Near Infrared Spectroscopy

Materials for solid photoacoustic breast phantoms, based on poly(vinyl alcohol) hydrogels, are presented. Phantoms intended for use in photoacoustics must possess both optical and acoustic properties of tissue. To realize the optical properties of tissue, one approach was to optimize the number of freezing and thawing cycles of aqueous poly(vinyl alcohol) solutions, a procedure which increases the turbidity of the gel while rigidifying it. The second approach concentrated on forming a clear matrix of the rigid poly(vinyl alcohol) gel without any scattering, so that appropriate amounts of optical scatterers could be added at the time of formation, to tune the optical properties as per requirement. The relevant optical and acoustic properties of such samples were measured to be close to the average properties of human breast tissue. Tumour simulating gel samples of suitable absorption coefficient were created by adding appropriate quantities of dye at the time of formation; the samples were then cut into spheres. A breast phantom embedded with such 'tumours' was developed for studying the applicability of photoacoustics in mammography.

Comparison of the spatial and temporal information retrieved from near-infrared phase and average intensity (DC) data reveals that these data types can play a complementary role in the study of the temporal and spatial features of the optical response associated with brain activation during a finger-tapping test. The optical data have been collected with a frequency-domain tissue imager at two wavelengths (690 and 830 nm) and have been analyzed using standard filtering and folding-average procedures. DC and phase data show different temporal and spatial features. A plausible explanation of the different behavior of DC and phase data has been attempted by using Monte Carlo simulations.

The functional properties of fats are determined by the distribution pattern of fatty acid residues in their acylglycerols, which may be modified by ester interchange (transesterification). In the margarine industry, the time course of the transesterification of fat blends is monitored by assaying for the amount of the solid fraction at different temperatures (SFC-solid fat content) currently measured by nuclear magnetic resonance (NMR). The aim of this study was to evaluate the feasibility of near infrared spectroscopy (NIRS) to quantify ...

Unlike other cancers, the Sentinel Lymph Node (SLN) procedure in bladder cancer requires special attention to the injection technique. The aim of this study was to assess feasibility and to optimize tracer injection technique for SLN mapping in bladder cancer patients using NIR fluorescence imaging. Twenty patients with invasive bladder cancer scheduled for radical cystectomy were prospectively enrolled. Indocyanine green (ICG) bound to human serum albumin (complex ICG:HSA; 500 µM) was injected peritumourally to permit SLN mapping. ICG:HSA was first administrated serosally (n = 5), and subsequently mucosally by cystoscopic injection (n = 15). In the last cohort of 12 patients treated with cystoscopic injection, the bladder was kept filled with saline for at least 15 min. Fluorescent lymph nodes were observed only in the patient group with cystoscopic injection of ICG:HSA. Filling of the bladder post-injection was of added value to promote drainage of ICG:HSA to the lymph nodes, and ...

Polarization-sensitive optical coherence tomography ͑PS-OCT͒ and near-infrared ͑NIR͒ imaging are promising new technologies under development for monitoring early carious lesions. Fluorosis is a growing problem in the United States, and the more prevalent mild fluorosis can be visually mistaken for early enamel demineralization. Unfortunately, there is little quantitative information available regarding the differences in optical properties of sound enamel, enamel developmental defects, and caries. Thirty extracted human teeth with various degrees of suspected fluorosis were imaged using PS-OCT and NIR. An InGaAs camera and a NIR diode laser were used to measure the optical attenuation through transverse tooth sections ͑ϳ200 m͒. A digital microradiography system was used to quantify the enamel defect severity by measurement of the relative mineral loss for comparison with optical scattering measurements. Developmental defects were clearly visible in the polarizationresolved OCT images, demonstrating that PS-OCT can be used to nondestructively measure the depth and possible severity of the defects. Enamel defects on whole teeth that could be imaged with high contrast with visible light were transparent in the NIR. This study suggests that PS-OCT and NIR methods may potentially be used as tools to assess the severity and extent of enamel defects.

