Search Results (9,608)

Dendrobium officinale, a perennial medicinal herb rich in flavonoids, exhibits multiple pharmacological properties including antioxidant and hypoglycemic effects. However, its medicinal quality is compromised by various abiotic stresses, such as heat, cold, and osmotic stresses. UDP-glycosyltransferases play critical roles in both flavonoid glycosylation and plant stress tolerance. Here, we report the identification of a heat-responsive glycosyltransferase gene, DoUGT71K2, from D. officinale transcriptomes, and a characterization of its stress-induced expression and transcriptional regulatory mechanisms. Quantitative real-time PCR (qRT-PCR) showed that DoUGT71K2 exhibits tissue-specific high expression in flowers, and its transcript abundance is strongly elevated in response to heat, cold, and abscisic acid (ABA) treatment. The direct promoter-binding and trans-activating function of DoMYB102 on DoUGT71K2 was confirmed via dual-luciferase reporter and yeast one-hybrid (Y1H) assays. These results establish a DoMYB102–DoUGT71K2 regulatory module that couples heat stress response with flavonoid biosynthesis, which provides a molecular basis for improving stress tolerance and medicinal quality in D. officinale through molecular breeding. Full article

Low-emission zones (LEZs) require cities to define policy rules, predict effects before deployment, and verify outcomes afterwards, yet mobility, emissions, meteorology, exposure, data governance, and public communication are commonly handled in separate systems. This paper presents envair360, a Physical Intelligence architecture and a four-stage, evidence-gated LEZ methodology connecting project definition, baseline feasibility, digital-twin design, deployment, and verified impact closure. A design-science method is combined with an operational case study of Cartagena, Spain, because the research object is both a socio-technical artefact and a context-dependent municipal deployment. The technology chain is selected to bridge complementary scales and functions: SUMO for link- and vehicle-level traffic, WRF and CHIMERE for meteorology and regional chemistry, MUNICH and street-canyon parameterisation for computationally tractable street resolution, model-output calibration anchored to measurements, and FIWARE/NGSI-LD for governed context exchange. The manuscript distinguishes city observations, peer-reviewed component validation, demonstrated platform capabilities, and policy or engineering targets. A Murcia component study reports lower hourly than daily agreement after deep-learning calibration (NO${}_2$: $r=0.79$ hourly and $0.94$ daily; O${}_3$: $r=0.85$ hourly and $0.97$ daily), illustrating the importance of temporal aggregation and transfer limits. Digitisation of the prior Madrid ozone-density figure indicates modal shifts of approximately +32.0 and +27.8 source-axis units at two stations; the supplied source does not permit a numerical NO${}_x$ bias estimate. A separate six-city export audit covers 24,384 records and 4064 street segments and demonstrates a common model-output schema, not predictive validation. In Cartagena, project documentation reports elevated PM${}_{10}$/PM${}_{2.5}$, urban heat and solar-radiation stress, and a plausible role for dry-climate dust resuspension, supporting a superblock-oriented LEZ proposal with a long-term 30% vehicular CO${}_2$ reduction target. The paper’s specific contribution is the governed orchestration, evidence taxonomy, quality gates, reproducible lineage, explicit policy-scenario representation, and portable city-onboarding protocol; it does not claim that the individual scientific models, the Cartagena deployment, or the cited project targets originated in this manuscript. Full article

As global warming raises ambient temperatures, plant growth and productivity are being profoundly affected. Although the impacts of extreme heat stress have received extensive attention, the developmental consequences of moderately elevated temperatures remain less understood. As sessile organisms, plants rely on developmental plasticity to adjust their growth and development in response to warm environments. Understanding how plants sense temperature and convert this signal into developmental outputs is crucial for determining their adaptive strategies to climate change and for applying this knowledge to breed climate-resilient crops. Here, we review current advances in understanding how moderately elevated temperatures regulate developmental plasticity throughout the plant life cycle, including the perception of moderate warmth, the resulting developmental plasticity during vegetative and reproductive growth, and the coordination and trade-offs between these two phases. We also highlight major unanswered questions in this field and propose strategies for manipulating developmental plasticity to breed climate-resilient crops. Full article

