Impact of a novel pre-hospital stroke notification programme on acute stroke care key performance indicators in Hong Kong: a multicentre prospective cohort study with historical controls

INTRODUCTION

Early identification and initiation of reperfusion therapy is essential for suspected acute ischaemic stroke. A pre-hospital stroke notification (PSN) protocol using FASE (facial drooping, arm weakness, speech difficulties, and eye palsy) was implemented to improve key performance indicators (KPIs) in acute stroke care delivery. We assessed KPIs and clinical outcomes before and after PSN implementation in Hong Kong.

METHODS

This prospective cohort study with historical controls was conducted in the Accident and Emergency Departments of four public hospitals in Hong Kong. Patients were screened using the PSN protocol between August 2021 and February 2022. Suspected stroke patients between August 2020 and February 2021 were included as historical controls. Door-to-needle (DTN) and door-to-computed tomography (DTC) times before and after PSN implementation were compared. Clinical outcomes including National Institutes of Health Stroke Scale score at 24 hours and modified Rankin Scale score at 3 months after intravenous recombinant tissue-type plasminogen activator (IV-rtPA) were also assessed.

RESULTS

Among the 715 patients (266 PSN and 449 non-PSN) included, 50.8% of PSN patients and 37.7% of non-PSN patients had a DTC time within 25 minutes (P<0.001). For the 58 PSN and 134 non-PSN patients given IV-rtPA, median DTN times were 67 and 75.5 minutes, respectively (P=0.007). The percentage of patients with a DTN time within 60 minutes was higher in the PSN group than in the non-PSN group (37.9% vs 21.6%; P=0.019). No statistically significant differences in clinical outcomes were observed.

CONCLUSION

Although the PSN protocol shortened DTC and DTN times, clinical outcomes did not significantly differ.

Vacuolar H+-ATPase and BZR1 form a feedback loop to regulate the homeostasis of BR signaling in Arabidopsis

Brassinosteroid (BR) is a vital plant hormone that regulates plant growth and development. BRASSINAZOLE RESISTANT 1 (BZR1) is a key transcription factor in BR signaling, and its nucleocytoplasmic localization is crucial for BR signaling. However, the mechanisms that regulate BZR1 nucleocytoplasmic distribution and thus the homeostasis of BR signaling remain largely unclear. The vacuole is the largest organelle in mature plant cells and plays a key role in maintenance of cellular pH, storage of intracellular substances, and transport of ions. In this study, we uncovered a novel mechanism of BR signaling homeostasis regulated by the vacuolar H+-ATPase (V-ATPase) and BZR1 feedback loop. Our results revealed that the vha-a2 vha-a3 mutant (vha2, lacking V-ATPase activity) exhibits enhanced BR signaling with increased total amount of BZR1, nuclear-localized BZR1, and the ratio of BZR1/phosphorylated BZR1 in the nucleus. Further biochemical assays revealed that VHA-a2 and VHA-a3 of V-ATPase interact with the BZR1 protein through a domain that is conserved across multiple species. VHA-a2 and VHA-a3 negatively regulate BR signaling by interacting with BZR1 and promoting its retention in the tonoplast. Interestingly, a series of molecular analyses demonstrated that nuclear-localized BZR1 could bind directly to specific motifs in the promoters of VHA-a2 and VHA-a3 to promote their expression. Taken together, these results suggest that V-ATPase and BZR1 may form a feedback regulatory loop to maintain the homeostasis of BR signaling in Arabidopsis, providing new insights into vacuole-mediated regulation of hormone signaling.

RLI2 regulates Arabidopsis female gametophyte and embryo development by facilitating the assembly of the translational machinery

Eukaryotic protein translation is a complex process that requires the participation of different proteins. Defects in the translational machinery often result in embryonic lethality or severe growth defects. Here, we report that RNase L inhibitor 2/ATP-BINDING CASSETTE E2 (RLI2/ABCE2) regulates translation in Arabidopsis thaliana. Null mutation of rli2 is gametophytic and embryonic lethal, whereas knockdown of RLI2 causes pleiotropic developmental defects. RLI2 interacts with several translation-related factors. Knockdown of RLI2 affects the translational efficiency of a subset of proteins involved in translation regulation and embryo development, indicating that RLI2 has critical roles in these processes. In particular, RLI2 knockdown mutant exhibits decreased expression of genes involved in auxin signaling and female gametophyte and embryo development. Therefore, our results reveal that RLI2 facilitates assembly of the translational machinery and indirectly modulates auxin signaling to regulate plant growth and development.

Spatiotemporal formation of the large vacuole regulated by the BIN2-VLG module is required for female gametophyte development in Arabidopsis

In Arabidopsis thaliana, female gametophyte (FG) development is accompanied by the formation and expansion of the large vacuole in the FG; this is essential for FG expansion, nuclear polar localization, and cell fate determination. Arabidopsis VACUOLELESS GAMETOPHYTES (VLG) facilitates vesicular fusion to form large vacuole in the FG, but the regulation of VLG remains largely unknown. Here, we found that gain-of-function mutation of BRASSINOSTEROID INSENSITIVE2 (BIN2) (bin2-1) increases VLG abundance to induce the vacuole formation at stage FG1, and leads to abortion of FG. Loss-of-function mutation of BIN2 and its homologs (bin2-3 bil1 bil2) reduced VLG abundance and mimicked vlg/VLG phenotypes. Knocking down VLG in bin2-1 decreased the ratio of aberrant vacuole formation at stage FG1, whereas FG1-specific overexpression of VLG mimicked the bin2-1 phenotype. VLG partially rescued the bin2-3 bil1 bil2 phenotype, demonstrating that VLG acts downstream of BIN2. Mutation of VLG residues that are phosphorylated by BIN2 altered VLG stability and a phosphorylation mimic of VLG causes similar defects as did bin2-1. Therefore, BIN2 may function by interacting with and phosphorylating VLG in the FG to enhance its stability and abundance, thus facilitating vacuole formation. Our findings provide mechanistic insight into how the BIN2-VLG module regulates the spatiotemporal formation of the large vacuole in FG development.

Integrative transcriptomic and proteomic analyses reveal a positive role of BES1 in salt tolerance in Arabidopsis

INTRODUCTION

Salt stress is a major environmental factor limiting plant growth and development. Previous studies have indicated that the steroidal hormones-brassinosteroids (BRs) are important regulators of plant responses to salt stress. However, the underlying molecular mechanisms have not been fully understood.

METHODS

(1) Phenotypic analysis of bes1-D, BES1-RNAi and their wild-type (Col-0) under salt treatments with different concentrations of NaCl. (2) Transcriptomic and proteomic profiling of BES1-regulated genes and proteins under salt treatment; (3) qRT-PCR validation of selected BES1-regulated genes under salt stress; (4) Transient transcriptional assay of BES1 regulation on its putative target genes in Arabidopsis protoplasts; (5) Electrophoresis Mobility Shift Assay (EMSA) of BES1 binding with its potential target genes.

RESULTS AND DISCUSSION

Phenotypic analysis indicated that bes1-D, a gain-of-function mutant of the BR-regulated transcription factor BES1 in Arabidopsis showed better salt tolerance than the wild-type plant, while a BES1 RNA interference (BES1-RNAi) line was more sensitive to salt stress. Global gene expression profiling and time series clustering analyses identified a total of 1,170 genes whose expression was boosted in bes1-D under salt stress. Further GO enrichment and gene functional network analyses identified several key modules that are regulated by BES1 and most sensitive to salt stress perturbations, including stress response, response to ABA and ROS, flavonoid biosynthesis and transmembrane transport. A comparative proteomic analysis performed under the same stress conditions supported the results from the transcriptome analysis. In addition, transient gene transcription assays in Arabidopsis protoplasts and in vitro DNA binding assays verified that BES1 regulates the expression of some ion transporter genes directly and indirectly. Taken together, our results support a positive role of BES1 in plant salt tolerance.

