bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isocyanide‐Induced Activation of Copper Sulfate: Direct Access to Functionalized Heteroarene Sulfonic Esters
Authors: Hong Xiaohu , Tan Qitao , Liu Bingxin , Xu Bin 
Published: March 2017

AbstractA novel and direct approach to alkyl/aryl heteroarene sulfonic esters using copper sulfate as the environmentally benign inorganic sulfonation reagent was first realized with the aid of isocyanide. A variety of heterocycles reacted to afford the corresponding sulfonic esters through C−H functionalization. In this transformation, the otherwise inert copper sulfate was unusually activated by an isocyanide and employed as the source of the sulfonic substituents in an unprecedented fashion. The findings suggest that an appropriate activator may liberate the chemical activities of some relatively inert inorganic salts for organic synthesis.
Facile Two‐Step Synthesis of 1,10‐Phenanthroline‐Derived Polyaza[7]helicenes with High Fluorescence and CPL Efficiency
Authors: Otani Takashi , Tsuyuki Ami , Iwachi Taiki , Someya Satoshi , Tateno Kotaro , Kawai Hidetoshi , Saito Takao , Kanyiva Kyalo Stephen , Shibata Takanori 
Published: March 2017

AbstractA facile two‐step synthesis of aza[7]helicenes possessing a 6‐5‐6‐6‐6‐5‐6 skeleton from commercially available 2,9‐dichloro‐1,10‐phenanthroline via double amination with aniline derivatives followed by hypervalent iodine reagent‐mediated intramolecular double‐NH/CH couplings was developed. Single‐crystal X‐ray analyses of the helicenes revealed unique structures, including both a significantly twisted center and planar terminals of the skeleton. The azahelicenes show high fluorescent quantum yields (Φs) under both neutral (Φ: 0.25–0.55) and acidic conditions (Φ: up to 0.80). An enantiomerically pure aza[7]helicene showed high circularly polarized luminescence (CPL) activity under both neutral and acidic conditions (glum: up to 0.009).
B(C6F5)3‐Catalyzed Ring Opening and Isomerization of Unactivated Cyclopropanes
Authors: Zhang Zi‐Yu , Liu Zhi‐Yun , Guo Rui‐Ting , Zhao Yu‐Quan , Li Xiang , Wang Xiao‐Chen 
Published: March 2017

AbstractCatalytic amounts of B(C6F5)3 promote the ring opening and subsequent isomerization of a series of unactivated cyclopropanes to afford terminal olefins in good yields when a hydrosilane and 2,6‐dibromopyridine are employed as additives.
Cobalt‐Catalyzed Z‐Selective Hydrosilylation of Terminal Alkynes
Authors: Teo Wei Jie , Wang Chao , Tan Ye Wei , Ge Shaozhong 
Published: March 2017

AbstractA cobalt‐catalyzed Z‐selective hydrosilylation of alkynes has been developed relying on catalysts generated from bench‐stable Co(OAc)2 and pyridine‐2,6‐diimine (PDI) ligands. A variety of functionalized aromatic and aliphatic alkynes undergo this transformation, yielding Z‐vinylsilanes in high yields with excellent selectivities (Z/E ratio ranges from 90:10 to >99:1). The addition of a catalytic amount of phenol effectively suppressed the Z/E‐isomerization of the Z‐vinylsilanes that formed under catalytic conditions.
Polymeric Halogen‐Bond‐Based Donor Systems Showing Self‐Healing Behavior in Thin Films
Authors: Tepper Ronny , Bode Stefan , Geitner Robert , Jäger Michael , Görls Helmar , Vitz Jürgen , Dietzek Benjamin , Schmitt Michael , Popp Jürgen , Hager Martin D. , Schubert Ulrich S. 
Published: March 2017

