Lilo, TahaMorais, Camilo L. M.Ashton, Katherine M.Davis, Charles...
8页
查看更多>>摘要：Meningiomas remains a clinical dilemma. They are the commonest "benign" types of brain tumours and, although being typically benign, they are divided into three WHO grades categories (I, II and III) which are associated with the tumour growth rate and likelihood of recurrence. Recurrence depends on extend of surgery as well as histopathological diagnosis. There is a marked variation amongst sur-geons in the follow-up arrangements for their patients even within the same unit which has a signif-icant clinical, and financial implication. Knowing the tumour grade rapidly is an important factor to predict surgical outcomes and adequate patient treatment. Clinical follow up sometimes is haphazard and not based on clear evidence. Spectrochemical techniques are a powerful tool for cancer diagnos-tics. Raman hyperspectral imaging is able to generate spatially-distributed spectrochemical signatures with great sensitivity. Using this technique, 95 brain tissue samples (66 meningiomas WHO grade I, 24 meningiomas WHO grade II and 5 meningiomas that reoccurred) were analysed in order to dis-criminate grade I and grade II samples. Newly-developed three-dimensional discriminant analysis algorithms were used to process the hyperspectral imaging data in a 3D fashion. Three-dimensional principal component analysis quadratic discriminant analysis (3D-PCA-QDA) was able to distinguish grade I and grade II meningioma samples with 96% test accuracy (100% sensitivity and 95% specificity). This technique is here shown to be a high-throughput, reagent-free, non-destructive, and can give accurate predictive information regarding the meningioma tumour grade, hence, having enormous clinical potential with regards to being developed for intraoperative real-time assessment of disease. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Disrelation mapping was applied to Raman imaging data for the first time to investigate submolecularlevel variations that occurred at the interface between glass fiber (GF) and polypropylene (PP). Disrelation maps constructed with Raman spectra provided spatial as well as spectral information, which are not readily accessible from hypercubic data. For example, patterns that appeared in the disrelation maps showed the predominant development of a long helix band (1002 cm-1) at the interface between the GF and PP, rather than a short helix band (974 cm-1). The development of the disrelation intensity was observed inside the sample as well as at the surface. These results clearly reveal that the GF or compatibilizer works intrinsically as a nucleating agent to induce additional development of the crystalline structure of the PP, which eventually makes the polymer system harder but more brittle. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Nitroreductase (NTR) detection in tumor is critical because NTR level is correlated with hypoxia degree and cancer prognosis. With the feature of high sensitivity and selectivity, fluorescence organic probes for NTR detection exhibited a promising future for tumor hypoxia detection. However, the discovery and design of such probes have been impeded due to the lack of the understanding of spatial match and mismatch of these probes with NTR. Here, we have developed two new nitrophenyl-functionalized trimethincyanine (Cy3) probes with para-or meta-positions of nitro-group in phenyl ring. Paranitrophenyl substituted Cy3 (pNP-Cy3) exhibited a remarkable response to NTR (20-fold fluorescence enhancement) with good selectivity and sensitivity. Experimental and theoretical analysis verified that the substituent position of nitro group on phenyl ring of dyes altered the spatial arrangement of nitrosubstituent group, thereby modulated the spatial match and mismatch between Cy3 dyes and binding domain of NTR, and consequently led to a different fluorescent turn-on response. In tumor-bearing mice model, hypoxia status of A549 xenografted tumor of mice was successfully delineated by using pNP-Cy3. These results may provide a clue for designing new cyanine-derived NTR probe to monitor NTRoverexpressed hypoxia cancer cells.(c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Fluorogenic chemosensors using pyridoxal derivatized ligands as fluorophore is a rapidly growing field of research. Here we report a new Fe(III) complex, [Fe(HBala-pydx)(Bala-pydx)] (H(2)Bala-pydx is the Schiff base of pyridoxal with beta-alanine), which can serve as a sensitive and selective turn-on fluorescent sensor for the detection of cyanide(CN-) in micromolar concentrations (L.O.D. is 1.134 mu M), via the ligand displacement approach, in aqueous-acetonitrile medium. The Fe(III) complex is adequately characterized by analytical and spectroscopic methods along with X-ray crystal structure determination. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Pure fishmeal (PFM) from whole marine-origin fish is an expensive and indispensable protein ingredient in most aquaculture feeds. In China, the supply shortage of domestically produced PFM has caused frequent PFM adulteration with low-cost protein sources such as feather meal (FTM) and fishmeal from by-products (FBP). The aim of this study was to develop a rapid and nondestructive detection method using near-infrared hyperspectral imaging (NIR-HSI) combined with machine learning algorithms for the identification of PFM adulterated with FTM, FBP, and the binary adulterant (composed of FTM and FBP). A hierarchical modelling strategy was adopted to acquire a better classification accuracy. Partial least squares discriminant analysis (PLS-DA) and support vector machine (SVM) coupled with four spectral preprocessing methods were employed to construct classification models. The SVM with baseline offset (BO-SVM) model using 20 effective wavelengths selected by successive projections algorithm (SPA) and competitive adaptive reweighted sampling (CARS) achieved classification accuracy of 100% and 99.43% for discriminating PFM from the adulterants (FTM, FBP) and adulterated fishmeal (AFM), respectively. This study confirmed that NIR-HSI offered a promising technique for feed mills to identify AFM containing FTM, FBP, or binary adulterants. