Temperature Response Research Articles

7 days of L-citrulline supplementation does not improve running performance in the heat whilst in a hypohydrated state.

7days L-citrulline supplementation has been reported to improve blood pressure, O2 kinetics, gastrointestinal (GI) perfusion and endurance cycling performance through increasing arterial blood flow. In situations where blood volume is compromised (e.g., hyperthermia/hypohydration), L-citrulline may improve thermoregulation and exercise performance by redistributing blood flow to aid heat loss and/or muscle function. This study assessed 7days L-citrulline supplementation on running performance in the heat, whilst mildly hypohydrated. 13 endurance runners (2 female, 31 ± 8y, O2peak 60 ± 6mL/kg/min) participated in a randomised crossover study with 7days L-citrulline (CIT; 6g/d) or placebo (maltodextrin powder; PLA) supplementation. Participants completed a 50min running 'preload' at 65% O2peak (32°C, 50% relative humidity) to induce hyperthermia and hypohydration before a 3km running time trial (TT). Body mass and blood samples were collected at baseline, pre-preload, post-preload and post-TT, whilst core and skin temperature, heart rate and perceptual responses were collected periodically throughout. TT performance was not different between trials (CIT 865 ± 142s; PLA 892 ± 154s; P = 0.437). Core and skin temperature and heart rate (P ≥ 0.270), hydration (sweat rate, plasma volume, osmolality) indices (P ≥ 0.216), GI damage (P ≥ 0.260) and perceptual responses (P ≥ 0.610) were not different between trials during the preload and TT. 7days of L-citrulline supplementation had no effect on 3km running performance in the heat or any effects on thermoregulation or GI damage in trained runners in a hypohydrated state.

Three-Dimensional Structural Analysis of Sea Temperature During Typhoon Transit

This study uses the Finite-Volume Community Ocean Model (FVCOM) to simulate the hydrodynamic processes during typhoon “Saola”. The simulation results closely match observed data. Typhoon “Saola” was a major system in the Pacific typhoon season, highlighting the complexity and uncertainty of tropical cyclone dynamics. By analyzing historical sea surface temperature data and the typhoon’s trajectory, the three-dimensional response of sea temperature during typhoon “Saola” was explored. The key findings are as follows: 1. Typhoon passage affects both coastal and deep-sea warming and cooling. Temperature changes are more pronounced near the coast, with the highest warming and cooling occurring within five days after the typhoon. In deep-sea areas, the highest warming occurs within five days, while the lowest cooling occurs within two days. 2. The nearshore water layers respond quickly to the typhoon, while the deep-sea water layers primarily respond in the middle depths, with a delayed effect. 3. In coastal shallow waters, the response is intense, with the maximum temperature increase and decrease occurring near the bottom, reaching 5.26 °C and −5.17 °C, respectively. In deep-sea areas, the response is weaker, with the maximum temperature change occurring near the surface: an increase of 0.49 °C and a decrease of −0.98 °C. The deepest response in coastal waters reaches about 80 m, while in the deep-sea area, it only reaches 50 m due to the thicker mixed layer.

Application of Active Heating Tests with the Distributed Temperature Sensing to Characterize Flow Dynamics in a Tidal-Influenced Coastal Aquifer

Aquifer storage and recovery have gained attention as a solution that utilizes submarine groundwater discharge (SGD) as a surrogate water resource to alleviate water scarcity and fill the demand gap. Characterizing SGD is crucial for using coastal groundwater and improving understanding of the interaction between continental water and seawater. This study employs fiber-optical distributed temperature sensing (FODTS) and the heat tracer to quantify the groundwater flux in a coastal aquifer in northern Taiwan. The fluxes in different sections along the borehole were estimated from the temperature response caused by the active heating tests and campier groundwater flux under different tidal conditions, providing information on potential water resources for water resource planning and management. According to the active heating tests, the material of the sections with high-temperature response mainly consists of a gravel–sand mixture. Based on the estimations of groundwater fluxes along the well, the sections with low sensitivity of temperature response have low hydraulic conductivity and low groundwater flux. The estimated thermal parameters at the site are consistent with those obtained from the borehole samples in the laboratory tests. The groundwater fluxes in different sections are calculated based on the temperature response observed from the FODTS. The groundwater fluxes along the well vary between 0.02 and 1.77 m/day. There are considerable differences between the estimated fluxes during the tidal cycle in a heterogeneous coastal aquifer, indicating the high uncertainty of estimated SGD along coastlines.

