bluuebunny/crossref_metadata_2025 huggingface dataset:
Process as Product: Scholarly Communication Experiments in the Digital Humanities
Authors: Coble Zach , Potvin Sarah , Shirazi Roxanne
Published: July 2014

Scholarly communication outreach and education activities are proliferating in academic libraries. Simultaneously, digital humanists—a group that includes librarians and non-librarians based in libraries, as well as scholars and practitioners without library affiliation—have developed forms of scholarship that demand and introduce complementary innovations focused on infrastructure, modes of dissemination and evaluation, openness, and other areas with implications for scholarly communication. Digital humanities experiments in post-publication filtering, open peer review, middle-state publishing, decentering authority, and multimodal and nonlinear publication platforms are discussed in the context of broader library scholarly communication efforts.
Foxes Propose New Guidelines for Henhouse Design: Comments on NISO’s Proposed Open Access Metadata Standards
Authors: Royster Paul
Published: July 2014

This commentary is in response to: NISO RP-22-201x, Open Access Metadata and Indicators (draft for comment), which is available at: http://www.niso.org/apps/group_public/document.php?document_id=12047
Diel variability of the beam attenuation and backscattering coefficients in the northwestern Mediterranean Sea (BOUSSOLE site)
Authors: Kheireddine Malika , Antoine David
Published: July 2014

The diel variability of the particulate beam attenuation coefficient, cp, and of the particulate backscattering coefficient, bbp, were investigated during five seasonal cycles at an oceanic site in the northwestern Mediterranean Sea, covering contrasting physical and trophic situations. We observed a diel cycle in cp and bbp, related to changes in phytoplankton properties (i.e., size and refractive index) induced by the accumulation of carbon within phytoplankton cells associated with photosynthetic processes, during the winter mixing of the water column, the development of the spring phytoplankton bloom, its decline, and during the summer oligotrophy. The relative amplitude of the cp diel variability was much larger during the spring bloom (20–50%) than during other seasons (10–20%), whereas that of bbp is steadily around 20% and does not show significant seasonal variability. The minimal cp and bbp occurred at sunrise and are synchronized, whereas maximum bbp values are often reached 3–6 h before those for cp (except during bloom conditions), which occur near sunset. These different amplitudes and timing are tentatively explained using Mie computations, which allow discerning the respective roles of changes in the particle size distribution and refractive index. The differences observed here in the diel cycles of cp and bbp show that they cannot be used interchangeably to determine the daily increase of the particle pool. This result has implications on the feasibility to determine net community production from the bbp diel changes, when only bbp is measured in situ or available from ocean color observations.
Characterizing the radiative impacts of precipitating snow in the ECMWF Integrated Forecast System global model
Authors: Li J.‐L. F. , Forbes R. M. , Waliser D. E. , Stephens G. , Lee Seungwon
Published: July 2014

Global weather and climate models often exclude the effects of precipitating hydrometeors and convective core mass on radiative fluxes. In particular, many models split the ice phase into separate “cloud ice” and “snow” categories representing the smaller and larger ice particles, respectively; a separation that is generally not well defined in observations. A version of the European Centre for Medium‐Range Weather Forecasts (ECMWF) global numerical weather prediction model which includes the radiative effects of cloud liquid, cloud ice, and precipitating snow is used to investigate the impact of including and excluding the radiative effects of the precipitating snow category. The results show that exclusion of precipitating snow in the radiation calculations leads to differences in the shortwave and longwave radiative fluxes of 5–15 W m−2 in strongly precipitating and convective areas. These differences are of the same order of magnitude as the systematic errors in the model compared to satellite observations. Corresponding biases in the radiative heating profiles are on the order of 0.15 K d−1. The results imply that precipitating snow should be included in the radiative calculations in all weather and climate models in the context of improving model fidelity and reducing compensating errors.
Scattering properties of modeled complex snowflakes and mixed‐phase particles at microwave and millimeter frequencies
Authors: Ori D. , Maestri T. , Rizzi R. , Cimini D. , Montopoli M. , Marzano F. S.
Published: July 2014

A microphysically based algorithm (named Snow Aggregation and Melting (SAM)) that models snowflakes composed of a collection of hexagonal columns by simulating a random aggregation process is presented. SAM combines together pristine columns with multiple dimensions to derive complex aggregates constrained to size‐mass relationship obtained by data collected from in situ measurements. The model also simulates the melting processes occurring for environmental temperatures above 0°C and thus define the mixed‐phase particles structure. The single‐scattering properties of the modeled snowflakes (dry and mixed phased) are computed by using a discrete dipole approximation (DDA) algorithm which allows to model irregularly shaped targets. In case of mixed‐phased particles, realistic radiative properties are obtained by assuming snow aggregates with a 10% of melted fraction. The single‐scattering properties are compared with those calculated through Mie theory together with Maxwell‐Garnett effective medium approximation using both a homogeneous sphere and a layered‐sphere models. The results show that for large‐size parameters there are significant differences between the radiative properties calculated using complex microphysical and optical algorithms (i.e., SAM and DDA) and those obtained from simplified assumptions as the layered‐sphere models (even when the radial ice density distribution of the aggregated snowflakes is perfectly matched). Finally, some applications to quantitative precipitation estimation using radar data are presented to show how the resulting differences in the basic optical properties would propagate into radar measurable. Large discrepancies in the derivation of the equivalent water content and snowfall rate from radar measurements could be observed when large‐size parameters are accounted for.
Ultrafast Electrically Tunable Polaritonic Metasurfaces
Authors: Lee Jongwon , Jung Seungyong , Chen Pai‐Yen , Lu Feng , Demmerle Frederic , Boehm Gerhard , Amann Markus‐Christian , Alù Andrea , Belkin Mikhail A.
Published: July 2014

