Spectroscopy - Volume 25, issue 3-4

Authors: So, C.F. | Chung, Joanne W.Y. | Siu, Maggie S.M. | Wong, Thomas K.S.

Article Type: Research Article

Abstract: Near infrared (NIR) spectroscopy has become a promising technique for blood glucose monitoring. However, an appropriate model of spectral response in humans is yet to be determined because of the reliability problem. In this study, 48 subjects were recruited. The subjects' left forearms were scanned using near infrared spectroscopy to obtain NIR spectra. Simultaneously, a blood sample of glucose was drawn. A new method based on Monte Carlo approach is applied for partial least squares (PLS), named as PLSMC , is proposed. A large numbers of models are built from calibration subsets which are randomly selected from the whole calibration …set in order to minimize the noises. It is then determining the mean value over the models with high correlation and small prediction errors. The results show that the method can enhance the stability of PLS model. Also, the performance of the PLSMC shows more accurate prediction results as compared with conventional PLS. Show more

Keywords: Blood glucose, partial least squares, near infrared, prediction model, spectroscopy

DOI: 10.3233/SPE-2011-0507

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 137-145, 2011

Authors: Lázaro, João Carlos | de Paula Jr., Alderico Rodrigues | Moreira, Leonardo Marmo | Lyon, Juliana Pereira | Pacheco, Marcos Tadeu T. | de Lima, Carlos José

Article Type: Research Article

Abstract: Raman spectroscopy is considered a very powerful tool for biochemical characterization, especially regarding biological samples. This technique allows the diagnosis of several diseases, such as cancer and atherosclerosis. In this context, the non invasive or minimally invasive character of the spectroscopic resources is an auspicious clinical advancement when compared with conventional procedures, which are associated to significant trauma and possible decrease in the quality of life of patients. Recently, the use of catheter with optical fibers associated to Raman spectroscopy has significantly minimized the invasive character of several clinical procedures. It is important to notice that this optical sensor already …presents flexibility due to the employment of optical fibers to applications of lasers. Nowadays, this kind of device possesses autonomy of use and can be coupled to an optic fiber in order to permit the treatment with lasers. In this way, it is possible to develop an electronic automated optic system that achieves a diagnosis through catheter with optic fiber connected to a Raman spectrometer in order to analyze a certain organ and, considering the diagnosis obtained, to develop the adequate optical treatment can be automatically selected and applied to the respective organ. In the present work, the structure of this device will be presented with the more suitable optical techniques available to the laboratories. The minimum intervals of time involving each step of the sequence are evaluated and the efficiency of the spectroscopic system is discussed in details in agreement with the literature. Show more

Keywords: Raman spectroscopy, catheter, optical fiber, laser, diagnosis

DOI: 10.3233/SPE-2011-0505

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 147-154, 2011

Authors: İde, Semra | Haman Bayarı, Sevgi | Türkeş, Tuncay | Mergen, Y. Orhan | Çelik, Ömer | Bütün, Vural | Sargon, Mustafa F. | Kocatepe, Neslihan | Kriechbaum, Manfred

Article Type: Research Article

Abstract: Various experimental methods (XRD, FTIR, SAXS, DLS and SEM) were used to investigate structures of the silk samples weaved by spiders in Turkey. Silk samples were collected from the natural habitats belonging to the spider species (i.e., Near Salt Lake/Şereflikoçhisar, İvriz Dam/Ereğli-Konya, Karataş Lake/Burdur and several locations in Black Sea Region of Turkey). Among all collected species, Araneidae (Araneus angulatus, Argiope bruennichi, Argiope lobata, Larinoides cornutus), Eresidae (Eresus cinnaberinus), Agelenidae (Agelena labyrinthica), Oecobidae (Uroctea durandi), Miturgidae (Cheiracanthium erraticum), Salticidae (Heliophanus flavipes, Philaeus chrysops), Theridiidae (Steatoda paykulliana) and Gnaphosidae were found significant amongst other spider species. Structural differences and similarities of …these species were reported. Diameter range of draglines, inter crystallite distance of nano-size structures, mean size range of nano-structure aggregations, crystallite size range, information about protein content were obtained. The mechanical properties of some silk fibers were also investigated. Show more

Keywords: Spider silk, XRD, FTIR, scattering methods, SEM, mechanical testing

DOI: 10.3233/SPE-2011-0495

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 155-167, 2011

Authors: Rohman, Abdul | Che Man, Yaakob B.

