2,568 research outputs found

    An Internationalized Stewardship of Urban Places

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    Metropolitan universities in the United States are driven by the intertwined missions of broadening educational access and serving their surrounding communities. International education historically has been placed somewhat apart from such missions. This separation has little justification in these globalized times, however--a realization that changes how such institutions might approach the civic engagement and stewardship at their core. Metropolitan areas must now be understood not only in terms of geographic proximity but also in terms of intersecting "spheres of engagement," from local to global. Cities, their universities, and the graduates they produce, must learn to operate across these spheres with skill, wisdom, and responsibility. The result is the internationalized academic stewardship of urban places discussed in this article

    Hybrid Unification in the Description Logic EL

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    Unification in Description Logics (DLs) has been proposed as an inference service that can, for example, be used to detect redundancies in ontologies. For the DL EL, which is used to define several large biomedical ontologies, unification is NP-complete. However, the unification algorithms for EL developed until recently could not deal with ontologies containing general concept inclusions (GCIs). In a series of recent papers we have made some progress towards addressing this problem, but the ontologies the developed unification algorithms can deal with need to satisfy a certain cycle restriction. In the present paper, we follow a different approach. Instead of restricting the input ontologies, we generalize the notion of unifiers to so-called hybrid unifiers. Whereas classical unifiers can be viewed as acyclic TBoxes, hybrid unifiers are cyclic TBoxes, which are interpreted together with the ontology of the input using a hybrid semantics that combines fixpoint and descriptive semantics. We show that hybrid unification in EL is NP-complete and introduce a goal-oriented algorithm for computing hybrid unifiers

    From colloidal dispersions of zeolite monolayers to effective solid catalysts in transformations of bulky organic molecules : role of freeze-drying and dialysis

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    We investigated the properties and catalytic activity of zeolites with MWW topology obtained by unprecedented liquid exfoliation of the MCM-56 zeolite into solutions of monolayers and isolation/reassembly of the dispersed layers by various methods, with optional purification by dialysis or ammonium exchange. The layers were recovered by flocculation with alcohol or ammonium nitrate and freeze-drying. Flocculation alone, even with ammonium nitrate, did not ensure removal of residual sodium cations resulting in catalysts with low activity. Dialysis of the solutions with dispersed monolayers proved to be efficient in removing sodium cations and preserving microporosity. The monolayers were also isolated as solids by freeze-drying. The highest BET area and pore volume obtained with the freeze-dried sample confirmed lyophilization efficiency in preserving layer structure. The applied test reaction, Friedel–Crafts alkylation of mesitylene, showed high benzyl alcohol conversion due to increased concentration of accessible acid centers caused by the presence of secondary mesoporosity. The applied treatments did not change the acid strength of the external acid sites, which are the most important ones for converting bulky organic molecules. Zeolite acidity was not degraded in the course of exfoliation into monolayers, showing the potential of such colloid dispersions for the formation of active catalysts

    The influence of Si/Al ratio on the distribution of OH groups in zeolites with MWW topology

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    A series of MWW-type zeolites of increasing Si/Al ratio were investigated with respect to their acidic properties. Concentration of the Brønsted acid centers located at the external crystal surface was invariant for the entire series. Ethanol conversion to ethyl-tert-butyl ether, proceeding only at the external surface, was also constant. The OH groups in MWW zeolites were found to be homogeneous with proton affinity value equal to 1142.7 kJ/mol

    Oral complaints in patients with acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation

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    Acute myeloid leukemia belongs to proliferative diseases of the hematopoietic system. It is currently the leading indication for allogeneic hematopoietic stem cell transplantation. This study was designed to determine the most common subjective oral mucosa complaints in patients with acute myeloid leukemia after allogeneic hematopoietic cell transplantation, in relation to the type of conditioning used. Eighty patients diagnosed with acute myeloid leukemia were assigned to two groups depending on the intensity of the conditioning regimen before transplantation: myeloablative and reduced-intensity chemotherapy. The oral symptoms were evaluated based on an authorial questionnaire designed for this analysis. The following oral mucosa subjective complaints were included: pain, paraesthesia, burning mouth sensation, taste disorders, excessive salivation, halitosis, and dryness of the oral mucosa. The most commonly reported subjective oral complaint in the examined patients was xerostomia, which was found in 92% of patients during the second visit, followed by spontaneous pain in the mouth (55%), burning (36%), and dysgeusia (20%). It occurred significantly more frequently in patients who underwent myeloablative conditioning. Moreover, it was observed that the frequency of complaints increased considerably after the transplantation, reaching a peak intensity during the second week following the procedure. Oral complaints significantly decrease the patients' quality of life during the transplantation and may lead to premature termination of the treatment. As the number of transplantations in patients with acute myeloid leukemia increases, further investigations of oral complaints and symptoms induced by the disease itself and by the therapeutic approaches are required