Electrically tunable mid‐infrared metasurfaces with nanosecond response time and broad tuning range are reported. Electrical tuning is achieved by employing strong polaritonic coupling of electromagnetic modes in metallic nanoresonators with voltage‐tunable inter‐subband transitions in semiconductor heterostructures, tailored for a giant quantum‐confined Stark effect. Experimentally, a 220‐nm‐thick multi‐quantum‐well semiconductor layer is sandwiched between a ground plane and a metal layer patterned with plasmonic nanoresonators. Approximately 300 nm absorption peak tuning and over 30% absorption change are demonstrated at around 7 μm wavelength at normal incidence by changing the DC bias voltage from 0 to +5 V. Fast reflectivity modulation of the metasurface is shown with a response time less than ∼10 ns using bias voltage modulation between +2 V and +4 V. Since the bias affects the optical response at the individual nanoresonator level, this approach may be used to create metasurfaces for ultrafast electrical wavefront tuning and beam steering.
Diamond Nanophotonics
Authors: Aharonovich Igor , Neu Elke
Published: July 2014

The burgeoning field of nanophotonics has grown to be a major research area, primarily because of the ability to control and manipulate single quantum systems (emitters) and single photons on demand. For many years, studying nanophotonic phenomena was limited to traditional semiconductors (including silicon and GaAs) and experiments were carried out predominantly at cryogenic temperatures. In the last decade, however, diamond has emerged as a new contender to study photonic phenomena at the nanoscale. Offering a plethora of quantum emitters that are optically active at room temperature and ambient conditions, diamond has been exploited to demonstrate super‐resolution microscopy and realize entanglement, Purcell enhancement, and other quantum and classical nanophotonic effects. Elucidating the importance of diamond as a material, this progress report highlights the recent achievements in the field of diamond nanophotonics, and conveys a roadmap for future experiments and technological advancements.
Synthesis of α‐Methylidene‐γ‐amino Acid Esters from Aldehydes via an Aminative Umpolung Strategy
Authors: Xu Juan , Chen Jing , Yang Qin , Ding Lei , Liu Xuliang , Xu Dongfang , Zhao Baoguo
Published: July 2014

This paper describes an efficient method for the synthesis of α‐methylidene‐γ‐amino acid esters from readily available aldehydes by using aminative umpolung strategy. Electrophilic aromatic aldehydes were converted to α‐imino anions via amination with 2,2‐diphenylglycine in methanol and subsequent decarboxylation in acetonitrile. The in situ generated α‐imino anions displayed high activity in the reaction with Morita‐Baylis–Hillman adducts in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as catalyst, to give a variety of substituted α‐methylidene‐γ‐amino acid esters in 54–96% yields with 3.2–7.1:1 diastereoselectivity. The resulting α‐methylidene‐γ‐amino acid esters can be efficiently converted into biologically important α‐exo‐methylidene‐γ‐lactams under mild conditions.

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Regioselective Synthesis of β‐Aryl Enaminones and 1,4,5‐ Trisubstituted 1,2,3‐Triazoles from Chalcones and Benzyl Azides
Authors: Xie Yu‐Yang , Wang Ying‐Chun , Qu Hong‐En , Tan Xian‐Chun , Wang Heng‐Shan , Pan Ying‐Ming
Published: July 2014

A highly regioselective synthesis of β‐aryl enaminones and 1,4,5‐trisubstituted 1,2,3‐triazoles from chalcones and benzyl azides based on reaction solvent selection is reported. In the presence of a catalytic amount of Ce(OTf)3, reactions of chalcones with benzyl azides in DMF at 100 °C afforded densely substituted Z‐β‐aryl enaminones in good to excellent yields, whereas treatment of chalcones with benzyl azides in toluene at 100 °C selectively produced 1,4,5‐trisubstituted 1,2,3‐triazoles in excellent yields.

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Rapid Asymmetric Synthesis of Highly Functionalized Indanols via a Michael/Henry Organocascade with Submol% Squaramide Catalyst Loadings
Authors: Loh Charles C. J. , Chauhan Pankaj , Hack Daniel , Lehmann Christian , Enders Dieter
Published: July 2014

An expedient asymmetric synthesis of polyfunctionalized indanols bearing four contiguous stereogenic centres, including a quarternary centre through the use of sub‐mol% amounts of a squaramide catalyst within minutes is presented. A gram‐scale experiment of this Michael/Henry organcascade pushes the frontier of catalyst loading of organocascades down to only 0.1 mol%, attaining a TON of up to 910.

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Palladium‐Catalyzed Direct α‐Arylation of Benzyl Thioethers with Aryl Bromides
Authors: Frensch Gustavo , Hussain Nusrah , Marques Francisco A. , Walsh Patrick J.
Published: July 2014

The arylation of sp3‐hybridized CH bonds is a powerful strategy to build molecular complexity and diversity. A novel and efficient palladium‐catalyzed direct sp3 CH arylation of aryl and alkyl benzyl thioether derivatives with aryl bromides is reported. The reaction involves reversible deprotonation of the benzylic CH bond of the thioether with either lithium or sodium bis(trimethylsilyl)amide [LiN(SiMe3)2 or NaN(SiMe3)2] and subsequent cross‐coupling to provide the functionalized products in up to 97% yield. A screen of 24 of the most successful ligands in cross‐coupling chemistry led to the identification of NiXantPhos as the only viable ligand for this challenging coupling.

