bluuebunny/crossref_metadata_2025 huggingface dataset:
PEGylated Cationic Serum Albumin for Boosting Retroviral Gene Transfer
Authors: Palesch David , Boldt Felix , Müller Janis A. , Eisele Klaus , Stürzel Christina M. , Wu Yuzhou , Münch Jan , Weil Tanja
Published: May 2016

Retroviral vectors are common tools for introducing genes into the genome of a cell. However, low transduction rates are a major limitation in retroviral gene transfer, especially in clinical applications. We generated cationic human serum albumin (cHSA) protected by a shell of poly(ethylene glycol) (PEG); this significantly enhanced retroviral gene transduction with potentially attractive pharmacokinetics and low immunogenicity. By screening a panel of chemically optimized HSA compounds, we identified a very potent enhancer that boosted the transduction rates of viral vectors. Confocal microscopy revealed a drastically increased number of viral particles attached to the surfaces of target cells. In accordance with the positive net charge of cationic and PEGylated HSA, this suggests a mechanism of action in which the repulsion of the negatively charged cellular and viral vector membranes is neutralized, thereby promoting attachment and ultimately transduction. Importantly, the transduction‐enhancing PEGylated HSA derivative evaded recognition by HSA‐specific antibodies and macrophage activation. Our findings hold great promise for facilitating improved retroviral gene transfer.
Methylene blue toxicity in zebrafish cell line is dependent on light exposure
Authors: Costa Simone Rutz da , Monteiro Mauricio da Costa , da Silva Júnior Flavio Manoel Rodrigues , Sandrini Juliana Zomer
Published: May 2016

Methylene blue (MB) has been widely applied in the clinical area and is currently being used in aquaculture as biocide. Some recent studies have emphasized the importance of understanding the action mechanism and the MB cellular targets. In this sense, zebrafish is considered a relevant model to study the intrinsic pathway of apoptosis as well as the cellular responses involving DNA damage and repair. So, the aim of the present study was to compare MB action mechanisms in a zebrafish cell line, both in the absence (MB alone; dark toxicity) and in the presence of photosynthetically active radiation (MB+PAR; phototoxicity). There was a significant increase of the levels of reactive oxygen and nitrogen species 3 h after MB treatment, whereas this increase was only observed 12 h after treatment with MB+PAR. All treatments with MB resulted in an increase in DNA damage after 3 and 6 h. However, cell death by apoptosis was observed from 6 h after treatment with MB+PAR and 12 h after treatment with MB alone. The expression of genes related to apoptosis was altered after MB and MB+PAR treatment. Therefore, this zebrafish cell line is sensitive to the photodynamic action of MB; MB is able to generate DNA damage and induce apoptosis in this cell line both alone and in the presence of PAR. However, the pathways leading to apoptosis in this model appear to be dependent on the type of MB exposure (in the presence or absence of PAR).
Vinylic Addition Polynorbornene as Support for N‐Heterocyclic Carbene Palladium Complexes: Use as Reservoir of Active Homogeneous Catalytic Species in C−C Cross‐Coupling Reactions
Authors: Molina de la Torre Jesús A. , Albéniz Ana C.
Published: May 2016

A vinylic addition polynorbornene (VA‐PNB) functionalized with imidazolium groups can be used to synthesize a well‐defined supported palladium carbene complex. This complex is a suitable precatalyst for Suzuki and Negishi cross‐coupling reactions, and it can be reused. A close look at how the catalysis works reveals that palladium aggregates form on the polymer surface after the first catalytic reaction. However, they are not easily washed out and serve as a source of small amounts of homogeneous palladium active species (about 0.01% mol), which are responsible for the catalysis. The recovered polymer can be reused several times although increased induction and reaction times are observed in consecutive uses from one run to the next. The reaction was followed up by in situ IR spectroscopy by using the ν(C−Br) absorption band of the electrophile, so there is no need for an additional functional group to apply this technique.
Porous Graphitic Carbon Nitride Derived from Melamine–Ammonium Oxalate Stacking Sheets with Excellent Photocatalytic Hydrogen Evolution Activity
Authors: Li Kui , Xie Xin , Zhang Wei‐De
Published: May 2016

A facile strategy to synthesize porous graphitic carbon nitride with stacking nanotubes by thermal condensation of melamine–ammonium oxalate stacking sheets is reported. The photocatalytic generation rate of hydrogen over the porous graphitic carbon nitride (99.7 μmol h−1) is nearly 9.5 times as that of pristine g‐C3N4 (10.5 μmol h−1). Such enhancement is attributed to the large specific surface area (91.1 m2 g−1), improved visible‐light absorption and efficient separation of photogenerated electrons and holes. The strategy of preparing the porous graphitic carbon nitride with modified melamine as a precursor opens a new gate for the regulation of the morphologies of g‐C3N4 to get higher photocatalytic activity.
Synthesis of Oxazolidinones from Epoxides and Isocyanates Catalysed by Aluminium Heteroscorpionate Complexes
Authors: Castro‐Osma José A. , Earlam Amy , Lara‐Sánchez Agustín , Otero Antonio , North Michael
Published: May 2016

