Optical wireless communication using a flexible and waterproof perovskite color converter.

In this Letter, the CH3NH3PbBr3 nanocrystals (NCs) are embedded into the interstices of the fluorine (polyvinyl fluoride/polyvinylidene fluoride, PVF/PVDF) matrix on polyethylene terephthalate (PET) substrate to introduce new advantages, such as being flexible and waterproof, while maintaining the high optical performance of perovskites. The sample's photoluminescence (PL) spectra under 325 nm laser is a green emission peaked at 537 nm with full width at half maximum (FWHM) of about 21.2 nm and a fast PL decay time. As a color converter, it shows high optical absorption and can transform light from solar-blind ultraviolet to a blue region into a green region in air, water, and bending conditions. While excited by a 270 nm ultraviolet light-emitting diode (LED), the system's observed -3 dB bandwidth with the color converter is near 4.4 MHz in air and water conditions with well-eye diagrams at a data rate of 30 Mbps. Finally, we demonstrate an audio transmission application with an ultraviolet light source, a color conversion layer, and a low-cost silicon-based photodetector.

Dynamic Pore Network Modeling of Imbibition in Real Porous Media with Corner Film Flow.

Wetting films can develop in the corners of pore structures during imbibition in a strongly wetting porous medium, which may significantly influence the two-phase flow dynamics. Due to the large difference in scales between main meniscus and corner film, accurate and efficient modeling of the dynamics of corner film remains elusive. In this work, we develop a novel two-pressure dynamic pore network model incorporating the interacting capillary bundle model to analyze the competition between the main meniscus and corner film flow in real porous media. A pore network with four-point star-shaped pore bodies and throat bonds is extracted from the real porous medium based on the pore shape factor and pore cross-sectional area, which is then decomposed into several layers of sub-pore networks, where the first layer of sub-pore network simulates the main meniscus flow while the upper layers characterize the corner film flow. The two-phase flow conductance of throat bonds for different layers of sub-pore networks are determined by high-resolution two-phase lattice Boltzmann modeling, thus inherently considering the viscous coupling effect. In addition, two artificial neural network models are developed to predict the two phases' flow conductance based on the shape of the throat cross section and the fluid properties. The accuracy of the developed model is validated with a lattice Boltzmann simulation of imbibition in a strongly wetting square tube. Then the model is used to simulate imbibition in a strongly wetting sandstone porous medium, and the competition between the main meniscus and the corner film flow is analyzed. The results show that with decreasing capillary number and viscosity ratio between wetting and nonwetting fluids, the development of the wetting corner film becomes more significant.

Linear hair growth rates in preschool children.

BACKGROUND: Human scalp hair is a validated bio-substrate for monitoring various exposures in childhood including contextual stressors, environmental toxins, prescription or non-prescription drugs. Linear hair growth rates (HGR) are required to accurately interpret hair biomarker concentrations. METHODS: We measured HGR in a prospective cohort of preschool children (N = 266) aged 9-72 months and assessed demographic factors, anthropometrics, and hair protein content (HPC). We examined HGR differences by age, sex, race, height, hair pigment, and season, and used univariable and multivariable linear regression models to identify HGR-related factors. RESULTS: Infants below 1 year (288 ± 61 µm/day) had slower HGR than children aged 2-5 years (p = 0.0073). Dark-haired children (352 ± 52 µm/day) had higher HGR than light-haired children (325 ± 50 µm/day; p = 0.0019). Asian subjects had the highest HGR overall (p = 0.016). Younger children had higher HPC (p = 0.0014) and their HPC-adjusted HGRs were slower than older children (p = 0.0073). Age, height, hair pigmentation, and HPC were related to HGR in multivariable regression models. CONCLUSIONS: We identified age, height, hair pigment, and hair protein concentration as significant determinants of linear HGRs. These findings help explain the known hair biomarker differences between children and adults and aid accurate interpretation of hair biomarker results in preschool children. IMPACT: Discovery of hair biomarkers in the past few decades has transformed scientific disciplines like toxicology, pharmacology, epidemiology, forensics, healthcare, and developmental psychology. Identifying determinants of hair growth in children is essential for accurate interpretation of hair biomarker results in pediatric clinical studies. Childhood hair growth rates define the time-periods of biomarker incorporation into growing hair, essential for interpreting the biomarkers associated with environmental exposures and the mind-brain-body connectome. Our study describes age-, sex-, and height-based distributions of linear hair growth rates and provides determinants of linear hair growth rates in a large population of children. Age, height, hair pigmentation, and hair protein content are determinants of hair growth rates and should be accounted for in child hair biomarkers studies. Our findings on hair protein content and linear hair growth rates may provide physiological explanations for differences in hair growth rates and biomarkers in preschool children as compared to adults.

