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1.
采用注塑方法,以医用纳米羟基磷灰石僳酰胺66(n-HA/PA66)复合材料为原料,使用专用发泡剂,制备出了一种具有贯通孔,平均孔隙尺寸约为500衄1的多孔材料,并参照GB/T16886和GB/T16175标准方法,对其生物安全性进行了相关评价。细胞毒性试验、致敏试验、热原试验和溶血试验结果表明本研究制备的多孔n-HA/PA66复合材料无细胞毒性、无致敏性、无热原反应,溶血率为0.59%(〈5%),可初步认为n—HA/PA66多孔材料具有良好的生物安全性,可用于骨组织修复。  相似文献
2.
Oligonucleotide microarrays are widely used to investigate gene expression in a large-scale approach. A major limitation is the dependency on frozen material to obtain high-quality ribonucleic acid because most clinical specimens are formalin-fixed and paraffin-embedded (FFPE). The ability to analyze these samples using microarrays would enlarge the investigable sample stocks manifold. We conducted a comparison of snap-frozen and FFPE tissues investigating two malignomas. Gene expression profiles were obtained from both materials of the tumors. Independently processed triplicates of snap-frozen and FFPE specimen, respectively, were two-round-amplified and hybridized on Affymetrix GeneChips (Palo Alto, CA, USA). Differentially expressed genes were identified in both FFPE and frozen material. All replicates had a correlation coefficient (R) of greater than 0.95 after normalization. Only direct comparison of FFPE to frozen replicates resulted in a mean R of 0.86, rendering a "mixed" investigation unfeasible. More than 50% (419 genes) of the more than fivefold differentially expressed genes (800 in FFPE, 685 in frozen material) were detected concomitantly regardless of the material used, which is similar to other comparisons of different gene expression analysis platforms. Thus, global gene expression analyses using solely FFPE material seem to be feasible with nearly comparable results to frozen tissue studies.  相似文献
3.
目的以人成骨细胞(MG-63细胞)复合纳米羟基磷灰石/胶原/聚乳酸[nano-hydroxyapatite/collagen/poly(L-lactic)acid,nHAC/PLA]支架材料进行体外培养,观察其早期附着生长情况。方法将MG-63细胞在nHAC/PLA支架材料上培养,通过倒置显微镜观察、HE染色、ALP染色、细胞增殖指数测定等方法对细胞在nHAC/PLA支架材料上的早期附着情况进行研究。结果细胞在nHAC/PLA上生长良好;ALP染色阳性度高,细胞增殖指数比空白对照组有显著提高。结论nHAC/PLA支架有利于MG-63细胞的早期黏附、生长,可以用作骨组织工程的支架材料。  相似文献
4.
可吸收骨折内固定材料要求具有良好的生物相容性。对自行研制的可吸收羟基磷灰石/聚DL乳酸(HA/PDLLA)复合骨折内固定材料进行了一系列生物相容性实验,包括Am es 实验、微核实验、急性和亚急性毒性实验、溶血实验、凝血试验和肌肉、骨内长期植入实验。结果表明,HA/PDLLA 材料无毒,无致突变性,不引起溶血和凝血。结论:HA/PDLLA 复合材料具有很好的生物相容性。  相似文献
5.
Template assisted fabrication of magnetic silica nanospheres with large nanopores (MSNLP) and their adsorption and delivery of nucleic acids are reported in this paper. Silica spheres with controlled particle diameter (∼400 nm) and large nanopore size (13-24 nm) are prepared by using Brij56 as a template of mesopore, enabling incorporation of magnetic nanocrystals into the particles under mild neutral synthesis conditions. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and field-dependent magnetisation measurements confirm that the magnetic nanocrystals have been encapsulated into the silica spheres. The saturation magnetisation values of the resulted magnetic-silica nanocomposites are tunable by adjusting the amount of Fe3O4 magnetic nanocrystals used in the synthesis process. The nitrogen sorption analysis reveals that mesopores with large pore size exist in the silica matrix. After functionalisation of the silica surface with poly-(l-lysine) (PLL), the nanoparticles show strong adsorption capacity (qm ranging from 10 to 22.5 μg/mg) for CpG DNA. We have further demonstrated successful delivery of miRNA into rat proximal tubular epithelial cells, facilitated by efficient cellular uptake of the nanocomposites. This work provides a convenient strategy to prepare MSNLP which can offer a versatile platform for biological applications such as simultaneous drug delivery and magnetic resonance imagining under external magnetic field.  相似文献
6.
