bluuebunny/crossref_metadata_2025 huggingface dataset:
Stiff, Multistimuli‐Responsive Supramolecular Hydrogels as Unique Molds for 2D/3D Microarchitectures of Live Cells
Authors: Komatsu Harunobu , Tsukiji Shinya , Ikeda Masato , Hamachi Itaru
Published: June 2011

Supramolecular hydrogels constructed through molecular self‐assembly of small molecules have unique stimuli‐responsive properties; however, they are mechanically weak in general, relative to conventional polymer gels. Very recently, we developed a zwitterionic amino acid tethered amphiphilic molecule 1, which gave rise to a remarkably stiff hydrogel comparable with polymer‐based agarose gel, retaining reversible thermal‐responsive properties. In this study, we describe that rational accumulation of multiple and orthogonal noncovalent interactions in the supramolecular nanofibers of 1 played crucial roles not only in the mechanical reinforcement but also in the multistimuli responsiveness. That is, the zwitterionic amino acid moiety and the CC double bond unit of the hydrogelator 1 can function as a pH‐responsive unit and a light‐responsive unit, respectively. We also demonstrated that this stiff and multistimuli‐responsive supramolecular hydrogel 1 is applied as a unique mold for 2D and 3D‐patterning of various substances. More significantly, we succeeded in the fabrication of a collagen gel for spatial patterning, culturing, and differentiation of live cells by using hydrogel 1 molds equipped with 2D/3D microspace channels (100–200 μm in diameter).
Synthesis and Photophysical Properties of Dimethoxybis(3,3,3‐trifluoropropen‐1‐yl)benzenes: Compact Chromophores Exhibiting Violet Fluorescence in the Solid State
Authors: Shimizu Masaki , Takeda Youhei , Higashi Masahiro , Hiyama Tamejiro
Published: June 2011

Dimethoxybis(3,3,3‐trifluo‐ropropen‐1‐yl)benzenes were prepared through palladium‐catalyzed double cross‐coupling reactions of diiododimethoxybenzenes with CF3C≡CZnCl, followed by reduction of CF3C≡C groups with LiAlH4 or H2 in the presence of the Lindlar catalyst. The edges of the absorption spectra of 1,2‐(MeO)2‐4,5‐(CF3CHC=CH)2benzenes 1 and 1,3‐(MeO)2‐4,6‐(CF3CH=CH)2benzenes 2 in cyclohexane ranged from 348 to 360 nm, whereas the absorption spectra of 1,4‐(MeO)2‐2,5‐[(E)‐CF3CH=CH]2 benzene ((E)‐3) ended at 406 nm. These findings indicate that the effective conjugation length of (E)‐3 was significantly larger than those of 1 and 2. Consistently, 1 and 2 in cyclohexane exhibited fluorescence with emission maxima in the UV region, whereas (E)‐3 in cyclohexane emitted violet light with an emission maximum at 407 nm. All the fluorescence spectra of 1–3 in various solvents redshifted as the solvent polarity increased. The photoluminescence of 1, E‐1, Z‐1, 2, E‐2, E‐2H, Z‐2, E‐3, E‐3H, Z‐3 in the solid states was also observed with emission maxima in the violet region. It is important to note that the quantum yields of (E)‐3 in a neat thin film and in a doped polymer film were 0.37 and 0.49, respectively. Density functional theory calculations suggested that the fluorine atoms contribute to a slight extension of both the HOMOs and the LUMOs, as well as narrowing of the HOMO–LUMO gaps when compared with the corresponding fluorine‐free analogues. In the case of (E)‐3, it is suggested that the HOMO–LUMO transition includes charge transfer from the ethereal oxygen atoms to the C(sp2)CF3 moieties.
Microwave‐Assisted Tandem Transformation on an Ionic‐Liquid Support: Efficient Synthesis of Pyrrolo/Pyridobenzimidazolones and Isoindolinone‐Fused Benzimidazoles
Authors: Thummanagoti Suman , Yellol Gorakh S. , Sun Chung‐Ming
Published: June 2011

A tandem transformation that involves the formation of three bonds and two heterocyclic rings in a one‐pot fashion through amino‐alkylation of an ionic‐liquid‐immobilized diamine with keto acids followed by successive double intramolecular cyclizations to afford a tricyclic framework has been explored. This tandem cyclization has been utilized to develop a rapid and efficient method to synthesize various pyrrolo[1,2‐a]benzimidazolones and pyrido[1,2‐a]benzimidazolones on an ionic‐liquid support by using focused microwave irradiation. The application of this tandem cyclization was further extended to the aromatic keto acids to provide isoindolinone‐fused benzimidazoles, a structurally heterogeneous library with skeletal diversity. The outcome of the cascade reaction was confirmed by the X‐ray crystallographic study of the product directly attached to the ionic‐liquid support. Use of the ionic liquid as a soluble support facilitates purification by simple precipitation along with advantages like high loading capacity, homogeneous reaction conditions, and monitoring of the reaction progress by regular conventional spectroscopic methods, whereas application of microwave irradiation greatly accelerates the rate of the reactions.
Bio‐entity network for analysis of protein–protein interaction networks
Authors: Ren Li‐Hong , Shen Yi‐Zhen , Ding Yong‐Sheng , Chou Kuo‐Chen
Published: June 2011

Protein–protein interactions (PPIs) are vitally important for every process in a living cell. Information about these interactions can improve our understanding of diseases and provide the basis to revolutionize therapeutic treatments. However, since PPIs are involved with extremely complicated biological processes, it is necessary to develop novel tools to deal with this kind of network systems. To realize this, a bio‐entity network approach is introduced to show the topology structure of dynamic and collective performances of PPI networks and analyze the variance of the protein node that plays an important role in the PPI network. Also, spectrum analysis is used to capture the discrete and stochastic feature of PPIs. The yeast protein interaction network is considered as a paradigm. It is demonstrated that the proposed approach can easily and clearly identify the hub‐proteins that have the most impact on the PPI system concerned. It is expected that the bio‐entity network approach as presented in this paper might become a useful tool in system biology.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
How do we establish a biological marker for a behaviorally defined disorder? Autism as a test case
Authors: Yerys Benjamin E. , Pennington Bruce F.
Published: June 2011

