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Streptococcus pneumoniae is a pathogen that causes community-associated infections in young children Whole-genome sequencing (WGS) has become a powerful tool for bacterial genotyping; costs have been decreasing as accessibility increases. [...]

Objective To analyze the modeling elements and subjects of the animal model of skin photoaging, and to provide a reference for the preparation and improvement of the model and a basis for the scientific evaluation of the subject. Methods By searching and collecting relevant literature on the preparation of animal models of skin photoaging from 2010 to 2022 in the China National Knowledge Infrastructure, Wanfang Database, and PubMed database, the model animal species, gender, modeling method, modeling cycle, radiation source and its distance from the modeling site, cumulative radiation volume, detection indicators, and subjects (drugs or treatments) recorded in the literature were collated and summarized, and a database was established for statistical analysis. Results 257 articles that met the inclusion criteria were selected. Among them, the most common animal model was SKH-1 hairless mice, followed by SD rats and KM mice; the gender of animals was mainly female, medium-wave ultraviolet B (UVB) was often used as the radiation source, the distance between the radiation source and the modelling site was mostly 30 cm, and the modelling period was usually 40-60 days. The cumulative dose of long-wave ultraviolet A (UVA) was between 100-150 J/cm2, and the cumulative dose of UVB was between 5-10 J/cm2. The tests used after model establishment were skin histopathological examination, skin tissue homogenization, fibre staining, immunoblotting, etc. Subjects included Chinese herbal medicines, Chinese herbal extracts, Chinese patent medicines, Chinese herbal compound medicines, chemical drugs, biological agents and other treatments, while the animal model of skin photoaging was also used for clinical efficacy studies of external Chinese medicine, physiotherapy and positive control drugs. Conclusion In skin photoaging animal experiments, female SKH-1 hairless mice are often used, and UVB is used as the radiation source. The modeling period is usually 40-60 days, and the minimum erythema dose (MED) is incremented week by week. The cumulative UVB irradiation dose ranges from 0 to 10 J/cm2, which has the advantages of high success rate, good reproducibility and high similarity with clinical disease.

The effects of different concentrations (0%–20%) of soybean oil or lard added to pomfret surimi gel on its physicochemical properties and protein structure were studied. The addition of 8% lard or soybean oil significantly increased the whiteness, water-holding capacity (WHC), gel strength, storage modulus (G’) and sensory evaluation of surimi. When the addition level was higher than 8%, the strength, WHC, and G’ decreased. Surimi gel with 8% lard was better than that with the same concentration of soybean oil. The results of scanning electron microscopy (SEM) showed that lipids not only filled the void between protein molecules, but also formed an interfacial protein film on the surface, which combined with the protein matrix through protein filaments. It was shown that there was an interaction between lipids, the interfacial protein membrane and proteins in surimi gels. Raman spectra showed that the addition of lipids decreased the relative content of α-helix, and the first increases and then decreases of β-sheet. The addition of soybean oil also significantly increased the relative content of random coils, while the change in random coils of lard was not as significant as that of the soybean oil treatment group. Both soybean oil and lard led to the exposure of hydrophobic groups on the side chain of proteins in surimi gels. These results suggest that the addition of oil changes protein structure and microenvironment in surimi, which in turn affects the physicochemical properties of surimi gels. The surimi gel with 8% lard has better properties.

The advancement of bio‐ionotronics for the brain‐computer interaction necessitates an exploration of the mechanisms of electron‐ion coupled transport in solid state devices. In this study, a bio‐p–n junction composed of n‐type bacteriorhodopsin and p‐type P3HT are proposed. By leveraging electron‐proton synergistic effects, an opto‐ionotronic bio‐diode capable of performing ionotronic switching and rectification functions is fabricated. The switching behavior of the bio‐diode can be controlled both optically and electrically. Under light illumination, the ionotronic bio‐diode exhibits a rectification effect approaching that of an ideal diode, with a reliability of 99% and a rectification ratio of ≈661. Additionally, this bio‐organic composite ionotronic bio‐diode exhibits wide pH responsiveness, good photostability, and high biocompatibility. The proposed opto‐ionotronic bio‐diode can be utilized as a fundamental component in logic circuits, bridging the gap between semiconductor technology and biological systems, and represents a novel paradigm for the advancement of brain‐computer interaction. [ABSTRACT FROM AUTHOR]

