359 research outputs found

    The Brigham City Co-Op: Case Study of an Efficient Economic and Social Institution

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    The leaders of the Church of Jesus Christ of Latter-day Saints raced a twin dilemma in the years between 1868 to 1874. The specter of non-Mormon infiltration of society and destruction of the Mormon empire loomed menacingly on the horizon, and internal divisions and inequities threatened to destroy the religious ideals of unity and equality fostered by Mormons since the time of Joseph Smith, Jr. This twin crisis led Mormon leaders to institute church-wide economic and social programs of reform, culminating in 1874 with the establishment of the Second United Order of Enoch

    Bioinorganic Chemistry

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    This book covers material that could be included in a one-quarter or one-semester course in bioinorganic chemistry for graduate students and advanced undergraduate students in chemistry or biochemistry. We believe that such a course should provide students with the background required to follow the research literature in the field. The topics were chosen to represent those areas of bioinorganic chemistry that are mature enough for textbook presentation. Although each chapter presents material at a more advanced level than that of bioinorganic textbooks published previously, the chapters are not specialized review articles. What we have attempted to do in each chapter is to teach the underlying principles of bioinorganic chemistry as well as outlining the state of knowledge in selected areas. We have chosen not to include abbreviated summaries of the inorganic chemistry, biochemistry, and spectroscopy that students may need as background in order to master the material presented. We instead assume that the instructor using this book will assign reading from relevant sources that is appropriate to the background of the students taking the course. For the convenience of the instructors, students, and other readers of this book, we have included an appendix that lists references to reviews of the research literature that we have found to be particularly useful in our courses on bioinorganic chemistry

    Mapping the Human Plasma Proteome by SCX-LC-IMS-MS

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    The advent of on-line multidimensional liquid chromatography-mass spectrometry has significantly impacted proteomic analyses of complex biological fluids such as plasma. However, there is general agreement that additional advances to enhance the peak capacity of such platforms are required to enhance the accuracy and coverage of proteome maps of such fluids. Here, we describe the combination of strong-cation-exchange and reversed-phase liquid chromatographies with ion mobility and mass spectrometry as a means of characterizing the complex mixture of proteins associated with the human plasma proteome. The increase in separation capacity associated with inclusion of the ion mobility separation leads to generation of one of the most extensive proteome maps to date. The map is generated by analyzing plasma samples of five healthy humans; we report a preliminary identification of 9087 proteins from 37,842 unique peptide assignments. An analysis of expected false-positive rates leads to a high-confidence identification of 2928 proteins. The results are catalogued in a fashion that includes positions and intensities of assigned features observed in the datasets as well as pertinent identification information such as protein accession number, mass, and homology score/confidence indicators. Comparisons of the assigned features reported here with other datasets shows substantial agreement with respect to the first several hundred entries; there is far less agreement associated with detection of lower abundance components

    Just picking it up? Young children learning with technology at home

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    We describe a two-year empirical investigation of three- and four-year-old children's uses of technology at home, based on a survey of 346 families and 24 case studies. Using a sociocultural approach, we discuss the range of technologies children encounter in the home, the different forms their learning takes, the roles of adults and other children, and how family practices support this learning. Many parents believed that they do not teach children how to use technology. We discuss parents' beliefs that their children 'pick up' their competences with technology and identify trial and error, copying and demonstration as typical modes of learning. Parents tend to consider that their children are mainly self-taught and underestimate their own role in supporting learning and the extent to which learning with technology is culturally transmitted within the family

