Cellulose-reinforced highly stretchable and adhesive eutectogels as efficient sensors.

A cellulose-reinforced eutectogel was constructed by deep eutectic solvent (DES) and cotton linter cellulose. Cellulose was dispersed in the ternary DES consisting of acrylic acid, choline chloride and AlCl3·6H2O. The photoinitiator was then introduced into the system to in situ polymerize acrylic acid monomer to form transparent and ionic conductive eutectogels while keeping all the DES. The crosslinks formed by Al3+ induced ionic bonds and reversible links formed by hydrogen bonds give the eutectogels high stretchability (3200 ± 200 % tensile strain), self-adhesive (52.1 kPa to glass), self-healing and good mechanical strength (670 kPa). The eutectogels were assembled into sensors and epidermal patch electrodes that demonstrated high quality human motion sensing and physiological signal detection (electrocardiogram and electromyography). This work provides a facile way to design flexible electronics for sensing.

Self-Healing and Wide Temperature-Tolerant Cellulose-Based Eutectogels for Reversible Humidity Detection.

A kind of ionic conductive gel (also named eutectogel) is developed from an inorganic salt (ZnCl2)-based deep eutectic solvent (DES). The ternary DES consists of ZnCl2, acrylic acid, and water, and cotton linter cellulose is introduced into the DES system to tailor its mechanical and conductive properties. Enabled by the extensive hydrogen bonds and ion-dipole interactions, the obtained eutectogel displays superior ionic conductivity (0.33 S/m), high stretchability (up to 2050%), large tensile strength (1.82 MPa), and wide temperature tolerance (-40 to 60 °C). In particular, the water-induced coordination interactions can tune the strength of hydrogen/ionic bonds in the eutectogels, imparting them with appealing humidity sensing ability in complex and extreme conditions.

MiR-548t-5p regulates pancreatic ductal adenocarcinoma metastasis through an IL-33-dependent crosstalk between cancer cells and M2 macrophages.

IL-33 has been associated with pro- and anticancer functions in cancer. However, its role in pancreatic cancer metastasis remains unknown. This study aimed to explore the role of miR-548t-5p/IL-33 axis in the metastasis of pancreatic cancer. Luciferase activity assay, qRT-PCR, Western blot and ELISA were performed to prove whether IL-33 is the target of miR-548t-5p. In vivo metastasis assay and cellular transwell assay were performed to explore the role of miR-548t-5p/IL-33 axis in the invasion and metastasis of pancreatic cancer. Co-culture experiments and immunohistochemistry were performed to observe whether IL-33 affects cell invasion and metastasis dependent on the involvement of M2 macrophages. THP-1 cell induction experiment and flow cytometry were performed to explore the effect of IL-33 on macrophage polarization. CCK-8, colony formation, cell apoptosis, cell cycle, cell wound healing and transwell assay were performed to investigate the effect of IL-33 induced M2 macrophages on cell malignant biological behavior by coculturing pancreatic cancer cells with the conditioned medium (CM) from macrophages. We found that miR-548t-5p regulated the expression and secretion of IL-33 in pancreatic cancer cells by directly targeting IL-33 mRNA. IL-33 secreted by cancer cells promoted the recruitment and activation of macrophages to a M2-like phenotype. In turn, IL-33 induced M2 macrophages promoted the migration and invasion of cancer cells. Moreover, IL-33 affected pancreatic cancer cell invasion dependent on the involvement of M2 macrophages in the co-culture system. Thus, our study suggested that manipulation of this IL-33-dependent crosstalk has a therapeutic potential for the treatment of pancreatic cancer metastasis.

Cellulose-based bi-layer hydrogel evaporator with a low evaporation enthalpy for efficient solar desalination.

Interfacial evaporation through hydrogel-based evaporators is emerging as a sustainable and cost-effective strategy for drinkable water production. Herein, a specially designed bi-layer hydrogel evaporator was fabricated and used for efficient solar water desalination. With cotton linter as cellulose precursor, it was dispersed in a highly concentrated ZnCl2 (65 %) solution, and cross-linked by epichlorohydrin to prepare cellulose composite hydrogel. After removing inorganic salts by salt-leaching, polyaniline (PANi) with broadband and wide-range light absorption was then integrated into the top surface of hydrogel through in situ polymerization to construct a bi-layer evaporator. As a solar evaporator, the water could be evaporated with a low-energy demand, and the heat from the sunlight could be confined at the interface to achieve efficient water evaporation. Therefore, the hydrogel evaporator demonstrates an optimal water evaporation rate of 3.02 kg m-2 h-1 and photothermal conversion efficiency of 89.09 % under 1 sun (1 kW m-2) irradiation. This work provides new possibilities for efficient solar water purification systems with assured water quality.

