bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Mild Generation of Selenolate Nucleophiles by Thiol Reduction of Diselenides: Convenient Syntheses of Selenyl‐Substituted Aryl Aldehydes.
Authors: Dubey Rashmi , Lee Hangeun , Nam Do‐Hyun , Lim Dongyeol
Published: March 2012

In the presence of base and dithiothreitol as reducing agent, selenyl‐substituted aromatic and heteroaromatic aldehydes are readily available from ortho‐halogenated precursors and diorganyl diselenides.
ChemInform Abstract: Unique Salt Effect on the High Yield Synthesis of Acid‐Labile Terpene Oxides Using Hydrogen Peroxide under Acidic Aqueous Conditions.
Authors: Hachiya Houjin , Kon Yoshihiro , Ono Yutaka , Takumi Kiyoshi , Sasagawa Naoki , Ezaki Yoichiro , Sato Kazuhiko
Published: March 2012

The use of sodium sulfate as an additive in the oxidation of various terpenes with hydrogen peroxide allows the synthesis of acid‐labile epoxides in high yields.
ChemInform Abstract: Diabetic Nephropathy‐Related Active Cyclic Peptides from the Roots of Brachystemma calycinum.
Authors: Cheng Yong‐Xian , Zhou Li‐Li , Yan Yong‐Ming , Chen Ke‐Xin , Hou Fan‐Fan
Published: March 2012

Three new cyclic peptides, duanbanhuains A (I), B (II), and C (III), are isolated from the roots of Brachystemma calycinum used in traditional Chinese medicine to treat rheumatic diseases.
ChemInform Abstract: Enzymatic Synthesis of D‐Sorbose and D‐Psicose with Aldolase RhaD: Effect of Acceptor Configuration on Enzyme Stereoselectivity.
Authors: Li Zijie , Cai Li , Qi Qingsheng , Wang Peng George
Published: March 2012

The synthesis of the rare title sugars (III) and (IV) starts from D‐glyceraldehyde (I).
ChemInform Abstract: Novel Cytotoxic Chalcones from Litsea rubescens and Litsea pedunculata.
Authors: Li Liang , Zhao Xing‐Tang , Luo Yi‐Ping , Zhao Jing‐Feng , Yang Xiao‐Dong , Zhang Hong‐Bing
Published: March 2012

Litseanone A (I) and B (II) are isolated together with 7 known flavanoids from the stem bark of the title plant.
ChemInform Abstract: Environmental Impact of Coal Beneficiation and Its Mitigation Measures
Authors: Sahu H. B. , Dash S. , Swar A. K.
Published: March 2012

Review: 12 refs.
ChemInform Abstract: A Review of the Kinetics and Mechanisms of Formation of Supported‐Nanoparticle Heterogeneous Catalysts
Authors: Mondloch Joseph E. , Bayram Ercan , Finke Richard G.
Published: March 2012

Review: 300 refs.
ChemInform Abstract: Insights into Uranyl Chemistry from Molecular Dynamics Simulations
Authors: Buehl Michael , Wipff Georges
Published: March 2012

Review: 110 refs.
ChemInform Abstract: Selective Reductive Transformations Using Samarium Diiodide‐Water
Authors: Szostak Michal , Spain Malcolm , Parmar Dixit , Procter David J.
Published: March 2012

Review: 62 refs.
ChemInform Abstract: Chemistry of β‐Carbolines as Synthetic Intermediates
Authors: Dominguez Gema , Perez‐Castells Javier
Published: March 2012

Review: 76 refs.
ChemInform Abstract: Recent Progress in Transition Metal Complex Catalyzed Hydrosilylation of Carbon—Carbon Multiple Bonds
Authors: Peng Jiajian , Bai Ying , Li Jiayun , Lai Guoqiao
Published: March 2012

Review: 131 refs.
ChemInform Abstract: Substituted Cucurbit[n]uril Rings, Catenanes and Channels
Authors: Day Anthony I. , Xiao Xin , Zhang Yun‐Qian , Zhu Qian‐Jiang , Xue Sai‐Feng , Tao Zhu
Published: March 2012

Review: 22 refs.
ChemInform Abstract: Conjugated Molecular Belts Based on 3D Benzannulene Systems
Authors: Iyoda Masahiko , Kuwatani Yoshiyuki , Nishinaga Tohru , Takase Masayoshi , Nishiuchi Tomohiko
Published: March 2012

Review: 138 refs.
Acetalization of Carbonyl Compounds as Pentaerythritol Diacetals and Diketals in the Presence of Cellulose Sulfuric Acid as an Efficient, Biodegradable and Reusable Catalyst
Authors: Shaterian Hamid Reza , Rigi Fatemeh
Published: March 2012

This paper reports a practical and green method for the acetalization of carbonyl compounds as pentaerythritol diacetals and diketals derivatives using cellulose sulfuric acid as a biodegradable and reusable solid acid catalyst under thermal solvent‐free conditions.
β‐Cyclodextrin Immobilized onto Dowex Resin: A Unique Microvessel and Heterogeneous Catalyst in Nucleophilic Substitution Reactions
Authors: Kiasat Ali Reza , Zarinderakht Nasrollah , Sayyahi Soheil
Published: March 2012

The catalytic activity of β‐cyclodextrin immobilized on Dowex resin as an efficient solid‐liquid phase transfer catalyst was developed for the synthesis of alkyl thiocyanates and phenacyl derivatives in water. The nucleophilic substitution reactions were performed under mild reaction condition and gave the products in excellent yields. Furthermore, the catalyst could be recycled by facile separation without any loss of activity.
Synthesis and Antioxidant Activities of Novel 4,4′‐Arylmethylene‐bis(1H‐pyrazole‐5‐ol)s from Lignin
Authors: Yang Xiaohui , Zhang Pinghu , Zhou Yonghong , Wang Junsong , Liu Hongjun
Published: March 2012

