UV Absorption Research Articles

Comparing the VANDELS Sample to a Zoom-in Radiative Hydrodynamical Simulation: Using the Si ii and C ii Line Spectra as Tracers of Galaxy Evolution and Lyman Continuum Leakage

We compare mock ultraviolet C ii and Si ii absorption and emission line features generated using a ∼109 M ⊙ virtual galaxy with observations of 131 z ∼ 3 galaxies from the vandels survey. We find that the mock spectra reproduce reasonably well a large majority (83%) of the vandels spectra (χ 2 < 2), but do not resemble the most massive objects (⪆1010 M ⊙), which exhibit broad absorption features. Interestingly, the best-matching mock spectra originate from periods of intense star formation in the virtual galaxy, where its luminosity is 4 times higher than in periods of relative quiescence. Furthermore, for each galaxy, we predict the Lyman continuum (LyC) escape fractions ( fesc(pred)LyC ) using the environment of the virtual galaxy. We derive an average fesc(pred)LyC of 0.01 ± 0.02, consistent with other estimates from the literature. The fesc(pred)LyC are tightly correlated with the Lyα escape fractions and highly consistent with observed empirical trends. Additionally, galaxies with larger fesc(pred)LyC exhibit bluer β slopes, more Lyα flux, and weaker low-ionization absorption lines. Building upon the good agreement between fesc(pred)LyC and observationally established LyC diagnostics, we examine the LyC leakage mechanisms in the simulation. We find that LyC photon leakage is enhanced in directions where the observed flux dominantly emerges from compact regions depleted of neutral gas and dust, mirroring the scenario inferred from observational data. In general, this study further highlights the potential of high-resolution radiation hydrodynamics simulations in analyzing UV absorption and emission line features and providing valuable insights into the LyC leakage of star-forming galaxies.

Performance of Chitosan/Carbon Nanotube-Coated Ultrafiltration Membranes for Natural Organic Matter Removal from Drinking Water

The objective of this study is to improve the filtration efficiency of commercially available polyethersulfone (PES) ultrafiltration (UF) membranes, with a specific focus on removing natural organic matter (NOM) and preventing membrane fouling. The modification of UF membranes was accomplished by utilizing chitosan/multi-walled carbon nanotubes (CS/MWCNT-OH) and employing both dip and spin coating techniques. The membrane surface morphologies were evaluated using the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and Energy-Dispersive X-ray Spectroscopy (EDX) techniques. Tests were carried out to assess the effectiveness of the membranes in a laboratory-scale system using two primary water sources from Istanbul, specifically the Melen River and Terkos Lake. Total organic carbon (TOC), UV254 absorbance, turbidity, and trihalomethane formation potential (THMFP) were all measured as part of a thorough analysis. The surface morphology investigations verified the effective deposition of MWCNT-OH nanoparticles onto the membrane surface. This was corroborated by the reduction in the water contact angle, showing an improvement in the hydrophilicity of the membrane. The modified membranes demonstrated much higher TOC removal rates compared to the original membranes. Specifically, the removal efficiencies for Melen River and Terkos Lake were 37.14% and 56.86%, respectively. Nevertheless, the alteration of the surface led to a decline in membrane flux as a result of the concurrent drop in pore size. To summarize, the results of this work highlights the considerable capability of surface modification using CS/MWCNT-OH to improve the performance and antifouling characteristics of commercial PES UF membranes.

In-line fiber optical sensor for detection of IgG aggregates in affinity chromatography

Therapeutic monoclonal antibodies (mAbs) are critical for treatment of a wide range of diseases. Immunoglobulin G (IgG) is the most predominant form of mAb but is prone to aggregation during production. Detection and removal of IgG aggregates are time-consuming and laborious. Chromatography is central for purification of biopharmaceuticals in general and essential in the production of mAbs. Protein purification systems are usually equipped with detectors for monitoring pH, UV absorbance, and conductivity, to facilitate optimization and control of the purification process. However, specific in-line detection of the target products and contaminating species, such as aggregates, is currently not possible using convectional techniques. Here we show a novel fiber optical in-line sensor, based on localized surface plasmon resonance (LSPR), for specific detection of IgG and IgG aggregates during affinity chromatography. A flow cell with a Protein A sensor chip was connected to the outlet of the affinity column connected to three different chromatography systems operating at lab scale to pilot scale. Samples containing various IgG concentrations and aggregate contents were analyzed in-line during purification on a Protein A column using both pH gradient and isocratic elution. Because of avidity effects, IgG aggregates showed slower dissociation kinetics than monomers after binding to the sensor chips. Possibilities to detect aggregate concentrations below 1 % and difference in aggregate content smaller than 0.3 % between samples were demonstrated. In-line detection of aggregates can circumvent time-consuming off-line analysis and facilitate automation and process intensification.