Safety evaluation of surgical materials by cytotoxicity testing   总被引:2,自引:1,他引:1  
The cytotoxicity of three kinds of commercially available absorbable hemostats [oxidized cellulose (Surgicel, gauze and cotton types), microfibrillar collagen (Avitene), and cotton-type collagen (Integran)] and one adhesion barrier [sodium hyaluronate and carboxymethyl-cellulose membrane (Seprafilm)] were comparatively assessed by a colony assay using V79 cells and a minimum essential medium (MEM) elution assay in combination with a neutral red assay using L929 cells. Strong cytotoxicity was detected for Surgicel by both the MEM elution assay and the colony assay. For Avitene, both methods revealed weak cytotoxicity. For Seprafilm, no cytotoxicity was detected by the MEM elution assay, while a moderate degree of cytotoxicity was observed in the colony assay. For Integran cytotoxicity was not detected by either the MEM elution or the colony assay. The results of the different methods showed some inconsistency in terms of the degree of cytotoxicity of the materials. It is proposed that the combination of two or more sensitive cytotoxicity testing methods for the evaluation of biomaterials is necessary to avoid false-negative results for biomaterials at the preclinical stage. Furthermore, investigation of the correlation between the cytotoxicity and the extraction period of the surgical materials is helpful for predicting the effect of prolonged in vivo use of biomaterials on surrounding cells, tissues, and organs.  相似文献
7.
脱细胞软骨生物支架材料的生物学特性   总被引:2,自引:0,他引:2  
目的 探讨脱细胞软骨生物支架材料(ACM)在细胞毒性、溶血试验、急性全身毒性等方面的生物学特性:方法①ACM的制备:猪膝关节软骨冻干加工为粉末,胰酶消化,曲拉通洗脱,蒸馏水洗净冻干,紫外线照射(UVI)后成型;③细胞毒性测定:材料浸提液培养细胞进行细胞形态人体观察,MTT法观察细胞活性;③急性全身毒性反应:材料浸提液注射入SD大鼠腹腔观察材料对动物表现及体重变化的影响;④溶血试验:材料浸提液与稀释动物鲜血混合观察红细胞溶解情况,492nm下检测OD值计算相对溶血率;结果 ①细胞毒性试验:24h、48h、72h各时间段内三组细胞OD值两两比较(P〉0.05),无显著差异,ACM细胞毒性为0级;②动物急性毒性实验:Ⅰ生物材料处理组和Ⅱ生理盐水处理组对动物体重影响没有差异(P〉0.05),Ⅰ生物材料处珊组和Ⅲ苯酚处理组对动物体重有显著差异(P〈0.05);③溶血试验:材料相对溶血率为2.92%,低于5%的标准,尢明显溶血现象;结论ACM存细胞毒性、溶血实验、动物急性毒件反应方面符合软骨组织工程中对于支架材料的要求,提示支架材料何良好的牛物相容性和安全性。  相似文献
8.
