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A novel bionic underwater glider with a wire-driven flexible tail fin is proposed. The hydrodynamic properties of the wake are analyzed to determine the parameter characteristics associated with the propulsion performance. The structural design and the mathematical model of the bionic wire-driven tail are presented. The motion models of the wire-driven tail are derived. The computational fluid dynamics method is adopted to simulate the changes in the surrounding flow field during the wire-driven tail movement, and the impact of the motion parameters on the hydrodynamics is investigated. Experiments are conducted in a pool, and the results are consistent with those of the simulation. The maximum propulsion force can be achieved by changing the flapping frequency and the amplitude of the tail, which is associated with the reverse Karman vortex streets. The prototype is capable of forward and yaw motions, with a maximum average propulsion speed of 0.67 m/s, which is 34% higher than that (0.5 m/s) of the traditional hybrid-driven underwater glider. The rotation period is around 64 s. Bionic underwater gliders have considerable potential for application in various fields such as ocean science, marine engineering, marine safety, national defence, underwater resource exploration, and environmental protection. • A new bionic underwater glider with a wire-driven flexible tail fin is proposed. • A structural design and the mathematical model of the bionic wire-driven tail are presented. • Some tests are carried out to verify the kinematic performance of bionic AUG. • The results indicate that the average propulsion speed is 34% higher than that of the traditional underwater glider. [ABSTRACT FROM AUTHOR]

It is significant to develop new approaches to incorporate naturally active agents into gelatin-based edible films for effective antioxidant and long-term antibacterial activities. Here the naturally active compound rosmarinic acid (RosA) was firstly conjugated onto gelatin backbone via EDC/NHS chemistry. Then the conjugates were plasticized by glycerol and crosslinked by dialdehyde xanthan gum to fabricate active RosA-gelatin edible films. The results indicate that the RosA-gelatin edible films present good water resistance property, strong mechanical property and excellent ultraviolet light barrier ability. The conjugation of RosA confers gelatin-based edible films with effective antioxidant and antibacterial activities as expected. It is interesting that RosA-gelatin edible films after 3 months of storage still show good antibacterial activity as that of newly prepared ones, demonstrating the long-term antibacterial activity. Overall, the fabricated RosA-gelatin edible films may have promising application in the fields of food and pharmaceutical packaging. [ABSTRACT FROM AUTHOR]

In this study, the degradation of organophosphate esters (OPEs) in sewage sludge with aerobic composting and anaerobic digestion was investigated. The total concentrations of six OPEs (ΣOPEs) in the whole treatment process reduced in the order of anaerobic digestion combined with pig manure (T3) > aerobic composting combined with pig manure (T1) > aerobic composting (T2) > anaerobic digestion (T4). The addition of pig manure significantly enhanced the removal rate of OPEs in both aerobic and anaerobic treatments. The abundance and diversity of bacterial community reduced after the treatment process. Shannon index, principal component analysis, network analysis, and heat map further confirmed the variation of bacterial community compositions among different treatments. Five genera (i.e., Flavobacterium , Bacillus , Alcaligene , Pseudomonas , and Bacillus megaterium ) might be responsible for the degradation of OPE compounds in sewage sludge. [ABSTRACT FROM AUTHOR]

The oxidized κ -carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ -carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ -carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ -carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ -carrageenans against Gram-positive bacteria ( Staphylococcus aureus and Listeria monocytogenes ) and Gram-negative bacteria ( Escherichia coli and Pseudomonas aeruginosa ) was systematically investigated. The results showed that the oxidized κ -carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ -carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. [ABSTRACT FROM AUTHOR]

