Automated interpretation of retinal vein occlusion based on fundus fluorescein angiography images using deep learning: A retrospective, multi-center study.

Purpose: Fundus fluorescein angiography (FFA) is the gold standard for retinal vein occlusion (RVO) diagnosis. This study aims to develop a deep learning-based system to diagnose and classify RVO using FFA images, addressing the challenges of time-consuming and variable interpretations by ophthalmologists. Methods: 4028 FFA images of 467 eyes from 463 patients were collected and annotated. Three convolutional neural networks (CNN) models (ResNet50, VGG19, InceptionV3) were trained to generate the label of image quality, eye, location, phase, lesions, diagnosis, and macular involvement. The performance of the models was evaluated by accuracy, precision, recall, F-1 score, the area under the curve, confusion matrix, human-machine comparison, and Clinical validation on three external data sets. Results: The InceptionV3 model outperformed ResNet50 and VGG19 in labeling and interpreting FFA images for RVO diagnosis, achieving 77.63%-96.45% accuracy for basic information labels and 81.72%-96.45% for RVO-relevant labels. The comparison between the best CNN and ophthalmologists showed up to 19% accuracy improvement with the inceptionV3. Conclusion: This study developed a deep learning model capable of automatically multi-label and multi-classification of FFA images for RVO diagnosis. The proposed system is anticipated to serve as a new tool for diagnosing RVO in places short of medical resources.

Dynamic bond crosslinked maca polysaccharide hydrogels with reactive oxygen species scavenging and antibacterial effects on infected wound healing.

In this study, a polysaccharide fragment with antioxidant and reactive oxygen species (ROS) scavenging activities was extracted from Maca (Lepidium meyenii Walp.) and subjected to structural analyses. The fragment, characterized by the α-D-Glcp-(1 â†’ terminal group of the main chain linked to the →4)-Glcp-(1 â†’ end unit through an O-6 bond and the O-3 bond of 1-3-4Glcp, was modified by introducing dialdehyde structures on its glucose units. It was then crosslinked with N-carboxymethyl chitosan via the Schiff base reaction to create a multifunctional hydrogel with antibacterial and ROS scavenging properties. Polyvinyl alcohol was incorporated to form a double crosslinked gel network, and the addition of silver nanoparticles enhanced its antibacterial efficacy. This gel system can scavenge excess ROS, mitigate wound inflammation, eradicate harmful bacteria, and aid in the restoration of skin microecology. The multifunctional maca polysaccharide hydrogel shows significant potential as a medical dressing for the treatment of infected wounds.

Molecular insights into effects of chemical conditioning on dissolved organic phosphorus transformation and bioavailability during sludge composting.

Phosphorus is enriched in waste activated sludge (WAS) during wastewater treatment, and organic phosphorus (OP) is a potential slow-release P fertilizer. The chemical coagulants used in sludge dewatering leave numerous residues in WAS that affect sludge composting. In this study, the effects of polyaluminum chloride (PAC) and polyferric sulfate (PFS) on the bioconversion of dissolved OP (DOP) during sludge composting were investigated. The results revealed that PFS conditioning promoted the transformation and bioavailability of DOP, whereas PAC conditioning inhibited. Results indicated that PFS conditioning enhanced the transformation of OP molecules in the thermophilic phase. Through oxidation and dehydrogenation reactions, 1-hydroxy-pentane-3,4-diol-5-phosphate and D-ribofuranose 5-phosphate with high bioactivity were generated in the PFS-conditioned compost. Enzymatic hydrolysis experiments further verified that PFS conditioning enhanced the DOP bioavailability in the compost, whereas PAC conditioning inhibited it. The study has provided molecular insights into the effects of chemical conditioning on DOP conversion during sludge composting.

Mechanistic insights into chemical conditioning on transformation of dissolved organic matter and plant biostimulants production during sludge aerobic composting.

