bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Glucose Biosensor Based on Tb@Mesoporous Metal‐Organic Frameworks/Carbon Nanotube Nanocomposites
Authors: Song Yonghai , Shen Yuan , Gong Coucong , Chen Jingyi , Xu Mengli , Wang Linyu , Wang Li
Published: March 2017

This study demonstrates the exploitation of carbon nanotubes (CNTs) combined with mesoporous metal‐organic frameworks (Tb@mesoMOFs) to form a novel nanocomposite as the platform to construct electrochemical biosensors for glucose detection. Energy‐dispersive X‐ray spectroscopy, UV/Vis spectroscopy, scanning electron microscopy, and electrochemical techniques were used to characterize the Tb@mesoMOFs‐CNT nanocomposites. The results showed that a thin layer of Tb@mesoMOFs uniformly covered the surface of CNTs. The Tb@mesoMOFs‐CNT nanocomposites served as a supporting matrix to load both methylene green (MG) as electron mediators and glucose dehydrogenases (GDH) as electrocatalysts on a glassy carbon electrode (GCE) for constructing an electrochemical glucose biosensor, owing to the large number of micropores of Tb@mesoMOFs and excellent electrical conductivity of the CNTs together with ultrahigh surface area of the nanocomposites. GDH/MG−Tb@MOF‐CNTs/GCE showed good performance for glucose detection with a wide linear range of approximately 25 μM to 17 mM and a low detection limit of 8 μM (R=0.998, n=10). The work also provided a novel idea to prepare excellent MOFs/CNT‐based materials for electrochemical sensing.
Water‐Based Synthesis of Palladium Trigonal Bipyramidal/Tetrahedral Nanocrystals with Enhanced Electrocatalytic Oxidation Activity
Authors: Shang Changshuai , Hong Wei , Guo Yaxiao , Wang Jin , Wang Erkang
Published: March 2017

Well‐defined palladium trigonal bipyramidal/tetrahedral nanocrystals were synthesized by an aqueous‐phase hydrothermal method. The final products were a mixture of trigonal bipyramidal and tetrahedral nanocrystals. Statistics indicated that there were more trigonal bipyramids than tetrahedra in the products. Ethylenediamine tetraacetic acid disodium salt (EDTA‐2Na) was proven to be essential in controlling the final shapes of palladium nanocrystals. Some control experiments were also conducted to investigate the shape evolution and formation mechanisms. The synthesized palladium nanocrystals showed enhanced catalytic properties for ethanol and glycerol electrooxidation in alkaline medium. This work provides a new method in preparing Pd nanomaterials with well‐defined shapes.
Ohmic Heating: An Emerging Concept in Organic Synthesis
Authors: Silva Vera L. M. , Santos Luis M. N. B. F. , Silva Artur M. S.
Published: March 2017

The ohmic heating also known as direct Joule heating, is an advanced thermal processing method, mainly used in the food industry to rapidly increase the temperature for either cooking or sterilization purposes. Its use in organic synthesis, in the heating of chemical reactors, is an emerging method that shows great potential, the development of which has started recently. This Concept article focuses on the use of ohmic heating as a new tool for organic synthesis. It presents the fundamentals of ohmic heating and makes a qualitative and quantitative comparison with other common heating methods. A brief description of the ohmic reactor prototype in operation is presented as well as recent examples of its use in organic synthesis at laboratory scale, thus showing the current state of the research. The advantages and limitations of this heating method, as well as its main current applications are also discussed. Finally, the prospects and potential implications of ohmic heating in future research in chemical synthesis are proposed.
The Effects of Macromolecular Crowding on Calmodulin Structure and Function
Authors: Xu Guohua , Zhao Jiajing , Cheng Kai , Wu Qiong , Liu Xiaoli , Liu Maili , Li Conggang
Published: March 2017

Macromolecular crowding and confinement are two factors that potentially affect protein structure and function in a complex cellular environment. The confinement effect on the structure and function of holoCaM [Ca2+‐loaded calmodulin (CaM)], a two‐domain protein involved in many calcium‐mediated signaling pathways, has been investigated previously. However, little is known about how macromolecular crowding affects holoCaM structure and function. Here, the structure–function correlations of holoCaM are investigated in macromolecular crowded environments. It was found that macromolecular crowding impacts its structure and function mildly. The major conformational states are still extended conformation with inter‐domain separation in crowded environment as well as those in dilute solution, but the population of transiently compact conformation increases compared to dilute solution. Furthermore, macromolecular crowding facilitates the binding of CaM with AcN19 peptide (CaM‐bind domain of α‐syn). This study provides a direct comparison for macromolecular crowding and confinement effects on protein structure and function, which helps to understand chemistry regulation in living cells.
Dicyano‐Substituted Diazaacenes
Authors: Müller Matthias , Beglaryan Stella S. , Koser Silke , Hahn Sebastian , Tverskoy Olena , Rominger Frank , Bunz Uwe H. F.
Published: March 2017

