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ABSTRACT: Rhododendron fortune belongs to a scented Rhododendron species native to China, which produces fragrant flowers of great ornamental and environmental values for landscaping or indoor beautification. However, the scents in Rhododendron fortuneihave not yet been investigated, let alone the mechanism of the formation of these fragrance in the flowers. In this study, we measured the scents in terms of its volatile components and contents (VOC) in Rhododendron fortuneiat four different flowering stages and in different tissues of the plant by headspace solid-phase micro-extraction combined (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). Then the characteristic aromatic values, which reflects the degree of scent perception by human, of each VOC in the plant was calculated according to its respective aromatic thresholds. Results showed that three main VOCs measured from highest to lowest are methyl benzoates, terpenes and fatty acid derivatives. Their content increased after the flower bud opening and reached the highest at half to full blossom. In a flower most VOC contents were measured in petals and only trace amount in other tissues such as stamen, pistil. A small amount of VOCs was determined in leaves as well.All aromatic values were almost corresponded to the contents of three main VOCs, indicating that the flower fragrance arises truly from these VOC components. S-adenosyl-L-methionine: benzoic acid carboxyl methyl transferase (BAMT) catalyzes the final step to form methyl benzoates. To understand the mechanism of the formation of this main type fragrance and its regulation, we firstly isolate a gene of RfBAMT from petal of Rhododendron fortuneiby using homologous cloning and RACE technology. The full length of its cDNA was 1383 bp，with an open reading frame of 1104 bp, encoding a total of 368 amino acids. The phylogenetic tree analysis showed that RfBAMT was the closest to the BSMT of Camellia japonica, belonging to methyltransferases family. Then we measured the expression level of RfBAMT again at four flower developmental stages and in different flower tissues and leaves. The results showed that the expression level of this gene was highly positively correlated with the emitted content of methyl benzoates in the flowering, implying that RfBAMT plays a pivotal role in the formation and regulation of methyl benzoates in Rhododendron fortune.Thisresearchshowed that the RfBAMT was cloned and identified in our study and its expression level was highly positively correlated with the emitted content of methyl benzoates in the flowers and leaves, which indicated this gene may play an important role on regulation of methyl benzoate synthesis in Rhododendron fortunei.

Abstract Background Nitrogen (N) fertilizer is commonly considered as one of the most important limiting factors in the agricultural production. As a result, a large amount of N fertilizer is used to improve the yield in modern tea production. Unfortunately, the large amount of N fertilizer input has led to increased plant nitrogen-tolerance and decreased amplitude of yield improvement, which results in significant N loss, energy waste and environment pollution. However, the effects of N-deficiency on the metabolic profiles of tea leaves and roots are not well understood. Results In this study, seedlings of Camellia sinensis (L.) O. Kuntze Chunlv 2 were treated with 3 mM NH4NO3 (Control) or without NH4NO3 (N-deficiency) for 4 months by sandy culture. The results suggested that N-deficiency induced tea leaf chlorosis, impaired biomass accumulation, decreased the leaf chlorophyll content and N absorption when they were compared to the Control samples. The untargeted metabolomics based on GC-TOF/MS approach revealed a discrimination of the metabolic profiles between N-deficient tea leaves and roots. The identification and classification of the altered metabolites indicated that N deficiency upregulated the relative abundances of most phenylpropanoids and organic acids, while downregulated the relative abundances of most amino acids in tea leaves. Differentially, N-deficiency induced the accumulation of most carbohydrates, organic acids and amino acids in tea roots. The potential biomarkers screened in N-deficient leaves compared to Control implied that N deficiency might reduce the tea quality. Unlike the N-deficient leaves, the potential biomarkers in N-deficient roots indicated an improved stress response might occur in tea roots. Conclusions The results demonstrated N deficiency had different effects on the primary and secondary metabolism in tea leaves and roots. The findings of this study will facilitate a comprehensive understanding of the N-deficient tea plants and provide a valuable reference for the optimized N nutrient management and the sustainable development in the tea plantations.

Cell differentiation is traditionally monitored with a few marker genes, which may bias results. To understand the evolution and regulation of the spore, stalk, cup and basal disc cells in Dictyostelia, we previously performed RNAseq on purified cell-types of taxon-group representative dictyostelids. Using promoter-lacZ constructs in D. discoideum, we here investigate the spatio-temporal expression pattern of 29 cell-type specific genes. Genes selected for spore- or cup-specificity in RNAseq were validated as such by lacZ expression, but genes selected for stalk-specificity showed variable additional expression in basal disc, early cup or prestalk populations. We measured responses of 25 genes to 15 single or combined regimes of induction by stimuli known to regulate cell differentiation. The outcomes of these experiments were subjected to hierarchical clustering to identify whether common modes of regulation were correlated with specific expression patterns. The analysis identified a cluster combining the spore and cup genes, which shared upregulation by 8-bromo cyclic AMP and down-regulation by Differentiation Inducing Factor 1 (DIF-1). Most stalk-expressed genes combined into a single cluster and shared strong upregulation by cyclic di-guanylate (c-di-GMP), and synergistic upregulation by combined DIF-1 and c-di-GMP. There was no clustering of genes expressed in other soma besides the stalk, but two genes that were only expressed in the stalk did not respond to any stimuli. In contrast to current models, the study indicates the existence of a stem-cell like soma population in slugs, whose members only acquire ultimate cell fate after progressing to their terminal location during fruiting body morphogenesis.

