bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of Tailor‐Made Enzymes for Detergents
Authors: Rähse Wilfried
Published: February 2014

Incorporated in detergents, special enzymes are able to remove natural stains from laundry at temperatures of 60 °C and below. The various enzymes form complexes with the substrates (stains) and hydrolyze fixed proteins and polysaccharides as well fats. Surfactants rinse the resulting fragments into the wash liquor. The genes for the synthesis of these enzymes, which predominantly originate from Bacillus strains, are optimized for the desired performance of the enzymes. They work nonspecifically and are resistant to the detergent ingredients in the liquor. Industrial production of the enzymes takes place in fermenters 40 to 125 m3 in size. During the fermentation, microorganisms secrete the enzyme into the medium to cleave proteins with high molecular weight, which swim in the broth. The fragments penetrate into the cell and serve as energy source. After the end of fermentation, the enzymes are separated from the microorganisms, concentrated and converted into the final product. Granulated products, containing the enzymes in the matrix, require a coating to ensure product safety. Product design is determined on the one hand by protein engineering and on the other hand by design of the final product.
200 Years in Innovation of Continuous Distillation
Authors: Kockmann Norbert
Published: February 2014

Distillation is one of the oldest and most frequently used purification methods today. In 1813, Jean‐Baptiste Cellier‐Blumenthal patented the first continuously working distillation column, starting an impressive development of process equipment. New product areas were discovered as well as improved equipment installations. 100 years ago, Fritz Raschig patented his rings as packing material. Current developments are guided by deeper knowledge of heat and mass transfer as well as the integration of various process functions.
Current Developments in Cellulase Engineering
Authors: Kellermann Stefanie J. , Rentmeister Andrea
Published: February 2014

Degradation of cellulose represents a key step for efficient generation of biofuels such as ethanol or butanol from nonfood crops. Several strategies aim to improve the performance of cellulases in order to make the overall process more cost‐efficient.

In one strategy, novel arrangements of cellulases are developed. The resulting so‐called designer cellulosomes might allow to equip the fermenting hosts with sufficient cellulase activity to grow on cellulose as sole carbon source and thus enable consolidated bioprocessing.

Other strategies aim to engineer cellulases with higher thermostability and activity to make cellulose hydrolysis more efficient. This review summarizes current developments in the field of cellulase engineering and highlight achievements as well as limitations.
Using 15N‐Ammonium to Characterise and Map Potassium Binding Sites in Proteins by NMR Spectroscopy
Authors: Werbeck Nicolas D. , Kirkpatrick John , Reinstein Jochen , Hansen D. Flemming
Published: February 2014

A variety of enzymes are activated by the binding of potassium ions. The potassium binding sites of these enzymes are very specific, but ammonium ions can often replace potassium ions in vitro because of their similar ionic radii. In these cases, ammonium can be used as a proxy for potassium to characterise potassium binding sites in enzymes: the 1H,15N spin‐pair of enzyme‐bound 15NH4+ can be probed by 15N‐edited heteronuclear NMR experiments. Here, we demonstrate the use of NMR spectroscopy to characterise binding of ammonium ions to two different enzymes: human histone deacetylase 8 (HDAC8), which is activated allosterically by potassium, and the bacterial Hsp70 homologue DnaK, for which potassium is an integral part of the active site. Ammonium activates both enzymes in a similar way to potassium, thus supporting this non‐invasive approach. Furthermore, we present an approach to map the observed binding site onto the structure of HDAC8. Our method for mapping the binding site is general and does not require chemical shift assignment of the enzyme resonances.
Mafia and psychopathy
Authors: Schimmenti Adriano , Caprì Chiara , La Barbera Daniele , Caretti Vincenzo
Published: February 2014

Background

In popular culture, Mafia members are often portrayed as ruthless, callous and remorseless, but there is no empirical research on their personality traits.

Aims

The goal of this research was to examine levels of psychopathic traits among Mafia members who have been convicted of a criminal offence.

Methods

The Psychopathy Checklist‐Revised (PCL‐R) rated 30 Italian adult male prisoners who had been convicted for Mafia‐related crimes (86% resident in one 6‐month period) and 39 next adjacent convicted men who were not enrolled in any criminal organisation.

Results

Mafia members obtained lower PCL‐R total scores, interpersonal and affective (PCL‐R factor 1) scores and lifestyle scores (factor 2) than the other offenders. Logistic regression analysis showed that lower PCL‐R factor 1 scores with higher factor 2 scores in the absence of a history of substance misuse disorder distinguished Mafia from non‐Mafia offenders. A probability curve confirmed an exponential growth in the probability of classification as a Mafia member in relation to lower PCL‐R factor 1 scores.

Conclusions

Our findings bring new hope for resocialisation of convicted Mafia members, because they showed significant antisocial traits but they maintained a capacity for emotional connection and greater likelihood of engaging with training and resocialisation programmes than other imprisoned offenders in Italy. Copyright © 2014 John Wiley & Sons, Ltd.
Association of ischemic stroke, hormone therapy, and right to left shunt in postmenopausal women
Authors: Greep Nancy C. , Liebeskind David S. , Gevorgyan Rubine , Truong Tam , Cua Bennett , Tseng Chi‐Hong , Dodick David W. , Demaerschalk Bart M. , Thaler David E. , Tobis Jonathan M.
Published: February 2014

Background

Postmenopausal hormone therapy (HT) increases the risk of venous thrombosis and ischemic stroke.

Objectives

We postulated that HT might increase the risk of ischemic stroke by promoting venous clots that travel to the brain through a right to left shunt (RLS).

