BACKGROUND & AIMS: :Infrared spectra of 13 globular proteins have been obtained in the 1800-1480-cm-1 region for H2O solutions. A method for estimating protein secondary structure from the ir spectrum has been developed. The method can also be used for estimating polypeptide and fibrous protein conformation. For the globular and fibrous proteins and polypeptides analyzed, the correlation coefficients between the ir and x-ray estimates of ordered helix, disordered helix, ordered beta-structure, disordered beta-structure, turns, and remainder were 0.98, 0.80, 0.99, 0.87, 0.90, and 0.92 respectively.

背景与目标： ：在H2O溶液的1800-1480-cm-1区域中已获得13种球状蛋白质的红外光谱。已经开发了一种从红外光谱估计蛋白质二级结构的方法。该方法还可用于估计多肽和纤维蛋白构象。对于所分析的球状和纤维状蛋白质和多肽，有序螺旋，无序螺旋，有序β结构，无序β结构，无序β和剩余的ir和x射线估计值的相关系数分别为0.98、0.80、0.99、0.87 ，分别为0.90和0.92。

BACKGROUND & AIMS: OBJECTIVES:To analyse the residual monomer (MMA) elution of polymethyl methacrylate (PMMA) in distilled water after diverse fabrication methods and aging procedures. MATERIALS AND METHODS:PMMA specimens (N = 192, PalaXpress; Kulzer, Hanau, Germany) were manufactured (pouring, n = 96/injection, n = 96) and polymerized in water (55°C) without pressure (n = 48) and with 2 bar pressure (n = 48). Specimens were grinded (n = 24) or polished (n = 24) and aged for 12 h in distilled water/37°C (n = 12) or at air/20°C (n = 12) and stored afterwards in distilled water at 37°C. MMA elution was evaluated after 1, 2, 3, 4, 5, 6, 7, 10, 15 days (UV/Vis spectrophotometry). Data were analysed with Kolmogorov-Smirnov, Mann-Whitney-U and Cohen-d test using SPSS (α < 0.5). RESULTS:The pouring procedure resulted in significantly higher MMA elution than the injection procedure up to 5 days. Polymerization with a pressure of 2 bar reduced the MMA elution significantly for poured specimens. Polishing reduced the MMA elution in comparison to grinding. CONCLUSIONS:The fabrication procedure (pouring/injection) showed the strongest correlation to the MMA elution (r = 0.500), followed by polishing (r = 0.243), the pressure during polymerization (r = 0.109) and the storage medium (r = 0.053). CLINICAL RELEVANCE:Higher MMA elution may increase the risk of chemical irritations, allergic reactions and hypersensitivities of the oral mucosa. Technicians and dentists should be aware about the elution differences dependent on the fabrication procedure.

背景与目标： 目的：通过各种制备方法和老化程序，分析蒸馏水中聚甲基丙烯酸甲酯（PMMA）的残留单体（MMA）洗脱。
材料与方法：制造PMMA样品（N = 192，PalaXpress; Kulzer，Hanau，Germany）（浇注，n = 96 /进样量，n = 96）并在水（55°C）中无压力聚合（n = 48）压力为2 bar（n = 48）。将样品研磨（n = 24）或抛光（n = 24），并在蒸馏水/ 37°C（n = 12）或在空气/ 20°C（n = 12）中老化12 h，然后保存在蒸馏水中在37°C下。在1、2、3、4、5、6、7、10、15天后评估MMA洗脱（UV / Vis分光光度法）。使用SPSS（α<0.5）使用Kolmogorov-Smirnov，Mann-Whitney-U和Cohen-d检验分析数据。
结果：在最多5天的时间内，浇注过程比注入过程产生的MMA洗脱液明显更高。在2 bar的压力下进行聚合可显着降低倒入标本的MMA洗脱量。与研磨相比，研磨减少了MMA洗脱。
结论：制备过程（浇注/注入）显示出与MMA洗脱最强的相关性（r = 0.500），随后是抛光（r = 0.243），聚合过程中的压力（r = 0.109）和存储介质（r = 0.053） ）。
临床意义：较高的MMA洗脱液可能会增加化学刺激，过敏反应和口腔粘膜超敏反应的风险。技术人员和牙医应了解取决于制造程序的洗脱差异。