We discuss the recent push to develop support vector machines and other cluster analyses as a means for biological signatures as early screens for autism. These methods not only hold great promise but also require careful consideration prior to implementation. We outline three validity tests and potential methods for addressing them. Autism Res 2011,4:239–241. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Some implications of biofuel development for engineering infrastructures in the United States
Authors: Ng Tze Ling , Cai Ximing , Ouyang Yanfeng
Published: June 2011

Under the US Environmental Protection Agency's Renewable Fuel Standard (RFS) program, mandates to increase the consumption of renewable fuels in transportation in the USA are leading to the emergence of a biofuel economy with infrastructure implications. This shift requires immediate consideration, as current engineering infrastructures may not be sufficient to support the realization of the mandates. New biorefineries will need to be established where suitable land is available and the climate is appropriate for growing feedstocks. Investments may need to be made to accommodate increases in local, regional, and national traffic from the transport of feedstocks and finished biofuels. Further, the large water demands of biorefineries and of growing feedstocks impose even greater pressure on water supply utilities. Higher sediment and nutrient runoffs from more intensive cultivation of corn (as feedstock for ethanol) have negative water quality effects that may lead to the need for upgrading drinking‐water treatment facilities. Any infrastructure expansion should be conducted strategically, keeping in mind resource constraints, and environmental and social impacts. To understand the infrastructure needs and bottlenecks of biofuel development, a systems approach encompassing all aspects of the problem is essential. Research is needed to quantify the interdependencies, resiliency, and sustainability of the entire system in meeting biofuel goals. Research is also needed to integrate the social and physical aspects of the problem into a holistic framework for planning and management purposes. This paper reviews the literature to gain insights into some implications of biofuel development for engineering infrastructures in the USA. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Near‐field dosimetry for in vitro exposure of human cells at 60 GHz
Authors: Zhadobov Maxim , Sauleau Ronan , Augustine Robin , Le Quément Catherine , Le Dréan Yves , Thouroude Daniel
Published: June 2011

Due to the expected mass deployment of millimeter‐wave wireless technologies, thresholds of potential millimeter‐wave‐induced biological and health effects should be carefully assessed. The main purpose of this study is to propose, optimize, and characterize a near‐field exposure configuration allowing illumination of cells in vitro at 60 GHz with power densities up to several tens of mW/cm2. Positioning of a tissue culture plate containing cells has been optimized in the near‐field of a standard horn antenna operating at 60 GHz. The optimal position corresponds to the maximal mean‐to‐peak specific absorption rate (SAR) ratio over the cell monolayer, allowing the achievement of power densities up to 50 mW/cm2 at least. Three complementary parameters have been determined and analyzed for the exposed cells, namely the power density, SAR, and temperature dynamics. The incident power density and SAR have been computed using the finite‐difference time‐domain (FDTD) method. The temperature dynamics at different locations inside the culture medium are measured and analyzed for various power densities. Local SAR, determined based on the initial rate of temperature rise, is in a good agreement with the computed SAR (maximal difference of 5%). For the optimized exposure setup configuration, 73% of cells are located within the ±3 dB region with respect to the average SAR. It is shown that under the considered exposure conditions, the maximal power density, local SAR, and temperature increments equal 57 mW/cm2, 1.4 kW/kg, and 6 °C, respectively, for the radiated power of 425 mW. Bioelectromagnetics 33:55–64, 2012. © 2011 Wiley Periodicals, Inc.
Two‐compartment method for determination of the oxygen transfer rate with electrochemical sensors based on sulfite oxidation
Authors: Glazyrina Julia , Materne Eva , Hillig Friederike , Neubauer Peter , Junne Stefan
Published: June 2011

The dissolved oxygen concentration is a crucial parameter in aerobic bioprocesses due to the low solubility of oxygen in water. The present study describes a new method for determining the oxygen transfer rate (OTR) in shaken‐culture systems based on the sodium sulfite method in combination with an electrochemical oxygen sensor. The method replaces the laborious titration of the remaining sulfite by an on‐line detection of the end point of the reaction. This method is a two‐step procedure that can be applied in arbitrary flasks that do not allow the insertion of electrodes. The method does not therefore depend on the type of vessel in which the OTR is detected. The concept is demonstrated by determination of the OTR for standard baffled 1‐L shake flasks and for opaque Ultra Yield™ flasks. Under typical shaking conditions, kLa values in the standard baffled flasks reached values up to 220 h‐1, whereas the kLa values of the Ultra Yield flasks were significantly higher (up to 422 h‐1).
Improving outcome for patients with pancreatic cancer through centralization
Authors: Lemmens V E P P , Bosscha K , van der Schelling G , Brenninkmeijer S , Coebergh J W W , de Hingh I H J T
Published: June 2011

Background

High-volume institutions are associated with improved clinical outcomes for pancreatic cancer. This study investigated the impact of centralizing pancreatic cancer surgery in the south of the Netherlands.

Methods

All patients diagnosed in the Eindhoven Cancer Registry area in 1995–2000 (precentralization) and 2005–2008 (implementation of centralization agreements) with primary cancer of the pancreatic head, extrahepatic bile ducts, ampulla of Vater or duodenum were included. Resection rates, in-hospital mortality, 2-year survival and changes in treatment patterns were analysed. Multivariable regression analyses were used to identify independent risk factors for death.