The utilization of petroleum-derived synthetic materials causes severe ecological problems, such as environmental pollution and soil degradation. Hence, using naturally derived and renewable materials to fabricate novel biodegradable films for safe and effective food packaging has been a subject of interest over the years. Here, the novel antimicrobial and controlled biodegradable gelatin-based edible films were developed using nisin as the antimicrobial agent, amino-functionalized montmorillonite as the nanoparticle filler, and dialdehyde xanthan gum as the crosslinking agent. The results indicate that the ultraviolet barrier ability, water resistance, and mechanical properties of gelatin-based edible films are obviously improved on account of the crosslinking effect. Moreover, the resulting films demonstrate antimicrobial activity against Staphylococcus aureus owning to the addition of nisin. Furthermore, the crosslinking can slow down the erosion of the edible films by fungi due to the improved hydrophobicity and compact structure. Particularly, the edible films can be completely biodegraded in soil within 30 days. Meanwhile, the rate of soil biodegradation can be well controlled by adjusting the crosslinking degree. Overall, this novel gelatin-based edible films have potential applications in food packaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • DSA-PL conjugates were obtained by Schiff's base reaction between PL and DSA. • Spherical DSA-PL MPs show good dispersity and acid-sensitive degradation property. • DSA-PL MPs possess effective and broad-spectrum antibacterial activity. • DSA-PL MPs have potential application as antibacterial agents for fruit preservation. Food security is an important global public health issue, which will not only endanger consumers' life and health, but also cause serious food waste. Herein, antibacterial dialdehyde sodium alginate/ ε -polylysine microspheres (DSA-PL MPs) were developed to effectively prolong the shelf life of fruit. DSA was prepared by periodate oxidation of sodium alginate. Then the PL was conjugated onto DSA backbone via the Schiff's base reaction to synthesize DSA-PL conjugates, followed by the emulsification and Ca2+ ions crosslinking to obtain DSA-PL MPs. The results indicate that DSA-PL MPs show smooth spherical particle, relatively narrow size distribution and good dispersity. In vitro degradation rate of DSA-PL MPs is higher in acetate buffer (pH = 5.0) than that in PBS buffer (pH = 7.4), showing acid-sensitive degradation property. Significantly, DSA-PL MPs possess strong broad-spectrum antibacterial activity, which can effectively extend the shelf life of fruit. Overall, DSA-PL MPs possess promising application as antibacterial agents for fruit preservation. [ABSTRACT FROM AUTHOR]

The amino-functionalized montmorillonite (NH 2 -MMT) with different amino content is successfully prepared by adjusting the solvents proportion of anhydrous ethanol and toluene. Then NH 2 -MMT is incorporated into gelatin to prepare composite edible films using dialdehyde xanthan gum (DXG) as the crosslinking agent. The XRD studies indicate that the amino-functionalization is beneficial for MMT to disperse and exfoliate in gelatin matrix and the incorporation of NH 2 -MMT can induce gelatin molecules to renature into triple-helix structure. The amino-functionalization of MMT provides active sites for the crosslinking by Schiff's base reaction to produce compact networks among gelatin, NH 2 -MMT and DXG. Moreover, the increase of amino content of NH 2 -MMT consequentially improves the crosslinking density of the composite films. Hence, the UV light barrier property, water resistance, mechanical property and thermal stability of the composite films are improved with the addition of NH 2 -MMT and increase along with the increase of amino content of NH 2 -MMT. The study demonstrates that NH 2 -MMT is an ideal filler for gelatin based composite edible films. [ABSTRACT FROM AUTHOR]

Abstract: Oxidized xanthan gum with different aldehyde content is successfully prepared by periodate oxidization and used as a crosslinking agent for gelatin edible films. X-ray diffraction measurements and atomic force microscopy images demonstrate that degradation is concomitant with the oxidization process, leading to the decrease in crystallinity and the structure changes. Glycerol-plasticized gelatin–xanthan gum and gelatin–oxidized xanthan gum edible films are prepared using casting techniques. The optical properties studies show that all films are very transparent and have excellent barrier properties against UV light. Introducing aldehyde groups can improve the UV barrier properties, resulting from the increased C N groups by Schiff's base formation. Properties studies show that xanthan gum can drastically reduce the total soluble matter, moisture content and water vapor permeability and greatly improve the mechanical properties and thermal stability of gelatin films. With the increase of oxidization level of oxidized xanthan gum, the enhancement of water barrier properties, mechanical properties and thermal stability of gelatin–oxidized xanthan gum films is observed, which is mainly due to the covalently linking between the two polymers. Subsequently, the excessive degradation of xanthan gum will reduce the mechanical properties and thermal stability of gelatin films. [Copyright &y& Elsevier]