Spectral characteristics of dissolved organic matter in Plateau Lakes: Identifying eutrophication indicators in Southwest China

Dissolved organic matter (DOM) acts as a chemical intermediary between terrestrial and lacustrine ecosystems and significantly affects the structure and function of lakes. The trophic state of lakes, driven by terrestrial input and phytoplankton biomass, alters the optical properties of DOM. From November 2018 to July 2019, we collected 119 water samples from the Erhai watershed and analyzed them using UV–Vis and EEM-PARAFAC to study the optical properties of DOM in relation to the trophic conditions. Our result indicated that the tyrosine-like protein (C1), tryptophan-like protein (C2), and humic-like compounds (C3) were among the mostly autochthonous components of the DOM. The percentage of the C3 was higher in eutrophic lakes than in mesotrophic and light-eutrophic lakes. The ultraviolet absorption coefficients at 254 nm (aCDOM(254)) and fluorescence intensity at 355 nm (Fn(355)) increased significantly (p < 0.01) with an increased trophic state. Our findings indicate that the influence of nutrients and environmental factors (such as pH and water temperature) on DOM varies with the trophic state. The development of novel predictive models for trophic state assessment was largely based on the significant correlations between TSI and aCDOM(254) (R2 = 0.762, p < 0.01) and Fn(355) (R2 = 0.705, p < 0.01). This neural network model facilitates the creation of a novel fast assessment tool by highlighting the connection between DOM features and the trophic state index. By enabling swift experimental measurements, this model offers a high-resolution monitoring solution for tracking the eutrophication of plateau lakes and rivers.

Prediction of Vacuum Ultraviolet/Ultraviolet Gas-Phase Absorption Spectra Using Molecular Feature Representations and Machine Learning.

Ultraviolet (UV) absorption spectroscopy is a widely used tool for quantitative and qualitative analyses of chemical compounds. In the gas phase, vacuum UV (VUV) and UV absorption spectra are specific and diagnostic for many small molecules. An accurate prediction of VUV/UV absorption spectra can aid the characterization of new or unknown molecules in areas such as fuels, forensics, and pharmaceutical research. An alternative to quantum chemical spectral prediction is the use of artificial intelligence. Here, different molecular feature representation techniques were used and developed to encode chemical structures for testing three machine learning models to predict gas-phase VUV/UV absorption spectra. Structure data files (.sdf) and VUV/UV absorption spectra for 1397 volatile and semivolatile chemical compounds were used to train and test the models. New molecular features (termed ABOCH) were introduced to better capture pi-bonding, aromaticity, and halogenation. The incorporation of these new features benefited spectral prediction and demonstrated superior performance compared to computationally intensive molecular-based deep learning methods. Of the machine learning methods, the use of a Random Forest regressor returned the best accuracy score with the shortest training time. The developed machine learning prediction model also outperformed spectral predictions based on the time-dependent density functional theory.

Landfill leachate treatment using sequential natural zeolite adsorption and peroxymonosulfate activated by UV/Fe2+ system: Effects of main operating parameters and application of fluorescence EEM to monitor organic matters’ transformation

