Glycated walnut meal peptide­calcium chelates (COS-MMGGED-Ca): Preparation, characterization, and calcium absorption-promoting.

This study isolated a novel peptide MMGGED with strong calcium-binding capacity from defatted walnut meal and synthesized a novel peptide­calcium chelate COS-MMGGED-Ca with high stability via glycation. Structural characterization and computer simulation identified binding sites, while in vitro digestion stability and calcium transport experiments explored the chelate's properties. Results showed that after glycation, COS-MMGGED bound Ca2+ with 88.75 ± 1.75 %, mainly via aspartic and glutamic acids. COS-MMGGED-Ca released Ca2+ steadily (60.27 %), with thermal denaturation temperature increased by 18 °C and 37 °C compared to MMGGED-Ca, indicating good processing performance. Furthermore, COS-MMGGED significantly enhanced Ca2+ transport across Caco-2 monolayers, 1.13-fold and 1.62-fold higher than CaCl2 and MMGGED, respectively, at 240 h. These findings prove glycation enhances structural properties, stability, calcium loading, and transport of peptide­calcium chelates, providing a scientific basis for developing novel efficient calcium supplements and high-value utilization of walnut meal.

A new method for the rapid identification of external water types in rainwater pipeline networks using UV-Vis absorption spectroscopy.

Ultraviolet-visible (UV-Vis) absorption spectroscopy, due to its high sensitivity and capability for real-time online monitoring, is one of the most promising tools for the rapid identification of external water in rainwater pipe networks. However, difficulties in obtaining actual samples lead to insufficient real samples, and the complex composition of wastewater can affect the accurate traceability analysis of external water in rainwater pipe networks. In this study, a new method for identifying external water in rainwater pipe networks with a small number of samples is proposed. In this method, the Generative Adversarial Network (GAN) algorithm was initially used to generate spectral data from the absorption spectra of water samples; subsequently, the multiplicative scatter correction (MSC) algorithm was applied to process the UV-Vis absorption spectra of different types of water samples; following this, the Variational Mode Decomposition (VMD) algorithm was employed to decompose and recombine the spectra after MSC; and finally, the long short-term memory (LSTM) algorithm was used to establish the identification model between the recombined spectra and the water source types, and to determine the optimal number of decomposed spectra K. The research results show that when the number of decomposed spectra K is 5, the identification accuracy for different sources of domestic sewage, surface water, and industrial wastewater is the highest, with an overall accuracy of 98.81%. Additionally, the performance of this method was validated by mixed water samples (combinations of rainwater and domestic sewage, rainwater and surface water, and rainwater and industrial wastewater). The results indicate that the accuracy of the proposed method in identifying the source of external water in rainwater reaches 98.99%, with detection time within 10 s. Therefore, the proposed method can become a potential approach for rapid identification and traceability analysis of external water in rainwater pipe networks.

A nonparametric point-by-point method to measure time-dependent frequency in wavelength modulation spectroscopy.

A nonparametric point-by-point (NPP) method is presented for high-accuracy measurement of the time-dependent frequency (laser frequency) in tunable laser absorption spectroscopy, crucial for ensuring ultimate measurement accuracy. In wavelength modulation spectroscopy in particular, the parametric methods in current use for time-dependent frequency measurement are insufficiently accurate and are difficult to apply to complex modulation scenarios. Based on a multi-scale viewpoint, point-by-point measurement of the frequency is realized by linear superposition of the frequency information mapped from the interferometric signal on a unit scale and on a local scale. Validation experiments indicate that the measurement accuracy of the proposed NPP method is three times that of the existing parametric methods, while effectively immunizing against non-ideal tuning effects. Additionally, the NPP method is suitable for use with arbitrarily complex modulations such as square wave modulation, for which parametric methods are inapplicable.

Air-microwave simultaneously induced carbon fiber surface oxidation and magnetism adjustment by CoOx nanoparticles rapid assembly for interface enhancement and electromagnetic wave absorption of its composites.

