bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of ZnO nanoparticles using a hydrothermal method and a study its optical activity
Authors: Bharti Dattatraya B. , Bharati A. V. 
Published: July 2016

AbstractZnO nanoparticles (NPs) with a granular morphology were synthesized using a hydrothermal method. Structural analysis revealed that ZnO NPs had a single crystal wurtzite hexagonal structure. Solvent polarity was responsible for varying and controlling their size and morphology. The process was very trouble free and scalable. In addition, it could be used for fundamental studies on tunable morphology formation. This hydrothermal method showed different morphology with different co‐surfactants such as a floral‐like or wire‐like belt sheet structures etc. Based on their surface morphology, the same material had different applications as a catalyst in various organic reactions and also could be used as a photocatalyst and fuel cell, solar cell or in semiconductors etc. X‐ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy and photoluminescence of the resulting product was performed to study its purity, morphology and size, plus its optical properties via measurement of band gap energy and light absorbance.
NMR‐based conformation and dynamics of a tetrasaccharide‐repeating sulfated fucan substituted by different counterions
Authors: Soares Paulo A.G. , Queiroz Ismael N.L. , Santos Gustavo R.C. , Mourão Paulo A.S. , Pomin Vitor H. 
Published: July 2016

AbstractThe sulfated fucan from the sea urchin Lytechinus variegatus is composed of the repetitive sequence [‐3)‐α‐l‐Fucp‐4(
)‐(1‐3)‐α‐l‐Fucp‐2,4‐di(
)‐(1‐3)‐α‐l‐Fucp‐2(
)‐(1‐3)‐α‐l‐Fucp‐2(
)‐(1‐]n. Conformation (of rings and chains) and dynamics of this tetrasaccharide‐repeating sulfated fucan substituted by Na+, Ca2+, and Li+ as counterions have been examined through experiments of liquid‐state nuclear magnetic resonance spectroscopy. Scalar coupling and nuclear Overhauser effect (NOE)‐based data have confirmed that all composing units occur as 1C4 chair conformer regardless of the cation type, unit position within the repeating sequence, and sulfation type. Chain conformation determined by NOE signal pattern assisted by molecular modeling for a theoretical octasaccharide has shown a similar linear 3D structure for the three differently substituted forms. Data derived from spin‐relaxation measurements have indicated a contribution of counterion type to dynamics. The calcium‐based preparation has shown the highest mobility while the sodiated one showed the lowest mobility. The set of results from this work suggests that counterion type can affect the physicochemical properties of the structurally well‐defined sulfated fucan. The counterion effect seems to impact more on the structural mobility than on average conformation of the studied sulfated glycan in solution.
The impact of complete surgical resection of spinal metastases on the survival of patients with thyroid cancer
Authors: Kato Satoshi , Murakami Hideki , Demura Satoru , Fujimaki Yoshiyasu , Yoshioka Katsuhito , Yokogawa Noriaki , Tsuchiya Hiroyuki 
Published: July 2016

AbstractSpinal metastases (SMs) from thyroid cancers significantly reduce the quality of life by causing pain and neurological deficits and increase mortality. Complete surgical resection of isolated thyroid SMs is a promising treatment option; however, the postoperative outcome is unknown. This study aimed to compare the postoperative courses of patients undergoing complete resection of thyroid SMs with those of patients undergoing incomplete resection, with a minimum 4‐year follow‐up. We performed a retrospective analysis of 32 patients who underwent tumor excision surgery for thyroid SMs at our medical center during a 28‐year period. Twenty patients underwent complete excision, and 12 underwent incomplete excision. Survival was defined as the time from the first spinal surgery to death or last follow‐up. Kaplan–Meier analysis with the long‐rank test was used to compare the overall survival rates between the groups. For all patients, the overall 5‐ and 10‐year survival rates were 71% and 31%, respectively. The median overall survival time was 6.4 years. The patients undergoing complete excision survived longer than those undergoing incomplete excision (5‐year survival: 84% vs. 50%; 10‐year survival: 52% vs. 8%; P < 0.01). Only one patient undergoing complete excision experienced local tumor recurrence in the operated spine, whereas all long‐term survivors (>18 months after surgery) in the incomplete excision group experienced local tumor recurrence and a consequent deterioration in performance status. Complete surgical resection of thyroid SMs, if achievable, has the potential not only to maintain performance status, but also to prolong survival.
Tris(2,2′‐bipyridine)ruthenium Derivatives with Multiple Viologen Acceptors: Quadratic Dependence of Photocatalytic H2 Evolution Rate on the Local Concentration of the Acceptor Site
Authors: Kitamoto Kyoji , Sakai Ken 
Published: July 2016

