bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecology of rare water plant communities in lakes of north-eastern Poland
Authors: Jabłońska Ewa , Kłosowski Stanisław
Published: March 2012

Habitat studies were conducted on three rare plant communities dominated by Nuphar pumila, Nymphaea candida and Hydrilla verticillata in lakes of north-eastern Poland. The comparison of habitat properties of these three types of phytocoenoses with those of Nuphar lutea common in the area under study was also performed. It was demonstrated that the plant communities studied were ecologically distinct. The habitats of the phytocoenoses of N. pumila differed most significantly from those of the other phytocoenoses. They often inhabited softer waters poor in Mg2+, dissolved SiO2, but rich in total Fe, PO43−, NO3−, and were associated with acidic substrates containing lower levels of Ca2+ and Na+, but greater amounts of total Fe and NO3−. The differences in the habitats of H. verticillata and N. candida phytocoenoses were most pronounced in the case of four properties of water: Na+, K+, Cl−, and Mg+. Their values were lower in waters of the H. verticillata phytocoenoses. The habitats of all the three types of rare phytocoenoses differed considerably from those of N. lutea. The most significant differences were found between the N. lutea and N. pumila phytocoenoses and the smallest differences were between the patches of N. lutea and N. candida. The properties of water were more important in differentiating the habitats of the phytocoenoses studied than the substrate properties. Due to alkalization and increase in water hardness in the lakes studied the stands of N. pumila are among the most threatened. The patches of N. candida and H. verticillata, which occur in waters with a wider range of hardness and tolerating a slight increase in trophy, can still continue to persist in the lakes for a long time.
Leukocytosis as an important risk factor for arterial thrombosis in WHO‐defined early/prefibrotic myelofibrosis: An international study of 264 patients
Authors: Buxhofer‐Ausch Veronika , Gisslinger Heinz , Thiele Jürgen , Gisslinger Bettina , Kvasnicka Hans‐Michael , Müllauer Leonhard , Frantal Sophie , Carobbio Alessandra , Passamonti Francesco , Rumi Elisa , Ruggeri Marco , Rodeghiero Francesco , Randi Maria L. , Bertozzi Irene , Vannucchi Alessandro M. , Antonioli Elisabetta , Finazzi Guido , Gangat Naseema , Tefferi Ayalew , Barbui Tiziano
Published: April 2012

We aimed to determine risk factors for thrombotic events in early/prefibrotic myelofibrosis diagnosed according to the World Health Organization criteria. Multivariate Cox regression analysis was calculated on a total number of 264 patients derived from an international database. After a median follow‐up of 6.28 years, 42 (15.9%) patients experienced arterial (n = 31) or venous thrombosis (n = 11). A higher leukocyte count correlated with an increased risk for total thrombosis and in particular, with an increased risk for arterial thrombosis (P = 0.005, HR 1.15 and P = 0.047, HR 1.12, respectively). A platelet count above 870 × 109/L was associated with a lower risk for total thrombosis and also for venous thrombosis (P = 0.022, HR 0.44 and P = 0.027, HR 0.19). Moreover, a lower hemoglobin level was associated with an increased risk for venous thrombosis (P = 0.007, HR 0.59). Our data indicate that leukocytosis is a prominent risk factor for thrombosis in early/prefibrotic MF. Am. J. Hematol. 87:669–672, 2012. © 2012 Wiley Periodicals, Inc.
Geotechnik im Bauwesen, RWTH Aachen, Mies‐van‐der‐Rohe‐Straße 1, 52074 Aachen
Authors: Ziegler Martin , Tafur Elias
Published: April 2012

Die geotechnische Bemessung nach EC7‐1 zusammen mit dem zugehörigen Nationalen Anhang und den ergänzenden Regelungen in DIN 1054:2010‐12 ermöglicht bei der Bestimmung der Bemessungswerte der Einwirkungen die Anwendung von Kombinationsregeln, wodurch nicht alle voneinander unabhängigen veränderlichen Einwirkungen gleichzeitig mit ihrer vollen Größe berücksichtigt werden. Hingegen wurden nach der bisherigen Norm DIN 1054:2005‐01 alle veränderlichen Einwirkungen gleichzeitig in voller Höhe angesetzt. Im Rahmen eines vom Deutschen Institut für Bautechnik geförderten Forschungsvorhabens wurden am Lehrstuhl für Geotechnik im Bauwesen der RWTH Aachen zwei Beispielrechnungen mit beiden Bemessungskonzepten durchgeführt, um den Einfluss der Kombinationsregeln auf die geotechnische Bemessung zu untersuchen. Die Ergebnissen zeigten, dass die Unterschiede bei der Bemessung nach beiden Konzepten nicht signifikant waren, während der Rechenaufwand nach dem neuen Bemessungskonzept um ein Vielfaches anstieg.

Combination rules in geotechnics – Chance or curse?

The geotechnical design according to EC7‐1, including the German National Annex and the complementary rules in DIN 1054:2010‐12 allows the application of combination rules for the determination of the design values for actions, whereby not all transient actions are taken into account with their full amount at the same time. On the other hand the former version of DIN 1054:2005‐01 considers all transient actions with their full amount. Within the framework of a research project, which was funded by Deutsches Institut für Bautechnik, two geo‐technical examples were calculated at the Chair of Geotechnical Engineering at RWTH Aachen University applying both design concepts, in order to investigate the influence of the combination rules on the geotechnical design. The results showed that the design with both concepts does not differ significantly, while the calculation effort with the new concept is many times greater.
ArborTUM – Umsetzung eines historischen Tragsystems mit modernen Entwurfs‐ und Ausführungsmöglichkeiten
Authors: Sieder Mike , Krecker Tobias , Marsik Michal
Published: April 2012

In einer interdisziplinären Zusammenarbeit zwischen Studenten der Architektur‐ und der Bauingenieurfakultät der Technischen Universität München entstand ein skulpturales Holzobjekt, bei dem das historische Tragprinzip des Hebelstabwerks durch die zukunftsweisende Möglichkeit des parametrischen Entwerfens umgesetzt und mithilfe moderner CNC‐Holzbearbeitungstechnik ausgearbeitet wurde.