It is a significant challenge to develop a fast carbon fiber (CF) surface modification method, especially for the high strength electromagnetic wave (EMW) absorption materials. Herein, magnetic CoOx nanoparticles are successfully synthesized and uniformly assembled on CF surface with high oxygen-containing groups by rapid ambient microwave carbon thermal shock (MCTS). The presence of oxygen defect sites on CF surface promotes CoOx nanoparticles nucleation. The number of oxygen defects and the types of magnetic nanoparticles on the CF surface effectively adjust the surface chemical activity and the electromagnetic properties of CF, which is conducive to improving the EMW absorption performance and interface compatibility of the CoOx nanoparticles modified CF reinforced polyamide 6 (CO@CF/PA6) composites. Compared with CO@CF-0 s/PA6, the tensile strength and modulus of CO@CF-3.5 s/PA6 composite are increased by 18.1 % and 18.6 %, respectively. It also displays a minimum reflection loss value (-59.9 dB) at a thinner thickness of 1.9 mm while the maximum effective absorption bandwidth reaches 5.02 GHz with a thickness of 1.8 mm. Its radar cross-section values exhibit less than -10 dBm2 at all tested detection angles. This rapid MCTS shows great potential for large-scale production of CF modification with low-cost, efficient and environmentally friendly process.

A review of Per- and polyfluoroalkyl substances (PFASs) removal in constructed wetlands: mechanisms, enhancing strategies and environmental risks.

PER: and polyfluoroalkyl substances (PFASs), typical persistent organic pollutants detected in various water environments, have attracted widespread attention due to their undesirable effects on ecology and human health. Constructed wetlands (CWs) have emerged as a promising, cost-effective, and nature-based solution for removing persistent organic pollutants. This review summarizes the removal performance of PFASs in CWs, underlying PFASs removal mechanisms, and influencing factors are also discussed comprehensively. Furthermore, the environmental risks of PFASs-enriched plants and substrates in CWs are analyzed. The results show that removal efficiencies of total PFASs in various CWs ranged from 21.3% to 98%. Plant uptake, substrate absorption and biotransformation are critical pathways in CWs for removing PFASs, which can be influenced by the physiochemical properties of PFASs, operation parameters, environmental factors, and other pollutants. Increasing dissolved oxygen supply and replacing traditional substrates in CWs, and combining CWs with other technologies could significantly improve PFASs removal. Further, CWs pose relatively lower ecological and environmental risks in removing PFASs, which indicates CWs could be an alternative solution for controlling PFASs in aquatic environments.

An optimized method for PFAS analysis using HR-CS-GFMAS via GaF detection.

The analysis of per- and polyfluoroalkyl substances (PFAS) via sum parameters like extractable organic fluorine (EOF) in combination with high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) is highly promising regarding fluorine sensitivity and selectivity. However, the HR-CS-GFMAS method includes several drying and heating steps which can lead to losses of volatile PFAS before the molecular formation step using e.g., GaF formation. Hence, the method leads to a strong discrimination of PFAS within the EOF depending on their physical/chemical properties and is therefore associated with reduced accuracy. To reduce this discrepancy and to indicate realistic PFAS pollution values, an optimization of the HR-CS-GFMAS method for PFAS analysis is needed. Hence, we determined fluorine response factors of several PFAS with different physical/chemical properties upon application of systematic optimization steps. We could therefore improve the method's sensitivity for PFAS analysis using a modifier drying pre-treatment step followed by a sequential injection of sample solutions. The highest improvement in sensitivity of volatile PFAS was shown upon addition of a Mg modifier during drying pre-treatment. Thereby, during optimization the relative standard deviation of fluorine response factors could be reduced from 55 % (initial method) to 27 % (optimized method) leading to a more accurate determination of organofluorine sum parameters. The method provides an instrumental LOD and LOQ of ß(F) 1.71 µg/L and 5.13 µg/L, respectively. Further validation aimed to investigate several matrix effects with respect to water matrices. Here, substance-specific behavior was observed. For example, perfluorooctanoic acid (PFOA) which was used as calibrator, showed signal suppressions upon high chloride concentrations (>50 mg/L). Hence, a thorough separation of Cl from analytes during sample preparation is needed for accurate sum parameter analysis.

