Slight Contraction Research Articles

Marangoni-driven pattern formation in an absorbing binary mixture

We investigate the evolution of convective instability in a LiBr–water binary mixture, driven by thermal and solutal Marangoni stresses, through numerical simulations. A small perturbation in absorption at the surface disturbs the equilibrium, generating surface tension gradients that drive Marangoni flows. To isolate and better understand the interplay between the Marangoni effect and absorption, we extended the previous study by investigating the LiBr–water binary system in the absence of gravity. For the first time, we observed the formation of a stable rim in an absorbing binary mixture, which underwent a slight contraction followed by rapid Marangoni spreading. This behavior shows similarities with the flow patterns seen in the “coffee-ring” and Marangoni spreading phenomena in evaporating binary mixtures. On the subsurface, convective motion breaks into several vortices, accompanied by the formation of plumes with reduced mass fraction. As the system evolves, the symmetry of the flow pattern around the cell center breaks down. The absence of buoyancy-driven forces eliminates a key counterforce to Marangoni flows, transforming the previously ordered patterns into non-periodic oscillations, followed by the development of non-stationary but regular patterns. These results complement our earlier findings [P. F. Arroiabe et al., Phys. Fluids 36, 022119 (2024)] where gravitational forces obscured these phenomena.

Current and future environmental suitability for bats hosting potential zoonotic pathogens in rural Kenya.

Synanthropic bats live in close proximity to humans and domestic animals, creating opportunities for potential pathogen spillover. We explored environmental correlates of occurrence for a widely distributed synanthropic African bat, Mops pumilus-a species associated with potential zoonotic viruses-and estimated current and future environmental suitability in the Taita Hills region and surrounding plains in Taita-Taveta County in southeast Kenya. To project future environmental suitability, we used four Coupled Model Intercomparison Project Phase 6 general circulation models that capture temperature and precipitation changes for East Africa. The models were parameterized with empirical capture data of M. pumilus collected from 2016 to 2023, combined with satellite-based vegetation, topographic, and climatic data to identify responses to environmental factors. The strongest drivers for current environmental suitability for M. pumilus were short distance to rivers, higher precipitation during the driest months, sparse vegetation-often related to urban areas-and low yearly temperature variation. To predict current and future areas suitable for M. pumilus, we created ensemble niche models, which yielded excellent predictive accuracies. Current suitable environments were located southward from the central and southern Taita Hills and surrounding plains, overlapping with urban centers with the highest human population densities in the area. Future projections for 2050 indicated a moderate increase in suitability range in the southern portion of the region and surrounding plains in human-dominated areas; however, projections for 2090 showed a slight contraction of environmental suitability for M. pumilus, potentially due to the negative impact of increased temperatures. These results show how environmental changes are likely to impact the human exposure risk of bat-borne pathogens and could help public health officials develop strategies to prevent these risks in Taita-Taveta County, Kenya, and other parts of Africa.

On the elastic–plastic behaviors of centrifugal steam compressor impeller under cyclic thermomechanical loading

AbstractIn this paper, the cyclic elastic–plastic behaviors of the centrifugal steam compressor impeller (CSCI) structure under practical operating conditions are discussed employing the linear matching method (LMM). The three‐stage strategy of the LMM is employed to determine the shakedown and ratchet boundaries by conducting a series of iterative direct steady cyclic analysis, and based on this, the load regions corresponding to different types of damage behavior that may occur during the operation are identified. Computational results reveal slight contraction in the structural response diagram when considering actual material constitutive relationships, compared to ideal elastic–plastic models. Meanwhile, by integrating the unified ratchet and fatigue program with fatigue experimental data, a series of constant low‐cycle fatigue life curves has been presented for different service conditions. Furthermore, a comparison with detailed step‐by‐step inelastic analyses confirms the applicability and great efficiency of the LMM in practical engineering problems.