Green manure increases peanut production by shaping the rhizosphere bacterial community and regulating soil metabolites under continuous peanut production systems.

BACKGROUND: Green manure (GM) is a crop commonly grown during fallow periods, which has been applied in agriculture as a strategy to regulate nutrient cycling, improve organic matter, and enhance soil microbial biodiversity, but to date, few studies have examined the effects of GM treatments on rhizosphere soil bacterial community and soil metabolites from continuous cropping peanut field. RESULTS: In this study, we found that the abundances of several functionally significant bacterial groups containing Actinobacteria, Acidobacteria, and genus Sphingomonas, which are associated with nitrogen cycling, were dramatically increased in GM-applied soils. Consistent with the bacterial community results, metabolomics analysis revealed a strong perturbation of nitrogen- or carbon-related metabolisms in GM-applied soils. The substantially up-regulated beneficial metabolites including sucrose, adenine, lysophosphatidylcholine (LPC), malic acid, and betaines in GM-applied soils may contribute to overcome continuous cropping obstacle. In contrast to peanut continuous cropping, planting winter wheat and oilseed rape in winter fallow period under continuous spring peanut production systems evidently improved the soil quality, concomitantly with raised peanut pod yield by 32.93% and 25.20%, in the 2020 season, respectively. CONCLUSIONS: GMs application is an effective strategy to overcome continuous cropping obstacle under continuous peanut production systems by improving nutrient cycling, soil metabolites, and rhizobacterial properties.

Lasing mode manipulation in a Benz-shaped GaN cavity via the Joule effect of individual Ni wires.

Silicon-based gallium nitride lasers are considered potential laser sources for on-chip integration. However, the capability of on-demand lasing output with its reversible and wavelength tunability remains important. Herein, a Benz-shaped GaN cavity is designed and fabricated on a Si substrate and coupled to a Ni metal wire. Under optical pumping, excitation position-related lasing and exciton combination properties of pure GaN cavity are studied systematically. Under electrically driven, joule thermal of Ni metal wire makes it easy to change the temperature of the cavity. And then, we demonstrate a joule heat-induced contactless lasing mode manipulation in the coupled GaN cavity. The driven current, coupling distance, and excitation position influence the wavelength tunable effect. Compared with other positions, the outer ring position has the highest lasing properties and lasing mode tuning abilities. The optimized structures demonstrate clear wavelength tuning and an even mode switch. The thermal reduction of the band gap is identified to account for the modification of the lasing profile, but the thermo-optic effect is non-negligible under a high-driven current.

Spiritual Care in PICUs: A U.S. Survey of 245 Training Fellows 2020-2021.