The significant increase in global Landfill Leachate is a pressing challenge directly linked to the growing global population. Among the strategies for landfill leachate treatment, advanced oxidation processes using sulfate radical (SR-AOP) have gained considerable interest, despite the challenge of nitrate generation during ammonia oxidation. This study introduces a sequential treatment method that combines adsorption and a UV/PMS/Fe2+ system to assess its impact on COD (Chemical Oxygen Demand) and ammonia removal efficiencies.The results show that the sequential process achieves optimal COD and ammonia removal rates of 88 % and 88.3 % respectively. The increase in UV254 absorbance removal during the adsorption phase indicates the removal of UV quenching substances (UVQS), supporting the effectiveness of using adsorption as a pretreatment for the UV-assisted systems (UV/PMS/Fe2+). Additionally, analysis using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) reveals that the adsorption treatment before the SR-AOP process not only enhances COD and ammonia removal efficiencies, but also eliminates heavy metals such as vanadium (V), titanium (Ti), zinc (Zn), and aluminum (Al) present in leachate.Moreover, the higher BOD/COD ratio suggests improved biodegradability of the effluent. When compared to other systems at optimal conditions, the sequential adsorption and UV/PMS/Fe2+ systems demonstrate superior performance, focusing on removing refractory matter and reducing ammonia content, especially effective at a pH level of 7.25. Analysis using Excitation-Emission Matrix (EEM) shows a shift from primary peaks in raw leachate spectra associated with humic and fulvic acid-like compounds to lower-intensity peaks from fulvic-like small molecule materials in the treated effluent.

Investigational Study of Mesalamine Dissolution Discrepancy: Utilization of Hyphenated Ultrahigh Performance Liquid Chromatography‐Charged Aerosol Detection‐High‐Resolution Mass Spectrometry

ABSTRACTPentasa (mesalamine/MSLM) is a widely prescribed delayed‐release capsule formulation for the treatment of inflammatory bowel disease. During dissolution study of Pentasa through ultraviolet (UV) spectroscopy, an unusual end‐release of about 110% has been observed. Initial liquid chromatography‐UV (LC‐UV) analyses of these dissolution samples confirmed three prominent peaks other than MSLM with a significant area percentage. Further systematic investigation was carried out by incubating active pharmaceutical ingredient in dissolution media for a longer duration and at elevated temperature followed by analysis through an inverse gradient LC‐charged aerosol detector (CAD). LC–high‐resolution mass spectrometry (HRMS) and online hydrogen‐deuterium exchange (HDX) mass spectrometry were also employed to identify and characterize these artifact products. The area % of prominent artifacts in LC‐UV was found to be way significant when compared to the area % obtained through inverse LC‐CAD, as CAD quantifies the peaks independent of the UV wavelength of absorbance. Inverse LC‐CAD was suitable to determine the relative response factor, whereas LC‐HRMS/MS and online HDX‐MS supported the characterization of these artifacts. These artifacts were found to be trimers, tetramers of MSLM formed due to polymerization, imparting additional pi‐bonds resulting in high UV absorptivity. These techniques when used in combinations serve complimentary to each other during such investigations.

The Gas Phase Protonation Sites of Six Naturally Occurring Nicotinoids.

The gas phase protonation sites of six naturally occurring nicotinoids, namely nicotine (NIC), nornicotine (NOR), anabasine (ANB), anatabine (ANT), cotinine (COT), and myosmine (MYO), consisting of a common Pyridine and differing non-Pyridine rings, have been determined for the first time at the physiological temperature from cryogenic ion trap infrared spectroscopy and electronic structure calculations. The protonation site on either of these two rings is related to the nicotinoid's biological activity. At room temperature, NIC is a mixture of Pyridine and Pyrrolidine (non-Pyridine) protomers, whereas NOR, ANB, ANT, and COT are pure Pyridine protomers and finally MYO is mostly a Pyroline (non-Pyridine) protomer. The nearly planar structure of MYO-H+, induced by the presence of a conjugated π system and confirmed from calculations and the UV absorption spectra, breaks from the trends observed for NIC, NOR, and ANB, since its structure is drastically different from the structures of the other nicotinoids.

Examining the dual effect of copper nanoparticles and nitrogen doping on Cu@N-TiO2