BACKGROUND & AIMS: :An ultraviolet (UV) spectrophotometric procedure was devised for the determination of polycyclic aromatic compound-oriented organic soluble matter in vapors and particulate collected from emissions of hot asphalt mix. Ultrasonic extraction was carried out with acetonitrile, followed by UV measurements at 254 nm. Polycyclic aromatic compounds (PACs) in volatile and particulate fraction were quantified as phenanthrene or benzo[k]fluoranthene equivalents. A comparison between UV and high-pressure liquid chromatography with fluorescence detection showed that PACs were one to three orders of magnitude higher than the sum of 15 priority polycyclic aromatic hydrocarbons (PAHs); still, significant correlations were found between volatile or particulate PACs and, respectively, total volatile or particulate PAHs. Moreover, in the particulate phase, PACs correlated with total particulate matter quantified by gravimetry. The proposed procedure was employed in a field study for monitoring personal exposure to asphalt emissions of workers engaged in road construction. Observed levels of acetonitrile-soluble PACs in air samples were very low (2-20 microg/m3); however, asphalt pavers were exposed to significantly higher concentrations of volatile PACs than construction workers (geometric mean, 5.9 microg/m3 vs. 4.1 microg/m3). This method for estimating the global content of volatile or particulate PACs in air samples satisfies our requirements of simplicity and is suitable for conducting an initial screening to assess exposure to airborne polyaromatic organics in asphalt pavers.

背景与目标： ：设计了紫外（UV）分光光度法，用于测定从热沥青混合料排放中收集的蒸气和颗粒中多环芳族化合物导向的有机可溶性物质。超声提取用乙腈进行，然后在254 nm处进行UV测量。挥发性和颗粒部分中的多环芳族化合物（PAC）定量为菲或苯并[k]荧蒽的当量。紫外和高压液相色谱与荧光检测的比较表明，PAC比15种优先多环芳烃的总和高1-3个数量级。仍然，挥发性或颗粒状PAC与总挥发性或颗粒状PAH之间存在显着相关性。此外，在颗粒相中，PAC与通过重量分析法定量的总颗粒物相关。拟议的程序被用于实地研究中，以监测从事道路施工的工人的个人暴露于沥青排放的情况。空气样品中可观察到的乙腈可溶性PAC的水平非常低（2-20微克/立方米）。但是，沥青摊铺机比建筑工人要暴露的挥发性PAC浓度要高得多（几何平均值为5.9微克/立方米，而建筑工人为4.1微克/立方米）。这种估算空气样品中挥发性或颗粒状PAC总量的方法满足了我们的简便性要求，适用于进行初步筛查以评估沥青摊铺机中空气传播的多芳族有机物的暴露程度。

BACKGROUND & AIMS: :Clinical studies have demonstrated the efficacy of submucosal epinephrine injection in the control of bleeding ulcers. Since endoscopic techniques for assessing gastroduodenal blood flow are limited, we employed an animal model to study the mechanism of control of bleeding. The effect of submucosal epinephrine injection on local gastric blood flow was studied in the rat using laser Doppler flowmetry and reflectance spectrophotometry. Submucosal injection of 0.1 ml of 1/10,000 epinephrine caused a significantly greater drop in local gastric blood flow (laser Doppler flowmetry) compared with vehicle (10% sodium metabisulfite) injection. The reduction persisted for up to 120 min. This vasoconstrictive effect of epinephrine was confirmed by observations with reflectance spectrophotometry, which documented a pattern of ischemia without congestion (lower index of hemoglobin concentration, lower index of oxygen saturation). The autoregulatory escape from adrenergic vasoconstriction was not evident in either instance. We conclude that, after submucosal injection of epinephrine, the absence of autoregulatory escape from adrenergic vasoconstriction and the marked and prolonged decrease in local gastric blood flow enhance the homeostatic mechanisms (eg, platelets and other coagulative factors) to effect hemostasis in bleeding ulcers.