Lattice variation as a function of concentration and grain size in MgO–NiO solid solution system

The study aimed to understand how changes in crystal's size affect the lattice parameters and crystal structure of Mg1-xNixO solid solution for six X values ranging from x = 0 to x = 1. Mg1-xNixO was synthesized via two different wet-chemical techniques: the sol-gel and the microwave hydrothermal method, both followed by calcination at different temperatures of 673, 873, 1073, 1273 and 1473 K. As annealing caused grain growth, the varied temperature range allowed to examine a wide range of grain sizes. The lattice parameters and x values were determined from XRD (X-ray diffraction) peak positions and intensities respectively. The grain size was evaluated by XRD line profile analysis and supported by SEM (scanning electron microscope) observations. At the temperatures of 673 and 873 K grain size was in the nanometric range and from 1073 K and above grain size was in the micrometric range. A non-monotonic lattice variation versus grain size was found for each concentration. When grain size decreased there was a slight contraction, however for grain size in the nanometric range there was a severe lattice expansion. Both lattice parameter changes were explained by two effects acting together: contraction due to surface stress and expansion due to weakening of the ionic bonding at nanocrystalline particles. In this current research study, the lattice parameter was mapped in two dimensions: concentration and grain size. The findings of this study provided valuable insights into the lattice variation in the MgO–NiO solid solution system.

Comparative genomics on chloroplasts of Rubus (Rosaceae)

Rubus, the largest genus in Rosaceae, contains over 1400 species that distributed in multiple habitats across the world, with high species diversity in the temperate regions of Northern Hemisphere. Multiple Rubus species are cultivated for their valuable fruits. However, the intrageneric classification and phylogenetic relationships are still poorly understood. In this study, we sequenced, assembled, and characterized 17 plastomes of Rubus, and conducted comparative genomics integrating with 47 previously issued plastomes of this genus. The 64 plastomes of Rubus exhibited typical quadripartite structure with sizes ranging from 155,144 to 156,700 bp, and contained 132 genes including 87 protein-coding genes, 37 tRNA genes and eight rRNA genes. All plastomes are conservative in the gene order, the frequency of different types of long repeats and simple sequence repeats (SSRs), the codon usage, and the selection pressure of protein-coding genes. However, there are also some differences in the Rubus plastomes, including slight contraction and expansion of the IRs, a variation in the numbers of SSRs and long repeats, and some genes in certain clades undergoing intensified or relaxed purifying selection. Phylogenetic analysis based on whole plastomes showed that the monophyly of Rubus was strongly supported and resolved it into six clades corresponding to six subgenera. Moreover, we identified 12 highly variable regions that could be potential molecular markers for phylogenetic, population genetic, and barcoding studies. Overall, our study provided insight into plastomic structure and sequence diversification of Rubus, which could be beneficial for future studies on identification, evolution, and phylogeny in this genus.

Enforcing accurate volume conservation in VOF‐based long‐term simulations of turbulent bubble‐laden flows on coarse grids

AbstractThis study proposes two different strategies to enforce accurate volume conservation in volume‐of‐fluid (VOF)‐based simulations of turbulent bubble‐laden flows on coarse grids. It is demonstrated that, without a correction, minimal volume errors on a time‐step level, caused by the under‐resolution of the interface, can accumulate to significant deviations from the intended flow conditions despite the comparably good volume conservation properties of the geometric VOF method. In particular, large volume errors are observed for challenging setups combining coarse grid resolutions and comparably high Reynolds and Eötvös numbers. The problem is reinforced for long‐term simulations in periodic domains, which are often performed to collect flow statistics of bubbly flows. The first proposed volume conservation method simply corrects the volume error of a bubble by uniformly adding or removing the respective amount of gas volume in the interface cells. The second proposed method performs an additional reconstruction and advection step of the VOF field using a non‐divergence‐free velocity field, which can be interpreted as a slight dilatation or contraction of the bubble. A comparison between the global flow statistics as well as the individual bubble dynamics for both volume conservation methods reveals that the results are quasi‐identical for a number of challenging test cases, while the gas volume is accurately conserved. The proposed methods allow to perform numerical simulations of freely deformable bubbles in turbulent flows for setups that have previously been out of reach for this numerical framework.