A Smart Slippery Surface with Reversible Dynamic Temperature Responsiveness for Long‐Term Controllable Anti‐Icing

AbstractRecently, slippery liquid‐infused porous surface (SLIPS) is widely utilized for anti‐icing. Nevertheless, a major challenge hindering the practical applications of SLIPS is the depletion of lubricating oil, significantly deteriorating its deicing performance. Given that super‐slippery effects are not required during most non‐icing periods, this research introduces a novel dynamic wettability‐adjustable SLIPS anti‐icing coating inspired by the nepenthes. This coating‐comprising modified diatomaceous earth and soft silicone rubber‐releases lubricating oil only when temperatures fall below −2 °C, thus exhibiting super‐slippery characteristics and effectively preventing icing. The porous modified diatomaceous earth retains lubricating oil for prolonged periods and facilitates its controlled release under external forces. The high elasticity and strength of the soft silicone rubber endow the coating with thermal expansion and contraction capabilities, enabling the active absorption and release of lubricating fluid in response to temperature variations. This coating, prepared using a straightforward strategy, demonstrates an ice adhesion strength and an oil loss rate of less than 23 kPa and 13%, respectively, after 50 icing/de‐icing cycles. These findings highlight the remarkable performance of the coating, providing valuable insights for achieving long‐term anti‐icing on the external surfaces of equipment in extreme working conditions.

Assessing the Spurious Impacts of Ice-Constraining Methods on the Climate Response to Sea Ice Loss Using an Idealized Aquaplanet GCM

Abstract Coupled climate model simulations designed to isolate the effects of Arctic sea ice loss often apply artificial heating, either directly to the ice or through modification of the surface albedo, to constrain sea ice in the absence of other forcings. Recent work has shown that this approach may lead to an overestimation of the climate response to sea ice loss. In this study, we assess the spurious impacts of ice-constraining methods on the climate of an idealized aquaplanet general circulation model (GCM) with thermodynamic sea ice. The true effect of sea ice loss in this model is isolated by inducing ice loss through reduction of the freezing point of water, which does not require additional energy input. We compare the results of freezing point modification experiments with experiments where sea ice loss is induced using traditional ice-constraining methods and confirm the result of previous work that traditional methods induce spurious additional warming. Furthermore, additional warming leads to an overestimation of the circulation response to sea ice loss, which involves a weakening of the zonal wind and storm-track activity in midlatitudes. Our results suggest that coupled model simulations with constrained sea ice should be treated with caution, especially in boreal summer, where the true effect of sea ice loss is weakest, but we find the largest spurious response. Given that our results may be sensitive to the simplicity of the model we use, we suggest that devising methods to quantify the spurious effects of ice-constraining methods in more sophisticated models should be an urgent priority for future work. Significance Statement The potential effects of Arctic sea ice loss on midlatitude weather have been investigated using climate models where sea ice loss is artificially induced, without increasing greenhouse gas concentrations. Recently, this approach has been challenged because the artificial heating used to melt sea ice may also have direct effects on climate, which are not caused by sea ice loss. We run simulations with a simplified climate model that allows us to separate the “spurious” direct effects of the artificial heating from the “true” effect of sea ice loss. In our simulations, the responses of temperature and atmospheric circulation are amplified by spurious effects. Consequently, we argue that previous studies using more complex climate models may overestimate the effect of sea ice loss on climate.

