bluuebunny/crossref_metadata_2025_split huggingface dataset:
β‐turn tendency in N‐methylated peptides with dehydrophenylalanine residue: DFT study
Authors: Buczek Aneta , Wałęsa Roksana , Broda Małgorzata A. 
Published: February 2012

AbstractThe tendency to adopt β‐turn conformation by model dipeptides with α,β‐dehydrophenylalanine (ΔPhe) residue in the gas phase and in solution is investigated by theoretical methods. We pay special attention to a dependence of conformational properties on the side‐chain configuration of dehydro residue and the influence of N‐methylation on β‐turn stability. An extensive computational study of the conformational preferences of Z and E isomers of dipeptides Ac‐Gly‐(E/Z)‐ΔPhe‐NHMe (1a / 1b) and Ac‐Gly‐(E/Z)‐ΔPhe‐NMe2 (2a/2b) by B3LYP/6‐311++G(d,p) and MP2/6‐311++G(d,p) methods is reported. It is shown that, in agreement with experimental data, Ac‐Gly‐(Z)‐ΔPhe‐NHMe has a great tendency to adopt β‐turn conformation. In the gas phase the type II β‐turn is preferred, whereas in the polar environment, the type I. On the other hand, dehydro residue in Ac‐Gly‐(E)‐ΔPhe‐NHMe has a preference to adopt extended conformations in all environments. N‐methylation of C‐terminal amide group, which prevents the formation of 1←4 intramolecular hydrogen bond, change dramatically the conformational properties of studied dehydropeptides. Especially, the tendency to adopt β‐turn conformations is much weaker for the N‐methylated Z isomer (Ac‐Gly‐(Z)‐ΔPhe‐NMe2), both in vacuo and in the polar environment. On the contrary, N‐methylated E isomer (Ac‐Gly‐(E)‐ΔPhe‐NMe2) can easier adopt β‐turn conformation, but the backbone torsion angles (ϕ1, ψ1, ϕ2, ψ2) are off the limits for common β‐turn types. © 2012 Wiley Periodicals, Inc. Biopolymers 97:518–528, 2012.
Hundegenom: die Auswirkungen der Domestikation
Authors: Kronberg Inge 
Published: February 2012

AbstractWindhund und Mops, Bernhardiner und Pinscher – kaum zu glauben, dass sich diese Hunderassen noch als ihresgleichen erkennen. Die Variabilität des Haushundes ist erstaunlich und übertrifft die aller anderen domestizierten Arten. Nicht nur Spötter behaupten, der Hund gleiche seinem Halter in Temperament und Figur. Parallelen zwischen Mensch und Hund findet man tatsächlich bei Erkrankungen wie Diabetes, Rheuma oder Krebs, das gilt aber nicht für jede Rasse gleichermaßen. Das entschlüsselte Genom des Haushundes eröffnet die Chance, die genetische Basis von Variabilität, Domestikation und Evolution besser zu verstehen und liefert vielleicht auch Erkenntnisse für die Humanmedizin.
Erste Erfolge bei der künstlichen Ansiedlung von Korallenlarven im Riff
Authors: Loch Karen , Loch Wolfgang 
Published: February 2012

AbstractIn BIUZ 5/2011 wurde über die künstliche Aufzucht von rund 500.000 reifen Steinkorallen‐Larven bei den Malediven berichtet. Durch fortlaufende mikroskopische Kontrolluntersuchungen der einzelnen Entwicklungsstadien gelang es nun, deren Siedlungskompetenz zu dokumentieren.
Innervation of the elbow joint: Is total denervation possible? A cadaveric anatomic study
Authors: De Kesel Renata , Van Glabbeek Francis , Mugenzi Dominique , De Vos Joris , Vermeulen Katrien , Van Renterghem Debbie , Bortier Hilde , Schuind Frédéric 
Published: February 2012

