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Universal existence of fluorescent carbon dots in beer and assessment of their potential toxicity
摘要： Nanosized materials may produce adverse physiological effects or potential health risks due to their unique physical and chemical properties. Herein, the universal presence of fluorescent carbon dots (CDs) in commercial beers was confirmed through a systematic survey. The beer CDs were roughly spherically shaped in appearance and emitted bright blue fluorescence under ultraviolet light with quantum yields (QYs) ranging from 1.42% to 3.92%. Furthermore, digestion, biodistribution, and cytotoxicity assessments of CDs from Snow beer were conducted as an example. The CDs were significantly quenched during in vitro digestion. The dynamic distribution of CDs in mice showed that they easily accumulated in the intestine and liver, and more importantly, the beer CDs were found in the brain, which indicated that they were able to cross the blood–brain barrier. Acute toxicity of the beer CDs was evaluated using BALB/c mice, and the results revealed that the biochemical parameters of mice after administration of a single dose of 2 g kg?1 body weight were almost same as those of the control groups. Histological analysis showed no obvious organ damage in the tested mice. The in vitro results indicated that CDs dispersed onto both the cell membrane and the cytoplasm of MC3T3-E1 cells, alter the cell cycle progression, and caused cell apoptosis at high doses. This work reports the potential risk of CDs in beer and provides valuable information regarding CDs in food.
关键词： beer,cytotoxicity,biodistribution,Carbon dots,digestion
更新于2025-09-23 15:23:52
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Rare Earth Element || Optimisation of Parameters for Spectroscopic Analysis of Rare Earth Elements in Sediment Samples
摘要： The rapid demand for rare earth elements (REEs) in recent years due to increased use in various technological applications, agriculture, etc. has led to increased pollution and prevalence of REEs in the environment. Therefore, monitoring for REEs in the aquatic environment has become essential including the risk assessment to aquatic organisms. Since direct determination of REEs in sediment samples prove difficult at times, due to low concentrations available and complex matric effects, separation and enrichment steps are sometimes used. In this work, various REEs were determined employing wet acid digestion and lithium metaborate fusion in our optimised analytical technique. A com-parison of the two analytical techniques was also made. The results obtained from the optimised ICP-OES radial view technique were in 5% agreement with the ICP-MS results from the same samples. The accuracy of the method was checked with the geological ref-erence material GRE-03 and found to be in reasonable agreement. We demonstrated that there is a consistent relationship between the signals of the REEs and nebuliser gas flow rates, plasma power and pump speed. The detection limits for all the REEs ranged from 0.06 mg L-1 Yb to 2.5 mg L-1 Sm using the ICP-OES fusion technique.
关键词： spectroscopy optimization,rare earths elements,fusion digestion and sediment,lithium metaborate
更新于2025-09-23 15:21:21
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A potentially more eco-friendly chemical pathway for production of high purity TiO2 from titanium slag
摘要： TiO2 is an important inorganic material which is commercially produced by either the chloride or the sulfate process. In general, the latter has lower cost and lower entry barrier than the former. However, the environmental impact associated with the sulfate process is more visible than the chloride process because the sulfuric acid with a low concentration (~20 wt%) cannot be cost-effectively recycled; therefore, it has to be neutralized, generating a large amount of wet and useless red gypsum (RG). In this research, a potentially more eco-friendly chemical pathway for TiO2 production from concentrated titanium ore, aka titania slag, is presented. The new method consists of three critical steps including transformation of the titania slag to a lower valence titanium sub-oxide by aluminothermic reduction, digestion by using mild acid, and controlled hydrolysis accompanied by acid recycling. As a result of the phase transformation, the digestion of titanium from the titanium feedstock becomes easier such that it is feasible to use relatively mild acid to replace concentrated acid, reducing the environmental impact from the red gypsum because the need for neutralizing the waste acid can be eliminated. High purity hydrous TiO2 can be prepared after hydrolysis, and the spent liquor can be effectively recycled back to the digestion unit.