Hurricane Frances in Florida: Past and Future

Tropical cyclones (TC) are common high-impact weather events in the southeastern United States. One of the most intense TCs to hit north-central Florida in recent decades was Hurricane Frances (2004), which resulted in over $10B in damages. Given the growing concern about the relationship between anthropogenic climate change, precipitation, and TCs, we investigated how a Hurricane Frances-like event would affect north-central Florida in the late 21st century under an RCP- 8.5 scenario. Using a ‘pseudo’ global warming dataset based on the high-resolution Weather Research and Forecasting (WRF) model, we explore historical and future simulations of Hurricane Frances’s path, precipitation rates, and wind speeds. We discover that, across north-central Florida sub-daily to daily rainfall totals in the future simulation exceed that of the historical, having return period events in some cases reaching 500-year thresholds. We also find more broadly across the spatial domain of the hurricane that rainfall rates in all temporal categories and total rainfall accumulation increased significantly. Results for wind speeds were mixed, with an evident expansion of tropical storm winds, but a slight contraction of the spatial extent of strongest winds at the surface. We discuss the implications of these findings for decision-makers in Florida.

Compressive reactive molecular dynamics on mechanical and structural behaviors of geopolymers: Imposing lateral constraints and varied temperatures

Geopolymer concrete offers superior mechanical properties and microstructure, yet micro-level compressive properties and structural evolutions remain insufficiently understood. This study employed molecular dynamics to simulate the uniaxial compressions of the sodium aluminosilicate hydrate (N-A-S-H) under UCZ, BCZ, and TCZ (z-axial compressions with zero, one, and two dimensions restrictions, respectively) conditions at 263 K, 300 K, and 800 K. The results provided valuable insights linking mechanical behavior with structural properties. Stress fluctuations in the yield stage were attributed to the continuous formation and fracture of Al-O-H bonds during micro-molecule processes. In the later compression stages, the rapid increase in Si-O-H groups suggested that water molecules equally attacked Al and Si tetrahedra due to limited voids. Under UCZ and BCZ conditions, slight bond contraction occurred, with the main structural resistance arising from bond angle bending within the skeleton. In contrast, TCZ experienced notable changes in both bond lengths and bond angles due to bilateral displacement constraints. The evolutionary molecular processes exhibited insensitive response to the temperature, especially under TCZ conditions. Additionally, varying trends were observed in different bond-angle styles (e.g., within or inside tetrahedra), providing a crucial insight for the design of N-A-S-H to determine optimal components.

DYNAMICS OF CHANGES OF IRRIGATED CROPLANDS IN THE STATE OF GUANAJUATO, MEXICO

Abstract. Irrigated agriculture requires extensive land areas and consumes high volumes of water. This study aims to determine and analyze the dynamics of irrigated croplands and their water consumption in Guanajuato State, located in the central region of Mexico. Guanajuato is among the Mexican states with the country's most considerable agricultural land extent, with more than half of its territory dedicated to agricultural activities. The work offers an innovative approach by adding official statistical information on irrigated agriculture crops and geospatial data for a considerable period. First, land use and cover change patterns were studied using a multidate land cover cartographic database. We observed some reduction in irrigated areas due to urban expansion; nevertheless, most irrigated regions remained stable over time. After that, we computed the areal evolutions of ten main crops and their associated water consumption. We observed a slight contraction of irrigated agriculture. However, the most notorious changes in water consumption are due to changes in the types of crops and agricultural intensification can burden water scarcity.