背景与目标： ：临床研究证明粘膜下肾上腺素注射液在控制出血性溃疡中的功效。由于评估胃十二指肠血流的内窥镜技术是有限的，我们采用了动物模型来研究控制出血的机制。使用激光多普勒血流仪和反射分光光度法研究了大鼠粘膜下肾上腺素注射对局部胃血流的影响。与媒介物（10％的焦亚硫酸钠）注射相比，粘膜下注射0.1 ml的1 / 10,000肾上腺素导致局部胃血流量（激光多普勒血流仪）的下降明显更大。减少持续长达120分钟。肾上腺素的这种血管收缩作用已通过反射分光光度法的观察得到了证实，该光谱法记录了缺血而无充血的模式（血红蛋白浓度指数降低，氧饱和度指数降低）。在这两种情况下，肾上腺素能血管收缩的自动调节性逃逸均不明显。我们得出的结论是，在粘膜下注射肾上腺素后，没有肾上腺素能血管收缩引起的自动调节逃逸以及局部胃血流量的明显和长期下降增强了稳态机制（例如血小板和其他凝血因子），从而影响了出血性溃疡的止血。

BACKGROUND & AIMS: :We investigated the suppressive effects of phosphate on calcium determinations with lanthanum-air/acetylene and potassium-nitrous oxide/acetylene methods, and we evaluated the ability of these methods to meet the suggested analytical goals for urine samples. The 20 g/L La-air/acetylene method was the most nearly accurate for predicting the actual calcium concentrations (t-test value = -0.042), followed by the 2 g/L K-nitrous oxide/acetylene method (t-test value = 0.450), 10 g/L La-air/acetylene (t-test value = -0.733), and finally 5 g/L La-air/acetylene (t-test value = -2.446). The dilution used significantly influences the apparent calcium concentration measured with the La-air/acetylene methods.

背景与目标： ：我们研究了镧-空气/乙炔和亚硝酸钾钾/乙炔方法对磷酸盐测定钙的抑制作用，并评估了这些方法满足尿液样品建议分析目标的能力。 20 g / L La-air /乙炔法最准确地预测实际钙浓度（t-检验值= -0.042），其次是2 g / L K-一氧化二氮/乙炔法（t检验）值= 0.450），10 g / L La-空气/乙炔（t-检验值= -0.733），最后是5 g / L La-空气/乙炔（t-检验值= -2.446）。使用的稀释液会显着影响用La-air /乙炔法测得的表观钙浓度。

BACKGROUND & AIMS: :Two approaches have been adopted to increase the steepness of the slopes and the sharpness of the curvature of an absorption curve in the visible region. These are recording (i) A (1cm) versus log wavelength or (ii) A (1cm) versus wavenumber. The computer program was tested by calculating the ratios of the first derivative optima for a Gaussian band, and proved that changing wavelength into log wavelength or wavenumber is effective to squeeze an absorption curve non-linearly. Spectrophotometric identification of cyanocobalamin in the visible region was carried out using the ratios (Delta D1/D2) calculated for lambda, log lambda and nu scales. The ratios were highly reproducible and independent of concentration. First, second and fourth-order derivative determination of cyanocobalamin in injection solutions was performed in the visible region at 20040.08, 17452.01, (20040.08 - 17452.01) cm(-1) for D11(nu), D12(nu) Delta D1 (D11-D12) (nu), respectively, and at 18018.02 cm(-1) for D2(nu) and D4(nu).

背景与目标： ：已采用两种方法来增加可见区域中的斜率的陡度和吸收曲线的曲率的锐度。这些记录的是（i）A（1cm）对数波长或（ii）A（1cm）对波数。通过计算高斯带的一阶导数最优值的比率对计算机程序进行了测试，并证明了将波长更改为对数波长或波数可以有效地非线性地压缩吸收曲线。使用计算λ，对数λ和nu比例的比率（ΔD1 / D2）进行可见光区氰钴胺的分光光度鉴定。该比率是高度可再现的，并且与浓度无关。对于D11（nu），D12（nu）Delta D1（D11- D12）（nu），对于D2（nu）和D4（nu）分别为18018.02 cm（-1）。