Herein, we report the synthesis, spectroscopic, and structural properties of novel 2,3‐dicyano‐substituted azaacenes containing three to six annelated rings as a framework. The targets were prepared by Pd‐catalyzed coupling of diamino‐bis(tri‐isopropylsilylethynyl)benzene, ‐naphthalene, and ‐anthracene with either 4,5‐dibromophthalonitrile or 6,7‐dibromonaphthalene‐2,3‐dicarbonitrile into the respective N,N′‐dihydrodiazaacenes. Oxidation with MnO2 or PbO2 furnishes the dicyano‐substituted diazaacenes in reasonable to good yields. An exception is the diazahexacene, where the N,N′‐dihydrodiazaacene is difficult to oxidize. Most of the targets could be crystallized and pack in isolated pairs, stacks, and brick‐wall motifs. The n‐type behavior of these molecules was illustrated in a proof‐of‐concept organic field‐effect transistor, showing mobilities up to 7×10−3 cm2 V−1 s−1.
Synthesis of an S‐Linked α(2→8) GD3 Antigen and Evaluation of the Immunogenicity of Its Glycoconjugate
Authors: Kuan Ting‐Chun , Wu Hsin‐Ru , Adak Avijit K. , Li Ben‐Yuan , Liang Chien‐Fu , Hung Jung‐Tung , Chiou Shih‐Pin , Yu Alice L. , Hwu Jih Ru , Lin Chun‐Cheng
Published: March 2017

Replacing the interglycosidic oxygen atom of oligosaccharides with a nonhydrolyzable sulfur atom has attracted significant interest because it provides opportunities for developing new glycoconjugate vaccines. Herein, a stereocontrolled and highly convergent method to synthesize a non‐reducing‐end inter‐S‐glycosidic variant of the GD3 antigen (S‐linked α(2→8) GD3) that is resistant to enzymatic hydrolysis is reported. The key steps in the synthesis are a regio‐ and stereoselective α(2→3) sialylation of a lactoside acceptor with a C8‐iodide‐derivatized sialyl donor and an anomeric S‐alkylation, which enable stereoselective construction of a terminal S‐linked α(2→8) disialyl residue. The sulfhydryl‐reactive maleimide group was used as the linker for the well‐defined conjugation of these antigens to the immunogenic protein keyhole limpet hemocyanin (KLH). Groups of mice were immunized with the GD3–KLH and S‐linked GD3–KLH glycoconjugates in the presence of complete Freund's adjuvant. Microarray analysis of the sera showed the promise of the S‐linked GD3–KLH vaccine: it stimulated a high immunoglobulin G response against S‐linked GD3 and cross‐reactivity with the O‐linked GD3 antigen was low. The activity of the S‐linked GD3–KLH vaccine was comparable to that of the O‐linked GD3–KLH vaccine, which highlighted the effectiveness of generating glycoconjugate vaccines and immunotherapies by relatively simple means.
Suzuki–Miyaura Cross‐Coupling Reactions of Highly Fluorinated Arylboronic Esters: Catalytic Studies and Stoichiometric Model Reactions on the Transmetallation Step
Authors: Kohlmann Johannes , Braun Thomas , Laubenstein Reik , Herrmann Roy
Published: March 2017

Fluorinated 4‐aryl phenylalanine amino acid derivatives (aryl=2‐C5NF4, 4‐C6H4SF5, 2‐C6H4SCF3, C6F5) were obtained in Suzuki–Miyaura cross‐coupling reactions of phenylalanine precursors with highly fluorinated aryl boronic acid and esters in the presence of CsF. PdII complexes that possessed phenyl alanine derived ligands, such as trans‐[PdBr{4‐C6H4CH2CH{NHC(O)CH3}CO2Et}(PiPr3)2], were used as catalysts. Stoichiometric model reactions indicate the intermediate generation of the boronate Cs[BF(2‐C5NF4)(pin)] (pin=pinacolato=O2C2Me4). The transmetallation step with Cs[BF(4‐C6H4SF5)(pin)], [NMe4][BF(2‐C5NF4)(pin)] and/or the fluorido complex trans‐[PdF{4‐C6H4CH2C{NHC(O)CH3}(CO2Et)2}(PiPr3)2] was investigated. A comparison of the reactions of trans‐[PdX{4‐C6H4CH2C{NHC(O)CH3}(CO2Et)2}(PiPr3)2] (X=Br, F) with 2‐Bpin‐C5NF4 or [NMe4][BF(2‐C5NF4)(pin)] revealed the remarkable high reactivity of the fluorido complex towards 2‐BpinC5NF4. Low‐temperature NMR studies indicated the ionic species trans‐[Pd{4‐C6H4CH2C{NHC(O)CH3}(CO2Et)2}(PiPr3)2][BF(2‐C5NF4)(pin)] to be a highly reactive intermediate.
Ternary Ni‐Co‐F Nanocrystal‐Based Supercapacitors
Authors: Li Xudong , Ding Rui , Shi Wei , Xu Qilei , Liu Enhui
Published: March 2017

Ternary nickel cobalt fluoride (Ni‐Co‐F) nanocrystals are constructed solvothermally for use as the positive electrode materials in supercapacitors. The optimal Ni‐Co‐F (Ni/Co=2:1) shows slight chemical shifts in X‐ray diffraction (XRD) data and X‐ray photoelectron spectra (XPS) compared with bare Ni‐F and Co‐F. The Ni‐Co‐F (Ni/Co=2:1) exhibits typical square nanocrystal morphology together with a mesoporous surface structure, as observed through TEM observations and nitrogen sorption measurements. Owing to the stronger synergistic effect of Ni and Co redox species originated from the richer Ni and Co surface electroactive sites, Ni‐Co‐F (Ni/Co=2:1) shows superior performances of specific capacitance, rate capability, and charge‐transfer kinetics (564 F g−1 at 1 Ag−1, 418 F g−1 at 16 Ag−1, 449 Ω) compared with all the other Ni‐Co‐F candidates. Moreover, the activated carbon (AC)//Ni‐Co‐F (Ni/Co=2:1) asymmetric capacitor designed based on charge balance delivers superior energy and power densities (18.4 Wh kg−1, 6.64 kW kg−1) together with longer cycle life (77 % retention after 10 000 cycles at 4 A g−1).
Simulation and experimental research on coarse coal slime particles’ separation in inclined tapered diameter separation bed
Authors: Sheng Cheng , Duan Chenlong , Zhao Yuemin , Zhou Chenyang , Zhang Yong
Published: March 2017

