558 research outputs found

    Reciprocal transmittances and reflectances: An elementary proof

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    We present an elementary proof concerning reciprocal transmittances and reflectances. The proof is direct, simple, and valid for the diverse objects that can be absorptive and induce diffraction and scattering, as long as the objects respond linearly and locally to electromagnetic waves. The proof enables students who understand the basics of classical electromagnetics to grasp the physical basis of reciprocal optical responses. In addition, we show an example to demonstrate reciprocal response numerically and experimentally.Comment: 6 pages, 5 figures. RevTEX4. Improved wording. Physics Educatio

    Examples of inclusions of unital C\sp*-algebras of index-finite type with the Rokhlin property

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    In this note, we provide several examples of inclusions of unital C\sp*-algebras of index finite-type with the Rokhlin property lacking in literature and more importantly we construct the example which does not belong to the fixed point algebra model which means that for the inclusion PAP \subset A there is neither finite group action GA G \curvearrowright A such that P=AGP=A^{G} nor finite dimensional C\sp*- Hopf algebra action HAH \curvearrowright A such that P=AHP=A^{H}.Comment: 12pages, 1 figur

    Marine Cyanobacteria Compounds with Anticancer Properties: Implication of Apoptosis

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    Marine cyanobacteria have been proved to be an important source of potential anticancer drugs. Although several compounds were found to be cytotoxic to cancer cells in culture, the pathways by which cells are affected are still poorly elucidated. For some compounds, cancer cell death was attributed to an implication of apoptosis through morphological apoptotic features, implication of caspases and proteins of the Bcl-2 family, and other mechanisms such as interference with microtubules dynamics, cell cycle arrest and inhibition of proteases other than caspases

    JAK2/IDH-mutant–driven myeloproliferative neoplasm is sensitive to combined targeted inhibition

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    Patients with myeloproliferative neoplasms (MPNs) frequently progress to bone marrow failure or acute myeloid leukemia (AML), and mutations in epigenetic regulators such as the metabolic enzyme isocitrate dehydrogenase (IDH) are associated with poor outcomes. Here, we showed that combined expression of Jak2V617Fand mutant IDH1R132Hor Idh2R140Q induces MPN progression, alters stem/progenitor cell function, and impairs differentiation in mice. Jak2V617FIdh2R140Q–mutant MPNs were sensitive to small-molecule inhibition of IDH. Combined inhibition of JAK2 and IDH2 normalized the stem and progenitor cell compartments in the murine model and reduced disease burden to a greater extent than was seen with JAK inhibition alone. In addition, combined JAK2 and IDH2 inhibitor treatment also reversed aberrant gene expression in MPN stem cells and reversed the metabolite perturbations induced by concurrent JAK2 and IDH2 mutations. Combined JAK2 and IDH2 inhibitor therapy also showed cooperative efficacy in cells from MPN patients with both JAK2mutand IDH2mutmutations. Taken together, these data suggest that combined JAK and IDH inhibition May offer a therapeutic advantage in this high-risk MPN subtype.Damon Runyon Cancer Research Foundation (DRG-2241-15)Howard Hughes Medical Institute (Faculty Scholars Award)Stand Up To CancerNational Cancer Institute (U.S.) (P50CA165962)National Cancer Institute (U.S.) (P30CA14051)Koch Institute for Integrative Cancer Research ( Dana-Farber Harvard Cancer Center Bridge Project)Leukemia & Lymphoma Society of America. Specialized Center of Research (SCOR) ProgramNational Institutes of Health (U.S.) (grant U54OD020355-01)National Institutes of Health (U.S.) (grant NCI R01CA172636)National Institutes of Health (U.S.) (grant R35CA197594)National Cancer Institute (U.S.) (Cancer Center Support Grant (P30 CA008747)

    International multicenter observational study on assessment of ventilatory management during general anaesthesia for robotic surgery and its effects on postoperative pulmonary complication (AVATaR) : study protocol and statistical analysis plan

