bluuebunny/crossref_metadata_2025_split huggingface dataset:
Web‐based laboratory for engineering education
Authors: Stefanovic Miladin , Matijevic Milan , Cvijetkovic Vladimir , Simic Visnja 
Published: April 2009

AbstractLaboratory experiments and practical work by their nature are unavoidable, important, and costly in the engineering education environment. The web laboratory is an educational tool for teaching students the basic principles and methodology in performing a series of experiments on different equipment at any time and from any location through the Internet. In this paper, pre‐requests, architecture, and software realization of the Web Laboratory at University of Kragujevac are presented. Organization, development, goals, and possible demands of the laboratory exercise: The inverted pendulum/gantry crane controls (with the capability to test different control algorithms) are also discussed. The applications of the web lab have been tested with the students enrolled at University of Kragujevac and the initial educational results of the implementation of this laboratory exercise are presented. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 526–536, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20222
Parathyroid hormone inhibits phosphorylation of mitogen‐activated protein kinase (MAPK) ERK1/2 through inhibition of c‐Raf and activation of MKP‐1 in osteoblastic cells
Authors: Lai Lick Pui , Mitchell Jane 
Published: April 2009

AbstractParathyroid hormone (PTH) regulation of mitogen‐activated protein kinases (MAPK) ERK1/2 contributes to PTH regulation of osteoblast growth and apoptosis. We investigated the mechanisms by which PTH inhibits ERK1/2 activity in osteoblastic UMR 106‐01 cells. Treatment with PTH significantly inhibited phosphorylated ERK1/2 between 5 and 60 min. Transient transfection of cells with a cDNA encoding MAPK phosphatase‐1 (MKP‐1) resulted in 30–40% inhibition of pERK1/2; however MKP‐1 protein levels were only significantly stimulated by PTH after 30 mins, suggesting another mechanism for the early phase of pERK1/2 inhibition. The active upstream kinase c‐Raf phosphorylation at serine 338 (ser338) was significantly inhibited by PTH treatment within 5 min and transfection of the cells with constitutively‐active c‐Raf blocked PTH inhibition of pERK1/2. Inhibition of pERK1/2 and phosphor‐c‐Raf were seen when cells were treated with PTH(1‐34) or PTH(1‐31) analogues that stimulate cAMP, but not with PTH(3‐34), PTH(7‐34) or PTH(18‐48) that do not stimulate cAMP. Stimulation of the cells with forskolin or 8BrcAMP also inhibited pERK1/2 and c‐Raf.p338. Our results suggest that rapid PTH inhibition of ERK1/2 activity is mediated by PKA dependent inhibition of c‐Raf activity and that stimulation of MKP‐1 may contribute to maintaining pERK1/2 inhibition over prolonged time. Copyright © 2009 John Wiley & Sons, Ltd.
Cloning and Sequencing of the Biosynthetic Gene Cluster for Saquayamycin Z and Galtamycin B and the Elucidation of the Assembly of Their Saccharide Chains
Authors: Erb Annette , Luzhetskyy Andriy , Hardter Uwe , Bechthold Andreas 
Published: April 2009

AbstractSweet ways: We have investigated the glycosyltransferase genes of the saquayamycin Z (shown) and galtamycin B biosynthetic gene cluster from Micromonospora sp. Tü6368. The results unambiguously show that both compounds are derived from the same cluster. Furthermore, the function of five glycosyltransferases was elucidated, and the results have shed light on the assembly of the sugar chains.magnified imageThe Gram‐positive bacterium, Micromonospora sp. Tü6368 produces the angucyclic antibiotic saquayamycin Z and the tetracenequinone galtamycin B. The structural similarity of both compounds suggests a common biosynthetic pathway. The entire biosynthetic gene cluster (saq gene cluster) was cloned and characterized. DNA sequence analysis of a 36.7 kb region revealed the presence of 31 genes that are probably involved in saquayamycin Z and galtamycin B formation. Heterologous expression experiments and targeted gene inactivations were carried out to specifically manipulate the saquayamycin Z and galtamycin B pathways; this demonstrated unambiguously that both compounds are derived from the same cluster. The inactivation of glycosyltransferase genes led to the production of novel saquayamycin and galtamycin derivatives, provided information on the assembly of the sugar chains, and showed that tetracenequinones are formed from angucyclines.
Fragment Formal Concept Analysis Accurately Classifies Compounds with Closely Related Biological Activities
Authors: Krüger Felix , Lounkine Eugen , Bajorath Jürgen 
Published: April 2009

