Transition metal-free cycloisomerization of propargylic amides to oxazoles in hexafluoroisopropanol (HFIP)

A transition metal-free method for the cycloisomerization of propargylic amides to oxazoles was developed. The reaction utilizes in situ generated hydrogen chloride in hexafluoroisopropanol (HFIP). With the aid of Design of Experiments optimization a wide range of substrates was transformed into the desired oxazoles. The method allows product formation without side reactions eliminating the need for extensive work-up and purification

Entwicklung Übergangsmetall-freier Cycloisomerisierungen in Hexafluorisopropanol

Die zielgerichtete Entwicklung Metall-freier Reaktionen, um damit Übergangsmetalle in chemischen Prozessen zu substituieren, ist Thema aktueller Forschung. Dies hat den Hintergrund, dass Metall-Kontaminationen in Erzeugnissen der Industrie stark reguliert sind, da sie das Potential bergen, Menschen und Umwelt zu schädigen. Zudem wenden sich viele Zweige der Industrie nachhaltigeren Prozessen zu. Metalle sind in dieser Hinsicht ambivalent, da sie zwar sehr gut rezykliert werden können, aber die Gewinnung und Reinigung mit Belastungen verbunden ist. Diese Arbeit zeigt eine Möglichkeit auf, wie typischerweise Metall-katalysierte Reaktionen durch BRØNSTEDT-Säuren ersetzbar sind. Dazu wird das von AUBÉ publizierte System von Acetylchlorid (AcCl) in Hexafluorisopropanol (HFIP) verwendet und auf Trimethylsilylchlorid (TMSCl) erweitert. Die Reaktion der beiden Reagenzien mit HFIP erzeugt in situ HCl. Dieses kann genutzt werden um Propargylamide zu cyclisieren. Für Propargylamide mit terminalen Dreifachbindungen werden Oxazole (und ihre Hydrochloride) gewonnen, die Reaktion von Propargylamiden mit internen Dreifachbindungen ergeben in der Mehrzahl Oxazoline mit (Z) konfigurierten exo-ständigen Doppelbindung

Enhancing Scholarly Publications: Developing Hybrid Monographs in the Humanities and Social Sciences

Enhancing publications has a long history but is gaining acceleration as authors and publishers explore electronic tablets as devices for dissemination and presentation. Enhancement of scholarly publications, in contrast, more often takes place in a Web environment and is coupled with presentation of supplementary materials related to research. The approach to enhancing scholarly publications presented in this article goes a step further and involves the interlinking of the “objects” of a document: datasets, supplementary materials, secondary analyses, and post-publication interventions. This approach connects the user-centricity of Web 2.0 with the Semantic Web. It aims at facilitating long-term content structure through standardized formats intended to improve interoperability between concepts and terms within and across knowledge domains. We explored this conception of enhancement on a small set of books prepared for traditional academic publishers. While the project was primarily an exercise in development, the conclusion section of the article reflects on areas where conceptual and empirical studies could be initiated to complement this new direction in scholarly publishing.&nbsp

IMPACT: The Journal of the Center for Interdisciplinary Teaching and Learning. Volume 8, Issue 1, Winter 2019

IMPACT: The Journal of the Center for Interdisciplinary Teaching & Learning is a peer-reviewed, biannual online journal that publishes scholarly and creative non-fiction essays about the theory, practice and assessment of interdisciplinary education. Impact is produced by the Center for Interdisciplinary Teaching & Learning at the College of General Studies, Boston University (www.bu.edu/cgs/citl).In this issue of Impact you will find a humanities scholar deeply engaged with the arcing out of a new territory: the interdisciplinary study of the Grateful Dead. Impact’s own Christopher Coffman’s review essay should be required reading for scholars of popular music, performance studies and history. His review also serves as an important reference for those who aspire to teach a course on the Grateful Dead, as well as for those who wish to write review essays. In this issue we also hear from those who are engaged in teaching people who are incarcerated. Importantly, Stephanie Cage’s essay looks to incarcerated people themselves to find out what they think about prison education. Peter Wakefield encourages us to see The Great Gatsby anew, in particular in the context of American racism and White supremacy. Wakefield’s essay is important too because it had its genesis in Writing, the State, and the Rise of Neo-Nationalism: Historical Contexts and Contemporary Concerns, a conference sponsored by the Center for Interdisciplinary Teaching & Learning