ArborTUM – Realization of a historic structural principle by the possibilities of modern design and processing technology.

Students of the faculty of architecture and civil engineering of the Technische Universität München created a sculptural timber object in an interdisciplinary cooperation. Thereby the historic structural principle of the selfsupporting‐framework was realized by the forward‐looking possibility of the parametric design and by modern CNC‐wood processing technology.
Exploring the seasonality of birth defects in the New York State Congenital Malformations Registry
Authors: Caton Alissa R.
Published: April 2012

BACKGROUND

Examining seasonal patterns of birth defects may help to identify environmental risk factors. Because the teratogenic window for most birth defects is during gestational weeks 3 to 8, investigating exposures closer to the timing of conception is important. However, studies are usually based on month of birth, which is not the biologically relevant exposure period and does not account for differences in gestational length. We aimed to determine whether the occurrence of birth defects varied by month of conception using the population‐based New York State Congenital Malformations Registry (CMR).

METHODS

We merged live birth certificates (n = 2,044,091) with CMR records for mothers residing in New York State, excluding New York City, for the years 1992 through 2006. We categorized birth defects according to the National Birth Defects Prevention Network guidelines and performed Cochran‐Armitage trend, Hewitt‐Rogerson, and Walter‐Elwood tests on month of conception and chi‐square tests on season of conception. We graphed seasonal distributions and seasonality test results. We performed stratified analyses by maternal and infant characteristics.

RESULTS

Of 42 groups examined in the 15‐year period, 24 (57%) had at least one statistically significant test result, suggesting a trend or seasonal variation: Cochran‐Armitage (18), Hewitt‐Rogerson (17), Walter‐Elwood (4), and chi‐square (5). Ventricular septal defect showed the most consistent results: Cochran‐Armitage (p = 0.0006), Hewitt‐Rogerson (December to May; p = 0.0130), Walter‐Elwood (March 14; p = 0.0027), and chi‐square (winter; p = 0.0046). Congenital cataract, pulmonary valve atresia/stenosis, coarctation of aorta, biliary atresia, and renal agenesis or hypoplasia had at least three significant tests.

DISCUSSION

These results may help to generate hypotheses about environmental factors that vary by season for further studies. Birth Defects Research (Part A) 2012. © 2012 Wiley Periodicals, Inc.
Transient recombinant protein expression in a human amniocyte cell line: The CAP‐T® cell system
Authors: Fischer Simon , Charara Nadine , Gerber Andrea , Wölfel Jens , Schiedner Gudrun , Voedisch Bernd , Geisse Sabine
Published: April 2012

The impact of transient gene expression approaches (TGE) on the rapid production of recombinant proteins is undisputed, despite that all efforts are currently relying on two host cell families only, namely HEK293 derivatives and CHO cell line(s). Yet, the increasing complexity of biological targets calls for more than two host cell types to meet the challenges of difficult‐to‐express proteins. For this reason, we evaluated the more recently established novel CAP‐T® cell line derived from human amniocytes for its performance and potential in transient gene expression. Upon careful analyses and adaptation of all process parameters we show here that indeed the CAP‐T® cells are extremely amenable to transient gene expression and recombinant protein production. Additionally, they possess inherent capabilities to express and secrete complex and difficult target molecules, thus adding an attractive alternative to the repertoire of existing host cell lines used in transient production processes. Biotechnol. Bioeng. 2012;109: 2250–2261. © 2012 Wiley Periodicals, Inc.
Cloning, mutagenesis, and characterization of the microalga Parietochloris incisa acetohydroxyacid synthase, and its possible use as an endogenous selection marker
Authors: Grundman Omer , Khozin‐Goldberg Inna , Raveh Dina , Cohen Zvi , Vyazmensky Maria , Boussiba Sammy , Shapira Michal
Published: April 2012

Parietochloris incisa is an oleaginous fresh water green microalga that accumulates an unusually high content of the valuable long‐chain polyunsaturated fatty acid (LC‐PUFA) arachidonic acid within triacylglycerols in cytoplasmic lipid bodies. Here, we describe cloning and mutagenesis of the P. incisa acetohydroxyacid synthase (PiAHAS) gene for use as an herbicide resistance selection marker for transformation. Use of an endogenous gene circumvents the risks and regulatory difficulties of cultivating antibiotic‐resistant organisms. AHAS is present in plants and microorganisms where it catalyzes the first essential step in the synthesis of branched‐chain amino acids. It is the target enzyme of the herbicide sulfometuron methyl (SMM), which effectively inhibits growth of bacteria and plants. Several point mutations of AHAS are known to confer herbicide resistance. We cloned the cDNA that encodes PiAHAS and introduced a W605S point mutation (PimAHAS). Catalytic activity and herbicide resistance of the wild‐type and mutant proteins were characterized in the AHAS‐deficient E. coli, BUM1 strain. Cloned PiAHAS wild‐type and mutant genes complemented AHAS‐deficient bacterial growth. Furthermore, bacteria expressing the mutant PiAHAS exhibited high resistance to SMM. Purified PiAHAS wild‐type and mutant proteins were assayed for enzymatic activity and herbicide resistance. The W605S mutation was shown to cause a twofold decrease in enzymatic activity and in affinity for the Pyruvate substrate. However, the mutant exhibited 7 orders of magnitude higher resistance to the SMM herbicide than that of the wild type. Biotechnol. Bioeng. 2012;109: 2340–2348. © 2012 Wiley Periodicals, Inc.
In vitro 3D human small intestinal villous model for drug permeability determination
Authors: Yu Jiajie , Peng Songming , Luo Dan , March John C.
Published: April 2012