Objective: Congenital defects/diseases Background: Laparoscopic-perineal neovagina construction by sigmoid colpoplasty is a popular therapeutic approach for patients with Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome. The conventional approach requires an auxiliary abdominal incision to exteriorize the descending colon to fix the anvil for end-to-end colorectal anastomosis. We modified the natural orifice specimen extraction surgery (NOSES) approach by exteriorizing the descending colon through the artificial neovaginal tunnel to replace the anvil extracorporeally, without requiring an auxiliary abdominal incision. It was a more minimally invasive technique. Case Report: We performed this modified laparoscopic-perineal sigmoid colpoplasty in a 26-year-old woman with MRKH syndrome. We cut off a segment of the sigmoid colon with a vascular pedicle to make a new vagina out of it, the same as in the traditional laparoscopic-perineal sigmoid colpoplasty. What is new about this technique is that it has no need for abdominal incision and is more minimally invasive. The operating time was 315 min. No postoperative complications occurred. The postoperative hospital stay was 4 days. The modified laparoscopic-perineal approach, free from an auxiliary abdominal incision, demonstrated advantages, including a shorter hospital stay, expedited recovery, and comparable anatomical outcomes, when compared with the traditional approach. This innovation improves the surgical experience for patients with MRKH syndrome, addressing the physical and psychological aspects of their condition. Conclusions: This refined laparoscopic-perineal neovagina construction by sigmoid colpoplasty represents a feasible and minimally invasive technique. It is an attractive option for MRKH syndrome patients in need of vaginal reconstruction, offering a streamlined procedure with reduced postoperative recovery time and enhanced patient outcomes. [ABSTRACT FROM AUTHOR]

This paper presents a scalable 1024-element transmit dual-circularly-polarized phased array for Ka-band satellite communication (SATCOM) terminal applications. The transmit array based on the CMOS beamformer and a multilayer printed circuit board (PCB) can steer up to large scan angles (±60°) with a scan loss less than 4.5 dB. With the 8-channel transmit beamformer, the array can realize dual circular polarization and the axial ratio (AR) of the array is less than 3 dB in the scanning range of ±30° in both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) mode. The effective isotropic radiated power (EIRP) of the array achieves 74 dBm from 29.5 GHz to 30 GHz. The design and measurement of the 1024-element transmit array have presented a feasible way for mass production of a low cost active phased array.

In microfluidic detection, the distance between the fluorescent nanoparticles (FNPs) and the structure is usually in far-field range. In previous work, the enhancement of emission will decay exponentially with the increase of the distance between FNPs and the structures, which brings a challenge to the development of high-sensitivity biosensors. In this paper, a hybrid structure consisting of a silver channel and a microlens is proposed to enhance far-field directional emission when the FNP is in far-field range. It is shown that the far-field total power enhancement of our structure is obvious compared to the polymethyl methacrylate channel. This is due to scattering, constructive interference, and resonance modes created by the silver channel and microlens. This structure will contribute to high-sensitivity biosensors.

Encoding functionalities in covalent organic frameworks (COFs) is important for widening their application field but the development of fluorescent COFs is hampered by a lack of guiding design principles. Here the authors demonstrate tuning and switching of the photoluminescence in 2D COFs made of non-emissive building blocks.

Gluconeogenesis is a key interface between organic acid/amino acid/lipid and sugar metabolism. The aims of this article are four-fold. First, to provide a concise overview of plant gluconeogenesis. Second, to emphasise the widespread occurrence of gluconeogenesis and its utilisation in diverse processes. Third, to stress the importance of the vacuolar storage and release of Krebs cycle acids/nitrogenous compounds, and of the role of gluconeogenesis and malic enzyme in this process. Fourth, to outline the contribution of fine control of enzyme activity to the coordinate-regulation of gluconeogenesis and malate metabolism, and the importance of cytosolic pH in this.

In grapevines, as in other plants, sucrose and its constituents glucose and fructose are fundamentally important and carry out a multitude of roles. The aims of this review are three-fold. First, to provide a summary of the metabolism and transport of sucrose in grapevines, together with new insights and interpretations. Second, to stress the importance of considering the compartmentation of metabolism. Third, to outline the key role of acid invertase in osmoregulation associated with sucrose metabolism and transport in plants.

Enhanced directional fluorescence emission (DFE) is crucial for the optical signal collection by spectrometer/microscopy in biological and medical detection. In this paper, we systematically report the enhanced excitation and DFE of quantum dot (QD) by silver nanoparticles (AgNPs) through theoretical calculations. A finite difference time-domain method is used in the calculations. By changing the size and the number of AgNPs, as well as relative position between QD and AgNPs, we found that when QD is in the middle of two AgNPs (the diameters of two AgNPs are 90 nm and 70 nm, respectively) and the spacing between them is 20 nm (surface to surface), the DFE is enhanced by 70 times compared to the QD on bare glass. The reason for the DFE enhancement is the geometrical scattering and localized surface plasmon resonance (LSPR) created by AgNPs. The enhancement is the largest when the peak wavelengths of geometrical scattering and LSPR are close to each other. Furthermore, we conclude that monolayer AgNPs play a main role in the DFE enhancement of monolayer or low-concentration QDs, and uniform-sized AgNPs are not the best choice for enhancing the DFE. This will be of significance for designing and developing high-sensitivity fluorescent biosensors and high-efficiency QD LEDs.

