Dark Conditions Research Articles

Emergence of metabolic coupling to the heterotroph Alteromonas promotes dark survival in Prochlorococcus

Abstract Prochlorococcus is found throughout the euphotic zone in the oligotrophic open ocean. Deep mixing and sinking while attached to particles can, however, transport Prochlorococcus cells below this sunlit zone, depriving them of light for extended periods of time. Previous work has shown that Prochlorococcus by itself cannot survive extended periods of darkness. However, when co-cultured with a heterotrophic microbe and subjected to repeated periods of extended darkness, Prochlorococcus cells develop an epigenetically inherited dark-tolerant phenotype that can survive longer periods of darkness. Here we examine the metabolic and physiological changes underlying this adaptation using co-cultures of dark-tolerant and parental strains of Prochlorococcus, each grown with the heterotroph Alteromonas under diel light:dark conditions. The relative abundance of Alteromonas was higher in dark-tolerant than parental co-cultures, while dark-tolerant Prochlorococcus cells were larger, contained less chlorophyll, and were less synchronized to the light:dark cycle. Meta-transcriptome analysis revealed that dark-tolerant co-cultures undergo a joint change, in which Prochlorococcus undergoes a relative shift from photosynthesis to respiration, while Alteromonas shifts towards using more organic acids instead of sugars. Furthermore, the transcriptome data suggested enhanced biosynthesis of amino acids and purines in dark-tolerant Prochlorococcus and enhanced degradation of these compounds in Alteromonas. Collectively, our results demonstrate that dark adaptation involves a strengthening of the metabolic coupling between Prochlorococcus and Alteromonas, presumably mediated by an enhanced, and compositionally modified, carbon exchange between the two species.

Production of Microspore-Derived Plants by Anther Culture Oof Cyclamen coum

Cyclamen is one of the most important ornamental crops sold worldwide as a potted flower for winter production. Cyclamen species take up a wide swathe of habitats across Turkey. Ten wild Cyclamen species grow naturally in Turkey, some of them endemic. This study aimed to produce haploid plants of C. coum using anther culture. The microspore developmental stage was evaluated by staining anther with acetocarmine (%2), and then the stage was correlated with bud size. It was determined that the buds between 7.64-8.23 mm had the appropriate bud size for the late uninuclear stage. Anthers were cultured in B5 medium containing different levels of NAA (0.1, 1, 2 mg/L), 2,4-D (0.1, 1, 2 mg/L), and kinetin (0, 1 mg/L), 90 g/L sucrose and 3 g/L gelrite for haploid embryo production. Anthers were kept at 4°C for 4 days after culture. The explants were incubated at 24°C in a completely dark condition until the embryo was formed, then embryos were transferred to hormone-free media in 8:16 hours (light: dark) photoperiod. The experiment was carried out for two years. In the first year, 12 different media were examined in view of regeneration and the experiments were continued with selected 7 media in the second year. The highest callus regeneration rates were %5.71 and 14.5% and the highest embryo induction rates varied between 8.57% and 4.0% in the first and second year respectively. Embryo/callus formation was observed in 7 of a total of 12 different media tested for haploid plant production, and the best media were kinetin (1 mg/L) + NAA (1, 2 mg/L) and kinetin (1 mg/L) +2,4-D (2 mg/L). Our findings indicated that cold pre-treated anther explants collected at appropriate flower bud size resulted in embryo production Additionally, B5 medium supplemented with NAA and kinetin ensured successful embryo regeneration from anther explants in wild C. coum.

