Negative Shift Research Articles

The Digital Paradox: Increased Connectivity and the Decline in Student Attitudes

In the contemporary educational landscape, digital technology has become ubiquitous, promising enhanced learning experiences and improved academic performance. This study investigates the paradoxical relationship between increased digital connectivity and the decline in student attitudes toward learning. The primary aim is to explore how extensive use of digital devices and social media impacts students' engagement, motivation, and overall academic outlook. A mixed-methods approach was employed, combining quantitative surveys and qualitative interviews with high school students across various socioeconomic backgrounds. The data reveals a significant correlation between high levels of digital connectivity and negative shifts in students' attitudes. Specifically, students reporting higher usage of digital devices exhibited lower levels of motivation, increased feelings of distraction, and a general disengagement from academic activities. The study concludes that while digital tools offer numerous educational benefits, their overuse can lead to detrimental effects on student attitudes. This finding contributes to the education field by highlighting the need for balanced digital integration strategies that foster positive student engagement and attitudes toward learning. The research underscores the importance of developing educational policies and practices that mitigate the adverse effects of digital overconnectivity while leveraging its potential benefits.

Polarization conversion and lateral shifts in multilayered structure with finitely-gapped topological surface states

Abstract The polarizatison conversion and the Goos–Hänchen (GH) shifts of the reflected electromagnetic wave for the multilayered structure made of topological insulator (TI) layers with finite surface energy gap are investigated. The transfer matrix formalism is adopted to analyze the reflection of electromagnetic wave through the multilayered structure, and the influences of surface energy gap, thickness and number of the TI layers are discussed. We find that maximum polarization conversion rate can be obtained with appropriate surface energy gap of TI, and within a certain range of finite energy gap, the polarization conversion effect is stronger than that for the case under the infinite surface energy gap limit. Greater polarization conversion rate for TI with small surface energy gap can be found than that for TI with larger energy gap in some range of layer numbers. At large incident angles the GH shifts vary considerably with the layer number for TI with relatively larger energy gap. Result of the combined influence of surface energy gap and layer number shows that, there exists both the positive and negative enhancement peaks of the GH shifts, and for smaller energy gap, fewer TI layers are required to obtain the transition between positive and negative GH shifts.

Electrodeposited Phosphorous-Doped Graphitic Carbon Nitride as A Versatile Metal Free Interface for Tryptophan Detection in Dietary, Nutritional, and Clinical Samples

Tryptophan (TRP) is an essential amino acid that is crucial for human growth and must be obtained through a dietary source or nutritional supplements. Both, the overconsumption or deficiency induces clinical symptoms. Therefore, a sensitive and selective method for quantifying TRP in dietary products, nutritional supplements, and clinical samples is essential. In this work, we have electrodeposited phosphorous doped graphitic carbon nitride (P-gCN) for developing a TRP voltammetric sensor. Outlining the benefits of electrodeposition over drop-casting, the developed P-gCN | GCE sensor demonstrated 7.83 times more sensitivity and a negative shift of ∼0.10 V for TRP electro-oxidation compared to unmodified electrode implying its remarkable electrocatalytic activity. The sensor featured a detection-limit of 7.1 nM and showcased excellent stability, repeatability and reproducibility. The practical utility of the sensor was manifested by estimating TRP in over 12 real samples including, food products, nutritional supplements and clinical samples (urine and human blood serum).

Multi-proxy record of the Austrian Upper Triassic Polzberg Konservat-Lagerstätte in light of the Carnian Pluvial Episode