We present a novel method for testing drug permeability that features human cells cultured on hydrogel scaffolds made to accurately replicate the shape and size of human small intestinal villi. We compared villous scaffolds to more conventional 2D cultures in paracellular drug absorption and cell growth experiments. Our results suggest that 3D villous platforms facilitate cellular differentiation and absorption more similar to mammalian intestines than can be achieved using conventional culture. To the best of our knowledge, this is the first accurate 3D villus model offering a well‐controlled microenvironment that has strong physiological relevance to the in vivo system. Biotechnol. Bioeng. 2012;109: 2173–2178. © 2012 Wiley Periodicals, Inc.
Maßgeschneiderte Mikroorganismen
Authors: Pelzer Stefan
Published: April 2012

Die Diversität der Mikroorganismen stellt eine unerschöpfliche Quelle für industriell relevante Prozesse und Produkte dar. Schon zu Beginn des vergangenen Jahrhunderts wurden Mikroorganismen zur großtechnischen Produktion von biobasierten Wertstoffen eingesetzt. Der Zugriff auf moderne Methoden der mikrobiellen Stammentwicklung, wie die Synthetische Biologie, ermöglicht die Konstruktion von maßgeschneiderten Mikroorganismen. Diese stellen schon heute Plattformchemikalien, Enzyme, Polymere, Biokraftstoffe und pflanzliche Wirkstoffe wie Artemisinin nicht nur nachhaltig, sondern auch ökonomisch attraktiv her. Zukunftstrends der mikrobiellen Forschung, wie die Produktion neuer Biokraftstoffe, mikrobielle Brennstoffzellen und Nutzung von CO2 als Rohstoff, bieten die große Chance, globalen Herausforderungen zu begegnen. Die mikrobielle Forschung steht im Mittelpunkt der Weißen Biotechnologie, die für die notwendige Transformation der Chemieindustrie in eine wissensbasierte Bioökonomie essenziell ist.
Vom Klostergarten ins Labor
Authors: Jacobsen H.‐J.
Published: April 2012

Die Geschichte der Pflanzenzüchtung zeigt eindrucksvoll das Bestreben der Menschheit, Pflanzen durch genetische Eingriffe stetig zu verbessern. Dabei wurden Wildmerkmale entfernt und Sorten entwickelt, die für den Menschen nützliche Eigenschaften aufwiesen. Allerdings stoßen die klassischen Methoden immer dann an Grenzen, wenn erwünschte Merkmale nicht im Genpool der kreuzbaren Arten liegen. Oft sind erwünschte Merkmale – wie beispielsweise Resistenzen – nicht oder nicht mehr im Genpool vorhanden oder sie sind mit negativen Eigenschaften gekoppelt. Dann kann es sinnvoll sein, fremde Genpools anzuzapfen, d.h. diese Eigenschaften mittels Gentransfer neu in die Kulturarten zu integrieren. Beispiele dafür werden vorgestellt und diskutiert. Zusammenfassend wird dafür plädiert, nicht so sehr die Methode zu diskutieren, mit der eine Pflanze verändert wurde, sondern das Ergebnis auf Nützlichkeit zu überprüfen.
Frühe Telomermessung sagt Lebensdauer voraus
Authors: Brennicke Axel
Published: April 2012

Bei allen Tieren und Pflanzen ist die genetische Information in linearen DNA‐Molekülen codiert, den Chromosomen. Bei jeder normalen Zellteilung werden die Enden dieser Moleküle ein Stückchen kürzer, so dass alte Individuen kürzere Endstücke haben als junge. Diese Verkürzung scheint eine der Ursachen für das Altern und den unausweichlichen Tod zu sein. Eine neue Untersuchung zum Zusammenhang zwischen der Länge dieser Enden und der Lebenserwartung bei Zebrafinken zeigt jetzt, dass junge Individuen mit besonders langen Chromosomenenden deutlich länger leben als solche mit kürzeren Endstücken.
Wanderausstellung LandschafftRessourcen
Authors: Sehm Julia
Published: April 2012

Was ist Landschaft? Wie wird sie vom Menschen genutzt und verändert? Wie wirkt sich ihre Nutzung auf ihre Funktionsweise aus? Wie können diese Veränderungen erforscht und eingeschätzt werden? Mit diesen spannenden Fragen beschäftigt sich die Wanderausstellung LandschafftRessourcen, die zur Zeit in Gießen zu sehen ist.
Selective and Sensitive Recognition of Cu2+ in an Aqueous Medium: A Surface‐Enhanced Raman Scattering (SERS)‐Based Analysis with a Low‐Cost Raman Reporter
Authors: Sarkar Sougata , Pradhan Mukul , Sinha Arun Kumar , Basu Mrinmoyee , Pal Tarasankar
Published: April 2012

In the present study, surface‐enhanced Raman spectra of a bifunctional Raman reporter, 2‐mercaptobenzimidazole, has been found to be responsive exclusively towards Cu2+ ions while the reporter remains anchored on the Au nanoparticle surface. Thus a specific Cu2+‐ion‐detection protocol emerges. The simplicity, sensitivity, and reproducibility of the method allow routine and quantitative detection of Cu2+ ions. An interference study involving a wide number of other metal ions shows the procedure to be uniquely selective and analytically rigorous. A theoretical study was carried out to corroborate the experimental results. Finally, the method is promising for real‐time assessment of Cu2+ ions in aqueous samples and also has the ability to discriminate CuI and CuII ions in solution.
DFT Studies on Cobalt‐Catalyzed Cyclotrimerization Reactions: The Mechanism and Origin of Reaction Improvement under Microwave Irradiation
Authors: Rodriguez Antonio M. , Cebrián Cristina , Prieto Pilar , García José Ignacio , de la Hoz Antonio , Díaz‐Ortiz Ángel
Published: April 2012

