bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Tetraethoxysilane‐Templated Porous Ba0.5Sr0.5Co0.8Fe0.2O3−δ Perovskite for the Oxygen Evolution Reaction
Authors: Yang Yisu , Zhou Wei , Liu Ruochen , Li Mengran , Rufford Thomas E. , Zhu Zhonghua
Published: October 2014

The perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) is one of the best catalysts for the oxygen evolution reaction (OER), which is critical to many energy‐storage applications. However, the catalytic activity of BSCF perovskites is constrained by a low specific surface area (0.5 m2 g−1). We report here, for the first time, a facile, in situ template method using tetraethoxysilane (TEOS) to synthesize porous BSCF with surface areas of up to 32.1 m2 g−1, which to our knowledge is the highest reported surface area in a BSCF perovskite, and with excellent catalytic activity for the OER. For example, the BCSF prepared using a TEOS‐to‐BSCF ratio of 3.4 exhibited up to 35.2 A g−1 at 1.63 V versus a reversible hydrogen electrode (overpotential, η=0.4 V) and this current is 5.3 times that exhibited by nonporous BSCF (6.6 A g−1). The high activity of the porous BCSF is attributed to the additional catalytic surface sites available in the pores created by the in situ TEOS‐template method. The general application of this technique to produce porous perovskites is demonstrated in the synthesis of a second example, porous LaMnO3.
Preparation, Structural Properties and Thermal Isomerization of Hex‐3‐ene‐1,5‐diyne Bridged [2.2]Paracyclophanes
Authors: Dix Ina , Bondarenko Lidija , Jones Peter G. , Ernst Ludger , Ibrom Kerstin , Grunenberg Jörg , Boese Roland , Hopf Henning
Published: October 2014

The [2.2]paracyclophane moiety is used as a spacer to connect the ends of a hex‐3‐ene‐1,5‐diyne unit, a π‐system that on thermolysis usually cycloaromatizes to a benzene ring (Bergman cyclization). For the preparation of the pseudo‐geminally‐bridged system 9, the diacetylene 3 was chain‐extended to the diol 16, which after conversion to the pseudo‐geminal dibromide 17 was ring‐closed by treatment with LiHMDS/HMPA to the [2.2]paracyclophane enediyne 9. Whereas the McMurry coupling of the pseudo‐ortho bisaldehyde 24 resulted in the formation of the hexadienyne‐bridged cyclophane 27, the pseudo‐ortho‐bridged hydrocarbon 11 was obtained by preparing first the diol 28 from 24, converting the latter into the dioxolane 29, which in the last step furnished the olefin 11 by treatment with Tf2O/EtN(iPr)2. The authentic Bergman product 10 of the pseudo‐gem‐bridged hexenediyne 9 was synthesized by a conventional sequence starting from the ethynyl formyl substrate 18. Since the pseudo‐ortho‐enediyne‐bridged hydrocarbon 11 is thermally labile, its benzannelated derivate 34 was prepared. No classical Bergman cyclization reactions could be observed for any of the [2.2]paracyclophane‐bridged hexenediynes prepared here. In the pseudo‐gem‐series the fulvenes 14 and 15 were the only products that could be identified under thermal conditions (McMurry coupling); the benzannelated substrate 34 gave the benzofulvene‐bridged cyclophane 36 on photolysis. Bergman cyclizations yielding fulvene derivatives are extremely rare. The mechanism of the cyclization of 9 and 34 is discussed, using compliance constants. The structure assignments of the hydrocarbons synthesized in this study are based on spectroscopic studies as well as X‐ray structural analyses for 9, 10, 11, 27, and 34.
Triarylboranes with a 2‐Dimesitylboryl‐2’‐(N,N‐dimethylamino)biphenyl Core Unit: Structure–Property Correlations and Sensing Abilities to Discriminate Between F− and CN− Ions
Authors: Wang Chen , Jia Jiong , Zhang Wei‐Ning , Zhang Hong‐Yu , Zhao Cui‐Hua
Published: October 2014

A series of triarylboranes, in which different substituents are introduced at the para position of the dimethylamino group of a 2‐dimesitylboryl‐2’‐(N,N‐dimethylamino)biphenyl core unit, have been comprehensively investigated to explore the effect of structural modification on photophysical properties. The introduction of electron‐accepting substituents would facilitate the HOMO→LUMO charge transfer (CT) transition. In contrast, the intramolecular CT transition is significantly prohibited when electron‐donating substituents are incorporated. Notably, the HOMO→LUMO CT transition mainly consists of the transition from the electron‐donating amino group to an electron acceptor other than boryl when a strong electron acceptor such as the dicyanovinyl group is present. This dicyanovinyl‐substituted compound displays sensing abilities to discriminate fluoride and cyanide ions. In solution in THF, the fluoride ions first bind to the boron center, then attack the α‐carbon atom of the dicyanovinyl group, whereas the cyanide anion acts on the electron‐accepting centers in the reverse sequence. As a result, the absorption and emission change in different manners upon addition of fluoride and cyanide ions.
Designed Benzothiadiazole Fluorophores for Selective Mitochondrial Imaging and Dynamics
Authors: Carvalho Pedro H. P. R. , Correa Jose R. , Guido Bruna C. , Gatto Claudia C. , De Oliveira Heibbe C. B. , Soares Thereza A. , Neto Brenno A. D.
Published: October 2014