BACKGROUND & AIMS: :The present study reports on the application of modified groundnut shell as a new, easily prepared, and stable sorbent for the extraction of trace amount of Cr(III) in aqueous solution. 2-Hydroxybenzaldiminoglycine was immobilized on groundnut shells in alkaline medium and then used as a solid phase for the column preconcentration of Cr(III). The elution was carried out with 3 mL of 2 mol L(-1) HCl. The amount of eluted Cr(III) was determined by spectrophotometry using cefaclor as a complexing reagent and by flame atomic absorption spectrometry (FAAS). Different experimental variables such as pH, amount of solid sorbent, volume and concentration of eluent, sample and eluent flow rate, and interference of other metal ions on the retention of Cr(III) were studied. Under the optimized conditions, the calibration curves were found to be linear over the concentration range of 13-104 and 10-75 μg L(-1) with a detection limit of 3.64 and 1.24 μg L(-1) for spectrophotometric method and FAAS, respectively. An enrichment factor of 200 and RSD of ±1.19-1.49 % for five successive determinations of 25 μg L(-1) were achieved. The column preconcentration was successfully applied to the analysis of tap water and underground water samples.

背景与目标： ：本研究报道了改性花生壳作为一种新型，易于制备且稳定的吸附剂在萃取水溶液中痕量Cr（III）中的应用。将2-羟基苯扎尔二氨基甘氨酸固定在碱性介质中的花生壳上，然后用作固相用于Cr（III）的柱预浓缩。用3 mL 2 mol L（-1）HCl进行洗脱。 Cr（III）的洗脱量通过使用头孢克洛作为络合剂的分光光度法和火焰原子吸收光谱法（FAAS）确定。研究了不同的实验变量，例如pH，固体吸附剂的量，洗脱液的体积和浓度，样品和洗脱液的流速以及其他金属离子对Cr（III）保留的干扰。在优化的条件下，发现校正曲线在13-104和10-75μgL（-1）的浓度范围内是线性的，分光光度法和FAAS的检出限为3.64和1.24μgL（-1）。 ， 分别。连续5次测定25μgL（-1）的富集系数为200，相对标准偏差为±1.19-1.49％。柱预浓缩成功地用于自来水和地下水样品的分析。

BACKGROUND & AIMS: :This study assesses the incidence, histogenesis, and significance of eccrine sweat duct involvement in Bowen's disease (BD). In a review of 96 cases of BD, four showed eccrine duct involvement on hematoxylin and eosin-stained histologic sections. One case was analyzed for deoxyribonucleic acid (DNA) ploidy by using computerized image analysis on Feulgen-stained slides. Sections were also stained immunohistochemically, using antibodies to carcinoembryonic antigen (CEA), gross cystic disease fluid protein (GCDFP), and S-100 protein, and for cytokeratins (CAM 5.2, AE 1/3). Our results showed that, in BD, (a) the eccrine sweat ducts can be extensively involved by atypical cells, (b) the atypical eccrine duct cells had an aneuploid DNA pattern, and (c) the atypical eccrine duct cells were negative for CEA, GCDFP, and S-100 protein but were positive for cytokeratins. We conclude that (a) the frequency of eccrine duct involvement in BD is relatively low (approximately 4 to 9%), (b) the aneuploid DNA pattern makes a benign squamous metaplasia unlikely, (c) the immunohistochemical results exclude coincidental Paget's disease or carcinoma of eccrine sweat glands, (d) the involvement of eccrine sweat ducts may represent a direct extension of the neoplastic epidermal keratinocytes, and (e) this process may have practical implications in the recurrence of superficially treated cases of BD.