A DFT computational mechanistic study of the [2+2+2] cyclotrimerization of a diyne with benzonitrile, catalyzed by a cobalt complex, has been carried out. Three alternative catalytic cycles have been examined together with the precatalytic step (responsible for the induction period). The favored mechanism takes place by means of an intramolecular metal‐assisted [4+2] cycloaddition. The beneficial role of microwave activation has been studied. It is concluded that microwave irradiation can decrease the catalytic induction period through thermal effects and can also increase the triplet lifetime and promote the reaction, thus improving the final yield.
Versatile Logic Devices Based on Programmable DNA‐Regulated Silver‐Nanocluster Signal Transducers
Authors: Huang Zhenzhen , Tao Yu , Pu Fang , Ren Jinsong , Qu Xiaogang
Published: April 2012

A DNA‐encoding strategy is reported for the programmable regulation of the fluorescence properties of silver nanoclusters (AgNCs). By taking advantage of the DNA‐encoding strategy, aqueous AgNCs were used as signal transducers to convert DNA inputs into fluorescence outputs for the construction of various DNA‐based logic gates (AND, OR, INHIBIT, XOR, NOR, XNOR, NAND, and a sequential logic gate). Moreover, a biomolecular keypad that was capable of constructing crossword puzzles was also fabricated. These AgNC‐based logic systems showed several advantages, including a simple transducer‐introduction strategy, universal design, and biocompatible operation. In addition, this proof of concept opens the door to a new generation of signal transducer materials and provides a general route to versatile biomolecular logic devices for practical applications.
Usage of Solid Recovered Fuels in Power Plants
Authors: Gehrmann Hans‐Joachim , Seifert Helmut , Beckmann Michael , Glorius Thomas
Published: April 2012

Alternative Brennstoffe können Regelbrennstoffe direkt, z. B. in Kohlekraftwerken, und indirekt, z. B. durch thermochemische Konversion zu gasförmigen, flüssigen und festen Brennstoffen, ersetzen. Die Bandbreite reicht dabei von abfallbasierten Brennstoffen, sog. Ersatzbrennstoffe (EBS), bis hin zu einer Vielzahl biogener Brennstoffe. Vor dem Hintergrund der CO2‐Reduktionsziele und der Energiewende leistet die effiziente energetische Nutzung dieser alternativen Brennstoffe einen wesentlichen Beitrag zur Verringerung des Einsatzes fossiler Energieträger. Ausgehend von der Brennstoffcharakterisierung werden prozesstechnische Anforderungen und die Effizienz verschiedener Verfahrensketten zur energetischen Nutzung der EBS betrachtet sowie ein Überblick über den EBS‐Einsatz im Kraftwerksbereich in Deutschland gegeben.
Faltungshelfer in Bewegung
Authors: Groß Michael
Published: April 2012

Molekulare Anstandsdamen (Chaperone) schützen Proteine vor unerwünschten molekularen Wechselwirkung bei ihrer Strukturfindung. Die komplexesten Mitglieder der Familie, die Chaperonine, fungieren – naiv betrachtet – als molekularer Kochtopf: Protein hinein, Deckel drauf, und erst wenn das Protein fertig ist, kommt es wieder heraus. Strukturbiologen haben nun herausgefunden, dass die Komponenten des Topfes komplizierte Bewegungen ausführen, um dem Protein die jeweils benötigte Umgebung zu bieten.
Erster Syntheseschritt zur 22. Aminosäure
Authors: Feil Sylvia
Published: April 2012

Die Aminosäure Pyrrolysin wurde vor zehn Jahren erstmals beschrieben. Sie ist die 22. natürliche Aminosäure, wird allerdings nur von Archaebakterien und Bakterien synthetisiert. Den ersten Schritt ihrer Biosynthese entschlüsselte nun ein Team von Wissenschaftlern um Michael Groll an der TU München.
Beitragsserie: Eurocode 6 für Deutschland – Beispiele zur Bemessung von Mauerwerk
Authors: Steinigen Frank
Published: April 2012

Anm. der Redaktion: Mit dieser Beitragsserie sollen fortlaufend Beispiele für die Berechnung und Bemessung von Bauteilen aus Mauerwerk nach Eurocode 6 (DIN EN 1996‐1‐1 und ‐3 mit dem jeweiligen deutschen Nationalen Anhang) unseren Lesern zur Verfügung gestellt werden, um dem Anwender die Einarbeitung in die neue Norm, die nunmehr ab 01. 07. 2012 in Deutschland angewendet werden darf, zu erleichtern.

Eurocode 6 for Germany – examples for the design of masonry. Editorial staff: This series presents working examples for the design of masonry members according to Eurocode 6 (DIN EN 1996‐1‐1 and ‐3 together with the German national Annex) in the future. It should facilitate our readers the adjustment to the new code which can be applied from July 1 2012 in Germany.

Nachfolgend wird die Nachweisführung einer Kellerwand in einem Mehrfamilienhaus nach Eurocode 6 mit NA vorgestellt. Es handelt sich dabei um einen Anwendungsfall mit relativ geringer Auflast, bei dem die Einstellung der Bogenwirkung und die Tragfähigkeit der Wand überprüft werden sollen. Der Nachweis auf Querkrafttragfähigkeit ist bei Anwendung des genaueren Verfahrens obligatorisch und wird ebenfalls geführt.