关键词： Aluminothermic reduction,Titania slag,Controlled hydrolysis,Titanium dioxide,Mild acid digestion
更新于2025-09-19 17:15:36
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Infrared attenuated total reflection spectroscopic analysis and quantitative detection of forage spectral features in ruminant systems
摘要： This study aimed to (1) access protein molecular structure profile and metabolic characteristics of model forages [Foreign sourced-origin (coded as: “FSO”, n = 7 vs. Chinese sourced-origin alfalfa hay “CSO”, n = 5] in ruminant systems; (2) Quantify the relationship between forage protein molecular structures and protein utilization and availability. Advanced non-invasive vibrational molecular spectroscopic technique (ATR-FTIR: Attenuated Total Reflection Fourier Transform Infrared spectroscopy) with chemometrics was applied to reveal forage protein molecular structure. Both univariate and multivariate molecular spectral analyses were applied to study molecular structure features in model forages. The molecular structure study provided the detailed protein structure profiles of Amide I and Amide II areas and height, total Amide I and II area ratios, Amide I to II height ratio as well as Amide I to II area ratio using ATR-FTIR spectroscopy. The results showed FSO and CSO had similar (P > 0.05) protein rumen degradation kinetics. However, FSO had superior quality than CSO in intestinal (IDP) and total digestible protein (TDP) and truly absorbed nutrient supply (P < 0.05). As intestinal digestion of protein, FSO was higher (P < 0.05) in protein digestion in terms of: intestinal digestibility of rumen undegraded protein (dIDP: 47.5 vs. 38.3 %RUP); Intestinal digestible protein (IDP: 17.6 vs. 13.7 %CP). As truly absorbed nutrient supply, FSO contained higher (P < 0.05) truly absorbed rumen synthesized microbial protein, absorbable rumen undegradable feed protein in the small intestine, total truly digested protein in the small intestine, metabolizable protein and Feed Milk Value (FMVDVE: 1.2 vs. 1.1 g/kg DM). The molecular structure-nutrition interactive relationship study showed that protein molecular structure profiles were highly associated to protein rumen degradation kinetics, significantly correlated to protein subfractions, protein intestinal digestion, and truly absorbed nutrient supply in ruminant systems.
关键词： Vibrational molecular spectroscopy-ATR-FTIR,Intestine digestion,Model forages,Truly absorbed protein supply,Rumen degradation,Protein molecular structure and conformation,Univariate and multivariate molecular spectral analyses
更新于2025-09-12 10:27:22
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8.78% Efficient All‐Polymer Solar Cells Enabled by Polymer Acceptors Based on a B←N Embedded Electron‐Deficient Unit
摘要： Mono-cardboard waste digestion in batch tests associated with different impact factors was investigated. The maximum methane generation was 394 mL/gVSadd with the best F/M of 0.5 at mesophilic conditions. The highest methane content reached 75% in the dynamic water bath feeding with an average particle size of 1?3 mm. Hydrolysis and methanogenesis were significantly different between static and dynamic states, especially at particle size over 3 mm. The modified Gompertz model (R2 > 0.98) and the modified Aiba model (R2 > 0.88) were the most appropriate models for methane generation among the six kinds of models. At different TS, the variation of dissolved organic matters reflects the metabolic rate of the microbial community. The soluble microbial product-like and protein-like components half split by excitation?emission factors significantly negatively corresponded to biomethane production. Moreover, a rapid loss of matrix-parallel methanogenesis was observed with high organics concentration. A strong correlation between the F/M ratio and the CH4 generation ability was observed with an optimized F/M of 0.5. The maximum energy production was also investigated based on the optimized particle size of 2?5 mm and F/M of 0.5, in which long-term stability was maintained.