Article Type: Research Article

Abstract: Four types of animal fats, namely lard (LD) and body fats of lamb (LBF), cow (Cow-BF) and chicken (Ch-BF), in quaternary mixtures were quantitatively analyzed using FTIR spectroscopy in combination with multivariate calibration of partial least square (PLS). The animal fats, either individual or in quaternary mixtures, were subjected to horizontal total attenuated total reflectance (HATR) as sample handling technique and scanned at mid-infrared region (4000–650 cm−1 ) with resolution of 4 cm−1 and with 32 interferograms. PLS calibration revealed that the first derivative FTIR spectrum was well suited for the correlation between actual value of LD and FTIR …calculated value. The other animal fats (LBF, Cow-BF and Ch-BF) were better determined using normal FTIR spectra. The coefficient of determination (R2 ) obtained using the optimized spectral treatments was higher than 0.99. The root mean standard error of calibration (RMSEC) values obtained were in the range of 0.773–1.55. Analysis of animal fats using FTIR spectroscopy allows rapid, no excessive sample preparation, and can be regarded as “green analytical technique” due to the absence of solvent and chemical reagent used during the analysis. Show more

Keywords: Analysis, animal fats, FTIR spectroscopy, partial least square, quaternary systems

DOI: 10.3233/SPE-2011-0500

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 169-176, 2011

Authors: Sade, Asli | Banerjee, Sreeparna | Severcan, Feride

Article Type: Research Article

Abstract: The effects of different concentrations of celecoxib on the acyl chain order, dynamics and the hydration status of the head group and interfacial region of model membranes containing DSPC and cholesterol were investigated in detail using Fourier transform infrared spectroscopy. Our results reveal that regardless of the presence of cholesterol, celecoxib is able to alter the physical properties of membranes. It exerts opposing effects on membrane order at high and low concentrations and decreases membrane fluidity in the presence of cholesterol. An evidence of phase separation has also been observed. The decrease in membrane fluidity supports the hypothesis that celecoxib …may induce changes in the activity of membrane bound enzymes through modulating physical properties of the membrane thereby contributing to its anticancer activity. A possible change in the location of celecoxib in DSPC membranes when cholesterol is present has also been proposed. These results clarify, to a certain extent, the molecular interactions of celecoxib with membrane systems and may additionally contribute to a better understanding of COX-2 independent mechanisms of celecoxib action. Show more

Keywords: Celecoxib, cholesterol, DSPC, FTIR, MLV

DOI: 10.3233/SPE-2011-0506

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 177-185, 2011

Authors: Nasiruzzaman Shaikh, M. | Al-Maythalony, Bassem A. | Wazeer, Mohammed I.M. | Isab, Anvarhusein A.

Article Type: Research Article

Abstract: Cadmium and mercury selenocyanate complexes of 2-thiouracil (TU) and 2,4-dithiouracil (DTU) ligands have been synthesized to form complexes of the type [M(SeCN)2 (TU)] and [M(SeCN)2 (DTU)] (where M is Cd2+ or Hg2+ ) and studied by various spectroscopic techniques such as IR, 1 H and 13 C NMR in solution and in the solid state for 13 C, 15 N, and 113 Cd nuclei. Based on IR, and solution and solid-state 13 C NMR data, stronger cadmium bonding to the thiouracil was observed compared to that of mercury. Anti-bacterial activities of these complexes have been investigated with standard type …culture of Escherichia coli (MTCC 443), Klebsiella pneumoniae (MTCC 109), Pseudomonas aeruginosa (MTCC 1688), Salmonella typhi (MTCC 733) and Staphylococcus aureus (MTCC 737) and show that ligands exhibit more anti-bacterial activities than that of the corresponding Cd(II) and Hg(II) complexes. Show more

Keywords: Cadmium(II) complexes, mercury(II) complexes, thiouracil ligands, solid-state NMR, anti-bacterial activities

DOI: 10.3233/SPE-2011-0503

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 187-195, 2011

Authors: Najder-Kozdrowska, Lidia | Pilawa, Barbara | Buszman, Ewa | Wrześniok, Dorota | Więckowski, Andrzej B.

Article Type: Research Article

Abstract: This work comprises the study of DOPA–melanin complexes with kanamycin and copper(II) ions made by electron paramagnetic resonance EPR spectroscopy. The high concentration of paramagnetic centers in melanin makes the use of EPR spectroscopy possible. The unpaired electron localized on the oxygen atom in indol-5,6-quinone groups is the paramagnetic centers in this polymer. The aim of this work was the analysis of EPR parameters of recorded spectra. For researches were prepared melanin complexes which differed in complexing order of drug and Cu(II) ions, and in concentration of CuCl2 solutions used during synthesis. The introduction of drugs and metal ions …into melanin causes changes in EPR parameters of recorded spectra. Kanamycin causes the increase and copper(II) ions the decrease of concentrations of paramagnetic centres in melanin. Shape of EPR signal of DOPA–melanin was analyzed by fitting method. Results indicate that EPR line of DOPA–melanin is superposition of Gaussian and Lorentzian function. Show more

Keywords: EPR, DOPA–melanin, kanamycin, Cu(II)

DOI: 10.3233/SPE-2011-0504

Citation: Spectroscopy, vol. 25, no. 3-4, pp. 197-205, 2011