A series of novel bispyrazoles joined by arylmethylene at C‐4 position were synthesized with aromatic aldehydes obtained from lignin and screened for their in vitro antioxidant activities by N,N‐diphenyl‐N′‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis(3‐ethylenzothiazoline‐sulphonic acid) diammonium salt (ABTS+) radical scavenging assays. All of these compounds exhibited good DPPH and ABST+ radical scavenging activities as compared to the standard, Trolox, which suggested their potential as promising agents for curing tumors or other free radical‐related diseases.
Modified Activated Carbon as Solid Phase Extraction Adsorbent for the Preconcentration and Determination of Trace As(III) in Environmental Samples by Graphite Furnace Atomic Absorption Spectrometry
Authors: Tavakkoli Nahid , Habibollahi Saeed , Amini Tehrani Shahla
Published: March 2012

A simple and selective method was developed for the preconcentration, separation, and determination of trace amounts of As(III) in an aqueous solution by solid phase extraction combined with graphite furnace atomic absorption spectrometry. Activated carbon (AC) was modified by sodium diethyldithiocarbamate (NaDDTC) and then used as a new, stable and easily prepared solid sorbent in a mini column for the extraction of As(III) in aqueous solution. Factors influencing the sorption and desorption of As(III), such as volume and concentration of eluent, sample pH, flow rate and effect of interfering ions on the recovery of As(III) have been systemically investigated. At pH 2.0 As(III) could be adsorbed quantitatively by NaDDTC‐AC, and then eluted completely with 2 mL of 3.0 mol·L−1 HNO3. The amount of eluted As(III) was measured using graphite furnace atomic absorption spectrometry. The detection limit of As(III) was 0.04 ng·mL−1 with enrichment factor of 100 and the relative standard deviation (RSD, n=8) was 1.58% at 10 ng·mL−1 level.
Density Functional Theoretical Study of Polynitrogen Compounds N5+Y− (Y=B(CF3)4, BF4, PF6 and B(N3)4)
Authors: Lian Peng , Lai Weipeng , Chang Haibo , Li Yanan , Li Hui , Yang Wei , Wang Youbing , Wang Bozhou , Xue Yongqiang
Published: March 2012

The structures and the stabilities of polynitrogen compounds N5+Y− [Y=B(CF3)4, BF4, PF6, and B(N3)4], as the potential high energy density compounds, have been investigated at the B3LYP/6‐31G(d,p) and B3LYP/6‐311+G(d,p) levels. On the basis of our geometry optimization calculations, the structural properties of the N5+Y− compounds are discussed, and it is found that the combination of the N5+ cation and the Y− anions leads to distortion of the structures of the Y− anions. Based on the TS calculations for the N2‐loss dissociations of the N5+Y− compounds, the stabilities of these compounds are discussed, and the following conclusion can be drawn that among the four compounds, N5+B(CF3)4− is the most stable one and N5+B(N3)4− is the most unstable, and the relative stability of these compounds is always consistent using different basis sets. From these discussions, it is revealed that there are close correlations between the stuctrual distortions of the Y? anions and the stabilities of the N5+Y− compounds, and between the nitrogen content in the compounds and the stabilities of the N5+Y− compounds.
Environmental Friendly Azide‐Alkyne Cycloaddition Reaction of Azides, Alkynes, and Organic Halides or Epoxides in Water: Efficient "Click" Synthesis of 1,2,3‐Triazole Derivatives by Cu Catalyst
Authors: Liu Jianming , Liu Muwen , Yue Yuanyuan , Yao Meihuan , Zhuo Kelei
Published: March 2012

An efficient click synthesis of 1,2,3‐triazole derivatives from benzyl halides or alkyl halides, epoxides, terminal alkynes, and sodium azides in the presence of copper salts and relative benzimidazole salts have been developed. This procedure eliminates the need to handle potentially organic azides, which are generated in situ. A broad spectrum of substrates can participate in the process effectively to produce the desired products in good yields.
Alum (KAl(SO4)2·12H2O) Catalyzed Multicomponent Transformation: Simple, Efficient, and Green Route to Synthesis of Functionalized Spiro[chromeno[2,3‐d]pyrimidine‐5,3′‐indoline]‐tetraones in Ionic Liquid Media
Authors: Mirhosseini Moghaddam Mojtaba , Bazgir Ayoob , Mohammad Mehdi Akhondi , Ghahremanzadeh Ramin
Published: March 2012

The combination of isatin, barbituric acid, and cyclohexane‐1,3‐dione derivatives in the presence of alum (KAl(SO4)2·12H2O) as a catalyst for 15 min was found to be a suitable and efficient method for the synthesis of spiro[chromeno[2,3‐d]pyrimidine‐5,3′‐indoline]‐tetraones.
Thermal Stability, Microstructure and Photocatalytic Activity of the Bismuth Oxybromide Photocatalyst
Authors: Yu Changlin , Zhou Wanqin , Yu Jimmyc , Cao Fangfang , Li Xin
Published: March 2012

