In this paper, a double artificial neural network （DANN） algorithm was used to parse near infrared （NIR） reflectance spectrum of Cofrel medicines. The contents of benproperine phosphate, which is the effective ing...In this paper, a double artificial neural network （DANN） algorithm was used to parse near infrared （NIR） reflectance spectrum of Cofrel medicines. The contents of benproperine phosphate, which is the effective ingredient in Cofrel medicines, were accurately nondestructive quantitatively predicted. Compared the results with those of HPLC, the relative errors （RE %） were less than 0.18%. The analytical results could be applied to qualitative control of Cofrel medicines.展开更多
It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are ...It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are in their shells, it would save lot of labor and money spent in shelling and cleaning the nuts. Grain and nuts absorb low levels of NIR, and when NIR radiation is incident on them, a substantial portion of the radiation is reflected back. Thus, studying the NIR reflectance spectra emanating from in-shell peanuts, an attempt is made for the first time to determine the MC of in-shell peanuts. In-shell peanuts of two different market types, Virginia and Valencia, were conditioned to different moisture levels between 6% and 26% (wet basis), and separated into calibration and validation groups. NIR absorption spectral data from 1000 nm to 2500 nm in 1 nm intervals were collected from both groups. Measurements were obtained on 30 replicates within each moisture level. Reference MC values for each moisture level in these groups were obtained using standard air-oven method. Partial Least Square (PLS) analysis was performed on the calibration data, and prediction models were developed. The Standard Error of Calibration (SEC), and R2 of the calibration models were computed to select the best calibration model. The selected models were used to predict the moisture content of peanuts in the validation sets. Predicted MC values of the validation samples were compared with their standard air-oven moisture values. Goodness of fit was determined based on the lowest Standard Error of Prediction (SEP) and highest R2 value obtained for the prediction models. The model, with reflectance plus normalization spectral data with an SEP of 0.74 for Valencia and 1.57 for Virginia type in-shell peanuts was selected as the best model. The corresponding R2 values were 0.98 for both peanut types. This work establishes the possibility of sensing MC of intact in-shell peanuts by NIR reflectance method, and would be useful for the peanut and allied industries.展开更多
The near infrared （NIR） spectroscopy technique has been applied in many fields because of its advantages of simple preparation, fast response, and non-destructiveness. We investigated the potential of NIR spectrosco...The near infrared （NIR） spectroscopy technique has been applied in many fields because of its advantages of simple preparation, fast response, and non-destructiveness. We investigated the potential of NIR spectroscopy in diffuse reflectance mode for determining the soluble solid content （SSC） and acidity （pH） of intact loquats. Two cultivars of loquats （Dahongpao and Jiajiaozhong） harvested from two orchards （Tangxi and Chun＇an, Zhejiang, China） were used for the measurement of NIR spectra between 800 and 2500 nm. A total of 400 loquats （100 samples of each cultivar from each orchard） were used in this study. Relationships between NIR spectra and SSC and acidity of loquats were evaluated using partial least square （PLS） method. Spectra preprocessing options included the first and second derivatives, multiple scatter correction （MSC）, and the standard normal variate （SNV）. Three separate spectral windows identified as full NIR （800-2500 nm）, short NIR （800-1100 rim）, and long NIR （1100-2500 nm） were studied in factorial combination with the preprocessing options. The models gave relatively good predictions of the SSC of loquats, with root mean square error of prediction （RMSEP） values of 1.21, 1.00, 0.965, and 1.16 °Brix for Tangxi-Dahongpao, Tangxi-Jiajiaozhong, Chun＇an-Dahongpao, and Chun＇an-Jiajiaozhong, respectively. The acidity prediction was not satisfactory, with the RMSEP of 0.382, 0.194, 0.388, and 0.361 for the above four loquats, respectively. The results indicate that NIR diffuse reflectance spectroscopy can be used to predict the SSC and acidity of loquat fruit.展开更多
Cation-anion interaction with different ratios of salt to solvent is investigated by FT-Raman spectroscopy. The fitting result of the C-N-C bending vibration manifests that the cation-anion coordination structure chan...Cation-anion interaction with different ratios of salt to solvent is investigated by FT-Raman spectroscopy. The fitting result of the C-N-C bending vibration manifests that the cation-anion coordination structure changes tremendously with the variation of salt concentration. It is well known that lithium-ion transport in ultrahigh salt concentration electrolyte is dramatically different from that in dilute electrolyte, due to high viscosity and strong cation-anion interaction. In ultrahigh salt concentrated ＂solvent-in-salt＂ electrolyte （SIS-7#）, we found, on one hand, that the cation and anion in the solution mainly formed cation-anion pairs with a high Li＋ coordination number （〉 1）, including intimate ion pairs （20.1%） and aggregated ion pairs （79.9%）, which not only cause low total ionic conductivity but also cause a high lithium transference number （0.73）. A possible lithium transport mechanism is proposed： in solvent-in-salt electrolytes, lithium ions＇ direct movement presumably depends on Li-ion exchange between aggregated ion pairs and solvent molecules, which repeats a dissolving and re-complexing process between different oxygen groups of solvent molecules.展开更多