Foreign direct investment (FDI) technology spillovers play an increasingly important role in a host country's development. Evaluating the positive effect of FDI inflows on green innovation is essential for correct city design. Based on the panel data of 262 cities in China from 2004 to 2018, we first analyzed the impact of FDI technology spillovers on green innovation in Chinese cities and then tested the threshold effect in four absorptive capacity factors: environmental regulation, economic growth, human capital, and industry size. Finally, we compared the time and space of two types of cities crossing the threshold from the perspective of innovative and non-innovative cities. The results show that FDI can significantly promote green innovation in Chinese cities and the promoting effect of FDI on green innovation has nonlinear characteristics, namely, such effects only make sense when absorptive capacity is above the threshold points. Additionally, among the four absorptive capacity factors, the development degrees of innovative cities are ahead of non-innovative cities; in particular, there is a significant difference between them in terms of economic growth. Local governments should develop reasonable policy combination tools according to the absorptive capacity characteristics of different cities to effectively promote the technology spillover effect of FDI and achieve coordinated ecological and economic development. [ABSTRACT FROM AUTHOR]

Proves a basic result about tensor products of a II1 factor with a finite von Neuman algebra. Solution to a problem about maximal injective factors.

Proves the existence of prime factors using Voiculescu's free probability theory. Answer to the longstanding problem in the theory of von Neumann algebras; Basic construction of factors of type II by using regular representation of discrete groups; Main examples of von Neumann algebras introduced by Murray and von Neumann.

Microsphere with sphere-in-capsule structure is a multi-drugs delivery system to achieve the purpose of combination therapy. In this paper, we have prepared gelatin/alginate-based microspheres with sphere-in-capsule structure by a relatively fast, simple, and easily large-scale industrialized emulsification method for spatiotemporal manipulative drug release in gastrointestinal tract. Calcium alginate microspheres encapsulated with bovine serum albumin (BSA) were first prepared as inner microspheres, and then inner microspheres and ranitidine hydrochloride (RH) were co-encapsulated by gelatin microspheres to form double-layer microspheres with sphere-in-capsule structure. The size and distribution of microspheres can be easily controlled by emulsifying conditions. The microspheres with sphere-in-capsule structure displayed desirable encapsulation efficiency of BSA (61.52 %) and RH (56.07 %). The in vitro simulated drug release showed the spatiotemporal release feature of microspheres with sphere-in-capsule structure. In the specific simulated fluid, the release behavior and cumulative release of RH (sustainedly released 95 % in simulated gastric fluid) and BSA (rapidly released 73 % in simulated intestinal fluid) were different. The drug release mechanisms were analyzed to determine RH and BSA's release behavior. Overall, the microspheres with sphere-in-capsule structure have the potential application of spatiotemporal manipulative drug delivery in the gastrointestinal tract. [Display omitted] • Emulsification method was used to obtain microsphere with sphere-in-capsule structure. • Gastrointestinal model drugs were loaded in sphere and capsule layers of microsphere. • Microspheres show the spatiotemporal manipulative release in gastrointestinal tract. • Microspheres as a multi-drugs delivery system can achieve combination therapy. [ABSTRACT FROM AUTHOR]

We present a novel online decision-making solution, where the optimal path of a given decision tree is dynamically found based on the contextual bandits analysis. At each round, the learner finds a path in the decision tree by making a sequence of decisions following the tree structure and receives an outcome when a terminal node is reached. At each decision node, the environment information is observed to hint on which child node to visit, resulting in a better outcome. The objective is to learn the context-specific optimal decision for each decision node to maximize the accumulated outcome. In this paper, we propose Dynamic Path Identifier (DPI), a learning algorithm where the contextual bandit is applied to every decision node, and the observed outcome is used as the reward of the previous decisions of the same round. The technical difficulty of DPI is the high exploration challenge caused by the width (i.e., the number of paths) of the tree as well as the large context space. We mathematically prove that DPI's regret per round approached zero as the number of the rounds approaches infinity. We also prove that the regret is not a function of the number of paths in the tree. Numerical evaluations are provided to complement the theoretical analysis. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, are regarded as emerging pollutants. OPEs are prone to concentrate into residual activated sludge, which might cause secondary pollution if not suitably treated. Composting is an economical and effective approach to make sewage sludge stable and harmless. Therefore, it is essential to develop a novel method for analyzing OPEs in sewage sludge compost samples. However, in the composting process, large amounts of amendments are doped into the sludge to adjust the carbon-nitrogen ratio. Amendment has a strong capacity for adsorption and thus induces a decrease of extraction efficiency. This study developed a novel procedure for determining OPEs in compost samples. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used for extracting and concentrating the OPEs from sewage sludge compost samples, and then analyzed by UHPLC-MS/MS. Some parameters were optimized in this study, mainly including the extraction solvent type, extraction temperature, static extraction time, extraction cycles, and flush volume. Under the optimal conditions, the proposed method showed good linearity between 0.50 and 100 μg kg with regression coefficients in the range of 0.9984-0.9998. Detection limits were in the range of 0.02-3 μg kg with standard deviations ranging from 2 to 6%. Acceptable recoveries between 56 and 119% for samples spiked at different concentration levels were achieved. In contrast, the recoveries merely ranged from 24 to 58% by using ultrasonic-assisted extraction. [ABSTRACT FROM AUTHOR]

