Janus electro-microenvironment membrane with surface-selective osteogenesis/gingival healing ability for guided bone regeneration.

Guided bone regeneration is widely applied in clinical practice to treat alveolar bone defects. However, the rate of healing of severe alveolar bone defects is slow, and there is a high incidence of soft tissue wound dehiscence. In this study, we propose a barrier membrane with a Janus electro-microenvironment (JEM) to achieve side-selective bone regeneration and soft tissue healing. The JEM membrane was constructed using a polarized polyvinylidene fluoride ferroelectric membrane with different surface potentials on either side. It promoted osteogenic differentiation and bone regeneration on the negatively polarized side (JEM-) and soft tissue regeneration on the positively polarized side (JEM+). Further investigation revealed that the JEM-mediated promotion of bone formation was related to mitochondrial autophagy, as indicated by depolarization of the mitochondrial membrane potential and the expression of LC3, Pink I, and Parkin. Moreover, the gingival healing promoted by JEM+ was related to oxidative phosphorylation in mitochondria, as indicated by the upregulation of mitochondrial complexes I-V and an increase in ATP generation. The design concept of the JEM provides a new avenue for regulating tissue regeneration between different tissue interfaces.

Radical 1,4/5-Amino Shift Enables Access to Fluoroalkyl-Containing Primary ß(γ)-Aminoketones under Metal-Free Conditions.

A novel radical 1,4/5-amino shift from the oxygen center of alkene-tethered diphenyl ketoxime ethers to the carbon center to achieve high value-added fluoroalkyl-containing primary ß(γ)-amino-ketones is reported. Mechanism studies reveal that the migration is triggered by the alkene addition of fluoroalkyl radical derived from the electron donor-acceptor (EDA) complex of Togni's reagent II or fluoroalkyl iodides and quinuclidine, and involves a unique 5(6)-exo-trig cyclization of the carbon-centered radical onto the N-atom of ketoxime ethers followed by a cascade sequence of N-O bond cleavage and dehydrogenation. Notably, besides Togni's reagent II and fluoroalkyl iodides, this protocol is also compatible with other radical precursors to provide various functionalized primary aminoketones.

Transcription factors DkBZR1/2 regulate cell wall degradation genes and ethylene biosynthesis genes during persimmon fruit ripening.

BRASSINAZOLE RESISTANT (BZR) transcription factors are critical components of the brassinosteroid signalling pathway, but their possible roles in fruit ripening have rarely been reported. In this study, four BZR sequences were isolated from persimmon fruit. Among the four BZR genes, DkBZR1/2 were expressed in persimmon fruit; DkBZR1 protein amount decreased and dephosphorylated DkBZR2 gradually accumulated during the storage period. DkBZR1/2 proteins were localized in both the nucleus and cytoplasm and accumulated in the nucleus after 24-epibrassinolide treatment. DkBZR1 suppressed the transcription of Diospyros kaki endo-1,4-betaglucanase 1 (DkEGase1) and 1-aminocyclopropane-1-carboxylate synthase 1 (DkACS1) by binding to the BR response element (BRRE) in their promoters, and DkBZR2 activated the transcription of pectate lyase 1 (DkPL1) and 1-aminocyclopropane-1-carboxylate oxidase 2 (DkACO2) by binding to the E-box motif in their promoters. Transient overexpression of DkBZR2 promoted the conversion of acid-soluble pectin to water-soluble pectin and increased ethylene production in persimmon fruit. Our findings indicate that DkBZR1 and DkBZR2 serve as repressors and activators of persimmon fruit ripening, respectively.

Genome-wide analysis of the bZIP gene family and the role of AchnABF1 from postharvest kiwifruit (Actinidia chinensis cv. Hongyang) in osmotic and freezing stress adaptations.

