Changes In Intensity Research Articles

Exploring the significance of true substrates in a Pennsylvanian fluvio-estuarine tidal flat

The Pennsylvanian Tonganoxie Sandstone of Kansas contains examples of true substrates in tidal rhythmites formed in a tidal flat at the fluvio-estuarine transition of a macrotidal valley. These surfaces are characterized by an impressive preservation of biogenic and physical sedimentary structures, indicative of the coexistence of low-energy tidal currents and freshwater conditions together with brief periods of subaerial exposure. Biogenic activity corresponds to a time of stasis during or immediately after accumulation of ebb-phase clay followed by low tide. Deposition-stasis-deposition (D-S-D) was involved in the formation and preservation of these true substrates, with only a few instances of deposition-stasis-erosion-deposition (D-S-E-D). Crosscutting relationships among biogenic structures and of these with physical sedimentary structures suggest a tidally controlled taphonomic pathway, which indicates that these true substrates represent short-term time-averaged surfaces at the scale of a few hours, rather than snapshots. True substrates preserved in tidal rhythmites are widespread in other late Palaeozoic tide-dominated estuarine deposits of the North American Midcontinent. The likelihood and quality of preservation seem to show spatial and temporal trends at various scales that ultimately reflect a complex interplay of abiotic factors (e.g. sedimentary dynamics) and biotic factors (e.g. secular changes in intensity and depth of bioturbation).

Influence of large-scale atmospheric circulation and Mediterranean sea surface temperature to extreme land precipitation: the case of storm Alex

Abstract Extreme (greater than 500 mm) amount of rain fell in southeastern France and northern Italy on 2nd and 3rd October 2020 during a "Mediterranean episode" triggered by the powerful extratropical cyclone Alex. Here we use a dynamical adjustment methodology based on constructed analogues to assess the contributions of different drivers to the magnitude of this extreme precipitation event. We first show that the mean effect of the observed atmospheric circulation pattern, an intense low-pressure system centered over the coasts of Western Europe associated with a cold pool and a secondary low-pressure system, can explain about 80 percent of the precipitation event magnitude. By contrasting the effect of Alex atmospheric circulation with an anomalously warm Mediterranean sea and eastern Atlantic ocean versus neutral sea surface temperature conditions, we show that the influence of September 2020 positive sea surface temperature anomalies can explain a large fraction of the 20 percent residual precipitation over southeastern France and northern Italy. Finally, based on a storyline approach, we find that the dynamic component, the atmospheric circulation contribution to the extreme precipitation event, was more extreme than it would have been, had it occurred during the mid-20th century. The increase in the magnitude of the dynamic component since 1950 follows a Clausius-Clapeyron scaling, in agreement with previous studies about the intensity changes of Mediterranean extreme precipitation episodes. (limit =300 words)

Case studies of different types of precipitation at Ny-Ålesund, Arctic

Arctic precipitation plays a crucial role in shaping the surface mass balance of Arctic sea ice and has wide-ranging impacts on local climate, ecosystems, and global sea level dynamics. With the Arctic undergoing warming trends, historical data and climate models indicate a shift from primarily snowfall to a rise in liquid and mixed forms of precipitation. This study tried to explain the microphysical characteristics and atmospheric conditions associated with different forms of precipitation and their transitions. The phase changes were explained by the vertical precipitation profiles over Ny-Ålesund, Svalbard ( 55’ N, 56’ E), observed using a Micro Rain Radar (MRR) and vertical atmospheric profiles using the ground-based microwave radiometer (MWR). Atmospheric conditions were also analysed based on ERA5 reanalysis data at different pressure levels. For the cases studied here, it was found that the southerly warm-moist air mass plays a crucial role in the change of precipitation phase and intensity. Warm and moist winds at 2-3 km altitude facilitated high temperature and moisture that helped snow to melt in liquid, resulted in rainfall over the location. Additionally, hourly winds from ERA5 reanalysis indicated upward wind motion was responsible for the formation of graupel. The insight gained from this study will be useful to predict the further precipitation trend over the Arctic more accurately.