Flake BiOBr was first prepared by a solution method at room temperature. Then, the produced BiOBr was calcined at different temperatures. It was found that BiOBr is not a stable compound. It transforms to plate‐like Bi24O31Br11at around 750°C and the formed Bi24O31Br11 can further convert to rod‐like α‐Bi2O3 at around 850°C. The prepared compounds were characterized with X‐ray diffraction (XRD), N2 physical adsorption, scanning electron microscopy (SEM), and UV‐Vis diffuse reflectance spectra (DRS), respectively. The photocatalytic activity of the produced bismuth oxybromides was evaluated by photocatalytic decomposition of acid orange II under both visible light (λ>420 nm) and UV light (λ=365 nm) irradiation. Results show that these compounds have different band gaps and different photocatalytic properties. The band gap energies of the as‐prepared samples were found to be 2.82, 2.79, 2.60 and 3.15 eV for BiOBr, BiOBr/Bi24O31Br, Bi24O31Br, and α‐Bi2O3, respectively. Under both UV light and visible light irradiation, the photocatalytic activity follows the order: BiOBr/Bi24O31Br mixture>BiOBr>Bi24O31Br>α‐Bi2O3. The change in photocatalytic activity could be attributed to the different light absorption ability and microstructures of the photocatalysts.
Hydrogen Peroxide Sensor Based on Carbon Nanotubes/β‐Ni(OH)2 Nanocomposites
Authors: Zhang Xiaojun , Huang Yan , Gu Aixia , Wang Guangfeng , Fang Bin , Wu Huaqiang
Published: March 2012

Ni(OH)2 nanoflowers were synthesized by a simple and energy‐efficient wet chemistry method. The product was characterized by scanning electron microscopy (SEM) and X‐ray powder diffraction (XRD). Then Ni(OH)2 nanoflowers attached multi‐walled carbon nanotubes (MWCNTs) modified glassy carbon electrodes (GCE) were proposed (MWCNTs/Ni(OH)2/GCE) to use as electrochemical sensor to detect hydrogen peroxide. The results showed that the synergistic effect was obtained on the MWCNTs/Ni(OH)2/GCE whose sensitivity was better than that of Ni(OH)2/GCE. The linear range is from 0.2 to 22 mmol/L, the detection limit is 0.066 mmol/L, and the response time is <5 s. Satisfyingly, the MWCNTs/Ni(OH)2/GCE was not only successfully employed to eliminate the interferences from uric acid (UA), acid ascorbic (AA), dopamine (DA), glucose (GO) but also NO2− during the detection. The MWCNTs/Ni(OH)2/GCE allows highly sensitive, excellently selective and fast amperometric sensing of hydrogen peroxide and thus is promising for the future development of hydrogen peroxide sensors.
The chemical complexity of cellular microtubules: Tubulin post‐translational modification enzymes and their roles in tuning microtubule functions
Authors: Garnham Christopher P. , Roll‐Mecak Antonina
Published: March 2012

Cellular microtubules are marked by abundant and evolutionarily conserved post‐translational modifications that have the potential to tune their functions. This review focuses on the astonishing chemical complexity introduced in the tubulin heterodimer at the post‐translational level and summarizes the recent advances in identifying the enzymes responsible for these modifications and deciphering the consequences of tubulin's chemical diversity on the function of molecular motors and microtubule associated proteins. Published 2012 Wiley Periodicals, Inc.
Stabilization of actin filaments prevents germinal vesicle breakdown and affects microtubule organization in Xenopus oocytes
Authors: Okada Iyo , Fujiki Saburo , Iwase Shohei , Abe Hiroshi
Published: March 2012

In Xenopus oocytes, extremely giant nuclei, termed germinal vesicles, contain a large amount of actin filaments most likely for mechanical integrity. Here, we show that microinjection of phalloidin, an F‐actin‐stabilizing drug, prevents the germinal vesicle breakdown (GVBD) in oocytes treated with progesterone. These nuclei remained for more 12 h after control oocytes underwent GVBD. Immunostaining showed significant elevation of actin in the remaining nuclei and many actin filament bundles in the cytoplasm. Furthermore, microtubules formed unusual structures in both nuclei and cytoplasm of phalloidin‐injected oocytes stimulated by progesterone. Cytoplasmic microtubule arrays and intranuclear microtubules initially formed in phalloidin‐injected oocytes as control oocytes exhibited white maturation spots; these structures gradually disappeared and finally converged upon intranuclear short bundles when control oocytes completed maturation. In contrast, treatment of oocytes with jasplakinolide, a cell membrane‐permeable actin filament‐stabilizing drug, did not affect GVBD. This drug preferentially induced accumulation of actin filaments at the cortex without any increase in cytoplasmic actin staining. Based on these results, intranuclear and cytoplasmic actin filament dynamics appear to be required for the completion of GVBD and critically involved in the regulation of microtubule assembly during oocyte maturation in Xenopus laevis. © 2012 Wiley Periodicals, Inc
Synthesis, Chiral Resolution, and Absolute Configuration of Functionalized Tröger’s Base Derivatives: Part II
Authors: Benkhäuser‐Schunk Christian , Wezisla Boris , Urbahn Kirstin , Kiehne Ulf , Daniels Jörg , Schnakenburg Gregor , Neese Frank , Lützen Arne
Published: March 2012

Seven racemic derivatives of Tröger’s base—the 1,7‐dibromo‐substituted derivative 3, the 2,8‐dibromo‐substituted derivative 4, the 2,8‐diiodo‐substituted derivative 5, the 3,9‐diiodo‐substituted derivative 6, the 4,10‐dibromo‐substituted derivative 7, its singly debrominated analogue 8, and the 2,8‐diamino‐substituted derivative 9 in its Fmoc‐protected form—were synthesized and successfully resolved by (recycling) HPLC on a stationary Whelk‐O1 phase at a semipreparative scale. These are valuable functionalized C2‐symmetric building blocks for further applications. Their absolute configurations were determined by X‐ray crystal structure analysis and/or by comparison of their quantum chemically calculated circular dichroism and UV/Vis spectra with the experimental obtained spectra.
Catalytic Oxidation of Toluene and CO over Nanocatalysts Derived from Hydrotalcite‐Like Compounds (X62+Al23+): Effect of the Bivalent Cation
Authors: Genty Eric , Cousin Renaud , Capelle Sylvie , Gennequin Cédric , Siffert Stéphane
Published: March 2012