    Hand ischemia associated with elbow trauma in children

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    ObjectivesPrevious observational studies suggest that children with hand ischemia following elbow trauma can be safely observed if Doppler signals are present in the wrist arteries (pink pulseless hand, PPH). Nonoperative management of PPH is predicated on the assumption that PPH results from local arterial spasm, but the mechanism of arterial compromise has not been investigated. We hypothesized that PPH signifies a brachial artery injury that requires surgical repair.MethodsRetrospective review of operations performed on children with hand ischemia following elbow trauma at a level I trauma center pediatric hospital.ResultsBetween 2003 and 2010, 12 children (seven males, mean age 7.4 years) underwent brachial artery exploration for hand ischemia following elbow trauma (11 supracondylar fractures, one elbow dislocation) due to falls (n = 10) or motor vehicle crashes (n = 2). At presentation, three subjects had normal radial pulses, eight subjects had Doppler signals but no palpable pulses, and one had weak Doppler flow with advanced hand ischemia. Six of the nine subjects without palpable pulses also had neurosensory changes. All 12 subjects underwent brachial artery exploration either initially (n = 2) or following orthopedic fixation (n = 10) due to persistent pulselessness. At operation, eight of 12 patients (67%) had focal brachial artery thrombosis due to intimal flaps, and four had brachial artery and median nerve entrapment within the pinned fracture site. At discharge, all 12 subjects had palpable radial pulses, but three with entrapment had dense median nerve deficits. One of the three subjects with dense neurologic deficit had complete recovery of neurologic function at ten months. The other two subjects had residual median nerve deficits with partial recovery at 5 and 6 months follow-up, respectively. No patient developed Volkman's contracture.ConclusionsBrachial artery injuries should be anticipated in children with hand ischemia associated with elbow trauma. Neurovascular entrapment at the fracture site is a possible complication of orthopedic fixation. Absence of palpable wrist pulses after orthopedic fixation should prompt immediate brachial artery exploration. PPH should not be considered a consequence of arterial spasm in these patients

    Accuracy and utility of three-dimensional contrast-enhanced magnetic resonance angiography in planning carotid stenting

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    BackgroundContrast-enhanced magnetic resonance angiography (CE-MRA) is a proven diagnostic tool for the evaluation of carotid stenosis; however, its utility in planning carotid artery stenting (CAS) has not been addressed. This study assessed the accuracy of three-dimensional CE-MRA as a noninvasive screening tool, compared with digital subtraction angiography (DSA), for evaluating carotid and arch morphology before CAS.MethodsIn a series of 96 CAS procedures during a 2-year period, CE-MRAs and DSAs with complete visualization from the aortic arch to the intracranial circulation were obtained before CAS in 60 patients. Four additional patients, initially considered potential candidates for CAS, were also evaluated with CE-MRA and DSA. The two-by-two table method, receiver operating characteristic curve, and Bland-Altman analyses were used to characterize the ability of CE-MRA to discriminate carotid and arch anatomy, suitability for CAS, and degree of carotid stenosis.ResultsThe sensitivity and specificity of CE-MRA were, respectively, 100% and 100% to determine CAS suitability, 87% and 100% to define aortic arch type, 93% and 100% to determine severe carotid tortuosity, and 75% and 98% to detect ulcerated plaques. CE-MRA had 87% sensitivity and 100% specificity for the detection of carotid stenosis ≥80%. The accuracy of CE MRA to determine optimal imaging angles and stent and embolic protection device sizes was >90%. The operative technique for CAS was altered because of the findings of preoperative CE-MRA in 22 procedures (38%). The most frequent change in the operative plan was the use of the telescoping technique in 11 cases (18%). CAS was aborted in four patients (5%) due to unfavorable anatomy identified on CE-MRA, including prohibitive internal carotid artery tortuosity (n = 1), long string sign of the internal carotid artery (n = 2), and concomitant intracranial disease (n = 1). Among patients considered suitable for CAS by CE-MRA, technical success was 100%, and the 30-day stroke/death rate was 1.6%.ConclusionsContrast-enhanced magnetic resonance angiography of the arch and carotid arteries is accurate in determining suitability for CAS and may alter the operative technique. Certain anatomic contraindications for CAS may be detected without DSA. Although CE-MRA is less accurate to estimate the degree of stenosis, it can accurately predict imaging angles, and stent and embolic protection device size, which may facilitate safe and expeditious CAS