Analysis of Stress Response Genes in Microtuberization of Potato Solanum tuberosum L.: Contributions to Osmotic and Combined Abiotic Stress Tolerance

Wild Solanum species have contributed many introgressed genes during domestication into current cultivated potatoes, enhancing their biotic and abiotic stress resistance and facilitating global expansion. Abiotic stress negatively impacts potato physiology and productivity. Understanding the molecular mechanisms regulating tuber development may help solve this global problem. We made a transcriptomic analysis of potato microtuberization under darkness, cytokinins, and osmotic stress conditions. A protein–protein interaction (PPI) network analysis identified 404 genes with high confidence. These genes were involved in important processes like oxidative stress, carbon metabolism, sterol biosynthesis, starch and sucrose metabolism, fatty acid biosynthesis, and nucleosome assembly. From this network, we selected nine ancestral genes along with eight additional stress-related genes. We used qPCR to analyze the expression of the selected genes under osmotic, heat–osmotic, cold–osmotic, salt–osmotic, and combined-stress conditions. The principal component analysis (PCA) revealed that 60.61% of the genes analyzed were associated with osmotic, cold–osmotic, and heat–osmotic stress. Seven out of ten introgression/domestication genes showed the highest variance in the analysis. The genes H3.2 and GAPCP1 were involved in osmotic, cold–osmotic, and heat–osmotic stress. Under combined-all stress, TPI and RPL4 were significant, while in salt–osmotic stress conditions, ENO1, HSP70-8, and PER were significant. This indicates the importance of ancestral genes for potato survival during evolution. The targeted manipulation of these genes could improve combined-stress tolerance in potatoes, providing a genetic basis for enhancing crop resilience.

Bacterial Responses and Material-Cell Interplays With Novel MoAlB@MBene.

Developing efficient antibacterial nanomaterials has potential across diverse fields, but it requires a deeper understanding of material-bacteria interactions. In this study, a novel 2D core-shell MoAlB@MBene structure is synthesized using a mild wet-chemical etching approach. The growth of E. coli, S. aureus, and B. subtilis bacteria in the presence of MoAlB@MBene decreased in a concentration-dependent manner, with a prolonged lag phase in the initial 6h of incubation. Even under dark conditions, MoAlB@MBene triggered the formation of intercellular reactive oxygen species (ROS) and singlet oxygen (1O2) in bacteria, while the bacteria protected themselves by forming biofilm and altering cell morphology. The MoAlB@MBene shows consistent light absorption across the visible range, along with a distinctive UV absorption edge. Two types of band gaps are identified: direct (1.67eV) and indirect (0.74eV), which facilitate complex light interactions with MoAlB@MBene. Exposure to simulated white light led to decreased viability rates of E. coli (20.6%), S. aureus (22.9%), and B. subtilis (21.4%). Altogether, the presented study enhances the understanding of bacteria responses in the presence of light-activated 2D nanomaterials.

Microscopic analysis of low but stable perovskite solar cell device performance using electron spin resonance

Perovskite solar cells have attracted much attention as next-generation solar cells. However, a typical hole-transport material, spiro-OMeTAD, has associated difficulties including tedious synthesis and high cost. To overcome these shortcomings, an easily synthesized and low-cost hole-transport material has been developed: HND-2NOMe. Although HND-2NOMe has high local charge mobility because of the quasi-planar structure, its lower device performance is a weak point, the cause of which has not yet been clarified. Here, we analyse the source of the lower performance by clarifying the internal states from a microscopic viewpoint using electron spin resonance. We observe hole diffusion from perovskite to HND-2NOMe under dark conditions, indicating hole barrier formation at the perovskite/HND-2NOMe interface, leading to lower performance. Although such a barrier is formed, less hole accumulation for the HND-2NOMe-based cells under solar irradiation occurs, which is related to the stable performance. The sources of the lower but stable performance are crucially important for providing guidelines for improving the device performance.

Late-onset caloric restriction improves cognitive performance and restores circadian patterns of neurotrophic, clock and epigenetic factors in the hippocampus of male old rats.

