bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometry and sedimentary evolution of the transpresssive Roquebrune-Cap Martin basin: implications on the kinematics and timing of the Nice arc deformation during Miocene times, SW Alps
Authors: Giannerini Gérard , Sanchez Guillaume , Schreiber Dimitri , Lardeaux Jean-Marc , Rolland Yann , de Castro Antoine Bellando , Bauve Victorien
Published: January 2012

The Roquebrune-Cap Martin basin (RCMB), developed along the eastern rim of the Nice arc, represents an exclusive sedimentary marker constraining the timing of the deformation in the Nice arc (southern Subalpine chain) during Miocene times. Structural and sedimentological analyses as well as 3D geometrical modeling of the RCMB revealed morphological, structural and sedimentological features characterizing an active tectonic control of the sedimentary infills and the basin development. Structural and microstructural analyses along the eastern boundary of the Nice arc evidenced a N-S left-lateral strike-slip ‘en echelon’ faults system named Mont Gros-St Agnès Castillon relayed by the Biancon E-W thrusts and sheets. The formation of the RCMB appears to be genetically linked to these strike-slip ‘en échelon’ faults. Such characteristics include the presence of the Mont Gros strike-slip fault structural high relief bounding the RCMB to the West, the West-East asymmetry of the sedimentary infill with a laterally transition facies from breccias directly below the fault relief to conglomerates and sandstones in the central part of the basin and the presence of mass wasting in all structural levels of the basin. The onset and the evolution of the basin were driven by transpresssive tectonics, generating a deep and narrow tectonic depression, bounded by steep tectonically controlled slopes. The transpresssive character of the eastern Nice arc boundary where the syn-tectonic RCMB is hosted, accommodate a general southward translation of the Nice arc in response to a N-S shortening regime. The sedimentological and previous paleontological analyses suggest that the activity of the eastern Nice arc transpresssive boundary generating the RCMB and thus the southward motion of the Nice arc, started during the Early Miocene (Aquitanian), continuing through the Late Miocene (Tortonian). The style and the timing of the syn-sedimentary deformation of the Nice arc is coherent in space and time with the one affecting the Digne and Castellane arc.
Faune corallienne des récifs toarciens du Moyen Atlas marocain, première approche
Authors: Lathuilière Bernard
Published: January 2012

Des récifs ont été décrits dans le Toarcien supérieur du Moyen Atlas Marocain [Elmi et al., 2002]. Ils sont localisés dans le synclinal de Awragh-Afennourir (Moyen Atlas occidental) immédiatement au sud du Moyen Atlas tabulaire. Ce sont des biohermes placés au sommet de blocs basculés. Leur épaisseur varie de 1 à 12 m. Ils reposent sur une formation datée de la zone à Levisoni, sous zone à Gemma et sont couverts par des sédiments appartenant à la partie supérieure de la zone à Meneghini. Leur paléolatitude était de 18°N. Un ensemble de 18 échantillons de coraux collectés par S. Elmi sont ici analysés. Ils constituent un témoignage exceptionnel de faune corallienne récifale pour cet étage. Les taxons appartenant aux genres Cladophyllia, Diplocoenia ?, Montlivaltia (deux espèces), Thecosmilia (deux espèces), Isastrea ?, Latomeandra, Periseris, Microphyllia (trois espèces), et Proleptophyllia (deux espèces), ont été identifiés. La faune inclut 12 formes coloniales et 7 solitaires. Parmi les spécimens coloniaux, les formes méandroïdes avec un haut niveau d’intégration colonial sont bien représentées et fournissent un argument fort pour la présence de zooxanthelles symbiotiques. L’examen des textures micritiques et des croûtes microbialitiques, associé avec le développement important des microarchitectures pennulaires suggèrent un récif sous le niveau d’action des vagues de beau temps et des eaux plutôt mésotrophiques. Les coraux, leur forme et leur diversité, permettent de diagnostiquer des récifs de zone photique, à une profondeur et une latitude optimale. Les extensions stratigraphiques de plusieurs genres sont agrandies : nouvelle première occurrence pour Cladophyllia, Latomeandra et Periseris (peut être aussi Diplocoenia) et nouvelle dernière occurrence pour Proleptophyllia classiquement considéré comme Pliensbachien. La seule monographie disponible à caractère général sur les coraux du Lias du Maroc [Beauvais, 1986] identifie 15 taxons génériques pour le Toarcien. Tous proviennent du Haut Atlas et seulement 3 taxons sont communs avec les résultats présentés ici. La vue générale est celle d’une faune qui ressemble davantage à celle des communautés récifales du Dogger qu’à celle du Pliensbachien.
Environmental Jolts, Clocks, and Strategic Change in the U.S. Airline Industry: The Effects of Deregulation and the 9/11/2001 Terrorist Attacks
Authors: Goll Irene , Rasheed Abdul A.
Published: December 2011

This study examines the effects of two major environmental jolts, the Airline Deregulation Act of 1978 and the 9/11/2001 terrorist attacks, on strategic change and performance in the U.S. air carrier industry. The sample includes the Major U.S. air carriers during two periods of time: deregulation (1974-1986) and 9/11/2001 (1997-2008). Data were collected from archival sources and analyzed using cross-sectional time series regressions with fixed effects. The results show that following both environmental jolts, the initial response of the airlines was emphasis on cost control. However, over the long run, there was a deceleration of the emphasis on cost control. Further, following deregulation, the long run response involved the acceleration of differentiation change. We also found a significant relationship between strategic change and firm performance. The results contribute towards a reconciliation of the conflicting predictions of the repetitive momentum hypothesis and the deceleration hypothesis.
K-quasiderivations
Authors: Emmons Caleb , Krebs Mike , Shaheen Anthony
Published: January 2012