A novel inclined tapered diameter separation bed (ITDSB) was designed for the beneficiation of coarse coal slime. Computational fluid dynamics (CFD) coupled with the discrete element method (DEM) was explored to study particle separation and the effect of underscreen water on particle movements over time. Results show that coal particles and gangue particles have disparate movements. Coal particles are drifted by the force of water flow and have the analogous trend of movements as water flow, while gangue particles sink towards the lower part of the bed under the effect of the gravity. Secondary separation was achieved through forcing particles to bounce back into the flow field and benefited from the invention and application of underscreen holes. The three factor orthogonal experiments of separating coarse coal slime (3–0.5 mm) have been performed. The obtained clean coals and tailings were tested and further analyzed with an X‐ray fluorescence spectrometer (XRF) and scanning electron microscope (SEM). XRF and SEM results show that gangue minerals were discarded significantly after the separation. Orthogonal experimental results reveal that with reasonable combination of various levels of factors, the average combustible recovery is approximately 60 %, which shows that the inclined tapered diameter separation bed is efficient equipment for coarse coal slime beneficiation. Secondary separation and the effect of underscreen water were simultaneously verified as efficient methods in particle separation processes.
Short‐ and long‐term clinical predictors of pharmacological cardioversion of persistent atrial fibrillation by dofetilide: A retrospective cohort study of 160 patients
Authors: Hassan Virk Hafeez Ul , Qureshi Waqas T. , Makkar Nayani , Bastawrose Joseph , Souvaliotis Nektarios , Aziz Joshua , Aziz Emad
Published: March 2017

Introduction

Dofetilide is a class III antiarrhythmic prescribed to cardiovert persistent atrial fibrillation (AF) to sinus rhythm (SR).

Hypothesis

To determine the clinical predictors of cardioversion and readmission in persistent AF patients on dofetilide.

Methods

We analyzed 160 patients with persistent AF who were started on dofetilide and followed for 1 year. We examined age, sex, race, hypertension, diabetes, smoking, dyslipidemia, CAD, left ventricular ejection fraction (LVEF), creatinine, BMI and concomitant use of calcium channel blockers (CCB), β‐blockers in a multivariable logistic regression model. We also examined the same predictors in Cox regression model for AF‐related readmission within 1 year of follow‐up.

Results

13.5% individuals did not convert to SR on dofetilide. 55.6% converted on the first dose and 83.1% converted by the fourth dose. In multivariable logistic models, dyslipidemia (OR: 2.4, CI: 1.12‐5.16) and LVEF (OR: 3.83,CI: 1.37‐10.8) were associated with failure to convert with the first dose. Female sex and LVEF also were associated with increased risk of failure to convert at all. Concomitant use of CCB associated with decreased risk of failure to convert to SR. In Cox proportional model, female sex, age <63 years and CAD were associated with increased AF readmission within 1 year.

Conclusions

Dyslipidemia and LVEF <40% were associated with failure to cardiovert after first dose, and female sex and LVEF 40% were related to failure to convert at all on dofetilide in persistent AF patients. After 1‐year follow‐up, female sex, known CAD, and age <63 years were associated with increased AF readmissions.
Echocardiographic evaluation of the right ventricle: Clinical implications
Authors: Dutta Tanya , Aronow Wilbert S.
Published: March 2017

Interest in evaluation of the right ventricle (RV) has increased recently. With the growth of new echocardiographic techniques and technology, there has been a corresponding increase in the ability to evaluate the RV, both qualitatively and quantitatively. Older echocardiographic techniques, such as right ventricular fractional area of change, tricuspid annular plane systolic excursion, and tissue S′, and newer echocardiographic techniques including 3‐dimensional evaluation and global longitudinal strain, can improve our evaluation of RV function. These techniques provide both diagnostic and prognostic data on a large variety of clinical diseases including pulmonary hypertension and congestive heart failure. With the continuing and exponential advances in technology, echocardiography is well poised to become the primary modality to evaluate the RV.
Body mass index, PAM50 subtype, recurrence, and survival among patients with nonmetastatic breast cancer
Authors: Cespedes Feliciano Elizabeth M. , Kwan Marilyn L. , Kushi Lawrence H. , Chen Wendy Y. , Weltzien Erin K. , Castillo Adrienne L. , Sweeney Carol , Bernard Philip S. , Caan Bette J.
Published: March 2017

BACKGROUND

Studies of obesity and survival among patients with breast cancer produce conflicting results, possibly because of heterogeneity by molecular subtype.

METHODS

This study examined whether the association of body mass index (BMI) at diagnosis with breast cancer recurrence and survival varied across subtypes defined by PAM50 (Prediction Analysis of Microarray 50) gene expression. Included were 1559 Kaiser Permanente Northern California members ages 18 to 79 years who had PAM50 assays and were diagnosed with American Joint Committee on Cancer stage I through III breast cancer from 1996 to 2013. Patients reported weight and height. Cox regression models were adjusted for age, menopause, race/ethnicity, stage, and chemotherapy.

RESULTS

Over a median of 9 years (maximum, 19 years), 378 women developed recurrent disease, and 312 died from breast cancer. Overall, BMI was not associated with breast cancer recurrence or survival when controlling for subtype (eg, the hazard ratio per 5 kg/m2 of BMI was 1.05 [95% confidence interval, 0.95‐1.15] for breast cancer‐specific death). However, associations varied by subtype. Among women with luminal A cancers, those who had class II/III obesity, but not class I obesity or overweight, had worse outcomes. When women who had a BMI ≥35 kg/m2 were compared with those who had a BMI from 18.5 to <25 kg/m2, the hazard ratio was 2.24 (95% confidence interval,1.22‐4.11) for breast cancer‐specific death and 1.24 (95% confidence interval, 1.00‐1.54) for recurrence. There was no association within luminal B, basal‐like or human epidermal growth factor over‐expressing subtypes.

