bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Synthetic Route to Microporous Silica with Well‐Defined Pores by Replication of a Metal–Organic Framework
Authors: Kondo Atsushi , Hall Anthony Shoji , Mallouk Thomas E. , Maeda Kazuyuki
Published: July 2015

Microporous amorphous hydrophobic silica materials with well‐defined pores were synthesized by replication of the metal–organic framework (MOF) [Cu3(1,3,5‐benzenetricarboxylate)2] (HKUST‐1). The silica replicas were obtained by using tetramethoxysilane or tetraethoxysilane as silica precursors and have a micro–meso binary pore system. The BET surface area, the micropore volume, and the mesopore volume of the silica replica, obtained by means of hydrothermal treatment at 423 K with tetraethoxysilane, are 620 m2g−1, 0.18 mL g−1, and 0.55 mL g−1, respectively. Interestingly, the silica has micropores with a pore size of 0.55 nm that corresponds to the pore‐wall thickness of the template MOF. The silica replica is hydrophobic, as confirmed by adsorption analyses, although the replica has a certain amount of silanol groups. This hydrophobicity is due to the unique condensation environment of the silica precursors in the template MOF.
Synthesis and Characterization of Carbazole‐Linked Porphyrin Tweezers
Authors: Chang Yi , Michelin Clément , Bucher Léo , Desbois Nicolas , Gros Claude P. , Piant Sébastien , Bolze Frédéric , Fang Yuanyuan , Jiang Xiaoqin , Kadish Karl M.
Published: July 2015

Herein the synthesis, spectroscopic characterization, two‐photon absorption and electrochemical properties of 3,6‐disubstituted carbazole tweezers is reported. A dimer resulting from a Glaser homocoupling was isolated during a Sonogashira coupling reaction between a diethynyl‐carbazole spacer and a 5‐bromo‐triarylporphyrin and the properties of this original compound were compared with the 3,6‐disubstituted carbazole bisporphyrin tweezers. The dyads reported herein present a two‐photon absorption maximum at 920 nm with two‐photon absorption cross‐section in the 1200 GM range. Despite a strong linear absorption in the Soret region and moderate fluorescence quantum yield, they both lead to a high brightness reaching 30 000 M−1 cm−1.
Highly Stable trans‐Cyclooctene Amino Acids for Live‐Cell Labeling
Authors: Hoffmann Jan‐Erik , Plass Tilman , Nikić Ivana , Aramburu Iker Valle , Koehler Christine , Gillandt Hartmut , Lemke Edward A. , Schultz Carsten
Published: July 2015

trans‐Cyclooctene groups incorporated into proteins via non‐canonical amino acids (ncAAs) are emerging as specific handles for bioorthogonal chemistry. Here, we present a highly improved synthetic access to the axially and the equatorially linked trans‐cyclooct‐2‐ene isomers (1 a,b). We further show that the axially connected isomer has a half‐life about 10 times higher than the equatorial isomer and reacts with tetrazines much faster, as determined by stopped‐flow experiments. The improved properties resulted in different labeling performance of the insulin receptor on the surface of intact cells.
A New Strategy for Enantioselective Construction of Multisubstituted Five‐Membered Oxygen Heterocycles via a Domino Michael/Hemiketalization Reaction
Authors: Hua Yuan‐Zhao , Liu Meng‐Meng , Huang Pei‐Jin , Song Xixi , Wang Min‐Can , Chang Jun‐Biao
Published: July 2015

A new highly enantioselective domino Michael/hemiketalization reaction of α‐hydroxyacetophenone with β,γ‐unsaturated α‐keto esters for the synthesis of 2,2,4,5‐tetrasubstituted chiral tetrahydrofurans is reported. With 2 mol % intramolecular dinuclear zinc‐AzePhenol complex prepared in situ from the reaction of multidentate semi‐azacrown ether ligand with ZnEt2, the corresponding anti‐multisubstituted tetrahydrofuran products were obtained in up to 90 % yields, and 98 % enantiomeric excess (ee) at 0 °C for 45 min. Moreover, the products were easily converted to 2,3,5‐trisubstituted 2,3‐dihydrofurans without any loss in optical activity.
Functionalized Pentafluoroethylphosphanes
Authors: Allefeld Nadine , Neumann Beate , Stammler Hans‐Georg , Ignat'ev Nikolai , Hoge Berthold
Published: July 2015

Bis(diethylamino)pentafluoroethylphosphane represents a versatile starting material for the synthesis of functionalized pentafluoroethylphosphanes. Perfluoroalkyl substituted aminophosphanes themselves already exhibit interesting coordination properties and were treated with the catalytically relevant salts PtCl2 and PdCl2 affording trans‐[Cl2M{P(C2F5)(NEt2)2}2]. The hitherto unknown (C2F5)PBr2, accessible in good yields by treatment of C2F5P(NEt2)2 with HBr, was smoothly transformed into the corresponding phosphane, C2F5PH2, or fluoro derivative, C2F5PF2. Acidic hydrolysis of C2F5P(NEt2)2 yielded the phosphinic acid C2F5P(O)(OH)H, the anion of which was structurally characterized. The phosphinic acid smoothly adds to the carbonyl group of acetone under PC bond formation. An analogous reaction with aldehydes, for example, salicyl aldehyde, offers the possibility to generate stereocenters.
An Artificial Enzyme Made by Covalent Grafting of an FeII Complex into β‐Lactoglobulin: Molecular Chemistry, Oxidation Catalysis, and Reaction‐Intermediate Monitoring in a Protein
Authors: Buron Charlotte , Sénéchal‐David Katell , Ricoux Rémy , Le Caër Jean‐Pierre , Guérineau Vincent , Méjanelle Philippe , Guillot Régis , Herrero Christian , Mahy Jean‐Pierre , Banse Frédéric
Published: July 2015

