Heat exposure impacts on urban health: A meta-analysis.

The escalating health risks posed by warm weather in urban areas have become a pressing global public health issue. This study undertakes a meta-analysis to evaluate the impact of warm weather on health in urban settings. We comprehensively searched PubMed, Embase, Scopus, and Web of Science for literature published before September 6, 2023, evaluating evidence quality using the Navigation Guide Criteria. We included original studies utilizing high temperatures or heatwaves as exposure metrics and employing observational designs. A random-effects meta-analysis assessed the relative risk (RR) of the association between high temperatures (or heatwaves) and disease outcomes. Out of 12,893 studies identified, 188 met the inclusion criteria for meta-analysis. Results demonstrate a statistically significant association between a 1 °C temperature increase and a 2.1 % elevation in disease-related mortality (RR 1.021 [95 % CI 1.018-1.023]), alongside a 1.1 % increase in morbidity (RR 1.011 [95 % CI 1.007-1.016]). Heatwaves also showed associations with increased total mortality (RR 1.224 [95 % CI 1.186-1.264]) and morbidity (RR 1.038 [95 % CI 1.010-1.066]). Subgroup analyses for diseases, sex, age, climatic zones, countries, and time periods consistently indicated heightened disease-related mortality and morbidity linked to high temperatures. Notably, China's urban populace faced an elevated mortality risk (RR 1.027 [95 % CI 1.018-1.036]) compared to other countries (RR 1.021 [95 % CI 1.019-1.024]). Mortality associated with high temperatures after 2007 (RR 1.022 [95 % CI 1.015-1.029]) was higher than before 2007 (RR 1.017 [95 % CI 1.013-1.021]), reflecting increased health risks as the global warming accelerates. Our findings underscore the positive association between rising temperatures and/or heatwaves and adverse health outcomes in urban populations. The broad exposure to high temperatures amplifies health risks across various diseases, demographics, climates, and countries, with potential exacerbation under ongoing global warming. Further research is imperative to delineate factors influencing altered heat exposure impacts.

The involvement of CaMKKI in activating AMPKα in Yesso scallop Patinopecten yessoensis under high temperature stress.

Calcium/calmodulin dependent protein kinase kinase (CaMKK), a highly conserved protein kinase, is involved in the downstream processes of various biological activities by phosphorylating and activating 5'-AMP-activated protein kinase (AMPK) in response to the increase of cytosolic-free calcium (Ca2+). In the present study, a CaMKKI was identified from Yesso scallop Patinopecten yessoensis. Its mRNA was ubiquitously expressed in haemocytes and all tested tissues with the highest expression level in mantle. The expression level of PyCaMKKI mRNA in adductor muscle was significantly upregulated at 1, 3 and 6 h after high temperature treatment (25 °C), which was 3.43-fold (p < 0.05), 5.25-fold (p < 0.05), and 5.70-fold (p < 0.05) of that in blank group, respectively. At 3 h after high temperature treatment (25 °C), the protein level of PyAMPKα, as well as the phosphorylation level of PyAMPKα at Thr170 in adductor muscle, and the positive co-localized fluorescence signals of PyCaMKKI and PyAMPKα in haemocyte all increased significantly (p < 0.05) compared to blank group (18 °C). The pull-down assay showed that rPyCaMKKI and rPyAMPKα could bind each other in vitro. After PyCaMKKI was silenced by siRNA, the mRNA and protein levels of PyCaMKKI and PyAMPKα, and the phosphorylation level of PyAMPKα at Thr170 in adductor muscle were significantly down-regulated (p < 0.05) compared with the negative control group receiving an injection of siRNA-NC. These results collectively suggested that PyCaMKKI was involved in the activation of PyAMPKα in response to high temperature stress and would be helpful for understanding the function of PyCaMKKI-PyAMPKα pathway in maintaining energy homeostasis under high temperature stress in scallops.

Influence of climatic variables on maize grain yield and its components by adjusting the sowing date.