X6Al2HT hydrotalcites, where X represents Fe, Cu, Zn, Ni, Co, Mn or Mg, were synthesized as precursors of catalysts for the toluene and CO total oxidation reactions. Specific area, Fourier transformed infrared spectroscopy analysis, XRD measurements and Thermal analysis of these dried solids were performed. After calcination at 500 °C, different mixed oxides were obtained. The structural analysis (XRD, FTIR) and specific areas of these solids were done. Concerning the total oxidation of toluene, the best activity is obtained with Mn6Al2HT catalyst with T50 at 249 °C. X6Al2 nano‐oxides synthesized using hydrotalcite‐type solids as precursors, are then very promising candidates for an utilisation as CO and VOC oxidation catalysts. The nature of bivalent cation in these compounds is essential for the efficacy of the catalyst.
Relaxivity Enhancement in Macromolecular and Nanosized GdIII‐Based MRI Contrast Agents
Authors: Botta Mauro , Tei Lorenzo
Published: March 2012

In recent years, novel, better, and more complex systems have been developed in which GdIII chelates are attached to macromolecular substrates or incorporated into nanoparticles. These magnetic resonance imaging (MRI) nanoprobes make it possible to deliver to the site of interest a large number of Gd3+ ions, thus increasing the sensitivity of the technique. In this paper, we review the most important systems developed, the conjugation methods, and the procedures devised to optimize the relaxivity. These involve the use of GdIII complexes with higher hydration number, the control of the rate of exchange of the bound water molecule(s), and the reduction of the local rotational motions of the conjugated complexes. The increase in relaxivity of the individual Gd chelates leads to significant relaxivity enhancement of the nanosized systems.
Synthesis, Crystal Structure, and Catecholase Activity of Three Trinuclear Heterometallic NiII2–MnII Complexes Derived from a Salen‐Type Schiff Base Ligand
Authors: Seth Piya , Das Lakshmi K. , Drew Michael G. B. , Ghosh Ashutosh
Published: March 2012

Three new trinuclear heterometallic nickel(II)–manganese(II) complexes, [(NiL)2Mn(NCS)2] (1), [(NiL)2Mn(NCO)2] (2), and [{NiL(EtOH)}2Mn(NO2)2]·2EtOH (3), have been synthesized by using [NiL] as the so‐called “ligand complex” [where H2L = N,N′‐bis(salicylidene)‐1,3‐propanediamine] and have been structurally characterized. Crystal structure analyses revealed that complexes 1 and 2 are angular trinuclear species, in which two terminal four‐coordinate square planar [NiL] moieties are coordinated to a central MnII through double phenoxido bridges. The MnII is in a six‐coordinate distorted octahedral environment that is bonded additionally to two mutually cis nitrogen atoms of terminal thiocyanate (in 1) and cyanate (in 2). In complex 3, in addition to the double phenoxo bridge, the two terminal NiII ions are linked to the central MnII by means of a nitrite bridge (1κN:2κO) that, together with a coordinated ethanol molecule, gives rise to an octahedral environment around the NiII ions and consequently the structure becomes linear. Catecholase activity of these three complexes was examined by using 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) as the substrate. All three complexes mimic catecholase activity and the rate of catechol oxidation follows saturation kinetics with respect to the substrate and first‐order kinetics with respect to the catalyst. The EPR spectra of the complexes exhibit characteristic six line spectra, which indicate the presence of high‐spin octahedral MnII species in solution state. The ESI‐MS positive spectrum of 1 in the presence of 3,5‐DTBC has been recorded to investigate possible complex–substrate intermediates.
TROP2 is epigenetically inactivated and modulates IGF‐1R signalling in lung adenocarcinoma
Authors: Lin Jau‐Chen , Wu Yi‐Ying , Wu Jing‐Yi , Lin Tzu‐Chieh , Wu Chen‐Tu , Chang Yih‐Leong , Jou Yuh‐Shan , Hong Tse‐Ming , Yang Pan‐Chyr
Published: March 2012

Trop‐2, a cell surface glycoprotein, contains both extracellular epidermal growth factor‐like and thyroglobulin type‐1 repeat domains. Low TROP2 expression was observed in lung adenocarcinoma tissues as compared with their normal counterparts. The lack of expression could be due to either the loss of heterozygosity (LOH) or hypermethylation of the CpG island DNA of TROP2 upstream promoter region as confirmed by bisulphite sequencing and methylation‐specific (MS) polymerase chain reaction (PCR). 5‐Aza‐2′‐deoxycytidine treatment on lung cancer cell (CL) lines, CL1‐5 and A549, reversed the hypermethylation status and elevated both TROP2 mRNA and protein expression levels. Enforced expression of TROP2 in the lung CL line H1299 reduced AKT as well as ERK activation and suppressed cell proliferation and colony formation. Conversely, silencing TROP2 with shRNA transfection in the less efficiently tumour‐forming cell line H322M enhanced AKT activation and increased tumour growth. Trop‐2 could attenuate IGF‐1R signalling‐mediated AKT/β‐catenin and ERK activation through a direct binding of IGF1. In conclusion, inactivation of TROP2 due to LOH or by DNA methylation may play an important role in lung cancer tumourigenicity through losing its suppressive effect on IGF‐1R signalling and tumour growth.
Antibody detection of translocations in Ewing sarcoma
Authors: Luo Wen , Milash Brett , Dalley Brian , Smith Richard , Zhou Holly , Dutrow Natalie , Cairns Bradley R. , Lessnick Stephen L.
Published: March 2012