Inorganic coagulants (aluminum and iron salt) are widely used to improve sludge dewaterability, resulting in numerous residues in dewatered sludge. Composting refers to the controlled microbial process that converts organic wastes into fertilizer, and coagulant residues in dewatered sludge can affect subsequent compost efficiency and resource recycling, which remains unclear. This work investigated the effects of two typical metal salt coagulants (poly aluminum chloride [PAC] and poly ferric sulfate [PFS]) conditioning on sludge compost. Our results revealed that PAC conditioning inhibited composting with decreased peak temperature, microbial richness, enzymatic reaction intensities, and compost quality, associated with decreased pH and microbial toxicity of aluminum. Nevertheless, PFS conditioning selectively enriched Pseudoxanthomonas sp. and resulted in more fertile compost with increased peak temperature, enzymatic reaction intensities, and humification degree. Spectroscopy and mass difference analyses indicated that PFS conditioning enhanced reaction intensities of labile biopolymers at the thermophilic stage, mainly comprising hydrolyzation (H2O), dehydrogenation (-H2, -H4), oxidation (+O1H2), and other reactions (i.e., +CH2, C2H4O1, C2H6O1). Unlike the common composting process primarily conducts humification at the cooling stage, PFS conditioning changed the main occurrence stage to the thermophilic stage. Non-targeted metabolomics revealed that indole (a humification intermediate) is responsible for the increased humification degree and indoleacetic acid content in the PFS-conditioned compost, which then promoted compost quality. Plant growth experiments further confirmed that the dissolved organic matter (DOM) in PFS-conditioned compost produced the maximum plant biomass. This study provided molecular-level evidence that PFS conditioning can promote humification and compost fertility during sludge composting, enabling chemical conditioning optimization for sustainable management of sludge.

Biodegradable Polyurethane Scaffolds in Regeneration Therapy: Characterization and In Vivo Real-Time Degradation Monitoring by Grafted Fluorescent Tracer.

There is an urgent need to assess material degradation in situ and in real time for their promising application in regeneration therapy. However, traditional monitoring methods in vitro cannot always profile the complicated behavior in vivo. This study designed and synthesized a new biodegradable polyurethane (PU-P) scaffold with polycaprolactone glycol, isophorone diisocyanate, and l-lysine ethyl ester dihydrochloride. To monitor the degradation process of PU-P, calcein was introduced into the backbone (PU-5) as a chromophore tracing in different sites of the body and undegradable fluorescent scaffold (CPU-5) as the control group. Both PU-P and PU-5 can be enzymatically degraded, and the degradation products are molecularly small and biosafe. Meanwhile, by virtue of calcein anchoring with urethane, polymer chains of PU-5 have maintained the conformational stability and extended the system conjugation, raising a structure-induced emission effect that successfully achieved a significant enhancement in the fluorescence intensity better than pristine calcein. Evidently, unlike the weak fluorescent response of CPU-5, PU-5 and its degradation can be clearly imaged and monitored in real time after implantation in the subcutaneous tissue of nude mice. Meanwhile, the in situ osteogeneration has also been promoted after the two degradable scaffolds have been implanted in the rabbit femoral condyles and degraded with time. To sum up, the strategy of underpinning tracers into degradable polymer chains provides a possible and effective way for real-time monitoring of the degradation process of implants in vivo.

Affiliation With Delinquent Peers as a Mediator of the Relationships Between Family Conflict and School Bullying: A Short-Term Longitudinal Panel Study.

Despite a hypothesized link between family conflict and school bullying perpetration, previous findings on the direct association have been inconsistent. It has been argued that affiliation with delinquent peers may be a potential psychosocial mechanism mediating the relationships between family conflict and school perpetration. However, such a proposition has not been examined employing longitudinal panel data. Using longitudinal panel data (two waves with a 9-month interval) from Hong Kong collected from 424 lower secondary students (grades 7-9), this study examined how affiliation with delinquent peers mediates the relationships between family conflict and adolescent school perpetration. The results of the half-longitudinal mediation model indicated no significant link between family conflict at T1 and school bullying perpetration at T2. However, family conflict at T1 was indirectly linked to school bullying perpetration at T2 through affiliation with delinquent peers. The findings imply that affiliation with delinquent peers mediates the association between family conflict and adolescent school bullying perpetration. The findings provide insights into the future development of policies and interventions to reduce school bullying perpetration.