Design of a basement wall with the standard method of EC 6. The verification of a basement wall of an apartment house in accordance with Eurocode 6 and NA is presented subsequently. It’s a question of an application with relative small surcharge, where the existence of the structural behaviour of an arch and the load‐bearing capacity of the wall are checked. The verification of the shear capacity is mandatory by appliance of the standard method and is accomplished too.
Synthesis, Structure and Transmetalation Activity of Various C,Y‐Chelated Organogold(I) Compounds
Authors: Hejda Martin , Dostál Libor , Jambor Roman , Růžička Aleš , Jirásko Robert , Holeček Jaroslav
Published: April 2012

A set of organogold(I) compounds L1–4Au(PPh3), where L1 = [o‐C6H4(CH=NC6H3iPr2‐2,6)]– (1), L2 = {o,o‐C6H3[C(Me)=NC6H3Me2‐2,6]2}– (2), L3 = [o,o′‐C6H3(CH2OMe)(CH2NMe2)]– (3), L4 = [o,o‐C6H3(CH2OMe)2]– (4), were synthesized by the reaction of parent organolithium derivatives L1–4Li with [AuCl(PPh3)] in good yields. The molecular structures of 1–4 were characterized by ESI mass spectrometry and 1H NMR, 13C NMR and 31P NMR spectroscopy, and their structures in the solid state were determined using single‐crystal X‐ray diffraction analyses. The transmetalation potential of 1–4 was tested by the reaction with either [PdCl2(CH3CN)2] or [PtCl2(Et2S)2] complexes. While the reaction of compounds 1 and 2 proceeded smoothly with the formation of the desired transition‐metal complexes, i.e. (L1PdCl)2 (5), L1PtCl(Et2S) (6) and L2MCl [M = Pd (7) or Pt (8). In the case of the O,C,N‐ and O,C,O‐chelated derivatives 3 and 4 only the platinum(II) compounds L3PtCl(PPh3) (9) and L4PtCl(Et2S)2 (10) could be isolated after the reaction, as a result of the labile behaviour of the corresponding palladium compounds. All derivatives 5–10 were characterized by the help of ESI mass spectrometry and 1H NMR, 13C NMR and 31P NMR spectroscopy, and in the case of compounds 5–7 and 9 using single‐crystal X‐ray diffraction analyses.
Preparation of α‐Sulfonylethanone Oximes from Oxidized Hydroxylamine
Authors: Liu Nan , Yin Ping , Chen Yue , Deng Yong , He Ling
Published: April 2012

Alkenes react with substituted N‐hydroxysulfonamides and tetrabutylammonium periodate under metal catalyst free conditions to give oximes in good to high yields. The reaction proceeds in a one‐pot manner, giving rise to the formation of intermolecular C–N and C–S bonds simultaneously. The method is mild, highly efficient, and convenient.
A New Heated Nickel Oxyhydroxide Covered Nickel Wire Electrode and Its Improved Electrocatalytic Oxidation for Methanol
Authors: Wu Shao‐Hua , Zhu Bao‐Jian , Huang Zong‐Xiong , Sun Jian‐Jun
Published: April 2012

A new heated nickel oxyhydroxide covered nickel wire electrode (HNONE) was fabricated and AC heating circuit was used to heat the electrode. Furthermore, the improved electrocatalytic activity of the HNONE for methanol oxidation at elevated electrode temperature was demonstrated. A detection limit of 2.1×10−4 M (S/N=3) could be obtained with an electrode temperature of 80 °C, about one magnitude lower than that at room temperature 20°. And the sensitivity was also enhanced about 10 times.
IOFI recommended practice for the quantitative analysis of volatile flavouring substances using coupled gas chromatography/mass spectrometry with selected‐ion monitoring (SIM)
Authors:   IOFI (International Organization of the Flavor Industry) Working Group on Methods of Analysis
Published: April 2012

The present recommended practice concerns the quantification of volatile flavouring substances by coupled gas chromatography/mass spectrometry with selected‐ion monitoring (SIM). This technique is especially suitable for unresolved peaks in classical gas chromatography (e.g. quantification in a complex chromatogram) and is more sensitive than the use of the mass spectrometer in the full‐scan mode. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of Ionic Transport and Separation on the Meniscus in Molten Carbonate Electrolyte
Authors: Hsieh P. H. , Chen C. C. , Selman J. R.
Published: April 2012

Migrational separation due to differences in cationic mobility is commonly observed during current passage in molten carbonate mixtures, and this might be responsible for the improved wetting observed upon polarization, as found experimentally according to the literature. To check this, a 2D transport model based on concentrated‐solution theory was applied to analyze the movement of ions in and near the meniscus. The effect of differences in cationic mobility and of ionic transport in general on current distribution, reaction rate, and electrolyte composition in the meniscus region was quantified, and corresponding surface tension gradients over the meniscus surface predicted. The resulting surface tension gradients were found to be too small to account for the experimentally observed meniscus rise. It is, therefore, concluded that the polarization effect on electrode wetting is not due to the gradient of surface tension caused by cationic separation. A plausible alternative explanation is that a gradient of the S/L interfacial tension exists but that this is due to specifically adsorbed intermediate reaction products, in particular oxides. Such a current density dependent adsorption layer would be in dynamic equilibrium with the local melt composition, and, thereby, drive the wetting/dewetting of the electrode surface that is experimentally observed.
The Eyholz Tunnel for the Visp southern bypass / Der Tunnel Eyholz der Südumfahrung Visp
Authors: Schneider Alex , Tanner Simon
Published: April 2012

The Visp bypass is an important link on the Swiss national road A9 from Lausanne to Brig‐Glis in the Canton of Valais, which is being improved to provide continuous dual carriageway. About 7 km of the alignment of this 8.8 km long section of the A9 will run through tunnels, with the core structures being the 4.2 km Eyholz Tunnel and the 3.2 km Visp Tunnel. Altogether five underground junction structures have to be constructed for the Visp bypass, of which three will be newly excavated and two are enlargements of the existing Vispertal Tunnel. The following report only deals with the Eyholz Tunnel, which has already been largely excavated. Construction of the main contract of the Visp Tunnel is planned to start in 2012.

