General Semi-Solid Freeze Casting for Uniform Large-Scale Isotropic Porous Scaffolds: An Application for Extensive Oral Mucosal Reconstruction.

Ice-templated porous biomaterials possess transformative potential in regenerative medicine; yet, scaling up ice-templating processes for broader applications-owing to inconsistent pore formation-remains challenging. This study reports an innovative semi-solid freeze-casting technique that draws inspiration from semi-solid metal processing (SSMP) combined with ice cream-production routines. This versatile approach allows for the large-scale assembly of various materials, from polymers to inorganic particles, into isotropic 3D scaffolds featuring uniformly equiaxed pores throughout the centimeter scale. Through (cryo-)electron microscopy, X-ray tomography, and finite element modeling, the structural evolution of ice grains/pores is elucidated, demonstrating how the method increases the initial ice nucleus density by pre-fabricating a semi-frozen slurry, which facilitates a transition from columnar to equiaxed grain structures. For a practical demonstration, as-prepared scaffolds are integrated into a bilayer tissue patch using biodegradable waterborne polyurethane (WPU) for large-scale oral mucosal reconstruction in minipigs. Systematic analyses, including histology and RNA sequencing, prove that the patch modulates the healing process toward near-scarless mucosal remodeling via innate and adaptive immunomodulation and activation of pro-healing genes converging on matrix synthesis and epithelialization. This study not only advances the field of ice-templating fabrication but sets a promising precedent for scaffold-based large-scale tissue regeneration.

Synergistic Effect of Co3(HPO4)2(OH)2 Cocatalyst and Al2O3 Passivation Layer on BiVO4 Photoanode for Enhanced Photoelectrochemical Water Oxidation.

Bismuth vanadate (BVO) is regarded as an exceptional photoanode material for photoelectrochemical (PEC) water splitting, but it is restricted by the severe photocorrosion and slow water oxidation kinetics. Herein, a synergistic strategy combined with a Co3(HPO4)2(OH)2 (CoPH) cocatalyst and an Al2O3 (ALO) passivation layer was proposed for enhanced PEC performance. The CoPH/ALO/BVO photoanode exhibits an impressive photocurrent density of 4.9 mA cm-2 at 1.23 VRHE and an applied bias photon-to-current efficiency (ABPE) of 1.47% at 0.76 VRHE. This outstanding PEC performance can be ascribed to the suppressed surface charge recombination, facilitated interfacial charge transfer, and accelerated water oxidation kinetics with the introduction of the CoPH cocatalyst and ALO passivation layer. This work provides a novel and synergistic approach to design an efficient and stable photoanode for PEC applications by combining an oxygen evolution cocatalyst and a passivation layer.

A chromosome-level genome assembly of the Echiura Urechis unicinctus.

Echiura is a distinctive family of unsegmented sausage-shaped marine worms whose phylogenetic relationship still needs strong evidence from the phylogenomic analysis. In this family, Urechis unicinctus is known for its high nutritional and medicinal value and adaptation to harsh intertidal conditions. Herein, we combined PacBio long-read, short-read Illumina and Hi-C sequencing, generating a high-quality chromosome-level genome assembly of U. unicinctus. The assembled genome spans ~1,138.6 Mb with a scaffold N50 of 68.3 Mb, of which 1,113.8 Mb (97.82%) were anchored into 17 pseudo-chromosomes. The BUSCO analysis demonstrated the completeness of the genome assembly and gene model prediction are 93.5% and 91.5%, respectively. A total of 482.1 Mb repetitive sequences, 21,524 protein-coding genes, 1,535 miRNAs, 3,431 tRNAs, 124 rRNAs, and 348 snRNAs were annotated. This study significantly improves the quality of U. unicinctus genome assembly, sets the footsteps for molecular breeding and further study in genome evolution, genetic and molecular biology of U. unicinctus.

Porous Three-Dimensional Polyurethane Scaffolds Promote Scar-Free Endogenous Regeneration After Acute Brain Hemorrhage.

