Moisture Factors Research Articles

Investigating the role of temperature and moisture on the degradation of 3D-printed polymethyl methacrylate dental materials through molecular dynamics simulations

This study aimed to comprehensively investigate the degradation behavior of 3D printed polymethyl methacrylate (PMMA) dental materials, with a specific focus on the influential factors of temperature and moisture, by employing molecular dynamics simulations. Owing to their aesthetic properties, 3D-printed PMMA dental materials play a pivotal role in dental applications. However, understanding their degradation mechanisms, particularly in the context of temperature and moisture variations, is crucial for their long-term durability. A Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was utilized for the molecular dynamics simulations. The simulation setup included temperature variations from 300 to 600 K and relative humidity (RH) levels ranging from 20 to 100%. Various mechanical properties and structural changes were analyzed to determine the degradation behavior. Energetic profiling during equilibration and the subsequent temperature variations were studied. The spatial distribution of the mean squared displacement, non-bond energy, Young’s modulus, bending stress, and volume expansion coefficient of the particles were quantitatively analyzed, revealing temperature- and moisture-dependent trends. The study concluded that temperature and moisture significantly affected the degradation behavior of 3D-printed PMMA dental materials. Higher temperatures and increased humidity levels contribute to reduced mechanical strength and altered structural properties, emphasizing the importance of controlling environmental conditions during fabrication.

Structure and function of skin barrier lipids: Effects of hydration and natural moisturizers in vitro

Lipid membranes play a crucial role in regulating the body’s water balance by adjusting their properties in response to hydration. The intercellular lipid matrix of the stratum corneum (SC), the outermost skin layer, serves as the body’s primary defense against environmental factors. Osmolytes, including urocanic acid (UCA) and glycerol, are key components of the natural moisturizing factor that help the SC resist osmotic stress from dry environments. This study examines the effects of UCA and glycerol (each at 5 mol %) on isolated human SC lipids. For this, different techniques were employed, offering complementary information of the system’s multiscale characteristics, including humidity-scanning quartz crystal microbalance with dissipation monitoring, infrared spectroscopy, x-ray diffraction, electrical impedance spectroscopy, and studies of water loss and permeability. Our results show that UCA increases water sorption and makes lipid films more liquid-like at high relative humidity, without significantly altering the lipid lamellar structure, chain order, or orthorhombic chain packing. Lipid films containing UCA exhibited higher water loss and significantly higher model drug permeability compared to lipid films without UCA. Further, incorporation of UCA resulted in kinetically faster changes in electrical properties upon contact with aqueous solution compared with control lipids. These observations suggest that UCA reduces lipid cohesion in regions other than the acyl chain-rich leaflets, which may impact SC desquamation. In contrast, glycerol did not influence the hydration or permeability of the SC lipid matrix. However, it increased the proportion of orthorhombic domains at high humidities and slowed the kinetics of the hydration process, as evidenced by slower changes in the dielectric properties of the lipid film. These findings suggest that glycerol enhances lipid cohesion rather than increasing water uptake, which is typically the expected function of humectants. Consequently, UCA and glycerol appear to have distinct roles in maintaining epidermal homeostasis.

Effects of Environmental Factors on the Diversity of Grasshopper Communities along Altitude Gradients in Xizang, China.

To determine the grasshopper species composition, altitudinal distribution patterns, and their main drivers, we conducted a study in Xizang using 33 sample plots ranging from 600 to 4100 m. Grasshoppers were collected from August to October during 2020-2022 using sweep nets. A total of 1159 grasshoppers from six families, 28 genera, and 44 species were identified, with Omocestus cuonaensis and Aserratus eminifrontus as the dominant species, comprising 30.03% and 10.26% of total grasshoppers, respectively. The results showed that species richness and the Margalef richness index of grasshopper communities decreased significantly (p < 0.05) with increasing altitude, peaking at 1100-1600 m and lowest values at 2600-3100 m. Similarly, the Shannon-Wiener index and Simpson dominance index also decreased significantly (p < 0.05) with an increase in altitude, showing the highest and lowest values at 600-1100 m and 3100-3600 m, respectively. The Jaccard similarity coefficients among grasshopper communities varied from 0 to 0.40 across altitudinal gradients, indicating different degrees of dissimilarity. The results of Pearson correlation analyses showed that the Shannon-Wiener index, species richness, Margalef richness index, and Simpson dominance index of grasshopper communities were significantly negatively correlated with the temperature factors and soil pH, but they were significantly positively correlated with the moisture factors. Hierarchical partitioning identified annual mean temperature-daily difference, precipitation in the coldest season, and driest month precipitation as the primary factors explaining variance in grasshopper community diversity in Xizang. These findings provided greater insights into the mechanisms underlying insect community structure, distribution patterns, and diversity in Xizang ecosystems, including implications for the effects of global warming on insect communities.

