scholarly journals Intrinsic Near-Infrared Spectroscopic Markers of Breast Tumors

2008 ◽  
Vol 25 (6) ◽  
pp. 281-290 ◽  
Author(s):  
Shwayta Kukreti ◽  
Albert Cerussi ◽  
Bruce Tromberg ◽  
Enrico Gratton
Keyword(s):  
Cancer Detection ◽  
Near Infrared ◽  
Breast Tumors ◽  
Normal Breast ◽  
Differential Method ◽  
Patient Specific ◽  
Spectral Variation ◽  
Absorption Bands ◽  
Specific Tumor ◽  
Nir Absorption

We have discovered quantitative optical biomarkers unique to cancer by developing a double-differential spectroscopic analysis method for near-infrared (NIR, 650–1000 nm) spectra acquired non-invasively from breast tumors. These biomarkers are characterized by specific NIR absorption bands. The double-differential method removes patient specific variations in molecular composition which are not related to cancer, and reveals these specific cancer biomarkers. Based on the spectral regions of absorption, we identify these biomarkers with lipids that are present in tumors either in different abundance than in the normal breast or new lipid components that are generated by tumor metabolism. Furthermore, the O-H overtone regions (980–1000 nm) show distinct variations in the tumor as compared to the normal breast. To quantify spectral variation in the absorption bands, we constructed the Specific Tumor Component (STC) index. In a pilot study of 12 cancer patients we found 100% sensitivity and 100% specificity for lesion identification. The STC index, combined with other previously described tissue optical indices, further improves the diagnostic power of NIR for breast cancer detection.

Structure and microstructure of near infrared-absorbing Au–Au2S nanoparticles

2007 ◽  
Vol 22 (9) ◽  
pp. 2531-2538 ◽  
Author(s):  
Mei Chee Tan ◽  
Jackie Y. Ying ◽  
Gan Moog Chow
Keyword(s):  
Optical Properties ◽  
Surface Segregation ◽  
Near Infrared ◽  
Small Degree ◽  
Core Shell ◽  
Shell Microstructure ◽  
Absorption Bands ◽  
Interfacial Effects ◽  
Nir Absorption ◽  
Structure And Microstructure

Near infrared (NIR) absorbing nanoparticles synthesized by the reduction of HAuCl4 with Na2S exhibited absorption bands at ∼530 nm, and in the NIR region of 650–1100 nm. The NIR optical properties were not found to be related to the earlier proposed Au2S–Au core-shell microstructure in previous studies. From a detailed study of the structure and microstructure of as-synthesized particles in this work, S-containing, Au-rich, multiply-twinned nanoparticles were found to exhibit NIR absorption. They consisted of amorphous AuxS (where x = 2), mostly well mixed within crystalline Au, with a small degree of surface segregation of S. Therefore, NIR absorption was likely due to interfacial effects on particle polarization from the introduction of AuxS into Au particles, and not the dielectric confinement of plasmons associated with a core-shell microstructure.

Composition, particle size, and near-infrared irradiation effects on optical properties of Au–Au2S nanoparticles

2008 ◽  
Vol 23 (1) ◽  
pp. 281-293 ◽  
Author(s):  
Mei Chee Tan ◽  
Jackie Y. Ying ◽  
Gan Moog Chow
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Thermal Effects ◽  
Near Infrared ◽  
Sodium Sulfide ◽  
Irradiation Effects ◽  
Absorption Bands ◽  
Molar Ratios ◽  
Nir Absorption ◽  
Structure And Microstructure

Near-infrared (NIR)-absorbing nanoparticles synthesized by the reduction of tetrachloroauric acid (HAuCl4) using sodium sulfide (Na2S) exhibited absorption bands at ∼530 nm and at the NIR region of 650−1100 nm. A detailed study on the structure and microstructure of as-synthesized nanoparticles was reported previously. The as-synthesized nanoparticles were found to consist of amorphous AuxS (x = ∼2), mostly well mixed within crystalline Au. In this work, the optical properties were tailored by varying the precursor molar ratios of HAuCl4 and Na2S. In addition, a detailed study of composition and particle-size effects on the optical properties was discussed. The change of polarizability by the introduction of S in the form of AuxS (x = ∼2) had a significant effect on NIR absorption. Also, it was found in this work that exposure of these particles to NIR irradiation using a Nd:YAG laser resulted in loss of the NIR absorption band. Thermal effects generated during NIR irradiation had led to microstructural changes that modified the optical properties of particles.

