bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arylphosphonylation and Arylazidation of Activated Alkenes
Authors: Kong Wangqing , Merino Estíbaliz , Nevado Cristina 
Published: April 2014

AbstractTwo radical‐mediated processes of activated alkenes, namely arylphosphonylation and arylazidation, are described. The difunctionalization of alkenes by a tandem process that involves radical addition, 1,4‐aryl migration, and desulfonylation generates α‐aryl‐β‐heterofunctionalized amides bearing a quaternary stereocenter when the substituent on the nitrogen atom is an aryl group. Alternatively, heterooxindoles or spirobicycles can be obtained with excellent regioselectivity in the presence of an alkyl substituent on the nitrogen atom.
Stereocontrolled Synthesis of syn‐β‐Hydroxy‐α‐Amino Acids by Direct Aldolization of Pseudoephenamine Glycinamide
Authors: Seiple Ian B. , Mercer Jaron A. M. , Sussman Robin J. , Zhang Ziyang , Myers Andrew G. 
Published: April 2014

Abstractβ‐Hydroxy‐α‐amino acids figure prominently as chiral building blocks in chemical synthesis and serve as precursors to numerous important medicines. Reported herein is a method for the synthesis of β‐hydroxy‐α‐amino acid derivatives by aldolization of pseudoephenamine glycinamide, which can be prepared from pseudoephenamine in a one‐flask protocol. Enolization of (R,R)‐ or (S,S)‐pseudoephenamine glycinamide with lithium hexamethyldisilazide in the presence of LiCl followed by addition of an aldehyde or ketone substrate affords aldol addition products that are stereochemically homologous with L‐ or D‐threonine, respectively. These products, which are typically solids, can be obtained in stereoisomerically pure form in yields of 55–98 %, and are readily transformed into β‐hydroxy‐α‐amino acids by mild hydrolysis or into 2‐amino‐1,3‐diols by reduction with sodium borohydride. This new chemistry greatly facilitates the construction of novel antibiotics of several different classes.
Strictly Biphasic Soft and Hard Janus Structures: Synthesis, Properties, and Applications
Authors: Pang Xinchang , Wan Congshan , Wang Mengye , Lin Zhiqun 
Published: April 2014

AbstractJanus structures, named after the ancient two‐faced Roman god Janus, comprise two hemistructures (e.g. hemispheres) with different compositions and functionalities. Much research has been carried out over the past few years on Janus structures because of the intriguing properties and promising potential applications of these unusually shaped materials. This Review discusses recent progress made in the synthesis, properties, and applications of strictly biphasic Janus structures possessing symmetrical structures but made of disparate materials. Depending on the chemical compositions, such biphasic structures can be categorized into soft, hard, and hybrid soft/hard Janus structures of different architectures, including spheres, rodlike, disclike, or any other shape. The main synthetic routes to soft, hard, and hybrid soft/hard Janus structures are summarized and their unique properties and applications are introduced. The perspectives for future research and development are also described.
Development of methods for encapsulation of viruses into polymeric nano‐ and microparticles for aquaculture vaccines
Authors: Ulanova Lilia S. , Isapour Golnaz , Maleki Atoosa , Fanaian Shirin , Zhu Kaizheng , Hoenen Antje , Xu Cheng , Evensen Øystein , Griffiths Gareth , Nyström Bo 
Published: April 2014

ABSTRACTTo meet an urgent need for improved vaccines against viral diseases in aquaculture, encapsulating the viruses into biodegradable and biocompatible polymers was suggested to protect viral antigens from premature degradation and gradually expose them to the immune system. We used water‐in‐oil‐in‐water emulsion to first encapsulate model red fluorescent polystyrene (PS) particles and then infectious salmon anemia virus (ISAV) into poly‐lactic‐co‐glycolic acid (PLGA) together with coumarin 6. A milder layer‐by‐layer method was applied to incorporate both PS and ISAV into chitosan (Cs)‐fluorescein isothiocyanate and alginate (Alg) followed by ionic crosslinking. All particles were characterized by dynamic light scattering, zeta‐sizer, fluorescence, transmission‐ and scanning electron microscopy. Successful encapsulation of PS beads and ISAV into PLGA, Cs, and Alg was accomplished. The prepared particles were of different size, surface charge density, and morphology. This yields opportunities for further developments of these structures as vaccine candidates to be delivered by injection or oral administration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40714.
Finite‐Elemente‐Analyse von Stahlbetonbauteilen im ebenen Spannungszustand
Authors: Thoma Karel , Roos Patrick , Weber Marius 
Published: April 2014