The aerobic oxidation of C(sp3)–H bonds is an important issue in organic synthesis, and hydrogen atom transfer (HAT) is an effective process to initiate the oxidation reaction. Here, we demonstrate an innovative strategy for the oxidation of C(sp3)–H bonds based on γ-valerolactone, which can be produced from biomass. This reaction system promotes the aerobic oxidation of various benzylic and allylic C(sp3)–H bonds and alcohols. Excellent chemoselectivity for 1-isochromanone was achieved with the assistance of Ni2Al-layered double hydroxide by increasing the difference in bond dissociation energy between the 1- and 4-C–H bonds of isochroman. The excellent application potential of the reaction system has been demonstrated via the synthesis of pharmaceutical molecules, modification of steroidal substrates, scaled-up oxidation experiments, and the ready availability of γ-valerolactone from biomass. This work also reports on a new carbon-centered radical for the activation of C(sp3)–H bonds. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in the atmosphere that have drawn intense attention due to their carcinogenicity and mutagenicity. In this work, 1424 air samples were collected between January 2016 and December 2021 in three areas of Shenzhen, China to determine the concentrations of PM2.5 and PAHs and their spatiotemporal variation. Human health risks due to the daily intake and uptake of PAHs and the resulting incremental lifetime cancer risk (ILCR) were also evaluated. PAHs were detected frequently in the samples at concentrations between 0.28 and 32.7 ng/m3 (median: 1.04 ng/m3). PM2.5 and PAH concentrations decreased from 2016 to 2021, and the Yantian area had lower median concentrations of PM2.5 (23.0 μg/m3) and PAHs (0.02 ng/m3) than the Longgang and Nanshan areas. The concentrations of PM2.5 and PAHs were significantly higher in winter than in summer. Analysis of diagnostic ratios indicated that petroleum combustion was the dominant source of airborne PAHs in Shenzhen. The estimated daily intake (EDI) and uptake (EDU) of PAHs by local residents decreased gradually with increasing age, indicating that infants are at particular risk of PAH exposure. However, the incremental lifetime cancer risks (ILCRs) were below the threshold value of 10–6, indicating that inhalation exposure to PAHs posed a negligible carcinogenic risk to Shenzhen residents. While promising, these results may underestimate actual PAH exposure levels, so further analysis of health risks due to PAHs in Shenzhen is needed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Nano starch‐lutein (NS‐L) can be used in three‐dimensional (3D) printed functional surimi. However, the lutein release and printing effect are not ideal. The purpose of this study was to facilitate the function and printing properties of surimi by adding the combination of calcium ion (Ca2+) and NS‐L. RESULTS: Printing properties, lutein release and antioxidation of printed Ca2+‐NS‐L‐surimi were determined. The NS‐L‐surimi with 20 mM kg−1 Ca2+ had the best printing effects (fine accuracy, 99 ± 1%). Compared to NS‐L‐surimi, the structure became denser after adding Ca2+, the gel strength, hardness, elasticity, yield stress (τ), water holding capacity of Ca2+‐NS‐L‐surimi increased by about 17 ± 4%, 3 ± 1%, 9 ± 2%, 20 ± 4%, 40 ± 5% respectively. These enhanced mechanical strength and self‐supporting ability to resist binding deformation and improve printing accuracy. Moreover, salt dissolution and increased hydrophobic force by Ca2+ stimulated protein stretching and aggregation, leading to enhancement of gel formation. Decreased printing effects of NS‐L‐surimi with excessive Ca2+ (> 20 mM kg−1) caused by excessive gel strength and τ, leading to strong extrusion force and low extrudability. Additionally, Ca2+‐NS‐L‐surimi had higher digestibility and lutein release rate (increased from 55 ± 2% to 73 ± 3%), because Ca2+ made NS‐L‐surimi structure porous, which promoted contact of enzyme‐protein. Furthermore, weakened ionic bonds reduced electron binding bondage that combined with released lutein to provide more electrons for enhancing antioxidation. CONCLUSION: Collectively, 20 mM kg−1 Ca2+ could better promote printing process and function exertion of NS‐L‐surimi, facilitating the application of 3D printed functional surimi. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The gel is an important factor in 3D printability of Pennahia argentata surimi. While surimi gel is sensitive to temperature and influenced by chemical bonds changes. Hence, preheating effects on printing and material properties of surimi were investigated. Results shown hydrogen bonds and ionic bonds contents in surimi under different heating conditions decreased about 20%–90%. Meanwhile, hydrophobic force and disulfide bonds increased about 0.2–6 times. These changes formed more gel, as well as 6.5% at most immovable water transferred into free water which enhanced texture properties and made solid properties of rheology in surimi dominant. This phenomenon occurred significantly in temperature range of gel formation (35–40°C, 90°C) while became extinct at 45°C with 10–30 min due to gel degradation. These made surimi by heating exhibit strong mechanical strength, which is conducive to forming process when printing after extrusion. However, if they occurred before extrusion, these could increase extrusion difficulty to make filamentous materials be broken easily after extrusion, weakening printing effect. Hence, preheating of surimi before extrusion was not suitable for 3D printing. While short‐time heating during or after extrusion might be more appropriate for printed surimi, promoting the application of surimi in 3D printing technology. Practical Applications: 3D printing is a new technology in food processing that refers the process of connecting or curing materials to form 3D objects by continuously adding layers of materials. Surimi is one of the suitable materials which can promote the process of printing. While the material properties of surimi are affected by temperature that influences the printing effects. The purpose of this study was to investigate the effects of different temperatures on the material properties of Pennahia argentata surimi, and determine the suitable heating process of printed surimi products. These results could promote the application of 3D printing technology in surimi processing. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the advantages of liquid nitrogen freezing (LNF) over normal contact freezing (NCF) and individual quickly freezing (IQF). The quality attributes of LNF on crayfish (Procambarus clarkia) were characterized by biochemical and structural properties. Compared with NCF and IQF, LNF presented lower total viable counts (TVC) value of 5.83 log(CFU/g), thiobarbituric acid (TBA) value of 0.74 mg/kg, total volatile basic nitrogen (TVB‐N) content of 23.43 mg/100 g and α‐glucosidase and β‐acetyl glucosaminidase enzyme activities. SDS‐PAGE patterns confirmed less protein denaturation in LNF. Meanwhile, texture parameters analysis indicated LNF held texture quality better, while scanning electron microscope patterns revealed that muscle fibers in LNF were more uniform. The mathematical models exhibited the significant correlation among biochemical and structural properties. Therefore, LNF was a promising freezing process for crayfish preservation, due to the formation of small intracellular ice crystals and maintenance of cell integrity. Novelty impact statement: The LNF which was considered as a promising freezing method was applied in crayfish preservation.The preservation behavior of LNF was characterized and the related protective mechanism was illustrated.The mathematical models were established to clarify the inner relationship between freezing conditions and quality attributes. [ABSTRACT FROM AUTHOR]