Application of near-infrared spectroscopy for the detection of internal insect infestation inPiceaabiesseed lots

2004 ◽  
Vol 34 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Mulualem Tigabu ◽  
Per Christer Odén ◽  
Tong Yun Shen
Keyword(s):  
Near Infrared ◽  
Nir Spectroscopy ◽  
Least Squares Regression ◽  
Absorption Bands ◽  
Classification Rate ◽  
Data Set ◽  
Storage Lipids ◽  
Nir Absorption ◽  
Seed Origin ◽  
Single Seeds

The use of near-infrared (NIR) spectroscopy to discriminate between uninfested seeds of Picea abies (L.) Karst and seeds infested with Plemeliella abietina Seitn (Hymenoptera, Torymidae) larva is sensitive to seed origin and year of collection. Five seed lots collected during different years from Sweden, Finland, and Belarus were used in this study. Initially, seeds were classified as infested or uninfested with X-radiography, and then, NIR spectra from single seeds were collected with a NIR spectrometer from 1100 to 2498 nm with a resolution of 2 nm. Discriminant models were derived by partial least squares regression using raw and orthogonal signal corrected spectra (OSC). The resulting OSC model developed on a pooled data set was more robust than the raw model and resulted in 100% classification accuracy. Once irrelevant spectral variations were removed by using OSC pretreatment, single-lot calibration models resulted in similar classification rates for the new samples irrespective of origin and year of collection. Dis criminant analyses performed with selected NIR absorption bands also gave nearly 100% classification rate for new samples. The origin of spectral differences between infested and uninfested seeds was attributed to storage lipids and proteins that were completely depleted in the former by the feeding larva.

scholarly journals NIR Absorbance Characteristics of Deoxynivalenol and of Sound and Fusarium-Damaged Wheat Kernels

2009 ◽  
Vol 17 (4) ◽  
pp. 213-221 ◽  
Author(s):  
Kamaranga H.S. Peiris ◽  
Michael O. Pumphrey ◽  
Floyd E. Dowell
Keyword(s):  
Absorption Spectra ◽  
Near Infrared ◽  
Peak Height ◽  
Second Derivative ◽  
Absorption Bands ◽  
Derivative Spectra ◽  
Nir Absorption ◽  
Second Derivative Spectra ◽  
Food Reserves ◽  
Wheat Kernels

The near infrared (NIR) absorption spectra of deoxynivalenol (DON) and single wheat kernels with or without DON were examined. The NIR absorption spectra of 0.5–2000 ppm of DON in acetonitrile were recorded in the 350–2500 nm range. Second derivative processing of the NIR spectra and spectral subtractions showed DON absorption bands at 1408 nm, 1904 nm and 1919 nm. NIR spectra of sound and Fusarium-damaged kernels were also acquired using two instruments. Subtraction of average absorption spectra and second derivative spectra were evaluated to identify different NIR signatures of the two types of kernel. Differences in peak height and positions of the NIR absorption bands of the kernels were noted. At 1204 nm, 1365 nm and 1700 nm, the differences were in the heights of the absorption peaks. Such differences may be attributed to changes in the levels of grain food reserves such as starches, proteins and lipids and other structural compounds. Shifts in absorption peak positions between the two types of kernels were observed at 1425–1440 nm and 1915–1930 nm. These differences may arise from other NIR active compounds, such as DON, which are not common for the two types of kernel. Since the NIR absorption of DON may have contributed to the shifts between sound and Fusarium-damaged kernels, this study indicates the potential for NIR spectrometry to evaluate Fusarium damage in single kernels based on the DON levels.