Corrigendum: Tonoplast proton pumps regulate nuclear spacing of female gametophytes via mediating polar auxin transport in arabidopsis

[This corrects the article DOI: 10.3389/fpls.2022.1006735.].

Phosphatidic acid suppresses autophagy through competitive inhibition by binding GAPC (glyceraldehyde-3-phosphate dehydrogenase) and PGK (phosphoglycerate kinase) proteins

Macroautophagy/autophagy is a finely-regulated process in which cytoplasm encapsulated within transient organelles termed autophagosomes is delivered to lysosomes or vacuoles for degradation. Phospholipids, particularly phosphatidic acid (PA) that functions as a second messenger, play crucial and differential roles in autophagosome formation; however, the underlying mechanism remains largely unknown. Here we demonstrated that PA inhibits autophagy through competitive inhibition of the formation of ATG3 (autophagy-related)-ATG8e and ATG6-VPS34 (vacuolar protein sorting 34) complexes. PA bound to GAPC (glyceraldehyde-3-phosphate dehydrogenase) or PGK (phosphoglycerate kinase) and promoted their interaction with ATG3 or ATG6, which further attenuated the interactions of ATG3-ATG8e or ATG6-VPS34, respectively. Structural and mutational analyses revealed the mechanism of PA binding with GAPCs and PGK3, and that GAPCs or ATG8e competitively interacted with ATG3, and PGK3 or VPS34 competitively interacted with ATG6, at the same binding interface. These results elucidate the molecular mechanism of how PA inhibits autophagy through binding GAPC or PGK3 proteins and expand the understanding of the functional mode of PA, demonstrating the importance of phospholipids in plant autophagy and providing a new perspective for autophagy regulation by phospholipids.Abbreviation: ATG: autophagy-related; BiFC: bimolecular fluorescence complementation; co-IP: co-immunoprecipitation; Con A: concanamycin A; ER: endoplasmic reticulum; EZ: elongation zone; FRET-FLIM: fluorescence resonance energy transfer with fluorescence lifetime imaging microscopy; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GST: glutathione S-transferase; MDC: monodansylcadaverine; MZ: meristem zone; PA: phosphatidic acid; PAS: phagophore assembly site; PC: phosphatidylcholine; PE: phosphatidylethanolamine; PGK3: phosphoglycerate kinase; PtdIns3K: phosphatidylinositol 3-kinase; PLD: phospholipase D; TEM: transmission electron microscopy; TOR: target of rapamycin; VPS34: vacuolar protein sorting 34; WT: wild type; Y2H: yeast two-hybrid.

The transcription factor OsGATA6 regulates rice heading date and grain number per panicle

Heading date, panicle architecture, and grain size are key traits that affect the yield of rice (Oryza sativa). Here, we identified a new gene, OsGATA6, whose product regulates heading date. Overexpression of OsGATA6 resulted in delayed heading, increased grain number, and decreased grain size. Knockdown lines generated by artificial microRNA (amiRNA) and CRISPR genome-edited lines of OsGATA6 both showed earlier heading, decreased grain number, and increased grain size. These results suggested that OsGATA6 negatively regulates heading date, positively regulates panicle development, and affects grain size. OsGATA6 was found to be constitutively expressed in rice, and strongly expressed in young leaves and panicles. In situ hybridization analyses showed that OsGATA6 was specifically localized in superficial cells of the panicle primordium. Overexpression lines show decreased expression of RFT1 and Hd3a, which promote heading. OsMFT1, which delays heading date and increases grain number, was down-regulated in amiRNA lines. Further analyses showed that OsGATA6 could bind to the promoter of OsMFT1 and induce its expression, thereby regulating heading date and panicle development. Overexpression of OsGATA6 in Arabidopsis resulted in repressed expression of AtFT and late flowering, suggesting that its function is similar. Taken together, we have identified a new GATA regulator that influences rice heading date and grain number, which potentially increases rice yield.

Tonoplast proton pumps regulate nuclear spacing of female gametophytes via mediating polar auxin transport in Arabidopsis

The vacuole is an important organelle with multiple functions in plants, and the tonoplast that wraps the vacuole also plays essential roles in intracellular trafficking and ion homeostasis. Previous studies found that tonoplast proton pumps regulate embryo development and morphogenesis through their effects on vacuole biogenesis and distribution, as well as polar auxin transport and concomitant auxin gradient. However, the precise roles of the tonoplast proton pumps in gametophyte development remain unclear. Here we demonstrated that the lack of two types of tonoplast proton pumps or the absence of V-ATPase alone leads to abnormal development and nuclear localization of female gametophyte (FG), and slowed endosperm nuclei division after fertilization of the central cell. We further revealed that V-ATPase regulates auxin levels in ovules through coordinating the content and localization of PIN-FORMED 1 (PIN1) protein, hence influencing nuclear spacing between centra cell and egg cell, and subsequent endosperm development. Collectively, our findings revealed a crucial role of V-ATPase in auxin-mediated FG development in Arabidopsis and expanded our understanding of the functions of tonoplast proton pumps in seed plants reproductive development.

Ovule initiation: the essential step controlling offspring number in Arabidopsis

Seed is the offspring of angiosperms. Plants produce large numbers of seeds to ensure effective reproduction and survival in varying environments. Ovule is a fundamentally important organ and is the precursor of the seed. In Arabidopsis and other plants characterized by multi-ovulate ovaries, ovule initiation determines the maximal ovule number, thus greatly affecting seed number per fruit and seed yield. Investigating the regulatory mechanism of ovule initiation has both scientific and economic significance. However, the genetic and molecular basis underlying ovule initiation remains unclear due to technological limitations. Very recently, rules governing the multiple ovules initiation from one placenta have been identified, the individual functions and crosstalk of phytohormones in regulating ovule initiation have been further characterized, and new regulators of ovule boundary are reported, therefore expanding the understanding of this field. In this review, we present an overview of current knowledge in ovule initiation and summarize the significance of ovule initiation in regulating the number of plant offspring, as well as raise insights for the future study in this field that provide potential routes for the improvement of crop yield.

PIN3 positively regulates the late initiation of ovule primordia in Arabidopsis thaliana

Ovule initiation determines the maximum ovule number and has great impact on seed number and yield. However, the regulation of ovule initiation remains largely elusive. We previously reported that most of the ovule primordia initiate asynchronously at floral stage 9 and PINFORMED1 (PIN1) polarization and auxin distribution contributed to this process. Here, we further demonstrate that a small amount of ovule primordia initiate at floral stage 10 when the existing ovules initiated at floral stage 9 start to differentiate. Genetic analysis revealed that the absence of PIN3 function leads to the reduction in pistil size and the lack of late-initiated ovules, suggesting PIN3 promotes the late ovule initiation process and pistil growth. Physiological analysis illustrated that, unlike picloram, exogenous application of NAA can’t restore these defective phenotypes, implying that PIN3-mediated polar auxin transport is required for the late ovule initiation and pistil length. qRT-PCR results indicated that the expression of SEEDSTICK (STK) is up-regulated under auxin analogues treatment while is down-regulated in pin3 mutants. Meanwhile, overexpressing STK rescues pin3 phenotypes, suggesting STK participates in PIN3-mediated late ovule initiation possibly by promoting pistil growth. Furthermore, brassinosteroid influences the late ovule initiation through positively regulating PIN3 expression. Collectively, this study demonstrates that PIN3 promotes the late ovule initiation and contributes to the extra ovule number. Our results give important clues for increasing seed number and yield of cruciferous and leguminous crops.