We present a multi-proxy investigation of a lower Carnian basinal succession from Polzberg in the Northern Calcareous Alps (Lower Austria). A section comprising a unique Konservat-Lagerstätte was studied based on bio- and chemostratigraphy along with geophysical methods, yielding a detailed and robust stratigraphic calibration of the Polzberg succession. The Polzberg section revealed the paleoceanographic history and helped to identify a global climatic reversal, the Carnian Pluvial Episode. The age of the Upper Triassic Reingraben formation in the Northern Calcareous Alps is refined as the Austrotrachyceras austriacum Zone within the lower Carnian (Julian 2). Ammonoids and conodonts provide a detailed biostratigraphic subdivision that serves as a basis for analyses of the faunal distribution and the paleoenvironmental evolution of the Upper Triassic Reifling Basin. The succession includes lithological and facies changes similar to those of coeval units in the Tethys. The Carnian was characterized by a weak (~ 1‰) positive δ13C trend, punctuated by a negative shift during the lower Carnian corresponding to the initiation of the Carnian Pluvial Episode, a period representing the onset of early/late Carnian transitional global greenhouse conditions. Organic maturity parameters and the conodont alteration index (CAI) show that the thermal overprint of the Polzberg section is low. Biomarker proxies suggest that the organic matter of the uppermost Göstling formation is a mixture of marine and terrestrial material deposited in a dysoxic environment. Within the overlaying Reingraben formation, the amount of marine biomass decreased gradually upwards. Oxygen-depleted conditions, probably due to water-column stratification, continued during deposition of the Reingraben formation. Bacterial sulfate reduction played a major role in organic matter degradation.

Steric interaction of iridium sites towards efficient oxygen and hydrogen evolution

Transition metal materials that loaded with trace of Iridium (Ir) are widely accepted as effective catalysts for oxygen evolution (OER) and hydrogen evolution reaction (HER), in which the Ir atoms exposed on the surface can directly affect the electrocatalytic reaction. However, this neglects the Ir – Ir interaction of distinct locations, which may be benefit for the fine-tuning of electronic structure. Herein, we changed the locations (surface and inside) of Ir atoms in the cobalt oxide (Co3O4@NC), and investigated their alkaline OER and HER performances. Combined with X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and theoretical calculations, we infer that the steric interaction induced by the surface – internal Ir sites can weaken the Ir-O bond and optimize the adsorption of intermediates on catalyst surface with a negative shift of d-band center, enabling the surface-Ir sites with lower energy barrier for water dissociation and hydrogen adsorption for HER. Therefore, the as-prepared Irw-Co3O4@NC with surface − inside Ir distribution significantly improve the HER without degrading OER performance, with low overpotential of −173 / −71 mV for HER at −10 mA/cm2 in 0.1 M KOH / 1.0 M KOH, and 244 / 249 mV at 10 mA/cm2 for OER.

Effects of two common antibiotics on the skin microbiome of ornamental reef fishes: Implications for manipulative experiments in microbial dynamics

AbstractAn understanding of the mechanistic drivers of animal‐microbial symbiosis and associations generally requires experiments that manipulate specific symbionts or microbial communities. As part of an ongoing study of the mechanisms that drive microbial communities in coral reef fishes, and specifically the role of cleanerfish in microbial transmission, we tested the effects of the commonly used antibiotics Enrofloxacin and Nitrofurazone on the skin microbiome of three ornamental reef fish species: the four‐eyed butterflyfish, Chaetodon capistratus (Chaetodontidae), the cleanerfish neon goby Elacatinus oceanops (Gobiidae) and the beaugregory damselfish Stegastes leucostictus (Pomacentridae). Our main aim was to characterize dysbiosis prompted by the delivery of the two antibiotics and understand whether both could be used to establish good starting points for microbial transmission experiments. We bathed the fish in antibiotic (or no exposure in the controls), sampled the skin microbiota via swabbing at zero (before treatment) and 3 and 7 days during the treatments, and examined the microbial community using a 16S rRNA gene sequencing approach. Nitrofurazone reduced skin‐associated microbial diversity in all species, whereas the same effect for Enrofloxacin was only seen in S. leucostictus. Although each antibiotic had its own, unique impact in microbial community, all treatments showed positive and negative shifts in the most abundant microbial taxa over time. Moreover, soon after the delivery of both antibiotics, increases in the abundance of opportunistic bacteria or potential pathogens, such as Alteromonas and Vibrio, were observed. Although both antibiotics are effective, Nitrofurazone more successfully reduces microbial diversity and therefore may be more ideal for experiments seeking to disrupt fish microbiomes.

