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.     

近红外光谱技术在中成药质量控制中的应用进展

中成药传统质量控制方法一般采用TLC鉴别、HPLC含量测定等方法进行。但这些方法一般需要耗费很长的时间,较为繁琐。近红外技术以其检测时间短、灵敏度高、无需对样品进行复杂处理等优点越来越多的被用到药品的质量控制上,特别是中成药质量控制。本文在介绍了近红外光谱技术的原理及其应用现状的基础上,对该技术在中成药质量控制中的应用进行了综述。     

近红外漫反射光谱法快速测定积雪草总苷中积雪草苷的含量

目的：建立近红外漫反射光谱法快速测定积雪草总苷中积雪草苷的含量方法。方法：采用高效液相色谱法测定市场上流通的66批次积雪草总苷中积雪草苷的含量,同时采集近红外漫反射光谱,对原始光谱进行多元散射校正（ MSC）、二阶导数（2D）和Norris导数（ND）平滑等光谱预处理方法,采用偏最小二乘回归法（PLSR）建立近红外定量校正模型,实现积雪草总苷中指标性成分积雪草苷含量的快速测定。结果：所建立的积雪草苷近红外定量校正模型,验证集相对误差RMSEP、标准偏差与标准误差的比值RPD分别为0.0352和6.47,表明所建近红外模型预测准确度高。同时,校正集均方根误差RMSEC和验证集均方根误差RMSEP接近,分别为1.17和1.25,交叉验证均方根误差RMSECV为3.43,表明所建近红外模型稳健性好。结论：所建立的积雪草苷近红外定量校正模型具有很好的预测准确度和稳健性,为市场上积雪草总苷质量的快速评价提供方法。     

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.     

运用近红外对牛黄解毒片中异性有机物的应急检验研究

目的运用近红外(NIR)对牛黄解毒片中异性有机物进行检查。方法将收集的3个厂家7批次的牛黄解毒片扫描近红外光谱和显微鉴别后,将法定检验结果与近红外光谱结合,建立应急检验模型。结果用牛黄解毒片正品的QCM检验模型对实验室判定为不合格的2批样品进行检查,均呈阳性。结论建立的应急检验模型具有方法简单、易操作等特点,适用于药品检测车对牛黄解毒片中异性有机物的快速筛查。     

利用近红外光谱法测定洛伐他汀胶囊的含量

目的利用近红外光谱法测定洛伐他汀胶囊含量。方法采集洛伐他汀胶囊NIR光谱,采用偏最小二乘法(PLS)进行回归,通过建立洛伐他汀胶囊NIR光谱与HPLC法测定值之间的多元校正模型,测定洛伐他汀胶囊的含量。结果定量模型的外部验证决定系数R2为95.8,外部验证均方差(RMSEP)为0.457,内部交叉验证均方差(RMSECV)为0.542。结论本方法快速、简便、无损,结果准确,适用于药品的现场快检。     

近红外光谱法快速分析头孢氨苄片

目的:建立测定头孢氨苄片含量的近红外光谱(NIR)快速分析方法。方法:以全国不同企业生产的头孢氨苄片建立校正集,采集其近红外漫反射光谱,经内部交叉验证,建立校正模型,进而对预测集的样品进行分析。结果:头孢氨苄糖衣片的浓度范围为0.2569～0.6039mg.mg-1,头孢氨苄薄膜衣片的浓度范围为0.3478～0.8755mg.mg-1,内部交叉验证决定系数(r)分别为94.31,97.92,内部交叉验证均方差(RMSECV)为1.98,1.55,外部验证预测均方差(RMSEP)为1.58,1.22,预测值与真值的相关系数为0.9799,0.9894。结论:该法具有快速、简便、结果准确的特点,可用于头孢氨苄片药品的快速检验。     

Estimation of active pharmaceutical ingredients content using locally weighted partial least squares and statistical wavelength selection

Development of quality estimation models using near infrared spectroscopy (NIRS) and multivariate analysis has been accelerated as a process analytical technology (PAT) tool in the pharmaceutical industry. Although linear regression methods such as partial least squares (PLS) are widely used, they cannot always achieve high estimation accuracy because physical and chemical properties of a measuring object have a complex effect on NIR spectra. In this research, locally weighted PLS (LW-PLS) which utilizes a newly defined similarity between samples is proposed to estimate active pharmaceutical ingredient (API) content in granules for tableting. In addition, a statistical wavelength selection method which quantifies the effect of API content and other factors on NIR spectra is proposed. LW-PLS and the proposed wavelength selection method were applied to real process data provided by Daiichi Sankyo Co., Ltd., and the estimation accuracy was improved by 38.6% in root mean square error of prediction (RMSEP) compared to the conventional PLS using wavelengths selected on the basis of variable importance on the projection (VIP). The results clearly show that the proposed calibration modeling technique is useful for API content estimation and is superior to the conventional one.     

Aluminate-Based Nanostructured Luminescent Materials: Design of Processing and Functional Properties

Interest in luminescent materials has been continuously growing for several decades, looking for the development of new systems with optimized optical properties. Nowadays, research has been focused on the development of materials that satisfy specific market requirements in optoelectronics, radioelectronics, aerospace, bio-sensing, pigment applications, etc. Despite the fact that several efforts have made in the synthesis of organic luminescent materials, their poor stability under light exposure limits their use. Hence, luminescent materials based on inorganic phosphors are considered a mature topic. Within this subject, glass, glass-ceramics and ceramics have had great technological relevance, depending on the final applications. Supposing that luminescent materials are able to withstand high temperatures, have a high strength and, simultaneously, possess high stability, ceramics may be considered promising candidates to demonstrate required performance. In an ongoing effort to find a suitable synthesis method for their processing, some routes to develop nanostructured luminescent materials are addressed in this review paper. Several ceramic families that show luminescence have been intensively studied in the last few decades. Here, we demonstrate the synthesis of particles based on aluminate using the methods of sol-gel or molten salts and the production of thin films using screen printing assisted by a molten salt flux. The goal of this review is to identify potential methods to tailor the micro-nanostructure and to tune both the emission and excitation properties, focusing on emerging strategies that can be easily transferred to an industrial scale. Major challenges, opportunities, and directions of future research are specified.