Regulation of the RNAPII Pool Is Integral to the DNA Damage Response.

In response to transcription-blocking DNA damage, cells orchestrate a multi-pronged reaction, involving transcription-coupled DNA repair, degradation of RNA polymerase II (RNAPII), and genome-wide transcription shutdown. Here, we provide insight into how these responses are connected by the finding that ubiquitylation of RNAPII itself, at a single lysine (RPB1 K1268), is the focal point for DNA-damage-response coordination. K1268 ubiquitylation affects DNA repair and signals RNAPII degradation, essential for surviving genotoxic insult. RNAPII degradation results in a shutdown of transcriptional initiation, in the absence of which cells display dramatic transcriptome alterations. Additionally, regulation of RNAPII stability is central to transcription recovery-persistent RNAPII depletion underlies the failure of this process in Cockayne syndrome B cells. These data expose regulation of global RNAPII levels as integral to the cellular DNA-damage response and open the intriguing possibility that RNAPII pool size generally affects cell-specific transcription programs in genome instability disorders and even normal cells.

UV Irradiation Induces a Non-coding RNA that Functionally Opposes the Protein Encoded by the Same Gene.

The transcription-related DNA damage response was analyzed on a genome-wide scale with great spatial and temporal resolution. Upon UV irradiation, a slowdown of transcript elongation and restriction of gene activity to the promoter-proximal ∼25 kb is observed. This is associated with a shift from expression of long mRNAs to shorter isoforms, incorporating alternative last exons (ALEs) that are more proximal to the transcription start site. Notably, this includes a shift from a protein-coding ASCC3 mRNA to a shorter ALE isoform of which the RNA, rather than an encoded protein, is critical for the eventual recovery of transcription. The non-coding ASCC3 isoform counteracts the function of the protein-coding isoform, indicating crosstalk between them. Thus, the ASCC3 gene expresses both coding and non-coding transcript isoforms with opposite effects on transcription recovery after UV-induced DNA damage.

Differential effects of benzo[a]pyrene exposure on glutathione and purine metabolism in keratinocytes: Dose-dependent and UV co-exposure effects.

Polycyclic aromatic hydrocarbons with the key substance benzo[a]pyrene (B[a]P) are widespread pollutants in the environment and at working places. Nonetheless, the exact underlying mechanisms of toxicological effects caused by B[a]P especially in absence and presence of UV irradiation remain uncertain. This study examines variations in exposure conditions: low B[a]P (4 nM), low B[a]P + UV and high B[a]P (4 µM), selected based on pertinent cytotoxicity assessments. Following cell viability evaluations post-treatment with varied B[a]P concentrations and UV irradiation, the identified concentrations underwent detailed metabolomic analysis via gas chromatography-mass spectrometry. Subsequently, resulting changes in metabolic profiles across these distinct exposure groups are comprehensively compared. Chemometric analyses showed modest regulation of metabolites after low B[a]P exposure compared to control conditions. High B[a]P and low B[a]P + UV exposure significantly increased regulation of metabolic pathways, indicating that additional UV irradiation plus low B[a]P is as demanding for the cells as higher B[a]P treatment alone. Further analysis revealed exposure-dependent regulation of glutathione-important for oxidative defence-and purine metabolism-important for DNA base synthesis. Only after low B[a]P, oxidative defence appeared to be able to compensate for B[a]P-induced perturbations of the oxidative homeostasis. In contrast, purine metabolism already responded towards adversity at low B[a]P. The metabolomic results give an insight into the mechanisms leading to the toxic response and confirm the strong effects of co-exposure on oxidative defence and DNA repair in the model studied.

Duo photoprotective effect via silica-coated zinc oxide nanoparticles and Vitamin C nanovesicles composites.

