Increase In Intensity Research Articles

Conditionally Activated ROS Generation by MMP2/9-Specific C60-Based Fluorescence Probes.

A C60-coumarin conjugate, covalently connected via a matrix metalloproteinase (MMP2/9)-cleavable peptide linker (Pro-Leu-Gly-Val-Arg-Gly), is developed as a probe for both imaging and photodynamic treatment of MMP2/9-expressing malignant cells. In the synthesized probe, the coumarin fluorescence is completely suppressed intramolecularly by the C60 moiety, while an intensive fluorescence increase is observed in the presence of MMP2/9 dependent on cleavage of the peptide linker. The specificity of the probe to detect MMP2 is confirmed by control experiments resulting in no emission 1) with a control probe bearing a shuffled peptide (Val-Arg-Leu-Gly-Pro-Gly) or 2) in the presence of an MMP2 inhibitor (1,10-phenantheoline). The probe is added to three types of tumor cell lines with different MMP2/9-expression levels to perform in vitro cellular imaging. MMP2/9 is successfully detected by the probe in DAOY cells with the highest expression level of MMP2/9. Upon cleavage of the probe by MMP2/9, photoinduced 1O2 generation is much enhanced, resulting in the MMP-dependent induction of higher photocytotoxicity of the probe in DAOY compared to HCT116 with much lower expression. The results suggest that the probe can serve as (I) a fluorescent reporter for MMP2/9 and (II) a photosensitizer for selective photodynamic treatment of malignant cells with MMP2/9 overexpression.

Characterization of Luffa-reinforced Polyaniline Films

Herein, Polyaniline (PANI)/polyethylene oxide (PEO) - luffa cylindrica bio-composite films of various mass fractions (%) have been prepared via casting solution of emeraldine base polyaniline and cellulose extracted from luffa. The biopolymer films were structurally and thermally characterized using X-ray diffraction (XRD), Fournier Transform-InfraRed (FT-IR) spectroscopy, and differential scanning calorimetry analysis (DSC). Moreover, the electrical properties of conductive biopolymer solutions were measured by using the conductivity meter. According to the obtained results, treated luffa increases the conductivity of biopolymers. XRD results reveal that luffa increases the crystallinity of bio-composite films in comparison to PANI/PEO films. FTIR analysis proved the presence of functional groups of PANI, PEO, and luffa in the film structure. Also, an increase in the weight of luffa in the bio-composite film brings about an increase in the peak intensities of the O-H group. It is determined that luffa enhances the thermal stability of composites via the results of DSC analysis.

Mesial Temporal Lobe Epilepsy as a Common but Elusive Case: A Case Report

Epilepsy is a common neuronal disorder that could include partial or generalized seizures due to abnormal brain electrical activity. A 32-year-old female patient was presented to the emergency room with a chief complaint of seizure. The seizure semiology started with epigastric pain, which then progressed into sudden speech arrest. Afterward, the patient experienced left-sided head movement followed by jerkings on the left hand. The patient then became unconscious and experienced full body rigidity. Physical examinations, vital signs, and laboratory results showed no abnormalities. Diagnostic assessments only showed unspecific signs of diffuse cerebral edema through a CT Scan and an atrophy of the right hippocampus with a slight increase in FLAIR signal intensity and dilatation of the right lateral ventricle pericornu through MRI. The patient was given phenytoin and folic acid twice daily. The presence of right mesial temporal sclerosis served as a possible cause of epilepsy in this patient despite having several obscurities. The patient showed atypical signs of generalized tonic seizure progression, adult-onset seizures, and increased MRI FLAIR signal intensity. More detailed examinations and constant reports of epilepsy cases are highly needed among physicians to provide more specific methods and tools to diagnose, classify, and treat epilepsy in the future.

Nanoparticles-Based Optical Chemosensors for Lead Acetate Sensing in Water: ZnO, Zn0.97Ce0.03O, and Zn0.97Nd0.03O.

