DRAMIŃSKI - Niranalyser

DRAMIŃSKI NIR-DRAM 100 - Near Infra Red Analyser of grain and flour content
The analyser is an advanced hi-tech device for measuring grain & flour composition by spectral analysis in the near-infrared spectral range.

Abstract. Near-infrared spectroscopy (NIRS) offers a non-invasive, real-time monitoring of cerebral oxygenation. This method is based on the oxygenation and the light wavelength dependent absorption of near-infrared light by tissue chromophores, e.g. oxyhaemoglobin and deoxyhaemoglobin. The objective of the present study was the application of NIRS for evaluation of the brain function during vasovagal syncope (VVS). The VVS is a clinical syndrome affecting ca 3.5% of the population and for which the widely used diagnostic examination in this disease entity is the head-up tilt table test (HUT). In this study 69 patients with a history of VVS were examined using HUT. In 42 patients VVS was provoked. Results of the examination have shown that the changes in cerebral oxygenation measured by the NIRS technique are distinctly visible before the syncope. A gradual decrease of oxyhaemoglobin followed by its sudden drop was observed in all the VVS patients. Changes in the oxyhaemoglobin concentration measured by NIRS were observed on average 3.3 min before the syncope. They preceded the presyncope symptoms about 1.3 min (p < 0.005), the blood pressure and heart rate drop 2.2 min (p < 0.0001) and the arterial blood saturation 2.6 min (p < 0.000 01).

Softness and tensile strength are two major tissue paper properties that govern consumer acceptance. In this work an attempt was made to use Near Infrared Spectroscopy combined with chemometric techniques to predict these properties.

For this study four variables were chosen; raw material, amount of debonder, amount of wet strength resin and the level of refining. For each condition, handsheet spectra were taken and then the softness and the tensile strength were measured in a conventional manner. Data and the spectral absorbance values were then used with Quant + software to generate a model which was used to predict the properties of the unknown samples.

Predictions obtained from this study show that it is possible to use NIR spectroscopy combined with multivariate calibration and chemometric techniques to predict the softness and tensile properties of tissue paper. Results show the model capability of prediction is of same magnitude for each phase. The Root mean square error of prediction (RMSEP) value obtained was approximately 2.0% for tensile strength and 0.15% for softness in each phase. The technique can be used to replace the conventional procedures. The results indicate the applicability of NIR and chemometric procedures for tissue. The technique can be evaluated in actual mill conditions for maximum utilization. Although there could be certain limitations of high instrumental cost but once installed the procedure can be used to measure properties of paper very effectively and quickly. Also it could reduce the amount of broke generated while maintaining a uniform product.

Background: Near-infrared spectroscopy is proposed as a method for providing real-time urea concentrations during hemodialysis treatments. The feasibility of such noninvasive urea measurements is evaluated in undiluted dialysate fluid.

Methods: Near-infrared spectra were collected from calibration solutions of urea prepared in dialysate fluid. Spectra were collected over three distinct spectral regions, and partial least-squares calibration models were optimized and compared for each. Selectivity for urea was demonstrated with two-component samples composed of urea and glucose in the dialysate matrix. The clinical significance of this approach was assessed by measuring urea in real hemodialysate samples.

Results: Urea absorptions within the combination and short-wavelength, near-infrared spectral regions provided sufficient spectral information for sound calibration models in the dialysate matrix. The combination spectral region had SEs of calibration (SEC) and prediction (SEP) of 0.38 mmol/L and 0.26 mmol/L, respectively, over the 4720–4600 cm-1 spectral range with 5 partial least-square factors. A second calibration model was established over the combination region from a series of solutions prepared with independently variable concentrations of urea and glucose. The best calibration model for urea in the presence of variable glucose concentrations had a SEC of 0.6 mmol/L and a SEP of 0.4 mmol/L for a 5-factor model over the 4600–4350 cm-1 spectral range. There was no significant decrease in SEP when the 4720–4600 cm-1 calibration model was used to measure urea in real samples collected during actual hemodialysis.

Conclusions: Urea can be determined with sufficient sensitivity and selectivity for clinical measurements within the matrix of the hemodialysis fluid.

Near infrared spectroscopy (NIRS) is a new technique that permits noninvasive monitoring of cerebral blood and tissue oxygenation. Recently, we and others have shown that NIRS measurements are sensitive enough to follow changes in cerebral hemoglobin oxygenation due to activation of brain function. Based on these findings we have assessed the influence of aging as well as the influence of neurodegeneration on cerebral hemoglobin oxygenation during mental work. The typical NIRS pattern in young healthy subjects while performing calculation tasks measured in the frontal cortex were increases in oxygenated hemoglobin [HbO2] and total hemoglobin [HbT] while reduced hemoglobin [HbR] decreased. Elderly healthy subjects showed a significant lower mean increase in [HbO2] and [HbT] levels. Regression analysis revealed an age-dependent decline in activation-induced local increase of [HbO2] as well as [HbT]. Furthermore, we monitored changes in cerebral hemoglobin oxygenation in the frontal cortex while patients with probable Alzheimer’s disease (AD) performed cognitive tasks. Whereas elderly healthy subjects (as well as patients with major depression, age-associated memory impairments or vascular dementia) again showed clear increases in the local concentrations of [HbO2] and [HbT] during brain activation, AD patients showed significant decreases compared to the baseline levels in both variables that were most pronounced in the parietal cortex. To clarify whether the different patterns in cerebral hemoglobin oxygenation during cognitive activation were due to an altered functional brain organization in AD or to alterations in the cerebrovascular response to neuronal activation, we are currently performing simultaneous NIRS and (015-H20-)PET measurements during performance of a cognitive task (Stroop test). Our finding of a regional reduced oxygen supply during activation of brain function may be of relevance to the development and the time course of neurodegeneration.