The potential of near-infrared reflectance spectroscopy (NIRS) to estimate the oil content, fatty acid composition, and protein content of Jatropha curcas seeds was studied. Seventy-four intact kernels from various sources were scanned by NIRS. All samples were analyzed for oil content (hexane extractions), fatty acid composition (gas chromatography), and protein content (Kjeldahl). Calibration equations were developed for oil content, individual fatty acids (oleic C18:1, linoleic C18:2, stearic C18:0 and palmitic C16:0), and protein content. The performance of the calibration equations was evaluated through external and cross-validation. The results showed that NIRS was a reliable, accurate and nondestructive technique to estimate oil and protein contents, as well as oleic and linoleic fatty acid concentrations in J. curcas kernels; NIRS provides a rapid, simple, and cost-effective alternative method for screening intact J. curcas kernels.

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.

Visible and near-infrared (Vis-NIR, 350-2500 nm) diffuse reflection spectroscopy (DRS) models built from ''as-collected'' samples of solid cattle manure accurately predict concentrations of moisture and crude ash. Because different organic molecules emit different spectral signatures, variations in livestock diet composition may affect the predictive accuracy of these models. This study investigates how differences in livestock diet composition affect Vis-NIR DRS prediction of moisture and crude ash. Spectral signatures of solid manure samples (n ¼ 216) from eighteen groups of cattle on six different diets were used to calibrate and validate partial least squares (PLS) regression models. Seven groups of PLS models were created and validated. In the first group, two-thirds of all samples were randomly selected as the calibration set and the remaining one-third were used for the validation set. In the remaining six groups, samples were grouped by livestock diet (ration). Each ration in turn was held out of calibrations and then used as a validation set. When predicting crude ash, the fully random calibration model produced a root mean square deviation (RMSD) of 2.5% on a dry basis (db), ratio of standard error of prediction to the root mean squared deviation (RPD) of 3.1, bias of 0.14% (db), and correlation coefficient r 2 of 0.90., When predicting moisture, an RMSD of 1.5% on a wet basis (wb), RPD of 4.3, bias of À0.09% (wb), and r 2 of 0.95 was achieved. Model accuracy and precision were not impaired by exclusion of any single ration from model calibration.

Indocyanine green (ICG) is a near-infrared (NIR) imaging agent and is also an ideal light absorber for laser-mediated photothermal therapy. This NIR dye could serve as a basis of a dualfunctional probe with integrated optical imaging and photothermal therapy capabilities. However, applications of ICG remain limited by its concentration-dependent aggregation, poor aqueous stability, nonspecific binding to proteins and lack of target specificity. To overcome these limitations, a novel ICG-containing nanostructure is designed utilizing the noncovalent self-assembly chemistry between phospholipid-polyethylene glycol (PL-PEG) and ICG. The interactions between both amphiphilic ICG and PL-PEG were studied using absorption and fluorescence spectroscopy. The properties of ICG-PL-PEG nanoprobe, such as absorption and fluorescence spectra, stability, morphology and size distribution, were also investigated. Two representative targeting molecules, namely, a small molecule, folic acid (FA), and a large protein, integrin R v β 3 monoclonal antibody (mAb), were conjugated to the surface of ICG-PL-PEG nanoprobe, displaying the diversity of ligand conjugation. The target specificity was confirmed using three cell lines with different levels of available folate receptors (FRs) or integrin R v β 3 expression via laser scanning confocal microscope and flow cytometry. This targeting ICG-PL-PEG nanoprobe could be internalized into targeted cells via ligand-receptor mediated endocytosis pathway. Our in vitro experiments showed that internalized ICG-PL-PEG could be used for cell imaging and selective photothermal cell destruction. These results represent the first demonstration of the dual functionality of ICG-containing nanostructure for targeted optical imaging and photothermal therapy of cancerous cells. This novel ICG-PL-PEG nanostructure, when conjugated with other therapeutic and imaging agents, could become a multifunctional probe for cancer diagnosis and treatment.

