bluuebunny/crossref_metadata_2025 huggingface dataset:
Local text cohesion, reading ability and individual science aspirations: key factors influencing comprehension in science classes
Authors: Hall Sophie S. , Kowalski Rebecca , Paterson Kevin B. , Basran Jaskaran , Filik Ruth , Maltby John
Published: February 2014

In response to the concern of the need to improve the scientific skills of school children, this study investigated the influence of text design (in terms of text cohesion) and individual differences, with the aim of identifying pathways to improving science education in early secondary school (Key Stage 3). One hundred and four secondary school children (56 females, 48 males), aged 12–13 years took part in the study. To assess the influence of local cohesion (lexical and grammatical links between adjacent sentences) in science texts, we measured students' comprehension (through multiple choice questions) of science text that was high and low in local cohesion. To explore the role of individual differences, students completed tests to measure general reading ability, general intelligence, facets of conscientiousness, science self‐concept and individual, friends and family aspirations in science. Students were more accurate in answering comprehension questions after reading text that was high in cohesion than low in cohesion, suggesting that high local text cohesion improved students' comprehension of science text. Reading ability predicted increased comprehension for both text designs. Individual aspirations in science accounted for unique variance for comprehension for high cohesion text. Implications for the teaching of secondary school science are discussed.
EFFECTS OF VERBAL REPRIMANDS ON TARGETED AND UNTARGETED STEREOTYPY
Authors: Cook Jennifer L. , Rapp John T. , Gomes Lindsey A. , Frazer Tammy J. , Lindblad Tracie L.
Published: February 2014

Results of brief functional analyses indicated that motor and vocal stereotypy persisted in the absence of social consequences for five participants diagnosed with autism spectrum disorder (ASD). Subsequently, effects of a stimulus control procedure involving contingent reprimands for each participant's higher probability (targeted) stereotypy were evaluated. Results indicated that contingent verbal reprimands (i) decreased the targeted stereotypy for all five participants, (ii) decreased the untargeted stereotypy for two of five participants, and (iii) increased the untargeted stereotypy for one of five participants. Although response suppression was not achieved for any participant, three participants maintained low levels of the target stereotypy with one or two reprimands during 5‐min sessions. Furthermore, two of those participants maintained near‐zero levels of motor and vocal stereotypy during 10‐min sessions. These findings suggest that signaled verbal reprimands may be a practical intervention for reducing stereotypy in some children with ASD. Some limitations of the findings and areas of future research are briefly discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Chemiluminescence accompanied by the reaction of acridinium ester and manganese (II)
Authors: Ren Lingling , Cui Hua
Published: February 2014

An acridinium ester (AE) alkaline solution can react with Mn(II) to generate a strong chemiluminescence (CL) centered at 435 nm. The effects of reaction conditions such as pH and Mn(II) concentration on CL intensity were examined. In order to explore the CL mechanism, the effect of oxygen on the CL reaction was examined and an X‐ray photoelectron spectroscopy study of the reaction precipitate was carried out. The results indicated that oxygen participated in the CL reaction and Mn(IV) was the primary product in the system. A possible mechanism was proposed that involved two pathways: (1) dissolved oxygen was reduced to reactive oxygen radicals by Mn(II), these reactive intermediates then reacted with AE to produce excited state acridone; (2) Mn(II) could reduce AE to partly reduced AE, which then reacted with oxygen to form excited state acridone. The reactions of other metal ions with AE were also tested, and only Mn(II) was shown to trigger strong CL emission of AE, which indicated that the system had good selectivity for Mn(II). Copyright © 2014 John Wiley & Sons, Ltd.
Surgical resection strategy and the influence of radicality on outcomes in oesophageal cancer
Authors: Davies A R , Sandhu H , Pillai A , Sinha P , Mattsson F , Forshaw M J , Gossage J A , Lagergren J , Allum W H , Mason R C
Published: February 2014

Background

The optimal surgical approach to tumours of the oesophagus and oesophagogastric junction remains controversial. The principal randomized trial comparing transhiatal (THO) and transthoracic (TTO) oesophagectomy showed no survival difference, but suggested that some subgroups of patients may benefit from the more extended lymphadenectomy typically conducted with TTO.

Methods

This was a cohort study based on two prospectively created databases. Short- and long-term outcomes for patients undergoing THO and TTO were compared. The primary outcome measure was overall survival, with secondary outcomes including time to recurrence and patterns of disease relapse. A Cox proportional hazards model provided hazard ratios (HRs) and 95 per cent confidence intervals (c.i.), with adjustments for age, tumour stage, tumour grade, response to chemotherapy and lymphovascular invasion.

Results

Of 664 included patients (263 THO, 401 TTO), the distributions of age, sex and histological subtype were similar between the groups. In-hospital mortality (1·1 versus 3·2 per cent for THO and TTO respectively; P = 0·110) and in-hospital stay (14 versus 17 days respectively; P < 0·001) favoured THO. In the adjusted model, there was no difference in overall survival (HR 1·07, 95 per cent c.i. 0·84 to 1·36) or time to tumour recurrence (HR 0·99, 0·76 to 1·29) between the two operations. Local tumour recurrence patterns were similar (22·8 versus 24·4 per cent for THO and TTO respectively). No subgroup could be identified of patients who had benefited from more radical surgery on the basis of tumour location or stage.