AbstractDer ebene Spannungszustand nimmt in der Analyse von Stahlbetonbauteilen eine zentrale Rolle ein. Das Last‐Verformungs‐Verhalten von Balken, Scheiben und dünnen Platten kann mithilfe des ebenen Spannungszustands ausreichend genau beschrieben werden. Im Folgenden wird eine Finite‐Elemente‐Analyse von Stahlbetonscheiben und Stahlbetonplatten auf Basis nichtlinearer Materialmodelle vorgestellt. Das den Berechnungen zugrunde gelegte mechanische Modell ist das gerissene Scheibenmodell, das einen ebenen Spannungszustand voraussetzt und frei drehbare Risse mit diskretem Rissabstand berücksichtigt. Für die Berechnung des Last‐Verformungs‐Verhaltens von Stahlbetonscheiben wird das gerissene Scheibenmodell um das linear elastische Werkstoffgesetz und das zweiachsige Druckmodell für Beton ergänzt. Die Analyse dünner Platten erfolgt mit einem Schichtenmodell. Die Voraussetzung eines ebenen Spannungszustands in jeder Schicht erlaubt die Betrachtung der Schichten als Stahlbetonscheiben. Die der Berechnung vorausgesetzten mechanischen Modelle und Werkstoffgesetze werden in Form eines “User Defined Materials” in das nichtlineare Finite‐Elemente‐Programm ANSYS Mechanical APDL implementiert. Folgend werden ausgewählte Scheiben‐ und Plattenversuche nachgerechnet.Finite‐element‐analysis of reinforced concrete structural elements under plane stress – Membrane and thin plate calculations based on the cracked membrane model.Plane stress fields play a central role in the analysis of reinforced concrete structural elements. The load‐deformation behavior of beams, membranes and thin plates can be represented with sufficient accuracy by plane stress states. This paper presents a finite‐element‐analysis approach of reinforced concrete membranes and plates, which is based on the cracked membrane model. The cracked membrane model assumes a plane stress state and considers discrete crack patterns that spacing are rotationally unconstrained. In order to compute the load‐deformation behavior of reinforced concrete membranes, the cracked membrane model is combined with a linear elastic material law and a biaxial compression model for the concrete. The analysis of thin reinforced concrete plates is based on a multi‐layer model. Assuming that each of the layers is under plane stress, it is possible to model a thin plate as an assemblage of reinforced concrete membranes. The presented mechanical models are implemented in the nonlinear finite‐element‐analysis software, ANSYS Mechanical APDL, by developing specialized “user defined materials”. To validate the finite‐element‐implementation, analysis results are compared with experimental results from selected membrane and plate tests.
A Tryptophan 6‐Halogenase and an Amidotransferase Are Involved in Thienodolin Biosynthesis
Authors: Milbredt Daniela , Patallo Eugenio P. , van Pée Karl‐Heinz 
Published: April 2014

AbstractThe biosynthetic gene cluster for the plant growth‐regulating compound thienodolin was identified in and cloned from the producer organism Streptomyces albogriseolus MJ286‐76F7. Sequence analysis of a 27 kb DNA region revealed the presence of 21 ORFs, 14 of which are involved in thienodolin biosynthesis. Three insertional inactivation mutants were generated in the sequenced region to analyze their involvement in thienodolin biosynthesis and to functionally characterize specific genes. The gene inactivation experiments together with enzyme assays with enzymes obtained by heterologous expression and feeding studies showed that the first step in thienodolin biosynthesis is catalyzed by a tryptophan 6‐halogenase and that the last step is the formation of a carboxylic amide group catalyzed by an amidotransferase. The results led to a hypothetical model for thienodolin biosynthesis.
Artemisinin
Authors: Schäfer Bernd 
Published: April 2014

AbstractArtemisinin wurde in den 1970er Jahren aus dem Einjährigen Beifuß (Artemisia annua) isoliert, den man zur Behandlung der Malaria in der traditionellen chinesischen Volksmedizin schon seit mindestens 1600 Jahre nutzt. Artemisinin entstammt dem Terpenstoffwechsel. Der Biosyntheseweg ist weitgehend bekannt. In den zurückliegenden 30 Jahren wurde eine Reihe interessanter Totalsynthesen publiziert, die auf beeindruckende Weise den präparativen Fortschritt der modernen organischen Chemie wiederspiegeln. Im industriellen Maßstab gewinnt man Artemisinin durch Extraktion aus dem Einjährigen Beifuß und durch Fermentation und Partialsynthese.
Label‐Free Biosensing over a Wide Concentration Range with Photonic Force Microscopy
Authors: Heo Seungjin , Kim Kipom , Cho Yong‐Hoon 
Published: April 2014