Evaluation of the effect of the water-energy nexus on the performance of the water-energy supply system.

In this study, the water-energy nexus is investigated throughout coupling the Water Evaluation and Planning (WEAP) and Low Emission Analysis Platform (LEAP) models under the climate change effects in the Marun basin, Iran. For this purpose, first, the climate change effects on water resources and consumption nodes are calculated under representative concentration pathway (RCP) scenarios from the fifth report of the International Panel on Climate Change (IPCC). Artificial neural network (ANN) is used to model river inflow and Cropwat model is used for agricultural water demand in future time (2015-2040). In the next step, water system is modeled in WEAP and energy system is modeled in LEAP. Then, three water-energy nexus scenarios include (1) calculating the actual hydropower generation capacity in LEAP model (W-E-N1), (2) water-energy nexus evaluation indexes in the WEAP model (W-E-N2), and (3) changes in the electricity consumption intensity in the LEAP model (W-E-N3) are modeled under RCP 2.6, RCP 4.5 and RCP 8.5 climate scenarios. The results of W-E-N1 scenario show that the actual hydropower generation capacity with water-energy nexus is reduced by 78%, 89%, and 91%, respectively, compared to no water-energy nexus under RCP 2.6, RCP 4.5, and RCP 8.5 scenarios. The results of W-E-N2 show that the hydropower generation reliability index will be reduced by 19%, 31%, and 13%, respectively under RCP 2.6, RCP 4.5, and RCP 8.5 compared no water-energy nexus. The results of W-E-N3 scenario show that the electricity consumption intensity will increase considering the electricity required for water transferring to demand sites. The results of the present study show that the water-energy nexus will lead to more accurate results and, as a result, more realistic planning for water and energy resources.

Disruption of boreal lake circulation in response to mid-Holocene warmth; evidence from the varved sediments of Lake Nautajärvi, southern Finland.

Future climate projections are expected to have a substantial impact on boreal lake circulation regimes. Understanding lake sensitivity to warmer climates is therefore critical for mitigating potential ecological and societal impacts. The Holocene Thermal Maximum (HTM; ca 7-5ka BP) provides a valuable analogue to investigate lake responses to warmer climates devoid of major anthropogenic influences. Here, we analyse the micro-X-ray core scanning profiles (μ-XRF) of the annually laminated (varved) sediments from Lake Nautajärvi (NAU-23) in southern Finland to elucidate changes in lake circulation and sedimentation patterns. Principal component analysis (PCA) identifies two key components in the geochemical data associated with the nature of the sediments, i.e. detrital vs organic sedimentation (PC1), and hypolimnetic oxidation (PC2). Our findings reveal that during the HTM, the lake became more sensitive to changes in oxygenation and mixing intensity. These changes were triggered by a warmer climate, which increased organic matter and redox sensitive metal solute concentrations in the water column, strengthening lake stratification and weakening dimictic circulation patterns. Superimposed on HTM weakened circulation are distinct phases of increased oxidation and iron-rich varve formation that do not happen when the background conditions are cooler (i.e. the early and late Holocene). This is driven by temporary strengthening of the mixing regime in response to climatic variability and storminess cycles across southern Scandinavia. These findings demonstrate that whilst warmer conditions weaken boreal lake circulation regimes, they can also make them increasingly vulnerable to short term oscillations in prevalent climatic conditions and weather patterns, which could have significant impacts on lake water quality and aquatic ecosystems. These findings underscore the non-stationary nature of lake sensitivity to short-term climatic variability and emphasize the potential for similar shifts to occur under future warming scenarios.

