Age estimation in biopsy specimens of dentin

Determination of age at death on the basis of aspartic acid racemization in dentin is one of the most reproducible and accurate methods. In Germany, age estimation by this method has so far generally not been applied to living persons, since the extraction of a tooth exclusively for age estimation when it is not medically indicated is regarded as ethically and legally problematic. The development of a biopsy technique applicable to dentin took place against this background. Testing the technique and analysis of dentinal biopsy specimens revealed that the biopsy technique is a low-risk procedure that causes only minor discomfort to the affected person. It is readily practicable and facilitates standardized specimen removal. The relationship between the extent of aspartic acid racemization in dentinal biopsy specimens and age is very close, facilitating age estimation. A prerequisite for accurate results is the performance of biopsies under strictly standardized conditions. If this is guaranteed, age determination on the basis of aspartic acid racemization in dentinal biopsy specimens appears to be superior in precision to most other methods in living persons and can be used for all age groups.     

醋酸曲安缩松注射液的一阶导数分光光度测定

采用一阶导数分光光度法测定醋酸曲安缩松注射液的含量，平均回收率为９９．８２％，ＲＳＤ为０．３９％。方法简便快速，结果满意。     

Magnetization Transfer and T2 Relaxation Components in Tissue

T₂ relaxation makes an important contribution to tissue contrast in magnetic resonance (MR) imaging. Many tissues are known to exhibit multicomponent T₂ relaxation that suggests some compartmental segregation of mobile protons on a T₂ timescale. Magnetization transfer (MT) is another relaxation mechanism that can be used to produce tissue contrast in MR imaging. The MT process depends strongly on water-macromolecular interactions. To investigate the relationship between multicomponent T₂ relaxation and the MT process, multiecho T₂ measurements have been combined with MT measurements for freshly excised samples of cardiac muscle, striated muscle, and white matter. For muscle, short T₂ components show greater MT than long T₂ components, consistent with the belief that they represent distinct water environments. For white matter, quantitative MT measurements were identical for the two major T₂ components, apparently because of exchange between the T₂ compartments on a timescale characteristic of the MT experiment. Implications for accurate modeling of MT in tissue and the use of MT for MR image contrast are discussed.     

去痛片中四组分的HPLC测定

以十八烷基硅烷键合硅胶为固定相，采用ＨＰＬＣ法测定去痛片中氨基比林、非那西丁、咖啡因、苯巴比妥的含量。各组分的回收率分别为９９．８±０．５０％、９９．７±０．７６％、９９．３±０．５４％、９９．６±０．５８％。     

食品中铬元素的含量分析

目的：了解常见食品中铬的含量，指导人群合理摄取铬元素，对糖尿病、动脉粥样硬化、冠心病患者的合理膳食提供理论依据。方法：用石墨炉原子吸收分光光度法测定25种食品中铬含量。选用357．9μm波长，采用二步干燥。测定回收率为92．6％--98．1％，相关系数r＝0．9987，回归方程Y＝0．0l19C 0．0766。结果：肉、蛋类中铬含量在102—532μg/kg之间，谷、豆和坚果类铬含量在104．1—355μg/kg之间，蔬菜、水果类铬合量在35．8—214．7μg/kg之间。结论：铬含量以动物性食品最高，谷类食物居中，蔬菜、水果较低。     

亚硝酸根与中性红显色反应的分光光度研究及其分析应用

本文研究了亚硝酸根与中性红显色反应的条件。在0.09～0.4mol/L HCl介质中,亚硝酸根与中性红生成紫蓝色化合物,其最大吸收峰位于535nm处,反应灵敏(∑_(645)nm=7.40×10~3和9.81×10~3L·mol~(-1)·cm~(-1),选择性好。亚硝酸根含量在0～5μg/25ml及5～25μg/25ml范围内遵守比尔定律。本法曾用于水、土壤及蔬菜中微量亚硝酸根的测定获得满意的结果。     

成人全唾液与血浆中醛固酮含量测定

本文采用直接放射免疫测定法,固定条件,按标准程序测得30名正常成人全唾液及血浆中的醛固酮(Aldosterone,Aldo)浓度。均值唾液为6.6±1.9nmol/L,血浆为32.5±8.0nmol/L,两者呈平行关系(r=0.4,P<0.05,=11.29+0.79X),浓度比平均为20.2％。结果进一步证实唾液作为临床测定Aldo标本的有效性与实用性,有助于对一些全身及口腔疾病进行诊断及估计预后,并可据以评价皮质类固醇治疗效果及用药的合理性。     

微量尿和血清样品中氟的测定方法研究

本研究利用改进的氟测定方法，测定尿和血清样品中氟离子的含量。结果表明，该方法样品用且少，线性响应范围、精密度、回收率和重现性等指标均符合方法学的要求，与常规法比较，显示测定结果间无显著性差异。可广泛使用于要求高、样品量少的生物材料氟检测。     

ATP片剂的UV—HPLC测定

采用ＵＶ－ＨＰＬＣ法测定ＡＴＰ片剂的含量，较地方标准收载的方法方便易行，重现性好。测定的回收率为１００．８±１．５％。     

头孢克洛在健康人体内的药物动力学研究

采用ＨＰＬＣ测定健康志愿者血浆中头孢克洛的浓度。方法简便快速，结果准确。平均回收率为１０２．１８±４．０１％，日间及日内ＲＳＤ均小于６％。血药浓度－时间曲线符合一室模型。