Yield and its components are greatly affected by climate change. Adjusting the sowing date is an effective way to alleviate adverse effects and adapt to climate change. Aiming to determine the optimal sowing date of summer maize and clarify the contribution of climatic variables to grain yield and its components, a consecutive 4-year field experiment was conducted from 2016 to 2019 with four sowing dates at 10-day intervals from 5 June to 5 July. Analysis of historical meteorological data showed that more solar radiation (SR) was distributed from early June to mid-August, and the maximum temperature (Tmax) > 32°C appeared from early July to late August, which advanced and lasted longer in 1991-2020 relative to 1981-1990. Additionally, the precipitation was mainly distributed from early June to late July. The climate change in the growing season of summer maize resulted in optimal sowing dates ranging from 5 June to 15 June, with higher yields and yield stability, mainly because of the higher kernel number per ear and 1,000-grain weight. The average contribution of kernel number per ear to grain yield was 58.7%, higher than that of 1,000-grain weight (41.3%). Variance partitioning analysis showed that SR in 15 days pre-silking to 15 days post-silking (SS) and silking to harvest (SH) stages significantly contributed to grain yield by 63.1% and 86.4%. The extreme growing degree days (EDD) > 32°C, SR, precipitation, and diurnal temperature range (DTR) contributed 20.6%, 22.9%, 14.5%, and 42.0% to kernel number per ear in the SS stage, respectively. Therefore, we concluded that the early sowing dates could gain high yield and yield stability due to the higher SR in the growing season. Meanwhile, due to the decreasing trend in SR and increasing Tmax trend in this region, in the future, new maize varieties with high-temperature resistance, high light efficiency, shade tolerance, and medium-season traits need to be bred to adapt to climate change and increased grain yield.

The involvement of CgRHIM-containing protein in regulating haemocyte apoptosis after high temperature stress in Pacific oyster Crassostrea gigas.

The interactions induced by RIP homotypic interaction motif (RHIM) are essential for the activation of inflammatory signaling and certain cell death pathways. In the present study, a RHIM-containing protein was identified from Pacific oyster Crassostrea gigas, which harbored a RHIM and a Death domain (designated CgRHIM-containing protein). The mRNA transcripts of CgRHIM-containing protein were constitutively expressed in all the examined tissues of oysters, with the highest expression level in mantle. The CgRHIM-containing protein was mainly distributed in the cytoplasm of oyster haemocytes. After high temperature stress, the expression levels of CgRel and CgBcl-2 increased significantly, and reached the peak level at 12 h, then decreased gradually. The transcripts of CgRHIM-containing protein, Cgcaspase-8 and Cgcaspase-3 in haemocytes up-regulated at 12 h after high temperature stress. Moreover, the protein abundance of CgRHIM-containing protein increased significantly, and the ubiquitination level of CgRHIM-containing protein in haemocytes showed an increasing trend at first and then decreased. After the expression of CgRHIM-containing protein was knocked down by siRNA, the mRNA expression levels of CgRel and CgBcl-2 decreased significantly at 6 h after high temperature stress, and those of CgFADD-like, Cgcaspase-8 and Cgcaspase-3, as well as the apoptosis rate of haemocytes also decreased significantly at 24 h. These results indicated that CgRHIM-containing protein might regulate haemocyte apoptosis in oysters upon high temperature stress via mediating the expression of Rel, Bcl-2 and caspase-8/3.

Wheat TaNACα18 functions as a positive regulator of high-temperature adaptive responses and improves cell defense machinery.