Responses of Methane Emission and Bacterial Community to Fertilizer Reduction Plus Organic Materials over the Course of an 85-Day Leaching Experiment

Methane produced from paddy fields has a negative impact on global climate change. However, the role of soil bacterial community composition in mediating methane (CH4) emission from waterlogged paddy soil using the column experiment is poorly known. In the present study, various fertilization treatments were adopted to investigate the effects of fertilizer reduction combined with organic materials (CK: control; CF: conventional fertilization; RF: 20% fertilizer reduction; RFWS: RF plus wheat straw amendment; RFRS: RF plus rapeseed shell amendment; RFAS: RF plus astragalus smicus amendment) on CH4 emission and soil bacterial community during an 85-day leaching experiment. We hypothesized that the fertilizer reduction plus the organic materials could enrich the bacterial communities and increase CH4 emission. The average CH4 flux varied from 0.03 μg m−2 h−1 to 76.19 μg m−2 h−1 among all treatments in the nine sampling times, which may account for the experimental conditions such as air temperature, moisture, and anthropogenic factors. In addition, high-throughput sequencing was utilized to investigate the alteration of the soil bacterial community structure. It was revealed that the diversity and composition of the bacterial community in the topsoil amended with organic materials underwent significant shifts after the 85-day leaching experiment. Proteobacteria was identified as the dominant phylum of the soil bacteria, with an average proportion of 35.2%. For Firmicutes, the proportion of RFRS (11%) was higher than that in the CK (8%), RF (8%), RFWS (7%), RFAS (6%), and CF (5%) treatments. Additionally, Gammaproteobacteria and Alphaproteobateria were supposed to be the major class bacterial communities, with average proportions of 12.8% and 12.2%, respectively. For the RFWS treatment, the contribution of Alphaproteobateria was the highest among all the bacterial relative abundance. According to the correlation heatmap analysis, the top ten bacterial communities were positively related to soil microbial biomass carbon (MBC) and ammonia nitrogen (NH4+-N) (p &lt; 0.01). The findings also indicated that the RFRS treatment was the favorable management to alleviate CH4 emission during an 85-day leaching experiment or possibly in paddy production. Collectively, these results predict that the impacts of different treatments on CH4 production are strongly driven by soil microbial communities and soil properties, with soil bacteria being more prone to the crop residue degradation stage and more sensitive to soil properties. The discoveries presented in this study will be useful for assessing the efficacy and mechanisms of organic material amendments on CH4 emissions in paddy soil.

Preventive effects of dietary fucoxanthin on ultraviolet A induced photoaging in hairless mice.

Repeated exposure to ultraviolet A (UVA) irradiation, which can penetrate the epidermis and reach the dermis, is one of the major causes of skin photoaging. Photoaged skin is characterized clinically by generalized wrinkling, a dry and loose appearance, and seborrheic keratoses, along with skin barrier dysfunction. Fucoxanthin, a xanthophyll carotenoid with a specific allenic bond and 5,6-monoepoxide in its structure, has been found to serve various functions as a food supplement. In the present study, the protective effects of orally administered fucoxanthin at relatively low concentrations (0.001% and 0.01%) against UVA induced photoaging were evaluated in vivo using hairless mice. Oral supplementation of 0.001% fucoxanthin was sufficient for its metabolites to accumulate in the skin, thereby inhibiting pathological changes induced by UVA irradiation, including impaired skin barrier function and accelerated wrinkle formation. Analysis of gene expression revealed that dietary fucoxanthin exerted antiphotoaging effects, possibly by modulating natural moisturizing factor (NMF) synthesis, desquamation, and ceramide composition in the epidermis, and by inhibiting the UVA induced degradation of collagen fibers and inflammation in the dermis. Taken together, our data indicate the potential application of dietary fucoxanthin as a novel ingredient in nutricosmetics for skin care against photoaging. © 2024 Society of Chemical Industry.

