bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal effects of 2450 MHz microwave exposure near a titanium alloy plate implanted in rabbit limbs
Authors: Ye Dongmei , Xu Yiming , Wang Gang , Feng Xianxuan , Fu Tengfei , Zhang Han , Jiang Lan , Bai Yuehong 
Published: March 2015

AbstractThis study aimed to examine the safety profile of microwave therapy on limbs with metal implants. New Zealand white rabbits were implanted with titanium alloy internal fixation plates. Femurs were exposed to 20, 40, 60, or 80 W of microwave radiation for 30 min (microwave applicator at 2450 MHz), and temperatures of the implants and muscles adjacent to implants were recorded. To evaluate thermal damage, nerves were electrodiagnostically assessed immediately after radiation, and histologic studies performed on nerve and muscle sections. As expected, implant temperature was highest in the exposure field. Temperatures of limbs with titanium alloy implants increased significantly at 60 and 80 W, with a significant decline in the nerve conduction velocity and acute thermal injuries in nerves and muscles adjacent to implants. However, temperature remained unchanged and no adverse effects were observed in nerves and muscles at 20 and 40 W. These findings are inconsistent with the current notion that surgical metal implants in the treatment field are contraindications for microwave therapy. Hence, we believe that a lower dose of continuous wave microwave irradiation is safe for limbs with titanium alloy implants. Bioelectromagnetics. 36:309–318, 2015. © 2015 Wiley Periodicals, Inc.
Validation of a HPLC‐ESI MS/MS method for the determination of clonidine in human plasma and its application in a bioequivalence study in Chinese healthy volunteers
Authors: Zhuang Jialang , Chen Jiangying , Wang Xueding , Pang Yin , Bi Huichang , Huang Lihui , Zeng Guixiong , Liao Xiaoxing , Ma Zhongfu , Chen Xiao , Zhong Guoping , Huang Min , Zhao Xianglan 
Published: March 2015

AbstractA rapid and sensitive liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) method to determine clonidine in human plasma was developed and fully validated. Sample preparation was involved an one‐step extraction with diethyl ether. Donepezil was employed as the internal standard (IS). Chromatographic separation was performed on a Hypersil BDS C18 column (i.d. 2.1 × 50 mm, particle size 3μm) with a mobile phase of methanol–water (containing 0.1% formic acid; 60:40, v/v) at a flow rate of 200 μL/min. The peaks were detected by mass spectrometry using the electrospray ion source in selected reaction monitoring mode. The extraction recovery was 72.53–85.25%. The method was found to be linear in a concentration range of 0.02–6.00 ng/mL and the lower limit of quantification was 0.02 ng/mL. The within‐ and between‐batch precisions at three concentrations were 4.33–16.47 and 7.24–17.24% with accuracies of −2.47–10.91 and 1.86–10.19%, respectively. This validated method was successfully used for a bioequivalence study of two clonidine transdermal patches on healthy volunteers. The results suggested that the test formulation of clonidine patch met the regulatory criterion for bioequivalence to the reference formulation, but a larger sample size should be needed for the estimation of bioequivalence. Copyright © 2015 John Wiley & Sons, Ltd.
Design of an experimental twin‐rotor multi‐input multi‐output system
Authors: Bayrak Alper , Dogan Firat , Tatlicioglu Enver , Ozdemirel Barbaros 
Published: March 2015

ABSTRACTTwin‐rotor multi‐input multi‐output system (TRMS) is a popular experimental setup utilized mostly for development and evaluation of aerovehicle control algorithms. Motivated by its popularity, construction steps of a TRMS setup in an academic setting are presented in this paper. Specifically, design of mechanical and electronic hardware components and development of related computer software are described in detail. Preliminary experiment results are also presented to demonstrate the performance of the system. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:578–586, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21628
Demonstrating students' skills on integrating knowledge of math and engineering in an applied programming course in civil engineering
Authors: Oreta Andres Winston C. , Balili Alden Paul 
Published: March 2015

ABSTRACTInnovative approaches in teaching and learning can be introduced in the classroom using the computer. In a laboratory class on Computer Methods in Civil Engineering at De La Salle University, students develop simple computer software applications and computer‐based games on topics related to civil engineering using Visual Basic. By creating their own software applications, the students demonstrate the student outcomes on application of mathematics, science and engineering in solving engineering problems using modern engineering tools. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:630–637, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21637
Lexical analysis of student research drafts in computing
Authors: González‐López Samuel , López‐López Aurelio 
Published: March 2015