An artificial metalloenzyme based on the covalent grafting of a nonheme FeII polyazadentate complex into bovine β‐lactoglobulin has been prepared and characterized by using various spectroscopic techniques. Attachment of the FeII catalyst to the protein scaffold is shown to occur specifically at Cys121. In addition, spectrophotometric titration with cyanide ions based on the spin‐state conversion of the initial high spin (S=2) FeII complex into a low spin (S=0) one allows qualitative and quantitative characterization of the metal center’s first coordination sphere. This biohybrid catalyst activates hydrogen peroxide to oxidize thioanisole into phenylmethylsulfoxide as the sole product with an enantiomeric excess of up to 20 %. Investigation of the reaction between the biohybrid system and H2O2 reveals the generation of a high spin (S=5/2) FeIII(η2‐O2) intermediate, which is proposed to be responsible for the catalytic sulfoxidation of the substrate.
A Highly Triflated Rare‐Earth Ion in [Eu(O3SCF3)8]5−
Authors: Bruns Jörn , Krüger Sascha , Adlung Matthias , Wickleder Claudia , Niehaus Oliver , Pöttgen Rainer , Klüner Thorsten , Kräuter Jessica , Wickleder Mathias S.
Published: July 2015

The reaction of Eu2O3 with fuming nitric acid, trifluormethanesulfonic acid, and its anhydride in torch‐sealed glass ampoules at 120 °C gave the europium compound (NO)5[Eu(O3SCF3)8] (orthorhombic, Fddd, Z=16, a=1932.69(4), b=2878.44(7), c=2955.12(7) pm, V=16439.7(7) Å3). The compound exhibits the [Eu(O3SCF3)8]5− anion showing for the first time a lanthanide ion that is exclusively coordinated by eight triflate anions. The anion has been further investigated by DFT calculations, which also allowed clear assignment of the vibrational spectra. Moreover, magnetochemical and luminescence measurements gave additional insight into the properties of this complex. The luminescence spectra revealed that the Eu3+ ions are in a pseudo D4d symmetric environment.
Structural Characterization of the Complex between Hen Egg‐White Lysozyme and ZrIV‐Substituted Keggin Polyoxometalate as Artificial Protease
Authors: Sap Annelies , De Zitter Elke , Van Meervelt Luc , Parac‐Vogt Tatjana N.
Published: July 2015

Successful co‐crystallization of a noncovalent complex between hen egg‐white lysozyme (HEWL) and the monomeric ZrIV‐substituted Keggin polyoxometalate (POM) (Zr1 K1), (Et2NH2)3[Zr(PW11O39)] (1), has been achieved, and its single‐crystal X‐ray structure has been determined. The dimeric ZrIV‐substituted Keggin‐type polyoxometalate (Zr1 K2), (Et2NH2)10[Zr(PW11O39)2] (2), has been previously shown to exhibit remarkable selectivity towards HEWL hydrolysis. The reported X‐ray structure shows that the hydrolytically active ZrIV‐substituted Keggin POM exists as a monomeric species. Prior to hydrolysis, this monomer interacts with HEWL in the vicinity of the previously identified cleavage sites found at Trp28‐Val29 and Asn44‐Arg45, through water‐mediated H‐bonding and electrostatic interactions. Three binding sites are observed at the interface of the negatively charged Keggin POM and the positively charged regions of HEWL at: 1) Gly16, Tyr20, and Arg21; 2) Asn44, Arg45, and Asn46; and 3) Arg128.
Porphyrinylboranes Synthesized via Porphyrinyllithiums
Authors: Fujimoto Keisuke , Yorimitsu Hideki , Osuka Atsuhiro
Published: July 2015

As the most nucleophilic porphyrins, meso‐ or β‐lithiated porphyrins were generated by iodine–lithium exchange reactions of the corresponding iodoporphyrins with n‐butyllithium at −98 °C. Porphyrinyllithiums thus prepared were used for synthesis of dimesitylporphyrinylboranes through reactions with fluorodimesitylborane. The boryl groups proved to serve as an electron‐accepting unit to alter the photophysical and electrochemical properties. In addition, 5‐diarylamino‐15‐dimesitylboryl‐substituted donor–accepter porphyrins showed increased intramolecular charge‐transfer character in the S1 state. Furthermore, the reaction of β‐lithiated porphyrin with dichloromesitylborane provided a boron‐bridged porphyrin dimer, which exhibited a conjugative interaction between two porphyrin units through the vacant p‐orbital on the boron center.
Aggregation‐Induced‐Emission‐Active Macrocycle Exhibiting Analogous Triply and Singly Twisted Möbius Topologies
Authors: Wang Erjing , He Zikai , Zhao Engui , Meng Luming , Schütt Christian , Lam Jacky W. Y. , Sung Herman H. Y. , Williams Ian D. , Huang Xuhui , Herges Rainer , Tang Ben Zhong
Published: July 2015

Molecules with Möbius topology have drawn increasing attention from scientists in a variety of fields, such as organic chemistry, inorganic chemistry, and material science. However, synthetic difficulties and the lack of functionality impede their fundamental understanding and practical applications. Here, we report the facile synthesis of an aggregation‐induced‐emission (AIE)‐active macrocycle (TPE‐ET) and investigate its analogous triply and singly twisted Möbius topologies. Because of the twisted and flexible nature of the tetraphenylethene units, the macrocycle adjusts its conformations so as to accommodate different guest molecules in its crystals. Moreover, theoretical studies including topological and electronic calculations reveal the energetically favorable interconversion process between triply and singly twisted topologies.
Source of Selectivity in Oxidative Cross‐Coupling of Aryls by Solvent Effect of 1,1,1,3,3,3‐Hexafluoropropan‐2‐ol
Authors: Elsler Bernd , Wiebe Anton , Schollmeyer Dieter , Dyballa Katrin M. , Franke Robert , Waldvogel Siegfried R.
Published: July 2015