A series of new rationale designed 2,1,3‐benzothiadiazole (BTD) fluorescent derivatives has been synthesized and applied for cellular selective staining of cancer cells in cell‐imaging experiments. Four new synthesized BTD derivatives showed only poor or reasonable cellular selection, but with excellent fluorescence intensity and almost no background signal emitting at the blue or green channels. The knowledge gained by analysing their molecular architecture, however, allowed the planning and synthesis of a fluorescent BTD, which was then successfully tested and showed superior mitochondrial selection with outstanding results in bioimaging experiments in living cells. The new marker (named Splendor) was then compared with the commercially available MitoTracker Red (also through co‐staining experiments) and showed far better mitochondrial selection, fluorescence intensity and chemical stability. Mitochondrial imaging and tracking (dynamic changes) was possible using Splendor during the whole cellular division cycle. DFT calculations were performed to offer insights into the origin of the chemical‐ and photostability of BTD derivatives. In addition, molecular docking calculations hint at a potential molecular target for the BTD derivatives in the mitochondrial protein adenine nucleotide translocase, which may explain the mitochondrial selectivity of Splendor versus the other four BTD derivatives.
Molecularly Imprinted Photonic Polymers as Sensing Elements for the Creation of Cross‐Reactive Sensor Arrays
Authors: Xu Dan , Zhu Wei , Wang Chen , Tian Tian , Cui Jiecheng , Li Jian , Wang Hui , Li Guangtao
Published: October 2014

By combining molecular imprinting and colloidal crystal templating, molecularly imprinted inverse‐opal photonic polymers (MIPPs) acting as sensing elements have been exploited to create sensor arrays for the first time. With this new strategy, abundant sensing elements with differential sensing abilities were easily accessible. Because of the unique hierarchical porous structure integrated in each sensing element, high sensitivity and selectivity, fast response and self‐reporting (label‐free) detection could be simultaneously achieved. All these fascinating features indicate that MIPPs are ideal sensing elements for creating sensor arrays. By integrating the individual sensing elements on a substrate, the formed array chip delivers better portability and high‐throughput capability. As a demonstration, six kinds of contaminants were selected as analytes. The detection and discrimination of these analytes and even their mixtures in a wide range of concentrations, particularly trace amounts of analyte against a high background of other components, could be achieved, indicating the powerful capability of MIPPs‐based sensor array for sensing. These results suggest that the described strategy opens a new route for sensor array creation and should find important applications in a wide range of areas.
Domino Hydroformylation/Aldol Condensation/Hydrogenation Catalysis: Highly Selective Synthesis of Ketones from Olefins
Authors: Fang Xianjie , Jackstell Ralf , Börner Armin , Beller Matthias
Published: October 2014

A general and highly chemo‐ and regioselective synthesis of ketones from olefins by domino hydroformylation/aldol condensation/hydrogenation reaction has been developed. A variety of olefins are efficiently converted into various ketones in good to excellent yields and regioselectivities in the presence of a specific rhodium phosphine/base–acid catalyst system.
Silver Nanoparticles Supported on CeO2‐SBA‐15 by Microwave Irradiation Possess Metal–Support Interactions and Enhanced Catalytic Activity
Authors: Qian Xufang , Kuwahara Yasutaka , Mori Kohsuke , Yamashita Hiromi
Published: October 2014

Metal–support interactions (MSIs) and particle size play important roles in catalytic reactions. For the first time, silver nanoparticles supported on CeO2‐SBA‐15 supports are reported that possess tunable particle size and MSIs, as prepared by microwave (MW) irradiation, owing to strong charge polarization of CeO2 clusters (i.e., MW absorption). Characterizations, including TEM, X‐ray photoelectron spectroscopy, and extended X‐ray absorption fine structure, were carried out to disclose the influence of CeO2 contents on the Ag particle size, MSI effect between Ag nanoparticles and CeO2‐SBA‐15 supports, and the strong MW absorption of CeO2 clusters that contribute to the MSIs during Ag deposition. The Ag particle sizes were controllably tuned from 1.9 to 3.9 nm by changing the loading amounts of CeO2 from 0.5 to 2.0 wt %. The Ag nanoparticle size was predominantly responsible for the high turnover frequency (TOF) of 0.41 min−1 in ammonia borane dehydrogenation, whereas both particle size and MSIs contributed to the high TOF of 555 min−1 in 4‐nitrophenol reduction for Ag/0.5CeO2‐SBA‐15, which were twice as large as those of Ag/SBA‐15 without CeO2 and Ag/CeO2‐SBA‐15 prepared by conventional oil‐bath heating.
A Strategy for the Preparation of Thioantimonates Based on the Concept of Weak Acids and Corresponding Strong Bases
Authors: Anderer Carolin , Delwa de Alarcón Natalie , Näther Christian , Bensch Wolfgang
Published: October 2014

By following a new synthetic approach, which is based on the in situ formation of a basic medium by the reaction between the strong base Sb(V)S43− and the weak acid H2O, it was possible to prepare three layered thioantimonate(III) compounds of composition [TM(2,2′‐bipyridine)3][Sb6S10] (TM=Ni, Fe) and [Ni(4,4′‐dimethyl‐2,2′‐bipyridine)3][Sb6S10] under hydrothermal conditions featuring two different thioantimonate(III) network topologies. The antimony source, Na3SbS4 ⋅ 9 H2O, undergoes several decomposition reactions and produces the SbIIIS3 species, which condenses to generate the layered anion. The application of transition‐metal complexes avoids crystallization of dense phases. The reactions are very fast compared to conventional hydrothermal/solvothermal syntheses and are much less sensitive to changes of the reaction parameters.
Fused Perylene–Phthalocyanine Macrocycles: A New Family of NIR‐Dyes with Pronounced Basicity
Authors: Schönamsgruber Jörg , Maid Harald , Bauer Walter , Hirsch Andreas
Published: October 2014

