 nm ± 6.23) with a very narrow size distribution (0.169 ± 0.003), high zeta potential (−12.5 mV ± 5.46) and entrapment efficiency (88.0%). The optimized nanoparticles were characterized by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, infrared spectroscopy and in vitro dissolution studies. In-vitro dissolution study of PLGA nanoparticles exhibited sustained release with approximately 93% release of baricitinib during 24-h period.  相似文献   
70.
目的:探讨丹参酮ⅡA多级靶向纳米粒的制备及其工艺优化。方法采用乳化溶剂蒸发法制备丹参酮ⅡA多级靶向纳米粒;考察单因素在纳米粒制备过程中的影响,包括TSⅡA载药纳米粒中的药物浓度、乳化剂浓度、有机相/外水相、超声时间和强度等的改变;并通过正交设计优化TSⅡA多级靶向纳米粒的制备工艺。结果本实验成功制备了含RGD修饰的丹参酮ⅡA多级靶向纳米粒,优选工艺参数为:药物浓度1mg/mL,载体材料浓度20mg/mL,有机相/外水相为1∶10,超声强度和时间分别为200W,20×5s。结论此丹参酮ⅡA多级靶向纳米粒的制备工艺切实可行。所制备的TNP包封率和载药量较高,为丹参酮ⅡA的临床应用提供了更广阔的前景。  相似文献   
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