Characterization of oral drug absorption from jelly formulations: effects of membrane permeability and intestinal fluid volume.

This study aims to clarify the process of oral drug absorption from jelly formulations. Agar and pectin-based jellies containing drugs with different membrane permeability (high: antipyrine [ANT], medium: metoprolol [MET], low: atenolol [ATE]) were prepared and tested for in vitro drug release and in vivo drug absorption in rats. All drugs showed similar release profiles in vitro from both jelly formulations, except for the faster release from pectin jelly at neutral pH. In contrast, in vivo absorption of ATE but not of ANT from jelly formulations was significantly lower than from solution. Absorption of ATE and MET was low from agar jelly after oral administration, whereas additional water intake significantly increased the absorption. The process of drug absorption was described by the compartmental model consisting of jelly, intestinal fluid, and blood compartments. Drugs in the jelly diffuse into the intestinal fluid and then permeate the intestinal membrane. By considering the rate-limiting process, membrane permeability-dependent drug absorption from agar jelly and the effects of water intake were identified. In conclusion, jelly formulations may potentially decrease and delay drug oral absorption, especially of poorly permeable drugs. Intestinal fluid volume is one of the important factors to control the drug absorption.

Statistical estimation theory detection limits for label-free imaging.

Significance: The emergence of label-free microscopy techniques has significantly improved our ability to precisely characterize biochemical targets, enabling non-invasive visualization of cellular organelles and tissue organization. However, understanding each label-free method with respect to the specific benefits, drawbacks, and varied sensitivities under measurement conditions across different types of specimens remains a challenge. Aim: We link all of these disparate label-free optical interactions together and compare the detection sensitivity within the framework of statistical estimation theory. Approach: To achieve this goal, we introduce a comprehensive unified framework for evaluating the bounds for signal detection with label-free microscopy methods, including second-harmonic generation, third-harmonic generation, coherent anti-Stokes Raman scattering, coherent Stokes Raman scattering, stimulated Raman loss, stimulated Raman gain, stimulated emission, impulsive stimulated Raman scattering, transient absorption, and photothermal effect. A general model for signal generation induced by optical scattering is developed. Results: Based on this model, the information obtained is quantitatively analyzed using Fisher information, and the fundamental constraints on estimation precision are evaluated through the Cramér-Rao lower bound, offering guidance for optimal experimental design and interpretation. Conclusions: We provide valuable insights for researchers seeking to leverage label-free techniques for non-invasive imaging applications for biomedical research and clinical practice.

Peripheral serotonin controls dietary fat absorption and chylomicron secretion via 5-HT4 receptor in males.

Postprandial dyslipidemia is commonly present in people with type II diabetes and obesity and is characterized by overproduction of apolipoproteinB48 (apoB48)-containing chylomicron particles from the intestine. Peripheral serotonin is emerging as a regulator of energy homeostasis with profound implications for obesity, however, its role in dietary fat absorption and chylomicron production is unknown. Chylomicron production was assessed in Syrian golden hamsters by administering an olive oil gavage and i.p. poloxamer to inhibit lipoprotein clearance. Administration of serotonin or selective serotonin reuptake inhibitor, fluoxetine, increased postprandial plasma triglyceride (TG) and TG-rich lipoproteins (TRLs). Conversely, inhibiting serotonin synthesis pharmacologically by p-chlorophenylalanine (PCPA) led to a reduction in both the size and number of TRL particles, resulting in lower plasma TG and apoB48 levels. The effects of PCPA occurred independently of gastric emptying and vagal afferent signaling. Inhibiting serotonin synthesis by PCPA led to increased TG within the intestinal lumen and elevated levels of TG and cholesterol in the stool when exposed to a high-fat/high-cholesterol diet. These findings imply compromised fat absorption, as evidenced by reduced lipase activity in the duodenum and lower levels of serum bile acids, which are indicative of intestinal bile acids. During the postprandial state, mRNA levels for serotonin receptors (5HTRs) were upregulated in the proximal intestine. Administration of cisapride, a 5HT4 receptor agonist, alleviated reductions in postprandial lipemia caused by serotonin synthesis inhibition, ind---icating that serotonin controls dietary fat absorption and chylomicron secretion via 5HT4 receptor.