The synthesis and characterization of a new type of chromophore, namely PePc consisting of a central phthalocyanine core and four fused perylene–bisimide (PBI) units is described for the first time. The entire architecture represents a highly extended conjugated heterocyclic π‐system with C4h symmetry. In order to guarantee pronounced solubility in organic solvents the corresponding PBI units were bay‐functionalized with tert‐butylphenoxy substituents. Next to the metal‐free macrocycle, PePcH2, also metallated macrocycles PePcM (M=Zn, Ni, Pb, Ru, Fe) were synthesized. The extensive fusion of the corresponding aromatic building blocks to the very large extended π‐system leads to a very narrow HOMO–LUMO gap and as a consequence to transparency in the visible but light absorption in the NIR region. Significantly, the azomethine N‐atoms N1N4 of PePcM and PePcH2 are highly basic. The corresponding tetraprotonated systems can only be deprotonated with very strong non‐nucleophilic bases such as phosphazene bases. In the protonated forms PePcMH44+ and PePcMH64+ the absorption maximum is shifted back to the visible region due to the loss of conjugation. The experimental findings were corroborated with quantum mechanical calculations.
Environment‐Sensitive Probes Containing a 2,6‐Diethynylpyridine Motif for Fluorescence Turn‐On Detection and Induction of Nanoarchitectures of Human Telomeric Quadruplex
Authors: Das Rabindra Nath , Debnath Manish , Gaurav Abhiket , Dash Jyotirmayee
Published: October 2014

Bis(phenylethynyl)pyridylcarboxamides with amide side chains at the para position of the NH2 group possess strong solvatochromic properties compared with the meta analogues. Fluorescence binding titrations show that these probes exhibit remarkable fluorescence turn‐on responses upon interacting with the human telomeric G‐quadruplex (h‐TELO). Förster resonance energy transfer melting analysis shows the high selectivity of these probes for h‐TELO over duplex DNA. Isothermal titration calorimetry, as well as UV/Vis and fluorescence spectroscopy studies, show that the meta analogue has a twofold binding affinity for h‐TELO over the para analogue. The noncovalent interaction of these small‐molecule probes with h‐TELO has been used to regulate the assembly of novel supramolecular nanoarchitectures.
Synthesis of a Rigid C3v‐Symmetric Tris‐salicylaldehyde as a Precursor for a Highly Porous Molecular Cube
Authors: Elbert Sven M. , Rominger Frank , Mastalerz Michael
Published: October 2014

The development of a synthetic approach to a C3v‐symmetric tris‐salicylaldehyde based on triptycene is presented. The tris‐salicylaldehyde is a versatile precursor for porous molecular materials, as demonstrated in the [4+4] condensation reaction with a triptycene triamine to form a molecular shape‐persistent porous cube. The amorphous material of the molecular porous cube shows a very high surface area of 1014 m2 g−1 (BET model) and a high uptake of CO2 (18.2 wt % at 273 K and 1 bar). Furthermore, during the multistep synthesis of the tris‐salicylaldehyde precursor, a relatively rare (twofold) addition of the aryne to the anthracene in the 1,4‐ and 1,4,5,8‐positions have been found during a Diels–Alder reaction, as proven by X‐ray structure analysis.
Metal–Organic Framework‐Derived Copper Nanoparticle@Carbon Nanocomposites as Peroxidase Mimics for Colorimetric Sensing of Ascorbic Acid
Authors: Tan Hongliang , Ma Chanjiao , Gao Li , Li Qian , Song Yonghai , Xu Fugang , Wang Tao , Wang Li
Published: October 2014

Metal–organic frameworks (MOFs) have emerged as very fascinating functional materials due to their diversity nature. A nanocomposite consisting of copper nanoparticles dispersed within a carbon matrix (Cu NPs@C) is prepared through a one‐pot thermolysis of copper‐based metal–organic framework precursors. Cu NPs@C can catalyze the oxidation of 3,3′,5,5′‐tetramethylbenzidine (TMB) to form a colored product in the presence of H2O2. As a peroxidase mimic, Cu NPs@C not only has the advantages of low cost, high stability, and easy preparation, but also follows Michaelis–Menten behaviors and shows strong affinity to H2O2. As the Cu NPs’ surfaces are free from stabilizing agent, Cu NPs@C exhibited a higher affinity to H2O2 than horseradish peroxidase. On the basis of the inhibitory effect of ascorbic acid (AA) on oxidation of TMB, this system serves as a colorimetric method for the detection of AA, suggesting that the present work would expand the potential applications of MOF‐derived nanocomposites in biomedical fields.
Versatile Reagent Ph3As(OTf)2: One‐Pot Synthesis of [P7(AsPh3)3][OTf]3 from PCl3
Authors: Donath Maximilian , Bodensteiner Michael , Weigand Jan J.
Published: October 2014

Compound Ph3As(OTf)2 as a pentacoordinated AsV Lewis acid readily forms dicationic Lewis acid/base adducts upon addition of various Lewis bases. It also represents a stronger chloride‐abstracting agent than Me3SiOTf and facilitates the reductive coupling of PCl3 in the presence of AsPh3 to the unprecedented cation [P7(AsPh3)3]3+ as triflate salt. This crystallographically characterized nortricyclane‐type cation represents a P7R3‐derivative with the most electron‐withdrawing substituents, resulting in a pronounced effect on the structural parameters of the P7 core.
Oxygen‐Initiated Stereoselective Thermal Isomerisation of a Cyclobutane Derivative in the Solid State
Authors: Chanthapally Anjana , Yang Hui , Quah Hong Sheng , Webster Richard D. , Schreyer Martin K. , Wong Ming Wah , Vittal Jagadese J.
Published: October 2014