AbstractFragment formal concept analysis (FragFCA) for compound classification: Signature fragment combinations for compound classes with closely related biological activity were identified using FragFCA. These combinations are used to accurately classify active test compounds on the basis of fragment mapping. FragFCA can extract class‐specific fragment combinations from compounds active against different target families that have signature character and practical utility in compound classification and database searching.magnified imageFormal concept analysis (FCA), originally developed in information science, has been adapted to identify relationships between fragments of compounds and their biological activity. Here applications of the FragFCA approach with practical utility for medicinal chemistry are explored. Hierarchically derived fragment populations of 24 classes of compounds active against eight target families were subjected to FragFCA analysis, and fragment combinations were identified that distinguished compounds with closely related biological activity from each other. Mapping of signature fragment combinations was carried out to classify active compounds for different target families with high accuracy. The results indicate that compound‐class‐specific structural information and selectivity determinants are predominantly encoded by fragment combinations, rather than individual fragments. Furthermore, class‐specific fragment combinations were successfully applied in similarity searching. The results demonstrate that FragFCA is capable of identifying fragment combinations that differentiate between compound sets with closely related biological activity and that can be used to predict structure–activity relationships.
Relationship between caffeine intake and plasma sex hormone concentrations in premenopausal and postmenopausal women
Authors: Kotsopoulos Joanne , Eliassen A. Heather , Missmer Stacey A. , Hankinson Susan E. , Tworoger Shelley S. 
Published: April 2009

AbstractBACKGROUND:Circulating estrogens and androgens are important factors in the development of various female cancers. Caffeine intake may decrease risk of breast and ovarian cancer, although the data are not entirely consistent. Whether or not caffeine affects cancer risk by altering sex hormone levels is currently unknown.METHODS:We examined the relationship of caffeine, coffee, decaffeinated coffee, and tea with plasma concentrations of estrogens, androgens, progesterone, prolactin, and sex hormone–binding globulin (SHBG) in 524 premenopausal and 713 postmenopausal women from the Nurses' Health Study (NHS) and NHSII.RESULTS:In premenopausal women, caffeine intake was inversely associated with luteal total and free estradiol, and positively associated with luteal progesterone levels (P‐trend = .02, .01, .03, respectively). Coffee intake was significantly associated with lower luteal total and free estradiol levels, but not luteal progesterone levels (P‐trend = .007, .004, .20, respectively). Among the postmenopausal women, there was a positive association between caffeine and coffee intake and SHBG levels (P‐trend = .03 and .06, respectively). No significant associations were detected with the other hormones.CONCLUSIONS:Data from this cross‐sectional study suggest that caffeine may alter circulating levels of luteal estrogens and SHBG, representing possible mechanisms by which coffee or caffeine may be associated with pre‐ and postmenopausal malignancies, respectively. Future studies evaluating how caffeine‐mediated alterations in sex hormones and binding protein levels affect the risk of female cancers are warranted. Cancer 2009. © 2009 American Cancer Society.
Remarks on some properties of conic yield restrictions in limit analysis
Authors: Makrodimopoulos Athanasios 
Published: April 2009