Copper sulfide integrated functional cellulose hydrogel for efficient solar water purification.

Hydrogels are emerging materials for solar steam generation to alleviate water scarcity. Herein, a semiconductor of copper sulfide (CuS) was integrated into cellulose hydrogel to fabricate a solar steam evaporator. Sustainable and low-cost cotton linter (cellulose) was regenerated by NaOH/urea solvent. Epichlorohydrin was added as a cross-linking agent to enhance the mechanical robustness of the composite hydrogel, and CuS crystals were tightly attached to cellulose fibers and uniformly distributed in the hydrogel matrix. Under simulated solar light, a heating zone was established at the top surface of the composite hydrogel, and CuS can efficiently absorb and convert light into heat. The hydrophilic cellulose network affords an adequate water supply and a low water vaporization enthalpy. By tuning the CuS loadings, the optimized evaporation rate and solar-to-vapor efficiency could reach 2.2 kg/m2/h and 87 %, respectively, under 1 sun irradiation. The evaporation rate remained above 2.1 kg/m2/h after 48 h of irradiation. Moreover, the hydrogels (with a CuS loading of 30 wt%) showed a efficiently photocatalytic degradation of 95 % for methylene blue and 92 % for Rhodamine B. Such functional hydrogel evaporator holds great potential for practical water treatment and solar-driven applications.

Facile fabrication of strong and conductive cellulose hydrogels with wide temperature tolerance for flexible sensors.

Cellulose-based ionic conductive hydrogels (ICHs) have found extensive applications in flexible electronics and multifunctional sensors. However, simultaneous realization of sufficient conductivity, superior mechanical property and extreme environment tolerance for ICHs remains to be a huge challenge. In this work, a facile one-pot approach was developed to fabricate ICHs by directly dissolving cotton linter cellulose and polyvinyl alcohol (PVA) in a concentrated ZnCl2 solution. By regulating the content of PVA in ICHs, the optimal hydrogel (Gel-5) exhibits a tensile strength of 0.30 MPa, a compressive strength of 2.05 MPa and a conductivity of 8.16 S m-1. Moreover, the resulting dual-network ICHs present high transparency, good thermal reversibility and desirable ionic conductivity. Due to the high concentration of inorganic salts in the porous dual-network structure, the ICH presents good anti-drying and anti-freezing (as low as -90 °C) properties. Such hydrogel can be assembled into multi-functional sensors for human motion and temperature monitoring, and they demonstrate durable sensitivity, cycling stability in a wide operating temperature. This work will shed light on the design of cellulose-based hydrogels with good ionic conductivity and mechanical performance under extreme conditions.

Highly conductive and anti-freezing cellulose hydrogel for flexible sensors.

Ionic conducting hydrogels (ICHs) are emerging materials for multi-functional sensors in the fields of healthcare monitoring and flexible electronics. However, there is a long-standing dilemma between ionic conductivity and mechanical properties of the ICHs. In this work, ionic conductive, flexible, transparent, and anti-freezing hydrogels are fabricated by dissolving cotton linter pulp in ZnCl2/CaCl2 solution and cross-linking with epichlorohydrin (ECH). The presence of inorganic salt imparts the hydrogel with high ionic conductivity and low-temperature tolerance. While the introduction of ECH as the second network gives the hydrogel with desirable mechanical performance. By tailoring the ECH addition, the tensile strength, compressive strength, elongation at break, and conductivity of the hydrogel could reach 0.82 MPa, 2.80 MPa, 260 %, and 5.48 S m-1, respectively. The prepared ICHs are fabricated into sensors for detecting full-range human body motions, and they demonstrate fast response and durable sensitivity to both tensile strain and compressive deformation. Moreover, flexible sensors can work at subzero temperatures. This work provides a new idea for the preparation of cellulose-based hydrogels with good ionic conductivity and mechanical properties under extreme conditions.

Metal-organic frameworks decorated wood aerogels for efficient particulate matter removal.