AbstractThree Ru(bpy)32+ derivatives tethered to multiple viologen acceptors, [Ru(bpy)2(4,4′‐MV2)]6+, [Ru(bpy)2(4,4′‐MV4)]10+, and [Ru(bpy)(4,4′‐MV4)2]18+ [bpy=2,2′‐bipyridine, 4,4′‐MV2=4‐ethoxycarbonyl‐4′‐(N‐G1‐carbamoyl)‐2,2′‐bipyridine, and 4,4′‐MV4=4,4′‐bis(N‐G1‐carbamoyl)‐2,2′‐bipyridine, where G1=Asp(NHG2)‐NHG2 and G2=‐(CH2)2‐N+C5H4‐C5H4N+‐CH3] were prepared as “photo‐charge separators (PCSs)”. Photoirradiation of these complexes in the presence of a sacrificial electron donor (EDTA) results in storage of electrons per PCS values of 1.3, 2.7, and 4.6, respectively. Their applications in the photochemical H2 evolution from water in the presence of a colloidal Pt H2‐evolving catalyst were investigated, and are discussed along with those reported for [Ru(bpy)2(5,5′‐MV4)]10+, [Ru(4,4′‐MV4)3]26+, and [Ru(5,5′‐MV4)3]26+ (Inorg. Chem. Front. 2016, 3, 671–680). The PCSs with high dimerization constants (Kd=105–106 m−1) are superior in driving H2 evolution at pH 5.0, whereas those with lower Kd values (103–104 m−1) are superior at pH 7.0, where Kd=[(MV+)2]/[MV+.]2. The (MV+)2 site can drive H2 evolution only at pH 5.0 as a result of its 0.15 eV lower driving force for H2 evolution relative to MV+., whereas the PCSs with lower Kd values exhibit higher performance at pH 7.0 owing to the higher population of free MV+.. Importantly, the rate of electron charging over the PCSs is linear to the apparent H2 evolution rate, and shows an intriguing quadratic dependence on the number of MV2+ units per PCS.
Tuning of the Electronic Levels of Oligothiophene–Naphthalimide Assemblies by Chemical Modification
Authors: de la Peña Alejandro , Arrechea‐Marcos Iratxe , Mancheño María J. , Ruiz Delgado M. Carmen , López Navarrete J. Teodomiro , Segura José L. , Ponce Ortiz Rocío 
Published: July 2016

AbstractInversion of the connections of amidine linkers combined with controlled oligothiophene chain catenation in oligothiophene–naphthalimide assemblies provides an efficient method to tune the HOMO and LUMO values in this type of assemblies. This modification also suppresses the intramolecular charge transfer (ICT) band normally found in this type of derivatives, also delocalizing the frontier molecular orbitals over the whole conjugated skeleton. The resultant assemblies were used in the fabrication of field‐effect transistors, which showed well‐balanced ambipolar transport.
Photoelectrochemical CO2 Reduction by a Molecular Cobalt(II) Catalyst on Planar and Nanostructured Si Surfaces
Authors: He Da , Jin Tong , Li Wei , Pantovich Sebastian , Wang Dunwei , Li Gonghu 
Published: July 2016

AbstractIn the presence of a molecular CoII catalyst, CO2 reduction occurred at much less negative potentials on Si photoelectrodes than on an Au electrode. The addition of 1 % H2O significantly improved the performance of the CoII catalyst. Photovoltages of 580 and 320 mV were obtained on Si nanowires and a planar Si photoelectrode, respectively. This difference likely originated from the fact that the multifaceted Si nanowires are better in light harvesting and charge transfer than the planar Si surface.
Comparative study between physicochemical characterization of biochar and metal organic frameworks (MOFs) as gas adsorbents
Authors: Bamdad Hanieh , Hawboldt Kelly 
Published: July 2016