Quantum dots (QDs) show great promise for use in nanotechnology, owing to their high quantum efficiency, color tenability, narrow emission, and high luminescence efficiency. As a new generation of light-emitting devices (LEDs), QD-LEDs have attracted a great deal of attention in displays and lighting. To meet the commercial requirements, the brightness of QD-LEDs needs to be further improved. In this work, we propose multilayer heterostructures on a SiO2 substrate, which provides multiple reflective bands with the very high reflective efficiency of nearly up to 100%. Electric field distributes mostly in the superficial layer. The proposed structure provides highly multiband reflection covering the emission peaks of QDs in LEDs; hence, it can eventually enhance QDs' fluorescence and enhance the brightness of QD-LEDs. We investigate four typical emission wavelengths, mainly aiming for red QD-LEDs and infrared QD-LEDs, which correspond to the applications of displays, infrared illumination, optical communication, and so on. The total reflection bands can be adjusted according to practical requirements by tuning the thickness of every layer. One fabrication procedure can be used for different kinds of QDs or the same kind of QD with different sizes without changing their processing properties. The proposed structure has fewer flat layers compared with 1-D photonic crystals, which leads to lower cost and easier fabrications.

In our previous study we found that the expression of stlA showed peaks both in the early and last stages of development and that a product of SteelyA, 4-methyl-5-pentylbenzene-1,3-diol (MPBD), controlled Dictyostelium spore maturation during the latter. In this study we focused on the role of SteelyA in early stage development.Our stlA null mutant showed aggregation delay and abnormally small aggregation territories. Chemotaxis analysis revealed defective cAMP chemotaxis in the stlA null mutant. cAMP chemotaxis was restored by MPBD addition during early stage development. Assay for cAMP relay response revealed that the stlA null mutant had lower cAMP accumulation during aggregation, suggesting lower ACA activity than the wild type strain. Exogenous cAMP pulses rescued the aggregation defect of the stlA null strain in the absence of MPBD. Expression analysis of cAMP signalling genes revealed lower expression levels in the stlA null mutant during aggregation.Our data indicate a regulatory function by SteelyA on cAMP signalling during aggregation and show that SteelyA is indispensable for full activation of ACA.

Well dispersed Y2O3 nanoparticles are prepared by azeotropic co-precipitation method. (Ba0.90Ca0.10)(Ti0.9Sn0.1)O3 lead-free piezoelectric ceramics doped with the nano-sized Y2O3 (BCTZY, x = 0.01-0.09%) are synthesized at 1460 °C for 2h via solid-state sintering method. X-ray diffraction suggests typical perovskite structure of all the compositions. The addition of the nano-Y2O3 results in the improvement in dielectric and piezoelectric properties. The optimized piezoelectric properties is obtained at x = 0.01 with d33 of 596pC/N and Kp of 57.1%, respectively. [ABSTRACT FROM AUTHOR]

Coordination of cell movement with cell differentiation is a major feat of embryonic development. The Dictyostelium stalk always forms at the organizing tip, by a mechanism that is not understood. We previously reported that cyclic diguanylate (c-di-GMP), synthesized by diguanylate cyclase A (DgcA), induces stalk formation. Here we used transcriptional profiling of dgca-structures to identify target genes for c-di-GMP, and used these genes to investigate the c-di-GMP signal transduction pathway. We found that knockdown of cAMP-dependent protein kinase (PKA) activity in prestalk cells reduced stalk gene induction by c-di-GMP, whereas PKA activation bypassed the c-di-GMP requirement for stalk gene expression. c-di-GMP caused a persistent increase in cAMP, which still occurred in mutants lacking the adenylate cyclases ACG or ACR, or the cAMP phosphodiesterase RegA. However, both inhibition of adenylate cyclase A (ACA) with SQ22536 and incubation of a temperature-sensitive ACA mutant at the restrictive temperature prevented c-di-GMP-induced cAMP synthesis as well as c-di-GMP-induced stalk gene transcription. ACA produces the cAMP pulses that coordinate Dictyostelium morphogenetic cell movement and is highly expressed at the organizing tip. The stalk-less dgca-mutant regained its stalk by expression of a light-activated adenylate cyclase from the ACA promoter and exposure to light, indicating that cAMP is also the intermediate for c-di-GMP in vivo. Our data show that the more widely expressed DgcA activates tip-expressed ACA, which then acts on PKA to induce stalk genes. These results explain why stalk formation in Dictyostelia always initiates at the site of the morphogenetic organizer. [ABSTRACT FROM AUTHOR]

Abstract Background Mechanical ventilation (MV) with positive end-expiratory pressure (PEEP) is commonly applied in patients with severe traumatic brain injury (sTBI). However, the individual responsiveness of intracranial pressure (ICP) to PEEP varies. Thus, identifying an indicator detecting ICP responsiveness to PEEP is of great significance. As central venous pressure (CVP) could act as an intermediary to transduce pressure from PEEP to ICP, we developed a new indicator, PICGap, representing the gap between baseline ICP and baseline CVP. The aim of the current study was to explore the relationship between PICGap and ICP responsiveness to PEEP. Methods A total of 112 patients with sTBI undergoing MV were enrolled in this prospective cohort study. ICP, CVP, cerebral perfusion pressure (CPP), static compliance of the respiratory system (Cst), and end-tidal carbon dioxide pressure (PetCO2) were recorded at the initial (3 cmH2O) and adjusted (15 cmH2O) levels of PEEP. PICGap was assessed as baseline ICP - baseline CVP (when PEEP = 3 cmH2O). The patients were classified into the ICP responder and non-responder groups based on whether ICP increment with PEEP adjusted from 3 cmH2O to 15 cmH2O was greater than 20% of baseline ICP. The above parameters were compared between the two groups, and prediction of ICP responsiveness to PEEP adjustment was evaluated by receiver operating characteristic (ROC) curve analysis. Results Compared with the non-responder group, the responder group had lower PICGap (1.63 ± 1.33 versus 6.56 ± 2.46 mmHg; p