Die Umfahrung Visp stellt ein wichtiges Teilstück der zukünftig von Lausanne bis Brig‐Glis durchgehenden richtungsgetrennten Nationalstraße A9 im Kanton Wallis dar. Die Linienführung des rund 8,8 km langen Teilstücks der A9 verläuft zu rund 7 km in Tunnelbauwerken. Kernstücke sind der 4,2 km lange Tunnel Eyholz und der 3,2 km lange Tunnel Visp. Insgesamt sind für die Umfahrung Visp fünf unterirdische Verzweigungsbauwerke zu erstellen, von denen drei komplett neu auszubrechen sind und zwei aus einer Ausweitung des bestehenden Vispertaltunnels hervorgehen. Die nachfolgenden Erläuterungen beschränken sich auf den Tunnel Eyholz, der bereits zu einem großen Teil ausgebrochen ist. Der Baubeginn des Hauptloses des Tunnels Visp ist für 2012 geplant.
Durchmesser Line, Zürich – section under the Südtrakt / Durchmesserlinie Zürich – Unterfahrung Südtrakt
Authors: Hessler Nicolas , Grieder Lukas , Ceriani Marco , Erzinger Oliver
Published: April 2012

The 9.6 km long section of the Durchmesser underground line in Zürich starts at the Altstetten station at the western edge of the city and runs from there along the existing access route to the new Löwenstraße station under the Zürich main station, and from there northwards to Oerlikon. The project is split into four sections. The 4.8 km two‐track Weinberg Tunnel with escape and rescue tunnels forms Section 3 and runs from the Löwenstraße station to the railway cutting in Oerlikon. Section 3 is sub‐divided into the two structural contracts 3.1 and 3.2. The section below the Südtrakt (south wing) and the Südtrakt shaft together form contract 3.1. This article deals with the requirements for the construction works and describes the chosen concept of “mined top‐down construction”.

Die 9,6 km lange Strecke der Durchmesserlinie Zürich beginnt am westlichen Stadtrand von Zürich beim Bahnhof Altstetten und verläuft von dort entlang der bestehenden Zufahrtsstrecke zum neuen Bahnhof Löwenstraße unter dem Hauptbahnhof Zürich und von dort nordwärts bis Oerlikon. Das Projekt ist in vier Abschnitte gegliedert. Der 4,8 km lange doppelspurige Weinbergtunnel mit Flucht‐ und Rettungsstollen bildet den Abschnitt 3 und führt vom Bahnhof Löwenstraße zum Bahneinschnitt Oerlikon. Der Abschnitt 3 ist wiederum in die zwei Rohbaulose 3.1 und 3.2 unterteilt. Die Unterfahrung des Südtrakts und der Schacht Südtrakt bilden zusammen das Los 3.1. Der Beitrag fasst die Anforderungen an die Baumaßnahme zusammen und stellt das gewählte Konzept der “bergmännischen Deckelbauweise” vor.
Construction of a cavern under an autobahn embankment for the Ceneri Base Tunnel / Unterquerung eines Autobahndamms durch eine Kaverne beim Ceneri‐Basistunnel
Authors: Filippini Raffaele , Kovári Kalman , Rossi Francesco
Published: April 2012

The driving of a cavern with large dimensions with little cover under an autobahn embankment while preserving road safety results in challenging design and construction problems. The embankment is filled against a mountainside and is founded on an intermediate layer of loose ground several metres thick above the rock. The acute angle between the centreline of the cavern and the autobahn and the rock boundary made for a markedly three‐dimensional structure. The chosen concept for the tunnel structure has the following features: top heading advance with previously concreted abutments to support the shotcrete temporary lining under the protection of a double jet grout canopy. Each concrete abutment is also supported on a foundation body formed of jet grout columns, so that the loading on the vault is transferred directly into the undisturbed rock. The face of the top heading with an excavated area of up to 160 m2 is supported partially by passive steel anchors and partially by reinforced jet grout columns. The maximum surface settlements of the carriageway resulting from the driving of the top heading and the bench/invert were only 35 mm.

Die Unterfahrung eines Autobahndammes durch eine Kaverne mit großen Abmessungen bei geringer Überlagerung und bei Gewährleistung der Verkehrssicherheit stellt anspruchsvolle planerische und ausführungstechnische Probleme. Der Dammkörper lehnt sich an eine Felsböschung und ruht auf einer Zwischenschicht von Lockergesteinen von einigen Metern Stärke, auf die dann wieder Felsmaterial folgt. Der schiefe Schnitt zwischen der Achse der Kaverne und der Autobahn sowie die Felsbegrenzung schufen ein ausgesprochen dreidimensionales Tragwerk. Das gewählte tunnelstatische Konzept wies folgende grundlegende Merkmale auf: Kalottenvortrieb mit voraus erstellten Betonwiderlagern für die Spritzbetonschale im Schutz eines doppelten HDI‐Gewölbes. Die Betonwiderlager selbst werden auf Fundationskörper aus HDI‐Säulen gestellt, sodass die Gewölbebelastung direkt zum anstehenden Fels geführt wird. Die Ortsbrust der Kalotte mit einer Ausbruchfläche von bis zu 160 m2 wird teils durch Passivanker aus Stahl, teils durch bewehrte HDI‐Säulen gesichert. Die größte Oberflächensetzung auf der Fahrbahn betrug, infolge des Vortriebs der Kalotte und der Strosse/Sohle insgesamt lediglich 35 mm.
Implications of Medical School Selection Research for the Counseling of Premedical Students
Authors: JARECKY ROY K. , JOHNSON DAVIS G.
Published: April 2012

A valid complaint voiced by advisers of preprofessional students is that once their charges have entered graduate school, news relative to the student's academic progress is hard to come by. The adviser will, of course, in due time be informed as to whether his protégés have in general passed or specifically failed. The trouble is that the adviser rarely learns why his former students have failed. Because of this lack of information, he is hard put to assess the effectiveness of his own counseling.