Ultrasensitive, near-infrared (NIR), time-resolved fluorescence is evaluated as a detection method for reading DNA hybridization events on solid surfaces for microarray applications. In addition, the potential of mulitiplexed analyses using time-resolved identification protocols is described. To carry out this work, a NIR time-resolved confocal imager was constructed to read fluorescence signatures from the arrays. The device utilized a 780-nm pulsed diode laser, a single-photon avalanche diode (SPAD), and a high-numerical-aperture microscope objective mounted in an epi-illumination format. Due to the small size of the components that are required to construct this imager, the entire detector could easily be mounted on high-resolution translational stages and scanned over the stationary arrays. The instrument response function of the device was determined to be 275 ps (fwhm), which is adequate for measuring fluorophores with subnanosecond lifetimes. To characterize the system, NIR dyes were deposited directly on different substrate materials typically used for DNA microarrays, and the fluorescence lifetimes of two representative dyes were measured. The fluorescence lifetime for aluminum tetrasulfonated naphthalocyanine was found to be 1.92 ns, and a value of 1.21 ns was determined for the tricarbocyanine dye, IRD800, when it was deposited onto poly(methyl methacrylate) (PMMA) and measured in the dry state. Finally, the imager was used to monitor hybridization events using probe oligonucleotides chemically tethered to a PMMA substrate via a glutardialdehyde linkage to an aminated-PMMA surface. The limit of detection for oligonucleotides containing a NIR fluorescent reporter was determined to be 0.38 molecules/µm 2 , with this detection limit improving by a factor of 10 when a time-gate was implemented. Fluorescence lifetime analysis of the hybridization events on PMMA indicated a lifetime value of 1.23 ns for the NIR-labeled oligonucleotides when using maximum-likelihood estimators.

The accelerated transformation of three azithromycin pseudo-polymorphs (viz. the anhydrous, monohydrate (MH), and dihydrate (DH) forms) at a high temperature and moisture level was examined by near infrared spectroscopy (NIRS). The most marked spectral differences between the pseudo-polymorphs occurred in the 1800-2200 nm region, which corresponds to the first overtone for water. The qualitative analysis of the NIR spectra for the pseudo-polymorphs following storage in a stove at 608C at 100% relative humidity for 60 days suggests that the crystalline forms (viz. the MH and DH) are stable, whereas the amorphous (anhydrous) form evolves to the DH. This was confirmed by determining the amounts of water and DH present in anhydrous azithromycin and the MH by use of partial least-squares regression (PLSR). The method used to quantify the DH in MH samples was developed and validated in accordance with the standards of the International Conference of Harmonization (ICH) and the European Medicines Agency (EMEA) with a view to its subsequent application by the pharmaceutical industry. The limits of detection (LD) and quantitation (LQ) for the DH in MH provided by the NIRS method were consistent with those obtained by X-ray diffraction (XRD) methodology. This testifies to the accuracy of the proposed method.

Background: The capacity to memorize speech sounds is crucial for language acquisition. Newborn human infants can discriminate phonetic contrasts and extract rhythm, prosodic information, and simple regularities from speech. Yet, there is scarce evidence that infants can recognize common words from the surrounding language before four months of age.

Samples of magnesium stearate monohydrate and dihydrate were used to prepare standard mixtures of known pseudopolymorphic composition. Near infrared spectra (NIR) of the standard mixtures were measured to develop multivariate calibration models for the pseudopolymorphic composition of magnesium stearate by partial least squares (PLS) regression. Magnesium stearate hydrate compositions of the standard mixtures were compared against the hydrate composition based on thermogravimetric analysis (TGA). The mixture compositions determined from TGA mass loss on drying (LOD) measurements were found to be inaccurate. PLS regression was applied to the TGA thermograms of the standard mixtures to generate more accurate reference values, and this model was then applied to a set of validation samples. Application of the NIR PLS model to the validation sample set resulted in precise estimates of sample pseudopolymorphic composition when compared to the TGA PLS reference values. The NIR PLS model was found to be more sensitive than TGA LOD to small quantities of hydrates, and the TGA PLS model was also found to be more sensitive that TGA LOD. The results demonstrate the challenges and opportunities that arise when rapid, nondestructive spectroscopic methods depend on insensitive or inaccurate reference methods for development of multivariate calibration models. ß c When the fatty acid composition of the samples is 90% stearic acid and 5% palmitic acid, the theoretical loss on drying of pure monohydrate and dihydrate samples is 2.97% and 5.77%, respectively.