A K-quasiderivation is a map which satisfies both the Product Rule and the Chain Rule. In this paper, we discuss several interesting families of K-quasiderivations. We first classify all K-quasiderivations on the ring of polynomials in one variable over an arbitrary commutative ring R with unity, thereby extending a previous result. In particular, we show that any such K-quasiderivation must be linear over R. We then discuss two previously undiscovered collections of (mostly) nonlinear K-quasiderivations on the set of functions defined on some subset of a field. Over the reals, our constructions yield a one-parameter family of K-quasiderivations which includes the ordinary derivative as a special case.
Trichobilharzia regenti: Antigenic structures of intravertebrate stages
Authors: Chanová Marta , Lichtenbergová Lucie , Bulantová Jana , Mikeš Libor , Horák Petr
Published: December 2011

Like several other bird schistosomes, neurotropic schistosome of Trichobilharzia regenti can invade also mammals, including humans. Repeated infections cause cercarial dermatitis, a skin inflammatory reaction leading to parasite elimination in non-specific mammalian hosts. However, in experimentally primo-infected mice, the worms escape from the skin and migrate to the central nervous system. In order to evade host immune reactions, schistosomes undergo cercaria/schistosomulum transformation accompanied with changes of surface antigens. The present study is focused on localization of the main antigens of T. regenti; cercariae, schistosomula developed under different conditions and adults were compared. Antigens were localized by immunofluorescence and ultrastructural immunocytochemistry using sera of mice repeatedly infected with T. regenti. Detected antibody targets were located in glycocalyx and penetration glands of cercariae and in tegument of cercariae, schistosomula and adults. Shedding of cercarial glycocalyx significantly reduced surface reactivity; further decrease was reported during ongoing development of schistosomula. Spherical bodies, probably transported from subtegumental cell bodies to worm surface, were identified as the most reactive tegumental structures. Based on similar results for schistosomula developed in specific, non-specific hosts and in vitro, it seems that the ability of T. regenti to decrease the surface immunoreactivity during ontogenesis is independent on the host type.
In vitro plantlet production of the endangered Pinguicula vulgaris
Authors: Grevenstuk Tomás , Romano Anabela
Published: December 2011

This study describes the development of a micropropagation protocol for Pinguicula vulgaris using cultures initiated from in vitro produced seedlings. P. vulgaris is a carnivorous plant with a northern, disjunctly circumpolar distribution and specific habitat requirements, and is hence becoming increasingly rare. Shoot proliferation was significantly influenced by Murashige and Skoog (MS) macronutrient concentration, showing higher proliferation rates in 1/4MS, but was not affected by the addition of 0.1 mg/L 6-benzyladenine (BA) or zeatin (Zea). The best medium for propagating P. vulgaris was plant growth regulator (PGR) free ¼MS. An average of 7.62 new shoots per initial explant could be obtained after 8 weeks of culture, of which over 79% produced roots during proliferation. Moreover, rooting percentages of 100% were obtained for the initial explants in all the tested media, including media without PGRs. The plantlets were successfully acclimatized to ex vitro conditions, exhibiting normal development.
Ni-W alloy coatings deposited from a citrate electrolyte
Authors: Zemanová Matilda , Kurinec Robert , Jorík Vladimír , Kadlečíová Magdaléna
Published: December 2011

Ni-W alloy coatings were deposited by applying current pulses with different pulse parameters at 60°C onto mild steel substrates from aqueous electrolytes with different tungstate concentration. Morphology and composition of the alloys were analyzed by SEM and EDX, respectively. XRD was used to determine metallic phases. Scanning electron micrographs revealed that deposition parameters had a strong effect on the morphology of the coatings. Increasing the duty cycle or decreasing the off time led to a compact morphology. Corrosion properties of the coatings were investigated by potentiodynamic polarization in a chloride medium. It was found that compact morphology of the deposits and high content of tungsten in the coating contribute to satisfactory corrosion results of Ni-W alloy coatings under the conditions studied.
Synthesis of rare earth ternary complexes using tryptophan and sodium citrate and their anticoagulant action
Authors: Wang Xi-Cun , Gao Qi-Kuan , Wang Kun-Jie , Wang Jian-Rong
Published: December 2011

Using rare earth nitrates, tryptophan (L), and sodium citrate (NaL′), three new rare earth ternary complexes (Nd-L-L′· 4H2O, Eu-L-L′ · 4H2O, and La-L-L′ · 4H2O) were prepared. The complexes were characterized by IR, molar conductivity, TG-DTA (thermo gravimetric-differential thermal analysis), 1H NMR, and elemental analyses. TG and elemental analyses of the prepared complexes showed good agreement with their stoichiometry. Compared with two individual ligands, IR spectra of synthesized complexes showed dramatic shift and intensity changes; 1H NMR also showed a slight downfield shift. All analytical results of complexes proved constant composition of M-L-L′ · 4H2O (M = rare earth metal, namely Nd, Eu, or La). Animal tests were also performed to study the anti-coagulation time of these complexes considering also the different concentration of complex Nd-L-L′ · 4H2O. PC-12 pheochromocytoma cells were used to study cell adhesion. Compared with ions of rare earth compounds, rare earth ternary complexes have lower cell toxicity, better cell adhesion, and better anticoagulant action.
The problem of gerontocracy in Africa: The Yorùbá perspective as illustrated in the Ifá corpus
Authors: Adegbindin Omotade
Published: December 2011

