Under global warming, a novel category of extreme events has become increasingly apparent, where flood and hot extremes occur in rapid succession, causing significant damages to infrastructure and ...ecosystems. However, these bivariate compound flood‐hot extreme (CFH) hazards have not been comprehensively examined at the global scale, and their evolution under climate warming remains unstudied. Here, we present the first global picture of projected changes in CFH hazards by using a cascade modeling chain of CMIP6 models, satellite and reanalysis data sets, bias correction, and hydrological models. We find an increasing percentage of floods will be accompanied by hot extremes under climate change; the joint return periods of CFHs are projected to decrease globally, particularly in the tropics. These decreasing joint return periods are largely driven by changes in hot extremes and indicate a likely increase of CFH hazards, and ultimately highlight the urgent need to conduct adaptation planning for future risks.
Plain Language Summary
Climate change alters the Earth's energy budget and accelerates the hydrological cycle, bringing new hazards such as temporally compounding flood and hot extremes. Rapid transitions from devastating floods to deadly heat, or vice versa, which used to be rare, are already occurring under the present climate and bring new threats to infrastructure and the public. However, these bivariate CFH hazards have been poorly understood at the global scale, and their future evolution in the context of climate change has not yet been assessed. Here, we provide the first systematic assessment of projected changes and attributions in the multivariate hazards of global flood‐hot extremes. We find that the fraction of flooding accompanied by hot extremes could rise markedly under global warming. Changes in hot extremes dominate the exacerbation of global CFH hazards, especially in tropical climate zones. Our study identifies the tropics as the new global hotspot of flood‐hot extreme events in a warming future, and reveals an increasing global risk of unexpected sequential wet‐hot extremes, highlighting the need to better prepare adaptation and mitigation solutions.
Key Points
We present the first global assessment of projected changes in compound river flood‐hot extremes
Future flood‐hot extremes are mainly driven by changes in hot extremes
Substantial increases in compound flood‐hot extremes are projected in tropical regions
MicroRNA‐24‐3p (miR‐24‐3p) has been implicated as a key promoter of chemotherapy resistance in numerous cancers. Meanwhile, cancer‐associated fibroblasts (CAFs) can secret exosomes to transfer ...miRNAs, which mediate tumour development. However, little is known regarding the molecular mechanism of CAF‐derived exosomal miR‐24‐3p in colon cancer (CC). Hence, this study intended to characterize the functional relevance of CAF‐derived exosomal miR‐24‐3p in CC cell resistance to methotrexate (MTX). We identified differentially expressed HEPH, CDX2 and miR‐24‐3p in CC through bioinformatics analyses, and validated their expression in CC tissues and cells. The relationship among HEPH, CDX2 and miR‐24‐3p was verified using ChIP and dual‐luciferase reporter gene assays. Exosomes were isolated from miR‐24‐3p inhibitor–treated CAFs (CAFs‐exo/miR‐24‐3p inhibitor), which were used in combination with gain‐of‐function and loss‐of‐function experiments and MTX treatment. CCK‐8, flow cytometry and colony formation assays were conducted to determine cell viability, apoptosis and colony formation, respectively. Based on the findings, CC tissues and cells presented with high expression of miR‐24‐3p and low expression of HEPH and CDX2. CDX2 was a target gene of miR‐24‐3p and could up‐regulate HEPH. Under MTX treatment, overexpressed CDX2 or HEPH and down‐regulated miR‐24‐3p reduced cell viability and colony formation and elevated cell apoptosis. Furthermore, miR‐24‐3p was transferred into CC cells via CAF‐derived exosomes. CAF‐derived exosomal miR‐24‐3p inhibitor diminished cell viability and colony formation and increased cell apoptosis in vitro and inhibited tumour growth in vivo under MTX treatment. Altogether, CAF‐derived exosomal miR‐24‐3p accelerated resistance of CC cells to MTX by down‐regulating CDX2/HEPH axis.
