Carbon nanotubes for biomedical imaging: The recent advances

This article reviews the latest progresses regarding the applications of carbon nanotubes (CNTs), including single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs), as multifunctional nano-probes for biomedical imaging. Utilizing the intrinsic band-gap fluorescence of semi-conducting single-walled carbon nanotubes (SWNTs), fluorescence imaging in the near infrared II (NIR-II) region with enhanced tissue penetration and spatial resolution has shown great promise in recent years. Raman imaging based on the resonance Raman scattering of SWNTs has also been explored by a number of groups for in vitro and in vivo imaging of biological samples. The strong absorbance of CNTs in the NIR region can be used for photoacoustic imaging, and their photoacoustic signals can be dramatically enhanced by adding organic dyes, or coating with gold shells. Taking advantages of metal nanoparticle impurities attached to nanotubes, CNTs can also serve as a T2-contrast agent in magnetic resonance (MR) imaging. In addition, when labeled with radioactive isotopes, many groups have developed nuclear imaging with functionalized CNTs. Therefore CNTs are unique imaging probes with great potential in biomedical multimodal imaging.     

阿奇霉素颗粒剂近红外通用性定量分析模型的建立(英文)

用近红外漫反射光谱法建立了阿奇霉素颗粒剂的通用性定量分析模型。以21个厂家的103批阿奇霉素颗粒剂建立模型,其浓度范围为3.0%至24.5%。对模型进行外部验证,均方根差(RMSEP)为0.613。此外,还参照ICH的指导原则对模型进行方法学验证,验证项目有:专属性、线性、准确度和精密度。可见,通过选择合适的训练集样本,并精心的挑选建模谱段,建立阿奇霉素颗粒剂的近红外通用性定量分析模型是可行的,该模型可用于快速分析国内各厂家产品的含量。     

Integrated real‐time Raman system for clinical in vivo skin analysis

Background: Raman spectroscopy is a non‐invasive optical technique that can probe the molecular structure and conformation of biochemical constituents. The probability of Raman scattering is exceedingly low (∼10⁻¹⁰), and consequently up to now the practical application of Raman spectroscopy to clinical medicine has been limited by either the weak spectral signal or by the long data acquisition times. Recent advances in Raman hardware and probe design have reduced spectral acquisition times, paving the way for clinical applications. Methods: We present an integrated real‐time Raman spectroscopy system for skin evaluation and characterization, which combines customized hardware features and software implementation. Real‐time data acquisition and processing includes CCD dark‐noise subtraction, wavelength calibration, spectral response calibration, intensity calibration, signal saturation detection, cosmic ray rejection, fluorescence background removal, and composition modeling. Real‐time in vivo Raman measurement of volar forearm skin is presented to illustrate the methods and modeling. Results: The system design implemented full‐chip vertical hardware binning to improve the signal‐to‐noise ratio by 16‐fold. The total time for a single in vivo measurement with analysis can be reduced to 100 ms with this implementation. Human skin was well modeled using the base Raman spectra. Conclusion: In vivo real‐time Raman can be a very promising research and practical technique for skin evaluation.     

Noninvasive early detection of brain edema in mice by near-infrared light scattering

Brain edema accounts for significant morbidity and mortality in many neurologic conditions such as head trauma, stroke, meningitis, and brain tumor. The water channel aquaporin-4 (AQP4) has been found to be an important determinant of brain water accumulation and clearance of excess brain water. We report the development of a noninvasive near-infrared (NIR) light-scattering method to compare the early kinetics of brain swelling in normal and AQP4-deficient mice. Brain tissue was illuminated through the intact skull with NIR light at 850 nm, and steady-state scattered light intensity was monitored at an angle of 90 degrees at a position on the skull approximately 10 mm from the illuminated site. NIR light scattering reversibly increased with brain swelling (DeltaI/Io approximately 25% per 1% increase in brain water content), but was insensitive to changes in cerebral blood flow, blood oxygenation, or blood flow-related changes in intracranial pressure (ICP). DeltaI/Io increased approximately linearly with brain water content as measured by wet-to-dry weight ratios. Acute water intoxication (intraperitoneal water, 20% body weight) produced a gradual increase in DeltaI/Io of 12 +/- 4% in wild-type mice at 5 min, much greater than that of 2 +/- 1% in AQP4-null mice. Correlation of the NIR signal with ICP showed that increased DeltaI/Io preceded measurable increases in ICP, indicating the ability of the NIR method to detect early brain edema before ICP elevation. NIR light scattering provides a simple noninvasive method to monitor brain edema in mice, with potential clinical applications.     