This study reports the synthesis, characterization, and optical properties of ZnO, Zn0.97Ce0.03O, and Zn0.97Nd0.03O nanoparticles and their interactions with lead acetate solutions. X-ray diffraction (XRD) confirmed that the nanoparticles were synthesized in a single-phase hexagonal structure, with crystallite sizes of 12.48nm, 50.79nm, and 39.00nm, respectively. Doping ZnO with Ce and Nd ions significantly enhanced its paramagnetic properties, as evidenced by squareness ratios of 11.18 × 10-3, 41.60, and 20.25 for ZnO, Zn0.97Ce0.03O, and Zn0.97Nd0.03O, respectively. UV-Vis absorption spectra revealed a redshift in lead acetate upon interaction with ZnO, indicating the formation of new chemical species. Ce and Nd doping further modified the optical properties by introducing additional absorption peaks and altering spectral profiles. Significant enhancement in photoluminescence (PL) intensity is observed due to the addition of ZnO, Zn0.97Ce0.03O, and Zn0.97Nd0.03O nanoparticles, as compared to the pure PbC2H3O2​ solution across various concentrations. The incorporation of ZnO nanoparticles increases the PL intensity by approximately tenfold (from 13 to over 100 a.u.). Similarly, Zn0.97Ce0.03O exhibits a comparable level of enhancement. Notably, the introduction of Zn0.97Nd0.03O nanoparticles achieves a remarkable 100-fold increase in PL intensity, establishing it as a highly effective material for detecting lead contamination in water. This exceptional performance highlights its potential for environmental monitoring and water quality applications. These results highlight the potential of ZnO, Zn0.97Ce0.03O, and Zn0.97Nd0.03O nanoparticles as sensitive and effective chemosensors for detecting trace lead levels in environmental samples.

Comprehensive demonstration of link fiber-induced spurious signals in interferometric FBG hydrophones

The interferometric Fiber Bragg Grating (FBG) hydrophone has wide applications in ocean acoustic detection and seismic wave monitoring. The interference signal from external sources is routed to the elements through the link fiber connecting the dry and wet ends, which is a critical bottleneck that limits system performance. This paper presents a comprehensive model for link fiber-induced spurious signals, which demonstrates the physical processes and signal characteristics of the Doppler effect and the Rayleigh scattering effect, illustrating how they interact to generate the link interference signal. It is found that the dominant physical mechanism depends on the location of the link interference signal source. The interference signal source closer to the dry end mainly transmits signals to hydrophone elements through the Doppler effect, and the amplitude of the induced spurious signal depends on the frequency. When the link fiber is longer, the interference signal from the source near the wet end is simultaneously transmitted to hydrophone elements through the Doppler effect and Rayleigh scattering effect, during which the Rayleigh scattering effect leads to a spurious signal intensity increase of up to 10 dB. Additionally, the correlation with signal frequency decreases as instability rises. This thorough analysis of the physical process of link fiber-induced spurious signals will advance the development of interference suppression techniques, substantially boosting the sensitivity and reliability of interferometric FBG hydrophones for applications in harsh environments with disturbances.

Dielectrophoresis-Enhanced Microfluidic Device with Membrane Filter for Efficient Microparticle Concentration and Optical Detection

This paper presents a novel microfluidic device that integrates dielectrophoresis (DEP) forces with a membrane filter to concentrate and trap microparticles in a narrow region for enhanced optical analysis. The device combines the broad particle capture capability of a membrane filter with the precision of DEP to focus particles in regions optimized for optical measurements. The device features transparent indium tin oxide (ITO) top electrodes on a glass substrate and gold (Au) bottom electrodes patterned on a small area of the membrane filter, with spacers to control the gaps between the electrodes. This configuration enables precise particle concentration at a specific location and facilitates real-time optical detection. Experiments using 0.8 μm fluorescent polystyrene (PS) beads and Escherichia coli (E. coli) bacteria demonstrated effective particle trapping and concentration, with fluorescence intensity increasing proportionally to particle concentration. The application of DEP forces in a small region of the membrane filter resulted in a significant enhancement of fluorescence intensity, showcasing the effectiveness of the DEP-enhanced design for improving particle concentration and optical measurement sensitivity. The device also showed promising potential for bacterial detection, particularly with E. coli, by achieving a linear increase in fluorescence intensity with increasing bacterial concentration. These results highlight the device’s potential for precise and efficient microparticle concentration and detection.

Effects of Hydration and a Hyaluronic Acid-Containing Lozenge on Voice Parameters in Conjunction With a Vocal Loading Test.