CONCLUSIONS

Among patients who had accurately classified breast cancer subtypes based on gene expression, a BMI ≥35 kg/m2 was adversely associated with outcomes only among those who had luminal A cancers. Research is needed into whether tailoring recommendations for weight management to tumor characteristics will improve outcomes. Cancer 2017;123:2535–42. © 2017 American Cancer Society.
Using the National Cancer Data Base for quality evaluation to assess adherence to treatment guidelines for nonmetastatic inflammatory breast cancer
Authors: Lin Heather Y. , Bedrosian Isabelle , Babiera Gildy V. , Shaitelman Simona F. , Kuerer Henry M. , Woodward Wendy A. , Ueno Naoto T. , Shen Yu
Published: March 2017

BACKGROUND

Guidelines for the treatment of nonmetastatic inflammatory breast cancer (IBC) using trimodality therapy (TT) (chemotherapy, surgery, and radiotherapy) have remained largely unchanged since 2000. However, many patients with nonmetastatic IBC do not receive TT. It is unknown how patient‐level (PL) and facility‐level (FL) factors contribute to TT use.

METHODS

Using the National Cancer Data Base, patients with nonmetastatic IBC who underwent locoregional treatment from 2003 through 2011 were identified. The authors correlated PL factors, including demographic and tumor characteristics, with TT use. An observed‐to‐expected ratio for the number of patients treated with TT was calculated for each hospital by adjusting for significant PL factors. Hierarchical mixed effects models were used to assess the percentage of variation in TT use attributable to PL and FL factors, respectively.

RESULTS

Of the 542 hospitals examined, 55 (10.1%) and 24 (4.4%), respectively, were identified as significantly low and high outliers for TT use (P<.05). The percentage of the total variance in the use of TT attributable to the facility (11%) was nearly triple the variance attributable to the measured PL factors (3.4%). The nomogram generated from multivariate logistic regression of PL factors only allows a facility to assess TT use given their PL data.

CONCLUSIONS

FL factors rather than PL factors appear to contribute disproportionately to the underuse of TT in patients with nonmetastatic IBC. To improve treatment guideline adherence for patients with nonmetastatic IBC, it is critical to identify the specific FL factors associated with TT underuse. More organized FL intervention is required to train physicians and to build multidisciplinary teams. Cancer 2017;123:2618‐25. © 2017 American Cancer Society.
A comparative analysis of the physiological properties of neurons in the anterolateral bed nucleus of the stria terminalis in the Mus musculus, Rattus norvegicus, and Macaca mulatta
Authors: Daniel Sarah E. , Guo Jidong , Rainnie Donald G.
Published: March 2017

The anterolateral group of the bed nucleus of the stria terminalis (BNSTALG) is a critical modulator of a variety of rodent and primate behaviors spanning anxiety behavior and drug addiction. Three distinct neuronal cell types have been previously defined in the rat BNSTALG based on differences in the voltage‐response to hyperpolarizing and depolarizing current injection. Differences in genetic expression profile between these three cell types suggest electrophysiological cell type may be an indicator for functional differences in the circuit of the rat BNSTALG. Although the behavioral role of the BNST is conserved across species, it is unknown if the same electrophysiological cell types exist in the BNSTALG of the mouse and nonhuman primate. Here, we used whole‐cell patch clamp electrophysiology and neuronal reconstructions of biocytin‐filled neurons to compare and contrast the electrophysiological and morphological properties of neurons in the BNSTALG from the mouse, rat, and rhesus macaque. We provide evidence that the BNSTALG of all three species contains neurons that match the three defined cell types found in the rat; however, there are intriguing differences in the relative frequency of these cell types as well as electrophysiological and morphological properties of the BNSTALG neurons across species. This study suggests that the overall landscape of the BNSTALG in the primate and mouse may be similar to that of the rat in some aspects but perhaps significantly different in others.
Neurochemistry of neurons in the ventrolateral medulla activated by hypotension: Are the same neurons activated by glucoprivation?
Authors: Parker Lindsay M. , Le Sheng , Wearne Travis A. , Hardwick Kate , Kumar Natasha N. , Robinson Katherine J. , McMullan Simon , Goodchild Ann K.
Published: March 2017

Previous studies have demonstrated that a range of stimuli activate neurons, including catecholaminergic neurons, in the ventrolateral medulla. Not all catecholaminergic neurons are activated and other neurochemical content is largely unknown hence whether stimulus specific populations exist is unclear. Here we determine the neurochemistry (using in situ hybridization) of catecholaminergic and noncatecholaminergic neurons which express c‐Fos immunoreactivity throughout the rostrocaudal extent of the ventrolateral medulla, in Sprague Dawley rats treated with hydralazine or saline. Distinct neuronal populations containing PPCART, PPPACAP, and PPNPY mRNAs, which were largely catecholaminergic, were activated by hydralazine but not saline. Both catecholaminergic and noncatecholaminergic neurons containing preprotachykinin and prepro‐enkephalin (PPE) mRNAs were also activated, with the noncatecholaminergic population located in the rostral C1 region. Few GlyT2 neurons were activated. A subset of these data was then used to compare the neuronal populations activated by 2‐deoxyglucose evoked glucoprivation (Brain Structure and Function (2015) 220:117). Hydralazine activated more neurons than 2‐deoxyglucose but similar numbers of catecholaminergic neurons. Commonly activated populations expressing PPNPY and PPE mRNAs were defined. These likely include PPNPY expressing catecholaminergic neurons projecting to vasopressinergic and corticotrophin releasing factor neurons in the paraventricular nucleus, which when activated result in elevated plasma vasopressin and corticosterone. Stimulus specific neurons included noncatecholaminergic neurons and a few PPE positive catecholaminergic neuron but neurochemical codes were largely unidentified. Reasons for the lack of identification of stimulus specific neurons, readily detectable using electrophysiology in anaesthetized preparations and for which neural circuits can be defined, are discussed.
Analysis of Nitroxide‐Based Distance Measurements in Cell Extracts and in Cells by Pulsed ESR Spectroscopy
Authors: Lawless Matthew J. , Shimshi Amit , Cunningham Timothy F. , Kinde Monica N. , Tang Pei , Saxena Sunil
Published: March 2017