Anthromes and forest carbon responses to global change

Societal Impact StatementForest ecosystems absorb and store about 25% of global carbon dioxide emissions annually and are increasingly shaped by human land use and management. Climate change interacts with land use and forest dynamics to influence observed carbon stocks and the strength of the land carbon sink. We show that climate change effects on modeled forest land carbon stocks are strongest in tropical wildlands that have limited human influence. Global forest carbon stocks and carbon sink strength may decline as climate change and anthropogenic influences intensify, with wildland tropical forests, especially in Amazonia, likely being especially vulnerable.Summary Human effects on ecosystems date back thousands of years, and anthropogenic biomes—anthromes—broadly incorporate the effects of human population density and land use on ecosystems. Forests are integral to the global carbon cycle, containing large biomass carbon stocks, yet their responses to land use and climate change are uncertain but critical to informing climate change mitigation strategies, ecosystem management, and Earth system modeling. Using an anthromes perspective and the site locations from the Global Forest Carbon (ForC) Database, we compare intensively used, cultured, and wildland forest lands in tropical and extratropical regions. We summarize recent past (1900‐present) patterns of land use intensification, and we use a feedback analysis of Earth system models from the Coupled Model Intercomparison Project Phase 6 to estimate the sensitivity of forest carbon stocks to CO2 and temperature change for different anthromes among regions. Modeled global forest carbon stock responses are positive for CO2 increase but neutral to negative for temperature increase. Across anthromes (intensively used, cultured, and wildland forest areas), modeled forest carbon stock responses of temperate and boreal forests are less variable than those of tropical forests. Tropical wildland forest areas appear especially sensitive to CO2 and temperature change, with the negative temperature response highlighting the potential vulnerability of the globally significant carbon stock in tropical forests. The net effect of anthropogenic activities—including land‐use intensification and environmental change and their interactions with natural forest dynamics—will shape future forest carbon stock changes. These interactive effects will likely be strongest in tropical wildlands.

Leaf warming in the canopy of mature tropical trees reduced photosynthesis due to downregulation of photosynthetic capacity and reduced stomatal conductance.

Tropical forests play a large role in the global carbon cycle by annually absorbing 30% of our annual carbon emissions. However, these forests have evolved under relatively stable temperature conditions and may be sensitive to current climate warming. Few experiments have investigated the effects of warming on large, mature trees to better understand how higher temperatures affect these forests in situ. We targeted four tree species (Endiandra microneura, Castanospermum australe, Cleistanthus myrianthus and Myristica globosa) of the Australian tropical rainforest and warmed leaves in the canopy by 4°C for 8 months. We measured temperature response curves of photosynthesis and respiration, and determined the critical temperatures for chloroplast function based on Chl fluorescence. Both stomatal conductance and photosynthesis were strongly reduced by 48 and 35%, respectively, with warming. While reduced stomatal conductance was likely in response to higher vapour pressure deficit, the biochemistry of photosynthesis responded to higher temperatures via reduced Vcmax25 (-28%) and Jmax25 (-29%). There was no shift of the Topt of photosynthesis. Concurrently, respiration rates at a common temperature did not change in response to warming, suggesting limited respiratory thermal acclimation. This combination of physiological responses to leaf warming in mature tropical trees may suggest a reduced carbon sink with future warming in tropical forests.

Diagnosing the factors that contribute to the intermodel spread of climate feedback in CMIP6