NIR spectroscopy was used to measure the moisture concentration of wood pellets. Pellets were conditioned to various moisture levels between 0.63% and 14.16% (wet basis) and the moisture concentration was verified usi...NIR spectroscopy was used to measure the moisture concentration of wood pellets. Pellets were conditioned to various moisture levels between 0.63% and 14.16% (wet basis) and the moisture concentration was verified using a standard oven method. Samples from various moisture levels were separated into two groups, as calibration and validation sets. NIR absorption spectral data from 400 nm to 2500 nm with 0.5 nm intervals were collected using pellets within the calibration and validation sample sets. Spectral wavelength ranges were taken as independent variables and the MC of the pellets as the dependent variable for the analysis. Measurements were obtained on 30 replicates within each moisture level. Partial Least Square (PLS) analysis was performed on both raw and preprocessed spectral data of calibration set to determine the best calibration model based on Standard Error of Calibration (SEC) and coefficient of multiple determinations (R2). The PLS model that yielded the best fit was used to predict the moisture concentration of validation group pellets. Relative Percent Deviation (RPD) and Standard Error of Prediction (SEP) were calculated to validate goodness of fit of the prediction model. Baseline and Multiple Scatter Corrected (MSC) reflectance spectra with 1st derivative model gave the highest RPD value of 4.46 and R2 of 0.95. Also it’s SEP (0.670) and RMSEP (0.782) were less than the other models those had RPD value more than 3.0 with less number of factors. Therefore, this model was selected as the best model for moisture content prediction of wood pellets.展开更多
Presenteeism refers to impaired performance attributed to attending work with health problems. There has been no study examining the state of presenteeism with objective measures. We compared cerebral hemodynamic chan...Presenteeism refers to impaired performance attributed to attending work with health problems. There has been no study examining the state of presenteeism with objective measures. We compared cerebral hemodynamic changes, measured by near-infrared spectroscopy (NIRS), during neuropsychological tests conducted by university students with presenteeism and healthy controls. Twenty-two university students participated in the study;11 of them with impaired performance caused by mental health problem were allocated to the presenteeism group and 11 without health problems to the control group. Presenteeism was assessed by the Presenteeism Scale for Students. To evoke hemodynamics changes, the participants completed a Word Fluency Test (WFT) and a Trail Making Test (TMT). The NIRS probes were located over the bilateral prefrontal area. Students with presenteeism had significantly higher incidences of depression than controls. However, there was no significant difference in behavioral performance examinations between the two groups. With regard to hemodynamics changes, the repeated measures analysis of covariance of the NIRS signals revealed significant interactions between group and task activation. Although we observed a significant increase in oxygenated hemoglobin concentration during the WFT among controls (simple main effect;left channel, F(1, 19) = 27.34, P F(1, 19) = 22.05, P < 0.001), no changes were found in students with presenteeism during either the WFT (simple main effect;left channel, F(1, 19) = 0.12, P F(1, 19) = 0.08, P t = ﹣0.94, P with Bonferroni correction = 0.745;right channel, t = ﹣2.19, P with Bonferroni correction < 0.113). This is the first study to reveal differences in activity in the cerebral cortex associated with presenteeism. The fact that students with presenteeism have prefrontal dysfunction might reinforce the concept of presenteeism.展开更多
Human serum albumin(HSA)is the most abundant protein in plasma and plays an essential physiological role in the human body.Ethanol precipitation is the most widely used way to obtain HSA,and pH and ethanol are crucial...Human serum albumin(HSA)is the most abundant protein in plasma and plays an essential physiological role in the human body.Ethanol precipitation is the most widely used way to obtain HSA,and pH and ethanol are crucial factors affecting the process.In this study,infrared(IR)spectroscopy and near-infrared(NIR)spectroscopy in combination with chemometrics were used to investigate the changes in the secondary structure and hydration of HSA at acidic pH(5.6-3.2)and isoelectric pH when ethanol concentration was varied from 0%to 40%as a perturbation.IR spectroscopy combined with the two-dimensional correlation spectroscopy(2DCOS)analysis for acid pH system proved that the secondary structure of HSA changed significantly when pH was around 4.5.What's more,the IR spectroscopy and 2DCOS analysis showed different secondary structure forms under different ethanol concentrations at the isoelectric pH.For the hydration effect analysis,NIR spectroscopy combined with the McCabe-Fisher method and aquaphotomics showed that the free hydrogen-bonded water fluctuates dynamically,with ethanol at 0-20%enhancing the hydrogen-bonded water clusters,while weak hydrogen-bonded water clusters were formed when the ethanol concentration increased continuously from 20%to 30%.These measurements provide new insights into the structural changes and changes in the hydration behavior of HSA,revealing the dynamic process of protein purification,and providing a theoretical basis for the selection of HSA alcoholic precipitation process parameters,as well as for further studies of complex biological systems.展开更多
FT-Raman spectroscopy was used to monitor the polymerization of acrylic acid in aqueous solution. A simple method to avoid the noise in the background during the signal processing via Fourier transformation was used i...FT-Raman spectroscopy was used to monitor the polymerization of acrylic acid in aqueous solution. A simple method to avoid the noise in the background during the signal processing via Fourier transformation was used in this work. The effects of the amount of initiator used on the polymerization are studied. When the amount of the initiator in the polymerization was increased, both the rate and extent of polymerization of acrylic acid will be increased.展开更多
Cowpea (Vigna unguiculata L. Walp) is a multi-purpose legume with high quality protein for human consumption and livestock. The objective of this work was to develop near-infrared spectroscopy (NIRS) prediction models...Cowpea (Vigna unguiculata L. Walp) is a multi-purpose legume with high quality protein for human consumption and livestock. The objective of this work was to develop near-infrared spectroscopy (NIRS) prediction models to estimate protein content in cowpea. A total of 116 cowpea breeding lines with a wide range of protein contents (19.28 % to 32.04%) were selected to build the model using whole seed and ground seed samples. Partial least-squares discriminant analysis (PLS-DA) regression technique with different pre-treatments (derivatives, standard normal variate, and multiplicative scatter correction) were carried out to develop the protein prediction model. Results showed: 1) spectral plots of both the whole seed and ground seed showed higher spectral scatter at higher wavelengths (>1450 nm), 2) data pre-processing affects prediction accuracy for bot whole seed and ground seed samples, 3) prediction using ground seed samples (0.64 R<sup>2</sup> 0.85) is better than the whole seed (0.33 R<sup>2</sup> 0.78), and 4) the data pre-processing second derivative with standard normal variate has the best prediction (R<sup>2</sup>_whole seed = 0.78, R<sup>2</sup>_ground seed = 0.85). The results will be of interest in cowpea breeding programs aimed at improving total seed protein content.展开更多