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...     

不同品种药用菊花与其他菊花的近红外光谱聚类分析及相似度研究

目的建立不同品种药用菊花与其他菊花的近红外光谱(NIR)聚类分析和相似度研究方法。方法采用OPUS光谱分析软件对光谱预处理方法和波段进行筛选,优选最佳预处理方法;采用NIR聚类分析模式识别法,从聚类分析树状图中类间距大小鉴别不同品种药用菊花和其他菊花,同时计算光谱间的相似度,判断不同品种药用菊花与其他菊花间的亲缘关系。结果通过光谱分析软件筛选最佳光谱预处理方法为一阶导数+矢量归一化法,波段为8971.5～7054.5,6518.4～5372.8,4964.0～4038.3 cm^-1,聚类分析树状图中类间距>2时,药用菊花、金丝皇菊和其他菊花分为两大类,在类间距为0.2左右时,各类菊花各自聚为一类;相似度判断中雪菊与各类菊花相似度均<0.2,大马牙与怀菊、滁菊、贡菊、洋甘菊、金丝皇菊、金盏菊,野菊与亳菊、滁菊、金盏菊,怀菊与亳菊、滁菊、金盏菊相似度在0.9700～0.9900之间,其他各类菊花相似度均>0.9900。结论 NIR聚类分析模式识别法及相似度研究法可作为不同药用菊花与其他菊花的品种鉴别依据。     

A pilot study of ICG laser therapy of acne vulgaris: photodynamic and photothermolysis treatment

BACKGROUND AND OBJECTIVES: The near-infrared (NIR) laser radiation due to its high penetration depth is widely used in phototherapy. In application to skin appendages, a high selectivity of laser treatment is needed to prevent light action on surrounding tissues. Indocyanine green (ICG) dye may provide a high selectivity of treatment due to effective ICG uploading by a target and its narrow band of considerable absorption just at the wavelength of the NIR diode laser. The goal of this study is to demonstrate the efficacy of the NIR diode laser phototherapy in combination with topical application of ICG suggested for soft and thermal treatment of acne vulgaris. STUDY DESIGN/MATERIALS AND METHODS: Twenty-two volunteers with facile or back-located acne were enrolled. Skin sites of subjects were stained by ICG and irradiated by NIR laser-diode light (803 or 809 nm). One mg/ml solution of ICG was applied for 5 or 15 minutes to the cleaned skin site. Untreated, only stained and only light irradiated skin areas served as controls. For soft acne treatment, the low-intensity (803 nm, 10-50 mW/cm(2), 5-10 minutes) or the medium-intensity (809 nm, 150-190 mW/cm(2), 15 minutes) protocols were used. The single and multiple (up to 8-9) treatments were provided. The individual acne lesions were photothermally treated at 18 W/cm(2) (803 nm, 0.5 seconds) without skin surface cooling or at 200 W/cm(2) (809 nm, 0.5 seconds) with cooling. RESULTS: The observations during 1-2 months showed that soft acne treatment decreased the number of active elements, reduced erythema and inflammation, and considerably improved the skin state without any side effects. At high power densities (up to 200 W/cm(2)), ICG stained acne inflammatory elements were destroyed for light exposures of 0.5 seconds. CONCLUSIONS: Based on the concept that hair follicle, especially sebaceous gland, can be intensively and selectively stained by ICG due to dye diffusion through pilosebaceous canal and its fast uptake by living microorganisms, by vital keratinocytes of epithelium of the canal and sebaceous duct, and by rapidly proliferating sebocytes, new technologies of soft and thermal acne lesions treatment that could be used in clinical treatment of acne were proposed.     

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。