Invited for the cover of this issue is the group of Siegfried R. Waldvogel at the Johannes Gutenberg‐Universität Mainz (Germany). The image depicts a monkey wrench to represent the adjustability of the oxidation potential by solvent sphere. Read the full text of the article at 10.1002/chem.201501604.
Heat transfer and mixing in flow through pinched pipe
Authors: Hasabnis Nilesh S. , Totlani Kartik A. , Ranade Vivek V.
Published: July 2015

There is an increasing trend of using tubular reactors either with passive or active augmentation methods for process intensification. A new passive method with ‘pinching of pipe’ is proposed and investigated for its performance. In the present work, initially, flow in a pinched pipe was studied experimentally and the same was reproduced numerically. The computational model was then used to investigate influences of key geometrical parameters of pinched pipe configuration on pressure drop, heat transfer, and mixing. The simulated results obtained with the pinched pipe were compared with a straight pipe, and with a commonly‐used passive augmentation method (twisted tape inserts). The pinched pipe configuration offers better performance and more flexibility in manipulating heat transfer and mixing in intensified devices.
Kinetic study of the hydrogenation of a monoterpene over spent FCC catalyst‐supported nickel
Authors: Wang Linlin , Guo Huiqing , Chen Xiaopeng , Huang Yingying , Ren Lu , Ding Shengfang
Published: July 2015

A feasible route toward the sustainable synthesis of chemicals was provided via the transformation of monoterpene pinenes into pinane. This article discusses the conversion of pinenes to pinane over spent fluid catalytic cracking catalyst (SFCCC)‐supported nickel (Ni/SFCCC) at 110–130 °C and 2–6 MPa. The Ni/SFCCC catalyst was characterized by BET, XRD, SEM‐EDS, ICP, and FTIR. These measurements revealed that not only did the noble metal‐free catalyst Ni/SFCCC enhance the hydrogenation of pinenes to pinane, but a high cis‐trans ratio was also obtained: the conversion of pinenes and the cis‐trans ratio reached 98.48 % and 13.89, respectively. By fitting the kinetic data via the power‐law model, the hydrogenation of pinenes followed first‐order reaction kinetics, with the apparent activation energies for the hydrogenation of pinenes to cis‐ and trans‐pinane being 59.42 kJ/mol and 98.38 kJ/mol, respectively. The kinetic models described the formation of cis‐ and trans‐pinane well, with satisfactory accuracy compared to experimental observations. Furthermore, the reaction mechanism was derived via the Langmuir–Hinshelwood (L‐H) approach.
Water removal from biodiesel/diesel blends and jet fuel using natural resin as dehydration agent
Authors: Tsanaktsidis Constantinos G. , Favvas Evangelos P. , Tzilantonis George T. , Christidis Stavros G. , Katsidi Elissavet C. , Scaltsoyiannes Apostolos V.
Published: July 2015

Water removal from both biodiesel and diesel/biodiesel blends was studied using a natural removable additive, natural resin. Specifically, two different samples of biodiesel/diesel blends and one of JP8 fuel were studied before and after the blending process with the natural additive. As well as moisture concentration, the properties of density, kinematic viscosity, conductivity, flash point, and heat of combustion were also investigated. Using the proposed method of water removal improves the physicochemical properties of biodiesel/diesel fuel blends, increases the heat of combustion up to 361 J/g, reduces the moisture by ∼66 %, and reduces the conductivity down to 39.5 %. In the case of JP8 fuel decreasing moisture content increases the heat of combustion by 187 J/g, decreases the conductivity by 60 %, and establishes the moisture level within accepted values, from 68 to lower than 50 mg/kg.
Profiling heteroscedasticity in linear regression models
Authors: Zhou Qian M. , Song Peter X.‐K. , Thompson Mary E.
Published: July 2015

Diagnostics for heteroscedasticity in linear regression models have been intensively investigated in the literature. However, limited attention has been paid on how to identify covariates associated with heteroscedastic error variances. This problem is critical in correctly modelling the variance structure in weighted least squares estimation, which leads to improved estimation efficiency. We propose covariate‐specific statistics based on information ratios formed as comparisons between the model‐based and sandwich variance estimators. A two‐step diagnostic procedure is established, first to detect heteroscedasticity in error variances, and then to identify covariates the error variance structure might depend on. This proposed method is generalized to accommodate practical complications, such as when covariates associated with the heteroscedastic variances might not be associated with the mean structure of the response variable, or when strong correlation is present amongst covariates. The performance of the proposed method is assessed via a simulation study and is illustrated through a data analysis in which we show the importance of correct identification of covariates associated with the variance structure in estimation and inference.The Canadian Journal of Statistics43: 358–377; 2015 © 2015 Statistical Society of Canada
A phase I dose‐escalation study to assess safety, tolerability, pharmacokinetics, and preliminary efficacy of the dual mTORC1/mTORC2 kinase inhibitor CC‐223 in patients with advanced solid tumors or multiple myeloma
Authors: Bendell Johanna C. , Kelley Robin K. , Shih Kent C. , Grabowsky Jennifer A. , Bergsland Emily , Jones Suzanne , Martin Thomas , Infante Jeffrey R. , Mischel Paul S. , Matsutani Tomoo , Xu Shuichan , Wong Lilly , Liu Yong , Wu Xiaoling , Mortensen Deborah S. , Chopra Rajesh , Hege Kristen , Munster Pamela N.
Published: July 2015

BACKGROUND

The mammalian target of rapamycin (mTOR) pathway is essential for tumor development, yet mTOR inhibitors have yielded modest results. This phase 1 study investigated the mTORC1/mTORC2 inhibitor CC‐223 in patients with advanced cancer.