Chilling injury (CI) is a barrier to the refrigeration of kiwifruit, resulting in decreased fruit quality and increased nutrient loss during storage. Understanding the molecular basis underlying the cold response and its regulation in refrigerated kiwifruit is therefore highly important. Basic (region) leucine zipper (bZIP) transcription factors (TFs) have been widely studied for their roles in abiotic stress resistance in various species. In this study, we identified 81 bZIP family proteins in kiwifruit and classified them into 11 groups. Further transcriptome analysis revealed that the expression of members of the AREB/ABF family was strongly induced by low temperature and abscisic acid (ABA). Ectopic expression of AchnABF1 enhanced plant cold tolerance by upregulating the expression of several key genes associated with ABA-dependent and ABA-independent pathways in Arabidopsis thaliana. Reactive oxygen species (ROS) metabolism was suggested to be involved in the AchnABF1-mediated osmotic stress response. For instance, enhanced ROS-scavenging ability was observed in transgenic plants with enhanced activity of catalase (CAT) and peroxidase (POD), which resulted in decreased in situ O2.- and H2O2 accumulation, ion leakage, and malondialdehyde (MDA) content under various abiotic stresses. In addition, AchnABF1 also participated in the osmotic stress response during both the germination and postgermination stages. We concluded that AchnABF1 may play an important role in kiwifruit during refrigeration.

Gender, Socioeconomic Status, Cultural Differences, Education, Family Size and Procrastination: A Sociodemographic Meta-Analysis.

Procrastination describes a ubiquitous scenario in which individuals voluntarily postpone scheduled activities at the expense of adverse consequences. Steel (2007) pioneered a meta-analysis to explicitly reveal the nature of procrastination and sparked intensive research on its demographic characteristics. However, conflicting and heterogeneous findings reported in the existing literature make it difficult to draw reliable conclusions. In addition, there is still room to further investigate on more sociodemographic features that include socioeconomic status, cultural differences and procrastination education. To this end, we performed quantitative sociodemographic meta-analyses (k = 193, total n = 106,764) to fill this gap. It was found that the general tendency and academic procrastination tendency of males were stronger than females (r = 0.04, 95% CI: 0.02-0.05). No significant effects of differences in socioeconomic status (i.e., poor or rich), multiculturalism (i.e., Han nation or minorities), nationality (i.e., China or other countries), family size (i.e., one child or > 1 child), and educational background (i.e., science or arts/literature) were found to affect procrastination tendencies. Furthermore, it was noteworthy that the gender differences in procrastination tendencies were prominently moderated by measurements, which has a greater effect on the Aitken Procrastination Inventory (API) (r = 0.035, 95% CI: -0.01-0.08) than on the General Procrastination Scale (GPS) (r = 0.018, 95% CI: -0.01-0.05). In conclusion, this study provides robust evidence that males tended to procrastinate more than females in general and academic profiles, and further indicates that procrastination tendencies do not vary based on sociodemographic situations, including socioeconomic status, multiculturalism, nationality, family size, and educational background.

The role of PHF8 and TLR4 in osteogenic differentiation of periodontal ligament cells in inflammatory environment.