The wireless distributed acquisition system for near infrared spectrosecopy(WDA-NIRS)is a portable,ultra-compact,contimuous wave(CW)NIRS system.Its main advantage is that it allows continuous synchronized multi-site h...The wireless distributed acquisition system for near infrared spectrosecopy(WDA-NIRS)is a portable,ultra-compact,contimuous wave(CW)NIRS system.Its main advantage is that it allows continuous synchronized multi-site hemodynarnic monitoring.The WDA-NIRS syster calculates online changes in hemoglobin concentration based on modifed Beer-Lambert law and the tissue oxy genation index based on the spatial resolved spectroscopy method.It consists of up to seven signal acquisition units,sufficiently small to be easily attached to any part of the body.These units are remotely synchronized by a PC base station for independent acquisition of NIRS signals.Each acquisition module can be freely adapted to individual requirements such as local skin properties and the microcirculation of interest,e.g,different muscles,brain,skin,etc.For this purpose,the light emitted by each LED can be individually,interactively or automatically adjusted to local needs.Furthermore,the user can freely create an emitter time multiplexing protocol and choose the detector sensitivity most suitable to a particular situation.The potential diagnostic value of this advanced device is demonstrated by three typical applications.展开更多
Near infrared spectroscopy (NIRS) is a method for non-invasive monitoring of cerebral oxygenation and haemodynamics. Different devices provide information on changes of oxygenated (HbO2) and deoxygenated haemoglobin (...Near infrared spectroscopy (NIRS) is a method for non-invasive monitoring of cerebral oxygenation and haemodynamics. Different devices provide information on changes of oxygenated (HbO2) and deoxygenated haemoglobin (HHb), oxidized cytochrome aa3 (CytOx) or regional oxygen saturation (rSO2). NIRS has been used during adult and paediatric cardiac surgery.展开更多
Depression has been known to reduce the prefrontal activity associated with the execution of certain cognitive tasks, although whether a temporarily depressed or anxious mood in healthy individuals affects the prefron...Depression has been known to reduce the prefrontal activity associated with the execution of certain cognitive tasks, although whether a temporarily depressed or anxious mood in healthy individuals affects the prefrontal blood oxygen level during cognitive tasks is unknown. Combining the measurement of prefrontal activity with near-infrared spectroscopy (NIRS) and the two cognitive tasks, namely the letter version of the verbal fluency test (VFT-l) and the Stroop test, we measured the effect of a depressed or anxious mood and gender on the changes in the prefrontal oxygenated hemoglobin (Oxy-Hb) levels during those cognitive tests in healthy individuals. Depressed mood or anxious mood was assessed by the Hospital Anxiety and Depression Scale (HADS). Thereby we aimed to explore the possibility of NIRS measurement for detecting the early subclinical manifestation of major depression. Moreover, we examined the possible relationships between prefrontal activation and the functional Val66Met polymorphisms of the brain derived neurotropic factor (BDNF) gene and serum BDNF level. As a result, the increased prefrontal Oxy-Hb levels during cognitive tasks were significantly correlated with the severity of depressed mood in males. The course of the prefrontal Oxy-Hb increase was different depending on the cognitive tasks, i.e., the VFT-l or the Stroop test, in both genders. Correlations of BDNF genotype and serum BDNF level with the prefrontal Oxy-Hb levels during those cognitive tasks were negative. Our results suggest that the early subclinical manifestation of depressed mood in males might be detected by the NIRS measurement, which is not correlated with the individual properties of BDNF.展开更多
In this paper,the Fourier transform near-infrared(FTNIR)diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares(PLS)regression is successfully used as an ...In this paper,the Fourier transform near-infrared(FTNIR)diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares(PLS)regression is successfully used as an effective multivariate calibration technique.The calibration set is composed of 20 standard millet samples that the protein contents were determined by the traditional Kjeldahl method.The optimal model dimension is found to be 5 by cross-validation.22 millet samples were determined by the proposed FTNIR-PLS method.The correlation coefficient between the concentration values obtained by the FTNIR-PLS method and the traditional Kjeldahl method is 0.9805.The standard error of prediction(SEP)is 0.28% and the mean recovery is 100.2%.The proposed method has been successfully applied for the routine analysis of protein in about 10,000 grain samples.展开更多
Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration proc...Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration processes on water structure detected by spectral variations in NIR region. Samples of ultrapure water （MilliQ-Millipore, Vimodrone, Milan, Italy） before and after iterated filtrations were analyzed. NIR spectra were collected in transmission mode in the whole NIR range, by using NIRFIex N500 spectrometer at constant temperature （40 ± 1 ℃）. NIR data were processed using Unscrambler software v. 9.2 in evaluating qualitative differences between filtered and not filtered samples. The information related to possible solvent physical stresses were highlighted in the range 6500-7500 cm^-1. The shifts observed were ascribable to a different distribution of the number of water molecules involved in hydrogen bonds in filtered and not filtered water samples, at constant temperature. NIR spectroscopy, commonly used to study relationship between spectral changes and hydrogen bonds in water at increasing temperature values, was applied to evaluate effects of filtration processes on water structure. The obtained results are in agreement with literature data and allowed the improvement of the knowledge about pure water characteristics when some mechanical perturbations are applied.展开更多