The spectral reflectance measurements in tissue reveal physiological meaning. Normally, functional changes like, increase in total hemoglobin concentration, decrease in oxygen saturation, etc., are observed when there is an abnormality creeping in the normal tissue. These functional changes can act together to reveal disease by non-invasive near-infrared (NIR) spectroscopy, as it influence its optical properties. In the present study, a simple two dimensional, four layer model of breast is proposed. The four layers are (i) skin (ii) adipose layer (iii) glandular tissue and (iv) muscle. Each layer is modeled with appropriate biological chromophores like hemoglobin, water, lipid and melanin. From the literature, the concentrations and molar extinction coefficients of the chromophores in various layers of the model are obtained. These values are used to calculate the wavelength dependent absorption characteristics of a particular layer. Monte Carlo simulation of diffuse reflectance (percentage of back reflected photons after multiple scattering with the broad variety of angles) are simulated for the modeled breast tissue with and without diseased condition. Near-infrared wavelengths are chosen, as the depth of penetration in tissue is more compared to UV and visible region. Simulations are carried out on the modeled breast tissue for different races (skin colors) at different NIR wavelengths. Results show significant changes in diffuse reflectance and relative absorbance for normal and diseased breast tissues for differently pigmented model. This model can be used to study the photo dynamical therapy, drug delivery and prognosis of cancer.

Moisture content in commercially available milk powder was investigated using near infrared (NIR) diffuse reflectance spectroscopy with an Indian low-cost dispersive NIR spectrophotometer. Different packets of milk powder of the same batch were procured from the market. Forty-five samples with moisture range 4–10% were prepared in the laboratory. Spectra of the samples were collected in the wavelength region 800–2500 nm. Moisture values of all the samples were simultaneously determined by Karl Fischer (KF) titration. These KF values were used as reference for developing calibration model using partial least squares regression (PLSR) method. The calibration and validation statistics areR cal2:0.9942,RMSEC:0.1040, andR val2:0.9822,RMSEV:0.1730. Five samples of unknown moisture contents were taken for NIR prediction using developed calibration model. The agreement between NIR predicted results and those of Karl Fischer values is appreciable. The result shows that the instrument can be ...

The hybrid material copper (II) tetrachloro-bis(phenyl ethyl ammonium) (C 6 H 5 CH 2 CH 2 NH 3 ) 2 CuCl 4 , or PEACuCl, has been investigated by temperature-dependent spectroscopic absorption experiments. The absorption bands observed in the near-infrared region (1.3-1.9 eV) generally exhibit redshifts with increasing temperature. The temperature-induced energy shifts of the spectral components are shown to be consistently related to temperature-induced Cu-Cl bond length changes. Additionally, the thermochromic color change is caused by a charge transfer band edge redshifting (in the visible region 2.0-2.8 eV) with increasing temperature. By comparison with similar Cu-based systems, it is suggested that this shift is caused by broadening and strengthening of the band.

Sustainable forest production demands a continuous supply of high quality seeds for the production of seedlings in the nursery or for direct sowing. Here, we demonstrated the potential of near infrared spectroscopy as a rapid technique to discriminate viable and empty seeds of Pinus patula Schiede & Deppe. Near infrared spectra were collected from single seeds in transmittance and reflectance modes. To discriminate viable and empty seeds, multivariate classification models were developed with partial least squares (PLS) regression using the digitized spectra as a regressor and a y-vector of artificial values (1 for viable and −1 for empty seeds) as a regressand. Viable and empty seeds were perfectly distinguished by PLS models computed on full and selected transmittance spectroscopy data, while those derived from ‘full’ NIR reflectance spectra recognized 96 % of viable and 88 % of empty seeds. Analyses made on selected NIR reflectance spectra improved the classification rate of empty seeds to 100%. Difference spectra and PLS weights indicated that the origin of spectral differences between viable and empty seeds was attributed to differences in fatty acids and proteins that were totally absent in empty seeds. The result shows the prospect of developing rapid filter-based sorting equipment that can easily be automated.

