Chitosan/zein-based sustained-release composite films: Fabrication, physicochemical properties and release kinetics of tea polyphenols from polymer matrix.

This study investigated the properties of chitosan/zein/tea polyphenols (C/Z/T) films and analyzed the release kinetics of tea polyphenols (TP) in various food simulants to enhance the sustainability and functionality of food packaging. The results revealed that TP addition enhanced the hydrophilicity, opacity and mechanical properties of film, and improved the compatibility between film matrix. 1.5 % TP film showed the lowest lightness (76.4) and the highest chroma (29.1), while 2 % TP film had the highest hue angle (1.5). However, the excessive TP (above 1 % concentration) led to a decrease in compatibility and mechanical properties of film. The TP concentration (2 %) resulted in the highest swelling degree in aqueous (750.6 %), alcoholic (451.1 %), and fatty (6.4 %) food simulants. The cumulative release of TP decreased to 16.32 %, 47.13 %, and 5.87 % with the increase of TP load in the aqueous, alcoholic, and fatty food simulants, respectively. The Peleg model best described TP release kinetics. The 2 % TP-loaded film showed the highest DPPH (97.13 %) and ABTS (97.86 %) free radical scavenging activity. The results showed TP release influenced by many factors and obeyed Fick's law of diffusion. This study offered valuable insights and theoretical support for the practical application of active films.

Development and application of mathematical modeling of thymol release from environmental-responsive potato starch active packaging films.

Traditional active packaging materials are easily affected by the environment, resulting in their inability to release active substances in specified quantities at specified times and locations. In this study, MCM-41 was used as a thymol (THY) carrier and added to the potato starch (PS) matrix to design an intelligent release active packaging film based on storage microenvironment. MCM-41 encapsulation improved thermal stability of THY. THY-MCM-41 addition significantly improved the tensile strength (TS, 7.18 MPa) of the film (P < 0.05) and endowed the film excellent gas and water barrier protection. THY release was responsive to temperature and relative humidity (RH), and the First-order model better explained the THY release pattern (R2 > 0.980). The THY-MCM-41/PS film exhibited long-term antibacterial effect during 10-day storage due to the sustained release of THY. Additionally, strawberries packaged in the THY-MCM-41/PS film exhibited the best sensory characteristics during 5-day storage (25 °C and 50 % RH). Overall, the present THY-MCM-41/PS film provides a novel alternative for the sustained release of active substances in order to achieve the excellent preservation of goods such as fruits and vegetables.

Isolation of a novel multiple-heavy metal resistant Lampropedia aestuarii GYF-1 and investigation of its bioremediation potential.

BACKGROUND: Heavy metal contamination has been a severe worldwide environmental issue. For industrial pollutions, heavy metals rarely exist as singular entities. Hence, researches have increasingly focused on the detrimental effect of mixed heavy metal pollution. Genome analysis of Lampropedia strains predicted a repertoire of heavy metal resistance genes. However, we are still lack of experimental evidence regarding to heavy metal resistance of Lampropedia, and their potential in mixed heavy metal removal remain elusive. RESULTS: In this study, a Lampropedia aestuarii strain GYF-1 was isolated from soil samples near steel factory. Heavy metal tolerance assay indicated L. aestuarii GYF-1 possessed minimal inhibition values of 2 mM, 10 mM, 6 mM, 4 mM, 6 mM, 0.8 mM, and 4 mM for CdCl2, K2CrO4, CuCl2, NiCl2, Pb(CH3COO)2, ZnSO4, and FeCl2, respectively. The biosorption assay demonstrated its potential in soil remediation from mixed heavy metal pollution. Next the draft genome of L. aestuarii GYF-1 was obtained and annotated, which revealed strain GYF-1 are abundant in heavy metal resistance genes. Further evaluations on differential gene expressions suggested adaptive mechanisms including increased lipopolysaccharides level and enhanced biofilm formation. CONCLUSION: In this study, we demonstrated a newly isolated L. aestuarii GYF-1 exhibited mixed heavy metal resistance, which proven its capability of being a potential candidate strain for industrial biosorption application. Further genome analysis and differential gene expression assay suggest enhanced LPS and biofilm formation contributed to the adaptation of mixed heavy metals.