BACKGROUND: Histone methylation is considered to play an important role in the occurrence and development of periodontitis. Plant homeodomain finger protein 8 (PHF8), a histone demethylase, has been shown to regulate inflammation and osteogenic differentiation of bone marrow stromal cells (BMSCs). This study aimed to detect the functions of PHF8 and TLR4 in osteogenic differentiation in an inflammatory environment induced by Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) METHODS: A periodontitis mouse model was established, and the mice were treated with TAK-242. Immunohistochemical staining was used to detect the expression of PHF8 in periodontal tissue. Periodontal ligament cells (PDLCs) were treated with mineralization induction medium supplemented with Pg-LPS and/or TAK-242, and a Cell Counting Kit-8 (CCK-8) assay was used to detect the proliferation of PDLCs. Real-time PCR and western blotting were used to detect the mRNA and protein expression levels, respectively, of PHF8, toll-like receptor 4 (TLR4) and the other osteogenic markers alkaline phosphatase (ALP), osteocalcin (OCN), Special AT-rich sequence-binding protein 2 (Satb2) and Runt-related transcription factor 2 (Runx2) RESULTS: Periodontitis reduced PHF8 expression in periodontal tissue, and TAK-242 partially reversed this downregulation. An in vitro experiment revealed that the mRNA and protein expression levels of PHF8 were significantly upregulated during the osteogenic differentiation of PDLCs. Alizarin red staining showed that the mineralized nodules of PDLCs in osteogenic induction group were more than those in control group. Real-time PCR and western blot results indicated that Pg-LPS inhibited PHF8 expression and upregulated TLR4 expression in PDLCs. TAK-242 inhibited TLR4 and partially reversed the inhibition of PHF8 expression and osteogenic differentiation induced by Pg-LPS in PDLCs CONCLUSION: PHF8 and TLR4 play important roles in periodontitis. Pg-LPS inhibits the expression of PHF8 via upregulation of TLR4 and might further inhibit the osteogenic differentiation of PDLCs. However, the specific mechanisms involved remain to be explored.

Effects of calcium treatment on malate metabolism and γ-aminobutyric acid (GABA) pathway in postharvest apple fruit.

Calcium treatment effects on malate metabolism and the GABA pathway in 'Cripps Pink' apple fruit during storage were investigated. Postharvest apple fruit treated with 1% and 4% calcium chloride solutions were stored at 25 ± 1 °C. The 4% calcium treatment suppressed declines in titratable acidity and malate content and increased succinate and oxalate concentrations. Calcium treatment also reduced the respiration rate and decreased ethylene production peak during storage. Moreover, 4% calcium treatment significantly enhanced cyNAD-MDH and PEPC activities and upregulated MdMDH1, MdMDH2, MdPEPC1 and MdPEPC2 expression while inhibiting cyNADP-ME and PEPCK activities and downregulating MdME1, MdME4 and MdPEPCK2 expression. Surprisingly, calcium treatment changed the content of some free amino acids (GABA, proline, alanine, aspartic acid and glutamate), two of which (glutamate and GABA) are primary metabolites of the GABA pathway. Furthermore, calcium application enhanced GABA pathway activity by increasing MdGAD1, MdGAD2, MdGABA-T1/2 and MdSSADH transcript levels.

Deconstructive Oxygenation of Unstrained Cycloalkanamines.

A deconstructive oxygenation of unstrained primary cycloalkanamines has been developed for the first time using an auto-oxidative aromatization promoted C(sp3 )-C(sp3 ) bond cleavage strategy. This metal-free method involves the substitution reaction of cycloalkanamines with hydrazonyl chlorides and subsequent auto-oxidative annulation to in situ generate pre-aromatics, followed by N-radical-promoted ring-opening and further oxygenation by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and m-cholorperoxybenzoic acid (mCPBA). Consequently, a series of 1,2,4-triazole-containing acyclic carbonyl compounds were efficiently produced. This protocol features a one-pot operation, mild reaction conditions, high regioselectivity and ring-opening efficiency, broad substrate scope, and is compatible with alkaloids, osamines, and peptides, as well as steroids.

Silver-Catalyzed Site-Selective Ring-Opening and C-C Bond Functionalization of Cyclic Amines: Access to Distal Aminoalkyl-Substituted Quinones.

Distal aminoalkyl-substituted quinones have been efficiently prepared through silver-catalyzed site-selective deconstruction and C-C bond transformation of unstrained N-acylated cyclic amines. This method enjoys mild reaction conditions, high selectivity, a broad scope of substrates, and a low catalytic loading of silver. This strategy can also be applied to the modification of peptides bearing cyclic amine residues.

Exogenous γ-Aminobutyric Acid Treatment That Contributes to Regulation of Malate Metabolism and Ethylene Synthesis in Apple Fruit during Storage.

