Wavelength-dependent photodegradation of wood and its effects on fluorescence

Apart from some strongly fluorescent wood species, the general fluorescence of wood has long been ignored. Recent studies suggest that each species has a distinct fluorescence, originating from both basic components and characteristic extractives. However, wood colour and fluorescence rapidly change upon exposure to sunlight. In this study, 288 samples of Acer pseudoplatanus, Quercus robur, Picea abies and Juglans nigra were irradiated with different bands of ultraviolet (UV) and visible (VIS) light. Photosensitivity was examined in regards of colour, infrared absorbance (FTIR), and fluorescence imaging. UV light caused strong yellowing in all examined species, mostly correlating with lignin degradation, carbonyl formation and the appearance of a broad banded fluorescence emission. VIS light above 420 nm, however, caused different, partly contradicting effects in colour and fluorescence, and did not affect lignin. J. nigra proved to be most sensitive towards VIS-induced yellowing and bleaching. The main new finding of this study is that the native long wave fluorescence of wood was strongly decreased by VIS-irradiation above 510 nm wavelength in all samples. This effect was not species-specific, probably originating from a cross-species wood component. The results have potential impacts on non-destructive image-based evaluation methods and wood identification.

Comparative analysis of the antioxidant capacity and lipid and protein oxidation of soy and oats beverages

Soy (Glycine max) and oats (Avena sativa) are plant sources used in milk-alternative beverages. However, protein and lipid constituents of these food matrices can undergo alterations during the storage. In this work, a commercial formulation of soy and oat-based beverages were comparatively evaluated. During the 12 months of shelf life and two following months, their phenolic content, antioxidant capacity, lipid peroxidation, protein carbonyl formation and protein breakdown were assessed. Total phenolic content and antioxidant capacity of soy and oat-based beverages were maintained during the entire period of 14 months. Both beverages did not show any increase in spontaneous lipid peroxidation beyond the basal level, however, due to the different content of unsaturated fats, when lipid peroxidation was stimulated, soy exhibited a major peroxidizability with respect to oat beverage. Oxidative alteration of proteins, estimated as carbonyl group formation, presented no increase with respect to the basal levels both in soy and oat beverages for all 14 months. Finally, soy proteins showed a gradual increase of proteolytic activity up until half of the shelf life, while oat did not show significant changes in protein fragmentation. In conclusion, both soy and oat beverages resulted oxidatively stable throughout their storage. We suggest that phytochemicals might guarantee the oxidative stability of the product, possibly in combination with antioxidant bioactive peptides, which already have well-known benefits on human health. Graphical abstract

Palladium-Catalyzed and Alcohol-Enabled Transformation to Synthesize Benzocyclic Ketones

Catalytic carbonyl formation ranks as one of the most important synthetic methodology. Herein, a highly effective palladium-catalyzed and alcohol-promoted transformation of nitrile to synthesize benzocyclic ketones is described. It allows...

Impact of storage conditions on protein oxidation of rendered by-product meals1

Rendered products used in animal feed and pet food undergo extreme temperatures during manufacturing and may be stored up to 2 yr. No information is available on protein oxidation in these products. The objective of this study was to determine the extent to which typical antioxidant inclusion at different storage conditions may limit protein oxidation in typical rendered protein meals. Two experiments were conducted on 14 rendered products stored at either 45 °C for 7 or 14 d, or at 20 °C for 3 or 6 mo to determine the extent to which time, temperature, and antioxidants affect protein oxidation. Results from this study show that fish meal and chicken blood meal are susceptible to protein oxidation during storage at 45 °C (P = 0.05; 0.03) as well as during storage at 20 °C (P = 0.01; 0.04). Natural antioxidants were effective at limiting carbonyl formation in fish meal during short-term storage at 45 °C, whereas ethoxyquin was effective at limiting the extent of protein oxidation in fish meal stored long term at 20 °C.