Preparation, characterization and application of pH-responsive smart film based on chitosan/zein and red radish anthocyanin.

This research was aimed at developing a novel pH-responsive smart film made of chitosan, zein and red radish anthocyanin (RRA). The morphology, interaction, crystallization, thermal stability, physiochemical properties and pH sensitivity of films were analyzed. The smart film was applied to monitor the freshness of mushroom (Agaricus bisporus). The results of morphology (SEM) and spectrum (FT-IR and XRD) indicated that the incorporation of RRA could enhance the interaction between polymer matrix. The addition of RRA had no significant effect on the thermal stability of films. The chitosan/zein/red radish anthocyanin (C/Z/R) films exhibited higher tensile strength, Young's modulus, hydrophobicity, antioxidant activity and lower elongation at break. The C/Z/R films had stronger water vapor and gas barrier capacity. The C/Z/R films showed a pH-sensitive color variation from red (pH 2) to green (pH 12) and good reversibility under alkaline and acidic environment. The prepared smart film could be successfully used for the quality monitoring of mushroom.

Bacterial community dynamics and metabolic functions prediction in white button mushroom (Agaricus bisporus) during storage.

White button mushroom (Agaricus bisporus) is rich in nutritional value, but it is easily infected by microorganisms during storage, which leads to spoilage and shortens the storage time. In this paper, A. bisporus at different storage times was sequenced by Illumina Novaseq 6000 platform. QIIME2 and PICRUSt2 were used to analyze the changes of bacterial community diversity and predict metabolic functions during storage of A. bisporus. Then, the pathogenic bacteria were isolated and identified from the spoilt samples of A. bisporus with black spot. The results showed that the bacterial species richness of A. bisporus surface gradually decreased. 2,291 ASVs were finally obtained through DADA2 denoising, belonging to 27 phyla, 60 classes, 154 orders, 255 families and 484 genera. The abundance of Pseudomonas on the surface of fresh A. bisporus sample was 22.8%, which increased to 68.7% after 6 days of storage. The abundance significantly increased and became a dominant spoilage bacterium. In addition, A total of 46 secondary metabolic pathways belonging to 6 categories of primary biological metabolic pathways were predicted during storage of A. bisporus, and metabolism (71.8%) was the main functional pathway. Co-occurrence network analysis revealed that the dominant bacterium Pseudomonas was positively correlated with 13 functional pathways (level 3). A total of 5 strains were isolated and purified from diseased A. bisporus surface. The test of pathogenicity showed that Pseudomonas tolaasii caused serious spoilage of A. bisporus. The study provided a theoretical basis for the development of antibacterial materials to reduce related diseases and prolong the storage time of A. bisporus.

Effects of tributyrin and alanyl-glutamine dipeptide on intestinal health of largemouth bass (Micropterus salmoides) fed with high soybean meal diet.

To investigate the effects of dietary tributyrin (TB) and alanyl-glutamine (AGn) on the intestinal health of largemouth bass (Micropterus salmoides) fed with high-level soybean meal (SM) diet, six isonitrogenous (41.36%) and isolipidic (10.25%) diets were formulated and fed to largemouth bass (initial body weight 25.5 ± 0.5g) for 8 weeks. The two control diets contained 34.8% peanut meal (PM) and 41.3% SM, while the other four experimental diets supplemented TB at 0.1% (TB0.1), 0.2% (TB0.2) and AGn at 1% (AGn1), 2% (AGn2) in SM, respectively. The results showed that there were no significant differences in weight gain, survival rate, and hepatosomatic index among all groups (P>0.05), while feed coefficient rate in AGn1, AGn2 and TB0.2 groups was significantly lower than that in SM group (P< 0.05). Compared with the PM group, the intestinal inflammation of largemouth bass in SM group were obvious, accompanied by the damage of intestinal structure, the decrease of digestive enzyme activity, and the up-regulation of proinflammatory cytokines. Compared with the SM group, the activities of intestinal trypsin, lipase and foregut amylase in TB and AGn groups increased significantly (P<0.05), and the gene expression levels of acetyl-CoA carboxylase (ACC), caspase-3, caspase-8, caspase-9, tumor necrosis factor alpha (TNF-α), and interleukin-1 beta (IL-1ß) were down-regulated, while the gene expression levels of target of rapamycin (TOR) and eIF4E-binding protein (4E-BP) were up-regulated in all experimental groups (P<0.05). It can be concluded that supplementation of 1%-2% AGn and 0.1%-0.2% TB can alleviate enteritis caused by high-level soybean meal, and the recommend level is 2% AGn and 0.2% TB.