Conclusion

There was no difference in survival or tumour recurrence for TTO and THO.
The Efficacies of Cell‐Penetrating Peptides in Accumulating in Large Unilamellar Vesicles Depend on their Ability To Form Inverted Micelles
Authors: Swiecicki Jean‐Marie , Bartsch Annika , Tailhades Julien , Di Pisa Margherita , Heller Benjamin , Chassaing Gérard , Mansuy Christelle , Burlina Fabienne , Lavielle Solange
Published: February 2014

In this study, the direct translocation of cell‐penetrating peptides (CPPs) into large unilamellar vesicles (LUVs) was shown to be rapid for all the most commonly used CPPs. This translocation led within a few minutes to intravesicular accumulation up to 0.5 mM, with no need for a transbilayer potential. The accumulation of CPPs inside LUVs was found to depend on CPP sequence, CPP extravesicular concentration and phospholipid (PL) composition, either in binary or ternary mixtures of PLs. More interestingly, the role of anionic phospholipid flip‐flopping in the translocation process was ascertained. CPPs enhanced the flipping of PLs, and the intravesicular CPP accumulation directly correlated with the amount of anionic PLs that had been transferred from the external to the internal leaflet of the LUV bilayer, thus demonstrating the transport of peptide/lipid complexes as inverted micelles.
Long‐term survival after two surgical resections of peritoneal metastases from hepatocellular carcinoma with an interval of 4 years
Authors: Kitajima Toshihiro , Hashimoto Masaji , Sasaki Kazunari , Matsuda Masamichi , Kuroda Yoko , Fujii Takeshi , Watanabe Goro
Published: February 2014

Key Clinical Message

We propose that surgical resections of peritoneal metastases arising from hepatocellular carcinoma are an option for selected patients with controlled HCC in the liver, and without metastases in other organs, when the complete removal of such metastases can be achieved, especially in the case of patients with normal liver function.
Carbon Nanotube Growth on Nanozirconia under Strong Cathodic Polarization in Steam and Carbon Dioxide
Authors: Tao Youkun , Ebbesen Sune D. , Zhang Wei , Mogensen Mogens B.
Published: February 2014

Growth of carbon nanotubes (CNTs) catalyzed by zirconia nanoparticles was observed in the Ni–yttria doped zirconia (YSZ) composite cathode of a solid oxide electrolysis cell (SOEC) at approximately 875 °C during co‐electrolysis of CO2 and H2O to produce CO and H2. CNT was observed to grow under large cathodic polarizations specifically at the first 1 to 2 μm Ni–YSZ active cathode layer next to the YSZ electrolyte. High resolution transmission electron microscopy (HRTEM) shows that the CNTs are multi‐walled with diameters of approximately 20 nm and the catalyst particles have diameters in the range of 5 to 25 nm. The results of HRTEM and energy dispersive X‐ray spectroscopy (EDS) analysis confirm that the catalyst particles attached to the CNT are cubic zirconia. Most of the zirconia particles are located at one end of the CNTs, but particles embedded in the walls or inside the CNTs are also observed. Apart from the CNTs, graphitic layers covering zirconia nanoparticles are also widely observed. This work describes nano‐zirconia acting as a catalyst for the growth of CNT during electrochemical conversion of CO2 and H2O in a Ni‐YSZ cermet under strong cathodic polarization. An electrocatalytic mechanism is proposed for the CNT growth in SOECs. These findings provide further understanding not only on the mechanism of the catalytic growth of CNTs, but also on the local electrochemical properties of a highly polarized Ni–YSZ cathode at the micro and nano level.
Visible‐Light‐Induced Selective Photocatalytic Oxidation of Benzylamine into Imine over Supported Ag/AgI Photocatalysts
Authors: Zheng Zhanfeng , Chen Chao , Bo Arixin , Zavahir Fathima Sifani , Waclawik Eric R. , Zhao Jian , Yang Dongjiang , Zhu Huaiyong
Published: February 2014

Titanate nanotubes (TNT) supported AgI nanoparticles were prepared by a two‐step method: the deposition of Ag2O on titanate nanotubes from AgNO3 solution and the subsequent I‐adsorption process from NaI solution. It is found that the supported AgI samples exhibited excellent photoactivity for the selective oxidation of benzylamine to the corresponding imine under visible light illumination and the photocatalyst can be used for many times without apparent activity loss. X‐ray diffraction studies, transmission electron microscopy, diffuse reflectance UV‐Vis spectroscopy and nitrogen adsorption measurements were used for the characterization of the as‐prepared and recycled AgI samples. It is found that under visible light irradiation, AgI partially decomposed to produce Ag/AgI nanostructure and thus stabilized. The photoactivity of supported Ag/AgI for the selective oxidation of benzylamine was studied in terms of the light intensity, wavelength, temperature and substituent. It is proposed that the formation of plasmonic Ag nanoparticles should be responsible for the high activity and selectivity.
Aqueous Sodium‐Ion Battery using a Na3V2(PO4)3 Electrode
Authors: Song Weixin , Ji Xiaobo , Zhu Yirong , Zhu Hanjun , Li Fangqian , Chen Jun , Lu Fang , Yao Yinpeng , Banks Craig. E.
Published: February 2014

The NASICON‐type Na3V2(PO4)3 (NVP) cathode material is investigated in an aqueous sodium‐ion battery, which is explored by using a three‐electrode system. The battery behaviors and capacitive properties of this electrode system are critically investigated by using 1 m Li2SO4, Na2SO4, and K2SO4 electrolytes, with an optimal performance found to arise in Na+‐based electrolyte, which exhibits a capacitance of 209 Fg−1 at 8.5 C as well as enhanced ion diffusion. Larger, hydrated Li+ is less able to diffuse into the network of NVP, and the low conductivity and mobility leads to near noncapacitive behavior. In the case of K+‐based electrolyte, NVP presents asymmetric cyclic voltammograms, owing to weak solvation and the high conductivity of K+, making the ions more easily able to form electric double‐layer capacitance on the surface or pores of NVP, rather than insert into the network. The equivalent circuit based on electrochemical impedance spectroscopy result is analyzed to account for the electrochemical insertion behavior of Na+ into NVP, involving ion transfer in electrolyte solution, ion diffusion from the electrolyte to the electrode surface, as well as charge transfer and ion diffusion in the electrode solid.
Dispersion and Orientation of Zeolite ZSM‐5 Crystallites within a Fluid Catalytic Cracking Catalyst Particle
Authors: Sprung Christoph , Weckhuysen Bert M.
Published: February 2014