OBJECTIVE: Zinc Oxide nanoparticles (ZnO NPs) are used widely in nowadays personal care products, especially sunscreens, as a protector against UV irradiation. Yet, they have some reports of potential toxicity. Silica is widely used to cage ZnO NPs to reduce their potential toxicity. Vitamin C derivative, Magnesium Ascorpyl Phosphate (MAP), is a potent antioxidant that can efficiently protect human skin from harmful impacts of UV irradiation and oxidative stress. The combination of silica coated ZnO NPs and MAP nanovesicles could have potential synergistic protective effect against skin photodamage. METHODS: Silica coated ZnO NPs and MAP nanovesicles (ethosomes and niosomes) were synthesized, formulated, and evaluated as topical gels. These gel formulations were evaluated in mice for their photoprotective effect against UV irradiation through histopathology and immuno-histochemistry study. Split-face clinical study was conducted to compare the effect of application of silica coated ZnO NPs either alone or combined with MAP nanovesicles. Their photoprotective action was evaluated, using Antera 3D® camera, for melanin level, roughness index and wrinkles depth. RESULTS: Silica coated ZnO NPs when combined with MAP nanovesicles protected mice skin from UV irradiation and decreased the expression of the proinflammatory cytokines, NF-κB. Clinically, silica coated ZnO NPs, alone or combined with MAP nanovesicles, could have significant effect to decrease melanin level, roughness index and wrinkles depth with higher effect for the combination. CONCLUSION: A composite of silica coated ZnO NPs and MAP nanovesicles could be a promising cosmetic formulation for skin protection against photodamage signs such as hyperpigmentation, roughness, and wrinkles.

Influence of UV irradiation on the luminescence properties of CsPbBr3 perovskite quantum dots and CsPbBr3 perovskite quantum dots/PVDF composite film - for white LED application.

Perovskite quantum dots (QDs) have been widely investigated for their excellent properties such as high color purity in displays, tunable emission wavelength, and high photoluminescence quantum yield. For device applications, improving the stability is an area of interest. In this study, the effects of UV irradiation on the structural and luminescence properties of CsPbBr3 perovskite quantum dots (CPB QDs) excited at 365 nm were investigated. To overcome the effects of UV irradiation, a CPB QDs/PVDF composite flexible film was prepared. It exhibits high structural and optical stability under UV irradiation and emits a highly intense green color. The emission wavelength and intensity were observed for three years, and the stability of the temperature-dependent emission intensity up to 400 K has been reported. In addition, it is stable in water. A white LED, fabricated by integrating a blue LED with CPB QDs/PVDF composite film and red phosphor, produces bright natural white light [(CIE x, CIE y) = (0.3704, 0.3611), and CCT = 4177 K] with a color gamut area coverage of 86.4% of the standard NTSC (1953) color space. .

Single-Particle Analysis of the Photodegradation of Submicron Polystyrene Particles Using Infrared Photothermal Heterodyne Imaging.

Sunlight irradiation is the predominant process for degrading plastics in the environment, but our current understanding of the degradation of smaller, submicron (<1000 nm) particles is limited due to prior analytical constraints. We used infrared photothermal heterodyne imaging (IR-PHI) to simultaneously analyze the chemical and morphological changes of single polystyrene (PS) particles (∼1000 nm) when exposed to ultraviolet (UV) irradiation (λ = 250-400 nm). Within 6 h of irradiation, infrared bands associated with the backbone of PS decreased, accompanied by a reduction in the particle size. Concurrently, the formation of several spectral features due to photooxidation was attributed to ketones, carboxylic acids, aldehydes, esters, and lactones. Spectral outcomes were used to present an updated reaction scheme for the photodegradation of PS. After 36 h, the average particle size was reduced to 478 ± 158 nm. The rates of size decrease and carbonyl band area increase were -24 ± 3.0 nm h-1 and 2.1 ± 0.6 cm-1 h-1, respectively. Using the size-related rate, we estimated that under peak terrestrial sunlight conditions, it would take less than 500 h for a 1000 nm PS particle to degrade to 1 nm.

Mitigating the detrimental impacts of low- and high-density polyethylene microplastics using a novel microbial consortium on a soil-plant system: Insights and interactions.