Aging is a complex multifactorial process that results in a general functional decline, including cognitive impairment. Caloric restriction (CR) can positively influence the aging processes and delay cognitive decline. There is a rhythmic variation in memory and learning processes throughout the day, indicating the involvement of the circadian clock in the regulation of these processes. Despite growing evidence on the efficacy of CR, it has not yet been fully determined whether starting this strategy at an advanced age is beneficial for improving quality of life and eventually, for protection against age-related diseases. Here, we investigated the effect of late-onset CR on the temporal organization of the molecular clock machinery, molecules related to cognitive processes and epigenetic regulation, in the hippocampus of male old rats maintained under constant darkness conditions. Our results evidenced the existence of a highly coordinated temporal organization of Bmal1, Clock, Bdnf, Trkb, Dnmts, Sirt1, and Pgc-1α in the hippocampus of young adult rats. We observed that aging led to cognitive deficits and loss of circadian oscillations of all the above variables. Interestingly, CR restored circadian rhythmicity in all cases and, in addition, improved the cognitive performance of the old animals. This work would highlight the importance of the circadian clock and its synchronization with feeding signals, as the basis of the beneficial effects of CR. Thus, lifestyle modifications, such as CR, might be a powerful intervention to preserve hippocampal circadian organization and cognitive health during aging.

Genome-wide identification of CAMTA genes and their expression dependence on light and calcium signaling during seedling growth and development in mung bean

BackgroundCalmodulin-binding transcription activator (CAMTA) is comprised of a group of transcription factors and plays an important role in the Ca2+ signaling pathway, mediating various molecular responses via interactions with other transcription factors and binding to the promoter region of specific genes. Mung beans (Vigna radiata) are one of the most commonly consumed commodities in Asia. To date, CAMTA proteins have not been characterized in this important crop plant.ResultsEight paralogous VrCAMTA genes were identified and found to be distributed on five of the 11 chromosomes. The proteins possessed CG-1 DNA-binding domains with bipartite NLS signals, ankyrin domains, CaM-binding IQ motifs, and CaM-binding domain (CaMBD). The 2 kb upstream regions of VrCAMTA genes contained sequence motifs of abscisic acid-responsive elements (ABRE) and ethylene-responsive elements (ERE), and binding sites for transcription factors of the bZIP and bHLH domains. Analysis of RNA-seq data from a public repository revealed ubiquitous expression of the VrCAMTA genes, as VrCAMTA1 was expressed at the highest level in seedling leaves, whereas VrCAMTA8 was expressed at the lowest level, which agreed with the RT-qPCR analysis performed on the first true leaves. On day four after leaf emergence, all VrCAMTA genes were upregulated, with VrCAMTA1 exhibiting the highest degree of upregulation. In darkness on day 4, upregulation was not observed in most VrCAMTA genes, except VrCAMTA7, for which a low degree of upregulation was found, whereas no difference was found in VrCAMTA8 expression between light and dark conditions. Treatment with calcium ionophores enhanced VrCAMTA expression under light and/or dark conditions at different times after leaf emergence, suggesting that calcium signaling is involved in the light-induced upregulation of VrCAMTA gene expression.ConclusionsThe expression dependence of nearly all VrCAMTA genes on light and calcium signaling suggests their possible differential but likely complementary roles during the early stages of mung bean growth and development.

Porous biochar supported PET plastic waste MOF heterostructure as a novel, efficient and recyclable catalyst for acetaminophen degradation