Organophosphate esters, widely used as flame retardants and plasticizers, are regarded as a class of emerging pollutants. In this work, a novel approach was developed for the fabrication of a solid-phase microextraction fiber by using hybrid silica-based materials with immobilized ionic liquids with sol-gel technology, and the prepared solid-phase microextraction fiber was then coupled with gas chromatography and flame photometric detection for the analysis of six organophosphate esters. The high loading of 1-hexadecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide was confined within the hybrid network. The developed solid-phase microextraction fiber possesses a coating thickness of ∼35 μm with good thermal stability and long lifetime. The parameters affecting the extraction efficiency such as extraction time, temperature, pH, and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.04−0.95 μg L−1, and the precision of the method assessed with repeatability and reproducibility of (RSD%) ˂13 and ˂29%, respectively. The proposed method was successfully applied to determine the six organophosphate esters in three real water samples, with recoveries in the range of 64.8−125.4% at two different spiking concentration levels. As a result, the proposed method demonstrated its potential for application in trace determination of organophosphate esters in actual water samples. [ABSTRACT FROM AUTHOR]

Guided bone regeneration technique is an effective approach to repair bone defects, in which a barrier membrane is essential. However, the collagen barrier membranes commonly used lose stability quickly, leading to connective tissue invasion and failure of osteogenesis. Herein, we presented an oxidized sodium alginate (OSA)-collagen heterogeneous bilayer barrier membrane with well-controlled pore size and osteogenesis-promoting ability. The OSA crosslinking significantly improved the structural stability, compressive strength, swelling behavior, and slowed down the biodegradation rate of collagen membranes. Meanwhile, the collagen-based membranes exhibited superior cytocompatibility, osteogenesis-promotion, and barrier function against fibroblasts. Especially, the osteogenic differentiation was most promoted on the membrane with a large pore size (240–310 μm), while the barrier function was most improved on the membrane with a small pore size (30–60 μm). Then the above two membranes were combined together to obtain a heterogeneous bilayer membrane. This bilayer barrier membrane showed excellent osteogenesis-promoting ability in rats. • Oxidized sodium alginate-collagen barrier membranes were fabricated. • Barrier membranes had heterogeneous bilayer structure. • Barrier membranes showed good physicochemical properties and biocompatibility. • Barrier membranes showed good barrier function against fibroblasts. • Barrier membranes showed excellent osteogenesis-promoting ability. [ABSTRACT FROM AUTHOR]

Surfactant-free Pickering emulsion has been considered as a promising carrier to load oil-soluble active agents for preparation of active edible films to keep food quality and safety. Herein, dialdehyde cellulose nanocrystals (DCNC) were obtained by the periodate oxidation. Then, the DCNC-stabilized Pickering emulsion loaded with dihydromyricetin was prepared and incorporated into gelatin matrix to fabricate gelatin-based active edible films. Interestingly, DCNC was used to cross-link gelatin, besides stabilizing Pickering emulsion, to effectively improve the physicochemical properties of gelatin-based films. The results indicate that the Pickering emulsion stabilized by DCNC3 (DCNC3-DP) is quite stable during storage and centrifugation. And DCNC3-DP was homogeneously dispersed in gelatin films. Significantly, the gelatin-based active edible films incorporated with DCNC3-DP have strong UV barrier ability, high transparency, good water resistance, favorable mechanical property, and effective antioxidant activity. Overall, the as-prepared gelatin-based active edible films have advantages in the application of food and drug packaging. [ABSTRACT FROM AUTHOR]