The accumulation of polyethylene microplastics (PE-MPs) in soil has raised considerable concerns; however, the effects of their persistence and mitigation on agroecosystems have not been explored. This study aimed to assess the detrimental effects of PE-MPs on a soil-plant system and evaluate their mitigation using a novel microbial consortium (MC). We incorporated low-density polyethylene (LDPE) and high-density polyethylene (HDPE) at two different concentrations, along with a control (0 %, 1 %, and 2 % w/w) into the sandy loam soil for a duration of 135 days. The samples were also treated with a novel MC and incubated for 135 days. The MC comprised three bacterial strains (Ralstonia pickettii (MW290933) strain SHAn2, Pseudomonas putida strain ShA, and Lysinibacillus xylanilyticus XDB9 (T) strain S7-10F), and a fungal strain (Aspergillus niger strain F1-16S). Sunflowers were subsequently cultivated, and physiological growth parameters were measured. The results showed that adding 2 % LDPE significantly decreased soil pH by 1.06 units compared to the control. Moreover, adding 2 % HDPE resulted in a more significant decrease in soil electrical conductivity (EC) relative to LDPE and the control. A dose-dependent increase in dissolved organic carbon (DOC) was observed, with the highest DOC found in 2 % LDPE. The addition of higher dosages of LDPE reduced soil bulk density (BD) more than HDPE. The addition of 2 % HDPE increased the water drop penetration time (WDPT) but decreased the mean weight diameter of soil aggregates (MWD) and water-stable aggregates (WSA) compared to LDPE. The results also revealed that higher levels of LDPE enhanced soil basal respiration (BR) and microbial carbon biomass (MBC). The interaction of MC and higher MP percentages considerably reduced soil pH, EC, BD, and WDPT but significantly increased soil DOC, MWD, WSA, BR, and MBC. Regarding plant growth, incorporating 2 % PE-MPs significantly reduced physiological responses of sunflower: chlorophyll content (Chl; -15.2 %), Fv/Fm ratio (-25.3 %), shoot dry weight (ShD; -31.3 %), root dry weight (RD; -40 %), leaf area (LA; -38.4 %), and stem diameter (StemD; -25 %) compared to the control; however, the addition of novel MC considerably reduced and ameliorated the harmful effects of 2 % PE-MPs on the investigated plant growth responses.

Photoinduced Metal-Free Atom Transfer Radical Polymerization for the Modification of Cellulose with Poly(N-isopropylacrylamide) to Create Thermo-Responsive Injectable Hydrogels.

Photoinduced metal-free ATRP has been successfully applied to fabricate thermo-responsive cellulose graft copolymer (PNIPAM-g-Cell) using 2-bromoisobuturyl bromide-modified cellulose as the macroinitiator. The polymerization of N-isopropylacrylamide (NIPAM) from cellulose was efficiently activated and deactivated with UV irradiation in the presence of an organic-based photo-redox catalyst. Both FTIR and 13C NMR analysis confirmed the structural similarity between the obtained PNIPAM-g-Cell and that synthesized via traditional ATRP methods. When the concentration of the PNIPAM-g-Cell is over 5% in water, it forms an injectable thermos-responsive hydrogel composed of micelles at 37 °C. Since organic photocatalysis is a metal-free ATRP, it overcomes the challenge of transition-metal catalysts remaining in polymer products, making this cellulose-based graft copolymer suitable for biomedical applications. In vitro release studies demonstrated that the hydrogel can continuously release DOX for up to 10 days, and its cytotoxicity indicates that it is highly biocompatible. Based on these findings, this cellulose-based injectable, thermo-responsive drug-loaded hydrogel is suitable for intelligent drug delivery systems.

Photoaging Elevated the Genotoxicity of Polystyrene Microplastics to Marine Mussel Mytilus trossulus (Gould, 1850).

Micro-sized particles of synthetic polymers (microplastics) are found in all parts of marine ecosystems. This fact requires intensive study of the degree of danger of such particles to the life activity of hydrobionts and needs additional research. It is evident that hydrobionts in the marine environment are exposed to microplastics modified by biotic and abiotic degradation. To assess the toxic potential of aging microplastic, comparative studies were conducted on the response of cytochemical and genotoxic markers in hemocytes of the mussel Mytilus trossulus (Gould, 1850) after exposure to pristine and photodegraded (UV irradiation) polystyrene microparticles (µPS). The results of cytochemical tests showed that UV-irradiated µPS strongly reduced metabolism and destabilized lysosome membranes compared to pristine µPS. Using a Comet assay, it was shown that the nuclear DNA of mussel hemocytes showed high sensitivity to exposure to both types of plastics. However, the level of DNA damage was significantly higher in mussels exposed to aging µPS. It is suggested that the mechanism of increased toxicity of photo-oxidized µPS is based on free-radical reactions induced by the UV irradiation of polymers. The risks of toxic effects will be determined by the level of physicochemical degradation of the polymer, which can significantly affect the mechanisms of toxicity.

Photodegradation of a Broad-Spectrum Antibiotic Azithromycin Using H2O2 under Ultraviolet Irradiation.

