779 research outputs found

    Rhodium-Catalyzed Asymmetric Arylation of Cyclobutenone Ketals

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    Complex cyclobutanes are important motifs in both bioactive molecules and natural products, yet their enantioselective preparation has not been widely explored. In this work, we describe rhodium-catalyzed enantioselective additions of aryl and vinyl boronic acids to cyclobutenone ketals. This transformation involves enantioselective carbometalation to give cyclobutyl-rhodium intermediates, followed by ÎČ-oxygen elimination to afford enantioenriched enol ethers. Overall, this addition serves as a surrogate for Rh-catalyzed 1,4-additions to cyclobutenone

    Effect of a traditional control method (tree removal) on the spread of sharka in an apricot orchard in Southeastern Spain

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    The spatial spread of sharka disease (Plum pox virus, PPV) was studied from 1990 to 2002 in a traditional apricot (Prunus armeniaca L.) orchard located in Murcia (Southeast of Spain). The occurrence of sharka was determined by the visual observation of symptoms on leaves and fruits during the ripening stage, when symptoms are most visible. To ascertain PPV in doubtful samples, an ELISA-DASI assay was applied to the leaves. All trees infected the previous year were pulled up and were not replanted. Results showed that the virus was introduced to the farm by natural vectors (aphids) from a neighbouring sharka-infected plum orchard. It was then transmitted from these infected trees mainly to nearby trees by the same vectors, although also often to trees standing quite a distance away. The long interval between infection and symptom appearance makes eradication of the disease more difficult. Pulling up infected trees as a control method reduced the percentage of trees ultimately lost, and over the long term could stop the further spread of the disease

    Effect of a traditional control method (tree removal) on the spread of sharka in an apricot orchard in Southeastern Spain

    Get PDF
    The spatial spread of sharka disease (Plum pox virus, PPV) was studied from 1990 to 2002 in a traditional apricot (Prunus armeniaca L.) orchard located in Murcia (Southeast of Spain). The occurrence of sharka was determined by the visual observation of symptoms on leaves and fruits during the ripening stage, when symptoms are most visible. To ascertain PPV in doubtful samples, an ELISA-DASI assay was applied to the leaves. All trees infected the previous year were pulled up and were not replanted. Results showed that the virus was introduced to the farm by natural vectors (aphids) from a neighbouring sharka-infected plum orchard. It was then transmitted from these infected trees mainly to nearby trees by the same vectors, although also often to trees standing quite a distance away. The long interval between infection and symptom appearance makes eradication of the disease more difficult. Pulling up infected trees as a control method reduced the percentage of trees ultimately lost, and over the long term could stop the further spread of the disease

    Micro and nano smart composite films based on copper-iodine coordination polymer as thermochromic biocompatible sensors

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    Herein is presented the preparation and characterization of a composite material obtained by the combination of nanosheets of a coordination polymer (CP) based on the copper(I)-I double chain with response to temperature and pressure with polylactic acid (PLA) as biodegradable organic matrix. The new films of composite materials are generated using a simple and low-cost method and can be created with long lateral dimensions and thicknesses ranging from a few microns to a few nanometers. Studies show that the new material maintains the optical response versus the temperature, while the elasticity and flexibility of the PLA totally quenches the response to pressure previously observed for the CP. This new material can act as a reversible sensor at low temperatures, thanks to the flexibility of the copper(I)-iodine chain that conforms the CP. The addition of CP to the PLA matrix reduces the elastic modulus and ultimate elongation of the organic matrix, although it does not reduce its tensile strength

    Plant water status indicators for detecting water stress in pomegranate trees

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    Measurements obtained by the continuous monitoring of trunk diameter fluctuations were compared with discrete measurements of midday stem water potential (stem) and midday leaf conductance (gl) in adult pomegranate trees (Punica granatum (L.) cv. Mollar de Elche). Control plants (T0) were irrigated daily above their crop water requirements in order to attain non‐limiting soil water conditions, while T1 plants were subjected to water stress by depriving them of irrigation water for 34 days, after which time irrigation was restored and plant recovery was studied for 7 days. T1 plants showed a substantial degree of water stress, which developed slowly. Maximum daily trunk shrinkage (MDS) was identified to be the most suitable plant‐based indicator for irrigation scheduling in adult pomegranate trees, because its signal:noise ((T1/T0):coefficient of variation) ratio was higher than that for stem ((T1/T0):coefficient of variation) and gl ((T0/T1):coefficient of variation). MDS increased in response to water stress, but when the stem fell below −1.67 MPa, the MDS values decreased.This research was supported by CICYT/FEDER (AGL2010‐19201‐C04‐01AGR) and AECID (A1/035430/11) grants to the authors. AG, JCG and ZNC were funded by a FPU, a FPI and a AECID grant, respectively

    Assessing the Influence of Salmon Farming through Total Lipids, Fatty Acids, and Trace Elements in the Liver and Muscle of Wild Saithe Pollachius virens