Dietary Soybean Lecithin Improves Growth, Immunity, Antioxidant Capability and Intestinal Barrier Functions in Largemouth Bass Micropterus salmoides Juveniles.

This study evaluated the effects of dietary soybean lecithin (SBL) on the growth, haematological indices, immunities, antioxidant capabilities, and inflammatory and intestinal barrier functions because little information of dietary SBL could be obtained in juvenile largemouth bass (Micropterus salmoides). The fish were fed identical diets except for SBL added at 0, 2, 4 and 8%. It was found that 4 and 8% SBL significantly increased fish weight gain and daily growth rate (p < 0.05), while 4% SBL was optimal for enhancing RBC, HGB, PLT, MCV, MCH, WBC and MON in blood, and ALB and ALP in serum (p < 0.05). SBL (4%) also significantly elevated the antioxidant enzymes activities of T-SOD, CAT, GR, GPx, GST and T-AOC and GSH contents; increased mRNA transcription levels of Nrf2, Cu/Zn-SOD, CAT, GR, GST3 and GPx3; and decreased MDA contents. Keap1a and Keap1b levels were markedly down-regulated (p < 0.05). SBL (4%) significantly enhanced levels of the immune factors (ACP, LZM and C3) and the mRNA expression levels of innate immune-related genes (C3, C4, CFD, HEPC and MHC-I) compared with the control groups (0%) (p < 0.05). SBL (4%) significantly increased IgM and T-NOS in the intestine (p < 0.05) and significantly decreased levels of TNF-α, IL-8, IL-1ß and IFN-γ and increased TGF-ß1 at both transcription and protein levels in the liver and intestine (p < 0.05). The mRNA expression levels of MAPK13, MAPK14 and NF-κB P65 were significantly decreased in the intestine in the 4% SBL groups (p < 0.05). Histological sections also demonstrated that 4% SBL protected intestinal morphological structures compared with controls. This included increased intestinal villus height and muscular thickness (p < 0.05). Furthermore, the mRNA expression levels of the intestinal epithelial cell tight junction proteins (TJs) (ZO-1, claudin-3, claudin-4, claudin-5, claudin-23 and claudin-34) and mucin-5AC were significantly up-regulated in the 4% SBL groups compared with the controls (p < 0.05). In conclusion, these results suggested that 4% dietary SBL could not only improve growth, haematological indices, antioxidant capabilities, immune responses and intestinal functions, but also alleviate inflammatory responses, thereby providing reference information for the feed formulations in cultured largemouth bass.

Design of carboxymethyl chitosan-reinforced pH-responsive hydrogels for on-demand release of carvacrol and simulation of release kinetics.

pH-responsive carboxymethyl chitosan (CC)/sodium alginate (SA)/carvacrol (CA) hydrogels were prepared using CC and SA as wall materials. The formation of hydrogels is attributed to electrostatic interactions and hydrogen bonding. The thermostability of the hydrogels was improved with increasing CC content. The swelling degree of the hydrogels increased with increasing pH of the buffer solution. The mechanism of CA release was mainly controlled by Fickian diffusion. Notably, the release rate of CA was positively correlated with temperature and environmental pH, thus the on-demand release of CA can be achieved through pH stimulation. The hydrogels showed good storage stability via determination of antioxidant and antibacterial activities. Furthermore, the C4S1-CA hydrogels (CC/SA blends with dry mass ratios of 4:1, w/w) have good biocompatibility and biosafety. The CC/SA/CA hydrogels provide a unique route for environmentally-responsive preservatives and present new avenues for precise release and intelligent preservation.

Characterization and release kinetics model of thymol from starch-based nanocomposite film into food simulator.