The photodegradation of azithromycin present was carried out in water using H2O2 under UV irradiation. The reaction variables considered in this study were the amount of H2O2 solution and the initial concentration of azithromycin to evaluate the performance of the photodegradation process. The azithromycin degradation was not observed in the dark during stirring for 20 min. The study showed an efficient photodegradation of azithromycin using H2O2 as an oxidant in the presence of UV irradiation. The azithromycin degradation was altered significantly by the pH of the irradiated solution. The degradation was low at an acidic pH and showed an increasing trend as the pH changed to basic. The azithromycin degradation increased with a higher amount (higher concentration) of H2O2. The degradation of azithromycin decreased with a higher concentration of azithromycin in the reacting solution. The highest degradation of AZT was achieved in 1 h using a 1.0 ppm AZT solution containing 3 mL of H2O2. The experimental data obtained were well-fitted to zero-order reaction kinetics. The results of this study were found quite excellent. They showed 100% degradation in 1 h when compared with those reported in the literature, both with photocatalysis using nanomaterials and photolysis using light irradiation and/or H2O2. The UV/H2O2 system was found to be quite efficient for the photodegradation of azithromycin, and this system can be applied to degrade other organic pollutants present in industrial wastewater.

Study on preparation of UV-CDs/Zeolite-4A/TiO2 composite photocatalyst coupled with ultraviolet-irradiation and their application of photocatalytic degradation of dyes.

In this work, ultraviolet irradiation was employed to assist in the preparation of a novel photocatalyst composite in the form of carbon dots/zeolite-4A/TiO2, using coal tailings as the source of silicon-aluminum and carbon. The composite was designed for the degradation of methylene blue under 500 W of UV light irradiation. Zeolite-4A was used as a support for the well-dispersed carbon dots and TiO2 nanoparticles. The as-prepared composites were subjected to thorough characterization, confirming the successful formation of zeolite-4A with a cube structure, along with the loading of TiO2 and coal-based CDs in the composites. The experimental results demonstrated that the UV-CZTs nanocomposites exhibited a remarkable removal efficiency of 90.63% within 90 min for MB. The corresponding rate constant was exceptionally high at 0.0331 min-1, surpassing that of the Dark-CZTs and pure TiO2. This significant enhancement was possibly due to the synergistic effect of adsorption photocatalysis of the UV-CZTs, combined with the excellent electron-accepting capabilities of the coal-based CDs, which led to highly improved charge separation. An investigation of the spent photocatalyst's recyclability revealed that it retained a remarkable 82.94% MB removal efficiency after five consecutive cycles, signifying the stability of the composite. Trapping experiments also elucidated the primary reactive species responsible for MB degradation, which were identified as photo-generated holes and ⸱O2- species. By this process, the hydroxyl radicals generated in the system successfully promoted the transformation of coal tailings to coal-based zeolite and coal-based CDs. Coal-based zeolite served as an excellent carrier of titanium dioxide, which improved its dispersibility. The inhibition of e--h+ recombination of titanium dioxide by introducing coal-based CDs improved the photocatalytic ability of titanium dioxide. Through this study, coal tailings, as a coal processing waste, were transformed into high-value materials, and relevant photocatalytic composite materials could be prepared with broad application prospects.

O-Phthalaldehyde Derivatization for the Paper-Based Fluorometric Determination of Glutathione in Nutritional Supplements.

Herein, a new, direct paper-based fluorimetric method is described for the quantitative determination of glutathione (GSH) molecules in nutritional supplements. Briefly, the proposed analytical method is based on the fluorescence emission resulting from the direct and selective chemical reaction of GSH molecules with the derivatization reagent that is o-phthalaldehyde (OPA) in acidic conditions at room temperature. The intensity of the emitted fluorescence on the surface of the analytical paper devices after irradiation with a lamp at 365 nm is proportional to the concentration of GSH and is measured using a smartphone as the detector. This methodology, which is suitable for measurements in laboratories with limited resources, does not require specialized instrumentation or trained personnel. The protocol governing the proposed method is simple and easily applicable. Essentially, the chemical analyst should adjust the value of pH on the surface of the paper by adding a minimal amount of buffer solution; then, after adding a few microliters of the derivatization reagent, wait for the surface of the paper to dry and, finally, add the analyte. Subsequently, the irradiation of the sensor and the measurement of the emitted fluorescence can be recorded with a mobile phone. In the present study, several parameters affecting the chemical reaction and the emitted fluorescence were optimized, the effect of interfering compounds that may be present in dietary supplements was examined, and the stability of these paper sensors under different storage conditions was evaluated. Additionally, the chemical stability of these paper devices in various maintenance conditions was studied, with satisfactory results. The detection limit calculated as 3.3 S/N was 20.5 µmol L-1, while the precision of the method was satisfactory, ranging from 3.1% (intra-day) to 7.3% (inter-day). Finally, the method was successfully applied to three different samples of dietary supplements.

