Instrumental Requirements for Non-Invasive Blood Glucose Measurement Using NIR Spectroscopy

The magnitude of spectral change in blood glucose measurements with diffuse reflectance spectroscopy is investigated. Spectral change is estimated by simulation of light propagation in skin tissue and measurements of absorbance spectra of aqueous glucose solution. Required sensitivity of spectrophotometers for monitoring change in the blood glucose concentration as small as 10 mg/dL has been obtained using the estimated change in the absorbance spectrum and mean pathlength of light in tissue.     

STUDY OF THE COPRECIPITATED IRON/MANGANESE FISCHER-TROPSCH CATALYSTS

IntroductionInFTsynthesis,metalMnhasbeenregardedasanicepromotertoincreaselightolefinselectivity.Coprecipitationhasbeenusedextensivelyinthepreparationofcommercialcatalysts.AnumberofpublicationsdealingwiththerelationbetWcenphysical-chemistry'proPertiesofcatalystsandFTs}nthesishaveappeared,butdifferentcatal})stcompositionsandpreparationconditi0nsmakedifferentconclusions.Therearetu)omainrespects.0neisthatcarelystswithhighacivityandolefinselectivityhavedifferentMMieratiovaryingoverawiderange(Mn…     

Segmental orientations and deformation mechanism of a poly(ether‐block‐amide) film

Simultaneous measurements of microscopic infrared dichroism, mesoscale deformation, and macroscopic stress have been made for a microphase‐separated film of poly(ether‐block‐amide) 4033 during uniaxial stretching at temperatures between 30 and 91 °C, well below the melting point of the hard polyamide‐12 (PA) domains. Before the onset of dramatic microstructural alterations, the true stress–strain relationship on the mesoscale can be described with an interpenetrating network model, and poly(tetramethylene oxide) (PTMO) soft segments undergo affine deformation. Beyond a threshold strain at which stress from the soft network becomes larger than that from the hard network, plastic deformation occurs in the hard PA domains, and this is accompanied by the downward derivations of the true stress and molecular orientation of PTMO blocks from the model predictions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1161–1167, 2005     

Oxygen‐barrier properties of cold‐crystallized and melt‐crystallized poly(ethylene terephthalate‐co‐4,4′‐bibenzoate)

This study examined the oxygen‐transport properties of poly(ethylene terephthalate‐co‐bibenzoate) (PETBB55) crystallized from the melt (melt crystallization) or quenched to glass and subsequently isothermally crystallized by heating above the glass‐transition temperature (cold crystallization). The gauche–trans conformation of the glycol linkage was determined by infrared analysis, and the crystalline morphology was examined by atomic force microscopy. Oxygen solubility decreased linearly with volume fraction crystallinity. For melt‐crystallized PETBB55, extrapolation to zero solubility corresponded to an impermeable crystal with 100% trans glycol conformations, a density of 1.396 g cm^?3, and a heat of melting of 83 J g^?1. From the melt, PETBB55 crystallized as space‐filling spherulites with loosely organized lamellae and pronounced secondary crystallization. The morphological observations provided a structural model for permeability consisting of impermeable platelets randomly dispersed in a permeable matrix. In contrast, cold‐crystallized PETBB55 retained the granular texture of the quenched polymer despite the high level of crystallinity, as measured by the density and heat of melting. Oxygen solubility decreased linearly with volume fraction crystallinity, but zero solubility corresponded to an impermeable defective crystal with a trans fraction of 0.83 and a density of 1.381 g cm^?3. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2489–2503, 2002     

An empirical study of PLAD regression using the bootstrap

Partial LAD regression uses the L ₁ norm associated with least absolute deviations (LAD) regression while retaining the same algorithmic structure of univariate partial least squares (PLS) regression. We use the bootstrap in order to assess the partial LAD regression model performance and to make comparisons to PLS regression. We use a variety of examples coming from NIR experiments as well as two sets of experimental data.     

