查看更多>>摘要：Wild mushroom market is an important economic source of Yunnan province in China, and its wild mushroom resources are also valuable wealth in the world. This work will put forward a method of species identification and optimize the method in order to maintain the market order and protect the economic benefits of wild mushrooms. Here we establish deep learning (DL) models based on the two-dimensional correlation spectroscopy (2DCOS) images of near-infrared spectroscopy from boletes, and optimize the identification effect of the model. The results show that synchronous 2DCOS is the best method to establish DL model, and when the learning rate was 0.01, the epochs were 40, using stipes and caps data, the identification effect would be further improved. This method retains the complete information of the samples and can provide a fast and noninvasive method for identifying boletes species for market regulators. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The dielectric characteristics in the terahertz region contribute to a revealing insight into the material components and provide intermolecular information. The dielectric properties of adulterated honey, described as the real and imaginary parts of the complex dielectric constant (Re[epsilon] and Im[epsilon]), were obtained from 0.3 to 1.5 THz. The relationship between invert syrup proportions and complex dielectric constants at different frequencies implied the possibility of using the dielectric property as an indicator of honey authenticity. The selected effective dielectric variables of Re[epsilon] and Im[epsilon] and their combination were chosen by stability competitive adaptive reweighted sampling (SCARS) algorithm and then used to establish PLS models. The accuracy and uncertainty result revealed SCARS-PLS model based on the combination of Re[epsilon] and Im[epsilon] is the best model relatively. These findings indicated the potential utility of this rapid, non-destructive, and on-site method for authenticity verification. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Traumatic brain injury (TBI) is one of the most common mechanical injuries and plays a significant role in forensic practice. For cadavers, however, accurate diagnosis of TBI becomes a more and more challenging task as the level of decomposition increases. Our main purpose was to investigate whether TBI in putrefied mouse cadavers can be identified by Fourier Transform Infrared (FT-IR). The method proposed by Feeney et al. was used to establish the mouse TBI model. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) modeling were used to distinguish fresh and putrefied brain tissues. Then, we established two PLS-DA models to identify injured area samples in fresh and putrefied brain tissue samples. The accuracy of the two models were 100% and 92.5%. Our preliminary research has proved that the use of FT-IR spectroscopy combined with chemometrics can identify TBI more quickly and accurately in cadavers, providing crucial evidence for judicial proceedings. (c)(C)2022 Published by Elsevier B.V.
查看更多>>摘要：Cysteine serves a wide range of important biological and chemical functions and may have an association to neurodegenerative disease and cancer. Rapid, accurate analytical methods for cysteine detection are thus highly desirable. In this work, we report an investigation into the utility of in situ Raman spec-troscopy as a Process Analytical Technology (PAT) for real time monitoring of cysteine. Cysteine concen-trations are tracked in real time using Raman spectroscopy across a range of pharmaceutically-relevant concentrations, demonstrating the capability of Raman spectroscopy detection for in situ cysteine mon-itoring. The concentration range over which this analytical methodology can be applied is successfully established. As such, the results herein serve as a proof-of-principle investigation to demonstrate and evaluate the capabilities of a real time Raman spectroscopic approach for in situ cysteine detection, thus informing the range of important chemical and biological processes to which this approach can be applied. To the best of our knowledge, this is the first report of in situ Raman spectroscopy for real time monitoring of dynamically changing cysteine process concentrations.(c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：As a highly toxic reagent, hydrazine (N2H4) is notorious to human beings and the environment. To simply and conveniently detect N2H4 in environmental and biological systems, a ratiometric fluorescent probe MA-N2H4 was developed with excellent sensitivity and selectivity. Probe MA-N2H4 was readily prepared based on a naphthalene as the fluorescent scaffold and an indanedione group as the responsive moiety for N2H4. This probe displayed a red-emitting fluorescence at 670 nm with a large Stokes shift (200 nm). After treatment with N2H4, a significant blue-shifted emission at 440 nm could be observerd, which led to an extremely large emission wavelength shift (230 nm). The fluorescent intensity ratio (I-440/I-670) of probe MA-N2H4 was rapidly and significantly increased (273-fold) within 18 min. The detection limit for N2H4 was 0.5 mM. In addition, the probe was successfully employed for tracking N2H4 in living cells and zebrafish through a ratiometric manner.