背景与目标： ：本研究评估了鲍文氏病（BD）中内分泌汗管受累的发生率，组织发生和意义。在对96例BD病例的回顾中，有4例显示苏木精和曙红染色的组织切片受累于内分泌管。通过对Feulgen染色载玻片进行计算机图像分析，对一例进行了脱氧核糖核酸（DNA）倍性分析。还使用抗癌胚抗原（CEA），总胆囊疾病液蛋白（GCDFP）和S-100蛋白以及细胞角蛋白（CAM 5.2，AE 1/3）的抗体对切片进行免疫组织化学染色。我们的研究结果表明，在BD中，（a）非典型分泌管可广泛参与非典型分泌管的分泌汗管，（b）非典型分泌管具有非整倍体DNA模式，（c）非典型分泌管对CEA呈阴性，GCDFP和S-100蛋白，但细胞角蛋白呈阳性。我们得出的结论是：（a）BD内分泌管受累的频率相对较低（约4％至9％），（b）非整倍体DNA模式使得良性鳞状化生不太可能，（c）免疫组织化学结果排除了巧合的Paget病或内分泌汗腺癌；（d）内分泌汗管受累可能代表赘生性表皮角质形成细胞的直接延伸；（e）此过程可能对表面治疗的BD病例的复发具有实际意义。

BACKGROUND & AIMS: :We describe a method for determining plasma and erythrocyte lithium concentrations by atomic absorption spectrophotometry. Plasma and hemolyzed whole-blood are diluted and analyzed, with use of a lithium hollow-cathode lamp, at 670.8 nm. Erythrocyte lithium concentrations are calculated indirectly from the hematocrit. The standard deviation for a 0.43 mmol/liter pool of whole blood, run daily over 11 months, was +/-20 mumol/liter (CV=5.1). The lithium concentration of a lyophilized pool assayed periodically over the same period (n=127) was 1.84+/-0.05 mmol/liter (CV=2.7%). The relatively low erythrocyte/plasma lithium ratio and the microhematocrit centrifugation force (9600 to 13 600 X g) make corrections for trapped plasma insignificant. Problems with matrix matching and viscosity are overcome by using a plasma pool standard for calculations. Values for erythrocyte lithium concentrations were unchanged in samples stored at room temperature up to 24 h. Hemolysis appears to be of possible clinical significance. This method is useful as a routine clinical laboratory procedure for monitoring patients with affective disorders, who are undergoing therapy with lithium.

背景与目标： ：我们描述了一种通过原子吸收分光光度法测定血浆和红细胞锂浓度的方法。使用锂空心阴极灯在670.8 nm处对血浆和溶血的全血进行稀释和分析。从血细胞比容间接计算出红细胞锂的浓度。在11个月内每天运行的全血0.43 mmol / L池的标准偏差为/ -20μmol/ L（CV = 5.1）。在同一时间段（n = 127）定期测定的冻干池的锂浓度为1.84 /-0.05 mmol / L（CV = 2.7％）。相对较低的红细胞/血浆锂比率和微量血细胞比容离心力（9600至13600 X g）使校正的血浆微不足道。通过使用等离子池标准进行计算，可以解决基体匹配和粘度方面的问题。在室温下保存长达24小时的样品中，红细胞锂浓度的值没有变化。溶血似乎具有潜在的临床意义。该方法可作为常规的临床实验室程序，用于监测正在接受锂疗法治疗的情感障碍患者。

BACKGROUND & AIMS: :Cell viability and cell proliferation are endpoints that can be used to identify cytotoxic effects. In a study of the cytotoxicity of four biomaterials and drugs, these two criteria were determined by different techniques. There were notable similarities and differences among the different methods used. Cell viability, which was determined by the trypan blue exclusion test, spectrophotometric microtitration (neutral red) and flow cytometry (fluorescein diacetate) gave similar results. However, the neutral red assay was found to be the most sensitive method for determining the cytotoxicity of these biomaterials and drugs. Cell proliferation measurement, by cell counts and quantitative protein estimation (coomassie blue), revealed important variations between the two methods and indicated poor sensitivity for the protein assay. A slight variability in the determination of the inhibitory concentration 50 (IC(50)) for the two drugs was observed for all the techniques.

