bluuebunny/crossref_metadata_2025 huggingface dataset:
Triple‐Layer Structured Composite Separator Membranes with Dual Pore Structures and Improved Interfacial Contact for Sustainable Dye‐Sensitized Solar Cells
Authors: Hong Soo Bong , Park So Hyun , Kim Jeong‐Hoon , Lee Sang‐Young , Kwon Young Soo , Park Taiho , Kang Phil‐Hyun , Hong Sung Chul
Published: April 2014

A composite separator membrane (CSM) with an A/B/A type layered structure, composed of a microporous electrolyte‐philic poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF‐HFP) gel layer (A) and a submicrometer porous polyethylene (PE) or a macroporous poly(ethylene terephthalate) (PET) non‐woven matrix (B), is introduced in a dye‐sensitized solar cell (DSSC). Commercially available PE and PET separator membranes (SMs) act as matrices that provide mechanical stability to the DSSC and permanent pore structures for facilitated ion transport. PVdF‐HFP is used as a microporous gelator for improved interfacial contact between the solid SM and the electrodes. The PVdF‐HFP gel impedes the charge recombination process between electron and I3
− at the TiO2/electrolyte interface, resulting in improved electron lifetimes. The DSSC assembled with the CSM exhibits high initial solar energy conversion efficiency (η, 6.1%) and stable η values over 1400 h, demonstrating good long term stability. The behaviors of the DSSC are attributed to the synergistic factors of the CSM, such as improved ion conductivity, electrolyte affinity, electrolyte retention capability, effective interfacial contact, and plausible passivation of the dyes. This study demonstrates a practical combination of short‐ and long‐term DSSC performance through the introduction of the CSM.
Remarkable Enhancement of the Rate of the Intramolecular Morita–Baylis–Hillman Reaction by the Combination of a Nucleophilic Catalyst and 1,3‐Diphenyl‐2‐thiourea
Authors: Mandai Hiroki , Shimowaki Keita , Mitsudo Koichi , Suga Seiji
Published: April 2014

The rate of the intramolecular Morita‐Baylis–Hillman (MBH) reaction is remarkably enhanced by the combination of catalytic amounts of a nucleophilic catalyst (4‐dimethylaminopyridine (DMAP), 4‐pyrrolidinopyridine (PPY), or PBu3) and 1,3‐diphenyl‐2‐thiourea, and the desired MBH adducts are obtained in good to high yields within a few hours.
Phosphine‐Initiated General‐Base‐Catalyzed Quinolone Synthesis
Authors: Khong San , Kwon Ohyun
Published: April 2014

Phosphinocatalysis provides a new approach toward 3‐substituted‐4‐quinolones. A simple procedure, which uses Ph3P as an inexpensive catalyst and S‐phenyl 2‐(N‐tosylamido)benzothioates and activated alkynes as starting materials, provides direct access to several 3‐aroyl‐4‐quinolones and methyl 4‐quinolone‐3‐carboxylate esters. The reaction presumably occurs through general base catalysis, with the initial addition of Ph3P to the activated alkyne generating the phosphonium enoate zwitterion, which acts as the strong base that initiates the reaction.
Heterolytic Cleavage of Hydrogen by an Iron Hydrogenase Model: An Fe‐H⋅⋅⋅H‐N Dihydrogen Bond Characterized by Neutron Diffraction
Authors: Liu Tianbiao , Wang Xiaoping , Hoffmann Christina , DuBois Daniel L. , Bullock R. Morris
Published: April 2014

Hydrogenase enzymes in nature use hydrogen as a fuel, but the heterolytic cleavage of HH bonds cannot be readily observed in enzymes. Here we show that an iron complex with pendant amines in the diphosphine ligand cleaves hydrogen heterolytically. The product has a strong Fe‐H⋅⋅⋅H‐N dihydrogen bond. The structure was determined by single‐crystal neutron diffraction, and has a remarkably short H⋅⋅⋅H distance of 1.489(10) Å between the protic N‐Hδ+ and hydridic Fe‐Hδ− part. The structural data for [CpFeH(PtBu2NtBu2H)]+ provide a glimpse of how the HH bond is oxidized or generated in hydrogenase enzymes. These results now provide a full picture for the first time, illustrating structures and reactivity of the dihydrogen complex and the product of the heterolytic cleavage of H2 in a functional model of the active site of the [FeFe] hydrogenase enzyme.
Polymeric Schiff Bases as Low‐Voltage Redox Centers for Sodium‐Ion Batteries
Authors: Castillo‐Martínez Elizabeth , Carretero‐González Javier , Armand Michel
Published: April 2014

The redox entity comprising two Schiff base groups attached to a phenyl ring (NCHArHCN) is reported to be active for sodium‐ion storage (Ar=aromatic group). Electroactive polymeric Schiff bases were produced by reaction between non‐conjugated aliphatic or conjugated aromatic diamine block with terephthalaldehyde unit. Crystalline polymeric Schiff bases are able to electrochemically store more than one sodium atom per azomethine group at potentials between 0 and 1.5 V versus Na+/Na. The redox potential can be tuned through conjugation of the polymeric chain and by electron injection from donor substituents in the aromatic rings. Reversible capacities of up to 350 mA h g−1 are achieved when the carbon mixture is optimized with Ketjen Black. Interestingly, the “reverse” configuration (CHNArNHC) is not electrochemically active, though isoelectronic.
Coordination Adducts of Niobium(V) and Tantalum(V) Azide M(N3)5 (M=Nb, Ta) with Nitrogen Donor Ligands and their Self‐Ionization
Authors: Haiges Ralf , Deokar Piyush , Christe Karl O.
Published: April 2014