    The structure-catalytic activity relationship for the transient layered zeolite MCM-56 with MWW topology

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    Zeolite MCM-56 is a high alumina, monolayered form of the commercially useful framework MWW but it is a transient product during crystallization, so many factors influence its state and quality. This work examines properties of a series of MCM-56 and MCM-49 samples synthesized for different times using Aerosil, Ultrasil and Ludox as silica sources, hexamethyleneimine as the structure directing agent and additionally aniline as structure promoting agent. It was found that the most important parameter, governing the catalytic activity in the test reaction of Friedel-Crafts alkylation of mesitylene with benzyl alcohol, was availability of the Brønsted acid centers located at the external surfaces of the crystals. The key role in correlating physical characteristic with activity was played by infrared spectroscopy as it enabled the study of many properties of the tested materials, starting from the total concentration of acid centers, and their type (Brønsted or Lewis acids) through the concentration of centers available for the reagent molecules, to investigating the correlation of acidity with the degree of zeolite crystallinity

    New psychological therapies for Irritable Bowel Syndrome:Mindfulness and acceptance and commitment therapy (ACT)

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    The current goal of treatment in irritable bowel syndrome (IBS) focuses primarily on symptom management and attempts to improve quality of life. Several treatments are at the disposal of physicians; lifestyle and dietary management, pharmacological treatments and psychological interventions are the most used and recommended. Psychological treatments have been proposed as viable alternatives or compliments to existing care models. Most forms of psychological therapies studied have been shown to be helpful in reducing symptoms and in improving the psychological component of anxiety/depression and health-related quality of life. According to current NICE/NHS guidelines, physicians should consider referral for psychological treatment in patients who do not respond to pharmacotherapy for a period of 12 months and develop a continuing symptom profile (described as refractory irritable bowel syndrome). Cognitive behavioral therapy (CBT) is the best studied treatment and seems to be the most promising therapeutic approach. However, some studies have challenged the effectiveness of this therapy for irritable bowel syndrome. One study concluded that cognitive behavioral therapy is no more effective than attention placebo control condition and another study showed that the beneficial effects wane after six months of follow-up. A review of mind/body approaches to irritable bowel syndrome has therefore suggested that alternate strategies targeting mechanisms other than thought content change might be helpful, specifically mindfulness and acceptance-based approaches. In this article we review these new psychological treatment approaches in an attempt to raise awareness of alternative treatments to gastroenterologists that treat this clinical syndrome

    Keyed User Datagram Protocol: Concepts and Operation of an Almost Reliable Connectionless Transport Protocol

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    Departing from the well-known problem of the excessive overhead and latency of connection oriented protocols, this paper describes a new almost reliable connectionless protocol that uses user datagram protocol (UDP) segment format and is UDP compatible. The problem is presented and described, the motivation, the possible areas of interest and the concept and base operation modes for the protocol named keyed UDP are presented (here called KUDP). Also, discussed are some of the possible manners in which the KUDP can be used, addressing potential problems related with current networking technologies. As UDP is a connectionless protocol, and KUDP allows for some degree of detection of loss and re-ordering of segments received out-of-sequence, we also present a proposal for a stream reconstruction algorithm. This paper ends by mentioning some of the research issues that still need to be addressed.info:eu-repo/semantics/publishedVersio

    Pulmonary Surfactant Lipid Reorganization Induced by the Adsorption of the Oligomeric Surfactant Protein B Complex

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    Surfactant protein B (SP-B) is essential in transferring surface-active phospholipids from membrane-based surfactant complexes into the alveolar air-liquid interface. This allows maintaining the mechanical stability of the surfactant film under high pressure at the end of expiration; therefore, SP-B is crucial in lung function. Despite its necessity, the structure and the mechanism of lipid transfer by SP-B have remained poorly characterized. Earlier, we proposed higher-order oligomerization of SP-B into ring-like supramolecular assemblies. In the present work, we used coarse-grained molecular dynamics simulations to elucidate how the ring-like oligomeric structure of SP-B determines its membrane binding and lipid transfer. In particular, we explored how SP-B interacts with specific surfactant lipids, and how consequently SP-B reorganizes its lipid environment to modulate the pulmonary surfactant structure and function. Based on these studies, there are specific lipid-protein interactions leading to perturbation and reorganization of pulmonary surfactant layers. Especially, we found compelling evidence that anionic phospholipids and cholesterol are needed or even crucial in the membrane binding and lipid transfer function of SP-B. Also, on the basis of the simulations, larger oligomers of SP-B catalyze lipid transfer between adjacent surfactant layers. Better understanding of the molecular mechanism of SP-B will help in the design of therapeutic SP-B-based preparations and novel treatments for fatal respiratory complications, such as the acute respiratory distress syndrome. (C) 2020 The Author(s). Published by Elsevier Ltd.Peer reviewe
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