bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Octahedral, Head–Tail Iron(II) Complexes with Spin Crossover Properties
Authors: Schlamp Stephan , Thoma Peter , Weber Birgit 
Published: December 2011

AbstractThe synthesis and characterisation of four new Schiff base‐like ligands with long alkyl chains in the outer periphery and their iron(II) complexes with methanol and pyridine as axial ligands is reported. Two of the methanol complexes crystallise in a lipid layer‐like arrangement with the alkyl chain (tail) packed in the middle and the iron centres (head) in the outer sites. The pyridine complexes show varying types of spin transition (step wise, incomplete, with hysteresis), which depends on the alkyl chain length and substituents in the outer periphery of the ligand. Investigations in solution using 1H NMR spectroscopy demonstrate that the differences in the spin transition behaviour are due to packing effects as the same transition curve is obtained independently of the alkyl chain length.
Spontaneous transformation of murine epithelial cells requires the early acquisition of specific chromosomal aneuploidies and genomic imbalances
Authors: Padilla‐Nash Hesed M. , Hathcock Karen , McNeil Nicole E. , Mack David , Hoeppner Daniel , Ravin Rea , Knutsen Turid , Yonescu Raluca , Wangsa Danny , Dorritie Kathleen , Barenboim Linda , Hu Yue , Ried Thomas 
Published: December 2011

AbstractHuman carcinomas are defined by recurrent chromosomal aneuploidies, which result in a tissue‐specific distribution of genomic imbalances. In order to develop models for these genome mutations and to determine their role in tumorigenesis, we generated 45 spontaneously transformed murine cell lines from normal epithelial cells derived from bladder, cervix, colon, kidney, lung, and mammary gland. Phenotypic changes, chromosomal aberrations, centrosome number, and telomerase activity were assayed in control uncultured cells and in three subsequent stages of transformation. Supernumerary centrosomes, binucleate cells, and tetraploidy were observed as early as 48 hr after explantation. In addition, telomerase activity increased throughout progression. Live‐cell imaging revealed that failure of cytokinesis, not cell fusion, promoted genome duplication. Spectral karyotyping demonstrated that aneuploidy preceded immortalization, consisting predominantly of whole chromosome losses (4, 9, 12, 13, 16, andY) and gains (1, 10, 15, and 19). After transformation, focal amplifications of the oncogenesMycandMdm2were frequently detected. Fifty percent of the transformed lines resulted in tumors on injection into immunocompromised mice. The phenotypic and genomic alterations observed in spontaneously transformed murine epithelial cells recapitulated the aberration pattern observed during human carcinogenesis. The dominant aberration of these cell lines was the presence of specific chromosomal aneuploidies. We propose that our newly derived cancer models will be useful tools to dissect the sequential steps of genome mutations during malignant transformation, and also to identify cancer‐specific genes, signaling pathways, and the role of chromosomal instability in this process. © 2011 Wiley Periodicals, Inc.
WNT5A is induced by inflammatory mediators in bone marrow stromal cells and regulates cytokine and chemokine production
Authors: Rauner Martina , Stein Nicola , Winzer Maria , Goettsch Claudia , Zwerina Jochen , Schett Georg , Distler Jörg HW , Albers Joachim , Schulze Jochen , Schinke Thorsten , Bornhäuser Martin , Platzbecker Uwe , Hofbauer Lorenz C 
Published: December 2011