Cyclic di-GMP (c-di-GMP) is currently recognized as the most widely used intracellular signal molecule in prokaryotes, but roles in eukaryotes were only recently discovered. In the social amoeba Dictyostelium discoideum, c-di-GMP, produced by a prokaryote-type diguanylate cyclase, induces the differentiation of stalk cells, thereby enabling the formation of spore-bearing fruiting bodies. In this review, we summarize the currently known mechanisms that control the major life cycle transitions of Dictyostelium and focus particularly on the role of c-di-GMP in stalk formation. Stalk cell differentiation has characteristics of autophagic cell death, a process that also occurs in higher eukaryotes. We discuss the respective roles of c-di-GMP and of another signal molecule, differentiation-inducing factor 1, in autophagic cell death in vitro and in stalk formation in vivo. [ABSTRACT FROM AUTHOR]

(Ba0.85Ca0.15)(Ti0.90Zr0.10)O3(BCTZ)+ xwt%Dy2O3(x = 0–0.20) ceramics were prepared by conventional solid-state process, and the effects of Dy2O3on the microstructure and the electrical properties were investigated. X-ray diffraction pattern confirmed that the BCTZ ceramics exhibit tetragonal structure, and stable solid solutions between BCTZ and Dy2O3were well established in the range investigated. SEM images show that the addition of Dy2O3restrains abnormal grain growth and leads to the formation of homogeneous microstructures during sintering. Dy3+occupies B-site at x = 0–0.15, and A-site at x = 0.20 respectively. A-site occupation of Dy3+into BCZT ceramic facilitates the ferroelectric domains reorientation and thus improves the piezoelectric properties significantly from 315pC/N(x = 0) to 425pC/N(x = 0.20). The corresponding planar electromechanical coupling factor at x = 0.20 was 49.1%. The A-site occupation(x = 0.2) also exhibits superiority to the improvement of dielectric properties and ferroelectric properties for BCZT ceramics (ϵ33= 3264 at 1 kHz, 2Pr = 28.4μC/cm2, 2Ec = 5.28 kV/cm). [ABSTRACT FROM AUTHOR]

Bi3.15Dy0.85(Ti3-xFex)O12(x = 0−0.3) lead-free piezoelectric ceramics were prepared by a solid-state reaction method. The effects of the amount of Dy2O3and Fe2O3on the microstructure and electrical properties of the ceramics were investigated. X-ray diffraction shows that the introduction of Dy and Fe does not change the layered perovskite structure of Bi4Ti3O12. SEM images indicated that Bi3.15Dy0.85(Ti3-xFex)O12ceramics with nearly pore-free microstructures and high densities were obtained. The dielectric constant decreases with the addition of Dy2O3, but remarkably increased with the amount of Fe2O3, and it decreases with frequency, showing a diffuse phase transition behavior. [ABSTRACT FROM AUTHOR]

xDy2O3-Bi0.5(Na0.82K0.18)0.5TiO3(0-0.4wt%) ceramics were synthesized by conventional solid-state processes. X-ray diffraction pattern confirmed that the tetragonal and rhombohedral phases co-existed in the Dy2O3 doped Bi0.5(Na0.82K0.18)0.5TiO3 ceramics from x = 0.05 to 0.4 wt% Dy2O3. SEM images indicate that doping of Dy2O3 promotes the formation of the ceramics with homogenous microstructures and high density. The Bi0.5(Na0.82K0.18)0.5TiO3 ceramics remain a diffuse phase transition behavior after the addition of Dy2O3. The electrical properties of BNKT ceramics can be improved by adding suitable amount of Dy2O3, giving optimum value of 1765 (1 kHz) at x = 0.10, 152 pC/N and 32.5μC/cm2 at x = 0.15 respectively. [ABSTRACT FROM PUBLISHER]

Bone marrow mensenchyme cells (BMSCs) can differentiate into endothelial progenitor cells which then migrate to injured sites for the repair of neointima, and stromal cell-derived factor-1a (SDF-1α) can mediate the migration of CXCR4 expressing stem/progenitor cells to injured sites for pair. Protein and mRNA expression of SDF-1α and CXCR4 were determined by RT-PCR, Western blot and ELISA. Immediately after common carotid artery balloon injury, the mRNA expression of SDF-1α in vascular smooth muscle cells (VSMCs) first increased and then decreased 7 days later. VSMCs transfected with SDF-1α siRNA did not express SDF-1α mRNA, but after transfection with SDF-1α siRNA, the SDF-1α content in injured VSMCs gradually returned to the baseline level. Normal BMSCs rarely expressed CXCR4 mRNA, but the CXCR4 mRNA expression on BMSCs increased significantly 4 days after common carotid artery injury and was maintained. The migration of BMSCs after artery injury was enhanced when compared with normal BMSCs, but SDF-1α siRNA transfection of VSMCs and AMD3100 treatment remarkably decreased the chemotaxis of BMSCs to VSMCs and SDF-1α, respectively. We conclude that the SDF-1α/CXCR4 axis plays an important role in the migration of BMSCs after balloon injury and can ultimately cause abnormal proliferation of the intima. [ABSTRACT FROM AUTHOR]

(1-x)Bi0.5(Na0.82K0.18)0.5TiO3-xBiFeO3 (x = 0.01-0.07) lead-free piezoelectric ceramics were fabricated by citrate method. The influence of the BiFeO3 additive on the structure and electrical properties of the ceramics was investigated. XRD measurement confirmed that a single perovskite phase can be obtained in all the specimen sintered at 1120°C for 2 h, and the morphotropic phase boundary (MPB) with rhombohedral and tetragonal coexistence for the ceramics locates in range of x = 0-0.07. BiFeO3 doping (x = 0.03) improves densification of the specimen with relative density reaching up to 96.5%. Compared with Bi0.5(Na0.82K0.18)0.5TiO3, the specimen with BiFeO3 added gave an obvious increase of the dielectric constant and a remarkable increase of piezoelectric constant (135 pC N-1) at x = 0.03. [ABSTRACT FROM AUTHOR]