Crosstalk Between Abiotic and Biotic Stresses Responses and the Role of Chloroplast Retrograde Signaling in the Cross-Tolerance Phenomena in Plants

In the natural environment, plants are simultaneously exposed to multivariable abiotic and biotic stresses. Typical abiotic stresses are changes in temperature, light intensity and quality, water stress (drought, flood), microelements availability, salinity, air pollutants, and others. Biotic stresses are caused by other organisms, such as pathogenic bacteria and viruses or parasites. This review presents the current state-of-the-art knowledge on programmed cell death in the cross-tolerance phenomena and its conditional molecular and physiological regulators, which simultaneously regulate plant acclimation, defense, and developmental responses. It highlights the role of the absorbed energy in excess and its dissipation as heat in the induction of the chloroplast retrograde phytohormonal, electrical, and reactive oxygen species signaling. It also discusses how systemic- and network-acquired acclimation and acquired systemic resistance are mutually regulated and demonstrates the role of non-photochemical quenching and the dissipation of absorbed energy in excess as heat in the cross-tolerance phenomenon. Finally, new evidence that plants evolved one molecular system to regulate cell death, acclimation, and cross-tolerance are presented and discussed.

Establishing and Investigating an Effective Atmosphere‐Ocean Cross‐Medium Propagation Model Based on GSM Beams

AbstractUsing the Gaussian‐Schell model (GSM) beam as the light source, this study creates a blue‐green beam atmosphere‐ocean cross‐medium propagation model (AOCPM) based on the extended Huygens‐Fresnel principle and the linear filtering method. The closed expression of the Cross Spectral Density Function (CSDF) of the GSM beam after propagation through atmospheric turbulence, atmosphere‐ocean interface, and ocean turbulence are derived. And the correctness of the model is verified by simulating the changes in intensity, relative beam width, and speckle normalized intensity autocorrelation function during the propagation of the GSM beam through the atmosphere‐ocean cross‐medium under different parameters. The findings demonstrate that the intensity of the GSM beam after being propagated through the atmosphere‐ocean medium presents a speckle‐like Gaussian distribution, the intensity of the GSM beam gradually attenuates, the relative beam width gradually grows, and the speckle normalized intensity autocorrelation function gradually decreases as the turbulence intensity and propagation distance increase. In addition, the increase in wind speed at rough sea surface mainly leads to the attenuation of intensity. The work of this paper provides a new idea for the study of atmosphere‐ocean cross‐medium propagation of blue‐green beams.

Effects of Hypergravity on Phase Evolution, Synthesis, Structures, and Properties of Materials: A Review

In a hypergravity environment, the complex stress conditions and the change in gravity field intensity will significantly affect the interaction force inside solid- and liquid-phase materials. In particular, the driving force for the relative motion of the phase material, the interphase contact interaction, and the stress gradient are enhanced, which creates a nonlinear effect on the movement mode of the phase material, resulting in a change in the material’s behavior. These changes include increased stress and contact interactions; accelerated phase separation; changes in stress distribution; shear force and phase interface renewal; enhanced interphase mass transfer and molecular mixing; and increased volume mass transfer and heat transfer coefficients. These phenomena have significant effects on the synthesis, structural evolution, and properties of materials in different phases. In this paper, the basic concepts of hypergravity and the general rules of the effects of hypergravity on the synthesis, microstructure evolution, and properties of materials are reviewed. Based on the development of hypergravity equipment and characterization methods, this review is expected to broaden the theoretical framework of material synthesis and mechanical property control under hypergravity. It provides theoretical reference for the development of high-performance materials under extreme conditions, as well as new insights and methods for research and application in related fields.

Amplified Bimodal Distribution of Western North Pacific Tropical Cyclone Lifetime Maximum Intensity

AbstractThe impact of a warming climate on tropical cyclones (TCs) remains unclear. Here, we find that the probability density function for western North Pacific TC lifetime maximum intensity (LMI) has an amplified bimodal distribution in recent years. This change implies a trend toward more extreme TCs and fewer moderate TCs. Changes in the TC LMI distribution are associated with alterations in the occurrence of rapidly intensifying TCs. Changes in TC tracks, due to alterations in the steering flow linked to a weakening Hadley cell, cause more TCs to move northwestward into a more favorable environment for intensification with large ocean heat content. Consequently, more rapidly intensifying TCs reach higher intensities, significantly contributing to the observed amplified bimodal distribution. These findings provide new insights into changes in TC intensity and highlight the increasing threat to coastal areas from more intense TCs in a warming climate.