The feasibility of using near infrared transmission spectroscopy to discriminate between Basmati and other long-grain rice samples was investigated. A discriminant rule was derived using the Fisher linear discriminant function calculated from the first few principal component scores of the NIR spectra. The discriminant rule was assessed by cross-validation. Nine Basmati and 53 other rice samples were classified correctly from NIR spectra measured on 200 g bulk samples but 8% of the Basmatis and 14% of the others were misclassified on the basis of spectra of individual grains. Using average spectra from 23 grains resulted in correct classification of 16 Basmatis but a 20% error rate on 100 other samples.

The coherent time-stretch transform enables high-throughput acquisition of complex optical fields in single-shot  measurements. Full-field spectra are recovered via temporal interferometry on waveforms dispersed in the temporal near field. Real-time absorption spectra, including both amplitude and phase information, are acquired at 37 MHz.

The registration of functional brain data to common stereotaxic brain space facilitates data sharing and integration across different subjects, studies, and even imaging modalities. Thus, we previously described a method for the probabilistic registration of functional near-infrared spectroscopy (fNIRS) data onto Montreal Neurological Institute (MNI) coordinate space that can be used even when magnetic resonance images of the subjects are not available. This method, however, requires the careful measurement of scalp landmarks and fNIRS optode positions using a 3D-digitizer. Here we present a novel registration method, based on simulations in place of physical measurements for optode positioning. First, we constructed a holder deformation algorithm and examined its validity by comparing virtual and actual deformation of holders on spherical phantoms and real head surfaces. The discrepancies were negligible. Next, we registered virtual holders on synthetic heads and brains that represent size and shape variations among the population. The registered positions were normalized to MNI space. By repeating this process across synthetic heads and brains, we statistically estimated the most probable MNI coordinate values, and clarified errors, which were in the order of several millimeters across the scalp, associated with this estimation. In essence, the current method allowed the spatial registration of completely stand-alone fNIRS data onto MNI space without the use of supplementary measurements. This method will not only provide a practical solution to the spatial registration issues in fNIRS studies, but will also enhance cross-modal communications within the neuroimaging community.

Visible (VIS) and near infrared (NIR) reflectance spectroscopy combined with multivariate data analysis were explored to predict fibre diameter in both clean and greasy Merino wool samples. Fifty clean and 400 greasy wool samples were analysed. Samples were scanned in a large cuvette using a NIRSystems 6500 monochromator instrument by reflectance in the VIS and NIR regions (400 to 2500 nm). Partial least square (PLS) regression was used to develop a number of calibration models between the spectral and reference data. Different mathematical treatments were used during model development. Cross validation was used to assess the performance and avoid overfitting of the models. The NIR calibration models gave a coefficient of determination in calibration (R2) > 0·90 for clean wool samples and a R2 < 0·50 for greasy wool samples. The values for the residual predictive value, RPD (ratio of standard deviation (s. d.) to the root mean square of the standard error of cross validation (...

Handball is a sport with high anaerobic demands in lower body as has been indicated by Wingate test (WT) performed with the legs, but there are no data available concerning power production during a WT performed with the arms in handball players (HndP). Therefore, the purpose of this study was to explore the arm anaerobic profile of HndP during a WT. Twenty-one elite HndP and 9 physical education students (CON), performed a 30-s arm WT. Power production and muscle oxygenation were recorded. Peak power (PP) as well as mean power (MP) was higher (P = .017 and 0.03, and ES = 1.00 and 0.86, respectively) for HndP (HndP PP: 7.6 +/- 0.8 W x kg(-1); CON PP: 6.7 +/- 1.1 W x kg(-1); HndP MP 5.3 +/- 0.6 W x kg(-1); CON MP 4.7 +/- 0.9 W x kg(-1)) with no significant difference in fatigue index between the two groups. Muscle oxygen saturation (StO2) declined approximately 30% with exercise with no differences between groups. During recovery the HndP group had higher StO2 (P = .01, ES= 3.04), to...