Is Psychological Distress a Risk Factor or an Outcome of School Violence and Cyberbullying Perpetrated by Adolescents? A Short-Term Longitudinal Panel Study.

Although the associations between adolescent psychological distress (i.e., depression, anxiety, and somatization), school violence, and cyberbullying have been examined using cross-sectional data, little evidence from longitudinal panel data exists to determine the temporal association. A two-wave longitudinal panel data with a 10-month interval were obtained from a random sample of 487 Chinese junior high school students (grades 7-9) in Tianjin in Mainland China. The cross-lagged panel analysis showed that adolescent psychological distress in the first wave of the survey was significantly associated with subsequent school violence against peers and teachers in the second wave but not in the opposite direction. Student psychological distress in the first wave of the survey was not significantly associated with cyberbullying perpetration in the second wave and vice versa. The findings suggested that adolescent psychological distress was a risk factor rather than the consequence of violence against peers and teachers in school. However, the temporal associations between adolescent psychological distress and cyberbullying perpetration were non-significant. These findings were relevant to both sex groups. The findings may imply that potential interventions and policies to prevent students from committing school violence should consider reducing students' psychological distress as one of the core elements.

Optimal designs of LID based on LID experiments and SWMM for a small-scale community in Tianjin, north China.

Urban flooding and waterlogging are becoming increasingly serious due to rapid urbanization and climate change. The stormwater management philosophy of low-impact development (LID) has been applied in urban construction to alleviate these problems. The selection and placement of LID designs are the most important tasks. In this study, LID experiments were performed to calibrate the Storm Water Management Model (SWMM). Then, a multi-objective optimization model, which adopted the minimum surface runoff coefficient, surcharge time, and investment cost as objectives, was established by coupling the SWMM and non-dominated sorting genetic algorithm-II (NSGA-II). Hydrological simulations were performed with the SWMM, and optimal calculations were conducted with NSGA-II. Real-coded optimal variables containing detailed size and location information of multiple LID measures were generated, and a decision space for LID design selection was obtained. The optimization designs reduced the surface runoff coefficient from 0.7 to approximately 0.5, the conduit surcharge duration was reduced from 1.62 h to 0.04-0.47 h, and the total investment cost only ranged from 395,000-872,000 ¥. Thus, the optimization model could achieve synchronous optimization of all objectives. This study could provide valuable information for LID design with the aim of urban flooding and waterlogging control.

Chromosome-scale Amaranthus tricolor genome provides insights into the evolution of the genus Amaranthus and the mechanism of betalain biosynthesis.

Amaranthus tricolor is a vegetable and ornamental amaranth, with high lysine, dietary fibre and squalene content. The red cultivar of A. tricolor possesses a high concentration of betalains, which has been used as natural food colorants. Here, we constructed the genome of A. tricolor, the first reference genome for the subgenus Albersia, combining PacBio HiFi, Nanopore ultra-long and Hi-C data. The contig N50 size was 906 kb, and 99.58% of contig sequence was anchored to the 17 chromosomes, totalling 520 Mb. We annotated 27,813 protein-coding genes with an average 1.3 kb coding sequence and 5.3 exons. We inferred that A. tricolor underwent a whole-genome duplication (WGD) and that the WGD shared by amaranths occurred in the last common ancestor of subfamily Amaranthoideae. Moreover, we comprehensively identified candidate genes in betalain biosynthesis pathway. Among them, DODAα1 and CYP76ADα1, located in one topologically associated domain (TAD) of an active (A) compartment on chromosome 16, were more highly expressed in red leaves than in green leaves, and DODAα1 might be the rate-limiting enzyme gene in betalains biosynthesis. This study presents new genome resources and enriches our understanding of amaranth evolution, betalains production, facilitating molecular breeding improvements and the understanding of C4 plants evolution.

