Power spectral density-based nearinfrared sub-band detection for noninvasive blood glucose prediction in both in-vitro and in-vivo studies

Diabetes is a widespread and serious disease and noninvasive measurement has been in high demand.To address this problem,a power spectral density-based method was offered for determining glucose sensitive sub-bands in the nearinfrared(NIR)spectrum.The experiments were conducted using phantoms of different optical properties in-vitro conditions.The optical bands 1200–1300 nm and 2100–2200 nm were found feasible for measuring blood glucose.After that,a photoplethysmography(PPG)-based low cost and portable optical system was designed.It has six di®erent NIR wavelength LEDs for illumination and an InGaAs photodiode for detection.Optical density values were calculated through the system and used as independent variables for multiple linear regression analysis.The results of blood glucose levels for 24 known healthy subjects showed that the optical system prediction was nearly 80%in the A zone and 20%in the B zone according to the Clarke Error Grid analysis.It was shown that a promising easyuse,continuous,and compact optical system had been designed.

Filter-free self-power CdSe/Sb_(2)(S_(1-x),Se_(x))_(3)nearinfrared narrowband detection and imaging

Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.

Near-infrared spectroscopy for evaluation of global and skeletal muscle tissue oxygenation

Non-invasive clinical examination has well-recognized limitations in detecting compensated and uncompensated low flow states and their severity.This paper describes the principles of near-infrared absorption spectroscopy(NIRS)and the basis for its proposed use in heart failure/cardiogenic and septic shock to assess global and regional tissue oxygenation.The vascular occlusion test is explained.Limitations of NIRS,current controversies,and what is necessary in the future to make this technology a part of the initial and ongoing assessment of a patient are also discussed.The ultimate goal of such techniques is to prevent miss-assessment and inadequate resuscitation of patients,two major factors in the development of multisystem organ failure and death.

Investigation of the Potential of Near Infrared Spectroscopy for the Detection and Quantification of Pesticides in Aqueous Solution

This research investigates the potential of near infrared spectroscopy (NIRS) for the detection and quantification of pesticides in aqueous solution. Standard solutions of Alachlor and Atrazine (ranging in concentration from 1.25 - 100 ppm) were prepared by dilution in a Methanol/water solvent (1:1 methanol/water (v/v)). Near infrared transmission spectra were obtained in the wavelength region 400 - 2500 nm;however, the wavelength regions below 1300 nm and above 1900 nm were omitted in subsequent analysis due to the poor signal repeatability in these regions. Partial least squares analysis was applied for discrimination between pesticide and solvent and for prediction of pesticide concentration. Limits of detection of 12.6 ppm for Alachlor and 46.4 ppm for Atrazine were obtained.

食品检测中红外光谱的应用

水、脂肪、碳水化合物、维生素、蛋白质是食品的主要组成成分,这些组分在红外线区域内均有吸收光谱。利用红外光谱技术可以准确检测出食品组分及其结构性质。本文以食品红外光谱检测为研究对象,介绍红外光谱的检测原理,分析食品检测中红外光谱的应用进展,并对红外光谱在食品检测中的应用进行简单的探究。

The application of near-infrared spectra micro-image in the imaging analysis of biology samples

In this research,suitable imaging methods were used for acquiring single compound images ofbiology samples of chicken pectorales tissue section,tobacco dry leaf,fresh leaf and plantglandular hair,respectively.The adverse effects caused by the high water content and thethermal effect of near infrared(NIR)light were effectively solved during the experiment procedures and the data procesing.PCA algorithm was applied to the NIR micro-image of chickenpectorales tissue.Comparing the loading vector of PC3 with the NIR spectrum of dry albumen,the information of PC3 was confimmed to be provided mainly by protein,i.e.,the 3rd score imagerepresents the distribution trend of protein mainly.PCA algorithm was applied to the NIR micro-image of tobacco dry leaf.The information of PC2 was confimed to be provided by carbohydrateindluding starch mainly.Compared to the 2nd score image of tobacco dry leaf,the comparedcorelation image with the reference spectrum of starch had the same distribution trend as the 2nd score image.The comparative correla tion images with the reference spectra of protein,glucose,fructose and the total plant alkaloid were acquired to confirm the distribution trend ofthese compounds in tobacco dry leaf respectively.Comparative correlation images of fresh leafwith the reference spectra of protein,starch,fructose,ghucose and water were acquired to confim the distribution trend of these compounds in fresh leaf.Chemimap imaging of plant glandularhair was acquired to show the tubular structure clearly.