Results

Some 2129 patients were identified. Resection rates increased from 19·0 to 30·0 per cent (P < 0·001). The number of hospitals performing resections decreased from eight to three, and the annual number of resections per hospital increased from two to 16. The in-hospital mortality rate dropped from 24·4 to 3·6 per cent (P < 0·001) and was zero in 2008. The 2-year survival rate after surgery increased from 38·1 to 49·4 per cent (P = 0·001), and the rate irrespective of treatment increased from 10·3 to 16·0 per cent (P < 0·001). There was no improvement in 2-year survival in non-operated patients. After adjustment for relevant patient and tumour factors, those undergoing surgery more recently had a lower risk of death (hazard ratio 0·70, 95 per cent confidence interval 0·51 to 0·97). Changes in surgical patterns seemed largely to explain the improvements.

Conclusion

High-quality care can be achieved in regional hospitals through collaboration. Centralization should no longer be regarded as a threat by general hospitals but as a chance to improve outcomes in pancreatic cancer.
Long-term functional results and quality of life after transanal endoscopic microsurgery
Authors: Allaix M E , Rebecchi F , Giaccone C , Mistrangelo M , Morino M
Published: June 2011

Background

Of the few studies that have investigated quality-of-life (QoL) outcomes after transanal endoscopic microsurgery (TEM), the majority have reported only short-term follow-up data. This study assessed long-term clinical and instrumental outcomes (QoL, sexual, urinary and sphincter function) after TEM for extraperitoneal rectal cancer.

Methods

Preoperative and postoperative anorectal function was assessed in consecutive patients with benign rectal lesions or early rectal cancer, based on clinical scores and anorectal manometry.

Results

Between January 2000 and July 2005, 93 patients undergoing TEM completed the 60-month study protocol. The mean Wexner continence score increased from baseline at 3 months, began to decline within 12 months, and had returned to the preoperative value at 60 months. Urgency was reported by 65·0, 30·0 and 5 per cent of patients at 3, 12 and 60 months respectively (P < 0·050). A significant improvement was noted in various clinical and QoL scores at 12 and 60 months. Postoperative manometry values at 3 months were significantly lower than at baseline (P < 0·050), but had returned to preoperative values at 12 months. Tumour size of 4 cm or above was the only factor that significantly (P = 0·008) affected the rectal sensitivity threshold, the urge to defaecate threshold and the maximum tolerated volume at 3 months after TEM.

Conclusion

TEM had no long-term effect on anorectal function or QoL. Lower anal resting pressure at early follow-up was not associated with defaecation problems in patients who were continent before surgery.
Long-term results after laparoscopic reoperation for failed antireflux procedures
Authors: Dallemagne B , Arenas Sanchez M , Francart D , Perretta S , Weerts J , Markiewicz S , Jehaes C
Published: June 2011

Background

Surgery for failed antireflux procedures is technically more demanding than primary fundoplication. The success rate does not equal that of the primary procedures. This retrospective analysis aimed to assess long-term subjective and objective outcomes in patients who underwent laparoscopic surgery for fundoplication failure.

Methods

Objective and subjective outcomes were assessed by radiological and endoscopic methods, symptom questionnaire and quality-of-life index at a minimum follow-up of 12 (mean 75·8) months.

Results

The study included 129 consecutive patients who had laparoscopic redo surgery after fundoplication had failed. The most frequent patterns of failure were hiatal herniation (50 patients) and slippage (45). Resolution of the symptoms that led to redo surgery was achieved in 27 of 37 and 11 of 16 patients operated for recurrence and for dysphagia respectively. Objective failure was demonstrated in 16 of 39 patients with herniation and six of 22 with slippage. Seven patients underwent an additional surgical procedure.

Conclusion

Long-term assessment of objective and subjective results after laparoscopic repair for failed fundoplication revealed a high failure rate that increased with the length of follow-up. Unexpected and untreated oesophageal shortening may be responsible for this failure rate.
Comparison of open and laparoscopic live donor left lateral sectionectomy
Authors: Kim K H , Jung D H , Park K M , Lee Y J , Kim D Y , Kim K M , Lee S G
Published: June 2011

Background

The present study was undertaken to determine whether laparoscopic live donor left lateral sectionectomy (LLS) in paediatric liver transplantation is a feasible, safe and reproducible procedure, compared with open live donor left lateral sectionectomy (OLS).

Methods

A retrospective review was conducted of all consecutive live donor procedures for paediatric liver transplantation performed between May 2008 and October 2009. All live donor hepatectomies were carried out by a single surgeon.

Results

A total of 26 live donor procedures for paediatric liver transplantation were performed, of which 11 were LLS and 11 OLS; four left hepatectomies were excluded. The LLS group had a significantly shorter hospital stay (mean(s.d.) 6·9(0·3) versus 9·8(0·9) days; P = 0·001) and time to oral diet (2·1(0·3) versus 2·7(0·4) days; P = 0·012). Duration of operation, blood loss, warm ischaemia time and out-of-pocket medical costs were comparable between groups. There was no death in either donor group and only one complication, a wound seroma, in the OLS group.

Conclusion

LLS seemed to be a safe, feasible and reproducible procedure, and was associated with reduced hospital stay.
Methodology for determining major constituents of ayahuasca and their metabolites in blood
Authors: McIlhenny Ethan H. , Riba Jordi , Barbanoj Manel J. , Strassman Rick , Barker Steven A.
Published: June 2011

