Distribution characteristics of microplastics in soil of Loess Plateau in northwest China and their relationship with land use type.

The widespread distribution of microplastics (MPs) in soil has aroused great concern. The land use type can affect the distribution characteristics of MPs, whereas the abundance of MPs in the Loess Plateau region and the influence of different land use types on it are unclear. This study checked into the distribution of MPs in the Loess Plateau region, studied the abundance of MPs in woodland, construction land, grassland and cultivated land, and analyzed the distribution characteristics of their shape, size, and color. The abundance of MPs in the Loess Plateau region reached 2982.34 items/kg, dominated by black, small size and fragment MPs. The order of average abundance of MPs was: cultivated land (3535 items/kg) > construction land (2809 items/kg) > woodland (2781 items/kg) > grassland (2658 items/kg). Fragment MPs were predominant in woodland, construction land and cultivated land, but film and fiber MPs were predominant in grassland. MPs in cultivated land and construction land mainly sourced from human activities, MPs in woodland and grassland were more likely to come from atmospheric deposition. Human activities and sunlight exposure can cause MPs to break down, while trees in woodland block rays of light, slowing MPs breakage to some extent. And the polymer type of MPs was mostly PE and the main ones were black. This study may provide important data for follow-up research on MPs in terrestrial ecosystems.

Structural Color Medical Patch with Surface Dual-Properties of Wet Bioadhesion and Slipperiness.

Developing a self-reporting bioadhesive patch that has strong adhesion to the wet tissues and meanwhile can avoid adhering to the adjacent tissues is a current research difficulty and challenge. In this paper, inspired by the wet adhesion of spider web, slippery surface of Nepenthes, and structural color phenomena of chameleons, a novel structural color medical patch with surface dual-properties of wet bioadhesion and slipperiness for internal tissue repair based on inverse opal scaffold is presented. The adhesive surface made by poly(acrylic acid)-polyethylene glycol-N-hydroxysuccinimide ester and gelatin hydrogel can attain tough adhesion to internal wet tissues by absorbing tissue interfacial water and the covalent cross-linking between the hydrogel and tissue. Besides, the slippery surface made by liquid paraffin infused inverse opal scaffold can avoid adhesion to the adjacent tissues. It is demonstrated that the designed patch can adhere tightly to the defect tissue and improve the tissue repair without adjacent adhesion when applied in a rat model with full-thickness perforation of the stomach wall. In addition, the responsive structural color can supply a color-sensing monitoring to evaluate the adhesive and repair process. These features impart the bioinspired patch with great scientific significance and broad clinical application prospects.

Pollen-Inspired Photonic Barcodes with Prickly Surface for Multiplex Exosome Capturing and Screening.

Exosomes, which play an important role in intercellular communication, are closely related to the pathogenesis of disease. However, their effective capture and multiplex screening are still challenging. Here, inspired by the unique structure of pollens, we present novel photonic crystal (PhC) barcodes with prickly surface by hydrothermal synthesis for multiplex exosome capturing and screening. These pollen-inspired PhC barcodes are imparted with extremely high specific surface area and excellent prickly surface nanostructures, which can improve the capture rate and detection sensitivity of exosomes. As the internal periodic structures are kept during the hydrothermal synthesis process, the pollen-inspired PhC barcodes exhibit obvious and stable structural colors for identification, which enables multiplex detection of exosomes. Thus, the pollen-inspired PhC barcodes can not only effectively capture and enrich cancer-related exosomes but also support multiplex screening of exosomes with high sensitivity. These features make the prickly PhC barcodes ideal for the analysis of exosomes in medical diagnosis.

Indole-3-Carbinol (I3C) Protects the Heart From Ischemia/Reperfusion Injury by Inhibiting Oxidative Stress, Inflammation, and Cellular Apoptosis in Mice.