AbstractThe synthesis and comprehensive characterization of a systematic series of cleft‐type anion receptors imbedded into a polymeric architecture is presented. For the first time, isothermal calorimetric titrations on polymeric halogen‐bond‐based donors were exploited to evaluate the dependence of the anion affinity on different key parameters (i.e. monomeric versus polymeric receptor, halogen versus hydrogen bonding, charge assistance). The combination of these donor systems with a copolymer bearing accepting carboxylate groups led to supramolecular cross‐linked polymer networks showing excellent intrinsic self‐healing behavior. FT‐Raman spectroscopy and nano‐indentation measurements were utilized to clarify the thermally induced self‐healing mechanism based on the formation of halogen bonds. These first self‐healing materials based on halogen bonds pave the way for new applications of halogen‐bond donors in polymer and material science.
Nanomechanical Infrared Spectroscopy with Vibrating Filters for Pharmaceutical Analysis
Authors: Kurek Maksymilian , Carnoy Matthias , Larsen Peter E. , Nielsen Line H. , Hansen Ole , Rades Thomas , Schmid Silvan , Boisen Anja 
Published: March 2017

AbstractStandard infrared spectroscopy techniques are well‐developed and widely used. However, they typically require milligrams of sample and can involve time‐consuming sample preparation. A promising alternative is represented by nanomechanical infrared spectroscopy (NAM‐IR) based on the photothermal response of a nanomechanical resonator, which enables the chemical analysis of picograms of analyte directly from a liquid solution in only a few minutes. Herein, we present NAM‐IR using perforated membranes (filters). The method was tested with the pharmaceutical compound indomethacin to successfully perform a chemical and morphological analysis on roughly 100 pg of sample. With an absolute estimated sensitivity of 109±15 fg, the presented method is suitable for ultrasensitive vibrational spectroscopy.
Polyurethane/esterified cellulose nanocrystal composites as a transparent moisture barrier coating for encapsulation of dye sensitized solar cells
Authors: Yuwawech Kitti , Wootthikanokkhan Jatuphorn , Wanwong Sompit , Tanpichai Supachok 
Published: March 2017

ABSTRACTThis research work aims to investigate the effects of types and concentration of cellulose nanocrystals (CNCs) prepared from bacterial cellulose (BC) and nanofibrillated cellulose (NFC) on structure properties of polyurethane (PU) composites. Feasibility of applying the polymer composite for encapsulation of dye sensitized solar cells was of interest. Both CNCs were pretreated via esterification before mixing with the polyurethane by a solution process. Tensile strength and thermal stability of the PU/esterified CNCs were found to be superior to those of the systems reinforced with untreated CNCs. With the introduction of both untreated and esterified CNCs, water vapor transmission rates through the PU composite films were lowered while their visible light transmittance values were maintained to be above 80%. Also, better efficiency and stability of the solar cell were obtained when the PU was reinforced with CNCs, indicating its longer lifetime usage. The most suitable cell, described in terms of durability, was obtained when the PU was mixed with 2 wt % of esterified CNCs obtained from BC. Overall, this study shows that the surface modification of the CNCs is an important factor, affecting the reinforcing efficacy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45010.
Loading the polyol carbonization agent into clay nanotubes for the preparation of environmentally stable UV‐cured epoxy materials
Authors: Zheng Tiancheng , Ni Xiuyuan 
Published: March 2017

ABSTRACTThe halloysite nanotubes (HNTs) were loaded with pentaerythritol (PER). The as‐prepared composite (HNT‐P) and ammonium polyphosphate (APP) was subsequently added to the UV‐curable epoxy resins, giving a new flame‐resistant system. Loading of the hydrophilic PER into HNT can reduce the moisture absorption in the UV‐curable epoxy resins. The flame retardancy was evaluated by means of the cone calorimeter and limit oxygen index test. The results showed that the flame retardancy of the modified epoxy resin was greatly improved with an obvious decrease in both the heat release and smoke release. Moreover, it was revealed that HNT could catalyze the reaction of APP and PER, and the burning surface of the epoxy resin should be covered by the polyphosphoric‐HNT intumescent char layer. We have measured the moisture sorption and dynamic mechanical properties of the UV‐cured epoxy resins. As compared to the use of the simple mixture of PER and HNT, the use of the HNT‐P nearly kept the storage modulus at about 1809 Mpa and reduced the moisture absorption by 58.2 wt % at 40 °C. The results proved that the addition of the HNT‐P obtained lower moisture absorption and higher stability of the mechanical properties than adding the simple mixture. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45045.
Insertion of Group 12–16 Hydrides into NHCs: A Theoretical Investigation
Authors: Iversen Kalon J. , Dutton Jason L. , Wilson David J. D. 
Published: March 2017