As atmospheric moisture holding capacity is positively dependent on temperatures, a large intensification of precipitation extremes is projected under foreseeable climate warming. Flooding that is ...mainly attributed to extreme storms usually accounts for an ambitious target in weather‐related hazard mitigation over China. Previous works seldom focused on flooding evolution patterns under climate change at a national scale, and fewer flooding projections considered the estimation uncertainty sourced from limited samples. This study systematically projected changes in flood quantiles based on annual maximum series and seasonality and also evaluated the variations of sampling uncertainty for 151 catchments over mainland China under the emission scenario of representative concentration pathway (RCP) 8.5. In order to project future streamflow series, the bias‐corrected outputs of six global climate models (GCMs) were input into a best‐performing hydrological model, which was selected from four calibrated hydrological models based on the KGE criteria. The Pearson type‐III (P‐III) distribution and L‐moments (L‐M) method were employed to derive the flood quantiles for different return periods during historical (1961–2005) and future (2056–2100) periods, and the bootstrapping method was applied to estimate the sampling uncertainty. A regression trend method was used to track the variations of flood seasonality in the context of climate warming. Our results project earlier flood timing and larger flood quantiles for most catchments in future period than those in the historical period, despite being accompanied by substantial spatial variations. We also project that the sampling uncertainty in estimating flood quantiles is increased in a warming future. Many catchments are exposed to dramatic changes in both flood quantile and estimation uncertainty by over 50%, while only a few catchments are projected to have decreasing flood risks. These results suggest an urgent need to improve the functionality of early warning systems and increase societal resilience to warming climates over China.
Projected changes in flood dynamics and estimation uncertainty are evaluated for 151 catchments over mainland China.
The bias‐corrected multi‐model climate ensemble outputs are combined with four hydrological models to project hydrological scenarios.
The floods will occur earlier under future climate warming in most catchments.
The flood quantiles and sampling uncertainty are both projected to increase by over 50% for most catchments in a warming future.
•Marine macroalgae derived compounds are potential therapeutic agents in dermatology.•Seaweed extracts has been shown to protect skin from photo-damage.•Antibacterial compounds derived from ...macroalgae can fight acne and chronic wounds.•Anti-tumor activity of macroalgae extracts can be exploited to treat melanoma.•Skin whitening and anti-pigmentation properties of seaweed extracts are also discussed.
Functional components extracted from algal biomass are widely used as dietary and health supplements with a variety of applications in food science and technology. In contrast, the applications of algae in dermal-related products have received much less attention, despite that algae also possess high potential for the uses in anti-infection, anti-aging, skin-whitening, and skin tumor treatments. This review, therefore, focuses on integrating studies on algae pertinent to human skin care, health and therapy. The active compounds in algae related to human skin treatments are mentioned and the possible mechanisms involved are described. The main purpose of this review is to identify serviceable algae functions in skin treatments to facilitate practical applications in this high-potential area.
Anthropogenic climate warming is expected to accelerate the hydrological cycle with significant consequences for hydrological droughts. However, a systematic understanding of climate warming impacts ...on the global hydrological droughts and their driving mechanisms is still lacking. Here, we integrate bias‐corrected climate experiments, multiple hydrological models (HYs), and a multivariate analysis of variance (ANOVA) with a machine learning modeling framework, to examine the evolving frequency and multivariate characteristics of hydrological droughts and their mechanisms under climate warming for 6,688 catchments in the five principal Köppen‐Geiger climate zones. Results show that the total frequency of hydrological droughts is likely to stay unchanged while extreme hydrological droughts (e.g., events with a 30 yr joint return period, JRP) are projected to occur more frequently across the 21st century. The historical 30 yr JRP events assessed during the historical baseline period of 1985–2014 could become twice as frequent over ∼60% of global catchments by 2071–2100 under the middle and high emission scenarios (ESs). Climate uncertainty (i.e., from global climate models and ESs) is the major source of uncertainty over temperate and tropical catchments, versus HY uncertainty in arid catchments with locally complex runoff regimes. Our machine learning framework indicates that precipitation stress controls the development of historical droughts over ∼87% of global catchments. However, with climate warming, air temperature variations are expected to become the new primary driver of droughts in high‐latitude cold catchments. This study highlights an increasing risk of global extreme hydrological droughts with warming and suggests that rising temperatures in high latitudes may lead to more extreme hydrological droughts.