Great attentions have been paid on the safety and quality of food products, leading to emerging innovations in food packaging industry. The natural colorants with eco-friendly and multi-functional properties are widely integrated into packaging films. And the natural colorant-based film can not only protect food from surrounding environment, but also behave indicator and active functions as a promising component for novel food packaging. This review provides a thoroughly insight into recent advances in natural colorant-based food packaging. Main 7 kinds of natural pigments were critically summarized. The molecular interaction between natural colorants and bio-polymers was investigated. Meanwhile, the influences of molecular interaction on physical and functional properties of natural colorant-based films were clearly discussed. Additionally, the applications of natural colorant-based film in terms of indicator and active food packaging were systematically summed. Furthermore, the major bottlenecks and future prospects were also illustrated for the further application of natural colorant-based film. The molecular interactions which were varied due to different charged natures of natural colorants, exerted significant influences on film physical properties, including structural, mechanical, hydrophobic, thermal and oxygen permeability properties. The natural colorant-based film which exhibited great pH-responsive, active and barrier characteristics, was suitable for the freshness monitoring and maintenance of food products, being regarded as indicator and active food packaging. Nevertheless, further studies focusing on the stabilization modification of colorants as well as the commercial production method of natural colorant-based films are critically needed. [Display omitted] • Indicator and active packaging have been prepared by incorporating natural colorants. • Molecular interactions affect both film physical and functional properties. • Natural colorant-based film can be applied as potential indicator. • Natural colorant-based film has the ability to maintain food quality. • Natural colorant-based film has a promising prospect in food packaging industry. [ABSTRACT FROM AUTHOR]

Objectives The bacteriostatic effects of a citral nanoemulsion against Shewanella putrefaciens CN-32 (SHP CN-32) were investigated using in vitro culture and gene expression analysis, for building a potential application in spoilage microorganism control and aquatic products quality maintenance. Materials and Methods SHP CN-32 was treated by prepared citral nanoemulsion when the minimal inhibitory concentration (MIC) was verified. The growth curve, membrane integrity, scanning electron microscope (SEM) observation, biofilm formation and quorum sensing (QS) signaling molecule AI-2 content were evaluated in different MIC treatment groups (0 to 1.00 MIC). The gene expression status of SHP CN-32 in 0 and 0.50 MIC groups were compared using transcriptome sequencing and quantitative polymerase chain reaction (PCR). Results The in vitro culture revealed that the citral nanoemulsion could inhibit the growth of SHP CN-32 with MIC of approximately 200 μg/mL. Images of membrane integrity, SEM and biofilm formation suggested significant biological structure damage in bacteria after treatment. Meanwhile, the QS signaling molecule AI-2 content showed a decline with increasing treatment concentration. Transcriptome sequencing and quantitative PCR revealed that the majority genes related diversified functional metabolic pathways of SHP CN-32 were downregulated at varying degree. Conclusion A significant bacteriostasis of citral nanoemulsion against SHP CN-32 was verified via the results of growth inhibition, structural destruction, signal molecular decrease and gene expression downregulation of strains. These synergies significantly affect the characteristic expression of SHP CN-32, revealing the application potential as bacteriostat, QS inhibitor and preservative in aquatic products. [ABSTRACT FROM AUTHOR]