The combination of an aluminium(heteroscorpionate) complex and tetrabutylammonium bromide acts as a highly efficient catalyst system for the synthesis of oxazolidinones from epoxides and isocyanates. Twenty two complexes were tested derived from a range of bispyrazole ligands and containing 1–3 aluminium atoms per complex. The optimal catalyst was found to be a bimetallic complex of a thioacetamidate ligand. Under the optimal reaction conditions (80 °C in toluene for 24 h using 5 mol % of both aluminium catalyst and tetrabutylammonium bromide co‐catalyst), six epoxides were reacted with six aromatic isocyanates, giving 25 oxazolidinones in moderate to excellent yields showing broad substrate scope. The regiochemistry of the reaction (to produce 3,4‐ or 3,5‐oxazolidinones) is controlled by the substrate with epoxide ring opening occurring preferentially at the less hindered end of the epoxide unless a substituent on the epoxide can stabilise a positive charge.
Effect of Hydrodynamic Forces onmeso‐(4‐Sulfonatophenyl)‐Substituted Porphyrin J‐Aggregate Nanoparticles: Elasticity, Plasticity and Breaking
Authors: El‐Hachemi Zoubir , Balaban Teodor Silviu , Campos J. Lourdes , Cespedes Sergio , Crusats Joaquim , Escudero Carlos , Kamma‐Lorger Christina S. , Llorens Joan , Malfois Marc , Mitchell Geoffrey R. , Tojeira Ana P. , Ribó Josep M.
Published: May 2016

The J aggregates of 4‐sulfonatophenylmeso‐substituted porphyrins are non‐covalent polymers obtained by self‐assembly that form nanoparticles of different morphologies. In the case of high aspect‐ratio nanoparticles (bilayered ribbons and monolayered nanotubes), shear hydrodynamic forces may modify their shape and size, as observed by peak force microscopy, transmission electron microscopy of frozen solutions, small‐angle X‐ray scattering measurements in a disk‐plate rotational cell, and cone–plate rotational viscometry. These nanoparticles either show elastic or plastic behaviour: there is plasticity in the ribbons obtained upon nanotube collapse on solid/air interfaces and in viscous concentrated nanotube solutions, whereas elasticity occurs in the case of dilute nanotube solutions. Sonication and strong shear hydrodynamic forces lead to the breaking of the monolayered nanotubes into small particles, which then associate into large colloidal particles.
Active Esters as Pseudostoppers for Slippage Synthesis of [2]Pseudorotaxane Building Blocks: A Straightforward Route to Multi‐Interlocked Molecular Machines
Authors: Legigan Thibaut , Riss‐Yaw Benjamin , Clavel Caroline , Coutrot Frédéric
Published: May 2016

The efficient synthesis and very easy isolation of dibenzo[24]crown‐8‐based [2]pseudorotaxane building blocks that contain an active ester motif at the extremity of the encircled molecular axle and an ammonium moiety as a template for the dibenzo[24]crown‐8 is reported. The active ester acts both as a semistopper for the [2]pseudorotaxane species and as an extensible extremity. Among the various investigated active ester moieties, those that allow for the slippage process are given particular focus because this strategy produces fewer side products. Extension of the selected N‐hydroxysuccinimide ester based pseudorotaxane building block by using either a mono‐ or a diamino compound, both containing a triazolium moiety, is also described. These provide a pH‐dependent two‐station [2]rotaxane molecular machine and a palindromic [3]rotaxane molecular machine, respectively. Molecular machinery on both interlocked compounds through variation of pH was studied and characterized by means of NMR spectroscopy.
Postoperative Strokes and Intracranial Bleeds in Patients With Atrial Fibrillation: The FibStroke Study
Authors: Palomäki Antti , Kiviniemi Tuomas , Hartikainen Juha E.K. , Mustonen Pirjo , Ylitalo Antti , Nuotio Ilpo , Hartikainen Päivi , Jaakkola Jussi , Luite Riho , Airaksinen K.E. Juhani
Published: May 2016

Background

Patients with atrial fibrillation (AF) frequently undergo invasive procedures. Optimal perioperative use of oral anticoagulation (OAC) and heparin bridging is not well defined.

Hypothesis

Discontinuation of OAC for minor procedures/operations places AF patients at risk for thromboembolism.

Methods

In this study, we assessed perioperative antithrombotic treatment in patients with AF who suffered a postoperative stroke or intracranial bleeding. The FibStroke Study includes AF patients with an ischemic stroke or intracranial bleed identified from the discharge registries of 4 Finnish hospitals. In total, 3632 consecutive patients developed 3252 ischemic strokes and 794 intracranial bleeds. All invasive procedures during the 30 days preceding the stroke or intracranial bleed were identified.

Results

A total of 194/3252 (6.0%) ischemic strokes and 23/794 (2.9%) intracranial bleeds were preceded by a procedure. Altogether, 69% of the patients were on OAC prior to index procedure, OAC was interrupted in 81.2% of the procedures preceding a stroke, and heparin bridging was used in 27.8% of interruptions. Of the procedures leading to stroke, 42.3% were low‐bleeding‐risk procedures, and OAC was interrupted in 84.7% of these procedures. The median time from procedure to stroke was 4 days. Heparin bridging was used in 54.5% of OAC interruptions preceding intracranial bleeding and combination of anticoagulation with antiplatelet therapy by 43.5% of patients with postoperative intracranial bleeding.

Conclusions

Perioperative interruption of OAC is common in patients who suffer a postoperative stroke, even in patients with low‐bleeding‐risk procedures. Postoperative intracranial bleeding is frequently preceded by perioperative heparin bridging.
α‐Fluoro‐o‐cresols: The Key Role of Intramolecular Hydrogen Bonding in Conformational Preference and Hydrogen‐Bond Acidity
Authors: Bogdan Elena , Quarré de Verneuil Alexis , Besseau François , Compain Guillaume , Linclau Bruno , Le Questel Jean‐Yves , Graton Jérôme
Published: May 2016