Key Points
Impacts of climate change on hydrological droughts are assessed in 6,688 catchments worldwide
Total frequency of droughts is projected to stay unchanged while the frequency of extreme episodes may increase significantly with warming
Air temperature variation, rather than precipitation, is the main factor driving future drought development in high‐latitude catchments
In Einstein-Æther theory, the Lorentz symmetry is locally broken in the high-energy regime due to the presence of the Æther field. This shall leave significant imprint on astronomical observation. In ...this paper, we investigate the optical appearance of two types of the static and spherically symmetric black holes in Einstein-Æther theory. Via Euler-Lagrange equation, we obtain the equations of motion of the photon and calculate the total deflection angle of the photon trajectory around the black hole. By classifying the light rays with the total number of orbits, we study the effects of coupling constants on the direct image, lensing ring, and photon ring. The features of the light trajectories are also investigated by comparing with the Einstein-Æther theory and general relativity. Moreover, we also show the explicit optical appearance of black holes surrounded by thin disk emissions with three characteristic emitted models. The results indicate that the direct image gives the main contribution to the total flux, and the lensing ring just gives a very small contribution, whereas the role of the photon ring is negligible. The optical appearances are also found to significantly rely on these coupling constants.
•Algae extract combats skin aging, de-pigmentation and anti-microorganism.•Algae can be functional antioxidants, alginates, polysaccharides and carotenoids.•Algae extract contributes skin health and ...beauty in practical cosmetic uses.
The applications of microalgae in cosmetic products have recently received more attention in the treatment of skin problems, such as aging, tanning and pigment disorders. There are also potential uses in the areas of anti-aging, skin-whitening, and pigmentation reduction products. While algae species have already been used in some cosmetic formulations, such as moisturizing and thickening agents, algae remain largely untapped as an asset in this industry due to an apparent lack of utility as a primary active ingredient. This review article focuses on integrating studies on algae pertinent to skin health and beauty, with the purpose of identifying serviceable algae functions in practical cosmetic uses.
Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of ...this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.
The pickled radish can be kept at room temperature for years without spoilage. 2,6-dihydroxyacetophenone (DHAP), 4-hydroxybenzaldehyde (HBA), and 4-hydroxyphenethyl alcohol (4-HPEA) were first found ...from the pickled radish. The structures of three phenolic compounds were elucidated by analysis of their nuclear magnetic resonance and high-resolution electro-spray ionization mass spectrometry data. All these phenolic compounds showed good free radical scavenging capacity except HBA. Both DHAP and 4-HPEA also showed high ferric reducing ability. DHAP showed good antimicrobial activity against Escherichia coli, Bacillus subtilis, and Canidia albicans. HBA demonstrated antimicrobial activity against E. coli and C. albicans but not B. subtilis. Based on the results of MTT assay, these compounds did not show cytotoxicity to LO2 cell line. All results indicated the pickled radish had antioxidant and antimicrobial phenolic compounds. To the best of our knowledge, this report is the first to answer partially the question of why pickled foods can be kept at room temperature for years without spoilage based on the evidence of three phenolic compounds.
Display omitted
•3 phenolic compounds are purified from the pickled radish for the first time.•DHAP displays good abilities of free radical scavenging and ferric reducing power.•4-HPEA has good abilities of free radical scavenging and ferric reducing power.•DHAP shows antimicrobial activity against E. coli, B. subtilis and C. albicans.•HBA demonstrates antimicrobial activity against E. coli and C. albicans.
PDF