Abstract The study of six compositions of Cu@N-TiO2 with different amounts of copper and nitrogen synthesized using a sol–gel method is reported. X-ray diffraction patterns and Raman spectra indicated the formation of a single anatase TiO2 phase in all materials without evidence of secondary phases including copper or nitrogen. Electron microscopy images showed a homogeneous distribution of the copper particles around a TiO2 matrix, just as that the insertion of nitrogen did not have a significant effect on the morphology of the particles. X-ray photoelectron spectroscopy analysis confirmed that nitrogen was inserted in the atomic arrangement of titanium dioxide, while copper was presented mainly as metallic element on the TiO2 surface. Characterization of the optical properties and photoactivity test confirm that band gap strongly depends on the copper and nitrogen content phenomenon attributed to the combined presence of modifiers over the TiO2 surface and the promotion of a plasmonic effect, which displaced the absorption UV bands to higher wavelengths with respect to un-doped TiO2. The catalytic test performed using rhodamine-B as probe molecule, confirm that TiCuN2 and TiCuN3 samples exhibit the best decomposition percentages of 38 and 36 % respectively. Such results confirm the surface plasmon resonance effect associated to Cu particles on the TiO2 as main cause in the increase in current along synthesized samples and the use of cyclic voltammetry technique to identify these effects between 0.0 and 1.5 V.

A DFT study on structural, electronic, and optical properties of cubic perovskite semiconductors InXF3 (X = Be and Ca) for optoelectronic applications

First principles calculations were employed to study the structural, electronic and optical properties of Indium based cubic perovskite materials, specifically focusing on InBeF3 and InCaF3 compounds. The generalized gradient approximation Perdew–Burke–Ernzerhof (GGA_PBE) approximation and Tran–Blaha modified Becke–Johnson (TB-mBJ) approximations were used to study and compare the electronic and optical properties. The compound InBeF3 is predicted to have an indirect band gap of 2.51 eV in GGA_PBE and 2.96 eV in TB-mBJ. InCaF3 is found to have a direct wide band gap of 3.61 eV in GGA_PBE and 4.37 eV in TB-mBJ approximation. The partial density of states predicts the significance of In-5p and F-2p states in the conduction and valence bands, respectively. The dielectric constants decrease under the TB-mBJ approximation, with InCaF3 demonstrating lower values owing to its larger band gap. Optical activity analysis indicates transparency for both compounds with notable absorption peaks, suggesting potential applications in transparent coatings. Refractive indices decrease with photon energy, with values dropping below 1.0 in the TB-mBJ approximation, indicating superluminal behavior in wave propagation. The drop in refractive index value below1.0 is earlier for InCaF3 than InBeF3. Examination of the extinction coefficient reveals UV absorption peaks, indicating potential for optoelectronic applications. From this study it can be noticed that the compounds under study can be used for optoelectronic applications, supported by their predicted structural and optical properties study.

Collaborative polarization in a solution of coupled hydroxychloroquine-graphene oxide: Optoelectrical measurements

Optical UV–vis and electrical impedance measurements were conducted at room temperature on aqueous solutions with hydroxychloroquine (HCQ) and graphene oxide (GO) molecules. Remarkably, at sufficiently high GO concentration, the HCQ-GO solution exhibited the least loss factor and the Debye relaxation process, suggesting that the polarization of coupled HCQ-GO molecules is cooperative and, hence, correlated within the Debye relaxation time. Indeed, our systematic molecular dynamic calculations of the equilibrium Dipole Auto-Correlation Function (DACF) showed that adding GO enhances the decay relaxation time of DACF for HCQ samples. Moreover, the depression of the characteristic UV absorption peak (at ∼ 342 nm) with increasing GO concentration validated the presence of the HCQ-GO interaction in our samples, agreeing with our calculation based on the simplified time-dependent density functional theory. Our work is, thus, timely regarding the current high demand for a method to remove HCQ from the aqueous environment. It is also relevant to drug delivery applications considering the anticancer efficacy of HCQ and the biocompatible GO as a potential drug carrier.

Prolonged Lifespan of Superhydrophobic Thin Films and Coatings Using Recycled Polyethylene.

High-density polyethylene (HDPE) waste poses a significant environmental challenge due to its non-biodegradable nature and the vast quantities generated annually. However, conventional recycling methods are energy-intensive and often yield low-quality products. Herein, HDPE waste is upcycled into anti-aging, superhydrophobic thin films suitable for outdoor applications. A two-layer spin-casting method combined with heating-induced crosslinking is utilized to produce an exceptionally rough superhydrophobic surface, featuring a root mean square (RMS) roughness of 50 nm, an average crest height of 222 nm, an average trough depth of -264 nm, and a contact angle (CA) of 148°. To assess durability, weathering tests were conducted, revealing the films' susceptibility to degradation under harsh conditions. The films' resistance to environmental factors is improved by incorporating a UV absorber, maintaining their hydrophobic properties and mechanical strength. Our research demonstrates a sustainable method for upcycling waste into high-performance, weather-resistant, superhydrophobic films.