ABSTRACTLexical Richness is a competence that students acquire while advancing in education. This article presents results analyzing lexical richness of drafts of students, in terms of lexical density, variety, and sophistication. A computational model allows reviewing some essential elements in drafts. Results show that there exists a difference in lexical richness between graduate and undergraduate texts, and that sophistication is the measure that best differentiates them. We also report results of a pilot test. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:638–644, 2015; View this article online atwileyonlinelibrary.com/journal/cae; DOI10.1002/cae.21638
Using educational software to enhance the teaching & learning in computer integrated manufacturing: Material requirements planning module
Authors: Cvetić Biljana , Ilić Oliver R. 
Published: March 2015

ABSTRACTThe material requirements planning (MRP) is a traditional topic in operations management and industrial engineering education. This paper presents an application of custom‐made selection procedure of MRP educational software. The results of evaluation from the three generations of students showed that the selected MRP educational software was very useful in acquiring advanced students’ MRP skills. © 2015 Wiley Periodicals, Inc. Comput. Appl. Eng. Educ. Comput Appl Eng Educ 23:682–693, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21641
Palladium‐Catalyzed Direct Arylation of Allylamines with Simple Arenes
Authors: Lei Yichao , Qiu Ruiying , Zhang Lingjuan , Xu Conghui , Pan Yixiao , Qin Xubo , Li Huanrong , Xu Lijin , Deng Yuheng 
Published: March 2015

AbstractThe Pd(OAc)2‐catalyzed direct CH bond olefination of unreactive arenes with allylamines in the presence of AgOAc was developed. A variety of allylamines including β‐substituted substrates underwent smooth coupling reactions with various arenes to give exclusively the terminal arylation products in high yields with excellent regioselectivities and stereoselectivities. The reaction is compatible with a range of functional groups in both coupling partners. The carbonyl group in the allylamine substrates is critical to catalysis, and the high regio‐ and stereocontrol observed is attributed to coordination between the carbonyl O and Pd atoms.
Efficient Biosynthesis of Ethyl (R)‐3‐Hydroxyglutarate through a One‐Pot Bienzymatic Cascade of Halohydrin Dehalogenase and Nitrilase
Authors: Yao Peiyuan , Wang Lei , Yuan Jing , Cheng Lihua , Jia Rongrong , Xie Meixian , Feng Jinhui , Wang Min , Wu Qiaqing , Zhu Dunming 
Published: March 2015

AbstractAn effective one‐pot bienzymatic synthesis of ethyl (R)‐3‐hydroxyglutarate (EHG) from ethyl (S)‐4‐chloro‐3‐hydroxybutyrate (ECHB) was achieved by using recombinant Escherichia coli cells expressing separately or co‐expressing a mutant halohydrin dehalogenase gene from Agrobacterium radiobacter AD1 and a nitrilase gene from Arabidopsis thaliana. The activity of nitrilase was inhibited by high concentration of ECHB and NaCN. Consequently, the one‐pot one‐step process was implemented by fed‐batch of ECHB and NaCN with high accumulative product concentration (up to 0.9 mol L−1). The biotransformation of ECHB to EHG was successfully achieved at 1.2 mol L−1 substrate concentration by a one‐pot two‐step process. As such, this one‐pot bienzymatic transformation should be useful in synthesizing these important optical pure β‐hydroxycarboxylic acids.
Assessments of Surface Coverage after Nanomaterials are Drop Cast onto Electrodes for Electroanalytical Applications
Authors: Chan Ya Yun , Eng Alex Y. S. , Pumera Martin , Webster Richard D. 
Published: March 2015

AbstractThe drop‐casting method for the suspension of nanomaterials on conducting surfaces is a commonly used procedure for evaluating the electrochemical properties of the drop‐cast materials. In this study, we pinpoint a key limitation of the method, which may lead to misinterpretation of the obtained data, especially when evaluating heterogeneous electron‐transfer rates. The electrochemical responses recorded at 1 mm‐diameter copper electrodes modified with porous layers of drop‐cast multiwalled carbon nanotubes (MWCNTs) in 0.1 M Na2SO4 aqueous solutions were examined. Standard amounts of the MWCNTs that are typically used for the drop‐casting procedure (1 mg MWCNT in 1 mL of dimethylformamide) were deposited drop wise on the surface of the copper electrodes. Layers of MWCNTs were progressively built up on the electrode surface by varying the number of drops from 0 to 10. The ability of the MWCNTs to cover and prevent diffusion to the base copper electrode was assessed by performing oxidative cyclic (CV) and linear‐sweep voltammetry (LSV) experiments in the presence of aggressive SO42− supporting electrolyte, where a large oxidative current indicated the occurrence of corroding copper metal. It was demonstrated that a total of 10 drops of the coating solution (equivalent to 640 μg cm−2 of MWCNTs per unit area) was still insufficient in providing complete coverage over the underlying electrode surface (as a corrosion current was still observed), even though considerably lower CNT loadings have been applied in many literature reports. The electrochemical results indicate that, for experiments that utilize the drop‐casting procedure to modify electrode surfaces, it cannot be assumed that the base electrode, nor the pore structure of the coating material, does not significantly contribute to the overall observed voltammetric response.
Rationalising the Geometric Variation between the A and B Monomers in the 1.9 Å Crystal Structure of Photosystem II
Authors: Petrie Simon , Stranger Robert , Pace Ron J. 
Published: March 2015

