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1.
A new ex vivo method for assaying adhesion of cancer cells to the greater omentum has been developed using mouse greater omentum and [3H]labelled human gastric and mouse colorectal cancer cells. Since the adhesion rates were found to increase up to 18 h and labelled cells seemed to be stable during the period, the present method could be useful for investigating adhesion of cancer cells to the greater omentum, which must occur at the first step of the peritoneal dissemination. The adhesion of cancer cells to the greater omentum was inhibited by a series of chemically synthesized oligosaccharides and Galβ1,3[3OMeGalβ1,4GlcNAcβ1,6]αBn was found to be the best inhibitor. The anti-tumor effect of this novel tetrasaccharide in vivo was shown in preliminary experiments using Balb/c mice and colon26 cells.  相似文献   
2.
牵引推拿于一体综合治疗脊柱相关疾病的临床研究   总被引:2,自引:2,他引:2  
苑庆皊  沙作合  杨雷 《河北医学》2006,12(2):102-104
目的:研究观察牵引推拿于一体综合治疗脊柱相关疾病的临床效果。方法:将2004年1月至2004年12月在我院就诊的498例患者,随机分为治疗组和观察组各249例。治疗组:采用“牵引推拿于一体的治疗方法”。(临沂市科技局鉴定的科研成果)。对照组:采用传统的牵引和推拿分别应用的方法。结果:治疗组:有效率为98.39%。对照组:有效率为89.56%。两组比较,治疗组优势明显(P<0.01)。结论:牵引推拿于一体的方法优于传统的牵引和推拿分别应用的方法。  相似文献   
3.
Building on diamond characteristics such as hardness, chemical inertness and low electron emission threshold voltage, the current microscopic, spectroscopic and voltammetric investigations are directed towards improving the properties of electrode coating materials for their future use in clinical studies of deep brain stimulation via fast-scan cyclic voltammetry (FSCV). In this study we combine the capabilities of confocal Raman mapping in providing detailed and accurate analysis of local distributions of material constituents in a series of boron-doped polycrystalline diamond films grown by chemical vapor deposition, with information from the more conventional techniques of scanning electron microscopy (SEM) and infrared absorption spectroscopy. Although SEM images show a uniform distribution of film crystallites, they have the limitation of being unable to differentiate the distribution of boron in the diamond. Values of 1018–1021 atoms/cm3 of boron content have been estimated from the absorption coefficient of the 1290 cm−1 infrared absorption band and from the 500 cm−1 Raman vibration. The observed accumulation of boron atoms and carbon sp2 impurities at the grain boundaries suggests that very high doping levels do not necessarily contribute to improvement of the material’s conductivity, corroborating with voltammetric data. FSCV results also indicate an enhanced stability of analyte detection.  相似文献   
4.
Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. We demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.  相似文献   
5.
Zirconia‐based dental restorations are becoming used more commonly. However, limited attention has been given to the difficulties experienced, concerning cutting, in removing the restorations when needed. The aim of the present study was to compare the cutting efficiency of diamond burs, operated using an electric high‐speed dental handpiece, on zirconia (Zir) with those on lithium disilicate glass–ceramic (LD) and leucite glass–ceramic (L). In addition, evaluation of the cutting efficiency of diamond burs on Zir of different thicknesses was performed. Specimens of Zir were prepared with thicknesses of 0.5, 1.0, 2.0, and 4.0 mm, and specimens of LD and L were prepared with a thickness of 1.0 mm. Cutting tests were performed using diamond burs with super coarse (SC) and coarse (C) grains. The handpiece was operated at 150,000 rpm with a cutting force of 0.9 N. The results demonstrated that cutting of Zir took about 1.5‐ and 7‐fold longer than cutting of LD and L, respectively. The SC grains showed significantly higher cutting efficiency on Zir than the C grains. However, when the thickness of Zir increased, the cutting depth was significantly decreased. As it is suggested that cutting of zirconia is time consuming, this should be taken into consideration in advance when working with zirconia restorations.  相似文献   
6.