OBJECTIVES: To understand the perspectives of pediatric fellows training in critical care subspecialties about providing spiritual care. DESIGN: Cross-sectional survey of United States National Residency Matching Program pediatric fellows training in critical care specialties. SETTING: Online survey open from April to May 2021. SUBJECTS: A total of 720 fellows (165 cardiology, 259 critical care, and 296 neonatology) were contacted, with a response rate of 245 of 720 (34%). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We assessed fellows' survey responses about spiritual care in neonatal and pediatric critical care units. Categorical data were compared using chi-square test or Fisher exact tests. The Wilcoxon rank-sum test was used to compare the percentage correct on ten multiple-choice questions about world religions. Free-text responses were independently coded by two research investigators. A total of 203 of 245 (83%) responding fellows had never received training about spiritual care and 176 of 245 (72%) indicated that they would be likely to incorporate spiritual care into their practice if they received training. Prior training was associated with increased familiarity with a framework for taking a spiritual history (p < 0.001) and increased knowledge of spiritual practices that could influence medical care (p = 0.03). Prior training was also associated with increased self-reported frequency of taking a spiritual history (p < 0.001) and comfort in referring families to spiritual care resources (p = 0.02). Lack of time and training were the most reported barriers to providing spiritual care. CONCLUSIONS: Providing spiritual care for families is important in critical care settings. In 2020-2021, in the United States, 245 pediatric critical care fellows responded to a survey about spiritual care in their practice and reported that they lacked training in this subject. An opportunity exists to implement spiritual care curricula into pediatric fellowship training.

Coupling biostimulation and phytoremediation for the restoration of petroleum hydrocarbon-contaminated soil.

Total petroleum hydrocarbons (TPH) continue to be among the most common pollutants in soil worldwide. Bioremediation and phytoremediation have become sustainable ways of dealing with TPH contamination and biostimulation-assisted phytoremediation is considered as a potential approach for the treatment of pollutants. In this study, the response surface was used to optimize the single-factor biological stimulation experiment of moisture content, leavening agent content and compound fertilizer content and got the best experimental plan of biological stimulation. It was found that TPH degradation rate was 28.6% by biostimulation after 70 days. Further, from 20 kinds of plant seeds, 5 kinds of suitable or growth and high germination rate were selected for petroleum hydrocarbon degradation experiment. In the phytoremediation, peanut was selected as the best plant species by measuring the TPH degradation rate, bacteria count, growth of test plants, germination rate and amount of catalase in the soil and it could achieved 31.1% degradation rate of petroleum hydrocarbons after 70 days. Finally, the artificial biostimulation and phytoremediation combined degradation experiment of petroleum hydrocarbons-contaminated soil was designed and it achieved 38.9% TPH degradation rate after 70 days.

In petroleum hydrocarbon-contaminated soils, single remediation methods are often limited and may be disturbed by environmental conditions. In the actual research process of coupling biostimulation and phytoremediation, it is necessary to play the role of microorganisms on the premise of ensuring plant growth. This may further present challenges for combined bioremediation attempts. In this work, the response surface methodology was used to optimize the single-factor biological stimulation experiment of moisture content, leavening agent content and compound fertilizer content. As a result, the best biological stimulation experimental scheme can be obtained to repair oil contaminated soil. Then, biostimulation-assisted phytoremediation degradation experiment of petroleum hydrocarbons-contaminated soil was designed and an effective degradation rate of petroleum hydrocarbons in the soil was obtained. HIGHLIGHTSBiostimulation combined with phytoremediation improved the degradation rate of soil petroleum hydrocarbons in 70 days.After 70 days of combine remediation, the microorganisms biomass almost recovered before being contaminated.

Comprehensive Transcriptome and Metabolome Analyses Reveal Primary Molecular Regulation Pathways Involved in Peanut under Water and Nitrogen Co-Limitation.

The yield and quality of peanut (Arachis hypogaea L.), an oil crop planted worldwide, are often limited by drought stress (DS) and nitrogen (N) deficiency. To investigate the molecular mechanism by which peanut counteracts DS and N deficiency, we conducted comprehensive transcriptomic and metabolomic analyses of peanut leaves. Herein, 829 known differentially accumulated metabolites, 324 differentially expressed transcription factors, and 5294 differentially expressed genes (DEGs) were identified under different water and N conditions. The transcriptome analysis demonstrated that drought-related DEGs were predominantly expressed in "glycolysis/gluconeogenesis" and "glycerolipid metabolism", while N-deficiency-related DEGs were mainly expressed in starch and sucrose metabolism, as well as in the biosynthesis of amino acid pathways. The biosynthesis, transport, and catabolism of secondary metabolites accounted for a large proportion of the 1317 DEGs present in water and N co-limitation. Metabolomic analysis showed that the metabolic accumulation of these pathways was significantly dependent on the stress conditions. Additionally, the roles of metabolites and genes in these pathways, such as the biosynthesis of amino acids and phenylpropanoid biosynthesis under different stress conditions, were discussed. The results demonstrated that different genes, metabolic pathways, and metabolites were related to DS and N deficiency. Thus, this study elucidates the metabolic pathways and functional genes that can be used for the improvement of peanut resistance to abiotic stress.