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Identification of ANKK1 rs1800497 variant in schizophrenia: New data and meta‐analysis
Authors: Zhang Chen , Zhang Jiangtao , Fan Juan , Cheng Wenhong , Du Yasong , Yu Shunying , Fang Yiru
Published: July 2014

One functional polymorphism (rs1800497) within the ankyrin repeat and kinase domain containing‐1 gene (ANKK1) was reported to be associated with schizophrenia, but results among different studies vary and conclusions remain controversial. The present study sought to clarify this potential association among a population of Han Chinese with early onset schizophrenia using a case‐control (396 patients and 399 controls) and family based study (103 trios). We then performed a meta‐analysis (comprising 11 case‐control and 2 family‐based studies) based on the present literature. Results of the association study revealed no significant difference in allele and genotype frequencies between the cases and controls, and no significant transmission distortion was detected. Kaplan–Meier survival analysis showed that age at onset in schizophrenia was significantly associated with the rs1800497 polymorphism in female patients, but not in males. Female T allele carriers had a lower age at onset than those without T allele (log rank statistic χ2 = 5.16, P = 0.023; corrected P = 0.046). Meta‐analysis results indicated that rs1800497 is not associated with schizophrenia in the overall population (P = 0.77 for the case‐control studies; P = 0.06 for the family‐based studies). Our results support the hypothesis that rs1800497 polymorphism is likely to have a modifying rather than causative effect on schizophrenia. These findings may represent a significant genetic clue for the etiology of schizophrenia in females, but further investigation is required to clarify the exact role of ANKK1 in the development of schizophrenia. © 2014 Wiley Periodicals, Inc.
Sleep and quality of life improvements after endoscopic sinus surgery in patients with chronic rhinosinusitis
Authors: Alt Jeremiah A. , Smith Timothy L. , Schlosser Rodney J. , Mace Jess C. , Soler Zachary M.
Published: July 2014

Background

Recent investigation has demonstrated that approximately 75% of patients with medically refractory chronic rhinosinusitis (CRS) report abnormal sleep quality, with strong correlation between worse sleep quality and more severe CRS disease severity. It remains unknown whether the treatment effect of endoscopic sinus surgery (ESS) for CRS results in appreciable sleep quality improvements.

Methods

Adult patients (aged ≥18 years) with a current diagnosis of recalcitrant chronic rhinosinusitis (CRS), who voluntarily elected ESS as the next treatment modality (n = 301), were prospectively evaluated within 4 academic, tertiary care centers using treatment outcome instruments: the Rhinosinusitis Disability Index, the 22‐item Sinonasal Outcome Test, the 2‐item Patient Health Questionnaire, and the Pittsburgh Sleep Quality Index (PSQI) both before and after ESS.

Results

Seventy‐two percent (72%) of patients with CRS were found to have poor sleep (PSQI > 5) at baseline with a mean (standard deviation) global PSQI score of 9.4 (4.6). Surgery improved overall mean global PSQI scores (by 2.2 points), and all 7 subdomain scores of the PSQI. Similarly, the odds of good sleep quality (PSQI ≤ 5) in patients treated with sinus surgery increased significantly (odds ratio [OR] 5.94; 95% confidence interval [CI], 3.06 to 11.53; p < 0.001). Stepwise multivariate linear regression found that acetylsalicylic acid (ASA) intolerance (β [standard error], −1.94 [0.93]; 95% CI, −3.77 to −0.11; p = 0.038), history of prior sinus surgery (β [standard error], 1.10 (0.54); 95% CI, 0.03 to 2.16; p = 0.044), and frontal sinusotomy (β [standard error], −1.03 [0.62]; 95% CI, −2.26 to 0.20; p = 0.099) were found to significantly associate with improvement in PSQI sleep scores.

Conclusion

Among patients with CRS, reduced sleep quality, poor disease‐specific quality of life, and greater disease severity were improved following ESS.
Chemie und Biologie von Theta‐Defensinen
Authors: Conibear Anne C. , Craik David J.
Published: July 2014

Cyclische Peptide werden in vielen verschiedenen Organismen vorgefunden und zeichnen sich durch ihre Stabilität und ihre Rolle bei Abwehrmechanismen aus. Warum wurde in Säugetieren nur eine Klasse cyclischer Peptide gefunden? Möglicherweise haben wir noch nicht gründlich genug nach ihnen geforscht, oder die für ihre Erkennung notwendigen Techniken sind noch nicht vollständig entwickelt. Wir verstehen auch ihre faszinierende Biosynthese aus zwei separaten Genprodukten noch nicht. Die Bewältigung dieser Schwierigkeiten wird die Anwendung chemischer Hilfsmittel sowie Erkenntnisse über andere Klassen cyclischer Peptide erfordern. Wir stellen hier die neuesten Entwicklungen bei der Charakterisierung von Theta‐Defensinen vor und beschreiben die wichtige Rolle, die die Chemie bei der Skizzierung ihrer Wirkmechanismen spielte. Darüber hinaus betonen wir das Potenzial von Theta‐Defensinen als antimikrobielle Substanzen und als Gerüste für Peptidwirkstoffe.
Tumorspezifische, Hypoxie‐basierte Aktivierung von EGFR‐Inhibitoren
Authors: Karnthaler‐Benbakka Claudia , Groza Diana , Kryeziu Kushtrim , Pichler Verena , Roller Alexander , Berger Walter , Heffeter Petra , Kowol Christian R.
Published: July 2014