EndHiC: assemble large contigs into chromosome-level scaffolds using the Hi-C links from contig ends.

BACKGROUND: The application of PacBio HiFi and ultra-long ONT reads have enabled huge progress in the contig-level assembly, but it is still challenging to assemble large contigs into chromosomes with available Hi-C scaffolding tools, which count Hi-C links between contigs using the whole or a large part of contig regions. As the Hi-C links of two adjacent contigs concentrate only at the neighbor ends of the contigs, larger contig size will reduce the power to differentiate adjacent (signal) and non-adjacent (noise) contig linkages, leading to a higher rate of mis-assembly. RESULTS: We design and develop a novel Hi-C based scaffolding tool EndHiC, which is suitable to assemble large contigs into chromosomal-level scaffolds. The core idea behind EndHiC, which distinguishes it from other Hi-C scaffolding tools, is using Hi-C links only from the most effective regions of contig ends. By this way, the signal neighbor contig linkages and noise non-neighbor contig linkages are separated more clearly. Benefiting from the increased signal to noise ratio, the reciprocal best requirement, as well as the robustness evaluation, EndHiC achieves higher accuracy for scaffolding large contigs compared to existing tools. EndHiC has been successfully applied in the Hi-C scaffolding of simulated data from human, rice and Arabidopsis, and real data from human, great burdock, water spinach, chicory, endive, yacon, and Ipomoea cairica, suggesting that EndHiC can be applied to a broad range of plant and animal genomes. CONCLUSIONS: EndHiC is a novel Hi-C scaffolding tool, which is suitable for scaffolding of contig assemblies with contig N50 size near or over 10 Mb and N90 size near or over 1 Mb. EndHiC is efficient both in time and memory, and it is interface-friendly to the users. As more genome projects have been launched and the contig continuity constantly improved, we believe EndHiC has the potential to make a great contribution to the genomics field and liberate the scientists from labor-intensive manual curation works.

Improved microbial genomes and gene catalog of the chicken gut from metagenomic sequencing of high-fidelity long reads.

BACKGROUND: Due to the importance of chicken production and the remarkable influence of the gut microbiota on host health and growth, tens of thousands of metagenome-assembled genomes (MAGs) have been constructed for the chicken gut microbiome. However, due to the limitations of short-read sequencing and assembly technologies, most of these MAGs are far from complete, are of lower quality, and include contaminant reads. RESULTS: We generated 332 Gb of high-fidelity (HiFi) long reads from the 5 chicken intestinal compartments and assembled 461 and 337 microbial genomes, of which 53% and 55% are circular, at the species and strain levels, respectively. For the assembled microbial genomes, approximately 95% were regarded as complete according to the "RNA complete" criteria, which requires at least 1 full-length ribosomal RNA (rRNA) operon encoding all 3 types of rRNA (16S, 23S, and 5S) and at least 18 copies of full-length transfer RNA genes. In comparison with the short-read-derived chicken MAGs, 384 (83% of 461) and 89 (26% of 337) strain-level and species-level genomes in this study are novel, with no matches to previously reported sequences. At the gene level, one-third of the 2.5 million genes in the HiFi-derived gene catalog are novel and cannot be matched to the short-read-derived gene catalog. Moreover, the HiFi-derived genomes have much higher continuity and completeness, as well as lower contamination; the HiFi-derived gene catalog has a much higher ratio of complete gene structures. The dominant phylum in our HiFi-assembled genomes was Firmicutes (82.5%), and the foregut was highly enriched in 5 genera: Ligilactobacillus, Limosilactobacillus, Lactobacillus, Weissella, and Enterococcus, all of which belong to the order Lactobacillales. Using GTDB-Tk, all 337 species-level genomes were successfully classified at the order level; however, 2, 35, and 189 genomes could not be classified into any known family, genus, and species, respectively. Among these incompletely classified genomes, 9 and 49 may belong to novel genera and species, respectively, because their 16S rRNA genes have identities lower than 95% and 97% to any known 16S rRNA genes. CONCLUSIONS: HiFi sequencing not only produced metagenome assemblies and gene structures with markedly improved quality but also recovered a substantial portion of novel genomes and genes that were missed in previous short-read-based metagenome studies. The novel genomes and species obtained in this study will facilitate gut microbiome and host-microbiota interaction studies, thereby contributing to the sustainable development of poultry resources.