To improve the performance of potato starch films and solve the problems of high volatility and low stability of thymol (Thy), thymol was loaded into the channel of SBA-15 to prepare Thy-SBA-15, and the Thy-SBA-15/potato starch film was prepared. The results showed thymol was successfully loaded into the pores of SBA-15. The addition of Thy-SBA-15 enhanced the tensile strength of potato starch film (3.93 Mpa), reduced the water vapor permeability (1.56 × 10-12  g·d-1  m-1  Pa-1 , WVP) and moisture absorption (80.97%, MA), which enhanced the barrier properties of the films. Thy-SBA-15 had good compatibility with potato starch films. Notably, the thymol released from Thy-SBA-15/potato starch film was initially explosive, and then continuous, which showed this film could effectively slow down the release rate of thymol and prolong the fresh-keeping period of food. The Korsmeyer-Peppas model M t M ∞ = k t n (R2  > .96) had the best fit for the release curve of thymol. PRACTICAL APPLICATIONS: This work offers a new method for the preparation of potato starch sustained-release antibacterial film, and provides a theoretical basis and technical support for the development of intelligent packaging.

Characterization and Release Kinetics Study of Active Packaging Films Based on Modified Starch and Red Cabbage Anthocyanin Extract.

Active packaging films were prepared by adding red cabbage anthocyanin extract (RCAE) into acetylated distarch phosphate (ADSP). This paper investigated the influence of the interaction relationship between RCAE and the film matrix on the structure, barrier, antioxidant and release properties of active films. Sixteen principal compounds in RCAE were identified as anthocyanins based on mass spectroscopic analysis. Micromorphological observations indicated that the RCAE distribution uniformity in the films decreased as the RCAE content increased. When the concentration of RCAE was not higher than 20%, the moisture absorption and oxygen permeability of films decreased. The stability of RCAE in the films was enhanced by the electrostatic interaction between RCAE and ADSP with the formation of hydrogen bonds, which facilitated the sustainability of the antioxidant properties of films. The release kinetics of RCAE proved that the release rate of RCAE in active films was the fastest in distilled water, and Fickian's law was appropriate for portraying the release behavior. Moreover, the cytocompatibilty assay showed that the test films were biocompatible with a viability of >95% on HepG2 cells. Thus, this study has established the suitability of the films for applications in active and food packaging.

De Novo Transcriptome Analysis Reveals Putative Genes Involved in Anthraquinone Biosynthesis in Rubia yunnanensis.

Rubia yunnanensis Diels (R. yunnanensis), a Chinese perennial plant, is well-known for its medicinal values such as rheumatism, contusion, and anemia. It is rich in bioactive anthraquinones, but the biosynthetic pathways of anthraquinones in R. yunnanensis remain unknown. To investigate genes involved in anthraquinone biosynthesis in R. yunnanensis, we generated a de novo transcriptome of R. yunnanensis using the Illumina HiSeq 2500 sequencing platform. A total of 636,198 transcripts were obtained, in which 140,078 transcripts were successfully annotated. A differential gene expression analysis identified 15 putative genes involved in anthraquinone biosynthesis. Additionally, the hairy roots of R. yunnanensis were treated with 200 µM Methyl Jasmonate (MeJA). The contents of six bioactive anthraquinones and gene expression levels of 15 putative genes were measured using ultra performance liquid chromatography coupled with mass spectrometry (UPLC-MS/MS) and real-time quantitative polymerase chain reaction (RT-qPCR), respectively. The results showed that the expressions levels for 11 of the 15 genes and the contents of two of six anthraquinones significantly increased by MeJA treatment. Pearson's correlation analyses indicated that the expressions of 4 of the 15 putative genes were positively correlated with the contents of rubiquinone (Q3) and rubiquinone-3-O-ß-d-xylopranosyl-(1→6)-ß-d-glucopyranoside (Q20). This study reported the first de novo transcriptome of R. yunnanensis and shed light on the anthraquinone biosynthesis and genetic information for R. yunnanensis.

Preparation, characterization and application of poly(lactic acid)/corn starch/eucalyptus leaf essential oil microencapsulated active bilayer degradable film.