AbstractIn this study, biochar produced from three different woody biomasses, softwood (shaving, bark (Balsam fir)), and hardwood (Ash wood), are compared in terms of chemical and physical properties. The biochar was produced via fast pyrolysis at 450 °C in a 4 kg/h capacity auger reactor. The produced biochars were characterized for elemental composition, surface area, morphology, proximate analysis, and thermal properties. The biochars were compared with a Metal Organic Framework (MOF) with respect to properties key to adsorbent applications. All biochars were basic (pH 8.9–10.7), while MOFs were acidic. The morphologies of biochar and MOF‐5 differ in pore size, chemistry, and structure. Biochar has higher carbon content and more aromatic functional groups than MOFs, which could play an important role for adsorption of acidic gases from natural/produced gas.
Prognostic nomogram for refining the prognostication of the proposed 8th edition of the AJCC/UICC staging system for nasopharyngeal cancer in the era of intensity‐modulated radiotherapy
Authors: Pan Jian Ji , Ng Wai Tong , Zong Jing Feng , Lee Sarah W. M. , Choi Horace C. W. , Chan Lucy L. K. , Lin Shao Jun , Guo Qiao Juan , Sze Henry C. K. , Chen Yun Bin , Xiao You Ping , Kan Wai Kuen , O'Sullivan Brian , Xu Wei , Le Quynh Thu , Glastonbury Christine M. , Colevas A. Dimitrios , Weber Randal S. , Lydiatt William , Shah Jatin P. , Lee Anne W. M. 
Published: July 2016

BACKGROUNDThe objective of this study was to develop a nomogram for refining prognostication for patients with nondisseminated nasopharyngeal cancer (NPC) staged with the proposed 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system.METHODSConsecutive patients who had been investigated with magnetic resonance imaging, staged with the proposed 8th edition of the AJCC/UICC staging system, and irradiated with intensity‐modulated radiotherapy from June 2005 to December 2010 were analyzed. A cohort of 1197 patients treated at Fujian Provincial Cancer Hospital was used as the training set, and the results were validated with 412 patients from Pamela Youde Nethersole Eastern Hospital. Cox regression analyses were performed to identify significant prognostic factors for developing a nomogram to predict overall survival (OS). The discriminative ability was assessed with the concordance index (c‐index). A recursive partitioning algorithm was applied to the survival scores of the combined set to categorize the patients into 3 risk groups.RESULTSA multivariate analysis showed that age, gross primary tumor volume, and lactate dehydrogenase were independent prognostic factors for OS in addition to the stage group. The OS nomogram based on all these factors had a statistically higher bias‐corrected c‐index than prognostication based on the stage group alone (0.712 vs 0.622, P <.01). These results were consistent for both the training cohort and the validation cohort. Patients with <135 points were categorized as low‐risk, patients with 135 to <160 points were categorized as intermediate‐risk, and patients with ≥160 points were categorized as high‐risk. Their 5‐year OS rates were 92%, 84%, and 58%, respectively.CONCLUSIONSThe proposed nomogram could improve prognostication in comparison with the TNM stage group. This could aid in risk stratification for individual NPC patients. Cancer 2016;122:3307–3315. © 2016 American Cancer Society.
Heteroepitaxial Growth of Well‐Dispersed Co3O4 Nanocatalysts on Porous ZnO Nanoplates via Successive Hydrothermal Deposition
Authors: Feng Zhenyu , Bao Wenya , Xu Xiaohong , Ma Xicheng , Zhan Jinhua , Yin Yadong 
Published: July 2016

AbstractWe report a unique successive hydrothermal deposition method for the heteroepitaxial growth of well‐dispersed crystalline Co3O4 nanoparticles on single‐crystalline porous ZnO nanoplates toward a Co3O4/ZnO nanocomposite catalyst. The specific heteroepitaxial crystal faces between Co3O4 and ZnO limit the size of Co3O4 particles to be approximately 5 nm and allow the exposure of more active sites. The intermediate of hydrozincite [Zn5(CO3)2(OH)6] plays a role as template in creating porous ZnO nanoplates and oriented Co3O4 grains via thermal decomposition process. The active exposure of the catalyst is probed by CO oxidation. The nanocomposite exhibits significantly enhanced catalytic efficiency towards CO oxidation at temperatures ranging from 30 to 115 °C, in comparison with a homogeneous Co3O4 sample and one‐step Co/ZnO products.
Tuning Gold Nanoparticle Aggregation through the Inhibition of Acid Phosphatase Bioactivity: A Plasmonic Sensor for Light‐Up Visual Detection of Arsenate (AsV)
Authors: Zhang Jia , Zhang Chuan‐Ling , Yu Shu‐Hong 
Published: July 2016