Solid‐state [2+2] photochemical cycloaddition reactions have been extensively studied after the classical work of Schmidt in the 1960s. Of these, trans‐1,2‐bis(4′‐pyridyl)ethylene (bpe) is one of the well‐studied alkenes to synthesize tetrakis(4‐pyridyl)cyclobutane (tpcb). However, almost all the solid‐state [2+2] cycloaddition reactions of bpe yielded, almost exclusively, one of the four possible isomers, namely, the rctt‐tpcb (r=regio c=cis and t=trans). Here we describe a stereoselective synthesis of the tetrahedrally disposed rtct‐tpcb by the solid‐state thermal isomerization of the rctt‐isomer in atmospheric air. We propose that this isomerization occurs through a topochemical unimolecular mechanism by a radical chain pathway, initiated by molecular oxygen. This is supported by the nature of products formed in air and nitrogen, detection of a radical in ESR spectral studies, ESI‐MS crossover experiments, VT PXRD studies along with QM, MD and docking calculations. The formation of a unique isomer by thermal isomerization may be a general phenomenon to quantitatively synthesize other useful stereoisomers from the existing isomers of cyclobutane derivatives.
Hospitalization Costs for Acute Myocardial Infarction Patients Treated With Percutaneous Coronary Intervention in the United States Are Substantially Higher Than Medicare Payments
Authors: Afana Majed , Brinjikji Waleed , Cloft Harry , Salka Samer
Published: October 2014

Background

Acute coronary syndromes account for half of all deaths secondary to cardiovascular disease and represent a significant economic burden in the United States. Therefore, assessing hospitalization costs relative to Medicare reimbursement for these patients is important in understanding the impact of these patients on hospitals. We hypothesized that hospitalization costs for acute myocardial infarction patients treated with percutaneous coronary intervention (PCI) were higher than their associated Medicare payments.

Methods

Using the Nationwide Inpatient Sample, we evaluated hospitalization costs for patients treated with PCI from 2001 through 2009 by multiplying hospital charges by the group average cost‐to‐charge ratio for each patient's hospitalization. Primary end points examined were total hospital costs and trends over time, which were correlated with clinical outcomes and insurance payments. Costs were inflation adjusted with 2009 as the reference year.

Results

Median hospitalization costs of PCI increased from $15 889 (interquartile range [IQR] = $12 057–$21 204) in 2001 to $19 349 (IQR = $14 660–$26 282) in 2009. From 2004 to 2009, inflation‐adjusted costs for PCI decreased at a rate of 0.3% per year. In 2009, a total of 265,531 patients received PCI for acute myocardial infarction. Of these, 143 654 were <65 years old, and 121 876 were ≥65 years old. Average 2009 Medicare payments ranged from $9303 to $17 500 depending on the Medicare Severity‐Diagnosis Related Groups (MS‐DRG) billed, leaving hospitals at a loss of anywhere from $4493 to $7940 per patient when comparing costs and reimbursements across all included MS‐DRG codes.

Conclusions

Hospitalization costs for patients treated with PCI have been stabilizing over the last few years; however, there still remains a significant disparity between Medicare reimbursements and hospitalization costs, which has potential implications on patient outcomes, quality of care, and hospital sustainability.
Design of gem‐Difluoro‐bis‐Tetrahydrofuran as P2 Ligand for HIV‐1 Protease Inhibitors to Improve Brain Penetration: Synthesis, X‐ray Studies, and Biological Evaluation
Authors: Ghosh Arun K. , Yashchuk Sofiya , Mizuno Akira , Chakraborty Nilanjana , Agniswamy Johnson , Wang Yuan‐Fang , Aoki Manabu , Gomez Pedro Miguel Salcedo , Amano Masayuki , Weber Irene T. , Mitsuya Hiroaki
Published: October 2014

The structure‐based design, synthesis, biological evaluation, and X‐ray structural studies of fluorine‐containing HIV‐1 protease inhibitors are described. The synthesis of both enantiomers of the gem‐difluoro‐bis‐THF ligands was carried out in a stereoselective manner using a Reformatskii–Claisen reaction as the key step. Optically active ligands were converted into protease inhibitors. Two of these inhibitors, (3R,3aS,6aS)‐4,4‐difluorohexahydrofuro[2,3‐b]furan‐3‐yl(2S,3R)‐3‐hydroxy‐4‐((N‐isobutyl‐4‐methoxyphenyl)sulfonamido)‐1‐phenylbutan‐2‐yl) carbamate (3) and (3R,3aS,6aS)‐4,4‐difluorohexahydrofuro[2,3‐b]furan‐3‐yl(2S,3R)‐3‐hydroxy‐4‐((N‐isobutyl‐4‐aminophenyl)sulfonamido)phenylbutan‐2‐yl) carbamate (4), exhibited HIV‐1 protease inhibitory Ki values in the picomolar range. Both 3 and 4 showed very potent antiviral activity, with respective EC50 values of 0.8 and 3.1 nM against the laboratory strain HIV‐1LAI. The two inhibitors exhibited better lipophilicity profiles than darunavir, and also showed much improved blood–brain barrier permeability in an in vitro model. A high‐resolution X‐ray structure of inhibitor 4 in complex with HIV‐1 protease was determined, revealing that the fluorinated ligand makes extensive interactions with the S2 subsite of HIV‐1 protease, including hydrogen bonding interactions with the protease backbone atoms. Moreover, both fluorine atoms on the bis‐THF ligand formed strong interactions with the flap Gly 48 carbonyl oxygen atom.
Combining DNA methyltransferase and histone deacetylase inhibition to treat acute myeloid leukemia/myelodysplastic syndrome: Achievements and challenges
Authors: Lübbert Michael , Kuendgen Andrea
Published: October 2014