AbstractA major difficulty when applying the kinematic theorem in limit analysis is the derivation of expressions of the dissipation functions and the set of plastically admissible strains. At present, no standard methodology exists. Here, it is shown that they can be readily obtained, provided that the yield restriction can be rewritten as an intersection of cones, and that the expression defining the dual cones is available. This is always possible for the case of self‐dual cones and some other classes, and covers many of the well‐known criteria. Therefore, a difficult obstacle with respect to the use of the kinematic theorem in conjunction with any numerical method can be overcome. The methodology is illustrated by giving the expressions of the dissipation functions for various conic yield restrictions. A special emphasis is given on upper bound finite element limit analysis. Taking advantage of duality in conic programming, we can obtain the dual problem, where knowledge of the dual cone is not necessary. Therefore, this formulation is feasible for any cone. Finally, it is interesting that the form of the dual problem, for varying yield strength within the finite element, differs from that presented in other papers. Copyright © 2009 John Wiley & Sons, Ltd.
Gibt es durch die harmonisierten europäischen Prüfnormen Auswirkungen auf das Brandverhalten von Mauerwerk?
Authors: Hahn Christiane , Nause Peter 
Published: April 2009

AbstractDie deutsche Mauerwerksindustrie ist in Europa führend. Nicht nur in der Vielfältigkeit der Mauerwerksarten, sondern insbesondere auch hinsichtlich der Brandschutznachweise. Aufgrund des hohen deutschen Sicherheitsniveaus wurde jede Neuerung im Mauerwerksbau zeitnah brandschutztechnisch nach DIN 4102 nachgewiesen. Da in Deutschland im Brandschutz hinsichtlich der Prüfverfahren eine umfangreiche Erfahrung vorlag, wurde in den 1990‐er Jahren intensiv an der Entwicklung der europäischen Prüfnormen mitgearbeitet. Bei der Erarbeitung der europäischen Extrapolationsregeln zu den Prüfnormen im Bereich Mauerwerk ist die Industrie aktiv eingebunden. Aufgrund der Privatisierung der Prüfanstalten ist dies in vielen anderen Bereichen nicht der Fall. Im Gegensatz zu Deutschland wird in anderen europäischen Ländern, insbesondere Großbritannien, die Mitarbeit in europäischen Normungsgremien als nationales und damit politisches Interesse eingestuft und daher staatlich finanziert. Für Mauerwerk kann zusammenfassend festgestellt werden, dass die bereits in den 90‐er Jahren harmonisierten europäischen Prüfnormen den deutschen Normenstandard sowie das deutsche Sicherheitsniveau widerspiegeln. Dadurch lässt sich die eingangs gestellte Frage, ob die harmonisierten europäischen Prüfnormen Auswirkungen auf das Brandverhalten von Mauerwerk haben, kurz mit nein beantworten. Lediglich der sich aus der europäischen Normung ergebende Formalismus im bauaufsichtlichen Verfahren hat massive Auswirkung auf den Aufwand beim Einsatz von Mauerwerk. Insofern sind die nachfolgenden Informationen und Einblicke für den Anwender sinnvoll und notwendig.
Pericellular matrix of decidua‐derived mesenchymal cells: A potent human‐derived substrate for the maintenance culture of human ES cells
Authors: Nagase Tomoko , Ueno Morio , Matsumura Michiru , Muguruma Keiko , Ohgushi Masatoshi , Kondo Naomi , Kanematsu Daisuke , Kanemura Yonehiro , Sasai Yoshiki 
Published: April 2009