Methods

A total of 2,389 records were studied. After eliminating the premenopausal patients, and those with TIAs and non‐ischemic strokes, the medical records of 1846 postmenopausal women hospitalized at four institutions for ischemic stroke were reviewed to identify those who had undergone an adequate study to assess for RLS. The proportion of women with a shunt in users and non‐users of HT was compared in stroke patients and in a reference population consisting of postmenopausal women undergoing elective cardiac catheterization.

Results

There were 363 (20%) records that had complete data and were included in the analysis. A shunt was more prevalent in patients with a cryptogenic stroke than in patients with a stroke of known cause (55/88 (63%) vs. 53/275 (19%), P < 0.001). In patients with a stroke of known cause, the frequency of a shunt was similar to that in reference women 31/136 (23%), and the proportion of women with a shunt was similar in non‐users and current users of HT (14% vs. 20%, P = 0.40). However, among patients with a cryptogenic stroke, the prevalence of a shunt was 1.5 times higher in current users than non‐users of HT (82% vs. 56%, P = 0.04).

Conclusions

Approximately 23% of older women have a RLS. HT in these women may increase the risk of ischemic stroke by promoting paradoxical embolism. © 2014 Wiley Periodicals, Inc.
Increased prosthetic valve gradients: Abnormal prosthetic function or pressure recovery?
Authors: Eleid Mackram F. , Thomas James D. , Nishimura Rick A.
Published: February 2014

The non‐invasive evaluation of prosthetic valve function is challenging. The effects of flow rate, valvular geometry, leaflet motion, and pressure recovery all impact the Doppler assessment of prosthetic performance. Differentiating prosthesis obstruction from pressure recovery in patients who are found to have high Doppler velocities across an aortic valve prosthesis is critical in order to direct appropriate management. In this manuscript, we present two cases of patients with aortic valve prosthesis with high Doppler velocities and review the pathophysiology and evaluation of prosthesis function. © 2014 Wiley Periodicals, Inc.
Bioreductions Catalyzed by an Alcohol Dehydrogenase in Non‐aqueous Media
Authors: Kara Selin , Spickermann Dominik , Weckbecker Andrea , Leggewie Christian , Arends Isabel W. C. E. , Hollmann Frank
Published: February 2014

Highly productive biocatalytic reductions were established using an isolated alcohol dehydrogenase (ADH) under water‐deficient conditions. First, a solvent‐free system was evaluated for the reduction of 2‐butanone catalyzed by ADH evo‐1.1.200 promoted by the “smart cosubstrate” 1,4‐butanediol. ADH evo‐1.1.200 excelled by its activity and stability under high reagent concentrations and hence was the enzyme of choice. However, conversion of 2‐butanone was limited to <1 % in 10 days under the solvent‐free conditions. Therefore, water‐immiscible organic solvents were evaluated whereby the highest conversions were achieved in MTBE and toluene. MTBE was chosen as its different boiling point compared to other reaction components (e.g., 2‐butanone, 2‐butanol, diol cosubstrate, and lactone coproduct) would simplify the downstream processing. Further on, by tuning substrate loading, the productivity of the ADH evo‐1.1.200 was successfully increased to a turnover number (TON) of 64 000.
Identification, Characterization, and Application of Three Enoate Reductases from Pseudomonas putida in In Vitro Enzyme Cascade Reactions
Authors: Peters Christin , Kölzsch Regina , Kadow Maria , Skalden Lilly , Rudroff Florian , Mihovilovic Marko D. , Bornscheuer Uwe T.
Published: February 2014

Enoate reductases are versatile enzymes for the enantio‐ and regioselective addition of hydrogen to double bonds. We identified three EREDs (XenA, XenB, NemA) from Pseudomonas putida ATCC 17453 through a sequence motif search. In addition to cloning, functional expression, and biochemical characterization of these enzymes, the enoate reductases were also applied in enzyme cascade reactions in combination with a Baeyer–Villiger monooxygenase and an alcohol dehydrogenase to produce lactones.
Reduced Vanadium and Molybdenum Oxides Catalyze the Equivalent Formation of Ethane and Acetaldehyde from Ethanol
Authors: Nakamura Yoichi , Murayama Toru , Ueda Wataru
Published: February 2014

Catalytic tests for ethanol conversion were performed on vanadium and molybdenum oxides with different oxidation states. We found for the first time that equivalent amounts of ethane and acetaldehyde were formed catalytically over V2O3 and MoO2. No influence of the reaction temperature was observed on the selectivity to ethane and acetaldehyde in the range of 533–653 K over V2O3 and MoO2. The reactions of methanol, 1‐propanol, and 2‐propanol also produced the corresponding alkanes and aldehydes in a 1:1 ratio. A reaction scheme for the formation of ethane and acetaldehyde from ethanol is proposed in which a hydrogen transfer reaction occurs between two ethanol molecules adsorbed on the adjacent metal cation–oxygen anion pair sites to form ethane, acetaldehyde, and water in one step.
Fe2O3@LaxSr1−xFeO3 Core–Shell Redox Catalyst for Methane Partial Oxidation
Authors: Shafiefarhood Arya , Galinsky Nathan , Huang Yan , Chen Yanguang , Li Fanxing
Published: February 2014

