Dynamic Acoustic Beamshaping with Coupling-Immune Moiré Metasurfaces.

Moiré effects arising from mutually twisted metasurfaces have showcased remarkable wave manipulation capabilities, unveiling tantalizing emerging phenomena such as acoustic moiré flat bands and topological phase transitions. However, the pursuit of strong near-field coupling in layers has necessitated acoustic moiré metasurfaces to be tightly stacked at narrow distances in the subwavelength range. Here, moiré effects beyond near-field interlayer coupling in acoustics are reported and the concept of coupling-immune moiré metasurfaces is proposed. Remote acoustic moiré effects decoupled from the interlayer distance are theoretically, numerically, and experimentally demonstrated. Tunable out-of-plane acoustic beam scanning is successfully achieved by dynamically controlling twist angles. The engineered coupling-immune properties are further extended to multilayered acoustic moiré metasurfaces and manipulation of acoustic vortices. Good robustness against external disturbances is also observed for the fabricated coupling-immune acoustic moiré metasurfaces. The presented work unlocks the potential of twisted moiré devices for out-of-plane acoustic beam shaping, enabling practical applications in remote dynamic detection, and multiplexed underwater acoustic communication.

[Genetic and clinical analysis of a child with Shwachman-Diamond syndrome due to compound heterozygous variants of SBDS gene].

OBJECTIVE: To analyze the clinical features and genetic characteristics of a patient with Shwachman-Diamond syndrome (SDS) due to compound heterozygous variants of SBDS gene. METHODS: A female child with SDS who was admitted to the Children's Hospital Affiliated to Zhengzhou University in February 2022 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and her elder sister and parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. RESULTS: The child, a 1-year-and-1-month-old girl, had mainly manifested with diarrhea, hematochezia, growth retardation and malnutrition, along with increased transaminases and decreased neutrophils and hemoglobin. Anteroposterior X-ray of her left wrist indicated significantly delayed bone age. Colonoscopy revealed that her colorectal mucosa was erosive with oily food residues attached to the intestinal lumen. Genetic testing revealed that she has harbored c.258+2T>C and c.100A>G compound heterozygous variants of the SBDS gene. The c.258+2T>C variant has derived from her father and known to be pathogenic, whilst the other has derived from her mother. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.100A>G variant was classified as likely pathogenic (PM1+PM2_Supporting+PM3+PM5+PP3). CONCLUSION: The compound heterozygous variants of c.258+2T>C and c.100A>G probably underlay the SDS in this child. For children with refractory diarrhea, liver damage and growth retardation, SDS should be suspected, and genetic testing can facilitate the diagnosis and treatment.

[Risk factors for delayed bleeding after intestinal polypectomy in children]. / å„¿ç«¥è‚ æ¯è‚‰åˆ‡é™¤æœ¯åŽè¿Ÿå‘æ€§å‡ºè¡€çš„å±é™©å› ç´ åˆ†æž.

OBJECTIVES: To investigate the clinical characteristics and risk factors of delayed bleeding after intestinal polypectomy in children, and to provide a theoretical basis for clinical surgical intervention of intestinal polyps. METHODS: A retrospective analysis was conducted on the clinical data of 2 456 children with intestinal polyps who underwent endoscopic high-frequency electrocoagulation loop resection in the Endoscopy Center of Children's Hospital Affiliated to Zhengzhou University from January 2014 to December 2021. According to the presence or absence of delayed bleeding after surgery, they were divided into bleeding group with 79 children and non-bleeding group with 2 377 children. A multivariate logistic regression analysis was used to investigate the risk factors for delayed bleeding. The receiver operating characteristic (ROC) curve was used to investigate the value of various indicators in predicting delayed bleeding. RESULTS: Of all 2 456 children, 79 (3.22%) experienced delayed bleeding, among whom 5 children with severe delayed bleeding underwent emergency colonoscopy for hemostasis and 74 received conservative treatment, and successful hemostasis was achieved for all children. There were significant differences between the bleeding and non-bleeding groups in age, body mass index, constipation rate, location of lesion, time of endoscopic procedure, resection method (P<0.05). Children with a diameter of polyps of 6-10 mm and >20 mm were more likely to develop delayed bleeding after resection (P<0.05). The multivariate logistic regression analysis showed that endoscopic operation time, polyp diameter, and resection method were significantly associated with delayed bleeding (P<0.05). The ROC curve analysis showed that the endoscopic operation time, polyp diameter, and resection method had a good value in predicting delayed bleeding after intestinal polypectomy, with an area under the ROC curve of 0.706, 0.688, and 0.627, respectively. CONCLUSIONS: Endoscopic high-frequency electrocoagulation loop resection has a lower incidence of delayed bleeding in children with intestinal polyps, and the endoscopic operation time, polyp diameter, and resection method are closely associated with the occurrence of postoperative delayed bleeding.