Confocal fluorescence microscopy was employed to selectively visualize the dispersion and orientation of zeolite ZSM‐5 domains inside a single industrially applied fluid catalytic cracking (FCC) catalyst particle. Large ZSM‐5 crystals served as a model system together with the acid‐catalyzed fluorostyrene oligomerization reaction to study the interaction of plane‐polarized light with these anisotropic zeolite crystals. The distinction between zeolite and binder material, such as alumina, silica, and clay, within an individual FCC particle was achieved by utilizing the anisotropic nature of emitted fluorescence light arising from the entrapped fluorostyrene‐derived carbocations inside the zeolite channels. This characterization approach provides a non‐invasive way for post‐synthesis characterization of an individual FCC catalyst particle in which the size, distribution, orientation, and amount of zeolite ZSM‐5 aggregates can be determined. It was found that the amount of detected fluorescence light originating from the stained ZSM‐5 aggregates corresponds to about 15 wt %. Furthermore, a statistical analysis of the emitted fluorescence light indicated that a large number of the ZSM‐5 domains appeared in small sizes of about 0.015–0.25 μm2, representing single zeolite crystallites or small aggregates thereof. This observation illustrated a fairly high degree of zeolite dispersion within the FCC binder material. However, the highest amount of crystalline material was aggregated into larger domains (ca. 1–5 μm2) with more or less similarly oriented zeolite crystallites. It is clear that this visualization approach may serve as a post‐synthesis quality control on the dispersion of zeolite ZSM‐5 crystallites within FCC particles.
Reaction of Alkynes and Azides: Not Triazoles Through Copper–Acetylides but Oxazoles Through Copper–Nitrene Intermediates
Authors: Haldón Estela , Besora Maria , Cano Israel , Cambeiro Xacobe C. , Pericàs Miquel A. , Maseras Feliu , Nicasio M. Carmen , Pérez Pedro J.
Published: February 2014

Well‐defined copper(I) complexes of composition [Tpm*,BrCu(NCMe)]BF4 (Tpm*,Br=tris(3,5‐dimethyl‐4‐bromo‐pyrazolyl)methane) or [Tpa*Cu]PF6 (Tpa*=tris(3,5‐dimethyl‐pyrazolylmethyl)amine) catalyze the formation of 2,5‐disubstituted oxazoles from carbonyl azides and terminal alkynes in a direct manner. This process represents a novel procedure for the synthesis of this valuable heterocycle from readily available starting materials, leading exclusively to the 2,5‐isomer, attesting to a completely regioselective transformation. Experimental evidence and computational studies have allowed the proposal of a reaction mechanism based on the initial formation of a copper–acyl nitrene species, in contrast to the well‐known mechanism for the copper‐catalyzed alkyne and azide cycloaddition reactions (CuAAC) that is triggered by the formation of a copper–acetylide complex.
New Synthetic Routes towards Soluble and Dissymmetric Triphenodioxazine Dyes Designed for Dye‐Sensitized Solar Cells
Authors: Nicolas Yohann , Allama Fouzia , Lepeltier Marc , Massin Julien , Castet Frédéric , Ducasse Laurent , Hirsch Lionel , Boubegtiten Zahia , Jonusauskas Gediminas , Olivier Céline , Toupance Thierry
Published: February 2014

New π‐conjugated structures are constantly the subject of research in dyes and pigments industry and electronic organic field. In this context, the triphenodioxazine (TPDO) core has often been used as efficient photostable pigments and once integrated in air stable n‐type organic field‐effect transistor (OFET). However, little attention has been paid to the TPDO core as soluble materials for optoelectronic devices, possibly due to the harsh synthetic conditions and the insolubility of many compounds. To benefit from the photostability of TPDO in dye‐sensitized solar cells (DSCs), an original synthetic pathway has been established to provide soluble and dissymmetric molecules applied to a suitable design for the sensitizers of DSC. The study has been pursued by the theoretical modeling of opto‐electronic properties, the optical and electronic characterizations of dyes and elaboration of efficient devices. The discovery of new synthetic pathways opens the way to innovative designs of TPDO for materials used in organic electronics.
Extensive Reduction in Back Electron Transfer in Twisted Intramolecular Charge‐Transfer (TICT) Coumarin‐Dye‐Sensitized TiO2 Nanoparticles/Film: A Femtosecond Transient Absorption Study
Authors: Debnath Tushar , Maity Partha , Lobo Hyacintha , Singh Balvant , Shankarling Ganapati S. , Ghosh Hirendra N.
Published: February 2014