The conformational preferences of o‐cresols driven by fluorination were thoroughly investigated from a theoretical point of view with quantum‐chemical methods, and the results were compared to those recently reported for benzyl alcohols. The key conformers of both families exhibit a six‐membered intramolecular hydrogen‐bond (IMHB) interaction. A significant enhancement in the strength of the IMHB is observed in α‐fluoro‐o‐cresols, owing to a simultaneous increase in the hydrogen bond (HB) basicity of the aliphatic fluorine and the HB acidity of the aromatic hydroxyl relative to that observed for o‐fluorobenzyl alcohols, which are characterized by aromatic fluorine atoms and aliphatic hydroxyl groups. In the cases of the di‐ and trifluorinated derivatives, the occurrence of a three‐centered HB is emphasized, and its features are discussed. The impact of these structural predilections on the HB properties of o‐cresol was characterized from the estimation of the HB acidity parameter, pKAHY, weighted according to their conformational populations. We found that α‐fluorination led to a decrease in the HB acidity of the hydroxyl group (in contrast with the o‐fluorination of benzyl alcohols), whereas α,α‐difluorination resulted in no significant variation in pKAHY. Finally, an increase in the HB acidity was predicted upon methyl perfluorination, which was confirmed experimentally. Theoretical descriptors based on atoms in molecules, noncovalent interactions, and natural bond orbital analyses allowed rationalization of the predicted trends and revealed a relationship with the strength of the established OH⋅⋅⋅F IMHB.
Alternative Single‐Solvent Electrolytes Based on Cyanoesters for Safer Lithium‐Ion Batteries
Authors: Brox Sebastian , Röser Stephan , Husch Tamara , Hildebrand Stephan , Fromm Olga , Korth Martin , Winter Martin , Cekic‐Laskovic Isidora
Published: May 2016

To identify alternative single‐solvent‐based electrolytes for application in lithium‐ion batteries (LIBs), adequate computational methods were applied to screen specified physicochemical and electrochemical properties of new cyanoester‐based compounds. Out of 2747 possible target compounds, two promising candidates and two structurally equivalent components were chosen. A constructive selection process including evaluation of basic physicochemical properties as well assessing the compatibility towards graphitic anodes was initiated to identify the most promising candidates. With addition of a film‐forming additive in a low concentration, the most promising candidate showed an adequate long‐term cycling stability with LiNi1/3Mn1/3Co1/3O2 [NMC(111)] in a full‐cell setup using graphite as anode material. The main advantages of the new electrolyte formulation are related to its good thermal behavior, especially with regard to safety in combination with satisfying electrochemical performance.
Asymptotic design of quantization and bit allocation for distributed estimation in wireless sensor networks
Authors: Chen Junyong , Shen Zhiping , Zhong Jun
Published: May 2016

This paper investigates the schemes of asymptotically optimal quantization and bit allocation for distributed estimation in wireless sensor networks in which a total bit rate constraint is imposed. Because there is no communication among all sensors, quantizers for observations need to be designed separately. The Lloyd‐Max quantizer is shown to be asymptotically optimal for each sensor. Moreover, it is shown that the level number of asymptotically optimal quantization for sensors is proportional to the signal‐to‐noise ratio, which is determined by the variances of observation and noise. Because the original quantized minimum mean‐square error estimator often corresponds to a high computational cost when a large number of sensors are active, in our work, an asymptotically equivalent algorithm of iterative quantized estimator (IQE), which enjoys a low computational cost, is proposed. In addition, an IQE algorithm can be applied to wireless sensor networks with delay or packet loss. Simulation results of this work indicate that the effectiveness of our IQE algorithm is obvious; that is, a significant improvement of estimation performance is achieved by using the optimal bit allocation when comparing with the uniform bit allocation. Copyright © 2016 John Wiley & Sons, Ltd.
Primary actinomycosis of breast—A diagnosis on cytology
Authors: Gosavi Alka Vikas , Anvikar Arti Rameshrao , Sulhyan Kalpana Ranjitsingh , Manek Dhruti Dinesh
Published: May 2016

Primary actinomycosis of breast is a rare disease with only a few cases reported in the literature. We present a case of a 25‐year‐old lactating woman with primary actinomycosis of breast which was diagnosed on cytology. The patient presented with lump in left breast with dull aching pain. Fine‐needle aspiration cytology smears showed acute suppurative inflammation with presence of fluffy basophilic colonies on Hematoxylin and Eosin staining and branched, Gram positive filamentous bacilli on Gram staining. The bacilli were non‐acid fast with 1% Zeihl Neelsen stain. A diagnosis of actinomycosis was suggested on cytology. Histopathological examination revealed an abscess with few Gram positive basophilic granules surrounded by eosinophilic Splendore‐Hoeppli material thus confirming the diagnosis of actinomycosis. Meticulous search for microorganisms with the aid of special stains should be done on cytology smears before labeling an inflammatory lesion as nonspecific. Diagn. Cytopathol. 2016;44:693–695. © 2016 Wiley Periodicals, Inc.
Association between severity of hypoglycemia and loss of heart rate variability in patients with type 1 diabetes mellitus
Authors: Silva Ticiana Paes , Rolim Luiz Clemente , Sallum Filho Celso , Zimmermann Livia M. , Malerbi Fernando , Dib Sergio Atala
Published: May 2016

Background

The occurrence of hypoglycemia has been associated with the presence of cardiovascular autonomic neuropathy. Cardiovascular autonomic reflex tests are the gold standard diagnostic method for cardiovascular autonomic neuropathy. Nevertheless, impaired heart rate variability indices on spectral analysis have been reported before cardiovascular autonomic reflex test abnormalities arise. The objective of the present study was to analyse the association between the severity of hypoglycemia and indices of heart rate variability on spectral analysis.

Methods

Consecutive type 1 diabetes patients were prospectively enrolled. Heart rate variability indices were assessed by spectral analysis. One abnormal test result was used to define impaired spectral analysis. The severity of hypoglycemia was evaluated by a hypoglycemia score and patients were classified into absent/minor or moderate/severe hypoglycemia groups.