This study aimed to develop a composite bilayer film based on corn starch (CS)/polylactic acid (PLA). The film had a hydrophobic outer layer and an absorbent inner layer. A natural bioactive substance was incorporated into the inner layer, namely, eucalyptus essential oil microcapsules (EOM). This allowed most of the bioactive substance to be released inside the storage environment. The effects of different amounts of EOM on the physical, mechanical, antioxidant, and antimicrobial properties of the films were investigated. Based on the results of scanning electron microscopy (SEM), the addition of 10-15 mL/100 mL of EOM could be uniformly distributed in the film. The addition of less than 15 mL/100 mL of EOM to the film improved its tensile strength, barrier properties, and elongation at break. The addition of too much EOM led to cracks in the film. The addition of EOM also greatly improved the antioxidant and antibacterial properties of the bilayer film. The best performance was obtained when the added amount was 15 mL/100 mL. Films with the best overall properties were used for preserving Agaricus bisporus. In preservation experiments, this film inhibited the respiration rate of A. bisporus, slowed down the consumption of organic matter, and maintained its moisture content. Compared with other cling films, the shelf life of A. bisporus was greatly extended.

Removal performance and mechanisms of toxic hexavalent chromium (Cr(VI)) with ZnCl2 enhanced acidic vinegar residue biochar.

Acidic vinegar residue (VR) and toxic hexavalent chromium (Cr(VI)) are unfavorable substances due to their toxicity against the environment. In this study, modified biochar was prepared to investigate the removal mechanisms of Cr(VI). The results showed that ZnCl2 could yield highly aromatic products with improved pore structures. The adsorption capacity of modified biochar reached the highest efficiency (236.81 mg g-1) when the mass ratio of ZnCl2/VR was 1, which is higher than the control (9.96 mg g-1). In addition, Cr(VI) adsorption coexisted with physical and chemical adsorption. The mechanisms of modified biochar to Cr(VI) removal included electrostatic attraction, pore filing, reduction and surface complexation. Notably, as a fermented product, VR biochar was a nitrogen-rich product; the formation of the amino group could provide a direct solid site for Cr(VI) adsorption. Subsequently, amorphous silica could be converted into silanol to provide additional adsorption sites. This work establishes the theoretical basis for efficient Cr(VI) removal and VR reuse.

Characterization and release kinetics study of potato starch nanocomposite films containing mesoporous nano-silica incorporated with Thyme essential oil.

This study aimed to develop potato starch nanocomposite films containing mesoporous nano-silica (SBA-15, SBA-16 and MCM-41) incorporated with Thyme essential oil (TEO). TEO-SBA-15/potato starch films, TEO-SBA-16/potato starch films and TEO-MCM-41/potato starch films were prepared based on potato starch. The physical and mechanical properties of the nanocomposite films were also investigated. The results showed that the addition of mesoporous nano-silica incorporated with TEO improved the properties of potato starch nanocomposite films. Especially, the addition of TEO-MCM-41 markedly enhanced the tensile strength (4.33 MPa), and reduced the water vapor permeability (1.80 g·m-1·h-1·KPa-1) and moisture absorption (37.67%) of potato starch nanocomposite films. The results of scanning electron microscopy (SEM) analysis showed that TEO-MCM-41 hardly agglomerated in the potato starch nanocomposite films. Additionally, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed that strong hydrogen bonds were formed between TEO-MCM-41 and potato starch. The release kinetics of TEO proved that incorporating TEO into the pores of mesoporous nano-silica could delay its release rate, and the Peleg model (t/(Mt - M0) = K1 + K2t) was suitable for describing the release behavior. The findings of this study suggested that TEO-MCM-41/potato starch films had a good application prospect in the field of slow-releasing and antimicrobial packaging materials.

The complete chloroplast genome of wild Magnolia officinalis Rehd. et Wils.

Magnolia officinalis Rehd. et Wils. is an important traditional Chinese herbal medicine and widely distributed in the south of Yangtze River in China. In this study, the complete chloroplast genome sequence of wild M. officinalis was assembled and characterized from high-throughput sequencing data. The chloroplast genome was 160,009 bp in length, consisting of large single-copy (LSC) and small single-copy (SSC) regions of 88,134 bp and 18,739 bp, respectively, which were separated by a pair of 26,568 bp inverted repeat (IR) regions. The genome is predicted to contain 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content of the genome is 39.3%. A phylogenetic tree reconstructed by 86 chloroplast genomes reveals that M. officinalis is mostly related to cultivated M. officinalis, M. obovata and M. tripetala.

