bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct projections of omnipause neurons to reticulospinal neurons: A double‐labeling light microscopic study in the cat
Authors: Grantyn Alexej , Kuze Bunya , Brandi Anne‐Marie , Thomas Marie‐Annick , Quenech'du Nicole 
Published: August 2010

AbstractOmnipause neurons (OPNs) are inhibitory neurons located in the midline region of the caudal pons. Their role in gating the discharges of saccade‐related burst neurons is well known, but there is no agreement concerning their influence on brainstem neurons that control other muscle groups participating in rapid gaze shifts. In the present study, we inquired whether OPNs project directly to pontobulbar reticulospinal neurons (RSNs) in the cat. Retrograde transport of horseradish peroxidase from the cervical spinal cord was used to label RSNs and an anterograde tracer (biocytin) was iontophoresed at sites of extracellular recording of the OPN activity. Somadendritic characteristics of biocytin‐labeled OPNs were largely similar to those obtained previously with intracellular labeling. Three‐dimensional reconstruction of axonal trajectories and collaterals revealed that projections of OPNs, regarded as a population, are bilateral. Their terminals were restricted to the reticular formation and midline structures throughout the rostral bulbar and pontine tegmentum. Appositions of synaptic boutons originating from five fully stained OPNs were detected on 38 retrogradely labeled RSNs, each of the OPNs contacting 3–13 cells. The numbers of boutons (1–46; mean 11.8) on the RSN somata and proximal dendrites indicate that the anatomical strength of paired OPN‐RSN connections is comparable to that of other similarly studied inhibitory neurons in the cat. The existence of connections with RSNs supports the hypothesis of a generalized influence of OPNs on several effectors participating in orienting gaze shifts as opposed to the idea of their strict specialization for the control of eye saccades. J. Comp. Neurol. 518:4792–4812, 2010. © 2010 Wiley‐Liss, Inc.
A Distinctive layering pattern of mouse dentate granule cells is generated by developmental and adult neurogenesis
Authors: Mathews Emily A. , Morgenstern Nicolás A. , Piatti Verónica C. , Zhao Chunmei , Jessberger Sebastian , Schinder Alejandro F. , Gage Fred H. 
Published: August 2010

AbstractNew neurons are continuously added throughout life to the dentate gyrus of the mammalian hippocampus. During embryonic and early postnatal development, the dentate gyrus is formed in an outside‐in layering pattern that may extend through adulthood. In this work, we sought to quantify systematically the relative position of dentate granule cells generated at different ages. We used 5′‐bromo‐2′‐deoxyuridine (BrdU) and retroviral methodologies to birth date cells born in the embryonic, early postnatal, and adult hippocampus and assessed their final position in the adult mouse granule cell layer. We also quantified both developmental and adult‐born cohorts of neural progenitor cells that contribute to the pool of adult progenitor cells. Our data confirm that the outside‐in layering of the dentate gyrus continues through adulthood and that early‐born cells constitute most of the adult dentate gyrus. We also found that substantial numbers of the dividing cells in the adult dentate gyrus were derived from early‐dividing cells and retained BrdU, suggesting that a subpopulation of hippocampal progenitors divides infrequently from early development onward. J. Comp. Neurol. 518:4479–4490, 2010. © 2010 Wiley‐Liss, Inc.
Dealloying to Nanoporous Silver and Its Implementation as a Template Material for Construction of Nanotubular Mesoporous Bimetallic Nanostructures
Authors: Xu Caixia , Li Yingying , Tian Fang , Ding Yi 
Published: August 2010

AbstractNanoporous silver (NPS) is fabricated by selectively dissolving Al from AgAl alloys in corrosive electrolytes at room temperature. Electron spectroscopy characterizations demonstrate that the NaOH electrolyte is beneficial to the formation of a three‐dimensional bicontinuous porous nanostructure with uniform and tunable pore and ligament dimensions of a few tens of nanometers, while processing in HCl electrolyte easily lead to coarsened porous nanostructures. The high‐surface‐area Ag nanostructures are demonstrated as novel effective template materials to the construction of nanotubular mesoporous Pt/Ag and Pd/Ag alloy structures, which are realized via room temperature galvanic replacement reactions with H2PtCl6 and K2PdCl4 solutions by adding a high concentration of Cl− ions as a coordinating agent. Electrochemical measurements indicate that the resulting hollow and porous bimetallic nanostructures show enhanced electrocatalytic activities and CO‐tolerance with better durability toward methanol and formic acid oxidation due to alloying with Ag.
Effect of citric acid concentration as emulsifier on perovskite phase formation of nano‐sized SrMnO3 and SrCoO3 samples
Authors: Khazaei M. , Malekzadeh A. , Amini F. , Mortazavi Y. , Khodadadi A. 
Published: August 2010