Strategies for treating myocardial ischemia in the clinic usually include re-canalization of the coronary arteries to restore blood supply to the myocardium. However, myocardial reperfusion insult often leads to oxidative stress and inflammation, which in turn leads to apoptosis and necrosis of myocardial cells, for which there are no standard treatment methods. The aim of this study was to determine the pharmacological effect of indole-3-carbinol (I3C), a phytochemical found in most cruciferous vegetables, in a mouse model of myocardial ischemia/reperfusion injury (MIRI). Our results showed that I3C pretreatment (100 mg/kg, once daily, i. p.) prevented the MIRI-induced increase in infarct size and serum creatine kinase (CK) and lactate dehydrogenase (LDH) in mice. I3C pretreatment also suppressed cardiac apoptosis in MIRI mice by increasing the expression levels of the anti-apoptotic protein Bcl-2 and decreasing the expression levels of several apoptotic proteins, including Bax, caspase-3, and caspase-9. In addition, I3C pretreatment was found to reduce the levels of parameters reflecting oxidative stress, such as dihydroethidium (DHE), malondialdehyde (MDA), reactive oxygen species (ROS), and nitric oxide (NO), while increasing the levels of parameters reflecting anti-oxidation, such as total antioxidant capacity (T-AOC) and glutathione (GSH), in MIRI-induced ischemic heart tissue. I3C pretreatment was also able to remarkably decrease the expression of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) mRNA in ischemic heart tissue. These results demonstrate that administration of I3C protects the heart from MIRI through its anti-apoptotic, antioxidant, and anti-inflammatory effects.

The first internal electromagnetic motion monitoring implementation for stereotactic liver radiotherapy in China: procedures and preliminary results.

BACKGROUND: Respiratory motion may compromise the dose delivery accuracy in liver stereotactic body radiation therapy (SBRT). Motion management can improve treatment delivery. However, external surrogate signal may be unstable and inaccurate. This study reports the first case of liver SBRT based on internal electromagnetic motion monitoring (Calypso, Varian Medical Systems, USA) in China. MATERIALS AND METHODS: The patient with a primary liver cancer was treated with respiratory-gated SBRT guided by three implanted electromagnetic transponders. The treatment was carried out in breath-hold end-exhale with beam-on when the centroid of the three transponders drifted within 5 mm (left-right (LR), anterior-posterior (AP) and cranio-caudal (CC) directions) from the planned position. The motion monitoring treatments were delivered in breath-hold end-exhale mode with the energy of 6 MV in FFF mode with 1200 monitor units (MU) per minute. For each fraction, QA results, intertransponder distances, geometric checks as well as tumor motion logs were explicitly recorded. RESULTS: Comparing with the plan data, distance variances between each two transponders were - 0.56 ± 0.32 mm, 0.17 ± 0.33 mm and - 0.82 ± 0.68 mm. Geometric residual, the pitch, roll and yaw angles were 0.48 ± 0.21 mm (threshold 2.0 mm), 2.17° ± 1.85° (threshold 10°), - 2.42° ± 1.51° (threshold 10°) and 1.67° ± 1.07° (threshold 10°), respectively. The delivery time of the five fields were 13.8 s, 13.1 s, 11.2 s, 11.6 s, and 11.6 s with the average value of 12.3 ± 1.1 s. Treatment duration of each fraction ranged from 6.2 to 21.4 min, with the average value of 11.3 ± 5.0 min. CONCLUSIONS: The first case of liver SBRT patient of China based on internal electromagnetic motion monitoring was performed. The system had a high tracking accuracy, and it did not delay the treatment time. In addition, the patient did not show any severe side effects except for grade I myelotoxicity. The internal electromagnetic motion monitoring system provides a real-time and direct way to track liver tumor targets.

Wide-Gamut Biomimetic Structural Colors from Interference-Assisted Two-Photon Polymerization.

Two-photon polymerization (TPP) is an emerging direct laser writing technique for the fabrication of structural colors. However, its coloration ability is suppressed as the vertical resolution is up to several microns. To solve this issue, an interference-assisted TPP technique was employed. Laser interference at a highly reflective interface produced the periodic energy redistribution along the vertical direction, turning the laser voxel into multilayer structures and confirming this technology as a facile and robust method for precise control of its vertical feature size. Biomimetic structural colors (BSCs) inspired from the ridge-lamella configurations in the Morph butterflies were fabricated using this improved TPP technique. The coloration mechanisms of the multilayer interference from the lamella layers, the thin-film interference from the fusion of multilayers, and the hybrid situations were systematically studied. These BSC colors were grouped as pixel palettes with various TPP parameters corresponding to each other, and they spanned almost the entire standard red-green-blue color space. Moreover, under optimized conditions, it was possible to fabricate a 1 cm2 area within 2.5 h. These features make interference-assisted TPP an ideal coloration method for practical applications, such as display, decoration, sensing, and so on.

Corrigendum to "Loss of Arp1, a putative actin-related protein, triggers filamentous and invasive growth and impairs pathogenicity in Candida albicans" (Computational and Structural Biotechnology Journal, 2020, 18: 4002-4015).