The orientation and structural characterization of the ultrathin film of azobenzene-containing amphiphilic compound, C_ 12AzoNaph(1,4)C_6N +Br -, were studied in the present study. The compound can form a stable m...The orientation and structural characterization of the ultrathin film of azobenzene-containing amphiphilic compound, C_ 12AzoNaph(1,4)C_6N +Br -, were studied in the present study. The compound can form a stable monolayer with sodium dextrin sulfate(SDS) by means of electrostatic interaction. Fourier-transform infrared(FT-IR) and near-infrared surface-enhanced Raman scattering(NIR-SERS) spectroscopies were used to study the orientation and characterize the structure of the Langmuir-Blodgett(LB) film and the dipping film. The FT-IR spectra indicate that the alkyl tail is nearly perpendicular to the substrate surface without any aggregation and adopts largely trans-zigzag conformation in the LB film. The NIR-SERS spectra demonstrate that the chromorphoric part in C_ 12AzoNaph(1,4)C_6N +Br is also nearly perpendicular to the surface of silver substrate both in the dipping film and the LB film. A new 'sandwiched system' model was designed to investigate the orientation and structural characterization of the chromophoric part in the multi-monolayer LB films on the non-SERS active substrate. The SERS mechanism of the 'sandwiched system' is discussed in the present paper.展开更多
Nowadays, biomedicine development is caused by the necessity of fast premalignant and malignant diagnosis. In the case of cancer, it is important to identify degree of tumor’s malice. We investigated the differences ...Nowadays, biomedicine development is caused by the necessity of fast premalignant and malignant diagnosis. In the case of cancer, it is important to identify degree of tumor’s malice. We investigated the differences of Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) and FT-Raman spectroscopy between leukoplakia, oral cancer and normal tissues. Human tissue contains many compounds with known absorption spectra in the range of Near Infrared (NIR) spectroscopy. These compounds have a fingerprint region, which permits their characterization. FTIR spectroscopy is a promising diagnostic tool. There is ability to detect skin, cervix, prostate, breast, esophagus, stomach, bladder and oral cancers [1]. Imaging using FTIR microscope allows analysis of biochemical compounds in microregions of biological materials. FTIR microspectroscopy is the perfect technique for tissues and individual cells analysis [1]. It delivers information about biochemistry of cell or tissue samples and has been applied in many areas of medical research [2]. IR absorption spectra of abnormal tissues and normal tissues are compared by lipid (2800 - 3000 cm–1), protein (1500 - 1700 cm–1), and nucleic acids (1000 - 1250 cm–1) regions [2]. One of the mucous membrane lesions of the mouth is leukoplakia. This change has a “fingerprint region” in the range of 900 - 1800 cm–1 [3]. Raman spectroscopy has high potential of medical diagnosis. This method is a molecular specific technique that can be used to develop a fundamental biochemical understanding of tissue physiology and pathology. Both methods are dedicated to screening of preneoplastic and neoplastic tissues and have a potential to reduce morbidity of leucoplakia and oral cancers. Obtained data suggested that these infrared techniques are applicable to biomedical and clinical diagnostics.展开更多
The characterization of Indian bituminous and subbituminous coal was performed by UVVisible– NIR spectroscopy. Chemical leaching with varying concentration of hydrofluoric acid was conducted on both the samples. Elec...The characterization of Indian bituminous and subbituminous coal was performed by UVVisible– NIR spectroscopy. Chemical leaching with varying concentration of hydrofluoric acid was conducted on both the samples. Electronic absorption at this region was higher for higher ranked coals. Chemical leaching increased electronic transitions in subbituminous coal with maximum transitions for HF (10%) leached samples. The absorption maximum of benzeneoxygen system was found between 235-270 nm and was showing a red shift with leaching. The characteristic naphthalene ring systems (220 & 280 nm) were masked by the absorption regions of monoaromatic rings;indicating the content of napthalenoid hydrocarbon was very low. The bands observed in the visible region (450nm) were attributed to SO2 in the sample and was showing a red shift. The weak band at the 680 nm was attributed to the Ⅱ-Ⅱ* electronic transitions of the polynuclear aromatic hydrocarbons which also showed red shift with leaching. It was found that the ash content is reduced by 87.5% & 76.2% in bituminous and subbituminous coal respectively with HF (30%) leaching.展开更多
We use several spectral vegetation indices obtained from UV-VIS-NIR spectroscopy to non-destructively evaluate chlorophyll, anthocyanin and flavonoid content in okra plants irradiated with 3 different artificial light...We use several spectral vegetation indices obtained from UV-VIS-NIR spectroscopy to non-destructively evaluate chlorophyll, anthocyanin and flavonoid content in okra plants irradiated with 3 different artificial light spectra in the blue, green and red regions of the electromagnetic spectrum;thus leading us to assess the effects of specific wavelength on the plants’ biochemical compounds and physiological state. The results show that blue light gives the highest anthocyanin and chlorophyll content, whereas the highest flavonoid content is found under red light. Therefore, these biochemical compounds with a well-known impact on human health, may be adjusted by selecting specific wavelengths to improve the quality of plants.展开更多
文摘In this paper, a double artificial neural network （DANN） algorithm was used to parse near infrared （NIR） reflectance spectrum of Cofrel medicines. The contents of benproperine phosphate, which is the effective ingredient in Cofrel medicines, were accurately nondestructive quantitatively predicted. Compared the results with those of HPLC, the relative errors （RE %） were less than 0.18%. The analytical results could be applied to qualitative control of Cofrel medicines.