Solid edible fat obtained by hydrogenation of vegetable oils is widely used in food market. However, the produced partially hydrogenated oils usually contain trans-fatty acids, which are harmful to health. It is meaningful to develop effective ways to directly structure edible liquid oil into gel-like state with good stability. Herein, we presented Pickering emulsions cooperatively stabilized by gelatin nanoparticles (GNPs) and dialdehyde starch nanoparticles (DASNPs) to structure liquid vegetable oils into gel state. It is interesting that Schiff's base reactions happened between GNPs and DASNPs on the surface of Pickering emulsion droplets as well as the interface among droplets, which effectively improved the stability of Pickering emulsions. The enhanced stability of Pickering emulsions contributed to the good solidification capacity to liquid oils. As a result, the emulsions could keep structure well after 6 months of storage. Moreover, the dense interfacial layer of Pickering emulsion droplets could protect β-carotene from being diffused out of the internal phase, indicating the potential of Pickering emulsions as container for encapsulating nutrients. In sum, the developed Pickering emulsion is a good strategy to structure liquid oils. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are effective antimicrobial reagent, especially for the treatment of multidrug-resistant microorganisms. However, it is difficult to remove the residual harmful reducing agents in AgNPs synthesized by the traditional chemical reduction method. In addition, AgNPs exhibit cytotoxicity when exposed directly to cells for biomedical applications and will rapidly aggregate in aqueous environment. Herein, we develop a new route to synthesize submicron-particles containing AgNPs (κ C@Ag MPs) with high aqueous stability, robust antibacterial activity and low cytotoxicity. AgNPs were firstly greenly synthesized using κ -carrageenan as environmental friendly reducing and stabilizing agent under heating in aqueous solution. Then the AgNPs were immobilized in the net of κ -carrageenan by adding KCl to obtain κ C@Ag MPs. The results indicated that κ C@Ag MPs were quite stable without any agglomeration and precipitation in aqueous solution for more than three months. κ C@Ag MPs exhibited robust antibacterial activity against Gram-positive and Gram-negative bacteria, even better than that of pure AgNPs. Notably, κ C@Ag MPs maintained the long-lasting retention of antibacterial activity. In addition, κ C@Ag MPs possessed well cytocompatibility towards the L02 and L929 cells. Overall, κ C@Ag MPs may have prospective application as effective and sustainable antibacterial agent in biomedical fields. Unlabelled Image • κ -Carrageenan was used as reducing and stabilizing agent to greenly synthesize AgNPs. • AgNPs were immobilized in the net of κ -carrageenan to obtain submicron-particles with K+. • The submicron-particles were quite stable in aqueous solution over 3 months. • The submicron-particles possessed robust antibacterial activity and low cytotoxicity. [ABSTRACT FROM AUTHOR]

It is of great significance to use safe raw materials, and spontaneously form covalent crosslinking during the fabrication process to obtain active edible films with excellent performance. Herein, l-cysteine as the source of thiol group was firstly conjugated onto gelatin backbone via 1-ethyl-3-(30-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) chemistry. Afterwards, the thiol groups in gelatin-l-cysteine (G-Cys) conjugates were oxidized in air to form disulfide bonds, meanwhile the antibacterial polypeptide ε-polylysine (ε-PL) was incorporated into gelatin matrix to fabricate gelatin/ε-polylysine active edible films. The results show that the amount of conjugated l-Cys in G-Cys conjugates ranges from 43.5 to 159.4 mg/g. The disulfide bond crosslinking generated by the oxidation of thiol groups resulted in compact and dense microstructure, which in turn could decrease the moisture content, total soluble matter, water vapor permeability and swelling behavior of gelatin-based edible films, means enhanced water resistance. Moreover, the fabricated gelatin-based edible films showed good mechanical properties, excellent UV light barrier property and effective antioxidant activity. In addition, the incorporated antibacterial polypeptide ε-PL endowed gelatin-based edible films with robust antibacterial activity. Overall, the disulfide bond crosslinked gelatin-based edible films incorporated with ε-PL could find potential application in the food and drug packaging fields. [ABSTRACT FROM AUTHOR]