Unit cell distortion of ferrierite induced by carbonaceous deposits during skeletal isomerization of 1-butene

In this study, high temperature and ambient X-ray powder diffraction (XRD) are employed to differentiate the impacts of temperature and carbon deposition on the catalytic activity of the zeolite H-ferrierite (H-FER) via changes in the unit cell structure. XRD serves as a straightforward tool to distinguish these influences on the lattice geometry of H-FER, which ultimately affects catalytic activity. Due to its industrial relevance, the isomerization reaction of 1-butene to iso-butene is selected. Pristine H-FER undergoes a thermal contraction when heated from room temperature to 450 °C. However, internal carbonaceous deposits (i.e., deposits inside the micropores of the zeolite) counterbalance this effect, and the unit cell expands anisotropically during the reaction startup phase. Internal carbon deposits act as the driving force for this expansion and counteract external forces. During catalyst deactivation (time on stream >100 h), a slight unit cell contraction (i.e., ΔV = −6 Å3) is observed that stems from external carbon deposit condensation (i.e., deposits on the crystal surface). Characterization of an oxidatively regenerated catalyst supports this finding by proving this structural distortion to be nearly reversible. This study concludes that internal carbon species are primarily responsible for structural distortion and counteract thermal contraction, whereas external coke species are the driving force for catalyst deactivation.

Immune checkpoint blockade therapy mitigates systemic inflammation and affects cellular FLIP-expressing monocytic myeloid-derived suppressor cells in non-progressor non-small cell lung cancer patients

ABSTRACT Cancer cells favor the generation of myeloid cells with immunosuppressive and inflammatory features, including myeloid-derived suppressor cells (MDSCs), which support tumor progression. The anti-apoptotic molecule, cellular FLICE (FADD-like interleukin-1β-converting enzyme)-inhibitory protein (c-FLIP), which acts as an important modulator of caspase-8, is required for the development and function of monocytic (M)-MDSCs. Here, we assessed the effect of immune checkpoint inhibitor (ICI) therapy on systemic immunological landscape, including FLIP-expressing MDSCs, in non-small cell lung cancer (NSCLC) patients. Longitudinal changes in peripheral immunological parameters were correlated with patients’ outcome. In detail, 34 NSCLC patients were enrolled and classified as progressors (P) or non-progressors (NP), according to the RECIST evaluation. We demonstrated a reduction in pro-inflammatory cytokines such as IL-8, IL-6, and IL-1β in only NP patients after ICI treatment. Moreover, using t-distributed stochastic neighbor embedding (t-SNE) and cluster analysis, we characterized in NP patients a significant increase in the amount of lymphocytes and a slight contraction of myeloid cells such as neutrophils and monocytes. Despite this moderate ICI-associated alteration in myeloid cells, we identified a distinctive reduction of c-FLIP expression in M-MDSCs from NP patients concurrently with the first clinical evaluation (T1), even though NP and P patients showed the same level of expression at baseline (T0). In agreement with the c-FLIP expression, monocytes isolated from both P and NP patients displayed similar immunosuppressive functions at T0; however, this pro-tumor activity was negatively influenced at T1 in the NP patient cohort exclusively. Hence, ICI therapy can mitigate systemic inflammation and impair MDSC-dependent immunosuppression.

Effect of Dihydroartemisinin on contractility to Drugs in isolated smooth muscle Preparations in guinea pig in vitro models

This study was aimed at evaluating the effect of Dihydroartemisinin (DHA)on contractility to drugs in ileum isolated smooth muscle preparations in guinea pigs using in Vitro experimental procedures / standard protocols in an organ bath set up. dihydroartemisinin (1.0 x 10 - 8 - 1.0 x 10 – 5mg/mL) when applied alone and separately excited marked variable effects on guinea pig ileum . In some preparation it showed no response, while in others it produced slight phasic contraction when external calcium (Ca2+) ion was introduced. The slight phasic contractile activity was abolished by verapamil (5x10-3mg/mL). Dihydroartemisinin (1.0 x 10 - 6 - 1.0 x 10 – 5mg/mL) caused marked significant induced contraction – dependent inhibition of acetylcholine, potassium chloride and histamine in depolarizing tyrode solution (p < 0.05).The Inhibitory response maxima of dihydroartemisinin on acetylcholine induced contraction is 17.0±0.1 mm(65.56% inhibition) ; and is moderate when compared to the inhibitory effect of atropine (10-5 M). The result shows that dihydroartemisinin seems to act via non-specific receptor mechanism, with appreciable calcium channel blocking activity and it is safe at therapeutic doses.