AbstractWe present a label‐free biosensor that measures molecular interactions between biomolecules on the surface of a probe bead and substrate over a wide concentration range. This system is capable of detecting target biomolecules with concentrations varying from 10 nM to 0.1 pM, with high selectivity and sensitivity.
Freely Floating Smectic Films
Authors: May Kathrin , Harth Kirsten , Trittel Torsten , Stannarius Ralf 
Published: April 2014

AbstractWe have investigated the dynamics of freely floating smectic bubbles using high‐speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin‐film fluid dynamics under well‐controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch‐off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments.
Intramolecular Interactions of Trityl Groups
Authors: Ściebura Jacek , Janiak Agnieszka , Stasiowska Agata , Grajewski Jakub , Gawrońska Krystyna , Rychlewska Urszula , Gawroński Jacek 
Published: April 2014

AbstractTrityl group, Tr, is a molecular dynamic rotor of which the conformation and helicity depend on other groups in the close vicinity. Interactions with another covalently linked Tr group and with other substituents are analyzed in terms of transfer of chirality to the trityl group. Two trityl groups in a molecule can mutually interact at a distance of two, three, or five bonds. Despite its size, a Tr group attached to a cyclohexane or cyclopentane ring through an oxygen or nitrogen atom adopts either an axial or equatorial position, depending on additional stabilizing interactions, such as hydrogen bonding.
Small Molecular Aryl Acetylenes: Chemically Tailoring High‐Efficiency Organic Semiconductors for Solar Cells and Field‐Effect Transistors
Authors: Broggi Alessandra , Tomasi Ivan , Bianchi Luca , Marrocchi Assunta , Vaccaro Luigi 
Published: April 2014

AbstractOver the last two decades, ever increasing interest has been focused on π‐conjugated triple‐bond‐containing systems, namely, (poly)aryl acetylenes, as a very promising class of semiconducting materials, owing to the availability of flexible/efficient synthetic protocols and the new conception of their conformational and steric advantages. In this review, the major design/synthetic strategies used to obtain molecular aryl acetylene semiconductors are discussed. A brief discussion of their key properties as well as their performance in organic field‐effect transistors and photovoltaic cell applications is also included.
Photocatalytic Hydrogen Evolution from Glycerol and Water over Nickel‐Hybrid Cadmium Sulfide Quantum Dots under Visible‐Light Irradiation
Authors: Wang Jiu‐Ju , Li Zhi‐Jun , Li Xu‐Bing , Fan Xiang‐Bing , Meng Qing‐Yuan , Yu Shan , Li Cheng‐Bo , Li Jia‐Xin , Tung Chen‐Ho , Wu Li‐Zhu 
Published: April 2014

AbstractNatural photosynthesis offers the concept of storing sunlight in chemical form as hydrogen (H2), using biomass and water. Herein we describe a robust artificial photocatalyst, nickel‐hybrid CdS quantum dots (Nih‐CdS QDs) made in situ from nickel salts and CdS QDs stabilized by 3‐mercaptopropionic acid, for visible‐light‐driven H2 evolution from glycerol and water. With visible light irradiation for 20 h, 403.2 μmol of H2 was obtained with a high H2 evolution rate of approximately 74.6 μmol h−1 mg−1 and a high turnover number of 38 405 compared to MPA‐CdS QDs (mercaptopropionic‐acid‐stabilized CdS quantum dots). Compared to CdTe QDs and CdSe QDs, the modified CdS QDs show the greatest affinity toward Ni2+ ions and the highest activity for H2 evolution. X‐ray photoelectron spectroscopy (XPS), inductively‐coupled plasma atomic emission spectrometry (ICP‐AES), and photophysical studies reveal the chemical nature of the Nih‐CdS QDs. Electron paramagnetic resonance (EPR) and terephthalate fluorescence measurements clearly demonstrate water splitting to generate ⋅OH radicals. The detection of DMPO‐H and DMPO‐C radicals adduct in EPR also indicate that ⋅H radicals and ⋅C radicals are the active species in the catalytic cycle.
Fluorescence in situ hybridization as an adjunct tool in the diagnosis of primary and metastatic renal cell carcinoma in fine needle aspiration specimens
Authors: Kos Zuzana , Williams Phillip A. , Belanger Eric C. , Mai Kien T. 
Published: April 2014