To mitigate the health and environmental risks of urbanisation and the urban heat island effect, urban planning is shifting towards promoting active mobility. The success of these efforts largely depends on understanding people’s thermal comfort on the move, driving research towards the investigation of the complex interdependencies between microclimatic conditions and the real-time experiences of pedestrians and cyclists. This literature review aims to present the state of the art of research at the neighbourhood and street levels by analysing the methodological frameworks employed and the outcomes achieved. The paper adopts a thematic clustering approach, grouping the articles on the basis of their research objectives, methodologies and the relationships between active mobility and comfort. The literature review highlights a shift from static to dynamic comfort assessments and a focus on active travel as a continuous experience rather than the sum of stationary moments. The primary findings include the consolidation of the thermal walk methodology and the emergence of cumulative stress indices. Evidence from heat stress contexts suggests that pedestrians prefer thermal diversity, which causes thermal alliesthesia, over monotonous conditions. The research highlights the role of heat stress as a barrier to walkability in hot and temperate climates, causing route deviations and lower walking speeds, with the opposite pattern in severely cold settings. This review identifies several research gaps, including a lack of standardised dynamic assessment methods, low generalisability and transferability of the results, and insufficient investigation of cyclists’ dynamic comfort compared with that of pedestrians. Full article

Urban areas face increasing challenges related to heat stress and urban heat islands, necessitating effective strategies for microclimate regulation and thermal comfort enhancement. This study investigates the cooling effect of three tree species, Ficus retusa, Ficus benjamina and Fraxinus spp. (Ash trees), on urban microclimates and thermal comfort in downtown Annaba, Algeria, during the summer. The methodology comprises two complementary methods. First, field measurements of air temperature (Ta), relative humidity (RH), and wind speed (Ws) were recorded hourly from 9 a.m. to 9 p.m. Second, collected data was inputted into the ENVI-met microclimate model to simulate various urban canopy scenarios. Microclimate variations, including air temperature (Ta), mean radiant temperature (T_mrt), relative humidity, wind speed, and the Physiological Equivalent Temperature (PET) index, were computed over a 13 h period, from 9 a.m. to 9 p.m., to examine the cooling effect of each species and their impact on outdoor thermal comfort. The results demonstrate the notable cooling effect of Ficus species and Fraxinus spp. with Ficus species generally exhibiting larger reductions in air temperature (0.9 °C to 2 °C) and PET index (7.3 °C to 7.7 °C), and higher increases in relative humidity (5.6% to 6.8%) compared to Ash trees. Full article

This study investigates the influence of laser spot size (Ø100 µm vs. Ø50 µm) on the microstructure, transformation behavior, and hardness of Ti-51.17 at.%Ni shape memory alloy samples fabricated by laser powder bed fusion. Samples were produced using identical processing parameters covering laser powers of 50–150 W, scanning speeds of 500–750 mm/s, and matched volumetric energy densities (28–83 J/mm³), with spot size as the only variable. Although both laser spot sizes produced comparable melt pool geometries and predominantly B2 austenite matrices with minor fractions of B19′ martensite, the Ø50 µm samples exhibited finer microstructures, higher residual stresses, and lower martensitic transformation temperatures in the as-built state. Heat treatment at 800 °C reduced residual stresses and partially homogenized the microstructure; however, differences in their transformation behavior remained. These differences were attributed to the spot-size-dependent Ni evaporation. Although transformation temperatures increased with increasing energy density for both conditions, the Ø50 µm samples consistently showed lower values. In the 55–83 J/mm³ volumetric energy density range, the estimated Ni content ranged from 51.15 to 50.42 at.%, and the Ø50 µm samples showed approximately 0.1–0.2 at.% greater Ni loss than their Ø100 µm counterparts. These findings demonstrate that Ni evaporation is a laser-spot-size-dependent phenomenon that must be considered when processing near-equiatomic Ti-Ni alloys. Full article