Organic acid is an important indicator of fruit quality, and malate is the predominant organic acid in apple fruit. However, the regulation of malate metabolism in postharvest fruit is rarely reported. Here, we found that, compared with a control treatment, a 10 mM γ-aminobutyric acid (GABA) treatment remarkably delayed the loss of tiftratable acidity and malate and increased the succinate and oxalate contents in "Cripps Pink" fruit stored in polyethylene bags at room temperature. The higher malate levels in GABA-treated fruit were accompanied by higher activities of cytosolic nicotinamide adenine dinucleotide-dependent malate dehydrogenase (cyNAD-MDH) and phosphoenolpyruvate carboxylase (PEPC) but lower cytosolic NAD phosphate-dependent malic enzyme (cyNADP-ME) and phosphoenolpyruvate carboxykinase (PEPCK) activities than those seen in control fruit. Notably, ethylene production was significantly reduced by GABA treatment, paralleling the downregulation of MdACS, MdACO, and MdERF expression. Meanwhile, GABA treatment also enhanced the activity of the GABA shunt and promoted the accumulation of GABA. This study provides new insights into the regulation of malate metabolism and reports for the first time the possible interplay between GABA and ethylene signaling pathways in apple fruit during postharvest storage.

Functional characterization of persimmon ß-galactosidase gene DkGAL1 in tomato reveals cell wall modification related to fruit ripening and radicle elongation.

Cell wall metabolism during fruit ripening is a highly organized process that involves complex interplay among various cell wall hydrolases. Among these cell wall hydrolases, ß-galactosidase has been identified to participate in cell wall metabolism via its ability to catalyze galactosyl metabolism from the large and complex side chains of cell walls. In this study, the galactose content in the pericarp increased during persimmon fruit ripening, but cell wall galactosyl residues decreased, indicating a relationship between galactose metabolism and persimmon fruit ripening. Expression of a previously isolated ß-galactosidase gene, DkGAL1, increased 25.01-fold during fruit ripening. Heterologous expression of DkGAL1 under the CaMV 35S promoter in tomato accelerated on-plant and postharvest fruits ripening. The fruit firmness of one of transgenic line, OE-18, was 23.83% lower than that of WT at the breaker stage. The transgenic fruits produced more ethylene by promoting the expression of ethylene synthesis-related genes and cell wall degradation-related genes. Overexpression of DkGAL1 in tomato also reduced cell-to-cell adhesion and promoted both wider intercellular spaces and less cell compaction in transgenic fruit structures. Moreover, DkGAL1 was involved in seed germination and radicle elongation in transgenic tomato seeds. These results confirm the role of DkGAL1 in fruit ripening and suggest that this gene alters galactose metabolism in the fruit, which can promote ripening and reduce cellular adhesion. In addition, the role of DkGAL1 is not limited to fruit softening; DkGAL1 was also involved in seed germination and radicle elongation in transgenic tomato seeds.

Role of Brassinosteroids in Persimmon ( Diospyros kaki L.) Fruit Ripening.

Brassinosteroids (BRs) are phytohormones that regulate numerous processes including fruit ripening. In this study, persimmon ( Diospyros kaki L.) fruits were treated with 24-epibrassinolide (EBR) or brassinazole (Brz, a BR biosynthesis inhibitor) and then stored at ambient temperature. The results show that endogenous BR contents gradually increased during persimmon fruit ripening. EBR treatment significantly increased both the content of water-soluble pectin and the activities of polygalacturonase, pectate lyase, and endo-1,4-beta-glucanase but significantly reduced the content of acid-soluble pectin and cellulose, resulting in rapid fruit softening. The EBR treatment also promoted ethylene production and respiration rate. In contrast, Brz treatment delayed persimmon fruit ripening. qRT-PCR analysis showed that DkPG1, DkPL1, DkPE2, DkEGase1, DkACO2, DkACS1, and DkACS2 were up-regulated (especially a 38-fold increase in DkEGase1) in the fruit of the EBR-treated group. These results suggest that BRs are involved in persimmon fruit ripening by influencing cell-wall-degrading enzymes and ethylene biosynthesis.