Microencapsulation of genetically engineered cells has attracted much attention as an alternative nonviral strategy to gene therapy. Though smaller microcapsules (i.e. less than 300 μm) theoretically have various advantages, technical limitations made it difficult to prove this notion. We have developed a novel microfabricated device, namely a micro-airflow-nozzle (MAN), to produce 100 to 300 μm alginate microcapsules with a narrow size distribution. The MAN is composed of a nozzle with a 60 μm internal diameter for an alginate solution channel and airflow channels next to the nozzle. An alginate solution extruded through the nozzle was sheared by the airflow. The resulting alginate droplets fell directly into a CaCl2 solution, and calcium alginate beads were formed. The device enabled us to successfully encapsulate living cells into 150 μm microcapsules, as well as control microcapsule size by simply changing the airflow rate. The encapsulated cells had a higher growth rate and greater secretion activity of marker protein in 150 μm microcapsules compared to larger microcapsules prepared by conventional methods because of their high diffusion efficiency and effective scaffold surface area. The advantages of smaller microcapsules offer new prospects for the advancement of microencapsulation technology.  相似文献
9.
Surface modifications and cell-materials interactions with anodized Ti   总被引:2,自引:0,他引:2  
The objective of this study was to investigate in vitro cell-materials interactions using human osteoblast cells on anodized titanium. Titanium is a bioinert material and therefore becomes encapsulated after implantation into the living body by a fibrous tissue that isolates it from the surrounding tissues. In this work, a bioactive TiO(2) layer was grown on commercially pure titanium substrate by an anodization process using different electrolyte solutions, namely H(3)PO(4), HF and H(2)SO(4). These electrolytes produced bioactive TiO(2) films with a nonporous structure showing three distinctive surface morphologies. Human osteoblast cell growth behavior was studied with as-received and anodized surfaces using an osteoprecursor cell line (OPC 1) for 3, 5 and 11days. When anodized surfaces were compared for cell-materials interaction, it was noticed that each of the surfaces has different surface properties, which led to variations in cell-materials interactions. Colonization of the cells was noticed with a distinctive cell-to-cell attachment in the HF anodized surface. Good cellular adherence with extracellular matrix extensions in between the cells was noticed for samples anodized with H(3)PO(4) electrolyte. The TiO(2) layer grown in H(2)SO(4) electrolyte did not show significant cell growth on the surface, and some cell death was also noticed. Cell adhesions and differentiation were more pronounced with vinculin protein and alkaline phosphatase, respectively, on anodized surfaces. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assays also showed an increase in living cell density and proliferation with anodized surfaces. It was clear that rough surface morphology, high surface energy and low values of contact angles were important factors for better cell materials interaction. A mineralization study was done in simulated body fluid with ion concentrations nearly identical to those of human blood plasma to further understand biomimetic apatite deposition behavior. Similar to cell-materials interaction, variations in mineral deposition behavior were also noticed for films grown with different electrolytes.  相似文献
10.
H. Løwenstein  P. Lind  B. Weeke 《Allergy》1985,40(6):430-441
Freeze-dried extracts from cat dander and the corresponding rabbit antibodies were used for establishing the CIE reference pattern for cat dander extracts. Anti-Cat Ag 1 and anti-cat albumin were used for identification of the corresponding antigens. CRIE on sera from selected groups of American and Danish cat-allergic patients demonstrated antigen-specific IgE binding to 10 of 15 cat dander antigens (Cat Ag 1 being the major allergen). Only minor differences were found between the two groups. Four of these allergens were serum proteins. Variable amounts of many of the 10 allergens were measured by QIE in saliva, serum, urine and three cat pelt extracts. However, extremely wide ranges for content of the serum allergens and the non-serum allergens were found. This was exemplified by an albumin/cat Ag 1 ratio between 1 and 400, smallest in cat dander. Immunoabsorption using anti-cat dander, anti-cat albumin and anti-Cat Ag 1 indicated that the anti-cat dander, anti-cat albumin, and the anti-Cat Ag 1 absorbed approximately 90%, 25%, and 56%, respectively, of the dander RAST activity, and 87%, 11%, and 45%, respectively, of the saliva RAST activity, confirming the major importance of Ag 1. It is concluded that cat allergenic extracts should contain only modest amounts of serum albumin and other serum-derived antigens and that any relevant standardization must include quantification of at least Cat Ag 1 and cat albumin.  相似文献
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