AbstractIn this study the effects of citric acid concentration, used as organic emulsifier, on the perovskite phase formation of the nano strontium manganite or cobaltite samples were studied. Stoichiometric perovskites in the absence and presence of citric acid were prepared by drying a solution containing molar ratio of Sr(NO3)2/Mn(NO3)2·4H2O and Sr(NO3)2/Co(NO3)2·6H2O = 1 followed by calcination at 900 °C for 5 h. Citric acid concentration, selected to be 0.0, 0.3, 0.6, 1.0, 1.3, 2.5 and 5 times of the total number of moles of the nitrate ions. The results revealed that increase in the citric acid concentration, larger than number of moles of the nitrate ions equivalent, deteriorates the perovskite phase formation. Instead, a new phase of carbonates and metal oxides are appeared. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of the specific surface free energy of natural quartz crystals using measurement of contact angle of liquid droplets
Authors: Suzuki T. , Kasahara H. 
Published: August 2010

AbstractContact angle of water and formamide droplets on natural quartz crystals were observed. The specific surface free energy (SSFE) of m, r, and z faces, calculated using the Fowkes approximation, were approximately 54‐69 mN/m. The length of the normal line from the center of the crystal to each face (hi) was observed and compared with the SSFE. Though, Wulff's relationship was well satisfied for synthesized crystals,hiwas not proportional to SSFE for natural crystal. We propose an idea of “γcenter”, which correspond to Wulff's point for ideal equilibrium shape crystal. We concluded that, crystal face with the larger SSFE has larger growth rate even for natural crystal. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of highly‐ordered hierarchical ZnO nanostructures and their application in dye‐sensitized solar cells
Authors: Zhu Y. F. , Zhou G. H. , Ding H. Y. , Liu A. H. , Lin Y. B. , Li N. L. 
Published: August 2010

AbstractIn order to improve the performance of ZnO‐based solar cells, highly‐ordered hierarchical ZnO nanostructures were design and fabricated. The hierarchical nanostructures were grown on FTO (fluorine doped tin oxide, SnO2:F) glass substrates via a facile, low‐temperature, and low‐cost chemical route. The morphology and structure of the obtained products has been confirmed by field‐emission scanning electron microscopy and X‐ray diffraction measurements. The performance investigation of the prepared dye‐sensitized solar cells (DSSCs) demonstrates that the hierarchical ZnO nanostructure‐based solar cell shows a higher short‐circuit current density compared with the ZnO nanowire counterpart. The enhanced current density may be due to the fact that the surface area of the hierarchical nanostructures is increased. These results indicate that hierarchical ZnO nanostructures are more suitable for the application as photoelectrode of DSSCs. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biomineralization of struvite crystals by Proteus mirabilis from artificial urine and their mesoscopic structure
Authors: Prywer J. , Torzewska A. 
Published: August 2010

AbstractIn order to investigate the mineralization of struvite we performed the experiment of struvite growth process from artificial urine. The crystallization process was induced by Proteus mirabilis, as these bacteria are mainly isolated from infectious stones. The crystallization process occurred at conditions mimicking the real urinary tract infection. Our results show that struvite exhibits polar properties. This feature of struvite crystals is potentially very important in the case of binding additives which may either enhance or inhibit crystallization process. It seems also that the differences in the polarity of opposite faces of c‐axis play important role in directing the struvite mesoscopic arrangement. We also described recent developments concerning curcumin – pigment extracted from the roots of turmeric commonly known as a spice added to various food preparations. Curcumin exhibited the effect against Proteus mirabilis inhibiting the activity of urease and consequently decreasing the efficiency of struvite growth. Therefore, curcumin belongs to phytoterapheutic components, which may be the alternative with relation to the antibiotic therapy. The paper concludes with a future outlook and goals in this field of research. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combustion synthesis of one‐dimensional nanocrystalline silicon carbide
Authors: Soszyński M. , Dąbrowska A. , Bystrzejewski M. , Huczko A. 
Published: August 2010