Herein, the innovative hybrid photocatalyst PET-based Zn-MOF on orange peel biochar (BC)(PZM/BC) was designed and synthesized via the hydrothermal method. Electrochemical methods have been used to demonstrate the action of the PET-MOF in the PZM/BC photocatalyst as a medium for electron transfer. The latter involved the synthesis of a zinc-containing metal–organic framework (MOF) in which the linkers were derived from the depolymerization of polyethylene terephthalate (PET) originating from plastic wastes. According to research, the catalytic reactions are sped up when porous BC and linker PET are assimilated into PZM/BC photocatalyst hetero-junction. Furthermore, BC stored electrons under light and released these electrons under dark conditions. When BC was combined with PET-MOF, the electrons on the biochar activated the catalytic redox activity of acetaminophen. Additionally, it lowers the reassimilation rate due to the combined meshed nanostructures and functionality of PET-MOF and PZM/BC. UV–Vis DRS, Mott-Schottky, Photoluminescence(PL), and Electrochemical Impedance spectra(EIS) results showed that the PZM/BC exhibited efficient spatial separation and transportation of photogenerated charge carriers and exhibited superior photocatalytic ability. Electron spin resonance(ESR) analysis confirmed that ⋅OH and h+ were the predominant radical species responsible for the degradation of acetaminophen(ACT). The optimum conditions for ACT removal were observed at pH 6.07, with a PZM/BC dosage of 0.1 g L−1, and an initial ACT concentration of 50 mg L−1, highlighting the pivotal role of the PZM/BC system in ACT degradation. Furthermore, potential photocatalytic degradation pathways of ACT were inferred renders on the identified intermediates which are responsible for the degradation of refractory intermediates. Regeneration trials were carried out to assess the stability of the photocatalyst. Additionally, the degraded intermediates generated during the degradation processes were examined, providing a comprehensive elucidation of the degradation mechanism.Graphical

Visible-light-activated Fe2O3–TiO2 nanoparticles enhance biofouling resistance of polyethersulfone ultrafiltration membranes against marine algae Chlorella vulgaris

This study investigated the modification of polyethersulfone (PES) ultrafiltration membranes with TiO2 and Fe2O3–TiO2 nanoparticles to enhance their hydrophilicity and biofouling resistance against the marine microalgae Chlorella vulgaris. It is a common freshwater and marine microalga that readily forms biofilms on membrane surfaces, leading to significant flux decline and increased operational costs in ultrafiltration processes. The microalgae cells and their extracellular polymeric substances (EPS) adhere to the membrane surface, creating a dense fouling layer that impedes water permeation. The modified membranes were characterized using contact angle measurements, scanning electron microscopy, and pure water flux/resistance tests. Short-term ultrafiltration experiments evaluated the membranes’ antifouling performance by measuring flux decline, flux recovery ratio, and relative flux reduction during C. vulgaris filtration. The TiO2 membrane showed improved hydrophilicity and antifouling over the pristine PES membrane, while the Fe2O3–TiO2 nanocomposite membrane exhibited the best performance. It reduced the water contact angle and showed only a 5% relative flux reduction compared to 60% for the pristine membrane. SEM images confirmed reduced microalgal deposition on the nanocomposite surface. Long-term tests with microalgal cells under dark and visible light conditions in saline water further assessed the membranes’ biofouling resistance. The Fe2O3–TiO2 membrane maintained 59 L/m2 h water flux under visible light after immersion in the microalgal solution, outperforming the pristine (38 L/m2 h) and TiO2 (52 L/m2 h) membranes. This superior antifouling was attributed to photocatalytic generation of reactive oxygen species inhibiting microalgal adhesion. This study demonstrates a promising strategy for mitigating biofouling in membrane-based water treatment and desalination processes.

Porphyrinoid-Functionalized ZnO Nanoflowers for Visible Light-Enhanced and Selective Benzylamine Detection at Room Temperature.