文摘It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are in their shells, it would save lot of labor and money spent in shelling and cleaning the nuts. Grain and nuts absorb low levels of NIR, and when NIR radiation is incident on them, a substantial portion of the radiation is reflected back. Thus, studying the NIR reflectance spectra emanating from in-shell peanuts, an attempt is made for the first time to determine the MC of in-shell peanuts. In-shell peanuts of two different market types, Virginia and Valencia, were conditioned to different moisture levels between 6% and 26% (wet basis), and separated into calibration and validation groups. NIR absorption spectral data from 1000 nm to 2500 nm in 1 nm intervals were collected from both groups. Measurements were obtained on 30 replicates within each moisture level. Reference MC values for each moisture level in these groups were obtained using standard air-oven method. Partial Least Square (PLS) analysis was performed on the calibration data, and prediction models were developed. The Standard Error of Calibration (SEC), and R2 of the calibration models were computed to select the best calibration model. The selected models were used to predict the moisture content of peanuts in the validation sets. Predicted MC values of the validation samples were compared with their standard air-oven moisture values. Goodness of fit was determined based on the lowest Standard Error of Prediction (SEP) and highest R2 value obtained for the prediction models. The model, with reflectance plus normalization spectral data with an SEP of 0.74 for Valencia and 1.57 for Virginia type in-shell peanuts was selected as the best model. The corresponding R2 values were 0.98 for both peanut types. This work establishes the possibility of sensing MC of intact in-shell peanuts by NIR reflectance method, and would be useful for the peanut and allied industries.
基金Project supported by the National Natural Science Foundation of China(No.30825027)the National Key Technology R&D Program of China(No.2006BAD11A12)
文摘The near infrared （NIR） spectroscopy technique has been applied in many fields because of its advantages of simple preparation, fast response, and non-destructiveness. We investigated the potential of NIR spectroscopy in diffuse reflectance mode for determining the soluble solid content （SSC） and acidity （pH） of intact loquats. Two cultivars of loquats （Dahongpao and Jiajiaozhong） harvested from two orchards （Tangxi and Chun＇an, Zhejiang, China） were used for the measurement of NIR spectra between 800 and 2500 nm. A total of 400 loquats （100 samples of each cultivar from each orchard） were used in this study. Relationships between NIR spectra and SSC and acidity of loquats were evaluated using partial least square （PLS） method. Spectra preprocessing options included the first and second derivatives, multiple scatter correction （MSC）, and the standard normal variate （SNV）. Three separate spectral windows identified as full NIR （800-2500 nm）, short NIR （800-1100 rim）, and long NIR （1100-2500 nm） were studied in factorial combination with the preprocessing options. The models gave relatively good predictions of the SSC of loquats, with root mean square error of prediction （RMSEP） values of 1.21, 1.00, 0.965, and 1.16 °Brix for Tangxi-Dahongpao, Tangxi-Jiajiaozhong, Chun＇an-Dahongpao, and Chun＇an-Jiajiaozhong, respectively. The acidity prediction was not satisfactory, with the RMSEP of 0.382, 0.194, 0.388, and 0.361 for the above four loquats, respectively. The results indicate that NIR diffuse reflectance spectroscopy can be used to predict the SSC and acidity of loquat fruit.