Comparison of multi-criteria decision-making methods for selection of optimum passive design strategy

In the pursuit of achieving high-performance building design, the selection of the most suitable passive design strategies often involves the use of multi-criteria decision-making (MCDM) methods to address multiple conflicting criteria simultaneously. However, identifying the appropriate MCDM method for a specific building design context poses a challenge, as methods commonly effective in other contexts may not yield equivalent results. This study evaluates five MCDM methods (AHP, COPRAS, TOPSIS, VIKOR, and WSM) to understand their sensitivity in recommending the best solution. The considered criteria are energy demand, thermal comfort and daylight availability. The sensitivity analysis involves the impact of the variability of assigned weights on the rank shifting given by the considered MCDM method and the sensitivity of each criterion to weights variability. The findings reveal that implementing a fair-weight allocation leads to similar top 5 solutions among all MCDM methods. However, when a negative shift is applied to each criterion weight, AHP demonstrates greater robustness to weight variability compared to the other methods evaluated, while VIKOR is the most sensitive to weight variation.

Optimized porous nanostructure of carbon fibers enabling excellent stability of Pt-based catalysts for oxygen reduction reaction

Facile synthesis of highly-dispersed Pt-based electrocatalysts on porous carbon supports with strong durability is extremely desirable for oxygen reduction reaction but remains challenging. The influence of pores in carbon supports on the stability and activity of catalysts is ambiguous and needs to be elucidated. Targeting this aim, herein, we prepared a series of carbon nanofibers with tunable pore diameter and specific surface area using the resorcinol-formaldehyde (RF) resins as a model system. Homogeneous composite precursors composed of RF resins and silica colloids were synthesized by the surfactant-assisted simultaneous polycondensation of RF resins and tetraethylorthosilicate (TEOS). The diameter of the pores induced by removal of silica could be controllable tailored through thermal treatment of the composite under various target temperatures. Pt3Co alloy nanoparticles loaded on the as-synthesized porous carbon nanofibers were prepared by an optimized wet-impregnation method. The experimental results indicated that the carbon nanofibers with pore size distribution focused on ∼1.27 nm and ∼2.34 nm provided the best stability without limiting current density decay, and negative shift of half-wave potential (E1/2) and mass activity (MA) loss of Pt after 20000 potential cycles are relatively mild. Conversely, negative shift of 21 mV, 15 mV and 22 mV in E1/2 and mass activity loss of 51.8%, 30.2% and 33.0% were observed for the Pt3Co nanoparticles supported on MC-60, MC-100 and MC-140 matrices which have pore size distribution focused on ∼2.73 nm, ∼2.73 nm as well as ∼4.66 nm, and ∼4.66 nm, respectively. This work demonstrates the importance of micropores and small mesopores for activity and long-term stability enhancement of carbon supported Pt-based electrocatalysts.

Planktic foraminifer response and paleoceanographic changes across the Danian – Selandian interval in the southern Tethys (Elles section, Central Tunisia)

