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111.
复方丹参合剂对去卵巢大鼠骨矿盐代谢的影响   总被引:2,自引:0,他引:2  
用测定骨矿盐含量的方法,分析了复方丹参合剂(三种不同剂量)对切除双侧卵巢后的大鼠骨矿盐代谢的影响。将健康4月龄雌性SD大鼠36只,随机分成6组:A组(正常对照组);B组(假去卵巢组);C组(去卵巢组);D组(去卵巢 合剂小剂量组);E组(去卵巢 合剂中等剂量组);F组(去卵巢 合剂大剂量组)。去卵巢手术后1 d开始,连续用药11周。结果表明,去卵巢大鼠骨干质量、干质量/体质量、骨灰质量、骨灰质量/体质量、骨灰质量占骨干质量比等均明显降低,复方丹参合剂可使去卵巢大鼠降低的骨干质量、骨干质量/体质量、骨灰质量、骨灰质量/体质量、骨灰质量占骨干质量比等均显著回升。提示复方丹参合剂具有良好的对抗由于去卵巢引起骨矿盐含量降低和骨丢失作用。  相似文献   
112.
Laser-induced breakdown spectroscopy (LIBS) has been used in the elemental analysis for a variety of environmental samples and as a proof of concept for a host of forensic applications. In the first application, LIBS was used for the rapid detection of carbon from a number of different soil types. In this application, a major breakthrough was achieved by using a multivariate analytical approach that has brought us closer towards a “universal calibration curve”. In a second application, it has been demonstrated that LIBS in combination with multivariate analysis can be employed to analyze the chemical composition of annual tree growth rings and correlate them to external parameters such as changes in climate, forest fires, and disturbances involving human activity. The objectives of using this technology in fire scar determinations are: 1) To determine the characteristic spectra of wood exposed to forest fires and 2) To examine the viability of this technique for detecting fire occurrences in stems that did not develop fire scars. These examples demonstrate that LIBS-based techniques are inherently well suited for diverse environmental applications. LIBS was also applied to a variety of proof of concept forensic applications such as the analysis of cremains (human cremation remains) and elemental composition analysis of prosthetic implants.  相似文献   
113.
新型骨吸收抑制剂唑来膦酸的合成   总被引:2,自引:1,他引:2  
以咪唑为起始原料,和溴乙酸乙酯经N-烷基化、水解、成盐得2-(1-咪唑基)乙酸盐酸盐(4),4再与三氯化磷的氯苯溶液反应得唑来膦酸。总收率25.4%(以咪唑计)。  相似文献   
114.
碳酸钙对去卵巢大鼠骨元素代谢的影响   总被引:4,自引:0,他引:4  
用测定骨元素含量的方法,分析了碳酸钙(CaCO3)对去卵巢大鼠骨元素代谢的影响。将健康4月龄雌性SD大鼠24只,用抽签法随机分成4组:正常对照组,假去卵巢组,去卵巢组,去卵巢 CaCO3组。去卵巢 CaCO3组大鼠于去卵巢手术后第2 d开始给予CaCO3灌胃,w(Ca)=20mg/kg,1次/d,持续11周。结果表明,去卵巢大鼠骨Ca、S、Mg、Mn等元素含量显著降低,Zn、Co含量降低,骨P含量增加;CaCO3可使去卵巢大鼠降低的骨Ca、S、Mg、Zn、Co、Mn等元素含量显著回升,骨P含量显著回降;CaCO3可纠正去卵巢大鼠的骨元素代谢紊乱。提示补钙防治骨质疏松是通过纠正骨矿物元素代谢紊乱而实现的。  相似文献   
115.
尼尔雌醇对去卵巢大鼠骨元素代谢的影响   总被引:2,自引:3,他引:2  
用测定骨元素含量的方法,分析了尼尔雌醇对去卵巢大鼠骨元素代谢的影响。将健康4月龄雌性SD大鼠35只随机分成正常对照组、假去卵巢组、去卵巢组和去卵巢 尼尔雌醇组。结果表明,去卵巢大鼠骨Ca、Mg、S、Mn、Zn含量显著降低,P含量显著增加。尼尔雌醇可使去卵巢大鼠降低的骨Ca、Mg、S、Mn、Zn含量显著回升,骨P含量显著回降。尼尔雌醇可纠正去卵巢所致的骨元素代谢紊乱。  相似文献   
116.