Undertaking a structured assessment of a hard-to-heal wound.

A thorough, holistic wound assessment is essential to identify the aetiology of a hard-to-heal wound and formulate a diagnosis, which will underpin the treatment plan. This article describes the fundamental elements of assessing a patient with a hard-to-heal wound holistically, including taking a patient history, performing a clinical examination and investigations, and considering the patient's physical, psychological, spiritual and social needs. The author also outlines the aspects of the TIMERS (tissue, infection/inflammation, moisture, edge, regeneration and social factors) wound assessment tool in detail, and explains some of the challenges associated with accurately assessing a wound.

Dihydroavenanthramide D Enhances Skin Barrier Function through Upregulation of Epidermal Tight Junction Expression.

Skin barrier dysfunction and thin epidermis are hallmarks of sensitive skin and contribute to premature aging. Avenanthramides are the primary bioactive components of colloidal oatmeal, a commonly used treatment to enhance skin barrier function. This study investigated the relationship between skin barrier function and epidermal characteristics and explored the potential of dihydroavenanthramide D (dhAvD), a synthetic avenanthramide, to improve the skin barrier. We observed a significant correlation between impaired skin barrier function and decreased epidermal thickness, suggesting that a weakened barrier contributes to increased sensitivity. Our in vitro results in HaCaT cells demonstrated that dhAvD enhances keratinocyte proliferation, migration, and tight junction protein expression, thereby strengthening the skin barrier. To mimic skin barrier dysfunction, we treated keratinocytes and full-thickness skin equivalents with IL-4 and IL-13, cytokines that are implicated in atopic dermatitis, and confirmed the downregulation of tight junction and differentiation markers. Furthermore, dhAvD treatment restored the barrier function and normalized the expression of key epidermal components, such as tight junction proteins and natural moisturizing factors, in keratinocytes treated with inflammatory cytokines. In the reconstructed human skin model, dhAvD promoted both epidermal and dermal restoration. These findings suggest that dhAvD has the potential to alleviate skin sensitivity and improve skin barrier function.

Influence of Soil Moisture in Semi-Fixed Sand Dunes of the Tengger Desert, China, Based on PLS-SEM and SHAP Models

Drought stress significantly limits the function and stability of desert ecosystems. This research examines the distribution characteristics of soil moisture across different microtopographic types in the semi-fixed dunes located at the southeastern edge of the Tengger Desert. We constructed a path model to examine the direct and indirect impacts of topography, shrub vegetation, and herbaceous vegetation. The data encompassed soil moisture, topography, and vegetation variables, which were collected from field experiments to ensure their accuracy and relevance. Furthermore, SHAP models based on machine learning algorithms were utilized to elucidate the specific mechanisms through which key factors influence soil moisture. The results of the descriptive statistics indicate the highest surface soil moisture content, recorded at 1.21%, was observed at the bottom of the dunes, while the leeward slopes demonstrated elevated moisture levels in the middle and deep soil layers, with measurements of 2.25% and 2.43%, respectively. Soil moisture at different depths initially decreases and then increases with greater herbaceous cover and slope direction, while surface soil moisture follows a similar trend in terms of height difference, with 3 m serving as the boundary for trend changes. Middle and deep soil moistures initially increase and then decrease with greater biomass and shrub coverage, with 30 g and 40% serving as the boundary for trend changes respectively. This study elucidates the spatial distribution patterns and influencing factors of soil moisture in semi-fixed dunes, offering valuable references for the establishment of sand-stabilizing vegetation in desert regions.

Correlation between Soil Moisture Change and Geological Disasters in E’bian Area (Sichuan, China)