AbstractThe endocyclic ring expansion of N‐heterocyclic carbene (NHC) rings by transition metal (group 12) and main group (group 13–16) element hydrides has been investigated in a computational study. In addition to previously reported insertion reactivity with Si, B, Be and Zn, similar reactivity is predicted to be feasible for heavier group 13 elements (Al, Ga, In, Tl), with the reaction barriers for Al–Tl calculated to be lower than for boron. Insertion is not expected with group 15–16 element hydrides, as the initial adduct formation is thermodynamically unfavorable. The reaction pathway with group 12 hydrides is calculated to be more favorable with two NHCs rather than a single NHC (analogous to Be), however hydride ring insertion with metal dihydrides is not feasible, but rather a reduced NHC is thermodynamically favored. For group 14, ring‐insertion reactivity is predicted to be feasible with the heavier dihydrides. Trends in reactivity of element hydrides may be related to the protic or hydridic character of the element hydrides.
An artificial TCA cycle selects for efficient α‐ketoglutarate dependent hydroxylase catalysis in engineered Escherichia coli
Authors: Theodosiou Eleni , Breisch Marina , Julsing Mattijs K. , Falcioni Francesco , Bühler Bruno , Schmid Andreas 
Published: March 2017

ABSTRACTAmino acid hydroxylases depend directly on the cellular TCA cycle via their cosubstrate α‐ketoglutarate (α‐KG) and are highly useful for the selective biocatalytic oxyfunctionalization of amino acids. This study evaluates TCA cycle engineering strategies to force and increase α‐KG flux through proline‐4‐hydroxylase (P4H). The genes sucA (α‐KG dehydrogenase E1 subunit) and sucC (succinyl‐CoA synthetase β subunit) were alternately deleted together with aceA (isocitrate lyase) in proline degradation‐deficient Escherichia coli strains (ΔputA) expressing the p4h gene. Whereas, the ΔsucCΔaceAΔputA strain grew in minimal medium in the absence of P4H, relying on the activity of fumarate reductase, growth of the ΔsucAΔaceAΔputA strictly depended on P4H activity, thus coupling growth to proline hydroxylation. P4H restored growth, even when proline was not externally added. However, the reduced succinyl‐CoA pool caused a 27% decrease of the average cell size compared to the wildtype strain. Medium supplementation partially restored the morphology and, in some cases, enhanced proline hydroxylation activity. The specific proline hydroxylation rate doubled when putP, encoding the Na+/l‐proline transporter, was overexpressed in the ΔsucAΔaceAΔputA strain. This is in contrast to wildtype and ΔputA single‐knock out strains, in which α‐KG availability obviously limited proline hydroxylation. Such α‐KG limitation was relieved in the ΔsucAΔaceAΔputA strain. Furthermore, the ΔsucAΔaceAΔputA strain was used to demonstrate an agar plate‐based method for the identification and selection of active α‐KG dependent hydroxylases. This together with the possibility to waive selection pressure and overcome α‐KG limitation in respective hydroxylation processes based on living cells emphasizes the potential of TCA cycle engineering for the productive application of α‐KG dependent hydroxylases. Biotechnol. Bioeng. 2017;114: 1511–1520. © 2017 Wiley Periodicals, Inc.
Understanding of decreased sialylation of Fc‐fusion protein in hyperosmotic recombinant Chinese hamster ovary cell culture: N‐glycosylation gene expression and N‐linked glycan antennary profile
Authors: Lee Jong Hyun , Jeong Yeong Ran , Kim Yeon‐Gu , Lee Gyun Min 
Published: March 2017