Voltage and e-liquid composition affect nicotine deposition within the oral cavity and carbonyl formation

IntroductionThe diversity of e-liquids along with higher powered e-cigarette nicotine delivery devices are increasing. This study evaluated the effect of voltage and e-liquid composition on particle size, nicotine deposition in a human oral-trachea cast model and generation of carbonyls.MethodsNineteen e-liquids were evaluated for 30 common chemicals by gas chromatography–mass spectrometry (GC-MS). E-cigarette aerosols containing nicotine (1.2%) were generated at 4 and 5 volts for assessment of particle size distribution using Aerodynamic Particle Sizer (APS), Fast Mobility Particle Size (FMPS) and an In-Tox cascade impactor and nicotine deposition by GC-MS. Carbonyl formation in aerosols was assessed by liquid chromatography tandem triple-quad mass spectrometry.ResultsTotal chemical burden ranged from 0.35 to 14.6 mg/mL with ethyl maltol present in all e-liquids. Increasing voltage was associated with an increase in median size of aerosol particles and the deposition of nicotine in the oral cast. Two e-liquids caused a 2.5-fold to 5-fold increase in nicotine deposition independent of particle size and voltage. Increasing voltage caused an increase in formaldehyde, acetaldehyde and acrolein in the presence and absence of nicotine. Most striking, aerosols from several e-liquids significantly increased levels of acetaldehyde and acrolein compared with unflavoured.ConclusionsIncreasing voltage and composition of e-liquid can increase the exposure of the oral pharynx and bronchial airways to carbonyls that can react with DNA to generate adducts, induce oxidative stress, inflammation and cell death. The elevated nicotine and carbonyls readily enter the circulation where they can also cause cardiovascular stress. The growing popularity of higher voltage e-cigarette delivery devices will likely further elevate health risks from chronic exposure to these complex aerosols.

In Vivo Metabolites of AB-PINACA in Solid Tissues Obtained from Its Abuser: Comparison with In Vitro Experiment

In this study, solid tissues such as the lung, liver, kidney and urine were highlighted to profile the AB-PINACA in vivo metabolites in a fatal abuse case, although such metabolite analysis is usually made with urine specimens. We compared the relative peak intensities of in vivo metabolites of AB-PINACA in lung, liver, kidney and urine specimens collected at the autopsy of its abuser with its in vitro metabolites in human hepatocytes. The metabolites of AB-PINACA in tissues were extracted after homogenization. The urine specimen and portions of the extracted metabolites from tissues were firstly hydrolyzed with β-glucuronidase, and the metabolites were extracted. For in vitro experiment, AB-PINACA was incubated with human hepatocytes for 3 h to produce its metabolites. The identification of the in vivo and in vitro metabolites was performed using liquid chromatography (LC)–high-resolution Orbitrap-tandem mass spectrometry (MS-MS), and the relative intensities of these metabolites were measured using low resolution LC–quadrupole-ion trap-MS-MS. Thirteen metabolites of AB-PINACA were characterized in vivo in several human specimens and in in vitro human hepatocytes. They were produced by the terminal amide hydrolysis to carboxylic acid, hydroxylation, carbonyl formation and/or glucuronidation. The most detectable metabolite in the hepatocytes, lung or liver was the one produced by the terminal amide hydrolysis, whereas the top metabolite in the kidney or urine was the one produced by hydroxylation or carbonyl formation on the pentyl side chain after the terminal amide hydrolysis, respectively. At least 12 metabolites of AB-PINACA were detected in authentic human lung, liver or kidney specimen from a cadaver. It is concluded that the postmortem metabolite profiling of AB-PINACA can be fulfilled with solid tissues, and the lung and kidney were most recommendable especially when urine specimen is not available.

Metallothionein expression in slow- vs. fast-twitch muscle fibers following 4 weeks of streptozotocin-induced type 1 diabetes

Type 1 diabetes (T1DM) is known to cause an increase in reactive oxygen species (ROS) and elevated intracellular glucose levels. We investigated the metallothionein I and II (MT I+II) antioxidants expression in soleus (mainly slow-twitch) and plantaris (predominantly fast-twitch) skeletal muscle using a rodent model of streptozotocin-induced diabetes. The presence of oxidative stress was confirmed by the detection of increased levels of protein carbonyl formation in the diabetic tissues. DAB (3,3′-diaminobenzidine) immunostaining and Western blotting analyses demonstrated that MT I+II expression was significantly upregulated in the diabetic soleus and plantaris muscle tissues compared with their respective controls. Moreover, no significant difference was detected between the plantaris and soleus controls or between the plantaris and soleus diabetic tissues. These findings suggest that there is an increase in MT protein expression in the soleus and plantaris muscles associated with the induction of T1DM. A better understanding of the molecular mechanisms that allow MT to prevent the oxidative stress associated with diabetes could lead to a novel therapeutic strategy for this chronic disease and its associated complications.