AbstractIn routine culture, human embryonic stem (hES) cells are maintained on either feeder cells or special culture substrates such as Matrigel. However, to expand hES cells for clinical applications, it is desirable to minimize animal‐derived materials in the culture for safety reasons. In this report, we show that the pericellular matrix prepared from human decidua‐derived mesenchymal cells (PCM‐DM) is a potent substrate material that supports the growth and pluripotency of hES cells as efficiently as Matrigel does. This supporting activity of PCM‐DM is stable and can be preserved for several months in the refrigerator. PCM‐DM‐based culture is compatible with non‐conditioned commercial defined medium, and with the maintenance of dissociated hES cells in the presence of ROCK inhibitor. Since decidual mesenchymal cells can be prepared and expanded in a large quantity, PCM‐DM is a practical human‐derived substitute for the animal‐derived substrates for use in clinical‐grade culture of hES cells. Developmental Dynamics 238:1118–1130, 2009. © 2009 Wiley‐Liss, Inc.
Fgf signaling components are associated with muscles and tendons during limb development
Authors: Eloy‐Trinquet Sophie , Wang Hui , Edom‐Vovard Fréderic , Duprez Delphine 
Published: April 2009

AbstractMuscle‐tendon interactions are important for the establishment of a functional musculoskeletal system. Fgf4 and Fgf8 are expressed in muscle and tendon boundary regions during limb development, suggesting a potential role for Fgf signaling pathway in muscle and tendon interactions. We have examined the expression of Fgf syn‐expression group components during muscle and tendon formation of vertebrate limb development. We observed that the transcriptional effector of Fgf signaling, Pea3, and the modulators of Fgf signal, Sprouty1 and 2, were expressed in muscles and tendons and that their expression was enhanced at the myotendinous junctions in chick and mouse limbs. Analysis of Pea3 and Sprouty gene expression in muscleless limbs of Pax3 mutant mice indicated a major expression in muscles but also revealed that the Pea3 and Sprouty expression in tendons depended on muscles. Finally, our data showed that Fgf4 positively regulated Pea3, Sprouty1, and 2 expression in chick limb mesenchyme. Developmental Dynamics 238:1195–1206, 2009. © 2009 Wiley‐Liss, Inc.
Increased Hox activity mimics the teratogenic effects of excess retinoic acid signaling
Authors: Waxman Joshua S. , Yelon Deborah 
Published: April 2009

AbstractExcess retinoic acid (RA) signaling can be teratogenic and result in cardiac birth defects, but the cellular and molecular origins of these defects are not well understood. Excessive RA signaling can completely eliminate heart formation in the zebrafish embryo. However, atrial and ventricular cells are differentially sensitive to more modest increases in RA signaling. Increased Hox activity, downstream of RA signaling, causes phenotypes similar to those resulting from excess RA. These results suggest that Hox activity mediates the differential effects of ectopic RA on atrial and ventricular cardiomyocytes and may underlie the teratogenic effects of RA on the heart. Developmental Dynamics 238:1207–1213, 2009. © 2009 Wiley‐Liss, Inc.
Tissue selective expression of conditionally‐regulated ROCK by gene targeting to a defined locus
Authors: Samuel Michael S. , Munro June , Bryson Sheila , Forrow Stephen , Stevenson David , Olson Michael F. 
Published: April 2009

AbstractROCK kinases regulate actin‐myosin structures downstream of Rho GTPases. We generated mice expressing 4‐hydroxytamoxifen (4HT)‐regulated human ROCK II (ROCKII:mER™) under the transcriptional control of the cytokeratin14 (K14) promoter. The K14‐ROCKII:mER™ minigene was recombineered into a novel cloning vector containing the promoter and first exon of the human HPRT gene, and second and third exons of the mouse Hprt gene. Homologous recombination into the Hprt locus, which is deleted for the promoter and first two exons in HM1 embryonic stem cells, reconstitutes a functional Hprt gene, allowing for growth in HAT (hypoxanthine‐aminopterin‐thymidine) medium. K14‐promoter‐driven ROCKII:mER™ expression was restricted to a superficial cell layer in embryoid bodies, with increased ROCK substrate phosphorylation induced by 4HT. ROCKII:mER™‐expressing primary murine keratinocytes responded to 4HT with increased substrate phosphorylation and cytoskeleton rearrangements, indicating that ROCKII:mER™ activity is regulated by 4HT in the target tissue. K14‐ROCKII:mER™ mice will be valuable for examining the role of ROCK in skin development and cancer. genesis 47:440–446, 2009. © 2009 Wiley‐Liss, Inc.
Prostaglandin E2 enhances Th17 responses via modulation of IL‐17 and IFN‐γ production by memory CD4+ T cells
Authors: Napolitani Giorgio , Acosta‐Rodriguez Eva V. , Lanzavecchia Antonio , Sallusto Federica 
Published: April 2009

