Carbon nitride/polyimide porous film via an NIPS method with advanced dielectric and hydrophobicity properties.

Herein, an ultra-low dielectric porous polyimide (PPI) composite film was fabricated by non-solvent induced phase separation (NIPS). High-performance carbon nitride nanosheets grafted by heptadecafluoro-1,1,2,2-tetradecyl-trimethoxysilane (CNNF) were incorporated into the PPI film to enhance thermomechanical and hydrophobic properties. The effects of non-solvent and filler content on the porous morphology, dielectric properties, hydrophobicity and thermomechanical properties of films were investigated. The porous morphology of the CNNF/PPI film changed from the coexistence of pipe-like and spongy structure via H2O, to a tightly-stacked porous structure via MeOH as non-solvent. The dielectric constants ε' of 0.5 wt%-CNNF/PPI(H2O) and 0.5 wt%-CNNF/PPI(MeOH) were 1.56 and 1.69 at 1 MHz, respectively, which were ∼50% lower than that of the original PI film (ε' = 3.33). With the introduction of CNNF, the water contact angle (WCA) of CNNF/PPI(H2O) increased from 66° to 107° and that of CNNF/PPI(MeOH) increased from 92° to 120°. Simultaneously, the storage modulus E' of 2 wt%-CNNF/PPI(MeOH) reached its highest value of ∼881 MPa, which was ∼350 MPa higher than that of PPI(MeOH), together with an enhancement in Tg. This method confirmed a promising prospect for the utilization of porous PI substrates in integrated circuits and microelectronic devices.

Ionic conductive konjac glucomannan/liquid crystal cellulose composite hydrogels with dual sensing of photo- and electro-signals capacities as wearable strain sensors.

The ionic conductive hydrogel-based sensor exhibits wide applications in wearable electronic devices. However, the strength and ductility trade-off, multimodal requirements, and water-soluble polymer alternatives are significant challenges for the hydrogel-based sensor. Herein, a stretchable and conductive hydrogel is developed with a double network formed by incorporating polyacrylamide and ionic liquid into the konjac glucomannan network. The hydrogel displays significantly enhanced mechanical properties, and good tear/puncture resistance owing to the existence of covalent and non-covalent interactions. In addition, by the introduction of nematic liquid crystal hydroxypropyl cellulose, the hydrogel/cellulose-based strain sensor demonstrates excellent sensing performance in monitoring human motions and writing recognition ability with optical and electrical bimodal sensing response. This work provides new insights to further expand the options of hydrogel-based sensor matrix and to construct bimodal sensors.

Three-dimensional printing of microfiber- reinforced hydrogel loaded with oxymatrine for treating spinal cord injury.

Spinal cord injury (SCI) causes severe neural tissue damage and motor/sensory dysfunction. Since the injured spinal cord tissue has limited self-regeneration ability, several strategies, including cell therapy, drug delivery, and tissue engineering scaffold implantation, have been employed to treat SCI. However, each of these strategies fails to obtain desirable outcomes due to their respective limitations. In comparison, advanced tissue engineering scaffolds with appropriate topographical features, favorable composition, and sustained drug delivery capability can be employed to recruit endogenous neural stem cells (NSCs), induce neuronal differentiation, and facilitate neuron maturation. This can lead to the regeneration of injured spinal cord tissue and the recovery of motor function. In this study, fiber bundle-reinforced spinal cord extracellular matrix hydrogel scaffolds loaded with oxymatrine (OMT) were produced through nearfield direct write electrospinning. The spinal cord extracellular matrix-based hydrogel was then coated with OMT. The physical/chemical properties and in vitro degradation behavior of the composite scaffolds were investigated. The in vitro cell culture results showed that composite scaffolds loaded with OMT promoted the differentiation of NSCs into neurons and inhibited differentiation into astrocytes. The in vivo results showed that the composite scaffolds loaded with OMT recruited NSCs from the host tissue, promoted neuronal differentiation and axon extension at the lesion site, inhibited glial scar formation at/around the lesion site, and improved the recovery of motor function in rats with SCI. To sum up, 3D-printed microfiber-reinforced spinal cord extracellular matrix hydrogel scaffolds loaded with OMT are promising biomaterials for the treatment of SCI.