Measurements of distances in cells by pulsed ESR spectroscopy afford tremendous opportunities to study proteins in native environments that are irreproducible in vitro. However, the in‐cell environment is harsh towards the typical nitroxide radicals used in double electron–electron resonance (DEER) experiments. A systematic examination is performed on the loss of the DEER signal, including contributions from nitroxide decay and nitroxide side‐chain cleavage. In addition, the possibility of extending the lifetime of the nitroxide radical by use of an oxidizing agent is investigated. Using this oxidizing agent, DEER distance measurements are performed on doubly nitroxide‐labeled GB1, the immunoglobulin‐binding domain of protein G, at varying incubation times in the cellular environment. It is found that, by comparison of the loss of DEER signal to the loss of the CW spectrum, cleavage of the nitroxide side chain contributes to the loss of DEER signal, which is significantly greater in cells than in cell extracts. Finally, local spin concentrations are monitored at varying incubation times to show the time required for molecular diffusion of a small globular protein within the cellular milieu.
Direct Access to Primary Amines and Particle Morphology Control in Nanoporous CO2 Sorbents
Authors: Dogan Nesibe A. , Ozdemir Ercan , Yavuz Cafer T.
Published: March 2017

Chemical tuning of nanoporous, solid sorbents for ideal CO2 binding requires unhindered amine functional groups on the pore walls. Although common for soluble organics, post‐synthetic reduction of nitriles in porous networks often fails due to insufficient and irreversible metal hydride penetration. In this study, a nanoporous network with pendant nitrile groups, microsphere morphology was synthesized in large scale. The hollow microspheres were easily decorated with primary amines through in situ reduction by widely available boranes. The CO2 capture capacity of the modified sorbent was increased to up to four times that of the starting nanoporous network with a high heat of adsorption (98 kJ mol−1). The surface area can be easily tuned between 1 and 354 m2 g−1. The average particle size (ca. 50 μm) is also quite suitable for CO2 capture applications, such as those with fluidized beds requiring spheres of micron sizes.
Operando Soft X‐ray Absorption Spectroscopic Study on a Solid Oxide Fuel Cell Cathode during Electrochemical Oxygen Reduction
Authors: Nakamura Takashi , Oike Ryo , Kimura Yuta , Tamenori Yusuke , Kawada Tatsuya , Amezawa Koji
Published: March 2017

An operando soft X‐ray absorption spectroscopic technique, which enabled the analysis of the electronic structures of the electrode materials at elevated temperature in a controlled atmosphere and electrochemical polarization, was established and its availability was demonstrated by investigating the electronic structural changes of an La2NiO4+δ dense‐film electrode during an electrochemical oxygen reduction reaction. Clear O K‐edge and Ni L‐edge X‐ray absorption spectra could be obtained below 773 K under an atmospheric pressure of 100 ppm O2/He, 0.1 % O2/He, and 1 % O2/He gas mixtures. Considerable spectral changes were observed in the O K‐edge X‐ray absorption spectra upon changing the P
and application of electrical potential, whereas only small spectral changes were observed in Ni L‐edge X‐ray absorption spectra. A pre‐edge peak of the O K‐edge X‐ray absorption spectra, which reflects the unoccupied partial density of states of Ni 3d–O 2p hybridization, increased or decreased with cathodic or anodic polarization, respectively. The electronic structural changes of the outermost orbital of the electrode material due to electrochemical polarization were successfully confirmed by the operando X‐ray absorption spectroscopic technique developed in this study.
Biolens behavior of RBCs under optically‐induced mechanical stress
Authors: Merola Francesco , Barroso Álvaro , Miccio Lisa , Memmolo Pasquale , Mugnano Martina , Ferraro Pietro , Denz Cornelia
Published: March 2017

In this work, the optical behavior of Red Blood Cells (RBCs) under an optically‐induced mechanical stress was studied. Exploiting the new findings concerning the optical lens‐like behavior of RBCs, the variations of the wavefront refracted by optically‐deformed RBCs were further investigated. Experimental analysis have been performed through the combination of digital holography and numerical analysis based on Zernike polynomials, while the biological lens is deformed under the action of multiple dynamic optical tweezers. Detailed wavefront analysis provides comprehensive information about the aberrations induced by the applied mechanical stress. By this approach it was shown that the optical properties of RBCs in their discocyte form can be affected in a different way depending on the geometry of the deformation. In analogy to classical optical testing procedures, optical parameters can be correlated to a particular mechanical deformation. This could open new routes for analyzing cell elasticity by examining optical parameters instead of direct but with low resolution strain analysis, thanks to the high sensitivity of the interferometric tool. Future application of this approach could lead to early detection and diagnosis of blood diseases through a single‐step wavefront analysis for evaluating different cells elasticity. © 2017 International Society for Advancement of Cytometry
The effects of stimulus symmetry on hierarchical processing in infancy
Authors: Guy Maggie W. , Reynolds Greg D. , Mosteller Sara M. , Dixon Kate C.
Published: March 2017