Results

Patients with moderate/severe hypoglycemia were older, had longer duration of diabetes and had higher rates of diabetic complications. After adjusting for baseline clinical characteristics, impaired spectral analysis (OR: 3.85; 95% IC 1.23 – 12.02; p = 0.020), nephropathy (OR: 4.15, 95% IC 1.27 – 13.54; p = 0.018) and macrovascular complications (OR: 12.18, 95% IC 1.14 – 129.84; p = 0.038) remained independent predictors of moderate/severe hypoglycemia. Patients with moderate/severe hypoglycemia had lower heart rate variability in the high frequency band of spectral analysis, reflecting a decreased parasympathetic tonus on the heart. These patients also had higher low frequency/high frequency ratios, ultimately denoting the occurrence of cardiovascular autonomic imbalance.

Conclusions

Impaired heart rate variability on spectral analysis, nephropathy and macrovascular complication were shown to independently predict moderate/severe hypoglycemia. Patients with moderate/severe hypoglycemia showed loss of the cardio protective effect of vagal activity according to spectral analysis. Copyright © 2016 John Wiley & Sons, Ltd.
Identification and analytical characterization of four synthetic cannabinoids ADB‐BICA, NNL‐1, NNL‐2, and PPA(N)‐2201
Authors: Qian Zhenhua , Jia Wei , Li Tao , Hua Zhendong , Liu Cuimei
Published: May 2016

Since the first appearance as psychotropic drugs in illegal markets in 2008, the spread of synthetic cannabinoids is becoming a serious problem in many countries. This paper reports on the analytical properties and structure elucidation of four cannabimimetic derivatives in seized material: 1‐benzyl‐N‐(1‐carbamoyl‐2,2‐dimethylpropan‐1‐yl)‐1H‐indole‐3‐carboxamide (ADB‐BICA, 1), N‐(1‐carbamoylpropan‐1‐yl)‐1‐(5‐fluoropentyl)‐1H‐pyrrolo[2,3‐b]pyridine‐3‐carboxamide (NNL‐1, 2), (4‐benzylpiperazin‐1‐yl)(1‐(5‐fluoropentyl)‐1H‐indol‐3‐yl)methanone (NNL‐2, 3), and N‐(1‐carbamoyl‐2‐phenylethyl)‐1‐(5‐fluoropentyl)‐1H‐indazole‐3‐carboxamide (PPA(N)‐2201, 4). The identifications were based on liquid chromatography‐quadrupole‐time‐of‐flight‐mass spectrometry (LC‐QTOF‐MS), gas chromatography‐mass spectrometry (GC‐MS), Fourier transform infrared spectroscopy (FT‐IR), and nuclear magnetic resonance (NMR) spectroscopy. No chemical or pharmacological data about compounds 1–3 have appeared until now, making this the first report on these compounds. The GC‐MS data of 4 has been reported, but this study added the LC‐MS, FT‐IR, and NMR data for additional characterization. Copyright © 2016 John Wiley & Sons, Ltd.
Raf kinase inhibitor protein1 is a myogenic inhibitor with conserved function in avians and mammals
Authors: Coulton Gary , Hou Yanwen , Mirczuk Samantha M. , Allen Steven P.
Published: May 2016

Background: Raf Kinase Inhibitor Protein1 (RKIP) is a tumor suppressor that is present in several adult tissues. It functions as an inhibitor of both Raf/Mek/Erk and NFĸB signaling when unphosphorylated, but following phosphorylation the ability to inhibit Raf/Mek/Erk signaling is lost and RKIP becomes an activator of G‐protein coupled receptor signaling. In neonates and adults, RKIP is known to be expressed in muscle; however, its physiological function is currently unknown. Results: In this study, we show by in situ hybridization and immunofluorescence that RKIP is also expressed in developing chick embryonic muscle, and mouse C2C12 myoblasts. Furthermore, we demonstrate that, in these systems, it functions as an inhibitor of myogenesis: increased levels of RKIP suppress myotube differentiation whereas decreasing RKIP promotes differentiation. Additionally, we show that the ability of RKIP to inhibit myogenesis is dependent upon its phosphorylation state as only the nonphosphorylated form of RKIP suppresses myogenesis. Conclusions: This study, therefore, clearly demonstrates that RKIP has conserved functions as a myogenic inhibitor in both mammalian and avian muscle. Developmental Dynamics 245:902–912, 2016. © 2016 Wiley Periodicals, Inc.
A Vanadogermanate Dimer‐Based Chain with Magnetic and Luminescent Properties
Authors: Li Ning , He Danfeng , Lu Ying , Liu Yiwei , Xu Li , Zhong Xiahua , Guo Zehong , Liu Shuxia
Published: May 2016

An arched dicadmium‐substituted vanadogermanate dimer, {[Cd(en)2][Cd(en)]2Ge8V12O40(OH)8}2{[Cd(en)(H2O)]2}·en·2H2O (1; en = ethylenediamine), was prepared hydrothermally and characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction, thermogravimetric analysis, UV/Vis diffuse reflectance spectroscopy, electrochemistry, and X‐ray single‐crystal diffraction. Notably, 1 represents the first vanadogermanate‐based dimer and contains two dicadmium‐substituted {[Cd(en)2][Cd(en)]2Ge8V12O40(OH)8} cluster units and rare dinuclear {[Cd(en)(H2O)]2+}2 cations as linkages. Then, the adjacent dimers are further extended by a pair of bridging [Cd(en)2]2+ complexes to form a 1D hybrid sinusoidal chain. All V ions are present in the valence of +4. The magnetic behavior demonstrates the antiferromagnetic interactions within the VIV centers. Furthermore, luminescence measurements demonstrate an intense blue luminescent emission in the solid state.
Efficient Photodegradation of Organics in Acidic Solution by ZnO–Smectite Hybrids
Authors: Khumchoo Nuttaporn , Khaorapapong Nithima , Ontam Areeporn , Intachai Sonchai , Ogawa Makoto
Published: May 2016