Abstract The global surface temperature climate feedback parameter (λ) varies significantly across climate models, and its real-world value remains uncertain. Studies have found that sea surface temperature (SST) response pattern and atmospheric model physics can each affect the climate feedback parameter in historical and idealized warming simulations. In this study, we design and analyze a series of targeted atmospheric global climate model (AGCM) experiments to quantify how much the SST (both the warming pattern and the base climatology) and atmospheric model physics contributes to the intermodel spread of the climate feedback parameter and cloud feedback in in the Coupled Model Intercomparison Project Phase 6 (CMIP6). We use three AGCMs, HiRAM, AM2.5, and AM4, developed in the Geophysical Fluid Dynamics Laboratory (GFDL), which span a wide range of feedbacks in response to uniform surface warming. The three GFDL models indicate that historical patterns of SST change systematically alter the λ, supporting the hypothesized role for a “pattern effect” in historical climate sensitivity. However, we found that forcing one AGCM with the different CO2-induced SST warming patterns or model SST climatology from a suite of climate models from CMIP6 can only reproduce ~10% the intermodel spread of CO2-induced λ, while the atmospheric model used determines the magnitude of λ (~45%). This underscores the role of atmospheric model physics in altering λ, particularly the cloud-related schemes. In addition, we demonstrate that the nonlinear interaction between SST and AGCM has a non-negligible role in affecting λ.

Temperature-responsive metamaterials made of highly sensitive thermostat metal strips.

Temperature-responsive metamaterials have remarkable shape-morphing ability during thermal energy conversion. However, integrating the thermal shape programmability, wide-working temperature range, fast temperature response, and actuation into metamaterials remains challenging. Here, we introduce using thermostat metal strips to assemble metamaterials with desirable and balanced temperature-responsive properties, and we systematically investigate the thermal deformation performance. Achieving 70 to 80% of the designed strain requires only 5 seconds of heating. A thermal strain of around 30% is achieved for the assembled metamaterials, surpassing other bimetallic metamaterials by a magnitude of 100 to 200. The actuation capacity of thermostat metal strips exceeds 26 times their weight. Further, by leveraging the highly programmable thermal deformation, the tuneable bandgap range is 3847 to 40,000 hertz. These fully integrated mechanical performances in the multiphysics have great application potential, for example, as soft actuators and soft robots in intelligent structure systems, vibration isolation and noise reduction in hypersonic vehicles, and unique thermal deformation in precision instruments.

Land-use induced changes in extreme temperature predominantly influenced by downward longwave radiation

Land use is key in regulating surface temperature, yet these relationships are often obscured by long-term mean responses. Here we employed numerical multi-model results to investigate the response of the surface temperature to land use change, especially its lower tails corresponding to boreal winter. The surface temperature decrease in the lower tails can exhibit up to ten times greater than the mean response to land use change over both the historical and future periods. Downward longwave radiation has emerged as the most remarkable contributing factor in controlling surface temperature change in mid-high latitudes of the Northern Hemisphere. Land use change can modify surface energy balance through land-atmosphere firstly, thereby regulate spatial patterns of water vapor and cloud cover in the Northern Hemisphere through teleconnection. The unity of local and remote effects influences the levels of downward longwave radiation and altering surface temperature at mid-high latitudes in extreme cold seasons.

Intensity and volume of physical exercise influence DOMS and skin temperature differently in healthy adults

It remains unclear whether exercises leading to different outcomes of delayed onset muscle soreness (DOMS) may also elicit different skin temperature responses. The aim of this study was to determine whether different intensities and volumes of a single-joint exercise influence the DOMS and skin temperature measurements differently in healthy adults. Thirty-nine men and women were randomly assigned to three groups performing different exercise of different intensities and volumes (Exhaustion, Fatigue, Submaximal) to induce DOMS in the biceps brachii. DOMS (numeric pain rate scale, NPRS), pressure pain threshold (PPT) and skin temperature (infrared thermography, IRT) were measured on exercise day and 48 h later. The different exercises resulted in lower PPT responses 48 h after exercise and different DOMS reported across the different groups. Skin temperature outcomes did not differ following the different protocols. We found an increased minimum skin temperature 48 h after exercise in groups performing more intense exercises, but such differences were found in both exercised and non-exercised arms. Differently of PPT outcomes, pain reported depended on exercise intensity, and skin temperature 48 h after exercise could not show acute exercise adaptations. Skin temperature responses are contingent upon the characteristics of the participants rather than exercise intensity.