背景与目标： ：细胞活力和细胞增殖是可用于鉴定细胞毒性作用的终点。在对四种生物材料和药物的细胞毒性的研究中，这两种标准是通过不同的技术确定的。使用的不同方法之间存在显着的异同。通过台盼蓝排除试验，分光光度微量滴定（中性红）和流式细胞术（双乙酸荧光素）测定的细胞活力得到了相似的结果。但是，发现中性红分析是确定这些生物材料和药物的细胞毒性的最灵敏方法。通过细胞计数和定量蛋白质估计（考马斯蓝）进行细胞增殖测量，揭示了这两种方法之间的重要差异，并表明蛋白质测定的灵敏度较差。在所有技术中，两种药物的抑制浓度50（IC（50））的测定均存在轻微差异。

BACKGROUND & AIMS: :Cloud point extraction with cold column trapping (CPE-CCT) was used for the rapid preconcentration and UV-Vis spectroscopy of beta-carotene in fruit juice samples. A central composite design was employed to optimize parameters such as pH, incubation time, cloud point temperature and surfactant concentration. A detection limit of 0.01 mg/L of beta-carotene (3SB/m), a coefficient of determination of 0.998 and a linear range of 0.04-10 mg/L were obtained. The CPE-CCT method was confirmed in comparison with the corresponding direct HPLC standard method. A simple, portable and cost-effective device was also utilized. Owing to eliminating centrifugation, the conditions of CPE-CCT were more moderate and its sample handling easier compared to conventional CPE.

背景与目标： ：使用冷柱捕集（CPE-CCT）进行浊点萃取可用于果汁样品中β-胡萝卜素的快速预富集和UV-Vis光谱分析。采用中央复合设计来优化参数，例如pH，孵育时间，浊点温度和表面活性剂浓度。 β-胡萝卜素（3SB / m）的检出限为0.01 mg / L，测定系数为0.998，线性范围为0.04-10 mg / L。与相应的直接HPLC标准方法相比，确定了CPE-CCT方法。还使用了一种简单，便携式且具有成本效益的设备。由于消除了离心作用，与传统的CPE相比，CPE-CCT的条件更为温和且样品处理更为轻松。

BACKGROUND & AIMS: One of the ulcerogenic mechanisms by which ethanol induces mucosal lesions in the stomach is the depression of gastric mucosal blood flow (GMBF). The goal of this study was to determine whether lesion formation is the result of vascular ischemia alone or ischemia combined with congestion. The aims of this study were to answer this question by evaluating the relationship between GMBF, oxygen saturation (ISO2) and hemoglobin volume (IHb) in the gastric mucosa under the influences of ethanol and prostaglandin E2 (PGE2) in the ischemic and congestive states, using a laser Doppler flowmeter and tissue spectrum analyzer. Ligation of the gastric celiac artery or vein markedly decreased the GMBF and the ISO2 level. The former procedure also reduced but the latter increased the IHb level. Ethanol administration produced effects similar to venous ligation, i.e. vascular stasis with ischemia. There was a negative correlation between GMBF and severity of lesion formation after ethanol administration. However, at the lesion site all the hemodynamic parameters were significantly reduced, indicating that a necrotic condition had occurred. PGE2 preincubation (25 micrograms) elevated GMBF, ISO2 and IHb levels. It also alleviated the reduction of blood flow induced by ethanol and increased the recovery rate of GMBF and ISO2 after the release of arterial or venous ligation. It is concluded that the decrease in blood flow due to ethanol is probably caused by constriction of venules rather than arterioles inside the mucosa, and this effect could lead to vascular congestion. PGE2 probably dilates both arterioles and venules in the gastric mucosa and thereby increases the blood flow in the gastric mucosa.(ABSTRACT TRUNCATED AT 250 WORDS)

背景与目标： 乙醇诱导胃粘膜损伤的致溃疡机制之一是胃粘膜血流（GMBF）降低。这项研究的目的是确定病变的形成是单独的血管缺血还是缺血与充血相结合的结果。这项研究的目的是通过评估在缺血和充血状态下乙醇和前列腺素E2（PGE2）的影响下胃粘膜中GMBF，血氧饱和度（ISO2）和血红蛋白量（IHb）之间的关系，以回答这一问题，使用激光多普勒流量计和组织频谱分析仪。胃腹腔动脉或静脉的结扎明显降低了GMBF和ISO2水平。前一种方法也减少了，但后者增加了IHb水平。乙醇给药产生的效果类似于静脉结扎，即具有缺血性的血管淤滞。乙醇施用后，GMBF与病变形成的严重程度之间呈负相关。但是，在病变部位，所有血流动力学参数均显着降低，表明已发生坏死病状。 PGE2预孵育（25微克）可提高GMBF，ISO2和IHb水平。在释放动脉或静脉结扎后，它还减轻了乙醇诱导的血流减少，并提高了GMBF和ISO2的回收率。结论是乙醇引起的血流减少可能是由于粘膜内的小静脉收缩而不是小动脉收缩引起的，这种作用可能导致血管充血。 PGE2可能会扩张胃粘膜中的小动脉和小静脉，从而增加胃粘膜中的血流量。（摘要截断为250个字）