Intracerebral hemorrhage (ICH) is the most lethal subtype of stroke and is associated with significant morbidity and mortality. Despite advances in the clinical treatment of ICH, limited progress has been made regarding endogenous brain regeneration after ICH. Failure of brain regeneration is mainly attributed to the inhibitive regenerative microenvironment caused by secondary injury after ICH. In this study, we investigated a three-dimensional biodegradable waterborne polyurethane (BWPU) scaffold as a tool to promote brain regeneration after ICH. After implantation into the cavity following hematoma evacuation, these implanted scaffolds could act as a reservoir; store a series of necrotic debris, cytokines, and chemokines; and attract microglia/macrophages to their pores. Subsequently, these microglia/macrophages were polarized into the M1-like subtype to eliminate these substances. This process disperses M1-like immune cells and prevents the formation of dense glial scar-free structures after ICH. Inflammatory cells in scaffolds include scar-free secreted growth factors and extracellular matrix (ECM) proteins, and further induce a M2-like immune cells enriched regeneration-predominant microenvironment to promote endogenous brain regeneration with functional recovery. In summary, in this work, we have revealed the potential and mechanism of the BWPU scaffold as a tool to promote endogenous brain tissue regeneration after ICH.

Experimental heatwaves facilitate invasion and alter species interactions and composition in a tropical host-parasitoid community.

As mean temperatures increase and heatwaves become more frequent, species are expanding their distributions to colonise new habitats. The resulting novel species interactions will simultaneously shape the temperature-driven reorganization of resident communities. The interactive effects of climate change and climate change-facilitated invasion have rarely been studied in multi-trophic communities, and are likely to differ depending on the nature of the climatic driver (i.e., climate extremes or constant warming). We re-created under laboratory conditions a host-parasitoid community typical of high-elevation rainforest sites in Queensland, Australia, comprising four Drosophila species and two associated parasitoid species. We subjected these communities to an equivalent increase in average temperature in the form of periodic heatwaves or constant warming, in combination with an invasion treatment involving a novel host species from lower-elevation habitats. The two parasitoid species were sensitive to both warming and heatwaves, while the demographic responses of Drosophila species were highly idiosyncratic, reflecting the combined effects of thermal tolerance, parasitism, competition, and facilitation. After multiple generations, our heatwave treatment promoted the establishment of low-elevation species in upland communities. Invasion of the low-elevation species correlated negatively with the abundance of one of the parasitoid species, leading to cascading effects on its hosts and their competitors. Our study, therefore, reveals differing, sometimes contrasting, impacts of extreme temperatures and constant warming on community composition. It also highlights how the scale and direction of climate impacts could be further modified by invading species within a bi-trophic community network.

Cancer-Erythrocyte Membrane-Mimicking Fe3O4 Nanoparticles and DHJS for Ferroptosis/Immunotherapy Synergism in Tumors.

Ferroptosis is characterized by iron accumulation and lipid peroxidation. However, a clinical dose of Fe3O4 nanoparticles could not cause effective ferroptosis in tumors, and the mechanism is yet to be completely understood. In this study, using RNA-seq data, we found that tumor cells could feedback-activate the antioxidant system by upregulating Nrf-2 expression, thus avoiding ferroptosis caused by Fe3O4 nanoparticles. We also found that DHJS (a probe for ROS generation) can antagonize Nrf-2 expression when it synergizes with Fe3O4 nanoparticles, thus inducing ferroptosis in tumor cells. Considering these findings, we created a biomimetic hybrid cell membrane camouflaged by PLGA-loaded Fe3O4 and DHJS to treat osteosarcoma. The hybrid cell membrane endowed the core nanoparticle with the extension of blood circulation life and enhanced homologous targeting ability. In addition, DHJS and Fe3O4 in nanoparticles prompted synergistically lethal ferroptosis in cancer cells and induced macrophage M1 polarization as well as the infiltration of CD8(+) T cells and dendritic cells in tumors. In summary, this study provides novel mechanistic insights and practical strategies for ferroptosis induction of Fe3O4 nanoparticles. Meanwhile, the synthesized biomimetic nanoparticles exhibited synergistic ferroptosis/immunotherapy against osteosarcoma.

DW-GAN: Toward High-Fidelity Color-Tones of GAN-Generated Images With Dynamic Weights.