One-pot synthesis of gamma-graphyne supported Pd nanoparticles with high catalytic activity.

As a unique member of the graphyne family, gamma-graphyne (γ-graphyne) is a novel kind of 2D carbon allotrope with potential high carrier mobility and large surface area. It remains a great challenge to synthesize graphynes with targeted topologies and good performance. Herein, a novel one-pot method was applied to the synthesis of γ-graphyne using hexabromobenzene and acetylenedicarboxylic acid via a Pd-catalyzed decarboxylative coupling reaction, which is easy to perform with mild reaction conditions, facilitating the possibility of mass production. As a result, the synthesized γ-graphyne reveals a two-dimensional γ-graphyne structure consisting of 1 : 1 sp/sp2 hybridized carbon atoms. Furthermore, γ-graphyne as a carrier for Pd (Pd/γ-graphyne) displayed a superior catalytic activity for the reduction of 4-nitrophenol with a short reaction time and high yields, even in aqueous media under aerobic conditions. Compared with Pd/GO, Pd/HGO, Pd/CNT, and commercial Pd/C, Pd/γ-graphyne showed more excellent catalytic performance with lower palladium loadings. Thus we expect that the novel approach for the synthesis of γ-graphyne will boost research on the design and application of graphyne-type functional materials for catalysis.

Phylogenomics and phylogeography of Menispermum (Menispermaceae).

Introduction: Phylogenomics have been widely used to resolve ambiguous and controversial evolutionary relationships among plant species and genera, and the identification of unique indels in plastomes may even help to understand the evolution of some plant families. Menispermum L. (Menispermaceae) consists of three species, M. dauricum DC., M. canadense L., and M. mexicanum Rose, which are disjuncly distributed among East Asia, Eastern North America and Mexico. Taxonomists continue to debate whether M. mexicanum is a distinct species, a variety of M. dauricum, or simply a synonym of M. canadense. To date, no molecular systematics studies have included this doubtful species in phylogenetic analyses. Methods: In this study, we examined phylogenomics and phylogeography of Menispermum across its entire range using 29 whole plastomes of Menispermaceae and 18 ITS1&ITS2 sequences of Menispermeae. We reconstructed interspecific relationships of Menispermum and explored plastome evolution in Menispermaceae, revealing several genomic hotspot regions for the family. Results and discussion: Phylogenetic and network analyses based on whole plastome and ITS1&ITS2 sequences show that Menispermum clusters into two clades with high support values, Clade A (M. dauricum) and Clade B (M. canadense + M. mexicanum). However, M. mexicanum is nested within M. canadense and, as a result, we support that M. mexicanum is a synonym of M. canadense. We also identified important molecular variations in the plastomes of Menispermaceae. Several indels and consequently premature terminations of genes occur in Menispermaceae. A total of 54 regions were identified as the most highly variable plastome regions, with nucleotide diversity (Pi) values > 0.05, including two coding genes (matK, ycf1), four introns (trnK intron, rpl16 intron, rps16 intron, ndhA intron), and 48 intergenic spacer (IGS) regions. Of these, four informative hotspot regions (trnH-psbA, ndhF-rpl32, trnK-rps16, and trnP-psaJ) should be especially useful for future studies of phylogeny, phylogeography and conservation genetics of Menispermaceae.

Retraction: Acellularized spinal cord scaffolds incorporating bpV(pic)/PLGA microspheres promote axonal regeneration and functional recovery after spinal cord injury.

[This retracts the article DOI: 10.1039/D0RA02661A.].

Double crosslinked biomimetic composite hydrogels containing topographical cues and WAY-316606 induce neural tissue regeneration and functional recovery after spinal cord injury.