High-carbon martensitic steels for bearing components are conventionally low-temperature tempered for stress relief, yet the influence of tempering temperature on compressive and fatigue wear resistance remains unclear, directly affecting the service life of bearing races and rollers. In this study, a high-carbon martensitic steel was tempered at 170 °C, 200 °C, and 230 °C. The microstructural evolution, compressive properties, and contact fatigue wear resistance were systematically investigated, along with the corresponding strengthening and wear mechanisms. After spheroidizing annealing and quenching, the microstructure consists of high-carbon martensite and retained austenite, with a high density of dislocations and fine twins. Tempering decomposes retained austenite into tempered martensite and promotes fine carbide precipitation, processes that become more pronounced at higher temperatures. Consequently, hardness decreases from 810 HV in the as-quenched state to 690 HV after 230 °C tempering, while compressive failure strain increases from 10.5% to 24.1%. More importantly, under cyclic contact stress, the 230 °C-tempered specimen exhibits approximately 33% lower wear mass loss than the 170 °C-tempered counterpart, despite its lower hardness. This unexpected improvement is attributed to the formation of a distinct plastic deformation zone in the near-surface region, which absorbs greater strain energy and delays fatigue spallation. The well-tempered martensitic matrix accommodates more long-range dislocation slip, enabling a transition from fatigue spallation to a more ductile failure mode. These findings provide new insights into the role of low-temperature tempering in balancing strength, ductility, and wear resistance, and offer practical guidance for optimizing heat treatment protocols to enhance the contact fatigue performance of bearing steels. Full article

Plant A/T-rich sequence and zinc-binding protein (PLATZ) transcription factors are pivotal regulators of plant growth, development, and abiotic stress responses. Although PLATZ genes have been extensively studied and functionally characterized in various plant species, little information is available regarding these genes in the legume model plant Medicago truncatula. In this study, a total of 16 PLATZ genes (designated MtPLATZ1 to MtPLATZ16) were identified from the M. truncatula genome and distributed across six of the eight chromosomes. Subcellular localization prediction analysis indicated that all MtPLATZ proteins are localized in the nucleus, with eight representative members experimentally validated by transient expression assays. Collinearity analysis indicated that five segmental duplication pairs were the primary driver of MtPLATZ gene expansion. Based on phylogenetic analysis, these genes were classified into four groups, comprising 6, 2, 4, and 4 genes, respectively. Gene structure analysis demonstrated that these genes possess three or four exons. Most MtPLATZ genes were found to contain at least one ABRE cis-element in their promoter regions, and a few also harbored LTR, CAT-box, ARE, and DRE cis-elements. Expression analysis revealed that MtPLATZ genes exhibit distinct expression patterns across different tissues, suggesting that they may be differentially regulated by abiotic stresses in a tissue-specific manner. Under PEG-induced osmotic stress, acute NaCl shock, acute heat shock, and acute cold shock, the expression levels of these eight genes exhibited significant changes, particularly MtPLATZ2, MtPLATZ6, and MtPLATZ9, indicating that MtPLATZ gene family members may play a broad role in abiotic stress responses. In summary, these findings provide valuable insights for future functional exploration of MtPLATZ genes and contribute to a deeper understanding of their roles in stress responses in M. truncatula. Full article

Grinding is the final precision machining step for bearing rings, which induces subsurface gradients in microstructure and mechanical properties. Rolling contact fatigue life and service reliability are directly determined by the gradients. Current research of the grinding metamorphic layer in bearing steels is synthesized in this review. The formation mechanisms, characterization approaches, and the influence of grinding parameters on metamorphic layers is covered. The coupled thermal–mechanical–phase transformation framework encompasses heat-driven phase transformation, high-strain-rate gradient plastic deformation, and their interactions, which collectively govern the formation of the three-layer gradient structure. When the surface temperature exceeds the austenitization threshold, the governing regime shifts from mechanically dominated to thermally dominated, producing an abrupt increase in white layer thickness and concurrent dark layer softening. The capabilities and limitations of characterization techniques for probing the gradient microstructure and residual stress profile are evaluated. The influence of grinding depth, wheel speed, feed rate, wheel characteristics, and cooling conditions on the metamorphic layer is analyzed. The areas requiring deeper investigation are identified. These insights aim to establish correlations between the grinding process and the surface integrity and service performance of bearing components, and to provide directions for future research on the grinding metamorphic layer. Full article