Interaction of brassinosteroid and cytokinin promotes ovule initiation and increases seed number per silique in Arabidopsis

Ovule initiation is a key step that strongly influences ovule number and seed yield. Notably, mutants with enhanced brassinosteroid (BR) and cytokinin (CK) signaling produce more ovules and have a higher seed number per silique (SNS) than wild-type plants. Here, we crossed BR- and CK-related mutants to test whether these phytohormones function together in ovule initiation. We determined that simultaneously enhancing BR and CK contents led to higher ovule and seed numbers than enhancing BR or CK separately, and BR and CK enhanced each other. Further, the BR-response transcription factor BZR1 directly interacted with the CK-response transcription factor ARABIDOPSIS RESPONSE REGULATOR1 (ARR1). Treatments with BR or BR plus CK strengthened this interaction and subsequent ARR1 targeting and induction of downstream genes to promote ovule initiation. Enhanced CK signaling partially rescued the reduced SNS phenotype of BR-deficient/insensitive mutants whereas enhanced BR signaling failed to rescue the low SNS of CK-deficient mutants, suggesting that BR regulates ovule initiation and SNS through CK-mediated and -independent pathways. Our study thus reveals that interaction between BR and CK promotes ovule initiation and increases seed number, providing important clues for increasing the seed yield of dicot crops.

A secretory phospholipase D hydrolyzes phosphatidylcholine to suppress rice heading time

Phospholipase D (PLD) hydrolyzes membrane phospholipids and is crucial in various physiological processes and transduction of different signals. Secretory phospholipases play important roles in mammals, however, whose functions in plants remain largely unknown. We previously identified a rice secretory PLD (spPLD) that harbors a signal peptide and here we reported the secretion and function of spPLD in rice heading time regulation. Subcellular localization analysis confirmed the signal peptide is indispensable for spPLD secretion into the extracellular spaces, where spPLD hydrolyzes substrates. spPLD overexpression results in delayed heading time which is dependent on its secretory character, while suppression or deficiency of spPLD led to the early heading of rice under both short-day and long-day conditions, which is consistent with that spPLD overexpression/suppression indeed led to the reduced/increased Hd3a/RFT1 (Arabidopsis Flowing Locus T homolog) activities. Interestingly, rice Hd3a and RFT1 bind to phosphatidylcholines (PCs) and a further analysis by lipidomic approach using mass spectrometry revealed the altered phospholipids profiles in shoot apical meristem, particularly the PC species, under altered spPLD expressions. These results indicate the significance of secretory spPLD and help to elucidate the regulatory network of rice heading time.

Secretory phospholipases play essential roles in physiological processes of mammals, while functions of them in plants remain unknown. We identified a rice secretory PLD (spPLD) harboring a signal peptide which is indispensable for secretion of spPLD. Functional studies showed that altered spPLD expression resulted in the changed heading time of rice under both short-day and long-day conditions, which is dependent on the secretory character of spPLD. Rice Hd3a and RFT1, the homologs of Arabidopsis Flowing Locus T (FT), bind to phosphatidylcholine (PC) to promote heading. Analysis of phospholipids profiles in shoot apical meristem by using a mass spectrometry-based lipidomic approach demonstrated that spPLD regulates heading time by hydrolyzing the light period-predominant PC species, further revealing the crucial role of secretory proteins in regulating plant growth and development.

Multiple functions of the vacuole in plant growth and fruit quality

Vacuoles are organelles in plant cells that play pivotal roles in growth and developmental regulation. The main functions of vacuoles include maintaining cell acidity and turgor pressure, regulating the storage and transport of substances, controlling the transport and localization of key proteins through the endocytic and lysosomal-vacuolar transport pathways, and responding to biotic and abiotic stresses. Further, proteins localized either in the tonoplast (vacuolar membrane) or inside the vacuole lumen are critical for fruit quality. In this review, we summarize and discuss some of the emerging functions and regulatory mechanisms associated with plant vacuoles, including vacuole biogenesis, vacuole functions in plant growth and development, fruit quality, and plant-microbe interaction, as well as some innovative research technology that has driven advances in the field. Together, the functions of plant vacuoles are important for plant growth and fruit quality. The investigation of vacuole functions in plants is of great scientific significance and has potential applications in agriculture.

[Recent advances in preoperative assessment of hepatic functional reserve for hepatectomy]

Hepatectomy represents the first choice of treatment for primary and secondary liver malignancies.However,post-hepatectomy liver failure(PHLF) remains a significant cause of morbidity and mortality after liver resection.Inadequate remnant liver volume and function are the determining factors of PHLF.Therefore,preoperative assessment of hepatic functional reserve is of paramount importance for prevention of PHLF.There are two main conventional assessment systems of preoperative hepatic functional reserve.The first is remnant liver volume(RLV) and its derivative indicators such as residual liver volume ratio,standardized residual liver volume ratio,RLV/body weight,and RLV/body surface area,calculated by imaging-based methods such as CT,that assess whether the volume of residual liver meets the requirements of safe hepatectomy.However,RLV is not an appropriate indicator of functional liver remnant,since the function of liver within equal volume among different persons is unequal due to the underlying liver diseases.Functional imaging techniques,such as ⁹⁹Tc^m-GSA,⁹⁹Tc^m-IDA and Gd-EOB-DTPA-enhanced MRI can simultaneously evaluate residual liver volume and function,leading to be a more appropriate indicator of functional liver remnant.The second is liver function tests,including serum biochemical parameters,clinical scoring systems and quantitative liver function tests.However,it can merely evaluate the overall liver function preoperatively,but not the residual one postoperatively.The residual liver function can be accurately measured by intraoperative indocyanine green clearance with the extrahepatic and intrahepatic blood flow of liver to be resected blocked.In addition,methods such as preoperative portal vein embolization and associating liver partition and portal vein ligation for staged hepatectomy,can be used for patients with a predicted inadequate RLV.Due to the unequal liver function within an equal volume increased by different methods,functional imaging techniques are more appropriate in predicting the increasing functional liver than traditional methods which just assess the increasing liver volume.

Single-cell transcriptome atlas and chromatin accessibility landscape reveal differentiation trajectories in the rice root

Root development relies on the establishment of meristematic tissues that give rise to distinct cell types that differentiate across defined temporal and spatial gradients. Dissection of the developmental trajectories and the transcriptional networks that underlie them could aid understanding of the function of the root apical meristem in both dicots and monocots. Here, we present a single-cell RNA (scRNA) sequencing and chromatin accessibility survey of rice radicles. By temporal profiling of individual root tip cells we reconstruct continuous developmental trajectories of epidermal cells and ground tissues, and elucidate regulatory networks underlying cell fate determination in these cell lineages. We further identify characteristic processes, transcriptome profiles, and marker genes for these cell types and reveal conserved and divergent root developmental pathways between dicots and monocots. Finally, we demonstrate the potential of the platform for functional genetic studies by using spatiotemporal modeling to identify a rice root meristematic mutant from a cell-specific gene cohort.