The Effect of Digital Economy Development on Carbon Emission Reduction—An Empirical Analysis Based on 80 Countries of the Belt and Road Initiative

Based on data from China and 80 countries belonging to the Belt and Road Initiative (BRI) for the period 2010–2022, this study employs a benchmark panel regression model to thoroughly analyze the impact of digital economy development on carbon emission reduction in BRI countries. The research findings indicate that the development of the digital economy in BRI countries has facilitated carbon emission reduction. This effect exhibits heterogeneity. Compared to other regions, the impact is more pronounced in countries with higher levels of socio-economic development, located in Africa and Europe, and along the Land Silk Road, and BRI countries neighboring China. The mechanisms through which this effect operates include industrial structure adjustment, technological innovation, and changes in energy intensity. Based on these insights, specific and targeted development recommendations for BRI countries at different levels of development and geographical distributions are proposed. These suggestions focus on strengthening infrastructure construction to bridge the digital divide; enhancing technological capabilities and promoting the integration of the digital economy with the real economy to upgrade industrial structures; and implementing differentiated digital economy development strategies to reduce energy consumption, among other measures.

Future changes in compound explosive cyclones and atmospheric rivers in the North Atlantic

Abstract. The explosive development of extratropical cyclones and atmospheric rivers plays a crucial role in driving extreme weather in the mid-latitudes, such as compound windstorm–flood events. Although both explosive cyclones and atmospheric rivers are well understood and their relationship has been studied previously, there is still a gap in our understanding of how a warmer climate may affect their concurrence. Here, we focus on evaluating the current climatology and assessing changes in the future concurrence between atmospheric rivers and explosive cyclones in the North Atlantic. To accomplish this, we independently detect and track atmospheric rivers and extratropical cyclones and study their concurrence in both ERA5 reanalysis and CMIP6 historical and future climate simulations. In agreement with the literature, atmospheric rivers are more often detected in the vicinity of explosive cyclones than non-explosive cyclones in all datasets, and the atmospheric river intensity increases in all the future scenarios analysed. Furthermore, we find that explosive cyclones associated with atmospheric rivers tend to be longer lasting and deeper than those without. Notably, we identify a significant and systematic future increase in the cyclones and atmospheric river concurrences. Finally, under the high-emission scenario, the explosive cyclone and atmospheric river concurrences show an increase and model agreement over western Europe. As such, our work provides a novel statistical relation between explosive cyclones and atmospheric rivers in CMIP6 climate projections and a characterization of their joint changes in intensity and location.

Characterization of the binding process between gallic acid and trivalent chromium in tannery wastewater: a spectroscopic perspective.

Trivalent chromium (Cr3+) is a heavy metal widely present in tannery wastewater, and organic ligands represented by gallic acid (GA) have significant effects on the environmental behavior of Cr3+. This study explored the binding process of Cr3+ with GA through the integration of ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR), and fluorescence spectroscopy coupled with two-dimensional correlation analyses (2DCOS). UV-vis results showed that the average molecular weight of the solutions gradually increased with the addition of Cr3+ ions. The vibration of FTIR characteristic peaks indicated that the hydroxyl and carboxyl functional groups of GA were complexed with Cr3+ ions. On the basis of the fluorescence quenching of GA after the addition of Cr3+ ions, the complexation coefficient was calculated as 4 × 104. 2DCOS and nuclear magnetic resonance (NMR) spectra demonstrated the binding sequence of GA with Cr3+ as meta-hydroxyl groups → carboxyl groups → para-hydroxyl groups, and heterospectral 2DCOS showed that the intensity change in UV-vis absorption bands occurred before that in IR absorption bands. Density functional theory (DFT) was used to quantify the binding energy of GA with Cr3+ at different binding sites, and it was shown that the binding energy of the meta-hydroxyl group was the lowest. Overall, this study provides a new approach to the analysis of the molecular structure of complexes and the binding process between organic ligands and metal ions in wastewater.