Several new donor–acceptor adducts of niobium and tantalum pentaazide with N‐donor ligands have been prepared from the pentafluorides by fluoride–azide exchange with Me3SiN3 in the presence of the corresponding donor ligand. With 2,2′‐bipyridine and 1,10‐phenanthroline, the self‐ionization products [MF4(2,2′‐bipy)2]+[M(N3)6]−, [M(N3)4(2,2′‐bipy)2]+[M(N3)6]− and [M(N3)4(1,10‐phen)2]+[M(N3)6]− were obtained. With the donor ligands 3,3′‐bipyridine and 4,4′‐bipyridine the neutral pentaazide adducts (M(N3)5)2⋅L (M=Nb, Ta; L=3,3′‐bipy, 4,4′‐bipy) were formed.
Highly Diastereo‐ and Enantioselective Silver‐Catalyzed Double [3+2] Cyclization of α‐Imino Esters with Isocyanoacetate
Authors: Shao Pan‐Lin , Liao Jia‐Yu , Ho Yee Ann , Zhao Yu
Published: April 2014

Presented herein is a new complexity‐generating method in which both functionalities of α‐imino esters undergo stereoselective cyclization with isocyanoacetates to produce directly linked oxazole‐imidazolines, which can be transformed into highly functionalized α,β‐diamino esters and imidazolinium salts in high diastereo‐ and enantiopurity.
Gold‐Catalyzed 1,2‐Oxoarylations of Nitriles with Pyridine‐Derived Oxides
Authors: Karad Somnath Narayan , Liu Rai‐Shung
Published: April 2014

We report the first success in the gold‐catalyzed oxoarylations of nitriles with pyridine‐derived N‐oxides using gold carbenes as initiators. These oxoarylations were also achieved satisfactorily in intermolecular three‐component oxidations, including diverse alkenyldiazo esters, nitriles, and pyridine‐based oxides.
Remote Enantioselective Friedel–Crafts Alkylations of Furans through HOMO Activation
Authors: Li Jun‐Long , Yue Cai‐Zhen , Chen Peng‐Qiao , Xiao You‐Cai , Chen Ying‐Chun
Published: April 2014

Catalytic asymmetric Friedel–Crafts alkylation is a powerful protocol for constructing a chiral C(sp2)C(sp3) bond. Most previous examples rely on LUMO activation of the electrophiles using chiral catalysts with subsequent attack by electron‐rich arenes. Presented herein is an alternative strategy in which the HOMO of the aromatic π system of 2‐furfuryl ketones is raised through the formation of a formal trienamine species using a chiral primary amine. Exclusive regioselective alkylation at the 5‐position occurred with alkylidenemalononitriles, and high reactivity and excellent enantioselectivity (up to 95 % ee) was obtained by this remote activation.
Pattern‐Based Detection of Toxic Metals in Surface Water with DNA Polyfluorophores
Authors: Yuen Lik Hang , Franzini Raphael M. , Wang Shenliang , Crisalli Pete , Singh Vijay , Jiang Wei , Kool Eric T.
Published: April 2014

Heavy metal contamination of water can be toxic to humans and wildlife; thus the development of methods to detect this contamination is of high importance. Here we describe the design and application of DNA‐based fluorescent chemosensors on microbeads to differentiate eight toxic metal ions in water. We developed and synthesized four fluorescent 2′‐deoxyribosides of metal‐binding ligands. A tetramer‐length oligodeoxy‐fluoroside (ODF) library of 6561 members was constructed and screened for sequences responsive to metal ions, of which seven sequences were selected. Statistical analysis of the response patterns showed successful differentiation of the analytes at concentrations as low as 100 nM. Sensors were able to classify water samples from 13 varied sites and quantify metal contamination in unknown specimens. The results demonstrate the practical potential of bead‐based ODF chemosensors to analyze heavy metal contamination in water samples by a simple and inexpensive optical method.
Study on the anti‐sulfur‐poisoning characteristics of platinum–acetylide–phosphine complexes as catalysts for hydrosilylation reactions
Authors: Li Jiayun , Niu Congbai , Peng Jiajian , Deng Yuan , Zhang Guodong , Bai Ying , Ma Chao , Xiao Wenjun , Lai Guoqiao
Published: April 2014

A series of platinum–acetylide–phosphine complexes were synthesized and their anti‐sulfur‐poisoning characteristics investigated. In comparison with Speier's and Karstedt's catalysts, the platinum–acetylide–phosphine complexes exhibited both higher catalytic activity and selectivity for the β‐adduct for the hydrosilylation reactions under the same conditions. Furthermore, the complexes also exhibited a strong ability to resist to sulfur‐poisoning. This indicated that the alkyne ligands containing the silyl group had a strong impact on the hydrosilylation reaction. Copyright © 2014 John Wiley & Sons, Ltd.
Artificial liver support systems: a patient‐device model
Authors: Annesni Maria Cristina , Piemonte Vincenzo , Turchetti Luca
Published: April 2014

Many efforts have been carried out for over 40 years in the attempt to design liver support devices suitable for a temporary clinical use, either to bridge the patients to liver transplantation or to help to keep them alive until the recovery of native liver function. Really, a deeper knowledge of the physicochemical basis of their functioning is essential to ‘engineer’ these devices, that is, to design new artificial liver devices, to optimize the existing ones and to taylor the patient treatment on his clinical state. In this framework, this work has been finalized to obtain a mathematical model of the whole patient‐artificial device system as useful tool for a chemical engineering point of view analysis. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Elaboration of small‐diameter vascular prostheses—Selection of appropriate sterilisation method
Authors: Chrzanowska Olga , Struszczyk Marcin Henryk , Krucinska Izabella , Puchalski Michał , Herczyńska Lucyna , Chrzanowski Michał
Published: April 2014