Abstract: (Bi0.5Na0.5)0.94Ba0.06TiO3 + x wt% Dy2O3 with x =0–0.3 ceramics were synthesized by conventional solid-state processes. The effects of Dy2O3 on the microstructure, the piezoelectric and dielectric properties were investigated. X-ray diffraction pattern confirmed that the coexistence of tetragonal and rhombohedral phases in the (Bi0.5Na0.5)0.94Ba0.06TiO3 composition was not changed by adding 0.05–0.3wt% Dy2O3. SEM images indicate that all the ceramics have pore-free microstructures with high density, and that doping of Dy2O3 inhibits the grain growth of the ceramics. The addition of Dy2O3 shows the double effects on decreasing the piezoelectric and dielectric properties for 0< x <0.15 when Dy3+ ions substitute B-site Ti4+ ions, and increasing the properties for 0.15< x <0.3 when Dy3+ ions enters into A-site of the perovskite structure. The optimum electric properties of piezoelectric constant d 33 =170pC/N and the dielectric constant ɛ r =1900 (at a frequency of 1kHz) are obtained at x =0.3. [Copyright &y& Elsevier]

Cyclic AMP acting on protein kinase A controls sporulation and encystation in social and solitary amoebas. In Dictyostelium discoideum, adenylate cyclase R (ACR), is essential for spore encapsulation. In addition to its cyclase (AC) domain, ACR harbors seven transmembrane helices, a histidine kinase domain, and two receiver domains. We investigated the role of these domains in the regulation of AC activity. Expression of an ACR-YFP fusion protein in acr― cells rescued their sporulation defective phenotype and revealed that ACR is associated with the nuclear envelope and endoplasmic reticulum. Loss of the transmembrane helices (ATM) caused a 60% reduction of AC activity, but ΔTM-ACR still rescued the acr― phenotype. The isolated AC domain was properly expressed but inactive. Mutation of three essential ATP-binding residues in the histidine kinase domain did not affect the AC activity or pheno- typic rescue. Mutation of the essential phosphoryl-accepting aspartate in receivers 1, 2, or both had only modest effects on AC activity and did not affect phenotypic rescue, indicating that AC activity is not critically regulated by phosphorelay. Remarkably, the dimerizing histidine phosphoacceptor subdo- main, which in ACR lacks the canonical histidine for auto- phosphorylation, was essential for AC activity. Transformation of wild-type cells with an ACR allele (ΔCRA) that is truncated after this domain inhibited AC activity of endogenous ACR and replicated the acr phenotype. Combined with the obser- vation that the isolated AC domain was inactive, the dominant-negative effect of ΔCRA strongly suggests that the defunct phosphoacceptor domain acquired a novel role in enforcing dimerization of the AC domain. [ABSTRACT FROM AUTHOR]

Abstract: Bi4Ti3O12 nanopowders were prepared by an azeotropic co-precipitation method and the phase evolution process, microstructure and sintering behavior were investigated. The results indicate that well dispersed and agglomerate-free nanocrystalline Bi4Ti3O12 with average particle size of 21nm can be obtained by calcinating the precursor at 750°C, which is 50°C lower than traditional solid reaction. The relative density of the ceramic reaches 96% at 1000°C and shows no evident decrease until 1100°C. The broadened sintering temperature range and the lower loss tangent of the ceramic show good sintering activity of the nanopowders. [Copyright &y& Elsevier]

Pi (inorganic phosphate) limitation severely impairs plant growth and reduces crop yield. Hence plants have evolved several biochemical and morphological responses to Pi starvation that both enhance uptake and conserve use. The mechanisms involved in Pi sensing and signal transduction are not completely understood. In the present study we report that a previously uncharacterized transcription factor, BHLH32, acts as a negative regulator of a range of Pi starvation-induced processes in Arabidopsis. In bhlh32 mutant plants in Pi-sufficient conditions, expression of several Pi starvation-induced genes, formation of anthocyanins, total Pi content and root hair formation were all significantly increased compared with the wild-type. Among the genes negatively regulated by BHLH32 are those encoding PPCK (phosphoenolpyruvate carboxylase kinase), which is involved in modifying metabolism so that Pi is spared. The present study has shown that PPCK genes are rapidly induced by Pi starvation leading to increased phosphorylation of phosphoenolpyruvate carboxylase. Furthermore, several Arabidopsis proteins that regulate epidermal cell differentiation [TTG1 (TRANSPARENT TESTA GLABRA1), GL3 (GLABRA3) and EGL3 (ENHANCER OF GL3)] positively regulate PPCK gene expression in response to Pi starvation. BHLH32 can physically interact with TTG1 and GL3. We propose that BHLH32 interferes with the function of TTG1-containing complexes and thereby affects several biochemical and morphological processes that respond to Pi availability. [ABSTRACT FROM AUTHOR]