A chromosome-level reference genome of a Convolvulaceae species Ipomoea cairica.

Ipomoea cairica is a perennial creeper that has been widely introduced as a garden ornamental across tropical, subtropical, and temperate regions. Because it grows extremely fast and spreads easily, it has been listed as an invasive species in many countries. Here, we constructed the chromosome-level reference genome of Ipomoea cairica by Pacific Biosciences HiFi and Hi-C sequencing, with the assembly size of 733.0 Mb, the contig N50 of 43.8 Mb, the scaffold N50 of 45.7 Mb, and the Benchmarking Universal Single-Copy Orthologs complete rate of 98.0%. Hi-C scaffolding assigned 97.9% of the contigs to 15 pseudo-chromosomes. Telomeric repeat analysis reveals that 7 of the 15 pseudo-chromosomes are gapless and telomere to telomere. The transposable element content of Ipomoea cairica is 73.4%, obviously higher than that of other Ipomoea species. A total of 38,115 protein-coding genes were predicted, with the Benchmarking Universal Single-Copy Orthologs complete rate of 98.5%, comparable to that of the genome assembly, and 92.6% of genes were functional annotated. In addition, we identified 3,039 tRNA genes and 2,403 rRNA genes in the assembled genome. Phylogenetic analysis showed that Ipomoea cairica formed a clade with Ipomoea aquatica, and they diverged from each other 8.1 million years ago. Through comparative genome analysis, we reconfirmed that a whole genome triplication event occurred specific to Convolvulaceae family and in the ancestor of the genus Ipomoea and Cuscuta. This high-quality reference genome of Ipomoea cairica will greatly facilitate the studies on the molecular mechanisms of its rapid growth and invasiveness.

Chromosome-level genome of the globe skimmer dragonfly (Pantala flavescens).

BACKGROUND: The globe skimmer dragonfly (Pantala flavescens) is a notable Odonata insect distributed in nature fields and farmlands worldwide, and it is commonly recognized as a natural enemy because it preys on agricultural pests and health pests. As one of the sister groups of winged insects, odonatan species are key to understanding the evolution of insect wings. FINDINGS: We present a high-quality reference genome of P. flavescens, which is the first chromosome-level genome in the Palaeoptera (Odonata and Ephemeroptera). The assembled genome size was 662 Mb, with a contig N50 of 16.2 Mb. Via Hi-C scaffolding, 648 Mb (97.9%) of contig sequences were clustered, ordered, and assembled into 12 large scaffolds, each corresponding to a natural chromosome. The X chromosome was identified by sequence coverage depth. The repetitive sequences and gene density of the X chromosome are similar to those of autosomal sequences, but the X chromosome shows a much lower degree of heterozygosity. Our analysis shows that the effective population size experienced 3 declining events, which may have been caused by climate change and environmental pollution. CONCLUSIONS: The genome of P. flavescens provides more information on the biology and evolution of insects and will help for the use of this species in pest control.

Applications for natural deep eutectic solvents in Chinese herbal medicines.