The severe indoor/outdoor air contamination caused by hazardous particulate matters (PMs) has a devastating impact on the environment and human health. Herein, air filters fabricated from delignified wood aerogels and metal-organic frameworks (MOFs) were used for PM removal. Two specially designed MOFs (i.e. Zn-based ZIF-L and Zr-based UiO-66-NH2) were deposited into a highly porous wood matrix through in situ growth approach. The MOF crystals are attached tightly to the highly available cellulose surface groups and distributed uniformly. The integration of MOFs can regulate the aerogel morphology and surface property, leading to enhanced PM removal performance. Bare wood aerogels beard removal efficiencies of 70.7% and 75.0% for PM2.5 and PM10, with a low-pressure drop of 15 Pa. By contrast, ZIF-L decorated wood aerogels exhibited PM2.5 and PM10 removal efficiencies of 97.6% and 99.5%, respectively, which are ascribed to the increased interception/impaction of PMs with the positively charged ZIF-L layer. While UiO-66-NH2 functionalized wood aerogels demonstrated PM2.5 and PM10 removal efficiencies of 96.4% and 98.9% because of the hierarchical filter matrix and the presence of polar -NH2 groups. Moreover, MOF modified wood aerogels can be easily regenerated and superior reusability can be achieved. This work provides an effective and economic strategy for the preparation of air filters from renewable materials.

Lignocellulose hydrogels fabricated from corncob residues through a green solvent system.

It is still a challenge to find an effective solvent system that can simultaneously dissolve the cellulose and lignin in biomass residues to fabricate lignocellulose hydrogels (LHs). Herein, corncob residues from furfural production were pretreated with alkaline peroxide to regulate the lignin content. The lignin/cellulose composites with various lignin content were then dissolved and regenerated by a green and facile ZnCl2/CaCl2 solvent system. The inorganic salt solvents were served as linkers and flexible LHs were obtained. Substrate material containing 10.75% lignin shows the best compressive stress (76.71 kPa). Inspired by its superior ionic conductivity, the hydrogels were assembled into a solid-state electrolyte for a zinc-ion hybrid supercapacitor. This research develops a feasible, simple, and low-cost route for lignin-containing hydrogel preparation and offers insights into the high-value application of agro-industrial lignocellulosic wastes.

Deep eutectic solvent with bifunctional Brønsted-Lewis acids for highly efficient lignocellulose fractionation.

Green and low cost deep eutectic solvents (DESs) are promising to replace the solid acids and ionic liquids in biomass fractionation process. To enhance the lignocellulose pretreatment efficiency, an acidic DES that composed of Brønsted acid (ZnCl2) as hydrogen bond acceptor and Lewis acid (lactic acid) as hydrogen bond donator was designed. This bifunctional DES was used for the extraction of lignin from poplar sawdust. Under the optimal pretreatment condition, the ZnCl2-lactic acid DES could recover 95.2 wt% of lignin with a purity of 92.1%. The recovered lignin demonstrated a low polydispersity of 1.67 and small amount of ß-aryl-ethers. Moreover, the acidic DES had a good recyclability and reusability. Such performance was attributed to the presence of bifunctional acid sites, which help selectively cleave lignin-carbohydrate complex linkages. The acidity and polarity of Brønsted acid can be modulated by the Lewis acid, thus synergistically promote the lignin extraction and production.

Structure reorganization of cellulose hydrogel by green solvent exchange for potential plastic replacement.

Petroleum-based plastics have raised great environmental concerns from the beginning of their production to the end-of-life cycle. It is urgently needed to develop sustainable and green materials with certain plastic properties. Herein, biobased cellulose films are fabricated from low quality cotton cellulose by manipulating its hydrogen bonding network with green solvents. The cellulose is dispersed in inorganic salts (ZnCl2/CaCl2) to form ionic hydrogels, and then transformed into tough and flexible films through ethanol exchange and air drying. Without extra hot-pressing treatment, the aggregate structure of cellulose is re-organized with the disruption and re-construction of hydrogen bonds. Benefiting from the densely packed structure and highly in-plane orientation, the cellulose film presents outstanding optical, thermal and mechanical properties. Such cellulose materials hold a potential for plastic replacement in the field of biodegradable packing.

Long noncoding RNA SOX2OT promotes pancreatic cancer cell migration and invasion through destabilizing FUS protein via ubiquitination.