This study explores the effects of water intake and a hyaluronic acid (HA)-containing lozenge on acoustic measurements and vocal oscillation patterns investigated after a vocal loading test (VLT). Ten healthy subjects (five females, five males) read out loud a standardized text for 10 min at a target level of 80 dB(A), measured 30 cm from the mouth, under three conditions but each after fasting for 2 hr: (a) drinking 0.7 l of water, (b) sucking an HA-containing lozenge, and (c) neither of both before the VLT. The dysphonia severity index (DSI) was assessed before and after the reading task. Additionally, high-speed videolaryngoscopy (HSV), electroglottography, and an audio signal during sustained phonation on the vowel /i/ before and after the VLT were analyzed. The glottal area waveform was derived from the HSV footage. DSI values decreased for the H2O and HA group, but reached statistical significance only for the H2O condition, while remaining stable for the control condition. These DSI decreases were driven by increases in minimum sound pressure level intensity (Imin)-again with statistical significance solely for the water intake intervention. Statistically nonsignificant changes were observed regarding periodicity and perturbation parameters across all conditions. No phase differences or aperiodicities were apparent in the phonovibrograms. Hydration and an HA lozenge did not significantly alter vocal fold biomechanics after a VLT. However, the decrease in DSI values with increased Imin suggests a reduced vocal capacity for the H2O condition. https://doi.org/10.23641/asha.28271285.

Russian Cargo Traffic in New Conditions: Opportunities and Restrictions

The article shows changes that affected cargo operations due to current transformation of the global situation, anti-Russia sanctions and replacement of key economic partners of Russia. The author analyzes accessible data of cargo traffic in home and international lines and explains possible underestimation of certain figures. Restrictions were investigated that hinder the development of some types of traffic, cause losses in cargo operations and shortage of resource capacity, in particular in moving-in and -out. The article shows reasons for impeding further intensive increase in cargo operations. The author studies such restrictions as distance of the route, fuel cost, nature and climatic conditions, the level of road network development, necessity to use transit communication in certain Russian regions, rising rates of utilization duties, high interest rate, risk of trucking companies’ leaving for the green zone, poor experience in using and maintaining Chinese cargo equipment that changed European trucks. The article assessed the dynamics of traffic and prospects of international transit in conditions of further scenario volatility, on the one hand and high adaptive capacity of national economic system to changing conditions and crises, on the other.

The impact of interplanetary magnetic field intensity on the Martian ionosphere

The interplanetary magnetic field (IMF) is one of the important external drivers that controls the Martian-induced magnetosphere and ionosphere. Previous studies have shown that the ion escape process is highly influenced by both the direction and intensity of the IMF. The enhanced IMF may decrease the ion escape rate by inducing a stronger magnetosphere that protects the Martian ionosphere, but the mechanisms have not been investigated thoroughly. Further studies are needed to reveal the response of ionospheric heavy ions to IMF variation as well as the underlying physical mechanism. This study aims to investigate the influence the IMF strength has on the Martian ionosphere. We adopted a multifluid magnetohydrodynamic (MHD) model in this study, which can self-consistently simulate the interaction between solar wind and Mars. By comparing different cases, we analyzed the ionospheric structure on the dayside and near nightside as well as the ion transport process. We aim to obtain a deeper understanding of how the IMF intensity variation impacts the Martian ionosphere and the escape of planetary ions. A three-dimensional multifluid MHD model was used to simulate the interaction between the upstream solar wind and Mars. Four major species in the Martian ionosphere, H^+, O_ O^+, and CO_ are considered in the model, with the chemical reactions and particle collisions included to calculate ion distribution and ion motions. We analyzed three cases where the IMF strength was set to nT ， nT and nT The enhancement of the IMF produces a stronger electromagnetic field in the Martian plasma environment. Both the electric field and magnetic field intensity increase, which provides a shielding effect to the Martian ionosphere, hindering the intrusion of solar wind particles. Thus, less planetary ions are produced by the chemical reactions between the solar wind and the Martian neutral particles, leading to shrinkage of the ionospheric upper boundary. As the IMF strength increases, both the day-to-night plasma transport and the ion outflow decreases. Thus, a more depleted nightside ionosphere is formed, and the tailward ion escape may be weakened, decreasing the global ion escape rate. Moreover, the strong crustal fields in the southern hemisphere enhance the electromagnetic field on the southern dayside, which withstand the penetration of solar wind plasma more effectively, resulting in asymmetry structures in the ionosphere.

