Green Preparation and Functional Properties of Reinforced All-Cellulose Membranes Made from Corn Straw.

In this study, all-cellulose nanocomposite (ACNC) was successfully prepared through a green and sustainable approach by using corn stalk as raw material, water as regeneration solvent, and recyclable two-component ionic liquid/DMSO as the solvent to dissolve cellulose. The morphology and structural properties of ACNC were determined by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis, indicating homogeneity and good crystallinity. In addition, a comprehensive characterization of ACNC showed that CNF not only improved the thermal stability and mechanical characteristics of ACNC, but also significantly improved the oxygen barrier performance. The ACNC prepared in this work has a good appearance, smooth surface, and good optical transparency, which provides a potential application prospect for converting cellulose wastes such as corn straws into biodegradable packaging materials and electronic device encapsulation materials.

A secure cross-domain interaction scheme for blockchain-based intelligent transportation systems.

In the intelligent transportation system (ITS), secure and efficient data communication among vehicles, road testing equipment, computing nodes, and transportation agencies is important for building a smart city-integrated transportation system. However, the traditional centralized processing approach may face threats in terms of data leakage and trust. The use of distributed, tamper-proof blockchain technology can improve the decentralized storage and security of data in the ITS network. However, the cross-trust domain devices, terminals, and transportation agencies in the heterogeneous blockchain network of the ITS still face great challenges in trusted data communication and interoperability. In this article, we propose a heterogeneous cross-chain interaction mechanism based on relay nodes and identity encryption to solve the problem of data cross-domain interaction between devices and agencies in the ITS. First, we propose the ITS cross-chain communication framework and improve the cross-chain interaction model. The relay nodes are interconnected through libP2P to form a relay node chain, which is used for cross-chain information verification and transmission. Secondly, we propose a relay node secure access scheme based on identity-based encryption to provide reliable identity authentication for relay nodes. Finally, we build a standard cross-chain communication protocol and cross-chain transaction lifecycle for this mechanism. We use Hyperledger Fabric and FISCO BCOS blockchain to design and implement this solution, and verify the feasibility of this cross-chain interaction mechanism. The experimental results show that the mechanism can achieve a stable data cross-chain read throughput of 2,000 transactions per second, which can meet the requirements of secure and efficient cross-chain communication and interaction among heterogeneous blockchains in the ITS, and has high application value.

Furoic acid-mediated konjac glucomannan/flaxseed gum based green biodegradable antibacterial film for Shine-Muscat grape preservation.

Considering the growing threats to the environment and human health, such as plastic pollution and food spoilage, the development of naturally antibacterial food packaging materials with biodegradable capabilities has recently attracted considerable attention. This work applies the concept of green environmental protection to packaging technology, and a new type of green edible antibacterial packaging film was developed. The basic idea is to incorporate furoic acid (FA), which possesses excellent antibacterial activity, into the flaxseed gum and konjac glucomannan matrix (FK) as a filler to obtain a series of FK-FA bioactive films. This incorporation simultaneously improves the hydrophobicity and UV-barrier ability by 12.28 % and 42.87 %, respectively. Meanwhile, the diameters of the antibacterial zone of the FK-FA0.4% films (composite FK films containing 0.4 % FA) against E. coli and S. aureus increased to 38.98 mm and 36.29 mm from 24.00 mm of pure FK film, respectively. As a consequence, the grape sample sealed with FK-FA0.4% film remained edible on the 18th day of storage, while those packaged with commercial PE film and pure FK were seriously rotted and lost edible value on the 12th day, further confirming the enhanced preservation capacity. Finally, the as-prepared films were established to be biodegradable and were almost completely degraded within 25 days under simulated environmental conditions. Overall, these promising results show the potential of FK-FA films for replacing plastic packaging materials as eco-friendly edible films with prolonged shelf life for active packaging.

Occurrence, formation mechanism, detection methods, and removal approaches for chloropropanols and their esters in food: An updated systematic review.

Chloropropanols, one of the major contaminants in food, and the corresponding esters or glycidyl esters (GEs) are of great concern in terms of product safety due to their potential carcinogenicity. During heat processing, glycerol, allyl alcohol, chloropropanol esters, sucralose, and carbohydrate in mixed foodstuffs are probable precursors of chloropropanol. The standard analytical techniques for chloropropanols or their esters are GC-MS or LC-MS following sample derivatization pretreatment. By comparing modern data against that five-year-old before, it appears that the levels of chloropropanols and their esters/GEs in food products have somewhat decreased. 3-MCPD esters or GEs may yet exceed the permitted intake set, however, especially in newborn formula which requires particularly stringent regulatory measures. Citespace (6.1. R2) software was employed in this study to examine the research focii of chloropropanols and their corresponding esters/GEs in the literature.