AbstractThe contribution of Th1 and Th17 cells in chronic inflammatory conditions leading to autoimmunity remains highly controversial. In inflamed tissues, production of prostaglandins by COX‐2 has been proposed to favor Th17 responses indirectly by increasing IL‐23 and blocking IL‐12 release from APC. We report here that prostaglandin E2 (PGE2) can directly modulate cytokine production by human memory CD4+ T cells. TCR triggering in the presence of PGE2 increased IL‐17 and reduced IFN‐γ production by freshly isolated memory T cells or T‐cell clones. PGE2 triggered the EP2 and EP4 receptors expressed on T cells leading to a rapid increase of retinoic‐acid‐related orphan receptor‐γt (ROR‐γt) and decrease of T‐cell‐specific T‐box transcription factor 21 (T‐bet) mRNA. Moreover, PGE2 promoted the selective enrichment of IL‐17‐producing cells by differentially modulating the proliferation of memory T‐cell subsets in vitro. Taken together our results indicate that T‐cell effector function is a direct target for PGE2 modulation and suggest a novel mechanism by which inhibitors of prostaglandin synthesis, such as COX‐2 inhibitors, exert their anti‐inflammatory effect.
Interleukin‐10‐secreting T cells define a suppressive subset within the HIV‐1‐specific T‐cell population
Authors: Torheim Eirik A. , Ndhlovu Lishomwa C. , Pettersen Frank O. , Larsen Trine‐Lise , Jha Aashish R. , Torgersen Knut M. , Kvale Dag , Nixon Douglas F. , Taskén Kjetil , Aandahl Einar M. 
Published: April 2009

AbstractRecent studies have indicated that Treg contribute to the HIV type 1 (HIV‐1)‐related immune pathogenesis. However, it is not clear whether T cells with suppressive properties reside within the HIV‐1‐specific T‐cell population. Here, PBMC from HIV‐1‐infected individuals were stimulated with a 15‐mer Gag peptide pool, and HIV‐1‐specific T cells were enriched by virtue of their secretion of IL‐10 or IFN‐γ using immunomagnetic cell‐sorting. Neither the IL‐10‐secreting cells nor the IFN‐γ‐secreting cells expressed the Treg marker FOXP3, yet the IL‐10‐secreting cells potently suppressed anti‐CD3/CD28‐induced CD4+ as well as CD8+ T‐cell proliferative responses. As shown by intracellular cytokine staining, IL‐10‐ and IFN‐γ‐producing T cells represent distinct subsets of the HIV‐1‐specific T cells. Our data collectively suggest that functionally defined HIV‐1‐specific T‐cell subsets harbor potent immunoregulatory properties that may contribute to HIV‐1‐associated T‐cell dysfunction.
γδ T cells in EAE: Early trafficking events and cytokine requirements
Authors: Wohler Jillian E. , Smith Sherry S. , Zinn Kurt R. , Bullard Dan C. , Barnum Scott R. 
Published: April 2009