Functionalization of hybrid organic molecules as layers on ZnO nanoflowers (NFs) gives an excellent combination of sensing toward visible light and vapors of various volatile organic compounds (VOCs). In this work, hybrid organic molecules functionalized ZnO NFs were utilized for the photoinduced detection of benzylamine at room temperature. The ZnO NFs were synthesized via a facile solution route and functionalized with four different porphyrin-conjugated molecules namely (i) pyrene-porphyrin (PP), (ii) pyrene- porphyrinato zinc (ZnPP), (iii) triphenylamine- porphyrin (TP) and (iv) triphenylamine- porphyrinato zinc (ZnTP). The diameter of the flower-like structure was found to be ∼3.2 μm with the thickness of petals being ∼24.1 nm. The gas adsorption performance of the functionalized ZnO NFs on light activation at room temperature was studied by using a scanning Kelvin probe (SKP) system. The improved adsorption properties of the samples can be attributed to the heterojunctions and light activation. In particular, an enhanced response of ZnTP functionalized ZnO (ZnTPZ) toward benzylamine was observed. Further, static gas sensing experiments using ZnTPZ under various concentrations (1, 3, 5, 10, 15, and 25 ppm) of benzylamine vapors both in dark and visible light conditions have exhibited a linear increase in the response. The selectively enhanced response of ZnTPZ compared to that of pristine ZnO was thus confirmed at 1 ppm of benzylamine. The sensitivity and limit of detection of the ZnTPZ sensor were calculated to be 0.0292 ppm-1 and 197 ppb, respectively. The coordination metal (Zn) has helped in effective charge transfer between benzylamine and ZnTPZ by providing additional active sites for interactions. Also, density functional theory calculations demonstrated the role of the hybrid organic molecules on the sensor surface in improving gas adsorption. Further, fresh cabbage was utilized for real sample analysis with the proposed sensor under visible light illumination conditions, and a linear response was obtained for low ppm evaluation at room temperature. Overall, the obtained results suggest the development of novel ZnTPZ-based light-activated gas sensors for low ppm benzylamine detection at room temperature. These kinds of sensors can be used to track the freshness of vegetables as they are transported from farms to commercial outlets.

I-V Characteristics of Polycrystalline CAZTSe Heterojunction Solar Cells at Different Ag Content and Annealing Temperatures

Since the polycrystalline (Cu1-xAgx)2ZnSnSe4 (CAZTSe) demonstrated good optical absorption performance in the visible region, the focus of the present study is to grow the polycrystalline (Cu1-xAgx)2ZnSnSe4 thin films deposited by thermal evaporation method on silicon substrates with 800 nm thickness and 0.53 nm/sec deposition rate as a function of Ag content (0.0,0.1,0.2) and annealing temperature at 373 K, 473 K. From I-V measurements of Al/n-CdS/p-CAZTSe/n-Si(111)/Al heterojunction solar cells under dark and illumination conditions, we observed that the forward bias current changes roughly exponentially with bias voltage and the ideality factor and saturation current dependence on both x content and different temperatures (Ta).

Research on Target Image Classification in Low-Light Night Vision.

In extremely dark conditions, low-light imaging may offer spectators a rich visual experience, which is important for both military and civic applications. However, the images taken in ultra-micro light environments usually have inherent defects such as extremely low brightness and contrast, a high noise level, and serious loss of scene details and colors, which leads to great challenges in the research of low-light image and object detection and classification. The low-light night vision image used as the study object in this work has an excessively dim overall picture and very little information about the screen's features. Three algorithms, HE, AHE, and CLAHE, were used to enhance and highlight the image. The effectiveness of these image enhancement methods is evaluated using metrics such as the peak signal-to-noise ratio and mean square error, and CLAHE was selected after comparison. The target image includes vehicles, people, license plates, and objects. The gray-level co-occurrence matrix (GLCM) was used to extract the texture features of the enhanced images, and the extracted image texture features were used as input to construct a backpropagation (BP) neural network classification model. Then, low-light image classification models were developed based on VGG16 and ResNet50 convolutional neural networks combined with low-light image enhancement algorithms. The experimental results show that the overall classification accuracy of the VGG16 convolutional neural network model is 92.1%. Compared with the BP and ResNet50 neural network models, the classification accuracy was increased by 4.5% and 2.3%, respectively, demonstrating its effectiveness in classifying low-light night vision targets.