The Danian – Selandian interval experienced several paleoceanographic changes with two prominent carbon cycle perturbations: the Dan-C2 and Latest Danian Event (LDE). We present integrated planktic foraminifer biostratigraphy, carbon isotope stratigraphy, and paleoceanographic interpretations from the Danian-Selandian at Elles, central Tunisia. Whereas the response of the planktic foraminifers to these events has been widely explored in deep sea sites, this shallow Tethyan shelf setting is significant for evaluating the expression of these global events in proximal environments. Both the Dan-C2 and LDE events are distinguished in our δ13Cbenthic record by biostratigraphically-constrained negative carbon isotope excursions. Recognition of these reliably dated excursions enables assessment of bioevent synchroneity. The lowest occurrence of Subbotina triloculinoides was diachronous at Dan-C2, but the highest occurrence of Praemurica was broadly synchronous at the onset of the LDE. Subsequent lowest occurrence of Igorina albeari shows latitudinal diachroneity between ocean basins. The planktic foraminifer assemblage composition indicates mesotrophic and stratified conditions in the early Danian, warming and increasing oligotrophy during the P2 Zone, peak oligotrophy and enhanced stratification across the LDE, shallowing-induced disruption of the upper water column niches in the latest Danian, and recovery with high diversity in the early Selandian. The Dan-C2 excursion shows a small 0.3‰ negative δ13C shift coinciding with increased abundance of low oxygen tolerant biserial Chiloguembelina, suggesting slightly stressed conditions. In contrast, the larger 0.6‰ LDE excursion coincides with the extinction of Praemurica and proliferation of Morozovella, reflecting an oligotrophic surge with warming in the surface ocean.

Attitudes Towards Filial Responsibility in 11 European Countries

This study examines how attitudes towards filial responsibility (AFR) have changed in 11 European countries between 2001 and 2017, based on data from the International Social Survey Programme. These countries include various types of welfare states and family traditions. The study also analyses the change in AFR according to the respondents’ gender and age. The findings indicate that in 2017, individuals reported lower filial responsibility than in 2001, with the exception of Great Britain, where the AFR increased. The most substantial decreases in AFR were observed in Hungary, France, Denmark, and Finland. This negative shift is visible in both genders and all age groups, particularly late middle-aged women. However, despite the varying intensity of AFR change, it was challenging to identify clear patterns in the variations between countries. These results highlight potential negative effects on political proposals for long-term care for older adults supported by younger generations.

Physiological paradigm for assessing reward prediction and extinction using cortical direct current potential responses in rats

Anticipating positive outcomes is a core cognitive function in the process of reward prediction. However, no neurophysiological method objectively assesses reward prediction in basic medical research. In the present study, we established a physiological paradigm using cortical direct current (DC) potential responses in rats to assess reward prediction. This paradigm consisted of five daily 1-h sessions with two tones, wherein the rewarded tone was followed by electrical stimulation of the medial forebrain bundle (MFB) scheduled at 1000 ms later, whereas the unrewarded tone was not. On day 1, both tones induced a negative DC shift immediately after auditory responses, persisting up to MFB stimulation. This negative shift progressively increased and peaked on day 4. Starting from day 3, the negative shift from 600 to 1000 ms was significantly larger following the rewarded tone than that following the unrewarded tone. This negative DC shift was particularly prominent in the frontal cortex, suggesting its crucial role in discriminative reward prediction. During the extinction sessions, the shift diminished significantly on extinction day 1. These findings suggest that cortical DC potential is related to reward prediction and could be a valuable tool for evaluating animal models of depression, providing a testing system for anhedonia.

Effect of cathodic polarizations on the failure behavior of epoxy coating/low alloy steel systems under high hydrostatic pressure

Failure behavior of epoxy coating/low alloy steel systems applied with cathodic polarization at 0.1 MPa and 15 MPa was investigated based on a deep−sea environment simulation test device. The results showed that the diffusion of water into the coating was significantly accelerated by the high hydrostatic pressure under the same polarization potential, and the time of water uptake of the coating that reached saturation was shortened; the coating's physical structure was significantly affected by the high hydrostatic pressure; the generation of highly conductive Fe3O4 was promoted in the corrosion products, which accelerated the metal corrosion process. Under the same hydrostatic pressure, with the negative shift of the polarization potential, the coating protective performance was significantly reduced and metal corrosion was mitigated to a certain extent; the water transport behavior showed a tendency to shorten the time of water uptake of the coating that reached saturation and lengthen the duration of the saturation state, which may be related to a more severe degree of cathodic delamination and the increase of water consumption for cathodic reactions under the coating. In addition, the increase of the weakly conductive α−Fe2O3 content in the corrosion products may cause a reduction in the cathodic protection current at the same polarization potential, resulting in the reduction of the protection effect on the metal.