E’bian Yi Autonomous County is a mineral-rich area located in a complex geological structure zone. The region experiences frequent geological disasters due to concentrated rainfall, steep terrain, and uneven vegetation cover. In particular, during the rainy season, large amounts of rainwater rapidly accumulate, increasing soil moisture and slope pressure, making landslides and debris flows more likely. Additionally, human activities such as mining, road construction, and building can alter the original geological structure, exacerbating the risk of geological disasters. According to publicly available data from the Leshan government, various types of geological disasters occurred in 2019, 2020, 2022, and 2023, resulting in economic losses and casualties. Although some studies have focused on geological disaster issues in E’bian, these studies are often limited to specific areas or types of disasters and lack comprehensive spatial and temporal analysis. Furthermore, due to constraints in technology, funding, and manpower, geophysical exploration, field geological exploration, and environmental ecological investigations have been challenging to carry out comprehensively, leading to insufficient and unsystematic data collection. To provide data support and monitoring for regional territorial spatial planning and geological disaster prevention and control, this paper proposes a new method to study the correlation between soil moisture changes and geological disasters. Six high-resolution Landsat remote sensing images were used as the main data sources to process the image band data, and terrain factors were extracted and classified using a digital elevation model (DEM). Meanwhile, a Normalized Difference Vegetation Index–Land Surface Temperature (NDVI-LST) feature space was constructed. The Temperature Vegetation Drought Index (TVDI) was calculated to analyze the variation trend and influencing factors of soil moisture in the study area. The research results showed that the variation in soil moisture in the study area was relatively stable, and the overall soil moisture content was high (0.18 &lt; TVDI &lt; 0.33). However, due to the large variation in topographic relief, it could provide power and be a source basis for geological disasters such as landslide and collapse, so the inversion value of TVDI was small. The minimum and maximum values of the correlation coefficient (R2) were 0.60 and 0.72, respectively, indicating that the surface water content was relatively large, which was in good agreement with the calculated results of vegetation coverage and conducive to the restoration of ecological stability. In general, based on the characteristics of remote sensing technology and the division of soil moisture critical values, the promoting and hindering effects of soil moisture on geological hazards can be accurately described, and the research results can provide effective guidance for the prevention and control of geological hazards in this region.

Skin Moisture Level of Chronic Kidney Disease Patients In the Hemodialysis Room of Dr. Soekardjo Hospital, Tasikmalaya City

CKD patients often experience fluctuations in body fluid volume, which is a major risk factor for infections such as cellulitis because it weakens the skin's natural defenses. Delayed wound healing in kidney disease patients increases the risk of infection and impaired skin integrity caused by loss of lipids and natural moisturizing factors in the outermost layer of skin (stratum corneum). This study aims to evaluate the skin moisture level of CKD patients in the Hemodialysis Room at RSUD dr. Soekardjo Tasikmalaya City uses a descriptive approach. The population of this study consisted of 76 CKD patients in this room using total sampling techniques. The research results showed that the majority of CKD patients in the Hemodialysis Room at RSUD dr. Soekardjo in Tasikmalaya City experienced dry skin on the face as many as 56 people (73.68%), and dry skin on the hands as many as 64 people (84.21%). The recommendation that can be given is that respondents continue to monitor and maintain the moisture level of their skin and use oil emulsions.

Multi-omics analysis to evaluate the effects of solar exposure and a broad-spectrum SPF50+ sunscreen on markers of skin barrier function in a skin ecosystem model.

Sun exposure induces major skin alterations, but its effects on skin metabolites and lipids remain largely unknown. Using an original reconstructed human epidermis (RHE) model colonized with human microbiota and supplemented with human sebum, we previously showed that a single dose of simulated solar radiation (SSR) significantly impacted the skin metabolome and microbiota. In this article, we further analyzed SSR-induced changes on skin metabolites and lipids in the same RHE model. Among the significantly altered metabolites (log2-fold changes with p ≤ 0.05), we found several natural moisturizing factors (NMFs): amino acids, lactate, glycerol, urocanic acid, pyrrolidone carboxylic acid and derivatives. Analyses of the stratum corneum lipids also showed that SSR induced lower levels of free fatty acids and higher levels of ceramides, cholesterols and its derivatives. An imbalance in NMFs and ceramides combined to an increase of proinflammatory lipids may participate in skin permeability barrier impairment, dehydration and inflammatory reaction to the sun. Our skin model also allowed the evaluation of an innovative ultraviolet/blue light (UV/BL) broad-spectrum sunscreen with a high sun protection factor (SPF50+). We found that using this sunscreen prior to SSR exposure could in part prevent SSR-induced alterations in NMFs and lipids in the skin ecosystem RHE model.