A Positive Feedback Loop Mediated by CsERF31 Initiates Female Cucumber Flower Development: ETHYLENE RESPONSE FACTOR31 mediates a positive feedback loop that initiates female cucumber flower development

Sex determination is a crucially important developmental event that is pervasive throughout nature and enhances the adaptation of species. Among plants, cucumber (Cucumis sativus L.) can generate both unisexual and bisexual flowers, and the sex type is mainly controlled by several 1-aminocyclopropane-1-carboxylic acid (ACC) synthases. However, the regulatory mechanism of these synthases remains elusive. Here, we used gene expression analysis, protein-DNA interaction assays and transgenic plants to study the function of a gynoecium-specific gene, ETHYLENE RESPONSE FACTOR31 (CsERF31), in female flower differentiation. We found that in a predetermined female flower, ethylene signalling activates CsERF31 by CsEIN3, and then CsERF31 stimulates CsACS2, which triggers a positive feedback loop to ensure female rather than bisexual flower development. A similar interplay is functionally conserved in melon (Cucumis melo L.). Knockdown of CsERF31 by RNAi causes defective bisexual flowers to replace female flowers. Ectopic expression of CsERF31 suppresses stamen development and promotes pistil development in male flowers, demonstrating that CsERF31 functions as a sex switch. Taken together, our data confirm that CsERF31 represents the molecular link between female-male determination and female-bisexual determination, and provide mechanistic insight into how ethylene promotes female flowers, rather than bisexual flowers, in cucumber sex determination.

Figure-eight arylene ethynylene macrocycles: facile synthesis and specific binding behavior toward Hg2+

Two figure-eight arylene ethynylene macrocycles (AEMs) were synthesized from non-helical precursors and the figure-eight shape was clearly imaged by STM.

Asynchrony of ovule primordia initiation in Arabidopsis

Plant ovule initiation determines the maximum of ovule number and has a great impact on the seed number per fruit. The detailed processes of ovule initiation have not been accurately described, although two connected processes, gynoecium and ovule development, have been investigated. Here, we report that ovules initiate asynchronously. The first group of ovule primordia grows out, the placenta elongates, the boundaries of existing ovules enlarge and a new group of primordia initiates from the boundaries. The expression pattern of different marker genes during ovule development illustrates that this asynchronicity continues throughout whole ovule development. PIN-FORMED1 polar distribution and auxin response maxima correlate with ovule primordia asynchronous initiation. We have established computational modeling to show how auxin dynamics influence ovule primordia initiation. Brassinosteroid signaling positively regulates ovule number by promoting placentae size and ovule primordia initiation through strengthening auxin response. Transcriptomic analysis demonstrates numerous known regulators of ovule development and hormone signaling, and many new genes are identified that are involved in ovule development. Taken together, our results illustrate that the ovule primordia initiate asynchronously and the hormone signals are involved in the asynchrony.

Summary: Ovule primordia initiation, which determines the maximum ovule number and subsequent seed number in Arabidopsis, is asynchronous and is regulated by PIN1 polar distribution and the auxin response.

Two tonoplast proton pumps function in Arabidopsis embryo development

Two types of tonoplast proton pumps, H⁺ -pyrophosphatase (V-PPase) and the H⁺ -ATPase (V-ATPase), establish the proton gradient that powers molecular traffic across the tonoplast thereby facilitating turgor regulation and nutrient homeostasis. However, how proton pumps regulate development remains unclear. In this study, we investigated the function of two types of proton pumps in Arabidopsis embryo development and pattern formation. While disruption of either V-PPase or V-ATPase had no obvious effect on plant embryo development, knocking out both resulted in severe defects in embryo pattern formation from the early stage. While the first division in wild-type zygote was asymmetrical, a nearly symmetrical division occurred in the mutant, followed by abnormal pattern formation at all stages of embryo development. The embryonic defects were accompanied by dramatic differences in vacuole morphology and distribution, as well as disturbed localisation of PIN1. The development of mutant cotyledons and root, and the auxin response of mutant seedlings supported the hypothesis that mutants lacking tonoplast proton pumps were defective in auxin transport and distribution. Taking together, we proposed that two tonoplast proton pumps are required for vacuole morphology and PIN1 localisation, thereby controlling vacuole and auxin-related developmental processes in Arabidopsis embryos and seedlings.

[The predictive value of epicardial adipose tissue and inflammatory factors for in-stent restenosis]

Objective: To investigate the predictive value of epicardial adipose tissue volume (EATV) and inflammatory factors on in-stent restenosis (ISR) after percutaneous coronary implantation (PCI) in patients with coronary heart disease (CAD). Methods: A total of 407 patients with CAD who were treated with drug-eluting stents in TEDA international cardiovascular disease hospital were enrolled from November 2016 to October 2017. Levels of inflammatory cytokines such as high sensitive c-reactive protein (Hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) were detected. EATV was measured preoperatively by multi-sliced CT. Patients were divided into ISR group (n=52) and N-ISR group (n=355) according to ISR occurred within 1 year after procedure. The relationship between EATV and inflammatory factors and ISR after PCI was analyzed. Results: The differences between ISR group (n=52) and N-ISR group (n=355) were statistically significant in terms of diabetes history, IL-6, TNF-α, EATV ((150±36) cm(3)vs(120±40) cm(3),P=0.001)), bifurcation lesions, stent length and Gensini score (P<0.05). Multivariate Logistic regression analysis results showed that diabetes history,bifurcation lesions, TNF-α, EATV, and Gensini score were risk factors for in-stent restenosis.The area under the ROC curve (AUC) of EATV, TNF-α, and IL-6 in patients with CAD after PCI was 0.712, 0.752 and 0.675 (95%CI 0.648-0.776, 0.686-0.819, 0.584-0.766, respectively, all P<0.001), with a sensitivity of 86.5%, 67.3% and 69.2%, a specificity of 53.8%, 74.4% and 70.1% and a cut-off value of 116.61 cm(3),138.40 µg/L and 126.4 µg/L, respectively. Conclusion: EATV, TNF-α, and IL-6 have certain predictive values for in-stent restenosis, and can be used as clinical indicators to predict in-stent restenosis.

Designed Manipulation of the Brassinosteroid Signal to Enhance Crop Yield

Brassinosteroid (BR), a plant steroid hormone, plays crucial role in modulating plant growth and development, which affect crop architecture and yield. However, BR application cannot highly benefit to agricultural production as expectation, because it regulates multiple processes in different tissues and leads to side effect. In addition, accurately modifying BR signal at transcriptional level is difficult. Effective manipulation of the BR signal and avoidance of side effects are required to enhance yield in different crops. Application of BR by spraying at specific developmental stages can enhance crop yield, but this method is impractical for use on a large scale. The accurate molecular design of crops would be much more helpful to manipulate the BR signal in specific organs and/or at particular developmental stages to enhance crop yield. This minireview summarizes the BR regulation of yield in different crops, especially horticultural crops, and the strategies used to regulate the BR signal to enhance crop yield. One popular strategy is to directly modulate the BR signal through modifying the functions of important components in the BR signal transduction pathway. Another strategy is to identify and modulate regulators downstream of, or in crosstalk with, the BR signal to manipulate its role in specific processes and increase crop yield. Efforts to accurately design a BR manipulation strategy will ultimately lead to effective control of the BR signal to avoid side effects and enhance crop yield.