In the first randomized trial of older patients with myelodysplastic syndrome/acute myeloid leukemia (adaptive randomization) to receive treatment with intravenous decitabine (5‐day schedule) either alone or in combination with the oral histone deacetylase (HDAC) inhibitor valproic acid (7‐day schedule), Issa and colleagues do not detect an improved response rate or overall survival with the combined treatment. The various factors potentially affecting clinical outcome in studies combining decitabine or 5‐azacytidine with valproic acid or other HDAC inhibitors are discussed.
Results of phase 2 randomized study of low‐dose decitabine with or without valproic acid in patients with myelodysplastic syndrome and acute myelogenous leukemia
Authors: Issa Jean‐Pierre , Garcia‐Manero Guillermo , Huang Xuelin , Cortes Jorge , Ravandi Farhad , Jabbour Elias , Borthakur Gautam , Brandt Mark , Pierce Sherry , Kantarjian Hagop M.
Published: October 2014

BACKGROUND

Hypomethylating agents have demonstrated activity in patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Preclinical and single‐arm trials have suggested that adding histone deacetylase (HDAC) inhibitors may synergize the epigenetic modulation of hypomethylating agents and improve treatment results.

METHODS

The objective of this study was to evaluate the possible benefit of adding valproic acid, an HDAC inhibitor, to decitabine in the treatment of MDS and AML.

RESULTS

Patients with higher risk MDS or with AML aged ≥60 years were eligible. Patients were randomized in a Bayesian response‐adaptive design to receive intravenous decitabine 20 mg/m2 daily for 5 days or decitabine plus oral valproic acid 50 mg/kg daily for 7 days. Courses were repeated every 4 to 6 weeks. A maximum of 150 patients were to be treated. In total, 149 patients were treated on study, including 87 patients with MDS and 62 patients with AML. The median patient age was 69 years (range, 20‐89 years; 42% of patients were aged ≥70 years). Overall, 34% of patients achieved complete remission, and 55% had an objective response. The median survival was 11.9 months, and the estimated 2‐year survival rate was 27%. Outcome was not different with the addition of valproic acid to decitabine versus decitabine alone in relation to the rates of complete remission, overall response, or survival. Subset analyses did not demonstrate a benefit within the MDS or AML categories. Toxicities—particularly neurotoxicities—were higher with the combination arm.

CONCLUSIONS

Adding valproic acid to decitabine was not associated with improved outcome in the treatment of patients with MDS or elderly patients with AML. Future therapies may consider combining hypomethylating agents with better HDAC inhibitors and using different schedules. Cancer 2015;121:556–561. © 2014 American Cancer Society.
Colloidal Synthesis and Photocatalytic Performance of Size‐Controllable Solid or Hollow CuInSe2 Nanocrystals
Authors: Sheng Pengtao , Li Weili , Wang Xin , Tong Xi , Cai Qingyun
Published: October 2014

Morphology evolution dependence on reaction time has been investigated to find a way to overcome polydispersity of the chalcopyrite CuInSe2 nanocrystals (NCs). A building–crumbling process is presented to understand the formation of small NCs. By carefully controlling magnetic stirring, ligand content, and duration, the polydispersity is fundamentally improved; thus solid and hollow spherical NCs and quantum dots can be easily obtained with tunable sizes. It is proposed that the NCs undergo Ostwald ripening induced morphology evolution from solid to hollow NCs. The photoelectric properties and photocatalytic activity have been investigated with TiO2 nanotube array based photoelectrodes. A maximum saturation photocurrent of 12.6 mA cm−2 has been achieved, and a structure‐dependent photocatalytic property has also been confirmed by using methyl orange as a model pollutant.
Controlled synthesis of barium chromate microcrystals
Authors: Xiao H. , Ding S.S. , Xu X. , Pan N. , Fan D.Y. , Yang H.J. , Lei M. , Du Y.X. , Zhang R. , Wang Y.G. , Tang W.H.
Published: October 2014

Barium chromate (BaCrO4) microcrystals with various morphologies such as shuttle‐like, x‐shaped, ellipsoid, leaf‐like crystals were synthesized from aqueous solutions using poly (sodium 4‐styrenesulfonate) (PSS) as template agent at room temperature. The characterization results show that pH values and concentrations of reactants and PSS are important parameters in the morphology and size evolution of BaCrO4. The possible formation mechanism of BaCrO4 crystals with different morphologies was proposed. PSS complexes Ba2+ first, then affects the nucleation and crystallization process by interacting with the plane face of crystal, which finally results in various morphologies and sizes of crystals. In addition, the possible mechanism of photoluminescence (PL) spectra was also proposed.
General Approach for High‐Power Li‐Ion Batteries: Multiscale Lithographic Patterning of Electrodes
Authors: Choi Sinho , Kim Tae‐Hee , Lee Jung‐In , Kim Jieun , Song Hyun‐Kon , Park Soojin
Published: October 2014

We demonstrate multiscale patterned electrodes that provide surface‐area enhancement and strong adhesion between electrode materials and current collector. The combination of multiscale structured current collector and active materials (anodes and cathodes) enables us to make high‐performance Li‐ion batteries (LIBs). When LiFePO4 (LFP) cathode and Li4Ti5O12 (LTO) anode materials are combined with patterned current collectors, their electrochemical performances are significantly improved, including a high rate capability (LiFePO4: 100 mAh g−1, Li4Ti5O12: 60 mAh g−1 at 100C rate) and highly stable cycling (LiFePO4: capacity retention of 99.8 % after 50 cycles at 10C rate). Moreover, we successfully fabricate full cell system consisting of patterned LFP cathode and patterned LTO anode, exhibiting high‐power battery performances [capacity of approximately 70 mAh g−1 during 1000 cycles at 10C rate (corresponding to charging/discharging time of 6 min)]. We extend this idea to Si anode that exhibits a large volume change during lithiation/delithiation process. The patterned Si electrodes show significantly enhanced electrochemical performances, including a high specific capacity (825 mAh g−1) at high rate of 5C and a stable cycling retention (88 % after 100 cycle at a 0.1C rate). This simple strategy can be extended to other cathode and anode materials for practical LIB applications.
A Catalytic Reactor for the Organocatalyzed Enantioselective Continuous Flow Alkylation of Aldehydes
Authors: Porta Riccardo , Benaglia Maurizio , Puglisi Alessandra , Mandoli Alessandro , Gualandi Andrea , Cozzi Pier Giorgio
Published: October 2014