Spatial heterogeneity of soil moisture caused by drainage and its effects on cadmium variation in rice grain within individual fields

Paddy drainage is the critical period for rice grain to accumulate cadmium (Cd), however, its roles on spatial heterogeneity of grain Cd within individual fields are still unknown. Herein, field plot experiments were conducted to study the spatial variations of rice Cd under continuous and intermittent (drainage at the tillering or grain-filling or both stages) flooding conditions. The spatial heterogeneity of soil moisture and key factors involved in Cd mobilization during drainages were further investigated to explain grain Cd variation. Rice grain Cd levels under continuous flooding ranged from 0.16 to 0.22 mg kg−1 among nine sampling sites within an individual field. Tillering drainage slightly increased grain Cd levels (0.19–0.31 mg kg−1) with little change in spatial variation. However, grain-filling drainage greatly increased grain Cd range to 0.33–0.95 mg kg−1, with a huge spatial variation observed among replicated sites. During two drainage periods, soil moisture decreased variously in different monitoring sites; greater variation (mean values ranged from 0.14 to 0.27 m3 m−3) was observed during grain-filling drainage. Accordingly, 2.9–3.3-fold variation in soil Eh and 0.55–0.67-unit variation in soil pH were observed among those sites. In the soil with low moisture, ferrous fractions such as ferrous sulfide (FeS) were prone to be oxidized to ferric fractions; meanwhile, the followed generation of hydroxyl radicals involved in Cd remobilization was enhanced. Consequently, soil dissolved Cd changed from 2.97 to 8.92 μg L−1 among different sampling sites during grain-filling drainage; thus, large variation was observed in grain Cd levels. The findings suggest that grain-filling drainage is the main process controlling spatial variation of grain Cd, which should be paid more attention in paddy Cd evaluation.

Stable gullies provide a suitable habitat for functional insects and reduce the threat of pests on crops in farmland of Northeast China.

Gullies with lower altitudes compared to the surrounding environment are widely distributed in farmland of the watershed and their numbers are still expanding. However, it is still unclear how these gullies regulate the functional insects in farmland. In this study, land use types combined with the herbaceous plant, herbicide application, soil moisture, topography and climatic factors during crop growth were considered to understand how gullies influence the dynamics of functional insects in farmland from a watershed (240 ha) of Northeast China. The primary findings demonstrate that the richness and abundance of functional insects are generally greatest in gullies, particularly in stable gullies, and decrease in the following order: forest belts, grasslands, and farmlands within the watershed. Notably, the ratios of beneficial insects to pests (BI/Pest) in terms of richness and abundance were lower in gullies before July but reversed after July, in comparison to farmland. Stable gullies exhibited higher BI/Pest abundance and diversity ratios than developing gullies. The richness and abundance of functional insects were higher in the middle sections of gullies compared to their heads and tails. Furthermore, the ratios of BI/Pest were generally lower in farmlands than in any gully position. Functional insect dynamics were mainly determined by season, followed by plant abundance and biomass in the gullies, and rarely by soil moisture in the both watershed and single gullies scales. Generally, the richness and abundance of functional insects in farmland were mainly influenced by gullies, especially influenced by the gully middle position. Insect composition in farmland influenced by stable gullies was stronger than by developing gullies, and stable gullies were more beneficial in reducing the threat of pests to crops in the farmland of the watershed.

Delivery of small hydrophilic molecules across the stratum corneum: Identification of model systems and parameters to study topical delivery of free amino acids

Free amino acids (FAAs) constitute the largest component (∼40 %) of the so-called natural moisturizing factors of the skin. Their level declines in dry skin conditions and one strategy to overcome this problem may involve the topical delivery of FAAs through appropriate strategy. The objective of the present study was therefore to identify alternative skin models and study the corneocyte-water partition coefficients (KCOR/W) and permeation coefficient (KP) of 18 FAAs. The KCOR/W was studied using standard protocols and the permeation studies were conducted using Franz diffusion cell. The results indicate that the FAAs have high partitioning behavior to the corneocytes. The KCOR/W values of the human COR and that of pig ear skin were better correlated with each other than that of keratin isolated from chicken feathers. The presence of lipid in the stratum corneum (SC), initial concentration of the FAAs, and permeation enhancers affect the KCOR/W. The FAAs have low permeation into the SC which suggests the need for permeation enhancers in designing dosage form containing these compounds. Even though the investigated mathematical models show good prediction of the Kp values, better prediction could be obtained by considering factors such as the possible entrapment of the FAAs by the CORs.