Previous studies of grapes and tomatoes have shown that the abundance of phosphoenolpyruvate carboxykinase (PEPCK) increases in their flesh at the start of ripening, and that this coincides with a decrease in its citrate and/or malate content. Thus, PEPCK might function in the catabolism of organic acid anions during the ripening of these fruits. In the present study, the abundance of PEPCK was determined in the flesh of blueberries, raspberries, red currants, and strawberries at different stages of their development. In addition, changes in the amounts of citrate, malate, soluble sugars, isocitrate lyase, NADP-malic enzyme, phosphoenolpyruvate carboxylase, and pyruvate, orthophosphate dikinase in the flesh were determined. PEPCK was not detected in strawberry flesh, in which there was no dissimilation of malate or citrate. In the flesh of the other fruits, the abundance of PEPCK increased during ripening to an amount that was similar to that in grapes and tomatoes. In the flesh of blueberries and red currants, PEPCK was most abundant when there was dissimilation of malate. In the flesh of raspberries, PEPCK was most abundant when there was dissimilation of malate and citrate. These results are consistent with PEPCK playing a role in the dissimilation of citrate and/or malate in the flesh of these fruits during ripening. However, PEPCK was also present in the flesh of blueberries, raspberries, and red currants when there was no dissimilation of malate or citrate, and this raises the possibility that PEPCK might have additional functions. Dissection of blueberries provided evidence that both PEPCK and phosphoenolpyruvate carboxylase were present in the same cells, and possible functions for this are discussed. [ABSTRACT FROM PUBLISHER]

An efficient matched-impedance scheme for the finite-difference time-domain (FDTD) analysis of microstrip circuits is presented. In conventional extended FDTD schemes, the resistive load is introduced as a thin-line model or is uniformly assigned into a number of cells. The assigning scheme does not agree with the electromagnetic distribution in the microstrip line, and thus causes some reflection errors. The proposed scheme uses the effective impedance of the microstrip line as the value of matched resistive load and assigns it into the resistive-load mesh region in a proper proportion in order to reduce the reflection errors. The results of the numerical examples show that the reflections can be significantly reduced by this novel scheme. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [ABSTRACT FROM AUTHOR]

An improved Hardy inequality will be proven in the present work. Using the improved Hardy inequality and variational techniques, we also discuss the existence of nontrivial solution for following the weighted eigenvalue problem: $$ \left\{ {\begin{array}{*{20}c} {{\vartriangle ^{2} u - \mu \frac{u} {{{\left| x \right|}^{4} }} = \lambda uf{\left( x \right)},}} & {{x \in \Omega ,}} \\ {{u = \frac{{\partial u}} {{\partial v}} = 0,}} & {{x \in \partial \Omega }} \\ \end{array} } \right. $$ [ABSTRACT FROM AUTHOR]

In cucumber ( Cucumis sativus L.), phosphoenolpyruvate carboxykinase (PEPCK) was shown by activity measurements and immunoblots to be present in leaves, stems, roots, flowers, fruit and seed. However, immunolocalisation showed that it was present only in certain cell types. PEPCK was present in the companion cells of the adaxial phloem of minor veins, the adaxial and abaxial phloem of larger veins, the internal and external phloem of vascular bundles in petioles and stems, the phloem in roots and the extra-fascicular phloem in leaves, cotyledons, petioles and stems. Immunohistochemical evidence suggests that both the extra-fascicular phloem and the adaxial phloem are involved in the transport of amino acids. In roots and stems, the abundance of PEPCK was greatly increased by watering plants with a solution of ammonium chloride at low, but not at high pH. PEPCK also increased in leaves, but not roots or stems, of seedlings grown in an atmosphere containing 5% CO 2, and in roots and stems of seedlings watered with butyric acid. All these treatments are known to lower the pH of plant cells. Amino acid metabolism in the phloem may produce an excess of carbon skeletons, pH perturbations and an imbalance in the production/utilisation of NADH. This raises the possibility that PEPCK may function in the conversion of these carbon skeletons to PEP, which, depending on the energy requirements of the phloem, is subsequently utilised by either gluconeogenesis or the Krebs cycle, which both consume protons. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether gluconeogenesis catalysed by phosphoenolpyruvate carboxykinase (PEPCK) occurs during leaf senescence. This was addressed by determining changes in the abundance and intercellular location of enzymes necessary for gluconeogenesis during the senescence of barley leaves and cucumber cotyledons. PEPCK was never present in barley leaves, despite the presence of large amounts of isocitrate lyase (ICL), a key enzyme of the glyoxylate cycle, and of its product, glyoxylate. Although PEPCK was present in non-senescent cucumber cotyledons, its abundance declined during senescence. Throughout senescence, PEPCK was only present in the trichomes and vasculature, whereas ICL was located in mesophyll cells. Pyruvate,Pi dikinase (PPDK) which, in concert with NAD(P)-malic enzyme, is also capable of catalysing gluconeogenesis, was present in non-senescent barley leaves and cucumber cotyledons, but in both plants its abundance decreased greatly during senescence. The abundance of ICL was greatly reduced in senescing detached barley leaves by either illumination or by co-incubation with sucrose, and greatly increased in darkened attached barley leaves. These results argue against the largescale occurrence of gluconeogenesis during senescence catalysed either by PEPCK or PPDK. In cucumber cotyledons, PEPCK may play a role in metabolic processes linked to the export of amino acids, a role in which phosphoenolpyruvate carboxylase may also be involved. The amount of ICL was increased by starvation and during senescence may function in the conversion of lipids to organic acids, which are then utilised in the mobilisation of amino acids from leaf protein. [ABSTRACT FROM AUTHOR]