Spinal cord injury (SCI) is an overwhelming and incurable disabling condition, for which increasing forms of multifunctional biomaterials are being tested, but with limited progression. The promising material should be able to fill SCI-induced cavities and direct the growth of new neurons, with effective drug loading to improve the local micro-organism environment and promote neural tissue regeneration. In this study, a double crosslinked biomimetic composite hydrogel comprised of acellularized spinal cord matrix (ASCM) and gelatin-acrylated-ß-cyclodextrin-polyethene glycol diacrylate (designated G-CD-PEGDA) hydrogel, loaded with WAY-316606 to activate canonical Wnt/ß-catenin signaling, and reinforced by a bundle of three-dimensionally printed aligned polycaprolactone (PCL) microfibers, was constructed. The G-CD-PEGDA component endowed the composite hydrogel with a dynamic structure with a self-healing capability which enabled cell migration, while the ASCM component promoted neural cell affinity and proliferation. The diffusion of WAY-316606 could recruit endogenous neural stem cells and improve neuronal differentiation. The aligned PCL microfibers guided neurite elongation in the longitudinal direction. Animal behavior studies further showed that the composite hydrogel could significantly recover the motor function of rats after SCI. This study provides a proficient approach to produce a multifunctional system with desirable physiological, chemical, and topographical cues for treating patients with SCI.

Facile Approach to Fabricate Oriented Porous PDMS Composites for Movements Monitoring and Identifying Motion Patterns.

The facile and rapid fabrication of oriented porous polymers is crucial for flexible pressure sensors. Herein, a pressure sensor is developed based on oriented porous polydimethylsiloxane (PDMS) composites for detecting human motion and identifying joint motion patterns. The oriented porous PDMS composite is first constructed through thiol-ene click chemistry and directional freezing within only 30 min, then fabricated by interfacial in situ polymerization of dopamine and pyrrole to generate robust interfaces. As a result, the as-prepared oriented porous PDMS composite is assembled into a pressure sensor that shows potential applications in pressure and human motion detection. Interestingly, a sensor assembled by orthogonally stacking the PDMS composites can be used for joint motion pattern recognition with potential monitoring of football motion due to their directional structures. This facile strategy coupled with the oriented porous structure is expected to help design advanced wearable electronic devices.

Plastid Phylogenomics and Plastome Evolution of Nandinoideae (Berberidaceae).

Subfamily Nandinoideae Heintze (Berberidaceae), comprising four genera and ca. 19 species, is disjunctively distributed in eastern North America vs. Eurasia (eastern Asia, Central Asia, Middle East, and southeastern Europe), and represents an ideal taxon to explore plastid phylogenomics and plastome evolution in Berberidaceae. Many species of this subfamily have been listed as national or international rare and endangered plants. In this study, we sequenced and assembled 20 complete plastomes, representing three genera and 13 species of Nandinoideae. Together with six plastomes from GenBank, a total of 26 plastomes, representing all four genera and 16 species of Nandinoideae, were used for comparative genomic and phylogenomic analyses. These plastomes showed significant differences in overall size (156,626-161,406 bp), which is mainly due to the expansion in inverted repeat (IR) regions and/or insertion/deletion (indel) events in intergenic spacer (IGS) regions. A 75-bp deletion in the ndhF gene occurred in Leontice and Gymnospermium when compared with Nandina and Caulophyllum. We found a severe truncation at the 5' end of ycf1 in three G. altaicum plastomes, and a premature termination of ropC1 in G. microrrhynchum. Our phylogenomic results support the topology of {Nandina, [Caulophyllum, (Leontice, Gymnospermium)]}. Within the core genus Gymnospermium, we identified G. microrrhynchum from northeastern Asia (Clade A) as the earliest diverging species, followed by G. kiangnanense from eastern China (Clade B), while the rest species clustered into the two sister clades (C and D). Clade C included three species from West Tianshan (G. albertii, G. darwasicum, G. vitellinum). Clade D consisted of G. altaicum from northern Central Asia, plus one species from the Caucasus Mountains (G. smirnovii) and three from southeastern Europe (G. odessanum, G. peloponnesiacum, G. scipetarum). Overall, we identified 21 highly variable plastome regions, including two coding genes (rpl22, ycf1) and 19 intergenic spacer (IGS) regions, all with nucleotide diversity (Pi) values > 0.02. These molecular markers should serve as powerful tools (including DNA barcodes) for future phylogenetic, phylogeographic and conservation genetic studies.

Waste Silicone Rubber in Three-Dimensional Conductive Networks as a Temperature and Movement Sensor.