Zinc oxide has been immobilized in layered clay minerals (natural montmorillonite and synthetic saponite) by ion exchange and simultaneous oxidation. The products exhibit blueshifted absorption bands (onsets at 346 and 374 nm for the montmorillonite and saponite systems, respectively) compared with that of bulk zinc oxide (393 nm), thereby showing the formation of zinc oxide nanoparticles. The samples are characterized by the broad photoluminescence centered at 545 nm for zinc oxide in montmorillonite and the relatively sharp and strong photoluminescence observed at 436 nm for zinc oxide in saponite. The photocatalytic activities of the ZnO–smectite hybrids towards the decomposition of an aqueous solution of Methylene Blue were examined and revealed that both catalysts function even in acidic solution, which is an advantage of nanoparticles (ZnO in the present case) supported on smectites.
CoII and CuII Fluorescent Complexes with Acridine‐Based Ligands
Authors: Dogaheh Samira Gholizadeh , Heras Ojea María José , Piquer Lidia Rosado , Artús Suàrez Lluís , Khanmohammadi Hamid , Aromí Guillem , Sañudo E. Carolina
Published: May 2016

The condensation reaction of salicylaldehyde or 2‐hydroxynaphthaldehyde with a diamino organic group (Acridine Yellow or diaminoacridine) resulted in the Schiff‐base ligands ACRI‐1, ACRI‐2 and ACRI‐3, with the last two hitherto unknown. Fluorescent ACRI‐1, ACRI‐2 and ACRI‐3 were designed to provide iminophenolic binding pockets for two transition metals and ferromagnetic exchange between the metals. Following our report on the complex [Co2(ACRI‐1)2] (1Co), we report herein the reactions of ACRI‐1, ACRI‐2 and ACRI‐3 with CoII and CuII salts, which afforded the new fluorescent complexes [Cu2(ACRI‐1)2] (1Cu), [Co2(ACRI‐2)2] (2Co), [Cu2(ACRI‐2)2] (2Cu), [Co2(ACRI‐3)2(H2O)4] (3Co) and [Cu2(ACRI‐3)2] (3Cu).
[4+2] Cycloadditions of Seven‐Membered‐Ring trans‐Alkenes: Decreasing Reactivity with Increasing Substitution of the Seven‐Membered Ring
Authors: Santucci John , Sanzone Jillian R. , Woerpel K. A.
Published: May 2016

The reactivity of trans‐oxasilacycloheptenes in [4+2] cycloadditions depends on the substitution pattern on the seven‐membered ring. Unhindered trans‐alkenes undergo [4+2] cycloadditions with 1,3‐diphenylisobenzofuran faster than the most reactive trans‐cyclooctene. Increasing the substitution of the seven‐membered ring or increasing the electron density of the trans‐alkene decreases reactivity with 1,3‐dienes in concerted cycloaddition reactions. Although highly substituted trans‐alkenes are unreactive in concerted cycloaddition reactions, these alkenes react rapidly in stepwise reactions with diethyl azodicarboxylate (DEAD), an electrophilic diene.
Chitosan‐carbon Nanofiber Modified Single‐use Graphite Electrodes Developed for Electrochemical Detection of DNA Hybridization Related to Hepatitis B Virus
Authors: Eksin Ece , Erdem Arzum
Published: May 2016

Chitosan (CHIT) and carbon nanofiber (CNF) modified pencil graphite electrodes (PGEs) were developed for the first time in the present study for enhanced monitoring of DNA hybridization. CHIT‐CNF modified PGE, CHIT modified PGE and unmodified PGE were firstly characterized by scanning electrone microscopy (SEM), and the electrochemical behaviour of each electrode was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The optimization of experimental studies; CNF concentration, or DNA probe concentration was performed by differential pulse voltammetry (DPV) technique. The sequence‐selective DNA hybridization related to Hepatitis B virus (HBV) was then performed in the case of hybridization between HBV probe and its target DNA, or different non‐complementary DNA sequences (NC1 and NC2), and also the hybridization case in the mixture samples containing both target and NC sequences in the ratio of 1 : 1. CHIT‐CNF‐PGEs presented very effective discrimination of HBV DNA hybridization, which also presented high sensitivity and better reproducibility due to the unique chemical and structural properties of CNF.
MIP‐esterase/Tyrosinase Combinations for Paracetamol and Phenacetin
Authors: Yarman Aysu , Scheller Frieder W.
Published: May 2016

A new electrochemical MIP sensor for the most frequently used drug paracetamol (PAR) was prepared by electropolymerization of mixtures containing the template molecule and the functional monomers o‐phenylenediamine, resorcinol and aniline. The imprinting factor of 12 reflects the effective target binding to the MIP as compared with the non‐imprinted electropolymer. Combination of the MIP with a nonspecific esterase allows the measurement of phenacetin – another analgesic drug. In the second approach the PAR containing sample solution was pretreated with tyrosinase in order to prevent electrochemical interferences by ascorbic acid and uric acid. Interference‐free indication at a very low electrode potential without fouling of the electrode surface was achieved with the o‐phenylenediamine: resorcinol‐based MIP.
Graphene Oxide/ZnO Nano Composite for Sensitive and Selective Electrochemical Sensing of Levodopa and Tyrosine Using Modified Graphite Screen Printed Electrode
Authors: Beitollahi Hadi , Garkani Nejad Fariba
Published: May 2016