Unveiling the Potential of Vitamin D3 Orodispersible Films: A Comprehensive FTIR and UV-Vis Spectroscopic Study.

Vitamin D3 is a crucial fat-soluble pro-hormone essential for bolstering bone health and fortifying immune responses within the human body. Orodispersible films (ODFs) serve as a noteworthy formulation strategically designed to enhance the rapid dissolution of vitamin D, thereby facilitating efficient absorption in patients. This innovative approach not only streamlines the assimilation process but also plays a pivotal role in optimizing patient compliance and therapeutic outcomes. The judicious utilization of such advancements underscores a paradigm shift in clinical strategies aimed at harnessing the full potential of vitamin D for improved patient well-being. This study aims to examine the vitamin D3 ODF structure using spectroscopic techniques to analyze interactions with excipients like mannitol. Fourier-transform infrared spectroscopy (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy were utilized to assess molecular composition, intermolecular bonding, and vitamin D3 stability. Understanding these interactions is essential for optimizing ODF formulation, ensuring stability, enhancing bioavailability, and facilitating efficient production. Furthermore, this study involves a translational approach to interpreting chemical properties to develop an administration protocol for ODFs, aiming to maximize absorption and minimize waste. In conclusion, understanding the characterized chemical properties is pivotal for translating them into effective self-administration modalities for Vitamin D films.

Decolorization enhancement of basic fuchsin by UV/H2O2 process: optimization and modeling using Box Behnken design.

The present work deals with the optimization of basic fuchsin dye removal from an aqueous solution using the ultraviolet UV/H2O2 process. Response Surface Modeling (RSM) based on Box-Behnken experimental design (BBD) was applied as a tool for the optimization of operating conditions such as initial dye concentration (10-50 ppm), hydrogen peroxide dosage (H2O2) (10-20 mM/L) and irradiation time (60-180 min), at pH = 7.4 under ultra-violet irradiation (254 nm and 25 W intensity). Chemical oxygen demand (COD abatement) was used as a response variable. The Box-Behnken Design can be employed to develop a mathematical model for predicting UV/H2O2 performance for COD abatement. COD abatement is sensitive to the concentration of hydrogen peroxide and irradiation time. Statistical analyses indicate a high correlation between observed and predicted values (R2 > 0.98). In the BBD predictions, the optimal conditions in the UV/H2O2 process for removing 99.3% of COD were found to be low levels of pollutant concentration (10 ppm), a high concentration of hydrogen peroxide dosage (20 mM/L), and an irradiation time of 80 min.

UV Irradiation of Vaccinia Virus-Infected Cells Impairs Cellular Functions, Introduces Lesions into the Viral Genome, and Uncovers Repair Capabilities for the Viral Replication Machinery.

Vaccinia virus (VV), the prototypic poxvirus, encodes a repertoire of proteins responsible for the metabolism of its large dsDNA genome. Previous work has furthered our understanding of how poxviruses replicate and recombine their genomes, but little is known about whether the poxvirus genome undergoes DNA repair. Our studies here are aimed at understanding how VV responds to exogenous DNA damage introduced by UV irradiation. Irradiation of cells prior to infection decreased protein synthesis and led to an ∼12-fold reduction in viral yield. On top of these cell-specific insults, irradiation of VV infections at 4 h postinfection (hpi) introduced both cyclobutene pyrimidine dimer (CPD) and 6,4-photoproduct (6,4-PP) lesions into the viral genome led to a nearly complete halt to further DNA synthesis and to a further reduction in viral yield (∼35-fold). DNA lesions persisted throughout infection and were indeed present in the genomes encapsidated into nascent virions. Depletion of several cellular proteins that mediate nucleotide excision repair (XP-A, -F, and -G) did not render viral infections hypersensitive to UV. We next investigated whether viral proteins were involved in combatting DNA damage. Infections performed with a virus lacking the A50 DNA ligase were moderately hypersensitive to UV irradiation (∼3-fold). More strikingly, when the DNA polymerase inhibitor cytosine arabinoside (araC) was added to wild-type infections at the time of UV irradiation (4 hpi), an even greater hypersensitivity to UV irradiation was seen (∼11-fold). Virions produced under the latter condition contained elevated levels of CPD adducts, strongly suggesting that the viral polymerase contributes to the repair of UV lesions introduced into the viral genome. IMPORTANCE Poxviruses remain of significant interest because of their continuing clinical relevance, their utility for the development of vaccines and oncolytic therapies, and their illustration of fundamental principles of viral replication and virus/cell interactions. These viruses are unique in that they replicate exclusively in the cytoplasm of infected mammalian cells, providing novel challenges for DNA viruses. How poxviruses replicate, recombine, and possibly repair their genomes is still only partially understood. Using UV irradiation as a form of exogenous DNA damage, we have examined how vaccinia virus metabolizes its genome following insult. We show that even UV irradiation of cells prior to infection diminishes viral yield, while UV irradiation during infection damages the genome, causes a halt in DNA accumulation, and reduces the viral yield more severely. Furthermore, we show that viral proteins, but not the cellular machinery, contribute to a partial repair of the viral genome following UV irradiation.