Modeling impacts of indoor environmental variables on secondary organic aerosol formation

There are numerous air pollutants indoors including chemicals emitted from building environments as well as outdoor-origin species due to human activities. Despite the significance of indoor air quality, the atmospheric process indoors is not well studied. In this study, the secondary organic aerosol (SOA) formation from the oxidation of α-pinene blended with toluene was simulated under varying indoor environments (lamps, NO2, ozone, and inorganic seed) using the UNIfied Partitioning Aerosol Reaction (UNIPAR) model. Explicitly predicted lumping species produced during the atmospheric oxidation of precursors are used in the model and they process multiphase partitioning and aerosol phase reactions. The performance of the model was demonstrated using indoor chamber experiments in both dark conditions (ozonolysis) and light conditions with commercialized fluorescent or LED lamps. α-Pinene SOA was dominated by ozonolysis even in the presence of indoor light. Toluene, which is known to be photochemically processed, was oxidized in the dark condition with OH radicals that were derived from ozonolysis products of α-pinene. At given dark simulation conditions (10 ppb α-pinene, 30 ppb ozone, and 50 ppb of toluene), toluene contributed 15 % of SOA mass. α-Pinene SOA was insensitive to hygroscopicity of inorganic seed, but toluene blended with α-pinene increased the sensitivity to seed conditions due to the formation of oligomeric matter via aqueous reactions of reactive toluene products. In the presence of NO2. α-pinene SOA formation significantly increased with increasing NO2 owing to the reaction of α-pinene with nitrate radicals to form low volatile products. This study concludes that ozone and NO2, intruded from outdoors to indoors, effectively oxidize terpenes and furthermore aromatic hydrocarbons with OH radicals originating from ozonolysis of terpenes. The reaction paths with ozone and nitrate radicals are more effective at forming SOA than that with OH radical under the indoor light condition with commercialized lamps.

Reactivity of Atomic Oxygen Radical Anions in Metal Oxide Clusters.

Atomic oxygen radical anion (O⋅-) represents an important type of reactive centre that exists in both chemical and biological systems. Gas-phase atomic clusters can be studied under isolated and well controlled conditions. Studies of O⋅--containing clusters in the gas-phase provide a unique strategy to interpret the chemistry of O⋅- radicals at a strictly molecular level. This review summarizes the research progresses made since 2013 for the reactivity of O⋅- radicals in the atomically precise metal oxide clusters including negatively charged, nanosized, and neutral heteronuclear metal clusters benefitting from the development of advanced experimental techniques. New electronic and geometric factors to control the reactivity and product selectivity of O⋅- radicals under dark and photo-irradiation conditions have been revealed. The detailed mechanisms of O⋅- generation have been discussed for the reaction systems of nanosized and heteroatom-doped metal oxide clusters. The catalytic reactions mediated by the O⋅- radicals in metal clusters have also been successfully established and the microscopic mechanisms about the dynamic generation and depletion of O⋅- radicals have been clearly understood. The studies of O⋅- containing metal oxide clusters in the gas-phase provided new insights into the chemistry of reactive oxygen species in related condensed-phase systems.

Ionized Phenanthroline Derivatives Suppressing Interface Chemical Interactions with Active Layer for High-efficiency Organic Solar Cells with Exceptional Device Stability.

The contact interface between the charge transport interlayer and the active layer is crucial for the non-fullerene organic solar cells (NF OSCs) to achieve high efficiency and long-term stability. In this study, two novel phenanthroline (Phen) derivatives, tbp-Phen and tbp-PhenBr, are developed as efficient cathode interfacial materials (CIMs). The larger steric hindrance substituents and the ionization of nitrogen atoms on the Phen framework jointly enable the tbp-PhenBr CIM with a stable film morphology and immensely suppress the detrimental interface chemical interactions with the NF active layer. Consequently, tbp-PhenBr-based OSC achieves a higher efficiency (PCE=16.34%) than bathocuproine (BCP)-based control device (PCE=13.70%) using PM6:Y6 as the active layer. More importantly, the tbp-PhenBr-based device maintains 80% of its initial efficiency (T80) for 3264 h in dark conditions and 220 h after being heated at 85°C, significantly outperforming the BCP-based device. The tbp-PhenBr CIM also shows broad applicability across various binary and ternary active layer systems, affording a notable PCE of 19.49%. Additionally, the tbp-PhenBr CIM can be processed via a thermal evaporation technique and the prepared devices exhibit high reproducibility. This work provides innovative insights into the molecular design of the CIMs for stable and efficient NF OSCs.