Evaluation of Aluminum and Magnesium Absorption Following the Oral Administration of an Antacid Suspension Containing Magaldrate in Healthy Women Under Fed Conditions.

INTRODUCTION: Antacids are commonly used during pregnancy, and they are approved for the relief of symptoms of gastroesophageal reflux disease (GERD) during pregnancy. However, there are no reports of the quantification of the absorption of aluminum and magnesium in the antacid magaldrate in women. The aim of this study was to quantify the rate and magnitude of absorption of aluminum and magnesium in magaldrate. METHODS: An open-label, controlled, randomized, one-treatment study with a two-group design was conducted in healthy women in a fed state. The volunteers had a standard breakfast, and 30 min later, they were given a single-medication sachet containing 500 mg of sodium alginate, 267 mg of sodium bicarbonate, 800 mg of magaldrate, and 120 mg of simethicone (group A, n = 8) or no medication (group B, n = 2). Blood samples were obtained 36 h before and up to 12 h after antacid administration. The method used for quantification was inductively coupled plasma-mass spectrometry. RESULTS: There was no absorption of aluminum in any of the blood samples from the healthy volunteers who received the drug or in those from the control group. Magnesium was detected at normal concentrations. CONCLUSION: These findings suggest that the use of this antacid is safe and without risk in healthy women, including pregnant women. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov registration: NCT06367452.

Detecting rare earth elements using EnMAP hyperspectral satellite data: a case study from Mountain Pass, California.

Rare earth elements (REEs) exhibit diagnostic absorption features in the visible-near infrared region, enabling their detection and identification via spectroscopic methods. Satellite-based remote sensing mapping of REEs, however, has not been attainable so far due to the necessity for high-quality hyperspectral data to resolve their narrow absorption features. This research leverages EnMAP hyperspectral satellite data to map REEs in Mountain Pass, California-a mining area known to host bastnaesite-Ce ore in sövite and beforsite carbonatites. By employing a polynomial fitting technique to characterize the diagnostic absorption features of Neodymium (Nd) at ∼740 and ∼800 nm, the surface occurrence of Nd was successfully mapped at a 30m pixel resolution. The relative abundance of Nd was represented using the continuum-removed area of the 800 nm feature. The resulting map, highlighting hundreds of anomalous pixels, was validated through laboratory spectroscopy, surface geology, and high-resolution satellite imagery. This study marks a major advancement in REE exploration, demonstrating for the first time, the possibility of directly detecting Nd in geologic environments using the EnMAP hyperspectral satellite data. This capability can offer a fast and cost-effective method for screening Earth's surfaces for REE signature, complementing the existing exploration portfolio and facilitating the discovery of new resources.

Speciation of copper and zinc compounds relevant for the hazard property (HP) 14 classification of municipal solid waste incineration bottom and fly ashes.

The analysis of the presence and content of substances that are toxic to aquatic life in waste is essential for classification of waste with regard to hazard property (HP) 14 'ecotoxic'. For the determination of HP14 classified copper (Cu) and zinc (Zn) compounds in various municipal solid waste incineration bottom ashes (IBA) and one fly ash (FA) from Germany we applied X-ray absorption near-edge structure (XANES) spectroscopy in combination with linear combination fitting. The analysis showed that approx. 50-70% of Cu in the IBA are Cu(I) compounds and elemental Cu(0), but these compounds were not equally distributed in the different IBA. In contrast, the majority (approx. 50-70%) of Zn in all IBA is elemental zinc, which originates from brass or other alloys and galvanized metals with a large content of zinc in the waste. The FA contain higher mass fraction on Zn and other toxic elements, but similar Cu and Zn species. Additional performed selective extraction at a pH of 4 with an organic acid of some IBA showed that the ecotoxic Zn fraction is mainly elemental zinc and zinc oxide. In contrast, for the ecotoxic Cu fraction within the IBA no specific compound could be identified. Furthermore, the XANES analysis showed that the HP14 properties of especially Cu in IBA is overestimated with current best-practice guidelines for sample processing for the current substance-related approach with the 0.1% cut-off rule for each substance. However, it should be considered whether it would not be better from an environmental point of view to take the ecotoxicologically leachable copper and zinc as a reference value.