AbstractWe have previously shown that γδ T cells traffic to the CNS during EAE with concurrently increased expression of β2‐integrins and production of IFN‐γ and TNF‐α. To extend these studies, we transferred bioluminescent γδ T cells to WT mice and followed their movement through the acute stages of disease. We found that γδ T cells rapidly migrated to the site of myelin oligodendrocyte glycoprotein peptide injection and underwent massive expansion. Within 6 days after EAE induction, bioluminescent γδ T cells were found in the spinal cord and brain, peaking in number between days 10 and 12 and then rapidly declining by day 15. Reconstitution of γδ T cell−/− mice with γδ T cells derived from β2‐integrin‐deficient mice (CD11a, ‐b or ‐c) demonstrated that γδ T‐cell trafficking to the CNS during EAE is independent of this family of adhesion molecules. We also examined the role of γδ T‐cell‐produced IFN‐γ and TNF‐α in EAE and found that production of both cytokines by γδ T cells was required for full development of EAE. These results indicate that γδ T cells are critical for the development of EAE and suggest a therapeutic target in demyelinating disease.
Synthesis and Characterization of Single‐Crystalline Lanthanum Fluoride with a Ring‐Like Nanostructure
Authors: Tian Yang , Wen Jing , Liu Bin , Sui Ning , Jin Qionghua , Jiao Xiuling 
Published: April 2009

AbstractLaF3 ring‐like nanostructures with a diameter of less than 2 μm have been fabricated by a facile, effective, and environmentally friendly molten salt synthesis route in which NaNO3 and KNO3 (2:1 molar ratio) act as reaction media and the rare‐earth nitrate and NaF as precursor. X‐ray diffraction, TEM, HR‐TEM, energy dispersive X‐ray spectroscopy, and photoluminescence spectroscopy are all used to characterize the as‐prepared samples. Experiments peformed with different reaction times indicate that a central‐etching of the plates from the inner part towards the edge during nanocrystal growth plays a key role in the formation of LaF3 nanorings since no other templates/surfactants are present in our system. Additionally, the luminescence properties of LaF3 nanorings doped with Eu3+ cation have been investigated andcompared with those of bulk materials and nanoparticles with a size of approximately 50 nm. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
31Phosphorus magnetic resonance spectroscopy study of tissue specific changes in high energy phosphates before and after sertraline treatment of geriatric depression
Authors: Forester Brent P. , Harper David G. , Jensen J. Eric , Ravichandran Caitlin , Jordan Brittany , Renshaw Perry F. , Cohen Bruce M. 
Published: April 2009

AbstractIntroductionWe investigated tissue specific differences in markers of energy metabolism, including high energy phosphate compounds (beta and total NTP, PCr) and pH, in older adults with depression compared with healthy controls, before and after a 12‐week treatment trial of sertraline.MethodsThirteen older adults, age ≥55, with Major Depressive Disorder (HAMD17 score of ≥18) were recruited along with ten age‐matched controls. The depression subjects had a pre‐ and post‐treatment 4T 31P‐MRS scan using a three‐dimensional chemical shift imaging sequence. The extracted brain images were segmented into white matter (WM), gray matter (GM) and CSF. A linear mixed effects model analyzed the effects of pre‐treatment and post‐treatment depression on phosphorus metabolite concentration estimates (including calculated pH and Mg++).ResultsTotal tissue beta‐NTP (−8%, t(18.66) = 3.50; p = 0.0024) and total tissue total NTP (−6%, t(17.41) = 2.68; p = 0.0156) were lower in subjects with geriatric depression compared with healthy controls. Total tissue levels of total‐NTP changed significantly with treatment (−2%, t(14.84) = −2.47; p = 0.0259). Total NTP was reduced in the WM, but not the GM, in the pre‐treatment depression group (t(51.65) = 4.02; p = 0.0002). Intracellular pH was higher in the GM of subjects with pre‐treatment depression (t(1133.84) = −2.10; p = 0.0353) and decreased to approximate control levels after treatment (t(648.86) = −2.53; p = 0.0115).DiscussionThese findings demonstrate bioenergetic changes including tissue specific differences in 31P‐MRS metabolites in geriatric depression. Decreased white matter total NTP may reflect alterations in white matter function. Copyright © 2009 John Wiley & Sons, Ltd.