AbstractA plasmonic biosensor for arsenate has been developed which uses gold nanoparticles (AuNPs) as the signal reporter and in which the biocatalytic activity of acid phosphatase (AcP) is modified by the target ion. The enzyme catalyzes the hydrolysis of negatively charged adenosine 5′‐monophosphate (AMP) to neutral adenosine, causing appreciable aggregation of AuNPs and then visible color change of the solution from red to blue. The presence of arsenate (AsV), as a molecular analogue of phosphate, can effectively interfere with the bioactivity of AcP by competitive inhibition, and so the hydrolysis process is slowed down. This is reflected by the change in the solution color from blue to red with increasing concentrations of AsV. In contrast to AuNP‐based sensors for arsenic (basically AsIII) that employ the strong interaction between AsIII‐specific molecules and AsIII, this sensor adopts a different sensing principle and is the first visible sensor for specifically AsV specifically using AuNPs. Finally the practical assay of AsV in groundwater and lake water was performed with satisfactory results, suggesting this approach can be used for quantification of AsV levels in real water samples.
Disease introduction is associated with a phase transition in bighorn sheep demographics
Authors: Manlove Kezia , Cassirer E. Frances , Cross Paul C. , Plowright Raina K. , Hudson Peter J. 
Published: July 2016

AbstractEcological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population‐level and 18 years of individual‐level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant‐to‐declining growth rates (λ = 0.98) over the next 20 years. Disease‐induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre‐invasion levels. Simulations suggested that models including persistent disease‐induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all‐age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under‐recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles.
Nonlinear disruption of ecological interactions in response to nitrogen deposition
Authors: Ochoa‐Hueso Raúl 
Published: July 2016

AbstractGlobal environmental change (GEC) is affecting species interactions and causing a rapid decline in biodiversity. In this study, I present a new Ecosystem Disruption Index to quantify the impacts of simulated nitrogen (N) deposition (0, 10, 20, and 50 kg N·ha−1·yr−1 + 6–7 kg N·ha−1·yr−1 background) on abiotic and biotic ecological interactions. This comparative index is based on pairwise linear and quadratic regression matrices. These matrices, calculated at the N treatment level, were constructed using a range of abiotic and biotic ecosystem constituents: soil pH, shrub cover, and the first component of several separate principal component analyses using soil fertility data (total carbon and N) and community data (annual plants, microorganisms, biocrusts, edaphic fauna) for a total of seven ecosystem constituents. Four years of N fertilization in a semiarid shrubland completely disrupted the network of ecological interactions, with a greater proportional increase in ecosystem disruption at low N addition levels. Biotic interactions, particularly those involving microbes, shrubs, and edaphic fauna, were more prone to be lost in response to N, whereas interactions involving soil properties were more resilient. In contrast, edaphic fauna was the only group directly affected by N addition, with mites and collembolans increasing their abundance with up to 20 kg N·ha−1·yr−1 and then decreasing, which supports the idea of higher‐trophic‐level organisms being more sensitive to disturbance due to more complex links with other ecosystem constituents. Future experimental studies evaluating the impacts of N deposition, and possibly other GEC drivers, on biodiversity and biotic and abiotic interactions may be able to explain results more effectively in the context of ecological networks as a key feature of ecosystem sensitivity.
Investigation of Electrochemical Oxidation of Methanol at a Carbon Paste Electrode Modified with Ni(II)‐BS Complex and Reduced Graphene Oxide Nano Sheets
Authors: Mousavi Zeinab , Benvidi Ali , Jahanbani Shahriar , Mazloum‐Ardakani Mohammad , Vafazadeh Rasoul , Zare Hamid R. 
Published: July 2016