We report the synthesis, characterization, and optical and electrochemical properties of two structurally similar coumarin dyes (C1 and C2). These dyes have been deployed as sensitizers in TiO2 nanoparticles and thin films, and the effect of molecular structure on interfacial electron‐transfer dynamics has been studied. Steady‐state optical absorption, emission, and time‐resolved emission studies on both C1 and C2, varying the polarity of the solvent and the solution pH, suggest that both photoexcited dyes exist in a locally excited (LE) state in solvents of low polarity. In highly polar solvents, however, C1 exists in an intramolecular charge‐transfer (ICT) state, whereas C2 exists in both ICT and twisted intramolecular charge‐transfer (TICT) states, their populations depending on the degree of polarity of the solvent and the pH of the solution. We have employed femtosecond transient absorption spectroscopy to monitor the charge‐transfer dynamics in C1‐ and C2‐sensitized TiO2 nanoparticles and thin films. Electron injection has been confirmed by direct detection of electrons in the conduction band of TiO2 nanoparticles and of radical cations of the dyes in the visible and near‐IR regions of the transient absorption spectra. Electron injection in both the C1/TiO2 and C2/TiO2 systems has been found to be pulse‐width limited (<100 fs); however, back‐electron‐transfer (BET) dynamics has been found to be slower in the C2/TiO2 system than in the C1/TiO2 system. The involvement of TICT states in C2 is solely responsible for the higher electron injection yield as well as the slower BET process compared to those in the C1/TiO2 system. Further pH‐dependent experiments on C1‐ and C2‐sensitized TiO2 thin films have corroborated the participation of the TICT state in the slower BET process in the C2/TiO2 system.
Synthesis and Reactivity Comparisons of 1‐Methyl‐3‐Substituted Cyclopropene Mini‐tags for Tetrazine Bioorthogonal Reactions
Authors: Yang Jun , Liang Yong , Šečkutė Jolita , Houk K. N. , Devaraj Neal K.
Published: February 2014

Substituted cyclopropenes have recently attracted attention as stable “mini‐tags” that are highly reactive dienophiles with the bioorthogonal tetrazine functional group. Despite this interest, the synthesis of stable cyclopropenes is not trivial and their reactivity patterns are poorly understood. Here, the synthesis and comparison of the reactivity of a series of 1‐methyl‐3‐substituted cyclopropenes with different functional handles is described. The rates at which the various substituted cyclopropenes undergo Diels–Alder cycloadditions with 1,2,4,5‐tetrazines were measured. Depending on the substituents, the rates of cycloadditions vary by over two orders of magnitude. The substituents also have a dramatic effect on aqueous stability. An outcome of these studies is the discovery of a novel 3‐amidomethyl substituted methylcyclopropene tag that reacts twice as fast as the fastest previously disclosed 1‐methyl‐3‐substituted cyclopropene while retaining excellent aqueous stability. Furthermore, this new cyclopropene is better suited for bioconjugation applications and this is demonstrated through using DNA templated tetrazine ligations. The effect of tetrazine structure on cyclopropene reaction rate was also studied. Surprisingly, 3‐amidomethyl substituted methylcyclopropene reacts faster than trans‐cyclooctenol with a sterically hindered and extremely stable tert‐butyl substituted tetrazine. Density functional theory calculations and the distortion/interaction analysis of activation energies provide insights into the origins of these reactivity differences and a guide to the development of future tetrazine coupling partners. The newly disclosed cyclopropenes have kinetic and stability advantages compared to previously reported dienophiles and will be highly useful for applications in organic synthesis, bioorthogonal reactions, and materials science.
Synthesis and Structure of a 1‐Phospha‐2‐boraacenaphthene Derivative and Its Chalcogenation Reactions
Authors: Tsurusaki Akihiro , Sasamori Takahiro , Tokitoh Norihiro
Published: February 2014

The first stable 1‐phospha‐2‐boraacenaphthene 1 was synthesized by the reduction of 1‐dimesitylboryl‐8‐dichlorophosphinonaphthalene (2 a) with elemental magnesium, and it was fully characterized. The chalcogenation reaction of 1 with elemental sulfur or selenium afforded the unique heterocycles, 2‐thia‐ and 2‐selena‐1‐phospha‐3‐boraphenalenes 9 S and 9 Se, respectively, through the insertion of the chalcogen atom into a PB bond of 1. Further chalcogenation of 9 afforded the corresponding phosphine chalcogenides. These newly obtained chalcogenated compounds have been characterized. The unique dynamic behavior of 2‐chalcogena‐1‐phospha‐3‐boraphenalene‐1‐chalcogenides 10 in solution has also been described.
Visible‐Light‐Induced CS Bond Activation: Facile Access to 1,4‐Diketones from β‐Ketosulfones
Authors: Xuan Jun , Feng Zhu‐Jia , Chen Jia‐Rong , Lu Liang‐Qiu , Xiao Wen‐Jing
Published: February 2014

A novel method for the synthesis of 1,4‐diketones from β‐ketosulfones was developed by means of a visible light‐induced CS bond activation process. Symmetrical and unsymmetrical 1,4‐diketones can be easily prepared in moderate to good yields.
Trapped in Imidazole: How to Accumulate Multiple Photoelectrons on a Black‐Absorbing Ruthenium Complex
Authors: Zedler Linda , Kupfer Stephan , de Moraes Inês Rabelo , Wächtler Maria , Beckert Rainer , Schmitt Michael , Popp Jürgen , Rau Sven , Dietzek Benjamin
Published: February 2014

Ruthenium dyes incorporating a 4H‐imidazole chromophore as a ligand exhibit a spectrally broad absorption in the UV/Vis region. Furthermore, they show the ability to store two electrons within the 4H‐imidazole ligand. These features render them promising molecular systems, for example, as inter‐ or intramolecular electron relays. To optimize the structures with respect to their electron‐storage capability, it is crucial to understand the impact of structural changes accompanying photoinduced charge transfer in the electronic intermediates of multistep electron‐transfer processes. The photophysical properties of these (reactive) intermediates might impact the function of the molecular systems quite substantially. However, the spectroscopic study of short‐lived intermediates in stepwise multielectron‐transfer processes is experimentally challenging. To this end, this contribution reports on the electrochemical generation of anions identical to intermediate structures and their spectroscopic characterization by in situ resonance Raman and UV/Vis spectroelectrochemistry and computational methods. Thereby, an efficient two‐electron pathway to the 4H‐imidazole electron‐accepting ligand is identified.
Management of Patients With ST‐Segment Elevation or Non–ST‐Segment Elevation Acute Coronary Syndromes in Cardiac Rehabilitation Centers
Authors: Reibis Rona , Völler Heinz , Gitt Anselm , Jannowitz Christina , Halle Martin , Pittrow David , Hildemann Steven
Published: February 2014

Background

Current data on the management of patients in cardiac rehabilitation (CR) after an acute hospital stay due to ST‐segment elevation or non–ST segment elevation acute coronary syndromes (STE‐ACS or NSTE‐ACS) are limited. We aimed to describe patient characteristics, risk factor management, and lipid target achievement of patients in CR in Germany and compare the 2 groups.