The detection of chromosomal translocations has important implications in the diagnosis, prognosis and treatment of patients with cancer. Current approaches to translocation detection have significant shortcomings, including limited sensitivity and/or specificity, and difficulty in application to formalin‐fixed paraffin‐embedded (FFPE) clinical samples. We developed a new approach called antibody detection of translocations (ADOT) that avoids the shortcomings of current techniques. ADOT combines a transcriptional microarray‐based approach with a novel antibody‐based detection method. ADOT allows for the accurate and sensitive identification of translocations and provides exon‐level information about the fusion transcript. ADOT can detect translocations in poor‐quality unprocessed total ribonucleic acid (RNA). Furthermore, the technique is readily generalizable to detect any potential fusion transcript, including previously undescribed fusions. We demonstrate the feasibility of ADOT by examples in which both known and unknown Ewing sarcoma translocations are identified from cell lines, tumour xenografts and FFPE primary tumours. These results demonstrate that ADOT may be an effective approach for translocation analysis in clinical specimens with significant RNA degradation and may offer a novel diagnostic tool for translocation‐based cancers.

→See accompanying article http://dx.doi.org/10.1002/emmm.201200226
Loss probability estimation for OFDM/TDMA‐based wireless systems considering a cascade‐based multifractal traffic model
Authors: Rocha Flávio G.C. , Vieira Flávio H.T.
Published: March 2012

In this paper, we analyze the queueing performance in terms of byte loss rate of an orthogonal frequency‐division multiplexing/time division multiple access based wireless system taking into account the multifractal behaviour of the wireless traffic flows. To this end, first, we show evidences of multifractal characteristics on wireless traffic traces. These findings motivated us to derive a loss probability equation for wireless traffic flows that can be applied to an orthogonal frequency‐division multiplexing/time division multiple access based wireless system. Simulations and comparisons to other methods are carried out to verify the accuracy of the proposed loss probability estimation approach in describing real traffic queueing behaviour. Copyright © 2012 John Wiley & Sons, Ltd.
Pricing and Hedging the Smile with SABR: Evidence from the Interest Rate Caps Market
Authors: Wu Tao L.
Published: March 2012

This is the first comprehensive study of the SABR (stochastic alpha‐beta‐rho) model (Hagan, Kumar, Lesniewski, & Woodward, 2002) on the pricing and hedging of interest rate caps. I implement several versions of the SABR interest rate model and analyze their respective pricing and hedging performance using two years of daily data with seven different strikes and ten different tenors on each trading day. In‐sample and out‐of‐sample tests show that the fully stochastic version of the SABR model exhibits excellent pricing accuracy and, more importantly, captures the dynamics of the volatility smile over time very well. This is further demonstrated through examining delta‐hedging performance based on the SABR model. My hedging result indicates that the SABR model produces accurate hedge ratios that outperform those implied by the Black model. © 2012 Wiley Periodicals, Inc. Jrl Fut Mark 32:773‐791, 2012
Variational constitutive updates for microstructure evolution in hcp metals
Authors: Mosler J. , Homayonifar M.
Published: March 2012

Magnesium and its alloys are promising materials for lightweight applications. Unfortunately, the macroscopic formability of such materials is relatively poor at room temperature and these metals are characterized by a complex mechanical response. This response is a result of the interplay between different deformation modes at the microscale. Since magnesium is a material showing a hexagonal close‐packed (hcp) structure of the underlying atomic lattice, plasticity caused by dislocations and deformation‐induced twinning are the most relevant deformation modes. Within the present paper, two different recently advocated modeling approaches suitable for capturing such modes at the microscale are analyzed. It is shown that both models can be rewritten into a variationally consistent format where every aspect is naturally driven by energy minimization. In addition to this already known feature, it turns out that both models are based on the same minimization problem. The difference between the models results from different constraints enforced within the variational principle. For getting further insight into the interaction between dislocations and twinning interfaces, accompanying atomistic simulations based on molecular dynamics are also performed. The results of such simulations enter the micromechanical model through the initial plastic deformation within the twinned phase (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Susceptibility loci affecting ERBB2/neu‐induced mammary tumorigenesis in mice
Authors: Quan Lei , Dittmar Ashley , Zhou Yuxun , Hutson Alan , Stassen Alphons P. M. , Demant Peter
Published: March 2012

Twenty percent of breast cancers exhibit amplification or overexpression of ERBB2/neu and a poor prognosis. As the susceptibility genes controlling ERBB2 tumorgenesis are unknown, in a genetic mapping project we crossed transgenic mice expressing the neu oncogene under control of MMTV promoter with recombinant congenic (RC) strains, which provided a high mapping power. RC strains differed considerably in tumor latency (P = 0.0002), suggesting a strong genetic control of tumor development. Linkage analysis in neu‐transgene carrying F2 hybrids between the most susceptible and most resistant RC strain revealed three mammary tumor susceptibility (Mts) loci with main effects, Mts1 (chr. 4), Mts2 (chr. 10), Mts3 (chr. 19), and two interacting loci Mts4 (chr.6) and Mts5 (chr. 8), significantly affecting mammary tumor latency. Suggestive significance levels indicated control of tumor numbers by Mts1 alone and in interaction with Mts5, and by two additional interacting loci on chromosomes 1 and 8. These loci combined explain to a large extent the tumor latency and number in individual F2 mouse. We also identified a suggestive locus on chromosome 17 controls metastasis to the lung. The loci Mts1, Mts1b, and Mts3 are located in the Naad4‐4,5 and Naad19‐2 LOH‐regions of neu‐induced mammary tumors, corresponding to the frequent human breast cancer LOH‐regions 1p34/1p36, and 10q25, respectively. These results expand the knowledge of ERBB2 tumorigenesis and point to a combined control of specific tumor phenotypes by germ‐line polymorphisms and somatic alterations. © 2012 Wiley Periodicals, Inc.
Predictive value and reward in implicit classification learning
Authors: Lam Judith M. , Wächter Tobias , Globas Christoph , Karnath Hans‐Otto , Luft Andreas R.
Published: March 2012