Chinese herbal medicines (CHMs), with a wide range of bioactive components, are considered to be an important source for new drug discovery. However, the process to isolate and obtain those bioactive components to develop new drugs always consumes a large amount of organic solvents with high toxicity and non-biodegradability. Natural deep eutectic solvents (NADES), a new type of green and designable solvents composed of primary plant-based metabolites, have been used as eco-friendly substitutes for traditional organic solvents in various fields. Due to the advantages of easy preparation, low production cost, low toxicity, and eco-friendliness, NADES have been also applied as extraction solvents, media, and drug delivery agents in CHMs in recent years. Besides, the special properties of NADES have been contributed to elucidating the traditional processing (also named Paozhi in Chinese) theory of CHMs, especially processing with honey. In this paper, the development process, preparation, classification, and applications for NADES in CHMs have been reviewed. Prospects in the future applications and challenges have been discussed to better understand the possibilities of the new solvents in the drug development and other uses of CHMs.

Recovery of metagenome-assembled microbial genomes from a full-scale biogas plant of food waste by pacific biosciences high-fidelity sequencing.

Background: Anaerobic digestion (AD) is important in treating of food waste, and thousands of metagenome-assembled genomes (MAGs) have been constructed for the microbiome in AD. However, due to the limitations of the short-read sequencing and assembly technologies, most of these MAGs are grouped from hundreds of short contigs by binning algorithms, and the errors are easily introduced. Results: In this study, we constructed a total of 60 non-redundant microbial genomes from 64.5 Gb of PacBio high-fidelity (HiFi) long reads, generated from the digestate samples of a full-scale biogas plant fed with food waste. Of the 60 microbial genomes, all genomes have at least one copy of rRNA operons (16S, 23S, and 5S rRNA), 54 have ≥18 types of standard tRNA genes, and 39 are circular complete genomes. In comparison with the published short-read derived MAGs for AD, we found 23 genomes with average nucleotide identity less than 95% to any known MAGs. Besides, our HiFi-derived genomes have much higher average contig N50 size, slightly higher average genome size and lower contamination. GTDB-Tk classification of these genomes revealed two genomes belonging to novel genus and four genomes belonging to novel species, since their 16S rRNA genes have identities lower than 95 and 97% to any known 16S rRNA genes, respectively. Microbial community analysis based on the these assembled genomes reveals the most predominant phylum was Thermotogae (70.5%), followed by Euryarchaeota (6.1%), and Bacteroidetes (4.7%), and the most predominant bacterial and archaeal genera were Defluviitoga (69.1%) and Methanothrix (5.4%), respectively. Analysis of the full-length 16S rRNA genes identified from the HiFi reads gave similar microbial compositions to that derived from the 60 assembled genomes. Conclusion: High-fidelity sequencing not only generated microbial genomes with obviously improved quality but also recovered a substantial portion of novel genomes missed in previous short-read based studies, and the novel genomes will deepen our understanding of the microbial composition in AD of food waste.

Trace Metal Lead Exposure in Typical Lip Cosmetics From Electronic Commercial Platform: Investigation, Health Risk Assessment and Blood Lead Level Analysis.

Lead (Pb) in lipstick products has become an increasing concern, which can cause safety problems to human body directly with diet. To investigate the Pb exposure and potential health risk level of typical popular lip cosmetics in Chinese e-commerce market, Python crawler was introduced to identify and select 34 typical popular lip cosmetics, including 12 lipsticks, 13 lip glosses, and 9 lip balms. And then this study used ICP-MS to determine the content of Pb. Furthermore, the ingestion health risk assessment method issued by United States Environmental Protection Agency (USEPA) and Monte Carlo simulation algorithm were applied to assess the probabilistic health risks of adults exposure. Finally, taking the possible exposure of children contacting with lip products, the health risk assessment of children blood Pb was carried out. The results showed that the concentration of Pb in lip products ranged from 0 to 0.5237 mg/kg, which was far lower than the limit set by various countries. The probabilistic non-carcinogenic risks and carcinogenic risks were 4.93 ×10-7~2.82 ×10-3 and 1.68 ×10-12~9.59 ×10-9, respectively, which were in an acceptable level. The results of blood Pb assessment suggested that the Pb content of lip cosmetics had no obvious influence on blood Pb concentration of children, and background Pb exposure is the main factor affecting children's blood Pb level (BLL). Overall, the samples of lip products are selected by Python crawler in this study, which are more objective and representative. This study focuses on deeper study of Pb, especially for the health risk assessment of blood Pb in children exposed to lip products. These results perhaps could provide useful information for the safety cosmetics usage for people in China and even the global world.