Constructing a three-dimensional (3D) conductive network in a polymer matrix is a common method for preparing flexible sensors. However, the previously reported methods for constructing a 3D conductive network generally have shortcomings such as uncontrollable processes and insufficient network continuity, which limit the practical application of this method. In this work, we report a method for constructing a dual 3D conductive network. The carbon nanotube/graphene oxide co-continuous network (primary network) was introduced on the surface of the waste silicone rubber particles (WSRPs) through the adhesion of polydopamine (PDA), and then WSRPs were bonded into a porous skeleton using nanocellulose. The carbon fiber/carbon ball interconnection network (secondary network) was constructed in liquid silicone rubber (LSR) through the interaction of host-guest dendrimers and was filled into the WSRP skeleton. The dual 3D conductive network structure endowed the sensor with high electrical and thermal conductivity, outstanding stability, and excellent durability. In addition, the sensor showed high strain sensitivity and excellent stability when detecting human body temperature and motion behavior, and the pressure distribution can be spatially mapped through the sensor matrix. These demonstrations give our sensor high potential in the fields of smart devices, body monitoring, and human-machine interfaces.

Study on preparation and application of a multifunctional microspheric soil conditioner based on Arabic gum, gelatin, chitosan and ß-cyclodextrin.

All kinds of soil conditioners have been used to improve soil quality. The application of many traditional soil conditioners was limited by single performance. In this study, a novel multifunctional microspheric soil conditioner was prepared based on Arabic gum, gelatin, chitosan and ß-cyclodextrin. Arabic gum and gelatin (AG-GL) microspheric carriers, which could load ferrous sulfate (FS), were synthesized via complex coagulation method. The AG-GL(FS) microspheres were covered by chitosan quaternary ammonium salt (CQAS) through single coagulation method. And ß-cyclodextrin (ß-CD) was used as the outermost shell to improve chemical stability of the soil conditioner by saturated solution method. Finally, the novel multifunctional microspheric soil conditioner AG-GL/CQAS/ß-CD-FS was obtained and characterized by Fourier transform infrared spectroscopy, thermogravimetric analyzer, polarizing microscope, scanning electron microscope and particle size analyzer. The novel soil conditioner shows good nutrient slowly-releasing, water retention, heavy metal ions adsorption and antibacterial performances with the particle size of 14-17 µm and high thermal decomposition temperature, which has the potential application in improving soil quality.

Balanced strength-toughness, thermal conductivity and self-cleaning properties of PMMA composites enabled by terpolymer grafted carbon nanotube.

Achieving a balanced strength-toughness in polymer composites is a challenge largely because of poor interfacial interaction between the fillers and matrix. Here, we report that terpolymer grafted multi-wall carbon nanotubes (Ter-CNT) imparted good dispersion of CNT in matrix and strong CNT-matrix interaction. With the addition of 2 vol% filler into polymethyl methacrylate (PMMA) matrix, the composite exhibited simultaneously a balanced strength-toughness property with flexural strength of 72.3 MPa, toughness of 10.1 MJ m-3, which increased by 40.1% and 578% compared with those of pure PMMA. In addition, the composite also shows a high static contact angle (110.3°), and thermal conductivity (0.50 Wm K-1), which endow the composite with good self-cleaning and thermal management capabilities. Thus, this preparation process shows guidance for the design of polymer composite with integrated high strength-toughness, thermal conductivity and good self-cleaning.

Diphenolic acid-modified PAMAM/chlorinated butyl rubber nanocomposites with superior mechanical, damping, and self-healing properties.

Based on its excellent damping properties, traditional rubber has been widely used in various industries, including aerospace, rail transit and automotive. However, the disadvantages of effective damping area, unstable damping performance, easy fatigue, and aging, greatly limited the further application of rubber materials. Thus, it is important to develop novel modified rubber damping materials. Herein, polyamidoamine dendrimers with terminal-modified phenolic hydroxyl and amine groups (G2 PAMAM-H) were designed and used as modifiers to improve the damping performance of chlorinated butyl rubber (CIIR). The results showed that the modification of G2 PAMAM by diphenolic acid can avoid its aggregation in the CIIR matrix. CIIR/G2 PAMAM-H nanocomposites exhibited high tan δ max of 1.52 and wide damping temperature region of 140°C (tan δ > 0.55)at a very low loading (4.32 wt.%), which were strongerthan that of pure CIIR and CIIR/G2 PAMAM nanocomposites. In addition, these nanocomposites also exhibited a unique self-healing ability by multiple hydrogen bonds, which can effectively extend the life of the rubber material in actual production. Therefore, the dendrimer modification provided unique development opportunities for elastomers in certain highly engineered fields, such as vehicles, rail transit, aerospace, etc.