Abstract Objectives We aimed to develop MRI-based radiomic models (RMs) to improve the diagnostic accuracy of radiologists in characterizing intestinal fibrosis in patients with Crohn’s disease (CD). Methods This retrospective study included patients with refractory CD who underwent MR before surgery from November 2013 to September 2021. Resected bowel segments were histologically classified as none-mild or moderate-severe fibrosis. RMs based on different MR sequence combinations (RM1: T2WI and enhanced-T1WI; RM2: T2WI, enhanced-T1WI, diffusion-weighted imaging [DWI], and apparent diffusion coefficient [ADC]); RM3: T2WI, enhanced-T1WI, DWI, ADC, and magnetization transfer MRI [MTI]), were developed and validated in an independent test cohort. The RMs’ diagnostic performance was compared to that of visual interpretation using identical sequences and a clinical model. Results The final population included 123 patients (81 men, 42 women; mean age: 30.26 ± 7.98 years; training cohort, n = 93; test cohort, n = 30). The area under the receiver operating characteristic curve (AUC) of RM1, RM2, and RM3 was 0.86 (p = 0.001), 0.88 (p = 0.001), and 0.93 (p = 0.02), respectively. The decision curve analysis confirmed a progressive improvement in the diagnostic performance of three RMs with the addition of more specific sequences. All RMs performance surpassed the visual interpretation based on the same MR sequences (visual model 1, AUC = 0.65, p = 0.56; visual model 2, AUC = 0.63, p = 0.04; visual model 3, AUC = 0.77, p = 0.002), as well as the clinical model composed of C-reactive protein and erythrocyte sedimentation rate (AUC = 0.60, p = 0.13). Conclusions The RMs, utilizing various combinations of conventional, DWI and MTI sequences, significantly enhance radiologists’ ability to accurately characterize intestinal fibrosis in patients with CD. Critical relevance statement The utilization of MRI-based RMs significantly enhances the diagnostic accuracy of radiologists in characterizing intestinal fibrosis. Key Points MRI-based RMs can characterize CD intestinal fibrosis using conventional, diffusion, and MTI sequences. The RMs achieved AUCs of 0.86–0.93 for assessing fibrosis grade. MRI-radiomics outperformed visual interpretation for grading CD intestinal fibrosis. Graphical Abstract

Abstract Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing research. Here, we explore landform-specific differences among montane floras based on a dataset comprising 17,576 angiosperm species representing 140 Chinese mountain floras, which we define as the collection of all angiosperm species growing on a specific mountain. Our results show that igneous bedrock (granitic and karst-granitic landforms) is correlated with higher species richness and phylogenetic overdispersion, while the opposite is true for sedimentary bedrock (karst, Danxia, and desert landforms), which is correlated with phylogenetic clustering. Furthermore, we show that landform type was the primary determinant of the assembly of evolutionarily older species within floras, while climate was a greater determinant for younger species. Our study indicates that landform type not only affects montane species richness, but also contributes to the composition of montane floras. To explain the assembly and differentiation of mountain floras, we propose the ‘floristic geo-lithology hypothesis’, which highlights the role of bedrock and landform processes in montane floristic assembly and provides insights for future research on speciation, migration, and biodiversity in montane regions.

Rhododendron fortunei belongs to a scented Rhododendron species native to China, which produces fragrant flowers of great ornamental and environmental values for landscaping or indoor beautification. However, the scents in Rhododendron fortunei have not yet been investigated, let alone the mechanism of the formation of these fragrance in the flowers. In this study, we measured the scents in terms of its volatile components and contents (VOC) in Rhododendron fortunei at four different flowering stages and in different tissues of the plant by headspace solid-phase micro-extraction combined (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). Then the characteristic aromatic values, which reflects the degree of scent perception by human, of each VOC in the plant was calculated according to its respective aromatic thresholds. Results showed that three main VOCs measured from highest to lowest are methyl benzoates, terpenes and fatty acid derivatives. Their content increased after the flower bud opening and reached the highest at half to full blossom. In a flower most VOC contents were measured in petals and only trace amount in other tissues such as stamen, pistil. A small amount of VOCs was determined in leaves as well.All aromatic values were almost corresponded to the contents of three main VOCs, indicating that the flower fragrance arises truly from these VOC components. S-adenosyl-L-methionine: benzoic acid carboxyl methyl transferase (BAMT) catalyzes the final step to form methyl benzoates. To understand the mechanism of the formation of this main type fragrance and its regulation, we firstly isolate a gene of RfBAMT from petal of Rhododendron fortunei by using homologous cloning and RACE technology. The full length of its cDNA was 1383 bp，with an open reading frame of 1104 bp, encoding a total of 368 amino acids. The phylogenetic tree analysis showed that RfBAMT was the closest to the BSMT of Camellia japonica, belonging to methyltransferases family. Then we measured the expression level of RfBAMT again at four flower developmental stages and in different flower tissues and leaves. The results showed that the expression level of this gene was highly positively correlated with the emitted content of methyl benzoates in the flowering, implying that RfBAMT plays a pivotal role in the formation and regulation of methyl benzoates in Rhododendron fortune.This researchshowed that the RfBAMT was cloned and identified in our study and its expression level was highly positively correlated with the emitted content of methyl benzoates in the flowers and leaves, which indicated this gene may play an important role on regulation of methyl benzoate synthesis in Rhododendron fortunei. [ABSTRACT FROM AUTHOR]

Aroma is an important factor in the measurement of the quality and market value of oolong tea. However, it is hard to develop an oolong tea with good aroma quality using unsuitable tea varieties. To explore the key factors of tea varieties in the formation of oolong tea aromas, the fresh leaves of the Chungui variety (CG, suitable for oolong tea, Camellia sinensis (L.) O. Kuntze) and the Fuyun No. 6 variety (F6, unsuitable for oolong tea, Camellia sinensis (L.) O. Kuntze) were harvested and treated by withering and mechanical stress in order. Then, aroma, transcriptome, and jasmonate (JA) contents, and weighted gene co-expression network analysis (WGCNA), of samples were investigated. The contents of characteristic oolong tea aromas, including indole, (E)-β-ocimene, (E)-nerolidol, α-farnesene, and jasmine lactone, were all accumulated in much higher quantities in the CG variety after withering and mechanical stress. Accordingly, the coding genes of aroma formation synthases TSB2, OCS, NES, AFS, and LOX1, and related genes in MVA, MEP, and ALA pathways, were all much more highly activated. These differential reactions are mainly caused by the higher accumulation of jasmonates, especially methyl jasmonate, a type of important plant signal chemical, in CG after mechanical stress. WGCNA analysis indicated 34 different transcription factors from different families are predicted to be involved in this jasmonate-responsive reaction.