Tuning optical and structural properties of polystyrene nanocomposites with rutile TiO₂ nanoparticles

ABSTRACT The surface morphology and structural properties of polystyrene (PS)/TiO₂ nanocomposites were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), while optical properties were assessed via UV-Vis spectroscopy and Fluorescence measurements. SEM images revealed uniform dispersion of TiO₂ nanoparticles with sizes ranging from 48 to 58.5 nm in the PS matrix, showing no significant agglomeration. XRD analysis revealed a decrease in crystallite size with increasing TiO₂ concentration. UV-Vis spectra demonstrated a decrease in the band gap with increasing TiO₂ concentration, indicating a shift towards enhanced visible light absorption. PL spectra excited at 330 nm revealed distinct emission peaks, with significant increases in intensity at higher TiO₂ concentrations, particularly at 399 nm and 422.5 nm, corresponding to near-band-edge and defect-related emissions. FTIR analysis demonstrated that the incorporation of TiO₂ led to disruption of C-O bonds in the PS matrix, particularly at 10% TiO₂, suggesting strong interactions between the TiO₂ nanoparticles and the polymer, which may weaken the polymer backbone. Overall, these findings suggest that TiO₂ incorporation not only impacts crystallite size and strain but also enhances the optical and fluorescence properties of PS/TiO₂ nanocomposites.

Emissive Bovine Serum Albumin‐Templated Osmium Nanoclusters: Synthesis and Optical Characterization

Synthesis of new nanomaterials with unique optical properties is of great importance in different fields such as energy, material science, and biomedicine. Here, for the first time, we report the synthesis of the emissive osmium nanoclusters (OsNCs) using bovine serum albumin (BSA) as template and sodium borohydride as strong reducing agent. The as‐synthesized emissive OsNCs had only 31 atoms, with deep‐blue color emission with an emission maximum at 415 nm and a photoluminescence quantum yield (PLQY) of 2.5%. The fluorescence emission of OsNCs could be attributed to the smaller number of atoms (31) in the as‐synthesized OsNCs in this work. The optical characterization of the emissive OsNCs revealed that the fluorescence intensity was more sensitive to pH than with temperature of the solution. When pH was increased from 1 to 12, there was 6‐fold increase in the emission intensity. We believe that the presented synthesis route as well as the results of this work could open new avenues to further investigate the OsNCs as new emissive nanomaterials and their potential applications in biomedical and energy fields.

Enhancing trace DNA profile recovery in forensic casework using the amplicon RX post-PCR clean-up kit

This study evaluated the effectiveness of the amplicon RX post-PCR clean-up kit in enhancing trace DNA profile recovery from forensic casework samples amplified using the GlobalFiler PCR amplification kit. The impact of post-PCR clean-up on allele recovery and signal intensity was assessed in both trace casework samples and control samples across a range of DNA concentrations. The results showed that the amplicon RX method significantly improved allele recovery compared to the 29-cycle protocol (p = 8.30 × 10−12) and achieved slightly better results than the 30-cycle protocol (p = 0.019). Additionally, the Amplicon RX method demonstrated a significant increase in signal intensity (p = 2.70 × 10−4), reflecting improved sensitivity in detecting trace DNA profiles compared to the 30-cycle protocol. In the evaluation of control samples, the amplicon RX method consistently outperformed both the 29- and 30-cycle protocols, especially at lower DNA concentrations (D3: 0.001 ng/µL). While the performance of all methods declined at the lowest concentration (D4: 0.0001 ng/µL), the Amplicon RX method still demonstrated superior allele recovery (p = 0.014 compared to 29 cycles; p = 0.011 compared to 30 cycles). Therefore, the Amplicon RX method should be widely adopted in forensic laboratories to enhance the analysis of extremely low-template and compromised samples. These findings highlight the potential of the amplicon RX post-PCR clean-up kit to improve trace DNA analysis in forensic casework. Further research is recommended to validate these results and explore its broader application in forensic DNA analysis, particularly in complex DNA mixtures and extremely low-template samples.

Enhanced optical response of n-type doped InAs quantum dots through interface state inactivation

Owing to the wide tuning range, high-temperature stability, flexible design, and fast recovery dynamics, quantum dots (QDs) have been widely used in many research fields, such as lasers, photodetectors, solar cells, and displays. Among these, III–V InAs/GaAs QDs are especially suited for infrared optoelectronic applications due to their strong working stability and enhanced light output efficiency. The doping technique has been admitted as a very effective method to enhance the modal gain and temperature insensitivity for InAs/GaAs QDs-based devices. Additionally, doping could modulate critical optical responses, like light absorption and carrier recovery dynamics, making these QDs ideal for ultrafast applications. In this work, p-type (Be) doping and n-type (Si) doping were introduced into multilayer QDs to mitigate the adverse effects of grown-in interface states, which were verified by temperature-dependent photoluminescence (PL) characterization. The results show a significant increase in PL intensity for n-doped samples, which was attributed to the effective suppression of interface states. This enhancement correlates with doping levels, with PL intensity increasing from 1.71 to 2.72 times as Si concentration rises from 1 × 1018/cm3 to 3 × 1018/cm3. In contrast, p-doped samples show a slight decrease in PL intensity and a 20 nm blueshift in PL emission peak, indicating different interdiffusion behaviors between In and Ga atoms compared to that in n-doped ones. By integrating with distributed Bragg mirrors, QD semiconductor saturable absorption mirrors were developed, where n-doped QDs presented superior performance in mode-locked ultrafast lasers with the shortest pulse width and highest output power.