METHODS

Patients with advanced solid tumors or multiple myeloma received an initial dose of 7.5‐60 mg of CC‐223, followed by oral daily dosing in 28‐day cycles until disease progression. The primary objective was to determine the safety, tolerability, nontolerated dosage, maximum tolerated dosage (MTD), and preliminary pharmacokinetic profile. Secondary objectives were to evaluate pharmacodynamic effects and to describe preliminary efficacy.

RESULTS

Twenty‐eight patients were enrolled and received ≥1 dose of CC‐223. The most common treatment‐related grade 3 adverse events were hyperglycemia, fatigue, and rash. Four patients had dose‐limiting toxicities, including hyperglycemia, rash, fatigue, and mucositis. Therefore, 45 mg/d was determined to be the MTD. The pharmacokinetics of CC‐223 demonstrated a mean terminal half‐life ranging from 4.86 to 5.64 hours and maximum observed plasma concentration ranging from 269 to 480 ng/mL in patients who received CC‐223 ≥45 mg/d. Phosphorylation of mTORC1/mTORC2 pathway biomarkers in blood cells was inhibited by CC‐223 ≥30 mg/d with an exposure‐response relationship. Best responses included 1 partial response (breast cancer; response duration 220 days; 30‐mg/d cohort), stable disease (8 patients across ≥15 mg/d cohorts; response duration range, 36‐168 days), and progressive disease (12 patients). The disease control rate was 32%.

CONCLUSIONS

CC‐223 was tolerable, with manageable toxicities. Preliminary antitumor activity, including tumor regression, and evidence of mTORC1/mTORC2 pathway inhibition were observed. Cancer 2015;121:3435–43. © 2015 American Cancer Society.
Phase 1 adaptive dose‐finding study of neoadjuvant gemcitabine combined with radiation therapy for patients with high‐risk extremity and trunk soft tissue sarcoma
Authors: Tseng William W. , Zhou Shouhao , To Christina A. , Thall Peter F. , Lazar Alexander J. , Pollock Raphael E. , Lin Patrick P. , Cormier Janice N. , Lewis Valerae O. , Feig Barry W. , Hunt Kelly K. , Ballo Matthew T. , Patel Shreyaskumar , Pisters Peter W. T.
Published: July 2015

BACKGROUND

This study was performed to determine the maximum tolerated dose (MTD) of gemcitabine given concurrently with preoperative, fixed‐dose external‐beam radiation therapy (EBRT) for patients with resectable, high‐risk extremity and trunk soft tissue sarcoma (STS).

METHODS

Gemcitabine was administered on days 1, 8, 22, 29, 43, and 50 with EBRT (50 Gy in 25 fractions over 5 weeks). The gemcitabine MTD was determined with a toxicity severity weight method (TSWM) incorporating 6 toxicity types. The TSWM is a Bayesian procedure that choses each cohort's dose to have a posterior mean total toxicity burden closest to a predetermined clinician‐defined target. Clinicopathologic and outcome data were also collected.

RESULTS

Thirty‐six patients completed the study. According to the TSWM, the gemcitabine MTD was 700 mg/m2. At this dose level, 4 patients (24%) experienced grade 4 toxicity; no toxicity‐related deaths occurred. All tumors were resected with microscopically negative margins. Pathologic responses of >90% tumor necrosis were achieved in 17 patients (47%); 14 (39%) had complete responses. With a median follow‐up of 6.2 years, the 5‐year locoregional recurrence–free survival, distant metastasis–free survival, and overall survival rates were 85%, 80%, and 86%, respectively.

CONCLUSIONS

The TSWM combines data from qualitatively different toxicities and can be used to determine the MTD for a drug given as part of a multimodality treatment. Neoadjuvant gemcitabine plus radiation therapy is feasible and safe in patients with high‐risk extremity and trunk STS. Major pathologic responses can be achieved, and after complete resection, long‐term clinical outcomes are encouraging. Cancer 2015;121:3659–3667. © 2015 American Cancer Society.
Everolimus combined with gefitinib in patients with metastatic castration‐resistant prostate cancer: Phase 1/2 results and signaling pathway implications
Authors: Rathkopf Dana E. , Larson Steven M. , Anand Aseem , Morris Michael J. , Slovin Susan F. , Shaffer David R. , Heller Glenn , Carver Brett , Rosen Neal , Scher Howard I.
Published: July 2015

BACKGROUND

The effects of mammalian target of rapamycin (mTOR) inhibition are limited by feedback reactivation of receptor tyrosine kinase signaling in phosphatase and tensin homolog–null tumors. Thus, this study tested the combination of mTOR inhibition (everolimus) and epidermal growth factor receptor inhibition (gefitinib) in castration‐resistant prostate cancer (CRPC).

METHODS

In phase 1, 12 patients (10 with CRPC and 2 with glioblastoma) received daily gefitinib (250 mg) with weekly everolimus (30, 50, or 70 mg). In phase 2, 27 CRPC patients received gefitinib with everolimus (70 mg).

RESULTS

Phase 1 revealed no pharmacokinetic interactions and no dose‐limiting toxicities. In phase 2, 18 of 27 patients (67%) discontinued treatment before the 12‐week evaluation because of progression as evidenced by prostate‐specific antigen (PSA) levels (n = 6) or imaging (n = 5) or because of a grade 2 or higher toxicity (n = 7). Thirteen of the 37 CRPC patients (35%) exhibited a rapidly rising PSA level after they had begun treatment, and this declined upon discontinuation. Fluorodeoxyglucose positron emission tomography 24 to 72 hours after the initiation of treatment showed a decrease in the standardized uptake value consistent with mTOR inhibition in 27 of the 33 evaluable patients (82%); there was a corresponding rise in PSA in 20 of these 27 patients (74%).