We investigated the role of fluorescence in situ hybridization (FISH) in the diagnosis of primary renal neoplasms and lesions suspicious for metastatic renal cell carcinoma. Consecutive fine‐needle aspiration biopsies (FNAB) of 39 renal masses and 41 metastatic tumours suspicious for renal cell origin were assessed with an immunohistochemical panel for CK7, RCC antigen, CD10, AMACR, PAX8, vimentin, and CD117. In addition, FISH was performed using probes for chromosomes 1p, 3p, 7, 17, X, and Y. A total of 31 of 39 primary renal masses and 33 of 41 metastatic tumors suspicious for renal origin demonstrated typical cytological and immunohistochemical (IHC) features of subtypes of renal neoplasms (40 clear cell renal cell carcinoma (RCC), 20 papillary RCC, and 4 renal oncocytomas). FISH analysis of 15 randomly selected cases each of primary and metastatic lesions revealed chromosomal abnormalities consistent with the diagnosis in 73% of these cases. Of 8 primary renal masses demonstrating atypical microscopic features and noncontributory IHC profiles, FISH was helpful in subtyping 5 (62%) of these lesions (2 clear cell RCC, 1 solid variant of oncocytic papillary RCC, 1 mixed clear cell and papillary RCC, and 1 chromophobe RCC with papillary architecture). Of 8 metastatic tumors clinically suspicious for renal cell origin and supportive, but nondiagnostic IHC, FISH revealed supportive chromosomal changes in 6 (75%) cases. In conclusion FISH analysis on FNAB material, even with limited tissue, may be contributory to the diagnosis and subtyping of RCC in diagnostically challenging biopsies. Diagn. Cytopathol. 2014;42:1013–1023. © 2014 Wiley Periodicals, Inc.
Cytologic features of the normal pineal gland on squash preparations
Authors: Murro Diana , Alsadi Alaa , Nag Sukriti , Arvanitis Leonidas , Gattuso Paolo 
Published: April 2014

As primary pineal lesions are extremely rare, many surgical pathologists are unfamiliar with normal pineal cytologic features. We describe cytologic features of the normal pineal gland in patients of varying ages and identify common diagnostic pitfalls.We performed a retrospective review of pineal gland biopsies performed at our institution, where approximately 30,000 surgical specimens are accessioned yearly, for the last 23 years. Only two pineal gland biopsies were found. Although both cases were initially diagnosed as low‐grade gliomas on frozen section, the final diagnosis was benign pineal tissue based on light microscopy and immunohistochemistry results. Additionally, we performed squash preparations of five normal pineal gland autopsy specimens with Papanicolaou and Diff–Quik® (Dade Behring, Newark, DE) stains.Infant preparations were highly cellular smears composed of numerous, uniform, single cells with indistinct cytoplasm, small round‐to‐oval nuclei, fine chromatin, and absent nucleoli and calcifications. The vague microfollicular pattern mimicked a pineocytoma and the fine fibrillary background mimicked a glial neoplasm. Young adult smears were similar; however, microcalcifications were present with fewer background single cells. Older patients had much less cellular smears composed of small clusters of cells with fusiform‐to‐spindle nuclei, a fine chromatin pattern, and indistinct cytoplasmic borders. There were fewer background single cells and more microcalcifications.The cytologic features of the native pineal gland vary with age. Normal pineal tissue can be confused with a pineocytoma or low‐grade glioma. Familiarity with normal pineal gland cytological features will help to avoid a potential misdiagnosis. Diagn. Cytopathol. 2014;42:939–943. © 2014 Wiley Periodicals, Inc.
Independence of the blood pressure lowering effect and efficacy of the angiotensin receptor neprilysin inhibitor, LCZ696, in patients with heart failure with preserved ejection fraction: an analysis of the PARAMOUNT trial
Authors: Jhund Pardeep S. , Claggett Brian , Packer Milton , Zile Michael R , Voors Adriaan A. , Pieske Burkert , Lefkowitz Martin , Shi Victor , Bransford Toni , McMurray John J. V. , Solomon Scott D 
Published: April 2014