Generation of core/shell iron oxide magnetic nanoparticles with polystyrene brushes by atom transfer radical polymerization

The functionalization of nanoparticle surfaces is required to improve the dispersion of an inorganic material inside an organic matrix. In this work, polystyrene (PS) brushes were grown on the surface of iron oxide magnetic nanoparticles with atom transfer radical polymerization and a grafting‐from approach. After polymerization, the magnetic nanoparticles had a graft density of 0.9 PS chains/nm². A sacrificial initiator was used to obtain a satisfactory result for the control of the polymerization, as its addition had to generate a sufficient concentration of persistent radicals (deactivator). A variety of techniques, such as Fourier transform infrared spectroscopy, thermogravimetric analysis, gel permeation chromatography, water contact‐angle measurements, and atomic force microscopy, were used to characterize the nanoparticles. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4744–4750, 2007     

NIR FT－Raman研究铝酸钠溶液的碳酸化过程

本文用ＮＩＲＦＴ－Ｒａｍａｎ光谱仪原位跟踪了铅酸钠溶液的碳酸化过程，观察到此过程的Ｒａｍａｎ光谱呈现振荡现象和非重线性，认为在碳酸化过程中，可能产生Ａｌ２（ＯＨ）离子和进一步缩聚形成的离子。     

FTIR spectroscopic investigation of thermal effects in semi‐syndiotactic polypropylene

The temperature‐dependent behavior of individual components within metallocene‐catalyzed semisyndiotactic polypropylenes (semi‐sPP) with a wide range of stereoregular content (26 to 96% rr) is studied using Fourier transform infrared (FTIR) spectroscopy and temperature‐modulated differential scanning calorimetry (DSC). Changes in sensitive, high‐resolution absorbance spectra are observed as melt‐slow‐cooled thin films are subjected to stepwise temperature increases. In general, spectral bands previously identified as being sensitive to ordered structures (e.g., conformed chains, crystal morphs) appear to follow overall trends of shifting to lower wavenumbers (energies), broadening, and decreasing in peak area intensity as temperature increases. Peaks that appear due to “splitting” (observed in more stereoregular materials) show a trend toward coalescence as temperature increases; this corresponds to a gradual loss of chain conformational order. Gauche‐gauche‐trans‐trans (ggtt)_n helical and all‐trans (tttt)_n planar zigzag‐conformed chains that participate in the crystalline‐amorphous interfacial region (“mesophase”) appear to be more stable (i.e., they do not lose their conformational order as easily) with increasing temperature in materials with a greater degree of syndiotacticity. Moreover, IR data correspond well with modulated DSC endotherms located near 50 °C and 70 °C. At each transition temperature—thought to represent, respectively, a thermally driven chain conformation from planar zigzags to helices, and a dynamic disorder of helices marked by rapid gauche ? trans isomerization—the IR absorbance ratio, A₉₇₈/A₉₆₃, which represents the relative population of helical chains, undergoes an accelerated decrease. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 439–461, 2005     

近红外光谱法同时测定鱼粉中脂肪,蛋白质和水份

本文使用近红外光谱分析法同时测定鱼粉中的蛋白质，脂肪和水份。本法简便，无污染。     

meso‐Dibenzoporphycene has a Large Bathochromic Shift and a Porphycene Framework with an Unusual cis Tautomeric Form

meso‐Monobenzoporphycene (mMBPc) and meso‐dibenzoporphycene (mDBPc), in which one or two benzene moieties are fused at ethylene‐bridged positions (meso‐positions) of porphycene, were prepared in an effort to further delocalize the π‐electrons within the porphycene molecule. mMBPc and mDBPc were fully characterized by mass spectrometry, ¹H and ¹³C NMR spectroscopy, and X‐ray crystallography. The longest‐wavelength Q‐bands of mMBPc and mDBPc are red‐shifted by 92 nm and 418 nm, respectively, compared to that of the unsubstituted porphycene (Pc). Electrochemical measurements indicate that the HOMO is destabilized and the LUMO is stabilized by the fused benzene moieties at the meso positions. Furthermore, both XPS and theoretical studies support the presence of a cis tautomeric form in the ground state of mDBPc, despite the fact that essentially all known porphycene derivatives adopt the trans tautomeric form.