Hypothesis

With respect to the risk factor pattern and treatment effects during a CR stay, there are important differences between STE‐ACS and NSTE‐ACS patients.

Methods

Comparison of 7950 patients by STE‐ACS or NSTE‐ACS status in the Transparency Registry to Objectify Guideline‐Oriented Risk Factor Management registry (2010) who underwent an inpatient CR period of about 3 weeks.

Results

STE‐ACS patients compared to NSTE‐ACS patients were significantly younger (60.5 vs 64.4 years, P < 0.0001), and had diabetes mellitus, hypertension, or any risk factor (exception: smoking) less often. At discharge, in STE‐ACS compared to NSTE‐ACS patients, the low‐density lipoprotein cholesterol (LDL‐C) <100 mg/dL goal was achieved by 75.3% and 76.2%, respectively (LDL‐C <70 mg/dL by 27.7% and 27.4%), the high‐density lipoprotein cholesterol goal of >50 mg/dL in women and >40 mg/dL in men was achieved by 49.3% and 49.0%, respectively, and the triglycerides goal of <150 mg/dl was achievedby 72.3% and 74.3%, respectively (all comparisons not significant). Mean systolic and diastolic blood pressure were 121/74 and 123/74 mm Hg, respectively (P < 0.0001 systolic, diastolic not significant). The maximum exercise capacity was 110 and 102 W, respectively (P < 0.0001), and the maximum walking distance was 581 and 451 meters, respectively (P value not significant).

Conclusions

Patients with STE‐ACS and NSTE‐ACS differed moderately in their baseline characteristics. Both groups benefited from the participation in CR, as their lipid profile, blood pressure, and physical fitness improved.
Plasma Soluble ST2 Levels Correlate With Disease Severity and Predict Clinical Worsening in Patients With Pulmonary Arterial Hypertension
Authors: Zheng Ya‐Guo , Yang Tao , He Jian‐Guo , Chen Guo , Liu Zhi‐Hong , Xiong Chang‐Ming , Gu Qing , Ni Xin‐Hai , Zhao Zhi‐Hui
Published: February 2014

Background

Soluble suppression of tumorigenicity (sST2) has been proposed to be a marker for biomechanical strain and a possible predictor of mortality in patients with chronic heart failure. The use of sST2 in pulmonary arterial hypertension (PAH) has not been well defined.

Hypothesis

Plasma sST2 levels may correlate with the disease severity and predict clinical worsening in PAH.

Methods

We performed a cohort study of 40 idiopathic PAH patients with data on demographics, exercise capacity, echocardiographic parameters, laboratory tests, hemodynamics, and medications. Plasma sST2 was assessed with the high‐sensitivity ST2 ELISA kit at diagnostic catheterization. All patients were followed up from the date of blood sampling. The endpoint was clinical worsening.

Results

sST2 was significantly elevated in patients with idiopathic PAH compared with control subjects (28.9 ± 13.9 vs 20.7 ± 7.5 ng/mL, P = 0.003). Pearson correlation analysis revealed that sST2 levels correlated with cardiac index (r = −0.534, P = 0.000) and pulmonary vascular resistance (r = 0.350, P = 0.027), and could reflect disease severity of PAH. After a mean follow‐up of 14 ± 5 months, 12 patients showed clinical worsening. Receiver operating characteristic analysis suggested that sST2 levels >31.4 ng/mL discriminated clinical worsening with a sensitivity and specificity of 83.3% and 78.6%, respectively. Kaplan‐Meier analysis showed that higher sST2 levels (>31.4 ng/mL) were associated with poor clinical outcomes (P = 0.008). Multivariate Cox regression analysis showed that sST2 was an independent predictor of clinical worsening (hazard ratio: 6.067, 95% confidence interval: 1.317–27.948, P = 0.021).

Conclusions

sST2 correlates with disease severity and is a significant predictor of clinical worsening in patients with PAH.
Crystal Structure of Human Soluble Adenylate Cyclase Reveals a Distinct, Highly Flexible Allosteric Bicarbonate Binding Pocket
Authors: Saalau‐Bethell Susanne M. , Berdini Valerio , Cleasby Anne , Congreve Miles , Coyle Joseph E. , Lock Victoria , Murray Christopher W. , O'Brien M. Alistair , Rich Sharna J. , Sambrook Tracey , Vinkovic Mladen , Yon Jeff R. , Jhoti Harren
Published: February 2014