Assessing GFDL‐ESM4.1 Climate Responses to a Stratospheric Aerosol Injection Strategy Intended to Avoid Overshoot 2.0°C Warming

AbstractIn this work, we apply the GFDL Earth System Model (GFDL‐ESM4.1) to explore the climate responses to a stratospheric aerosol injection (SAI) scenario that aims to restrict global warming to 2.0°C above pre‐industrial levels (1850–1900) under the CMIP6 overshoot scenario (SSP5‐34‐OS). Simulations of this SAI scenario with the CESM Whole Atmosphere Community Climate Model (CESM2‐WACCM6) showed nearly unchanged interhemispheric and pole‐to‐Equator surface temperature gradients relative to present‐day conditions around 2020, and reduced global impacts, such as heatwaves, sea ice melting, and shifting precipitation patterns (Tilmes et al., 2020, https://doi.org/10.5194/esd‐11‐579‐2020). However, model structural uncertainties can lead to varying climate projections under the same forcing. Implementing identical stratospheric aerosol radiative properties in GFDL‐ESM4.1, which has a much lower Effective Climate Sensitivity compared to CESM2‐WACCM6, resulted in a decrease in global‐mean surface temperature by more than 1.5°C and a corresponding reduction in precipitation responses. Two major reasons contribute to the different temperature response between the two models: first, GFDL‐ESM4.1 has less warming in the SSP534‐OS scenario; second, GFDL‐ESM4.1 has shown more pronounced cooling in response to the same stratospheric AOD perturbation. Notably, the Southern Hemisphere experiences substantial cooling compared to the Northern Hemisphere, accompanied by a northward shift of the Intertropical Convergence Zone (ITCZ). Furthermore, our analysis reveals that spatially heterogeneous forcing within the SAI scenario results in diverse climate feedback parameters in the GFDL‐ESM4.1 model, through varying surface warming/cooling patterns. This research highlights the importance of considering model structural uncertainties and forcing spatial patterns for a comprehensive evaluation of future scenarios and geoengineering strategies.

A controlled co-assembly approach to tune temperature responsiveness of biomimetic proteins.

The controlled co-assembly of biomacromolecules through tuneable interactions offers a simple and fascinating opportunity to assemble multiple molecules into a single entity with enhanced complexity and unique properties. Herein, our study presents a dynamic co-assembled system using the multistimuli responsive intrinsically disordered protein Rec1-resilin and the adhesive hydrophilic protein silk sericin (SS). We utilized advanced characterization techniques including circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and small/ultra-small angle neutron scattering (SANS/USANS) to elucidate the detailed co-assembly behavior of the system and its evolution over time and temperature. To achieve sufficient neutron contrast, we successfully biosynthesised deuterium-labeled Rec1-resilin (D-Rec1). Our research demonstrates that this co-assembly allows the formation of a robust entity with dynamic conformational assembly and disassembly, exhibiting both the upper critical solution temperature (UCST) and lower critical solution temperature (LCST) with reversibility. The assembly and disassembly dynamics of the co-assembled entity at UCST are very fast, while the process is kinetically controlled at LCST. This study provides significant new insights into the interplay of a hydrophilic, multi-responsive IDP and a highly hydrophilic protein, shaping the thermoresponsive and stable properties of the co-assembled entity.