Prolyl Endopeptidase Is Involved in Filaggrinolysis and Cornification

Filaggrin (FLG) is a well-known biomarker of atopic dermatitis and skin dryness. Its full proteolysis (or filaggrinolysis) produces the major constituents of the natural moisturizing factor. Some proteases/peptidases remain to be identified in this multistep process. Mining 16 omics analyses, we identified prolyl endopeptidase (PREP) as a candidate peptidase. Indirect immunofluorescence and confocal analysis demonstrated its localization in the granular and deep cornified layers, where it co-localized with FLG. Tandem mass spectroscopy and fluorescent quenching activity assays showed that PREP cleaved several synthetic peptides derived from the FLG sequence, at the carboxyl side of an internal proline. Deimination of these peptides increased PREP enzymatic efficiency. Specific inhibition of PREP in reconstructed human epidermis (RHEs) using benzyloxycarbonyl-Pro-Prolinal (ZPP) induced the accumulation of FLG monomers. Down-regulation of PREP expression in RHEs using RNA interference confirmed the impact of PREP on FLG metabolism, and highlighted a more general role of PREP in keratinocyte differentiation. Indeed, quantitative global proteomic, Western blotting and RT-qPCR analyses showed a strong reduction in the expression of bleomycin hydrolase, known to be involved in filaggrinolysis, and of several other actors of cornification like loricrin. Consequently, at the functional level, the trans-epidermal electric resistance was drastically reduced.

Classification of powdery mildew disease symptoms on sandalwood using machine learning techniques

Powdery mildew (Oidium sp.) is a fungal disease that infects plants by creating white powdery spots on plants and trees, resulting in a reduction in yield. Powdery mildew is often influenced by changes in climatic conditions with cloud factors, humidity, and temperature playing a major role. This study focuses on building a Machine learning model that will classify powdery mildew disease symptoms on sandalwood trees based on abiotic features like soil moisture, temperature, humidity, and cloud factors. Various machine learning algorithms such as Decision Tree, Logistic Regression, Random Forest, Support Vector Machine, and K-Nearest Neighbors were used on the dataset and the model with the highest accuracy was chosen for building a powdery mildew prediction web application on the cloud platform.

Photochemical optimization of fluorescent dye-doped PDMS for enhanced luminescent solar concentrator performance

Luminescent solar concentrators (LSCs) that incorporate organic dyes face challenges such as self-absorption loss and aggregation-caused quenching (ACQ) as doping concentration increases, limiting the dye loading capacity. Particularly for dyes with a small Stokes shift, losses due to self-absorption or quenching are prominent even at low concentrations, hindering the attainment of high power conversion efficiency (PCE) in LSCs. Additionally, exposure of the dye-impregnated polymer matrix to oxygen, moisture, UV light, and other factors leads to a decrease in luminescence efficiency and stability due to the photooxidation reaction of the phosphor. This study presents a facile approach for enhancement of the efficiency and environmental stability of coumarin 6 (C6) dye-doped polydimethylsiloxane (PDMS) LSC through ultraviolet ozone (UVO) treatment. Photocleavage of the C6 dimer into a C6 monomer through UVO treatment leads to a significant enhancement in luminescence. Additionally, thin SiOx layers formed on both sides of the LSC not only assist in capturing luminescent light more efficiently but also block the penetration of oxygen and moisture into the LSC, resulting improved device stability. UVO-treated LSC shows approximately 32 % improvement in PCE compared to bare LSCs and exhibits significantly better stability during the 30-day long-term performance test.

Estimating Evapotranspiration in the Qilian Mountains Using GRACE/GRACE-FO Satellite Data