AbstractThe aim of this anatomical study was to find out if total denervation of the elbow joint is technically feasible. The endbranches of the brachial plexus of eight fresh‐frozen upper arm cadavers were dissected with optical loupe magnification. All major nerves of the upper limb (except the axillary and the medial brachial cutaneous nerve) give some terminal articular endbranches to the elbow. The articular endbranches arise from muscular endbranches, cutaneous endbranches, or arise straight from the main nerves of the brachial plexus. A topographic diagram was made of the different nerves innervating the elbow joint. The ulno‐posterior part of the elbow is innervated by the ulnar nerve and some branches of medial antebrachial cutaneous nerve. The radial‐posterior part of the elbow is innervated exclusively by the radial nerve. The ulno‐anterior part of the elbow is innervated by the median nerve and the musculocutaneous nerve. The radio‐anterior part of the elbow is innervated by the radial nerve and the musculocutaneous nerve. These elbow innervation findings are relevant to both anatomical and clinical field as they provide evidence that the total denervation of the elbow joint is impossible. Nevertheless, partial denervation, like denervation of the lateral epicondyle or the ulnar part of elbow, is technically possible. Clin. Anat. 25:746–754, 2012. © 2012 Wiley Periodicals, Inc.
Oliver Wendell Holmes, Sr. (1809–1894): Physician, jurist, poet, inventor, pioneer, and anatomist
Authors: Tubbs R. Shane , Shoja Mohammadali M. , Loukas Marios , Carmichael Stephen W. 
Published: February 2012

AbstractOliver Wendell Holmes, Sr. was a physician, dean of the Harvard Medical School, one of the best regarded American poets of the 19th century, father of a future United States Supreme Court Justice, inventor and — unknown to many — an anatomist. His friends included Ralph Waldo Emerson, Henry Wadsworth Longfellow, and Louis Pasteur. He trained with some of the most influential anatomists/surgeons of his day including Lisfranc, Larrey, Velpeau, Bigelow, and Dupuytren. As a teacher of anatomy, he had strong feelings regarding medical curricular reform and to some, was considered one of the best lecturers in the discipline. As dean, he pioneered social reform by admitting both white women and free black men to Harvard Medical School. He coined the term “anesthesia,” was the first American to introduce microscopy to a medical curriculum, and made important contributions to the understanding of the spread of infectious disease. Herein, we review the life of this influential American academic and focus on his contributions to the field of anatomy. Clin. Anat. 25:992–997, 2012. © 2012 Wiley Periodicals, Inc.
Efficient Hydrogenolysis of Alkanes at Low Temperature and Pressure Using Tantalum Hydride on MCM‐41, and a Quantum Chemical Study
Authors: Polshettiwar Vivek , Pasha Farhan A. , De Mallmann A. , Norsic S. , Thivolle‐Cazat Jean , Basset Jean‐Marie 
Published: February 2012

AbstractHydrogenolysis of hydrocarbons is of considerable technological importance for applications such as the hydroprocessing of petrochemical feedstocks to generate high‐value and useful chemicals and fuels. We studied the catalytic activity of tantalum hydride supported on MCM‐41 for the hydrogenolysis of alkanes at low temperature and low atmospheric pressure in a dynamic reactor. The reactions proceed with good turnover numbers, and the catalyst could be reused for several times, which makes the overall catalytic process sustainable. We derived the plausible mechanism by using DFT calculations and identified the preferred pathways by the analysis of potential energy surface. Our results and the proposed reaction mechanism demonstrate the viability of the “catalyst‐by‐design” approach.
Aminomethylation of Michael Acceptors: Complementary Radical and Polar Approaches Mediated by Dialkylzincs
Authors: Maury Julien , Mouysset Dominique , Feray Laurence , Marque Sylvain R. A. , Siri Didier , Bertrand Michèle P. 
Published: February 2012

AbstractPhtalimidomethyl iodide and substituted maleimidomethyl iodide were used as radical precursors in dialkylzinc‐mediated radical addition to diethyl fumarate. The reactions led stereoselectively to functionalized pyrrolizidines. The radical mechanism was supported by spin‐trapping experiments and rationalized by theoretical calculations. Radical additions, on the one hand, and carbozincation followed by transmetalation with copper(I), on the other, were shown to be complementary methods to achieve the formal aminomethylation of activated unsaturated compounds.
F‐actin distribution at nodes of Ranvier and Schmidt‐Lanterman incisures in mammalian sciatic nerves
Authors: Kun Alejandra , Canclini Lucía , Rosso Gonzalo , Bresque Mariana , Romeo Carlos , Hanusz Alicia , Cal Karina , Calliari Aldo , Sotelo Silveira José , Sotelo José R. 
Published: February 2012