The use of immobilized metal‐free catalysts offers the unique possibility to develop sustainable processes in flow mode. The challenging intermolecular organocatalyzed enantioselective alkylation of aldehydes was performed for the first time under continuous flow conditions. By using a packed‐bed reactor filled with readily available supported enantiopure imidazolidinone, different aldehydes were treated with three distinct cationic electrophiles. In the organocatalyzed α‐alkylation of aldehydes with 1,3‐benzodithiolylium tetrafluoroborate, excellent enantioselectivities, in some cases even better than those obtained in the flask process (up to 95 % ee at 25 °C), and high productivity (more than 3800 h−1) were obtained, which thus shows that a catalytic reactor may continuously produce enantiomerically enriched compounds. Treatment of the alkylated products with Raney‐nickel furnished enantiomerically enriched α‐methyl derivatives, key intermediates for active pharmaceutical ingredients and natural products.
On elastic traffic via contention resolution diversity slotted aloha satellite access
Authors: Celandroni Nedo , Davoli Franco , Ferro Erina , Gotta Alberto
Published: October 2014

This paper presents a performance study relative to the coupling of the Transmission Control Protocol (TCP) with the Contention Resolution Diversity slotted aloha (CRDSA) protocol, in the case of greedy TCP connections (also called elephants) on Digital Video Broadcasting‐Return Channel via a geostationary satellite. CRDSA, which takes advantage of interference cancellation algorithms for collision/contention resolution, has already exhibited interesting performance when the power levels of all received bursts are perfectly balanced. In this paper, we extend the study to a more realistic case, where a certain spreading of the bursts' power levels is taken into account. The consequent capture effect even facilitates the collision resolution mechanism and yields an improvement in the overall TCP performance with respect to the balanced case. Furthermore, in certain conditions, the adoption of packet level forward error correction allows achieving even higher peaks of throughput than the expected ones. Copyright © 2014 John Wiley & Sons, Ltd.
Mitigation of the moving radio interferences in the OFDM‐based power line communication channels in China
Authors: Ming‐Yue Zhai
Published: October 2014

Under some special environments in China, there exist moving radio radiations with high transmission powers that can degrade the performance of the power line communications systems significantly. Such radiations overlap with the OFDM‐based signals in time and frequency domains, and hence, it is very difficult to mitigate directly if not possible. The paper introduced the fractional Fourier transform trying to deal with such moving radio interferences. When using the fractional Fourier transform to separate signals and noises/interferences, the fractional order plays a key role, but there is no method to obtain its optimal value in the published papers. In the paper, like for the time‐frequency representations, we defined the second moments of the fractional Fourier transform of the signal. The fractional order, corresponding the maximum of the second moments, is the one used to separate the OFDM signals and the moving radio interferences, which is modelled as the Doppler signals in our scheme. The proposed method can mitigate the moving radio interferences significantly by applying the proposed method to the simulated OFDM signals and the measurements data. The results also show that the system's BERs can be improved from 10−2 to 10−5 for lower signal‐noise‐rate (SNR), and from 10−4 to 10−9 for high SNRs. Copyright © 2014 John Wiley & Sons, Ltd.
Diagnosis of intraocular lesions using vitreous humor and intraocular perfusion fluid cytology: Experience with 83 Cases
Authors: Kinoshita Yuichi , Takasu Kosho , Kobayashi Tadao K , Yuri Takashi , Tsubura Airo , Shikata Nobuaki
Published: October 2014

Objective

The objective of the study was to evaluate the use of vitreous humor and/or intraocular perfusion fluid (IPF) from pars plana vitrectomy as a diagnostic and therapeutic procedure for intraocular diseases.

Methods

The cytologic findings with respect to the clinical data, the anatomical findings, and the final diagnosis in 83 cases that underwent intraocular cytologic examinations at the Kansai Medical University Takii Hospital were evaluated. For cytologic examination, the Papanicolaou stain, Giemsa stain, and in some cases, molecular biology and immunocytochemical techniques were used.

Results

Most of the clinical diagnoses were uveitis or endophthalmitis. Sixty‐eight cases (81.9%) were negative on cytodiagnosis, while 15 cases (18.9%) were positive or suspicious for malignancy. Negative cases included infections and intraocular sarcoidosis (IOS), and all of the positive or suspicious cases were intraocular lymphomas. Some of these latter cases were also diagnosed using immunocytochemical staining or molecular biological procedures as ancillary techniques, performed using vitreous body cytology from IPF.