There is an increasing interest in potential medical applications of ayahuasca, a South American psychotropic plant tea with a long cultural history of indigenous medical and religious use. Clinical research into ayahuasca will require specific, sensitive and comprehensive methods for the characterization and quantitation of these compounds and their metabolites in blood. A combination of two analytical techniques (high‐performance liquid chromatography with ultraviolet and/or fluorescence detection and gas chromatography with nitrogen–phosphorus detection) has been used for the analysis of some of the constituents of ayahuasca in blood following its oral consumption. We report here a single methodology for the direct analysis of 14 of the major alkaloid components of ayahuasca, including several known and potential metabolites of N,N‐dimethyltryptamine and the harmala alkaloids in blood. The method uses 96‐well plate/protein precipitation/filtration for plasma samples, and analysis by HPLC–ion trap–ion trap–mass spectrometry using heated electrospray ionization to reduce matrix effects. The method expands the list of compounds capable of being monitored in blood following ayahuasca administration while providing a simplified approach to their analysis. The method has adequate sensitivity, specificity and reproducibility to make it useful for clinical research with ayahuasca. Copyright © 2011 John Wiley & Sons, Ltd.
Sustainable Development of Maritime Operations in Ports
Authors: Dinwoodie John , Tuck Sarah , Knowles Harriet , Benhin James , Sansom Mark
Published: June 2011

Globalisation has heralded burgeoning ship movements and maritime operations in ports alongside increased international concerns regarding potential environmental impacts. In particular, smaller ports require accessible tools to manage them. A framework to facilitate environmental management applies business process principles to identify relevant inputs, processes and outputs. A case study of Falmouth Harbour Commissioners compares functional units and flows that define input–output processes for anchoring and bunkering operations. Strategic‐level processes affect present and future operations while tactical service processes guarantee service level and quality through their integrity. Operational processes occur at the output level. An accessible generic framework supports planning of more sustainable maritime operations, facilitates mitigation of potential risks and encourages authorities to engage with sustainability agendas and manage development proposals proactively. Ongoing interlocution with business strategists will refocus port managers on educational and commercial missions and increase stakeholder engagement. Simplification and optimisation phases of business process re‐engineering remain untapped by business strategists. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
Finite element implementation for computer‐aided education of structural mechanics: Frame analysis
Authors: Lee Jae Young , Ahn Sung Youll
Published: June 2011

Instructional tools for the computer‐aided education of structural analysis have been implemented as an extension of a finite element analysis program, VisualFEA. They are devised to promote understanding in structural analysis, and stimulate interest in the subject by substantiating the conceptual principles and visually exhibiting the complex computational processes with the aid of interactive computer graphics. In lieu of manipulation with pre‐supplied conditions or the input of assumed data, the instructional tools are operated through a real and practical process of structural analysis from the creation of modeling data to the presentation of solution results. The basic principles, computing formulae, and methods of analysis in structural mechanics are simulated for instructional purposes on the basis of finite element technology. VisualFEA has a number of educational functions for use in teaching and learning structural analysis. Among them, only those related to frame analysis are introduced in this article. There are numerous programs for frame analysis. However, the educational features described in this article are not common in any other programs for similar purposes. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:387–409, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.10.1002/cae.20563
Iminodipropionic Acid as the Leaving Group for DNA Polymerization by HIV‐1 Reverse Transcriptase
Authors: Song Xiao‐Ping , Bouillon Camille , Lescrinier Eveline , Herdewijn Piet
Published: June 2011

Previous studies have demonstrated that some selected amino monoacids and amino diacids can function as leaving groups in the polymerase‐catalyzed incorporation of deoxynucleotides into DNA. Among these, the iminodiacetic acid phosphoramidate of deoxyadenosine monophosphate (IDA‐dAMP) represents an interesting example, as it could overcome some of the problems observed when using L‐aspartic acid as the leaving group, that is, poor chain elongation. We have now synthesized and evaluated a series of IDA‐dAMP analogues that bear either an extended aliphatic chain in the amino acid function, or a phosphonic acid moiety (substituting for the carboxylic acid function). Among these compounds, the nucleotide with an iminodipropionic acid leaving group (IDP‐dAMP) was identified as the best substrate; the excellent single incorporation (91 % conversion to a P+1 strand at 50 μM) was at a substrate concentration ten times lower than that used for IDA‐dAMP). This nucleotide also presented improved kinetics and elongation capability compared to IDA‐dAMP. The analogues with T, G, and C base moieties were also investigated for their incorporation ability with HIV‐1 RT. The incorporation efficiency was found to decrease in the order A>T>G>C. The properties of the iminodipropionic acid as the leaving group surpass those of previously evaluated leaving groups; this acid will be a prime candidate for in vivo testing.
Glycosynthase‐Mediated Assembly of Xylanase Substrates and Inhibitors
Authors: Goddard‐Borger Ethan D. , Fiege Brigitte , Kwan Emily M. , Withers Stephen G.
Published: June 2011

An exo‐β‐xylosidase mutant with glycosynthase activity was created to aid in the synthesis of xylanase substrates and inhibitors. Simple monosaccharides were easily elaborated into di‐, tri‐ and tetrasaccharides by using this enzyme. Some products proved to be surprisingly potent inhibitors of xylanases from glycoside hydrolase families 10 and 11.
High‐Temperature Produced Catalytic Sites Selective for n‐Alkane Dehydrogenation in Acid Zeolites: The Case of HZSM‐5
Authors: Al‐majnouni Khalid A. , Yun Jang Ho , Lobo Raul F.
Published: June 2011