BACKGROUND & AIMS: PURPOSE:To assess transepithelial stromal riboflavin absorption with an enhanced riboflavin solution (riboflavin 0.1%, 15% dextran T500 with trometamol (Tris-[hydroxymethyl]aminomethane) and sodium ethylenediaminetetraacetic acid by analyzing light-transmission properties of ex vivo rabbit corneas. SETTING:School of Optometry and Vision Sciences, Cardiff, Wales. DESIGN:Experimental study. METHODS:The enhanced riboflavin drops (Ricrolin TE) were applied every 3 minutes for 1 hour to 12 corneas (4 with intact epithelium, 4 with superficial scratches, 4 with 8.0 mm epithelial debridement). As a comparison, riboflavin drops without the enhancers (riboflavin 0.1%, 20% dextran T500) (normal riboflavin group) were applied to 12 corneas (4 with intact epithelium, 4 with superficial scratches, 4 with central epithelial debridement). A control group of 4 corneas with intact epithelium received balanced saline 0.9%. To assess enhanced riboflavin absorption, light-transmission spectra of the corneas were analyzed with a spectrophotometer. RESULTS:The spectra in corneas with intact epithelium in both riboflavin groups and in eyes with superficial scratches treated with normal riboflavin were similar to controls. Those with enhanced riboflavin and superficial scratches showed a homogeneous yellow discoloration of the cornea with a dip in light transmission between 400 and 490 nm, similar to that of the enhanced riboflavin solution. This was also seen, albeit of a greater magnitude, with complete epithelial removal, with eyes receiving enhanced riboflavin having a greater dip in transmission than eyes receiving normal riboflavin. CONCLUSIONS:Administration of enhanced riboflavin and superficial epithelial scratches allowed sufficient riboflavin stromal absorption to homogeneously alter the transmission spectra of rabbit corneas. This did not occur to the same extent with an intact epithelium or normal riboflavin with superficial scratches. FINANCIAL DISCLOSURE:No author has a financial or proprietary interest in any material or method mentioned.

背景与目标： 目的：通过分析离体兔角膜的透光特性，评估增强的核黄素溶液（核黄素0.1％，15％右旋糖酐T500和丁苯三酚（Tris-[[羟甲基]氨基甲烷））和乙二胺四乙酸钠对上皮间质核黄素的吸收。
地点：威尔士卡迪夫验光与视觉科学学院。
设计：实验研究。
方法：每3分钟将增强的核黄素滴剂（Ricrolin TE）应用于12个角膜（4个完整的上皮，4个表面刮擦，4个8.0 mm上皮清创术）。作为比较，将不使用增强剂的核黄素滴剂（核黄素0.1％，右旋糖酐T500）（正常核黄素组）应用于12个角膜（4个完整上皮，4个表面刮擦，4个中央上皮清创）。带有完整上皮的4个角膜对照组接受0.9％的平衡盐水。为了评估核黄素吸收的增强，用分光光度计分析了角膜的透光光谱。
结果：核黄素组中角膜完整上皮的光谱和正常核黄素治疗后表面划痕的眼睛的光谱与对照组相似。具有增强的核黄素溶液和表面刮痕的那些显示出角膜的均匀黄变色，并且具有在400至490nm之间的光透射率的下降，类似于增强的核黄素溶液。还可以看到这种情况，尽管幅度更大，完全去除了上皮，与接受正常核黄素的眼睛相比，接受增强核黄素的眼睛的透射率下降更大。
结论：施用增强的核黄素和浅表上皮擦伤可使核黄素基质吸收充分，从而均匀地改变兔角膜的透射光谱。完整的上皮细胞或正常的核黄素表面有划痕时，发生这种情况的程度不同。
财务披露：任何作者都不会对所提及的任何材料或方法具有财务或专有利益。