Effects of reaction temperature and oxygen pressure on dissolved organic matter in hydrothermal reactions of municipal sludge: A comprehensive analysis

The impact of temperature and oxygen pressure on the basic performance of hydrothermal reactions and dissolved organic matter (DOM) was investigated. The results showed that total chemical oxygen demand and volatile suspended solids removal rate achieved a maximum of 72 % and 99 %, respectively, at 260 °C and 0.9 MPa oxygen pressure. Oxygen demonstrated a significant role in enhancing sludge particle dissolution. The interaction with temperature resulted in a complex trend for dissolved organic carbon (DOC) and specific ultraviolet absorbance at 254 nm. Acetic acid and formic acid were identified as the prominent volatile fatty acids, with formic acid prevalent at lower temperatures, while acetic acid accumulated with increasing temperature and oxygen pressure. Three-dimensional excitation emission matrix and Fourier transform ion cyclotron resonance mass spectrometry was also employed to analyse DOM as over half of the DOC remained unknown. Parallel factor analysis indicated that three components with 8 peaks in total might represent a universal feature for fluorescent DOM in hydrothermal reaction solution. The deciphered data from FTICR-MS indicated that lipids and lignins as well as CHOS and CHON molecules were the main components of DOM. Meanwhile, condensed hydrocarbons were formed at high temperatures in wet oxidation runs. Moreover, identification of C19H32O3S, C18H30O3S and C18H26N2O3 as crucial intermediates further enriched the understanding of hydrothermal reactions in municipal sludge.

Research on COD parameter in water based on the combination of UV absorption photometry and laser spectroscopy

Chemical Oxygen Demand (COD) is widely utilized as a representative and required measurement indicator of water pollution as well as water quality monitoring. The spectral technology is an important development direction in water quality detection. In this paper, a novel COD monitoring instrument is designed based on ultraviolet (UV) absorption photometry and laser spectroscopy. The instrument consists of CODcr and CODmn detection modules. The CODcr module is based on the Lambert-Beer law to measure UV absorption of organic matter in water, which can be used to measure the COD parameter in high concentration organic pollution in water. The CODmn module is based on the ratio method of fluorescence and Raman to analyze the spectral signals generated by the laser-excited water body, which can determine the COD parameter in low contaminated water. By analyzing the CODcr and CODmn parameters together, the comprehensive evaluation of organic pollutants in water can be realized. In the experiment, the CODcr and CODmn modules are respectively calibrated with the potassium hydrogen phthalate (KHP) solution as well as the mixed solution of humic acid sodium and glucose. Then the stabilities of the two detection modules are tested, and the detected result drifts are stable within six days. In addition, to verify the reliability of measuring results in complex environments, we test the instruments at 10 monitoring sites of the Sow River in Weihai city. The results of on-site monitoring are highly consistent with those of national standard method. The study result shows that the instrument developed in this paper can measure both CODcr and CODmn simultaneously, which can expand the COD detection range, and provide a new method for the comprehensive detection of organic pollutants in water.

Revisiting and Updating the Interaction between Human Serum Albumin and the Non-Steroidal Anti-Inflammatory Drugs Ketoprofen and Ketorolac.

Ketoprofen (KTF) and ketorolac (KTL) are among the most primarily used non-steroidal anti-inflammatory drugs (NSAIDs) in humans to alleviate moderate pain and to treat inflammation. Their binding affinity with albumin (the main globular protein responsible for the biodistribution of drugs in the bloodstream) was previously determined by spectroscopy without considering some conventional pitfalls. Thus, the present work updates the biophysical characterization of the interactions of HSA:KTF and HSA:KTL by 1H saturation-transfer difference nuclear magnetic resonance (1H STD-NMR), ultraviolet (UV) absorption, circular dichroism (CD), steady-state, and time-resolved fluorescence spectroscopies combined with in silico calculations. The binding of HSA:NSAIDs is spontaneous, endothermic, and entropically driven, leading to a conformational rearrangement of HSA with a slight decrease in the α-helix content (7.1% to 7.6%). The predominance of the static quenching mechanism (ground-state association) was identified. Thus, both Stern-Volmer quenching constant (KSV) and binding constant (Kb) values enabled the determination of the binding affinity. In this sense, the KSV and Kb values were found in the order of 104 M-1 at human body temperature, indicating moderate binding affinity with differences in the range of 0.7- and 3.4-fold between KTF and KTL, which agree with the previously reported experimental pharmacokinetic profile. According to 1H STD-NMR data combined with in silico calculations, the aromatic groups in relation to the aliphatic moiety of the drugs interact preferentially with HSA into subdomain IIIA (site II) and are stabilized by interactions via hydrogen bonding and hydrophobic forces. In general, the data obtained in this study have been revised and updated in comparison to those previously reported by other authors who did not account for inner filter corrections, spectral backgrounds, or the identification of the primary mathematical approach for determining the binding affinity of HSA:KTF and HSA:KTL.