AimsThe first in class angiotensin receptor neprilysin inhibitor, LCZ696 has been shown to reduce levels of N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), reduce left atrial size and improve New York Heart Association (NYHA) class in patients with heart failure with preserved ejection fraction (HFpEF). We examined whether the effects of LCZ696 were independent of systolic blood pressure (SBP) lowering.Methods and resultsIn the Prospective comparison of ARNi (angiotensin receptor neprilysin inhibitor) with ARB (angiotensin receptor blocker) on Management Of heart failUre with preserved ejectioN fracTion (PARAMOUNT) trial 301 patients were randomly assigned to LCZ696 or valsartan. We examined the relationship between SBP lowering and LCZ696 on NT‐proBNP level, left atrial size, NYHA class and estimated glomerular filtration rate (eGFR). By 12 weeks blood pressure was reduced by 9 mmHg (SD 15)/5 mmHg (SD 11) in patients receiving LCZ696 in comparison with 3 mmHg (SD 17)/2 mmHg (SD 12) in those receiving valsartan. The change in NT‐proBNP was poorly correlated with change in SBP (LCZ696, r = 0.17, P = 0.06; valsartan, r = 0.05, P = 0.58) After adjustment for change in SBP, the ratio of change in NT‐proBNP at 12 weeks for LCZ696 vs. valsartan was 0.76 (95% CI 0.63–0.93, P = 0.008), and similar to the ratio not adjusting for SBP (0.76, 95% CI 0.63–0.92, P = 0.006); P for interaction was 0.38). Similarly, reduction in left atrial volume index at 36 weeks, improvement in NYHA class and eGFR were all independent of the change in SBP.ConclusionIn patients with HFpEF, the effect of the angiotensin receptor neprilysin inhibitor LCZ696 on NT‐proBNP, left atrial volume, functional class, and eGFR was independent of reduction in SBP.
Amperometric Glucose Biosensor Based on Pt‐Pd Nanoparticles Supported by Reduced Graphene Oxide and Integrated with Glucose Oxidase
Authors: Hossain M. F. , Park Jae Y. 
Published: April 2014

AbstractA novel glucose biosensor was developed based on the immobilization of glucose oxidase (GOx) on reduced graphene oxide incorporated with electrochemically deposited platinum and palladium nanoparticles (PtPdNPs). Reduced graphene oxide (RGO) was more hybridized by chemical and heat treatment. Bimetallic nanoparticles were deposited electrochemically on the RGO surface for potential application of the PdPt alloy in biosensor preparation. The as‐prepared hybrid electrode exhibited high electrocatalytic activities toward H2O2, with a wide linear response range from 0.5 to 8 mM (R2=0.997) and high sensitivity of 814×10−6 A/mMcm2. Furthermore, glucose oxidase with active material was integrated by a simple casting method on the RGO/PdPtNPs surface. The as‐prepared biosensor showed good amperometric response to glucose in the linear range from 2 mM to 12 mM, with a sensitivity of 24×10−6 A/mMcm2, a low detection limit of 0.001 mM, and a short response time (5 s). Moreover, the effect of interference materials, reproducibility and the stability of the sensor were also investigated.
Multiparameter Sensor Chip with Barium Strontium Titanate as Multipurpose Material
Authors: Huck Christina , Poghossian Arshak , Kerroumi Iman , Schusser Sebastian , Bäcker Matthias , Zander Willi , Schubert Jürgen , Buniatyan Vahe V. , Martirosyan Norayr W. , Wagner Patrick , Schöning Michael J. 
Published: April 2014

AbstractIt is well known that biochemical and biotechnological processes are strongly dependent and affected by a variety of physico‐chemical parameters such as pH value, temperature, pressure and electrolyte conductivity. Therefore, these quantities have to be monitored or controlled in order to guarantee a stable process operation, optimization and high yield. In this work, a sensor chip for the multiparameter detection of three physico‐chemical parameters such as electrolyte conductivity, pH and temperature is realized using barium strontium titanate (BST) as multipurpose material. The chip integrates a capacitively coupled four‐electrode electrolyte‐conductivity sensor, a capacitive field‐effect pH sensor and a thin‐film Pt‐temperature sensor. Due to the multifunctional properties of BST, it is utilized as final outermost coating layer of the processed sensor chip and serves as passivation and protection layer as well as pH‐sensitive transducer material at the same time. The results of testing of the individual sensors of the developed multiparameter sensor chip are presented. In addition, a quasi‐simultaneous multiparameter characterization of the sensor chip in buffer solutions with different pH value and electrolyte conductivity is performed. To study the sensor behavior and the suitability of BST as multifunctional material under harsh environmental conditions, the sensor chip was exemplarily tested in a biogas digestate.