Diabetic chronic wound healing still faces huge clinical challenge. The arrangement and coordination of healing processes are disordered in diabetic wound caused by the persistent inflammatory response, microbial infection, impaired angiogenesis, resulting in the delayed and even non-healing wounds. Here, the dual-drug loaded nanocomposite polysaccharide-based self-healing hydrogels (OCM@P) with multifunctionality were developed to promote diabetic wound healing. Curcumin (Cur) loaded mesoporous polydopamine nanoparticles (MPDA@Cur NPs) and metformin (Met) were introduced into the polymer matrix formed by the dynamic imine bonds and electrostatic interactions between carboxymethyl chitosan and oxidized hyaluronic acid to fabricate OCM@P hydrogels. OCM@P hydrogels show homogeneous and interconnected porous microstructure, which possess good tissue adhesiveness, enhanced compression strength, great anti-fatigue behavior, excellent self-recovery capacity, low cytotoxicity, rapid hemostatic ability and robust broad-spectrum antibacterial activity. Interestingly, OCM@P hydrogels exhibit rapid release of Met and long-term sustained release of Cur, thereby to effectively scavenge extracellular and intracellular free radicals. Significantly, OCM@P hydrogels remarkably promote re-epithelization, granulation tissue formation, collagen deposition and arrangement, angiogenesis as well as wound contraction in diabetic wound healing. Overall, the multifunctional synergy of OCM@P hydrogels greatly contributes to accelerating diabetic wound healing, which demonstrate promising application as scaffolds in regenerative medicine. [Display omitted] [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers in many products and materials. Because of the potential biologic toxicity on human beings, OPEs are regarded as a class of emerging pollutants. Dissolved organic matters (DOM) have significant effects on the bioavailability and toxicity of the pollutants in the environment. Negligible-depletion solid-phase microextraction (nd-SPME) is an efficient way for measuring the freely dissolved pollutants but suffers from long equilibrium time. Metal-organic frameworks (MOFs) are a class of porous crystalline materials with unique properties such as high pore volume, regular porosity, and tunable pore size, being widely used for the extraction of various organic compounds. Here we developed a novel method for quick determination the sorption coefficients of OPEs to DOM in aquatic phase using Fe 3 O 4 @MIL-100 (Fe) core-shell magnetic microspheres. The mesoporous structures of the as-synthesized microspheres hindered the extraction of OPEs which associated with humic acid due to the volume exclusion effect. However, the freely dissolved OPEs can access into the mesoporous and then were extracted by MIL-100 (Fe). Due to the small pore size (4.81 nm), large surface area (141 m 2  g −1 ), high pore volume (0.17 g 3  g −1 ), and ultra-thin MOFs layers, Fe 3 O 4 @MIL-100 (Fe) core-shell magnetic microspheres have large contact area for the analytes in aqueous phase and therefore the diffusion distance was largely shortened. Besides, the microspheres can be collected conveniently after the extraction process by applying a magnetic field. Compared to the nd-SPME method with 35 h equilibration time ( t 90% ), the proposed method for these studied OPEs only need 24 min to achieve equilibration. The sorption coefficients (log K DOC ) of the OPEs to humic acid were ranged from 3.84–5.28, which were highly consistent with the results by using polyacrylate-coated fiber and polydimethylsiloxane-coated fiber with nd-SPME. [ABSTRACT FROM AUTHOR]

In this paper, a convenient method was developed for preparing polymeric ionic liquid based fiber coating onto a fused silica fiber by using covalent bonding for headspace solid-phase microextraction of five organophosphorus esters from real water samples. 1-vinyl-3-(3-triethoxysilylpropyl)-4,5-dihydroimidazolium chloride was anchored on the silica layer by covalent bonding and then the polymeric ionic liquid layer was formed via free radical copolymerization with vinyl-substituted imidazolium in the presence of azobisisobutyronitrile as initiator. The limits of detection ranged from 0.68 to 100 ng L−1. The intra- and inter-day precisions, evaluated by relative standard deviation, were in the range of 4–8% and 1–10%, respectively. The recoveries of spiked real water samples were in the range of 73–110% and 77–118%, respectively, at two different concentration levels. [ABSTRACT FROM AUTHOR]