Influence of different heat transfer models on therapeutic temperature prediction and heat-induced damage during magnetic hyperthermia.

Magnetic hyperthermia regulates the therapeutic temperature within a specific range to damage malignant cells after exposing the magnetic nanoparticles inside tumor tissue to an alternating magnetic field. The therapeutic temperature of living tissues can be generally predicted using Pennes' bio-heat equation after ignoring both the inhomogeneity of biological structure and the microstructural responses. Although various of the bio-heat transfer models proposed in literature fix these shortages, there is still a lack of a comprehensive report on investigating the discrepancy for different models when applied in the magnetic hyperthermia context. This study compares four different bio-heat equations in terms of the therapeutic temperature distribution and the heat-induced damage situation for a proposed geometric model, which is established based on computed tomography images of a tumor bearing mouse. The therapeutic temperature is also used as an index to evaluate the effect of two key relaxation times for the phase lag behavior on bio-heat transfer. Moreover, this work evaluates the effects of two blood perfusion rates on both the treatment temperature and the cumulative equivalent heating minutes at 43 °C. Numerical analysis results reveal that relaxation times for phase-lag behavior as well as the porosity for living tissues directly affect the therapeutic temperature variation and ultimately the thermal damage for the malignant tissue during magnetic hyperthermia. The dual-phase-lag equation can be converted into Pennes' equation and simple-phase-lag equation when relaxation times meet specific conditions during the process of heat transfer. In addition, different blood perfusion rates can result in an amplitude discrepancy for treatment temperature, but this parameter does not change the characteristics of thermal propagation during therapy.

Comprehensive Analyses of Breads Supplemented with Tannic Acids.

Tannic acid (TA) has been recently considered as a new dough additive for improving the bread-making quality of wheat. However, the effects of TA supplementation on the sensory quality parameters (color, crumb grain structure, and sensory properties) of bread have not been studied. Further, the potential of TA supplementation in bread-making quality improvement has not been evaluated by using commercial flour. In the present study, three commercial wheat flours (namely, XL, QZG, and QZZ) with different gluten qualities were used to evaluate the effects of TA supplementation (in concentrations of 0.1% and 0.3%, respectively). TA supplementation did not change the proximate composition of the breads but increased the volumes and specific volumes of XL and QZG breads. TA supplementation enhanced antioxidant activities, with 0.3% TA significantly increasing the antioxidant capacities of bread made from all three flour samples by approximately four-fold (FRAP method)/three-fold (ABTS method). Positive effects of TA on the reduction in crumb hardness, gumminess, and chewiness were observed in the XL bread, as determined by the texture profile analysis. For the analyses on visual and sensory attributes, our results suggest that TA did not affect the crust color, but only slightly reduced the L* (lightness) and b* (yellowness) values of the crumb and increased the a* (redness) value. TA supplementation also increased the porosity, total cell area, and mean cell area. Satisfactorily, the sensory evaluation results demonstrate that TA-supplemented breads did not exhibit negative sensory attributes when compared to the non-TA-added breads; rather, the attributes were even increased. In summary, TA-supplemented breads generally had not only better baking quality attributes and enhanced antioxidant activities, but, more importantly, presented high consumer acceptance in multiple commercial flour samples. Our results support the commercial potential of TA to be used as a dough improver.

Self-Assembled Virus-Like Particle Vaccines via Fluorophilic Interactions Enable Infection Mimicry and Immune Protection.