AbstractVery little is known about the function of the F‐actin cytoskeleton in the regeneration and pathology of peripheral nerve fibers. The actin cytoskeleton has been associated with maintenance of tissue structure, transmission of traction and contraction forces, and an involvement in cell motility. Therefore, the state of the actin cytoskeleton strongly influences the mechanical properties of cells and intracellular transport therein. In this work, we analyze the distribution of F‐actin at Schmidt‐Lanterman Incisures (SLI) and nodes of Ranvier (NR) domains in normal, regenerating and pathologic Trembler J (TrJ/+) sciatic nerve fibers, of rats and mice. F‐actin was quantified and it was found increased in TrJ/+, both in SLI and NR. However, SLI and NR of regenerating rat sciatic nerve did not show significant differences in F‐actin, as compared with normal nerves. Cytochalasin‐D and Latrunculin‐A were used to disrupt the F‐actin network in normal and regenerating rat sciatic nerve fibers. Both drugs disrupt F‐actin, but in different ways. Cytochalasin‐D did not disrupt Schwann cell (SC) F‐actin at the NR. Latrunculin‐A did not disrupt F‐actin at the boundary region between SC and axon at the NR domain. We surmise that the rearrangement of F‐actin in neurological disorders, as presented here, is an important feature of TrJ/+ pathology as a Charcot‐Marie‐Tooth (CMT) model. © 2012 Wiley Periodicals, Inc
Targeting of Nphp3 to the primary cilia is controlled by an N‐terminal myristoylation site and coiled‐coil domains
Authors: Nakata Kana , Shiba Dai , Kobayashi Daisuke , Yokoyama Takahiko 
Published: February 2012

AbstractPrimary cilia are organelles that extend from the cell surface. More than 600 proteins have been identified in cilia, but ciliary targeting mechanisms are poorly understood. Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease with 11 responsible genes (NPHP1–11) thus far being identified. The mouse Nphp3 gene product is localized in the cilia and contains coiled‐coil (CC) domains and tetratricopeptide repeats, but the ciliary targeting sequences (CTSs) are unknown. In the present study, we generated a series of GFP‐tagged deletion constructs of Nphp3 and tried to find the CTSs of Nphp3. We found that the N‐terminal 201 amino acid fragment (Nphp3 [1–201]), which contains two CC domains, is necessary and sufficient for cilia localization. Further analysis revealed that an N‐terminal glycine (G2), which is a conserved myristoylation site among vertebrates, is also essential for trafficking of Nphp3 to the ciliary shaft. Interestingly, the N‐terminal fragments, Nphp3 (8–201), Nphp3 (52–201), and Nphp3 (96–201), that contain the CC domains, targeted the basal body, but could not enter into the ciliary shaft. Our results showed the importance of myristoylation in ciliary trafficking, and suggest that Nphp3 trafficking to the ciliary shaft occurs in a two‐step process. © 2012 Wiley Periodicals, Inc.
Repulsive axon guidance cues ephrin‐A2 and slit3 stop protrusion of the growth cone leading margin concurrently with inhibition of ADF/cofilin and ERM proteins
Authors: Marsick Bonnie M. , Roche Florence K. , Letourneau Paul C. 
Published: February 2012