Bound valley edge states in the continuum.

Topological valley photonics provides a unique way to manipulate the flow of light. In general, valley edge states that exhibit unidirectional propagation and are immune to defects and disorders could be realized at the interface between two valley photonic crystals with opposite valley Chern numbers. Herein, by merging the physics of valley edge states and bound states in the continuum, we propose and numerically demonstrate a novel, to the best of our knowledge, concept of edge states termed bound valley edge states in the continuum, which enjoys the topological features of valley edge states, such as, unidirectional propagation and immunity to disorders, but are formed at the interface between air and a single valley photonic crystal. Our results not only provide an effective way to reduce the size of valley photonic structures but also facilitate new applications where the proposed concept of bound valley edge states in the continuum could be exploited for optical sensing and unidirectional waveguiding.

Transverse Kerker Effect for Dipole Sources.

Transverse Kerker effect is known by the directional scattering of an electromagnetic plane wave perpendicular to the propagation direction with nearly suppression of both forward and backward scattering. Compared with plane waves, localized electromagnetic emitters are more general sources in modern nanophotonics. As a typical example, manipulating the emission direction of a quantum dot is of vital importance for the investigation of on-chip quantum optics and quantum information processing. Herein, we introduce the concept of transverse Kerker effect for dipole sources utilizing a subwavelength dielectric antenna, where the radiative power of magnetic, electric, and more general chiral dipole emitters can be dominantly redirected along their dipole moments with nearly suppression of radiation perpendicular to the dipole moments. This type of transverse Kerker effect is also associated with Purcell enhancement mediated by electromagnetic multipolar resonances induced in the dielectric antenna. Analytical conditions of transverse Kerker effect are derived for the magnetic, electric, and chiral dipole emitters. We further provide microwave experiment validation for the magnetic dipole emitter. Our results provide new physical mechanisms to manipulate the emission properties of localized electromagnetic source which might facilitate the on-chip quantum optics and beyond.

Pore-Scale Study on Convective Drying of Porous Media.

In this work, a numerical model for isothermal liquid-vapor phase change (evaporation) of the two-component air-water system is proposed based on the pseudopotential lattice Boltzmann method. Through the Chapman-Enskog multiscale analysis, we show that the model can correctly recover the macroscopic governing equations of the multicomponent multiphase system with a built-in binary diffusion mechanism. The model is verified based on the two-component Stefan problem where the measured binary diffusivity is consistent with theoretical analysis. The model is then applied to convective drying of a dual-porosity porous medium at the pore scale. The simulation captures a classical transition in the drying process of porous media, from the constant rate period (CRP, first phase) showing significant capillary pumping from large to small pores, to the falling rate period (FRP, second phase) with the liquid front receding in small pores. It is found that, in the CRP, the evaporation rate increases with the inflow Reynolds number (Re), while in the FRP, the evaporation curves almost collapse at different Res. The underlying mechanism is elucidated by introducing an effective Péclet number (Pe). It is shown that convection is dominant in the CRP and diffusion in the FRP, as evidenced by Pe > 1 and Pe < 1, respectively. We also find a log-law dependence of the average evaporation rate on the inflow Re in the CRP regime. The present work provides new insights into the drying physics of porous media and its direct modeling at the pore scale.

Diffuse Axonal Injury Grade on Early MRI is Associated with Worse Outcome in Children with Moderate-Severe Traumatic Brain Injury.