Influenza epidemics persistently threaten global health. Vaccines based on virus-like particles (VLPs), which resemble the native conformation of viruses, have emerged as vaccine candidates. However, the production of VLPs via genetic engineering remains constrained by challenges such as low yields, high costs, and being time consuming. In this study, a novel VLP platform is developed that could mimic infection and confer influenza protection through fluorination-driven self-assembly. The VLPs closely mimick the key steps in viral infection including dendritic cell (DC) attachment and pH-responsive endo-lysosomal escape, which enhances DC maturation and antigen cross-presentation. It is also observed that the VLPs migrate from the injection site to the draining lymph nodes efficiently. Immunization with VLPs triggers both Th1 and Th2 cellular responses, thereby inducing an improved CD8+ T cell response along with strong antigen-specific antibody responses. In several infected mouse models, VLP vaccines ameliorate weight loss, lung virus titers, pulmonary pathologies, and confer full protection against H1N1, H6N2, H9N2, and mixed influenza viruses. Therefore, the results support the potential of VLPs as an effective influenza vaccine with improved immune potency against infection. A methodology to generate VLPs based on fluorophilic interactions, which can be a general approach for development of pathogenic VLPs, is reported.

Integrative gene duplication and genome-wide analysis as an approach to facilitate wheat reverse genetics: An example in the TaCIPK family.

INTRODUCTION: Reverse genetic studies conducted in the plant with a complex or polyploidy genome enriched with large gene families (like wheat) often meet challenges in identifying the key candidate genes related to important traits and prioritizing the genes for functional experiments. OBJECTIVE: To overcome the above-mentioned challenges of reverse genetics, this work aims to establish an efficient multi-species strategy for genome-wide gene identification and prioritization of the key candidate genes. METHODS: We established the integrative gene duplication and genome-wide analysis (iGG analysis) as a strategy for pinpointing key candidate genes deserving functional research. The iGG captures the evolution, and the expansion/contraction of large gene families across phylogeny-related species and integrates spatial-temporal expression information for gene function inference. Transgenic approaches were also employed to functional validation. RESULTS: As a proof-of-concept for the iGG analysis, we took the wheat calcineurin B-like protein-interacting protein kinases (CIPKs) family as an example. We identified CIPKs from seven monocot species, established the orthologous relationship of CIPKs between rice and wheat, and characterized Triticeae-specific CIPK duplicates (e.g., CIPK4 and CIPK17). Integrated with our analysis of CBLs and CBL-CIPK interaction, we revealed that divergent expressions of TaCBLs and TaCIPKs could play an important role in keeping the stoichiometric balance of CBL-CIPK. Furthermore, we validated the function of TaCIPK17-A2 in the regulation of drought tolerance by using transgenic approaches. Overexpression of TaCIPK17 enhanced antioxidant capacity and improved drought tolerance in wheat. CONCLUSION: The iGG analysis leverages evolutionary and comparative genomics of crops with large genomes to rapidly highlight the duplicated genes potentially associated with speciation, domestication and/or particular traits that deserve reverse-genetic functional studies. Through the identification of Triticeae-specific TaCIPK17 duplicates and functional validation, we demonstrated the effectiveness of the iGG analysis and provided a new target gene for improving drought tolerance in wheat.

Impairment of intestinal barrier associated with the alternation of intestinal flora and its metabolites in cow's milk protein allergy.

Cow's milk protein allergy (CMPA), one of the most prevalent food allergies, seriously affects the growth and development of infants and children with the rising incidence and prevalence. The dysbiosis of intestinal flora acts to promote disease including allergic disease. Therefore, studying the role of intestinal flora in allergic diseases holds great promise for developing effective strategies to mitigate the risk of food allergies. This study aims to elucidate the role of disrupted intestinal flora and its metabolites in children with CMPA.16S rDNA sequence analysis was applied to characterize the changes in the composition of intestinal flora. The findings revealed heightened diversity of intestinal flora in CMPA, marked by decreased abundance of Firmicutes and Bacteroidetes, and increased abundance of Proteobacteria and Actinobacteria. Furthermore, metabolite analysis identified a total of 1245 differential metabolites in children with CMPA compared to those in healthy children. Among these, 765 metabolites were down-regulated, while 480 were up-regulated. Notably, there were 10 negative differential metabolites identified as bile acids and derivatives, including second bile acids, such as deoxycholic acid, ursodeoxycholic acid and isoursodexycholic acid. The intestinal barrier was further analyzed and showed that the enterocytes proliferation and the expression of Claudin-1, Claudin-3 and MUC2 were down-regulated with the invasion of biofilm community members in the CMPA group. In summary, these findings provide compelling evidence that food allergies disrupt intestinal flora and its metabolites, consequently damaging the intestinal barrier's integrity to increase intestinal permeability and immune response.