Abstract
WNT5A has recently been implicated in inflammatory processes, but its role as a bone marrow stromal cell (BMSC)–derived mediator of joint inflammation in arthritis is unclear. Here, we investigated whether inflammatory stimuli induce WNT5A in BMSC to control inflammatory responses. WNT5A levels were determined in human BMSC after stimulation with lipopolysaccharide (LPS) or tumor necrosis factor α (TNF-α,) and in synovial cells and tissue of patients with rheumatoid arthritis (RA) and human TNF-α transgenic (hTNFtg) mice. A microarray analysis of WNT5A-treated murine osteoblasts was performed using Affymetrix gene chips. The regulation of cytokine/chemokine expression was confirmed by qPCR, ELISA, and Luminex technology in BMSC after stimulation with WNT5A or WNT5A knockdown. Relevant signaling pathways were identified using specific inhibitors. Migration of MACS-purified T lymphocytes and monocytes was assessed using the FluoroBlok system. WNT5A expression was increased threefold in BMSC after stimulation with LPS or TNF-α. Synovial fibroblasts from patients with RA showed a twofold increase of WNT5A expression compared with control cells, and its expression was highly induced in the synovial tissue of patients with RA and hTNFtg mice. Microarray analysis of WNT5A-treated osteoblasts identified cytokines and chemokines as targets. The induction of IL-1β, IL-6, CCL2, CCL5, CXCL1, and CXCL5 by WNT5A was confirmed in BMSC and depended on the activation of the NF-κB, mitogen-activated protein (MAPK), and Akt pathways. Accordingly, knockdown of WNT5A markedly reduced the basal and LPS-induced cytokine/chemokine production. Finally, migration of monocytes and T cells toward the supernatant of WNT5A-treated BMSC was increased by 25% and 20%, respectively. This study underlines the critical role of BMSC-derived WNT5A in the regulation of inflammatory processes and suggests its participation in the pathogenesis of RA. © 2012 American Society for Bone and Mineral Research.
Effects of disease-modifying antirheumatic drugs on nonvertebral fracture risk in rheumatoid arthritis: A population-based cohort study
Authors: Kim Seo Young , Schneeweiss Sebastian , Liu Jun , Solomon Daniel H 
Published: December 2011

Abstract
Several prior investigations demonstrate an improvement in bone mineral density associated with use of tumor necrosis factor inhibitors (TNFi). We compared the risk of osteoporotic fractures among patients with rheumatoid arthritis (RA) initiating a disease-modifying antirheumatic drug (DMARD). A population-based cohort study was conducted using health care utilization data (1996–2008) from a Canadian province and a U.S. commercial insurance plan. Patients with at least two RA diagnoses were identified, and follow-up began with the first prescription for a DMARD. Drug regimens were categorized into three mutually exclusive hierarchical groups: (1) TNFi with or without nonbiologic DMARDs (nbDMARD), (2) methotrexate (MTX) without a TNFi, or (3) other nbDMARD without a TNFi or MTX. Main outcomes were hospitalizations for fractures of the hip, wrist, humerus, or pelvis based on diagnoses and procedure codes. The study cohort consisted of 16,412 RA patients with 25,988 new treatment episodes: 5856 TNFi, 12,554 MTX, and 7578 other nbDMARD. The incidence rate per 1000 person-years for osteoporotic fracture were 5.11 [95% confidence interval (CI) 3.50–7.45] for TNFi, 5.35 (95% CI 4.08–7.02) for MTX, and 6.38 (95% CI 3.78–10.77) for other nbDMARD. After multivariable adjustment for osteoporosis and fracture-related risk factors, the risk of nonvertebral osteoporotic fracture was not different in either TNFi [hazard ratio (HR) 1.07, 95% CI 0.57–1.98] or MTX (HR 1.18, 95% CI 0.60–2.34) compared with nbDMARD. Among subjects diagnosed with RA, the adjusted risk of nonvertebral fracture was similar across persons starting a TNFi, MTX, or other nbDMARD. © 2012 American Society for Bone and Mineral Research.
Parathyroid hormone treatment improves the cortical bone microstructure by improving the distribution of type I collagen in postmenopausal women with osteoporosis
Authors: Ascenzi Maria-Grazia , Liao Vivian P , Lee Brittany M , Billi Fabrizio , Zhou Hua , Lindsay Robert , Cosman Felicia , Nieves Jeri , Bilezikian John P , Dempster David W 
Published: December 2011

