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A new method for simultaneously determining five polycyclic aromatic hydrocarbons (PAHs) (fluorene, benzofluorene, pyrene, benzo(a)pyrene, and perylene) in dairy products using constant-wavelength synchronous fluorescence spectrometry (CWSFS) was established in this study. Acetonitrile was chosen as the extraction solvent to extract the five PAHs from the dairy products, and an ultrasound extraction method was adopted. The supernatants were filtered using a 0.45-μm microporous filter membrane and concentrated to dryness with a nitrogen dryer. The extracts were then re-dissolved in cyclohexane for analysis. To overcome interference from the background matrix and between PAHs, the difference in wavelength (Δλ) at 40 nm was chosen for CWSFS scanning. With only one single scan, the five PAHs in dairy products could be distinguished and determined using the standard curve method without the need for previous chromatographic separation of the analyte solution. Detection limits of fluorene, benzofluorene, pyrene, benzo(a)pyrene, and perylene were 0.0051 μg·L-1 , 0.016 μg·L-1 , 0.021 μg·L-1 , 0.0056 μg·L-1 , and 0.0062 μg·L-1 , respectively. Recoveries were between 85.60% and 98.42%. These five PAHs in dairy products were determined with good results and therefore expected to be a routine detection method for PAHs in dairy products.The accumulation of toxic carboxylic compounds may cause severe effects on the environment and living organisms. A luciferase-like enzyme, previously cloned from the Malpighian tubules of the non-luminescent Zophobas morio mealworm, displays thioesterification activity with a wide range of carboxylic substrates, and produces weak red luminescence in the presence of ATP and firefly d-luciferin, a xenobiotic for this organism. To better investigate the function of this enzyme in carboxylic xenobiotic detoxification, we analyzed the inhibitory effect of different xenobiotic carboxylic acids on the luminescence activity of this enzyme, including environmental pollutants and pharmaceutical compounds. ARS853 Noteworthy, the anti-inflammatory drug diclofenac severely inhibited this luciferase-like enzyme luminescence activity, both in in vitro (IC50 20 μM) and in vivo in bacterial cells assays, when compared with other beetle luciferases. Similar results were obtained with its brighter I327S mutant. Kinetic analysis of diclofenac's effect on luminescence activity indicated mixed-type inhibition for both ATP and d-luciferin. Modelling studies showed five potential binding sites for diclofenac, including the coenzyme A binding site, which showed one of the highest binding constant. Taken together, these results raise the possibility of using this luciferase-like enzyme for the development of novel whole-cell luminescent biosensors for diclofenac and similar drugs.In certain forensic cases, a quantification of direct-acting oral anticoagulants (DOACs) can be necessary. We evaluate the applicability of a previously described liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology for the determination of DOACs in plasma to postmortem specimen. Postmortem internal quality control (PIQC) samples were prepared in pooled blank postmortem heart blood, femoral blood, cerebrospinal fluid (CSF), and urine as well in plasma. To examine the application of the clinical method to forensic cases, the main validation parameters were reinvestigated using PIQC samples. Postmortem samples of 12 forensic cases with evidence of previous rivaroxaban intake and unknown bleeding disorders were analyzed. Interday variability remained within the acceptance criterion of ±15%. Matrix effects were comparable in blank plasma and postmortem matrix extracts. After 4 weeks of storage in the refrigerator, no relevant decrease of DOACs was evident. After 96 h of storage at room temperature, a slight decrease in edoxaban concentration was observed in CSF and urine, while plasma edoxaban decreased by about 50%. Median (range) rivaroxaban concentrations determined in specimen of forensic cases were as follows heart blood (n = 6), 17.2 ng/ml ( less then LOQ, 56.6 ng/ml); femoral blood (n = 12), 27.6 ng/ml ( less then LOQ, 110.5 ng/ml); CSF (n = 7), 11.7 ng/ml ( less then LOQ, 17.5 ng/ml); urine (n = 6), 275.7 ng/ml (14.5-870.9 ng/ml). The median heart/femoral blood rivaroxaban ratio was 1.2 (n = 5). Exemplary, a forensic case with detection of edoxaban in femoral blood, CSF, and urine, is presented. DOACs can be detected in postmortem heart and femoral blood, CSF, and urine specimen by LC-MS/MS. Based on limited forensic cases, no significant redistribution was evident for rivaroxaban, which was found at highest concentrations in urine.Polymethine cyanine dyes have been widely recognized as promising chemical tools for a range of life science and biomedical applications, such as fluorescent staining of DNA and proteins in gel electrophoresis, fluorescence guided surgery, or as ratiometric probes for probing biochemical pathways. The photophysical properties of such dyes can be tuned through the synthetic modification of the conjugated backbone, for example, by altering aromatic cores or by varying the length of the conjugated polymethine chain. Alternative routes to shaping the absorption, emission, and photostability of dyes of this family are centered around the chemical modifications on the polymethine chain. This Minireview aims to discuss strategies for the introduction of substituents in the meso-position, their effect on the photophysical properties of these dyes and some structure-activity correlations which could help overcome common limitations in the state of the art in the synthesis.The production of hydrogen by water electrolysis benefits from the development of water oxidation catalysts. This development process can be aided by the postulation of design rules for catalytic systems. The analysis of the reactivity of molecular complexes can be complicated by their decomposition under catalytic conditions into nanoparticles that may also be active. Such a misinterpretation can lead to incorrect design rules. In this study, the nickel-based water oxidation catalyst [NiII (meso-L)](ClO4 )2 , which was previously thought to operate as a molecular catalyst, is found to decompose to form a NiOx layer in a pH 7.0 phosphate buffer under prolonged catalytic conditions, as indicated by controlled potential electrolysis, electrochemical quartz crystal microbalance, and X-ray photoelectron spectroscopy measurements. Interestingly, the formed NiOx layer desorbs from the surface of the electrode under less anodic potentials. Therefore, no nickel species can be detected on the electrode after electrolysis. Catalyst decomposition is strongly dependent on the pH and buffer, as there is no indication of NiOx layer formation at pH 6.5 in phosphate buffer nor in a pH 7.0 acetate buffer. Under these conditions, the activity stems from a molecular species, but currents are much lower. This study demonstrates the importance of in situ characterization methods for catalyst decomposition and metal oxide layer formation, and previously proposed design elements for nickel-based catalysts need to be revised.Chirality is ubiquitous within biological systems where many of the roles and functions are still undetermined. Given this, there is a clear need to design and develop sensitive chiral optical probes that can function within a biological setting. Here we report the design and synthesis of magnetically responsive Circularly Polarized Luminescence (CPL) complexes displaying exceptional photophysical properties (quantum yield up to 31 % and |glum | up to 0.240) by introducing chiral substituents onto the macrocyclic scaffolds. Magnetic CPL responses are observed in these chiral EuIII complexes, promoting an exciting development to the field of magneto-optics. The |glum | of the 5 D0 → 7 F1 transition increases by 20 % from 0.222 (0 T) to 0.266 (1.4 T) displaying a linear relationship between the Δglum and the magnetic field strength. These EuIII complexes with magnetic CPL responses, provides potential development to be used in CPL imaging applications due to improved sensitivity and resolution.The actin cytoskeleton operates in a multitude of cellular processes including cell shape and migration, mechanoregulation, and membrane or organelle dynamics. However, its filamentous properties and functions inside the mammalian cell nucleus are less well explored. We previously described transient actin assembly at mitotic exit that promotes nuclear expansion during chromatin decondensation. Here, we identify non-muscle α-actinin 4 (ACTN4) as a critical regulator to facilitate F-actin reorganization and bundling during postmitotic nuclear expansion. ACTN4 binds to nuclear actin filament structures, and ACTN4 clusters associate with nuclear F-actin in a highly dynamic fashion. ACTN4 but not ACTN1 is required for proper postmitotic nuclear volume expansion, mediated by its actin-binding domain. Using super-resolution imaging to quantify actin filament numbers and widths in individual nuclei, we find that ACTN4 is necessary for postmitotic nuclear actin reorganization and actin filament bundling. Our findings uncover a nuclear cytoskeletal function for ACTN4 to control nuclear size and chromatin organization during mitotic cell division.AC-262536 is one of a number of selective androgen receptor modulators that are being developed by the pharmaceutical industry for treatment of a range of clinical conditions including androgen replacement therapy. Though not available therapeutically, selective androgen receptor modulators are widely available to purchase online as (illegal) supplement products. The growth- and bone-promoting effects, along with fewer associated negative side effects compared with anabolic-androgenic steroids, make these compounds a significant threat with regard to doping control in sport. The aim of this study was to investigate the metabolism of AC-262536 in the horse following in vitro incubation and oral administration to two Thoroughbred horses, in order to identify the most appropriate analytical targets for doping control laboratories. Urine, plasma and hair samples were collected and analysed for parent drug and metabolites. Liquid chromatography-high-resolution mass spectrometry was used for in vitro metabolite identification and in urine and plasma samples. Nine phase I metabolites were identified in vitro; four of these were subsequently detected in urine and three in plasma, alongside the parent compound in both matrices. In both urine and plasma samples, the longest detection window was observed for an epimer of the parent compound, which is suggested as the best target for detection of AC-262536 administration. AC-262536 and metabolites were found to be primarily glucuronide conjugates in both urine and plasma. Liquid chromatography-tandem mass spectrometry analysis of post-administration hair samples indicated incorporation of parent AC-262536 into the hair following oral administration. No metabolites were detected in the hair.Individuals with inhibited immunity may develop lethal toxoplasmosis; thus, a safe and effective vaccine is urged to be developed. Toxoplasma gondii (T. gondii) α-amylase (α-AMY) is one of the enzymes responsible for starch digestion. In the present study, we first generated a ME49Δα-amy mutant and discovered that loss of α-AMY robustly grew in vitro but contributed to significant virulence attenuation in vivo. Therefore, we established a mouse model to explore the protective immunity of Δα-amy mutant against acute and chronic toxoplasmosis. The results indicated that the survival rates of short-term or long-term immunized mice re-infected with the tachyzoites of multiple T. gondii strains were nearly 100%. ME49Δα-amy not only could provide protective immunity against tachyzoites infection but also could resist the infection of tissue cysts. Furthermore, we detected that ME49Δα-amy vaccination could effectively eliminate the proliferation of parasites in mice and prevent the formation of cysts. The significant increases of Th1-type cytokines, Th2-type cytokines and specific total IgG and IgG subclasses (IgG2a and IgG1) confirmed efficiency of a combination of cellular and humoral immunity against infection.
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