A straight-forward gene mining strategy to identify TaCIPK19 as a new regulator of drought tolerance in wheat.

Drought stress is one of the most impactful abiotic stresses to global wheat production. Therefore, identifying key regulators such as the calcineurin B-like protein interacting protein kinase (CIPK) in the signaling cascades known to coordinate developmental cues and environmental stimuli represents a useful approach to improve drought tolerance. However, functional studies have been very limited partly due to the difficulties in prioritizing candidate genes from the large TaCIPK family. To address this issue, we demonstrate a straight-forward strategy by analyzing gene expression patterns in response to phytohormones or stresses and identified TaCIPK19 as a new regulator to improve drought tolerance. The effects of TaCIPK19 on drought tolerance were evaluated in both tobacco and wheat through transgenic approach. Ectopic expression of TaCIPK19 in tobacco greatly improves drought tolerance with enhanced ABA biosynthesis/signaling and ROS scavenging capacity. TaCIPK19 overexpression in wheat also confers the drought tolerance at both seedling and mature stages with enhanced ROS scavenging capacity. Additionally, potential CBL partners interacting with TaCIPK19 were investigated. Collectively, our finding exemplifies a straight-forward approach to facilitate reverse genetics related to abiotic stress improvement and demonstrates TaCIPK19 as a new candidate gene to improve ROS scavenging capacity and drought tolerance, which is useful for genetic improvement and breeding application in wheat.

Genome-wide characterization of the VQ genes in Triticeae and their functionalization driven by polyploidization and gene duplication events in wheat.

Valine-glutamine motif-containing (VQ) proteins are transcriptional cofactors widely involved in plant growth, development, and response to various stresses. Although the VQ family has been genome-wide identified in some species, but the knowledge regarding duplication-driven functionalization of VQ genes among evolutionarily related species is still lacking. Here, 952 VQ genes have been identified from 16 species, emphasizing seven Triticeae species including the bread wheat. Comprehensive phylogenetic and syntenic analyses allow us to establish the orthologous relationship of VQ genes from rice (Oryza sativa) to bread wheat (Triticum aestivum). The evolutionary analysis revealed that whole-genome duplication (WGD) drives the expansion of OsVQs, while TaVQs expansion is associated with a recent burst of gene duplication (RBGD). We also analyzed the motif composition and molecular properties of TaVQ proteins, enriched biological functions, and expression patterns of TaVQs. We demonstrate that WGD-derived TaVQs have become divergent in both protein motif composition and expression pattern, while RBGD-derived TaVQs tend to adopt specific expression patterns, suggesting their functionalization in certain biological processes or in response to specific stresses. Furthermore, some RBGD-derived TaVQs are found to be associated with salt tolerance. Several of the identified salt-related TaVQ proteins were located in the cytoplasm and nucleus and their salt-responsive expression patterns were validated by qPCR analysis. Yeast-based functional experiments confirmed that TaVQ27 may be a new regulator to salt response and regulation. Overall, this study lays the foundation for further functional validation of VQ family members within the Triticeae species.

Integrated omic analysis provides insights into the molecular regulation of stress tolerance by partial root-zone drying in rice.