基金supported by the National Basic Research Program of China(Grant No.2014CB932300)the National Natural Science Foundation of China(Grant Nos.51222210+1 种基金51472268,and 11234013)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09010300)
文摘Cation-anion interaction with different ratios of salt to solvent is investigated by FT-Raman spectroscopy. The fitting result of the C-N-C bending vibration manifests that the cation-anion coordination structure changes tremendously with the variation of salt concentration. It is well known that lithium-ion transport in ultrahigh salt concentration electrolyte is dramatically different from that in dilute electrolyte, due to high viscosity and strong cation-anion interaction. In ultrahigh salt concentrated ＂solvent-in-salt＂ electrolyte （SIS-7#）, we found, on one hand, that the cation and anion in the solution mainly formed cation-anion pairs with a high Li＋ coordination number （〉 1）, including intimate ion pairs （20.1%） and aggregated ion pairs （79.9%）, which not only cause low total ionic conductivity but also cause a high lithium transference number （0.73）. A possible lithium transport mechanism is proposed： in solvent-in-salt electrolytes, lithium ions＇ direct movement presumably depends on Li-ion exchange between aggregated ion pairs and solvent molecules, which repeats a dissolving and re-complexing process between different oxygen groups of solvent molecules.
文摘NIR spectroscopy was used to measure the moisture concentration of wood pellets. Pellets were conditioned to various moisture levels between 0.63% and 14.16% (wet basis) and the moisture concentration was verified using a standard oven method. Samples from various moisture levels were separated into two groups, as calibration and validation sets. NIR absorption spectral data from 400 nm to 2500 nm with 0.5 nm intervals were collected using pellets within the calibration and validation sample sets. Spectral wavelength ranges were taken as independent variables and the MC of the pellets as the dependent variable for the analysis. Measurements were obtained on 30 replicates within each moisture level. Partial Least Square (PLS) analysis was performed on both raw and preprocessed spectral data of calibration set to determine the best calibration model based on Standard Error of Calibration (SEC) and coefficient of multiple determinations (R2). The PLS model that yielded the best fit was used to predict the moisture concentration of validation group pellets. Relative Percent Deviation (RPD) and Standard Error of Prediction (SEP) were calculated to validate goodness of fit of the prediction model. Baseline and Multiple Scatter Corrected (MSC) reflectance spectra with 1st derivative model gave the highest RPD value of 4.46 and R2 of 0.95. Also it’s SEP (0.670) and RMSEP (0.782) were less than the other models those had RPD value more than 3.0 with less number of factors. Therefore, this model was selected as the best model for moisture content prediction of wood pellets.
文摘Presenteeism refers to impaired performance attributed to attending work with health problems. There has been no study examining the state of presenteeism with objective measures. We compared cerebral hemodynamic changes, measured by near-infrared spectroscopy (NIRS), during neuropsychological tests conducted by university students with presenteeism and healthy controls. Twenty-two university students participated in the study;11 of them with impaired performance caused by mental health problem were allocated to the presenteeism group and 11 without health problems to the control group. Presenteeism was assessed by the Presenteeism Scale for Students. To evoke hemodynamics changes, the participants completed a Word Fluency Test (WFT) and a Trail Making Test (TMT). The NIRS probes were located over the bilateral prefrontal area. Students with presenteeism had significantly higher incidences of depression than controls. However, there was no significant difference in behavioral performance examinations between the two groups. With regard to hemodynamics changes, the repeated measures analysis of covariance of the NIRS signals revealed significant interactions between group and task activation. Although we observed a significant increase in oxygenated hemoglobin concentration during the WFT among controls (simple main effect;left channel, F(1, 19) = 27.34, P F(1, 19) = 22.05, P < 0.001), no changes were found in students with presenteeism during either the WFT (simple main effect;left channel, F(1, 19) = 0.12, P F(1, 19) = 0.08, P t = ﹣0.94, P with Bonferroni correction = 0.745;right channel, t = ﹣2.19, P with Bonferroni correction < 0.113). This is the first study to reveal differences in activity in the cerebral cortex associated with presenteeism. The fact that students with presenteeism have prefrontal dysfunction might reinforce the concept of presenteeism.
基金support of the National Key Research and Development Program of China (Grant Numbers 2021YFB3201200 and 2021YFB3201202)the Shandong Province Natural Science Foundation (Grant Numbers ZR2021QB177 and ZR2022QB205).
文摘Human serum albumin(HSA)is the most abundant protein in plasma and plays an essential physiological role in the human body.Ethanol precipitation is the most widely used way to obtain HSA,and pH and ethanol are crucial factors affecting the process.In this study,infrared(IR)spectroscopy and near-infrared(NIR)spectroscopy in combination with chemometrics were used to investigate the changes in the secondary structure and hydration of HSA at acidic pH(5.6-3.2)and isoelectric pH when ethanol concentration was varied from 0%to 40%as a perturbation.IR spectroscopy combined with the two-dimensional correlation spectroscopy(2DCOS)analysis for acid pH system proved that the secondary structure of HSA changed significantly when pH was around 4.5.What's more,the IR spectroscopy and 2DCOS analysis showed different secondary structure forms under different ethanol concentrations at the isoelectric pH.For the hydration effect analysis,NIR spectroscopy combined with the McCabe-Fisher method and aquaphotomics showed that the free hydrogen-bonded water fluctuates dynamically,with ethanol at 0-20%enhancing the hydrogen-bonded water clusters,while weak hydrogen-bonded water clusters were formed when the ethanol concentration increased continuously from 20%to 30%.These measurements provide new insights into the structural changes and changes in the hydration behavior of HSA,revealing the dynamic process of protein purification,and providing a theoretical basis for the selection of HSA alcoholic precipitation process parameters,as well as for further studies of complex biological systems.