Penile Fracture with Associated Urethral Rupture

Penile fracture of the erect penis is an uncommon but emergent urological trauma. Potential outcomes include erectile dysfunction, penile curvature, and urethral injury. Treatment is emergent surgical repair. We present the case of a 42-year-old man with a penile fracture complicated by a urethral rupture and subsequent repair. A discussion of the key aspects of this condition is presented

Radiological findings in patients undergoing revision endoscopic sinus surgery: a retrospective case series study

<p>Abstract</p> <p>Background</p> <p>Functional endoscopic sinus surgery (FESS) is now a well-established strategy for the treatment of chronic rhinosinusitis which has not responded to medical treatment. There is a wide variation in the practice of FESS by various surgeons within the UK and in other countries.</p> <p>Objectives</p> <p>To identify anatomic factors that may predispose to persistent or recurrent disease in patients undergoing revision FESS.</p> <p>Methods</p> <p>Retrospective review of axial and coronal CT scans of patients undergoing revision FESS between January 2005 and November 2008 in a tertiary referral centre in South West of England.</p> <p>Results</p> <p>The CT scans of 63 patients undergoing revision FESS were reviewed. Among the patients studied, 15.9% had significant deviation of the nasal septum. Lateralised middle turbinates were present in 11.1% of the studied sides, and residual uncinate processes were identified in 57.1% of the studied sides. There were residual cells in the frontal recess in 96% of the studied sides. There were persistent other anterior and posterior ethmoidal cells in 92.1% and 96% of the studied sides respectively.</p> <p>Conclusions</p> <p>Analysis of CT scans of patients undergoing revision FESS shows persistent structures and non-dissected cells that may be responsible for persistence or recurrence of rhinosinusitis symptoms. Trials comparing the outcome of conservative FESS techniques with more radical sinus dissections are required.</p

Identification of Lineage-Uncommitted, Long-Lived, Label-Retaining Cells in Healthy Human Esophagus and Stomach, and in Metaplastic Esophagus

Background & Aims The existence of slowly cycling, adult stem cells has been challenged by the identification of actively cycling cells. We investigated the existence of uncommitted, slowly cycling cells by tracking 5-iodo-2'-deoxyuridine (IdU) label-retaining cells (LRCs) in normal esophagus, Barrett's esophagus (BE), esophageal dysplasia, adenocarcinoma, and healthy stomach tissues from patients. Methods Four patients (3 undergoing esophagectomy, 1 undergoing esophageal endoscopic mucosal resection for dysplasia and an esophagectomy for esophageal adenocarcinoma) received intravenous infusion of IdU (200 mg/m2 body surface area; maximum dose, 400 mg) over a 30-minute period; the IdU had a circulation half-life of 8 hours. Tissues were collected at 7, 11, 29, and 67 days after infusion, from regions of healthy esophagus, BE, dysplasia, adenocarcinoma, and healthy stomach; they were analyzed by in situ hybridization, flow cytometry, and immunohistochemical analyses. Results No LRCs were found in dysplasias or adenocarcinomas, but there were significant numbers of LRCs in the base of glands from BE tissue, in the papillae of the basal layer of the esophageal squamous epithelium, and in the neck/isthmus region of healthy stomach. These cells cycled slowly because IdU was retained for at least 67 days and co-labeling with Ki-67 was infrequent. In glands from BE tissues, most cells did not express defensin-5, Muc-2, or chromogranin A, indicating that they were not lineage committed. Some cells labeled for endocrine markers and IdU at 67 days; these cells represented a small population (<0.1%) of epithelial cells at this time point. The epithelial turnover time of the healthy esophageal mucosa was approximately 11 days (twice that of the intestine). Conclusions LRCs of human esophagus and stomach have many features of stem cells (long lived, slow cycling, uncommitted, and multipotent), and can be found in a recognized stem cell niche. Further analyses of these cells, in healthy and metaplastic epithelia, is required

Nucleus reuniens of the thalamus contains head direction cells

Discrete populations of brain cells signal heading direction, rather like a compass. These ‘head direction’ cells are largely confined to a closely-connected network of sites. We describe, for the first time, a population of head direction cells in nucleus reuniens of the thalamus in the freely-moving rat. This novel subcortical head direction signal potentially modulates the hippocampal CA fields directly and, thus, informs spatial processing and memor