AbstractAxonal growth cones turn away from repulsive guidance cues. This may start with reduced protrusive motility in the region the growth cone leading margin that is closer to the source of repulsive cue. Using explants of E7 chick temporal retina, we examine the effects of two repulsive guidance cues, ephrin‐A2 and slit3, on retinal ganglion cell growth cone protrusive activity, total F‐actin, free F‐actin barbed ends, and the activities (phosphorylation states) of actin regulatory proteins, ADF/cofilin and ezrin, radixin, moesin (ERM) proteins. Ephrin‐A2 rapidly stops protrusive activity simultaneously with reducing F‐actin, free barbed ends and the activities of ADF/cofilin and ERM proteins. Slit3 also stops protrusion and reduces the activities of ADF/cofilin and ERM proteins. We interpret these results as indicating that repulsive guidance cues inhibit actin polymerization and actin‐membrane linkage to stop protrusive activity. Retrograde F‐actin flow withdraws actin to the C‐domain, where F‐actin bundles interact with myosin II to generate contractile forces that can collapse and retract the growth cone. Our results suggest that common mechanisms are used by repulsive guidance cue to disable growth cone motility and remodel growing axon terminals. © 2012 Wiley Periodicals, Inc
The immune inhibitory complex CD200/CD200R is developmentally regulated in the mouse brain
Authors: Shrivastava Kalpana , Gonzalez Pau , Acarin Laia 
Published: February 2012

AbstractThe CD200/CD200R inhibitory immune ligand–receptor system regulates microglial activation/quiescence in adult brain. Here, we investigated CD200/CD200R at different stages of postnatal development, when microglial maturation takes place. We characterized the spatiotemporal, cellular, and quantitative expression pattern of CD200 and CD200R in the developing and adult C57/BL6 mice brain by immunofluorescent labeling and Western blotting. CD200 expression increased from postnatal day 1 (P1) to P5–P7, when maximum levels were found, and decreased to adulthood. CD200 was located surrounding neuronal bodies, and very prominently in cortical layer I, where CD200+ structures included glial fibrillary acidic protein (GFAP)+ astrocytes until P7. In the hippocampus, CD200 was mainly observed in the hippocampal fissure, where GFAP+/CD200+ astrocytes were also found until P7. CD200+ endothelium was seen in the hippocampal fissure and cortical blood vessels, notably from P14, showing maximum vascular CD200 in adults. CD200R+ cells were a population of ameboid/pseudopodic Iba1+ microglia/macrophages observed at all ages, but significantly decreasing with increasing age. CD200R+/Iba1+ macrophages were prominent in the pial meninges and ventricle lining, mainly at P1–P5. CD200R+/Iba1+ perivascular macrophages were observed in cortical and hippocampal fissure blood vessels, showing maximum density at P7, but being prominent until adulthood. CD200R+/Iba1+ ameboid microglia in the cingulum at P1–P5 were the only CD200R+ cells in the nervous tissue. In conclusion, the main sites of CD200/CD200R interaction seem to include the molecular layer and pial surface in neonates and blood vessels from P7 until adulthood, highlighting the possible role of the CD200/CD200R system in microglial development and renewal. J. Comp. Neurol. 520:2657–2675, 2012. © 2012 Wiley Periodicals, Inc.
Auslaugverhalten von Putzen und Mörteln
Authors: Nebel Holger , Vollpracht Anya , Brameshuber Wolfgang 
Published: February 2012

AbstractDie Umweltverträglichkeit von Putzen und Mörteln in der Nutzungsphase ist ein wissenschaftlich bislang wenig untersuchtes Thema. Das Institut für Bauforschung (ibac) der RWTH Aachen University hat das Auslaugverhalten von drei Putzen und einem Mauermörtel durch Langzeitstandtests, Labortauchverfahren und bei künstlicher Beregnung im Labor untersucht. Diese Ergebnisse wurden Ergebnissen des Fraunhofer‐Instituts für Bauphysik (IBP) in Holzkirchen gegenübergestellt, welches mit den gleichen Putzen und Mörteln einen mehrjährigen Freilandversuch durchgeführt hat. Der Vergleich der Ergebnisse zeigt, dass es nicht immer möglich ist, ein worst‐case‐Szenario vorherzusagen. Welches Prüfverfahren das ungünstigste ist, hängt von dem jeweiligen Baustoff ab.Leaching behaviour of renderings and masonry mortars. The environmental compatibility of renderings and mortars in the utilisation phase is a scientific theme which is so far poorly investigated. The Institute of Building Materials Research (ibac) of the RWTH Aachen University has investigated the leaching behaviour of three renderings and one masonry mortar by conducting long term tank tests, laboratory immersion method and artificial irrigation in the laboratory. The results of the laboratory experiments were compared to several years lasting outdoor experiments of the Fraunhofer‐Institute for Building Physics (IBP) at Holzkirchen. The comparison of the results shows that it is not always possible to predict the worst‐case, which depends on the building material properties.
Eigenschaften industrieller Lehmbauprodukte für den Mauerwerksbau und Verhalten von Lehmsteinmauerwerk
Authors: Müller Urs , Ziegert Christof , Kaiser Caroline , Röhlen Ulrich 
Published: February 2012