Nanoemulsion containing Yellow Monascus pigment : Fabrication, characterization, storage stability, and lipase hydrolytic activity in vitro digestion.

The natural pigment of monascus is favored by human for its special coloring and physiological activity, and its development and application have attracted much attention. In this study, a novel corn oil-based nanoemulsion encapsulated with Yellow Monascus Pigment crude extract (CO-YMPN) was successfully prepared via the phase inversion composition method. The fabrication and stable conditions of the CO-YMPN including Yellow Monascus pigment crude extract (YMPCE) concentration, emulsifier ratio, pH, temperature, ionic strength, monochromatic light and storage time were investigated systemically. The optimized fabrication conditions were the emulsifier ratio (5:3 ratio of Tween 60 to Tween 80) and the YMPCE concentration (20.00% wt%)). Additionally, the DPPH radical scavenging capability of the CO-YMPN (19.47 ± 0.52%) was more excellent than each YMPCE or corn oil. Moreover, the kinetic analysis results based on Michaelis-Menten equation and constant revealed that CO-YMPN could improve lipase hydrolysis capacity. Therefore, the CO-YMPN complex had excellent storage stability and water solubility in the final water system, and the YMPCE showed brilliant stability.

Detecting Personal Medication Intake in Twitter via Domain Attention-Based RNN with Multi-Level Features.

Personal medication intake detection aims to automatically detect tweets that show clear evidence of personal medication consumption. It is a research topic that has attracted considerable attention to drug safety surveillance. This task is inevitably dependent on medical domain information, and the current main model for this task does not explicitly consider domain information. To tackle this problem, we propose a domain attention mechanism for recurrent neural networks, LSTMs, with a multi-level feature representation of Twitter data. Specifically, we utilize character-level CNN to capture morphological features at the word level. Subsequently, we feed them with word embeddings into a BiLSTM to get the hidden representation of a tweet. An attention mechanism is introduced over the hidden state of the BiLSTM to attend to special medical information. Finally, a classification is performed on the weighted hidden representation of tweets. Experiments over a publicly available benchmark dataset show that our model can exploit a domain attention mechanism to consider medical information to improve performance. For example, our approach achieves a precision score of 0.708, a recall score of 0.694, and a F1 score of 0.697, which is significantly outperforming multiple strong and relevant baselines.

Regulating polymerization degree of heptazines in carbon nitride with fumaric acid to enhance photocatalytic activity.

Carbon nitride (CN) has a wide range of applications in photocatalytic treatment of environmental pollution. One of key challenges in the field is to conveniently prepare CN with tunable band gap towards efficient pollution degradation, which can be overcome by regulating the polymerization degree of its heptazines. Herein, a facile and green strategy to construct CN through co-firing urea, melamine and fumaric acid was reported. By simply inducing appropriate amount of fumaric acid during amidation reaction between fumaric acid and amino groups, the distance between heptazines of CN could be modified to obtain optimized polymerization degree and morphology. Among the considered CN systems, the modulated CN sample with the doped ratio of 2.50: 0.50: 0.03 m urea/m melamine/m fumaric acid (CNF30) displayed remarkable photocatalytic ability due to the largest specific surface area, the lowest photoluminescence emission intensity, and narrowest band gap, which led to the highest 98.0% methyl orange degradation within 60 min under a 10 W lamp and room temperature with the harmless and valuable carboxylic acids products. This study provides a new sight for the design of photocatalysts with tunable band structure towards green and efficient photocatalytic degradation of environmental pollution.

Effects of seasons and parts on volatile N-nitrosamines and their exposure and risk assessment in raw chicken and duck meats.