Die Entwicklung von Rezeptor‐Tyrosinkinase‐Inhibitoren (TKIs) ist ein Meilenstein in der Entwicklung neuer Tumortherapeutika. Allerdings geht die TKI‐Therapie mit starken Nebenwirkungen und Chemotherapieresistenz einher. Ziel dieser Studie war die Synthese und präklinische Entwicklung eines neuen Inhibitors des Epidermalen Wachstumsfaktorrezeptors (EGFR), der durch die spezifischen Eigenschaften des malignen Gewebes aktiviert wird. Zu diesem Zweck wurde ein CoIII‐basiertes “Prodrug‐Design” verwendet, das die gezielte Freisetzung des aktiven EGFR‐Inhibitors durch den im soliden Tumor auftretenden Sauerstoffmangel (Hypoxie) ermöglicht. Hierfür wurden mehrere neue EGFR‐hemmende Liganden mit Chelateinheiten synthetisiert, und derjenige mit dem größten EGFR‐hemmenden Potenzial wurde für die Komplexierung mit CoIII ausgewählt. Anschließend wurden hypoxische Aktivierung und Hemmung des EGFR‐Signalwegs nachgewiesen, und eine vielversprechende Aktivität des neuen Komplexes in vivo wurde gezeigt.
Immunological Multimetal Deposition for Rapid Visualization of Sweat Fingerprints
Authors: He Yayun , Xu Linru , Zhu Yu , Wei Qianhui , Zhang Meiqin , Su Bin
Published: July 2014

A simple method termed immunological multimetal deposition (iMMD) was developed for rapid visualization of sweat fingerprints with bare eyes, by combining the conventional MMD with the immunoassay technique. In this approach, antibody‐conjugated gold nanoparticles (AuNPs) were used to specifically interact with the corresponding antigens in the fingerprint residue. The AuNPs serve as the nucleation sites for autometallographic deposition of silver particles from the silver staining solution, generating a dark ridge pattern for visual detection. Using fingerprints inked with human immunoglobulin G (hIgG), we obtained the optimal formulation of iMMD, which was then successfully applied to visualize sweat fingerprints through the detection of two secreted polypeptides, epidermal growth factor and lysozyme. In comparison with the conventional MMD, iMMD is faster and can provide additional information than just identification. Moreover, iMMD is facile and does not need expensive instruments.
Paenilamicin – Struktur und Biosynthese eines hybriden Polyketid‐/nichtribosomalen Peptidantibiotikums des bienenpathogenen Bakteriums Paenibacillus larvae
Authors: Müller Sebastian , Garcia‐Gonzalez Eva , Mainz Andi , Hertlein Gillian , Heid Nina C. , Mösker Eva , van den Elst Hans , Overkleeft Herman S. , Genersch Elke , Süssmuth Roderich D.
Published: July 2014

Das sporenbildende Bakterium Paenibacillus larvae ist der Erreger der Amerikanischen Faulbrut, einer weltweit auftretenden, hochpathogenen Bienenkrankheit. Wir konnten ein komplexes Hybrid‐Gencluster aus nichtribosomalen Peptidsynthetasen (NRPS) und Polyketidsynthasen (PKS) im Genom von P. larvae aufklären. Hier präsentieren wir die Isolierung und die Strukturaufklärung der antibakteriellen und antifungalen Produkte dieses Genclusters, die Paenilamicine genannt wurden. Die einzigartigen Strukturen der Paenilamicine geben tiefe Einblicke in die zugrunde liegende, komplexe Biosynthese‐Maschinerie. Bienenlarven‐Koinfektionstests zeigten, dass die Paenilamicine von P. larvae für den Kampf um seine ökologische Nische benötigt werden und nicht direkt für das Sterben der Bienenlarven verantwortlich sind. Ihre antibakterielle und antimykotische Aktivität machen die Paenilamicine zu vielversprechenden Kandidaten für die Wirkstoffentwicklung.
Synthesis of α,α‐Difluoromethylene Alkynes by Palladium‐Catalyzed gem‐Difluoropropargylation of Aryl and Alkenyl Boron Reagents
Authors: Yu Yan‐Bo , He Guo‐Zhen , Zhang Xingang
Published: July 2014

gem‐Difluoropropargyl bromides are versatile intermediates in organic synthesis, but have rarely been employed in transition‐metal‐catalyzed cross‐coupling reactions. The first palladium‐catalyzed gem‐difluoropropargylation of organoboron reagents with gem‐difluoropropargyl bromides is now reported. The reaction proceeds under mild reaction conditions with high regioselectivity; it features a broad substrate scope and excellent functional‐group compatibility and thus provides an attractive approach for the synthesis of complex fluorinated molecules, in particular for drug discovery and development.
π‐Conjugated Carbon Radicals at Graphene Oxide to Initiate Ultrastrong Chemiluminescence
Authors: Yang Liang , Zhang Ruilong , Liu Bianhua , Wang Jianping , Wang Suhua , Han Ming‐Yong , Zhang Zhongping
Published: July 2014

Graphene oxide has widely been employed in various fields, but its structure and composition has still not been fully understood. Here we report that freshly prepared graphene oxide exhibits a large number of π‐conjugated carbon radicals at its π‐network plane, which result from the addition reaction of hydroxyl radicals from H2O2 onto the conjugated double bonds of graphene oxide. The π‐conjugated carbon radicals can directly initiate the long‐lasting visible chemiluminescence of luminol, which is even stronger than that obtained when horseradish peroxidase and H2O2 are used. Previously, graphene oxide was mainly reported to be a quencher of chemiluminescence instead. Remarkably, the reacted radicals can be regenerated, thereby enabling the repetitive initiation of chemiluminescence by re‐treatment of graphene oxide. The results reported here provide a new understanding of the structure, properties, and applications of graphene oxide.
Visualizing the Stoichiometry of Industrial‐Style Co‐Mo‐S Catalysts with Single‐Atom Sensitivity
Authors: Zhu Yuanyuan , Ramasse Quentin M. , Brorson Michael , Moses Poul G. , Hansen Lars P. , Kisielowski Christian F. , Helveg Stig
Published: July 2014