Abstract
Although an important index, the level of bone mineral density (BMD) does not completely describe fracture risk. Another bone structural parameter, the orientation of type I collagen, is known to add to risk determination, independently of BMD, ex vivo. We investigated the Haversian system of transiliac crest biopsies from postmenopausal women before and after treatment with parathyroid hormone (PTH). We used the birefringent signal of circularly polarized light and its underlying collagen arrangements by confocal and electron microscopy, in conjunction with the degree of calcification by high-resolution micro-X-ray. We found that PTH treatment increased the Haversian system area by 11.92 ± 5.82 mm2 to 12.76 ± 4.50 mm2 (p = 0.04); decreased bright birefringence from 0.45 ± 0.02 to 0.40 ± 0.01 (scale zero to one, p = 0.0005); increased the average percent area of osteons with alternating birefringence from 48.15% ± 10.27% to 66.33% ± 7.73% (p = 0.034); and nonsignificantly decreased the average percent area of semihomogeneous birefringent osteons (8.36% ± 10.63% versus 5.41% ± 9.13%, p = 0.40) and of birefringent bright osteons (4.14% ± 8.90% versus 2.08% ± 3.36%, p = 0.10). Further, lamellar thickness significantly increased from 3.78 ± 0.11 µm to 4.47 ± 0.14 µm (p = 0.0002) for bright lamellae, and from 3.32 ± 0.12 µm to 3.70 ± 0.12 µm (p = 0.045) for extinct lamellae. This increased lamellar thickness altered the distribution of birefringence and therefore the distribution of collagen orientation in the tissue. With PTH treatment, a higher percent area of osteons at the initial degree of calcification was observed, relative to the intermediate-low degree of calcification (57.16% ± 3.08% versus 32.90% ± 3.69%, p = 0.04), with percentage of alternating osteons at initial stages of calcification increasing from 19.75 ± 1.22 to 80.13 ± 6.47, p = 0.001. In conclusion, PTH treatment increases heterogeneity of collagen orientation, a starting point from which to study the reduction in fracture risk when PTH is used to treat osteoporosis. © 2012 American Society for Bone and Mineral Research
Graphene‐coated fiber for solid‐phase microextraction of triazine herbicides in water samples
Authors: Wu Qiuhua , Feng Cheng , Zhao Guangying , Wang Chun , Wang Zhi 
Published: December 2011

AbstractGraphene is a novel and interesting carbon material that could be used for the separation and purification of some chemical compounds. In this investigation, graphene was used as a novel fiber‐coating material for the solid‐phase microextraction (SPME) of four triazine herbicides (atrazine, prometon, ametryn and prometryn) in water samples. The main parameters that affect the extraction and desorption efficiencies, such as the extraction time, stirring rate, salt addition, desorption solvent and desorption time, were investigated and optimized. The optimized SPME by graphene‐coated fiber coupled with high‐performance liquid chromatography‐diode array detection (HPLC‐DAD) was successfully applied for the determination of the four triazine herbicides in water samples. The linearity of the method was in the range from 0.5 to 200 ng/mL, with the correlation coefficients (r) ranging from 0.9989 to 0.9998. The limits of detection of the method were 0.05‐0.2 ng/mL. The relative standard deviations varied from 3.5 to 4.9% (n=5). The recoveries of the triazine herbicides from water samples at spiking levels of 20.0 and 50.0  ng/mL were in the range between 86.0 and 94.6%. Compared with two commercial fibers (CW/TPR, 50 μm; PDMS/DVB, 60 μm), the graphene‐coated fiber showed higher extraction efficiency.
Habitat selection by grassland snakes at northern range limits: Implications for conservation
Authors: Martino Jessica A. , Poulin Ray G. , Parker Dennilyn L. , Somers Christopher M. 
Published: December 2011

AbstractAnimal populations at northern range limits may use habitat differently from those at range cores, requiring distinct conservation plans. Snakes are ectotherms that often have very specific requirements, but few studies have focused on the effect of northern latitudes on habitat selection by grassland snakes. We studied movement and habitat selection of 2 sympatric snake species at their northern range limits on the North American Great Plains: the eastern yellow‐bellied racer (Coluber constrictor flaviventris, hereafter racer), a Threatened species in Canada, and the bullsnake (Pituophis catenifer sayi), which is listed as Data Deficient. Both of these species are potentially vulnerable to extinction in Canada because of habitat loss. Snakes from our study populations traveled up to 10‐times farther from winter dens and occupied home ranges 3–104 times larger than populations further south. Both snake species moved from winter dens in the slopes of a major river valley to habitat in adjacent lowlands, including riparian zones (racers) and hilly areas with native grass species (bullsnakes). Multivariate modeling revealed that proximity to retreat sites was a significant predictor of snake site use for both species. Considering the need for winter dens and summering areas, our data suggest that snakes in northern latitudes should ideally have much larger protected areas compared to snakes near the core of their range. An alternative strategy is to conserve corridors linking wintering dens and summer habitats. Retreat sites such as burrows and shrubs are critical components of local habitat and should be included in conservation plans. © 2011 The Wildlife Society.
Unique in utero identification of fetuses in multifetal mouse pregnancies by placental bidirectional arterial spin labeling MRI
Authors: Avni Reut , Raz Tal , Biton Inbal E. , Kalchenko Vyacheslav , Garbow Joel R. , Neeman Michal 
Published: December 2011