文摘FT-Raman spectroscopy was used to monitor the polymerization of acrylic acid in aqueous solution. A simple method to avoid the noise in the background during the signal processing via Fourier transformation was used in this work. The effects of the amount of initiator used on the polymerization are studied. When the amount of the initiator in the polymerization was increased, both the rate and extent of polymerization of acrylic acid will be increased.
文摘Cowpea (Vigna unguiculata L. Walp) is a multi-purpose legume with high quality protein for human consumption and livestock. The objective of this work was to develop near-infrared spectroscopy (NIRS) prediction models to estimate protein content in cowpea. A total of 116 cowpea breeding lines with a wide range of protein contents (19.28 % to 32.04%) were selected to build the model using whole seed and ground seed samples. Partial least-squares discriminant analysis (PLS-DA) regression technique with different pre-treatments (derivatives, standard normal variate, and multiplicative scatter correction) were carried out to develop the protein prediction model. Results showed: 1) spectral plots of both the whole seed and ground seed showed higher spectral scatter at higher wavelengths (>1450 nm), 2) data pre-processing affects prediction accuracy for bot whole seed and ground seed samples, 3) prediction using ground seed samples (0.64 R<sup>2</sup> 0.85) is better than the whole seed (0.33 R<sup>2</sup> 0.78), and 4) the data pre-processing second derivative with standard normal variate has the best prediction (R<sup>2</sup>_whole seed = 0.78, R<sup>2</sup>_ground seed = 0.85). The results will be of interest in cowpea breeding programs aimed at improving total seed protein content.
文摘The wireless distributed acquisition system for near infrared spectrosecopy(WDA-NIRS)is a portable,ultra-compact,contimuous wave(CW)NIRS system.Its main advantage is that it allows continuous synchronized multi-site hemodynarnic monitoring.The WDA-NIRS syster calculates online changes in hemoglobin concentration based on modifed Beer-Lambert law and the tissue oxy genation index based on the spatial resolved spectroscopy method.It consists of up to seven signal acquisition units,sufficiently small to be easily attached to any part of the body.These units are remotely synchronized by a PC base station for independent acquisition of NIRS signals.Each acquisition module can be freely adapted to individual requirements such as local skin properties and the microcirculation of interest,e.g,different muscles,brain,skin,etc.For this purpose,the light emitted by each LED can be individually,interactively or automatically adjusted to local needs.Furthermore,the user can freely create an emitter time multiplexing protocol and choose the detector sensitivity most suitable to a particular situation.The potential diagnostic value of this advanced device is demonstrated by three typical applications.
文摘Near infrared spectroscopy (NIRS) is a method for non-invasive monitoring of cerebral oxygenation and haemodynamics. Different devices provide information on changes of oxygenated (HbO2) and deoxygenated haemoglobin (HHb), oxidized cytochrome aa3 (CytOx) or regional oxygen saturation (rSO2). NIRS has been used during adult and paediatric cardiac surgery.
文摘Depression has been known to reduce the prefrontal activity associated with the execution of certain cognitive tasks, although whether a temporarily depressed or anxious mood in healthy individuals affects the prefrontal blood oxygen level during cognitive tasks is unknown. Combining the measurement of prefrontal activity with near-infrared spectroscopy (NIRS) and the two cognitive tasks, namely the letter version of the verbal fluency test (VFT-l) and the Stroop test, we measured the effect of a depressed or anxious mood and gender on the changes in the prefrontal oxygenated hemoglobin (Oxy-Hb) levels during those cognitive tests in healthy individuals. Depressed mood or anxious mood was assessed by the Hospital Anxiety and Depression Scale (HADS). Thereby we aimed to explore the possibility of NIRS measurement for detecting the early subclinical manifestation of major depression. Moreover, we examined the possible relationships between prefrontal activation and the functional Val66Met polymorphisms of the brain derived neurotropic factor (BDNF) gene and serum BDNF level. As a result, the increased prefrontal Oxy-Hb levels during cognitive tasks were significantly correlated with the severity of depressed mood in males. The course of the prefrontal Oxy-Hb increase was different depending on the cognitive tasks, i.e., the VFT-l or the Stroop test, in both genders. Correlations of BDNF genotype and serum BDNF level with the prefrontal Oxy-Hb levels during those cognitive tasks were negative. Our results suggest that the early subclinical manifestation of depressed mood in males might be detected by the NIRS measurement, which is not correlated with the individual properties of BDNF.
文摘In this paper,the Fourier transform near-infrared(FTNIR)diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares(PLS)regression is successfully used as an effective multivariate calibration technique.The calibration set is composed of 20 standard millet samples that the protein contents were determined by the traditional Kjeldahl method.The optimal model dimension is found to be 5 by cross-validation.22 millet samples were determined by the proposed FTNIR-PLS method.The correlation coefficient between the concentration values obtained by the FTNIR-PLS method and the traditional Kjeldahl method is 0.9805.The standard error of prediction(SEP)is 0.28% and the mean recovery is 100.2%.The proposed method has been successfully applied for the routine analysis of protein in about 10,000 grain samples.