The functional properties of transition metal dichalcogenides (TMDs) may be promoted by the inclusion of other elements. Here, we studied the local stoichiometry of single cobalt promoter atoms in an industrial‐style MoS2‐based hydrotreating catalyst. Aberration‐corrected scanning transmission electron microscopy and electron energy loss spectroscopy show that the Co atoms occupy sites at the (−100) S edge terminations of the graphite‐supported MoS2 nanocrystals in the catalyst. Specifically, each Co atom has four neighboring S atoms that are arranged in a reconstructed geometry, which reflects an equilibrium state. The structure agrees with complementary studies of catalysts that were prepared under vastly different conditions and on other supports. In contrast, a small amount of residual Fe in the graphite is found to compete for the S edge sites, so that promotion by Co is strongly sensitive to the purity of the raw materials. The present single‐atom‐sensitive analytical method therefore offers a guide for advancing preparative methods for promoted TMD nanomaterials.
Sequential Logic Operations with a Molecular Keypad Lock with Four Inputs and Dual Fluorescence Outputs
Authors: Jiang Xiong‐Jie , Ng Dennis K. P.
Published: July 2014

A novel coumarin–rhodamine conjugate was prepared, and its metal binding properties were studied by UV/Vis and fluorescence spectroscopy. The conjugate serves as a ratiometric and highly selective fluorescent sensor for Hg2+ ions. Its metal‐responsive spectral properties were utilized to construct a molecular keypad lock with four inputs and dual fluorescence outputs. The complexity of this molecular logic network can greatly enhance the security level of this device.
Mathematical modeling of the extractables release from multi‐layered plastic films used in drug product containers
Authors: Jenke Dennis , Barge Vishal J.
Published: July 2014

The release of extractables from multi‐layered plastic films such as those used in containers for liquid drug products has been investigated. Targeted extractables were chosen from the film's extractable profile, as elucidated by a controlled extraction study. The total available pool of targeted extractables was ascertained via exhaustive sequential extraction of the film and the film layer responsible for the target extractables was established. This information, along with the film's structure, was used to produce a mathematical migration model for each of these targets. The film was fashioned into pouches, filled with a simulating solvent and the release of the targeted extractables to the pouches' contents was measured. The measured and modeled concentrations were found to be very similar, establishing the model's ability to effectively mimic the experimental system. This result suggests that mathematical modeling, which is widely used in the food industry to assess the safety of food packaging, may be applicable to packaged pharmaceutical products. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41223.
Catalytic Glucose Isomerization by Porous Coordination Polymers with Open Metal Sites
Authors: Akiyama George , Matsuda Ryotaro , Sato Hiroshi , Kitagawa Susumu
Published: July 2014

Highly efficient catalytic isomerization reactions from glucose to fructose in aqueous media using porous coordination polymers (PCPs) or metal–organic frameworks (MOFs) is reported for the first time. The catalytic activity of PCPs functionalized with NH2, (CH3)2, NO2, and SO3H groups on the pore surface is systematically tested. The catalytic activity can be tuned by the acidity of open metal sites (OMSs) by modifying the organic linkers with the functional groups. As a result, it is demonstrated that MIL‐101 functionalized with SO3H not only shows high conversion of glucose but also selectively produces fructose. Further, catalytic one‐pot conversion of amylose to fructose is achieved, thanks to the high stability of the framework in an acidic solution. These results show that MOF/PCP compounds having OMSs are promising materials for various useful heterogeneous catalytic reactions, in particular in the biomass field.
The importance of physiological oxygen concentrations in the sandwich cultures of rat hepatocytes on gas‐permeable membranes
Authors: Xiao Wenjin , Shinohara Marie , Komori Kikuo , Sakai Yasuyuki , Matsui Hitoshi , Osada Tomoharu
Published: July 2014

Oxygen supply is a critical issue in the optimization of in vitro hepatocyte microenvironments. Although several strategies have been developed to balance complex oxygen requirements, these techniques are not able to accurately meet the cellular oxygen demand. Indeed, neither the actual oxygen concentration encountered by cells nor the cellular oxygen consumption rates (OCR) was assessed. The aim of this study is to define appropriate oxygen conditions at the cell level that could accurately match the OCR and allow hepatocytes to maintain liver specific functions in a normoxic environment. Matrigel overlaid rat hepatocytes were cultured on the polydimethylsiloxane (PDMS) membranes under either atmospheric oxygen concentration [20%‐O2 (+)] or physiological oxygen concentrations [10%‐O2 (+), 5%‐O2 (+)], respectively, to investigate the effects of various oxygen concentrations on the efficient functioning of hepatocytes. In parallel, the gas‐impermeable cultures (polystyrene) with PDMS membrane inserts were used as the control groups [PS‐O2 (−)]. The results indicated that the hepatocytes under 10%‐O2 (+) exhibited improved survival and maintenance of metabolic activities and functional polarization. The dramatic elevation of cellular OCR up to the in vivo liver rate proposed a normoxic environment for hepatocytes, especially when comparing with PS‐O2 (−) cultures, in which the cells generally tolerated hypoxia. Additionally, the expression levels of 84 drug‐metabolism genes were the closest to physiological levels. In conclusion, this study clearly shows the benefit of long‐term culture of hepatocytes at physiological oxygen concentration, and indicates on an oxygen‐permeable membrane system to provide a simple method for in vitro studies. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1401–1410, 2014
Capacity optimization and scheduling of a multiproduct manufacturing facility for biotech products
Authors: Shaik Munawar A. , Dhakre Ankita , Rathore Anurag S. , Patil Nitin
Published: July 2014