The purpose of this paper is to present relevant findings from two studies recently conducted by the Student Personnel Office of the Upstate Medical Center in Syracuse, New York. The major concern of both studies was to determine whether any relationship might exist between certain background data and the student's academic progress in medical school. It is convenient to refer to the investigations as studies A and B. Study A was concerned with 688 medical students who entered the Upstate Medical Center during the nine‐year period from September, 1949, through September, 1957 [4]. It provides a detailed analysis of past experience with medical students of various ages, mental abilities, college majors, and so forth. Study B, not yet fully completed, reports experience with the validity of a 16‐factor interview approach for 293 members of the classes entering 1956–1959.
Realistic Occupational Appraisal by High School Seniors
Authors: MILLIKEN ROBERT L.
Published: April 2012

Many colleges throughout the country have become increasingly selective in the quality of students they allow to matriculate. The trend appears to be toward even more selectivity. Nevertheless, Havighurst has suggested that an increasing number of students will attend schools. This will include schools which have one‐ and two‐year terminal programs [5].

How realistic are students in considering their potential to succeed in college? Are those who plan to work rather than attend college utilizing their full potential? Are the able students more realistic in their educational and vocational plans than the less able? Lockwood, in 1958, indicated that intelligence seemed directly related to the students' level of realism of their vocational preference. However, he noted that “… pupils of high mental ability sometimes select vocations offering limited opportunities and pupils of low mental ability sometimes select occupations for which they are not intellectually fitted” [9].
Pre‐College Experiences and Curriculum Changes By College Students
Authors: GAMBLE GLENN W.
Published: April 2012

For perhaps the first time in the history of our country, education has become a topic of primary concern to the American public. Daily, our newspapers and magazines inform us of the large numbers of students who will be seeking a college education within the next few years. It is the responsibility of the school to find ways of meeting this need so that “quality in quantity” [6] may be the outcome.

In the past few years, with school enrollments increasing so rapidly many studies have been conducted to determine ways of predicting college success and adjustment. Because of the emphasis on the general theme of college adjustment, it was felt that there are other factors such as vocational maturity and curriculum certainty which might also be studied to learn more about this general adjustment problem.
“I Was Skeptical at First”: Content Literacy in the Art Museum
Authors: Barry Arlene Lundmark
Published: April 2012

This manuscript describes 51 preservice teachers’ reactions to their engagement with works of art in a community art museum. Participants were individuals in an adolescent literacy course who were future teachers of middle and secondary content subjects. They were initially skeptical about using artwork to support their content and serve as a catalyst for reading and writing. Based on their written reflections, however, attitudes changed dramatically following their experiences at the art museum and their application of the images to specific issues in their subject specialization. Analysis of their feedback showed perceived benefits to fall into five categories: (1) increased understanding of ways to integrate content, (2) development of additional resources, (3) practice thinking outside the proverbial box, (4) the ability to provide for multiple intelligences and learning preferences, and (5) an opportunity to get out of the classroom. Such benefits, they concluded, better prepared them as teachers.
Reading Culturally Relevant Literature Aloud to Urban Youths With Behavioral Challenges
Authors: Verden Claire E.
Published: April 2012

This article discusses the viability of reading culturally relevant literature aloud to urban middle school youth. The findings from a research study are shared and guidelines for implementing a culturally sensitive read aloud program in your own middle school or high school classroom are discussed. Anecdotes from students involved in the study are discussed to demonstrate the learning that took place as a result of the literature that was read aloud.
A Different Kind of Reading Instruction: Using Visualizing to Bridge Reading Comprehension and Critical Literacy
Authors: Park Jie Y.
Published: April 2012

Many literacy teachers are creating contexts for students to learn and use a range of reading comprehension strategies. As useful as reading strategy instruction is, relatively little has been documented on the ways in which reading strategies can become tools for critical literacy. In this paper, the author illustrates how a reading strategy can become a tool for critical literacy, focusing on the specific strategy of visualizing. Drawing on data collected from a yearlong qualitative study of three after‐school book clubs for adolescent girls, the author discusses how adolescents visualize texts and what happens when they share their visualizations. In sharing their visualizations, the adolescents were sharing how they “see” people and the world, and why they see that way. The author argues for a different kind of reading instruction, one in which reading strategies are seen as resources to be used for exploring written texts and texts of students' lives.
Calcium upregulated survivin expression and associated osteogenesis of normal human osteoblasts
Authors: Ortiz Jan , Chou Laisheng Lee
Published: April 2012