The effect of high‐temperature treatment on the catalytic activity and selectivity of two HZSM5 samples has been investigated by using propane activation as the test reaction. The samples have been characterized by using X‐ray powder diffraction, nitrogen adsorption, FTIR spectroscopy, and ammonia temperature‐programmed desorption (TPD). Before high‐temperature treatment, the samples have activation energies and selectivity toward propane cracking versus dehydrogenation comparable with similar samples reported in the literature. After high‐temperature treatment (825 °C in N2), the sample’s microporous and crystalline structure remains nearly intact, but a clear decrease in the number of Brønsted‐acid sites is detected by using FTIR and ammonia TPD. Despite the decrease (≈70 %), the rate of reaction is about the same before and after heating. The selectivity toward dehydrogenation, however, increases by at least a factor of 2, whereas the activation energy for dehydrogenation decreases considerably. This is evidence that new catalytic sites are formed upon dehydroxylation. By using naphthalene as a probe molecule, it is shown that the new sites have the ability to form stable radical cations out of the neutral naphthalene, which suggests that the new sites activate propane by a redox mechanism. The kinetic isotope effect on the rate of dehydrogenation is also consistent with a redox process. The effect of heating in an oxygen atmosphere at lower temperatures was also investigated and only minor effects on reaction rates and selectivity were observed. Naphthalene adsorption experiments on oxygen‐treated samples, however, produce more radical cations than on the samples treated at high temperatures, a result that does not correlate with the dehydrogenation activity of oxygen‐treated samples.
Probing the Dynamics of CO2 and CH4 within the Porous Zirconium Terephthalate UiO‐66(Zr): A Synergic Combination of Neutron Scattering Measurements and Molecular Simulations
Authors: Yang Qingyuan , Jobic Hervé , Salles Fabrice , Kolokolov Daniil , Guillerm Vincent , Serre Christian , Maurin Guillaume
Published: June 2011

Quasi‐elastic neutron scattering (QENS) measurements combined with molecular dynamics (MD) simulations were conducted to deeply understand the concentration dependence of the self‐ and transport diffusivities of CH4 and CO2, respectively, in the humidity‐resistant metal–organic framework UiO‐66(Zr). The QENS measurements show that the self‐diffusivity profile for CH4 exhibits a maximum, while the transport diffusivity for CO2 increases continuously at the loadings explored in this study. Our MD simulations can reproduce fairly well both the magnitude and the concentration dependence of each measured diffusivity. The flexibility of the framework implemented by deriving a new forcefield for UiO‐66(Zr) has a significant impact on the diffusivity of the two species. Methane diffuses faster than CO2 over a broad range of loading, and this is in contrast to zeolites with narrow windows, for which opposite trends were observed. Further analysis of the MD trajectories indicates that the global microscopic diffusion mechanism involves a combination of intracage motions and jump sequences between tetrahedral and octahedral cages.
Synthesis and Photophysics of Silicon Phthalocyanine–Perylenebisimide Triads Connected through Rigid and Flexible Bridges
Authors: Céspedes‐Guirao F. Javier , Martín‐Gomis Luis , Ohkubo Kei , Fukuzumi Shunichi , Fernández‐Lázaro Fernando , Sastre‐Santos Ángela
Published: June 2011

Three new bisperylenebisimide–silicon phthalocyanine triads [(PBI)2–SiPcs 1, 2, and 3] connected with either rigid or flexible bridges were synthesized and characterized. A new synthetic approach to connect SiPc and PBI moieties through click chemistry produced triad 3 with an 80 % yield. In (PBI)2–SiPc 1, PBI and SiPc are orthogonal and were connected with a rigid connector; triads 2 and 3 bear flexible aliphatic bridges, resulting in a tilted (2) or nearly parallel arrangement (3) of PBI and SiPc. Photoinduced intramolecular processes in these (PBI)2–SiPcs were studied and the results are compared with those of the reference compounds SiPc‐ref and PBI‐ref. The occurrence of electron‐transfer processes between the SiPc and PBI units was confirmed by time‐resolved emission and transient absorption techniques. Charge‐separated (CS) states with lifetimes of 0.91, 1.3 and 2.0 ns for triads 1, 2, and 3, respectively, were detected using femtosecond laser flash photolysis. Upon the addition of Mg(ClO4)2, an increase in the lifetime of the CS states to 59, 110 and 200 μs was observed for triads (PBI)2–SiPcs 1, 2, and 3, respectively. The energy of the CS state (SiPc.+–PDI.−/Mg2+) is lower than the energy of both silicon phthalocyanine (3SiPc*–PDI) and perylenebisimide (SiPc–3PDI*) triplet excited states, which decelerates the metal ion‐decoupled electron‐transfer process for charge recombination to the ground state, thus increasing the lifetime of the CS state. The photophysics of the three triads demonstrate the importance of the rigidity of the spacer and the orientation between donor and acceptor units.
Meaningful Structural Descriptors from Charge Density
Authors: Stalke Dietmar
Published: June 2011

This paper provides a short introduction to the basics of electron density investigations. The two predominant approaches for the modelling and various interpretations of electron density distributions are presented. Their potential translations into chemical concepts are explained. The focus of the article lies on the deduction of chemical properties from charge density studies in some selected main group compounds. The relationship between the obtained numerical data and commonly accepted simple chemical concepts unfortunately is not always straightforward, and often the chemist relies on heuristic connections rather than rigorously defined ones. This article tries to demonstrate how charge density analyses can shed light on aspects of chemicalbondingandreactivityresulting from the determined bonding situation. Sometimes this helps to identify misconceptions and sets the scene for new unconventional synthetic approaches.
A New Phosphine Oxide Host based on ortho‐Disubstituted Dibenzofuran for Efficient Electrophosphorescence: Towards High Triplet State Excited Levels and Excellent Thermal, Morphological and Efficiency Stability
Authors: Han Chunmiao , Xie Guohua , Li Jing , Zhang Zhensong , Xu Hui , Deng Zhaopeng , Zhao Yi , Yan Pengfei , Liu Shiyong
Published: June 2011