BACKGROUND & AIMS: :A novel diffusion cell has been constructed which allows study of membrane diffusion processes without the need for sampling of the receiver compartment, that is highly sensitive and, being based around a diode array spectrophotometer also allows for continuous, real-time recording of multi-species concentration changes in the receiving compartment. The system is controlled to operate isothermally (via a Peltier control system) at temperatures between 15 and 85 degrees C. To examine the performance of this novel design, the transfer of tetracaine from a preparation in PEG 400 (20% tetracaine in PEG 400) has been studied. The results have been used to determine flux, lag time and related parameters. The performance of the novel cell is compared with results from traditional Franz cell diffusion studies.

背景与目标： ：已构建了一种新型扩散池，该池可以进行膜扩散过程的研究，而无需对接收室进行采样，该池非常灵敏，并且基于二极管阵列分光光度计，还可以连续，实时地记录多个接收室中物种浓度的变化。控制该系统使其在15到85摄氏度之间的温度下等温运行（通过Peltier控制系统）。要检查该新颖设计的性能，可从制剂中将丁卡因转移到PEG 400中（在PEG 400中为20％丁卡因）已经研究过了。结果已用于确定通量，滞后时间和相关参数。将该新型电池的性能与传统Franz细胞扩散研究的结果进行了比较。

BACKGROUND & AIMS: :The aim was to examine the effect of retreatment process on the surface roughness and nickel titanium (NiTi) composition of ProTaper Universal Retreatment (PTUR; consists of 3 files; D1, D2, D3) and WaveOne Gold (WOG) (primary) instruments. Twenty extracted mandibular molar teeth with severe curved (30-40°) mesial roots were selected and divided into two groups (n = 10) based on the instrument used for the removal of the root canal filling. Before and after using the instruments in two canals, they were subjected to atomic force microscopy (AFM) and energy dispersive X-ray spectrophotometry (EDX) analysis. The EDX analysis data and roughness average (Ra) and root mean square (RMS) values were analyzed statistically using a one-way analysis of variance and post hoc Tukey's test at the 5% significant level. There was no significant difference between the new and used D1 and D2 PTUR and WOG instruments in terms of the Ni composition (p > .05). The Ti contents of the used D2 and D3 PTUR instruments were lower those of the new instruments (p < .05). In both new and used instruments, PTUR and WOG have no difference in terms of Ra and RMS values. (p > .05). The Ra and RMS values of the PTUR and WOG systems significantly increased after removal of the root canal filling (p < .05). The use of PTUR and WOG instruments for removal of root canal filling in severely curved root canals affected the surface topography of the files. The NiTi composition of the WOG instruments was unaffected by the retreatment process.

背景与目标： ：目的是研究再处理工艺对ProTaper通用再处理（PTUR；包括3个文件； D1，D2，D3）和WaveOne Gold（WOG）（主要）仪器的表面粗糙度和镍钛（NiTi）成分的影响。根据用于去除根管充盈的器械，选择二十颗拔除的具有严重弯曲（30-40°）近中根的下颌磨牙，并将其分为两组（n = 10）。在两条运河中使用该仪器之前和之后，都要对它们进行原子力显微镜（AFM）和能量色散X射线分光光度法（EDX）分析。使用单向方差分析和事后Tukey检验在5％显着水平下对EDX分析数据和粗糙度平均值（Ra）和均方根（RMS）值进行统计分析。在新的和使用过的D1和D2 PTUR和WOG仪器之间，在镍成分方面没有显着差异（p> .05）。所用的D2和D3 PTUR仪器中的Ti含量比新仪器要低（p <.05）。在新仪器和旧仪器中，PTUR和WOG的Ra和RMS值都没有差异。 （p> .05）。去除根管充盈后，PTUR和WOG系统的Ra和RMS值显着增加（p <0.05）。使用PTUR和WOG器械去除严重弯曲的根管中的根管充填会影响锉刀的表面形貌。 WOG仪器的NiTi成分不受再处理过程的影响。