Survivin is an antiapoptotic protein expressed in all phases of the normal cell cycle but is at its highest level during the G2/M interphase. This protein has been recently identified in normal human osteoblasts and has raised questions about the regulation of its expression. This study intends to verify if survivin expression could be manipulated by external factors such as calcium ions. Normal human alveolar bone explants recovered from six healthy donors were cultured to 2nd passage. Cells were cultured with essential medium as a control and with medium containing supplemental calcium ions at a concentration of 30 parts per million as a study group. Vitamin D3 was added to all culture groups at the 5th and 18th days to promote differentiation. Differentiation markers were confirmed by performing mineralization, alkaline phosphatase (ALP), and osteocalcin assays at 7 and 21 days. Cell attachment was measured at 16 h and used as a reference for cell proliferation at 7 days and 21 days. Survivin levels were measured at 16 h, 7 and 21 days. Compared with the control group, the study group presented a significant increase of survivin expression at 16 h (p < 0.01), at 7 days (p < 0.01), and at 21 days (p < 0.05), a significant increase of cell proliferation, ALP activity and mineralization at 7 days (p < 0.05) and 21 days (p < 0.05), and a significant increase in osteocalcin expression only at 21 days (p < 0.01). This study demonstrated that survivin expression could be significantly upregulated by calcium‐enhanced normal human osteoblast cultures, which might correlate to subsequent upregulation of cell proliferation and differentiation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Poly(propylene fumarate) reinforced dicalcium phosphate dihydrate cement composites for bone tissue engineering
Authors: Alge Daniel L. , Bennett Jeffrey , Treasure Trevor , Voytik‐Harbin Sherry , Goebel W. Scott , Chu Tien‐Min Gabriel
Published: April 2012

Calcium phosphate cements have many desirable properties for bone tissue engineering, including osteoconductivity, resorbability, and amenability to rapid prototyping‐based methods for scaffold fabrication. In this study, we show that dicalcium phosphate dihydrate (DCPD) cements, which are highly resorbable but also inherently weak and brittle, can be reinforced with poly(propylene fumarate) (PPF) to produce strong composites with mechanical properties suitable for bone tissue engineering. Characterization of DCPD–PPF composites revealed significant improvements in mechanical properties for cements with a 1.0 powder to liquid ratio. Compared with nonreinforced controls, flexural strength improved from 1.80 ± 0.19 MPa to 16.14 ± 1.70 MPa, flexural modulus increased from 1073.01 ± 158.40 MPa to 1303.91 ± 110.41 MPa, maximum displacement during testing increased from 0.11 ± 0.04 mm to 0.51 ± 0.09 mm, and work of fracture improved from 2.74 ± 0.78 J/m2 to 249.21 ± 81.64 J/m2. To demonstrate the utility of our approach for scaffold fabrication, 3D macroporous scaffolds were prepared with rapid prototyping technology. Compressive testing revealed that PPF reinforcement increased scaffold strength from 0.31 ± 0.06 MPa to 7.48 ± 0.77 MPa. Finally, 3D PPF–DCPD scaffolds were implanted into calvarial defects in rabbits for 6 weeks. Although the addition of mesenchymal stem cells to the scaffolds did not significantly improve the extent of regeneration, numerous bone nodules with active osteoblasts were observed within the scaffold pores, especially in the peripheral regions. Overall, the results of this study suggest that PPF–DCPD composites may be promising scaffold materials for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Plasma expanders stabilize human microvessels in microfluidic scaffolds
Authors: Leung Alexander D. , Wong Keith H. K. , Tien Joe
Published: April 2012

Plasma expanders such as dextran and hydroxyethyl starch (HES) are important components of solutions designed to maintain vascular volume in the clinical setting and to preserve organs ex vivo before transplantation. Here, we show that these polymers also exert stabilizing effects on engineered microvessels in microfluidic type I collagen and fibrin scaffolds. Standard growth media, which did not contain dextran or HES, led to severe leakage, vascular collapse, and catastrophic failure of perfusion. Remarkably, vessels that were provided with 3% dextran or 5% HES had few focal leaks, maintained adhesion to the scaffold, and were typically viable and patent for at least 2 weeks. We found that the junctional marker VE‐cadherin localized to a wide band in the presence of plasma expanders, but only at concentrations that also stabilized vessels. In conjunction with a previous computational model (Wong et al., Biomaterials 2010;31:4706–4714), our results suggest that plasma expanders stabilize microvessels via physical mechanisms that enhance VE‐cadherin localization at junctions and thereby limit vascular leakiness. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Transformation of low‐molecular linear caprolactam oligomers by caprolactam‐degrading bacteria
Authors: Esikova Tatiana , Ponamoreva Olga , Baskunov Boris , Taran Serge , Boronin Alexander
Published: April 2012

BACKGROUND: Wastes generated in production of caprolactam (2‐oxohexamethylenimine, ε‐caprolactam) and caprolactam‐based polymers contain the unreacted monomer and its low‐molecular linear and cyclic oligomers. Application of microorganisms for biological treatment of caprolactam‐ and oligomer‐containing wastes can become an alternative to existing waste utilization methods. This work investigated the transformation of caprolactam low‐molecular linear oligomers by caprolactam‐degrading bacteria bearing degradative plasmids (CAP plasmids).

RESULTS Based on mass spectrometry data, a scheme for the biotransformation of caprolactam linear oligomers is proposed. Oxidative transamination to corresponding dicarboxylic acids can be one of the transformation mechanisms. Oxidative transamination occurs due to a broad substrate specificity of the caprolactam catabolism key enzymes 2‐oxoglutarate‐6‐aminohexanoate transaminase (EC.2.6.1‐) and 6‐oxohexanoate dehydrogenase (EC.1.2.1.63) whose synthesis is determined by CAP plasmids. Incubation of cells 2.0–3.0 × 109 CFU mL−1 of strains with various plasmid‐bacterial host combinations in 2 mmol L−1 solution of a dimer for 96 h leads to its almost complete transformation to a corresponding dicarboxylic acid. The dynamics of the process largely depends on the host strain.

CONCLUSION: Deamination of oligomers in their transformation by the enzyme systems of caprolactam‐degrading bacteria can substitute the chemical methods of pretreating caprolactam‐ and oligomer‐containing wastes for their subsequent biological purification. Copyright © 2012 Society of Chemical Industry