Learning efficacy depends on its emotional context. The contents learned and the feedback received during training tinges this context. The objective here was to investigate the influence of content and feedback on the efficacy of implicit learning and to explore using functional imaging how these factors are processed in the brain. Twenty‐one participants completed 150 trials of a probabilistic classification task (predicting sun or rain based on combinations of playing cards). Smileys or frowneys were presented as feedback. In 10 of these subjects, the task was performed during functional magnetic resonance imaging. Card combinations predicting sun were remembered better than those predicting rain. Similarly, positive feedback fortified learning more than negative feedback. The presentation of smileys recruited bilateral nucleus accumbens, sensorimotor cortex, and posterior cingulum more than negative feedback did. The higher the predictive value of a card combination, the more activation was found in the lateral cerebellum. Both context and feedback influence implicit classification learning. Similar to motor skill acquisition, positive feedback during classification learning is processed in part within the sensorimotor cortex, potentially reflecting the activation of a dopaminergic projection to motor cortex (Hosp et al., 2011). Activation of the lateral cerebellum during learning of combinations with high predictive value may reflect the formation of an internal model. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Right temporoparietal junction and attentional reorienting
Authors: Chang Chi‐Fu , Hsu Tzu‐Yu , Tseng Philip , Liang Wei‐Kuang , Tzeng Ovid J.L. , Hung Daisy L. , Juan Chi‐Hung
Published: March 2012

The interaction between goal‐directed and stimulus‐driven attentional control allows humans to rapidly reorient to relevant objects outside the focus of attention—a phenomenon termed contingent reorienting. Neuroimaging studies have observed activation of the ventral and dorsal attentional networks, but specific involvement of each network remains unclear. The present study aimed to determine whether both networks are critical to the processes of top‐down contingent reorienting. To this end, we combined the contingent attentional capture paradigm with the use of transcranial magnetic stimulation (TMS) to interfere with temporoparietal junction (TPJ; ventral network) and frontal eye field (dorsal network) activity. The results showed that only right TPJ (rTPJ) TMS modulated contingent orienting. Furthermore, this modulation was highly dependent on visual fields: rTPJ TMS increased contingent capture in the left visual field and decreased the effect in the right visual field. These results demonstrate a critical involvement of the ventral network in attentional reorienting and reveal the spatial selectivity within such network. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Spatial MEG Laterality maps for language: Clinical applications in epilepsy
Authors: D'Arcy Ryan C.N. , Bardouille Timothy , Newman Aaron J. , McWhinney Sean R. , DeBay Drew , Sadler R. Mark , Clarke David B. , Esser Michael J.
Published: March 2012

Functional imaging is increasingly being used to provide a noninvasive alternative to intracarotid sodium amobarbitol testing (i.e., the Wada test). Although magnetoencephalography (MEG) has shown significant potential in this regard, the resultant output is often reduced to a simplified estimate of laterality. Such estimates belie the richness of functional imaging data and consequently limit the potential value. We present a novel approach that utilizes MEG data to compute “complex laterality vectors” and consequently “laterality maps” for a given function. Language function was examined in healthy controls and in people with epilepsy. When compared with traditional laterality index (LI) approaches, the resultant maps provided critical information about the magnitude and spatial characteristics of lateralized function. Specifically, it was possible to more clearly define low LI scores resulting from strong bilateral activation, high LI scores resulting from weak unilateral activation, and most importantly, the spatial distribution of lateralized activation. We argue that the laterality concept is better presented with the inherent spatial sensitivity of activation maps, rather than being collapsed into a one‐dimensional index. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Structural analysis of oval-cell–mediated liver regeneration in rats
Authors: Dezsõ Katalin , Papp Veronika , Bugyik Edina , Hegyesi Hargita , Sáfrány Géza , Bödör Csaba , Nagy Péter , Paku Sándor
Published: March 2012

We have analyzed the architectural aspects of progenitor-cell–driven regenerative growth in rat liver by applying the 2-acetaminofluorene/partial hepatectomy experimental model. The regeneration is initiated by the proliferation of so-called oval cells. The oval cells at the proximal tips of the ductules have a more differentiated phenotype and higher proliferative rate. This preferential growth results in the formation of a seemingly random collection of small hepatocytes, called foci. These foci have no clonal origin, but possess a highly organized structure, which shows similarities to normal hepatic parenchyma. Therefore, they can easily remodel into the lobular structure. Eventually, the regenerated liver is constructed by enlarged hepatic lobules; no new lobules are formed during this process. The foci of the Solt-Farber experimental hepatocarcinogenesis model have identical morphological features; accordingly, they also represent only regenerative, not neoplastic, growth.