Efficient and environmentally friendly conversion of methane into syngas is a topic of practical relevance for the production of hydrogen, chemicals, and synthetic fuels. At present, methane‐derived syngas is produced primarily through the steam methane reforming processes. The efficiencies of such processes are limited owing to the endothermic steam methane reforming reaction and the high steam to methane ratio required by the reforming catalysts. Chemical looping reforming represents an alternative approach for methane conversion. In the chemical looping reforming scheme, a solid oxygen carrier or “redox catalyst” is used to partially oxidize methane to syngas. The reduced redox catalyst is then regenerated with air. The cyclic redox operation reduces the steam usage while simplifying the heat integration scheme. Herein, a new Fe2O3@LaxSr1−xFeO3 (LSF) core–shell redox catalyst is synthesized and investigated. Compared with several other commonly investigated iron‐based redox catalysts, the newly developed core–shell redox catalyst is significantly more active and selective for syngas production from methane. It is also more resistant toward carbon formation and maintains high activity over cyclic redox operations.
Resistance‐Switchable Graphene Oxide–Polymer Nanocomposites for Molecular Electronics
Authors: Liu Gang , Chen Yu , Li Run‐Wei , Zhang Bin , Kang En‐Tang , Wang Cheng , Zhuang Xiaodong
Published: February 2014

The front cover artwork is provided by Prof. Dr. Yu Chen and his co‐workers. The image represents how deliberately designed, solution‐processable, and electroactive polymer‐functionalized graphene‐oxide nanosheets can be reversibly switched ON and OFF for the development of next‐generation nonvolatile information‐storage applications. Read the full text of the article at 10.1002/celc.201300158.
Direct Growth of Cobalt Hydroxide Rods on Nickel Foam and Its Application for Energy Storage
Authors: Salunkhe Rahul R. , Bastakoti Bishnu Prasad , Hsu Chun‐Tsung , Suzuki Norihiro , Kim Jung Ho , Dou Shi Xue , Hu Chi‐Chang , Yamauchi Yusuke
Published: February 2014

The present work reports synthesis of cobalt hydroxide (Co(OH)2) rods on nickel foam and its supercapacitor application. Hierarchical Co(OH)2 rods with length of approximately 3.5 μm and diameter of approximately 400 nm were prepared by one‐step, simple, and inexpensive chemical‐bath‐deposition method. The direct growth of Co(OH)2 rods on the Ni foam gave three dimensional (3D) structure for easy access of electrolyte throughout material surface. Also, well‐adhered interface between Co(OH)2 rods and Ni‐foam surface gave better conduction channels. Detailed electrochemical study was performed by using cyclic voltammetry and galvanostatic charge/discharge measurements. The results demonstrate that Co(OH)2 rods on Ni foam are efficient electrodes for supercapacitor application.
Synthesis of Highly Functionalized Diaryl Ethers by Copper‐Mediated O‐Arylation of Phenols using Trivalent Arylbismuth Reagents
Authors: Crifar Cynthia , Petiot Pauline , Ahmad Tabinda , Gagnon Alexandre
Published: February 2014

Highly functionalized diaryl ethers were prepared by copper(II) acetate mediated O‐arylation reaction of phenols using trivalent organobismuthanes. The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N‐arylation of pyridones is also reported.
Nickel‐Catalyzed Csp2Csp3 Bond Formation by CarbonFluorine Activation
Authors: Sun Alex D. , Leung Kaylyn , Restivo Anita D. , LaBerge Nicole A. , Takasaki Harumi , Love Jennifer A.
Published: February 2014

We report herein a general catalytic method for Csp2Csp3 bond formation through CF activation. The process uses an inexpensive nickel complex with either diorganozinc or alkylzinc halide reagents, including those with β‐hydrogen atoms. A variety of fluorine substitution patterns and functional groups can be readily incorporated. Sequential reactions involving different precatalysts and coupling partners permit the synthesis of densely functionalized fluorinated building blocks.
Regioselective Ruthenium‐Catalyzed Carbonylative Direct Arylation of Five‐Membered and Condensed Heterocycles
Authors: Pospech Jola , Tlili Anis , Spannenberg Anke , Neumann Helfried , Beller Matthias
Published: February 2014

A ruthenium‐catalyzed carbonylative CH bond arylation process for the three‐component synthesis of complex aryl–(hetero)aryl ketones in an aqueous solution has been developed. By exploiting the ortho‐activating effect of nitrogen‐containing directing groups, a regioselective, successive twofold C(sp2)C(sp2) bond formation has been achieved. This straightforward catalytic process provides access to versatile products prevalent in multiple bioactive compounds and supplies a valuable functional group for subsequent transformations.
Manganese‐Containing Periodic Mesoporous Organosilica with Ionic‐Liquid Framework (Mn@PMO‐IL): A Powerful, Durable, and Reusable Nanocatalyst for the Biginelli Reaction
Authors: Elhamifar Dawood , Shábani Ahmad
Published: February 2014

The catalytic application of a novel manganese‐containing periodic mesoporous organosilica with ionic‐liquid framework (Mn@PMO‐IL) in the Biginelli reaction was investigated. First, the Mn@PMO‐IL nanocatalyst was prepared and characterized by TEM, SEM, X‐ray photoelectron spectroscopy, and nitrogen‐sorption analysis. The catalyst was then used in the one‐pot Biginelli condensation of various aldehydes with urea and alkyl acetoacetates under solvent‐free conditions. The corresponding dihydropyrimidone products were obtained in high to excellent yields and selectivities at short reaction times. Moreover, the catalyst was recovered and successfully reused many times with no notable decrease in activity and selectivity.
Transition‐Metal‐Free Catalytic Reduction of Carbon Dioxide
Authors: Fontaine Frédéric‐Georges , Courtemanche Marc‐André , Légaré Marc‐André
Published: February 2014