AbstractIn the present research, the electro oxidation of methanol was investigated by different electrochemical methods at a carbon paste electrode (CPE) modified with bis(salicylaldehyde)‐nickel(II)‐dihydrate complex (Ni(II)‐BS) and reduced graphene oxide (RGO) (which named Ni(II)‐BS/RGO/CPE) in an alkaline solution. This modified electrode showed very efficient activity for oxidation of methanol. It was found that methanol was oxidized by NiOOH groups generated by further electrochemical oxidation of nickel (II) hydroxide on the surface of the modified electrode. The rate constant and electron transfer coefficient were calculated to be 2.18 s−1 and 0.4, respectively. The anodic peak currents revealed a linear dependency with the square root of scan rate. This behaviour is the characteristic of a diffusion controlled process, so the diffusion coefficient of methanol was found to be 1.16×10−5 cm2 s−1 and the number of transferred electron was calculated to be 1. Moreover, differential pulse voltammetry (DPV) investigations showed that the peak current values were proportional to the concentration of methanol in two linear ranges. The obtained linear ranges were from 0.5 to 100.0 µM (R2=0.991) and 400.0 to 1300.0 µM (R2=0.992), and the detection limit was found to be 0.19 µM for methanol determination. Generally, the Ni(II)‐BS/RGO/CPE sensor was used for determination of methanol in an industrial ethanol solution containing 4.0 % methanol.
Redox Processes of Guanine Moieties in DNA Heptamers Related to Hydrogen Evolution
Authors: Triskova Iveta , Fiala Radovan , Trnkova Libuse 
Published: July 2016

AbstractThe paper is focused on the electrochemical investigation of DNA heptamers d(GCXXXGC) with different central triplets of nucleotides (XXX=GAA, AAA, CCC, GGG). On a hanging mercury electrode (HMDE), the reduction peaks of adenine (A) and cytosine (C) moieties are detectable, but those of guanine (G) moieties are covered by an intensive current of hydrogen evolution. Because cyclic voltammetry allows us to monitor only the oxidation processes of the G reduced species, the effect of hydrogen evolution reaction (HER) was studied by means of these anodic signals. For different vertex potentials (from −1.60 V to −1.85 V) and a different number of cycles (1–5), all heptamers in buffered solutions (pH 5.8) were tested and double‐peak G oxidation signals (GI and GII) evaluated. The different structures of the heptamers in solutions are confirmed by NMR spectra. Both the impact of hydrogen evolution into the production of 7,8‐dihydroguanine moieties forming together with hydrogen in negative potentials and the catalytic effect of heptamers on hydrogen evolution are discussed.
Temporal variation in circulating concentrations of organochlorine pollutants in a pelagic seabird breeding in the high Arctic
Authors: Bustnes Jan O. , Bårdsen Bård-Jørgen , Moe Børge , Herzke Dorte , Hanssen Sveinn A. , Sagerup Kjetil , Bech Claus , Nordstad Tore , Chastel Olivier , Tartu Sabrina , Gabrielsen Geir Wing 
Published: July 2016

Abstract

The present study explored short-term temporal variations in circulating concentrations of 3 legacy organochlorines with different physicochemical properties (polychlorinated biphenyl 153 [PCB-153], p,p′-dichlorodiphenyldichloroethylene [DDE], and hexachlorobenzene [HCB]) in breeding kittiwakes (Rissa tridactyla) in a colony in Svalbard (78°N), Norwegian Arctic. Concentrations were measured in blood of a large number (n = 412–521 blood samples, depending on the data analyses) of prebreeding, incubating, and chick-rearing birds over a period of 5 yr (2007–2011). The PCB-153 concentrations were equal in male and female blood in the prebreeding period, whereas females had significantly lower concentrations during incubation and chick rearing, probably because of their ability to eliminate organochlorines through egg laying. A similar temporal pattern was observed with DDE, although the lower concentrations in incubating females were not significant. Males and females had similar concentrations of HCB over all reproductive stages. The concentrations of all 3 compounds varied greatly between years. The concentrations of PCB-153 tended to decline over the study period, whereas concentrations of HCB showed an increasing trend, especially among chick-rearing males late in the season. Concentrations of PCB-153 increased approximately 2.5 times from the prebreeding to the chick-rearing period, concurrent with mobilization of body lipids (reduced body mass). A similar, but less pronounced trend was found for HCB. For DDE, however, kittiwakes had the highest concentrations in the prebreeding period, suggesting relatively high exposure in their winter areas. The present study documented large variations in circulating concentrations of legacy organochlorines among and within breeding seasons in kittiwakes, but the alterations within seasons were relatively consistent from year to year. Environ Toxicol Chem 2017;36:442–448. © 2016 SETAC