Conclusion

: Progenitor-cell–driven liver regeneration is a well-designed, highly organized tissue reaction, and better comprehension of the architectural events may help us to recognize this process and understand its role in physiological and pathological reactions. (Hepatology 2012)
Prevention of hepatocellular adenoma and correction of metabolic abnormalities in murine glycogen storage disease type Ia by gene therapy
Authors: Lee Young Mok , Jun Hyun Sik , Pan Chi-Jiunn , Lin Su Ru , Wilson Lane H. , Mansfield Brian C. , Chou Janice Y.
Published: March 2012

Glycogen storage disease type Ia (GSD-Ia), which is characterized by impaired glucose homeostasis and chronic risk of hepatocellular adenoma (HCA), is caused by deficiencies in the endoplasmic reticulum (ER)-associated glucose-6-phosphatase-α (G6Pase-α or G6PC) that hydrolyzes glucose-6-phosphate (G6P) to glucose. G6Pase-α activity depends on the G6P transporter (G6PT) that translocates G6P from the cytoplasm into the ER lumen. The functional coupling of G6Pase-α and G6PT maintains interprandial glucose homeostasis. We have shown previously that gene therapy mediated by AAV-GPE, an adeno-associated virus (AAV) vector expressing G6Pase-α directed by the human

G6PC

promoter/enhancer (GPE), completely normalizes hepatic G6Pase-α deficiency in GSD-Ia (G6pc−/−) mice for at least 24 weeks. However, a recent study showed that within 78 weeks of gene deletion, all mice lacking G6Pase-α in the liver develop HCA. We now show that gene therapy mediated by AAV-GPE maintains efficacy for at least 70-90 weeks for mice expressing more than 3% of wild-type hepatic G6Pase-α activity. The treated mice displayed normal hepatic fat storage, had normal blood metabolite and glucose tolerance profiles, had reduced fasting blood insulin levels, maintained normoglycemia over a 24-hour fast, and had no evidence of hepatic abnormalities. After a 24-hour fast, hepatic G6PT messenger RNA levels in G6pc−/− mice receiving gene therapy were markedly increased. Because G6PT transport is the rate-limiting step in microsomal G6P metabolism, this may explain why the treated G6pc−/− mice could sustain prolonged fasts. The low fasting blood insulin levels and lack of hepatic steatosis may explain the absence of HCA.

Conclusion :

These results confirm that AAV-GPE–mediated gene transfer corrects hepatic G6Pase-α deficiency in murine GSD-Ia and prevents chronic HCA formation.
Clinical cofactors and hepatic fibrosis in hereditary hemochromatosis: The role of diabetes mellitus
Authors: Wood Marnie J. , Powell Lawrie W. , Dixon Jeannette L. , Ramm Grant A.
Published: March 2012

The risk of hepatic fibrosis and cirrhosis in hereditary hemochromatosis relates to the degree of iron loading, but iron alone does not explain the variability in disease penetrance. This study sought to identify clinical cofactors that increase the risk of progressive liver disease. We identified 291 patients from our database who were homozygous for the C282Y mutation in HFE and had undergone a liver biopsy with quantification of hepatic iron concentration (HIC) and fibrosis staging. Data were collected from a retrospective chart review, including age, gender, alcohol consumption, medical therapy, smoking history, metabolic risk factors, mobilizable iron, and laboratory results. Male gender, excess alcohol consumption, HIC, and the presence of diabetes were independently associated with increasing fibrosis stage in multivariate analysis. Of these, the presence of diabetes showed the strongest association (odds ratio, 7.32;

P

= 0.03). The presence of steatosis was associated with higher fibrosis scores, but this was of borderline statistical significance. Risk factors for hepatic steatosis were male gender, impaired glucose tolerance, and increased body mass index.

Conclusion
: The presence of diabetes was associated with more severe hepatic fibrosis independent of iron loading, male gender, and alcohol consumption. The mechanism for this association is unknown and deserves further evaluation; however, it is possible that diabetes produces an additional hepatic oxidative injury from hyperglycemia. Thus, management of such cofactors in patients with hemochromatosis is important to reduce the risk of liver injury and fibrosis.
Beyond reasonable doubt: Who is the culprit in lipotoxicity in NAFLD/NASH?
Authors: van Rooyen D M , Larter C Z , Haigh W G , Yeh M W , Ioannou G , Kuver R
Published: March 2012

BACKGROUND & AIMS: Type 2 diabetes and nonalcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to the pathogenesis of NASH. METHODS: Alms1 mutant (foz/foz) and wild-type NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice. RESULTS: Hepatic cholesterol accumulation was attributed to up-regulation of low-density lipoprotein receptor via activation of sterol regulatory element binding protein 2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and low-density lipoprotein receptor and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol levels exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis. CONCLUSIONS: In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH.
Bias in relative survival methods when using incorrect life‐tables: Lung and bladder cancer by smoking status and ethnicity in New Zealand
Authors: Blakely Tony , Soeberg Matthew , Carter Kristie , Costilla Roy , Atkinson June , Sarfati Diana
Published: March 2012

Relative survival and excess mortality approaches are commonly used to estimate and compare net survival from cancer. These approaches are based on the assumption that the underlying (non‐cancer) mortality rate of cancer patients is the same as that of the general population. This assumption is likely to be violated particularly in the context of smoking‐related cancers. The magnitude of this bias has not been estimated. The objective of this article is to estimate the bias in relative survival ratios (RSRs) and excess mortality rate ratios (EMRRs) from using total population compared to correct subpopulation specific life‐tables. Analyses were conducted on 1996–2001 linked census–cancer data (including smoking status) for people with lung and bladder cancer, using sex‐specific (standard practice), sex‐ and ethnic‐specific, sex‐ and smoking‐specific and sex‐, ethnic‐ and smoking‐specific life‐tables. Five‐year RSRs using sex‐specific life‐tables, compared to fully stratified life‐tables, were underestimated by 10–25% for current smoking and Maori populations. For example, the current smoker male bladder cancer RSR was 0.700 for sex‐specific life‐tables, compared to 0.838 for fully stratified life‐tables. Similarly, EMRRs comparing current to never smokers and Maori to non‐Maori were overestimated using sex‐specific life‐tables only: modestly only for lung cancer, but markedly for bladder cancer. For example, the EMRR comparing current to never smokers with bladder cancer in a fully adjusted regression model was 1.475 when using sex‐specific life‐tables only, but reduced to 1.098 when using fully stratified life‐tables. Substantial bias can occur when estimating relative cancer survival across subpopulations if non‐matching life‐tables are used.
Synthesis and characterization of hydroxyapatite with different crystallinity: Effects on protein adsorption and release
Authors: Lee Wing‐Hin , Zavgorodniy Alexander V. , Loo Ching‐Yee , Rohanizadeh Ramin
Published: March 2012