运用克里斯塔勒中心地理论和引力模型等分析方法,以长江与南黄海交汇处的南通市为例,分析了以淤泥质海岸为主体江海交会处区域经济空间结构及内部差异形成的要素,以及此类地区沿海区域经济社会发展滞后的动力机制。论证了新一轮沿海开发和空间结构重构中,该类地区以沿江沿路经济轴带为基础,实施陆海统筹、江海陆协同发展的必然性。提出要充分利用原有基础,在不同区域利用各自优势,因地制宜实施发展战略,打造区域经济空间网络结构,实现区域空间均衡发展。力图从一个侧面探讨大的江河与淤泥质海岸交汇处区域发展问题的研究范式。  相似文献   
7.
Pyrolytic carbon (PyC) is widely used in manufacturing commercial artificial heart valve disks (HVD). Although PyC is commonly used in HVD, it is not the best material for this application since its blood compatibility is not ideal for prolonged clinical use. As a result thrombosis often occurs and the patients are required to take anti-coagulation drugs on a regular basis in order to minimize the formation of thrombosis. However, anti-coagulation therapy gives rise to some detrimental side effects in patients. Therefore, it is extremely urgent that newer and more technically advanced materials with better surface and bulk properties are developed. In this paper, we report the mechanical properties of PyC-HVD, i.e. strength, wear resistance and coefficient of friction. The strength of the material was assessed using Brinell indentation tests. Furthermore, wear resistance and coefficient of friction values were obtained from pin-on-disk testing. The micro-structural properties of PyC were characterized using XRD, Raman spectroscopy and SEM analysis. Also in this paper we report the preparation of freestanding nanocrystalline diamond films (FSND) using the time-modulated chemical vapour deposition (TMCVD) process. Furthermore, the sol-gel technique was used to uniformly coat PyC-HVD with dense, nanocrystalline-titanium oxide (nc-TiO2) coatings. The as-grown nc-TiO2 coatings were characterized for microstructure using SEM and XRD analysis.  相似文献   
8.
目的: 在药品检验机构改革的背景下,为省市级药品检验机构迎挑战、抓机遇、再发展提供思路。方法: 基于钻石理论模型的视角对省市级药品检验机构内外因素进行系统的分析,根据现状提出新业态发展模式,应用麦肯锡矩阵模型展开剖析并阐述新业态发展路径。结果: 各省市级药品检验机构面临着发展的困境和瓶颈,同时拥有再发展的机遇。结论: 可采取新业态发展模式调整业务结构,在自身发展的同时,扶助企业提升能力水平并做好政府依法行政的技术支持,保证公众健康。  相似文献   
9.
This paper presents the results of experimental research on the strength properties of porous structures with different degrees of density manufactured of Ti6Al4V titanium alloy by Laser Power Bed Fusion. In the experiment, samples with diamond structure of porosity: 34%, 50%, 73% and 81% were used, as well as samples with near-zero porosity. Monotonic tensile tests were carried out to determine the effective values of axial modulus of elasticity, ultimate tensile strength, offset yield strength, ultimate elongation and Poisson ratio for titanium alloys with different porosities. The paper also proposes relationships that can be easily used to estimate the strength and rigidity of a porous material manufactured by 3D printing. They were obtained by the approximation of two quotients. The first one refers to the relationship between the tensile strength of a material with a defined porosity to the strength of full-filled material. The second similarly determines the change in the value of the axial modulus of elasticity. The analysis of microscopic observations of fracture surfaces and also microtomography visualization of the material structure are also presented.  相似文献   
10.
Nanostructured diamond (NSD) films were grown on silicon and Ti–6Al–4V alloy substrates by microwave plasma chemical vapor deposition (MPCVD). NSD Growth rates of 5 μm/h on silicon, and 4 μm/h on Ti–6Al–4V were achieved. In a chemistry of H2/CH4/N2, varying ratios of CH4/H2 and N2/CH4 were employed in this research and their effect on the resulting diamond films were studied by X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. As a result of modifying the stock cooling stage of CVD system, we were able to utilize plasma with high power densities in our NSD growth experiments, enabling us to achieve high growth rates. Substrate temperature and N2/CH4 ratio have been found to be key factors in determining the diamond film quality. NSD films grown as part of this study were shown to contain 85% to 90% sp3 bonded carbon.  相似文献   
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