Color-tone represents the prominent color of an image, and training generative adversarial nets (GAN) to change color-tones of generated images is desirable in many applications. Advances such as HistoGAN can manipulate color-tones of generated images with a target image. Yet, there are challenges. Kullback-Leibler (KL) divergence adopted by HistoGAN might bring the color-tone mismatching, because it is possible to provide infinite score to a generator. Moreover, only relying on distribution estimation also produces images with lower fidelity in HistoGAN. To address these issues, we propose a new approach, named dynamic weights GAN (DW-GAN). We use two discriminators to estimate the distribution matching degree and details' similarity, with Laplacian operator and Hinge loss. Laplacian operator can help capture more image details, while Hinge loss is deduced from mean difference (MD) that could avoid the case of infinite score. To synthesize desired images, we combine the loss of the two discriminators with generator loss and set the weights of the two estimated scores to be dynamic through the previous discriminators' outputs, given that the training signal of a generator is from a discriminator. Besides, we innovatively integrate the dynamic weights into other GAN variants (e.g., HistoGAN and StyleGAN) to show the improved performance. Finally, we conduct extensive experiments on one industrial Fabric and seven public datasets to demonstrate the significant performance of DW-GAN in producing higher fidelity images and achieving the lowest Frechet inception distance (FID) scores over SOTA baselines.

Immune-microenvironment modulatory polyurethane-hyaluronic acid hybrid hydrogel scaffolds for diabetic wound treatment.

The healing of wounds in diabetic patients is a huge challenge issue in clinical medicine due to the disordered immune. Recruiting endogenous cells to play a role in the early stage and timely reducing inflammation to promote healing in the middle or late of injuring are both prerequisites for effective treatment. Here, inspired by natural extracellular matrix, three-dimensional porous polyurethane-hyaluronic acid hybrid hydrogel scaffolds (PUHA) were prepared to repair diabetic wound through activate cell immunity by moderate foreign body reaction, provide cell adhesion growth extracellular matrix of hyaluronic acid (HA) and exhibit anti-inflammatory effect of polyurethane (PU). The interaction between PU and HA alters the compact PU hydrogel into macroporous PUHA hydrogel scaffolds with super-swelling, elastic mechanical properties, and controllable degradation, which are suitable for endogenous cells infiltration, growth and immune activation. Additionally, incorporating with RGD, PUHA hydrogel scaffolds with bioactive physicochemical features can evidently reduce the inflammation and modulate the polarization of macrophage apparently both in vitro and in vivo, mainly through downregulation of cytokine-cytokine receptor interaction genes, leading to reprogramming immune-microenvironment and rapid diabetic wound healing. This method of gathering cells initially and intervening immune-microenvironment in time provides an expected way to design biomaterials for chronic wound healing.

Reducing Mode Collapse With Monge-Kantorovich Optimal Transport for Generative Adversarial Networks.

Mode collapse has been a persisting challenge in generative adversarial networks (GANs), and it directly affects the applications of GAN in many domains. Existing works that attempt to solve this problem have some serious limitations: models using optimal transport (OT) strategies (e.g., Wasserstein distance) lead to vanishing or exploding gradients; increasing the number of generators can cause several generators focusing on the same mode; and approaches that modify the loss also do not satisfactorily resolve mode collapse. In this article, we reduce mode collapse by formulating it as a Monge problem of OT map. We show that the Monge problem can be transformed to the distribution transformation problem in GAN, and a rectified affine neural network can be considered as a measurable function. In this way, we propose Monge GAN that uses this measurable function to transform the generated data distribution into the original data distribution. We utilize the Kantorovich formulation to obtain the OT cost, which is regarded as the OT distance between the two distributions. Finally, we conduct extensive experiments on both image and numerical datasets to validate our Monge GAN in reducing model collapse.

Electroactive scaffolds of biodegradable polyurethane/polydopamine-functionalized graphene oxide regulating the inflammatory response and revitalizing the axonal growth cone for peripheral nerve regeneration.