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    Introduction: Robotic-assisted surgery (RAS) has emerged as an alternative minimally invasive surgical option. Despite its growing applicability, the frequent need for pneumoperitoneum and Trendelenburg position could significantly affect respiratory mechanics during RAS. AVATaR is an international multicenter observational study aiming to assess the incidence of postoperative pulmonary complications (PPC), to characterise current practices of mechanical ventilation (MV) and to evaluate a possible association between ventilatory parameters and PPC in patients undergoing RAS. Methods and analysis: AVATaR is an observational study of surgical patients undergoing MV for general anaesthesia for RAS. The primary outcome is the incidence of PPC during the first five postoperative days. Secondary outcomes include practice of MV, effect of surgical positioning on MV, effect of MV on clinical outcome and intraoperative complications. Ethics and dissemination: This study was approved by the Institutional Review Board of the Hospital Israelita Albert Einstein. The study results will be published in peer-reviewed journals and disseminated at international conferences. Trial registration number: NCT02989415; Pre-results

    Novel Coagulation Test Detects Anticoagulation Resistance and Is Associated With Thrombotic Events in Pediatric Patients Requiring Extracorporeal Membrane Oxygenation

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    Objectives: Bivalirudin, an IV direct thrombin inhibitor, and unfractionated heparin (UFH) are frequently used anticoagulants in the pediatric critical care setting. An accurate, specific, point-of-care test to quantify and detect anticoagulation resistance is not currently available. This study evaluates the ability of a rapid (\u3c 10 min), micro-volume (\u3c 50 uL) coagulation test to detect and quantify the anticoagulation effect of bivalirudin and UFH using a functional, clot time endpoint in pediatric critical care patients. Design: Single-site retrospective laboratory sample analysis and chart review. Setting: A 105-bed pediatric and cardiac ICUs delivering extracorporeal membrane oxygenation. Subjects: Forty-one citrated, frozen, biobanked plasma specimens comprising 21 with bivalirudin and 20 with UFH from 15 anticoagulated pediatric patients were analyzed. Thirteen patients were on extracorporeal membrane oxygenation, one had a submassive pulmonary embolism, and one was on a left ventricular assist device. Interventions: None. Measurement and main results: A Clotting Time Score (CTS) was derived on each sample. The CTS detected patients that had developed a pathologic clotting event with 100% sensitivity and 82% specificity compared with prothrombin time with 25% sensitivity/76% specificity and activated partial thromboplastin time with 0% sensitivity/0% specificity. Additionally, the CTS detected subtherapeutic anticoagulation in response to UFH in patients that were clinically determined to be UFH resistant requiring alternative anticoagulation with bivalirudin. Conclusions: The CTS appears to be a clinically valuable indicator of coagulation status in patients treated with either UFH or bivalirudin. Results outside of the therapeutic range due to inadequate dosing or anticoagulation resistance appeared to be associated with clot formation. CTS testing may reduce the risk of anticoagulation-related complications via the rapid identification of patients at high risk for pathologic thrombotic events

    Software implementation of an Attribute-Based Encryption scheme

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    A ciphertext-policy attribute-based encryption protocol uses bilinear pairings to provide control access mechanisms, where the set of user\u27s attributes is specified by means of a linear secret sharing scheme. In this paper we present the design of a software cryptographic library that achieves record timings for the computation of a 126-bit security level attribute-based encryption scheme. We developed all the required auxiliary building blocks and compared the computational weight that each of them adds to the overall performance of this protocol. In particular, our single pairing and multi-pairing implementations achieve state-of-the-art time performance at the 126-bit security level

    Isolation, Synthesis, and Structure-Activity Relationship Study on Daphnane and Tigliane Diterpenes as HIV Latency-Reversing Agents

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    Three new diterpenes, stellejasmins A (1) and B (2) and 12-O-benzoylphorbol-13-heptanoate (3), were isolated from the roots of Stellera chamaejasme L. The structures of 1–3 were elucidated by extensive NMR and mass spectroscopic analyses. Compounds 1 and 2 are the first derivatives containing a hydroxy group at C-2 in the family of daphnane and tigliane diterpenes. The presence of a chlorine atom in 1 is unique in the plant metabolite. Compound 3 has an odd-number acyl group, which is biosynthetically notable. Human immunodeficiency virus (HIV) LTR-driven transcription activity was tested with 1–3 and 17 known diterpenes isolated from S. chamaejasme L. and Wikstroemia retusa A.Gray. Among these, gnidimacrin (4), stelleralide A (5), and wikstroelide A (20) were highly potent, with EC50 values of 0.14, 0.33, and 0.39 nM, respectively. The structure–activity relationship (SAR) was investigated using 20 natural and eight synthetic diterpenes. This is the first SAR study on natural daphnane and tigliane diterpenes.journal articl
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