Summary: 3D printing, as an emerging intelligent additive manufacturing processing technology, has been widely used in materials, aerospace, construction, medicine and other fields. Moreover, 3D printing technology has gradually emerged in field of food processing because of its characteristics of moulding without moulds and saving materials. The materials properties have a great influence on 3D‐printed food, especially mechanical strength and viscosity which affect accuracy and moulding ability of printed food. Moreover, the combination of materials also could change viscosity and rheology of printable materials (protein, starch, fat and hydrogel) and enhance the printing effect of not‐easy‐printable materials (cellulose). Additionally, the mixing of functional compounds and printing materials had great potential which was beneficial to personally customise functional nutritious foods to meet different people. This manuscript lays a foundation for the development and application of 3D printing technology in food processing. [ABSTRACT FROM AUTHOR]

Owing to increasing environmental concerns and growing demands for food quality maintenance, biodegradable active packaging is emerging on the market to overcome the challenges faced by traditional plastic packaging. Pectin, with characteristics of low price, non-toxic and good polymerization, is an ideal material for active food packaging. This review offers the current state of studies on pectin-based active packaging. Three different film formation methods were critically summarized. Physical properties of pectin-based packaging were systemically characterized regarding various pectin structural conformation. Furthermore, preservation behaviors and related mechanisms were fully illustrated to exhibit the outstanding advantages of pectin-based active packaging in food preservation. Pectin-based active packaging can be developed in either wet or dry processes. Wet process contains casting method leading to compact surface morphology and spraying method requiring specialized equipment, while dry process mainly refers to extrusion method with higher efficiency and meets the needs at commercial production. Physical properties of packaging including mechanical, hydrophobic and thermal characteristics are enhanced by modification of pectin conformation or incorporation with bio-polymers, overcoming the weaknesses of pure pectin packaging, such as thermal instability and strong hydrophilicity. After being functionalized with active compounds, pectin-based packaging with great antimicrobial, antioxidant and barrier properties is quite suitable for food preservation. Pectin-based packaging has great advantages to extend shelf-life of food by retarding lipid oxidation, inhibiting microbial growth, controlling water movement, etc. As a result, pectin-based active packaging with great physical and functional properties, has promising prospects in food preservation. • The main methods of pectin packaging preparation are casting, spraying and extrusion. • Film physical and functional properties are modified by incorporating other polymers. • Pectin active packaging can maintain quality and extend shelf-life of packaged food. • Pectin conformation exerts influences on film properties and preservation behaviors. • Pectin-based active packaging has a promising prospect in food packaging industry. [ABSTRACT FROM AUTHOR]

In this study, the effects of different amounts of oil addition on the properties of tuna paste were investigated. The whiteness gradually improved with the oil addition. The water holding capacity increased from 0.28 without oil addition to a peak of 0.47 with 15% oil addition before decreasing to 0.21% at 35% oil addition. Changes in properties were measured by a rotational rheometer. Changes in protein secondary structure were evaluated by Fourier transform infrared spectroscopy. The particle size measurements showed that the maximum amount of protein available to bind oil in the emulsification system is ~ 20% and excessive oil will destabilize the system. The oil droplet distribution in the emulsified system was shown by the optical microscope. The differential scanning calorimetry revealed that the oil addition could improve the transfer temperature of actin when the addition amount less than 20%. Overall, plant oil is suggested to improve the rough taste of processed tuna products. Novelty impact statement: This work investigates the effects of sunflower seed oil addition on the properties of tuna paste. We found that oil addition greatly changed the properties of tuna paste, such as whiteness, WHC, and rheology properties, thus affecting the taste of tuna paste. The present results showed that adding a suitable amount of oil can improve the property of tuna paste through lipid–protein interaction, thus not only potentially overcoming current limitation of tuna processing technology, but also encourages food processors to produce different forms of tuna products to satisfy consumers with different preferences. [ABSTRACT FROM AUTHOR]