58 patients who underwent on-pump coronary artery bypass graft surgery were evaluated for changes in regional cerebral oxygen saturation (rSO2) measured by near infrared spectroscopy (NIRS). If rSO2 during the operation fell to more than 20% under the baseline, standardized interventions were undertaken to maintain rSO2. Despite those interventions, in some cases we observed inability to maintain rSO2 above this threshold. Therefore we divided patients in two subgroups: 1. without prolonged rSO2 desaturation; 2. with prolonged rSO2 desaturation (area under the curve >150 min% for rSO2<20% of baseline and >50 min% for rSO2<50% of absolute value). The data were analyzed to determine whether there were major differences in outcome of these two groups. 18 out of 58 patients (31%) had prolonged rSO2 desaturation during operation. There was significantly higher number of diabetic patients in group with prolonged rSO2 desaturation (p=0.02). Intraoperative data revealed signific...

The relationship between human consciousness and oxygen saturation (rSO 2 ) in cerebral tissue under high +Gz stress was non-invasively monitored by near-infrared multiple wavelength spectroscopy (NIRS). We studied the drop in rSO 2 levels in human subjects during exposure to various head-to-foot acceleration (+Gz) profiles. These profiles included sustained +Gz plateaus and repeated short duration +Gz pulses of varying duration. The end point in this study was +Gz-induced loss of consciousness (G-LOC). The rSO 2 levels under normal (asymptomatic), almost loss of consciousness (A-LOC) and G-LOC conditions were recorded. Correlations among decrease in rSO 2 , +Gz pulse duration, +Gz stress level and incapacitation time (ICAP) after G-LOC were also investigated. It was found that once rSO 2 fell to a certain level, G-LOC occurred. This threshold was repeatable and independent of the +Gz level or duration. It was also observed that the total ICAP after G-LOC was dependent on the length of time that rSO 2 remained below the G-LOC threshold level, i.e. the longer the rSO 2 level remained below the G-LOC induction level, the longer the subject remained unconscious. These results may prove to be useful in designing closed loop control systems for personal protective gear for pilots of high performance aircraft.

The potential of noninvasive determination of glucose, lactic acid, and nisin in Lactococcus lactis subsp. lactis biofilm fermentation was investigated through fourier transform mid-infrared (FTIR) spectroscopy. Samples obtained from a biofilm bioreactor were analyzed with traditional methods and FTIR spectroscopy. The FTIR spectra were interpreted by using suitable spectra wavenumber regions through multivariate statistical techniques such as partial least square (PLS) and principal component regression (PCR). The standard error of calibration for the PLS-1 st derivative calibration models for glucose, lactic acid, and nisin were 3.87 g/l, 2.62 g/l, and 189.6 IU/ml, respectively. Prediction errors were low for glucose and lactic acid, whereas nisin could be reliably quantified when its concentration is higher than 800 IU/ml. Results indicated that FTIR spectroscopy could be used for rapid detection of glucose and lactic acid concentrations, and nisin activity in nisin fermentation.

Moisture content is an important parameter for lyophilized vaccines. Currently, Karl Fischer titration is widely used for moisture determination in routine analysis. However, this method is time-consuming, sample destructive and requires environment polluting reagents, as well as the results rely on the random samplings. In this study, near infrared spectroscopy was used as a fast, non-invasive and non-destructive method to determine the moisture content in lyophilized allergy vaccines. Five different vaccine products were investigated, which contained water in the range of 0.17-1.51% (w/w, KF). Different data pre-treatments, wavelength selection and partial least squares regression were applied to construct calibration models. Multi-products model and product-specific models were obtained, which show the possibility of NIR as a rapid method to discriminate whether moisture content fit into the specifications of a pharmaceutical company.

A near infrared reflectance spectroscopy (NIRS) method for rapid determination of nitrogen, phosphorous and potassium in diverse meadow grasses was developed with a view towards utilizing this material for biogas production and organic fertilizer. NIRS spectra between 12,000 cm −1 and 4,000 cm −1 were used. When validated on samples from different years to those used for the calibration set, the NIRS prediction of nitrogen was considered moderately useful with R 2 = 0.77, ratio of standard error of prediction to reference data range (RER) of 9.32 and ratio of standard error of prediction to standard deviation of reference data (RPD) of 2.33. Prediction of potassium was less accurate, with R 2 = 0.77, RER of 6.56 and RPD of 1.45, whilst prediction of phosphorous was not considered accurate enough to be of any practical use. This work is of interest from the point of view of both the removal of excess nutrients from formerly intensively farmed areas and also for assessing the plant biomass suitability for conversion into carbon neutral energy through biogas production.