The aim of study is the elaboration of semi‐biodegradable, multilayered tubular structures as substitutes for the reconstruction of small diameter vascular prostheses (<6 mm). The inert external layer of the prostheses will be fabricated via the melt electrospinning of poly (l‐lactide‐co‐glycolide) (PLGA). The middle layer will be constructed from polypropylene (PP); the first prototype will be produced via melt electrospinning and the second using the melt blowing technique. The general aim of this stage of the research is the selection of a sterilisation technique that is appropriate for semi‐biodegradable, multilayered tubular structures. For this purpose, single tubular structures created via the melt electrospinning of PLGA or PP and melt blown tubular structures of PP were elaborated. The influence of steam, ethylene‐oxide (EO), and radiation sterilisation techniques on the elaborated microstructure of tubular structures was analyzed during this study. The effect of each sterilisation technique was evaluated using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy analysis (SEM/EDS). The changes in average molecular weight (Mw) and crystallinity index (CI) of the PLGA tubular structures after EO and steam sterilisation were evaluated. The EO and steam sterilisation resulted in the complete destruction of PLGA tubular structures. Only the radiation sterilisation (accelerated electrons) did not influence on PLGA tubular structures morphology as well as thermal and chemical properties. FTIR and SEM/EDS analysis indicated that no changes in the chemical properties of PP tubular structures after each sterilisation occurred. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40812.
Prenatal Anti‐Ro Antibody Exposure, Congenital Complete Atrioventricular Heart Block, and High‐Dose Steroid Therapy: Impact on Neurocognitive Outcome in School‐Age Children
Authors: Kelly E. N. , Sananes R. , Chiu‐Man C. , Silverman E. D. , Jaeggi E.
Published: April 2014

Objective

To determine the impact of prenatal exposure to maternal anti‐Ro antibodies, slow fetal heart rate, and/or prolonged dexamethasone therapy for immune‐mediated congenital atrioventricular heart block (CAVB) on the cognitive and academic performance of these children at school age.

Methods

We performed a prospective, blinded assessment of the cognitive functioning of 3 cohorts of children ages 6–16 years with in utero exposure to maternal anti‐Ro antibodies in the following groups: no CAVB and no prenatal dexamethasone treatment (n = 14), CAVB without prenatal treatment (n = 10), and CAVB with prenatal dexamethasone treatment (n = 16). Domains assessed included intelligence, visual perceptual and visual motor skills, auditory and visual attention, verbal learning and memory, visual memory, executive function, and behavior.

Results

All cohorts scored within the normal range and were not significantly different in terms of intelligence scores, verbal comprehension, perceptional reasoning, working memory, and processing speed. For children with CAVB who were treated prenatally, there were no significant associations between the neurocognitive function scores, the minimal fetal heart rate (range 47–80 beats per minute), and either the duration (range 2–15 weeks) or dosage (range 56–824 mg) of dexamethasone therapy.

Conclusion

CAVB and transplacental treatment with dexamethasone was not associated with neurocognitive impairment in school‐age children. Larger numbers of children are needed to validate our observation, and assessment of other cognitive abilities is warranted.
Fabrication of Macroporous Films with Closed Honeycomb‐Like Pores from Exponentially Growing Layer‐by‐Layer Assembled Polyelectrolyte Multilayers
Authors: Chen Xiaoling , Sun Junqi
Published: April 2014

We report an innovative method for the fabrication of macroporous films with closed honeycomb‐like pores of several micrometers by post‐treatment of micrometer‐thick poly(acrylic acid) (PAA)/poly(allylamine hydrochloride) (PAH) films. The precursor PAA/PAH films are fabricated by exponential layer‐by‐layer assembly of PAA and PAH, which produces PAA/PAH films with highly interpenetrated structures. We disclose that the high mobility of PAA and PAH, which originates from the highly interpenetrated film structures, allows a large‐scale phase separation to take place upon post‐treatment to produce micrometer‐sized honeycomb pores. These macroporous PAA/PAH films can be conveniently released from substrates to produce free‐standing films with satisfactory mechanical stability.
Diketopyrrolopyrrole J‐Aggregates Formed by Self‐Organization with DNA
Authors: Tsuto Koji , Nakamura Mitsunobu , Takada Tadao , Yamana Kazushige
Published: April 2014

Bis(2‐thienyl)diketopyrrolopyrrole with two ZnII‐cyclens (ZnCyc‐DPP) was designed and synthesized to evaluate the selective binding of ZnII‐cyclen with thymine base in single‐strand DNA as a tool for the construction of a highly ordered multichromophore system on DNAs. Through UV/Vis titrations, gel filtration chromatography, and circular dichroism spectroscopy, ZnCyc‐DPP formed J‐type DPP aggregates with oligo‐dTn DNAs. The DPP aggregates absorbed on a gold electrode exhibited good photocurrent responses. The present results show that binding ZnII‐cyclen–chromophore conjugates and thymine bases together is a powerful tool for preparing DNA‐templated multichromophoric systems with specific functions.
Are Urinary Porphyrins a Valid Diagnostic Biomarker of Autism Spectrum Disorder?
Authors: Shandley Kerrie , Austin David W. , Bhowmik Jahar L.
Published: April 2014