Determination of levodopa and tyrosine as two important species for treatment of Parkinson's disease is described. A novel electrochemical sensor involving graphene oxide/ZnO nanorods (GR/ZnO) nano composite and the graphite screen‐printed electrodes (GSPE) was developed for the simultaneous detection of levodopa and tyrosine. The screen‐printed electrodes with several advantages, including low cost, versatility and miniaturization were employed. On the other hand, the graphene oxide/ZnO nanorods nano composite was casted on the surface of GSPE to obtain GR/ZnO/SPE. The proposed nano sensor has excellent performance such as high sensitivity, good selectivity and analytical application in real samples. The combination of graphene oxide/ZnO nanorods nano composite with the screen‐printed electrode is favorable for amplifying electrochemical signals. Under optimized conditions square wave voltammetry (SWV) exhibited linear dynamic ranges from 1.0×10−6 to 1.0×10−3 M and 1.0×10−6 to 8.0×10−4 M with detection limits of 4.5×10−7 M and 3.4×10−7 M for levodopa and tyrosine respectively.
Determination of Thiols and Free Thiol Content in a Protein with Liquid Chromatography Coupled to Amperometric Detection at a Silver Based Carbon Paste Electrode
Authors: Aydogmus Zeynep , Sarakbi Ahmad , Kauffmann Jean‐Michel
Published: May 2016

Liquid chromatography (LC) coupled to an electrochemical detector was applied for the determination of small thiols such as cysteine (Cys), glutathione (GSH) and dithiothreitol (DDT) and the free thiol content in a protein. The thio‐compounds were first derivatized by 2,2′‐dipyridyldisulfide (DPDS) at pH 4.5 to yield the corresponding disulfide and 2‐thiopyridone (2‐TP). The reaction mixture was separated isocratically on a reversed‐phase C18 column with amperometric detection (AD) at a carbon paste electrode modified with silver microparticles and polarized at 0.080 V versus Ag/AgCl. The LC‐AD response corresponding to the generated 2‐TP allowed for the indirect determination of the studied thiol derivatives in the 1×10−5–1×10−4 M range for Cys and GSH and 5×10−6–5×10−5 M range for DTT. The LOD and LOQ values were in the range of 9×10−7–4×10−6 M and 3×10−6−‐5.5×10−6 M, respectively for the three studied compounds. Application to the determination of the free thiol content of human and bovine serum albumin as model proteins was realized. The LC‐AD results were validated with respect to a developed spectrophotometric method performed under identical experimental derivatization conditions.
Individual variations in dose response for spatial memory learning among outbred wistar rats exposed from 5 to 20 cGy of 56Fe particles
Authors: Wyrobek Andrew J. , Britten Richard A.
Published: May 2016

Exposures of brain tissue to ionizing radiation can lead to persistent deficits in cognitive functions and behaviors. However, little is known about the quantitative relationships between exposure dose and neurological risks, especially for lower doses and among genetically diverse individuals. We investigated the dose relationship for spatial memory learning among genetically outbred male Wistar rats exposed to graded doses of 56Fe particles (sham, 5, 10, 15, and 20 cGy; 1 GeV/n). Spatial memory learning was assessed on a Barnes maze using REL3 ratios measured at three months after exposure. Irradiated animals showed dose‐dependent declines in spatial memory learning that were fit by a linear regression (P for slope <0.0002). The irradiated animals showed significantly impaired learning at 10 cGy exposures, no detectable learning between 10 and 15 cGy, and worsened performances between 15 and 20 cGy. The proportions of poor learners and the magnitude of their impairment were fit by linear regressions with doubling doses of ∼10 cGy. In contrast, there were no detectable deficits in learning among the good learners in this dose range. Our findings suggest that genetically diverse individuals can vary substantially in their spatial memory learning, and that exposures at low doses appear to preferentially impact poor learners. This hypothesis invites future investigations of the genetic and physiological mechanisms of inter‐individual variations in brain function related to spatial memory learning after low‐dose HZE radiation exposures and to determine whether it also applies to physical trauma to brain tissue and exposures to chemical neurotoxicants. Environ. Mol. Mutagen. 57:331–340, 2016. © 2016 Wiley Periodicals, Inc.
Higher mode effects in frame pin‐supported wall structure by using a distributed parameter model
Authors: Shoujun Wu , Peng Pan , Dongbin Zhang
Published: May 2016

Frame pin‐supported wall structure is a kind of rocking structure, which releases constraints at the bottom of the wall. The wall is affiliated to the frame and can rotate around the hinge. Previous studies have investigated seismic performance (such as deformation pattern and plastic hinge distribution) of frame pin‐supported wall structure. Strength demand of this system was investigated through static pushover analysis. However, dynamic characteristics, especially higher mode effects, remain to be quantified. As demonstrated in several researches, higher mode effects have non‐negligible effects on seismic response. For this purpose, a distributed model for analyzing higher mode effects in frame pin‐supported wall structure was proposed, where the pin‐supported wall and the frame were simplified as a bending beam and a shear beam, respectively. The model was solved by differential equations derived from equilibrium and compatibility. Displacement and inner force distribution of frame pin‐supported wall structure in higher modes were quantified according to the model. Influence of critical parameters, such as wall stiffness and structure period, was assessed on higher mode effects. It was demonstrated that response in higher modes cannot be neglected in the design of frame pin‐supported wall structure. Capacity design based on the fundamental mode is not conservative, especially in the wall. Furthermore, pin‐supported walls tend to force the frame to vibrate in the rocking mode and suppress higher mode effects in the frame. Copyright © 2016 John Wiley & Sons, Ltd.
Observations of asymmetry in contrasting wave‐ and tidally‐dominated environments within a mesotidal basin: implications for estuarine morphological evolution
Authors: Hunt Stephen , Bryan Karin R. , Mullarney Julia C. , Pritchard Mark
Published: May 2016

