436 research outputs found

    Structural and biochemical characterization of specific phosphodiesterases in the degradation pathway of c-di-AMP

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    The Effect of the Number of Lending Banks on the Liquidity Constraints of Firms: Evidence From a Quasi-Experiment

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    We empirically explore whether firms have a target for the number of banks from which they borrow, and whether having multiple bank relationships has an impact on firms’ liquidity situation. A bank merger in Chile provides a quasi-experiment as it constitutes an exogenous reduction in the number of lenders for firms that were previously borrowing from both merging banks. We find that a significant percentage of firms whose number of bank relationships was reduced by the merger regain their original number of lenders. In particular, firms whose number of bank lending relationships was reduced from two to one as a result of the merger have a 23% higher probability of adding a new bank lending relationship in the five years following the merger than similar firms unaffected by the merger. Overall, we find that a reduction in firms’ number of bank lenders resulting from the merger reduced firms’ access to credit. In particular, a reduction from two to one bank lending relationships generated, on average, a 14.4% decrease in loan size for the affected companies compared to firms unaffected by the merger.

    The Effect Of The Number Of Lending Banks On The Liquidity Constraints Of Firms: Evidence From A Quasi-Experiment

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    En este trabajo exploramos si las firmas tienen un objetivo para el número de bancos con los cuales deciden endeudarse, y si la presencia múltiples acreedores afecta su liquidez. La fusión de los bancos Santander y Santiago constituye un shock externo al número de acreedores para las firmas que mantenían deuda con ambas instituciones al momento de la fusión. En este estudio encontramos que una fracción significativa de las firmas que sufrieron una reducción en el número de acreedores por efecto de la fusión, vuelve al número original de bancos con los que trabajaba antes de la fusión. En particular, la probabilidad de agregar un nuevo acreedor en los cinco años que siguen a la fusión es 23% mayor para las firmas cuyo número de bancos disminuye de dos a uno como resultado de la fusión, comparada con la probabilidad de agregar un nuevo acreedor para firmas similares cuyo número de bancos no fue afectado por la fusión. Adicionalmente, encontramos que una reducción en el número de bancos a consecuencia de dicha fusión reduce el acceso al crédito para las firmas afectadas. En particular, pasar de dos relaciones bancarias a una genera, en promedio, una reducción de 14.4% en el monto total prestado a estas empresas comparado con el monto prestado a empresas similares que no fueron afectadas por la fusión

    Reconfigurable antenna pattern verification

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    A method of verifying programmable antenna configurations is disclosed. The method comprises selecting a desired antenna configuration from a plurality of antenna configuration patterns, with the selected antenna configuration forming at least one reconfigurable antenna from reconfigurable antenna array elements. The method validates the formation of the selected antenna configuration to determine antenna performance of the at least one reconfigurable antenna

    Antenna reconfiguration verification and validation

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    A method of testing the electrical functionality of an optically controlled switch in a reconfigurable antenna is provided. The method includes configuring one or more conductive paths between one or more feed points and one or more test point with switches in the reconfigurable antenna. Applying one or more test signals to the one or more feed points. Monitoring the one or more test points in response to the one or more test signals and determining the functionality of the switch based upon the monitoring of the one or more test points

    Chemical Synthesis of the Fluorescent, Cyclic Dinucleotides c(th)GAMP

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    The cGAS-STING pathway is known for its role in sensing cytosolic DNA introduced by a viral infection, bacterial invasion or tumorigenesis. Free DNA is recognized by the cyclic GMP-AMP synthase (cGAS) catalyzing the production of 2',3'-cyclic guanosine monophosphate-adenosine monophosphate (2',3'-cGAMP) in mammals. This cyclic dinucleotide acts as a second messenger, activating the stimulator of interferon genes (STING) that finally triggers the transcription of interferon genes and inflammatory cytokines. Due to the therapeutic potential of this pathway, both the production and the detection of cGAMP via fluorescent moieties for assay development is of great importance. Here, we introduce the paralleled synthetic access to the intrinsically fluorescent, cyclic dinucleotides 2'3'-c(th)GAMP and 3'3'-c(th)GAMP based on phosphoramidite and phosphate chemistry, adaptable for large scale synthesis. We examine their binding properties to murine and human STING and confirm biological activity including interferon induction by 2'3'-c(th)GAMP in THP-1 monocytes. Two-photon imaging revealed successful cellular uptake of 2'3'-c(th)GAMP in THP-1 cells

    A Click-Chemistry Linked 2’3’-cGAMP Analog

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    2’3’-cGAMP is an uncanonical cyclic dinucleotide where one A and one G base are connected via a 3’-5’ and a unique 2’-5’ linkage. The molecule is produced by the cyclase cGAS in response to cytosolic DNA binding. cGAMP activates STING and hence one of the most powerful pathways of innate immunity. cGAMP analogs with uncharged linkages that feature better cellular penetrability are currently highly desired. Here, we report the synthesis of a cGAMP analog with one amide and one triazole linkage. The molecule is best prepared via a first Cu(I) catalysed click reaction which establishes the triazole, while the cyclization is achieved by macrolactamization

    European multidisciplinary consensus statement on the use and monitoring of metal-on-metal bearings for total hip replacement and hip resurfacing.

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    Summary Introduction There is an ongoing debate about the optimal use of metal-on-metal (MoM) bearings in total hip replacement, since there are uncertainties about local and systemic adverse effects due to wear and corrosion of these bearings. Despite various national recommendations, efforts to achieve international harmonization of specific evidence-based recommendations for best practice are still lacking. Hypothesis An international consensus study group should be able to develop recommendations on the use and monitoring of MoM bearings, preferably at the European level, through a multidisciplinary approach, by integrating the perspectives of various stakeholders. Materials and methods Twenty-one experts representing three stakeholder groups and eight countries participated in this European consensus study, which consisted of a consensus meeting, subsequent structured discussion, and consensus voting. Results The current statement defines first of all benefits, local and systemic risks, as well as uncertain issues related to MoM bearings. Safety assessment after implantation of MoM comprises all patients. A closer follow-up is recommended for large head MoM (≥ 36 mm) and resurfacing. In these implants basic follow-up should consist of x-rays and metal ion measurement of cobalt in whole blood, performed with GF-AAS or ICP-MS. Clinical and/or radiographic abnormality as well as elevated ion levels needs additional imaging (ultrasound, CT-scan and/or MARS-MRI). Cobalt values less than 2 μg/L are probably devoid of clinical concern, the threshold value for clinical concern is expected to be within the range of 2–7 μg/L. Discussion This is the first multinational, interdisciplinary, and multiprofessional approach for developing a recommendation for the use and monitoring of MoM bearings in total hip replacement. The current recommendations are in partial agreement with previous statements regarding the extent of follow-up and imaging techniques. They however differ from previous communications regarding measurement of metal ions and especially the investigated medium, technique, and eventual threshold levels. Level of evidence Level V, expert opinion/agreement conference
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