A practical guide to the evaluation of the functional integrity of the corticospinal tract by transcranial magnetic stimulation in post-stroke patients

INTRODUCTION: Transcranial magnetic stimulation (TMS) can be a particularly useful tool to assess the integrity of corticospinal tract (CST) in post-stroke patients, based on the motor evoked potential (MEP) of which we can determine the extent of brain damage and predict motor recovery after brain injuries. OBJECTIVE: To provide a practical guide to assess the functional integrity of the CST in the hand area of primary motor cortex (Hand-M1) using single-pulse TMS. RESULTS: A step by step procedure should be initiated with markings to find C3 or C4 from the 10-20 system, depending on which hemisphere is damaged, with the proper coil positioning at a 45° angle for we to properly find the MEP navigating from the original point. If no potentials are evoked at rest condition, MEP should be searched during a slight tonic contraction of the target muscle. If no voluntary movement can be produced in the affected muscles, facilitated MEPs should be searched with an isometric recruitment of the contralateral homologous target muscles. MEP will be considered absent if no visible muscle contraction is identified after the pulse. In addition, we can perform MEP search with electromyographic recordings for a peak-to-peak signal analysis. CONCLUSION: We can use this practical guide to assess the functional integrity of CST in Hand-M1 with single pulse TMS to consider a present or absent MEP and determine the extent of brain damage and predict a possible motor recovery after stroke.

Unconventional Self-Reconstructed Trimer-like Metal Zigzag Edge of 1T-Phase Transition Metal Dichalcogenides

Undercoordination-induced slight bond contraction of the pristine edge is a conventional edge self-reconstructed pattern in two-dimensional materials that generally cannot drive the edge into its ground state. Despite reports of unconventional edge self-reconstructed patterns of 1H-phase transition metal dichalcogenides (TMDCs), there have been no reports of sister 1T-phase TMDCs. Here, we predict an unconventional (2 × 1) edge self-reconstructed pattern for 1T-TMDCs by considering 1T-TiTe2. A novel self-reconstructed trimer-like metal zigzag edge (TMZ edge) with one-dimensional metal atomic chains and Ti3 trimers is uncovered. Its metal triatomic 3d orbital coupling leads to Ti3 trimerization. This TMZ edge occurs in group IV, V, and X 1T-TMDCs and has an energetic advantage far beyond conventional bond contraction. The unique triatomic synergistic effect results in better catalysis of the hydrogen evolution reaction (HER) for the 1T-TMDCs than with commercial platinum-based catalysts. This study provides a new strategy for maximizing the HER catalytic efficiency of 1T-TMDCs by using atomic edge engineering.

Dynamic changes in forest cover and human activities during the Holocene on the northeast Tibetan plateau