Tides are often considered to be the dominant hydrodynamic process within mesotidal estuaries although waves can also have a large influence on intertidal erosion rates. Here, we use a combination of hydrodynamic measurements and sediment deposition records to determine the conditions under which observed waves are ‘morphologically significant’, in which case they influence tidal and suspended sediment flux asymmetry and subsequently infilling over geomorphological timescales. Morphological significant conditions were evaluated using data from contrasting arms in a dendritic mesotidal estuary, in which the orientation of the arms relative to the prevailing wind results in a marked difference in wave conditions, deposition rates and morphology. By defining the morphological significance of waves as a product of the magnitude of bed shear stress and frequency of occurrence, even small (but frequently occurring) winds are shown to be capable of generating waves that are morphologically significant given sufficient fetch. In the arm in which fetch length is restricted, only stronger but rare storm events can influence sediment flux and therefore tides are more morphologically significant over longer timescales. Water depth within this mesotidal estuary is shown to be a critical parameter in controlling morphological significance; the rapid attenuation of short period waves with depth results in contrasting patterns of erosion occurring during neaps and accretion during springs. Copyright © 2016 John Wiley & Sons, Ltd.
Option Pricing with Threshold Mean Reversion
Authors: Chi Zeyu , Dong Fangyuan , Wong Hoi Ying
Published: May 2016

Mean reversion and regime switching are well‐known features of commodity prices. Recent empirical research additionally documents the time variation of the mean reversion rate and volatility. This paper considers the option pricing framework for an underlying commodity price with mean reversion rate and volatility change according to a self‐exciting regime switching model. We offer empirical evidence for the proposed model and derive analytic pricing formulas for the European and barrier options. Numerical examples demonstrate the application and the ability of the proposed model in capturing volatility smile and regime‐switching in the mean reversion rate, simultaneously. © 2016 Wiley Periodicals, Inc. Jrl Fut Mark 37:107–131, 2017
On phase field modeling of ductile fracture
Authors: Kuhn Charlotte , Noll Timo , Müller Ralf
Published: May 2016

Recently, different extensions of phase field fracture models to ductile fracture scenarios where the crack evolution is affected by plastic deformation have been proposed. In most of these phase field models for ductile fracture, the coupling of the elastic‐plastic material laws and the phase field variable is rather complicated and staggered finite element solution schemes are employed in order to avoid the computation of the complicated coupling terms in the tangent matrix. In this work, we propose an elastic‐plastic phase field fracture model, where the coupling is such that a monolithic solution is possible. Through the proposed coupling of the elastic‐plastic material law and the phase field order parameter, a reinterpretation of the meaning of the plastic material parameters is necessary in order to obtain reasonable effective material properties for the ductile phase field fracture model that can be related to measured data. The respective relations are derived from an analysis of the model in one dimension. Finite element simulations of plane strain fracture problems demonstrate the appropriateness of the derived effective material parameters and the applicability of the monolithic solution scheme. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prevalence of germline mutations in the spindle assembly checkpoint gene BUB1B in individuals with early‐onset colorectal cancer
Authors: Hahn Marc‐Manuel , Vreede Lilian , Bemelmans Sonja A. S. A , van der Looij Erica , van Kessel Ad Geurts , Schackert Hans K. , Ligtenberg Marjolijn J. L. , Hoogerbrugge Nicoline , Kuiper Roland P. , de Voer Richarda M.
Published: May 2016

Germline mutations in BUB1B, encoding BUBR1, one of the crucial components of the spindle assembly checkpoint (SAC), have been shown to cause variable phenotypes, including the recessive mosaic variegated aneuploidy (MVA) syndrome, which predisposes to cancer. Reduced levels of the wild‐type BUBR1 protein have been linked to the development of gastrointestinal neoplasms. To determine whether mutations in BUB1B are enriched in individuals with colorectal cancer (CRC), we performed amplicon‐based targeted next‐generation sequencing of BUB1B on germline DNA of 192 individuals with early‐onset CRC (≤50 years). None of the individuals was found to be homozygous or compound heterozygous for mutations in BUB1B. However, we did identify two rare heterozygous variants, p.Glu390del and p.Cys945Tyr, in patients who developed CRC at the ages of 41 and 43 years, respectively. Both variants were shown not to affect BUBR1 protein expression levels and protein localization. Since the p.Glu390del variant is located in the BUB3‐binding domain, we also performed immunoprecipitation to examine whether this variant affects the binding of BUB1 or BUB3 to BUBR1 but, compared to wild‐type BUBR1, no difference was observed. Our data suggest that mutations in BUB1B do not occur frequently in the germline of individuals with CRC and that BUB1B unlikely plays a major role in the predisposition to early‐onset CRC. Whether carriers of pathogenic BUB1B mutations, such as the parents of MVA syndrome patients, have an increased risk for cancer remains of interest, as studies in mice have suggested that haploinsufficiency of BUB1B may cause an increase in carcinogen‐induced tumors. © 2016 Wiley Periodicals, Inc.
Hot and cold subduction systems in the Western Pacific Ocean: insights from heat flows
Authors: Kong X. C. , Li S. Z. , Suo Y. H. , Guo L. L. , Li X. Y. , Liu X. , Somerville I. D. , Dai L. M. , Zhao S. J.
Published: May 2016