Shenshuaikang enema restores the intestinal barrier and microbiota-gut-kidney axis balance to alleviate chronic kidney disease via NF-κB pathway.

Chronic kidney disease (CKD) is a chronic progressive disease characterized by abnormalities in kidney structure or function caused by variousfactors. It has become a significant public health problem, posing a threat to human health worldwide. Shenshuaikang enema (SSKE) has demonstrated notable efficacy and safety in treating CKD, although its mechanism of action remains unclear. The CKD rat model was induced using 2.5% adenine, and the effect of SSKE was evaluated by detecting uremic toxins, inflammatory cytokines, and renal function. The structure of the intestine and kidney was observed using electron microscopy. Pathological changes in the intestine and kidney were detected by H&E staining. The expression of Occludin, Claudin-1, and ZO-1 in the intestine was detected by immunohistochemistry. The degree of renal fibrosis was observed using Masson and PAS staining. The expression of NF-κB and MyD88 protein in the intestine, and the expression of F4/80, TLR4, NF-κB and MyD88 in the kidney were detected by immunofluorescence staining. NF-κB-RE-Luc transgenic mice were used to construct a CKD mouse model, and changes in fluorescence intensity in mice and isolated kidney tissues were detected within 1-6 days using a small animal live imager. Finally, 16S rRNA amplicon sequencing was used to monitor changes in intestinal flora in CKD patients before and after SSKE treatment. We found that SSKE improves renal function, attenuates renal fibrosis, reduces inflammatory factor levels, and decreases damage to intestinal and renal structures in adenine-induced CKD rats. Additionally, our results suggest that SSKE regulates NF-κB pathways, increases the expression of tight junction proteins, improves intestinal permeability, promotes the growth of beneficial bacteria, inhibits the proliferation of harmful bacteria, and reduces metabolic disorders. Ultimately, these effects contribute to the efficacy of SSKE in treating CKD. These results indicate that SSKE restores intestinal barrier function by regulating the microbiota-gut-kidney axis, thereby treating CKD.

Gas sensing by long-wavelength and long-afterglow pectin/melamine-formaldehyde aerogel via resonance energy transfer.

The exploration of pure organic ultra-long room temperature phosphorescence (RTP) materials has emerged as a research hotspot in recent years. Herein, a simple strategy for fabricating long-afterglow polymer aerogels with three-dimensional ordered structures and environmental monitoring capabilities is proposed. Based on the non-covalent interactions between pectin (PC) and melamine formaldehyde (MF), a composite aerogel (PCMF@phenanthrene) (PCMF@PA) doped with phosphorescent organic small molecules was constructed. It exhibits a stable and persistent afterglow, with a phosphorescence lifetime reaching up to 1.99s. Simultaneously, this aerogel possesses excellent mechanical properties, having a compressive modulus of 4.14MPa, which is 490.8 times that of the PC aerogel. Its friction coefficient is also much lower than that of the single MF aerogel, enabling the material to achieve a better balance between rigidity and service life in practical applications. Moreover, through resonance energy transfer, the afterglow wavelength was redshifted from 504nm to 576nm and 620nm, and aerogels with ultra-long yellow and red afterglows were successfully obtained. PCMF@PA aerogels display specific chemical stability in different organic solvents. Notably, PCMF@PA has a characteristic recognition for formic acid gas. The change in the luminous intensity and lifetime of the aerogel after gas absorption distinguishes it from gases such as ammonia and acetic acid. These phosphorescent polymer aerogels with self-monitoring and tracing capabilities not only foster the advancement of ordered phosphorescent materials but also broaden the application scope of RTP materials in environmental monitoring.