BACKGROUND: Traumatic brain injury (TBI) is the leading cause of death and disability in children, but effective tools for predicting outcome remain elusive. Although many pediatric patients receive early magnetic resonance imaging (MRI), data on its utility in prognostication are lacking. Diffuse axonal injury (DAI) is a hallmark of TBI detected on early MRI and was shown previously to improve prognostication in adult patients with TBI. In this exploratory study, we investigated whether DAI grade correlates with functional outcome and improves prognostic accuracy when combined with core clinical variables and computed tomography (CT) biomarkers in pediatric patients with moderate-severe TBI (msTBI). METHODS: Pediatric patients (≤ 19 years) who were admitted to two regional level one trauma centers with a diagnosis of msTBI (Glasgow Coma Scale [GCS] score < 13) between 2011 and 2019 were identified through retrospective chart review. Patients who underwent brain MRI within 30 days of injury and had documented clinical follow-up after discharge were included. Age, pupil reactivity, and initial motor GCS score were collected as part of the International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) model. Imaging was reviewed to calculate the Rotterdam score (CT) and DAI grade (MRI) and to evaluate for presence of hypoxic-ischemic injury (MRI). The primary outcome measure was the Pediatric Cerebral Performance Category Scale (PCPCS) score at 6 months after TBI, with favorable outcome defined as PCPCS scores 1-3 and unfavorable outcome defined as PCPCS scores 4-6. The secondary outcome measure was discharge disposition to home versus to an inpatient rehabilitation facility. RESULT: Of 55 patients included in the study, 45 (82%) had severe TBI. The most common mechanism of injury was motor vehicle collision (71%). Initial head CT scans showed acute hemorrhage in 84% of patients. MRI was acquired a median of 5 days after injury, and hemorrhagic DAI lesions were detected in 87% of patients. Each 1-point increase in DAI grade increased the odds of unfavorable functional outcome by 2.4-fold. When controlling for core IMPACT clinical variables, neither the DAI grade nor the Rotterdam score was independently correlated with outcome and neither significantly improved outcome prediction over the IMPACT model alone. CONCLUSIONS: A higher DAI grade on early MRI is associated with worse 6-month functional outcome and with discharge to inpatient rehabilitation in children with acute msTBI in a univariate analysis but does not independently correlate with outcome when controlling for the GCS score. Addition of the DAI grade to the core IMPACT model does not significantly improve prediction of poor neurological outcome. Further study is needed to elucidate the utility of early MRI in children with msTBI.

Roles of Species-Specific Legumains in Pathogenicity of the Pinewood Nematode Bursaphelenchus xylophilus.

Peptidases are very important to parasites, which have central roles in parasite biology and pathogenesis. In this study, by comparative genome analysis, genome-wide peptidase diversities among plant-parasitic nematodes are estimated. We find that genes encoding cysteine peptidases in family C13 (legumain) are significantly abundant in pine wood nematodes Bursaphelenchus genomes, compared to those in other plant-parasitic nematodes. By phylogenetic analysis, a clade of B. xylophilus-specific legumain is identified. RT-qPCR detection shows that these genes are highly expressed at early stage during the nematode infection process. Utilizing transgene technology, cDNAs of three species-specific legumain were introduced into the Arabidopsis γvpe mutant. Functional complementation assay shows that these B. xylophilus legumains can fully complement the activity of Arabidopsis γVPE to mediate plant cell death triggered by the fungal toxin FB1. Secretory activities of these legumains are experimentally validated. By comparative transcriptome analysis, genes involved in plant cell death mediated by legumains are identified, which enrich in GO terms related to ubiquitin protein transferase activity in category molecular function, and response to stimuli in category biological process. Our results suggest that B. xylophilu-specific legumains have potential as effectors to be involved in nematode-plant interaction and can be related to host cell death.

Randomized Controlled Trial of Personalized Colorectal Cancer Risk Assessment vs Education to Promote Screening Uptake.