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Hydrogen sulfide (H2S), one of redox-active sulfur species, is known as a signaling molecule and an antioxidant in biological tissues to maintain cellular functions. The development of selective and sensitive H2S detection is important to understand the role of H2S in vivo. Herein, a new two-photon probe NNE was developed to detect hydrogen sulfide using 6-acetyl-N-methyl-2-naphthylamine with an attachment of 7-nitrobenzo-oxadiazole. The probe NNE exhibits high selectivity towards hydrogen sulfide over other anions. Nucleophilic substitution of H2S leads to a turn-on response with 28-fold enhance-ment in quantum yield (from 0.004 to 0.117). NNE shows a high sensitivity towards hydrogen sulfide with an extremely low detection limit at 6.8 nM. Furthermore, the probe NNE exhibits two-photon excited fluorescence, making it a suitable probe for monitoring H2S distribution in live cells and tissues without background fluorescence interference. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Recently, ionic liquids (ILs) have attracted attention as prospective electrolytes for Li-ion batteries, with safe performance. Herein, the dynamics of the IL at the electrochemical interface, which is the key to the electrochemical reaction, was monitored using attenuated total reflectance far- and deep-ultraviolet (ATR-FUV-DUV) spectroscopy. An original measurement system, which combined an ATR-FUV-DUV spectrometer with a Kretschmann type (fully metal-coated prism) electrochemical setup, was assembled. Spectral measurements and assignments were performed for the 1-ethyl-3-methylimidazolium bis(tri fluoromethanesulfonyl)imide ([EMIM][TFSI])/Pt electrode (similar to 7 nm) interface. The incident light in the FUV and DUV regions entered a measurement system comprising an [EMIM][TFSI]/Pt electrode/ATR sapphire prism, and the potential-dependent absorption spectra were measured in the 180-450 nm range. This in-situ spectroscopic technique is unique in that the electronic transition spectra of the interfacial IL can be obtained. By switching the applied potentials, temporal spectral changes (i.e. relaxation signals) were tracked at wavelengths of 450 nm and 221 nm, where the direct electronic absorption of the IL was active and inactive, respectively. Comparing these relaxation times, it was revealed that the absorption signal at 221 nm changed more slowly than that at 450 nm. This indicated that the molecular conformations that affected the electronic absorption of the interfacial ILs changed slowly. Considering the surface-normal dipole selection rule for molecules on a metal surface, it is suggested that the slow changes in the molecular conformations can be ascribed to the potential-dependent interfacial orientations of [EMIM](+). (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Polycystic ovarian syndrome (PCOS) is a disease, which causes infertility in women. The factors for the development of the disease are still not well understood and diagnostic methods need to be improved. Therefore, in this study, Raman spectroscopy as a potential diagnostic tool, was investigated and spectra of blood serum were collected from PCOS and healthy women. The obtained spectra showed distinct changes in intensities as well as shift of peaks for the blood serum collected from PCOS compared to healthy individuals. Partial Last Square (PLS) analysis and Principal Component Analysis (PCA) allowed to determine that Raman shifts of amides (1500 - 1700 cm(-1)) and CH2, CH3 lipid groups (2700 - 3000 cm(-1)), could be thus used as potential PCOS markers. Furthermore, the Pearson correlation test showed a strong correlation between hormones (lutropin (LH), prolactin (PRL), follicle-stimulating (FSH), dehydroepiandrosterone (DHEAS), thyroid-stimulating (TSH), Estradiol) and lipids, as well as between hormones and protein functional groups in PCOS women, compared to the control. These results show, that the lipid and protein balance could be potentially applied as a helpful PCOS marker in Raman spectra. (C) 2022 Elsevier B.V. All rights reserved.
Khashaba, Pakinaz Y.Abdelgaleel, MahmoudDerayea, Sayed M.Nagy, Dalia M....
6页
查看更多>>摘要：A new sensitive spectrofluorimetric technique has been established for the estimation of midodrine hydrochloride. This method depends on the condensation reaction of ortho-phthalaldehyde with the primary aliphatic amine of midodrine in the presence of 2-mercapto-ethanol. The pH of the medium was adjusted to 9.0 using 0.1 M borate buffer. The fluorescence of the product was measured at wavelength of 451 nm after excitation at 334 nm. The method was rectilinear over a concentrations range of 0.1 to 1.5 mu g mL(-1). The lower detection and quantitation limits were 31 and 94 ng mL(-1), respectively. The method was investigated following the guidelines of the International Council of Harmonization. Analysis of commercial tablet dosage form was carried out successfully by the current method with excellent recovery percentages and with no influence from coexisted pharmaceutical additives .This method was used to evaluate the uniformity of the contents of commercial tablets according to the United States Pharmacopoeia. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Hypochlorous acid (HOCl), one of the most important ROS in living organisms, appears to serve an important role in the immune system in vivo. Endoplasmic reticulum (ER), the largest organelle in cells, manages many biological processes connected to vital activities. To better obtain insight into the relationship of ER stress and HOCl level, a ratiometric fluorescent probe RHE, based on rhodamine combined with HBT and ER-targeting group, was designed and synthesized for HOCl detection in the ER. Probe RHE shows a large stokes shift about 155 nm, which is derived to ESIPT principle. In addition, probe RHE exhibited excellent properties such as fast response (<80 s), high sensitivity with a low detection limit (40 nM), high selectivity and anti-interference. Moreover, probe RHE displayed an excellent ER-targeting ability and had been successfully applied for detection of exogenous and endogenous HOCl in HepG2 cells.(c) 2022 Elsevier B.V. All rights reserved.
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