An efficient host for blue and green electrophosphorescence, 4,6‐bis(diphenylphosphoryl)dibenzofuran (o‐DBFDPO), with the structure of a short‐axis‐substituted dibenzofuran was designed and synthesised. It appears that the greater density of the diphenylphosphine oxide (DPPO) moieties in the short‐axis substitution configuration effectively restrains the intermolecular interactions, because only very weak π–π stacking interactions could be observed, with a centroid‐to‐centroid distance of 3.960 Å. The improved thermal stability of o‐DBFDPO was corroborated by its very high glass transition temperature (Tg) of 191 °C, which is the result of the symmetric disubstitution structure. Photophysical investigation showed o‐DBFDPO to be superior to the monosubstituted derivative, with a longer lifetime (1.95 ns) and a higher photoluminescent quantum efficiency (61 %). The lower first singlet state excited level (3.63 eV) of o‐DBFDPO demonstrates the stronger polarisation effect attributable to the greater number of DPPO moieties. Simultaneously, an extremely high first triplet state excited level (T1) of 3.16 eV is observed, demonstrating the tiny influence of short‐axis substitution on T1. The improved carrier injection ability, which contributed to low driving voltages of blue‐ and green‐emitting phosphorescent organic light‐emitting diodes (PHOLEDs), was further confirmed by Gaussian calculation. Furthermore, the better thermal and morphological properties of o‐DBFDPO and the matched frontier molecular orbital (FMO) levels in the devices significantly reduced efficiency roll‐offs. Efficient blue and green electrophosphorescence based on the o‐DBFDPO host was demonstrated.
Facile Synthesis of Wide‐Bandgap Fluorinated Graphene Semiconductors
Authors: Chang Haixin , Cheng Jinsheng , Liu Xuqing , Gao Junfeng , Li Mingjian , Li Jinghong , Tao Xiaoming , Ding Feng , Zheng Zijian
Published: June 2011

The bandgap opening of graphene is extremely important for the expansion of the applications of graphene‐based materials into optoelectronics and photonics. Current methods to open the bandgap of graphene have intrinsic drawbacks including small bandgap openings, the use hazardous/harsh chemical oxidations, and the requirement of expensive chemical‐vapor deposition technologies. Herein, an eco‐friendly, highly effective, low‐cost, and highly scalable synthetic approach is reported for synthesizing wide‐bandgap fluorinated graphene (F‐graphene or or fluorographene) semiconductors under ambient conditions. In this synthesis, ionic liquids are used as the only chemical to exfoliate commercially available fluorinated graphite into single and few‐layer F‐graphene. Experimental and theoretical results show that the bandgap of F‐graphene is largely dependent on the F coverage and configuration, and thereby can be tuned over a very wide range.
Segmental Dynamics of PEO/LiClO4 Complex Crystals and Their Influence on the Li+‐Ion Transportation in Crystal Lattices: A 13C Solid‐State NMR Approach
Authors: Gao Yangwen , Hu Bingweng , Yao Yefeng , Chen Qun
Published: June 2011

The structure and chain dynamics of polyethylene oxide (PEO)/LiClO4 complex crystals were studied by employing state‐of‐the‐art solid‐state 13C NMR techniques. Remarkable helical jump motions of the PEO segments in the complex crystals at ambient temperatures were clearly demonstrated. The jump motions are believed to induce the transportation of the coordinated Li+ ions along the crystallographic c axis, providing a novel mechanism of ionic conductivity of the complex crystals. In addition, this work also shows that solid‐state high‐resolution 13C NMR spectroscopy can be a powerful and general tool for elucidating phase structures, dynamics, and subsequently the conduction mechanism of crystalline polymer electrolytes.
From Atomic to Molecular Anions: A Neutral Receptor Captures Cyanide Using Strong CH Hydrogen Bonds
Authors: Ramabhadran Raghunath O. , Hua Yuran , Li Yong‐jun , Flood Amar H. , Raghavachari Krishnan
Published: June 2011

The multifaceted character of cyanide as an acceptor of hydrogen bonds from a receptor has been examined for the first time using electronic‐structure theory and spectroscopic measurements (UV/Vis and NMR titrations). Motivated by the similar size and charge of the cyanide pseudohalide and the monoatomic chloride ion, strong interactions of cyanide with a rigid macrocyclic triazolophane receptor have been predicted by theory and confirmed by experimental findings. It was found that both anions bind with similar strength in the gas phase (computed) and in the solution phase (experimental) via CH hydrogen bonds. Theoretical calculations predict that the heterodiatomic cyanide prefers to bind in the plane of the macrocycle along the north–south axis. Examination of the possible binding modes reveal low computed barriers for in‐plane rotation. The predicted model is consistent with the experimental data. Overall, the binding of a molecular anion within the cavity of a triazolophane receptor has been characterized where the computed and experimental binding energies are consistent with the classification of cyanide as a pseudohalide in the context of supramolecular chemistry.
Multicolor Fluorescence of a Styrylquinoline Dye Tuned by Metal Cations
Authors: Shiraishi Yasuhiro , Ichimura Chizuru , Sumiya Shigehiro , Hirai Takayuki
Published: June 2011

A styrylquinoline dye with a dipicolylamine (DPA) moiety (1) has been synthesized. The dye 1 in acetonitrile demonstrates multicolor fluorescence upon addition of different metal cations. Compound 1 shows a green fluorescence without cations. Coordination of 1 with Cd2+ shows a blue emission, while with Hg2+ and Pb2+ exhibits yellow and orange emissions, respectively. The different fluorescence spectra are due to the change in intramolecular charge transfer (ICT) properties of 1 upon coordination with different cations. The DPA and quinoline moieties of 1 behave as the electron donor and acceptor units, respectively, and both units act as the coordination site for metal cations. Cd2+ coordinates with the DPA unit. This reduces the donor ability of the unit and decreases the energy level of HOMO. This results in an increase in HOMO–LUMO gap and blue shifts the emission. Hg2+ or Pb2+ coordinate with both DPA and quinoline units. The coordination with the quinoline unit decreases the energy level of LUMO. This results in a decrease in HOMO–LUMO gap and red shifts the emission. Addition of two different metal cations successfully creates intermediate colors; in particular, the addition of Cd2+ and Pb2+ at once creates a bright white fluorescence.
Energy Up‐Conversion by Low‐Power Excitation: New Applications of an Old Concept
Authors: Ceroni Paola
Published: June 2011