Optimization Design of the Multidimensional Heterostructure toward Lightweight, Broadband, Highly Efficient, and Flame-Retarding Electromagnetic Wave-Absorbing Composites.

A novel multidimensional electromagnetic wave-absorbing material was developed by combining carboxylated carbon nanotubes (CNT) with graphene oxide (GO) through multidimensional design, and cobalt/nickel-based metal organic frameworks (Co/Ni-MOF) were subsequently loaded onto the GO surface via its rich functional groups to form the composite absorbing material CNT-rGO-Co/Ni-MOF. Incorporating 25 wt % of CNT-rGO-Co/Ni-MOF into the paraffin matrix led to a remarkable RLmin value of -43 dB at 16.4 GHz, with an effective absorbing bandwidth (EAB) exceeding 4 GHz, all within a thickness of just 1.5 mm, showcasing its "lightweight, broadband, and high efficiency" characteristics. The exceptional electromagnetic wave absorption performance was attributed to multi-interface polarization loss, resistance loss, and magnetic medium loss. Furthermore, when incorporating 10 wt % of CNT-rGO-Co/Ni-MOF, the heat release capacity and peak heat release rate of EP/CNT-rGO-Co/Ni-MOF10 decreased by 59.2 and 52.6%, respectively.

Effect of alkali treatment on mechanical and water absorption properties of biodegradable wheat-straw/glass fiber reinforced epoxy hybrid composites: A sustainable alternative for conventional materials.

Fiber-reinforced polymer composites are preferred over conventional materials because of their superior strength and modulus. Previously limited due to high manufacturing costs, synthetic fibers have been replaced by some natural fibers, such as waste wheat straw fibers. Here, epoxy-based polymer composites' mechanical and physical properties have been investigated, focusing on fiber weight ratios for both treated and untreated fiber. The research found that treated fibers display more effective mechanical qualities than untreated fibers, with a higher tensile strength of 54.4 MPa. The untreated Wheat Straw-Glass fiber reinforced composite has a less tensile strength of 26.3 MPa (10 wt% fiber). Pure resin-based composite has the most minor tensile strength at 1.52 MPa. The highest flexural strength obtained for hybrid composite is 88.76 MPa for treated fiber with epoxy resin and 49.6 MPa for untreated 30 wt % fiber. At the same time, the sole epoxy resin composite has the lowest value of 10.60 MPa. Untreated fiber (30 wt%) has the highest impact energy of 8J. Untreated wheat straw fiber absorbs more water due to its hydrophilic nature. In contrast, treated fiber exhibits better bonding and minimal water content, and the sole epoxy resin composite exhibits hydrophobic properties, resulting in less water absorption. The treated fiber displays better bonding than the untreated fiber throughout the SEM analysis. Wheat Straw fiber is mainly used for biodegradable plastic formation, housing construction, building materials, etc.

A reliable method to prepare milligram size environmental samples to quantify metal(loid)s by high-resolution graphite furnace atomic absorption spectrometry.