A fundamental challenge to the timely diagnosis of Autism Spectrum Disorder (ASD) is the reliance on the observation of a set of aberrant behavior. Consequently, the diagnostic process requires that the child reach an age where the behaviors would typically be exhibited. The identification of a reliable biological marker (biomarker) could be of considerable benefit to the diagnostic process. As a diagnostic biomarker, porphyrins present an attractive prospect as previous studies have reported consistent findings of children with ASD showing significant elevations in porphyrin levels in contrast to controls. Furthermore, there is some evidence that ASD severity may be associated with porphyrins, which would be a valuable characteristic of any ASD biomarker. Importantly, for practical use, porphyrins can be tested non‐invasively via a sample of urine. The present study sought to investigate whether porphyrin profiles can reliably be used to (a) differentiate ASD cases from healthy controls; and (b) predict ASD severity. The study compared the porphyrin levels of three groups of children aged 2–6 years: Group 1—children diagnosed with ASD (n = 70); Group 2—healthy, normally developing siblings of children diagnosed with ASD (n = 36); and Group 3—healthy, normally developing children with no known blood relative diagnosed with ASD (n = 54). The results of logistic regression analyses failed to find support for the hypotheses that porphyrin levels could be used as a valid tool to detect ASD cases or predict severity. Autism Res 2014, 7: 535–542. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.
Survey of the literature on mechanoluminescence from 1605 to 2013
Authors: Jha P. , Chandra B. P.
Published: April 2014

Mechanoluminescence (ML) is a type of luminescence induced by any mechanical action on solids. The light emissions induced by elastic deformation, plastic deformation and fracture of solids are called elastico ML (EML), plastico ML (PML) and fracto ML (FML), respectively. Whereas nearly 50% of all organic molecular solids and inorganic salts exhibit FML, only a few solids exhibit EML and PML. The EML and FML of certain solids are so intense that they can be seen during daylight with the naked eye. Mechanolumnescence has a great potential for use in different types of mechano‐optical devices such as stress sensors, damage sensors, impact sensors, fracture sensors and safety management monitoring systems. This article reports a survey of the literature from 1605 to 2013. Mechanoluminescence is studied by physicists, chemists, material scientists, geologists, medical scientists, engineers and technologists, among others and researchers will certainly benefit from the literature survey on ML given here. In addition, the field of mechanoluminescence may attract the interest of many new researchers. Copyright © 2014 John Wiley & Sons, Ltd.
Binding characteristics and interactive region of 2‐phenylpyrazolo[1,5‐c]quinazoline with DNA
Authors: Song Yonghai , Zhong Dandan , Luo Jinhui , Tan Hongliang , Chen Shouhui , Li Ping , Wang Li , Wang Tao
Published: April 2014

The interaction between 2‐phenylpyrazolo[1,5‐c]quinazoline (PQ) and DNA under physiological conditions was investigated using multi‐spectroscopic techniques, atomic force microscopy and gel electrophoresis. The thermodynamic parameters were estimated and were discussed in detail. The results of fluorescence‐quenching experiments indicated that the main interactive force between PQ and DNA was a hydrophobic interaction and that it was a static quenching process. Potassium iodide and single‐strand (ss)DNA quenching studies, together with circular dichroism spectra implied groove binding of PQ with DNA. Atomic force microscopy and gel electrophoresis experiments suggested that there were no major conformational changes in DNA upon interaction with PQ. In addition, UV/vis absorption titration of DNA bases confirmed that PQ bound with DNA mainly through a minor groove interaction and preferentially interacted with adenine and thymine. We anticipate that this work will provide useful information for the application of quinazoline derivatives in the fields of medicinal and pharmaceutical chemistry. Copyright © 2014 John Wiley & Sons, Ltd.
Outcomes of routine ilioinguinal lymph node dissection for palpable inguinal melanoma nodal metastasis
Authors: Glover A R , Allan C P , Wilkinson M J , Strauss D C , Thomas J M , Hayes A J
Published: April 2014

Background

Patients who present with palpable inguinal melanoma nodal metastasis have two surgical options: inguinal or ilioinguinal lymph node dissection. Indications for either operation remain controversial. This study examined survival and recurrence outcomes following ilioinguinal dissection for patients with palpable inguinal nodal metastasis, and assessed the incidence and preoperative predictors of pelvic nodal metastasis.

Methods

This was a retrospective clinicopathological analysis of consecutive surgical patients with stage III malignant melanoma. All patients underwent a standardized ilioinguinal dissection at a specialist tertiary oncology hospital over a 12-year period (1998–2010).

Results

Some 38·9 per cent of 113 patients had metastatic pelvic nodes. Over a median follow-up of 31 months, the 5-year overall survival rate was 28 per cent for patients with metastatic inguinal and pelvic nodes, and 51 per cent for those with inguinal nodal metastasis only (P = 0·002). The nodal basin control rate was 88·5 per cent. Despite no evidence of pelvic node involvement on preoperative computed tomography (CT), six patients (5·3 per cent) with a single metastatic inguinal lymph node had metastatic pelvic lymph nodes. Logistic regression analysis showed that the number of metastatic inguinal nodes (odds ratio 1·56; P = 0·021) and suspicious CT findings (odds ratio 9·89; P = 0·001) were both significantly associated with metastatic pelvic nodes. The specificity of CT was good (89·2 per cent) in detecting metastatic pelvic nodes, but the sensitivity was limited (57·9 per cent).