Conclusions

An early diagnosis and treatment of intraocular diseases is necessary to maintain an acceptable degree of quality of life. For an accurate diagnosis, it is necessary to understand the anatomy of the eye. Giemsa staining is recommended in addition to Papanicolaou staining for cytologic diagnostic evaluation of intraocular diseases. Furthermore, for the diagnosis of clonality in intraocular lymphomas, it is often necessary to use ancillary molecular biological procedures, using vitreous fluid. Diagn. Cytopathol. 2015;43:353–359. © 2014 Wiley Periodicals, Inc.
SLy2 controls the antibody response to pneumococcal vaccine through an IL‐5Rα‐dependent mechanism in B‐1 cells
Authors: Schmitt Fee , Schäll Daniel , Bucher Kirsten , Schindler Theresa Isabell , Hector Andreas , Biedermann Tilo , Zemlin Michael , Hartl Dominik , Beer‐Hammer Sandra
Published: October 2014

The adaptor protein SLy2 (Src homology domain 3 lymphocyte protein 2) is located on human chromosome 21 and was reported to be among a group of genes amplified in Down's syndrome (DS) patients. DS patients characteristically show an impaired immunity to pneumococcal infections. However, molecular mechanisms linking gene amplifications with specific DS phenotypes remain elusive. To investigate the effect of SLy2 gene amplification on the mammalian immune system, we studied SLy2 overexpressing transgenic‐SLy2 (TG) mice. We found that baseline immunoglobulin M (IgM) levels as well as IgM responses following Pneumovax immunizations were reduced in TG mice. Moreover, B‐1 cells, the major natural IgM‐producing population in mice, were reduced in the peritoneal cavity of TG mice, while other immune cell compartments were unaltered. Mechanistically, SLy2 overexpression attenuated the expression of the IL‐5 receptor α chain on B‐1 cells, resulting in decreased B‐1 cell numbers and decreased differentiation into Ab‐secreting cells. Since B‐1 cells essentially contribute to immunity against Streptococcus pneumoniae, the present study provides a novel molecular link between SLy2 expression and pneumococcal‐specific IgM responses in vivo. These studies suggest that the adaptor protein SLy2 is a potential future target for immunomodulatory strategies for pneumococcal infections.
Halogenolysis of a Nickelalactone Complex Produces β‐Halo‐Anhydrides
Authors: Zarkesh Ryan A. , Hopkins Michael D. , Jordan Richard F.
Published: October 2014

Nickelalactone complex [(dppe)Ni{κ2‐C,O‐CH2CH2C(=O)O}] {dppe = 1,2‐bis(diphenylphosphino)ethane} reacts with halogens to form 3‐halo‐propionic anhydrides, [(dppe)NiX2], and [(dppeO2)3Ni][NiX4] (X = Cl, Br, I). Studies of model complexes [(dppe)Ni(O2CtBu)2] and [(dppe)NiBr(O2CtBu)] suggest that oxidation to NiIII and P–O reductive elimination are key steps in this reaction.
SNH‐ and SNipso‐Arylamination of 1,3,7‐Triazapyrenes
Authors: Borovlev Ivan , Demidov Oleg , Saigakova Nadezhda , Amangasieva Gulminat
Published: October 2014

The ability of the oxidative arylamination process to derivatize electron‐deficient 1,3,7‐triazapyrenes has been investigated. These triazapyrenes react with a wide range of sodium aryl(hetaryl) amides to give access to the corresponding 6‐aryl(hetaryl)amino‐1,3,7‐triazapyrenes in moderate to good yields. The reaction of 6,8‐dialkoxy‐1,3,7‐triazapyrene with sodium arylamides gives rise to 6,8‐bis(arylamino)‐1,3,7‐triazapyrenes or 6‐methoxy‐8‐arylamino‐1,3,7‐triazapyrenes, depending on the reaction conditions.
Recent Advances in Stereoselective [2+2+2] Cycloadditions
Authors: Amatore Muriel , Aubert Corinne
Published: October 2014

The [2+2+2] cycloaddition reaction is considered one of the most efficient methods for the rapid and straightforward preparation of complex polycyclic (and heterocyclic) compounds in a highly selective and atom‐economical fashion. Over the last half‐century, remarkable advances in terms of chemo‐ and regioselectivities have been realized, endowing this reaction with attractive features as a key step in the synthesis of various biologically active molecules and materials. The development of stereoselective methodologies is more recent. In this field, asymmetric transition‐metal catalysis has emerged as the most convenient tool with which to perform these [2+2+2] cycloadditions in their enantio‐ and diastereoselective variants. All the catalytic systems that have been developed so far are based on very close association of a transition metal (Co, Ni, Ir, Rh, ...) with a chiral ligand. The success of these reactions is then related to the reaction pattern involved (inter‐ and intramolecular), implying an efficient substrate/active species interaction. Thus, judicious design both of chiral ligands and of unsaturated substrates is necessary. In light of these aspects, numerous stereoselective cycloadditions have been reported; these allow the construction in one‐step fashion of central, axial, planar, and helical chiralities. This review details the recent advances in this area, with specific attention to catalysts and reaction scope.
AP/VP specific inelastic displacement ratio for seismic response estimation of structures
Authors: Durucan Cengizhan , Dicleli Murat
Published: October 2014

In this study, two new site specific statistical equations are proposed to estimate the inelastic displacement ratio, C1 of structures subjected to far fault (FF) and near fault (NF) ground motions. The proposed equations consider the effects of fundamental vibration period of the structure, T, lateral strength ratio, R and frequency content of the design earthquake record represented by the Ap/Vp ratio (or T0 = 2π/Ap/Vp), which is a function of the earthquake magnitude, distance to fault, faulting mechanism and site class. It was observed that the C1 values obtained from the proposed equations are in good agreement with the calculated results. The flare of the plotted C1 vs. T/T0 curves enables the proposed equations to cover nearly all the calculated C1 data range and give satisfactory results. However, the curves obtained using the C1 equations of several codes and those available in the literature do not cover the whole calculated C1 data range and generally give unconservative results (smaller C1 values) especially in the shorter period range. For the longer period range, the predictions of C1 obtained from the proposed equation and the ones available in the literature are in good agreement with the calculated C1 data. Copyright © 2014 John Wiley & Sons, Ltd.
Using meteorological observer data to compare wind erosion during two great droughts in eastern Australia; the World War II Drought (1937–1946) and the Millennium Drought (2001–2010)
Authors: O'Loingsigh Tadhg , McTainsh Grant H. , Parsons Katherine , Strong Craig L. , Shinkfield Phil , Tapper Nigel J.
Published: October 2014