The roselle anthocyanin extracts (RAE) were immobilized into polyvinyl alcohol (PVA)/hydroxypropyl methylcellulose (HPMC) film matrix, their interaction behavior and mechanism was fully understood for better shrimp freshness monitoring. Structural characterizations revealed RAE was firmly immobilized PVA/HPMC matrix by hydrogen bonds. With increasing RAE contents, dramatic increases of film thickness (from 15.90 ± 0.14 to 23.20 ± 3.35 μm), tensile strength (from 45.66 ± 1.07 to 56.98 ± 0.24 MPa), light barrier and active properties (increased by 83.18% for antioxidant and 146.91%, 59.18% for antibacterial activity against E. coli and S. aureus) were observed, while hydrophobic properties decreased significantly. Owing to great ammonia-sensitive ability, the PVA/HPMC/RAE (PHR) films were applied on shrimp freshness qualitative monitoring and greater visible color variations were identified with increasing RAE contents. Furthermore, mathematical models were established for quantitative monitoring. In conclusion, with the increasing RAE contents, the tighter interaction between RAE and PVA/HPMC matrix contributed to the better functional properties and freshness monitoring effects of PHR films. • The PHR films were developed for real-time shrimp freshness monitoring. • The interaction behavior and mechanism of RAE on PVA/HPMC matrix was studied. • Increasing RAE contents contributed to better film properties and monitoring effects. [ABSTRACT FROM AUTHOR]

pH-sensitive and antibacterial films based on chitosan/polyvinyl alcohol/nano-ZnO (CPZ) containing anthocyanins extracted from purple potato (PPE) or roselle (RE) were developed. When incorporated with PPE or RE, the moisture contents and flexibility of film significantly reduced (P < 0.05), while mechanical resistance of film was significantly enhanced (P < 0.05). Water vapor permeability (WVP) of film was slightly influenced by the addition of PPE or RE (P > 0.05). CPZ-RE film exhibited darker color and lower light transmittance than CPZ-PPE film at the same incorporation level. CPZ-PPE and CPZ-RE films exhibited distinguishable color changes in different pH buffer solutions. CPZ-PPE films exhibited higher antibacterial activity against Escherichia coli and Staphylococcus aureus than CPZ-RE films. Moreover, film could effectively monitor spoilage degree of shrimp when film changed from purple to light-green. Our results suggested CPZ-PPE and CPZ-RE films have promising potential as active and smart packaging materials for applications in food industry. • PPE or RE was added into chitosan/polyvinyl alcohol/nano-ZnO (CPZ) film. • PPE or RE could enhance the mechanical resistance of CPZ film. • CPZ-RE film exhibited darker color and lower light transmittance than CPZ-PPE film. • CPZ-PPE films exhibited higher antimicrobial activity than CPZ-RE films. • CPZ-PPE II film could effectively monitor shrimp freshness. [ABSTRACT FROM AUTHOR]

A novel indicator film incorporating roselle anthocyanin extracts (RAE) was prepared to monitor shrimp freshness. Hydroxypropyl methylcellulose (HPMC) modified polyvinyl alcohol (PVA) was applied as film-forming substrates to obtain better functions. Structural characterization results suggested compositions were well dispersed and confirmed the structural modification. The addition of HPMC would improve film functions through generation of new interactions. The films with a ratio (HPMC-to-PVA) of 3:1 exhibited stronger tensile strength (91.88 ± 0.13 MPa), hydrophobic (moisture content of 10.44 ± 0.65%, water contact angle of 56.40 ± 3.11°), barrier properties and larger color variations in response to pH changes, demonstrating positive influences of physical functions on indication properties. Thus, a relationship among structural, physical and indication functions was proposed. Furthermore, the films were applied for shrimp freshness real-time monitoring. The film color changed from rose-red to light green at 4 d, corresponding to the onset of spoilage, and then turned into yellow at 8 d, when the shrimp was severely spoilage. The strong correlation between total color difference and chemical spoilage indexes (P <.05) was observed. Therefore, the incorporation of HPMC could improve film functional characteristics by structural modification of new interaction formation, and the PVA/HPMC/RAE films could be applied as intelligent packaging for real-time shrimp freshness monitoring. • Novel indicator films incorporating roselle anthocyanins and HPMC modified PVA were developed. • Components of film matrix were combined by hydrogen bonds. • Film functional characteristics were significantly enhanced by the introduction of HPMC through structural modification. • The influences of film-forming substrate ratios on functional properties were studied. • The PVA/HPMC/RAE films exhibited promising capability to monitor shrimp freshness. [ABSTRACT FROM AUTHOR]