Application of γ-PGA as the primary carbon source to bioremediate a TCE-polluted aquifer: A pilot-scale study

The effectiveness of using gamma poly-glutamic acid (γ-PGA) as the primary carbon and nitrogen sources to bioremediate trichloroethene (TCE)-contaminated groundwater was studied in this pilot-scale study. γ-PGA (40 L) solution was injected into the aquifer via the injection well (IW) for substrate supplement. Groundwater samples were collected from monitor wells and IW and analyzed for TCE and its byproducts, geochemical indicators, dechlorinating bacteria, and microbial diversity periodically. Injected γ-PGA resulted in an increase in total organic carbon (TOC) (up to 9820 mg/L in IW), and the TOC biodegradation caused the formation of anaerobic conditions. Increased ammonia concentration (because of amine release from γ-PGA) resulted in the neutral condition in groundwater, which benefited the growth of Dehalococcoides. The negative zeta potential and micro-scale diameter of γ-PGA allowed its globule to distribute evenly within soil pores. Up to 93% of TCE removal was observed (TCE dropped from 0.14 to 0.01 mg/L) after 59 days of γ-PGA injection, and TCE dechlorination byproducts were also biodegraded subsequently. Next generation sequence (NGS) analyses were applied to determine the dominant bacterial communities. γ-PGA supplement developed reductive dechlorinating conditions and caused variations in microbial diversity and dominant bacterial species. The dominant four groups of bacterial communities including dechlorinating bacteria, vinyl chloride degrading bacteria, hydrogen producing bacteria, and carbon biodegrading bacteria.

Effective Modulating Brassinosteroids Signal to Study Their Specific Regulation of Reproductive Development and Enhance Yield

Brassinosteroid (BR) is a family of bioactive steroid hormones that plays vital roles in plant growth and development. The BR-mediated regulation of plant growth and architecture has been well studied. However, relatively few studies have investigated the BR-related regulation of reproductive development because of the difficulties in excluding non-specific regulation and secondary responses from severe vegetative phenotypes and poor nutritional status. Furthermore, differentially regulating the BR signal in vegetative and reproductive organs is problematic. Thus, establishing a method for modulating the BR signal only in reproductive organs or during reproductive developmental stages will be beneficial. Additionally, the utility of BR applications for crop production is limited because of deleterious side-effects, including the associated decrease in the planting density and lodging resistance. Moreover, enhancing the BR signal may lead to feedback inhibition. In this study, we developed a transformation system for modulating the BR signal differentially during reproductive and vegetative developmental stages. This system involves transformations with different combinations of a reproductive tissue-specific promoter, coding sequences that increase or decrease the BR signal, and various genotypic backgrounds with enhanced or decreased BR signals. The enhanced BR signal generated in transformants was targeted to reproductive organs without affecting vegetative organs. This system may be useful for studying the BR-specific regulation of plant reproductive development and shows promise for optimizing seed yield.

[Relationship between epicardial adipose tissue and clinical prognosis of patients with coronary heart disease after percutaneous coronary intervention]

Objective: To further evaluate the clinical value of epicardial adipose tissue volume (EATV) in predicting the prognosis of coronary heart disease (CHD) after percutaneous coronary intervention (PCI). Methods: From July 2013 to July 2016 in TEDA International Cardiovascular Disease Hospital, a total of 474 patients diagnosed with CHD were included in this study.According to the result of EATV, patients were divided into three groups, group A (EATV≤75 ml), group B (75 ml<EATV<150 ml), and group C (EATV≥150 ml). Then the level of body mass index (BMI), hypersensitive c-reactive protein (hs-CRP), interleukin (IL)-6 and tumor necrosis factor (TNF)-α were tested for all the three groups.All the patients were followed up for 1 year for major adverse cardiovascular events (MACE). The clinical value of EATV in predicting the occurrence of MACE events was evaluated. Results: The BMI, level of hs-CRP, TNF-α in group B were higher than group A, group C were significantly higher than group B, with statistically significant difference across all the comparisons (P<0.05). Spearman correlation analysis showed EATV was positively correlated with hs-CRP, IL-6, TNF-α (r=0.675-0.700, P<0.01). The incidence of MACE in the three groups were 8.50% in group C, 5.26% in group B, 3.13% in group A, and the differences were all significant (P<0.01). ROC curve showed the cut-off value of EATV level was 120.39 ml to predict MACE (area under cure: 0.751, 95%CI: 0.634-0.868, P<0.01), and the sensitivity was 72.7%, the specificity was 61%.EATV>120.39 ml can be used as an independent risk factor for predicting the occurrence of MACE. Conclusion: The level of EATV is closely related to the occurrence of MACE events, and EATV>120.39 ml is an independent risk factor for MACE in patients with CHD after PCI.

[Effects of epicardial adipose tissue and inflammatory factors on left ventricular diastolic function in patients with coronary heart disease]

Objective: To investigate the effects ofepicardial adipose tissue volume (EATV) and inflammatory factors on left ventricular diastolic function in patients with coronary heart disease(CHD). Methods: The clinical data of patients with coronary heart disease receiving coronary artery intervention therapy from January 2014 to October 2015 in TEDA international cardiovascular hospital were preoperatively collected.We measured the indexes of EATV and left ventricular diastolic function. Results: The difference of age (F=7.76, P=0.01), IL-6 (F=14.34, P<0.01), Hs-CRP (F=4.08, P=0.04), adiponect-in (F=4.50, P=0.04) and EATV (F=71.29, P<0.01) between the diastolicdysfunction group (n=156) and the normal group (n=76) was statistically significant.Multivariate logistic regression analysis showed that EATV was a risk factor for left ventricular diastolic dysfunction in patients with coronary artery disease (P<0.05), OR=1.05, 95%CI (1.03-1.06). The AUC value of EATV in the diagnosis of left ventriculardiastolic function in patients with coronary heart disease was 0.79, 95%CI (0.73-0.85) P<0.01. Conclusions: EATV can be used as an independent risk factor for left ventricular diastolic dysfunction.It has some non-invasive diagnosis and predictive value, and it can be used as a new therapeutic target.

Simple Culture Methods and Treatment to Study Hormonal Regulation of Ovule Development

Ovule development is one of the most important processes in the reproductive development of higher plants and is a determinant of seed quality and quantity. Phytohormones play key roles in this process since loss-of-function mutants in hormone signaling show defective ovule phenotypes and reduced fertility. However, it is difficult to distinguish the direct effects of hormones on ovule development because it is parts of reproductive development and the defective phenotypes would be the indirect effects following the defective vegetative development. The treatment of hormones is a direct method to investigate the hormonal regulation of ovule development, but ovule is embedded inside several layers of floral organs, and traditional methods for hormone (or inhibitor) treatments have various limitations. We have developed simple methods to apply treatments to the flowers in a living plant, where an inflorescence apex is immersed into a solution in an inverted tube. We have also developed a specific system to culture and treat excised flowers/pistils. These procedures will be useful for research on the hormonal regulation of ovule development. We provide examples of how treatments with brassinosteroids (BR) and BR biosynthesis inhibitor. We cultured and treated plant materials using our newly developed methods, and observed the morphology of wild type ovules and fluorescence signals in a marker line to monitor the progress of ovule development. The results demonstrate BR promotes ovule development and our new methods are efficient and repeatable.