De novo assembly and Transcriptome Analysis of the Momordica charantia Seedlings Responding to methyl jasmonate using 454 pyrosequencing.

Momordica charantia, a medicinal and edible species of the Cucurbitaceae family, has been widely used as a vegetable around the world. Hundreds of pharmacological compounds isolated from the M. charantia have been reported. However, the mechanism of action of the secondary metabolites has not been fully elucidated. In this study, 118,590 unigenes were gained by de novo assembly based on the raw data from high-throughput sequencing of mRNA (RNA-Sequencing) upon systemic analysis, among which, 51,860 (43.73%) could be annotated to the public sequence databases such as Nr, GO, Swiss-Prot, KEGG and KOG. The transcriptomic changes of M. charantia seedlings treated with or without methyl jasmonate (MeJA) were analyzed to identify key genes involved in MeJA treatment. Additionally, 554 differentially expressed genes (DEGs), including 328 up-regulated ones and 226 down-regulated genes, have been identified. Most DEGs were associated with secondary metabolism and stress responses. Meanwhile, six DEGs were further confirmed by quantitative real-time RT-PCR (qRT-PCR) analysis, resulting in similar expression patterns as compared to those of RNA-Sequencing. Nine significantly enriched pathways including 11 DEGs were identified to be possibly involved in the MeJA-responsive biosynthesis of secondary metabolites based on the transcriptome sequencing analysis. Among them, 4 DEGs, encoding two peroxidases, one cinnamyl alcohol dehydrogenase and one hypothetical protein Csa, might play important roles in the process of phenylpropanoid biosynthesis. In addition, 9 transcription factors (TFs) were also detected as DEGs from 1899 unigenes. Most of them up-regulated by MeJA treatment might be potentially involved in regulating secondary metabolites biosynthesis. This work is the first research on the large-scale assessment of M. charantia transcriptomic resources and the analysis of DEGs and TFs in secondary metabolites biosynthesis of M. charantia seedings treated with or without MeJA, which will be conducive to the further applications of M. charantia.

Characterization of antioxidant compounds extracted from Citrus reticulata cv. Chachiensis using UPLC-Q-TOF-MS/MS, FT-IR and scanning electron microscope.

Citrus reticulata cv. Chachiensis (CRC) has been widely used in many Chinese medicine prescriptions and developed as various health products. Due to its extensive biological activities, increased interest has focused on CRC as a potential source for the treatment of various diseases. However, there is no systematic and sufficient research on optimization and characterization of ultrasound extraction of antioxidant compounds from CRC up to now. In the present work, three parameters including ultrasonic amplitude (45, 55, 70, 85, 95 %), ultrasonic time (26, 40, 60, 80, 94 min) and ethanol concentration (16, 30, 50, 70, 84 %, v/v) were estimated using central-composite design. Determined optimum conditions, considering four responses (TPC, TFC, DPPH and ABTS) at the same time, were 72 % amplitude, 80 min and 70 % ethanol concentration. The maximum yields were TPC values (145.73 mg GAE/g), TFC values (135.21 mg QE/g), DPPH and ABTS scavenging capacity (87.88 and 76.18 mg TE/g, respectively). 55 phytochemicals were identified in the CRC extract using the UPLC-QTOF-MS/MS, 34 of which were flavonoids, which provided important support for various potential applications of CRC.

Anti-Inflammatory Property of the Essential Oil from Cinnamomum camphora (Linn.) Presl Leaves and the Evaluation of Its Underlying Mechanism by Using Metabolomics Analysis.