ABSTRACTTo understand the effects of hyperosmolality on protein glycosylation, recombinant Chinese hamster ovary (rCHO) cells producing the Fc‐fusion protein were cultivated in hyperosmolar medium resulting from adding NaCl (415 mOsm/kg). The hyperosmotic culture showed increased specific Fc‐fusion protein productivity (qFc) but a decreased proportion of acidic isoforms and sialic acid content of the Fc‐fusion protein. The intracellular and extracellular sialidase activities in the hyperosmotic cultures were similar to those in the control culture (314 mOsm/kg), indicating that reduced sialylation of Fc‐fusion protein at hyperosmolality was not due to elevated sialidase activity. Expression of 52 N‐glycosylation‐related genes was assessed by the NanoString nCounter system, which provides a direct digital readout using custom‐designed color‐coded probes. After 3 days of hyperosmotic culture, nine genes (ugp, slc35a3, slc35d2, gcs1, manea, mgat2, mgat5b, b4galt3, and b4galt4) were differentially expressed over 1.5‐fold of the control, and all these genes were down‐regulated. N‐linked glycan analysis by anion exchange and hydrophilic interaction HPLC showed that the proportion of highly sialylated (di‐, tri‐, tetra‐) and tetra‐antennary N‐linked glycans was significantly decreased upon hyperosmotic culture. Addition of betaine, an osmoprotectant, to the hyperosmotic culture significantly increased the proportion of highly sialylated and tetra‐antennary N‐linked glycans (P ≤ 0.05), while it increased the expression of the N‐glycan branching/antennary genes (mgat2 and mgat4b). Thus, decreased expression of the genes with roles in the N‐glycan biosynthesis pathway correlated with reduced sialic acid content of Fc‐fusion protein caused by hyperosmolar conditions. Taken together, the results obtained in this study provide a better understanding of the detrimental effects of hyperosmolality on N‐glycosylation, especially sialylation, in rCHO cells. Biotechnol. Bioeng. 2017;114: 1721–1732. © 2017 Wiley Periodicals, Inc.
Modifying CloudSim to accurately simulate interactive services for cloud autoscaling
Authors: Vondra T. , Šedivý J. , Castro J. M. 
Published: March 2017

SummaryWe study the problem of autoscaling in cloud deployments and issues related to autoscaling strategies and their formal evaluation. With this goal, we propose modifications of the CloudAnalyst distribution of CloudSim for improved autoscaler simulations. We extend the CloudSim platform with virtual machine addition/removal at simulation run time as well as more granular load reporting and implement a simple autoscaler simulation. We point out and fix multiple problems in CloudSim job duration computation methods and make it consistent with both theory and reality, improving the relative errors of simulation from as high as 333% to single‐figure percentages. Our main contribution is a formally evaluated autoscaling strategy and improved version of CloudAnalyst capable of realistic evaluations.
Using adaptive runtime filtering to support an event‐based performance analysis
Authors: Stolle Jonas , Wagner Michael , Doleschal Jens , Schmitt Felix , Brunst Holger 
Published: March 2017

SummaryEvent‐based performance monitoring and analysis are effective means when tuning parallel applications for optimal resource usage. In this article, we address the data capacity challenge that arises when applying the tracing methodology to large‐scale parallel applications and long execution times. Existing approaches use static, pre‐defined event filters to reduce the performance data to a manageable size. In contrast, we propose self‐guided filters that automatically adapt to an application's runtime behaviour and therefore, do not require any previous knowledge or application executions. Our contribution consists of four adaptive runtime filters, which target a specific type of data redundancy each. The filters focus on detecting identical events in loop iterations, constant events with no variation in time, and very short, highly frequent, typically not very meaningful events, having a severe impact on the total data volume. We evaluate our prototype implementation with five real‐world applications and achieve a data reduction of two orders of magnitude while increasing execution time less than 1%. Likewise, we show that the qualitative impact of our filters on performance analysis in state‐of‐the‐art analysis tools can be reduced by adding feedback methods and statistical information to the filtered traces. Copyright © 2017 John Wiley & Sons, Ltd.
Perfect or Imperfect Duties? Developing a Moral Responsibility Framework for Corporate Sustainability from the Consumer Perspective
Authors: Jung Sojin , Ha‐Brookshire Jung 
Published: March 2017

AbstractThe moral responsibility theory of corporate sustainability argues that the extent of corporations' commitment toward sustainable development depends on how they perceive sustainability within the moral spectrum – from perfect to imperfect duties. This study assessed consumers' perceptions toward corporate sustainability and whether the moral spectrum toward corporate sustainability exists. After reviewing the corporate sustainability reports of 22 consumer product companies considered sustainable, 44 unique sustainable business activities were identified. These activities were then tested by a national sample of 271 US consumers. The results showed that participants perceived working conditions and environmental support activities to be the most important corporate duties (or perfect duties), followed by community development and transparency enhancement activities (or imperfect duties). This study also found differences in perceptions according to participants' demographic characteristics. These findings add knowledge to the area of corporate moral responsibility, and help firms have a clear understanding of consumers' expectations on corporate moral responsibility toward sustainable development. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Utility of touch imprint cytology in the preoperative diagnosis of malignancy in low resource setting
Authors: Adhya Amit Kumar , Mohanty Ranjan 
Published: March 2017