Development of a two-stage biotransformation system for mercury-contaminated soil remediation

Utilization of bacterial volatilization can be problematic to remediate mercury (Hg)-contaminated soils because most of the Hg in soils is bound to soil particles. The objective of this study was to develop a two-stage system (chemical extraction followed by microbial reduction) for Hg-contaminated soil remediation. The tasks were to (1) select the extraction reagents for Hg extraction, (2) assess the effects of extraction reagents on the growth of Hg-reducing bacterial strains, and (3) evaluate the effectiveness of Ca²⁺ and Mg²⁺ addition on merA gene (Hg reductase) induction. Bacterial inhibition was observed with the addition of 0.1 M ethylenediaminetetraacetic acid or citric acid. Up to 65% of Hg was biotransformed (Hg concentration = 69 mg/kg) from the soils after a 24 h extraction using 0.5 M ammonium thiosulfate. Ca²⁺ and Mg²⁺ were selected because they have the same electric charge as Hg and the studied groundwater contained high concentrations of Ca²⁺ and Mg²⁺. Results showed that the addition of 200 mg/L Ca²⁺ or 650 mg/L Mg²⁺ could reach effective merA induction. In the two-stage experiment, 120 mg/kg Hg-contaminated soils were extracted with 2 rounds of extraction processes for 10 h using 0.5 M ammonium thiosulfate. Approximately 77% of Hg was extracted from the soils after the first-step extraction process. Up to 81% of Hg²⁺ was transformed from the washing solution via the biotransformation processes with Enterobacter cloacae addition and Ca²⁺ and Mg²⁺ supplementation. The two-stage remedial system has the potential to be developed into a practical technology to remediate Hg-contaminated sites.

[Premature outflow tract ventricular contraction combined with complete bundle branch block: the characteristic electrocardiographic and ablation target potential features]

Objective: To explore the characteristics of electrocardiogram(ECG) and target potential features of premature ventricular contraction (PVC) in patients with complete left/right bundle branch block (CL/RBBB) and compare with those without CL/RBBB. Methods: A retrospective analysis was done in 8 outflow tract PVC patients with CL/RBBB, who successfully underwent radiofrequency ablation from August 2009 to June 2017. According to the bundle branch block chamber, patients were divided into the complete right bundle branch block (CRBBB) group (n=4) and the complete left bundle branch block (CLBBB) group (n=4). The control group were those who successfully underwent ablation at the same position as the above two groups but without CL/RBBB. The characteristics of ECG and target potential features were compared among groups. Results: One case in the CRBBB group was successfully ablated in the great cardiac vein with precordial R/S>1 transition at V(1) and one case in the CLBBB group was successfully ablated in the right coronary cusp with precordial R/S>1 transition at V(2), while other 6 cases were all with precordial R/S>1 transition at lead V(4). Precordial R/S>1 transition was not later than sinus rhythm (SR) in the CLBBB group. No statistical difference was found in the QRS complex duration between SR and PVC in the CL/RBBB patients [(134.38±23.80)ms vs (156.75±25.93)ms, P>0.05], while statistical difference was shown in the control group [(92.63±5.76)ms vs (140.25±15.97)ms, P<0.05]. Conclusion: Bundle branch block can lead to misjudgment of PVC origin with CL/RBBB during sinus rhythm, thus the origin chamber of the PVC should be determined according to the mapping and ablation result.

[Effect of probucol on preventing contrast-induced nephropathy in patients undergoing percutaneous coronary intervention]

Objective: To investigate the preventive effect, possible mechanism and safety of probucol on contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI) in patients with coronary heart disease (CHD). Methods: A total of 641 patients with coronary heart disease were consecutively enrolled from Department of Cardiology, in Tianjin Chest Hospital, Tianjin TEDA International Cardiovascular Hospital, Tianjin First Central Hospital, Tianjin Fourth Central Hospital. They were randomly divided into probucol group (n=321) and control group (n=320). The probucol group was given oral probucol 500 mg twice daily for day 0 to day 3 after PCI; the control group was given only conventional therapy. All patients were given intravenous drip 0.9% sodium chloride solution before 12 to 24 hours of operation. The levels of serum creatinine (Scr), blood urea nitrogen (BUN), evaluate glomerular filtration rate (eGFR), cystatin C (Cys-C), and high-sensitivity C-reactive protein (hs-CRP), neutrophil gelatinase associated lipocalin (NGAL), superoxide dismutase (SOD) and glutathione (GSH) were measured before and 72 h after the PCI operation in both groups. The incidence rates of CIN, the adverse events during hospitalization and postoperative 14-day follow-up were recorded in two groups. Results: There was no statistically significantly difference in the levels of Scr, BUN, eGFR, Cys-C, hs-CRP, NGAL, SOD and GSH between the two groups before PCI (P>0.05). The levels of serum Scr, BUN, Cys-C, hs-CRP, NGAL, SOD and GSH after operation in the two groups were higher than those before the operation (P<0.05). The levels of hs-CRP and NGAL in the probucol group were lower than those in the control group [(10±4) vs (11±4)mg/L, (25±8)vs (34±7)U/ml, P<0.05]. The levels of eGFR, SOD and GSH in probucol group were higher than those in control group [(80±27) vs (72±26) ml·min(-1)·1.73 m(-2,) (67±9) vs (58±8)U/ml, (4.6±0.9) vs (3.9±0.8)U/ml, P<0.05]. The incidence of CIN was 4.0% in the probucol group and 10.9% in the control group, and the difference was statistically significant (P<0.05, χ(2)=-3.31). Multivariate Logistic regression analysis showed that probucol was an independent protective factor for CIN (OR=0.334, 95%CI 0.172-0.648, P=0.001). There were no adverse events such as myasthenia gravis, abnormal liver function and cardiovascular events during the hospitalization and 14-day follow-up. Conclusions: Probucol can reduce the incidence of contrast-induced nephropathy after PCI. The protection mechanism is related with its anti-inflammatory and anti-oxidative stress effects, and it has good safety.

[Efficacy and safety of Rivaroxaban anticoagulant therapy in the treatment of atrial fibrillation cryoablation]

Objective: To observe the efficacy and safety of the novel oral anticoagulant Rivaroxaban for anticoagulation therapy in patients with nonvalvular atrial fibrillation (AF) during cryoablation. Methods: A total of 137 AF patients from October 2013 to December 2016 underwent cryoablation were divided into two groups according to the application of anticoagulant drugs: Rivaroxaban group (65 cases) and Heparin group (72 cases). Rivaroxaban group: oral administration of Rivaroxaban 20 mg, once a day, was started 3 days before the cryoablation, no anticoagulant was additionally added during cryoablation, the activated clotting time (ACT) was measured, and oral administration of Rivaroxaban was continued for 3 months after cryoablation. Heparin group: oral administration of Rivaroxaban 20 mg, once a day, was stopped 24 hours before the cryoablation, heparin (100 U/kg) anticoagulation was given during cryoablation, ACT was controlled between 250 and 300 seconds, and oral administration of Rivaroxaban was continued for 3 months after cryoablation. The ACT results, the incidence of bleeding and thromboembolic events between the two groups were compared. Results: The ACT result between the two groups were with statistically significance[(110±16) vs (323±61) seconds, P=0.000)]. The bleeding events for Rivaroxaban group were two cases of local hematoma of the femoral vein puncture site, with the incidence rate of 3.1%(2/65); Heparin group were two cases of local hematoma of the femoral vein puncture site, and one case of epistaxis, with the incidence rate of 4.2%(3/72), with no statistical significance(P=0.549) between the two groups. No thromboembolic event occurred in the Rivaroxaban group, one cerebellar thromboembolic event occurred in the Heparin group during anticoagulant bridging phase after cryoablation. Conclusion: Rivaroxaban is safe and effective for anticoagulation therapy in patients with atrial fibrillation cryoablation.