Human activities strongly influenced the present-day environment of the Tibetan Plateau, especially in the northeastern area. The questions over when and to what extent humans began to utilize the plateau environment have been long investigated, but there are still gaps in our understanding, such as the relationship between forest dynamics and anthropogenic activities. Here, we simulate the potential Holocene geographical distribution of the three dominant coniferous species in the Northeast Tibetan Plateau in response to climate/environment and analyze pollen records and multi-proxies for anthropogenic activities to explore human impact on natural forest dynamics. Simulation results show marked expansion of Picea and Pinus coniferous forests in the Early Holocene (11.5–8.3 ka BP), continuing into the Mid Holocene (8.3–4.0 ka BP). However, there was a slight contraction of forest in the Late Holocene (4.0–2.6 ka BP) in the western part of the region, and near disappearance in the eastern Qaidam Basin, although both Pinus and Picea slightly increased in Hehuang Valley. Pollen analysis confirms the patterns, with an increase in arboreal pollen mainly comprising Pinus and Picea from Early to Early Mid Holocene (11.5–5.3 ka BP), followed by a decrease. Proxies of anthropogenic activities, including carbon concentration, archeological sites, and, synanthropic plants, increased significantly after 5.3 ka BP, with archeological evidence for intensive exploitation of forest and turnover of natural vegetation. We argue that forest retreat at 5.3–4.0 ka BP was due to the expansion of cropland and increasing demand for wood. Significant coniferous forest retreat and degradation from 4.0 to 2.6 ka BP, with forest succession in Hehuang Valley, was driven by the booming population, extensive grazing, and forest exploitation; the drying cooling climate may have aggravated the pace of deforestation at higher elevations. This study presents new insights into the deforestation on the Northeast Tibetan Plateau in the Holocene.

Diverging Fates of the Pacific Ocean Oxygen Minimum Zone and Its Core in a Warming World

AbstractGlobal ocean oxygen loss is projected to persist in the future, but Earth system models (ESMs) have not yet provided a consistent picture of how it will influence the largest oxygen minimum zone (OMZ) in the tropical Pacific. We examine the change in the Pacific OMZ volume in an ensemble of ESMs from the CMIP6 archive, considering a broad range of oxygen (O2) thresholds relevant to biogeochemical cycles and ecosystems (5–160 µmol/kg). Despite OMZ biases in the historical period of the simulations, the ESM ensemble projections consistently fall into three regimes across ESMs: an expansion of low oxygenated waters (+0.8 [0.6, 1.0] × 1016 m3/century for O2 ≤ 120 µmol/kg, ESM median and interquartile range); a slight contraction of the OMZ core although more uncertain across ESMs (−0.1 [−0.5, 0.0] × 1016 m3/century for O2 ≤ 20 µmol/kg); and at the transition from contraction to expansion regimes, a spatial redistribution but near‐zero change in the volume of hypoxic waters (0.0 [−0.3, +0.1] × 1016 m3/century for O2 ≤ 60 µmol/kg). Changes in circulation and biology dictate the shift from expansion to contraction. Specifically, reduced subtropical ventilation controls the expansion of low oxygenated waters, while a combination of circulation and biological changes explains the contraction of the core (likely changes in mixing, reduced intermediate ventilation and oxygen demand). Increased model complexity (e.g., ecosystem dynamics and equatorial circulation) likely stabilize the OMZ response, suggesting that future changes might lie in the lower bound of current projections. The expansion of low oxygenated waters which delimit the optimum habitat of numerous marine species would severely impact ecosystems and ecosystem services.

Formation of Ir–MgO Solid Solutions Analyzed with X-ray Absorption Spectroscopy

Thermal treatment of MgO-loaded Ir nanoparticles or Ir(OAc)3 formed Ir–MgO solid solutions. The valence of Ir in the Ir–MgO solid solution was 3 +, as evidenced by Ir L3-edge XANES combined with XPS analysis. A slight contraction of the Ir–O bond distance was observed compared to that of the nearest neighboring Mg–O bond in MgO. Ir–MgO dispersion exhibited a two-spike pattern depending on the treatment temperature owing to the formation and successive segregation of the solid solutions.