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    Saithe Pollachius virens are attracted to uneaten salmon feed underneath cages at open-cage salmon farms in Norway. The aggregated Saithe have modified their feeding habits as they have switched from wild prey to uneaten food pellets, which could lead to physiological and biochemical changes in the Saithe. Variations in profiles of total lipids, fatty acids, and trace elements in Saithe liver and muscle were measured to evaluate the influence of fish feed from salmon farms on wild Saithe populations. Farm-aggregated Saithe had higher fat content in liver tissues than did individuals captured more than 25 km away from farms, but no clear differences were found in muscle tissues. High proportions of fatty acids of terrestrial origin, such as oleic, linoleic, and linolenic acids, in liver and muscle tissues of farm-aggregated Saithe reflected the presence of wild Saithe at farms. Accordingly, low proportions of arachidonic, eicosapentaenoic, and docosahexaenoic acids in Saithe tissues mirrored the feeding activity at farms. Variations in specific trace element signatures among fish groups also revealed the farming influence on wild Saithe. High levels of Fe, As, Se, Zn, and B in liver, but also As, B, Li, Hg, and Sr in muscle of Saithe captured away from farms indicated the absence of feeding at farms.This study was part of the project “Evaluation of actions to promote sustainable coexistence between salmon culture and coastal fisheries – ProCoEx” funded by The Norwegian Seafood Research Fund (FHF). The study was also supported by the Norwegian Research Council through the EcoCoast project

    Mutations in TRAPPC11 are associated with a congenital disorder of glycosylation.

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    Congenital disorders of glycosylation (CDG) are a heterogeneous and rapidly growing group of diseases caused by abnormal glycosylation of proteins and/or lipids. Mutations in genes involved in the homeostasis of the endoplasmic reticulum (ER), the Golgi apparatus (GA), and the vesicular trafficking from the ER to the ER-Golgi intermediate compartment (ERGIC) have been found to be associated with CDG. Here, we report a patient with defects in both N- and O-glycosylation combined with a delayed vesicular transport in the GA due to mutations in TRAPPC11, a subunit of the TRAPPIII complex. TRAPPIII is implicated in the anterograde transport from the ER to the ERGIC as well as in the vesicle export from the GA. This report expands the spectrum of genetic alterations associated with CDG, providing new insights for the diagnosis and the understanding of the physiopathological mechanisms underlying glycosylation disorders

    Cyclophilin A/EMMPRIN Axis Is Involved in Pro-Fibrotic Processes Associated with Thoracic Aortic Aneurysm of Marfan Syndrome Patients

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    Background: Marfan syndrome (MFS) is a genetic disease, characterized by thoracic aortic aneurysm (TAA), which treatment is to date purely surgical. Understanding of novel molecular targets is mandatory to unveil effective pharmacological approaches. Cyclophilin A (CyPA) and its receptor EMMPRIN are associated with several cardiovascular diseases, including abdominal aortic aneurysm. Here, we envisioned the contribution of CyPA/EMMPRIN axis in MFS-related TAA. METHODS: We obtained thoracic aortic samples from healthy controls (HC) and MFS patients' aortas and then isolated vascular smooth muscle cells (VSMC) from the aortic wall. RESULTS: our findings revealed that MFS aortic tissue samples isolated from the dilated zone of aorta showed higher expression levels of EMMPRIN vs. MFS non-dilated aorta and HC. Interestingly, angiotensin II significantly stimulated CyPA secretion in MFS-derived VSMC (MFS-VSMC). CyPA treatment on MFS-VSMC led to increased levels of EMMPRIN and other MFS-associated pro-fibrotic mediators, such as TGF-\u3b21 and collagen I. These molecules were downregulated by in vitro treatment with CyPA inhibitor MM284. Our results suggest that CyPA/EMMPRIN axis is involved in MFS-related TAA development, since EMMPRIN is upregulated in the dilated zone of MFS patients' TAA and the inhibition of its ligand, CyPA, downregulated EMMPRIN and MFS-related markers in MFS-VSMC. CONCLUSIONS: these insights suggest both a novel detrimental role for CyPA/EMMPRIN axis and its inhibition as a potential therapeutic strategy for MFS-related TAA treatment

    Structures of the Signal Recognition Particle Receptor from the Archaeon Pyrococcus furiosus: Implications for the Targeting Step at the Membrane

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    In all organisms, a ribonucleoprotein called the signal recognition particle (SRP) and its receptor (SR) target nascent proteins from the ribosome to the translocon for secretion or membrane insertion. We present the first X-ray structures of an archeal FtsY, the receptor from the hyper-thermophile Pyrococcus furiosus (Pfu), in its free and GDP‱magnesium-bound forms. The highly charged N-terminal domain of Pfu-FtsY is distinguished by a long N-terminal helix. The basic charges on the surface of this helix are likely to regulate interactions at the membrane. A peripheral GDP bound near a regulatory motif could indicate a site of interaction between the receptor and ribosomal or SRP RNAs. Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution. Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP‱SR targeting complexes
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