Pancreatic cancer is a highly aggressive and lethal digestive system malignancy. Our previous studies revealed the correlation of high levels of lncRNA SOX2OT expression with patients' poor survival outcomes, the promoting role of SOX2OT in proliferation and cycle progression of pancreatic cancer cells, and the in vivo binding of SOX2OT to RNA binding protein FUS, which destabilized the protein expression of FUS. However, the mechanism of SOX2OT binding and inhibiting FUS protein stability remains unclear. In this study, we performed RNA pull-down, cycloheximide-chase, and ubiquitination assays to determine the effect of SOX2OT on FUS ubiquitination, and explored the specific regulatory mechanism of SOX2OT-FUS axis in pancreatic cancer cell migration, invasion, in vivo tumor growth, and metastasis through RNA sequencing. We found that SOX2OT binds to FUS through its 5' and 3' regions, resulting in FUS ubiquitination and degradation. The SOX2OT-FUS regulatory axis promotes migration, invasion, tumor growth, and metastasis ability of pancreatic cancer cells. The in-depth elaboration of the SOX2OT-FUS regulatory axis in pancreatic cancer may clarify the mechanism of action of SOX2OT and provide new ideas for pancreatic cancer treatment.

In situ growth of amino-functionalized ZIF-8 on bacterial cellulose foams for enhanced CO2 adsorption.

Zeolitic imidazolate frameworks (ZIFs) hold great potential for carbon capture, while a major challenge for the practical application of ZIFs is the development of convenient three-dimensional bulk materials. Here, sustainable and biodegradable bacterial cellulose (BC) was used as the substrate for ZIF growth. Amino-functionalized ZIF-8 (ZIF-8-NH2) was prepared within BC substrate via an in situ growth approach. ZIF crystals were wrapped uniformly over cellulose fibers and the chelating effect between metal (zinc) ions and hydroxyl groups makes the composites have high interface affinity and compatibility. The resulting foams presented a high CO2 adsorption capacity of 1.63 mmol/g (25 °C, 1 bar). Moreover, ZIF-8-NH2@BC foams are facile to be regenerated by heating at 80 °C. This work provides a new avenue to construct ZIF/cellulose composites for gas treatment applications.

Global view on virus infection in non-human primates and implications for public health and wildlife conservation.

Viruses can be transmitted from animals to humans (and vice versa) and across animal species. As such, host-virus interactions and transmission have attracted considerable attention. Non-human primates (NHPs), our closest evolutionary relatives, are susceptible to human viruses and certain pathogens are known to circulate between humans and NHPs. Here, we generated global statistics on VI-NHPs based on a literature search and public data mining. In total, 140 NHP species from 12 families are reported to be infected by 186 DNA and RNA virus species, 68.8% of which are also found in humans, indicating high potential for crossing species boundaries. The top 10 NHP species with high centrality in the NHP-virus network include two great apes (Pan troglodytes, Pongo pygmaeus) and eight Old World monkeys (Macaca mulatta, M. fascicularis, M. leonina, Papio cynocephalus, Cercopithecus ascanius, C. erythrotis, Chlorocebus aethiops, and Allochrocebus lhoesti). Given the wide distribution of Old World monkeys and their frequent contact with humans, there is a high risk of virus circulation between humans and such species. Thus, we suggest recurring epidemiological surveillance of NHPs, specifically Old World monkeys that are in frequent contact with humans, and other effective measures to prevent potential circulation and transmission of viruses. Avoidance of false positives and sampling bias should also be a focus in future work.

Fine tuning of CdxZn1-xS for photo-depolymerization of alkaline lignin into vanillin.

Lignin is abundant and contains a large number of aromatic groups. Herein, CdxZn1-xS photocatalyst with tunable band gap energy was successfully synthesized by using 3-mercaptopropionic acid as a structure tuning additive. CdxZn1-xS can depolymerize alkaline lignin to vanillin by the photocatalytic process. Each gram of alkaline lignin can produce 46.5 mg of vanillin. 2-Phenoxy-1-phenylethanol (PP-ol) and other model compounds were used to understand the depolymerizing process of lignin. Fine tuned CdxZn1-xS can effectively cleave the Cß-O-4 bond existed in PP-ol under simulated sunlight. The highest conversion of PP-ol was 89.5% with phenol and acetophenone yields of 66.2% and 33.5%, respectively. The mechanism studies confirm that the Cα-H in PP-ol and lignin is firstly dehydrogenated to form Cα radical intermediates, and then the photogenerated electrons break the adjacent Cß-O bond. This research provides a new strategy to prepare valuable chemicals by virtue of renewable biomass and simulated sunlight.

Photocatalytic depolymerization of organosolv lignin into valuable chemicals.

