Computerized Color Formulation for African-Canadian People Requiring Facial Prostheses: A Pilot Study

Purpose: The aim of this study was to investigate the effectiveness of spectrophotometry and a computerized color formulation system to predict pigment formulas for color mixing silicone elastomer to match the skin color of African-Canadian people.
Materials and Methods: In a prospective study, reflectance spectrophotometery was used to measure the skin color of 19 African-Canadian subjects. The spectral data for each subject was used in a computerized color formulation system to predict colorants required to mix silicone elastomer to match each subject's skin color. Delta-E values were recorded for each silicone sample in comparison to the subject's skin measurement. An analysis of variance was used to determine significance among variables, and a Tukey HSD post hoc test was used to assess paired comparisons.
Results: Delta-E decreased with iterative mixes of colored silicone for each subject, and pigment loading increased with iterative mixes. Delta-E values for the third iterative mix (fourth and final sample) ranged between 1.49 and 8.82.
Conclusion: Spectrophotometry and computerized color formulation provide a foundation in the color matching procedure for facial prostheses that offers objectivity to an otherwise subjective task. Through further study of spectrophotometry and computerized color formulation, and with the development of pigment databases appropriate for the African-Canadian population, it may be possible to establish a precise and repeatable color matching system that predicts required colorants and controls metamerism.     

氯硝柳胺测定方法研究进展

利用氯硝柳胺的理化特性,可采取多种不同方法对其进行定性或定量测定。但不同方法的精密度和准确度不同,可根据应用需求进行选择。本文主要对氯硝柳胺的生物测定法、滴定法、紫外-可见分光光度法、色谱法和电化学分析法进行综述。     

紫外分光光度法测定海滩牵牛中总香豆素类成分的浓度

目的：测定草药海滩牵牛（IS）药材中总香豆素浓度。方法：采用紫外分光光度法,检测波长320nm,以伞形花内酯为对照品。结果：IS在2-32μg/mL质量浓度范围内,对照品吸光度和浓度线性关系良好（r=0．999）。平均回收率99．31％,相对标准偏差=1．88。结论：该法简便、可靠,为有效控制Is药材质量奠定了一定的基础。     

分光光度法测定维吾尔药核桃分心木中总皂苷的含量

目的 研究维吾尔药核桃分心木总皂苷的含量测定方法.方法 用95%乙醇提取,水饱和正丁醇萃取的方法提取纯化核桃分心木中总皂苷.高氯酸显色,紫外分光光度法测定核桃分心木中总皂苷的含量.结果 以人参皂苷Rb1为标准品作标准曲线,A=0.059 3C+0.057 6,r=0.999 7,样品检测量在0.208 6～0.327 8mg的范围内与吸光度线性关系良好,回收率为89.11%,测得核桃分心木总皂苷的含量为4.187%.结论 此测定方法简便、快速、灵敏、准确,可作为维吾尔药核桃分心木中总皂苷含量测定方法的参考依据.     

导数紫外光谱法测定人血浆中三唑仑的血药浓度!

目的：建立测定人血浆中三唑仑浓度的一阶导数分光光度法,为临床应用提供技术参考。方法采用一阶导数光谱法在232.0 nm波长处测定人血浆中三唑仑浓度。结果三唑仑在2.55~15.30μg/mL范围呈良好线性关系;其回归方程为D=1.3487×10-3C＋3.7748×10-3（r =0.9965）;平均回收率为101.53豫,RSD=2.12豫（n=5）。结论该法操作简单,测定结果准确,适用于三唑仑血药浓度的监测。     

Somatostatin reduces gastric mucosal blood flow in patients with portal hypertensive gastropathy