The N-nitrosamine (NA) concentrations and types in raw chicken and duck meats of different parts and seasons were estimated by headspace solid-phase micro-extraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The exposure level and hazard quotient of each detected volatile N-nitrosamine (VNA) were conducted. The selected chicken and duck samples were contaminated by VNAs to some extent. The major types and contents of VNAs in different parts of chicken and duck meats varied seasonally. For chicken samples, the order of the total VNA concentrations was as follows: autumn > spring > winter > summer. For duck samples, the order was changed as follows: winter > autumn > summer > spring (thigh samples) and autumn > spring > winter > summer (breast samples). The estimated exposure levels for adults caused by duck consumption were slightly higher than those by chickens, which was consistent with the tendency in 2-3 years old children. According to the linear regression correlation between the 10% benchmark dose limit (BMDL10) and subtriplicate of median lethal dose (LD50), BMDL10 values of each VNA were calculated. Due to this hypothesis, the risk assessments of each detected VNA and total VNAs posed by consuming chicken and duck meats in Tianjin, China were of low concern. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05195-1.

Primary evaluation of nine volatile N-nitrosamines in raw red meat from Tianjin, China, by HS-SPME-GC-MS.

Monitoring of N-nitrosamines in red meats is vital for food safety. The aim of this paper is to describe the effect of tissue selection, species and seasonal variation on the contents of nine N-nitrosamines in raw red meats obtained from Tianjin, China. Headspace solid-phase microextraction along with gas chromatography-mass spectrometry was used for the determination of nine N-nitrosamines in the collected samples. Radar chart visualization is applied to describe the data. The results show HS-SPME-GC-MS is a simple, sensitive, precise and accurate method. The concentrations of N-nitrosodipropylamine, N-nitrosodiethylamine and N-nitrosomethylethylamine were high in almost all investigated samples and the levels of N-nitrosodimethylamine in all samples were less than 3.00 µg/kg. The risk assessment for N-nitrosodimethylamine indicates that the potential risks posed by N-nitrosodimethylamine in raw red meats ingested by people in Tianjin, China are negligible.

Structural Differences between the Lignin-Carbohydrate Complexes (LCCs) from 2- and 24-Month-Old Bamboo (Neosinocalamus affinis).

The lignin-carbohydrate complex (LCC) was isolated from milled wood lignin of 2- and 24-month-old crude bamboo (Neosinocalamus affinis) culms using acetic acid (AcOH) and then characterized. The results have shown that the LCC preparation from 2-month-old bamboo (L2) exhibited a slightly lower molecular weight than the LCC preparation from the 24-month-old bamboo (L24). Further studies using Fourier transform infrared spectroscopy (FT-IR) and heteronuclear single quantum coherence (2D-HSQC) NMR spectra analyses indicate that the LCC preparations included glucuronoarabinoxylan and G-S-H lignin-type with G>S>>H. The content of the S lignin units of LCC in the mature bamboo was always higher than in the young bamboo. Combined with sugar composition analysis, the contents of phenyl glycoside and ether linkages in the L24 preparation were higher than in the L2 preparation; however, there was a reverse relationship of ester LCC bonds in L2 and L24. Lignin-xylan was the main type of LCC linkage in bamboo LCCs. Lignin-lignin linkages in the LCC preparations included ß-ß, ß-5 and ß-1 carbon-to-carbon, as well as ß-O-4 ether linkages, but ß-1 linkages were not present in L2.

Choreography of importin-α/CAS complex assembly and disassembly at nuclear pores.

Nuclear pore complexes (NPCs) mediate the exchange of macromolecules between the cytoplasm and the nucleoplasm. Soluble nuclear transport receptors bind signal-dependent cargos to form transport complexes that diffuse through the NPC and are then disassembled. Although transport receptors enable the NPC's permeability barrier to be overcome, directionality is established by complex assembly and disassembly. Here, we delineate the choreography of importin-α/CAS complex assembly and disassembly in permeabilized cells, using single-molecule fluorescence resonance energy transfer and particle tracking. Monitoring interaction sequences in intact NPCs ensures spatiotemporal preservation of structures and interactions critical for activity in vivo. We show that key interactions between components are reversible, multiple outcomes are often possible, and the assembly and disassembly of complexes are precisely controlled to occur at the appropriate place and time. Importin-α mutants that impair interactions during nuclear import were used together with cytoplasmic Ran GTPase-activating factors to demonstrate that importin-α/CAS complexes form in the nuclear basket region, at the termination of protein import, and disassembly of importin-α/CAS complexes after export occurs in the cytoplasmic filament region of the NPC. Mathematical models derived from our data emphasize the intimate connection between transport and the coordinated assembly and disassembly of importin-α/CAS complexes for generating productive transport cycles.