    Slow magnetic relaxation in Fe(ii) m-terphenyl complexes

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    Two-coordinate transition metal complexes are exciting candidates for single-molecule magnets (SMMs) because their highly axial coordination environments lead to sizeable magnetic anisotropy. We report a series of five structurally related two-coordinate Fe(II) m-terphenyl complexes (4-R-2,6-Xyl2C6H2)2Fe [R = tBu (1), SiMe3 (2), H (3), Cl (4), CF3 (5)] where, by changing the functionalisation of the para-substituent (R), we alter their magnetic function. All five complexes are field-induced single-molecule magnets, with relaxation rates that are well-described by a combination of direct and Raman mechanisms. By using more electron donating R groups we were able to slow the rate of magnetic relaxation. Our ab initio calculations predict a large crystal field splitting (>850 cm−1) and sizeable zero-field splitting parameters (ca. −60 cm−1, |E| < 0.2 cm−1) for 1–5. These favourable magnetic properties suggest that m-terphenyl ligands have untapped potential as chemically versatile ligands able to impose highly axial crystal fields

    Oxidation of cadaverine by putrescine oxidase from Rhodococcus erythropolis

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    BACKGROUNDPutrescine oxidase (EC 1.4.3.10) is of interest for the microbial production of unsubstituted platform nitrogen (N-)heterocycles, because it only requires inexpensive oxygen as co-substrate. Putrescine oxidase from Rhodococcus erythropolis (Re-PuO) was shown previously to catalyze the oxidation of cadaverine; however, there is little information in the literature about the robustness of this enzyme for biotechnological applications. The aim of this study was to investigate the suitability of Re-PuO for the bioproduction of 1-piperideine from cadaverine under different reaction conditions.RESULTSThe formation of 1-piperideine catalyzed by Re-PuO was demonstrated using o-aminobenzaldehyde as a reagent to trap the cyclic imine and shift the equilibrium for cyclization. A direct assay of Re-PuO activity for cadaverine oxidation was then implemented, by monitoring oxygen consumption. Characterization of the reaction mixture by 1H NMR and mass spectrometry confirmed the presence of piperideine dimers and trimers, yet the quantification of the reaction products could not be achieved. The optimum temperature and pH conditions for enzyme activity were determined as 55 °C and 8.5, respectively. At pH 7.5, the enzyme retained its activity after 65 h incubation at 25 °C, but lost 75% of its activity after 1 h incubation at 55 °C. The enzyme showed no substrate inhibition at concentrations as high as 100 mmol L–1 cadaverine. Complete biotransformation of cadaverine was observed in whole cells at physiological conditions.CONCLUSIONSThese results successfully demonstrate the potential of putrescine oxidase for the bioproduction of N-heterocycles from cadaverine. © 2021 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI)

    A Database of Alkaline-Earth-Coordinated Peptide Cross Sections: Insight into General Aspects of Structure

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    Abstract. A database of 1470 collision cross sections (666 doubly-and 804 triplycharged) of alkaline-earth-coordinated tryptic peptide ions [where the cation (M 2+ ) correspond to Mg 2+ , Ca 2+ , or Ba 2+ ] is presented. The utility of such an extensive set of measurements is illustrated by extraction of general properties of M 2+ -coordinated peptide structures. Specifically, we derive sets of intrinsic size parameters (ISPs) for individual amino acid residues for M 2+ -coordinated peptides. Comparison of these parameters with existing ISPs for protonated peptides suggests that M 2+ binding occurs primarily through interactions with specific polar aliphatic residues (Asp, Ser, and Thr) and the peptide backbone. A comparison of binding interactions for these alkaline-earth metals with interactions reported previously for alkali metals is provided. Finally, we describe a new analysis in which ISPs are used as probes for assessing peptide structure based on amino acid composition
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