In the field of African philosophy, there exists the belief among the modernists or professional philosophers that gerontocracy is coterminous with authoritarian traditions in traditional Africa which, supposedly, are responsible for the lack of sustained curiosity to look at issues from different perspectives. Drawing from the Ifá literary corpus as a store-house for Yorùbá philosophy, I argue in this paper that gerontocracy in Africa does not construe the idea that the elderly in Africa are rigid in thoughts or have immutable authority which discourages independence of thought. I conclude that the position of the modernists on the supposed manifestation of authoritarianism in Africa derives its continuing force from a conception of philosophy which gives special overtones to the ideas of individuals as opposed to a collectivistic system of thought and the assumption that the multitude cannot produce philosophy.
Phenotypic Variation in IgG Receptors by Nonclassical FCGR2C Alleles
Authors: van der Heijden Joris , Breunis Willemijn B. , Geissler Judy , de Boer Martin , van den Berg Timo K. , Kuijpers Taco W.
Published: December 2011

The balance between activating and inhibitory signals from the different FcγRs for IgG ensures homeostasis of many inflammatory responses. FCGR2C is the product of an unequal crossover of the FCGR2A and FCGR2B genes encoding the activating FcγRIIa (CD32a) and inhibitory FcγRIIb (CD32b), respectively. A single nucleotide polymorphism (SNP) in exon 3 of FCGR2C results in either expression of the activating FcγRIIc (CD32c) (FCGR2C-open reading frame [ORF]) or its absence because of a stop codon (FCGR2C-Stop). Two additional variations in FcγRIIb/c expression on leukocytes have now been identified. In case of “nonclassical” FCGR2C-ORF alleles, FcγRIIc expression was unexpectedly absent, because of novel splice site mutations near exon 7 leading to another stop codon. In some individuals with FCGR2C-Stop alleles FcγRIIb was detected on NK cells, which normally are devoid of this protein. Individuals with these nonclassical FCGR2C-Stop alleles carried a deletion of FCGR2C-FCGR3B that extends into the promoter region of the adjacent FCGR2B gene and probably deletes a negative regulatory element in the FCGR2B promoter in NK cells. FcγRIIb expression on NK cells effectively inhibited killing mediated by FcγRIIIa (CD16a) in Ab-dependent cytotoxicity tests. Our findings demonstrate a more extensive and previously unnoticed variation in FcγR expression with relevance to immunity and inflammation.
TLR2 Is a Primary Receptor for Alzheimer’s Amyloid β Peptide To Trigger Neuroinflammatory Activation
Authors: Liu Shirong , Liu Yang , Hao Wenlin , Wolf Lisa , Kiliaan Amanda J. , Penke Botond , Rübe Claudia E. , Walter Jochen , Heneka Michael T. , Hartmann Tobias , Menger Michael D. , Fassbender Klaus
Published: December 2011

Microglia activated by extracellularly deposited amyloid β peptide (Aβ) act as a two-edged sword in Alzheimer’s disease pathogenesis: on the one hand, they damage neurons by releasing neurotoxic proinflammatory mediators (M1 activation); on the other hand, they protect neurons by triggering anti-inflammatory/neurotrophic M2 activation and by clearing Aβ via phagocytosis. TLRs are associated with Aβ-induced microglial inflammatory activation and Aβ internalization, but the mechanisms remain unclear. In this study, we used real-time surface plasmon resonance spectroscopy and conventional biochemical pull-down assays to demonstrate a direct interaction between TLR2 and the aggregated 42-aa form of human Aβ (Aβ42). TLR2 deficiency reduced Aβ42-triggered inflammatory activation but enhanced Aβ phagocytosis in cultured microglia and macrophages. By expressing TLR2 in HEK293 cells that do not endogenously express TLR2, we observed that TLR2 expression enabled HEK293 cells to respond to Aβ42. Through site-directed mutagenesis of tlr2 gene, we identified the amino acids EKKA (741–744) as a critical cytoplasmic domain for transduction of inflammatory signals. By coexpressing TLR1 or TLR6 in TLR2-transgenic HEK293 cells or silencing tlrs genes in RAW264.7 macrophages, we observed that TLR2-mediated Aβ42-triggered inflammatory activation was enhanced by TLR1 and suppressed by TLR6. Using bone marrow chimeric Alzheimer’s amyloid precursor transgenic mice, we observed that TLR2 deficiency in microglia shifts M1- to M2-inflammatory activation in vivo, which was associated with improved neuronal function. Our study demonstrated that TLR2 is a primary receptor for Aβ to trigger neuroinflammatory activation and suggested that inhibition of TLR2 in microglia could be beneficial in Alzheimer’s disease pathogenesis.
Mild Stroke Symptoms as the Initial Presentation of a Patient with Underlying Subacute Bacterial Endocarditis
Authors: Kamdar Ami , Debney Michael , Scott James , Ames Diane
Published: January 2012

We describe a patient with sub-acute bacterial endocarditis, whose chief presenting feature was mild expressive dysphasia.
Caecal Tumour Masquerading as an Appendicular Mass
Authors: Nixon Martha , Verwey Jes , Akoh Jacob A.
Published: January 2012

Appropriate management of appendix mass is based on an accurate diagnosis of the underlying pathology. This is a report of a complex patient presenting with an appendix mass, whose surgery was deferred due to severe comorbidities and who later died from severe metastatic disease. A 65-year-old lady presented with right iliac fossa pain and a mass. She was treated for an appendix mass initially and when the mass failed to resolve after four weeks, she was thoroughly investigated for the possibility of a tumour. Severe co-morbities had a significant impact on her management as definitive surgery was delayed. She represented 10 months after the initial admission with small bowel obstruction and died of metastatic caecal cancer. Management of appendix mass must entail a careful approach to investigating and treatment with emphasis on early intervention if the mass does not resolve promptly. This will avoid delayed diagnosis, treatment and a detrimental impact on prognosis.
Ellis Van Creveld Syndrome with Synpolydactyly, an Antenatal Diagnosis with Postnatal Correlation
Authors: Kundaragi Nischal G , Taori Kishor , Kumawat Ritesh , Rathod Jawahar , Sawant Atul E
Published: December 2011