Energy up‐conversion is the process by which two absorbed photons are converted in one photon of higher energy. Such a process can be conveniently performed by low‐power excitation through sensitized triplet–triplet annihilation and it is now an emerging technique with possible applications in different fields, including photovoltaic devices and bioimaging.
ChemInform Abstract: Liquefaction of Solid‐State BH3NH3 by Gaseous NH3.
Authors: Gao Liang , Fang Haocheng , Li Zhenhua , Yu Xuebin , Fan Kangnian
Published: June 2011

Under 1—4 bar ammonia, H3NBH3 (AB) reversibly absorbs up to 6 equivalents of NH3 forming liquid AB(NH3)n (n = 1—6) complexes at 0 °C.
ChemInform Abstract: Hydrothermal Growth and Structural Studies of Si1‐xGexO2 Single Crystals.
Authors: Ranieri V. , Darracq S. , Cambon M. , Haines J. , Cambon O. , Largeteau A. , Demazeau G.
Published: June 2011

Single crystals of α‐quartz type Si1‐xGexO2 are prepared by the temperature gradient hydrothermal method in Ni—Cr autoclaves using pure water and crystobalite‐type Si0.8Ge0.2O2 (<200 MPa, <400 °C) or Si0.7Ge0.3O2 glass (<200 MPa, <400 °C) as source.
ChemInform Abstract: K2Mg5‐xSn3 and K3Mg18Tt11 (Tt: Sn, Pb) with Two Types of Mg—Sn/Pb Frameworks.
Authors: Lei Xiao‐Wu
Published: June 2011

K2Mg4.72Sn3 and K3Mg18Tt11 (Tt: Sn, Pb) are synthesized from mixtures of the elements (800 °C for 2—3 d followed by annealing at 500—520 °C for 6—7 d) and characterized by single crystal XRD.
ChemInform Abstract: Cs8UIV(UVIO2)3 (Ge3O9)3·3H2O: A Mixed‐Valence Uranium Germanate with 9‐Ring Channels.
Authors: Nguyen Quang Bac , Liu Hsin‐Kuan , Chang Wen‐Jung , Lii Kwang‐Hwa
Published: June 2011

The title compound is hydrothermally synthesized from a mixture of UO3, CsOH, CsF, CsCl, Al, and GeO2 (Cs:U:Al:Ge = 14.6:1:0.3:7; gold ampule, autoclave, 585 °C, ≈160 MPa, 4 d, 45% yield).
ChemInform Abstract: Hydrothermal Synthesis of Pure‐Phase Copper Silicate Na2Cu2Si4O11·2H2 O with Ammonia as Complexing Agent.
Authors: Jiang Qizhou , Shi Qi , Xu Hong , Li Jinping , Dong Jinxiang
Published: June 2011

The title compound is hydrothermally synthesized from a CuO:3.2SiO2:3.02Na2O:4.57NH3 :146H2O mixture (autoclave, 220 °C, 96 h).
ChemInform Abstract: A Novel Allylic Transfer Reaction of Chirally Modified 2‐Borylbutadiene: Synthesis of Chiral Homoallenyl Alcohols.
Authors: Choi Jihoon , Lee Bobin , Yu Chan‐Mo
Published: June 2011

A variety of chiral homoallenyl alcohols (III) is readily prepared by reaction of bromoallenyl tin reagent (I) with an enantiopure bromoborane followed by an allylic transfer reaction of the intermediate borylbutadiene with aldehydes (II).
ChemInform Abstract: Nature‐Inspired Cascade Catalysis: Reaction Control Through Substrate Concentration—Double vs. Quadruple Domino Reactions.
Authors: Rueping Magnus , Haack Kyoung Lang , Ieawsuwan Winai , Sunden Henrik , Blanco Magda , Schoepke Fenja R.
Published: June 2011

The domino reaction of nitroolefins (I) with twofold excess of unsaturated aldehydes (II) in the presence of Hantzsch dihydropyridine leads to intermediate aldehydes, which are readily transformed into alcohols (III) by reduction with sodium borohydride.
ChemInform Abstract: Catalytic Enantioselective Alkynylation of Trifluoromethyl Ketones: Pronounced Metal Fluoride Effects and Implications of Zinc‐to‐Titanium Transmetallation.
Authors: Zhang Guang‐Wu , Meng Wei , Ma Hai , Nie Jing , Zhang Wen‐Qin , Ma Jun‐An
Published: June 2011

By application of pseudoenantiomeric cinchona alkaloids as chiral ligands, the synthesis of both enantiomers of trifluoromethylated propargylic tertiary alcohols is achieved.
ChemInform Abstract: Gosteli—Claisen Rearrangement of Propargyl Vinyl Ethers: Cascading Molecular Rearrangements.
Authors: Gille Annika , Rehbein Julia , Hiersemann Martin
Published: June 2011

2‐Alkoxycarbonyl‐substituted propargyl vinyl ethers are used as substrates for the unprecedented rearrangements.
ChemInform Abstract: Nanocrystalline Magnesium Oxide Stabilized Palladium(0): An Efficient Reusable Catalyst for Room Temperature Selective Aerobic Oxidation of Alcohols.
Authors: Layek Keya , Maheswaran H. , Arundhathi R. , Kantam M. Lakshmi , Bhargava Suresh K.
Published: June 2011

In competition reactions between primary and secondary alkohols, aldehydes are obtained with high selectivity.
ChemInform Abstract: Hydrogen‐Activated Benzylidynetricobalt Nonacarbonyl: Carbonylative Cyclization of Enynes in Synthesis Gas Without Reducing Substrates and Products.
Authors: Sugihara Takumichi , Wakabayashi Akihito , Nishizawa Mugio , Honzawa Shinobu
Published: June 2011

The hydrogen present in the synthesis gas is able to activate metal complexes which in turn catalyze the carbonylative cyclization of enynes to afford cyclopentenones.
ChemInform Abstract: A General Route to Mono‐ and Disubstituted Divinyl Sulfones: Acyclic Michael Acceptors for the Synthesis of Polyfunctionalized Cyclic Sulfones.
Authors: Pal Tarun Kumar , Dey Santu , Pathak Tanmaya
Published: June 2011