AbstractNoninvasive imaging is a critical part of the study of developing embryos/fetuses, particularly in the context of alterations of gene expression in genetically modified animals. However, in litter‐bearing animals, such as mice, the inability to accurately identify individual embryo/fetus in utero is a major obstacle to longitudinal, noninvasive in vivo studies. Arterial spin labeling MRI was adopted here to determine the fetal order along the uterine horns in vivo, based on the specific pattern of dual arterial blood supply within the mouse uterine horns. Blood enters the mouse uterus cranially through the ovarian artery and caudally through the uterine artery. Saturation slices were alternately placed on the maternal heart or on the bifurcation point of the common iliac artery, thereby saturating either downward inflow via the ovarian arteries or upward inflow via the uterine arteries, respectively. Saturation maps provided a unique signature with highly significant correlation between the direction‐dependent magnetization transfer and the position of the fetuses/placentas along the uterine horns. The bidirectional arterial spin labeling‐MRI method reported here opens possibilities to determine and pursue phenotypic alterations in fetuses and placentas in longitudinal studies of transgenic and knockout mice models, and for studying defects in placental vascular architecture. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Multi‐angle ratiometric approach to measure chemical exchange in amide proton transfer imaging
Authors: Zu Zhongliang , Janve Vaibhav A. , Li Ke , Does Mark D. , Gore John C. , Gochberg Daniel F. 
Published: December 2011

AbstractAmide proton transfer imaging, a specific form of chemical exchange saturation transfer imaging, has previously been applied to studies of acute ischemic acidosis, stroke, and cancer. However, interpreting the resulting contrast is complicated by its dependence on the exchange rate between amides and water, the amide concentration, amide and water relaxation, and macromolecular magnetization transfer. Hence, conventional chemical exchange saturation transfer contrast is not specific to changes such as reductions in pH due to tissue acidosis. In this article, a multi‐angle ratiometric approach based on several pulsed‐chemical exchange saturation transfer scans at different irradiation flip angles is proposed to specifically reflect exchange rates only. This separation of exchange effects in pulsed‐chemical exchange saturation transfer experiments is based on isolating rotation vs. saturation contributions, and such methods form a new subclass of chemical exchange rotation transfer (CERT) experiments. Simulations and measurements of creatine/agar phantoms indicate that a newly proposed imaging metric isolates the effects of exchange rate changes, independent of other sample parameters. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Four‐dimensional flow MRI using spiral acquisition
Authors: Sigfridsson Andreas , Petersson Sven , Carlhäll Carl‐Johan , Ebbers Tino 
Published: December 2011

AbstractTime‐resolved three‐dimensional phase‐contrast MRI is an important tool for physiological as well as clinical studies of blood flow in the heart and vessels. The application of the technique is, however, limited by the long scan times required. In this work, we investigate the feasibility of using spiral readouts to reduce the scan time of four‐dimensional flow MRI without sacrificing quality. Three spiral approaches are presented and evaluated in vivo and in vitro against a conventional Cartesian acquisition. In vivo, the performance of each method was assessed in the thoracic aorta in 10 volunteers using pathline‐based analysis and cardiac output analysis. Signal‐to‐noise ratio and background phase errors were investigated in vitro. Using spiral readouts, the scan times of a four‐dimensional flow acquisition of the thoracic aorta could be reduced 2–3‐fold, with no statistically significant difference in pathline validity or cardiac output. The shortened scan time improves the applicability of four‐dimensional flow MRI, which may allow the technique to become a part of a clinical workflow for cardiovascular functional imaging. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Using Knowledge Networks to Develop Preschoolers’ Content Vocabulary
Authors: Pollard‐Durodola Sharolyn D. , Gonzalez Jorge E. , Simmons Deborah C. , Davis Matthew J. , Simmons Leslie , Nava‐Walichowski Miranda 
Published: December 2011