AbstractBeta‐SiC (cubic phase) nanowires (SiCNWs) have been grown spontaneously during the autothermal self‐propagating high‐temperature synthesis (SHS) from elemental silicon and poly(tetrafluoroethylene) (PTFE) powder mixtures in oxygen‐enriched atmosphere. The combustion process was on‐line monitored using high‐speed photography in order to estimate the reaction processing time which was well below 1 s. From the emission spectroscopy the averaged combustion temperature was evaluated to be close to 2000 K. The products were characterized by wet chemical analysis, X‐ray diffraction, scanning and transmission microscopy, and Raman spectroscopy. The raw products were processed by wet chemistry to obtain pure (above 90%) well‐crystallized one‐dimensional single crystals of SiCNWs. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure–Property Relationship of Red‐ and Green‐Emitting Iridium(III) Complexes with Respect to Their Temperature and Oxygen Sensitivity
Authors: Tian Nan , Lenkeit Daniel , Pelz Simon , Fischer Lorenz H. , Escudero Daniel , Schiewek Ralf , Klink Dennis , Schmitz Oliver J. , González Leticia , Schäferling Michael , Holder Elisabeth 
Published: August 2010

AbstractWe report on the structural design and characterization of a series of neutral heteroleptic iridium(III) complexes equipped with 2‐phenylpyridine, 2‐(naphthalen‐1‐yl)pyridine, and 1‐phenylisoquinoline as cyclometalating ligands. To gradually increase the unsymmetrical architecture of the heteroleptic iridium(III) complexes, they have been furnished with 2,2,6,6‐tetramethylheptane‐3,5‐dione, 1‐(9H‐carbazol‐9‐yl)‐5,5‐dimethylhexane‐2,4‐dione, and 1‐[3,6‐bis(4‐hexylphenyl)‐9H‐carbazol‐9‐yl]‐5,5‐dimethylhexane‐2,4‐dione as ancillary ligands. The photophysical and electrochemical properties of these asymmetric IrIII complexes have been investigated experimentally as well as theoretically by using density functional theory (DFT) calculations. The properties of these new neutral heteroleptic iridium(III) complexes have been experimentally compared to homoleptic IrIII complex structures that reveal symmetrical architectures due to three similar cyclometalating ligands. The emission intensity of the herein described two classes of IrIII complexes is clearly influenced by applying changes to temperature and air pressure. The emphasis is on general design rules for oxygen‐sensitive IrIII emitters due to the correlation of the structure‐dependent oxygen sensitivity to their phosphorescence lifetimes.
Triple Alkyl C–H Bond Activation Mediated by Ruthenium(II): Preparation of Isopropenyl‐Substituted Carbene Complexes
Authors: Wolf Robert , Plois Markus 
Published: August 2010

AbstractThe reaction of [RuCl2(cod)]x (cod = 1,5‐cyclooctadiene), 1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene (IPr), tricyclohexylphosphane (PCy3) and KOtBu in a 1:1:2:1 ratio affords the new alkenyl carbene complex [RuCl(IPr″)(PCy3)2] (1) in 24 % isolated yield. Triphenylphosphane complex [RuCl(IPr″)(PPh3)2] (2) was isolated together with the single C–H activated complex [RuCl(IPr′)(PPh3)2] (3). Complexes 1 and 2 feature a metalated isopropenyl substituent on the IPr″ ligand, which results from the triple C–H activation of an isopropyl group. A stepwise mechanism for the formation of complexes 1 and 2 is proposed.
The First Cyanomethyl Complex of Gold, Synthesized by Reaction of a AuI Complex with Acetonitrile in the Presence of a New Guanidine N‐Superbase
Authors: Emeljanenko Dimitri , Peters Anastasia , Vitske Viktoriia , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: August 2010