A general mathematical framework has been proposed in this work for scheduling of a multiproduct and multipurpose facility involving manufacturing of biotech products. The specific problem involves several batch operations occurring in multiple units involving fixed processing time, unlimited storage policy, transition times, shared units, and deterministic and fixed data in the given time horizon. The different batch operations are modeled using state‐task network representation. Two different mathematical formulations are proposed based on discrete‐ and continuous‐time representations leading to a mixed‐integer linear programming model which is solved using General Algebraic Modeling System software. A case study based on a real facility is presented to illustrate the potential and applicability of the proposed models. The continuous‐time model required less number of events and has a smaller problem size compared to the discrete‐time model. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1221–1230, 2014
Gel filtration chromatography as a method for removing bacterial endotoxin from antibody preparations
Authors: London Anne Serdakowski , Mackay Kasey , Lihon Michael , He Yaqin , Alabi Busola Ruth
Published: July 2014

The removal of bacterial endotoxins from biological samples is critical to avoid the potentially fatal pyrogenic response possible when introduced to mammalian systems. Endotoxins have a variety of specific characteristics that can be exploited to target their isolation and subsequent removal, but one that has not been extensively characterized is their difference in size from that of monoclonal antibodies. Here, we present a study which utilizes gel filtration chromatography as a method for endotoxin removal from both aggregated and nonaggregated antibody preparations, outlining a mechanistically simple method for removal of this impurity. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1497–1501, 2014
The association between lifetime smoking exposure and breast cancer mortality – results from a Norwegian cohort
Authors: Bjerkaas Eivind , Parajuli Ranjan , Engeland Anders , Maskarinec Gertraud , Weiderpass Elisabete , Gram Inger Torhild
Published: July 2014

Several recent cohort studies have found an association between smoking and breast cancer, but the association between lifetime smoking exposure and breast cancer mortality is less well described. We examined whether smoking before breast cancer diagnosis is a predictor of breast cancer mortality in a large cohort with more than 4.1 million years of follow‐up, with a special focus on women who initiated smoking before first childbirth. Information on smoking status was collected before breast cancer diagnosis and used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of breast cancer mortality in a cohort of 302,865 Norwegian women with 1106 breast cancer deaths. Women were enrolled between 1974 and 2003 and followed up through linkages to national registries until 31 December 2007. We found that breast cancer mortality was slightly but significantly increased for current (HR = 1.15, 95% CI 1.01–1.32) and ever (HR = 1.15, 95% CI 1.02–1.30) smokers as compared to never smokers. No statistically significantly increased mortality was found for women who initiated smoking before first childbirth, and no dose‐response association was revealed for any of the different measures of smoking exposure. A large proportion of heavy smokers may have died from other causes than breast cancer during follow‐up, possibly diluting our results. This study found that lifetime smoking exposure had a significantly increased risk of breast cancer mortality compared with never smokers.
Exposure to high glutamate concentration activates aerobic glycolysis but inhibits ATP‐linked respiration in cultured cortical astrocytes
Authors: Shen Yao , Tian Yueyang , Shi Xiaojie , Yang Jianbo , Ouyang Li , Gao Jieqiong , Lu Jianxin
Published: July 2014

Astrocytes play a key role in removing the synaptically released glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. However, high concentration of glutamate leads to toxicity in astrocytes, and the underlying mechanisms are unclear. The purpose of this study was to investigate whether energy metabolism disorder, especially impairment of mitochondrial respiration, is involved in the glutamate‐induced gliotoxicity. Exposure to 10‐mM glutamate for 48 h stimulated glycolysis and respiration in astrocytes. However, the increased oxygen consumption was used for proton leak and non‐mitochondrial respiration, but not for oxidative phosphorylation and ATP generation. When the exposure time extended to 72 h, glycolysis was still activated for ATP generation, but the mitochondrial ATP‐linked respiration of astrocytes was reduced. The glutamate‐induced astrocyte damage can be mimicked by the non‐metabolized substrate d‐aspartate but reversed by the non‐selective glutamate transporter inhibitor TBOA. In addition, the glutamate toxicity can be partially reversed by vitamin E. These findings demonstrate that changes of bioenergetic profile occur in cultured cortical astrocytes exposed to high concentration of glutamate and highlight the role of mitochondria respiration in glutamate‐induced gliotoxicity in cortical astrocytes. Copyright © 2014 John Wiley & Sons, Ltd.
Ionic Liquid and Sulfonic Acid Based Bifunctional Periodic Mesoporous Organosilica (BPMO–IL–SO3H) as a Highly Efficient and Reusable Nanocatalyst for the Biginelli Reaction
Authors: Elhamifar Dawood , Nasr‐Esfahani Masoud , Karimi Babak , Moshkelgosha Ramin , Shábani Ahmad
Published: July 2014

The catalytic application of a novel ionic liquid and sulfonic acid based bifunctional periodic mesoporous organosilica (BPMO–IL–SO3H) in the one‐pot Biginelli reaction was developed. The BPMO–IL–SO3H catalyst was first prepared by hydrolysis and co‐condensation of tetramethoxysilane, 1,3‐bis(trimethoxysilylpropyl)‐imidazolium iodide and 3‐mercaptopropyl‐trimethoxysilane in the presence of surfactant template under acidic conditions followed by oxidation of SH groups in the presence of hydrogen peroxide. This catalyst was then characterized by thermal gravimetric analysis, transmission electron microscopy, small‐angle powder X‐ray diffraction, and nitrogen sorption analysis. The performance of the BPMO–IL–SO3H catalyst was investigated in the Biginelli condensation of a variety of different aldehydes with alkylacetoacetates and urea under solvent‐free conditions. The catalyst exhibited excellent activity and delivered corresponding Biginelli products in high to excellent yields and selectivities. Moreover, the reactivity, reusability, and stability of the BPMO–IL–SO3H were also investigated under the applied reaction conditions. Our study showed that the catalyst could be recovered and reused at least 10 times without any significant decrease in efficiency.
Efficient Catalytic Hydrogenation of N‐Unsubstituted Cyclic Imides to Cyclic Amines
Authors: Maj Anna M. , Suisse Isabelle , Pinault Nathalie , Robert Nicolas , Agbossou‐Niedercorn Francine
Published: July 2014