Functional characterization of GmBZL2 (AtBZR1 like gene) reveals the conserved BR signaling regulation in Glycine max

Brassinosteroids (BRs) play key roles in plant growth and development, and regulate various agricultural traits. Enhanced BR signaling leads to increased seed number and yield in Arabidopsis bzr1-1D (AtBZR1(P234L), gain-of-function mutant of the important transcription factor in BR signaling/effects). BR signal transduction pathway is well elucidated in Arabidopsis but less known in other species. Soybean is an important dicot crop producing edible oil and protein. Phylogenetic analysis reveals AtBZR1-like genes are highly conserved in angiosperm and there are 4 orthologues in soybean (GmBZL1-4). We here report the functional characterization of GmBZL2 (relatively highly expresses in flowers). The P234 site in AtBZR1 is conserved in GmBZL2 (P216) and mutation of GmBZL2(P216L) leads to GmBZL2 accumulation. GmBZL2(P216L) (GmBZL2*) in Arabidopsis results in enhanced BR signaling; including increased seed number per silique. GmBZL2* partially rescued the defects of bri1-5, further demonstrating the conserved function of GmBZL2 with AtBZR1. BR treatment promotes the accumulation, nuclear localization and dephosphorylation/phosphorylation ratio of GmBZL2, revealing that GmBZL2 activity is regulated conservatively by BR signaling. Our studies not only indicate the conserved regulatory mechanism of GmBZL2 and BR signaling pathway in soybean, but also suggest the potential application of GmBZL2 in soybean seed yield.

ANAC005 is a membrane-associated transcription factor and regulates vascular development in Arabidopsis

Vascular tissues are very important for providing both mechanical strength and long-distance transport. The molecular mechanisms of regulation of vascular tissue development are still not fully understood. In this study we identified ANAC005 as a membrane-associated NAC family transcription factor that regulates vascular tissue development. Reporter gene assays showed that ANAC005 was expressed mainly in the vascular tissues. Increased expression of ANAC005 protein in transgenic Arabidopsis caused dwarf phenotype, reduced xylem differentiation, decreased lignin content, repression of a lignin biosynthetic gene and genes related to cambium and primary wall, but activation of genes related to the secondary wall. Expression of a dominant repressor fusion of ANAC005 had overall the opposite effects on vascular tissue differentiation and lignin synthetic gene expression. The ANAC005-GFP fusion protein was localized at the plasma membrane, whereas deletion of the last 20 amino acids, which are mostly basic, caused its nuclear localization. These results indicate that ANAC005 is a cell membrane-associated transcription factor that inhibits xylem tissue development in Arabidopsis.

The complex interplay among bacterial motility and virulence factors in different Escherichia coli infections

Motility mediated by the flagella of Escherichia coli is important for the bacteria to move toward host cells. Here, we present the relationship among bacterial motility, virulence factors, antimicrobial susceptibility, and types of infection. A total of 231 clinical E. coli isolates from different infections were collected and analyzed. Higher-motility strains (motility diameter ≥6.6 mm) were more common in spontaneous bacterial peritonitis (SBP) (SBP 59 %, colonization 32 %, urinary tract infection 16 %, urosepsis 34 %, and biliary tract infection 29 %; p < 0.0001). Compared with the higher-motility group, there was a higher prevalence of afa and ompT genes (p = 0.0160 and p = 0.0497, respectively) in E. coli strains with lower motility. E. coli isolates with higher and lower motility were in different phylogenetic groups (p = 0.018), with a lower prevalence of A and B1 subgroups in higher-motility strains. Also, the patterns of virulence factors and antibiotic susceptibility of E. coli isolates derived from various infections were significantly different. This study demonstrates that the prevalence of higher-motility strains was greater in E. coli isolates from SBP compared to other types of infection. Various types of E. coli infection were associated with differences in bacterial motility, virulence factors, and antibiotic susceptibility. More bacterial virulence factors may be necessary for the development of extraintestinal infections caused by E. coli isolates with lower motility.

Clinical and microbiological characteristics of Klebsiella pneumoniae from community-acquired recurrent urinary tract infections

Understanding the pathogenesis of recurrent urinary tract infection (RUTI) and whether it is attributable to reinfection with a new strain or relapse with the primary infecting strain is of considerable importance. Because previous studies regarding community-acquired Klebsiella pneumoniae RUTI are inconclusive, we undertook this study to evaluate the characteristics of the host and the bacterial agent K. pneumoniae in RUTI. A prospective study was designed, using consecutive patients diagnosed with community-acquired K. pneumoniae-related UTI from January 2007 to December 2009. Of the total 468 consecutive episodes, we found 7 patients with RUTI. All the patients with RUTI were elderly (median, 74 years), with diabetes (100 %, 7 out of 7). Clinical K. pneumoniae isolates derived from the same patients with RUTI revealed identical genomic fingerprints, indicating that K. pneumoniae UTI relapsed despite appropriate antibiotic therapy. The antimicrobial resistance, growth curve and biofilm formation of the recurrent isolates did not change. K. pneumoniae strains causing RUTI had more adhesion and invasiveness than the colonization strains (p < 0.01). When we compared the recurrent strains with the community-acquired UTI strains, the prevalence of diabetes mellitus was significant (100 % vs 53.7 %, p = 0.03) in the RUTI group. Our data suggest that K. pneumoniae strains might be able to persist within the urinary tract despite appropriate antibiotic treatment, and the greater adhesion and invasiveness in the recurrent strains may play an important role in recurrent infections.

[Study on the relationship between odor intensity and components concentrations of odor mixture]

Odor pollution has become a serious environmental problem arising from volatile organic compounds (VOCs) and other pollutants. But the studies on odor intensity and other olfactory evaluations are seriously influenced by the diversity, distinct concentration fluctuation and complex interaction of pollutants. In order to explore the relationship between odor intensity and components concentrations of odor mixture, several typical VOCs in indoor environment were used to simulate odor mixtures. A panel of six sensory assessors was employed to rate the odor intensities of the mixture and its unmixed components. The outcome showed that the presence of an odorant barely influenced the odor intensity of the mixture when its nature logarithm of odor activity value (OAV) was lower than 20% of the mixture's total amount. The application of this method as a pretreatment method for the odor mixture could apparently simplify the studies on odor interaction and olfactory evaluation.

Brassinosteroid functions in Arabidopsis seed development

Seed development of flowering plant is a complicated process controlled by a signal network. Double fertilization generates 2 zygotic products (embryo and endosperm). Embryo gives rise to a daughter plant while endosperm provides nutrients for embryo during embryogenesis and germination. Seed coat differentiates from maternally derived integument and encloses embryo and endosperm. Seed size/mass and number comprise final seed yield, and seed shape also contributes to seed development and weight. Seed size is coordinated by communication among endosperm, embryo, and integument. Seed number determination is more complex to investigate and shows differences between monocot and eudicot. Total seed number depends on sillique number and seed number per sillique in Arabidopsis. Seed comes from fertilized ovule, hence the ovule number per flower determines the maximal seed number per sillique. Early studies reported that engineering BR levels increased the yield of ovule and seed; however the molecular mechanism of BR regulation in seed development still remained unclear. Our recent studies demonstrated that BR regulated seed size, shape, and number by transcriptionally modulating specific seed developmental pathways. This review summarizes roles of BR in Arabidopsis seed development and gives clues for future application of BR in agricultural production.