Global wheat production amounted to >780 MMT during 2022-2023 whose market size are valued at >$128 billion. Wheat is highly susceptible to high-temperature stress (HTS) throughout the life cycle and its yield declines 5-7% with the rise in each degree of temperature. Previously, we reported an array of HTS-response markers from a resilient wheat cv. Unnat Halna and described their putative role in heat acclimation. To complement our previous results and identify the key determinants of thermotolerance, here we examined the cytoplasmic proteome of a sensitive cv. PBW343. The HTS-triggered metabolite reprograming highlighted how proteostasis defects influence the formation of an integrated stress-adaptive response. The proteomic analysis identified several promising HTS-responsive proteins, including a NACα18 protein, designated TaNACα18, whose role in thermotolerance remains unknown. Dual localization of TaNACα18 suggests its crucial functions in the cytoplasm and nucleus. The homodimerization of TaNACα18 anticipated its function as a transcriptional coactivator. The complementation of TaNACα18 in yeast and overexpression in wheat demonstrated its role in thermotolerance across the kingdom. Altogether, our results suggest that TaNACα18 imparts tolerance through tight regulation of gene expression, cell wall remodeling and activation of cell defense responses.

Ultrahigh Energy Storage Performance of BiFeO3-BaTiO3 Flexible Film Capacitor with High-Temperature Stability via Defect Design.

Nanoengineering polar oxide films have attracted great attention in energy storage due to their high energy density. However, most of them are deposited on thick and rigid substrates, which is not conducive to the integration of capacitors and applications in flexible electronics. Here, an alternative strategy using van der Waals epitaxial oxide dielectrics on ultra-thin flexible mica substrates is developed and increased the disorder within the system through high laser flux. The introduction of defects can efficiently weaken or destroy the long-range ferroelectric ordering, ultimately leading to the emergence of a large numbers of weak-coupling regions. Such polarization configuration ensures fast polarization response and significantly improves energy storage characteristics. A flexible BiFeO3-BaTiO3 (BF-BT) capacitor exhibits a total energy density of 43.5 J cm-3 and an efficiency of 66.7% and maintains good energy storage performance over a wide temperature range (20-200 °C) and under large bending deformation (bending radii ≈ 2 mm). This study provides a feasible approach to improve the energy storage characteristics of dielectric oxide films and paves the way for their practical application in high-energy density capacitors.

Organosiloxane-Modified Auricularia Polysaccharide (Si-AP): Improved High-Temperature Resistance and Lubrication Performance in WBDFs.

This study introduces a novel organosilicon-modified polysaccharide (Si-AP) synthesized via grafting and comprehensively evaluates its performance in water-based drilling fluids (WBDFs). The molecular structure of Si-AP was characterized using Fourier-transform infrared spectroscopy (FTIR) and 1H-NMR experiments. Thermalgravimetric analysis (TGA) confirmed the good thermal stability of Si-AP up to 235 °C. Si-AP significantly improves the rheological properties and fluid loss performance of WBDFs. With increasing Si-AP concentration, system viscosity increases, API filtration rate decreases, clay expansion is inhibited, and drilling cuttings hydration dispersion is suppressed, especially under high-temperature conditions. Additionally, mechanistic analysis indicates that the introduction of siloxane groups can effectively inhibit the thermal degradation of AP chains and enhance their high-temperature resistance. Si-AP can form a lubricating film by adsorbing on the surface of clay particles, improving mud cake quality, reducing the friction coefficient, and significantly enhancing the lubricating performance of WBDFs. Overall, Si-AP exhibits a higher temperature-resistance limit compared to AP and more effectively optimizes the lubrication, inhibition, and control of the filtration rate of WBDFs under high-temperature conditions. While meeting the requirements of drilling fluid systems under high temperatures, Si-AP also addresses environmental concerns and holds promise as an efficient solution for the exploitation of deep-seated oil and gas resources.

The Quest for High-Temperature Superconductivity in Nickelates under Ambient Pressure.

Recently, superconductivity with Tc ≈ 80 K was discovered in La3Ni2O7 under extreme hydrostatic pressure (>14 GPa). For practical applications, we needed to stabilize this state at ambient pressure. It was proposed that this could be accomplished by substituting La with Ba. To put this hypothesis to the test, we used the state-of-the-art atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) technique to synthesize (La1-xBax)3Ni2O7 films, varying x and the distribution of La (lanthanum) and Ba (barium). Regrettably, none of the compositions we explored could be stabilized epitaxially; the targeted compounds decomposed immediately into a mixture of other phases. So, this path to high-temperature superconductivity in nickelates at ambient pressure does not seem promising.