Metal‐free systems, including frustrated Lewis pairs (FLPs) have been shown to bind CO2. By reducing the Lewis acidity and basicity of the ambiphilic system, it is possible to generate active catalysts for the deoxygenative hydroboration of carbon dioxide to methanol derivatives with conversion rates comparable to those of transition‐metal‐based catalysts.
An Imidazoline–Aminophenol (IAP) Nickel Catalyst: Structure and Catalytic Activity in the Enantioselective 1,4‐Addition of 3′‐Indolyl‐3‐Oxindoles to Nitroethylene
Authors: Awata Atsuko , Wasai Makiko , Masu Hyuma , Kado Sayaka , Arai Takayoshi
Published: February 2014

The structure of a nickel complex of imidazoline–aminophenol (IAP) prepared from IAP with Ni(OAc)2 was elucidated as cis‐bis(imidazolineaminophenoxide) [Ni(IAP)2]. The [Ni(IAP)2] complex smoothly promoted catalytic asymmetric 1,4‐addition of 3′‐indolyl‐3‐oxindole to nitroethylene to provide chiral mixed 3,3′‐bisindoles with high enantioselectivities. Mechanistic studies using ESI‐MS analyses suggest that one IAP ligand dissociated from [Ni(IAP)2] to generate the Ni–enolate of 3′‐indolyl‐3‐oxindole. From the optically active 3,3′‐mixed indole adduct, biologically important 3′‐indolyl‐3‐pyrrolidinoindoline was successfully synthesized in a three‐step reaction sequence.
Nanozeolite‐LTL with GdIII Deposited in the Large and EuIII in the Small Cavities as a Magnetic Resonance Optical Imaging Probe
Authors: Mayer Florian , Zhang Wuyuan , Brichart Thomas , Tillement Olivier , Bonnet Célia S. , Tóth Éva , Peters Joop A. , Djanashvili Kristina
Published: February 2014

The immense structural diversity of more than 200 known zeolites is the basis for the wide variety of applications of these fascinating materials ranging from catalysis and molecular filtration to agricultural uses. Despite this versatility, the potential of zeolites in medical imaging has not yet been much exploited. In this work a novel strategy is presented to selectively deposit different ions into distinct framework locations of zeolite‐LTL (Linde type L) and it is demonstrated that the carefully ion‐exchanged Gd/Eu‐containing nanocrystals acquire exceptional magnetic properties in combination with enhanced luminescence. This smart exploitation of the framework structure yields the highest relaxivity density (13.7 s−1 L g−1 at 60 MHz and 25 °C) reported so far for alumosilicates, rendering these materials promising candidates for the design of dual magnetic resonance/optical imaging probes, as demonstrated in preliminary phantom studies.
Gold‐Catalyzed Cycloisomerization of Yne‐Vinylidenecyclopropanes: A Three‐Carbon Synthon for [3+2] Cycloadditions
Authors: Yuan Wei , Tang Xiangying , Wei Yin , Shi Min
Published: February 2014

A novel type of yne‐vinylidenecyclopropanes (VDCPs) has been synthesized and applied in gold‐catalyzed cycloisomerization reactions. It was found that these compounds can undergo an intramolecular cycloisomerization and perform as a three‐carbon synthon for [3+2] cycloaddition under gold catalysis to give fused [4.3.0] and [5.3.0] bicyclic derivatives and VDCP rearranged products in moderated to good yields under mild conditions. The substrate scope of these novel transformations has been explored and plausible reaction mechanisms have been presented on the basis of deuterium labeling experiments and DFT calculations.
Phase‐Transfer‐Catalysed Synthesis of Pyrroloindolines and Pyridoindolines by a Hydrogen‐Bond‐Assisted Isocyanide Cyclization Cascade
Authors: Knipe Peter C. , Gredičak Matija , Cernijenko Artiom , Paton Robert S. , Smith Martin D.
Published: February 2014

A cascade reaction that generates pyrrolo‐ and pyridoindoline motifs from isocyanide precursors under phase‐transfer conditions is described. This transformation proceeds at room temperature in the presence of a quaternary ammonium catalyst and base to generate functionalized products containing an all‐carbon quaternary stereocentre. Quantum chemical calculations demonstrated that intramolecular general acid catalysis plays a key accelerating role through stabilization of developing charge in the transition state, and that the reaction is best described as a 5‐endo dig cyclization, rather than an anionic 6π electrocyclization. Investigations employing chiral phase‐transfer catalysts have given promising selectivities to date.
Characterization of Supramolecular Hidden Chirality of Hydrogen‐Bonded Networks by Advanced Graph Set Analysis
Authors: Sasaki Toshiyuki , Ida Yoko , Hisaki Ichiro , Yuge Tetsuharu , Uchida Yoshiaki , Tohnai Norimitsu , Miyata Mikiji
Published: February 2014

Invited for the cover of this issue is the group of Mikiji Miyata at Osaka University. The image depicts the concept of supramolecular hidden chirality of hydrogen‐bonded networks characterized by advanced graph set analysis. Read the full text of the article at 10.1002/chem.201303770.
Geomagnetic Intensity and Direction for the Last 14 ka Recorded in the Core from the Bering Sea
Authors: Shu‐Lan GE , Xue‐Fa SHI , Yuan‐Hui HUANG , Zhi‐Hua CHEN , Jian‐Xing LIU , Shi‐Juan YAN
Published: February 2014