Mapping the Distribution and Dispersal Risks of the Alien Invasive Plant Ageratina adenophora in China

Identifying the distribution dynamics of invasive alien species can help in the early detection of and rapid response to these invasive species in newly invaded sites. Ageratina adenophora, a worldwide invasive plant, has spread rapidly since its invasion in China in the 1940s, causing serious damage to the local socioeconomic and ecological environment. To better control the spread of this invasive plant, we used the MaxEnt model and ArcGIS based on field survey data and online databases to simulate and predict the spatial and temporal distribution patterns and risk areas for the spread of this species in China, and thus examined the key factors responsible for this weed’s spread. The results showed that the risk areas for the invasion of A. adenophora in the current period were 18.394° N–33.653° N and 91.099° E–121.756° E, mainly in the tropical and subtropical regions of China, and densely distributed along rivers and well-developed roads. The high-risk areas are mainly located in the basins of the Lancang, Jinsha, Yalong, and Anning Rivers. With global climate change, the trend of continued invasion of A. adenophora is more evident, with further expansion of the dispersal zone towards the northeast and coastal areas in all climatic scenarios, and a slight contraction in the Yunnan–Guizhou plateau. Temperature, precipitation, altitude, and human activity are key factors in shaping the distribution pattern of A. adenophora. This weed prefers to grow in warm and precipitation-rich environments such as plains, hills, and mountains; in addition, increasing human activities provide more opportunities for its invasion, and well-developed water systems and roads can facilitate its spread. Measures should be taken to prevent its spread into these risk areas.

Morphological and physiological changes induced by Achyranthes aspera-mediated silver nanocomposites in Aedes aegypti larvae.

Aedes aegypti is responsible for the global spread of several ailments such as chikungunya, dengue, yellow fever, and Zika. The use of synthetic chemicals is the primary intervention in mosquito management. However, their excessive utilization resulting in the spread of toxic ingredients in the environment and posing threats to beneficial organisms has prompted the recommendation for the use of biologically synthesized nanocomposites as a promising approach for vector control. Silver nanocomposites were synthesized using leaf (AL-AgNCs) and stem (AS-AgNCs) extracts of Achyranthes aspera. The early fourth instars of A. aegypti were exposed to lethal doses of these nanocomposites to evaluate their effects on larval development, behavior, morphology, and mid-gut histoarchitecture. The cellular damage and deposition of nanocomposite residues in the mid-gut were studied using light and transmission electron microscopy. The A. aspera silver nanocomposite (AA-AgNC)-exposed larvae exhibited dose-dependent extended duration of development and diminished adult emergence, but did not exhibit modified behavior. Intense damage to the cuticle membrane and slight contraction in the internal membrane of anal papillae were noticed. Morphologically, the mid-gut appeared disorganized, darkly pigmented, and shrunk. Histological investigations of the mid-gut revealed significantly disordered internal architecture with lysed cells, damaged peritrophic membrane and microvilli, disintegrated epithelial layer, and a ruptured and displaced basement membrane. Visualization of the larval mid-gut through TEM showed severe cellular damage and aggregation of black spots, indicating the deposition of silver particles released by AA-AgNCs. The investigations revealed the bio-efficacy of A. aspera-mediated AgNCs against A. aegypti inducing stomach and contact toxicity in the larvae. The utilization of AA-AgNCs is recommended for A. aegypti management as a safe and effective intervention.

Transparent Eu3+ doped oxyapatite glass ceramics: Crystallization kinetics, structural and optical properties

Transparent Eu3+-doped oxyapatite glass ceramics (GC) have been prepared. A mean crystallization activation energy of 389.58 kJ/mol is determined in crystallization kinetics study. The Avrami's parameter is evaluated to be 2.65, indicating that bulk crystallization is the dominant mechanism. Effect of Eu2O3 dopant on the crystallization behavior was discussed. The precipitation of oxyapatite nanocrystals exhibiting a slight lattice contraction in glass is confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements, resulting from the partition of some europium ions into crystals. Photoluminescence analysis reveals that crystallization could promote the oxidation of Eu2+ to Eu3+ possibly due to europium ions partition on La3+ lattice sites. Temperature-dependent photoluminescence spectra indicate that such oxyapatite GC phosphor exhibits excellent thermal stability with an activation energy of 0.326 eV. This study reports the possibility of developing oxyapatite GC phosphor for light conversion application.