Conclusion

Metastatic pelvic nodes are common when palpable metastatic inguinal nodes are present. Long-term survival can be achieved following their resection by ilioinguinal dissection. As metastatic pelvic nodes cannot be diagnosed reliably by preoperative CT, patients presenting with palpable inguinal nodal metastasis should be considered for ilioinguinal dissection.
Bright Coppertunities: Multinuclear CuI Complexes with N–P Ligands and Their Applications
Authors: Wallesch Manuela , Volz Daniel , Zink Daniel M. , Schepers Ute , Nieger Martin , Baumann Thomas , Bräse Stefan
Published: April 2014

Easy come, easy go: the great structural diversity of CuI complexes is an ambivalent trait. Apart from the well‐known catalytic properties of CuI, a great number of potent luminescent complexes have been found in the last ten years featuring a plethora of structural motifs. The downside of this variety is the undesired formation of other species upon processing. In here, strategies to avoid this behavior are presented: Only one favorable structural unit often exists for multinuclear CuI complexes with bridging ligands. In addition, these complexes exhibit favorable photophysical properties due to cooperative effects of the metal halide core. Furthermore, we demonstrate the broad range of applications of emitting CuI compounds.
SalenZn‐bridged D‐π‐A Dyes For Dye‐Sensitized Solar Cells
Authors: Jia Yongjian , Gou Faliang , Fang Ran , Jing Huanwang , Zhu Zhenping
Published: April 2014

A series of SalenZn based dyes with triphenylamine derivatives as the donor, benzoic acid as the acceptor, and coplanar Salen complexes as the spacer have been designed and synthesized for dye‐sensitized solar cells. The absorption, electrochemical, and photovoltaic properties for all sensitizers have been systematically investigated. When the tail length of the alkyl substituents is increased from C‐0 to C‐8 on the donor part, the efficiency of its DSSC augments evidently. It is found that the incorporation of bis‐carboxyl groups instead of the single carboxyl group as anchoring groups induces a remarkable enhancement of the electron injection efficiency from the excited dyes to the TiO2 semiconductor and generates higher electron density and voltage.
[2]Pseudorotaxanes Based on Naphtho‐21‐crown‐7 and Secondary Dialkylammonium Salts: Remarkably Improved Association Constants Among Four Threaded Structures
Authors: Zhou Qizhong , Luo Yan , Jiang Huajiang , Ye Yuyuan , Zhang Quan , Dai Guoliang , Chen Rener
Published: April 2014

This research article is focused on the recognition interaction of a new host naphtho‐21‐crown‐7 and four secondary dialkylammonium salts. In acetone, they can form 1:1 host‐guest complexes which belong to slow‐exchange systems. We also found the differences of binding affinity and binding selectivity between the host and its complementary guest moieties, which could be ascribed to the aromatic π‐π stacking effect and the acidity increase of N‐methylene and ammonium hydrogens due to the increasing electron withdrawing ability from butyl to methoxyphenyl to phenyl to p‐cyanophenyl substituents in the recognition motif.
Enatioselective Chalcogeno‐Baylis‐Hillman Reaction of Arylaldehydes with MVK and Acrylates Catalyzed by Chiral Thiepin‐TiCl4 Complex
Authors: Yin Yan , Sun Guofeng , Zhang Heng , Zhou Hong , Wu Fanhong
Published: April 2014

In a rational chiral molecular design of chalcogenides, optically active thiepin with C2‐symmetric chirality was synthesized from commercially available thiophene. Then enatioselective Chalcogeno‐Baylis‐Hillman reactions of arylaldehydes with methyl vinyl ketone (MVK) and acrylates were investigated in the presence of thiepin‐Lewis acid complex. Finally, up to 64% ee was achieved in the presence of 0.2 equiv. of (S)‐thiepin at 20°C.
Ethynylene‐Linked Oligomers Based on Benzodithiophene: Synthesis and Photoelectric Properties
Authors: Jiang Songyang , Ma Yuwen , Wang Yingyi , Wang Chengyun , Shen Yongjia
Published: April 2014

Two conjugated ethynyl‐linked oligomers, oligo(benzodithiophene‐ethynylene‐benzothiadiazole) (O1) and oligo(benzodithiophene‐ethynylene‐carbazole) (O2), were synthesized by Sonogashira coupling reaction. Their degrees of polymerization were 7 and 10, respectively. Their photophysical and electrochemical properties were investigated. O1 exhibitd two strong absorption bands at 404 nm and 483 nm, and O2 at 401 nm and 429 nm. The results of UV‐Vis, cyclic voltammetry (CV) and theoretical calculations showed that O1 has a narrower band gap than O2. The conductivities of O1 and O2 were 1.05×10−15 and 6.98×10−16 S/cm, respectively, and would increase to 1.23×10−10 and 1.05×10−10 S/cm after doping with iodine.
An [Fe‐Fe]‐Hydrogenase Mimic Immobilized on MCM‐41 for the Photochemical Production of Hydrogen in Pure Water
Authors: Wang Wen , Yu Tianjun , Zeng Yi , Chen Jinping , Li Yi
Published: April 2014

A composite proton‐reducing catalyst Hy@MCM‐41 was created by using a hydrophobic [Fe‐Fe]‐hydrogenase mimic (Hy) incorporated into the K+‐exchanged molecular sieve MCM‐41. Hy acts as the active site to generate H2 by reducing H+, and MCM‐41 provide a large surface area to maintain the dispersion of Hy and to prevent aggregation and precipitation. Hy@MCM‐41 was successfully applied to the light‐induced hydrogen production in pure water with an iridium compound [Ir(ppy)2bpy]Cl and triethylamine (TEA) as the photosensitizer and the sacrificial electron donor, respectively, exhibiting good stability and catalytic activity. The present study provides a general strategy for the application of water‐insoluble catalysts in pure water by using mesoporous molecular sieves.
Synthesis of (±)‐Bakuchiol via a Pot‐Economy Approach
Authors: Huang Meng‐Yuan , Chen Long , Li Ruoxi , Jia Xueshun , Hong Ran
Published: April 2014