Femtosecond laser pulses have been widely used as a tool to study molecular ionization and fragmentation. This article bridges the application of femtosecond laser technology in early research focused on small isolated molecules with that in modern biological mass spectrometry for proteomics and metabolomic analysis on large (140+ atoms) biomolecules. The single-shot interaction of a femtosecond laser with neutral paranitrotoluene (pNT) is investigated with time-of-flight mass spectrometry and compared with the ultrafast photodissociation of protonated pNT in an ion trap mass spectrometer accumulated over ∼1000 pulses. The ion trap experiment is then extended to longer biomolecules. As demonstrated in the examples of vasopressin and tomatine, this novel ion activation method provides greater sequence coverage and nonstatistical fragmentation, leading to valuable information complementary to conventional methods for structural analysis.

We have calculated fundamental and overtone CH-stretching vibrational band frequencies and intensities of neutral and cationic naphthalene and anthracene, the smallest of the polycyclic aromatic hydrocarbons. The calculations use a simple anharmonic oscillator local mode model with local mode parameters obtained from scaled ab initio calculations and ab initio calculated dipole moment functions. The ab initio calculations were performed at the self-consistent-field Hartree-Fock and the B3LYP hybrid density functional levels of theory with the 6-31G(d) and 6-311+G(d,p) basis sets. The vapor phase overtone spectra of anthracene and both cations have not yet been observed. We find that the cation frequencies are blue shifted and the overtone transitions are of comparable intensities to those in the neutral molecules, contrary to the fundamental transitions which are significantly weaker in the cations. The method presented here can provide an accurate estimate of CH-stretching overtone spectra of neutral and cationic polycyclic aromatic hydrocarbons.

In hyperspectral analysis, PLS-discriminant analysis (PLS-DA) is being increasingly used in conjunction with pure spectra where it is often referred to as PLS-Classification (PLS-Class). PLS-Class has been presented as a novel approach making it possible to obtain qualitative information about the distribution of the compounds in each pixel using little a priori knowledge about the image (only the pure spectrum of each compound is needed). In this short note it is shown that the PLS-Class model is the same as a straightforward classical least squares (CLS) model and it is highlighted that it is more appropriate to view this approach as CLS rather than PLS-DA. A real example illustrates the results of applying both PLS-Class and CLS.

We have employed near-infrared optical methods to measure noninvasively the dynamics of muscle blood flow and oxygen saturation (S t O 2 ) during cuff occlusion and plantar flexion exercise. Relative muscle oxygen consumption (rVO 2 ) was also computed from these data. Diffuse correlation spectroscopy provides information about blood flow, and diffuse reflectance spectroscopy provides information about blood oxygenation. Ten healthy subjects and one patient with peripheral arterial disease (PAD) were studied during 3-min arterial cuff occlusion of arm and leg, and during 1-min plantar flexion exercise. Signals from different layers (cutaneous tissues and muscles) during cuff occlusion were differentiated, revealing strong hemodynamic responses from muscle layers. During exercise in healthy legs, the observed ϳ4.7 fold increase in relative blood flow (rBF) was significantly lower than the corresponding increase in rVO 2 (ϳ7 fold). The magnitudes of rBF and rVO 2 during exercise in the PAD patient were ϳ1/2 of the healthy controls, and the S t O 2 recovery time was twice that of the controls. The hybrid instrument improves upon current technologies for measuring muscle responses by simultaneously measuring rBF and S t O 2 . The instrument thus provides a method for evaluation of microcirculation and muscle metabolism in patients with vascular diseases.