We calculate a predicted interpolating result of surface heat flow based on a data set with 2674 measurements in the Western Pacific. Comparisons of heat flow profiles between the back‐arc basin and the corresponding subduction slab show that the cold subducting slab may cause indirectly the thermal activities of back‐arc basins. We estimate that values of <50 mW/m2 for both the Philippine Sea Plate and the Pacific Plate may respectively cause the thermal activity of the Okinawa Trough and the Kuril Basin. Moreover, cold subduction may release carbonatitic liquid at different depths, and the process of releasing liquid ends up with the maximum range of serpentinization. The hot subduction system has released most of the water before being incorporated into the mantle wedge; therefore, at great depths, the amount of carbon may dominate the subducting process by controlling partial melting. Copyright © 2016 John Wiley & Sons, Ltd.
Cenozoic tectonic evolution of the Tibetan Plateau – the Nepal Himalaya and the provenance of their foreland basins
Authors: Neupane Bhupati , Ju Yiwen , Tan Fengqi , Baral Upendra , Ulak Prakash Das , Sun Ying
Published: May 2016

The Tibetan Plateau and the Himalayan region formed after 55–50 Ma, as a result of the intracontinental collision of the Indian and Eurasian plates, occupying the east–west trending, high‐altitude Himalaya and Karakorum ranges in the south and the vast Tibetan Plateau to the north of central Asia. The tectonic evolution of Tibet began between the late Palaeozoic and the Cenozoic, and the Himalayan mountain system evolved in a series of stages beginning 50–35 Ma and is still active.

Active tectonics significantly affect upheaval and the rate of erosion in the Himalaya. Therefore, different foreland basins of the Tibetan Plateau (e.g. the Lhasa terrane, the Hoh Xil Basin, the Qaidam Basin, and the Jiuquan Basin) and the Himalayan foreland basins (e.g. Gondwanaland Basin and the Siwalik and Quaternary basin) experience direct effects in terms of tectonic and sedimentary evolution. For the tectonic evolution and provenance analysis of foreland basins in the Tibetan Plateau and the Nepal Himalaya, researchers have adopted various techniques in past studies: This paper discusses petrography, U–Pb geochronology, and seismic reflection.

Provenance analyses have illustrated that the sediments of the Southern Tibetan foreland basin (i.e. the Lhasa terrane) derive from the Qiangtang, Tethys Himalaya, and southwest Australia. Similarly, the sediments of the Central Tibetan basin derive from the Qilian, Kunlun‐Qimantagh, and the Altyn Mountains; the sediments of northern side of the Tibetan foreland basin, from Qilian Shan Mountain; and the sediments of the Nepal Himalayan foreland basin, from the Tethys, Higher, and Lesser Himalaya. Copyright © 2016 John Wiley & Sons, Ltd.
Perceived communicative intent in gesture and language modulates the superior temporal sulcus
Authors: Redcay Elizabeth , Velnoskey Kayla R. , Rowe Meredith L.
Published: May 2016

Behavioral evidence and theory suggest gesture and language processing may be part of a shared cognitive system for communication. While much research demonstrates both gesture and language recruit regions along perisylvian cortex, relatively less work has tested functional segregation within these regions on an individual level. Additionally, while most work has focused on a shared semantic network, less has examined shared regions for processing communicative intent. To address these questions, functional and structural MRI data were collected from 24 adult participants while viewing videos of an experimenter producing communicative, Participant‐Directed Gestures (PDG) (e.g., “Hello, come here”), noncommunicative Self‐adaptor Gestures (SG) (e.g., smoothing hair), and three written text conditions: (1) Participant‐Directed Sentences (PDS), matched in content to PDG, (2) Third‐person Sentences (3PS), describing a character's actions from a third‐person perspective, and (3) meaningless sentences, Jabberwocky (JW). Surface‐based conjunction and individual functional region of interest analyses identified shared neural activation between gesture (PDGvsSG) and language processing using two different language contrasts. Conjunction analyses of gesture (PDGvsSG) and Third‐person Sentences versus Jabberwocky revealed overlap within left anterior and posterior superior temporal sulcus (STS). Conjunction analyses of gesture and Participant‐Directed Sentences to Third‐person Sentences revealed regions sensitive to communicative intent, including the left middle and posterior STS and left inferior frontal gyrus. Further, parametric modulation using participants' ratings of stimuli revealed sensitivity of left posterior STS to individual perceptions of communicative intent in gesture. These data highlight an important role of the STS in processing participant‐directed communicative intent through gesture and language. Hum Brain Mapp 37:3444–3461, 2016. © 2016 Wiley Periodicals, Inc.
Which way and how far? Tracking of translation and rotation information for human path integration
Authors: Chrastil Elizabeth R. , Sherrill Katherine R. , Hasselmo Michael E. , Stern Chantal E.
Published: May 2016

Path integration, the constant updating of the navigator's knowledge of position and orientation during movement, requires both visuospatial knowledge and memory. This study aimed to develop a systems‐level understanding of human path integration by examining the basic building blocks of path integration in humans. To achieve this goal, we used functional imaging to examine the neural mechanisms that support the tracking and memory of translational and rotational components of human path integration. Critically, and in contrast to previous studies, we examined movement in translation and rotation tasks with no defined end‐point or goal. Navigators accumulated translational and rotational information during virtual self‐motion. Activity in hippocampus, retrosplenial cortex (RSC), and parahippocampal cortex (PHC) increased during both translation and rotation encoding, suggesting that these regions track self‐motion information during path integration. These results address current questions regarding distance coding in the human brain. By implementing a modified delayed match to sample paradigm, we also examined the encoding and maintenance of path integration signals in working memory. Hippocampus, PHC, and RSC were recruited during successful encoding and maintenance of path integration information, with RSC selective for tasks that required processing heading rotation changes. These data indicate distinct working memory mechanisms for translation and rotation, which are essential for updating neural representations of current location. The results provide evidence that hippocampus, PHC, and RSC flexibly track task‐relevant translation and rotation signals for path integration and could form the hub of a more distributed network supporting spatial navigation.Hum Brain Mapp 37:3636–3655, 2016. ©2016 Wiley Periodicals, Inc.