Biohybrid chitosan/silica self-supported films by soft chemistry in aqueous media: Biomimetic mineralization of Diatoms exoskeleton

Herein, we present a biomimetic approach mimicking the composition of the diatom frustule to create biohybrid chitosan/silica self-supported films. To mimic the composition of this exoskeleton, the bio-sourced chitosan polymer has been considered to replace the silaffins, proteins bearing many amino groups able to complex the silica dissolved in seawater and at the origin of the biosilification process. The sol-gel process on soft and mild conditions was used with TetraEthoxyOrthoSilicate TEOS as a silica precursor. Functional hybrid chitosan-silica self-supported films were then elaborated with different chitosan/TEOS compositions and characterized by surface (FTIR/ATR, XPS, ToF-SIMS, contact angle, SEM) and bulk (UV–visible spectroscopy, SAXS, water uptake) techniques. The chemical interaction between the chitosan and the TEOS during the film formation was demonstrated, leading to the formation of a durable interconnected structure that remains cohesive and resistant in a 2 wt% acetic acid solution. Moreover, the films exhibit ultraviolet light absorption characteristics, which could be valuable for the achievement of materials for sun protection.

Pollution Characteristics and Ecological Impact of Screening Analysis of Fishing Port Sediments from Dalian, North China.

Environmental pollution from synthetic chemical mixtures has significant adverse impacts on marine ecosystems. However, identifying the main constituents of chemical mixtures that pose ecological threats is challenging due to the necessity of an integrated workflow for comprehensive identification and toxicological prioritization of pollutants. Here, an all-in-one mass spectrometric strategy integrating target, suspect, and nontarget analysis was used to investigate organic pollutants of concern in fishing port sediments, with 355 pollutants (32 from target analysis, 118 from suspect screening and 205 from nontarget analysis) identified in 11 categories. The chemical classes of polycyclic aromatic hydrocarbons (PAHs), pesticides, and intermediates were the extensively detected chemical classes. The ecological risks of absolutely quantified pollutants (i.e., 16 parent PAHs, 7 organophosphate esters (OPEs), 10 pesticides and 4 benzotriazole ultraviolet absorbers) were assessed using toxicity-weighted concentration ranking, with o,p'-DDT being the major contributor. Under the toxicological priority index (ToxPi) framework, an extended ranking of all identified pollutants was achieved by combining instrument response and detection frequency, with a priority control list of 15 pollutants obtained, of which benzo[ghi]perylene (BghiP) and p,p'-DDE had the highest risk priority. Due to frequent detection rates and significant environmental risks, routine monitoring of petroleum pollutants is considered essential. This study presents a general workflow that includes comprehensive identification and prioritization of pollutants, facilitating chemical management and ecological risk assessment.

Chromaticity of Gromwell, Cape jasmine Dyeing, and Effects of Zinc Oxide/Polyphenol Treatment with Copper Mordanting for UV Protection