Long-gap peripheral nerve injury remains a major challenge in regenerative medicine and results in permanent sensory and motor dysfunction. Nerve guidance scaffolds (NGSs) are known as a promising alternative to autologous nerve grafting. The latter, the current "gold standard" in clinical practice, is frequently constrained by the limited availability of sources and the inevitable damage to the donor area. Given the electrophysiological properties of nerves, electroactive biomaterials are being intensively investigated in nerve tissue engineering. In this study, we engineered a conductive NGS compounded of biodegradable waterborne polyurethane (WPU) and polydopamine-reduced graphene oxide (pGO) for repairing impaired peripheral nerves. The incorporation of pGO at the optimal concentration (3 wt%) promoted in vitro spreading of Schwann cells (SCs) with high expression of the proliferation marker S100 protein. In an in vivo study of sciatic nerve transection injury, WPU/pGO NGSs were found to regulate the immune microenvironment by activating macrophage M2 polarization and upregulate growth-associated protein 43 (GAP43) to facilitate axonal elongation. Histological and motor function analysis demonstrated that WPU/pGO NGSs had a neuroprosthetic effect close to that of an autograft, which significantly promoted the regeneration of myelinated axons, reduced gastrocnemius atrophy, and enhanced hindlimb motor function. These findings together suggested that electroactive WPU/pGO NGSs may represent a safe and effective strategy to manage large nerve defects.

Clinical and Molecular Characteristics and Antibacterial Strategies of Klebsiella pneumoniae in Pyogenic Infection.

Treatment of Klebsiella pneumoniae causing pyogenic infections is challenging. The clinical and molecular characteristics of Klebsiella pneumoniae causing pyogenic infections are poorly understood, and antibacterial treatment strategies are limited. We analyzed the clinical and molecular characteristics of K. pneumoniae from patients with pyogenic infections and used time-kill assays to reveal the bactericidal kinetics of antimicrobial agents against hypervirulent K. pneumoniae (hvKp). A total of 54 K. pneumoniae isolates were included, comprising 33 hvKp and 21 classic K. pneumoniae (cKp) isolates, and the hvKp and cKp isolates were identified using five genes (iroB, iucA, rmpA, rmpA2, and peg-344) that have been applied as hvKp strain markers. The median age of all cases was 54 years (25th and 75th percentiles, 50.5 to 70), 62.96% of individuals had diabetes, and 22.22% of isolates were sourced from individuals without underlying disease. The ratios of white blood cells/procalcitonin and C-reactive protein/procalcitonin were potential clinical markers for the identification of suppurative infection caused by hvKp and cKp. The 54 K. pneumoniae isolates were classified into 8 sequence type 11 (ST11) and 46 non-ST11 strains. ST11 strains carrying multiple drug resistance genes have a multidrug resistance phenotype, while non-ST11 strains carrying only intrinsic resistance genes are generally susceptible to antibiotics. Bactericidal kinetics revealed that hvKp isolates were not easily killed by antimicrobials at susceptible breakpoint concentrations compared with cKp. Given the varied clinical and molecular features and the catastrophic pathogenicity of K. pneumoniae, it is critical to determine the characteristics of such isolates for optimal management and effective treatment of K. pneumoniae causing pyogenic infections. IMPORTANCE Klebsiella pneumoniae may cause pyogenic infections, which are potentially life-threatening and bring great challenges for clinical management. However, the clinical and molecular characteristics of K. pneumoniae are poorly understood, and effective antibacterial treatment strategies are limited. We analyzed the clinical and molecular features of 54 isolates from patients with various pyogenic infections. We found that most patients with pyogenic infections had underlying diseases, such as diabetes. The ratio of white blood cells to procalcitonin and the ratio of C-reactive protein to procalcitonin were potential clinical markers for differentiating hypervirulent K. pneumoniae strains from classical K. pneumoniae strains that cause pyogenic infections. K. pneumoniae isolates of ST11 were generally more resistant to antibiotics than non-ST11 isolates. Most importantly, hypervirulent K. pneumoniae strains were more tolerant to antibiotics than classic K. pneumoniae isolates.

In Vitro Effects of Waterborne Polyurethane 3D Scaffolds Containing Poly(lactic-co-glycolic acid)s of Different Lactic Acid/Glycolic Acid Ratios on the Inflammatory Response.

