Correction of Temperature Variation with Independent Water Samples to Predict Soluble Solids Content of Kiwifruit Juice Using NIR Spectroscopy.

Using the framework of aquaphotomics, we have sought to understand the changes within the water structure of kiwifruit juice occurring with changes in temperature. The study focuses on the first (1300-1600 nm) and second (870-1100 nm) overtone regions of the OH stretch of water and examines temperature differences between 20, 25, and 30 °C. Spectral data were collected using a Fourier transform-near-infrared spectrometer with 1 mm and 10 mm transmission cells for measurements in the first and second overtone region, respectively.

Interactions of Linearly Polarized and Unpolarized Light on Kiwifruit Using Aquaphotomics.

Near infrared (NIR) spectroscopy is an important tool for predicting the internal qualities of fruits. Using aquaphotomics, spectral changes between linearly polarized and unpolarized light were assessed on 200 commercially grown yellow-fleshed kiwifruit ( var. 'Zesy002').

Thermal stability of intralipid optical phantoms.

We investigated the stability of light transmission through Intralipid-based optical phantoms in the wavelength range of 400-950 nm at temperatures between 35 and 70 °C. Optical phantoms are materials commonly used to simulate the light scattering and absorption properties of biological materials. These simulations require the phantom to be optically stable.

Temporal sensitivity of the wavelength calibration of a photodiode array spectrometer.

Subtle differences in the relationship between wavelength and pixel on photodiode array spectrometers contribute to difficulties in transferring calibrations from one instrument to another and may even introduce errors on a single instrument over time. To quantify the level of drift that might be expected in photodiode instruments, we calibrated the wavelength scale of two Zeiss MMS-1 photodiode spectrometers weekly over a 12-month period. We found no evidence of drift in the wavelength calibration.

Characterizing liquid turbid media by frequency-domain photon-migration spectroscopy.

We present a wavelength-tunable frequency-domain instrument for the characterization of liquid turbid media. The instrument employs a tunable titanium-sapphire laser modulated by an acousto-optic modulator. The absorption and reduced scattering coefficient of Intralipid(R) 20%, diluted to concentrations of 0.

Accurate and precise wavelength calibration for wide bandwidth array spectrometers.

Calibrating the wavelength scale of an array spectrometer typically involves measurements of lines at well-known wavelengths from a calibration lamp such as a mercury-argon source. This process is relatively straightforward when the lines are well separated, relative to the bandwidth of the spectrometer. When the spectrometer's bandwidth is large, compared with the distance between calibration wavelengths, it becomes increasingly difficult to accurately locate lines in the calibration spectrum.

Temperature dependence of near-infrared spectra of whole blood.

The temperature dependence (30 to 40 degrees C) of near-infrared spectra (500 to 1100 nm) of whole human blood, including red blood cells with intact physiological function, is investigated. Previous studies have focused on hemoglobin solutions, but the operation of red blood cells is critically dependent on intact cell membranes to perform normal oxygen transport and other physiological functions. Thus measurements of whole blood are more directly related to changes that occur in vivo.

Measuring optical temperature coefficients of Intralipid.

The temperature sensitivities of absorption and reduced scattering coefficients in the range 700-1000 nm are determined for the liquid phantom Intralipid using spatially resolved continuous wave measurements. The measurements were conducted on a 10 L heated volume of 1% Intralipid subjected to a 40-30 degrees C cooling regime. The temperature sensitivities of the absorbance coefficients are similar to that expected for pure water.

Asymptomatic bacteriuria in adults.

A common dilemma in clinical medicine is whether to treat asymptomatic patients who present with bacteria in their urine. There are few scenarios in which antibiotic treatment of asymptomatic bacteruria has been shown to improve patient outcomes. Because of increasing antimicrobial resistance, it is important not to treat patients with asymptomatic bacteriuria unless there is evidence of potential benefit.