Warming effects on a nonindigenous predator are not conserved across seasons

AbstractThe global proliferation of nonindigenous species remains a critical stressor driving both biodiversity loss and socioeconomic costs. These impacts frequently depend on environmental contexts, but few studies have investigated how seasonal variations coupled with climate changes, like warming, could modulate nonindigenous species ecological impacts. The Japanese brush‐clawed shore crab Hemigrapsus takanoi is a successful nonindigenous species in northern European waters and is currently spreading in the Baltic Sea. In this study, we used generalized linear models and the comparative functional response approach to examine the predatory impact of H. takanoi toward blue mussels Mytilus sp. across four seasons under current and future temperature scenarios (i.e., ambient and + 6°C warming). We further integrated H. takanoi Q10 values and field abundances across seasons to examine population‐level feeding impacts toward blue mussels. The nonindigenous species exhibited a consistent type II functional response (i.e., inversely prey density‐dependent response) across all seasons, temperatures and sexes, with males consistently consuming more mussels than females across all seasons. Warming generally decreased handling times and increased attack rates, but these effects varied by season and sex, with the most pronounced temperature responses observed in autumn and spring. Population‐level impact calculations integrating field abundance data of H. takanoi indicated that under ambient conditions, feeding impacts toward blue mussels currently peak in the summer months, but as temperature increases, this feeding impact is anticipated to shift later in the year into autumn. These findings underline the critical need for multifaceted research approaches to better understand and predict the context‐dependent ecological impacts of nonindigenous species, particularly in the face of ongoing climate change and shifting population characteristics.

Wearable System for Continuous Estimation of Transepidermal Water Loss

To maintain skin moisture, we need to maintain good stratum corneum barrier function, which prevents moisture evaporation from the inside of the skin. Transepidermal water loss (TEWL), the amount of water that evaporates from the skin, indicates the state of barrier function. The barrier function of facial skin is easily damaged in daily life, and the condition of the skin becomes worse without us noticing. We should constantly monitor TEWL to prevent worsening skin conditions. In this paper, we propose a wearable device that continuously measures TEWL. We estimate TEWL using machine learning from temperature and humidity values of water evaporation from the skin and parameters that affect TEWL, such as skin surface temperature and galvanic skin response. We experimented with the prototype device in a controlled environment. We confirmed that the prototype device could estimate TEWL accurately enough to judge the skin’s condition in stationary and conversational situations. Then, we experimented to verify the environmental conditions for estimating TEWL using the prototype device. The prototype device could estimate TEWL with sufficient precision in an office without airflow. However, we could not estimate TEWL in the office with airflow and outdoor.

Evaluation of thermal parameters with geothermal energy recovery from a cold climate municipal solid waste landfill

This study presents finite element method (FEM) modeling with COMSOL Multiphysics to estimate the thermal properties of a waste landfill through back-analysis of temperature responses from buried thermistors during a full-scale multi-week active thermal response test. Field tests were conducted at the Loraas MSW landfill in Saskatoon, Canada, using instrumented equipment, including a vertical borehole heat exchanger and thermistor strings. The test consisted of two phases: a heat injection test during the summer and a heat extraction test in the winter. The study focused on a landfill 25 m deep, observing temperature changes at various depths over time. The effect of heat generation rate (HGR) on landfill temperature was investigated. Thermal conductivity and volumetric heat capacity increase with depth, with close alignment between summer and winter results, validating the tests. This research enhances the understanding of thermal parameters in MSW landfills by combining field tests and numerical modeling, offering insights into landfill behavior in cold climates. These findings hold significance for optimizing geothermal energy recovery from such landfills, calibrating thermal parameters for coupled models in landfills, and improving waste management practices.

Systematic Regional Aerosol Perturbations (SyRAP) in Asia Using the Intermediate‐Resolution Global Climate Model FORTE2

AbstractEmissions of anthropogenic aerosols are rapidly changing, in amounts, composition and geographical distribution. In East and South Asia in particular, strong aerosol trends combined with high population densities imply high potential vulnerability to climate change. Improved knowledge of how near‐term climate and weather influences these changes is urgently needed, to allow for better‐informed adaptation strategies. To understand and decompose the local and remote climate impacts of regional aerosol emission changes, we perform a set of Systematic Regional Aerosol Perturbations (SyRAP) using the reduced‐complexity climate model FORTE 2.0 (FORTE2). Absorbing and scattering aerosols are perturbed separately, over East Asia and South Asia, to assess their distinct influences on climate. In this paper, we first present an updated version of FORTE2, which includes treatment of aerosol‐cloud interactions. We then document and validate the local responses over a range of parameters, showing for instance that removing emissions of absorbing aerosols over both East Asia and South Asia is projected to cause a local drying, alongside a range of more widespread effects. We find that SyRAP‐FORTE2 is able to reproduce the responses to Asian aerosol changes documented in the literature, and that it can help us decompose regional climate impacts of aerosols from the two regions. Finally, we show how SyRAP‐FORTE2 has regionally linear responses in temperature and precipitation and can be used as input to emulators and tunable simple climate models, and as a ready‐made tool for projecting the local and remote effects of near‐term changes in Asian aerosol emissions.