AbstractDer Beitrag gibt einen Überblick über die Eigenschaften industriell hergestellter Bauprodukte aus Lehm für den Mauerwerksbau. Die Qualität der industriellen Fertigung dieser Produktgruppe hat inzwischen einen Stand erreicht, der vergleichbar mit dem anderer Bauprodukte ist. Lehm‐Putzmörtel gibt es als Universalputze für ein‐ oder mehrlagige Anwendung oder in Form von Unter‐, Ober‐ oder Feinputzen. Lehmsteine werden in verschiedenen Größen und mit Lochung angeboten. Die mechanischen Eigenschaften verschiedener Lehmsteinsorten sind geprägt durch Druckfestigkeiten bis 11 N/mm2, mit üblichen Werten bei 2 bis 5 N/mm2. Ein kritischer Punkt ist die Abhängigkeit der Festigkeitseigenschaften der Lehmsteine von der Materialfeuchte. Die vorliegenden Untersuchungen haben jedoch gezeigt, dass in einem Luftfeuchtebereich von 40 bis 70 % RLF die Druckfestigkeit von Lehmsteinen verhältnismäßig konstant ist. Mauerwerk, errichtet mit Lehmsteinen und Lehm‐Mauermörtel, zeigt ähnliche Druckfestigkeiten und E‐Module wie Mauerwerk, das mit Porenbetonsteinen errichtet wurde. Infolge einer geringeren Haftscherfestigkeit zwischen Lehmmörtel und Lehmstein ist die Schubfestigkeit von Lehmsteinmauerwerk vergleichsweise niedrig.Properties of industrially produced earthen building products for masonry and behaviour of earth block masonry. The contribution gives an overview of the properties of industrially produced earthen building products for masonry. In the meantime the quality of the industrial production of this group of building materials reached a level similar to that of other products for construction. Earth plasters exist as plasters for universal, one or multi layer applications or as lower, upper or finish plasters. Earth blocks are provided in different sizes and with different perforations. The mechanical properties of different earth block types are signified by compressive strength of up to 11 N/mm2 but are typically in a range between 2 and 5 N/mm2. A critical point is the correlation of the strength of earthen materials with their moisture content. Results from earth blocks showed that in a relative humidity window between 40 and 70 % rh the compressive strength of earth blocks is fairly constant. Masonry made from earth block and earth mortar exhibited compressive strength and elastic modules similar to masonry made with aerated autoclaved concrete blocks. The shear strength of earth block masonry, however, is fairly low, due to the weak bond between earth block and earth mortar.
Erratum to “Characterization of the regulatory roles of the SUMO”
Authors: Hwang Kwang Woo , Won Tae Joon , Kim Hyunok , Chun Ha‐Jung , Chun Taehoon , Park Yongsoo 
Published: February 2012