NIR calibrations developed on whole grain barley for hot water extract display similar precision and accuracy as calibrations developed on malt. The validation data for diastatic power indicated a weaker relationship between NIR predicted values and reference values, but acceptable for classifying samples into low-high groups. The validation data of soluble protein, FAAN, wort β-glucan and β-glucanase demonstrated that the calibrations developed on whole grain barley could not be utilised in the selection of these constituents. These constituents are analysed in malted barley and it is difficult to develop NIR calibration for unmalted barley seed.

Calibrations developed for hot water extract, diastatic power, soluble protein, FAAN, wort β-glucan and β-glucanase on malted barley are suitable for the evaluation of F4 to F8 generation barley lines from a breeding program, although there is the added expense of micro-malting the samples.

After evaluating early generation barley lines, a large percentage of the population can be discarded using NIR testing protocols. The two-step protocol includes first applying hot water extract and diastatic power calibrations on whole grain barley, then malting the retained samples and applying malting quality calibrations on whole grain malt. This is an advantage to a barley breeding program, where the gain is in the reduced number of samples going through the lengthy process of micro-malting and laboratory analysis.

The NIR predicted hot water extract values of the calibration samples were highly correlated for both whole grain barley (R2=0.87) and whole grain malt (R2=0.89) to the laboratory reference data and were associated with low standard errors of calibration, 0.6 and 0.6, respectively. The validation data for hot water extract reflected those of the calibration samples, displaying good correlations and low standard errors (Table 1). The data in this study are in agreement with findings of other researchers and this constituent has been routinely analysed by NIR on whole grain barley to aid in the screening of early generation lines in southern Australian barley breeding programs (Nilsen and Panozzo, 1995; Roumeliotis et al., 2000).

The NIR predicted values for diastatic power were moderately correlated to the laboratory reference values (R2=0.57) for calibrations developed for whole grain barley (Table 1). Validation statistics for diastatic power indicated a weaker relationship between the NIR predicted values and the reference data than was observed for hot water extract (Table 1). However, the size of the standard error of validation suggested that NIR analysis could be useful for classification of early generation barley cultivars into high or low groups for diastatic power. In contrast, a higher correlation was observed between NIR predicted values and laboratory method for diastatic power in whole grain malt (R2=0.75). Calibrations developed on whole grain malt are currently used for the evaluation of diastatic power in the breeder’s lines that are retained after applying whole barley calibrations (Figure 1).

Calibrations for soluble protein, FAAN, wort β-glucan and β-glucanase, developed on whole grain barley, displayed a reasonably good relationship between the NIR predicted and laboratory reference values (Table 1). This relationship was not confirmed by statistics observed for the validation samples (Table 1), possibly due to the complex nature of these constituents. The unmalted barley contains proteins and starches in the storage form. The composition of barley is modified by the action of enzymes throughout the steeping and germination stages and by heating during the kilning stage of the malting process.

Calibrations developed on whole grain malt for soluble protein, FAAN, wort β-glucan and β-glucanase had high values of the coefficient of determination (R2>0.70) and were associated with low standard errors of calibration (Table 1). A combination of relatively high coefficients of determination and low standard errors for the validation samples indicated that the calibrations developed for these complex constituents on whole grain malt are suitable for the evaluation of F4 to F8 generation barley lines retained for malting in a breeding program

The reflectance spectra, Log (1/R), were collected on a Model 6500 monochromator (NIRSystems, Silver Springs, MD) equipped with transport module and a standard coarse NIR sample cell. Spectra were recorded across a range of 400-2498 nm and 2 nm wavelength increment. Diffuse reflectance readings of a ceramic tile were referenced before and after the sample scan. The barley and malt samples were equilibrated to 21°C for 24 hours prior to analysis.

The spectra were corrected for scatter with standard normal variance (SNV) and detrending. A second derivative mathematical treatment was applied with gap and smooth sizes of 5 and 5, respectively.

The spectral population was structured with three Global H units. The calibration set was optimised with Neighbourhood H units of 0.3. Calibrations were developed by using a modified partial least squares (mPLS) algorithm and cross-validation technique. ISI software V 4.01 (Infrasoft International, Silver Springs, MD) was used for all data processing.

A population of 131 barley samples from separate trials of the 1999 harvest was selected for validating the performance of developed calibrations.

The barley samples were malted according to Nilsen and Panozzo (1995) and analysed for hot water extract according to a small-scale version of the European Brewing Convention (EBC) fine grind method, with a grist:liquor ratio of 10g:70mL (Macleod et al., 1991). Malt samples were ground on a FN3100 Mill (Falling Number, Stockholm, Sweden) to pass a 0.8mm sieve and analysed for diastatic power (Fox et al., 1999) and β-glucanase according to the Megazyme method (Megazyme, Australia). The wort was analysed for: FAAN using the ninhydrin method (Institute of Brewing, 1982); soluble protein using the Dumas combustion method on a CNS-2000 (LECO Corporation, St Joseph, MI, USA); and wort β-glucan using the Megazyme method (Megazyme Australia).

The samples used in this study were from the barley breeding trials at VIDA. The samples represented a range of breeding generations grown at various sites throughout Victoria in 1999. The breeding generations included: early generation (F4 and F5), the first two years of field trials; F7, the third year of field trials; F8, the fourth year of field trials; and F9, the fifth year of field trials. The barley samples were passed over a 2.2mm sieve prior to NIR-testing and analysis.