Evapotranspiration (ET) is the most significant constituent of the response to climate warming. It serves as a crucial link in the soil–vegetation–atmospheric continuum. Analyzing the driving forces and response of ET to regional-scale climate warming holds scientific significance in improving global water resource assessment methods and drought monitoring techniques. The innovation presented in this article is the calculation of ET by using GRACE/GRACE-FO satellite data through the water balance equation. The inter-annual and seasonal changes in ET in different regions of the Qilian Mountains were analyzed, along with quantifying the contribution of environmental meteorological factors to ET. The ETGRACE and ETMonitor products have good consistency, with a monthly correlation coefficient of 0.92, an NSE coefficient of 0.80, and a root mean square error of 10.38 mm. The results indicate that the increasing trend of ET in the Qilian Mountains region exhibits a “medium–high–low” distribution pattern. The rate of increase in ET is 5.2 mm/year in the central segment. In spring and summer, the overall trend of ET is an increasing one. However, the central and western segments exhibit a slight decreasing trend of ET in autumn. During winter, the southern part of the Qilian Mountains experiences a notable reduction in ET. The correlation between the changes in ET and soil moisture exhibited a strong association, with soil moisture change contributing significantly to ET: 57.8% for the eastern section, 52.8% for the middle section, and 46.9% for the western section. The thermal effect primarily controls ET variations within eastern sections, where temperature change accounts for approximately 6.7% of the total variation in ET levels. Conversely, the moisture factor dominates western sections, where precipitation change accounts for about 6.5% of the total variation in ET levels. Due to the distinct gradient characteristics of environmental meteorological factors in the central segment, the fluctuation of these factors collaboratively drives ET changes. This article provides a new approach for obtaining continuous and reliable actual evapotranspiration in high-altitude areas.

P34 Evaluating the adaptation of the amputee skin owing to prosthesis use: a study using in vivo Raman spectroscopy

Abstract Introduction and aims Lower limb prosthesis has proven to be an extremely successful intervention for amputees. However, to achieve adequate function, the device places significant friction and load on the skin, which leads to substantial skin breakdown. Current rehabilitation practices require skin to be ‘trained’ to perform a load-bearing role. Despite this, there are very high injury statistics for skin on the residual limb in the literature, we hypothesize that rehabilitation practices to adapt amputee skin are limited. Methods To interrogate this, we used in vivo Raman spectroscopy to evaluate the lower limbs of 13 unilateral lower limb amputees. This enabled us to assess how key constituents of the stratum corneum (SC) such as natural moisturizing factor (NMF), water and lipid content vary with depth. We also analysed sebum content to quantify cytokines present and performed mechanical characterization of the lower limb to investigate stiffness and friction. Results We found that the Raman spectra of the amputated limb show reduced NMF, lipid content and water content at the top of the SC when compared with the intact limb (P &amp;lt; 0.05). In addition, we found that amputee skin contains higher levels of inflammatory cytokines compared with control skin. We also recorded that skin on the residuum is four times softer than the intact limb, while friction is much higher at 0.5 on the residuum skin, compared with 0.3 on the intact limb. Conclusions Here, we show the adaptations of amputee skin in response to rehabilitation to be minimal. Contrary to the dogma that rehabilitation trains skin to bear load, we found that skin barrier function in amputee skin is impaired, as indicated by altered water and lipid profile in addition to higher baseline inflammation.

Late Holocene vegetation diversity change and potential response to climate variations on the northern Qinghai-Tibetan Plateau

Biodiversity change under current global warming scenario has attracted wide attentions, representing general stability and balance in ecosystems. Understanding the temporal patterns and potential driving mechanisms of biodiversity changes would provide significant knowledge for ecosystem sustainability, which requires necessary investigations on long-term records during the late Holocene. The high elevation and specific environment on the Qinghai-Tibetan Plateau (QTP) promote the development of fragile alpine ecosystems, responding sensitively to regional climate variations. Based on a high-resolution fossil pollen record retrieved from Lake Kusai on the northern QTP, late Holocene vegetation diversities were estimated based on the Hill number indices, which were subsequently evaluated at three time scales, i.e., millennial, centennial and multi-decadal time scales. The results indicate that Hill number indices could represent vegetation diversity changes on the northern QTP. Reconstructed vegetation diversity indices indicate gradual variations on millennium scale in each diversity index, along with different responses to environmental factors of regional moisture and total solar irradiance. On the centennial time scale, high consistencies were identified among the vegetation diversity indices as well as correlations with environmental factors, revealing overall positive responses between diversity variations and environmental changes. Rather complicated correspondences to environmental factors appeared on the multi-decadal scale, showing different patterns in diversity indices, which illustrates variations through time as well. Accordingly, vegetation diversity changes of the alpine communities on the northern QTP experienced serious variations during the late Holocene, and revealed complicated responses to regional environmental changes, that further investigations particularly at different time scales would be necessary in the future.