The current study investigated the effects of stimulus symmetry on the processing of global and local stimulus properties by 6‐month‐old short‐ and long‐looking infants through the use of event‐related potentials (ERPs). Previous research has shown that individual differences in infant visual attention are related to hierarchical stimulus processing, such that short lookers show a global processing bias, while long lookers demonstrate a local processing bias (Guy, Reynolds, & Zhang, 2013). Additional research has shown that in comparison with asymmetry, symmetry is associated with more efficient stimulus processing and more accurate memory for stimulus configuration (Attneave, 1955; Perkins, 1932). In the current study, we utilized symmetric and asymmetric hierarchical stimuli and predicted that the presence of asymmetry would direct infant attention to the local features of stimuli, leading short lookers to regress to a local processing strategy. Results of the ERP analysis showed that infants familiarized with a symmetric stimulus showed evidence of global processing, while infants familiarized with an asymmetric stimulus did not demonstrate evidence of processing at the global or local level. These findings indicate that short‐ and long‐looking infants, who might otherwise fail to process global stimulus properties due to limited visual scanning, may succeed at global processing when exposed to symmetric stimuli. Furthermore, stimulus symmetry may recruit selective attention toward global properties of visual stimuli, facilitating higher‐level cognitive processing in infancy.
Context‐dependent extinction of an appetitive operant conditioned response in infant rats
Authors: Orellana Barrera Estefanía , Arias Carlos , González Felisa , Abate Paula
Published: March 2017

The present study evaluated context‐dependent learning under an operant conditioning procedure in infant rats. Preweanling rats were trained in context A during postnatal days (PDs) 16 and 17 to learn an appetitive operant conditioning task, employing milk chocolate as appetitive reinforcer. On PD18 the operant response was extinguished in context A, or in an alternative context B. The change from context A to B between acquisition and extinction did not affect the number of responses during extinction, but slightly modified the shape of the extinction curve. On PD19, a renewal test conducted in context A clearly showed ABA‐renewal of the extinguished operant response. These results add to the body of evidence indicating that infants are able to acquire and retain contextual information, and support the notion that extinction during this ontogenetic period involves new learning.
Initiation of Drosophila chorion gene amplification requires Claspin and mus101, whereas Claspin, but not mus101, plays a major role during elongation
Authors: Choi Seung Ho , Park Ji‐Hong , Nguyen Tram Thi Ngoc , Shim Hee Jin , Song Young‐Han
Published: March 2017

Background: Claspin and TopBP1 are checkpoint mediators that are required for the phosphorylation of Chk1 by ATR to maintain genomic stability. Here, we investigated the functions of Drosophila Claspin and mus101 (TopBP1 ortholog) during chorion (eggshell component) gene amplification, which occurs in follicle cells in the absence of global genomic DNA replication. Results: Unlike Drosophila mei‐41 (ATR ortholog) mutant embryos, Claspin and mus101 mutant embryos showed severe eggshell defects resulting from defects in chorion gene amplification. EdU (5‐ethynyl‐2′‐deoxyuridine) incorporation assay during initiation and elongation stages revealed that Claspin and mus101 were required for initiation, while only Claspin had a major role in the efficient progression of the replication forks. Claspin proteins were enriched in the amplification foci both in the initiation and elongation stage‐follicle cell nuclei in a mei‐41‐independent manner. The focal localization of ORC2, a component of the origin recognition complex, was not significantly affected in the Claspin mutant, whereas it was reduced in the mus101 mutant. Conclusions: Drosophila Claspin plays a major role in the initiation and elongation stages of chorion gene amplification by localizing to the amplification foci in a mei‐41‐independent manner. Drosophila mus101 is also involved in chorion gene amplification, mostly functioning in initiation, rather than elongation. Developmental Dynamics 246:466–474, 2016. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists
Structural drivers of biomass dynamics in two temperate forests in China
Authors: Zhang Chunyu , Cheng Yanxia , He Huaijiang , Gao Lushuang , Liang Jingjing , Zhao Xiuhai
Published: March 2017

This study evaluated the effects of forest attributes on the dynamics of aboveground coarse woody biomass (AWB) and belowground coarse root biomass (BRB) based on two large stem‐mapped field plots: a secondary conifer and broadleaved mixed forest (near‐mature forest) and an old‐growth Korean pine and broadleaved mixed forest. In 2015, the kernel densities of bothAWBandBRBhad a lower mass in the left tail and a greater mass in the right tail than those in 2010. BothAWBandBRBchanged especially at the right end of the biomass distribution and less at the left end. The counterfactual decomposition approach, used to identify the sources of kernel density changes in the biomass distributions from 2010 to 2015, revealed that forest attributes contributed jointly to the observed biomass dynamics. The change in species richness (SR), accounting for less than 10% of overall changes in biomass at all estimated quantiles, has only a minor effect on theAWBandBRBdynamics in two studied forests. But the decrease in tree density (TD) and the increase in stand density (SD) from 2010 to 2015 contributed positively toward the observed density changes inAWBandBRB. Therefore, the changes in TD (measured in terms of the number of trees per ha) and SD (measured in terms of the basal area per ha) were identified as important drivers of biomass dynamics in the two studied forests. Overall, diameter skewness and diameter inequality exert greater influence at the highest quantiles of biomass distribution than at the lowest. It indicates that the changes in diameter structures will further increase biomass dispersion. The results support the assumption that specific methods of selective thinning may be effective to improve the biomass production in the natural forests. Further studies are needed to explore relevant details.
Synthesis and Electrocatalytic Activity of [FeFe]‐Hydrogenase Model Complexes with Non‐Innocent Chelating Nitrogen‐Donor Ligands
Authors: Roy Souvik , Laureanti Joseph A. , Groy Thomas L. , Jones Anne K.
Published: March 2017