The hydrogenation of N‐unsubstituted cyclic imides to the corresponding cyclic amines has been performed selectively with heterogeneous catalysts obtained from rhodium and molybdenum carbonyl precursors. Various substrates were reduced in good to high yields and selectivities. Platinum‐based catalysts also proved to be efficient. Furthermore, gram‐scale experiments were performed and the catalysts could be recycled.
Catalytic Deoxygenation of Fatty Acids: Elucidation of the Inhibition Process
Authors: Hollak Stefan A. W. , de Jong Krijn P. , van Es Daan S.
Published: July 2014

Catalytic deoxygenation of unsaturated fatty acids in the absence of H2is known to suffer from significant catalyst inhibition. Thus far, no conclusive results have been reported on the cause of deactivation. Here we show that CC double bonds present in the feed or the products dramatically reduce the deoxygenation activity of supported palladium catalysts. In the case of stearic acid deoxygenation the addition of 0.1 equivalents of a mono‐unsaturated fatty acid or olefin already reduces the catalytic deoxygenation activity by 60 %. This effect becomes more pronounced with an increasing number of double bonds. The inhibition is shown to be reversible in H2atmosphere, indicating no significant contribution from irreversibly deposited hard coke. Furthermore, the type of support material has no apparent effect on catalyst inhibition. Hence we propose that initial catalyst inhibition proceeds through reversible adsorption of CC double bonds on the palladium active sites.
Corrosive Degeneration of Autoclaves for the Ammonothermal Synthesis: Experimental Approach and First Results
Authors: Hertweck Benjamin , Steigerwald Thomas G. , Alt Nicolas S. A. , Schluecker Eberhard
Published: July 2014

The ammonothermal growth of different bulk group III nitride materials enables cost‐efficient production of high‐quality single crystals. Despite its advantages this process is limited due to the corrosive ammonothermal environment. This environment consists of supercritical ammonia with acidic or basic additives at high temperatures and pressures in high‐pressure cells made of a nickel‐base alloy. As a consequence of corrosion, large amounts of metallic impurities are detectable in the grown crystals. The mechanisms of corrosion are not well understood. A method is presented to investigate corroded autoclaves, caused by the interaction with supercritical fluid, together with first results regarding the degeneration of autoclave material.
Combustion of Lithium Particles: Optical Measurement Methodology and Initial Results
Authors: Schiemann Martin , Fischer Peter , Scherer Viktor , Schmid Günter , Taroata Dan
Published: July 2014

Combustion examinations on the single‐grain level were carried out in order to get further fundamental insight into the ignition and combustion of lithium particles. Combustion of solid lithium particles in a defined size fraction was analyzed in a laminar‐flow reactor. The exhaust gases of a methane‐air flame provided the reactants O2, CO2, N2, and H2O for the lithium conversion. Two different atmospheres at various temperatures were investigated. A high‐speed camera system measured size and radiation intensity of burning particles. The results indicate that two different combustion phenomena occurred in lithium combustion. The first was identified as a homogeneously enveloping flame around the lithium particle and the second as a reaction zone next to the particle surface.
Effect of Water Flow Rate on Decontamination Efficiency of Emergency Safety Showers
Authors: Brock Thomas , Heil Volker , Philipp Hermann , Seifert Ulrich , Steffens Wilfried , Timm Kurt
Published: July 2014

Standards for overhead emergency safety showers used for decontamination in laboratories and production sites specify the spray pattern and the water flow rate. Up to now, there has not been a scientific basis for these requirements. The decontamination of water‐soluble contaminants has been investigated using 15 customary shower heads at different water flow rates. A general relationship between water flow rate and decontamination effectiveness could not be established: At a low flow rate, the wash‐off time in general did not exceed the time observed at considerably higher flow rates. The shortest decontamination time has been found with a spray pattern that does not fulfil current standards.
Toward a Consistent Interpretation of the QTAIM: Tortuous Link between Chemical Bonds, Interactions, and Bond/Line Paths
Authors: Foroutan‐Nejad Cina , Shahbazian Shant , Marek Radek
Published: July 2014

Currently, bonding analysis of molecules based on the Quantum Theory of Atoms in Molecules (QTAIM) is popular; however, “misinterpretations” of the QTAIM analysis are also very frequent. In this contribution the chemical relevance of the bond path as one of the key topological entities emerging from the QTAIM’s topological analysis of the one‐electron density is reconsidered. The role of nuclear vibrations on the topological analysis is investigated demonstrating that the bond paths are not indicators of chemical bonds. Also, it is argued that the detection of the bond paths is not necessary for the “interaction” to be present between two atoms in a molecule. The conceptual disentanglement of chemical bonds/interactions from the bonds paths, which are alternatively termed “line paths” in this contribution, dismisses many superficial inconsistencies. Such inconsistencies emerge from the presence/absence of the line paths in places of a molecule in which chemical intuition or alternative bonding analysis does not support the presence/absence of a chemical bond. Moreover, computational QTAIM studies have been performed on some “problematic” molecules, which were considered previously by other authors, and the role of nuclear vibrations on presence/absence of the line paths is studied demonstrating that a bonding pattern consistent with other theoretical schemes appears after a careful QTAIM analysis and a new “interpretation” of data is performed.
Self‐Assembly of Decoupled Borazines on Metal Surfaces: The Role of the Peripheral Groups
Authors: Kalashnyk Nataliya , Ganesh Nagaswaran Praveen , Kervyn Simon , Riello Massimo , Moreton Ben , Jones Tim S. , De Vita Alessandro , Bonifazi Davide , Costantini Giovanni
Published: July 2014