文摘Filtration processes are worldwide used for sterilizing solutions and substrates. Filtration seems to induce the formation of aqueous nanostructures. The aim of this work was to verify the influence of filtration processes on water structure detected by spectral variations in NIR region. Samples of ultrapure water （MilliQ-Millipore, Vimodrone, Milan, Italy） before and after iterated filtrations were analyzed. NIR spectra were collected in transmission mode in the whole NIR range, by using NIRFIex N500 spectrometer at constant temperature （40 ± 1 ℃）. NIR data were processed using Unscrambler software v. 9.2 in evaluating qualitative differences between filtered and not filtered samples. The information related to possible solvent physical stresses were highlighted in the range 6500-7500 cm^-1. The shifts observed were ascribable to a different distribution of the number of water molecules involved in hydrogen bonds in filtered and not filtered water samples, at constant temperature. NIR spectroscopy, commonly used to study relationship between spectral changes and hydrogen bonds in water at increasing temperature values, was applied to evaluate effects of filtration processes on water structure. The obtained results are in agreement with literature data and allowed the improvement of the knowledge about pure water characteristics when some mechanical perturbations are applied.
基金Supported by the Major State Basic Research Development Program( G2 0 0 0 0 7810 2 ) and the National Natural ScienceFoundation of China( No.2 0 0 0 3 0 0 4)
文摘The orientation and structural characterization of the ultrathin film of azobenzene-containing amphiphilic compound, C_ 12AzoNaph(1,4)C_6N +Br -, were studied in the present study. The compound can form a stable monolayer with sodium dextrin sulfate(SDS) by means of electrostatic interaction. Fourier-transform infrared(FT-IR) and near-infrared surface-enhanced Raman scattering(NIR-SERS) spectroscopies were used to study the orientation and characterize the structure of the Langmuir-Blodgett(LB) film and the dipping film. The FT-IR spectra indicate that the alkyl tail is nearly perpendicular to the substrate surface without any aggregation and adopts largely trans-zigzag conformation in the LB film. The NIR-SERS spectra demonstrate that the chromorphoric part in C_ 12AzoNaph(1,4)C_6N +Br is also nearly perpendicular to the surface of silver substrate both in the dipping film and the LB film. A new 'sandwiched system' model was designed to investigate the orientation and structural characterization of the chromophoric part in the multi-monolayer LB films on the non-SERS active substrate. The SERS mechanism of the 'sandwiched system' is discussed in the present paper.
文摘Nowadays, biomedicine development is caused by the necessity of fast premalignant and malignant diagnosis. In the case of cancer, it is important to identify degree of tumor’s malice. We investigated the differences of Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) and FT-Raman spectroscopy between leukoplakia, oral cancer and normal tissues. Human tissue contains many compounds with known absorption spectra in the range of Near Infrared (NIR) spectroscopy. These compounds have a fingerprint region, which permits their characterization. FTIR spectroscopy is a promising diagnostic tool. There is ability to detect skin, cervix, prostate, breast, esophagus, stomach, bladder and oral cancers [1]. Imaging using FTIR microscope allows analysis of biochemical compounds in microregions of biological materials. FTIR microspectroscopy is the perfect technique for tissues and individual cells analysis [1]. It delivers information about biochemistry of cell or tissue samples and has been applied in many areas of medical research [2]. IR absorption spectra of abnormal tissues and normal tissues are compared by lipid (2800 - 3000 cm–1), protein (1500 - 1700 cm–1), and nucleic acids (1000 - 1250 cm–1) regions [2]. One of the mucous membrane lesions of the mouth is leukoplakia. This change has a “fingerprint region” in the range of 900 - 1800 cm–1 [3]. Raman spectroscopy has high potential of medical diagnosis. This method is a molecular specific technique that can be used to develop a fundamental biochemical understanding of tissue physiology and pathology. Both methods are dedicated to screening of preneoplastic and neoplastic tissues and have a potential to reduce morbidity of leucoplakia and oral cancers. Obtained data suggested that these infrared techniques are applicable to biomedical and clinical diagnostics.
文摘The characterization of Indian bituminous and subbituminous coal was performed by UVVisible– NIR spectroscopy. Chemical leaching with varying concentration of hydrofluoric acid was conducted on both the samples. Electronic absorption at this region was higher for higher ranked coals. Chemical leaching increased electronic transitions in subbituminous coal with maximum transitions for HF (10%) leached samples. The absorption maximum of benzeneoxygen system was found between 235-270 nm and was showing a red shift with leaching. The characteristic naphthalene ring systems (220 & 280 nm) were masked by the absorption regions of monoaromatic rings;indicating the content of napthalenoid hydrocarbon was very low. The bands observed in the visible region (450nm) were attributed to SO2 in the sample and was showing a red shift. The weak band at the 680 nm was attributed to the Ⅱ-Ⅱ* electronic transitions of the polynuclear aromatic hydrocarbons which also showed red shift with leaching. It was found that the ash content is reduced by 87.5% & 76.2% in bituminous and subbituminous coal respectively with HF (30%) leaching.
文摘We use several spectral vegetation indices obtained from UV-VIS-NIR spectroscopy to non-destructively evaluate chlorophyll, anthocyanin and flavonoid content in okra plants irradiated with 3 different artificial light spectra in the blue, green and red regions of the electromagnetic spectrum;thus leading us to assess the effects of specific wavelength on the plants’ biochemical compounds and physiological state. The results show that blue light gives the highest anthocyanin and chlorophyll content, whereas the highest flavonoid content is found under red light. Therefore, these biochemical compounds with a well-known impact on human health, may be adjusted by selecting specific wavelengths to improve the quality of plants.