A rapid synthetic route toward (±)‐Bakuchiol is presented in 29% overall yield. After the sole all‐carbon quaternary carbon center is created via allylboration of 2‐aryl acetaldehyde, a "Pot‐Economy" approach including mesylation, elimination, and desilylation was realized in the presence of tBuOK under ambient temperature to provide (±)‐Bakuchiol.
From medical images to flow computations without user‐generated meshes
Authors: Dillard Seth I. , Mousel John A. , Shrestha Liza , Raghavan Madhavan L. , Vigmostad Sarah C.
Published: April 2014

Biomedical flow computations in patient‐specific geometries require integrating image acquisition and processing with fluid flow solvers. Typically, image‐based modeling processes involve several steps, such as image segmentation, surface mesh generation, volumetric flow mesh generation, and finally, computational simulation. These steps are performed separately, often using separate pieces of software, and each step requires considerable expertise and investment of time on the part of the user. In this paper, an alternative framework is presented in which the entire image‐based modeling process is performed on a Cartesian domain where the image is embedded within the domain as an implicit surface. Thus, the framework circumvents the need for generating surface meshes to fit complex geometries and subsequent creation of body‐fitted flow meshes. Cartesian mesh pruning, local mesh refinement, and massive parallelization provide computational efficiency; the image‐to‐computation techniques adopted are chosen to be suitable for distributed memory architectures. The complete framework is demonstrated with flow calculations computed in two 3D image reconstructions of geometrically dissimilar intracranial aneurysms. The flow calculations are performed on multiprocessor computer architectures and are compared against calculations performed with a standard multistep route. Copyright © 2014 John Wiley & Sons, Ltd.
A case study of cracks in the scientific enterprise: Reinvention of information‐theoretic measures for graphs
Authors: Dehmer Matthias , Mowshowitz Abbe
Published: April 2014

This article calls attention to flaws in the scientific enterprise, providing a case study of the lack of professionalism in published journal articles in a particular area of research, namely, network complexity. By offering details of a special case of poor scholarship, which is very likely indicative of a broader problem, the authors hope to stimulate editors and referees to greater vigilance, and to strengthen authors' resolve to take their professional responsibilities more seriously. © 2014 Wiley Periodicals, Inc. Complexity 21: 10–14, 2016
Molybdenum Carbide as a Highly Selective Deoxygenation Catalyst for Converting Furfural to 2‐Methylfuran
Authors: Xiong Ke , Lee Wen‐Sheng , Bhan Aditya , Chen Jingguang G.
Published: April 2014

Selectively cleaving the CO bond outside the furan ring of furfural is crucial for converting this important biomass‐derived molecule to value‐added fuels such as 2‐methylfuran. In this work, a combination of density functional theory (DFT) calculations, surface science studies, and reactor evaluation identified molybdenum carbide (Mo2C) as a highly selective deoxygenation catalyst for converting furfural to 2‐methylfuran. These results indicate the potential application of Mo2C as an efficient catalyst for the selective deoxygenation of biomass‐derived oxygenates including furanics and aromatics.
A simple extraction and LC‐MS/MS approach for the screening and identification of over 100 analytes in eight different matrices
Authors: Montenarh Deborah , Hopf Markus , Warth Stefan , Maurer Hans H. , Schmidt Peter , Ewald Andreas H.
Published: April 2014

In the present study, a liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) multi‐analyte approach using one single work‐up approach in whole blood, plasma, serum, post‐mortem blood, liver tissue, gastric content, hair, and urine was developed for fast target screening and reliable identification of 130 analytes often requested in clinical and forensic toxicology. Samples (500 μL each) of whole blood, plasma, serum, post‐mortem blood, tissue (homogenized 1 + 4 with water), as well as 3 g of distilled gastric contents, 1 mL of urine, or 20 mg of pulverized hair were extracted at different pH values with an diethyl ether‐ethyl acetate mixture (1:1). Separation and identification were performed using LC‐QTRAP with electrospray ionization in positive mode. For identification 1 scheduled multi‐reaction‐mode (sMRM) method with 390 transitions was developed covering benzodiazepines, Z‐drugs, antidepressants, neuroleptics, opioids, new synthetic drugs, and phosphodiesterase type 5 inhibitors. For positive sMRM transitions with intensities exceeding 5000 cps, dependent scans (EPI scan collision energy, 35 eV, collision energy spread, 15 eV) were performed for library search using our in‐house library. The method was developed with respect to selectivity, matrix effects, recovery, process efficiency, limit of detection, and applicability. The simple work‐up procedure was suitable for all biosamples with exception of urine in respect to low concentrated analytes, which showed median recovery values of 59%. The method was selective for 130 analytes in all 8 biosamples. For 106 analytes, the limit of detection in whole blood, plasma, and serum was lower than the lowest therapeutic concentration listed in blood level lists. Copyright © 2014 John Wiley & Sons, Ltd.
Copper thiocyanato complexes and cocaine – a case of ‘black cocaine’
Authors: Laussmann Tim , Grzesiak Ireneus , Krest Alexander , Stirnat Kathrin , Meier‐Giebing Sigrid , Ruschewitz Uwe , Klein Axel
Published: April 2014

The chemical composition of a black powder confiscated by German customs was elucidated. Black powders are occasionally used as a ‘transporter’ for cocaine and are obviously especially designed to cloak the presence of the drug. The material consisting of cocaine, copper, iron, thiocyanate, and graphite was approached by analytical tools and chemical modelling. Graphite is added to the material probably with the intention of masking the typical infrared (IR) fingerprints of cocaine and can be clearly detected by powder X‐ray diffraction (XRD) and Raman spectroscopy. Cu2+ and NCS− ions, when carefully reacted with cocaine hydrochloride, form the novel compound (CocH)2[Cu(NCS)4] (CocH+ = protonated cocaine), which has been characterised by single crystal XRD, IR, NMR, UV/Vis absorption and EPR spectroscopy. Based on some further experiments the assumed composition of the original black powder is discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Barrett's esophagus in anorexia nervosa: A case report
Authors: Pacciardi Bruno , Cargioli Claudio , Mauri Mauro
Published: April 2014

Barrett's esophagus (BE) is a metaplastic lesion that may result from long‐lasting gastroesophageal reflux and it is an established precursor of esophageal adenocarcinoma.