Electrochemical study on under-deposit corrosion evolution of oil pipelines

In the development of oil and gas fields, due to the sand, calcium, and magnesium ions in the produced liquid, the under-deposit corrosion formed by deposition during the transportation process has become one of the key factors of pipeline failure. Therefore, aiming at the problem of CaCO3 under-deposit corrosion in CO2-flooded oil pipelines, this paper studied the influence of deposit thickness change on metal corrosion based on electrochemical experiments, image characterization, and corrosion product analysis. The results showed that the corrosion process of the deposit layer can be divided into three stages. (1) The deposit layer promoted the movement of the electrolyte and then enhanced the corrosion rate of the matrix, leading to the increase of the size and maximum pit depth of the matrix, which was manifested as a rapid negative shift of the open circuit potential. (2) The deposit layer played a certain physical shielding role, leading to the size and maximum pit depth of the pit decreasing, and the number of pits increasing, at which the open circuit potential basically remained unchanged. (3) The deposit layer can play an effective physical shielding role, and the oxygen concentration corrosion inside and outside the deposit layer made the number of pits increase sharply, which was manifested as a slow negative shift of open circuit potential. The deposit layer mainly affected the cathode reaction process of the corrosion process. With the increase of the deposit thickness, the metal corrosion intensified with an increasing corrosion current density.

Enhanced photovoltaic performance of dye sensitized solar cells using cesium bromide modified TiO2 electron transport layer

TiO2 is one of the most widely explored materials as an electron transport layer (ETL) in dye sensitized solar cells (DSSCs) due to its excellent physical and chemical properties. However, recombination at the device's interface slackens the charge carrier movement, adversely affecting their device performance. Rapid extraction of photogenerated charge carriers plays a vital role in developing high efficiency DSSCs. The conduction band alignment of TiO2 ETL and N719 dye light absorber plays a crucial role in charge carrier dynamics of DSSCs. Herein, the band structure of TiO2 ETL is finely tuned by the incorporation of cesium bromide (CsBr). At the optimal concentration (0.4 Wt. %), DSSCs achieved the best power conversion efficiency (PCE) of 9.28 % compared to 7.61 % for pristine TiO2. The modified TiO2–CsBr ETL induced a negative shift in flat band potential (Vfb) from −0.46 to −0.50 V, which improved the open circuit voltage (VOC), its work function (ɸ) from −4.71 to −3.75 eV and increased conduction band minimum (CBM) from −3.58 to −2.42 eV. CsBr incorporation increased electron density in TiO2 matrix, indicating the suppression of trap state and significantly improved the overall photovoltaic performance of DSSCs.

NC Loaded PtM Alloy from M-NC with Ultralow Pt Loading for Oxygen Reduction Reaction

Developing low Pt or non-precious metal catalysts for oxygen reduction reaction (ORR) has becoming necessary in recent years. Herein, PtM alloy anchored on nitrogen-doped carbon (PtM/NC, M=Fe, Co) catalyst with ultralow Pt loading (∼1 wt%) is prepared from the simple two-process pyrolysis, namely from C to M-NC then to PtM/NC. The as-prepared PtM/NC (M=Fe, Co) shows an excellent ORR catalytic performance with the peak potential and half-wave potential of 0.901 and 0.870 V for PtFe/NC, 0.868 and 0.845 V for Pt3Co/NC. The ORR on PtM/NC (M=Fe, Co) is a mainly direct 4-electron reaction pathway (3.75–3.90) in alkaline solution. Moreover, they possess good methanol tolerance and stability. Synergistic effect of Pt and M together with N species result in the excellent ORR catalytic activity of PtM/NC (M=Fe, Co). The negative shift of Pt binding energy caused by both lattice contraction and electron orbital coupling from M is beneficial for reducing the d-band center of Pt, weakening the oxygen binding energy and enhancing the ORR intrinsic activity of Pt. The strong interactions between NC and PtM alloy are beneficial for anchoring PtM nanoparticles, promoting the stability of catalyst. This work provides a new strategy for preparing ultralow Pt loading catalysts.