Soluble adenylate cyclases catalyse the synthesis of the second messenger cAMP through the cyclisation of ATP and are the only known enzymes to be directly activated by bicarbonate. Here, we report the first crystal structure of the human enzyme that reveals a pseudosymmetrical arrangement of two catalytic domains to produce a single competent active site and a novel discrete bicarbonate binding pocket. Crystal structures of the apo protein, the protein in complex with α,β‐methylene adenosine 5′‐triphosphate (AMPCPP) and calcium, with the allosteric activator bicarbonate, and also with a number of inhibitors identified using fragment screening, all show a flexible active site that undergoes significant conformational changes on binding of ligands. The resulting nanomolar‐potent inhibitors that were developed bind at both the substrate binding pocket and the allosteric site, and can be used as chemical probes to further elucidate the function of this protein.
Development of a Growth‐Hormone‐Conjugated Nanodiamond Complex for Cancer Therapy
Authors: Chu Hsueh‐Liang , Chen Hung‐Wei , Tseng Shin‐Hua , Hsu Ming‐Hua , Ho Li‐Ping , Chou Fu‐Hsuan , Li MD. PhD. Hsing‐Yuan , Chang Yu‐Chuan , Chen Pei‐Hsin , Tsai Li‐Yun , Chou Ching‐Chung , Chen Jyh Shin , Cheng Tsai‐Mu , Chang Chia‐Ching
Published: February 2014

It is highly desirable to develop a therapeutic, observable nanoparticle complex for specific targeting in cancer therapy. Growth hormone (GH) and its antagonists have been explored as cancer cell‐targeting molecules for both imaging and therapeutic applications. In this study, a low toxicity, biocompatible, therapeutic, and observable GH–nanoparticle complex for specifically targeting growth hormone receptor (GHR) in cancer cells was synthesized by conjugating GH with green fluorescence protein and carboxylated nanodiamond. Moreover, we have shown that this complex can be triggered by laser irradiation to create a “nanoblast” and induce cell death in the A549 non‐small‐cell lung cancer cell line via the apoptotic pathway. This laser‐mediated, cancer‐targeting platform can be widely used in cancer therapy.
Dependence of NMR noise line shapes on tuning, matching, and transmission line properties
Authors: Bendet‐Taicher Eli , Müller Norbert , Jerschow Alexej
Published: February 2014

The tuning and matching conditions of rf circuits, as well as the properties of the transmission lines connecting these to the preamplifier, have direct consequences for NMR probe sensitivity and as for the optimum delivery of rf power to the sample. In addition, tuning/matching conditions influence radiation damping effects, which manifest themselves as fast signal flip‐back and line broadening effects, and can lead to concentration‐dependent frequency shifts. Previous studies have also shown that the appearance of spin‐noise and absorbed circuit noise signals heavily depended on tuning settings. Consequently, all these phenomena are linked together. The mutual connections and interdependences of these effects are highlighted and reviewed here. © 2014 The Authors Concepts in Magnetic Resonance, Part B: Magnetic Resonance Engineering Published by Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 44B: 1–11, 2014
Causes of death in long‐term survivors of head and neck cancer
Authors: Baxi Shrujal S. , Pinheiro Laura C. , Patil Sujata M. , Pfister David G. , Oeffinger Kevin C. , Elkin Elena B.
Published: February 2014

BACKGROUND

Survivors of head and neck squamous cell carcinoma (HNSCC) face excess mortality from multiple causes.

METHODS

We used the population‐based Surveillance, Epidemiology, and End Results (SEER) cancer registry data to evaluate the causes of death in patients with nonmetastatic HNSCC diagnosed between 1992 and 2005 who survived at least 3 years from diagnosis (long‐term survivors). We used competing‐risks proportional hazards regression to estimate probabilities of death from causes: HNSCC, second primary malignancy (SPM) excluding HNSCC, cardiovascular disease, and other causes.

RESULTS

We identified 35,958 three‐year survivors of HNSCC with a median age at diagnosis of 60 years (range = 18‐100 years) and a median follow‐up of 7.7 years (range = 3‐18 years). There were 13,120 deaths during the study period. Death from any cause at 5 and 10 years was 15.4% (95% confidence interval [CI]  = 15.0%‐15.8%) and 41.0% (95% CI = 40.4%‐41.6%), respectively. There were 3852 HNSCC deaths including both primary and subsequent head and neck tumors. The risk of death from HNSCC was greater in patients with nasopharynx or hypopharynx cancer and in patients with locally advanced disease. SPM was the leading cause of non‐HNSCC death, and the most common sites of SPM death were lung (53%), esophagus (10%), and colorectal (5%) cancer.

CONCLUSIONS

Many long‐term HNSCC survivors die from cancers other than HNSCC and from noncancer causes. Routine follow‐up care for HNSCC survivors should expand beyond surveillance for recurrent and new head and neck cancers. Cancer 2014;120:1507–1513. © 2014 American Cancer Society.
Increased clarity on the use of radiotherapy in the management of desmoplastic melanoma
Authors: Tishler Roy B.
Published: February 2014

Desmoplastic melanoma is a rare type of cutaneous melanoma with a distinct clinical behavior characterized by a propensity for local recurrence. The 2 articles in this issue of Cancer present significant information clarifying the role of adjuvant radiotherapy in the treatment of patients with desmoplastic melanoma.
Lack of reduction in racial disparities in cancer‐specific mortality over a 20‐year period
Authors: Aizer Ayal A. , Wilhite Tyler J. , Chen Ming‐Hui , Graham Powell L. , Choueiri Toni K. , Hoffman Karen E. , Martin Neil E. , Trinh Quoc‐Dien , Hu Jim C. , Nguyen Paul L.
Published: February 2014

BACKGROUND

To the authors' knowledge, it remains unknown whether race‐based differences in cancer outcomes have changed with time. In the current study, the authors assessed whether racial disparities in cancer‐specific mortality have improved over the last 20 years.

METHODS

The Surveillance, Epidemiology, and End Results program was used to identify 2,713,474 patients diagnosed between 1988 and 2007 with either lung, breast, prostate, or colorectal cancer (the leading 3 causes of cancer‐related mortality among each sex). After exclusions, 1,001,978 patients remained eligible for analysis. The impact of race on cancer‐specific mortality was assessed using the regression model of Fine and Gray; an interaction model evaluated trends over time.