CONCLUSIONS

The combination of gefitinib and everolimus did not result in significant antitumor activity. The induction of PSA in tumors treated with mTOR inhibitors was consistent with preclinical data showing that phosphoinositide 3‐kinase (PI3K) pathway signaling feedback inhibits the androgen receptor (AR). This clinical evidence of relief of feedback inhibition promoting enhanced AR activity supports future studies combining PI3K pathway inhibitors and second‐generation AR inhibitors in CRPC. Cancer 2015;121:3853–3861. © 2015 American Cancer Society.
Performance analysis of distributed symmetric sparse matrix vector multiplication algorithm for multi‐core architectures
Authors: Oryspayev Dossay , Aktulga Hasan Metin , Sosonkina Masha , Maris Pieter , Vary James P.
Published: July 2015

Sparse matrix vector multiply (SpMVM) is an important kernel that frequently arises in high performance computing applications. Due to its low arithmetic intensity, several approaches have been proposed in literature to improve its scalability and efficiency in large scale computations. In this paper, our target systems are high end multi‐core architectures and we use messaging passing interface + open multiprocessing hybrid programming model for parallelism. We analyze the performance of recently proposed implementation of the distributed symmetric SpMVM, originally developed for large sparse symmetric matrices arising in ab initio nuclear structure calculations. We study important features of this implementation and compare with previously reported implementations that do not exploit underlying symmetry. Our SpMVM implementations leverage the hybrid paradigm to efficiently overlap expensive communications with computations. Our main comparison criterion is the ‘CPU core hours’ metric, which is the main measure of resource usage on supercomputers. We analyze the effects of topology‐aware mapping heuristic using simplified network load model. We have tested the different SpMVM implementations on two large clusters with 3D Torus and Dragonfly topology. Our results show that the distributed SpMVM implementation that exploits matrix symmetry and hides communication yields the best value for the ‘CPU core hours’ metric and significantly reduces data movement overheads. Copyright © 2015 John Wiley & Sons, Ltd.
The σ‐Hole Interaction Between Sulfur Hexafluoride and Ammonia Characterised by Broadband Rotational Spectroscopy
Authors: Bittner Dror M. , Zaleski Daniel P. , Stephens Susanna L. , Walker Nicholas R. , Legon Anthony C.
Published: July 2015

A weakly‐bound complex of SF6 and NH3 is generated within an expanding gas jet and characterised by broadband rotational spectroscopy. The spectra of isotopologues 32SF6⋅⋅⋅14NH3, 32SF6⋅⋅⋅14ND3, 32SF6⋅⋅⋅15NH3 and 34SF6⋅⋅⋅15NH3 are observed and assigned to determine the spectroscopic parameters. These parameters are consistent with the complex having a C3v symmetric rotor geometry, in which the nitrogen atom of NH3 coordinates to SF6 such that the C3v axis of the NH3 sub‐unit is aligned with a local C3 axis on the SF6 sub‐unit. The geometry of the complex is rationalized in terms of a σ‐hole interaction. The observed spectra and ab initio calculations also reveal evidence of internal dynamics involving internal rotation of one monomer sub‐unit with respect to the other about the symmetry axis of the complex.
An extended discrete autoregressive model for variable bit rate video traffic encoded by scalable video codec
Authors: Ahmadpour Sima , Toghrayee Zohreh , Wan Tat‐Chee
Published: July 2015

Designing an effective and high performance network requires accurate characterization and modeling of network traffic. This paper provides a study of the transmission, modeling, and analysis of variable bit rate (VBR) video, which is fundamental for designing protocols and for effective utilization of networks in video transmission. To meet the specified requirements of future networks, the scalable video codec (SVC) was chosen as the video compression standard. The main objective of this work was to propose a statistical model that will allow better coordination between generated SVC video traffic and original video traffic. The performance of the proposed model was evaluated by comparing the model with three existing low‐complex statistical models using graphical and statistical measurements as well as cross‐validation. For all evaluation techniques, the accuracy of the proposed model was evaluated, and the frame size distribution of the modeled traffic was found to match that of the original video traffic better than other existing models. Copyright © 2015 John Wiley & Sons, Ltd.
Morphologic analysis of false negative SurePath® slides using Focalpoint™ GS computer‐assisted cervical screening technology: An Australian experience
Authors: Bowditch Ron C. , Clarke Joanne M. , Baird Phillip J. , Greenberg Merle L.
Published: July 2015

Background

The trial results of BD FocalPoint™ GS computer assisted screening(FP) of BD SurePath® liquid based cervical cytology slides (SP) were published in Diagnostic Cytopathology in 2012.1

Method

The FP‐reviewed SP slides were compared to conventional cervical Pap smears (CON) in a split sample of 2198 routine specimens. In all 47 confirmed high grade (HG) cases, FP either selected fields of view (FOV) containing cells suspicious or diagnostic of HG (46/47), or prompted full screening of the slide (1/47) leading to detection of the HG lesion. In this study for the HG cases which were reported initially as negative (NEG) or low grade (LG), the original slides were reviewed to determine the reasons for the false negative reporting and to identify features characteristic of a HG pattern.

Results

Indicators of a high risk pattern for HG Squamous Intraepithelial lesions (HSIL) included the recognition of pale abnormal immature metaplastic cells. Indicators of a high risk pattern for HG Glandular Intraepithelial lesion (AIS) were single columnar cells with the nucleus occupying the widest area of the cell. Pavemented sheets of glandular cells and isolated mitoses were additional clues to the diagnosis. In endocervical and endometrial adenocarcinomas tumour diathesis tends to be absent in SurePath slides. Single cells with ingested neutrophils and obscured eccentric nuclei were another clue to the detection of endometrial adenocarcinoma.

Conclusion

These morphological features are illustrated to help identify HSIL and HG glandular lesions when viewing the FOV presented by the FocalPointTM GS technology. Diagn. Cytopathol. 2015;43:870–878. © 2015 Wiley Periodicals, Inc.
A medium‐scale assay for enhancer validation in amniotes
Authors: Chen Jingchen , Streit Andrea
Published: July 2015

Background

Enhancers are key elements to control gene expression in time and space and thus orchestrate gene function during development, homeostasis, and disease. Whole genome approaches and bioinformatic predictions have generated a tremendous pool of potential enhancers, however their spatiotemporal activity often remains to be validated in vivo. Despite recent progress in developing high throughput strategies for enhancer evaluation, these remain mainly restricted to invertebrates and in vitro cell culture.