There are reports of an increased prevalence of BE, and eventually esophageal adenocarcinoma, in patients with eating disorders characterized by purging behaviors like those with bulimia nervosa (BN).

Among patients with eating disorders, those affected by anorexia nervosa binging purging subtype (ANBP), are behaviorally very similar to those with BN, but to our knowledge there are no data in literature about BE in patients with ANBP.

We present the case of a 37‐year‐old female with a 20‐year history of ANBP in comorbidity with bipolar disorder, who developed a BE requiring multi‐specialistic intervention. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48:147–150)
Comparison of the effects of symmetric and asymmetric temperature elevation and CO2 enrichment on yield and evapotranspiration of winter wheat (Triticum aestivum L.)
Authors: Qiao Yunzhou , Liu Huiling , Kellomäki Seppo , Peltola Heli , Liu Yueyan , Dong Baodi , Shi Changhai , Zhang Huizhen , Zhang Chao , Gong Jinnan , Si Fuyan , Li Dongxiao , Zheng Xin , Liu Mengyu
Published: April 2014

Under the changing climate, asymmetric warming pattern would be more likely during day and night time, instead of symmetric one. Concurrently, the growth responses and water use of plants may be different compared with those estimated based on symmetric warming. In this work, it was compared with the effects of symmetric (ETs) and asymmetric (ETa) elevation of temperature alone, and in interaction with elevated carbon dioxide concentration (EC), on the grain yield (GY) and evapotranspiration in winter wheat (Triticum aestivum L.) based on pot experiment in the North China Plain (NCP). The experiment was carried out in six enclosed‐top chambers with following climate treatments: (1) ambient temperature and ambient CO2 (CON), (2) ambient temperature and elevated CO2 (EC), (3) elevated temperature and ambient CO2 (ETs; ETa), and (4) elevated temperature and elevated CO2 (ECETs, ECETa). In symmetric warming, temperature was increased by 3°C and in asymmetric one by 3.5°C during night and 2.5°C during daytime, respectively. As a result, GY was in ETa and ETs 15.6 (P < 0.05) and 10.3% (P < 0.05) lower than that in CON. In ECETs and ECETa treatments, GY was 14.9 (P < 0.05) and 9.1% (P < 0.05) higher than that in CON. Opposite to GY, evapotranspiration was 7.8 (P < 0.05) and 17.9% (P < 0.05) higher in ETa and ETs treatments and 7.2 (P < 0.05) and 2.1% (P > 0.05) lower in ECETs and ECETa treatments compared with CON. Thus, GY of wheat could be expected to increase under the changing climate with concurrent elevation of CO2 and temperature as a result of increased WUE under the elevated CO2. However, the gain would be lower under ETa than that estimated based on ETs due to higher evapotranspiration.
Theoretical Investigation of the Controlled Metathesis Reactions of Methylruthenium(II) Complexes with Terminal Acetylenes
Authors: Liu Yuxia , Chen Guang , Wang Hongliang , Bi Siwei , Zhang Dongju
Published: April 2014

With the help of density functional theory (DFT) calculations, we theoretically investigated and rationalized the controlled metathesis reactions of methylruthenium complex trans‐[Ru(CH3)2(dmpe)2] [dmpe = 1,2‐bis(dimethylphosphanyl)ethane] (A) with terminal acetylenes. On the basis of the mechanistic study, two important issues related to the generation of mono‐ and bis‐acetylido Ru complexes have been addressed. One issue is why the formation of bis‐acetylido complex C, trans‐[Ru(C≡CPh)2] (dmpe)2, is more difficult than the formation of mono‐acetylido complex B, trans‐[Ru(C≡CPh)(CH3)(dmpe)2]. A strong d→π*(C≡C) interaction between Ru and the alkynyl in B is believed to weaken π back‐donation of Ru to the phenylacetylene C–H σ* bond, and then makes the phenylacetylene C–H bond difficult to break. The second issue is what role methanol plays in promoting the ligand metathesis between the methyl group in B and one alkynyl moiety in 1,4‐diethynylbenzene to give bis‐acetylido species D, trans‐[(PhC≡C)Ru(dmpe)2(C≡CC6H4C≡CH)]. The relatively strong proton‐donating ability of methanol was found to be the major reason. The present study is indicative of the controllable synthesis of mono‐ and bis‐acetylido, and even di‐ and trinuclear acetylide‐bridged ruthenium(II) complexes.
Buchwald–Hartwig Amination Approach for the Synthesis of Functionalized 1,2,3,4‐Tetrahydroacridine Derivatives
Authors: de Sousa Julien , Brown Richard C. D. , Baati Rachid
Published: April 2014

Electrophilic 1,2,3,4‐tetrahydroacridin‐9‐yl trifluoromethanesulfonates have been prepared and applied for the first time in the synthesis of functionalized tacrines with high efficacy by using the Buchwald–Hartwig amination reaction. Remarkably, secondary, poor nucleophilic, and functionalized amines also reacted efficiently by using our conditions. The versatility and convenience of these highly reactive derivatives is illustrated through their application in other valuable C–C (Sonogashira, Suzuki, and cyanation cross‐coupling), C–S, and C–O bond‐forming reactions under palladium catalysis.
Synthesis of Trifluoromethyl‐Substituted 3‐Azabicyclo[n.1.0]alkanes: Advanced Building Blocks for Drug Discovery
Authors: Artamonov Olexiy S. , Slobodyanyuk Evgeniy Y. , Volochnyuk Dmitriy M. , Komarov Igor V. , Tolmachev Andrey A. , Mykhailiuk Pavel K.
Published: April 2014