[This corrects the article DOI: 10.1016/j.csbj.2020.11.034.].

Facile Surface Functionalization Strategy for Two-Photon Lithography Microstructures.

Two-photon lithography (TPL) is a powerful tool to construct small-scale objects with complex and precise 3D architectures. While the limited selection of chemical functionalities on the printed structures has restricted the application of this method in fabricating functional objects and devices, this study presents a facile, efficient, and extensively applicable method to functionalize the surfaces of the objects printed by TPL. TPL-printed objects, regardless of their compositions, can be efficiently functionalized by combining trichlorovinylsilane treatment and thiol-ene chemistry. Various functionalities can be introduced on the printed objects, without affecting their micro-nano topographies. Hence, microstructures with diverse functions can be generated using non-functional photoresists. Compared to existed strategies, this method is fast, highly efficient, and non photoresist-dependent. In addition, this method can be applied to various materials, such as metals, metal oxides, and plastics that can be potentially utilized in TPL or other 3D printing technologies. The applications of this method on the biofunctionalization of microrobots and cell scaffolds are also demonstrated.

Capillary-Force-Driven Self-Assembly of 4D-Printed Microstructures.

Capillary-force-driven self-assembly is emerging as a significant approach for the massive manufacture of advanced materials with novel wetting, adhesion, optical, mechanical, or electrical properties. However, academic value and practical applications of the self-assembly are greatly restricted because traditional micropillar self-assembly is always unidirectional. In this work, two-photon-lithography-based 4D microprinting is introduced to realize the reversible and bidirectional self-assembly of microstructures. With asymmetric crosslinking densities, the printed vertical microstructures can switch to a curved state with controlled thickness, curvature, and smooth morphology that are impossible to replicate by traditional 3D-printing technology. In different evaporating solvents, the 4D-printed microstructures can experience three states: (I) coalesce into clusters from original vertical states via traditional self-assembly, (II) remain curved, or (III) arbitrarily self-assemble (4D self-assembly) toward the curving directions. Compared to conventional approaches, this 4D self-assembly is distance-independent, which can generate varieties of assemblies with a yield as high as 100%. More importantly, the three states can be reversibly switched, allowing the development of many promising applications such as reversible micropatterns, switchable wetting, and dynamic actuation of microrobots, origami, and encapsulation.

Loss of Arp1, a putative actin-related protein, triggers filamentous and invasive growth and impairs pathogenicity in Candida albicans.

The polymorphous cellular shape of Candida albicans, in particular the transition from a yeast to a filamentous form, is crucial for either commensalism or life-threatening infections of the host. Various external or internal stimuli, including serum and nutrition starvation, have been shown to regulate filamentous growth primarily through two classical signaling pathways, the cAMP-PKA and the MAPK pathways. Genotoxic stress also induces filamentous growth, but through independent pathways, and little is known about negative regulation during this reversible morphological transition. In this study, we established that ARP1 in C. albicans, similar to its homolog in S. cerevisiae, has a role in nuclei separation and spindle orientation. Deletion of ARP1 generated filamentous and invasive growth as well as increased biofilm formation, accompanied by up-regulation of hyphae specific genes, such as HWP1, UME6 and ALS3. The filamentous and invasive growth of the ARP1 deletion strain was independent of transcription factors Efg1, Cph1 and Ume6, but was suppressed by deleting checkpoint BUB2 or overexpressing NRG1. Deletion of ARP1 impaired the colonization of Candida cells in mice and also attenuated virulence in a mouse model. All the data suggest that loss of ARP1 activates filamentous and invasive growth in vitro, and that it positively regulates virulence in vivo, which provides insight into actin-related morphology and pathogenicity in C. albicans.

3D-printed cellular tips for tuning fork atomic force microscopy in shear mode.

Conventional atomic force microscopy (AFM) tips have remained largely unchanged in nanomachining processes, constituent materials, and microstructural constructions for decades, which limits the measurement performance based on force-sensing feedbacks. In order to save the scanning images from distortions due to excessive mechanical interactions in the intermittent shear-mode contact between scanning tips and sample, we propose the application of controlled microstructural architectured material to construct AFM tips by exploiting material-related energy-absorbing behavior in response to the tip-sample impact, leading to visual promotions of imaging quality. Evidenced by numerical analysis of compressive responses and practical scanning tests on various samples, the essential scanning functionality and the unique contribution of the cellular buffer layer to imaging optimization are strongly proved. This approach opens new avenues towards the specific applications of cellular solids in the energy-absorption field and sheds light on novel AFM studies based on 3D-printed tips possessing exotic properties.