High-Temperature Tensile Characteristics of an Al-Zn-Mg-Cu Alloy: Fracture Characteristics and a Physical Mechanism Constitutive Model.

High-temperature tensile tests were developed to explore the flow features of an Al-Zn-Mg-Cu alloy. The fracture characteristics and microstructural evolution mechanisms were thoroughly revealed. The results demonstrated that both intergranular fractures and ductile fractures occurred, which affected the hot tensile fracture mechanism. During high-temperature tensile, the second phase (Al2CuMg) at the grain boundaries (GBs) promoted the formation and accumulation of dimples. With the continual progression of high-temperature tensile, the aggregation/coarsening of dimples along GBs appear, aggravating the intergranular fracture. The coalescence and coarsen of dimples are reinforced at higher tensile temperatures or lower strain rates. Considering the impact of microstructural evolution and dimple formation/coarsening on tensile stresses, a physical mechanism constitutive (PMC) equation is herein proposed. According to the validation and analysis, the predictive results were in preferable accordance with the testing data, showing the outstanding reconfiguration capability of the PMC model for high-temperature tensile features in Al-Zn-Mg-Cu alloys.

Analytical Determination of Nusselt Numbers for Convective Heat Transfer Coefficients in Channel Macroporous Absorbers.

This article introduces a novel analytical equation for computing the Nusselt number within the macroporous structures of channel absorbers utilized in high-temperature solar receivers. The equation incorporates heat and mass transfer processes occurring within boundary layers as fluid flows through complex-shaped macroporous absorber channels. The importance of accounting for the length of the thermodynamic boundary layer within channel-type macroporous media when calculating heat transfer coefficients using the Nusselt equation is demonstrated. By incorporating proposed indicators of porosity and flow characteristics, this method significantly enhances the accuracy of heat transfer coefficient calculations for such media. Discrepancies observed in existing calculation relationships and experiments are attributed to the omission of certain proposed values in the Nusselt number for macroporous media. To address this, empirical coefficients for the Nusselt number are derived using statistical methods. The resulting semi-empirical equation is applied to macroporous absorbers in solar receivers. The findings enable more accurate predictions of future absorber characteristics, enhancing their efficiency. The derived equation is successfully validated against numerical data across various geometric structures of absorbers in concentrated solar power plants.

Effect of Yttrium Additions on the High-Temperature Oxidation Behavior of GH4169 Ni-Based Superalloy.

The effect of the active element yttrium and its content on the oxidation behavior of GH4169 Ni-based superalloy at extreme temperature was studied by isothermal oxidation experiments. The results show that the oxide scale of GH4169 alloy presents a multi-layer structure, in which the continuous and dense Cr2O3 oxide layer is located in the subouter layer (II layer) and the continuous Nb-rich layer is in the subinner layer (III layer). These layers can inhibit the diffusion of oxygen and alloying elements, preventing the further oxidation of the alloy. The appropriate addition of yttrium can promote the selective oxidation of Cr element, reduce the thickness of the oxide scale and the oxidation rate of the alloy, inhibit the formation of voids at the interface of the oxide scale/alloy matrix, improve the resistance of the alloy to spalling as well as the adhesion of the oxide scale, and improve the high-temperature oxidation resistance of the alloy. Of those tested, the alloy containing 0.04 wt.%Y has the lowest oxidation weight gain, the slowest oxidation rate, and less oxide scale spalling. Based on this, the effect of yttrium on the high-temperature oxidation behavior of GH4169 Ni-based superalloy and its mechanism were revealed.

Impact of extreme high temperatures on pollution emissions of enterprise: Evidence from China.