Ellis Van Creveld syndrome (EVC), also known as chondroectodermal dysplasia, presents at birth with short limbs accompanied by postaxial polydactyly, nail dysplasia, and dental anomalies. Other manifestations of EVC include atrial septum defects and other congenital heart diseases. We report a case of the EVC syndrome with postaxial polydactyly (Synpolydactyly with seven fingers on the right side and hexadactyly on the left side) and a partial atrioventricular canal defect diagnosed antenatally. This variation of EVS has not been reported in English literature till date.
Lifting Properties, Nehari Theorem and Paley Lacunary Inequality
Authors: Cotlar M. , Sadosky C.
Published: January 2012

A general notion of lifting properties for families of sesquilinear forms is formulated. These lifting properties, which appear as particular cases in many classical interpolation problems, are studied for the Toeplitz kernels in

\mathbb Z

, and applied for refining and extending the Nehari theorem and the Paley lacunary inequality.
Comparison Principles and Pointwise Estimates for Viscosity Solutions of Nonlinear Elliptic Equations
Authors: Trudinger Neil S.
Published: January 2012

We prove cornparison principles for viscosity solutions of nonlinear second order, uniforrnly elliptic equations, which extend previous results of P.L. Lions, R. Jensen and H. Ishii. Some basic pointwise estimates for classical solutions are also extended to continuous viscosity solutions.
Quantum vortex dynamics in Josephson arrays and optical lattices
Authors: Fazio R. , Schön G.
Published: December 2011

In Josephson junction arrays, vortices form stable topological excitations. A key step towards the understanding of their properties was the observation made by Eckern and Schmid that in low‐capacitance junction arrays a vortex behaves as a massive particle moving in a periodic potential and subject to dissipation. The mass is low and quantum effects become observable. The present contribution provides a review of these properties together with a discussion of similar scenarios realized in optical lattices.
Connectable DNA Logic Gates: OR and XOR Logics
Authors: Gerasimova Yulia V. , Kolpashchikov Dmitry M.
Published: December 2011

Modern computer processors are based on semiconductor logic gates connected to each other in complex circuits. This study contributes to the development of a new class of connectable logic gates made of DNA in which the transfer of oligonucleotide fragments as input/output signals occurs upon hybridization of DNA sequences. The DNA strands responsible for a logic function form associates containing immobile DNA four‐way junction structures when the signal is high and dissociate into separate strands when the signal is low. A basic set of logic gates (NOT, AND, and OR) was designed. Two NOT gates, two AND gates, and an OR gate were connected in a network that corresponds to an XOR logic function. The design of the logic gates presented here may contribute to the development of the first biocompatible molecular computer.
Air‐Stable, Narrow‐Band‐Gap Ambipolar C60 Fullerene–Hydrazone Hybrid Materials
Authors: Urnikaite Simona , Malinauskas Tadas , Gaidelis Valentas , Jankauskas Vygintas , Getautis Vytautas
Published: December 2011

Fullerene–hydrazone dyads have been synthesized using the Confalone reaction followed by condensation with phenylhydrazines. Room‐temperature xerographic time‐of‐flight, ionization potential, and cyclic voltammetry measurements indicate that these narrow‐band‐gap (Eg<1.5 eV), ambipolar charge‐transporting dyads with balanced hole‐ and electron mobilities, which operate in air, are attractive materials for various optoelectronic applications.
A minimum version of log‐rank test for testing the existence of cancer cure using relative survival data
Authors: Yu Binbing
Published: December 2011

Cancer survival is one of the most important measures to evaluate the effectiveness of treatment and early diagnosis. The ultimate goal of cancer research and patient care is the cure of cancer. As cancer treatments progress, cure becomes a reality for many cancers if patients are diagnosed early and get effective treatment. If a cure does exist for a certain type of cancer, it is useful to estimate the time of cure. For cancers that impose excess risk of mortality, it is informative to understand the difference in survival between cancer patients and the general cancer‐free population. In population‐based cancer survival studies, relative survival is the standard measure of excess mortality due to cancer. Cure is achieved when the survival of cancer patients is equivalent to that of the general population. This definition of cure is usually called the statistical cure, which is an important measure of burden due to cancer. In this paper, a minimum version of the log‐rank test is proposed to test the equivalence of cancer patients' survival using the relative survival data. Performance of the proposed test is evaluated by simulation. Relative survival data from population‐based cancer registries in SEER Program are used to examine patients' survival after diagnosis for various major cancer sites.
A Covalently Supported Pyrimidinylphosphane Palladacycle as a Heterogenized Catalyst for the Suzuki–Miyaura Cross Coupling
Authors: Farsadpour Saeid , Ghoochany Leila Taghizadeh , Shylesh Sankaranarayanapillai , Dörr Gunder , Seifert Andreas , Ernst Stefan , Thiel Werner R.
Published: December 2011

The amino moiety of an aminopyrimidinyl phosphane allows rapid functionalization of the ligand with a silylated side chain containing a urea linker for catalyst heterogenization. The urea group causes the resulting ligand to undergo spontaneous CH activation at the pyrimidinyl site when reacted with (C6H5CN)2PdCl2 in CH2Cl2. Grafting of the resulting zwitterionic palladacycle complex onto siliceous supports leads to highly active hetereogeneous catalysts for the Suzuki–Miyaura coupling. Leaching tests proved that the catalysts obtained this way are truly heterogeneous.
Catalysis with In Situ‐Generated (Hypo)iodite Ions for Oxidative Coupling Reactions
Authors: Uyanik Muhammet , Ishihara Kazuaki
Published: December 2011