Brassinosteroid regulates seed size and shape in Arabidopsis

Seed development is important for agriculture productivity. We demonstrate that brassinosteroid (BR) plays crucial roles in determining the size, mass, and shape of Arabidopsis (Arabidopsis thaliana) seeds. The seeds of the BR-deficient mutant de-etiolated2 (det2) are smaller and less elongated than those of wild-type plants due to a decreased seed cavity, reduced endosperm volume, and integument cell length. The det2 mutant also showed delay in embryo development, with reduction in both the size and number of embryo cells. Pollination of det2 flowers with wild-type pollen yielded seeds of normal size but still shortened shape, indicating that the BR produced by the zygotic embryo and endosperm is sufficient for increasing seed volume but not for seed elongation, which apparently requires BR produced from maternal tissues. BR activates expression of SHORT HYPOCOTYL UNDER BLUE1, MINISEED3, and HAIKU2, which are known positive regulators of seed size, but represses APETALA2 and AUXIN RESPONSE FACTOR2, which are negative regulators of seed size. These genes are bound in vivo by the BR-activated transcription factor BRASSINAZOLE-RESISTANT1 (BZR1), and they are known to influence specific processes of integument, endosperm, and embryo development. Our results demonstrate that BR regulates seed size and seed shape by transcriptionally modulating specific seed developmental pathways.

Preladenant, a selective adenosine A₂A receptor antagonist, is not associated with QT/QTc prolongation

PURPOSE

Preladenant is an orally administered adenosine2A (A2A) receptor antagonist in phase III development for Parkinson's disease treatment. This thorough QT/QTc study evaluated its potential effects on cardiac repolarization.

METHODS

This was a randomized, double-blind, positive- and placebo-controlled, four-period crossover study performed under steady-state exposure of clinical and supratherapeutic doses of preladenant (10 mg BID and 100 mg BID, respectively, for 5 days), moxifloxacin (400 mg on day 5), or placebo in 60 healthy adult volunteers. The potential effect on QTcF was measured by the largest upper bound of 95 % one-sided CIs for the mean changes from time-matched baseline ECG recordings compared with placebo. Plasma preladenant concentrations were also determined on day 5.

RESULTS

The QTcF difference for moxifloxacin compared with placebo exceeded 5 ms from 1 to 12 h postdose, establishing assay sensitivity. The QTcF interval was similar between the preladenant and placebo treatment groups: the upper bound of the 95 % one-sided CI for the mean difference in QTcF between preladenant and placebo was less than 10 ms at all time points for the supratherapeutic treatment group (1.3 to 5.7 ms, mean difference: -1.3 to 2.7 ms) and the therapeutic treatment group (0.4 to 4.3 ms, mean difference: -2.1 to 1.5 ms), substantially below the threshold of regulatory concern. The supratherapeutic dose (100 mg BID) provided a Cmax margin of 6.1-fold and AUC margin of 6.9-fold, respectively, compared with 10 mg BID.

CONCLUSIONS

At clinical and supratherapeutic doses, preladenant is not associated with QTc prolongation.

BR signal influences Arabidopsis ovule and seed number through regulating related genes expression by BZR1

Ovule and seed developments are crucial processes during plant growth, which are affected by different signaling pathways. In this paper, we demonstrate that the brassinosteroid (BR) signal is involved in ovule initiation and development. Ovule and seed numbers are significantly different when comparing BR-related mutants to wild-type controls. Detailed observation indicates that BR regulates the expression level of genes related to ovule development, including HLL, ANT, and AP2, either directly by targeting the promoter sequences or indirectly via regulation by BR-induced transcription factor BZR1. Also, Western blot demonstrates that the dephosphorylation level of BZR1 is consistent with ovule and seed number. The intragenic bzr1-1D suppressors bzs247 and bzs248 have much fewer ovules and seeds than bzr1-1D, which are similar to wild-type, suggesting that the phenotype can be rescued. The molecular and genetic experiments confirm that BZR1 and AP2 probably affect Arabidopsis ovule number determination antagonistically.

Role of K1 capsule antigen in cirrhotic patients with Escherichia coli spontaneous bacterial peritonitis in southern Taiwan

Spontaneous bacterial peritonitis (SBP) is one of the most serious complications in patients with cirrhosis. This study aimed to investigate the prevalence of SBP caused by Escherichia coli isolates with or without the K1 capsule antigen in cirrhotic patients and the outcome. From January 2004 to January 2012, a total of 54 and 41 E. coli strains derived from patients with SBP and intestinal perforation (IP), respectively, were included for comparison in this study. Bacterial characteristics including phylogenetic groups, K1 capsule antigen, and 14 virulence factor genetic determinants, as well as data regarding patient characteristics, clinical manifestations, and in-hospital deaths, were collected and analyzed. The prevalence of the K1 capsule antigen gene neuA was more common in SBP isolates compared to IP isolates (28 % vs. 10 %, p = 0.0385). Phylogenetic groups B2 and group D were dominant in E. coli isolates with and without the K1 capsule antigen, respectively. The prevalence of virulence factors genes papG II, ompT, and usp was higher in E. coli K1 strains. There were 26 deaths (48 %) during hospitalization. Presence of the K1 capsule antigen in E. coli isolates was significantly associated with in-hospital death in cirrhotic patients with SBP (42 % vs. 14 %, p = 0.0331). This study demonstrates a higher prevalence of the K1 capsule antigen in E. coli SBP compared to E. coli peritonitis caused by IP. There were significant associations between the K1 capsule antigen and in-hospital mortality and bacterial virulence in cirrhotic patients with E. coli SBP.

Field-induced expansion deformation in Pb islands on Cu(111): evidence from energy shift of empty quantum-well states

We use scanning tunneling microscopy and spectroscopy to measure the energy shift of empty quantum-well (QW) states in Pb islands on the Cu(111) surface. It is found that, with an increase of the electric field, the behavior of the energy shift can be grouped into two different modes for most QW states. In the first mode, the state energy moves toward high energy monotonically. In the second mode, the state energy shifts to a lower energy initially and then turns around to a higher energy. Moreover, we have observed that the QW states of higher energy behave in preference to the first mode, but they gradually change to the second mode as the Pb island becomes thicker. This thickness-dependent behavior reflects the existence of local expansion in the Pb islands, due to the electric field, and that the expansion is larger for a thicker island. QW states can thus be used for studying the localized lattice deformation in the nanometer scale.

Epidemiology and phylogenetic analysis of Taura syndrome virus in cultured Pacific white shrimp Litopenaeus vannamei B. in Taiwan

Taura syndrome virus (TSV) has spread worldwide, causing significant economic losses since Taura syndrome was first described in Ecuador in 1992. To determine the prevalence and impact of TSV infection on the shrimp farming industry in Taiwan, Pacific white shrimp Litopenaeus vannamei B. were collected from 220 farms between 2004 and 2006 for viral detection by reverse transcription polymerase chain reaction. Data showed that the overall TSV prevalence rate was 20% (43/220 farms). Comparing shrimp growth stages, TSV prevalence rates were 4% for postlarvae, 24% for juveniles, 24% for subadults, 32% for adults, and 5% for brooders. Among TSV-positive farms, average infection incidence was 35% in postlarvae farms, 55% in juvenile farms, 39% in subadult farms, 31% in adult farms, and 20% in brooder farms. Notably, TSV was also detected in Exopalaemon orientis H. from 1 of 10 farms. Tail fans and appendages had red pigmentation, which is characteristic of TSV infection. Of shrimp with pathological lesions, 100% had lesions on tail fans, 88% on appendages, and 80% in gills. Sequence comparison using the TSV VP1 (structural protein) gene showed that 9 isolates from the farms had 92.3 to 99.5% nucleotide sequence identity with strains in the GenBank database from Taiwan (AF406789 and AY355310) and Venezuela (DQ212790). This is the first broad epidemiological study of TSV infection in L. vannamei in Taiwan.