Results

Here we design a medium‐scale method to validate potential enhancers in an amniote embryo, the chick. Using a unique barcode for different reporter vectors allows us to detect the activity of nine separate enhancers in a single embryo by one‐step RT‐PCR. The assay is sufficiently sensitive to expand its capacity further by generating additional barcoded vectors.

Conclusions

As a rapid, sensitive, and cost‐effective way to assess enhancer activity in an amniote vertebrate, this method provides a major advance and a useful alternative to the generation of transgenic animals. Developmental Dynamics 244:1291–1299, 2015. © 2015 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists
Orai1 expression pattern in tooth and craniofacial ectodermal tissues and potential functions during ameloblast differentiation
Authors: Zheng Li , Zinn Vina , Lefkelidou Anna , Taqi Nawar , Chatzistavrou Xanthippi , Balam Tarek , Nervina Jeanne , Papagerakis Silvana , Papagerakis Petros
Published: July 2015

Background: Orai1 is a plasma membrane protein that forms the pore of the calcium release activated calcium channel. Humans with mutated Orai1 present with hereditary combined immunodeficiency, congenital myopathy and anhidrotic ectodermal dysplasia. Consistent with the ectodermal dysplasia phenotype, enamel formation and mineralization is also abnormal in Orai1 deficient patients. The expression pattern and potential functions of Orai1 in enamel formation remains unclear. To contribute toward understanding the role of Orai1 in amelogenesis we characterized ORAI1 protein developmental pattern in comparison with other ectodermal organs. We also examined the effects of Orai1 down‐regulation in ameloblast cell proliferation and differentiation. Results: Our data show strong expression of ORAI1 protein during the ameloblast secretory stage, which weans at the end of the maturation stage. In salivary glands, ORAI1 is expressed mainly in acini cells. ORAI1 expression is also found in hair follicle and oral epithelium. Knockdown of Orai1 expression decreases cell proliferation and results in RNA expression levels changes of key ameloblast genes regulating enamel thickness and mineralization. Conclusions: This study provides insights in the anhidrotic ectodermal dysplasia phenotype due to Orai1 mutation and highlights the importance of calcium signaling in controlling ameloblast differentiation and maturation during tooth development. Developmental Dynamics 244:1249–1258, 2015. © 2015 Wiley Periodicals, Inc.
Betaglycan knock‐down causes embryonic angiogenesis defects in zebrafish
Authors: Kamaid Andrés , Molina‐Villa Tonatiuh , Mendoza Valentín , Pujades Cristina , Maldonado Ernesto , Ispizua Belmonte Juan Carlos , López‐Casillas Fernando
Published: July 2015

Angiogenesis is an essential requirement for embryonic development and adult homeostasis. Its deregulation is a key feature of numerous pathologies and many studies have shown that members of the transforming growth factor beta (TGF‐β) family of proteins play important roles in angiogenesis during development and disease. Betaglycan (BG), also known as TGF‐β receptor type III, is a TGF‐β coreceptor essential for mice embryonic development but its role in angiogenesis has not been described. We have cloned the cDNA encoding zebrafish BG, a TGF‐β‐binding membrane proteoglycan that showed a dynamic expression pattern in zebrafish embryos, including the notochord and cells adjacent to developing vessels. Injection of antisense morpholinos decreased BG protein levels and morphant embryos exhibited impaired angiogenesis that was rescued by coinjection with rat BG mRNA. In vivo time‐lapse microscopy revealed that BG deficiency differentially affected arterial and venous angiogenesis: morphants showed impaired pathfinding of intersegmental vessels migrating from dorsal aorta, while endothelial cells originating from the caudal vein displayed sprouting and migration defects. Our results reveal a new role for BG during embryonic angiogenesis in zebrafish, which has not been described in mammals and pose interesting questions about the molecular machinery regulating angiogenesis in different vertebrates. genesis 53:583–603, 2015. © 2015 Wiley Periodicals, Inc.
Tetracycline‐exposed Drosophila melanogaster males produce fewer offspring but a relative excess of sons
Authors: O'Shea Kaitlyn L. , Singh Nadia D.
Published: July 2015

A large diversity of species possesses endosymbionts; these endosymbionts can exhibit mutualistic, parasitic, and commensal relationships with their hosts. Previous work has consistently revealed that depleting endosymbiont titer with antibiotic treatment can significantly alter host fitness and function, particularly with respect to reproductive phenotypes. Although these findings are often interpreted as resulting from the breakdown of highly coevolved symbioses, it is possible that antibiotic treatment itself rather than endosymbiont removal contributes to the observed perturbations in reproductive phenotypes. Here, we investigate the effect of tetracycline treatment on sex ratio and male reproductive fitness using Drosophila melanogaster as a model system. Our results indicate that tetracycline‐treated males produce a relative excess of sons. We also find that tetracycline treatment reduces the number of progeny produced by treated males but not treated females. These findings are independent of the effects of tetracycline on Wolbachia titer and implicate the antibiotic itself as mediating these changes. It is yet unclear whether the sex ratio shift and reduction in male reproductive fitness are direct or indirect consequences of tetracycline exposure, and more work is needed to determine the molecular mechanisms by which these disturbances in reproductive phenotypes arise. Our data highlight the importance of considering the potentially confounding effects of antibiotic treatment when investigating the effects of endosymbiont depletion on host phenotypes.
Historical comparisons reveal multiple drivers of decadal change of an ecosystem engineer at the range edge
Authors: Firth Louise B. , Mieszkowska Nova , Grant Lisa M. , Bush Laura E. , Davies Andrew J. , Frost Matthew T. , Moschella Paula S. , Burrows Michael T. , Cunningham Paul N. , Dye Stephen R. , Hawkins Stephen J.
Published: July 2015