This Concept highlights the discovery and development of oxidative coupling reactions catalyzed by the hypoiodite (IO−) or iodite (OIO−) ion, which are generated in situ from iodide (I−) ion with hydrogen peroxide or tert‐butyl hydroperoxide as an environmentally benign oxidant. The most important features of these catalytic systems are 1) metal‐free oxidation, 2) milder reaction conditions, 3) high chemoselectivity (they tolerate a wide range of various functional groups), 4) operational simplicity, and 5) water or tert‐butyl alcohol as the only byproduct derived from the co‐oxidant used.
Adsorption of Uranyl Species onto the Rutile (110) Surface: A Periodic DFT Study
Authors: Pan Qing‐Jiang , Odoh Samuel O. , Asaduzzaman Abu Md. , Schreckenbach Georg
Published: December 2011

To model the structures of dissolved uranium contaminants adsorbed on mineral surfaces and further understand their interaction with geological surfaces in nature, we have performed periodic density funtional theory (DFT) calculations on the sorption of uranyl species onto the TiO2 rutile (110) surface. Two kinds of surfaces, an ideal dry surface and a partially hydrated surface, were considered in this study. The uranyl dication was simulated as penta‐ or hexa‐coordinated in the equatorial plane. Two bonds are contributed by surface bridging oxygen atoms and the remaining equatorial coordination is satisfied by H2O, OH−, and CO32− ligands; this is known to be the most stable sorption structure. Experimental structural parameters of the surface–[UO2(H2O)3]2+ system were well reproduced by our calculations. With respect to adsorbates, [UO2(L1)x(L2)y(L3)z]n (L1=H2O, L2=OH−, L3=CO32−, x≤3, y≤3, z≤2, x+y+2z≤4), on the ideal surface, the variation of ligands from H2O to OH− and CO32− lengthens the UOsurf and UTi distances. As a result, the uranyl–surface interaction decreases, as is evident from the calculated sorption energies. Our calculations support the experimental observation that the sorptive capacity of TiO2 decreases in the presence of carbonate ions. The stronger equatorial hydroxide and carbonate ligands around uranyl also result in UO distances that are longer than those of aquouranyl species by 0.1–0.3 Å. Compared with the ideal surface, the hydrated surface introduces greater hydrogen bonding. This results in longer UO bond lengths, shorter uranyl–surface separations in most cases, and stronger sorption interactions.
Elemental Distribution and Thermoelectric Properties of Layered Tellurides 39R‐M0.067Sb0.667Te0.266 (M=Ge, Sn)
Authors: Schneider Matthias N. , Fahrnbauer Felix , Rosenthal Tobias , Döblinger Markus , Stiewe Christian , Oeckler Oliver
Published: December 2011

The isostructural phases 39R‐Ge0.067Sb0.667Te0.266 (R$\bar 3$m, a=4.2649(1), c=75.061(2) Å) and 39R‐Sn0.067Sb0.667Te0.266 (R$\bar 3$m, a=4.2959(1), c=75.392(2) Å) were prepared by quenching stoichiometric melts of the pure elements and subsequent annealing at moderate temperatures. Their structures are comparable to “superlattices” synthesized by layer‐by‐layer deposition onto a substrate. These structures show no stacking disorder by electron microscopy. The structure of the metastable layered phases are similar to that of 39R‐Sb10Te3 (equivalent to Sb0.769Te0.231), which contains four A7 gray‐arsenic‐type layers of antimony alternating with Sb2Te3 slabs. Joint refinements on single‐crystal diffraction data using synchrotron radiation at several K edges were performed to enhance the scattering contrast. These refinements show that the elemental distributions at some atom positions are disordered whereas otherwise the structures are long‐range ordered. The variation of the elemental concentration correlates with the variation in interatomic distance. Z‐contrast scanning transmission electron microscopy (HAADF‐STEM) on 39R‐Ge0.067Sb0.667Te0.266 confirms the presence of concentration gradients. The carrier‐type of the isostructural metal (A7‐type lamellae)‐semiconductor heterostructures (Ge/Sn‐doped Sb2Te3 slabs) varies from n‐type (Ge0.067Sb0.667Te0.266) to p‐type (Sn0.067Sb0.667Te0.266). Although the absolute values of the Seebeck coefficient reached about 50–70 μV/K and the electrical conductivity is relatively high, the two isotypic phases exhibit a maximal thermoelectric figure of merit (ZT) of 0.06 at 400 °C as their thermal conductivity (κ≈8–9.5 W/mK at 400 °C) lies interestingly in between that of antimony and pure Sb2Te3.
Platinum(II)–Bis(aryleneethynylene) Complexes for Solution‐Processible Molecular Bulk Heterojunction Solar Cells
Authors: Dai Feng‐Rong , Zhan Hong‐Mei , Liu Qian , Fu Ying‐Ying , Li Jin‐Hua , Wang Qi‐Wei , Xie Zhiyuan , Wang Lixiang , Yan Feng , Wong Wai‐Yeung
Published: December 2011