We searched for an extraction method that would allow a precise quantification of metal(loid)s in milligram-size samples using high-resolution graphite furnace atomic absorption spectrometry (HR-GFAAS). We digested biological (DORM-4, DOLT-5 and TORT-3) and sediment (MESS-4) certified reference materials (CRMs) using nitric acid in a drying oven, aqua regia in a drying oven, or nitric acid in a microwave. In addition, we digested MESS-4 using a mixture of nitric and hydrofluoric acids in a drying oven. We also evaluated the effect of sample size (100 and 200 mg) on the extraction efficiency. Nitric acid extraction in a drying oven yielded the greatest recovery rates for all metal(loid)s in all tested CRMs (80.0 %-100.0 %) compared with the other extraction methods tested (67.3 %-99.2 %). In most cases, the sample size did not have a significant effect on the extraction efficiency. Therefore, we conclude that nitric acid digestion in a drying oven is a reliable extraction method for milligram-size samples to quantify metal(loid)s with HR-GFAAS. This validated method could provide substantial benefits to environmental quality monitoring programs by significantly reducing the time and costs required for sample collection, storage, transport and preparation, as well as the amount of hazardous chemicals used during sample extraction and analysis. •Sample digestion with nitric acid in a drying oven yielded the greatest recovery rates of metal(loid)s from biological and sediment certified reference materials.•The recovery rates of metal(loid)s from biological and sediment certified reference materials using nitric acid digestion in a drying oven ranged from 73 % to 100 %.•Digestion with nitric acid in a drying oven is a simple and reliable method to extract small size environmental samples for metal(loid)s quantification by high-resolution graphite furnace atomic absorption spectrometry.

Impact of air pollution and heavy metal exposure on sperm quality: A clinical prospective research study.

Exposure to air pollution poses significant risks to human health, including detrimental effects on the reproductive system, affecting both men and women. Our prospective clinical study aimed to assess the impact of prolonged air pollution exposure on sperm quality in male patients attending a fertility clinic. The current study was conducted at Sri Narayani Hospital and Research Centre in Vellore, Tamil Nadu, India, and the study examined sperm samples obtained from individuals with extended exposure to air pollution. Microscopic analysis, including scanning electron microscopy (SEM), was conducted to evaluate sperm morphology. At the same time, atomic absorption spectroscopy (AAS) determined the presence of heavy metals, including Zinc (Zn), Magnesium (Mg), Lead (Pb) and Cadmium (Cd), known to affect sperm production. Our findings revealed that long-term exposure to air pollution adversely affects sperm quality, manifesting in alterations during the spermatogenesis cycle, morphological abnormalities observed through SEM, and impaired sperm motility. Additionally, epidemiological evidence suggests that elevated levels of cadmium and lead in the environment induce oxidative stress, leading to sperm DNA damage and reduced sperm concentrations. These results underscore the urgent need for environmental interventions to mitigate air pollution and protect reproductive health.

Medical associations and expert committees urge that ethanol be approved as a virucidal active substance for use in hand antiseptics under the European Biocidal Products Regulation, without a CMR classification.

Introduction: Since 2007, the classification of ethanol under the Biocidal Products Regulation has paradoxically remained unresolved due to conflicting views among experts and authorities. Initially, there was a discussion about classifying ethanol as carcinogenic. The current proposal to extend its harmonized classification includes, among other things, categorizing it as reproductive toxicity category 2 ("suspected to have CMR potential for humans"; carcinogenic, mutagenic, reprotoxic). If ethanol were classified under reproductive toxicity category 2, it would mean that the only active ingredient in hand antiseptics effective against non-enveloped viruses would no longer be available. Scientific assessment of the safety of ethanol-based hand rubs EBHR: Available epidemiological studies do not confirm an increased risk for cancer from EBHR in exposed individuals, except under uncommon or unlikely routes or levels of exposure.The evidence for ethanol's reprotoxic effect originates from the consumption of alcoholic beverages by pregnant women, where ethanol uptake is incomparably higher. The amount of transdermal ethanol absorption during hand antisepsis is up to ten times lower than the oral intake of beverages containing hidden ethanol, such as apple juice, kefir, or non-alcoholic beer. Blood alcohol levels after using EBHR remain within the physiological range associated with food intake. Conclusion: There is no epidemiological evidence of toxicity for workers handling ethanol-containing products in industry or using EBHR in healthcare settings. Given that the classification of EBHR as reproductive toxicity category 2 is not supported by current scientific research and that no alternative biocidal active substance in hand rubs is effective against non-enveloped viruses, medical associations and expert committees from Europe, the USA, Canada, the Asia-Pacific region, and the World Society for Virology unequivocally recommend, with the highest priority, that EBHR be approved as an active substance for PT1 biocides and not be classified as a reproductive toxicant in category 2.