INTRODUCTION: Risk stratification has been proposed as a strategy to improve participation in colorectal cancer (CRC) screening, but evidence is lacking. We performed a randomized controlled trial of risk stratification using the National Cancer Institute's Colorectal Cancer Risk Assessment Tool (CCRAT) on screening intent and completion. METHODS: A total of 230 primary care patients eligible for first-time CRC screening were randomized to risk assessment via CCRAT or education control. Follow-up of screening intent and completion was performed by record review and phone at 6 and 12 months. We analyzed change in intent after intervention, time to screening, overall screening completion rates, and screening completion by CCRAT risk score tertile. RESULTS: Of the patients, 61.7% of patients were aged <60 years, 58.7% female, and 94.3% with college or higher education. Time to screening did not differ between arms (hazard ratio 0.78 [95% confidence interval (CI) 0.52-1.18], P = 0.24). At 12 months, screening completion was 38.6% with CCRAT vs 44.0% with education (odds ratio [OR] 0.80 [95% CI 0.47-1.37], P = 0.41). Changes in screening intent did not differ between the risk assessment and education arms (precontemplation to contemplation: OR 1.52 [95% CI 0.81-2.86], P = 0.19; contemplation to precontemplation: OR 1.93 [95% CI 0.45-8.34], P = 0.38). There were higher screening completion rates at 12 months in the top CCRAT risk tertile (52.6%) vs the bottom (32.4%) and middle (31.6%) tertiles (P = 0.10). DISCUSSION: CCRAT risk assessment did not increase screening participation or intent. Risk stratification might motivate persons classified as higher CRC risk to complete screening, but unintentionally discourage screening among persons not identified as higher risk.

Invisible Mie scatterer.

Dielectric Mie scatterers possessing simultaneously magnetic and electric resonances can be used to tailor scattering utilizing the interference among electromagnetic multipole moments. Cloaking for this type of Mie scatterer is important for various applications. However, the existing cloaking mechanisms mainly focus on the elimination of net electric dipole moments, which have not been generalized to a Mie scatterer with both magnetic and electric responses yet. Herein, we propose and experimentally demonstrate an invisible Mie scatterer utilizing a hybrid skin cloak. The hybrid mechanism relies on the realization of a magnetic analog of a plasmonic cloak and the electric anapole condition to eliminate the net magnetic and electric dipole moments simultaneously. Microwave experiments are provided to validate the proposal. Our results not only introduce a new concept of skin cloaking for electromagnetic scatterers, but also provide new insight for the invisibility and illusion of Mie scatterers.

Comprehensive effects of salt stress and peanut cultivars on the rhizosphere bacterial community diversity of peanut.

Plant rhizosphere bacterial communities are central to plant growth and stress tolerance, which differ across cultivars and external environments. The goal of this study was to assess the comprehensive effects of salt stress and peanut cultivars on rhizosphere bacterial community diversity. In this study, we investigated the effects of salt stress on peanut morphology and pod yield and the associated rhizosphere bacterial diversity using statistical analysis and 16S rRNA gene sequencing, respectively. Statistical analysis exhibited that salt stress indeed affected peanut growth and pod yield, and various peanut cultivars showed divergences. Taxonomic analysis showed that the bacterial community predominantly consisted of phyla Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria, and Cyanobacteria in peanut rhizosphere soils. Among these bacteria, numbers of beneficial bacteria Cyanobacteria and Proteobacteria increased, especially in the salt-resistant cultivars, while that of Acidobacteria decreased after salt treatment. Nitrogen-fixing bacterium Rhizobium closely related to peanut nodulation was significantly improved in rhizosphere soils of salt-resistant cultivars after salt treatment. Metabolic function prediction showed that the percentages of reads categorized to signaling transduction and inorganic ion transport and metabolism were higher in the salt-treated soils, which may be conducive to peanut survival and salt tolerance to some extent. The study is, therefore, crucially important to develop the foundation for improving the salt tolerance of various peanut cultivars via modifying the soil bacterial community.

Demographic and psychosocial factors associated with hair cortisol concentrations in preschool children.