Regulated Deficit Irrigation to Boost Processing Tomato Sustainability and Fruit Quality

Improving water use efficiency is gaining relevance for the sustainability of agricultural practices. In semi-arid Mediterranean areas, recent studies highlighted that future climatic scenarios will be even more critical for crops, given the increase in water scarcity. In this context, the rationalization of irrigation water is necessary to sustain processing tomato (Solanum lycopersicum L.) yield and quality since this crop requires large volumes of water. The present research aimed to identify the effects of a regulated deficit irrigation (RDI) strategy on the environmental and economic sustainability and fruit technological and functional quality of the processing tomato crop in the Mediterranean area. A two-year, open-field experiment was carried out to compare full irrigation management (IRR, restoring 100% ETc) with an RDI strategy based on restoring 50% ETc when the first fruit cluster reached the typical size (BBCH 701 phenological stage, relative to Solanaceous fruits). Remarkable water saving (21.46%, average of the two years) was achieved under RDI without significant variations in total and marketable yield compared to the IRR regime. Consequently, improved economic water productivity (+23.17%) was observed, allowing enhanced processing tomato sustainability. The RDI strategy boosted the glucose content (+17.78%), soluble solids content (SSC, +10.17%), and dry matter of the fruits (+10.03 g%). Furthermore, a higher SSC-to-titratable acidity ratio (+15.47%) and a negative shift in fructose/glucose balance (−7.71%) were observed in RDI-treated plants. Higher levels of the drought stress markers proline (+38.99%) and total polyphenols (+20.58%) were detected in RDI- compared to IRR-irrigated tomato fruits. These findings suggested the RDI strategy as an effective and sustainable approach for increasing both water productivity and the fruit quality of the processing tomato crop under semi-arid Mediterranean climatic conditions.

Carbon cycle perturbations and environmental change of the middle permian and Late Triassic Paleo-Antarctic circle

During the middle Permian through the Triassic, Tasmania moved from paleo-latitudes of 78° to 69°S, wedged between Antarctica and Australia, within the paleo-South polar circle. During this time, significant global carbon cycle disturbances triggered major environmental and climatic changes and mass extinction events globally. The Bicheno-5 core from Eastern Tasmania, Australia, provides the opportunity to examine middle Permian and Upper Triassic sediments from the paleo-Antarctic, using high-resolution organic carbon isotope (δ13CTOC) chemostratigraphy, pXRF, and sedimentology, combined with new palynological data integrated with the existing radiometric age model. While there is a significant unconformity in the Upper Permian to the middle Triassic associated with eustatic sea-level fall as a result of regional uplift in eastern Australia, three distinct carbon isotope excursions (CIEs), characterized by negative shifts of up to − 6 ‰ were identified; the middle Permian Guadalupian Carbon Isotope Excursions (G-CIE), the Carnian Pluvial Episode (CPE), and the mid-Norian Event (MNE). These three events highlight a significant climate shift through glacial and interglacial cycles to warmer non-glacial intervals in the Late Triassic, with evidence of the polar record of the Carnian Pluvial Episode and the mid-Norian Event, which are poorly studied in the Southern Hemisphere, specifically within the Paleo-Antarctic circle.

Analysis of Monthly Rainfall Characteristics in Nusa Tenggara Timur and its Spatial and Temporal Shifts

The spatial characteristics of rainfall in Nusa Tenggara Timu for the periods 1961-1990 and 1991-2020 show similarities in terms of topography influencing local variations in rainfall intensity. Additionally, inland areas and the northern side of region experience higher rainfall compared to the coastal areas and the southern side. On the other hand, temporal characteristics reveal a monsoonal rainfall pattern with peak precipitation occurring in January and the lowest rainfall in August. Furthermore, there is a normal shift in rainfall patterns between the two periods, marked by a reduction in the intensity of dark colors in the 1991-2020 period compared to 1961-1990. There is also a positive shift in normal rainfall values for the months of April and December, while the remaining months experience a negative shift.