Mineral and Microbial Properties Drive the Formation of Mineral-Associated Organic Matter and Its Response to Increased Temperature.

A comprehensive understanding of the formation of mineral-associated organic matter (MAOM) is a prerequisite for the sustainable management of soil carbon (C) and the development of effective long-term strategies for C sequestration in soils. Nevertheless, the precise manner by which microbial and mineral properties drive MAOM formation efficiency and its subsequent response to elevated temperature at the regional scale remains unclear. Here, we employed isotopically labelled laboratory incubations (at 15°C and 25°C) with soil samples from a ~3000 km transect across the Tibetan Plateau to elucidate the mechanisms underlying MAOM formation and its temperature response. The results indicated that both mineral protection and microbial properties were critical predictors of MAOM formation across the geographic gradient. The efficiency of MAOM formation was found to increase with the content of iron (Fe) oxides and their reactivity [i.e., the ratio of poorly crystalline Fe oxides to total Fe oxides (Feo:Fed)] but to decrease with the relative abundance of Gammaproteobacteria and Actinobacteria across the plateau. Moreover, a notable decline in MAOM formation efficiency was observed under elevated temperatures, which was concomitant with a reduction in the content and reactivity of Fe oxides, as well as the microbial assimilation of the labelled substrate. The attenuation of mineral-organic associations was identified as the primary factor contributing to the warming-induced reduction in MAOM formation. These findings highlight the necessity of incorporating organo-mineral associations and microbial properties into Earth System Models to accurately project soil C dynamics under changing climate.

Interannual responses of Arctic temperatures to Eurasian snow cover variations in early spring

Interannual responses of Arctic temperatures to Eurasian snow cover variations in early spring

Mesoporous silica nanoparticles based on a dual environmental response corresponding to temperature and α-amylase for the control of Spodoptera litura

The design and development of stimuli-responsive nanocarriers hold the promise of the smart delivery of pesticides to target organisms. Herein, we successfully prepared mesoporous silica nanoparticles using the self-templating method, which were grafted with both N-isopropylacrylamide (NIPAM) and cyclodextrin (CD) and loaded with indoxacarb (IN) to afford a pesticide release system with a dual-stimulated response of temperature and α-amylase, referred to as IN@MSNs@NIPAM@CD. Physicochemical characterisation revealed the successful preparation of IN@MSNs@NIPAM@CD with 46.30 % indoxacarb loading. The results showed that IN@MSNs@NIPAM@CD was able to release IN rapidly in the environment of high temperature and α-Amylase, with excellent dual-responsive property. The UV resistance evaluation showed that IN@MSNs@NIPAM@CD could effectively improve the photodegradation resistance of indoxacarb. Fluorescent inverted microscope showed that FITC@MSNs@NIPAM@CD has excellent uptake and translocation properties in corn plants. Bioactivity tests showed that at 14 d, IN@MSNs@NIPAM@CD (LC50 = 9.83 mg L−1) exhibited higher insecticidal activity and longer effective duration than IN@EC (LC50 = 14.64 mg L−1). Acute toxicity test revealed that the IN@MSNs@NIPAM@CD nanoparticles were less acutely toxic to earthworms, zebrafish, BEAS-2B cells and MSNs@NIPAM@CD nanocarriers were safe for the growth of corn. Thus, the dual-responsive nano-controlled-release formulation of IN@MSNs@NIPAM@CD can provide an effective way of achieving the precise delivery and reduced use of pesticides.