Four new solution‐processible small‐molecular platinum(II)–bis(aryleneethynylene) complexes consisting of benzothiadiazole as the electron acceptor and triphenylamine and/or thiophene as the electron donor were conveniently synthesized and characterized by physicochemical and computational methods, and utilized as the electron‐donor materials in the fabrication of solution‐processed bulk heterojunction (BHJ) solar cells. The effect of different electron‐donor groups in these small molecules on the optoelectronic and photovoltaic properties was also examined. The optical and time‐dependent density functional theory studies showed that the incorporation of stronger electron‐donor groups significantly enhanced the solar‐absorption abilities of the complexes. These molecular complexes can serve as good electron donors for fabricating BHJ devices by blending them with the [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM) as the electron acceptor. The best power conversion efficiency of 2.37 % was achieved with the open‐circuit voltage of 0.83 V, short‐circuit current density of 7.10 mA cm−2 and fill factor of 0.40 under illumination of an AM 1.5 solar‐cell simulator. The spin‐coated thin films showed p‐channel field‐effect charge transport with hole mobilities of up to 2.4×10−4 cm2 V−1 s−1 for these molecules. The present work illuminates the potential of well‐defined organometallic complexes in developing light‐harvesting small molecules for efficient power generation in organic photovoltaics implementation.
Spreading and Stability of a Thin Droplet on a Heated Rotating Plate
Authors: Boettcher Konrad E. R. , Ehrhard Peter
Published: December 2011

Für die Ausbreitung eines dünnen rotierenden Tropfens wird, unter Ausnutzung der Schmierfilmapproximation, eine Entwicklungsgleichung zur Beschreibung der Position der freien Grenzfläche abgeleitet. Die dynamische Benetzung wird mit dem empirischen Tanner'schen Gesetz beschrieben und die Modellierung mit Experimenten aus der Literatur verglichen. Eine lineare Störungsanalyse liefert die instabilen Moden und das Einsetzen von Fingerbildung während der Ausbreitung. Betrachtet wird auch Konvektion aufgrund der temperaturabhängigen Oberflächenspannung und Dichte sowie deren Stabilität.
Electrochemiluminescence of SDBS‐Ru(bpy)32+‐CPM System and Its Application
Authors: Li Lijun , Gao Wenyan , Huang Wenyi , Cai Zhuo , Hu Dachun , Li Yanqing
Published: December 2011

When the concentration of dodecyl benzene sulfonic acid sodium salt (SDBS) is 0.7 mmol·L−1, the electrochemical and electrochemiluminescence (ECL) intensity of Ru(bpy)32+‐chlorpheniramine maleate (CPM) system at the Au electrode were studied. The results showed that compared with the absence of SDBS, enhancement of the ECL intensity was 14‐fold at Au electrode. Base on this, an ECL method was established for efficient and simple determination of CPM at Au electrode. Under the optimum experimental condition, the enhanced ECL intensities had good linear relationship with the concentration of CPM in the range of 1.0×10−4–1.0×10−7 mol·L−1, and a linear regression equation was obtained as follows: I (counts)=48.805×106c+394.03 (r=0.9975), the detection limit for CPM was 1.4×10−8 mol·L−1. The RSD for 5 times determinations of 1.0×10−5 mol·L−1 CPM was 3.2%. The results of recovery test were between 96.3%–102.5%, and the RSD of recovery test (n=5) was 2.7%. In addition, eleven kinds of tertiary amines‐Ru(bpy)32+ systems were investigated in the absence and presence of SDBS. The results showed that the enhancement of SDBS on ECL intensity of tertiary amines‐Ru(bpy)32+ systems was universal.
Theoretical Study of the Radical Scavenging Activity of Shikonin and Its Derivatives
Authors: Jin Ruifa , Li Jie
Published: December 2011

A series of shikonin derivatives have been designed and their radical scavenging activity has been characterized by the B3LYP/6‐31+G(d) approach. The hydrogen bond properties of the studied structures were investigated using the atoms in molecules (AIM) theory. The calculated results reveal that the hydrogen bond is important for good scavenging activity. The introduction of electron‐drawing (electron‐donating) groups increases (decreases) the scavenging activities of radical and radical cations of shikonin derivatives. Shikonin derivatives appear to be good candidates for the single‐electron‐transfer mechanism, particularly for N(CH3)2 derivative. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view. With the current work, we hope to highlight the radical scavenging activity of hydroxynaphthoquinones derivatives and stimulate the interest for further studies and exploitation in pharmaceutical industry.
Synthesis, Structure Elucidation and H+/K+‐ATPase Inhibitory Activity of Bisabolangelone Reduction Derivatives
Authors: Huang Nianyu , Chen Lei , Liao Zhaojiang , Fang Hubiao , Wang Junzhi , Zou Kun
Published: December 2011

Nine bisabolangelone reduction derivatives were synthesized and separated as potential anti‐ulcer agent. Their structures were characterized by 2D NMR, IR, ESI‐MS, elemental analysis and single‐crystal X‐ray diffraction analysis. Preliminarily H+/K+‐ATPase activity evaluation indicated that all the target compounds had a certain inhibitory effect, and compounds II and IV exhibited the better inhibitory activity against H+/K+‐ATPase than bisabolangelone and the commercial omeprazole with the IC50 of 23.21 and 65.32 μmol/L, respectively. The initial structure‐activity analysis suggested that the presence of carbonyl group in six‐membered ring and double bond in side‐chain seemed to be necessary to the activity.
A New Nanocatalytic Spectrophotometric Assay for Cationic Surfactant Using Phosphomolybdic Acid‐Formic Acid‐Nanogold as Indicator Reaction
Authors: Jiang Zhiliang , Qin Huimin , Liang Aihui
Published: December 2011