BackgroundTouch imprint cytology (TIC) is a very rapid, cheap, and easy method used for the rapid evaluation of intraoperative specimens and post mortem cases. This study aims to evaluate its utility in preoperative diagnosis of cancer.MethodsA total of 476 cases of suspected malignancy of different sites and different histological subtypes were studied. TIC was obtained in all the biopsies and the cytological findings were correlated with the corresponding biopsy diagnosis to evaluate the diagnostic accuracy.ResultsTIC was satisfactory for evaluation with respect to the cellularity and cell morphology in 468 (98.3%) cases. Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 96.9, 97.4, 99.1, 91.2, and 97.1%, respectively. The accuracy varied with the site of biopsy. The accuracy for soft tissue lesions was 92% whereas it was 100% for sites like thyroid, anal canal, rectum, and prostate.ConclusionsTIC is a simple and rapid technique and gives fairly accurate diagnosis while the cost is much less than the traditional histopathological techniques. The presence or absence of malignancy and the exact subtype can be diagnosed reliably making it quiet useful for preoperative cancer diagnosis. Diagn. Cytopathol. 2017;45:507–512. © 2017 Wiley Periodicals, Inc.
Organic sediment pulses impact rivers across multiple levels of ecological organization
Authors: Aspray Katie L. , Holden Joseph , Ledger Mark E. , Mainstone Chris P. , Brown Lee E. 
Published: March 2017

AbstractSedimentation is a pervasive environmental pressure affecting rivers globally. Headwaters draining catchments rich in organic soils (i.e., peat) are particularly vulnerable to enhanced sedimentation caused by land management and environmental change, yet many of the ecological consequences of peat deposition are poorly understood. We conducted a before‐after‐control‐impact experiment in two rivers draining blanket peatland in Northern England to test the effect of sediment inputs on water quality, macroinvertebrate drift, macroinvertebrate community structure, and ecosystem metabolism. Sediment addition increased concentrations of dissolved organic carbon, total oxidised nitrogen and suspended sediment concentration in rivers, and intensified the total drift of macroinvertebrates particularly at night. By contrast, the abundance and richness of benthic macroinvertebrates were unaffected, except for declines in Coleoptera abundance in one river. The gross primary production of both rivers was strongly suppressed as the benthos was smothered by sediment. Community respiration also declined, albeit by different extents in the two rivers. Our experiment revealed that short‐term pulses of organic sediment in rivers can have broad effects on water quality and biota, from influences on the dispersal of individual organisms to the modification of ecosystem processes. Organic sediments therefore warrant further examination, to include longer observation periods and more sites. It is particularly important to clarify the extent to which impacts extend from peatland streams into larger rivers downstream. Such studies are necessary to inform global management efforts to restore the integrity of river ecosystems under a range of water and biodiversity policy mechanisms.
A microstratigraphic reevaluation of the Florisbad spring site, Free State Province, South Africa: Formation processes and paleoenvironment
Authors: Toffolo Michael B. , Brink James S. , van Huyssteen Cornie , Berna Francesco 
Published: March 2017

AbstractThe Florisbad spring site has produced a large collection of fossil bones dating to the Middle Pleistocene and several assemblages of Middle Stone Age (MSA) artifacts. The species featured in the faunal collection define the Florisian Land Mammal Age, characterized mainly by grazing ungulates that reflect an open grassland environment. Early MSA artifacts found within the basal layers represent the earliest evidence of human presence at Florisbad, followed by an intact MSA occupation horizon characterized by stone tools and animal bones, in direct association and primary context. These fossils and artifacts were found embedded within sand and peat layers. Previous studies investigated the genesis of such deposits using field descriptions and bulk sedimentological analyses. However, sediments were never studied within their original context, thus leading to difficulties in determining the formation processes of the deposits. Using a multianalytical micro‐geoarchaeological approach including sediment micromorphology, FTIR and XRD, we were able to show that the site is characterized by alternating aeolian sand layers reworked by lacustrine water during the wet phases of the Pleistocene, and peat layers formed in marshes during dry phases. The results confirm most of the previous paleoenvironmental reconstructions and provide a refined stratigraphic sequence of the site.