Cinnamomum camphora (Linn.) Presl has been widely used in traditional Chinese medicine for a variety of purposes. Our previous study indicated the antibacterial mechanism of the essential oil (EO) from C. camphora leaves; however, its anti-inflammatory activity and the underlying mechanism have not been clearly demonstrated. Thus, the present study investigated its anti-inflammatory property. Our data revealed that EO significantly decreased the release of nitric oxide (NO) and the mRNA expression of inducible NO synthase (iNOS) in lipopolysaccharide (LPS)-induced BV2 microglial cells. EO also attenuated LPS-induced increase in the mRNA expression and secretion of inflammatory cytokines including interleukin-6 (IL-6), IL-18, IL-1ß and tumor necrosis factor-α (TNF-α). Furthermore, the metabolic profiles of LPS-induced BV2 microglial cells treated with or without EO were explored. Thirty-nine metabolites were identified with significantly different contents, including 21 upregulated and 18 downregulated ones. Five pathways were enriched by shared differential metabolites. Compared with the control cells, the glucose level was decreased, while the lactate level was increased, in the culture supernatant from LPS-stimulated cells, which were reversed by EO treatment. Moreover, compared to the LPS-treated group, the activities of phosphofructokinase (PFK) and pyruvate kinase (PK) in EO group were decreased. In summary, the current study demonstrated that EO from C. camphora leaves acts as an anti-inflammatory agent, which might be mediated through attenuating the glycolysis capacity of microglial cells.

Cooling effect and control factors of common shrubs on the urban heat island effect in a southern city in China.

Because the heat island effect can make cities warmer than their surroundings, it can make urban dwellers uncomfortable and even affect their health, which is particularly pronounced in developed cities in southern China. To reduce the heat island effect and improve the environment, various types of vegetation have been planted in the urban green belt. Though previous studies have been conducted on the beauty, air purification functions and cooling effect of vegetation, little is concentrated on the different cooling effects and control factors of various common shrubs on the heat island effect in cities. In this study, five of the most regionally common shrubs were selected to study the cooling effect in Guangzhou, southern China. The maximum surface temperatures of five shrubs and pavement were compared using infrared temperature sensors from April 1st 2019 to October 31st 2019. Results show that (1) All five shrubs showed noticeable seasonal variation, and the average surface temperatures of the five shrubs were between 38.0 and 42.2 °C during May-August and 30.7-34.1 °C during the other seasons (April, September and October);. (2) Murraya exotica L. exhibited the best cooling effect on the maximum surface temperature. Its value was 44.7 °C, and the absolute difference values of Murraya exotica L. (10.3 ± 1.7 °C) were higher than any other shrub during the study period; (3) Both the LAI (R2 = 0.57, p < 0.01) and plant height (R2 = 0.13, p < 0.01) are control factors of the cooling effect on vegetation surface temperature for the five shrubs. This study revealed the differences in the cooling effect and influencing factors of five regionally common shrubs on the heat island effect. Research on the functional characteristics of plants and plant selection in urban green belts has both theoretical and practical significance.

Development and characterization of corn starch/PVA active films incorporated with carvacrol nanoemulsions.

An active film was prepared by corn starch (CS), polyvinyl alcohol (PVA) and carvacrol nanoemulsions (CNE). The microstructure and properties of CNE/corn starch/PVA (CNE/CSP) films were characterized and investigated. Scanning electron microscopy (SEM) revealed the uniform distribution of CNE and discontinuity of the film matrix. Fourier transform infrared (FT-IR) and rheological analysis indicated that CNE could weaken molecular interaction of the film matrix. X-ray diffraction (XRD) show that the films are amorphous and CNE has no effect on crystal structure of the films. Incorporation of CNE significantly increased the tensile strength, Young's modulus, elongation at break, barrier (water vapor and ultraviolet), antioxidant and antifungal activity. With the CNE incorporated, the optimal tensile strength, Young's modulus, elongation at break and antioxidant activity of the films can reach 12 MPa, 11 MPa, 133%, 81%, respectively. Minimum water vapor permeability was 3.1 × 10-12 gd-1m-1Pa-1. Notably, films incorporated with CNE (≥20%) had good DPPH free radical scavenging ability (>50%) when stored up to 6 days. Films with 25% CNE exhibited excellent antifungal activity against Trichoderma sp. and its inhibitory zone was 47 mm. Overall, the CSP films loaded with CNE (>15%) could be used as food packing materials with good antioxidant and antimicrobial activities.