Comprehensive Evaluation Method for the Metrological Performance of Intelligent Energy Meters in Complex Electromagnetic Field Environments

The existing evaluation methods mainly focus on the basic measurement accuracy of electric energy meters, without fully considering the anti-interference ability of electric energy meters under different electromagnetic interference intensities. In order to comprehensively evaluate the metrological performance of electric energy meters in complex electromagnetic field environments, this article adopted a comprehensive and systematic AHP-EWM (Analytical Hierarchy Process-Entropy Weight Method) comprehensive evaluation algorithm. This article used the Finite Element Method (FEM) to simulate complex electromagnetic environments, designed a multidimensional performance index system, and combined AHP and FEM to construct a comprehensive evaluation model for systematically evaluating the metrological performance of Intelligent Energy Meters (IEM) in complex electromagnetic environments. The experimental results show that the measurement error of smart energy meters significantly increases with the increase of interference intensity. AHP-EWM has shown high consistency and reliability under different electromagnetic interference intensity conditions and multiple repeated experimental tests. The weight allocation of various indicators remains relatively stable in different testing environments, and the comprehensive evaluation score fluctuates slightly, with a range of only 0.01 to 0.03. The AHP-EWM model can overcome electromagnetic interference of different intensities in practical applications and conduct comprehensive IEM metrological performance evaluation.

Calcineurin governs baseline and homeostatic regulations of non–rapid eye movement sleep in mice

Sleep need accumulates during waking and dissipates during sleep to maintain sleep homeostasis (process S). Besides the regulation of daily (baseline) sleep amount, homeostatic sleep regulation commonly refers to the universal phenomenon that sleep deprivation (SD) causes an increase of sleep need, hence, the amount and intensity of subsequent recovery sleep. The central regulators and signaling pathways that govern the baseline and homeostatic sleep regulations in mammals remain unclear. Here, we report that enhanced activity of calcineurin Aα (CNAα)-a catalytic subunit of calcineurin-in the mouse brain neurons sharply increases the amount (to ~17-h/d) and delta power-a measure of intensity-of non-rapid eye movement sleep (NREMS). Knockout of the regulatory (CnB1) or catalytic (CnAα and CnAβ) subunits of calcineurin diminishes the amount (to ~4-h/d) and delta power of baseline NREMS, but also nearly abrogates the homeostatic recovery NREMS following SD. Accordingly, mathematical modeling of process S reveals an inability to accumulate sleep need during spontaneous or forced wakefulness in calcineurin deficient mice. Moreover, calcineurin promotes baseline NREMS by antagonizing wake-promoting protein kinase A and, in part, by activating sleep-promoting kinase SIK3. Together, these results indicate that calcineurin is an important regulator of sleep need and governs both baseline and homeostatic regulations of NREMS in mice.

Methionine Sulfoximine as a Tool for Studying Temporal Lobe Epilepsy: Initiator, Developer, Attenuator.

Methionine sulfoximine (MSO) is a compound originally discovered as a byproduct of agene-based milled flour maturation. MSO irreversibly inhibits the astrocytic enzyme glutamine synthase (GS) but also interferes with the transport of glutamine (Gln) and of glutamate (Glu), and γ-aminobutyric acid (GABA) synthesized within the Glu/Gln-GABA cycle, in this way dysregulating neurotransmission balance in favor of excitation. No wonder that intraperitoneal administration of MSO has long been known to induce behavioral and/or electrographic seizures. Recently, a temporal lobe epilepsy (TLE) model based on local continuous infusion of MSO into the hippocampus has been developed reproducing the main features of human mesial TLE: induction of focal seizures, their spreading, increase in intensity over time, and development of spontaneous recurrent seizures. Fully developed TLE in this model is associated with hippocampal degeneration, hallmarked by reactive astrogliosis, and causally related to the concomitant loss of GS-containing astrocytes. By contrast, short-term pre-exposure of rats to relatively low MSO doses that only moderately inhibited GS, attenuated and delayed the initial seizures in the lithium-pilocarpine model of TLE and in other seizure-associated contexts: in the pentylenetetrazole kindling model in rat, and in spontaneously firing or electrically stimulated brain slices. The anti-initial seizure activity of MSO may partly bypass inhibition of GS: the postulated mechanisms include: (i) decreased release of excitatory neurotransmitter Glu, (ii) prevention or diminution of seizure-associated brain edema, (iii) stimulation of glycogenesis, an energy-sparing process; (iv) central or peripheral hypothermia. Further work is needed to verify either of the above mechanisms.