Methods in molecular photocrystallography.

Over the last three decades, the technology that makes it possible to follow chemical processes in the solid state in real time has grown enormously. These studies have important implications for the design of new functional materials for applications in optoelectronics and sensors. Light-matter interactions are of particular importance, and photocrystallography has proved to be an important tool for studying these interactions. In this technique, the three-dimensional structures of light-activated molecules, in their excited states, are determined using single-crystal X-ray crystallography. With advances in the design of high-power lasers, pulsed LEDs and time-gated X-ray detectors, the increased availability of synchrotron facilities, and most recently, the development of XFELs, it is now possible to determine the structures of molecules with lifetimes ranging from minutes down to picoseconds, within a single crystal, using the photocrystallographic technique. This review discusses the procedures for conducting successful photocrystallographic studies and outlines the different methodologies that have been developed to study structures with specific lifetime ranges. The complexity of the methods required increases considerably as the lifetime of the excited state shortens. The discussion is supported by examples of successful photocrystallographic studies across a range of timescales and emphasises the importance of the use of complementary analytical techniques in order to understand the solid-state processes fully.

Electric-magnetic dual-gradient structure design of thin MXene/Fe3O4 films for absorption-dominated electromagnetic interference shielding.

The challenge of achieving high-performance electromagnetic interference (EMI) shielding films, which focuses on electromagnetic waves absorption while maintaining thin thickness, is a crucial endeavor in contemporary electronic device advancement. In this study, we have successfully engineered hybrid films based on MXene nanosheets and Fe3O4 nanoparticles, featuring intricate electric-magnetic dual-gradient structures. Through the collaborative influence of a unique dual-gradient structure equipped with transition and reflection layers, these hybrid films demonstrate favorable impedance matching, abundant loss mechanisms (Ohmic loss, interfacial polarization and magnetic loss), and an "absorb-reflect-reabsorb" process to achieve absorption-dominated EMI shielding capability. Compared with the single conductive gradient structure, the dual-gradient structure effectively enhances the absorption intensity per unit thickness, and thus reduces the thickness of the film. The optimized film demonstrates a remarkable EMI shielding effectiveness (SE) of 49.98 dB alongside an enhanced absorption coefficient (A) of 0.51 with a thickness of only 180 µm. The thin films with a dual-gradient structure hold promise for crafting absorption-dominated electromagnetic shielding materials, highlighting the potential for advanced electromagnetic protection solutions.

The synthesis of novel unnatural amino acid by intramolecular aza-Michael addition reaction as multitarget enzyme inhibitors.

Synthesis of novel unnatural amino acids (UAAs) from 4-oxo-4-phenylbut-2-enoic acid derivatives with intramolecular aza-Michael addition reaction in the presence of chlorosulfonyl isocyanate (CSI) was reported in soft conditions without any metal catalyst. Acids and base as a catalyst, and solvents effects were investigated for the synthesis of novel UAAs. This novel method provides inexpensive, practicable, and efficient approach to generate UAAs. The use of UAAs has attracted great interest in the development of therapeutic agents and drug discovery to improve their properties. In this context, in addition to the synthesis of new UAAs, their inhibition effects on important metabolic enzymes of acetylcholinesterase (AChE) and carbonic anhydrases I and II (hCA I and II) enzymes were investigated. The compound 2g showed the best inhibition for CA I and AChE enzymes, while compound 2i exhibited the best inhibition profile against CA II isoenzyme. The inhibition values of these compounds were found as 1.85 ± 0.64 for AChE, 0.53 ± 0.07 for hCA I, 0.44 ± 0.15 µM for hCA II, respectively, and they showed a stronger inhibitory property than acetazolamide (standard inhibitor for hCA I and II) and tacrine (standard inhibitor for AChE) molecules. The activity of the studied molecule against different proteins that are hCA I (PDB ID: 2CAB), hCA II (PDB ID: 5AML), and AChE (PDB ID: 1OCE) was examined. Finally, the drug properties of the studied molecule were examined by performing absorption, distribution, metabolism, excretion, and toxicity analysis.