Sulfolobus islandicus Employs Orc1-2-Mediated DNA Damage Response in Defense against Infection by SSV2.

All living organisms have evolved DNA damage response (DDR) strategies in coping with threats to the integrity of their genome. In response to DNA damage, Sulfolobus islandicus activates its DDR network in which Orc1-2, an ortholog of the archaeal Orc1/Cdc6 superfamily proteins, plays a central regulatory role. Here, we show that pretreatment with UV irradiation reduced virus genome replication in S. islandicus infected with the fusellovirus SSV2. Like treatment with UV or the DNA-damaging agent 4-nitroquinoline-1-oxide (NQO), infection with SSV2 facilitated the expression of orc1-2 and significantly raised the cellular level of Orc1-2. The inhibitory effect of UV irradiation on the virus DNA level was no longer apparent in the infected culture of an S. islandicus orc1-2 deletion mutant strain. On the other hand, the overexpression of orc1-2 decreased virus genomic DNA by ~102-fold compared to that in the parent strain. Furthermore, as part of the Orc1-2-mediated DDR response genes for homologous recombination repair (HRR), cell aggregation and intercellular DNA transfer were upregulated, whereas genes for cell division were downregulated. However, the HRR pathway remained functional in host inhibition of SSV2 genome replication in the absence of UpsA, a subunit of pili essential for intercellular DNA transfer. In agreement with this finding, lack of the general transcriptional activator TFB3, which controls the expression of the ups genes, only moderately affected SSV2 genome replication. Our results demonstrate that infection of S. islandicus by SSV2 triggers the host DDR pathway that, in return, suppresses virus genome replication. IMPORTANCE Extremophiles thrive in harsh habitats and thus often face a daunting challenge to the integrity of their genome. How these organisms respond to virus infection when their genome is damaged remains unclear. We found that the thermophilic archaeon Sulfolobus islandicus became more inhibitory to genome replication of the virus SSV2 after preinfection UV irradiation than without the pretreatment. On the other hand, like treatment with UV or other DNA-damaging agents, infection of S. islandicus by SSV2 triggers the activation of Orc1-2-mediated DNA damage response, including the activation of homologous recombination repair, cell aggregation and DNA import, and the repression of cell division. The inhibitory effect of pretreatment with UV irradiation on SSV2 genome replication was no longer observed in an S. islandicus mutant lacking Orc1-2. Our results suggest that DNA damage response is employed by S. islandicus as a strategy to defend against virus infection.

Response of occurrence in microplastics and its adsorped cadmium capacity to simulated agricultural environmental scenarios in sludge-amended soil.

Large amounts of microplastics (MPs) enter the soil along with the amendment of sludge to soil. However, it is still unclear about the response of MPs occurrence and the adsorption behaviors of cadmium (Cd)on MPs to typical agricultural environmental scenarios. In present work, three kinds of MPs (polyethylene, polypropylene, and polystyrene) were chosen to investigate that response in three agricultural environmental scenarios with sludge-amended soil, including dry-wet alteration (7 d, five cycles), microbial addition (Bacillus subtilis, 0.05 g/g soil), and Ultraviolet (UV) irradiation (340 nm, 4 × 15 W, 4 d). The results showed that there was the highest adsorption capacity of Cd on MPs (36.21, 45.15, 12.43 µg/g for PE, PP, PS, respectively) after UV irradiation exceeding those from MPs triggered by other two scenarios). UV irradiation caused an increase in the abundance of Streptomyces, an expansion in specific surface area, a significant change in surface morphologies, an improvement in crystallinity or the formation of new crystals, and an enhancement in C-O and CO content, and then resulted in the incremental adsorption capacity of Cd on MPs. The findings are important of significance for controlling the environmental risks from sludge MPs via carrying heavy metals in the soil-plant systems.