AbstractDensity functional theory calculations are reported on a set of models of the water‐oxidising complex (WOC) of photosystem II (PSII), exploring structural features revealed in the most recent (1.9 Å resolution) X‐ray crystallographic studies of PSII. Crucially, we find that the variation in the Mn–Mn distances seen between the A and B monomers of this crystal structure can be entirely accounted for, in the low oxidation state (LOS) paradigm, by consideration of the interplay between two hydrogen‐bonding interactions involving proximate amino acid residues with the oxo bridges of the WOC, that is, His337 with O3 (which leads to a general elongation in the Mn–Mn distances between Mn1, Mn2 and Mn3) and Arg357 with O2 (which results in a specific elongation of the Mn2Mn3 distance).
Tuning Coordination in s‐Block Carbazol‐9‐yl Complexes
Authors: Ortu Fabrizio , Moxey Graeme J. , Blake Alexander J. , Lewis William , Kays Deborah L. 
Published: March 2015

Abstract1,3,6,8‐Tetra‐tert‐butylcarbazol‐9‐yl and 1,8‐diaryl‐3,6‐di(tert‐butyl)carbazol‐9‐yl ligands have been utilized in the synthesis of potassium and magnesium complexes. The potassium complexes (1,3,6,8‐tBu4carb)K(THF)4 (1; carb=C12H4N), [(1,8‐Xyl2‐3,6‐tBu2carb)K(THF)]2 (2; Xyl=3,5‐Me2C6H3) and (1,8‐Mes2‐3,6‐tBu2carb)K(THF)2 (3; Mes=2,4,6‐Me3C6H2) were reacted with MgI2 to give the Hauser bases 1,3,6,8‐tBu4carbMgI(THF)2 (4) and 1,8‐Ar2‐3,6‐tBu2carbMgI(THF) (Ar=Xyl 5, Ar=Mes 6). Structural investigations of the potassium and magnesium derivatives highlight significant differences in the coordination motifs, which depend on the nature of the 1‐ and 8‐substituents: 1,8‐di(tert‐butyl)‐substituted ligands gave π‐type compounds (1 and 4), in which the carbazolyl ligand acts as a multi‐hapto donor, with the metal cations positioned below the coordination plane in a half‐sandwich conformation, whereas the use of 1,8‐diaryl substituted ligands gave σ‐type complexes (2 and 6). Space‐filling diagrams and percent buried volume calculations indicated that aryl‐substituted carbazolyl ligands offer a steric cleft better suited to stabilization of low‐coordinate magnesium complexes.
Thermal Conversion of Methane to Formaldehyde Promoted by Gold in AuNbO3+ Cluster Cations
Authors: Wang Li‐Na , Zhou Zhen‐Xun , Li Xiao‐Na , Ma Tong‐Mei , He Sheng‐Gui 
Published: March 2015

AbstractIn addition to generation of a methyl radical, formation of a formaldehyde molecule was observed in the thermal reaction of methane with AuNbO3+ heteronuclear oxide cluster cations. The clusters were prepared by laser ablation and mass‐selected to react with CH4 in an ion‐trap reactor under thermal collision conditions. The reaction was studied by mass spectrometry and DFT calculations. The latter indicated that the gold atom promotes formaldehyde formation through transformation of an AuO bond into an AuNb bond during the reaction.
Formal Total Synthesis of Aliskiren
Authors: Peters Byron K. , Liu Jianguo , Margarita Cristiana , Andersson Pher G. 
Published: March 2015