Fabrication of double S-scheme Sr2MgSi2O7:Eu2+,Dy3+/ZnIn2S4/UiO-66-NH2 heterojunctions with photon storage effect for enhanced round-the-clock photocatalysis

Persistent light-emitting materials (PLMs), which have the potential to store and release light energy after light irradiation, are receiving increasing attention for their role in prolonging the lifetime of photogenerated electrons for the development of photocatalysts with round-the-clock applications. In this paper, a double S-scheme Sr2MgSi2O7:Eu2+,Dy3+/ZnIn2S4/UiO-66-NH2 (SZU) heterojunction with round-the-clock catalytic activity was prepared by hydrothermal self-assembly method. The photocatalytic performance of the SZU heterojunction for RhB(MB) degradation was significantly improved compared with the pristine ZnIn2S4 and UiO-66-NH2. The SZU heterojunction has excellent catalytic degradation performance for RhB (MB), and the removal rate of RhB (MB) reaches 72.2 % (81.7 %) after visible light irradiation for 40 (60) minutes. After the end of light, the total removal rate of RhB (MB) reached 86.7 % (96.8 %) when the catalysis continued for several hours under dark conditions, which was 14 % and 15 % higher than that under visible light irradiation, respectively. Based on the characteristics of SMS photoluminescence, combined with a large number of photocatalytic experiments, The sustained photocatalytic activity was enhanced under both daytime and darkness conditions, not only because of the production of SZU complexes, which prolonged the visible light response of ZnIn2S4, but also because of the construction of double S-scheme heterojunctions, which facilitates the light storage capacity, charge transfer, and the separation of photo-induced charge carriers and effectively promoted the photocatalytic activity of the photocatalysts. This work contributes to a deeper understanding of the design of round-the-clock photocatalysts, and provides a useful exploration for the practical application of photocatalytic technology.

Usability and feasibility of an online intervention for older adults to support changes to routines and the home ('Light, activity and sleep in my daily life')

BackgroundIndoor lighting, exposure to outdoor daylight, physical activity and sleep interact to influence functioning, mood and cicadian rhythm. Older adults (≥ 65 years), who often spend more time at home, are less physically active and experience more sleep problems, could benefit from strategies to support behavioural change and self-managed modifications in the home. The study’s primary objective was to assess the usability and feasibility of the ‘Light, activity and sleep in my daily life’ intervention, delivered as a web-based course.MethodsThis 9-week intervention was delivered in a municipality in Sweden (55.70° N). Participants were eight healthy women (age 71–84), community-living in one-person households. We recruited through municipal staff and posters at senior citizen meeting points. Both qualitative and quantitative data were collected before and after the intervention. The outcome measures were intervention usability (ease of use, usefulness) and study feasibility (e.g., recruitment procedure, online engagement). Measures also included changes to routines and self-managed home adjustments to determine whether the participants applied what they had learnt.ResultsAll participants completed the intervention. Time logged in varied between 25 min and 3 h (M = 1 h 50 min) per week. Seven participants’ system usability scores were between 90 and 100 (‘Excellent’) out of 100. When interviewed, participants reported overall high satisfaction with what they had learnt. Six participants were particularly satisfied with the modules targeting light. Seven participants made changes to their lighting or darkness conditions, such as replaced bulbs with either 3-step dimming or higher colour temperature LEDs (samples were included in the intervention test kit). One suggestion to improve the online delivery was to enable participants to add text comments to the weekly evaluation form.ConclusionsThe web-based intervention was feasible to deliver but time for recruitment should be extended and advertisement in the local newspaper should be considered. Participants’ computer proficiency and access to the internet at home will be critical in a future study with a larger sample. Only minor changes to the online content of the intervention are needed based on participants’ feedback. The intervention will be possible to evaluate in a future pilot study.