The fluorescence enhancement of the protein adsorbed on the surface of Ag nanoparticle.

The fluorescence enhancement of the BSA adsorbed on the surface of Ag nanoparticles is reported, where non-fluorescent collagen is used as the separator between the BSA and Ag nanoparticles. The study indicates that Ag nanoparticles can enhance the fluorescence of the BSA, especially the fluorescence of the tyrosine residues with lower quantum. Three types of Ag nanoparticles are evaluated including Ag island film, Ag colloids and fractal Ag electrode. Of them Ag island film is the best. The investigation suggests that the fluorescence enhancement of the BSA is related to the adsorption of the BSA on the surface of Ag island film through the hydrophobic interaction, while the collagen can promote the adsorption of the BSA on the surface of Ag island film and change its conformation, resulting in the interaction between BSA and Ag island film.

Single-molecule measurements of importin alpha/cargo complex dissociation at the nuclear pore.

Macromolecules are transported between the cytoplasm and the nucleoplasm of eukaryotic cells through nuclear pore complexes (NPCs). Large (more than approximately 40 kDa) transport cargoes imported into the nucleus typically form a complex with at least one soluble transport cofactor of the importin (Imp) beta superfamily. Many cargoes require an accessory cofactor, Imp alpha, which binds to Imp beta and to the nuclear localization sequence on the cargo. We previously reported the use of narrow-field epifluorescence microscopy to directly monitor cargoes in transit through NPCs in permeabilized cells. We now report an expanded approach in which single-molecule fluorescence resonance energy transfer (FRET) is used to detect the disassembly of Imp alpha/cargo complexes as they transit through NPCs. We found that CAS, the recycling cofactor for Imp alpha, and RanGTP are essential for this dissociation process. After Imp alpha/cargo complex dissociation, most Imp alpha and cargo molecules entered the nucleoplasm. In contrast, the majority of Imp alpha/cargo complexes that did not dissociate at the NPC in the presence of CAS and RanGTP returned to the cytoplasm. These data are consistent with a model in which Imp alpha/cargo complexes are dissociated on the nucleoplasmic side of the NPC, and this dissociation requires both CAS and RanGTP.

The sensitive determination of nucleic acids using a fluorescence-quenching method.

Experiments indicated that nucleic acids can quench the fluorescence of the Eu3+ -2-thenoyltrifluoroacetone (TTA)-1,10-phenanthroline (Phen) system. Based on this, a sensitive method for the determination of nucleic acids was proposed. The experiments indicated that under the optimum conditions, the quenched fluorescence intensity was in proportion to the concentration of nucleic acids in the range 1.0 x 10(-11)-1.0 x 10(-6) g/mL for yeast RNA (yRNA), 5.0 x 10(-11)-5.0 x 10(-7) g/mL for fish sperm (fsDNA) and 1.0 x 10(-10)-1.5 x 10(-6) g/mL for calf thymus DNA (ctDNA). Their detection limits were 3.0 x 10(-12), 4.0 x 10(-12) and 5.0 x 10(-11) g/mL, respectively. Therefore, the proposed method is one of the most sensitive methods available. The interaction between nucleic acids and Eu3+ -TTA-Phen is also discussed.

The sensitive determination of nucleic acids using resonance light scattering quenching method.

It is found that in hexamethylene tetramine (HMTA)-HCl buffer of pH 7.00, nucleic acids can quench the resonance light scattering (RLS) of europium (III) (Eu3+)-2-thenoyltrifluoroacetne (TTA)-1,10-phenanthroline (Phen) system. Based on this, a sensitive method for the determination of nucleic acids is proposed. The experiments indicate that under the optimum conditions, the quenched RLS intensity is in proportion to the concentration of nucleic acids in the range of 1.0x10(-10) to 2.0x10(-6) g ml-1 for fish sperm (fsDNA), 1.0x10(-11) to 1.0x10(-6) g ml-1 for yeast RNA (yRNA), 5.0x10(-11) to 5.0x10(-7) g ml-1 for calf thymus DNA (ctDNA). Their detection limits (S/N=3) are 0.03, 0.006 and 0.002 ng ml-1, respectively. Therefore, the proposed method is the most sensitive RLS method for the determination of nucleic acids so far. The interaction between nucleic acids and Eu3+-TTA-Phen is also discussed.

Molecular self-assembling and the fluorescence enhancement in morin-Al3+-cetyltrimethylammonium bromide-protein system.