Regio- and Diastereoselective Cross-Dehydrogenative Coupling of Tetrahydropyridines with 1,3-Dicarbonyl Compounds.

A regio- and diastereoselective cross-dehydrogenative coupling of N-carbamoyl tetrahydropyridines with a variety of 1,3-dicarbonyl compounds is described. The method exhibits good functional group tolerance, diastereoselectively generating cis-2,6- or cis-2,4-substituted tetrahydropyridines by using different types of 1,3-dicarbonyls. Moreover, a two-step sequence involving diastereoselective cross-dehydrogenative coupling followed by epimerization was also developed, allowing facile access to trans-2,6-substituted tetrahydropyridines as single isomers. Applications in natural product synthesis and divergent analogue preparation were further demonstrated.

Exploring the Functions of 9-Lipoxygenase (DkLOX3) in Ultrastructural Changes and Hormonal Stress Response during Persimmon Fruit Storage.

Lipoxygenase (LOX) initiates the hydroperoxidation of polyunsaturated fatty acids and is involved in multiple physiological processes. In this study, investigation of various microscopic techniques showed that the fruit peel cellular microstructure of the two persimmon cultivars differed after 12 days of storage, resulting in fruit weight loss and an increased number and depth of microcracks. Analysis of subcellular localization revealed that greater amounts of DkLOX3-immunolabelled gold particles accumulated in "Fupingjianshi" than in "Ganmaokui" during storage. In addition, the expression of DkLOX3 was positively up-regulated by abscisic acid (ABA), concomitant with the promotion of ethylene synthesis and loss of firmness, and was suppressed by salicylic acid (SA), concomitant with the maintenance of fruit firmness, inhibition of ethylene production and weight loss. In particular, the expression of DkLOX3 differed from the ethylene trajectory after methyl jasmonate (MeJA) treatment. Furthermore, we isolated a 1105 bp 5' flanking region of DkLOX3 and the activity of promoter deletion derivatives was induced through various hormonal treatments. Promoter sequence cis-regulatory elements were analysed, and two conserved hormone-responsive elements were found to be essential for responsiveness to hormonal stress. Overall, these results will provide us with new clues for exploring the functions of DkLOX3 in fruit ripening and hormonal stress response.

Overexpression of persimmon DkXTH1 enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

KEY MESSAGE: DkXTH1 promoted cell elongation and more strength to maintain structural integrity by involving in cell wall assembly, thus enhanced tolerance to abiotic stress with broader phenotype in transgenic plants. Xyloglucan endotransglucosylase/hydrolase (XTH) is thought to play a key role in cell wall modifications by cleaving and re-joining xyloglucan, and participates in the diverse physiological processes. DkXTH1 was found to peak in immature expanding persimmon fruit, and its higher expression level exhibited along with firmer fruit during storage. In the present study, transgenic Arabidopsis and tomato plants were generated with DkXTH1 constitutively expressed. Overexpression of DkXTH1 enhanced tolerance to salt, ABA and drought stresses in transgenic Arabidopsis plants with respect to root and leaf growth, and survival. Transgenic tomatoes collected at the mature green stage, presented delayed fruit softening coupled with postponed color change, a later and lower ethylene peak, and higher firmness in comparison with the wild-type tomatoes during storage. Furthermore, broader leaves and tomato fruit with larger diameter were gained in transgenic Arabidopsis and tomato, respectively. Most importantly, transgenic plants exhibited more large and irregular cells with higher density of cell wall and intercellular spaces, resulting from the overactivity of XET enzymes involving in cell wall assembly. We suggest that DkXTH1 expression resulted in cells with more strength and thickness to maintain structural integrity, and thus enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.