Increasing demand exists for the development of a tissue‐engineered alternative in the repair of nonunion and critical‐sized bone defects. The delivery of osteoinductive proteins, such as bone morphogenetic proteins (BMPs), to replicate physiological bone‐healing process appears a logical and promising option, but is currently limited in its clinical application due to lack of a suitable drug carrier. The study aimed to investigate the effects of the crystallinity of hydroxyapatite (HA) drug carrier on adsorption of proteins onto and their release from the carrier. HA samples with different crystallinities were synthesized under controlled conditions, that is, pH, temperature, and maturation time, and characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and surface area analyzer. Results demonstrated that both bovine serum albumin (BSA) and cytochrome C had a greater tendency to bind onto amorphous calcium phosphate (ACP) than crystalline HA, and the adsorption rate was correlated oppositely with the HA crystallinity. For both BSA and cytochrome C, the release kinetics of protein from HA depended on the crystallinity of HA, in which ACP had the highest release rate at 74%, whereas only 15% of proteins were released from the highly crystalline HA over a 14‐day period. Burst release within 12 h of incubation was observed for all groups. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Perinuclear positioning of the inactive human cystic fibrosis gene depends on CTCF, A‐type lamins and an active histone deacetylase
Authors: Muck Joscha S. , Kandasamy Karthikeyan , Englmann Andreas , Günther Martin , Zink Daniele
Published: March 2012

The nuclear positioning of mammalian genes often correlates with their functional state. For instance, the human cystic fibrosis transmembrane conductance regulator (CFTR) gene associates with the nuclear periphery in its inactive state, but occupies interior positions when active. It is not understood how nuclear gene positioning is determined. Here, we investigated trichostatin A (TSA)‐induced repositioning of CFTR in order to address molecular mechanisms controlling gene positioning. Treatment with the histone deacetylase (HDAC) inhibitor TSA induced increased histone acetylation and CFTR repositioning towards the interior within 20 min. When CFTR localized in the nuclear interior (either after TSA treatment or when the gene was active) consistent histone H3 hyperacetylation was observed at a CTCF site close to the CFTR promoter. Knockdown experiments revealed that CTCF was essential for perinuclear CFTR positioning and both, CTCF knockdown as well as TSA treatment had similar and CFTR‐specific effects on radial positioning. Furthermore, knockdown experiments revealed that also A‐type lamins were required for the perinuclear positioning of CFTR. Together, the results showed that CTCF, A‐type lamins and an active HDAC were essential for perinuclear positioning of CFTR and these components acted on a CTCF site adjacent to the CFTR promoter. The results are consistent with the idea that CTCF bound close to the CFTR promoter, A‐type lamins and an active HDAC form a complex at the nuclear periphery, which becomes disrupted upon inhibition of the HDAC, leading to the observed release of CFTR. J. Cell. Biochem. 113: 2607–2621, 2012. © 2012 Wiley Periodicals, Inc.
Furanodiene enhances tamoxifen‐induced growth inhibitory activity of ERa‐positive breast cancer cells in a PPARγ independent manner
Authors: Zhong Zhang‐Feng , Li Ying‐Bo , Wang Sheng‐Peng , Tan Wen , Chen Xiu‐Ping , Chen Mei‐Wan , Wang Yi‐Tao
Published: March 2012

Herbal plants are enriched with compounds with a wide range of biological activities. Furanodiene is a sesquiterpene isolated from Rhizoma Curcumae. Growing evidence shows furanodiene exhibits diversified activities of hepatoprotection, anti‐inflammation, anti‐angiogenesis, and anti‐tumor. However, its biological activities against breast cancer have not been deeply understood, and its potential as an anti‐breast cancer agent combined with tamoxifen (TAM) has not been evaluated so far. This study describes the combined effects of furanodiene and TAM in human breast cancer cells in vitro. The results showed that ERa‐negative MDA‐MB‐231 cells were much more sensitive than ERa‐positive MCF‐7 cells to the growth inhibition due to furanodiene. Combined administration of furanodiene and TAM led to marked increase in growth inhibition, cell cycle arrest and pro‐apoptotic activity in ERa‐positive cells compared to individual agent, and enhanced the down‐regulation of p‐cyclin D1, cyclin D1, CDK2, CDK6, p‐Rb, Rb and p‐p44, and the up‐regulation of p27, Bax and Bad, but did not show increased cytotoxicity in ERa‐negative MCF‐10A non‐tumorigenic breast epithelial cells. Co‐incubation induced the typical PARP cleavage or caspase 9 cleavages compared to individual agent. In addition, PPARγ activity inhibition by its antagonist T0070907 did not significantly reverse the enhanced effect of furanodiene and TAM suggesting that anti‐cancer properties of combination were PPARγ independent. Our data indicated that furanodiene could enhance the growth inhibitory and pro‐apoptotic activity of TAM by inducing cell cycle arrest and cell apoptosis via CDKs–cyclins and mitochondria‐caspases‐dependent, and PPARγ‐independent signaling pathways in breast cancer cells, without contributions to the cytotoxicity of TAM. J. Cell. Biochem. 113: 2643–2651, 2012. © 2012 Wiley Periodicals, Inc.