Determination of temperatures of aqueous-based samples directly from near infrared spectra

2017 ◽  
Vol 25 (5) ◽  
pp. 289-300 ◽  
Author(s):  
Chamathca PS Kuda-Malwathumullage ◽  
Gary W Small
Keyword(s):  
Root Mean Square Error ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Predictive Ability ◽  
Spectral Variation ◽  
Mean Square ◽  
Absorption Bands ◽  
Near Infrared Spectra

The temperature sensitivity of underlying water absorption bands can lead to baseline artifacts or apparent spectral band shifts in near infrared spectra and can negatively impact multivariate calibration models used in quantitative analyses. To address this issue, efforts can be made to suppress the temperature-induced spectral variation or knowledge of the temperature can be used to adjust the calibration. To facilitate the latter approach, we explored the ability to estimate the aqueous temperature of the sample directly from the combination region of the near infrared spectrum. This temperature modeling strategy addresses applications in which it is difficult to obtain an accurate sample temperature with a conventional measurement probe. Temperature models were developed by use of partial least-squares regression combined with the discrete wavelet transform. Models were constructed from the 5000 to 4000 cm−1 region of near infrared spectra for pH 7.4 buffer solutions over the temperature range of 20.0–40.5℃. The long-term predictive ability of the models was assessed by use of 13 sets of prediction spectra collected over the course of 13 months, yielding values of the root mean square error of prediction ranging from 0.19 to 0.36℃. In addition, laboratory-prepared solutions of glucose, mixture solutions of glucose, lactate, urea in buffer, and bovine plasma were used to assess the predictive ability of the temperature models in increasingly complex matrixes. The effects of pH and buffer molarity were also studied. While increasing the complexity of the spectral background resulted in increases in root mean square error of prediction (0.33–1.01℃), retuning the models to incorporate the modified spectral backgrounds lowered the resulting root mean square error of prediction values to the range of 0.3℃. This work demonstrates the practical utility of spectral-based temperature measurements that employ the absorbance of the water baseline rather than the peak absorbance.

Electrochromic tuning of transparent gold nanorods with poly[(3,4-propylenedioxy)pyrrole] shells in the near-infrared region

2017 ◽  
Vol 5 (47) ◽  
pp. 12571-12584 ◽  
Author(s):  
Jing Zhou ◽  
Ju-Won Jeon ◽  
James F. Ponder ◽  
Jeffrey A. Geldmeier ◽  
Mahmoud A. Mahmoud ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Near Infrared ◽  
Infrared Region ◽  
Absorption Bands ◽  
Nir Absorption ◽  
Near Infrared Region

An electrochemically tunable plasmonic system with narrow visible-NIR absorption bands was designed by synthesizing poly[(3,4-propylenedioxy)pyrrole] nanoshells onto a AuNR core.

Synthesis of NIR-emitting O-chelated BODIPYs fused with benzene and acenaphthylene

2014 ◽  
Vol 18 (08n09) ◽  
pp. 752-761 ◽  
Author(s):  
Tetsuo Okujima ◽  
Yoichi Shida ◽  
Keishi Ohara ◽  
Yuya Tomimori ◽  
Motoyoshi Nishioka ◽  
...  
Keyword(s):  
Near Infrared ◽  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Fluorescence Measurement ◽  
Aromatic Rings ◽  
Nir Absorption ◽  
Intense Absorption ◽  
Near Infrared Dye

A series of O-chelated BODIPYs fused with aromatic rings such as benzene and acenaphthylene at β,β-positions was synthesized as a near-infrared dye. The photophysical properties were examined by UV-vis-NIR absorption and fluorescence measurement. Acenaphthylene-fused O-BODIPYs showed a intense absorption at 750–840 nm with the ε of 105 M-1.cm-1. and a fluorescence emission at 770–850 nm with the high Φ value of 0.06–0.43.

Sign in / Sign up

Export Citation Format

Share Document