Nursing case management for people with hypertension: A randomized controlled trial protocol.

OBJECTIVE: To explore the effect of management of nursing case on blood pressure control in hypertension patients. METHOD: This is a randomized controlled study which will be carried out from May 2021 to May 2022. The experiment was granted through the Research Ethics Committee of the People's Hospital of Chengyang District (03982808). Our research includes 200 patients. Patients who meet the following conditions will be included in this experiment: the patients aged 18 to 60 years; the patients had the diagnosis of hypertension; and the urban residents. While patients with the following conditions will be excluded: having renal failure, liver failure, heart and respiratory failure; and known pregnancy. Primary result is blood pressure, while secondary results are treatment compliance, waist circumference, body mass index (BMI), type and number of antihypertensive agents used, and the existence of metabolic and cardiovascular comorbidities. RESULTS: Table 1 shows the clinical outcomes between the two groups. CONCLUSION: Nursing case management is effective to improve the prognosis of hypertension patients.

The effect of enhancing quality of life in patients intervention for advanced lung cancer: Protocol for a randomized clinical study.

OBJECTIVE: The objective of this present research is to evaluate the effect of the intervention of enhancing quality of life in patients in patients with advanced lung cancer. METHODS: Our research is carried out as a randomized clinical trial which will be implemented from December 2020 to October 2021. It was approved by the Ethics Committee of People's Hospital of Chengyang District (03982790). This study includes 90 patients with advanced lung cancer. Patients diagnosed at our oncology clinic are eligible if they are diagnosed within 8 weeks of a novel diagnosis of stage 3 or stage 4 lung cancer. Patients with hepatic insufficiency, renal failure, and respiratory and heart failure, as well as a series of severe mental illness are excluded from our research. Patients are divided randomly into the intervention group and control group, each group is assigned 45 patients. Through utilizing functional assessment of cancer therapy-lung, the measurement of life quality is conducted. And the measurement of mood is carried out with Hospital Anxiety and Depression Scale. RESULTS: Table 1 indicates the patient's life quality and Hospital Anxiety and Depression Scale in both groups. CONCLUSION: Enhancing quality of life in patient intervention may be beneficial to improve the life quality in advanced lung cancer patients.Trial registration: The protocol was registered in Research Registry (researchregistry6243).

Novel Controlled Release Microspheric Soil Conditioner Based on the Temperature and pH Dual-Stimuli Response.

A novel type of temperature and pH dual-stimuli-responsive microspheric soil conditioner was prepared for the controlled release of urea. First, poly(N-isopropylacrylamide-co-methacrylic acid) [P(NIPAM-co-MAA)] was synthesized, and the microspheric soil conditioner was prepared on the basis of chitosan-coated P(NIPAM-co-MAA) via the emulsion cross-linking method. The structure and morphology of the microsphere were characterized by Fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance, polarization optical microscopy, and scanning electron microscopy. The microsphere showed controlled release behavior in different temperature and pH conditions, indicating good stimuli responsiveness. The plant experiment revealed that the microsphere can effectively promote plant growth in acidified soil and high-temperature conditions, and the pH value of acidified soil could be improved. In addition, the microsphere possessed good biodegradation property in the soil. Therefore, the multi-responsive microspheric soil conditioner owns a great potential value to amend soil conditions and promote plant growth in agriculture applications.

Synthesis and Characterization of Linear Polyisoprene Supramolecular Elastomers Based on Quadruple Hydrogen Bonding.

Supramolecular elastomers based on quaternary hydrogen bonding of ureido-pyrimidinone (UPy) groups own special properties such as reversibility, self-healing, and good processability, which can be used in many special fields. In this paper, a novel type of linear polyisoprene supramolecular elastomer (LPSE) was prepared via anionic polymerization by deliberately introducing hydroxyl, isocyanate, and UPy groups into the ends. The formation of supramolecular structure showed significant effects on the microphase structures of LPSE, which was characterized by Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), hydrogen nuclear magnetic resonance (1H-NMR), and dynamic mechanical analysis (DMA). Results showed that the introduction of UPy groups played a certain role in the improvement of the thermal stability, toughness, and tensile strength of the elastomer. Moreover, from self-healing tests, the hydrogen bonds of UPy showed dynamic characteristics which were different from covalent sacrificial bonds and exhibited the reassociation phenomenon. This study can not only extend our understanding of the toughening effect of strong hydrogen bonds, but also help us to rationally design new and tough elastomers.