Development of edible films based on sweet potato (Ipomoea batatas) starch and their application in candy packaging.

Recent studies have focused on the generation of biomaterials from natural sources, highlighting the use of starch from different sources to obtain edible films and coatings. In this study, edible films were developed from sweet potato starch, and their potential use in candy packaging was evaluated. Films were prepared by the casting method, and the effects of sweet potato starch (3 %-5 % w/w), glycerol (0.8 %-1.2 % v/v), and calcium carbonate (0.05 %-0.1 % w/w) on the physical, structural, optical, and barrier properties were examined using a completely randomized design. The sweet potato starch presented granules with a spherical appearance and a swelling capacity of 1.33 g/g at 80 °C. ANOVA results showed that starch content and glycerol-calcium carbonate interaction affected the thickness and color parameters. The water vapor permeability and water solubility increased with increasing starch and glycerol concentrations. Fourier transform infrared spectroscopy (FTIR) analysis of film microstructure showed increase in the band intensity, indicating modification of the starch structure. The film with sweet potato starch, glycerol, and calcium carbonate concentrations of 3 %, 0.8 %, and 0.1 %, respectively, used for candy packaging, endowed the product with good sensory acceptance during the 21 days of storage, although the product displayed slight changes in the color.

Toxic effects of deltamethrin on oxidative stress, behavioural, organosomatic indices and histopathological changes in Digitonthophagus gazella (Coleoptera: Scarabaeinae).

Pyrethroids pose a great concern to the declining population of dung beetles and the sustainability of ecosystem services. This study aimed to investigate the toxic effects of deltamethrin on Digitonthophagus gazella. First, the LC50 value (0.275 ppm) was determined, and sub-lethal concentrations (LD; low dose-0.014ppm, MD; medium dose-0.028ppm, and HD; high dose-0.055ppm) were assessed for physiological effects. The findings showed a significant dose and time dependent increase in fluorescence intensity (dcfda staining) and a decrease in antioxidant activity, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Furthermore, significant down regulation of cyp4g7, cyp6bq9, and cyp4q4 expression indicates enhanced oxidative stress. Additionally, a reduction in the organosomatic index, accompanied by histological changes in the brain, gut, and gonads, suggests potential functional disturbances. Overall, deltamethrin exposure had profound and irreversible pathological consequences on various vital organs and systems in D. gazella, affecting reproduction and nesting.

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.

Global urban greening and its implication for urban heat mitigation

Urban vegetation provides essential ecosystem services and benefits to support biodiversity and human well-being in urban areas. However, the dynamic trends, driving factors, and their implications to urban heat mitigation at the global scale remain largely unclear. Here, we used a high-resolution enhanced vegetation index (EVI) dataset to examine the vegetation dynamics in 11,235 urban areas worldwide, identify the driving factors behind its changes, and estimate the potential urban heat mitigation benefits of these changes. We found that 40.75% urban areas (1.51 Mha) evidenced a greening trend (showing increasing EVI), in contrast to 49.60% urban areas showing browning (decreasing EVI). Notably, urban centers in both developed and developing countries contribute to this greening trend. We, nevertheless, found significant spatial disparities in this greening trend, with cities in the Global North showing higher greening ratios than those in the Global South. The driving factors of urban vegetation change trend lead to significant differentiation in and around urban areas. The rapid increase in urbanization intensity and the negative effects of nitrogen deposition are the dominant factors leading to vegetation browning in urban peripheries. However, nitrogen deposition and urbanization intensity have shown positive effects on vegetation greening within urban centers. Crucially, compared to areas with vegetation browning or no significant change, vegetation greening areas have a more significant cooling effect, potentially mitigating the urban heat island effect, especially during summer daytime. Our findings highlight the importance of enhancing urban vegetation greening to promote equitable urban development and ensure effective climate change mitigation.