Five CF3‐substituted 3‐azabicyclo[n.1.0]alkanes were synthesized by CuCl‐mediated trifluoromethylcyclopropanation reaction of the corresponding cyclic enamides with CF3CHN2.
Growth and docosahexaenoic acid production performance of the heterotrophic marine microalgae Crypthecodinium cohnii in the wave‐mixed single‐use reactor CELL‐tainer
Authors: Hillig Friederike , Porscha Nadine , Junne Stefan , Neubauer Peter
Published: April 2014

The process development of docosahexaenoic acid (DHA) with the heterotrophic marine microalgae Crypthecodinium cohnii is challenging, since the oxygen demand of the cells is high and the cell itself sensitive to high shear forces. Furthermore, the marine medium, which comprises a high salt concentration, accelerates corrosion of steel typically applied in bioreactors. Single‐use bioreactors (SUBs) provide an alternative to common stainless steel stirred tank reactors (STR) for the development of bioprocesses with marine microorganisms, when the development stage does not allow for the application of special steel or the replacement of chloride ions in the medium. Among the readily‐available SUBs, the CELL‐tainer exhibits outstanding high oxygen transfer rates. A direct comparison of this SUB with a standard stirred tank bioreactor (STR) was performed for the cultivation of C. cohnii. The biomass and DHA concentrations were similar in both devices, while the biomass yield coefficient, related to the glucose consumption, was reduced by 35% and the DHA yield coefficient by 21% in the STR. The impact of shear stress on cell physiology was elucidated by flow cytometry, revealing a five times higher amount of cell debris in the STR and 14 times higher amount of cells with a low cell membrane potential as evaluated by bis‐(1,3‐dibutylbarbituric acid) trimethine oxonol staining. Foam and biofilm formation, which is a problem in the STR, did not occur in the SUB. The study underlines that the CELL‐tainer can replace the STR, ensuring sufficient oxygen transfer rates and decreasing cell damage and foam formation.
Large‐scale real‐time hybrid simulation of a three‐story steel frame building with magneto‐rheological dampers
Authors: Chae Yunbyeong , Ricles James M. , Sause Richard
Published: April 2014

A series of large‐scale real‐time hybrid simulations (RTHSs) are conducted on a 0.6‐scale 3‐story steel frame building with magneto‐rheological (MR) dampers. The lateral force resisting system of the prototype building for the study consists of moment resisting frames and damped brace frames (DBFs). The experimental substructure for the RTHS is the DBF with the MR dampers, whereas the remaining structural components of the building including the moment resisting frame and gravity frames are modeled via a nonlinear analytical substructure. Performing RTHS with an experimental substructure that consists of the complete DBF enables the effects of member and connection component deformations on system and damper performance to be accurately accounted for. Data from these tests enable numerical simulation models to be calibrated, provide an understanding and validation of the in‐situ performance of MR dampers, and a means of experimentally validating performance‐based seismic design procedures for real structures. The details of the RTHS procedure are given, including the test setup, the integration algorithm, and actuator control. The results from a series of RTHS are presented that includes actuator control, damper behavior, and the structural response for different MR control laws. The use of the MR dampers is experimentally demonstrated to reduce the response of the structure to strong ground motions. Comparisons of the RTHS results are made with numerical simulations. Based on the results of the study, it is concluded that RTHS can be conducted on realistic structural systems with dampers to enable advancements in resilient earthquake resistant design to be achieved. Copyright © 2014 John Wiley & Sons, Ltd.
The influence of Pacific salmon decay products on near‐field streambed sediment and organic matter dynamics: a flume simulation
Authors: Rex John F. , Petticrew Ellen L. , Albers Sam J. , Williams Neil D.
Published: April 2014

Pacific salmon are biogeomorphic agents shown to induce positive feedbacks on their natal watersheds. However, the literature documenting their ecological effects on in‐stream natal environments is more divisive. The disturbance salmon create during redd construction has the potential to reduce stream productivity. The pulse of salmon organic matter (SOM) and marine derived nutrients (MDNs) released during carcass decay has been reported as either stimulating in‐stream productivity or having no local effect. To evaluate the ecological costs and benefits of salmon spawning events, MDN delivery and storage processes need to be identified and quantified. A simulation was conducted in three flow‐through flumes (2 m × 2 m × 30 m) over a 33‐day period (consisting of 15 baseline, four MDN exposure, and 14 post‐exposure days) to assess near‐field sediment and organic matter dynamics during active and post‐spawn simulations. The objective of the study was to measure changes in the amounts and particle sizes of suspended and gravel‐stored fine sediment, in order to elucidate the process and significance of SOM recruitment to the gravel bed via sedimentation. Gravel beds in all flumes were enriched with SOM following treatments but the response was highest in the active spawn simulation. The more effective delivery in the active spawn simulation was attributed to its higher inorganic sediment concentration, which is known to enhance floc formation. Although the active spawn simulation delivered more SOM to the gravel bed, the post‐spawn phase may be equally important to natural streams because its decay phase is longer than the active spawn and consequently can provide SOM to the streambed as long as carcasses remain in‐stream. The delivery, and potential retention, of SOM to spawning streambeds and the intergravel environment may be particularly important for interior streams, which experience low flow conditions during the spawning phase and accordingly have the potential for hyporheic nutrient recruitment and storage. Copyright © 2014 John Wiley & Sons, Ltd.