A phenomenological Landau–Devonshire theory is developed to investigate the ferroelectric, dielectric, and piezoelectric properties of (110) oriented Pb(Zr1−xTix)O3 (x = 0.4, 0.5, 0.6, and 0.7) thin films. At room temperature, the tetragonal a1 phase, the orthorhombic a2c phase, the triclinic γ1 phase, and the triclinic γ2 phase are stable. The appearance of the negative polarization component P2 in the a2c phase and the γ1 phase is attributed to the nonlinear coupling terms in the thermodynamic potential. The γ phase of the Pb(Zr1−xTix)O3 thin films has better dielectric and piezoelectric properties than the a2c phase and the a1 phase. The largest dielectric and piezoelectric coefficients are obtained in the Pb(Zr0.5Ti0.5)O3 thin film. The piezoelectric coefficient of 110–150 pm/V is obtained in the (110) oriented Pb(Zr0.5Ti0.5)O3 thin film, and the Pb(Zr0.3Ti0.7)O3 thin film has the remnant polarization and relative dielectric constant of 50 μC/cm2 and 100, respectively, which are in agreement with the experimental measurements reported in the literature. [ABSTRACT FROM AUTHOR]

Abstract Background As an economically important crop, tea is strongly nitrogen (N)-dependent. However, the physiological and molecular mechanisms underlying the response of N deficiency in tea are not fully understood. Tea cultivar “Chunlv2” [Camellia sinensis (L.) O. Kuntze] were cultured with a nutrient solution with 0 mM [N-deficiency] or 3 mM (Control) NH4NO3 in 6 L pottery pots containing clean river sands. Results N deficiency significantly decreased N content, dry weight, chlorophyll (Chl) content, L-theanine and the activities of N metabolism-related enzymes, but increased the content of total flavonoids and polyphenols in tea leaves. N deficiency delayed the sprouting time of tea buds. By using the RNA-seq technique and subsequent bioinformatics analysis, 3050 up-regulated and 2688 down-regulated differentially expressed genes (DEGs) were isolated in tea leaves in response to N deficiency. However, only 1025 genes were up-regulated and 744 down-regulated in roots. Gene ontology (GO) term enrichment analysis showed that 205 DEGs in tea leaves were enriched in seven GO terms and 152 DEGs in tea roots were enriched in 11 GO items based on P

The Arabidopsis gene At5g21040 encodes a protein containing both WD40 and F-box motifs, termed FBX2. A T-DNA insertional mutant in this gene was obtained. Analysis of this mutant line showed that FBX2 is a negative regulator of several Pi starvation responses. FBX2 interacts with BHLH32, another negative regulator of Pi starvation responses. We suggest that FBX2 may be part of an SCF-like complex that recruits BHLH32 and its partners, potentially targeting the latter for proteolysis. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the occurrence of phosphoenolpyruvate carboxykinase (PEPCK) in different tissues of Arabidopsis thaliana throughout its vegetative and reproductive growth. The A. thaliana genome contains two PEPCK genes (PCK1 and PCK2), and these are predicted to generate 73,404 and 72,891 Da protein products, respectively. Both genes were transcribed in a range of tissues; however, PCK1 mRNA appeared to be more abundant and was present in a wider range of tissues. PEPCK protein was present in flowers, fruit, developing seed, germinating seed, leaves, stems and roots. Two PEPCK polypeptides, of ∼74 and ∼73 kDa were detected by immunoblotting, and these may arise from PCK1 and PCK2, respectively. PEPCK was abundant in cotyledons during post-germinative growth, and this is consistent with its well established role in gluconeogenesis. PEPCK was also abundant in sink tissues, such as young leaves, in developing flowers, fruit and seed. Immunohistochemistry and in situ hybridization showed that PEPCK was present in the nectaries, stigma, endocarp of the fruit wall and in tissues involved in the transfer of assimilates to the developing ovules and seeds, such as the vasculature and seed coat. The potential functions of PEPCK in A. thaliana are discussed. [ABSTRACT FROM AUTHOR]

Skeletal muscle injury is an acute inflammatory condition caused by an inflammatory response. To reduce inflammatory cell infiltration and relieve skeletal muscle injury, efficient treatment is urgently needed. Nitric oxide is a free radical molecule reported to have anti-inflammatory effects. In this study, we showed that NO could inhibit the inflammatory response of C2C12 cells in vitro and protect rat skeletal muscle injury from notexin in vivo. NO synthase inhibitor (L-NG-Nitroarginine Methyl Este, L-NAME) and NO donor (sodium nitroprusside dehydrate, SNP) were used to explore the vital role of lipopolysaccharides (LPSs) in LPS-stimulated C2C12 myoblasts. The expression of IL-18 and IL-1b was upregulated by L-NAME and downregulated by SNP, as indicated by the ELISA results. NO can reduce ASC, Caspase-1, and NLRP3 mRNA and protein levels. Furthermore, NO was detected in the rat model. The results of immunohistochemical staining showed that the production of DMD decreased. We conducted qRT-PCR and western blotting to detect the expression of Jo-1, Mi-2, TLR2, and TLR4 on day 6 post injury following treatment with L-NAME and SNP. The expression of Jo-1, Mi-2, TLR2, and TLR4 was upregulated by L-NAME and significantly reversed by SNP. NO can alleviate C2C12 cell inflammatory responses and protect rat skeletal muscle injury from notexin. [ABSTRACT FROM AUTHOR]