Probing the effects of dextran-coated CeO2 nanoparticles on lung fibroblasts using multivariate single-cell Raman spectroscopy

In this study, we investigated the cytotoxic effect of highly soluble dextran-coated CeO2 nanoparticles on human fetal lung fibroblasts MRC-5. We examined individual nanoparticle-treated cells by Raman spectroscopy and analyzed Raman spectra using non-negative principal component analysis and k-means clustering. In this way, we determined dose-dependent differences between treated cells, which were reflected through the intensity change of lipid, phospholipid and RNA-related Raman modes. Performing standard biological tests for cell growth, viability and induction of apoptosis in parallel, these changes were correlated with nanoparticle-induced apoptotic processes. The cells with specific spectral characteristics, referring to non-apoptotic, but possibly autophagic cell death modality, were also detected. Additionally, Raman imaging combined with principal component and vertex component analysis was used to map the spatial distribution of biological molecules in treated and untreated cells. This work provided the description of different resulting states of the treated cells depending on the dextran-coated CeO2 nanoparticles dose, which can be later used in the design of the nanoparticles for industrial or medical applications. The wide content of information resulting from single-cell Raman spectroscopy has the potential to detect biochemical changes caused by nanoparticles that would otherwise require a series of expensive and time-consuming standard biological techniques.

Quantifying tear exchange during rigid contact lens wear using corneoscleral profilometry: A proof of concept study.

Tear exchange during contact lens wear is essential for ocular surface integrity, facilitating debris removal, and maintaining corneal metabolism. Fluorophotometry and fluorogram methods are typically used to measure tear exchange, which require hardware modifications to a slit lamp biomicroscope. This manuscript introduces an alternative method using a corneoscleral profilometer, the Eye Surface Profiler (ESP), to quantify tear exchange during corneal and scleral rigid lens wear by assessing fluorescence intensity changes over time. As a proof of concept, a healthy participant wore a corneal and a scleral rigid lens on separate days. After lens application, 2% sodium fluorescein was instilled, and ESP images were captured at intervals over a 30-min period for corneal and a 90-min period for the scleral lens. Fluorescence intensity data were extracted and analysed using MATLAB, restricted to a region of interest centred on the contact lens. The fluorescence intensity was fitted with an exponential decay curve to quantify tear exchange. Fluorescence intensity decreased over time for both lenses, with a faster decay rate being observed for the corneal lens. The scleral lens showed an initial ingress of fluorescein into the fluid reservoir, then a slow decay in fluorescence intensity due to limited tear exchange. The decay rate for the corneal lens was approximately four times faster than the scleral lens, with the time to reach 50% decay of ~42 min for the corneal lens compared to ~157 min for the scleral lens. A new method was developed to quantify tear exchange using a commercially available corneoscleral profilometer, offering a wider field of view than existing techniques. This approach has clinical potential in scleral lens practice for identifying landing zone misalignment and improving the understanding of post-lens tear dynamics, particularly in cases involving scleral lens modifications or patients experiencing midday fogging.

In Situ X-Ray Study During Thermal Cycle Treatment Combined with Complementary Ex Situ Investigation of InGaN Quantum Wells.

In situ X-ray reciprocal space mapping was performed during the interval heating and cooling of InGaN/GaN quantum wells (QWs) grown via metal-organic vapor phase epitaxy (MOVPE). Our detailed in situ X-ray analysis enabled us to track changes in the peak intensities and radial and angular broadenings of the reflection. By simulating the radial diffraction profiles recorded during the thermal cycle treatment, we demonstrate the presence of indium concentration distributions (ICDs) in the different QWs of the heterostructure (1. QW, bottom, 2. QW, middle, and 3. QW, upper). During the heating process, we found that the homogenization of the QWs occurred in the temperature range of 850 °C to 920 °C, manifesting in a reduction in ICDs in the QWs. Furthermore, there is a critical temperature (T = 940 °C) at which the mean value of the indium concentration starts to decrease below 15% in 1. QW, indicating the initiation of decomposition in 1. QW. Moreover, further heating up to 1000 °C results in extended diffuse scattering along the angular direction of the diffraction spot, confirming the propagation of the decomposition and the formation of trapezoidal objects, which contain voids and amorphous materials (In-Ga). Heating InGaN QWs up to T = 1000 °C led to a simultaneous decrease in the indium content and ICDs. During the cooling phase, there was no significant variation in the indium concentrations in the different QWs but rather an increase in the defect area, which contributes to the amplification of diffuse scattering. A comparison of ex situ complementary high-resolution transmission microscopy (Ex-HRTEM) measurements performed at room temperature before and after the thermal cycle treatment provides proof of the formation of four different types of defects in the QWs, which result from the decomposition of 1. QW during the heating phase. This, in turn, has strongly influenced the intensity of the photoluminescence emission spectra without any detectable shift in the emission wavelength λMQWs.