AbstractBackgroundType 1 diabetes is a multi‐factorial autoimmune disease that results from the destruction of insulin‐producing β cells of the pancreas; both genetic and environmental factors are thought to contribute to its development. Recently, a novel gene encoding small ubiquitin‐like modifier protein 4 (SUMO4) was cloned and a single nucleotide substitution (M55V) was found to be strongly associated with type 1 diabetes. SUMO4 was shown to interact with IκBα and inhibit NFκB transcriptional activity. The M55V substitution of SUMO4 may affect its ability to modify IκBα by sumoylation, and so lead to activation of NFκB and transcription of genes implicated in the development of type 1 diabetes. However, the effects of sumoylation on immune cells are poorly understood.MethodsHuman SUMO1, 2, 3, 4 and mouse SUMO2 (mSUMO2) were cloned and overexpressed in T and B cells using retroviral transduction. We then investigated whether SUMO overexpression affected their functions in vitro. To study the function of mSUMO2 in vivo, we made transgenic mice overexpressing mSUMO2 in T cells and pancreatic β cells and compared them with transgenic mice expressing a super‐repressor of NFκB (a dominant negative form of NFκB, IκBαΔN) in T cells. Diabetes was induced in the two groups of mice by i.p. injection of streptozotocin.ResultsHuman SUMO1, 2, 3, 4 and mSUMO2 were all found to negatively regulate the transcriptional activity of T and B cells. Supporting this idea, mSUMO2 overexpression in T cells suppressed the production of both Th1 and Th2 cytokines unlike T cells from the IκBαΔN mice. However, transgenic mice overexpressing mSUMO2 had the same susceptibility to diabetes as wild type whereas the mice overexpressing IκBαΔN Tg were completely protected against diabetes.ConclusionThese results indicate that at least in T cells, whereas NFκB has pro‐apoptotic activity, mSUMO2 plays a more complex role in the development of autoimmune diabetes. The relative influence of NFκB and sumoylation on the development of autoimmune diabetes in vivo may vary depending on the developmental stage and cell type. Copyright © 2012 John Wiley & Sons, Ltd.
Emerging roles of neural stem cells in cerebral cortex development and evolution
Authors: Borrell Víctor , Reillo Isabel 
Published: February 2012

AbstractExpansion and folding of the cerebral cortex are landmark features of mammalian brain evolution, which are recapitulated during embryonic development. Neural stem cells and their derived germinal cells are coordinated during cerebral cortex development to produce the appropriate amounts and types of neurons. This process is further complicated in gyrencephalic species, where newborn neurons must disperse in the tangential axis to expand the cerebral cortex in surface area. Here, we review advances that have been made over the last decade in understanding the nature and diversity of telencephalic neural stem cells and their roles in cortical development, and we discuss recent progress on how newly identified types of cortical progenitor cell populations may have evolved to drive the expansion and folding of the mammalian cerebral cortex. © 2012 Wiley Periodicals, Inc. Develop Neurobiol 72: 955–971, 2012
Mechanistic Study of the Oxidative Carbonylation of Methanol Catalyzed by Palladium Diphosphane Complexes with Nitrobenzene as Oxidant
Authors: Mooibroek Tiddo J. , Bouwman Elisabeth , Drent Eite 
Published: February 2012

AbstractThe reactivity of Pd complexes having bidentate diarylphosphane ligands was studied in the oxidative carbonylation of CH3OH to dimethyl carbonate/oxalate (DMC/O) with PhNO2 as the oxidant. Different ligands were employed with variation in backbone length and aryl ring substituent, and the acidity, CO pressure, or the partial pressure of H2 was varied. At two different stages in the catalytic cycle, one equivalent of DMC/O may evolve for every equivalent of PhNO2 reduced, which means that the efficiency with which nitrobenzene can function as the oxidant for the oxidative carbonylation of methanol (EOC) can potentially be 200 % relative to nitrobenzene conversion. The selectivity for DMC relative to DMO is thought to be determined by a species of the type [P2PdC(O)OCH3(R)]; the DMO/DMC ratio can be increased by increasing the CO pressure, by addition of an acid, or by using a ligand with a relatively large bite angle. On the basis of the collected results, we conclude that an ideal catalyst for oxidative carbonylation would have a relatively acidic palladium center and be sterically undemanding in the axial positions but sterically demanding in the equatorial positions of palladium. The Pd complex of bis(diphenylphosphanyl)ferrocene meets these criteria and was found to function most efficiently with PhNO2 as oxidant for the oxidative carbonylation of methanol among the series of compounds studied, that is, with about 50 % of the theoretical maximum efficiency EOC.