Biogenic reefs are important for habitat provision and coastal protection. Long‐term datasets on the distribution and abundance of Sabellaria alveolata (L.) are available from Britain. The aim of this study was to combine historical records and contemporary data to (1) describe spatiotemporal variation in winter temperatures, (2) document short‐term and long‐term changes in the distribution and abundance of S. alveolata and discuss these changes in relation to extreme weather events and recent warming, and (3) assess the potential for artificial coastal defense structures to function as habitat for S. alveolata. A semi‐quantitative abundance scale (ACFOR) was used to compare broadscale, long‐term and interannual abundance of S. alveolata near its range edge in NW Britain. S. alveolata disappeared from the North Wales and Wirral coastlines where it had been abundant prior to the cold winter of 1962/1963. Population declines were also observed following the recent cold winters of 2009/2010 and 2010/2011. Extensive surveys in 2004 and 2012 revealed that S. alveolata had recolonized locations from which it had previously disappeared. Furthermore, it had increased in abundance at many locations, possibly in response to recent warming. S. alveolata was recorded on the majority of artificial coastal defense structures surveyed, suggesting that the proliferation of artificial coastal defense structures along this stretch of coastline may have enabled S. alveolata to spread across stretches of unsuitable natural habitat. Long‐term and broadscale contextual monitoring is essential for monitoring responses of organisms to climate change. Historical data and gray literature can be invaluable sources of information. Our results support the theory that Lusitanian species are responding positively to climate warming but also that short‐term extreme weather events can have potentially devastating widespread and lasting effects on organisms. Furthermore, the proliferation of coastal defense structures has implications for phylogeography, population genetics, and connectivity of coastal populations.
Local habitat conditions explain the variation in the strength of self‐thinning in a stream salmonid
Authors: Myrvold Knut Marius , Kennedy Brian P.
Published: July 2015

Self‐thinning patterns are frequently used to describe density dependence in populations on timescales shorter than the organism's life span and have been used to infer carrying capacity of the environment. Among mobile animals, this concept has been used to document density dependence in stream salmonids, which compete over access to food and space. The carrying capacity, growth conditions, and initial cohort sizes often vary between streams and stream sections, which would influence the onset and strength of the density dependence. Despite much effort in describing habitat relationships in stream fishes, few studies have explicitly tested how the physical environment affects the slope of the thinning curves. Here, we investigate the prevalence and strength of self‐thinning in juvenile stages of a steelhead (Oncorhynchus mykiss) population in Idaho, USA. Further, we investigate the roles of local physical habitat and metabolic constraints in explaining the variation in thinning curves among study sites in the watershed. Only yearling steelhead exhibited an overall significant thinning trend, but the slope of the mass–density relationship (−0.53) was shallower than predicted by theory and reported from empirical studies. There was no detectable relationship in subyearling steelhead. Certain abiotic factors explained a relatively large portion of the variation in the strength of the self‐thinning among the study reaches. For subyearling steelhead, the slopes were negatively associated with the average water depth and flow velocity in the study sites, whereas slopes in yearlings were steeper in sites that incurred a higher metabolic cost. Our results show that the prevalence and strength of density dependence in natural fish populations can vary across heterogeneous watersheds and can be more pronounced during certain stages of a species' life history, and that environmental factors can mediate the extent to which density dependence is manifested in predictable ways.
T cells compete by cleaving cell surface CD27 and blocking access to CD70‐bearing APCs
Authors: Burchill Matthew A. , Tamburini Beth A. , Kedl Ross M.
Published: July 2015

T cells compete against each other for access to molecules on APCs in addition to peptide/MHC complexes. However, the identity of cell surface molecules that influence T‐cell competition, other than peptide/MHC, have yet to be defined. Here, we identify CD70, a TNF ligand expressed on activated APCs, as an important mediator of T‐cell competition for APCs. Upon engagement of CD27 by CD70, CD27 is proteolytically cleaved from the surface of the interacting CD8+ T cell and captured by CD70 expressing dendritic cells. The capture of CD27 effectively masks CD70 on APCs, disallowing the interaction with CD27 on other competing T cells. Collectively, our data indicate that T cells compete against each other for access to the TNF‐ligand CD70, an interaction that affects the duration and potency of T cell/DC interactions, thus influencing the repertoire of responding CD8+ T cells to self or foreign antigens.
Synthesis and Reactivity of Ruthenium–Antimony Carbonyl Clusters
Authors: Li Ying‐Zhou , Ganguly Rakesh , Leong Weng Kee , Liu Yang
Published: July 2015

The reaction of Na[HRu3(CO)11] (2) with SbPh2Cl in dry tetrahydrofuran (THF) afforded the cluster Ru3(CO)10(μ‐H)(μ‐SbPh2) (3); in dry dichloromethane (DCM), the six‐membered ring Ru6(CO)20(μ‐H)2(μ‐SbPh2)2 (4) was obtained instead. The trimethylamine N‐oxide (TMNO) activated reaction of Ru3(CO)12 (1) with distibine Sb2Ph4 produced Ru3(CO)10(μ‐SbPh2)2 (6) through an Sb–Sb bond oxidative addition. Cluster 6 is fluxional through Ru–Ru bond isomerization. In contrast, its group 15 monosubstituted derivatives Ru3(CO)9(μ‐SbPh2)2(L) (7, L = phosphane, arsine or stibine) or the disubstituted derivatives Ru3(CO)8(μ‐SbPh2)2(L)2 (8) did not exhibit such fluxionality. Instead, isomerization through a turnstile mechanism involving the group 15 ligand occurred. The treatment of 6 with SbPh2Cl afforded the fused‐ring clusters Ru3(CO)9(μ‐SbPh2)3(Cl) (9) and Ru3(CO)8(μ‐SbPh2)3(Cl)(SbPh2CH2Cl) (10).
Fast and Efficient Microwave‐Assisted Synthesis of Perylenebisimides
Authors: Rigodanza Francesco , Tenori Eleonora , Bonasera Aurelio , Syrgiannis Zois , Prato Maurizio
Published: July 2015