Partial root-zone drying (PRD) is an effective water-saving irrigation strategy that improves stress tolerance and facilitates efficient water use in several crops. It has long been considered that abscisic acid (ABA)-dependent drought resistance may be involved during partial root-zone drying. However, the molecular mechanisms underlying PRD-mediated stress tolerance remain unclear. It's hypothesized that other mechanisms might contribute to PRD-mediated drought tolerance. Here, rice seedlings were used as a research model and the complex transcriptomic and metabolic reprogramming processes were revealed during PRD, with several key genes involved in osmotic stress tolerance identified by using a combination of physiological, transcriptome, and metabolome analyses. Our results demonstrated that PRD induces transcriptomic alteration mainly in the roots but not in the leaves and adjusts several amino-acid and phytohormone metabolic pathways to maintain the balance between growth and stress response compared to the polyethylene glycol (PEG)-treated roots. Integrated analysis of the transcriptome and metabolome associated the co-expression modules with PRD-induced metabolic reprogramming. Several genes encoding the key transcription factors (TFs) were identified in these co-expression modules, highlighting several key TFs, including TCP19, WRI1a, ABF1, ABF2, DERF1, and TZF7, involved in nitrogen metabolism, lipid metabolism, ABA signaling, ethylene signaling, and stress regulation. Thus, our work presents the first evidence that molecular mechanisms other than ABA-mediated drought resistance are involved in PRD-mediated stress tolerance. Overall, our results provide new insights into PRD-mediated osmotic stress tolerance, clarify the molecular regulation induced by PRD, and identify genes useful for further improving water-use efficiency and/or stress tolerance in rice.

A multi-omic resource of wheat seed tissues for nutrient deposition and improvement for human health.

As a globally important staple crop, wheat seeds provide us with nutrients and proteins. The trend of healthy dietary has become popular recently, emphasizing the consumption of whole-grain wheat products and the dietary benefits. However, the dynamic changes in nutritional profiles of different wheat seed regions (i.e., the embryo, endosperm and outer layers) during developmental stages and the molecular regulation have not been well studied. Here, we provide this multi-omic resource of wheat seeds and describe the generation, technical assessment and preliminary analyses. This resource includes a time-series RNA-seq dataset of the embryo, endosperm and outer layers of wheat seeds and their corresponding metabolomic dataset, covering the middle and late stages of seed development. Our RNA-seq experiments profile the expression of 63,708 genes, while the metabolomic data includes the abundance of 984 metabolites. We believe that this was the first reported transcriptome and metabolome dataset of wheat seeds that helps understand the molecular regulation of the deposition of beneficial nutrients and hence improvements for nutritional and processing quality traits.

Current advances in the molecular regulation of abiotic stress tolerance in sorghum via transcriptomic, proteomic, and metabolomic approaches.

Sorghum (Sorghum bicolor L. Moench), a monocot C4 crop, is an important staple crop for many countries in arid and semi-arid regions worldwide. Because sorghum has outstanding tolerance and adaptability to a variety of abiotic stresses, including drought, salt, and alkaline, and heavy metal stressors, it is valuable research material for better understanding the molecular mechanisms of stress tolerance in crops and for mining new genes for their genetic improvement of abiotic stress tolerance. Here, we compile recent progress achieved using physiological, transcriptome, proteome, and metabolome approaches; discuss the similarities and differences in how sorghum responds to differing stresses; and summarize the candidate genes involved in the process of responding to and regulating abiotic stresses. More importantly, we exemplify the differences between combined stresses and a single stress, emphasizing the necessity to strengthen future studies regarding the molecular responses and mechanisms of combined abiotic stresses, which has greater practical significance for food security. Our review lays a foundation for future functional studies of stress-tolerance-related genes and provides new insights into the molecular breeding of stress-tolerant sorghum genotypes, as well as listing a catalog of candidate genes for improving the stress tolerance for other key monocot crops, such as maize, rice, and sugarcane.

Molecular Cytological Analysis and Specific Marker Development in Wheat-Psathyrostachys huashanica Keng 3Ns Additional Line with Elongated Glume.

Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) is an excellent gene resource for wheat breeding, which is characterized by early maturity, low plant height, and disease resistance. The wheat-P. huashanica derivatives were created by the elite genes of P. huashanica and permeate into common wheat through hybridization. Among them, a long-glume material 20JH1155 was identified, with larger grains and longer spike than its parents. In the present study, the methods of cytological observation, GISH, and sequential FISH analysis showed that 20JH1155 contained 21 pairs of wheat chromosomes and a pair of P. huashanica. There were some differences in 5A and 7B chromosomes between 20JH1155 and parental wheat 7182. Molecular marker, FISH, and sequence cloning indicated 20JH1155 alien chromosomes were 3Ns of P. huashanica. In addition, differentially expressed genes during immature spikelet development of 20JH1155 and 7182 and predicted transcription factors were obtained by transcriptome sequencing. Moreover, a total of 7 makers derived from Ph#3Ns were developed from transcriptome data. Taken together, the wheat-P. huashanica derived line 20JH1155 provides a new horizon on distant hybridization of wheat and accelerates the utilization of genes of P. huashanica.

Hybrid Metasurfaces for Perfect Transmission and Customized Manipulation of Sound Across Water-Air Interface.

Extreme impedance mismatch causes sound insulation at water-air interfaces, limiting numerous cross-media applications such as ocean-air wireless acoustic communication. Although quarter-wave impedance transformers can improve transmission, they are not readily available for acoustics and are restricted by the fixed phase shift at full transmission. Here, this limitation is broken through impedance-matched hybrid metasurfaces assisted by topology optimization. Sound transmission enhancement and phase modulation across the water-air interface are achieved independently. Compared to the bare water-air interface, it is experimentally observed that the average transmitted amplitude through an impedance-matched metasurface at the peak frequency is enhanced by ≈25.9 dB, close to the limit of the perfect transmission 30 dB. And nearly 42 dB amplitude enhancement is measured by the hybrid metasurfaces with axial focusing function. Various customized vortex beams are experimentally realized to promote applications in ocean-air communication. The physical mechanisms of sound transmission enhancement for broadband and wide-angle incidences are revealed. The proposed concept has potential applications in efficient transmission and free communication across dissimilar media.

The additive interactions between high-molecular-weight glutenin subunits and tannic acid improve the wheat quality.

Wheat gluten proteins, especially high-molecular-weight glutenin subunits (HMW-GS), are the main contributor to flour processing quality. Tannic acid (TA) consisting of a central glucose unit and ten gallic acid molecules is a phenolic acid that improves the processing quality. However, the underlying mechanism of TA's improvement remains largely unknown. Here, we showed that TA's improving effects on gluten aggregation, dough-mixing and bread-making properties were directly associated with the kinds of HMW-GS expressed in wheat seeds in HMW-GS near-isogenic lines (NILs). We established a biochemical framework, elucidated the additive effects of HMW-GS-TA interaction and discovered that TA cross-linked specifically with wheat glutenins but not gliadins, and reduced gluten surface hydrophobicity and SH content depending on the kinds of expressed HMW-GS in the wheat seeds. We also demonstrated that hydrogen bonds play an essential role in TA-HMW-GS interactions and improvement of wheat processing quality. Additionally, the effects of TA on the antioxidant capacity and on nutrient (protein and starch) digestibility were also investigated in the NILs of HMW-GS. TA increased antioxidant capacity but did not affect the digestion of starches and proteins. Our results revealed that TA more effectively strengthened wheat gluten in the presence of more HMW-GS kinds, highlighting TA's potential as an improver toward healthy and quality bread and demonstrating that manipulating hydrogen bonds was a previously overlooked approach to improve wheat quality.

Nano-gold micelles loaded Dox and Elacridar for reversing drug resistance of breast cancer.

The aim of this study was to provide a new effective carrier for rescuing the sensitivity of drug-resistant in breast cancer cells. Nano-gold micelles loaded with Dox and Elacridar (FP-ssD@A-E) were chemically synthesised. With the increase in the amount of Dox and Elacridar, the encapsulation rate of FP-ssD@A-E gradually increased, and the drug loading rate gradually decreased. FP-ss@A-E had a sustained-release effect. Dox, Elacridar, FP-ss@AuNPs, and FP-ssD@A-E significantly improved cell apoptosis, in which, FP-ssD@A-E was the most significant. FP-ssD@A-E significantly decreased the cell viability and improved the Dox uptake. The levels of VEGFR-1, P-gp, IL-6, and i-NOS were significantly decreased after Dox, Dox + Elacridar, FP-ss@AuNPs, and FP-ssD@A-E treatment. It was worth noting that FP-ssD@A-E had the most significant effects. The prepared FP-ssD@A-E micelles, which were spherical in shape, uniform in particle size distribution, and had good drug loading performance and encapsulation efficiency.