Digital Technology Adoption and Changes in Energy Intensity in German Manufacturing Firms

Information and communication technologies (ICT) are generally believed to have significant potential to reduce energy intensity. In contrast to previous empirical studies, which have relied on aggregated data, we conduct the first large-scale firm-level investigation into this relationship. Our results, which are based on administrative panel data on 28,600 German manufacturing firms, confirm a robust negative relationship between software capital (our proxy for the degree of firm digitalization) and energy intensity for the years 2009 to 2017. However, the effect size is rather small. For the average firm, we find that a 1 percent increase in software usage relates to a decrease in energy intensity by 0.003 percent. Hence, contrary to previous industry-level results, we do not observe substantial energy intensity improvements in connection with ICT adoption. Moreover, we find that the relationship between ICT and energy intensity exhibits properties that can lead to an aggregation bias. JEL Classification: C32, H23, O33, O38, Q56, Q58.

Aggregation-induced emission in novel multilayered 3D polymers: development of a fluorescent probe for selective metal ion detection.

This study presents the characterization of a novel multilayered three-dimensional (3D) polymer exhibiting aggregation-induced emission (AIE) properties when excited at a low wavelength of 280 nm. Utilizing fluorescence spectroscopy, we demonstrate that the polymer displays a marked enhancement in luminescence upon aggregation, a characteristic behavior that distinguishes AIE-active materials from conventional fluorophores. Furthermore, we explore the potential application of this multilayered 3D polymer as a fluorescent probe for the selective detection of specified metal ions. By incorporating chelating functional groups into the polymer matrix, we facilitate specific interactions with target metal ions, leading to significant fluorescence intensity changes that correlate with ion concentration. According to their cyclic voltammetry characteristics, the polymers have potential applications in cutting-edge electrical and optoelectronic systems. Our findings indicate that this multilayered 3D polymer serves as an effective fluorescent sensor and offers tunable optical properties, paving the way for innovative applications in environmental monitoring and biomedical diagnostics. The results underscore the utility of AIE-active polymers in developing advanced materials for sensitive and selective detection of metal ions, contributing to the growing field of smart sensing technologies.

Carbon dots with red emission as nanoprobe for sensing of heparin in biofluids and pharmaceutical samples.

Heparin (HEP) is one of the oldest anticoagulant drugs, widely used in clinical settings, particularly in surgery and dialysis machines. Despite its long history, it remains extensively employed in medical practice. This study introduces a selective and cost-effective method for the rapid detection of HEP using red-emission carbon dots (R-CDs). These R-CDs were synthesized through a one-pot hydrothermal method, utilizing neutral red and thiourea for photostability, biocompatibility, and low cytotoxicity. Key parameters affecting the sensing process, including nanoprobe volume, pH, buffer type, and incubation time, were optimized to achieve potential assay conditions. The fluorescence intensity of the nanoprobe at 625 nm gradually decreased as the concentration of HEP increased from 60 to 240 nM. These changes in fluorescence intensity showed a linear relationship with HEP concentration within this range, achieving a limit of detection (LOD) of 5 nM. The proposed nanoprobes facilitate both quantitative and qualitative non-invasive analysis of HEP in various human biofluids, suggesting their potential for broader bioanalytical applications.