Environmental temperature significantly influences the evolutionary adaptation of poultry, while abdominal fat deposition represents a crucial economic trait affecting feed conversion efficiency and carcass quality. However, reports on the genetic mechanisms governing their co-evolutionary trade-offs remain scarce. This study employed whole-genome resequencing data from 469 chickens across 31 varieties. Through comparative analyses of heat- versus cold-adapted groups and high- versus low-fat groups, structural variations (SVs) were utilized as genetic markers. Selection signatures were identified via the population differentiation index (F_ST) and nucleotide diversity ratio (π ratio). We identified 103 overlapping genes located within significantly differentiated SVs at the intersection of temperature adaptation and fat deposition. Pathway analysis revealed significant enrichment in the thyroid hormone signaling pathway, pinpointing MED17 as a key selection target. Further validation via PCR genotyping in the heat-tolerant Wenchang chicken revealed that individuals harboring the MED17 mutation exhibited significantly higher abdominal fat deposition than those without. These results suggest that MED17 is associated with fat deposition in heat-tolerant Wenchang chickens, serving as a potential candidate gene for this trait, providing robust molecular markers for breeding novel strains with both thermotolerance and superior carcass traits. Full article

Despite the traditional application of Sophora moorcroftiana seeds (SMS) in Tibetan medicine for heat-clearing, damp-drying, anti-inflammatory and detoxifying properties, the anti-inflammatory mechanisms of SMS remain insufficiently understood and warrant systematic investigation. This study evaluated the protective effects of an ethanolic SMS extract against lipopolysaccharide (LPS)-induced oxidative stress and inflammation in RAW 264.7 macrophages, with emphasis on the p62/Keap1/Nrf2 signaling pathway. In vitro, the extract exhibited significant DPPH, ABTS and ·OH radical scavenging activities, as well as ferric-reducing antioxidant power, in a clear concentration dependent manner. An inflammatory model was established by stimulating RAW 264.7 cells with LPS, followed by treatment with graded concentrations of the ethanolic SMS extract. The extract significantly reduced LPS-induced nitric oxide production and decreased the secretion of TNF-α, IL-6 and IL-1β, while suppressing iNOS and COX-2 expression at both mRNA and protein levels. In parallel, the extract alleviated oxidative stress, as evidenced by reduced intracellular reactive oxygen species (ROS) and MDA levels, increased antioxidant defenses including SOD, GSH and CAT, and decreased LDH release. At the protein-expression level, SMS treatment was accompanied by differential changes in p62, Keap1, total Nrf2 and HO-1 expression, suggesting that its effects may involve regulatory processes associated with cellular stress and antioxidant defense. Collectively, the ethanolic extract of SMS attenuated LPS-induced inflammatory and oxidative stress responses in RAW 264.7 macrophages. These effects may be associated with the suppression of inflammatory mediator production, reduction in the cellular oxidative stress burden and modulation of proteins involved in cellular stress responses and antioxidant defense. Full article

Global climate change has posed a serious threat to agricultural production and food security. Crop growth models, with their excellent simulation and prediction capabilities, have become one of the important tools for guiding agricultural production and ensuring food security. This study provides a review of the research progress in crop growth models. The development history of the models is summarized into four stages, including process modeling, system simulation, model application, and algorithm expansion. According to different driving factors, the crop growth models can be categorized into solar radiation-driven, soil moisture content-driven, meteorological factor-driven, and integrated factor-driven models. In terms of the countries of development, the models mainly include those from the Netherlands, the United States, Australia, and China. Regarding applications, crop growth models are primarily applicable to adaptability assessment, agricultural resource and crop cultivation management, and climate change evaluation. Since their initial development, these models have enhanced their mechanistic nature through various approaches, such as incorporating surface mulching modules, considering the response of root water uptake to soil salt stress, and preliminarily introducing physiological regulation processes. By integrating with remote sensing technology, the spatial scale of the models has been expanded from the point scale to the regional or even global scale, and the accuracy of regional-scale yield estimation has been significantly improved through assimilation with remote sensing. Meanwhile, crop growth models have also been combined with intelligent algorithms to optimize irrigation scheduling, and to perform model parameter optimization. Looking forward, potential future research directions of crop growth models include extending the soil submodule from one-dimensional to two/three-dimensional water–heat–solute transport, moving toward a more mechanistic crop growth modeling, integration with remote sensing, and incorporating artificial intelligence. This study serves as a reference for further development and application of crop growth models, and provides technical support for the development of sustainable agriculture. Full article