To protect skin from harmful ultraviolet (UV) radiation, there has been a resurgence in the use of natural dyes with metal mordants to reduce contamination by advanced chemicals. This study achieved natural dyeing in violet and yellow colors from Gromwell red roots and Cape jasmine seeds for UV-protective materials. The dyed fabrics were subjected to zinc oxide (ZnO) and polyphenol treatments, as well as copper post-mordanting. The SEM, TEM, and XRD tests showed that the ZnO nanoparticles, with hexagonal crystal structures, stuck to the fiber surfaces, and twisted strands resulted in the K/S reduction. First, this study found that the untreated cotton in violet, despite the highest K/S, faded the most intensely when exposed to UV. The color variation of untreated polyester was narrow, with little change in L, a*, and K/S. The color change of yellow-dyed samples treated with ZnO/polyphenol was not considerable in yellowness (b*: 28.838), while the violet fabrics displayed a significant decrease in K/S and an increase in b*. The combination of ZnO and polyphenol treatment improved UV absorption at 350 to 250 nm. Among the Cu-mordanted fabrics after ZnO/phenols treatment, the violet cotton turned reddish from blueish (negative to positive b*), with a hue change of 316° to 59° and the highest ΔE (25.90 ± 4.34) after UV exposure. In this study, the combination of ZnO/polyphenol with Cu-mordants allowed the Cape jasmine-dyed polyester to achieve a minimum ΔE as well as to keep its chroma and hue after UV exposure.

Green route to synthesize zinc oxide nanoparticles (ZnO[sbnd]NPs) using leaf extracts of Merremia quinquefolia (L.) Hallier f. and their potential applications

The current investigation focus on the facile, cost-effective, ecologically sustainable and green synthesized zinc oxide nanoparticles (ZnO NPs) from the Merremia quinquefolia leaf aqueous extract and tests their biomedical application. The ultraviolet (UV) spectrometry absorption peak at 373 nm validated the synthesis of zinc oxide nanoparticles. The X-ray diffraction (XRD) pattern indicates the crystalline nature of the material, and Fourier transform infrared (FTIR) analysis reveals its functional groups. Morphological studies in the scanning electron microscopy (SEM) and transmission electron microscope (TEM) analysis revealed rod-like shapes for ZnO NPs with sizes in the range of 43–70 nm. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of zinc, oxygen and organic molecules. Additionally, the vibrational peak at 437 and 480 cm−1 in the Raman spectra indicated it. By using the disc diffusion method, the zinc oxide nanoparticles that were made more effective at killing gram-positive pathogens, with Staphylococcus aureus having the largest zone of inhibition (14 ± 0.23). Assays for DPPH and ABTS radical scavenging showed higher antioxidant activity. It had a strongest effect on the anti-inflammatory activity of the IC50 values for albumin denaturation (92.78 μg/mL) and human red blood cells (84.59 μg/mL). Furthermore, the IC50 value of 41.81 μg/mL for zinc oxide nanoparticles was good for stopping the development of breast cancer. These findings indicate that green synthesized zinc oxide nanoparticles will make great biocompatible, antibacterial, anti-inflammatory and anticancer drugs in the future.

Screening and characterization of antagonistic Streptomyces sp. JS20 from marine sediment in Vaan Island

In the present study, we have isolated twenty four different Actinomycetia strains from marine sediment in Vaan Island, Tuticorin district (8.83639°N/78.21047°E), Tamil Nadu, India. Among these, the isolate JS20 has been identified as Streptomyces sp. JS20 by 16S rRNA phylogenetic analysis, which exhibited prominent antibacterial activity against panel of WHO priority pathogens mostly, MRSA a clinical pathogen. The bioassay guided fractionation dependent active compound exhibits RT at 3.0 with maximum UV absorption of 250 nm. Furthermore, FT-IR, 1H NMR, 13C NMR and LC-MS spectral analysis confirms the existence of polyketide metabolites with molecular mass of m/z 380.74 [M+Na]+ and m/z 397.00 [M+K]+ adducts. Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC) value of the purified compound against MRSA was found to be 7.81 µg/mL and 125 µg/mL respectively. Additionally, the anti-MRSA campaign of the purified compound was upheld qualitatively using the high content screening (HCS) and quantitatively by Flow Cytometry (FACS) analysis which indicates concentration of bactericidal activity increases when the concentration of the purified compound was increased. The action of bioactive compound was determined by cell morphology disruption on MRSA bacterial cells as results, the cytoplasm cellular contents and ATP leaky were ahead. Apart from these studies, NaCl tolerant, the multiple passage studies and post antibiotic effect of bioactive compound has been evaluated against the MRSA. Hence, the study revealed that the bioactive compound from the Streptomyces sp. JS20 can be used as a lead compound to inhibit the MRSA in future.