The physical and chemical properties of tissue engineering scaffolds have considerable effects on the inflammatory response at the implant site in soft tissue repair. The development of inflammation-modulating polymer scaffolds for soft tissue repair is attracting increasing attention. In this study, in order to regulate the inflammatory response at the implant site, a series of waterborne polyurethane (WPU) scaffolds with different properties were synthesized using polyethylene glycol (PEG), polycaprolactone (PCL) and poly (lactic acid)-glycolic acid copolymers (PLGAs) with three lactic acid/glycolic acid (LA/GA) ratios as the soft segments. Then, scaffolds were obtained using freeze-drying. The WPU scaffolds exhibited a porous cellular structure, high porosity, proper mechanical properties for repairing nerve tissue and an adjustable degradation rate. In vitro cellular experiments showed that the degradation solution possessed high biocompatibility. The in vitro inflammatory response of C57BL/6 mouse brain microglia (immortalized) (BV2) cells demonstrated that the LA/GA ratio of the PLGA in WPU scaffolds can regulate the external inflammatory response by altering the secretion of IL-10 and TNF-α. Even the IL-10/TNF-α of PU5050 (3.64) reached 69 times that of the control group (0.053). The results of the PC12 culture on the scaffolds showed that the scaffolds had positive effects on the growth, proliferation and differentiation of nerve cells and could even promote the formation of synapses. Overall, these scaffolds, particularly the PU5050, indeed prevent BV2 cells from differentiating into a pro-inflammatory M1 phenotype, which makes them promising candidates for reducing the inflammatory response and repairing nerve tissue. Furthermore, PU5050 had the best effect on preventing the transformation of BV2 cells into the pro-inflammatory M1 phenotype.

A facile and scalable strategy for constructing Janus cotton fabric with persistent antibacterial activity.

Natural cotton fibers have attached considerable attention due to their excellent wearing comfort, breathability and warmth. However, it remains a challenge to devise a scalable and facile strategy to retrofit natural cotton fibers. Here, the cotton fiber surface was oxidized by sodium periodate with a mist process, then [2-(methacryloyloxy) ethyl] trimethylammonium chloride (DMC) was co-polymerized with hydroxyethyl acrylate (HA) to obtain an antibacterial cationic polymer (DMC-co-HA). The self-synthesized polymer was covalently grafted onto the aldehyde-functionalized cotton fibers via an acetal reaction between hydroxyl groups of the polymer and aldehyde groups of the oxidized cotton surface. Finally, the resulted Janus functionalized cotton fabric (JanCF) revealed robust and persistent antimicrobial activity. The antibacterial test showed that when the molar ratio of DMC/HA was 50: 1, JanCF possessed the best BR (bacterial reduction) values of 100 % against Escherichia coli and Staphylococcus aureus. Furthermore, the BR values could be maintained over 95 % even after the durability test. In addition, JanCF exhibited excellent antifungal activity against Candida albicans. The cytotoxicity assessment confirmed that JanCF exhibited a reliable safety effect on human skin. Particularly, the intrinsic outstanding characteristics (strength, flexibility, etc.) of the cotton fabric were not considerably deteriorated compared to the control samples.

Biodegradable polyurethane-incorporating decellularized spinal cord matrix scaffolds enhance Schwann cell reprogramming to promote peripheral nerve repair.

Decellularized extracellular matrix (dECM) nerve guide conduits (NGCs) are a promising strategy to replace autogenous nerve grafting for the treatment of peripheral nerve system (PNS) injury. However, dECM conduits with mechanical properties that match those of peripheral nerves are yet to be well developed. Herein, we developed polyurethane-based NGCs incorporating decellularized spinal cord (BWPU-DSC NGCs) to repair peripheral nerves. BWPU-DSC NGCs have an inner three-dimensional micro-nanostructure. The mechanical properties of BWPU-DSC NGCs were similar to those of polyurethane NGCs, which were proven to promote peripheral nerve regeneration. An in vitro study indicated that BWPU-DSC NGCs could boost the proliferation and growth of cell processes in Schwann and neuron-like cells. In a rat sciatic nerve transected injury model, BWPU-DSC NGCs exhibited a dramatic increase in nerve repair, similar to that obtained by the current gold standard autograft implantation at only 6 weeks post-implantation, whereas polyurethane NGCs still displayed incomplete nerve repair. Histological analysis revealed that BWPU-DSC NGCs could induce the reprogramming of Schwann cells to promote axon regeneration and remyelination. Moreover, reprogrammed Schwann cells together with BWPU-DSC NGCs had anti-inflammatory effects and altered the activation state of macrophages to M2 phenotypes to enhance PNS regeneration. In this study, we provided a strategy to prepare polyurethane-based dECM NGCs enriched with bioactive molecules to promote PNS regeneration.