关键词： dissolved organic matter,kinetic models,methane production,EEM-PARAFAC,Mono-cardboard digestion
更新于2025-09-11 14:15:04
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MALDI Imaging Mass Spectrometry Spatially Maps Age-Related Deamidation and Truncation of Human Lens Aquaporin-0
摘要： PURPOSE. To spatially map human lens Aquaporin-0 (AQP0) protein modifications, including lipidation, truncation, and deamidation, from birth through middle age using matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS). METHODS. Human lens sections were water-washed to facilitate detection of membrane protein AQP0. We acquired MALDI images from eight human lenses ranging in age from 2 months to 63 years. In situ tryptic digestion was used to generate peptides of AQP0 and peptide images were acquired on a 15T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Peptide extracts were analyzed by liquid chromatography–tandem mass spectrometry (LC-MS/MS) and database searched to identify peptides observed in MALDI imaging experiments. RESULTS. Unmodified, truncated, and fatty acid–acylated forms of AQP0 were detected in protein imaging experiments. Full-length AQP0 was fatty acid acylated in the core and cortex of young (2- and 4-month) lenses. Acylated and unmodified AQP0 were C-terminally truncated in older lens cores. Deamidated tryptic peptides (t0.9847 Da) were mass resolved from unmodified peptides by FTICR MS. Peptide images revealed differential localization of un-, singly-, and doubly-deamidated AQP0 C-terminal peptide (239–263). Deamidation was present at 4 months and increases with age. Liquid chromatography–MS/MS results indicated N246 undergoes deamidation more rapidly than N259. CONCLUSIONS. Results indicated AQP0 fatty acid acylation and deamidation occur during early development. Progressive age-related AQP0 processing, including deamidation and truncation, was mapped in human lenses as a function of age. The localization of these modified AQP0 forms suggests where AQP0 functions may change throughout lens development and aging.
关键词： deamidation,truncation,aging,MALDI IMS,in situ digestion,posttranslational modifications,ocular lens
更新于2025-09-11 14:15:04
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Rapid Determination of Mercury Speciation in Marine Products by Molecular Spectrometry
摘要： A method is developed for the determination of content of inorganic mercury, methylmercury, ethylmercury, and phenylmercury in marine products by molecular spectroscopy with microliquid extraction. Ultrasonic extraction pretreatment is performed, C18 column and rotary evaporator are used for concentrating eluent, and liquid chromatography–ultraviolet (UV) digestion molecular spectrometry is used for analysis. Detection conditions of various forms of mercury compounds are optimized, and the content and UV digestion conditions of each component in the mobile phase are compared through experiments. The standard recovery rate of experimental samples is generally in the range of 90–106%; measured results are satisfactory, and have less interference, which provides reliable technical support for speciation analysis of mercury in marine products.
关键词： Mercury,ultrasonic extraction,liquid chromatography–UV digestion
更新于2025-09-04 15:30:14
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Correlation Between Multimodal Microscopy, Tissue Morphology, and Enzymatic Resistance in Riboflavin-UVA Cross-Linked Human Corneas
摘要： PURPOSE. To explore the utility of multimodal microscopy as a noninvasive tool to assess corneal collagen cross-linking (CXL) efficacy, we investigated the correlation between riboflavin (RF) axial profile, second harmonic generation (SHG) imaging, and histological/biochemical changes of human corneas after RF-ultraviolet A (UVA)–catalyzed CXL. METHODS. De-epithelialized human corneoscleral tissues were imaged by confocal and multiphoton microscopy to study RF tissue diffusion profile and SHG-based roughness index (Rq) after CXL. We installed 0.1% RF for 5, 10, and 20 minutes, respectively, followed by UVA irradiation, while dextran drug vehicle–treated corneas served as controls. Masson’s trichrome staining and collagenase digestion assay were employed to assess ultrastructural modifications of collagen lamellae and bioenzymatic strength following RF-UVA CXL. RESULTS. Stromal absorption of RF was significantly higher in 20 minutes compared with 5- and 10-minute drug instillations. The roughness index of SHG images was reduced after RF-UVA CXL at all RF instillation time points compared with dextran controls. Interestingly, correlation between axial profiles of RF dosage and Rq index was only observed in 10- and 20-minute RF instillations (R2 ? 0.13 and 0.28, respectively, all P < 0.05), but not in the 5-minute group. Masson’s trichrome staining revealed collagen fibril compaction in cross-linked corneas in an RF dose-dependent manner. Collagenase digestion assay showed significantly increased biochemical strength by higher RF doses in cross-linked corneas. CONCLUSIONS. Intrastromal RF distribution profiles correlated with histological and functional property changes in RF-UVA cross-linked corneas. A riboflavin-defined threshold further determined the sensitivity of SHG imaging as a noninvasive imaging modality to assess the efficacy of RF-UVA CXL.
关键词： collagenase digestion,collagen cross-linking,second harmonic generation,Masson’s trichrome staining,riboflavin
更新于2025-09-04 15:30:14