AbstractHerein we report on the synthesis of the new strong N‐base and electron donor tdmegb [1,2,4,5‐tetrakis(N,N′‐dimethylethyleneguanidino)benzene]. Compared to the previously synthesized ttmgb [1,2,4,5‐tetrakis(tetramethylguanidino)benzene], this compound turned out to be a slightly better electron donor and a slightly weaker base. In experiments in which [AuCl(PPH3)] was dissolved in CH3CN together with tdmegb, we observed the formation of the first cyanomethyl complex of Au, namely [Au(CH2CN)(PPh3)] in good yield. This reaction does not take place for ttmgb. Moreover, in CH2Cl2 solutions containing the three components [AuCl(PPh3)], tdmegb and a nitrile (in large excess), only AuI reduction leading to a [Au11Cl3(PPh3)7] cluster is observed. Possible reaction mechanisms for this unusual reaction are discussed.
Intravenous bufadienolides‐loaded lipid microspheres for improving chemical stability
Authors: Weng Yan , Li Fang , Chen Wei , Miao Yuqiang , Tang Xing 
Published: August 2010

AbstractThis study focused on the degradation kinetics of bufalin (B), cinobufagin (C), and resibufogenin (R) in bufadienolides‐loaded lipid microsphere (BU‐LM) and bufadienolides‐loaded aqueous solution (BU‐S). The chemical stability of bufadienolides both in BU‐LM and BU‐S at different pH values and temperatures was monitored by HPLC. Photon correlation spectroscopy and electrophoretic light scattering technology were used to evaluate the physical characteristic of BU‐LM. Under the most stable pH range of 6.0–6.5, the half‐lives of B, C, and R in BU‐LM were 22, 15, and 20 days at 80 °C but 4510, 1717, and 3300 days at 25 °C, whereas for BU‐S only 11, 3, and 10 days at 80 °C and 71, 18, and 49 days at 25 °C. The results indicated that BU‐LM significantly increased the chemical stability of bufadienolides, especially at low temperatures. The degradation of bufadienolides took place mostly in the aqueous phase and the diffusion process of bufadienolides from the oil phase through the interfacial layer to the aqueous phase was the rate‐limiting step for the drug degradation. A low temperature slowed down of the diffusion rate leading to a slower degradation and longer half‐lives. Among the three bufadienolides in BU‐LM, C was protected from degradation to the greatest extent.Practical applications: Bufadienolides, consisting of bufalin (B), cinobufagin (C), and resibufogenin (R) have poor aqueous solubility between 20 and 60 µg/mL and are easily degradable by acids or bases. Here we propose a new strategy to overcome stability problems by using lipid microspheres (LM) as the drug vehicle. By incorporating the drugs into the interior oil phase and the oil–water interfacial film, a direct contact of the drug with body fluids and tissues is avoided. Thus the drug is protected from degradation and possible side effects are minimized. Our results indicate that BU‐LM significantly increased the chemical stability of bufadienolides, especially at low temperatures. Among the three bufadienolides in BU‐LM, C was protected from degradation to the greatest extent.
Expedient Pathway into Optically Active 2‐Oxopiperidines
Authors: van den Broek Sebastiaan (Bas) A. M. W. , Rensen Peter G. W. , van Delft Floris L. , Rutjes Floris P. J. T. 
Published: August 2010

AbstractThe piperidine ring system is one of the most common structural subunits and is found in many natural products. Moreover, piperidine alkaloids and derivatives thereof are of great interest for the pharmaceutical industry since they exhibit a wide range of biological activities. Consequently, short and valuable routes to highly functionalized building blocks for this important ring system are of general interest. A ring‐closing metathesis (RCM)‐mediated approach based on linear (substituted) dehydroamino esters was developed to provide cyclic dehydroamino esters. These structures represent valuable intermediates en route to highly substituted pipecolic acids as well as more elaborate heterocycles.
Electroporation of micro‐droplet encapsulated HeLa cells in oil phase
Authors: Xiao Kang , Zhang Mengying , Chen Shuyu , Wang Limu , Chang Donald Choy , Wen Weijia 
Published: August 2010