Undescribed phloroglucinol derivatives with antiviral activities from Dryopteris atrata (Wall. Ex Kunze) Ching.

Nine undescribed phloroglucinol derivatives (dryatraols A-I) with five different backbones and three known dimeric acylphloroglucinols were isolated from the rhizome of Dryopteris atrata (Wall. Ex Kunze) Ching (Dryopteridaceae). Dryatraol A contains an unprecedented carbon skeleton-a butyrylphloroglucinol and a rulepidanol-type sesquiterpene are linked via a furan ring to form a 6/5/6/6 ring system. Dryatraols B and C are the first examples of monomeric phloroglucinols coupled with the aristolane-type sesquiterpene through the C-C bond. Dryatraol D features a rare spiro [benzofuran-2',5″-furan] backbone. Dryatraols E-I are five undescribed adducts with a butyrylphloroglucinol or filicinic acid incorporated into the germacrene-type sesquiterpene via a pyran ring. These undescribed structures were determined by comprehensively analysing the spectroscopic data, X-ray diffraction results, and electronic circular dichroism calculations. The result of in vitro antiviral activity evaluation indicated that dryatraol C displayed the strongest antiviral effect against both respiratory syncytial virus and influenza A virus (H1N1), with IC50 values of 11.9 µM and 5.5 µM, respectively. Dryatraols F-H exhibited considerable inhibitory activity against herpes simplex virus type 1 (HSV-1), with IC50 values ranging from 2.6 to 6.3 µM. Analysis of the inhibitory mechanism using a time-of-addition assay revealed that dryatraol G may inhibit the replication of HSV-1 by interfering with the late stage of the viral life cycle.

IFL-GAN: Improved Federated Learning Generative Adversarial Network With Maximum Mean Discrepancy Model Aggregation.

The generative adversarial network (GAN) is usually built from the centralized, independent identically distributed (i.i.d.) training data to generate realistic-like instances. In real-world applications, however, the data may be distributed over multiple clients and hard to be gathered due to bandwidth, departmental coordination, or storage concerns. Although existing works, such as federated learning GAN (FL-GAN), adopt different distributed strategies to train GAN models, there are still limitations when data are distributed in a non-i.i.d. manner. These studies suffer from convergence difficulty, producing generated data with low quality. Fortunately, we found that these challenges are often due to the use of a federated averaging strategy to aggregate local GAN models' updates. In this article, we propose an alternative approach to tackling this problem, which learns a globally shared GAN model by aggregating locally trained generators' updates with maximum mean discrepancy (MMD). In this way, we term our approach improved FL-GAN (IFL-GAN). The MMD score helps each local GAN hold different weights, making the global GAN in IFL-GAN getting converged more rapidly than federated averaging. Extensive experiments on MNIST, CIFAR10, and SVHN datasets demonstrate the significant improvement of our IFL-GAN in both achieving the highest inception score and producing high-quality instances.

Treponema pallidum outer membrane proteins: current status and prospects.

The outer membrane proteins (OMPs) of Treponema pallidum subsp. pallidum (T. pallidum), the etiological agent of the sexually transmitted disease syphilis, have long been a hot research topic. Despite many hurdles to studying the pathogen, especially the inability to manipulate T. pallidum in vitro genetically, considerable progress has been made in elucidating the structure, pathogenesis and functions of T. pallidum OMPs. In this review, we integrate this information to garner fresh insights into the role of OMPs in the diagnosis, pathogenicity and vaccine development of T. pallidum. Collectively, the essential scientific discussions herein should provide a framework for understanding the current status and prospects of T. pallidum OMPs.