3D Bioinspired Microstructures for Switchable Repellency in both Air and Liquid.

In addition to superhydrophobicity/superoleophobicity, surfaces with switchable water/oil repellency have also aroused considerable attention because of their potential values in microreactors, sensors, and microfluidics. Nevertheless, almost all those as-prepared surfaces are only applicable for liquids with higher surface tension (γ > 25.0 mN m-1) in air. In this work, inspired by some natural models, such as lotus leaf, springtail skin, and filefish skin, switchable repellency for liquids (γ = 12.0-72.8 mN m-1) in both air and liquid is realized via employing 3D deformable multiply re-entrant microstructures. Herein, the microstructures are fabricated by a two-photon polymerization based 3D printing technique and the reversible deformation is elaborately tuned by evaporation-induced bending and immersion-induced fast recovery (within 30 s). Based on 3D controlled microstructural architectures, this work offers an insightful explanation of repellency/penetration behavior at any three-phase interface and starts some novel ideas for manipulating opposite repellency by designing/fabricating stimuli-responsive microstructures.

Programmable Liquid Adhesion on Bio-Inspired Re-Entrant Structures.

Surfaces combining antispreading and high adhesion can find wide applications in the manipulation of liquid droplets, generation of micropatterns and liquid enrichment. To fabricate such surfaces, almost all the traditional methods demand multi-step processes and chemical modification. And even so, most of them cannot be applied for some liquids with extremely low surface energy. In the past decade, multiply re-entrant structures have aroused much attention because of their universal and modification-independent antiadhesion or antipenetration ability. Unfortunately, theories and applications about their liquid adhesion behavior are still rare. In this work, inspired by the springtail skin and gecko feet in the adhered state, it is demonstrated that programmable liquid adhesion is realized on the 3D-printed micro doubly re-entrant arrays. By arranging the arrays reasonably, three different Cassie adhesion behaviors can be obtained: I) no residue adhesion, II) tunable adhesion, and III) absolute adhesion. Furthermore, various arrays are designed to tune macro/micro liquid droplet manipulation, which can find applications in the transportation of liquid droplets, liquid enrichment, generation of tiny droplets, and micropatterns.

Self-assembled colloidal arrays for structural color.

Structural color materials that are colloidally assembled as inspired by nature are attracting increased interest in a wide range of research fields. The assembly of colloidal particles provides a facile and cost-effective strategy for fabricating three-dimensional structural color materials. In this review, the generation mechanisms of structural colors from colloidally assembled photonic crystalline structures (PCSs) and photonic amorphous structures (PASs) are first presented, followed by the state-of-the-art and detailed technologies for their fabrication. The variable optical properties of PASs and PCSs are then discussed, focusing on their spatial long- and short-order structures and surface topography, followed by a detailed description of the modulation of structural color by refractive index and lattice distance. Finally, the current applications of structural color materials colloidally assembled in various fields including biomaterials, microfluidic chips, sensors, displays, and anticounterfeiting are reviewed, together with future applications and tasks to be accomplished.

Porous scaffolds from droplet microfluidics for prevention of intrauterine adhesion.

Severe intrauterine adhesions (IUAs) have a great negative impact on women's psychological and reproductive health. It remains a significant challenge to prevent postoperative IUAs because of the complications of various clinical preventive measures and incompatibility of uterine cavity morphology. Herein, we present a new drug-loadedporous scaffold based on a microfluidic droplet template, which combines the characteristics of the artificial biocompatible material GelMA and the natural polysaccharide material Na-alginate. By changing the containers that collect the microfluidic droplets, the porous scaffold conforming to the shape of the uterine cavity could be obtained. The porous structure, mechanical property, and flexibility impart the scaffold with compressibility and send it to the uterus through the vagina. In addition, the external-internal connected open structures could load and control the release of drugs to repair the damaged region continuously in vivo. To verify the antiadhesion and repair of drug-loaded porous scaffolds, we tested the system in the rat model of IUAs, and it was demonstrated that the system had the ability to improve neovascularization, cellularize the damaged tissue, and repair the endometrium. These features provide the drug-loaded porous scaffolds with new options for the improvement of postoperative IUAs. STATEMENT OF SIGNIFICANCE: Intrauterine adhesions are caused by various causes of damage to the endometrial basal layer, thus leading to part or entire adhesions in the cervical or uterine cavity. Clinically, various preventive measures reach the barrier effect through the physical barrier, which are difficult to further promote the repair of the damaged endometrium, and most of them have apparent side effects. This study aims to prepare compressible and biodegradable three-dimensional porous drug-loading biological scaffolds. GelMA and Na-alginate have desirable biocompatibility. The interconnect porous scaffolds, which were prepared through the combination of biomaterials and single emulsion microfluidics, not only have compressibility but also provide space for drug delivery and release. This system can further promote the repair of the endometrium while preventing adhesion.