& nbsp;(C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The combination of olanzapine and samidorphan has just been authorised for the treatment of schizophrenia. The current study created a very accurate, sensitive and selective spectroscopic technique based on the first derivative of synchronous fluorescence for determining olanzapine and samidorphan in their pharmaceutical prescriptions without prior separation. For the quantitative analysis of samidorphan and olanzapine, the adopted approach is focused on measuring the synchronised fluorescence intensity of the examined medicines at fixed wavelength range (Delta lambda) = 50 nm and the first derivative's peak magnitudes were observed at 300 and 350 nm, respectively. The effects of various factors on the synchronised fluorescence intensity of the referenced medications were researched and adjusted. Both medications' calibrating charts were shown to be linear throughout a range of concentrations of 0.1-1.1 mu g mL(-1). LOD for SAM and OLA were 0.02 and 0.01, respectively. In addition, LOQ was determined for SAM and OLA as follow, 0.07 and 0.06, respectively. The devised approach was effectively used to the quantitative measurement of the two medicines in Lybalvi (R) tablets with various samidorphan and olanzapine ratios, in addition to spiked human plasma. A variance ratio F-test and student t-test were needed to be able to compare the results to another published analytical technique and found no significant differences. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The development of fluorescence molecules for the fast and effective detection of L-tryptophan (L-Trp) has attracted a lot of attention because it is an important amino acid for baby growth, nitrogen equilibrium in adults, improving sleep, and mood regulation. A dimedone-phenylalanine-based chiral sensor (SDPA) was synthesized and exhibited a strong fluorescence quenching by Fe3+ and Cu2+ in a water/DMSO (3/7) solution with a detection limit of 2.29 x 10(-6) M and 6.37 x 10(-6) M, respectively. The factors affecting fluorescence sensings, such as the pH and competing cations, were studied. The sensor can be reused at least five times after being treated with EDTA. The Job plot, ESI-MS spectra, H-1 NMR spectra, absorbance, and fluorescence titration experiments were investigated to study the mechanism of SDPA-Fe3+ and SDPA-Cu2+ complexation. The SDPA-Cu2+ complex can detect L-tryptophan and L-cysteine at trace levels by turn-on fluorescence with a detection limit of 9.35 x 10(-6) M and 8.86 x 10(-6) M, respectively. Moreover, applying the SDPA-Cu2+ complex for quantitative analysis of L-tryptophan in real sleep-improving capsules resulted in good recovery. The L-tryptophan level of the Elining capsule was determined at 190.8 +/- 10.5 mg/g (mg L-tryptophan/g medicine), which is close to the announced quantity of 180 mg/g. Besides, the SDPA-Cu2+ complex can selectively detect free L-Try molecules and L-Try residues in proteins. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The formation of the uterus lining, i.e. the endometrium, outside the uterus (ex. in the abdominal cavity, ovaries, or anywhere in the body) is called endometriosis. The presence of endometrial tissue present in the ovaries, thickens after menstruation, leading to menstrual-like bleeding and to the formation of chocolate cyst (Endometrioma) because of the accumulation of old, brown blood in the ovary. It is still unknown, what triggers the development of endometrioma. However, it leads to excessive bleeding during menstrual periods or abnormal bleeding between periods and infertility. Endometriosis is often first diagnosed in those who seek medical attention for infertility. Therefore, new markers of endometrioma as well as new methods of its diagnosis are sought. In this study we used Raman spectra of serum collected from 50 healthy women and 50 women suffering from endometriosis. The obtained Raman data were used in multivariate analysis to determine the Raman range, which can be used for endometrioma diagnostics. Partial Least Square (PLS), Principal Component Analysis (PCA) and Hierarchical Component Analysis (HCA) showed, that it is possible to distinguish between the serum collected from healthy and un-healthy women using the Raman range between 800 cm-1 and 1800 cm-1 and between 2956 cm-1 and 2840 cm-1, while the first range corresponds to the fingerprint region and the second one to lipids vibrations. Consequently, the Pearson correlation test showed a significant positive correlation between values of lipid intensity in Raman spectra and volume of endometriomas. Summarizing,Raman spectroscopy can be a helpful tool in endometrioma diagnosis and the lipid vibrations are candidates for being a spectroscopic marker of the disease being studied. (c) 2022 Elsevier B.V. All rights reserved.
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