AbstractThe efficient and selective formal total synthesis of aliskiren is described. Aliskiren, a renin inhibitor drug, has received considerable attention, primarily because it is the first of the renin inhibitor drugs to be approved by the FDA. Herein, the formal synthesis of aliskiren by iridium‐catalyzed asymmetric hydrogenation of two allylic alcohol fragments is reported. Screening a number of N,P‐ligated iridium catalysts yielded two catalysts that gave the highest enantioselectivity in the hydrogenation, which gave the saturated alcohols in 97 and 93 % ee. In only four steps after hydrogenation, the fragments were combined by using the Julia–Kocienski reaction to produce late‐stage intermediate in an overall yield of 18 %.
Controlled Formation of Fluorescent Metalloporphyrin‐Containing Coordination Polymer Particles from Seed Structures by Designed Shape‐Transformation Reactions
Authors: Sun Yu , Li Xiaopeng , Caravella Alessio , Gao Rongke 
Published: March 2015

AbstractHerein, nanorod structures and four‐leaf clover structures of fluorescent zinc 5,10,15,20‐tetra(4‐pyridyl)‐21H,23H‐porphine (ZnTPyP)‐containing coordination polymer particles (CPPs) were first synthesized by a bottom‐up strategy assisted by surfactants and then employed as seed structures for further shape‐transformation reactions. We have successfully designed the morphological transformation for different dimensions, achieving the controlled formation of octahedron structures at both the nanometer scale and micrometer scale from the seed structures. Our approach illustrates a new method to design and synthesize metalloporphyrin‐containing CPPs in a systematic and controllable manner.
Photocurrent Generation through Charge‐Transfer Processes in Noncovalent Perylenediimide/DNA Complexes
Authors: Takada Tadao , Ido Misa , Ashida Akane , Nakamura Mitsunobu , Fujitsuka Mamoru , Kawai Kiyohiko , Majima Tetsuro , Yamana Kazushige 
Published: March 2015

AbstractThe charge‐transfer process in noncovalent perylenediimide (PDI)/DNA complexes has been investigated by using nanosecond laser flash photolysis (LFP) and photocurrent measurements. The PDI/DNA complexes were prepared by inclusion of cationic PDI molecules into the artificial cavities created inside DNA. The LFP experiments showed that placement of the PDI chromophore at a specific site and included within the base stack of DNA led to the efficient generation of a charge‐separated state with a long lifetime by photoexcitation. When two PDI chromophores were separately placed at different positions in DNA, the yield of the charge‐separated state with a long lifetime was dependent upon the number of A–T base pairs between the PDIs, which was explained by electron hopping from one PDI to another. Photocurrent generation of the DNA‐modified electrodes with the complex was also dependent upon the arrangement of the PDI chromophores. A good correlation was obtained between observed charge separation and photocurrent generation on the PDI/DNA‐modified electrodes, which demonstrated the importance of the defined arrangement and assembly of organic chromophores in DNA for efficient charge separation and transfer in multichromophore arrays.
Synthesis and Biological Evaluation of RGD Peptidomimetic–Paclitaxel Conjugates Bearing Lysosomally Cleavable Linkers
Authors: Dal Corso Alberto , Caruso Michele , Belvisi Laura , Arosio Daniela , Piarulli Umberto , Albanese Clara , Gasparri Fabio , Marsiglio Aurelio , Sola Francesco , Troiani Sonia , Valsasina Barbara , Pignataro Luca , Donati Daniele , Gennari Cesare 
Published: March 2015

AbstractTwo small‐molecule–drug conjugates (SMDCs, 6 and 7) featuring lysosomally cleavable linkers (namely the Val–Ala and Phe–Lys peptide sequences) were synthesized by conjugation of the αvβ3‐integrin ligand cyclo[DKP–RGD]‐CH2NH2 (2) to the anticancer drug paclitaxel (PTX). A third cyclo[DKP–RGD]–PTX conjugate with a nonpeptide “uncleavable” linker (8) was also synthesized to be tested as a negative control. These three SMDCs were able to inhibit biotinylated vitronectin binding to the purified αVβ3‐integrin receptor at nanomolar concentrations and showed good stability at pH 7.4 and pH 5.5. Cleavage of the two peptide linkers was observed in the presence of lysosomal enzymes, whereas conjugate 8, which possesses a nonpeptide “uncleavable” linker, remained intact under these conditions. The antiproliferative activities of the conjugates were evaluated against two isogenic cell lines expressing the integrin receptor at different levels: the acute lymphoblastic leukemia cell line CCRF‐CEM (αVβ3−) and its subclone CCRF‐CEM αVβ3 (αVβ3+). Fairly effective integrin targeting was displayed by the cyclo[DKP–RGD]–Val–Ala–PTX conjugate (6), which was found to differentially inhibit proliferation in antigen‐positive CCRF‐CEM αVβ3 versus antigen‐negative isogenic CCRF‐CEM cells. The total lack of activity displayed by the “uncleavable” cyclo[DKP–RGD]–PTX conjugate (8) clearly demonstrates the importance of the peptide linker for achieving the selective release of the cytotoxic payload.
Enantioselective Template‐Directed [2+2] Photocycloadditions of Isoquinolones: Scope, Mechanism and Synthetic Applications
Authors: Coote Susannah C. , Pöthig Alexander , Bach Thorsten 
Published: March 2015