A Novel Equipment-Free Paper-Based Fluorometric Method for the Analytical Determination of Quinine in Soft Drink Samples.

A simple, equipment-free, direct fluorometric method, employing paper-based analytical devices (PADs) as sensors, for the selective determination of quinine (QN) is described herein. The suggested analytical method exploits the fluorescence emission of QN without any chemical reaction after the appropriate pH adjustment with nitric acid, at room temperature, on the surface of a paper device with the application of a UV lamp at 365 nm. The devices crafted had a low cost and were manufactured with chromatographic paper and wax barriers, and the analytical protocol followed was extremely easy for the analyst and required no laboratory instrumentation. According to the methodology, the user must place the sample on the detection area of the paper and read with a smartphone the fluorescence emitted by the QN molecules. Many chemical parameters were optimized, and a study of interfering ions present in soft drink samples was carried out. Additionally, the chemical stability of these paper devices was considered in various maintenance conditions with good results. The detection limit calculated as 3.3 S/N was 3.6 mg L-1, and the precision of the method was satisfactory, being from 3.1% (intra-day) to 8.8% (inter-day). Soft drink samples were successfully analyzed and compared with a fluorescence method.

Photoinduced Processes in Lysine-Tryptophan-Lysine Tripeptide with L and D Tryptophan.

Optical isomers of short peptide Lysine-Tryptophan-Lysine (Lys-{L/D-Trp}-Lys) and Lys-Trp-Lys with an acetate counter-ion were used to study photoinduced intramolecular and intermolecular processes of interest in photobiology. A comparison of L- and D-amino acid reactivity is also the focus of scientists' attention in various specialties because today, the presence of amyloid proteins with D-amino acids in the human brain is considered one of the leading causes of Alzheimer's disease. Since aggregated amyloids, mainly Aß42, are highly disordered peptides that cannot be studied with traditional NMR and X-ray techniques, it is trending to explore the reasons for differences between L- and D-amino acids using short peptides, as in our article. Using NMR, chemically induced dynamic nuclear polarization (CIDNP) and fluorescence techniques allowed us to detect the influence of tryptophan (Trp) optical configuration on the peptides fluorescence quantum yields, bimolecular quenching rates of Trp excited state, and the photocleavage products formation. Thus, compared with the D-analog, the L-isomer shows a greater Trp excited state quenching efficiency with the electron transfer (ET) mechanism. There are experimental confirmations of the hypothesis about photoinduced ET between Trp and the CONH peptide bond, as well as between Trp and another amide group.

Determination of Anthraquinone-Tagged Amines Using High-Performance Liquid Chromatography with Online UV Irradiation and Luminol Chemiluminescence Detection.

Quinones are frequently used as derivatization reagents in HPLC analysis to improve detection sensitivity. In the present study, a simple, sensitive, and selective chemiluminescence (CL) derivatization strategy for biogenic amines, prior to their HPLC-CL analysis, was developed. The novel CL derivatization strategy was established based on using anthraquinone-2-carbonyl chloride as derivatizing agent for amines and then using the unique property of the quinones' moiety to generate reactive oxygen species (ROS) in response to UV irradiation. Typical amines such as tryptamine and phenethylamine were derivatized with anthraquinone-2-carbonyl chloride and then injected into an HPLC system equipped with an online photoreactor. The anthraquinone-tagged amines are separated and then UV-irradiated when they pass through a photoreactor to generate ROS from the quinone moiety of the derivative. Tryptamine and phenethylamine can be determined by measuring the chemiluminescence intensity produced by the reaction of the generated ROS with luminol. The chemiluminescence disappears when the photoreactor is turned off, suggesting that ROS are no longer generated from the quinone moiety in the absence of UV irradiation. This result indicates that the generation of ROS could be controlled by turning the photoreactor on and off. Under the optimized conditions, the limits of detection for tryptamine and phenethylamine were 124 and 84 nM, respectively. The developed method is successfully applied to determine the concentrations of tryptamine and phenethylamine in wine samples.