AbstractResearch shows that children accrue vocabulary knowledge by understanding relationships between new words and their connected concepts. This article describes three research‐based principles that preschool teachers can use to design shared book reading lessons that accelerate content vocabulary knowledge by helping young children to talk about important connections between words and related science and social studies concepts. These three principles guide teachers in building networks of content vocabulary knowledge in preschool children by making connections between words and world knowledge via informational and narrative texts.
Elektrospray‐Ionisation (ESI)
Authors: Altmann Korinna , Schulze Rolf‐Dieter , Hidde Gundula , Friedrich Jörg 
Published: December 2011

AbstractDie Elektrospray‐Ionisations (ESI)‐Vernebelung von Polymerlösungen wird analytisch zur massenspektrometrischen Bestimmung der Molmassen von Makromolekülen genutzt. Dabei werden die Polymermoleküle nach einem speziellen Mechanismus im Hochspannungsfeld unter Normaldruckbedingungen vereinzelt und in das Massenspektrometer überführt. Dieser Prozeß kann auch zur flächigen Abscheidung einzelner Polymermoleküle genutzt werden. Die Struktur und Zusammensetzung sowie die Molmassenverteilung der Polymere bleiben dabei erhalten. Schichten polarer oder ionischer Polymere der Dicke einer Quasi‐Monolage bis hin zu mehreren 100 Nanometern können abgeschieden werden. Erwähnenswert ist, daß der ESI‐Prozeß zu den elektrophoretischen Verfahren gehört, was die Ausbildung lochfreier Schichten auf elektrisch leitenden Substraten nicht nur auf der der Spraydüse zugewandten Seite ermöglicht, sondern auch auf der abgeschatteten Rückseite. Dieses Verhalten wurde zur vollständigen ESI‐Umhüllung von dichtgepackten Kohlenstoff‐Faser‐Bündeln mit haftvermittelnden Polymerschichten ausgenutzt.
Großflächige Plasmabeschichtungen: Niederdruck oder Atmosphärendruck?
Authors: Hegemann Dirk 
Published: December 2011

AbstractDie Forschung auf dem Gebiet der Atmosphärenplasmen wird häufig mit dem Argument motiviert, dass diese im Vergleich mit Niederdruckplasmen die kostengünstigeren Prozesse erwarten lassen. Ein Kostenvergleich von plasmachemischen Prozessen, die auch an Atmosphäre möglich sind, ergeben jedoch ein anderes Bild: Hohe Gasflüsse, die bei Atmosphärenplasmen notwendig sind, erweisen sich als kostenintensiver als Vakuumtechnologie für großflächige Plasmabeschichtungen.
Explanation of two non-blocking shared-variable communication algorithms
Authors: Bornat Richard , Amjad Hasan 
Published: December 2011

Abstract

Simpson and Harris have described multi-slot algorithms implementing a single-place buffer, each operating without explicit hardware synchronisation mechanisms. Conventional refinement and proof techniques have explained
that
these algorithms work, but do not give convincing descriptions of
how
they work. An unconventional refinement process starting from the classic single-variable buffer, using both data and atomicity refinement and drawing information from unsuccessful steps, derives each algorithm. The logic used is RGSep, a marriage of rely/guarantee and concurrent separation logic. Extensive detailed verifications are described. The result is an explanation of how the algorithms work and some pointers to how such algorithms might be devised.
Trainees' Clinical Exposure in the General Urological Outpatient Environment and its Relevance to Their Expected Clinic Throughput at Completion of Surgical Training
Authors: Vissamsetti Bharat , Pearce Ian , Payne Steve 
Published: December 2011

The aim of this study was to determine the number of patients seen in urological outpatient clinics by consultants and juniors in general urology clinics to determine whether trainees experience a workload they might expect in their future practice. Materials and methods: Data were acquired prospectively for two consultants' outpatient activity and the general urology component extracted. Collection of new and follow-up patients attendances, and who saw them, was recorded in addition to the booked patient load. Data were analysed to show clinical throughput by consultants and junior doctors in formalized training or in trust-grade posts. Results: 7645, 2465 new and 5180 follow-up, patients attended 467 general urology clinics. 54.9% of new, and 65% of follow up patients were seen by the consultants when they and junior were present. There was no apparent difference in the numbers of patients seen by trainees and trust doctors irrespective of their experience. Conclusion: In a general urology setting juniors' exposure to the available outpatient workload seems to be appropriate for what they might expect to encounter at the completion of training. Further research is required to determine the quality, and emphasis, in training necessary to optimize efficient patient management in this environment.