BACKGROUND: Early life stress has enduring effects on physical and mental health. Hair cortisol concentrations (HCCs) reflect exposures to contextual stressors in early life, but are understudied in preschool children. METHODS: Hair samples from children (N = 693) during clinic visits (CVs) scheduled at 1-4 years (CV1-CV4) were measured using validated assay methods for HCC. RESULTS: HCCs were highest at CV1 and decreased at CV2-CV4, with no sex differences. Black children had higher HCC than White/other children; these differences persisted even after adjusting for socioeconomic factors. Bivariable analyses showed significant effects on HCC for Black race, with specific demographic and psychosocial factors at different ages. Multivariable analyses showed that higher HCC at CV1 were associated with Black race and male sex; at CV2 with Black race, lower maternal self-esteem, socioeconomic adversity, and the child's risk for developmental delay; at CV3 with Black race; at CV4 with maternal depression and the child's prior HCC values. CONCLUSIONS: HCCs were higher in Black children than White/other races; differences were related to maternal factors, socioeconomic adversity, and the child's risk for developmental delay. Public health measures to reduce disparities between Blacks and other races must also consider the long-term effects of chronic stress in early life.

Influence of Salt Stress on Growth of Spermosphere Bacterial Communities in Different Peanut (Arachis hypogaea L.) Cultivars.

BACKGROUND: Exposure of seeds to high salinity can cause reduced germination and poor seedling establishment. Improving the salt tolerance of peanut (Arachis hypogaea L.) seeds during germination is an important breeding goal of the peanut industry. Bacterial communities in the spermosphere soils may be of special importance to seed germination under salt stress, whereas extant results in oilseed crop peanut are scarce. METHODS: Here, bacterial communities colonizing peanut seeds with salt stress were characterized using 16S rRNA gene sequencing. RESULTS: Peanut spermosphere was composed of four dominant genera: Bacillus, Massilia, Pseudarthrobacter, and Sphingomonas. Comparisons of bacterial community structure revealed that the beneficial bacteria (Bacillus), which can produce specific phosphatases to sequentially mineralize organic phosphorus into inorganic phosphorus, occurred in relatively higher abundance in salt-treated spermosphere soils. Further soil enzyme activity assays showed that phosphatase activity increased in salt-treated spermosphere soils, which may be associated with the shift of Bacillus. CONCLUSION: This study will form the foundation for future improvement of salt tolerance of peanuts at the seed germination stage via modification of the soil microbes.

Evaporation Induced Spontaneous Micro-Vortexes through Engineering of the Marangoni Flow.

Vortex flow fields are widely used to manipulate objects at the microscale in microfluidics. Previous approaches to produce the vortex flow field mainly focused on inertia flows. It remains a challenge to create vortexes in Stokes flow regime. Here we reported an evaporation induced spontaneous vortex flow system in Stokes flow regime by engineering Marangoni flow in a micro-structured microfluidic chip. The Marangoni flow is created by nonuniform evaporation of surfactant solution. Various vortexes are constructed by folding the air-water interface via microstructures. Patterns of vortexes are programmable by designing the geometry of the microstructures and are predictable using numerical simulations. Moreover, rotation of micro-objects and enrichment of micro-particles using vortex flow is demonstrated. This approach to create vortexes will provide a promising platform for various microfluidic applications such as biological analysis, chemical synthesis, and nanomaterial assembly.

Non-Lithography Hydrodynamic Printing of Micro/Nanostructures on Curved Surfaces.

A key issue of micro/nano devices is how to integrate micro/nanostructures with specified chemical components onto various curved surfaces. Hydrodynamic printing of micro/nanostructures on three-dimensional curved surfaces is achieved with a strategy that combines template-induced hydrodynamic printing and self-assembly of nanoparticles (NPs). Non-lithography flexible wall-shaped templates are replicated with microscale features by dicing a trench-shaped silicon wafer. Arising from the capillary pumped function between the template and curved substrates, NPs in the colloidal suspension self-assemble into close-packed micro/nanostructures without a gravity effect. Theoretical analysis with the lattice Boltzmann model reveals the fundamental principles of the hydrodynamic assembly process. Spiral linear structures achieved by two kinds of fluorescent NPs show non-interfering photoluminescence properties, while the waveguide and photoluminescence are confirmed in 3D curved space. The printed multiconstituent micro/nanostructures with single-NP resolution may serve as a general platform for optoelectronics beyond flat surfaces.