AbstractElectroporation (EP) is a method widely used to introduce foreign genes, drugs or dyes into cells by permeabilizing the plasma membrane with an external electric field. A variety of microfluidic EP devices have been reported so far. However, further integration of prior and posterior EP processes turns out to be very complicated, mainly due to the difficulty of developing an efficient method for precise manipulation of cells in microfluidics. In this study, by means of a T‐junction structure within a delicate microfluidic device, we encapsulated HeLa cells in micro‐droplet of poration medium in oil phase before EP, which has two advantages: (i) precise control of cell‐encapsulating droplets in oil phase is much easier than the control of cell populations or individuals in aqueous buffers; (ii) this can minimize the electrochemical reactions on the electrodes. Finally, we successfully introduced fluorescent dyes into the micro‐droplet encapsulated HeLa cells in oil phase. Our results reflected a novel way to realize the integrated biomicrofluidic system for EP.
Assessment of genotoxicity of waterpipe and cigarette smoking in lymphocytes using the sister‐chromatid exchange assay: A comparative study
Authors: Khabour Omar F. , Alsatari Enas S. , Azab Mohammad , Alzoubi Karem H. , Sadiq May F. 
Published: August 2010

AbstractTobacco smoking is a major world health problem. Recently, waterpipe smoking has become more popular in many countries. Although the genotoxicity associated with cigarette smoking has been extensively investigated, studies evaluating such toxicity in waterpipe users are still lacking. In this study, we examined the genotoxicity of waterpipe smoking in lymphocytes compared with the genotoxicity of cigarette smoking. Genotoxicity was evaluated using the sister chromatid exchanges (SCEs) assay. Fifty waterpipe smokers and 18 healthy nonsmokers participated in this study. Additionally, 18 heavy cigarette smokers (CS) were recruited for comparison. The results show that waterpipe smoking and cigarette smoking significantly increase the frequencies of SCEs (P < 0.01) compared with those of nonsmokers, indicating the genotoxic effect of tobacco smoking. In addition, frequencies of SCEs were significantly higher among waterpipe smokers compared with CS (P < 0.01), indicating that waterpipe smoking is more genotoxic than cigarette smoking. Moreover, the frequency of SCEs increased with the extent of waterpipe use. In conclusion, waterpipe smoking is genotoxic to lymphocytes and the magnitude of its genotoxicity is higher than that induced by regular cigarette smoking. Environ. Mol. Mutagen., 2011. © 2010 Wiley‐Liss, Inc.
Using a GIS filtering approach to replicate patterns of glacial erosion
Authors: Jansson K. N. , Stroeven A. P. , Alm G. , Dahlgren K. I. T. , Glasser N. F. , Goodfellow B. W. 
Published: August 2010

AbstractIn order to extend our knowledge of glacial relief production in mountainous areas new methods are required for landscape reconstructions on a temporal resolution of a glacial cycle and a spatial resolution that includes the most important terrain components. A generic data set and a 50 m resolution digital elevation model over a study area in northern Sweden and Norway (the present day landscape data set) were employed to portray spatial patterns of erosion by reconstructing the landscape over successive cycles of glacial erosion. A maximum‐value geographic information system (GIS) filtering technique using variable neighbourhoods was applied such that existing highpoints in the landscape were used as erosional anchor points for the reconstruction of past landscape topography. An inherent assumption, therefore, is that the highest surfaces have experienced insignificant down‐wearing over the Quaternary. Over multiple reconstruction cycles, proceeding backwards in time, the highest summits increase in area, valleys become shallower, and the valley pattern becomes increasingly simplified as large valleys become in‐filled from the sides. The sum of these changes reduces relief. The pattern of glacial erosion, which is to 60% correlated to slope angle and to 70% correlated to relative relief, is characterized by (i) an abrupt erosional boundary below preserved summit areas, (ii) enhanced erosion in narrow valleys, (iii) restricted erosion of smooth areas, independently of elevation, (iv) eradication of small‐scale irregularities, (v) restricted erosion on isolated hills in low‐relief terrain, and (vi) a valley widening independent of valley directions. The method outlined in this paper shows how basic GIS filtering techniques can mimic some of the observed patterns of glacial erosion and thereby help deduce the key controls on the processes that govern large‐scale landscape evolution beneath ice sheets. Copyright © 2010 John Wiley & Sons, Ltd.