In the pH 7.4 Na2HPO4‐NaH2PO4 buffer solution, the cationic surfactant (CS) interacted with nanogold particles (NG) to form NG aggregations (NGA) that resulted in its color changing from wine red to blue‐violet. NG has a strong catalysis on the formic acid‐phosphomolybdic acid (PMo) colored reaction, but that of the NGA catalysis is weak. With the increase of CS concentration, the NGA increased and the NG decreased, the catalysis decreased and the absorption value at 700 nm decreased linearly. The concentrations of 6.25–250 nmol/L tetradecyl dimethyl benzyl ammonium chloride (TDBAC), 0.625–250 nmol/L cetyltrimethyl ammonium bromide (CTMAB) and 12.5–500 nmol·L−1 dodecyldimethylbenzyl ammonium chloride (DDBAC) had good linear responses to the decreased absorption value (ΔA700 nm), with molar absorption coefficients of 2.2×106, 2.1×106 and 9×105 L·mol−1·cm−1 respectively. This method was simple, highly sensitive and low‐cost.
Methenamine as an Efficient Ligand for Copper‐catalyzed Coupling of Phenols with Aryl Halides
Authors: Qian Cunwei , Zong Qianshou , Fang Dong
Published: December 2011

Employing methenamine as a new supporting ligand, the copper‐catalyzed coupling reactions of aryl bromides or aryl iodides with various phenols successfully proceeded in good yields under mild conditions. A series of diaryl ethers were obtained with excellent yields in the presence of K3PO4 and copper(I) salt.
Orthogonal Enzymatic Reactions to Control Supramolecular Hydrogelations
Authors: Chen Guoqin , Ren Chunhua , Wang Ling , Xu Bing , Yang Zhimou
Published: December 2011

Enzyme‐responsive hydrogels have great potential in applications of controlled drug release, tissue engineering, etc. In this study, we reported on a supramolecular hydrogel that showed responses to two enzymes, phosphatase which was used to form the hydrogels and esterase which could trigger gel‐sol phase transitions. The gelation process and visco‐elasticity property of the resulting gel, morphology of the nanostructures in hydrogel, and peptide conformation in the self‐assembled nanostructure were characterized by rheology, transmission electron microscope (TEM), and circular dichroism (CD), respectively. Potential application of the enzyme‐responsive hydrogel in drug release was also demonstrated in this study. Though only one potential application of drug release was proved in this study, the responsive hydrogel system in this study might have potentials for the applications in fields of cell culture, controlled‐drug release, etc.
Influence of Temperatures on the Tautomerism of the N‐(1H‐imidazoline‐2‐yl)‐1H‐benzimidazol‐2‐amine and Investigation of Its Electrochemical Behaviour
Authors: Servi Süleyman , Genc Murat , Saydam Sinan
Published: December 2011

Synthesis of N‐(1H‐imidazoline‐2‐yl)‐1H‐benzimidazol‐2‐amine was carried out under microwave irradiation (MWI) conditions. Dynamic 1H NMR investigation of N‐(1H‐imidazoline‐2‐yl)‐1H‐benzimidazol‐2‐amine compound was reported at temperature range of 223–333 K in DMF‐d7. Some physical parameters, such as coalescence temperature (Tc), the free energy of activation (ΔG∗︁) and rate constant (k) values were calculated from its 1H NMR spectra at various temperatures. Electrochemical feature of this compound was investigated by cyclic (CV) and square wave voltammetry (SWV).
Theoretical Study of the Mechanism of Cycloaddition Reaction between Silylene Silylene (H2SiSi:) and Acetone
Authors: Wang Zhina , Shi Leyi , Li Yongqing , Lu Xiuhui
Published: December 2011

The mechanism of the cycloaddition reaction between singlet silylene silylene (H2SiSi:) and acetone has been investigated with the CCSD (T)//MP2/6‐31G∗︁ method. According to the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction channels. The present rule of this reaction is that the [2+2] cycloaddition reaction of the two π‐bonds in silylene silylene (H2SiSi:) and acetone leads to the formation of a four‐membered ring silylene (E3). Because of the unsaturated property of Si: atom in E3, it further reacts with acetone to form a silicic bis‐heterocyclic compound (P7). Simultaneously, the ring strain of the four‐membered ring silylene (E3) makes it isomerize to a twisted four‐membered ring product (P4).
Synthesis, Insecticidal Assay and Molecular Docking Study of Novel Neonicotinoids N‐Oxide Analogues
Authors: Zhang Wenwen , Fan Yefeng , Yu Tao , Xu Zhiping , Xu Xiaoyong , Cheng Jiagao , Li Zhong
Published: December 2011

Eight novel neonicotinoids N‐oxide analogues were designed and synthesized. All the compounds have been identified by 1H NMR and HRMS. The N‐oxide analogues exhibit high insecticidal activity against cowpea aphids (Aphis craccivora) at 250 mg·L−1. The influence of N‐oxide formation on the biological activity was elucidated by computational chemical study, and it indicated that the water bridge hydrogen bonding network was broken due to the influence of the O atom connected with the pyridine ring.
A DFT Study on the Structure and Properties of Cu/Cr2O3 Catalyst
Authors: Zhang Minhua , Li Ruzhen , Yu Yingzhe
Published: December 2011