RESULTS

African Americans presented with a more advanced stage of disease (P < .001) and underwent definitive therapy less often (P < .001) than whites. After adjustment for demographics and year of diagnosis, African Americans were found to have higher estimates of cancer‐specific mortality than whites for all cancers combined (hazards ratio, 1.28; 95% confidence interval, 1.26‐1.30 [P < .001]) and within each individual cancer (each P < .05). These differences did not change significantly between 1988 through 1997 and 1998 through 2007, except among patients with breast cancer, in whom survival disparities increased. These findings remained significant after adjustment for stage of disease at presentation and receipt of definitive therapy (hazards ratio for breast cancer mortality in African Americans vs whites: 1.37 from 1988‐1997 and 1.53 from 1998‐2007; P for interaction, < .001).

CONCLUSIONS

The survival gap for African Americans has not closed over time. Race‐based differences in outcome persist independent of stage of disease and treatment, suggesting that additional strategies beyond screening and improving access to care, such as further research into tumor biologies disproportionately affecting African Americans, are needed to improve survival for African American patients with cancer. Cancer 2014;120:1532–1539. © 2014 American Cancer Society.
Impact of timing and setting of palliative care referral on quality of end‐of‐life care in cancer patients
Authors: Hui David , Kim Sun Hyun , Roquemore Joyce , Dev Rony , Chisholm Gary , Bruera Eduardo
Published: February 2014

BACKGROUND

Limited data are available on how the timing and setting of palliative care (PC) referral can affect end‐of‐life care. In this retrospective cohort study, the authors examined how the timing and setting of PC referral were associated with the quality of end‐of‐life care.

METHODS

All adult patients residing in the Houston area who died of advanced cancer between September 1, 2009 and February 28, 2010 and had a PC consultation were included. Data were retrieved on PC referral and quality of end‐of‐life care indicators.

RESULTS

Among 366 decedents, 120 (33%) had an early PC referral (>3 months before death), and 169 (46%) were first seen as outpatients. Earlier PC referral was associated with fewer emergency room visits (39% vs 68%; P < .001), fewer hospitalizations (48% vs 81%; P < .003), and fewer hospital deaths (17% vs 31%; P = .004) in the last 30 days of life. Similarly, outpatient PC referral was associated with fewer emergency room visits (48% vs 68%; P < .001), fewer hospital admissions (52% vs 86%; P < .001), fewer hospital deaths (18% vs 34%; P = .001), and fewer intensive care unit admissions (4% vs 14%; P = .001). In multivariate analysis, outpatient PC referral (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.28‐0.66; P < .001) was independently associated with less aggressive end‐of‐life care. Men (OR, 1.63; 95% CI, 1.06‐2.50; P = .03) and hematologic malignancies (OR, 2.57; 95% CI, 1.18‐5.59; P = .02) were associated with more aggressive end‐of‐life care.

CONCLUSIONS

Patients who were referred to outpatient PC had improved end‐of‐life care compared with those who received inpatient PC. The current findings support the need to increase the availability of PC clinics and to streamline the process of early referral. Cancer 2014;120:1743–1749. © 2014 American Cancer Society.
Systematic comparison of adeno‐associated virus and biotinylated dextran amine reveals equivalent sensitivity between tracers and novel projection targets in the mouse brain
Authors: Wang Quanxin , Henry Alex M. , Harris Julie A. , Oh Seung Wook , Joines Kevin M. , Nyhus Julie , Hirokawa Karla E. , Dee Nick , Mortrud Marty , Parry Sheana , Ouellette Benjamin , Caldejon Shiella , Bernard Amy , Jones Allan R. , Zeng Hongkui , Hohmann John G.
Published: February 2014

As an anterograde neuronal tracer, recombinant adeno‐associated virus (AAV) has distinct advantages over the widely used biotinylated dextran amine (BDA). However, the sensitivity and selectivity of AAV remain uncharacterized for many brain regions and species. To validate this tracing method further, AAV (serotype 1) was systematically compared with BDA as an anterograde tracer by injecting both tracers into three cortical and 15 subcortical regions in C57BL/6J mice. Identical parameters were used for our sequential iontophoretic injections, producing injections of AAV that were more robust in size and in density of neurons infected compared with those of BDA. However, these differences did not preclude further comparison between the tracers, because the pairs of injections were suitably colocalized and contained some percentage of double‐labeled neurons. A qualitative analysis of projection patterns showed that the two tracers behave very similarly when injection sites are well matched. Additionally, a quantitative analysis of relative projection intensity for cases targeting primary motor cortex (MOp), primary somatosensory cortex (SSp), and caudoputamen (CP) showed strong agreement in the ranked order of projection intensities between the two tracers. A detailed analysis of the projections of two brain regions (SSp and MOp) revealed many targets that have not previously been described in the mouse or rat. Minor retrograde labeling of neurons was observed in all cases examined, for both AAV and BDA. Our results show that AAV has actions equivalent to those of BDA as an anterograde tracer and is suitable for analysis of neural circuitry throughout the mouse brain. J. Comp. Neurol. 522:1989–2012, 2014. © 2014 Wiley Periodicals, Inc.
Ab Initio Study of the Adsorption of CO2 on Functionalized Benzenes
Authors: Frysali Maria G. , Klontzas Emmanuel , Froudakis George. E.
Published: February 2014