A Formation of Atmospheric Aerosol Particles Due to Gas-to-Particle Conversion in Dark Conditions and the Particles’ Evolution in Large (3200 m3) Isolated Volume

A Formation of Atmospheric Aerosol Particles Due to Gas-to-Particle Conversion in Dark Conditions and the Particles’ Evolution in Large (3200 m3) Isolated Volume

Combined transcriptome and physiological analysis reveals exogenous sucrose enhances photosynthesis and source capacity in foxtail millet

Foxtail millet (Setaria italica (L.) P. Beauv.) is an environmentally friendly crop that meets the current requirements of international food security and is widely accepted as a photosynthesis research model. However, whether exogenous sucrose treatment has a positive effect on foxtail millet growth remains unknown. Here, we employed physiological and molecular approaches to identify photosynthesis and source capacity associated with exogenous sucrose during the growth of Jingu 21 seedlings. RNA-seq analysis showed that some differentially expressed genes (DEGs) related to photosynthesis and carotenoid biosynthesis were induced by exogenous sucrose and that most of these genes were up-regulated. An increase in gas exchange parameters, chlorophyll content, and chlorophyll fluorescence of Jingu 21 was noted after exogenous sucrose addition. Furthermore, exogenous sucrose up-regulated genes encoding sucrose and hexose transporters and enhanced starch and sucrose metabolism. More DEGs were up-regulated by sucrose, the nonstructural carbohydrate (NSC) content in the leaves increased and energy metabolism and sucrose loading subsequently improved, ultimately enhancing photosynthesis under normal and dark conditions. Further analysis revealed that WRKYs, ERFs, HY5, RAP2, and ABI5 could be key transcription factors involved in growth regulation. These results indicate that exogenous sucrose affects the normal photosynthetic performance of foxtail millet by increasing NSC transport and loading. They improve our understanding of the molecular mechanisms of the effects of exogenous sucrose on photosynthesis in foxtail millet, providing an effective measure to enhance source–sink relationships and improve yield.

Bacterial cellulose-based Janus energy storage phase change composite aerogel for efficient interfacial solar vapor generation

Interfacial solar evaporation systems based on Janus structures exhibit potential application prospects in terms of salt tolerance. However, intermittent and unstable light conditions limited the evaporation rate and water production performance of the evaporators. The introduction of energy storage phase change (ESPC) composite materials into the interface solar evaporators can effectively solve this problem. In this work, bacterial cellulose (BC) is selected as the matrix material, sodium alginate (SA) and multi-walled carbon nanotubes (MWCNTs) are added as functional fillers, and porous composite aerogels are prepared using direct freeze-drying. On this basis, Janus porous composite aerogel (J-BCS/CNT) with ESPC function is further constructed by depositing paraffin onto the upper layer of the aerogel through a unilateral vacuum impregnation method. The aerogel exhibits strong photothermal conversion capabilities and excellent thermal management properties. The addition of appropriate amount of MWCNTs enables it to obtain high latent heat storage and release functions, providing energy for operation in dark conditions. Under the solar irradiation of 1.5 kW m−2, J-BCS/CNT40% aerogel exhibits a high evaporation rate of 1.95 kg m−2h−1 in pure water and 0.67 kg m−2h−1 under dark conditions. The salt evaporation resistance test shows that the aerogel has excellent purification capabilities in high-concentration salt water (20 wt%) solutions. More importantly, the long-term energy storage-release tests of J-BCS/CNT in 3.5 wt% saline water indicate that the aerogel reveals excellent sustainability and latent heat release functions.