A general and efficient method to prepare mono‐ and disubstituted divinyl sulfones is reported.
ChemInform Abstract: Synthesis of 2‐Iodoynamides and Regioselective [2 + 2] Cycloadditions with Ketene.
Authors: Wang Yu‐Pu , Danheiser Rick L.
Published: June 2011

The iodoynamides are relatively stable and thus can be stored in CH2Cl2 below 0°C for weeks without any remarkable decomposition.
ChemInform Abstract: An Enantioselective Synthesis of 2‐Aryl Cycloalkanones by Sc‐Catalyzed Carbon Insertion.
Authors: Rendina Victor L. , Moebius David C. , Kingsbury Jason S.
Published: June 2011

The title compounds are prepared from the lower homologues and aryldiazoalkanes via a Sc‐catalyzed aryldiazomethyl insertion.
ChemInform Abstract: Efficient Phenolic Oxidations Using μ‐Oxo‐Bridged Phenyliodine Trifluoroacetate.
Authors: Dohi Toshifumi , Uchiyama Teruyoshi , Yamashita Daisuke , Washimi Naohiko , Kita Yasuyuki
Published: June 2011

The utility of OBP is demonstrated.
ChemInform Abstract: Synthesis of Polyfunctional Allenes by Successive Copper‐Mediated Substitutions.
Authors: Schade Matthias A. , Yamada Shigeyuki , Knochel Paul
Published: June 2011

A convenient synthesis of polyfunctionalized allenes is presented.
ChemInform Abstract: Enantioselective Silver‐Catalyzed Propargylation of Imines.
Authors: Wisniewska Hanna M. , Jarvo Elizabeth R.
Published: June 2011

Title reaction tolerates a range of aromatic and aliphatic aldimines to give the product propargylic amines (II) and (VI) in high to excellent yields and enantioselectivities (up to 98% e.e.).
ChemInform Abstract: Iron(III) Chloride‐Promoted Isomerization of Propargyl Alcohols to α,β‐Unsaturated Carbonyl Compounds.
Authors: El Douhaibi Ahmad Samih , Judeh Zaher M. A. , Basri Hedaya , Moussa Ziad , Messali Mouslim , Qi Gao
Published: June 2011

The compounds (I) and (III) can be easily prepared by Grignard reaction starting from the corresponding aryl aldehydes.
ChemInform Abstract: Catalytic Asymmetric Mannich‐Type Reactions of Fluorinated Ketoesters with N‐Boc Aldimines in the Presence of Chiral Palladium Complexes.
Authors: Kang Young Ku , Kim Dae Young
Published: June 2011

The reaction in the presence of BIP allows the access to various biologically interesting synthons with good to excellent enantioselectivity.
ChemInform Abstract: Copper‐Catalyzed N‐Arylation of Sulfonimidamides.
Authors: Azzaro Stephane , Desage‐El Murr Marine , Fensterbank Louis , Lacote Emmanuel , Malacria Max
Published: June 2011

A microwave‐assisted protocol is developed for the reaction of the substrates with aryl iodides in a short time.
ChemInform Abstract: Tributylphosphine‐Catalyzed Reaction of Ethanethiol with Alkynyl Ketones.
Authors: Zhao Shen , Zhou Qing Fa , Liu Jia Zhi , Tang Wei Fang , Lu Tao
Published: June 2011

The stereoselective Michael addition affords generally the (Z)‐isomers as main products.
ChemInform Abstract: Magnetically Separable and Versatile Pd/Fe3O4 Catalyst for Efficient Suzuki Cross‐Coupling Reaction and Selective Hydrogenation of Nitroarenes.
Authors: Zhang Rongzhao , Liu Jianming , Li Fuwei , Wang Shoufeng , Xia Chungu , Sun Wei
Published: June 2011

The catalyst can be conveniently recovered by an external magnet and reused several times without loss of its catalytic activity.
ChemInform Abstract: Asymmetric Intramolecular Aldol Reaction Mediated by (S)‐N‐Substituted‐N‐(2‐pyrrolidinylmethyl)amine to Prepare Wieland—Miescher Ketone.
Authors: Akahane Yuichi , Inomata Kohei , Endo Yasuyuki
Published: June 2011

Known and new N‐(2‐pyrrolidinylmethyl)amines, e.g. (I), containing alkyl, cycloalkyl, branched alkyl and arylalkyl substituents are applied as alternative chiral amine mediators in the HPESW reaction to get the Wieland—Miescher ketone (III).
ChemInform Abstract: Triflic Acid Catalyzed Cascade Cyclization of Arenyl Enynes via Acetylene‐Cation Cyclization and Friedel—Crafts‐type Reaction.
Authors: Jin Tienan , Uchiyama Junichi , Himuro Masafumi , Yamamoto Yoshinori
Published: June 2011

The process allows the access to a broad spectrum of polycyclic systems including the highly congested carbocycle (IX).
ChemInform Abstract: Site‐Selective Arylation of Alizarin and Purpurin Based on Suzuki—Miyaura Cross‐Coupling Reactions.
Authors: Mahal Ahmed , Villinger Alexander , Langer Peter
Published: June 2011

The triflates of alizarin and purpurin (I) and (VII), respectively, undergo site‐selective Suzuki—Miyaura cross‐coupling reactions.
ChemInform Abstract: Allene Functionalization via Bicyclic Methylene Aziridines.
Authors: Boralsky Luke A. , Marston Dagmara , Grigg R. David , Hershberger John C. , Schomaker Jennifer M.
Published: June 2011

A variety of allene substrates is transformed to bicyclic methylene aziridines bearing electron‐withdrawing groups at the aziridine nitrogen.