Changes in high-frequency aperiodic 1/f slope and periodic activity reflect post-stimulus functional inhibition in the visual cortex

Abstract It has been shown that cessation of intensive sensory stimulation is associated with a transient increase in functional inhibition in the sensory cortical areas. However, the electrophysiological correlates of this post-stimulus inhibition in the human brain have not been thoroughly investigated. To investigate post-stimulus inhibition, we analyzed magnetoencephalogram (MEG) recorded at rest and after cessation of visual stimulation of varying intensity (high-contrast gratings drifting at a slow, medium, or high rate) in 25 healthy women aged 18–40 years. We analyzed condition- and intensity-related changes in MEG parameters sensitive to functional inhibition: periodic alpha-beta power, peak alpha frequency (PAF), and 1/f aperiodic slope. We also investigated the association of these parameters with sensory sensitivity and avoidance assessed by a questionnaire. To evaluate the influence of hormonal status on the studied parameters, participants were examined twice, during the follicular and luteal phases of the menstrual cycle (MC). Regardless of the MC phase, increasing drift rate of visual gratings resulted in a proportional increase of post-stimulus posterior alpha-beta power, PAF, and a negative shift of the aperiodic (1/f) slope of the power spectrum in the high-frequency range. Compared to rest, the post-stimulus periods were characterized by higher PAF, more negative 1/f slope in posterior cortical areas, and a widespread increase in beta power. While condition- and drift-rate-dependent modulations of alpha-beta power and 1/f slope were correlated, changes in PAF did not correlate with either of them. A greater intensity-dependent increase in visual alpha-beta power predicted higher subjective sensory sensitivity/avoidance, suggesting stronger regulatory top-down modulation of the visual cortex in individuals with heightened sensitivity. Our results show that several MEG parameters concordantly indicate a post-stimulus enhancement of inhibition that is proportional to the intensity of the preceding visual stimulation. While post-stimulus changes in alpha-beta power and 1/f slope may share some common mechanisms, changes in PAF reflect a distinct aspect of inhibitory regulation. Our results inform potential inhibition-based biomarkers for clinical and translational research.

Assessment of the electrostatic binding of ferrocenylmethyl-nitroaniline derivatives to DNA: A combined experimental and theoretical study

The present study investigates the electrostatic binding interactions between ferrocenylmethylnitroaniline derivatives and DNA using a combination of experimental and theoretical approaches. The objective is to elucidate the binding mechanisms and evaluate the potential of these derivatives as DNA-targeting agents. Experimental techniques, including cyclic voltammetry (CV) and UV–Vis spectroscopy (UV–Vis), were employed to assess the binding affinity and conformational changes in DNA upon interaction with the derivatives. Our findings reveal that the ferrocenylmethylnitroaniline derivatives exhibit strong electrostatic interactions with DNA, as confirmed by the negative formal potential shift observed in CV. The binding constants and free binding energies obtained from the docking simulation were found to be consistent with those obtained from CV and UV–Vis spectral analysis. Furthermore, the binding site size was determined from the voltametric data. Complementary theoretical calculations such as geometry optimization, MEP analysis, Mulliken charge distribution, and HOMO-LUMO surface were performed by DFT approach (B3LYP/aug-cc-pVTZ/6-311++G (d,p)) to gain insights into the structural data, active regions, and chemical reactivity of derivatives. Molecular docking simulation verifies that electrostatic attraction plays a fundamental role in the interaction of Fc2N, Fc3N, and Fc4N with DNA. The molecular dynamics simulations elucidated the stability of DNA-ligand complexes formed with Fc2N, Fc3N, and Fc4N compounds. Analysis of root mean square deviation (RMSD) and radius of gyration (Rg) indicated stable binding and maintained compactness of DNA structures, underscoring the robustness of these interactions for potential therapeutic applications.Top of Form