Fast-track cardiac anaesthesia programs aiming at early tracheal extubation have not only been linked to a decrease in intensive care unit and hospital length of stay but also to a decrease in morbidity and mortality as well as a containment of rising medical costs. General recommendations for the inclusion criteria concerning fast-track programs are not available. The present study determined the factors influencing the time to extubation in patients undergoing a newly implemented fast-track protocol. Seventy-nine patients were retrospectively studied. Successful fast track was defined as time to extubation within 75 min after admission to ICU. Sixty patients fulfilled the successful fast-track criteria with a mean time to extubation of 43.9 min (range 15-75 min). Nineteen patients needed more than 75 min to be weaned from the respirator with a mean time to extubation of 135 min (range 90-320 min). Analysis of pre- and intraoperative factors revealed that these groups differed only...

Deception is commonly seen in everyday social interactions. However, most of the knowledge about the underlying neural mechanism of deception comes from studies where participants were instructed when and how to lie. To study spontaneous deception, we designed a guessing game modeled after Greene and Paxton (2009) ''Proceedings of the National Academy of Sciences, 106(30), 12506-12511'', in which lying is the only way to achieve the performance level needed to end the game. We recorded neural responses during the game using near-infrared spectroscopy (NIRS). We found that when compared to truth-telling, spontaneous deception, like instructed deception, engenders greater involvement of such prefrontal regions as the left superior frontal gyrus. We also found that the correct-truth trials produced greater neural activities in the left middle frontal gyrus and right superior frontal gyrus than the incorrect-truth trials, suggesting the involvement of the reward system. Furthermore, the present study confirmed the feasibility of using NIRS to study spontaneous deception.

The aim of the present study was to investigate the feasibility of near infrared (NIR) spectroscopy for rapid assessment of the Bloom value, viscosity, pH and moisture content of commercial edible gelatines. NIR spectra from both dry gelatine samples and freshly made gels (matured for 30 min) were calibrated against the four parameters. The lowest prediction errors for Bloom value and pH were obtained from the gel spectra, while dry gelatine spectra provided the lowest prediction errors for viscosity and moisture content. However, all four parameters could be predicted from dry gelatine spectra with cross-validated correlation coefficients between 0.80 and 0.86. All calibration models gave correlation coefficients in the region 0.80-0.92. q

In vitro model for penetration of sensory nerve fibres on a Matrigel basement membrane: implications for possible application to intractable pruritus. Br J Dermatol 161:1028-37 Tominaga M, Takamori K (2014) Itch and nerve fibers with special reference to atopic dermatitis: therapeutic implications. J Dermatol 41:205-12 van Scheppingen C, Lettinga AT, Duipmans JC et al. (2008) Main problems experienced by children with epidermolysis bullosa: a qualitative study with semi-structured interviews. Acta Derm Venereol 88: 143-50 Zhang LQ, Laato M (2001) Innervation of normal and hypertrophic human scars and experimental wounds in the rat.

Freeze drying is a complex, time consuming and thus expensive process, hence creating a need for understanding the material behaviour in the process environment and for process optimization. Near-infrared (NIR) spectroscopy offers the opportunity to monitor physicochemical changes of the formulation during freeze-drying. The aim of this work was to examine whether NIR spectroscopy allows in-line monitoring of all components during the entire freeze-drying process of a multi-component pharmaceutical formulation (a solution of fenofibrate and mannitol in a mixture of tertiary-butyl alcohol, and water). To extract useful information of all components in the formulation from the large multivariate data-sets obtained during in-line spectroscopic monitoring, several spectral pre-processing techniques and spectral data analysis techniques such as the mean of selected wavenumbers (Mws), the correlation coefficient (Cor-rCoef) and principal component analysis (PCA) have been evaluated and compared. To find out whether these chemometric techniques are also able to differentiate between changes in the process settings influencing the freeze-drying process of the formulation, freeze-drying processes were performed at four different conditions. Results demonstrated that in-line measurements using NIR spectroscopy were possible in an icy environment and that a further process understanding could be obtained. Data-analysis revealed the crystallization behaviour of each of the four components. In addition, using the three preprocessing techniques allowed observe the sublimation of the solvents. Mws and CorrCoef have proven to be adequate methods for monitoring the main physicochemical changes of product during the processes; this affirmation was confirmed by observing the outputs of PCA for entire processes.