Ultra fast magic angle spinning (MAS) has been a potent method to significantly average out homogeneous/inhomogeneous line broadening in solid‐state nuclear magnetic resonance (ssNMR) spectroscopy. It has given a new direction to ssNMR spectroscopy with its different applications. We present here the first and foremost application of ultra fast MAS (~60 kHz) for ssNMR spectroscopy of intact bone. This methodology helps to comprehend and elucidate the organic content in the intact bone matrix with resolution and sensitivity enhancement. At this MAS speed, amino protons from organic part of intact bone start to appear in 1H NMR spectra. The experimental protocol of ultra‐high speed MAS for intact bone has been entailed with an additional insight achieved at 60 kHz. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
117.
118.
Cécile Baron 《Ultrasonics》2011,51(2):123-130
As a non-destructive, non-invasive and non-ionizing evaluation technique for heterogeneous media, the ultrasonic method is of major interest in industrial applications but especially in biomedical fields. Among the unidirectionally heterogeneous media, the continuously varying media are a particular but widespread case in natural materials. The first studies on laterally varying media were carried out by geophysicists on the Ocean, the atmosphere or the Earth, but the teeth, the bone, the shells and the insects wings are also functionally graded media. Some of them can be modeled as planar structures but a lot of them are curved media and need to be modeled as cylinders instead of plates. The present paper investigates the influence of the tubular geometry of a waveguide on the propagation of elastic waves. In this paper, the studied structure is an anisotropic hollow cylinder with elastic properties (stiffness coefficients cij and mass density ρ) functionally varying in the radial direction. An original method is proposed to find the eigenmodes of this waveguide without using a multilayered model for the cylinder. This method is based on the sextic Stroh’s formalism and an analytical solution, the matricant, explicitly expressed under the Peano series expansion form. This approach has already been validated for the study of an anisotropic laterally-graded plate (Baron et al., 2007; Baron and Naili, 2010) [6] and [5]. The dispersion curves obtained for the radially-graded cylinder are compared to the dispersion curves of a corresponding laterally-graded plate to evaluate the influence of the curvature.Preliminary results are presented for a tube of bone in vacuum modelling the in vitro conditions of bone strength evaluation.  相似文献   
119.
《Mendeleev Communications》2022,32(6):810-812
Three dimensional composite matrices based on poly-d,l-lactide filled with 5 or 10 wt% of nanocrystalline cellulose modified by poly(glutamic acid) were produced using pre- optimized 3D printing technique. The composites demonstrated good biocompatibility and significantly improved osteoconductive properties compared with the matrix without filler or the one filled with neat nanocrystalline cellulose.  相似文献   
120.
In this paper, the finite-element method (FEM) simulation of ultrasound brain surgery is presented. The overheating problem of the post-target bone, which is one of the limiting factors for a successful ultrasound brain surgery, is considered. In order to decrease bone heating, precise choices of frequency, focal pressure, and scanning path are needed. The effect of variations in the mentioned scanning parameters is studied by means of the FEM. The resulting pressure and temperature distributions of a transdural ultrasound brain surgery are simulated by employing the FEM for solving the Helmholtz and bioheat equations in the context of a two-dimensional MRI-based brain model. Our results show that for a suitable value of the frequency, an increase in focal pressure leads to a decrease in the required duration of the treatment and is associated with less heating of the surrounding normal tissue. In addition, it is shown that at a threshold focal pressure, the target temperature reaches toxic levels whereas the temperature rise in the bone is minimal. Wave reflections from sinus cavities, which result in constructive interference with the incoming waves, are one of the reasons for overheating of the bone and can be avoided by choosing a suitable scanning path.   相似文献   
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