To probe the influence of redox non‐innocent ligands on a well‐known class of [FeFe]‐hydrogenase models, three new asymmetrically disubstituted diiron complexes of the general formula (µ‐SRS)[Fe(CO)3][Fe(CO)(N‐N)] {SRS = propane‐1,3‐dithiolate (pdt) or benzene‐1,2‐dithiolate (bdt), and N‐N = 2,2′‐bipyridine (bipy) or 2,2′‐bipyrimidine (bpym)} have been synthesized from their parent hexacarbonyls and characterized. The new complexes, (µ‐pdt)Fe2(CO)4(κ2‐bpym) (2), (µ‐bdt)Fe2(CO)4(κ2‐bipy) (3), and (µ‐bdt)Fe2(CO)4(κ2‐bpym) (4), were fully characterized by spectroscopic and electrochemical techniques, and the results are compared to those of a related complex, (µ‐pdt)Fe2(CO)4(κ2‐bipy) (1). The crystal structures of 2–4 show that, in each complex, the two iron units are in an eclipsed orientation, and the N‐N ligand lies in the basal plane. IR spectra and electrochemical analyses indicate that electron density at the iron centers decreases in the order 1 > 2 > 3 > 4. Furthermore, compound 2 undergoes a ligand‐centered reduction at the same potential that the hexacarbonyl precursor undergoes its first reduction. However, unlike the 2,2′‐bipy derivatives 1 and 3, the 2,2′‐bpym complexes 2 and 4 are not effective catalysts for electrochemical proton reduction from acetic acid.
Copper‐Catalyzed Multicomponent Reactions: Synthesis of Fused 1,2,3‐Triazolo‐1,3,6‐triazonines
Authors: Peringer Fernando , do Nascimento José Edmilson R. , Abib Paola B. , Barcellos Thiago , Van der Eycken Erik V. , Perin Gelson , Jacob Raquel G. , Alves Diego
Published: March 2017

We describe our results on the synthesis of fused 1,2,3‐triazolo‐1,3,6‐triazonines through a copper‐catalyzed multicomponent reaction. The products were obtained in moderate to excellent yields by the reaction of 2‐azidobenzaldehydes, substituted diaminobenzenes and a range of terminal alkynes in the presence of a catalytic amount of copper iodide, with Et3N as base, in DMSO at 100 °C. This method proved to be efficient for the combinatorial synthesis of new medium‐sized N‐heterocyclic rings with potential applications in biological studies.
Minimum‐cost optimization of nonlinear fluid viscous dampers and their supporting members for seismic retrofitting
Authors: Pollini Nicolò , Lavan Oren , Amir Oded
Published: March 2017

This paper presents an effective approach for achieving minimum‐cost designs for seismic retrofitting using nonlinear fluid viscous dampers. The damping coefficients of the dampers and the stiffness coefficients of the supporting braces are designed by an optimization algorithm. A realistic retrofitting cost function is minimized subject to constraints on inter‐story drifts at the peripheries of frame structures. The cost function accounts for costs related to both the topology and the sizes of the dampers. The behavior of each damper‐brace element is defined by the Maxwell model, where the force–velocity relation of the nonlinear dampers is formulated with a fractional power law. The optimization problem is first posed and solved as a mixed integer problem. For the reduction of the computational effort required in the optimization, the problem is then reformulated with continuous variables only and solved with a gradient‐based algorithm. Material interpolation techniques, which have been successfully applied in topology optimization and in multi‐material optimization, play a key role in achieving practical final design solutions with a reasonable computational effort. Promising results attained for 3‐D irregular frames are presented and discussed. Copyright © 2017 John Wiley & Sons, Ltd.
Key taxa in food web responses to stressors: the Deepwater Horizon oil spill
Authors: McCann Michael J , Able Kenneth W , Christian Robert R , Fodrie F Joel , Jensen Olaf P , Johnson Jessica J , López‐Duarte Paola C , Martin Charles W , Olin Jill A , Polito Michael J , Roberts Brian J , Ziegler Shelby L
Published: March 2017

Identifying key taxa in the response of ecosystems to perturbations relies on quantifying both their sensitivity to stressors and their importance in the overall web of interactions. If sensitive taxa occupy key network positions, then they may decrease the capacity of ecosystems to resist perturbations. Despite widespread concern for coastal marshes after the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, impacts on individual taxa were variable, and the effects on the overall marsh food web have not been assessed. Here, we synthesize published studies on trophic relationships and oil sensitivity to identify critical taxa in the response of marsh food webs to the oil spill. Taxa such as carnivorous marsh fishes are expected to enhance resilience, while gulls, terns, and omnivorous snails may destabilize the food web. Our framework for identifying key taxa can be applied to other environmental stressors or ecosystems if both the sensitivity of individual taxa to a stressor and the food web structure are known.
Variants in BAK1, SPRY4, and GAB2 are associated with pediatric germ cell tumors: A report from the children's oncology group
Authors: Marcotte Erin L. , Pankratz Nathan , Amatruda James F. , Frazier A. Lindsay , Krailo Mark , Davies Stella , Starr Jacqueline R. , Lau Ching C. , Roesler Michelle , Langer Erica , Hallstrom Caroline , Hooten Anthony J. , Poynter Jenny N.
Published: March 2017