Paleomagnetic and rock magnetic studies were conducted on the cores from the borehole B5‐4 in a continental slope of the Bering Sea to determine intensity and direction of the geomagnetic field. The results show that the magnetic properties are uniform except the finer magnetic grain size on the upper 0∼0.44 m. The relative paleointensity in the core is highly consistent with that of ODP983. According to the correlation between relative paleointensity in the borehole B5‐4 and ODP983 and an AMS 14C dating of foraminifera at 4.54∼4.56 m, three correlation points can be further determined, thus an age model for the borehole B5‐4 was obtained. The declination and inclination in B5‐4 agree highly with that of high latitude regions, such as the Lake Baikal, North America and Europe and the spherical harmonic model of local geomagnetic field, which provide additional tie points for the age model and a nearly linear sedimentation for the last 14 ka was revealed. The inclination correlation between B5‐4 and two cores from the China East Sea suggests the two discrete sections of shallow inclinations in B5‐4 are likely record of the Gothenburg event, but affected by the early diagenesis or smoothing effect. The above results prove that both relative paleointensity and direction can be obtained in appropriate sediments of the Bering Sea that serve as a time marker. This is very helpful in paleoenvironmental and paleoceanographic study in the Arctic and subarctic areas considering the awful scarcity of age information due to the shortage of calcareous tests and shells.
Rupture Details of the 20 April 2013 Lushan M7.0 Earthquake
Authors: Yan XU , Wen‐Li SHAO
Published: February 2014

An M7.0 earthquake struck Lushan, Sichuan, on 20 April 2013. We attempt to reveal its rupture details around 1 Hz using back‐projecting teleseismic P waves. The results show that this event was spawned by a 20‐km‐long and 26‐s‐duration rupturing of the source, which occurred bilaterally during the first 4 s, and unilaterally afterwards. The biggest energy release area is located north of the epicenter. We compared the rupture details of the Wenchuan and Lushan earthquakes, which occurred on the same fault, and found three common characters in rupture direction, location of the biggest energy burst and multi sub‐event. Two sources ruptured along the northeast trending Longmenshan fault zone. The biggest energy release regions are both off the epicenter. The source included more than one sub‐event, with the second one having the biggest energy release. The total rupture length of the Wenchuan and Lushan earthquakes accounts for about two thirds of the entire Longmenshan fault zone.
Study of Suppression of Diffracted Multiples from Steep Slope Zones in Deep Water
Authors: Song‐Lei XIE , Yi‐Ke LIU , Yi‐Bo WANG , Xu CHANG , Peng LI , De‐Gang JIN
Published: February 2014

In areas with steep slope zones in deep water and rugged seafloor, even using long acquisition cable, the reflected point out of the cable length, because of the variable direction of propagation of diffracted multiples. It makes diffracted multiple prediction without sufficient near offset or negative offset information, so that we cannot predict and suppress diffracted multiples exactly. This has been a big problem for us in suppression of diffracted multiples from steep slope zones in deep water. This paper presents a new method based on the feedback iteration model, introduces the adjacent shot record into the feedback iteration model, to supplement the near offset and negative offset data information. Tests on the Sigsbee2b model and real data show that this method can suppress well the diffracted multiples associated with the free surface of steep slopes in deep water.
Acoustic Wave Equation Modeling with New Time‐Space Domain Finite Difference Operators
Authors: Wen‐Quan LIANG , Chang‐Chun YANG , Yan‐Fei WANG , Hong‐Wei LIU
Published: February 2014

Numerical simulation of acoustic wave equation is widely used to theoretically synthesize seismograms, and also constitutes the basis of the reverse time migration. Under some stability conditions, grid dispersion often exists because of the discretization of time and spatial derivatives in wave equations. How to suppress the grid dispersion is therefore a key problem for finite difference approaches. Time‐space domain methods using plane‐wave theory and Taylor series expansion are proposed to suppress grid dispersion recently. However, these methods can only preserve the wavefield in a small range of frequencies and angles of propagation. To further suppress the grid dispersion, we propose to preserve the grid dispersion relationship in a large range of frequencies and angles of propagation. Dispersion analysis and seismic numerical simulations demonstrate the effectiveness of the proposed method.
Symplectic RKN Schemes for Seismic Scalar Wave Simulations
Authors: Shao‐Lin LIU , Xiao‐Fan LI , You‐Shan LIU , Shi‐Zhong CHEN
Published: February 2014

Seismic scalar wave equation is transformed into Hamiltonian system, and then a second‐order explicit Runge‐Kutta‐Nyström (RKN) scheme is proposed for high‐efficient acoustic wave simulations. The order conditions are obtained by the rooted tree theory. For order conditions with two free coefficients, one scheme with minimum error is obtained based on the optimal error truncation of the third‐order terms. We analyze the acoustic time advancing equation and choose coefficients to promote the stability upper bound, and then we develop an optimized scheme with strong stability. In the analysis of dispersion relation, the third optimized symplectic RKN scheme is constructed to substantially eliminate numerical dispersion. The theoretical properties of the three sets of symplectic RKN schemes have great advantages over other common schemes in terms of errors controlling, dispersion suppressing and stability promoting. Finally, we present numerical experiments to verify the theoretical analysis.
Two‐Dimensional Simulation of Magnetotelluric Anisotropy and Case Analysis
Authors: Xiang‐Yun HU , Guang‐Pu HUO , Rui GAO , Hai‐Yan WANG , Yi‐Fan HUANG , Yun‐Xia ZHANG , Bo‐Xin ZUO , Jian‐Chao CAI
Published: February 2014