Perylene‐3,4,9,10‐tetracarboxylic acid bisimides have been widely studied as industrial pigments. Lately, these dyes have drawn considerable attention because of applications as photocatalysts and organic semi‐conductors. Here, we report a novel method for fast and efficient synthesis of many different perylenebisimides, based on microwave‐assisted reactions.
Sensitivity Enhancement in Nickel Hydroxide/3D‐Graphene as Enzymeless Glucose Detection
Authors: Shackery Iman , Patil Umarkant , Song Min‐Jung , Sohn Ji Soo , Kulkarni Sachin , Some Surajit , Lee Su Chan , Nam Min Sik , Lee Wooyoung , Jun Seong Chan
Published: July 2015

A nickel hydroxide (Ni(OH)2)/3D‐graphene composite is used as monolithic free‐standing electrode for enzymeless electrochemical detection of glucose. Ni(OH)2 nanoflakes are synthesized by using a simple solution growth procedure on 3D‐graphene foam which was grown by chemical vapor deposition (CVD). The pore structure of 3D‐graphene allows easy access to glucose with high surface area, which leads to glucose detection with an ultrahigh sensitivity of 3.49 mA mM−1 cm−2 and a significant lower detection limit up to 24 nM. Cyclic voltammetry (CV) and potentionstatic mode is used for non‐enzymatic glucose sensing. The impedance and effective surface area have been studied well. The high sensitivity, low detection limit and simple configuration of Ni(OH)2/three dimensional (3D)‐graphene composite electrodes can evoke its industrial application in glucose sensing devices.
Simultaneous and Highly Sensitive Determination of Hydroquinone and Catechol Using Carboxyl Functionalized Graphene Self‐Assembled Monolayers
Authors: Li Yancai , Feng Shuqing , Zhong Yanmei , Li Yuhui , Li Shunxing
Published: July 2015

Carboxyl functionalized graphene (CFG) self‐assembled monolayers (SAMs) were constructed on the carboxylated glassy carbon electrode based on covalent interaction for simultaneous determination of hydroquinone (HQ) and catechol (CC). Scanning electron microscopy and electrochemical impedance spectroscopy results proved that the CFG SAMs was successfully formed with enhanced conductivity. According to electrochemical voltammetry experiments, the modified electrode showed excellent sensitivity and selectivity for HQ and CC. Under optimal conditions, the sensing platform showed wide linear response for HQ and CC with detection limit of 0.2 µM (S/N=3) and 0.6 µM (S/N=3), respectively. Moreover, the sensor also displays good reproducibility and stability.
Construction of a Novel Carbon Paste Clarithromycin Sensor for Low Level Concentration Measurement, Applications to Pharmaceutical and Biological Analysis
Authors: Soleymanpour Ahmad , Nadimi Najmeh
Published: July 2015

A potentiometric carbon paste sensor was fabricated for determination of clarithromycin based on incorporation of the ion association complex of the clarithromycin‐phosphotungstate. The proposed sensor exhibited a Nernstian slope of 59.2±0.3 mV per decade for clarithromycin over a wide concentration range of 7.4×10−7 to 1.5×10−3 M, with a low detection limit of 5.0×10−7 M. The proposed sensor manifested advantages of very fast response, long life time and, most importantly, excellent selectivity for clarithromycin relative to a wide variety of common foreign inorganic cation, and also biological species. The sensor was successfully applied to determine clarithromycin in clarithromycin tablet, blood serum and urine samples. The inclusion complex formation between β‐cyclodextrin and clarithromycin was studied by the proposed sensor. The influence of the temperature on the response of the sensor was investigated and the temperature coefficient of the sensor was calculated.
Codeposited Poly(benzoxazine) and Os‐Complex Modified Polymethacrylate Layers as Immobilization Matrix for Glucose Biosensors
Authors: Barwe Stefan , Andronescu Corina , Pöller Sascha , Schuhmann Wolfgang
Published: July 2015

Benzoxazine oligomers synthesized by a Mannich type reaction of bisphenol A, tetraethylenepentamine and formaldehyde were electrochemically crosslinked in presence of both an Os‐complex modified poly(methacrylate) polymer and glucose oxidase. The crosslinking led to the formation of a biocatalytically active layer on an electrode surface exhibiting a swelling process after immersion in an electrolyte solution containing glucose most likely due to the local decrease of the pH value upon glucose oxidation. Optimization of the poly(benzoxazine) to Os‐complex modified poly(methacrylate) ratio was performed leading to a reagentless glucose biosensor with improved stability.
Enantioselective Recognition of DOPA by Mesoporous Platinum Imprinted with Mandelic Acid
Authors: Yutthalekha Thittaya , Warakulwit Chompunuch , Limtrakul Jumras , Kuhn Alexander
Published: July 2015

Chiral imprinted mesoporous platinum was electrochemically synthesized in the presence of mandelic acid and Brij 56 surfactant as chiral and mesoporous templates, respectively. The chiral cavity obtained by using mandelic acid as a template can be used to distinguish between enantiomers of other chiral molecules in which the stereocentre has a correlated configuration with respect to the imprinted one. This recognition versatility was tested for the discrimination of DOPA enantiomers. Mesoporous platinum electrodes imprinted with (R)‐mandelic acid preferentially react with L‐DOPA and vice versa for the (S)‐mandelic acid imprinted one, which is more reactive for D‐DOPA.