Water-Triggered Stiffening of Shape-Memory Polyurethanes Composed of Hard Backbone Dangling PEG Soft Segments.

Shape-memory polymers (SMPs) induced by heat or water are commonly used candidates for biomedical applications. Shape recovery inevitably leads to a dramatic decrease of Young's modulus due to the enhanced flexibility of polymer chains at the transition temperature. Herein, the principle of phase-transition-induced stiffening of shape-memory metallic alloys (SMAs) is introduced to the design of molecular structures for shape-memory polyurethane (SMPUs), featuring all-hard segments composed of main chains that are attached with poly(ethylene glycol) (PEG) dangling side chains. Different from conventional SMPs, they achieve a soft-to-stiff transition when shape recovers. The stiffening process is driven by water-triggered segmental rearrangement due to the incompatibility between the hard segments and the soft PEG segments. Upon hydration, the extent of microphase separation is enhanced and the hard domains are transformed to a more continuous morphology to realize more effective stress transfer. Meanwhile, such segmental rearrangement facilitates the shape-recovery process in the hydrated state despite the final increased glass transition temperature (Tg ). This work represents a novel paradigm of simultaneously integrating balanced mechanics, shape-memory property, and biocompatibility for SMPUs as materials for minimally invasive surgery such as endoluminal stents.

[Effects of exogenous attapulgite addition on water conservation function of reclaimed soils in a semi-arid mining area]. / å¤–æºå‡¹å‡¸æ£’åœŸæ·»åŠ å¯¹åŠå¹²æ—±çŸ¿åŒºå¤åž¦åœŸå£¤æ°´åˆ†æ¶µå »åŠŸèƒ½çš„å½±å“.

Large-scale mining has greatly damaged vegetation and caused ecological degradation in the semi-arid area in China. It is urgent to restore the vegetation to solve the deteriorating ecological and environmental problems in mining area. How to reclaim soils for effectively storing and utilizing precipitation is the primary issue for vegetation restoration in the area. In this study, we proposed to take the mixture of attapulgite clay and local sandy soils as covering materials to improve the weak water conservation function of soils in mining areas, and studied the effects of the addition of attapulgite clay on soil infiltration, drainage and water storage sampled from the Shenmu mining area. The results showed that, with increasing application rates of attapulgite clay, the cumulated infiltration volumes decreased by 4.8%-37.4%, the infiltration rates dropped by 6.4%-46.3%, the wetting front advance rates decreased by 9.8%-116.9%, the saturated hydraulic conductivities decreased by 14.3%-59.5%, the drained water volumes reduced by 0.3%-4.3% for 24 hours and by 0.3%-2.5% for 72 hours, and the maximum soil water storages increased by 1.6%-22.4%. The maximum effect of attapulgite clay peaked at the application rate of 150 t·hm-2. Considering the economic cost, the optimum application rate should be 30-150 t·hm-2. The results syste-matically revealed the mechanism of reclaiming mining soils with attapulgite clay to restore the function of water conservation, and demonstrated that attapulgite clay is an effective material for soil reclamation in the semi-arid mining area, which can provide references for soil reclamation and ecological restoration in the semi-arid mining area.

Subversion of the immune response of human pathogenic spirochetes.

Spirochetes are a large group of prokaryotes that originated from Gram-negative bacteria and are capable of causing a variety of human and animal infections. However, the pathogenesis of spirochetes remains unclear, as different types of spirochetes play pathogenic roles through different pathogenic substances and mechanisms. To survive and spread in the host, spirochetes have evolved complicated strategies to evade host immune responses. In this review, we aimed to provide a comprehensive overview of immune evasion strategies in spirochetes infection. These strategies can be explained from the following points: (i) Antigenic variation: random, unidirectional, and segmental conversion of the gene to evade immune surveillance; (ii) Overcoming the attack of the complement system: recruitment of host complement regulators, cleavage of complement components and inhibition of complement activation to evade immune defenses; (iii) Interfering with immune cells to regulating the immune system; (iv) Persistent infection: invading and colonizing the host cell to escape immune damage.