Near-Infrared Light-Activatable Melanized Paclitaxel Nano-Self-Assemblies for Synergistic Anti-tumor Therapy

Building self-assembly nanostructures is an important way to overcome the limitations of paclitaxel in tumor therapy.However,this strategy is also faced with challenges,such as difficulties in efficient release and the potential for drug resistance.Herein,we developed a near-infrared light-activatable melanized paclitaxel self-assembly nanoparticles for synergistic anti-tumor therapy.In this strategy,paclitaxel dimer prodrugs were synthesized and paclitaxel nanoparticles were obtained through self-assembly.Finally,the paclitaxel dimer nanoparticles were capped with polydopamine(PDA,melanoidin)and human serum albumin(HSA).The disulfide bonds in paclitaxel dimeric prodrug specifically respond to high concentrations of glutathione(GSH)and reactive oxygen species(ROS)in tumor cells.PDA enhances the biocompatibility of the drug molecules and imparts near-infrared photothermal conversion capability to the nano-self-assemblies.Both the in vitro and in vivo experiments demonstrated that this paclitaxel nanoprodrug exhibited enhanced tumor therapeutic efficacy under near-infrared light irradiation.

Conformation Governed Reactivity of Fused Thia-Sapphyrin Dimers Bearing Multiply Fused Heteroaromatic Rings

Suitable conformations and proper alignment of complex natural macrocycles are essential for achieving their unique properties.However,such artificial macrocycle prototypes are still limited due to synthetic difficulties.In this respect,directly linked porphyrin analog dimers display tunable conformations and intriguing properties,and thus,they may be employed as a class of promising platforms.Herein,we report that one-pot oxidative dimerization of thiahydrosapphyrin 1 yields dimers,2anti and 2syn,comprising a transoid-oriented plate-like bipyrrolo[1,2-a]indolylidene.The thiophene-containing tetrapyrrole arching subunits in 2 lie at the opposite(anti)and same(syn)sides of the plate,respectively.Meanwhile,multiply fused cisoid-orientated dimer 3 was also obtained;a polycyclic pyrrolo-bridged bipyrroloindole derivative tethered with fullyπ-conjugated bridges was formed.Notably,the anti-dimer 2anti underwent subsequent oxidative fusion to furnish a further-fused[6.5.5.7.5.5.5.6]-octacyclic compound 4anti.In contrast,the syn-orientated 2syn could not be further fused due to the long distance between the potential reaction sites.This study provides a unique approach to the fused dimeric porphyrin analogs for potential near-infrared optical materials by a simple oxidation reaction.It also reveals the importance of conformation-modulated reactivity for constructing complex porphyrin arrays.

Neural network and principal component regression in non-destructive soluble solids content assessment:a comparison

Visible and near infrared spectroscopy is a non-destructive,green,and rapid technology that can be utilized to estimate the components of interest without conditioning it,as compared with classical analytical methods.The objective of this paper is to compare the performance of artificial neural network(ANN)(a nonlinear model)and principal component regression(PCR)(a linear model)based on visible and shortwave near infrared(VIS-SWNIR)(400-1000 nm)spectra in the non-destructive soluble solids content measurement of an apple.First,we used multiplicative scattering correction to pre-process the spectral data.Second,PCR was applied to estimate the optimal number of input variables.Third,the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models.The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN.Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.