Catalytic conversion of lignin to certain aromatic compounds has been extensively studied but still has great challenges. Photocatalytic depolymerizing lignin is a very promising method to obtain valuable chemicals. Herein, Zn4In2S7 (ZIS)-based photocatalyst was successfully synthesized by simply combining ZIS and graphene oxide (GO). Photocatalyst ZIS-100 can efficiently depolymerize organosolv lignin into phenols and ketones. The relative content of valuable compounds in the depolymerized product was increased by 2.5 times as compared that without photocatalyst. The photocatalyst can effectively break Cß-O bonds in 2-phenoxy-1-phenylethanol (PP-ol, a model compound) and the conversion of PP-ol is 93.27%. Mechanism studies show that the thiol groups on the surface of ZIS-100 play an important role in the formation of Cα radical intermediates. Photocatalytic cleavage of Cß-O bond mainly follows a one-step reaction mechanism through a self­hydrogen transfer process. This study provides a new strategy for selectively breaking Cß-O bond in lignin to form valuable chemicals.

Zirconium ion modified melamine sponge for oil and organic solvent cleanup.

Hydrophilic melamine sponge is transferred into hydrophobic melamine sponge by immersing the commercial melamine sponge cubes into zirconium oxychloride aqueous solution and followed by a simple dry process. The hydrophobicity transformation is assigned to the complex bonds constructed by the Zr4+ ions and N atoms, thus reducing the surface polarity. The modified melamine sponge presents excellent absorption capacities toward various oils and organic solvents (70-181 g/g). Its contact angle with water can reach 130° or more, and displays good oil-water selectivity for both heavy oil and light oil. Besides, the sponge has stable chemical properties and good recyclability. This work presents a facile and low-cost method for fabrication of hydrophobic materials that might be used for the cleanup of oil spills.

Highly transparent graphene oxide/cellulose composite film bearing ultraviolet shielding property.

This work investigates the ultraviolet (UV) shielding property of composite films synthesized with graphene oxide (GO) nanosheets and regenerated cellulose. Regenerated cellulose was prepared from ZnCl2/CaCl2/GO solution. The GO sheets presented a homogenous dispersion in the film matrix. The incorporation of GO endows the cellulose films with improved UV shielding capacity. When GO loading reaches 2%, the UVA and UVB blocking percentages are 66.7% and 54.2%, respectively. Moreover, the composite films had excellent visible light transmittance. The resulting films possess promising applications as protective and packing materials.

Bismuth sulfide bridged hierarchical Bi2S3/BiOCl@ZnIn2S4 for efficient photocatalytic Cr(VI) reduction.

Delicate construction based on 2D epitaxial heterostructure can be an effective route to adequately excavate and utilize its superiorities. Here, a core-shell Bi2S3/BiOCl@ZnIn2S4 hierarchical heterostructure is rationally designed and built by Bi2S3 epitaxial growth on two-dimensional template-like BiOCl and ZnIn2S4 nanosheets in-situ growth. The epitaxial growth of Bi2S3 on BiOCl endows the tight contact between them. More importantly, Bi2S3 as the interlayer could offer an extra intimate junction to ZnIn2S4 due to the chemical interaction of S2- between Bi2S3 and ZnIn2S4. Such a Bi2S3/BiOCl@ZnIn2S4 composite was explored for visible-light-driven reduction of Cr(VI), and much satisfactory performance was achieved, which is about 3.3 and 24.1-fold increase compared to that of ZnIn2S4 and Bi2S3/BiOCl respectively. Efficient generation, separation and transfer of photo-generated charge carriers inherited from this ternary hierarchical composite made significant contributions to the highly elevated photocatalytic activity. This work may stimulate the construction of multiple hierarchical composites based on 2D epitaxial heterostructure material for efficient photocatalysis or other optoelectronics.

Metal nanoparticle-embedded bacterial cellulose aerogels via swelling-induced adsorption for nitrophenol reduction.

Bacterial cellulose aerogels were chosen as the substrate for supporting and dispersing metal nanoparticles (Cu and Ni). During the catalyst preparation, we found that the swelling-induced adsorption process could control the metal size and dispersion simultaneously. Cu and Ni nanoparticles were confined into the bacterial cellulose network and SEM results demonstrated that Cu particles had a smaller size compared to Ni particles. The metal-loaded catalysts exhibited good catalytic performance in the 4-nitrophenol reduction reaction. The optimal sample (BC-Cu-0.5) prepared with 0.5 wt% CuSO4 solution could complete the reduction process within 8 min. Besides, the BC-Cu-0.5 catalyst showed excellent stability and reusability. This study sheds light on the deposition of metal particles and provides a wider application for bacterial cellulose.