Two borazine derivatives have been synthesised to investigate their self‐assembly behaviour on Au(111) and Cu(111) surfaces by scanning tunnelling microscopy (STM) and theoretical simulations. Both borazines form extended 2D networks upon adsorption on both substrates at room temperature. Whereas the more compact triphenyl borazine 1 arranges into close‐packed ordered molecular islands with an extremely low density of defects on both substrates, the tris(phenyl‐4‐phenylethynyl) derivative 2 assembles into porous molecular networks due to its longer lateral substituents. For both species, the steric hindrance between the phenyl and mesityl substituents results in an effective decoupling of the central borazine core from the surface. For borazine 1, this is enough to weaken the molecule–substrate interaction, so that the assemblies are only driven by attractive van der Waals intermolecular forces. For the longer and more flexible borazine 2, a stronger molecule–substrate interaction becomes possible through its peripheral substituents on the more reactive copper surface.
One‐Pot Asymmetric Synthesis of Quaternary Pyrroloindolones through a Multicatalytic N‐Allylation/Hydroacylation Sequence
Authors: Lu Hong , Lin Jun‐Bing , Liu Jin‐Yu , Xu Peng‐Fei
Published: July 2014

An intramolecular, quaternary carbon center forming hydroacylation of α‐substituted acrylates has been discovered. This interesting transformation can be readily incorporated into a multicatalytic tandem process enabled by a combination of nucleophilic tertiary amine and N‐heterocyclic carbene catalysis. With no additional stoichiometric base required, this transformation affords the quaternary pyrroloindolones with high levels of enantioselectivity.
Anion Recognition with Hydrogen‐Bonding Cyclodiphosphazanes
Authors: Klare Helge , Hanft Sebastian , Neudörfl Jörg M. , Schlörer Nils E. , Griesbeck Axel , Goldfuss Bernd
Published: July 2014

Modular cyclodiphosph(V)azanes are synthesised and their affinity for chloride and actetate anions were compared to those of a bisaryl urea derivative (1). The diamidocyclodiphosph(V)azanes cis‐[{ArNHP(O)(μ‐tBu)}2] [Ar=Ph (2) and Ar=m‐(CF3)2Ph (3)] were synthesised by reaction of [{ClP(μ‐NtBu)}2] (4) with the respective anilines and subsequent oxidation with H2O2. Phosphazanes 2 and 3 were obtained as the cis isomers and were characterised by multinuclear NMR spectroscopy, FTIR spectroscopy, HRMS and single‐crystal X‐ray diffraction. The cyclodiphosphazanes 2 and 3 readily co‐crystallise with donor solvents such as MeOH, EtOH and DMSO through bidentate hydrogen bonding, as shown in the X‐ray analyses. Cyclodiphosphazane 3 showed a remarkably high affinity (log[K]=5.42) for chloride compared with the bisaryl urea derivative 1 (log[K]=4.25). The affinities for acetate (AcO−) are in the same range (3: log[K]=6.72, 1: log[K]=6.91). Cyclodiphosphazane 2, which does not contain CF3 groups, exhibits weaker binding to chloride (log[K]=3.95) and acetate (log[K]=4.49). DFT computations and X‐ray analyses indicate that a squaramide‐like hydrogen‐bond directionality and CαH interactions account for the efficiency of 3 as an anion receptor. The CαH groups stabilise the Z,Z‐3 conformation, which is necessary for bidentate hydrogen bonding, as well as coordinating with the anion.
Silyl Ligand Mediated Reversible β‐Hydrogen Elimination and Hydrometalation at Palladium
Authors: Takaya Jun , Iwasawa Nobuharu
Published: July 2014

The mechanism and origin of the facile β‐hydrogen elimination and hydrometalation of a palladium complex bearing a phenylene‐bridged PSiP pincer ligand are clarified. Experimental and theoretical studies demonstrate a new mechanism for β‐hydrogen elimination and hydrometalation mediated by a silyl ligand at palladium, which enables direct interconversion between an ethylpalladium(II) complex and an η2‐(Si‐H)palladium(0) complex without formation of a square‐planar palladium(II) hydride intermediate. The flexibility of the PSiP pincer ligand enables it to act as an efficient scaffold to deliver the hydrogen atom as a hydride ligand.
Gold(I)‐Catalysed Direct Thioetherifications Using Allylic Alcohols: an Experimental and Computational Study
Authors: Herkert Lorena , Green Samantha L. J. , Barker Graeme , Johnson David G. , Young Paul C. , Macgregor Stuart A. , Lee Ai‐Lan
Published: July 2014

A gold(I)‐catalysed direct thioetherification reaction between allylic alcohols and thiols is presented. The reaction is generally highly regioselective (SN2′). This dehydrative allylation procedure is very mild and atom economical, producing only water as the by‐product and avoiding any unnecessary waste/steps associated with installing a leaving or activating group on the substrate. Computational studies are presented to gain insight into the mechanism of the reaction. Calculations indicate that the regioselectivity is under equilibrium control and is ultimately dictated by the thermodynamic stability of the products.