After more than half century development, remarkable achievements have been made in the study of earth's interior electrical structure by using the magnetotelluric (MT) method. The majority of these research results are based on the electrical isotropic assumption. However, the electrical anisotropy phenomenon is prevalent in the earth interior, and the presence of such anisotropy in the crust and upper mantle is an important link factor among geoelectric models, underground structure and tectonic models. In this paper, the tensor conductivity is first introduced by starting from the Maxwell equations, then we deduce a set of partial differential equations with respect to Ex and Hx according to the characteristic of two‐dimensional electrical anisotropic structure. By using the partial differential equations, the appropriate solutions of Ex and Hx are solved, and other field components are obtained on the basis of Ex and Hx. In order to recognize the characteristics of electromagnetic propagation under common and special geological conditions, the influence on the measured MT data is studied by the forward simulation on ordinary and special two‐dimension anisotropic electrical structure, which lays theoretical foundation for the subsequent processing and interpretation of MT data. Finally, the electrical anisotropy theory is introduced into processing and interpretation of MT data based on the results in the paper, and the widespread existence of electrical anisotropy is illuminated, and the exactness of this theory and practicability of the algorithm are verified by means of the two‐dimension forward fitting interpretation on the MT data from Xinjiang. This work would provide theoretical basis and technical guidance for analyzing and explaining the electrical anisotropy in MT data and help opens approaches for processing of measured MT data.
Immobilisation of Pb and Zn in Soils Using Stabilised Zero‐valent Iron Nanoparticles: Effects on Soil Properties
Authors: Mar Gil‐Díaz María , Pérez‐Sanz Araceli , Ángeles Vicente María , Carmen Lobo María
Published: February 2014

This study investigates the effectiveness of using nanoscale zero‐valent iron (nZVI) to immobilise Pb/Zn in two different soils (acidic and calcareous) and the effects of nZVI treatment on soil physico‐chemical and biological properties. Soil samples spiked with Pb(II) or Zn(II) were treated with commercial nZVI suspension at a dose of 20% (28–36 mg Fe(0)/g soil) for 72 h and one month. Sequential extraction procedures showed a significant decrease of Pb/Zn bound to exchangeable and carbonate fractions and an increase of residual fraction after the treatment with nZVI. There were no significant differences in the distribution of Pb/Zn in the soil fractions between the contact times studied; the immobilisation of Pb/Zn with nZVI in the described conditions was stable at least for a month. Better immobilisation results were found for Pb than for Zn. No negative effects on soil physico‐chemical and biological properties were observed. In fact, the application of nZVI stimulated the soil respiration and the dehydrogenase activity in both soils, especially in the case of Pb, probably due to the higher immobilisation percentages. These results suggest that the use of nZVI to remediate polluted soils with Pb or Zn is a promising in situ strategy, and more research is required both in the laboratory and field to investigate the effects of such a treatment to the soil ecosystem.
Abelson phosphorylation of CLASP2 modulates its association with microtubules and actin
Authors: Engel Ulrike , Zhan Yougen , Long Jennifer B. , Boyle Scott N. , Ballif Bryan A. , Dorey Karel , Gygi Steven P. , Koleske Anthony J. , VanVactor David
Published: February 2014

The Abelson (Abl) non‐receptor tyrosine kinase regulates the cytoskeleton during multiple stages of neural development, from neurulation, to the articulation of axons and dendrites, to synapse formation and maintenance. We previously showed that Abl is genetically linked to the microtubule (MT) plus end tracking protein (+TIP) CLASP in Drosophila. Here we show in vertebrate cells that Abl binds to CLASP and phosphorylates it in response to serum or PDGF stimulation. In vitro, Abl phosphorylates CLASP with a Km of 1.89 µM, indicating that CLASP is a bona fide substrate. Abl‐phosphorylated tyrosine residues that we detect in CLASP by mass spectrometry lie within previously mapped F‐actin and MT plus end interaction domains. Using purified proteins, we find that Abl phosphorylation modulates direct binding between purified CLASP2 with both MTs and actin. Consistent with these observations, Abl‐induced phosphorylation of CLASP2 modulates its localization as well as the distribution of F‐actin structures in spinal cord growth cones. Our data suggest that the functional relationship between Abl and CLASP2 is conserved and provides a means to control the CLASP2 association with the cytoskeleton. © 2014 The Authors. Cytoskeleton Published by Wiley Periodicals, Inc.
Computational and Experimental Insight into the Molecular Mechanism of Carboxamide Inhibitors of Succinate‐Ubquinone Oxidoreductase
Authors: Zhu Xiao‐Lei , Xiong Li , Li Hui , Song Xin‐Ya , Liu Jing‐Jing , Yang Guang‐Fu
Published: February 2014

Succinate‐ubiquinone oxidoreductase (SQR, EC 1.3.5.1), also known as mitochondrial respiratory complex II or succinate dehydrogenase (SDH), catalyzes the oxidation of succinate to fumarate as part of the tricarboxylic acid cycle. SQR has been identified as a novel target of a large family of agricultural fungicides. However, the detailed mechanism of action between the fungicides and SQR is still unclear, and the bioactive conformation of fungicides in the SQR binding pocket has not been identified. In this study, the kinetics of porcine SQR inhibition by ten commercial carboxamide fungicides were measured, and noncompetitive inhibition was observed with respect to succinate, DCIP, and cytochrome c, while competitive inhibition was observed with respect to ubiquinone. With the aim to uncover the binding conformation of these fungicides, molecular docking, molecular dynamics simulation, and molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) calculations were then performed. The excellent correlation (r2=0.94) between the calculated (ΔGcal) and experimental (ΔGexp) binding free energies indicates that the obtained docking conformation could be the bioactive conformation. The acid moiety of carboxamide fungicides inserts into the ubiquinone binding site (Q‐site) of SQR, forming van der Waals (vdW) interactions with C_R46, C_S42, B_I218, and B_P169, while the amine moiety extends to the mouth of the Q‐site, forming vdW interactions with C_W35, C_I43, and C_I30. The carbonyl oxygen atom of the carboxamide forms hydrogen bonds with B_W173 and D_Y91. These findings provide valuable information for the design of more potent and specific inhibitors of SQR.
Porphyrin‐Based Design of Bioinspired Multitarget Quadruplex Ligands
Authors: Laguerre Aurélien , Desbois Nicolas , Stefan Loic , Richard Philippe , Gros Claude P. , Monchaud David
Published: February 2014