Using DFT method, the stable adsorption configurations of Cu4 cluster on Cr2O3 (0001) surface were investigated. The regular tetrahedron structure and the planar structures were considered as the initial adsorption configuration of Cu4 cluster, respectively. The adsorption energies of the two structures were also calculated. The simulation result indicated that the adsorption energy of the regular tetrahedron structure was higher than that of the planar structure, and thus the regular tetrahedron structure was confirmed to be the stable adsorption configuration for Cu4 cluster on Cr2O3 (0001) surface. Moreover, it was observed that the Cu4 cluster showed the definite stable adsorption sites on Cr2O3 (0001) surface, namely 3‐fold O sites. During the adsorption process of Cu4 cluster onto Cr2O3 (0001) surface, the Cu4 cluster could bond with more Cr or O atoms on the surface, and the apparent charge transfer also occurred correspondingly. Meanwhile, the Cu4 cluster and Cr2O3 (0001) surface would bond in the form of local polarization to enhance the stability of adsorption configuration.
N‐Heterocyclic Carbene‐Catalyzed [2+2+2] Annulation of Allenoates with Trifluoromethylketones
Authors: Sun Lihui , Wang Tong , Ye Song
Published: December 2011

In contrast with the reported phosphine‐ and DABCO‐catalyzed [3+2] and [2+2] annulation of allenoates with trifluoromethylketone, the [2+2+2] annulation of allenoates and two molecules of trifluoromethylketone was found under the condition of N‐heterocyclic carbene catalysis.
CITIES – ein europäisches Projekt
Authors: Bader Hans Joachim , Gros Leo , Maciejowska Iwona
Published: December 2011

Es gibt nur wenige europäischer Ansätze, über die Grenzen einzelner Mitgliedsländer der Europäischen Union hinaus Impulse für die Fortbildung von Chemielehrern zu geben. Aus diesem Grund fanden sich im Rahmen des COMENIUS‐Projekts CITIES (Chemistry and Industry for Teachers in European Schools) Partner aus Hochschulen, Wissenschaftlichen Gesellschaften und Vertretungen von Arbeitgebern und Arbeitnehmern der Chemischen Industrie aus Großbritannien, Polen, Tschechien, Deutschland, Frankreich und Spanien zusammen. Die Gruppe erstellte eine gemeinsame, über das Internet zugängliche Plattform für die Chemielehrerfortbildung, auf der alle von den Partnern eingebrachten Materialien eingestellt werden.
Experimental Designs Applied to Desorption of Dichromate Ions after Separation and Preconcentration from Natural and Industrial Water by Modified Nano‐Alumina
Authors: Sayar Omid , Abadi Iman Jabbari Zahir , Sadeghi Omid , Zhad Hamid Reza Lotfi Zadeh , Tavassoli Najmeh
Published: December 2011

Nano‐alumina modified by 9‐aminoacridine was used as a sorbent for separation and determination of dichromate ions from water. Statistical method, based on surface response design, has been used for the optimization of dichromate ions elution from 9‐aminoacridine nano‐alumina. The adsorbed dichromate ions were found to be eluted quantitatively with 0.8 mol L−1 KCl in 1.6 mol L−1 NaOH which optimized by response surface design. Under optimum conditions, the accuracy, precision (relative standard deviation, RSD%) and R‐square of the method were calculated as >98, <3, and >94%, respectively. Remarkable agreement between experimental and theoretical data was confirmed the predicted assumption. The method was applied to the simultaneous determination of dichromate in natural and industrial water samples. We also examined the retention of dichromate anions in the presence of Cl−, ${\rm NO}_{3}^{- } $, and ${\rm SO}_{4}^{2- } $ anions at pH 3.
Improving Soil Enzyme Activities and Related Quality Properties of Reclaimed Soil by Applying Weathered Coal in Opencast‐Mining Areas of the Chinese Loess Plateau
Authors: Li Hua , Shao Hongbo , Li Weixiang , Bi Rutian , Bai Zhongke
Published: December 2011

There are many problems for the reclaimed soil in opencast‐mining areas of the Loess Plateau of China such as poor soil structure and extreme poverty in soil nutrients and so on. For the sake of finding a better way to improve soil quality, the current study was to apply the weathered coal for repairing soil media and investigate the physicochemical properties of the reclaimed soil and the changes in enzyme activities after planting Robinia pseucdoacacia. The results showed that the application of the weathered coal significantly improved the quality of soil aggregates, increased the content of water stable aggregates, and the organic matter, humus, and the cation exchange capacity of topsoil were significantly improved, but it did not have a significant effect on soil pH. Planting R. pseucdoacacia significantly enhanced the activities of soil catalase, urease, and invertase, but the application of the weathered coal inhibited the activity of catalase. Although the application of appropriate weathered coal was able to significantly increase urease activity, the activities of catalase, urease, or invertase had a close link with the soil profile levels and time. This study suggests that applying weathered coals could improve the physicochemical properties and soil enzyme activities of the reclaimed soil in opencast‐mining areas of the Loess Plateau of China and the optimum applied amount of the weathered coal for reclaimed soil remediation is about 27 000 kg hm−2.
On the Accuracy of DFT Methods in Reproducing Ligand Substitution Energies for Transition Metal Complexes in Solution: The Role of Dispersive Interactions
Authors: Jacobsen Heiko , Cavallo Luigi
Published: December 2011

The performance of a series of density functionals when tested on the prediction of the phosphane substitution energy of transition metal complexes is evaluated. The complexes FeBDA and RuCOD (BDA=benzylideneacetone, COD=cyclooctadiene) serve as reference systems, and calculated values are compared with the experimental values in THF as obtained from calorimetry. Results clearly indicate that functionals specifically developed to include dispersion interactions usually outperform other functionals when BDA or COD substitution is considered. However, when phosphanes of different sizes are compared, functionals including dispersion interactions, at odd with experimental evidence, predict that larger phosphanes bind more strongly than smaller phosphanes, while functionals not including dispersion interaction reproduce the experimental trends with reasonable accuracy. In case of the DFT‐D functionals, inclusion of a cut‐off distance on the dispersive term resolves this issue, and results in a rather robust behavior whatever ligand substitution reaction is considered.