Germ cell tumors (GCT) are a rare form of childhood cancer that originate from the primordial germ cell. Recent genome‐wide association studies (GWAS) have identified susceptibility alleles for adult testicular GCT (TGCT). We test whether these SNPs are associated with GCT in pediatric and adolescent populations. This case‐parent triad study includes individuals with GCT diagnosed between ages 0 and 19. We evaluated 26 SNPs from GWAS of adult TGCT and estimated main effects for pediatric GCT within complete trios (N = 366) using the transmission disequilibrium test. We used Estimation of Maternal, Imprinting and interaction effects using Multinomial modelling to evaluate maternal effects in non‐Hispanic white trios and dyads (N = 244). We accounted for multiple comparisons using a Bonferroni correction. A variant in SPRY4 (rs4624820) was associated with reduced risk of GCT (OR [95% CI]: 0.70 [0.57, 0.86]). A variant in BAK1 (rs210138) was positively associated with GCT (OR [95% CI]: 1.70 [1.32, 2.18]), with a strong estimated effect for testis tumors (OR [95% CI]: 3.31 [1.89, 5.79]). Finally, a SNP in GAB2 (rs948662) was associated with increased risk for GCT (OR [95% CI]: 1.56 [1.20, 2.03]). Nominal associations (P < 0.05) were noted for eight additional loci. A maternal effect was observed for KITLG SNP rs4474514 (OR [95% CI]: 1.66 [1.21, 2.28]) and a paternal parent‐of‐origin effect was observed for rs7221274 (P = 0.00007), near TEX14, RAD51C, and PPM1E. We observed associations between SNPs in SPRY4, BAK1, and GAB2 and GCTs. This analysis suggests there may be common genetic risk factors for GCT in all age groups.
Entrepreneurial and parental love—are they the same?
Authors: Halko Marja‐Liisa , Lahti Tom , Hytönen Kaisa , Jääskeläinen Iiro P.
Published: March 2017

Here we tested the hypothesis that entrepreneurs' emotional experience and brain responses toward their own firm resemble those of parents toward their own children. Using fMRI, we measured the brain activity while male entrepreneurs viewed pictures of their own and of a familiar firm, and while fathers viewed pictures of their own and of a familiar child. The entrepreneurs who self‐rated as being very closely attached with their venture showed a similar suppression of activity in the posterior cingulate cortex, temporoparietal junction, and dorsomedial prefrontal cortex as fathers during viewing pictures of their own children versus familiar children. In addition, individual differences in the confidence trait influenced the neural encoding of both paternal and entrepreneurial processing. For underconfident fathers, a picture of one's own child was associated with stronger activation and for overconfident fathers with weaker activation in the amygdala and in caudate nucleus, a brain structure associated with processing of rewards. Similar association with activation, yet more widespread in the emotional processing network, was observed in entrepreneurs suggesting a similar neural basis for increased sensitivity to threats and potential risks concerning one's venture and child. In conclusion, both entrepreneurial and parental love seem to be supported by brain structures associated with reward and emotional processing as well as social understanding. Hum Brain Mapp 38:2923–2938, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Demonstration of transoral robotic supraglottic laryngectomy and total laryngectomy in cadaveric specimens using the Medrobotics Flex System
Authors: Funk Emily , Goldenberg David , Goyal Neerav
Published: March 2017

Background

Current management of laryngeal malignancies is associated with significant morbidity. Application of minimally invasive transoral techniques may reduce the morbidity associated with traditional procedures. The purpose of this study was to present our investigation of the utility of a novel flexible robotic system for transoral supraglottic laryngectomy and total laryngectomy.

Methods

Transoral total laryngectomy and transoral supraglottic laryngectomy were performed in cadaveric specimens using the Flex Robotic System (Medrobotics, Raynham, MA).

Results

All procedures were completed successfully in the cadaveric models. The articulated endoscope allowed for access to the desired surgical site. Flexible instruments enabled an atraumatic approach and allowed for precise surgical technique.

Conclusion

Access to deep anatomic structures remains problematic using current minimally invasive robotic approaches. Improvements in visualization and access to the laryngopharyngeal complex offered by this system may improve surgical applications to the larynx. This study demonstrates the technical feasibility using the Flex Robotic System for transoral robotic supraglottic laryngectomy and total laryngectomy. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1218–1225, 2017
Long non‐coding RNA NEAT1 is a transcriptional target of p53 and modulates p53‐induced transactivation and tumor‐suppressor function
Authors: Idogawa Masashi , Ohashi Tomoko , Sasaki Yasushi , Nakase Hiroshi , Tokino Takashi
Published: March 2017

p53 is one of the most important tumor suppressor genes, and the direct transcriptional targets of p53 must be explored to elucidate its functional mechanisms. Thus far, the p53 targets that have been primarily studied are protein‐coding genes. Our previous study revealed that several long non‐coding RNAs (lncRNAs) are direct transcriptional targets of p53, and knockdown of specific lncRNAs modulates p53‐induced apoptosis. In this study, analysis of next‐generation chromatin immunoprecipitation‐sequencing (ChIP‐seq) data for p53 revealed that the lncRNA NEAT1 is a direct transcriptional target of p53. The suppression of NEAT1 induction by p53 attenuates the inhibitory effect of p53 on cancer cell growth and also modulates gene transactivation, including that of many lncRNAs. Furthermore, low expression of NEAT1 is related to poor prognosis in several cancers. These results indicate that the induction of NEAT1 expression contributes to the tumor‐suppressor function of p53 and suggest that p53 and NEAT1 constitute a transcriptional network contributing to various biological functions and tumor suppression.