An established protocol for generating transgenic wheat for wheat functional genomics via particle bombardment.

Wheat is one of the most important food crops in the world and is considered one of the top targets in crop biotechnology. With the high-quality reference genomes of wheat and its relative species and the recent burst of genomic resources in Triticeae, demands to perform gene functional studies in wheat and genetic improvement have been rapidly increasing, requiring that production of transgenic wheat should become a routine technique. While established for more than 20 years, the particle bombardment-mediated wheat transformation has not become routine yet, with only a handful of labs being proficient in this technique. This could be due to, at least partly, the low transformation efficiency and the technical difficulties. Here, we describe the current version of this method through adaptation and optimization. We report the detailed protocol of producing transgenic wheat by the particle gun, including several critical steps, from the selection of appropriate explants (i.e., immature scutella), the preparation of DNA-coated gold particles, and several established strategies of tissue culture. More importantly, with over 20 years of experience in wheat transformation in our lab, we share the many technical details and recommendations and emphasize that the particle bombardment-mediated approach has fewer limitations in genotype dependency and vector construction when compared with the Agrobacterium-mediated methods. The particle bombardment-mediated method has been successful for over 30 wheat genotypes, from the tetraploid durum wheat to the hexaploid common wheat, from modern elite varieties to landraces. In conclusion, the particle bombardment-mediated wheat transformation has demonstrated its potential and wide applications, and the full set of protocol, experience, and successful reports in many wheat genotypes described here will further its impacts, making it a routine and robust technique in crop research labs worldwide.

Identification of the active triple-phase boundary of a non-Pt catalyst layer in fuel cells.

The rational design of non-Pt oxygen reduction reaction (ORR) catalysts and catalyst layers in fuel cells is largely impeded by insufficient knowledge of triple-phase boundaries (TPBs) in the micropore and mesopore ranges. Here, we developed a size-sensitive molecular probe method to resolve the TPB of Fe/N/C catalyst layers in these size ranges. More than 70% of the ORR activity was found to be contributed by the 0.8- to 2.0-nanometer micropores of Fe/N/C catalysts, even at a low micropore area fraction of 29%. Acid-alkaline interactions at the catalyst-polyelectrolyte interface deactivate the active sites in mesopores and macropores, resulting in inactive TPBs, leaving micropores without the interaction as the active TPBs. The concept of active and inactive TPBs provides a previously unidentified design principle for non-Pt catalyst and catalyst layers in fuel cells.

A microfluidic demonstration of "cluster-sprout-infiltrating" mode for hypoxic mesenchymal stem cell guided cancer cell migration.

Mesenchymal stem cells (MSCs) play a critical role in tumor metastasis. However, the dynamic process of MSCs-mediated cancer cell invasion remains inconclusive. In breast cancer mouse models, we observed that MSCs promoted lung metastasis. We constructed a microfluidic-based 3D co-culture device to monitor MSCs-mediated cancer cell invasion in a nutrient-deficient hypoxic microenvironment. On biomimetic microfluidic devices, MSCs guided cancer cell migration in a "cluster-sprout-infiltrating" mode. Importantly, hypoxic conditions significantly promoted MSCs migration at the infiltration stage, leading to accelerated breast cancer cell invasion. Moreover, hypoxia related LncRNA analysis showed that H19 was dramatically upregulated in response to hypoxic conditions. Conversely, H19 depletion impaired MSCs-directed breast cancer cell invasion. Mechanistically, H19 functions as a competitive endogenous RNA (ceRNA) which sequesters miRNA let-7 to release its target matrix metalloproteinase-1 (MMP1). Intriguingly, aspirin dramatically suppressed H19 and MMP1 expression and blocked MSCs infiltration under hypoxic conditions, resulting in alleviated breast cancer cell invasion. These findings point to the metastatic promoting role of MSCs in tumor stroma and suggest that MSCs might be a therapeutic target for metastatic breast cancer.