Secondary nucleic acid structures, such as DNA and RNA quadruplexes, are potential targets for cancer therapies. Ligands that interact with these targets could thus find application as anticancer agents. Synthetic G‐quartets have recently found numerous applications, including use as bioinspired G‐quadruplex ligands. Herein, the design, synthesis and preliminary biophysical evaluation of a new prototype multitarget G‐quadruplex ligand, PNAPorphySQ, are reported, where peptidic nucleic acid guanine (PNAG) was incorporated in the porphyrin‐templated synthetic G‐quartet (PorphySQ). Using fluorescence resonance energy transfer (FRET)‐melting experiments, PorphySQ was shown to possess enhanced quadruplex‐interacting properties thanks to the presence of four positively charged PNAG residues that improve its electrostatic interactions with the binding site of both DNA and RNA quadruplexes (i.e., their negatively charged and accessible G‐quartets), thereby making PNAPorphySQ an interesting prototype of a multitarget ligand. Both the chemical stability and water solubility of PNAPorphySQ are improved over the non‐PNA derivative (PorphySQ), which are desirable properties for drug development, and while improvements remain to be made, this ligand is a promising lead for the further development of multitarget G‐quadruplex ligands.
A fast tumor‐targeting near‐infrared fluorescent probe based on bombesin analog for in vivo tumor imaging
Authors: Chen Haiyan , Wan Shunan , Zhu Fenxia , Wang Chuan , Cui Sisi , Du Changli , Ma Yuxiang , Gu Yueqing
Published: February 2014

Bombesin (BBN), an analog of gastrin‐releasing peptide (GRP), of which the receptors are over‐expressed on various tumor cells, is able to bind to GRP receptor specifically. In this study, a near‐infrared fluorescent dye (MPA) and polyethylene glycol (PEG) were conjugated to BBN analog to form BBN[7–14]–MPA and BBN[7–14]–SA–PEG–MPA. The successful synthesis of the two probes was proved by the characterization via sodium dodecylsulfate–polyacrylamide gel electrophoresis, infrared and optical spectra. Cellular uptakes studies indicated that BBN‐based probes were mediated by gastrin‐releasing peptide receptors (GRPR) on tumor cells and the PEG modified probe had higher affinity. The dynamic distribution and clearance investigations showed that the BBN‐based probes were eliminated by the liver–kidney pathway. Furthermore, both of the BBN‐based probes displayed tumor‐targeting ability in GRPR over‐expressed tumor‐bearing mice. The PEG modified probe exhibited faster and higher tumor targeting capability than BBN[7–14]–MPA. The results implied that BBN[7–14]–SA–PEG–MPA could act as an effective fluorescence probe for tumor imaging. Copyright © 2014 John Wiley & Sons, Ltd.
Quantitation of a spin polarization‐induced nuclear Overhauser effect (SPINOE) between a hyperpolarized 13C‐labeled cell metabolite and water protons
Authors: Marco‐Rius Irene , Bohndiek Sarah E. , Kettunen Mikko I. , Larkin Timothy J. , Basharat Meer , Seeley Colm , Brindle Kevin M.
Published: February 2014

The spin polarization‐induced nuclear Overhauser effect (SPINOE) describes the enhancement of spin polarization of solvent nuclei by the hyperpolarized spins of a solute. In this communication we demonstrate that SPINOEs can be observed between [1,4‐13C2]fumarate, hyperpolarized using the dissolution dynamic nuclear polarization technique, and solvent water protons. We derive a theoretical expression for the expected enhancement and demonstrate that this fits well with experimental measurements. Although the magnitude of the effect is relatively small (around 2% measured here), the SPINOE increases at lower field strengths, so that at clinically relevant magnetic fields (1.5–3 T) it may be possible to track the passage through the circulation of a bolus containing a hyperpolarized 13C‐labeled substrate through the increase in solvent water 1H signal. © 2014 The Authors. Contrast Media & Molecular Imaging published by John Wiley and Sons, Ltd.
Characteristics of individuals with breast cancer rearrangements in BRCA1 and BRCA2
Authors: Jackson Sarah A. , Davis Andrew A. , Li Jun , Yi Nengjun , McCormick Shelley R. , Grant Carly , Fallen Taya , Crawford Beth , Loranger Kate , Litton Jennifer , Arun Banu , Vande Wydeven Kimberly , Sidani Amer , Farmer Katie , Sanders Merideth , Hoskins Kent , Nussbaum Robert , Esserman Laura , Garber Judy E. , Kaklamani Virginia G. ,   the Northwestern Cancer Genetics Group
Published: February 2014

BACKGROUND

Large rearrangements in BRCA1 and BRCA2 occur in a small percentage (< 1%) of patients tested for hereditary breast (BC) and ovarian cancer. It is unclear what factors predict BRACAnalysis Large Rearrangement Test (BART) positivity.

METHODS

Data from 6 centers were included in this analysis. Individuals with negative Comprehensive BRACAnalysis tested for BART were included.