Frequently occurring extreme weather events can pose a challenge to people and production systems. Coping with extreme high temperatures requires promoting the synergy between pollution reduction and carbon reduction. Accordingly, this study examines the causal relationship between extreme high temperatures and corporate pollution emissions by using the panel data of a Chinese sample from 2000 to 2014. This study uses fixed-effects models for the analysis. Baseline results show that a unit increase in the standardized temperature will result in a 4.6% reduction in corporate pollutant emissions. The heterogeneous analysis shows that extreme high temperatures will have an obvious effect on enterprises with low financing constraints and high policy and public constraints as well as on enterprises in cities with a high level of economic development, in innovative cities, and in the eastern region. We also explore the mechanism through which extreme high temperatures reduce pollutant emissions from the two dimensions of external environmental pressure and internal environmental governance. Extreme high temperatures will prompt enterprises to improve their energy efficiency, engage in innovative production processes, adopt source-and-end governance measures, and curb their pollutant emissions while strengthening government environmental supervision. This study provides new ideas for enterprise pollution reduction and serves as an inspiration to the government in formulating environmental policies.

Diamond with Unexpected Multi-Scale Pores.

Following the diverse structural characteristics and primary usage, diamond products include nano-polycrystalline diamond (NPD), micron-polycrystalline diamond (MPD), diamond film, porous diamond, and diamond wire drawing die. Among them, porous diamond possesses a distinctive combination of flexible surface functionality and a remarkably high surface area-to-volume ratio (SA/V) compared to traditional bulk materials, which contributes to cross-cutting applications in catalysis, adsorption, and electrochemistry while retaining the superior traits of diamond, particularly its exceptional chemical inertia. To avoid etching or microwave plasma chemical vapor deposition (MPCVD) techniques, this study proposes a high-temperature and high-pressure method based on a soluble skeleton (HPHT-ss) as an efficient and inexpensive approach for synthesizing millimeter-level porous diamonds. Interestingly, porous diamond synthesized by HPHT-ss exhibits multiscale pores distributed as macropores (average 75 µm) and mesopores (average 19 nm), which gives it a unique feature compared with other methods. Pertinent temperature-pressure conditions, HPHT-ss synthesis, and the formation mechanism of porous diamonds are also thoroughly discussed.

Decay and Termite Resistance of Wood Modified by High-Temperature Vapour-Phase Acetylation (HTVPA), a Simultaneous Acetylation and Heat Treatment Modification Process.

High-temperature vapour-phase acetylation (HTVPA) is a simultaneous acetylation and heat treatment process for wood modification. This study was the first investigation into the impact of HTVPA treatment on the resistance of wood to biological degradation. In the termite resistance test, untreated wood exhibited a mass loss (MLt) of 20.3%, while HTVPA-modified wood showed a reduced MLt of 6.6-3.2%, which decreased with an increase in weight percent gain (WPG), and the termite mortality reached 95-100%. Furthermore, after a 12-week decay resistance test against brown-rot fungi (Laetiporus sulfureus and Fomitopsis pinicola), untreated wood exhibited mass loss (MLd) values of 39.6% and 54.5%, respectively, while HTVPA-modified wood exhibited MLd values of 0.2-0.9% and -0.2-0.3%, respectively, with no significant influence from WPG. Similar results were observed in decay resistance tests against white-rot fungi (Lenzites betulina and Trametes versicolor). The results of this study demonstrated that HTVPA treatment not only effectively enhanced the decay resistance of wood but also offered superior enhancement relative to separate heat treatment or acetylation processes. In addition, all the HTVPA-modified wood specimens prepared in this study met the requirements of the CNS 6717 wood preservative standard, with an MLd of less than 3% for decay-resistant materials.

Mitochondrial Protein-Coding Gene Expression in the Lizard Sphenomorphus incognitus (Squamata:Scincidae) Responding to Different Temperature Stresses.