Fluorescence enhancement effect of the morin-Al3+-cetyltrimethylammonium bromide (CTAB)-bovine serum albumin (BSA) system is reported here and the interaction mechanism is studied using fluorescence, resonance light scattering (RLS), absorption spectroscopy, Far-UV circular dichroism (CD) spectrum and small angle X-ray scattering (SAXS) measurement. It is considered that protein can bind with Al3+, morin and CTAB through self-assembling function with electrostatic attraction, hydrogen bond, hydrophobic interaction and Vander Waal force etc, and forms a supermolecular association with multilayer structure, in which morin-Al3+ is clamped between BSA and CTAB. In this system, the fluorescence enhancement of morin originates from both intermolecular energy transfer between BSA and morin, and the hydrophobic microenvironment provided by BSA and CTAB. Whereas Al3+ plays a key role for the enhancement of energy transfer efficiency because it provides an efficient channel for the energy transfer between BSA and morin.

Fluorescence enhancement effect of the morin-Al3+ -sodium dodecyl benzene sulphonate-protein system and the determination of proteins.

The fluorescence intensity of the morin-Al(3+) complex was greatly enhanced by proteins in the presence of sodium dodecyl benzene sulphonate (SDBS). Based on this, a new fluorimetric method for the determination of protein was developed. Under optimum conditions, the enhanced intensity of fluorescence was in proportion to the concentration of proteins in the range 1.0 x 10(-8)-1.3 x 10(-5) g/mL for bovine serum albumin (BSA), 4.0 x 10(-8)-1.2 x 10(-5) g/mL for egg albumin (EA) and 5.0 x 10(-8)-1.2 x 10(-5) g/mL for human serum albumin (HSA). Their detection limits (S:N = 3) were 5.0 x 10(-9), 1.8 x 10(-8) and 1.6 x 10(-8) g/mL, respectively. The interaction mechanism was also studied.

Resonance light scattering technique for the determination of proteins with Congo red and Triton X-100.

Resonance light scattering (RLS) of Congo red (CR) was greatly enhanced by BSA (HSA) in the presence of Triton X-100 (TX-100). In sodium citrate-HCl buffer (pH 2.7-3.0), the enhanced intensity of resonance light scattering at 360 nm was in proportion to the concentration of proteins [corrected] The linear relationship was obtained between the resonance light scattering intensity and proteins in the range 5.0 x 10(-8)-8.0 x 10(-6) g/mL and 1.0 x 10(-9)-6.0 x 10(-6) g/mL for BSA and HSA, respectively. Their detection limits were 1.4 x 10(-8) g/mL and 2.8 x 10(-10) g/mL (S:N = 3), respectively. Synthetic and actual samples were analysed satisfactorily.

Flow-injection-chemiluminescence method for the determination of penicillin G potassium.

The degradation product of penicillin G potassium can react with potassium permanganate in acidic medium and produce chemiluminescence, which is greatly enhanced by formaldehyde. The optimum conditions for this chemiluminescent reaction were studied in detail using a flow-injection system. The experiments indicated that under optimum conditions, the chemiluminescence intensity was linearly related to the concentration of penicillin G potassium within the range 1.0 x 10(-7)-1.0 x 10(-5) g/mL, with a detection limit (3sigma) of 7 x 10(-8) g/mL. The relative standard deviation was 1.0% for 4.0 x 10(-7) g/mL penicillin G potassium solution (n = 11). This method has the advantages of simple operation, fast response and high sensitivity. The method was successfully applied to the analysis of penicillin G potassium in raw medicines.

A fluorimetric method for the determination of nucleic acids using Ce(IV) and sodium triphosphate.

A novel and stable fluorimetric method was established for the determination of nucleic acids. The proposed method is based on the reduction by nucleic acids of Ce(IV) to fluorescent Ce(III). The fluorescence intensity can be greatly increased by sodium triphosphate. The enhanced fluorescence intensity is proportional to the concentration of nucleic acids in the range 4.2 x 10(-8)-4.2 x 10(-6) g/mL for fish sperm DNA and 5.0 x 10(-8)-6.5 x 10(-6) g/mL for yeast RNA, and the detection limits (S/N = 3) are 13.5 ng/mL and 45 ng/mL, respectively. The reaction mechanism of the hydrolytic scission of nucleic acids by Ce(IV) is discussed.