Australian meteorological observers started using the World Meteorological Organization (WMO) weather coding system in the 1950s. This system is still in use around the world today. However, observing and recording the weather in an organized and systematic manner had been ongoing for over 100 years prior to the adoption of this coding system, and much like Australia, most countries will have historical meteorological records. In this paper we compare the wind erosion of two of the greatest droughts in Australian recorded history; the World War II (WWII) Drought (1937–1945) and the Millennium Drought (2001–2009). To do this we analysed previously unavailable meteorological observer records from the Australian Bureau of Meteorology (ABM). Wind erosion records, mostly in long‐hand written form, were translated to the modern WMO coding system for the WWII Drought and compared with the wind erosion of Australia's recently‐ended Millennium Drought, one of the longest and harshest on record. We quantify wind erosion using Dust Event Days (DED) and a modified version of a published Dust Storm Index (DSI) to show that wind erosion during the WWII Drought was up to 4.6 times higher than during the Millennium Drought. This study has international significance because it demonstrates a methodology for tracking changes in wind erosion over the past 75 years based on observer records available in every country with a history of organized weather observation. Copyright © 2014 John Wiley & Sons, Ltd.
Food security and food self‐sufficiency in China: from past to 2050
Authors: Ghose Bishwajit
Published: October 2014

Reducing hunger and malnutrition and improving food security have come to the forefront of global political agenda. In the wake of recent spells of food price hike, national and supranational development organizations and governments have begun to express serious concerns about the world's capacity to feed its burgeoning population. In response to the target of increasing food production by 70% in 2050, many countries are formulating their agricultural policies to promote domestic food self‐sufficiency and many are building international networks for outsourcing food supply beyond national borders. In the face of massive demand for food for its growing population, China is both strengthening its food self‐sufficiency strategies and relying on large‐scale imports from international market which has been a major driver of food price inflation in recent years. In China, increase in income and socioeconomic status on one hand have dramatically improved dietary intake and overall nutritional status of the population, and are creating an enormous pressure on land and water resources and natural environments on the other. Maintaining food and water security and for its huge population with its limited resources while at the same time sustaining the economic growth momentum are offering significant challenges to China's macroeconomic prospects. China's domestic food production and self‐sufficiency status have certain repercussions on the volatility of global agri‐food market and food security in food‐import and food‐aid‐dependent countries. The objectives of this study is to provide an in‐depth overview of China's food production and demand scenario with a particular focus on its challenging perspectives toward food secure 2050. The first half of the paper is designed to show recent trends in food production and consumption and the impacts on global food market. The second half describes the major challenges with a brief discussion on policy implication.
Redox regulation of NF‐κB p50 and M1 polarization in microglia
Authors: Taetzsch Thomas , Levesque Shannon , McGraw Constance , Brookins Savannah , Luqa Rafy , Bonini Marcelo G. , Mason Ronald P. , Oh Unsong , Block Michelle L.
Published: October 2014

Redox‐signaling is implicated in deleterious microglial activation underlying CNS disease, but how ROS program aberrant microglial function is unknown. Here, the oxidation of NF‐κB p50 to a free radical intermediate is identified as a marker of dysfunctional M1 (pro‐inflammatory) polarization in microglia. Microglia exposed to steady fluxes of H2O2 showed altered NF‐κB p50 protein–protein interactions, decreased NF‐κB p50 DNA binding, and augmented late‐stage TNFα expression, indicating that H2O2 impairs NF‐κB p50 function and prolongs amplified M1 activation. NF‐κB p50−/− mice and cultures exhibited a disrupted M2 (alternative) response and impaired resolution of the M1 response. Persistent neuroinflammation continued 1 week after LPS (1 mg/kg, IP) administration in the NF‐κB p50−/− mice. However, peripheral inflammation had already resolved in both strains of mice. Treatment with the spin‐trap DMPO mildly reduced LPS‐induced 22 h TNFα in the brain in NF‐κB p50+/+ mice. Interestingly, DMPO failed to reduce and strongly augmented brain TNFα production in NF‐κB p50−/− mice, implicating a fundamental role for NF‐κB p50 in the regulation of chronic neuroinflammation by free radicals. These data identify NF‐κB p50 as a key redox‐signaling mechanism regulating the M1/M2 balance in microglia, where loss of function leads to a CNS‐specific vulnerability to chronic inflammation. GLIA 2015;63:423–440
Comparing the Explanatory Capacity of Three Constructs in the Prediction of Engineers’ Proficiency, Adaptivity, and Proactivity
Authors: García‐Chas Romina , Neira‐Fontela Edelmira , Varela‐Neira Concepción
Published: October 2014

Advances in the research of work performance have been due in large part to the conceptualization of performance as a multidimensional construct. Recently, Griffin, Neal, and Parker (2007), have identified three different dimensions of work role performance: proficiency, adaptivity, and proactivity. Social effectiveness constructs (i.e., political skill) have been receiving increased attention in research and there have been recent calls for further research in the area. This study compares the explanatory capacity of political skill, professional experience and intrinsic motivation in the prediction of engineers' proficiency, adaptivity, and proactivity. The relationships were tested with structural equations analysis of 180 supervisor‐engineer dyad data. Results indicate that the three dimensions of individual work performance are significantly influenced by political skill and professional experience, but not by intrinsic motivation. The results also indicate that political skill is the strongest predictor. © 2014 Wiley Periodicals, Inc.