3D Printing of Bioinspired Liquid Superrepellent Structures.

Bioinspired re-entrant structures have been proved to be effective in achieving liquid superrepellence (including anti-penetration, anti-adhesion, and anti-spreading). However, except for a few reports relying on isotropic etching of silicon wafers, most fluorination-dependent surfaces are still unable to repel liquids with extreme low surface energy (i.e., γ < 15 mN m-1 ), especially those fluorinated solvents. Herein, triply re-entrant structures, possessing superrepellence to water (with surface tension γ of 72.8 mN m-1 ) and various organic liquids (γ = 12.0-27.1 mN m-1 ), are fabricated via two-photon polymerization based 3D printing technology. Such structures can be constructed both on rigid and flexible substrates, and the liquid superrepellent properties can be kept even after oxygen plasma treatment. Based on the prepared triply re-entrant structures, micro open capillaries are constructed on them to realize directional liquid spreading, which may be applied in microfluidic platforms and lab-on-a-chip applications. The fabricated arrays can also find potential applications in electronic devices, gas sensors, microchemical/physical reactors, high-throughput biological sensors, and optical displays.

Enzymatic Inverse Opal Hydrogel Particles for Biocatalyst.

Enzymatic carriers have a demonstrated value for chemical reactions and industrial applications. Here, we present a novel kind of inverse opal hydrogel particles as the enzymatic carriers. The particles were negatively replicated from spherical colloidal crystal templates by using magnetic nanoparticles tagged acrylamide hydrogel. Thus, they were endowed with the features of monodispersity, small volume, complete penetrating structure, and controllable motion, which are all beneficial for improving the efficiency of biocatalysis. In addition, due to the ordered porous nanostructure, the inverse opal hydrogel particles were imparted with unique photonic band gaps (PBGs) and vivid structural colors for encoding varieties of immobilized enzymes and for constructing a multienzymes biocatalysis system. These features of the inverse opal hydrogel particles indicate that they are ideal enzymatic carriers for biocatalysis.

Anisotropic colloidal crystal particles from microfluidics.

Anisotropic colloidal crystal particles (CCPs) have showed their great potential in biotechnology and structural materials due to their anisotropic shapes and tunable optical property. However, their controllable generation is still a challenge. Here, a novel microfluidic approach is developed to generate anisotropic CCPs. The microfluidic device is composed of an injection capillary and a collection capillary with available size and shape. Based on the device, the anisotropic particles with non-close-packed colloidal crystal structures are achieved by photo-polymerizing droplet templates in a confined collection capillary with different shapes and sizes. Moreover, anisotropic close-packed CCPs can be made from non-close-packed CCPs through a thermal process. It is demonstrated that the anisotropic CCPs in different sizes, structural colors and shapes (rods, cuboids and disks) can be generated. These distinguishable features of resultant particles make them ideal barcodes for high-throughput bioassays. In order to prove it, DNA multiplex detection is carried out. The experimental results indicate that achieved particles have a great encoding capacity and are highly practical for multiplex coding bioassays. Therefore, we believe that the anisotropic CCPs would be highly promising barcodes in biomedical applications, including high-throughput bioassays and cell culture research where multiplexing is needed.

Photonic crystal microcapsules for label-free multiplex detection.

A novel suspension array, which possesses the joint advantages of photonic crystal encoded technology, bioresponsive hydrogels, and photonic crystal sensors with capability of full multiplexing label-free detection is developed.

An optical nose chip based on mesoporous colloidal photonic crystal beads.

An optical nose chip is developed using surface functionalized mesoporous colloidal photonic crystal beads as elements. The prepared optical nose chip displays excellent discrimination among a very wide range of compounds, not only the simplex organic vapors from the different or same chemical family, but also the complex expiratory air from different people.