The interaction of carbon dioxide with a series of functionalized aromatic molecules was studied by using quantum mechanical methods (MP2), to examine the effect of the substituent on the adsorption of CO2. Several different initial configurations of CO2 were taken into account for each functionalized benzene to locate the energetically most favorable configuration. To get a better estimation of the binding energies, we applied an extrapolation scheme to approach the complete basis set. CH2N3‐, COOH‐, and SO3H‐functionalized benzenes were found to have the strongest interaction with CO2, and the corresponding binding energies were calculated to be −3.62, −3.65, and −4.3 kcal mol−1, respectively. Electrostatic potential maps of the functionalized benzenes and electron redistribution density plots of the complexes were also created to get a better insight into the nature of the interaction of CO2 with the functionalized benzenes. The functional groups that were examined can be potentially incorporated in organic bridging molecules that connect the inorganic corners in MOF.
The Strained Sesquiterpene β‐Caryophyllene as a Probe for the Solvent‐Assisted Epoxidation Mechanism
Authors: Steenackers Bart , Neirinckx Alexander , De Cooman Luc , Hermans Ive , De Vos Dirk
Published: February 2014

In our attempt to synthesize β‐caryophyllene oxide in food‐compatible conditions, we observed the uncatalyzed and highly selective epoxidation of β‐caryophyllene, a strained bicyclic sesquiterpene, in ethanol with aqueous H2O2 under radical‐suppressing conditions without the addition of a catalyst. The unusual reactivity of β‐caryophyllene allowed us to use it as a probe for the mechanism of the solvent‐assisted epoxidation in a wide range of organic solvents. A kinetic study was performed to investigate the epoxidation mechanism; an excellent correlation was found between the observed epoxidation rates in different solvents and the Abraham’s hydrogen bond formation parameters of these solvents. By means of computational analysis, it was found that the main role of the solvent consists of the stabilization of the elongated OO bond of H2O2 in the transition state through hydrogen‐bond donation to the leaving OH moiety of H2O2. α‐Humulene was found to possess similar reactivity as β‐caryophyllene whereas isocaryophyllene—the unstrained isomer of β‐caryophyllene—was unreactive.
Synthesis of Liquid Crystal Silane‐Functionalized Gold Nanoparticles and Their Effects on the Optical and Electro‐Optic Properties of a Structurally Related Nematic Liquid Crystal
Authors: Mirzaei Javad , Urbanski Martin , Kitzerow Heinz‐S. , Hegmann Torsten
Published: February 2014

Chemically and thermally robust liquid crystal silane‐functionalized gold nanoparticles (i.e. AuNP1–AuNP3) were synthesized through silane conjugation. Colloidal dispersions of these particles with mesogenic ligands that are structurally identical (as in AuNP1, AuNP2) or compatible (as in AuNP3) with molecules of the nematic liquid crystal (N‐LC) host showed superior colloidal stability and dispersibility. The thermal, optical, and electro‐optic behaviors of the N‐LC composites at different concentrations of each gold nanoparticle were investigated. All dispersions showed lower values for the rotational viscosity and elastic constant, but only AuNP3 with a dissimilar structure between the nanoparticle ligand and the host displayed the most drastic thermal effects and overall strongest impact on the electro‐optic properties of the host. The observed results were explained considering both the structure and the density of the surface ligands of each gold nanoparticle.
Lamellar Lα Mesophases Doped with Inorganic Nanoparticles
Authors: Constantin Doru , Davidson Patrick
Published: February 2014

The development of nanostructured hybrid systems is a flourishing area of research, which brings together chemistry, physics and materials science. These systems are composed of nanoparticles with interesting properties (e.g. optical, magnetic, catalytic) dispersed within an organic matrix. Control of both the position and orientation of the particles in a precise and reproducible way is an important goal. Towards this goal, the use of lyotropic liquid crystals as host phases is a promising strategy that has prompted sustained experimental work over the last decade. Here we briefly review this field, with an emphasis on the structure and the physical characterization of these novel materials.
OH⋅⋅⋅N and CH⋅⋅⋅O Hydrogen Bonds Control Hydration of Pivotal Tropane Alkaloids: Tropinone⋅⋅⋅H2O Complex
Authors: Écija Patricia , Vallejo‐López Montserrat , Evangelisti Luca , Fernández José A. , Lesarri Alberto , Caminati Walther , Cocinero Emilio J.
Published: February 2014

The effect of monohydration in equatorial/axial isomerism of the common motif of tropane alkaloids is investigated in a supersonic expansion by using Fourier‐transform microwave spectroscopy. The rotational spectrum reveals the equatorial isomer as the dominant species in the tropinone⋅⋅⋅H2O complex. The monohydrated complex is stabilized primarily by a moderate OH⋅⋅⋅N hydrogen bond. In addition, two CH⋅⋅⋅O weak hydrogen bonds also support this structure, blocking the water molecule and avoiding any molecular dynamics in the complex. The water molecule acts as proton donor and chooses the ternary amine group over the carbonyl group as a proton acceptor. The experimental work is supported by theoretical calculations; the accuracy of the B3LYP, M06‐2X, and MP2 methods is also discussed.
Anion⋅⋅⋅Si Interactions in an Inverse Sandwich Complex: A Computational Study
Authors: Robertazzi Arturo , Platts James A. , Gamez Patrick
Published: February 2014

Combination of an electron‐rich molecule (e.g. chloride anion or nitrile group) with a chlorinated cyclohexasilane ring produces a supramolecular inverse sandwich complex formed by two guests (Cl− or RC≡N) strongly bonded to both faces of a planar host (Si6 ring). In‐depth theoretical studies were carried out to investigate the nature of the bonding interactions that generate such a stable complex. Second‐order Møller–Plesset perturbation theory (MP2) calculations confirmed that the presence of the Cl substituents is fundamental to the stability of the supramolecular assemblies. The density functional theory (DFT) functional wB97XD gave an estimation of the contribution of dispersion interactions to the binding energy. These interactions become more important as the Cl atoms of the rings are systematically replaced by methyl groups or hydrogen atoms. Analysis of the topology of the electron density and the reduced density gradient gave insight into the binding of the studied supramolecular assemblies.