Intelligent Electromagnetic Sensors for Non-Invasive Trojan Detection.

Rapid growth of sensors and the Internet of Things is transforming society, the economy and the quality of life. Many devices at the extreme edge collect and transmit sensitive information wirelessly for remote computing. The device behavior can be monitored through side-channel emissions, including power consumption and electromagnetic (EM) emissions. This study presents a holistic self-testing approach incorporating nanoscale EM sensing devices and an energy-efficient learning module to detect security threats and malicious attacks directly at the front-end sensors. The built-in threat detection approach using the intelligent EM sensors distributed on the power lines is developed to detect abnormal data activities without degrading the performance while achieving good energy efficiency. The minimal usage of energy and space can allow the energy-constrained wireless devices to have an on-chip detection system to predict malicious attacks rapidly in the front line.

Husk of Agarwood Fruit-Based Hydrogel Beads for Adsorption of Cationic and Anionic Dyes in Aqueous Solutions.

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2-10) of the dye solution, the adsorbent dosage (0.5-3.5 g/L), and contact time (0-540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.

Manipulating exchange bias by spin-orbit torque.

Exchange bias, a shift in the hysteresis loop of a ferromagnet arising from interfacial exchange coupling between adjacent ferromagnetic and antiferromagnetic layers, is an integral part of spintronic devices. Here, we show that spin-orbit torque generated from spin current, a promising approach to switch the ferromagnetic magnetization of next-generation magnetic random access memory, can also be used to manipulate the exchange bias. Applying current pulses to a Pt/Co/IrMn trilayer causes concurrent switching of ferromagnetic magnetization and exchange bias, but with different underlying mechanisms. This implies that the ferromagnetic magnetization and exchange bias can be manipulated independently. Our work demonstrates that spin-orbit torque in ferromagnet/antiferromagnet heterostructures facilitates independent manipulations of distinct magnetic properties, motivating innovative designs for future spintronics devices.

Synthesis and characterization of fluorescein-grafted polyurethane for potential application in biomedical tracing.

Redesigned multifunctional biopolymers represent a novel building bridge for interdisciplinary collaborations in biomaterials development. We prepared fluorescein-grafted polyurethane scaffolds (PU-C1, PU-C5, and PU-B1) to meet both clinical needs and biological safety evaluations, using different contents of calcein and different synthesis procedures for potential biomedical tracing. X-ray diffraction, infrared, X-ray photoelectron spectroscopy, nuclear magnetic resonance, scanning electron microscopy, and light microscopy were used to analyze the composition and structure of polyurethanes, as well as to observe their morphology with and without biomarkers. Fluorescence spectrophotometer and fluorescence microscopy were used to detect the fluorescence characteristics. The results showed that the grafting of calcein significantly affected the chemical structure and fluorescence sensitivities of copolymers. When compared to calcein, which was added before synthesis (PU-C1), the marker that was added during the extender process (PU-B1) presented higher fluorescence efficiency. Both PU-C5 and PU-B1 exhibited strong fluorescent response and good cytocompatibility in vitro and in vivo, with no interference from the autofluorescence of tissues after 4 weeks of implantation. The fluorescence-marked material can be used to continuously and noninvasively monitor the dynamic changes in polymers, which provides a way to clearly trace the material or to distinguish between the material and tissue in vivo.