In the context of global warming, the frequency of severe weather occurrences, such as unexpected cold spells and heat waves, will grow, as well as the intensity of these natural disasters. Lizards, as a large group of reptiles, are ectothermic. Their body temperatures are predominantly regulated by their environment and temperature variations directly impact their behavior and physiological activities. Frequent cold periods and heat waves can affect their biochemistry and physiology, and often their ability to maintain their body temperature. Mitochondria, as the center of energy metabolism, are crucial for maintaining body temperature, regulating metabolic rate, and preventing cellular oxidative damage. Here, we used RT-qPCR technology to investigate the expression patterns and their differences for the 13 mitochondrial PCGs in Sphenomorphus incognitus (Squamata:Scincidae), also known as the brown forest skink, under extreme temperature stress at 4 °C, 8 °C, 34 °C, and 38 °C for 24 h, compared to the control group at 25 °C. In southern China, for lizards, 4 °C is close to lethal, and 8 °C induces hibernation, while 34/38 °C is considered hot and environmentally realistic. Results showed that at a low temperature of 4 °C for 24 h, transcript levels of ATP8, ND1, ND4, COI, and ND4L significantly decreased, to values of 0.52 ± 0.08, 0.65 ± 0.04, 0.68 ± 0.10, 0.28 ± 0.02, and 0.35 ± 0.02, respectively, compared with controls. By contrast, transcript levels of COIII exhibited a significant increase, with a mean value of 1.86 ± 0.21. However, exposure to 8 °C for 24 h did not lead to an increase in transcript levels. Indeed, transcript levels of ATP6, ATP8, ND1, ND3, and ND4 were significantly downregulated, to 0.48 ± 0.11, 0.68 ± 0.07, 0.41 ± 0.08, 0.54 ± 0.10, and 0.52 ± 0.07, respectively, as compared with controls. Exposure to a hot environment of 34 °C for 24 h led to an increase in transcript levels of COI, COII, COIII, ND3, ND5, CYTB, and ATP6, with values that were 3.3 ± 0.24, 2.0 ± 0.2, 2.70 ± 1.06, 1.57 ± 0,08, 1.47 ± 0.13, 1.39 ± 0.56, and 1.86 ± 0.12, respectively, over controls. By contrast, ND4L exhibited a significant decrease (to 0.31 ± 0.01) compared with controls. When exposed to 38 °C, the transcript levels of the 13 PCGs significantly increased, ranging from a 2.04 ± 0.23 increase in ND1 to a 6.30 ± 0.96 rise in ND6. Under two different levels of cold and heat stress, the expression patterns of mitochondrial genes in S. incognitus vary, possibly associated with different strategies employed by this species in response to low and high temperatures, allowing for rapid compensatory adjustments in mitochondrial electron transport chain proteins in response to temperature changes. Furthermore, this underscores once again the significant role of mitochondrial function in determining thermal plasticity in reptiles.

Approaching Ultimate Synthesis Reaction Rate of Ni-Rich Layered Cathodes for Lithium-Ion Batteries.

Nickel-rich layered oxide LiNixCoyMnzO2 (NCM, x + y + z = 1) is the most promising cathode material for high-energy lithium-ion batteries. However, conventional synthesis methods are limited by the slow heating rate, sluggish reaction dynamics, high energy consumption, and long reaction time. To overcome these challenges, we first employed a high-temperature shock (HTS) strategy for fast synthesis of the NCM, and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time. In the HTS process, ultrafast average reaction rate of phase transition from Ni0.6Co0.2Mn0.2(OH)2 to Li- containing oxides is 66.7 (% s-1), that is, taking only 1.5 s. An ultrahigh heating rate leads to fast reaction kinetics, which induces the rapid phase transition of NCM cathodes. The HTS-synthesized nickel-rich layered oxides perform good cycling performances (94% for NCM523, 94% for NCM622, and 80% for NCM811 after 200 cycles at 4.3 V). These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries.

Amphiphilic Polymer Electrolyte Blocking Lattice Oxygen Evolution from High-Voltage Nickel-rich Cathodes for Ultra-Thermal Stabile Batteries.