AbstractA strategy for the enantioselective [2+2] photocycloaddition of isoquinolones with alkenes is presented, in which the formation of a supramolecular complex between a chiral template and the substrate ensures high enantioface differentiation by shielding one face of the substrate. Fifteen different electron‐deficient alkenes and ten different substituted isoquinolones undergo efficient photocycloaddition, yielding the cyclobutane products in excellent yields and with outstanding regio‐, diastereo‐ and enantioselectivities (up to 99 % ee). The mechanism of the reaction is investigated by means of triplet sensitization/quenching and radical clock experiments, the results of which are consistent with the involvement of a triplet excited state and a 1,4‐biradical intermediate. The variety of functionalized cyclobutanes obtained using this approach can be further increased by straightforward synthetic transformations of the photoadducts, allowing rapid access to libraries of compounds for various applications.
Bioinspired Hierarchical Nanotubular Titania Immobilized with Platinum Nanoparticles for Photocatalytic Hydrogen Production
Authors: Liu Xiaoyan , Li Jiao , Zhang Yiming , Huang Jianguo 
Published: March 2015

AbstractA bioinspired nanocomposite composed of platinum nanoparticles and nanotubular titania was fabricated in which the titania matter was templated by natural cellulose substance. The composite possesses three‐ dimensional hierarchical structures, and ultrafine metallic platinum particles with sizes of ca. 2 nm were immobilized uniformly on the surfaces of the titania nanotubes. Such a nanocomposite with 1.06 wt % of platinum content shows the optimal photocatalytic hydrogen production activity from water splitting of 16.44 mmol h−1 g−1, and excessive loading of platinum results in poorer photocatalytic performance. The structural integrity of the nanocomposite upon cyclic water‐splitting processes results in its sufficient photocatalytic stability.
Breast cancer risk after full‐term pregnancies among African women from Nigeria, Cameroon, and Uganda
Authors: Sighoko Dominique , Ogundiran Temidayo , Ademola Adeyinka , Adebamowo Clement , Chen Lin , Odedina Stella , Anetor Imaria , Ndom Paul , Gakwaya Antony , Ojengbede Oladosu , Huo Dezheng , Olopade Olufunmilayo I. 
Published: March 2015

BACKGROUNDThe breast cancer (BC) risk profiles of African women differ significantly from those of women of European ancestry. African women are younger at the age of onset and tend to have high parity. The purpose of this study was to examine the relationship between full‐term pregnancy (FTP) and the risk of BC.METHODSA case‐control study was conducted among 1995 women with invasive BC and 2631 controls in Nigeria, Cameroon, and Uganda. Odds ratios (ORs) for individual ages at FTP according to the time since delivery were calculated and adjusted for confounders. A fitted spline model was used to assess the impact of the number of pregnancies on BC risk.RESULTSIn comparison with a nulliparous woman, a parous woman with her first FTP at 20 years showed an OR of 0.76 (95% confidence interval [CI], 0.57‐0.99) for developing BC in the following 5 years. Ten years later, this risk was 0.76 (95% CI, 0.58‐0.99) and 0.76 (95% CI, 0.58‐0.98) for women aged 25 and 30 years, respectively. Similarly, a parous woman with 1 pregnancy had an OR of 0.69 (95% CI, 0.49‐0.96), whereas the OR was 0.66 (95% CI, 0.48‐0.91) with 2 or 5 pregnancies and 0.67 (95% CI, 0.47‐0.94) with 6 pregnancies in comparison with nulliparous women.CONCLUSIONSIn contrast to studies in women of European ancestry, this study showed no transient increase in the risk of developing BC after FTP among African women. Further studies are needed to examine the impact of reproductive factors on early‐onset BC in African women. Cancer 2015;121:2237–2243. © 2015 American Cancer Society.