The characterization of high-temperature plastic deformation behavior in centrifugally cast alloys has historically been based on curve fitting of experimentally obtained creep data. Although this approach provides acceptable results within the range of experimental conditions used for curve fitting, performance predictions under conditions outside conventional tests—typically derived from constant temperature and stress—remain insufficiently accurate for petrochemical engineering applications. In this study, constant-load creep tests were performed across a stress range of 5–33 MPa at 950–1100 °C. The minimum creep rate was calculated from the creep curves and used to fit Norton-law parameters by log–log regression. A global Norton-law fit was first carried out for each temperature, and an additional segmented fit was then performed by separating the low- and high-stress domains. The results reveal a systematic variation in the apparent Norton stress exponent (n) with the stress range considered. This variation suggests that the creep response changes from one apparent stress domain to another, contradicting the assumption of a single-valued Norton exponent inherent in standard curve-fitting procedures. Although the experimental database was obtained from conventional constant-load and constant-temperature creep tests, the results are discussed in terms of their implications for creep modeling under non-stationary operating conditions, where local stress and temperature fields may evolve during service. Parameters fitted over a broad stress range may produce systematic local errors when applied to stress domains with different apparent sensitivities. Furthermore, it is well known that classical steady-state creep models may be insufficient when their fitted parameters are transferred to non-stationary loading conditions, where thermal transients during start-up and shutdown generate differential thermal strains and high local stress levels. Geometric constraints, combined with these peak stresses, may lead to values exceeding the yield strength, a condition under which classical methods fail to adequately describe material behavior and stress relaxation mechanisms. This manuscript directly addresses this limitation through the analysis of three heats of the same centrifugally cast alloy. Full article

This paper investigates the design of aluminium I-beams under major axis bending, fabricated by MIG welding three plates to form the section. The study focuses on beam sizes relevant to pedestrian bridges, with depths ranging from 508 mm to over 2540 mm. The analysis is limited to local buckling behaviour. A total of 600 geometrical material non-linear imperfection analysis-GMNIA and linear buckling analysis-LBA reference numerical results were obtained from validated non-linear shell finite element models. The influence of the heat-affected zone (HAZ) is shown to be pronounced and detrimental to the resistance of welded aluminium beams. Unlike in steel beams, where buckling often governs, local buckling modes in aluminium members may arise but are typically dominated by HAZ-related failure. The effect of strain hardening on the behaviour and resistance of aluminium alloys is examined and compared with current design approaches, which typically assume an idealised plastic plateau similar to steel. The results show that strain hardening significantly enhances resistance and is not captured by existing design methods. The effect of residual stresses in welded aluminium members is also investigated. The results indicate that MIG-induced residual stresses are sufficiently small and have a negligible influence on both structural behaviour and strength. Their effect can be conservatively accounted for by increasing the amplitude of initial geometric imperfections. The study shows that current design recommendations are inconsistent and mostly unsafe for welded aluminium beams bridge sections governed by local buckling. The findings provide improved insight into the behaviour and resistance of such members and contribute to more accurate and efficient design methods. Full article

Germination traits and high-temperature tolerance are critical seed traits for species to respond to habitat changes through seed germination and population dynamics in tropical areas. This study investigated germination under temperature, water and NaCl stress and the seed high-temperature tolerance of three species growing in Xishuangbanna, i.e., one native vine species, Clematis subumbellata, and two introduced tree species, Handroanthus chrysanthus and Melaleuca viminalis. The results were compared with our previous studies in this region to assess the threatened status of C. subumbellata and invasion risk of H. chrysanthus and M. viminalis, in combination with their other traits. These three species are all characterized by the production of numerous small seeds with high viability every year, having the ability to increase their population rapidly under favorable conditions, though they all suffered viability loss and germination inhibition under high temperature and water stresses. The two introduced species, both H. chrysanthus and M. viminalis, produced seeds with wider germination temperature ranges and better high-temperature tolerance than the native C. subumbellata, but their seed heat tolerance was markedly lower than that of typical invasive weeds in this region. On the contrary, C. subumbellata seeds exhibited rather poor high-temperature tolerance, comparable to some rare and endangered species reported previously in the region; however, this species primarily grows on forest margins, slopes, and scrub and produces plumose achenes with good wind dispersal capacity. Thus, it was concluded that H. chrysanthus and M. viminalis may possess only low-to-moderate invasion risks, and their most probable invasive habitats are mainly forest edges. C. subumbellata can be regarded as not threatened currently, without urgent conservation demand. This information is useful for biodiversity conservation in Xishuangbanna. Full article