Acellularized spinal cord scaffolds incorporating bpV(pic)/PLGA microspheres promote axonal regeneration and functional recovery after spinal cord injury.

Spinal cord injury (SCI) is a traumatic injury to the central nervous system (CNS) with a high rate of disability and a low capability of self-recovery. Phosphatase and tensin homolog (PTEN) inhibition by pharmacological blockade with bisperoxovanadium (pic) (bpV(pic)) has been reported to increase AKT/mTOR activity and induce robust axonal elongation and regeneration. However, the therapeutic effect of bpV(pic) in treating SCI is limited due to the lack of efficient delivery approaches. In this study, a composite scaffold consisting of an acellular spinal cord (ASC) scaffold and incorporated bpV(pic) loaded poly (lactic-co-glycolic acid) (PLGA) microspheres was developed, in order to improve the therapeutic effect of bpV(pic) on SCI. The inhibition of PTEN activity and activation of the mTORC1/AKT pathway, the axonal regeneration and the markers of apoptosis were analyzed via western blot and immunofluorescence in vitro. The bpV(pic)/PLGA/ASC scaffolds showed excellent biocompatibility and promoted the viability of neural stem cells and axonal growth in vitro. Implantation of the composite scaffold into rats with hemi-sectioned SCI resulted in increased axonal regeneration and functional recovery in vivo. Besides, bpV(pic) inhibited the phosphorylation of PTEN and activated the PI3K/mTOR signaling pathway. The successful construction of the composite scaffold improves the therapeutic effect of bpV(pic) on SCI.

Preparation and properties of soil conditioner microspheres based on self-assembled potassium alginate and chitosan.

Fulvic acid (FA), as one type of soil conditioner, can enhance drought tolerance, improve nutrient ingestion, stabilize pH values of soil, and reduce fertilizer extracting behaviors. Moreover, it shows a good effect on increasing the permissiveness of plants to various environments, and the stress of salinity and drought is included. Therefore, it can be used as an ideal soil conditioner. In order to extend its effect, it may be loaded into the core-shell polymer microspheres. In this study, FA was added to calcium carbonate (CaCO3) microspheres, potassium alginate (PAL) and chitosan (CS) were assembled outside. Thus, PAL/CS/FA-CaCO3 microspheres were prepared using layer-by-layer self-assembly methods. The surface morphology, encapsulation efficiency and in vitro drug release characteristics were investigated. It was revealed that PAL/CS/FA-CaCO3 microspheres were formed with a particle size distribution between 2 and 6 µm due to self-assembly between PAL and CS. Drug release behavior analysis exhibited the sustained release processes were delayed to varying degrees due to different degradation degrees of CaCO3 microspheres at different pH values. Results also illustrated that these microspheres had a high loading capacity for FA, and possessed good biodegradability. Thus, PAL/CS/FA-CaCO3 microspheres exhibited promise for future applications compared with that of traditional soil conditioners.

A facile route to fabricate thermally conductive and electrically insulating polymer composites with 3D interconnected graphene at an ultralow filler loading.

Thermally conductive polymer composites show attractive prospects as thermal management materials in many applications such as microelectronic devices. However, traditional approaches in the preparation of thermally conductive polymer composites usually have the disadvantages of complex processes. In this study, a facile method for highly thermally conductive silicone rubber composites is reported, based on 3D interconnected graphene sponges by using an inorganic salt as a sacrificial template. The composites exhibit a high thermal conductivity of 1.50 W m-1 k-1 and a thermal conductivity enhancement of 752% at a very low graphene loading of 1.46 wt%. More significantly, highly thermally conductive epoxy and styrene-butadiene rubber composites are also fabricated by the same method. The composites also show excellent electrical insulating properties (>1013 Ω cm). Thus, this effective method is proved to be widely used for the facile fabrication of polymer composites of both plastic and rubber matrices which are thermally conductive and have excellent electrical insulating properties.