Ni-rich cathodes have been intensively adopted in Li-ion batteries to pursuit high energy density, which still suffering irreversible degradation at high voltage. Some unstable lattice O2- species in Ni-rich cathodes would be oxidized to singlet oxygen 1O2 and released at high volt, which lead to irreversible phase transfer from the layered rhombohedral (R) phase to a spinel-like (S) phase. To overcome the issue, the amphiphilic copolymers (UMA-Fx) electrolyte were prepared by linking hydrophobic C-F side chains with hydrophilic subunits, which could self-assemble on Ni-rich cathode surface and convert to stable cathode-electrolyte interphase layer. Thereafter, the oxygen releasing of polymer coated cathode was obviously depressed and substituted by the Co oxidation (Co3+→Co4+) at high volt (>4.2V), which could suppressed irreversible phase transfer and improve cycling stability. Moreover, the amphiphilic polymer electrolyte was also stable with Li anode and had high ion conductivity. Therefore, the NCM811//UMA-F6//Li pouch cell exhibited outstanding energy density (362.97 Wh/kg) and durability (cycled 200 times at 4.7V), which could be stalely cycled even at 120℃ without short circuits or explosions.

Emerging roles of plant transcriptional gene silencing under heat.

Plants continuously endure unpredictable environmental fluctuations that upset their physiology, with stressful conditions negatively impacting yield and survival. As a contemporary threat of rapid progression, global warming has become one of the most menacing ecological challenges. Thus, understanding how plants integrate and respond to elevated temperatures is crucial for ensuring future crop productivity and furthering our knowledge of historical environmental acclimation and adaptation. While the canonical heat-shock response and thermomorphogenesis have been extensively studied, evidence increasingly highlights the critical role of regulatory epigenetic mechanisms. Among these, the involvement under heat of heterochromatic suppression mediated by transcriptional gene silencing (TGS) remains the least understood. TGS refers to a multilayered metabolic machinery largely responsible for the epigenetic silencing of invasive parasitic nucleic acids and the maintenance of parental imprints. Its molecular effectors include DNA methylation, histone variants and their post-translational modifications, and chromatin packing and remodeling. This work focuses on both established and emerging insights into the contribution of TGS to the physiology of plants under stressful high temperatures. We summarized potential roles of constitutive and facultative heterochromatin as well as the most impactful regulatory genes, highlighting events where the loss of epigenetic suppression has not yet been associated with corresponding changes in epigenetic marks.

The synergistic effect of high temperature and relative humidity on non-accidental deaths at different urbanization levels.

Numerous studies have examined the impact of temperature on mortality, yet research on the combined effect of temperature and humidity on non-accidental deaths remains limited. This study investigates the synergistic impact of high temperature and humidity on non-accidental deaths in China, assessing the influence of urban development and urbanization level. Utilizing the distributed lag nonlinear model (DLNM) of quasi-Poisson regression, we analyzed the relationship between Wet Bulb Globe Temperature (WBGT) and non-accidental deaths in 30 Chinese cities from 2010 to 2016, including Guangzhou during 2012-2016. We stratified temperature and humidity across these cities to evaluate the influence of varying humidity levels on deaths under high temperatures. Then, we graded the duration of heat and humidity in these cities to assess the impact of deaths with different durations. Additionally, the cities were categorized based on gross domestic product (GDP), and a vulnerability index was calculated to examine the impact of urban development and urbanization level on non-accidental deaths. Our findings reveal a pronounced synergistic effect of high temperature and humidity on non-accidental deaths, particularly at elevated humidity levels. The synergies of high temperature and humidity are extremely complex. Moreover, the longer the duration of high temperature and humidity, the higher the risk of non-accidental death. Furthermore, areas with higher urbanization exhibited lower relative risks (RR) associated with the synergistic effects of heat and humidity. Consequently, it is imperative to focus on damp-heat related mortality among vulnerable populations in less developed regions.