Crosslinking is frequently used to improve the inherent poor physicochemical properties of collagen. However, local flocculation and irregular crosslinking of collagen would be unavoidably occurred once contacting with crosslinking agents due to widespread complex interactions. Herein, dialdehyde starch-based nanoparticles were developed to crosslink collagen as a new strategy. Starch was conjugated with cholesterol chloroformate before periodate oxidation to obtain dialdehyde cholesterol modified starch (DACS). DACS self-assembled into nanoparticles (DACSNPs) and crosslinked with collagen to fabricate collagen hydrogels (DACSNPs-Col). DACSNPs-Col hydrogels exhibited faster gelation rate, better uniform porous structure, higher mechanical properties and better degradation stability than dialdehyde starch crosslinked hydrogels. Significantly, DACSNPs-Col hydrogels show homogeneous structure, improved mechanical properties, low cytotoxicity, well blood compatibility, high cell adhesion and proliferation. Overall, the oxidized polysaccharide nanoparticles crosslinked collagen hydrogels have homogeneous and compact microstructure and improved physicochemical properties, which show potential application prospect in the field of tissue engineering scaffold. [Display omitted] [ABSTRACT FROM AUTHOR]

pH-Responsive nanoparticles (NPs) have emerged as an effective antitumor drug delivery system, promoting the drugs accumulation in the tumor and selectively releasing drugs in tumoral acidic microenvironment. Herein, we developed a new amphiphilic modified hydroxyethyl starch (HES) based pH-sensitive nanocarrier of antitumor drug delivery. HES was first modified by hydrophilic imidazole and hydrophobic cholesterol to obtain an amphiphilic polymer (IHC). Then IHC can self-assemble to encapsulate doxorubicin (DOX) and form doxorubicin-loaded nanoparticles (DOX/IHC NPs), which displayed good stability for one week storage and acidic sensitive long-term sustained release of DOX. As a result, cancer cell endocytosed DOX/IHC NPs could continuously release doxorubicin into cytoplasm and nucleus to effectively kill cancer cells. Additionally, DOX/IHC NPs could be effectively enriched in the tumor tissue, showing enhanced tumor growth inhibition effect compared to free doxorubicin. Overall, our amphiphilic modified HES-based NPs possess a great potential as drug delivery system for cancer chemotherapy. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanism of hydrothermal shrinkage behavior of pigskin was in situ studied. • The diameter of collagen fibrils increases sharply during shrinkage process. • Spaces between collagen fibrils and fibers are compressed to extruded water molecules. • Partial fibrils still retained their characteristic banding patterns after shrinkage. The present work focuses on in situ studying the transformation process of collagen molecules and fibrils in pigskin along with hydrothermal shrinkage. The results indicate that the triple helix of collagen molecules is firstly destabilized by hydrothermal treatment and more water molecules enter the space of three polypeptide chains of collagen molecules to slight increase the diameter of collagen fibrils. Then, the thermally labile domain of collagen molecules unfolds first to form tiny nodules. The nodules are shrinkage foci, which enlarge further and finally coalesce resulting in the shrinkage of pigskin. During the shrinkage process, the diameter of fibrils increases sharply. The spaces between collagen fibrils and fibers are compressed to form a more compact space arrangement than original extended forms, resulting in extrusion of water molecules. After shrinkage, partial fibrils structure was still observed and retained their characteristic banding patterns. Subsequently, the residual fibrils structure gradually disappeared and degraded. [ABSTRACT FROM AUTHOR]

Many strategies have been employed to artificially reconstruct adipose tissue in tissue engineering. The functionalization and survival of reconstructed adipose tissue depend on sufficient angiogenesis. Notably, agglomeration growth of adipose-derived stem cells (ASCs) is beneficial to promoting angiogenesis. Herein, we present a porous collagen-based hydrogel for spontaneous agglomeration growth of ASCs to promote angiogenesis. Oxidized starch with different oxidation degree was prepared and used to cross-link collagen to fabricate the porous hydrogel. The gelation time and pore size of hydrogels can be controlled by adjusting the oxidation degree of starch. Crosslinking enhances the mechanical properties, inhibits the swelling and biodegradation of the hydrogels. The hydrogels possess good blood compatibility and cytocompatibility. Significantly, ASCs tended to adhere to the hydrogels and spontaneously grew into spheres along with time. Effective expression of vascular endothelial growth and fibroblast growth factors were observed. Overall, the hydrogels have application prospects in vascularized adipose tissue engineering. Unlabelled Image • Oxidized starch cross-linked porous collagen-based hydrogels were prepared. • Crosslinking enhanced the physicochemical properties of the hydrogels. • The hydrogels possessed good blood compatibility and cytocompatibility. • Spontaneous agglomeration growth of adipose-derived stem cells was observed. • The hydrogels had application prospects in promoting angiogenesis. [ABSTRACT FROM AUTHOR]