RESULTS

From 1300 individuals, 42 (3.2%) were BART positivity. Factors positively associated with BART positivity were Myriad score, first‐degree relatives with BC, infiltrating BC with ductal carcinoma in situ, younger age at BC diagnosis, estrogen receptor–negative BC for both the first and second BC, and Latin American/Caribbean ethnicity. Presence of unilateral BC was inversely associated with BART positivity. Several analyses were performed on the variables available to find the model that best predicts for BART positivity. The BART predictive model, including first BC, ovarian cancer, primary maternal ancestry being Latin America/Caribbean, number of first‐degree relatives with BC of 1 or more versus 0, and family history of prostate and pancreatic cancer, had good predictive ability with an area under the curve of 0.77.

CONCLUSIONS

Several factors are significantly associated with BART positivity. Among them we have found that Latin American/Caribbean ancestry, Myriad score, first degree relatives with BC, younger age at BC diagnosis, estrogen receptor–negative status of BC, and infiltrating ductal carcinoma with ductal carcinoma in situ features are significantly associated with BART positivity. A BART predictive model may help in a clinical setting. Cancer 2014;120:1557–1564. © 2014 American Cancer Society.
Use of hybrid discrete cellular models for identification of macroscopic nutrient loss in reaction–diffusion models of tissues
Authors: Aristotelous Andreas C. , Haider Mansoor A.
Published: February 2014

Macroscopic models accounting for cellular effects in natural or engineered tissues may involve unknown constitutive terms that are highly dependent on interactions at the scale of individual cells. Hybrid discrete models, which represent cells individually, were used to develop and apply techniques for modeling diffusive nutrient transport and cellular uptake to identify a nonlinear nutrient loss term in a macroscopic reaction–diffusion model of the system. Flexible and robust numerical methods were used, based on discontinuous Galerkin finite elements in space and a Crank–Nicolson temporal discretization. Scales were bridged via averaging operations over a complete set of subdomains yielding data for identification of a macroscopic nutrient loss term that was accurately captured via a fifth‐order polynomial. Accuracy of the identified macroscopic model was demonstrated by direct, quantitative comparisons of the tissue and cellular scale models in terms of three error norms computed on a mesoscale mesh. Copyright © 2014 John Wiley & Sons, Ltd.
A computational study on brain tissue under blast: primary and tertiary blast injuries
Authors: Rezaei A. , Salimi Jazi M. , Karami G. , Ziejewski M.
Published: February 2014

In this paper, a biomechanical study of a human head model exposed to blast shock waves followed by a blunt impact with the surface of the enclosing walls of a confined space is carried out. Under blast, the head may experience primary blast injury (PBI) due to exposure to the shockwaves and tertiary blast injury (TeBI) due to a possible blunt impact. We examine the brain response data in a deformable finite element head model in terms of the inflicted stress/pressure, velocity, and acceleration on the brain for several blast scenarios with different intensities. The data will be compared for open space and confined spaces. Following the initial impact of the shock front in the confined space, one can see the fluctuations in biomechanical data due to wave reflections. Although the severity of the PBI and TeBI is dependent on the situation, for the cases studied here, PBI is considerably more pronounced than TeBI in confined spaces. Copyright © 2014 John Wiley & Sons, Ltd.
ResAna: a resource analysis toolset for (real‐time) JAVA
Authors: Kersten Rody W. J. , van Gastel Bernard E. , Shkaravska Olha , Montenegro Manuel , van Eekelen Marko C. J. D.
Published: February 2014

For real‐time and embedded systems, limiting the consumption of time and memory resources is often an important part of the requirements. Being able to predict bounds on the consumption of such resources during the development process of the code can be of great value. In this paper, we focus mainly on memory‐related bounds. Recent research results have advanced the state of the art of resource consumption analysis. In this paper, we present a toolset that makes it possible to apply these research results in practice for (real‐time) systems enabling JAVA developers to analyse symbolic loop bounds, symbolic bounds on heap size and both symbolic and numeric bounds on stack size. We describe which theoretical additions were needed in order to achieve this. We give an overview of the capabilities of the RESANA (Radboud University Nijmegen, The Netherlands) toolset that is the result of this effort. The toolset can not only perform generally applicable analyses, but it also contains a part of the analysis that is dedicated to the developers' (real‐time) virtual machine, such that the results apply directly to the actual development environment that is used in practice. Copyright © 2013 John Wiley & Sons, Ltd.
Fast construction of nanosecond level snapshots of financial markets
Authors: Gai Jiading , Choi Dong Ju , O'Neal David , Ye Mao , Sinkovits Robert S.
Published: February 2014

The goal of this project is to rapidly construct an order‐by‐order level snapshot of financial markets with nanosecond resolution time stamps. We are particularly interested in understanding the impact of high‐frequency traders on the security, stability, and fairness of these markets. In this paper, we describe our computational approach, the optimizations that were applied to improve the performance of the software by a factor of more than 125×, and the new capabilities that can be enabled using a combination of fast algorithms and XSEDE resources. Copyright © 2014 John Wiley & Sons, Ltd.
Preparation of Pt Nanoclusters with Different Emission Wavelengths and Their Application in Co2+ Detection
Authors: Huang Xin , Aoki Koichi , Ishitobi Hidekazu , Inouye Yasushi
Published: February 2014

Differently colored fluorescent Pt nanoclusters (NCs) are easily prepared using polyethyleneimine as the stabilizing ligand and environmentally friendly L‐ascorbic acid as the reducing agent. The quantum yields of the blue‐ (1:5), green‐ (1:20), and yellow‐emitting (1:25) NCs are 4 %, 11 %, and 7 %, respectively. The fluorescent Pt NCs show excellent photostability and are sensitive to Co2+ ions (with a detection limit of 500 nM).