NIR laser tissue welding of in vitro porcine cornea and sclera tissue

BACKGROUND AND OBJECTIVE: The objective of this study was to test the hypothesis that an near infrared (NIR) laser system (1,455 nm) in combination with a motorized translational stage to control the position and speed of the laser beam and a shutter to control the laser exposure to the tissue being welded could be used to successfully weld ocular tissues. STUDY DESIGN/MATERIALS AND METHODS: Seventy-five porcine corneas and 23 porcine scleral tissues were welded in vitro in this study. The welded tissues were examined using histopathology and tensile strength analysis. Eight different welding conditions were analyzed for porcine cornea and one for sclera tissues. The tensile strength of the welded groups was compared to a sutured cornea control group. RESULTS: The NIR laser welding system provides strong, full thickness welds and does not require the use of extrinsic dyes, chromophores, or solders. Mean weld strengths of 0.15-0.45 kg/cm(2) were obtained for the cornea and 1.01 kg/cm(2) for sclera welds. The native H(2)O in the ocular tissue serves as an absorber of the 1,455 nm radiation and helps to induce the welds. CONCLUSIONS: We conclude that an NIR laser system using an optimal laser radiation wavelength of 1,455 nm can effectively weld cornea and sclera tissue and that this laser tissue welding (LTW) methodology typically causes minimal disruption of tissue, and thus, avoids opacities and irregularities in the tissue which may result in decreased visual acuity. The optimization of a laser welding system that leads to a strong full thickness tissue bond without tissue destruction, an instant seal that promotes wound healing, and the absence of a continued presence of a foreign substance like a suture, is of considerable importance to the ophthalmology medical community. This need is especially apparent with respect to corneal transplantation and fixing the position of corneal flaps in Laser-Assisted In Situ Keratomileusis (LASIK), a laser procedure used to permanently change the shape of the cornea.     

Physical and Chemical Characterisation of the Pigments of a 17th-Century Mural Painting in the Spanish Caribbean

The arrival of Spaniards in the Caribbean islands introduced to the region the practice of applying pigments onto buildings. The pigments that remain on these buildings may provide data on their historical evolution and essential information for tackling restoration tasks. In this study, a 17th-century mural painting located in the Cathedral of Santo Domingo on the Hispaniola island of the Caribbean is characterised via UV–VIS–NIR, Raman and FTIR spectroscopy, XRD and SEM/EDX. The pigments are found in the older Chapel of Our Lady of Candelaria, currently Chapel of Our Lady of Mercy. The chapel was built in the 17th century by black slave brotherhood and extended by Spaniards. During a recent restoration process of the chapel, remains of mural painting appeared, which were covered by several layers of lime. Five colours were identified: ochre, green, red, blue and white. Moreover, it was determined that this mural painting was made before the end of the 18th century, because many of the materials used were no longer used after the industrialisation of painting. However, since both rutile and anatase appear as a white pigment, a restoration may have been carried out in the 20th century, and it has been painted white.     

Self-assembled multifunctional nanotheranostics against circulating tumor clusters in metastatic breast cancer

Circulating tumor clusters(CTC) disseminating from the primary tumor are responsible for secondary tumor formation where the conventional treatments such as chemotherapy and radiotherapy does not prevent the metastasis at locally advanced stage of breast cancer. In this study, a smart nanotheranostic system has been developed to track and eliminate the CTCs before it can colonize at a new site,which would reduce metastatic progression and increase the five-year survival rate of the breast cancer...     

近红外光谱法在线判断滴丸料液混合终点

 目的建立一种中药生产过程中料液混合终点的在线判断方法。方法用透反射光纤探头在线采集混合过程中料液的近红外光谱,以光谱偏差作为混合均匀度指标,判断混合终点。结果应用本法对复方丹参滴丸料液的混合过程进行在线终点判断,随后制备成滴丸,结果表明,经本法终点判断后制备的滴丸丸重均匀,有效成分含量稳定,能有效保证产品质量。结论本法可快速准确地对复方丹参滴丸料液混合终点实现在线判断。     

小型高精度近红外线成像乳腺癌检测仪的研制开发

近年来我国乳腺癌发病率逐年上升,提早检测乳腺癌是非常必要和有效的防范措施,本文介绍了此种新型检测仪的设计思想和结构特点。本检测仪扩大了检测范围以适应不同检测对象的检测要求,而且提高了近红外线成像的检测精度。实验证明本检测仪具有检测安全、操作简易、重复性好等优点。     

Feasibility of using a miniature NIR spectrometer to measure volumic mass during alcoholic fermentation

Volumic mass—a key component of must quality control tests during alcoholic fermentation—is of great interest to the winemaking industry. Transmitance near-infrared (NIR) spectra of 124 must samples over the range of 200–1,100–nm were obtained using a miniature spectrometer. The performance of this instrument to predict volumic mass was evaluated using partial least squares (PLS) regression and multiple linear regression (MLR). The validation statistics coefficient of determination (r²) and the standard error of prediction (SEP) were r² = 0.98, n = 31 and r² = 0.96, n = 31, and SEP = 5.85 and 7.49 g/dm³ for PLS and MLR equations developed to fit reference data for volumic mass and spectral data. Comparison of results from MLR and PLS demonstrates that a MLR model with six significant wavelengths (P < 0.05) fit volumic mass data to transmittance (1/T) data slightly worse than a more sophisticated PLS model using the full scanning range. The results suggest that NIR spectroscopy is a suitable technique for predicting volumic mass during alcoholic fermentation, and that a low-cost NIR instrument can be used for this purpose.     

Minimization of self‐quenching fluorescence on dyes conjugated to biomolecules with multiple labeling sites via asymmetrically charged NIR fluorophores

Self‐aggregation of dyes even at low concentrations poses a considerable challenge in preparing sufficiently bright molecular probes for in vivo imaging, particularly in the conjugation of near infrared cyanine dyes to polypeptides with multiple labeling sites. Such self‐aggregation leads to a significant energy transfer between the dyes, resulting in severe quenching and low brightness of the targeted probe. To address this problem, we designed a novel type of dye with an asymmetrical distribution of charge. Asymmetrical distribution prevents the chromophores from π‐stacking thus minimizing the energy transfer and fluorescence quenching. The conjugation of the dye to polypeptides showed only a small presence of an H‐aggregate band in the absorption spectra and, hence, a relatively high quantum efficiency. Copyright © 2014 John Wiley & Sons, Ltd.     

The obesity paradox: methodological considerations based on epidemiological and clinical evidence--new insights

Despite the well-known association of obesity with increased mortality and the development of chronic diseases, an "obesity paradox" has been reported in several patient categories; i.e., overweight and obese patients have a better prognosis than normal or low-weight individuals. The present review aims to identify potential factors lying beneath the beneficial effect of overweight and obesity. In particular, the role of nutritional status, malnutrition and catabolic state, as well as intentional vs. unintentional weight loss and the possibility of a U-shape relationship between body mass index and survival will be examined. Furthermore, methodological considerations framing the obesity paradox will be presented and discussed.