Agents which decrease gastric mucosal blood flow (GMBF) are postulated to have beneficial effects in arresting gastrointestinal bleeding in cirrhotic patients with portal hypertension. Our objective was to test the hypothesis that in a dose that significantly lowers wedged hepatic venous pressure (WHVP), a bolus injection of somatostatin will significantly decrease GMBF in patients with portal hypertensive gastropathy (PHG). In this placebo-controlled, double-blind, crossover study, 20 cirrhotic patients with PHG were randomly assigned to receive either somatostatin followed by placebo (Group A) or placebo followed by somatostatin (Group B). Wedged hepatic venous pressure was monitored. GMBF in the antrum and corpus was assessed by reflectance spectrophotometry. Indices of hemoglobin concentration (IHb) and indices of oxygen content (ISO₂) were recorded. Nine patients were assigned to Group A, and 11 to Group B. Mild PHG was seen in 16 patients, and severe PHG in 4 patients. Baseline WHVP, IHb, and ISO₂ were similar in both treatment groups. Wedged hepatic venous pressure (WHVP) was significantly lowered [median, 17.6%; interquartile range (–27.0, –12.6%); P=0.0008] after a 250-µg bolus injection of somatostatin. This dose of somatostatin significantly reduced IHb both in the antrum [–10.2% (–23.4, 0.4%)] and in the corpus [–5.8% (–16.6, 5.6%)] compared to placebo (P=0.02 and 0.04, respectively). Intravenous bolus injection of 250 µg somatostatin significantly reduces WHVP and GMBF in patients with PHG. Whether this ability to decrease the GMBF in PHG makes somatostatin an effective treatment in acute gastrointestinal bleeding in PHG deserves to be studied.     

对硝基酚荷移分光光度法测定组氨酸含量的研究

目的建立测定组氨酸含量的对硝基酚荷移分光光度法。方法组氨酸与对硝基酚在室温下可生成稳定1∶1型的荷移络合物。荷移络合物的最大吸收波长λmax=400 nm,表观摩尔吸光系数ε=1.0×104 L/(mol.cm)。结果组氨酸浓度在1-15μg/ml的范围内遵循比尔定律,回收率在93.3%-99.9%之间,相对标准偏差在2.5%以内。结论本方法简便、稳定性好,其测定组氨酸样品的含量结果与文献方法一致。     

Simple objective measurement of the cutaneous delayed-type hypersensitivity reaction to tuberculin using spectrophotometry

Background/aims:   A number of subjective methods have been used to quantify the extent of the cutaneous delayed-type hypersensitivity (DTH) reaction. However, because of their subjective nature, significant differences in measurements may be seen between individual observers or laboratories unless thorough training is given to each observer.
Methods:   Objective measurement of the DTH reaction using a hand-held spectrophotometer is described. Guinea pigs were primed using inoculation with Mycobacterium bovis Bacille Calmette-Guerin and challenged five weeks later in the shaved flank with three doses of bovine purified protein derivative. The extent of the ensuing DTH reaction was measured 24 and 48 h later. Spectrophotometric measurement of the reaction site was compared with a control region of skin on each animal and expressed as the change within a standard colour space. Data obtained with the spectrophotometer was compared with the subjective measurement of the area of the DTH reaction by an experienced operator.
Results:  T he measurements obtained with the spectrophotometer correlated very closely with conventional measurement of the reaction area by a trained operator. The reaction size in square mm and changes along the red/green colour axis was correlated most strongly.
Conclusion:   Spectrophotometric measurement of the DTH reaction had advantages over conventional measuring techniques in terms of speed, reproducibility and reduced operator to operator variation. We conclude that the cutaneous DTH reaction may be simply and objectively quantified with the use of a hand-held spectrophotometer.     

制药洁净厂房设备设施表面甲醛残留的测定

目前制药厂房仍普遍使用甲醛作为环境的消毒方式,但在厂房设施及设备表面的甲醛残留会对产品质量及人员安全造成危害。通过比较确定使用紫外吸光光度法进行检测,并对取样过程进行验证。     

紫外分光光度法测定胃炎合剂中盐酸普鲁卡因的含量

目的建立胃炎合剂中盐酸普鲁卡因含量的测定方法。方法紫外分光光度法。以6．82μg／ml的庆大霉素溶液为空白对照,测定波长为290nm。结果在0．477～14．31μg/ml的浓度范围内盐酸普鲁卡因的吸光度与浓度的线性关系良好（r=0．9997）,加样回收率为99．83％（RSD=0．30％,n=6）。结论本方法操作简便,灵敏度高快速,稳定,重现性好,可以用于胃炎合剂中盐酸普鲁卡因的含量测定。