bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of Solar Fuel Production Schemes by Using a Ru,Rh,Ru Supramolecular Photocatalyst Containing Hydroxide Labile Ligands
Authors: Rogers Hannah Mallalieu , Arachchige Shamindri M. , Brewer Karen J.
Published: October 2015

Polyazine‐bridged RuIIRhIIIRuII complexes with two halide ligands, Cl− or Br−, bound to the catalytically active Rh center are efficient single‐component photocatalysts for H2O reduction to H2 fuel, with the coordination environment on Rh impacting photocatalysis. Herein reported is a new, halide‐free RuIIRhIIIRuII photocatalyst with OH− ligands bound to Rh, further enhancing the photocatalytic reactivity of the structural motif. H2 production experiments using the photocatalyst bearing OH− ligands at Rh relative to the analogues bearing halides at Rh in solvents of varying polarity (DMF, CH3CN, and H2O) suggest that ion pairing with halides deactivates photocatalyst function, representing an exciting phenomenon to exploit in the development of catalysts for solar H2 production schemes.
Transition‐Metal‐Free N‐Arylation of Pyrazoles with Diaryliodonium Salts
Authors: Gonda Zsombor , Novák Zoltán
Published: October 2015

A new synthetic method was developed for the N‐arylation of pyrazoles using diaryliodonium salts. The transformation does not require any transition‐metal catalyst and provides the desired N‐arylpyrazoles rapidly under mild reaction condition in the presence of aqueous ammonia solution as a mild base without the use of inert atmosphere. The chemoselectivity of unsymmetric diaryliodonium salts was also explored with large number of examples.
Mechanistic Insight into the Facilitation of β‐Lactam Fragmentation through Metal Assistance
Authors: Casarrubios Luis , Esteruelas Miguel A. , Larramona Carmen , Lledós Agustí , Muntaner Jaime G. , Oñate Enrique , Ortuño Manuel A. , Sierra Miguel A.
Published: October 2015

The mechanism of OsH6(PiPr3)2‐mediated fragmentation of a 4‐(2 pyridyl)‐2‐azetidinone has been investigated by DFT calculations. The addition of the C4H bond of the substrate to OsH2(PiPr3)2 allows the active participation of an osmium lone pair in the B‐type β‐lactam fragmentation process. This new mechanism makes the N1C4/C2C3 fragmentation of the lactamic core thermally accessible through a stepwise process.
Iron‐Catalyzed Decarboxylation of Trifluoroacetate and Its Application to the Synthesis of Trifluoromethyl Thioethers
Authors: Exner Benjamin , Bayarmagnai Bilguun , Jia Fan , Goossen Lukas J.
Published: October 2015

Nucleophilic CF3 has been generated by decarboxylation of potassium trifluoroacetate, arguably the most easy‐to‐handle, inexpensive, and sustainable source of trifluoromethyl groups. Simple iron(II) chloride catalyzes the decarboxylation as well as a subsequent trifluoromethylation of organothiocyanates, resulting in a straightforward synthesis of trifluoromethyl thioethers. The KCN byproduct is absorbed by iron(II) with formation of nontoxic potassium hexacyanoferrate. An analogous trifluoromethylation of aldehydes with trifluoroacetate underlines the synthetic potential of such iron‐catalyzed decarboxylative trifluoromethylations.
Helical Polybissilsesquioxane Bundles Prepared Using a Self‐Templating Approach
Authors: Wang Qingfeng , Lin Shuwei , Qin Jiaming , Li Yi , Li Baozong , Yang Yonggang
Published: October 2015

Polybissilsesquioxanes with single‐handed helical morphologies attracted much attention during the last decade, which could be applied as asymmetric catalysts and chiral stationary phases. Herein, a pair of chiral biphenylene‐bridged bissilsesquioxanes were synthesized. They self‐assembled into helical bundles in ethanol, behavior that was confirmed in field emission scanning electron microscopy images. Circular dichroism analysis indicated that the biphenylene groups twisted in a single‐handed fashion. Single‐handed helical polybissilsesquioxane bundles were prepared via polycondensation of the bissilsesquioxanes, using a self‐templating approach. Because of the shrinkage that occurred during polycondensation, the helical pitches of the bundles were shorter than those of their corresponding organic self‐assemblies. The wide‐angle X‐ray diffraction pattern indicated that there were no π–π interactions among the diphenylene groups. The circular dichroism spectra indicated that the chirality was successfully transferred from the bissilsesquioxane self‐assemblies to the polybissilsesquioxane. The polybissilsesquioxanes displayed a capacity for the adsorption of nitrobenzene and had potential application for enantioseparation. Chirality 28:44–48, 2016. © 2015 Wiley Periodicals, Inc.
Gemeinsames Recycling von Flachbildschirmen und Bleigläsern
Authors: Wolf Robert , Stelter Michael
Published: October 2015

Derzeit werden weder Bleigläser noch Flachbildschirme wirtschaftlich recycelt. Kathodenstrahlröhren von Monitoren und alten Fernsehgeräten enthalten Blei, ein Massenmetall mit moderatem Preis. Flachbildschirme enthalten Indium und Zinn in so geringen Konzentrationen, dass ein Recycling unwirtschaftlich ist. Ein neues Verfahren wird präsentiert, das beide Abfälle in einem Prozess recycelt, um alle enthaltenen Metalle sowie Glas zurück zu gewinnen. Ein zusätzlicher Vorteil ist das Zero‐Waste‐Konzept des Verfahrens, da die Endprodukte verwertbares Glas sowie eine Metallphase, die alle Wertmetalle enthält, sind.
Schwermetallentfernung aus Gewässersediment durch Bioleaching im Praxismaßstab
Authors: Görsch Kati , Hoffmann Petra , Schlenker Uwe , Aurich Andreas , Zehnsdorf Andreas
Published: October 2015

Mit dem Ziel, die Materialeigenschaften zu verbessern und die Schwermetallgehalte von belasteten Gewässersedimenten soweit zu reduzieren, dass eine Verwertung möglich ist, wurde ein kombiniertes Konditionierungs‐ und Bioleaching‐Verfahren in den Praxismaßstab überführt. Am Beispiel eines schwermetallbelasteten Teichsedimentes konnte die Praxistauglichkeit des Verfahrens gezeigt werden. Aus zwei Chargen des Gewässersedimentes wurden Zink und Cadmium entfernt. Das Sediment wurde erfolgreich bei der Renaturierung von Bergbauhalden verwendet. Der bei der Prozesswasseraufbereitung anfallende Fällungsschlamm könnte als Quelle für strategische Elemente genutzt werden.
Effect of nickel promoter on solvent‐free sulphated zirconia catalyst for the esterification of acetic acid with n‐butanol
Authors: Wijayanti Hesti , Duangchan Apinya
Published: October 2015

A simple solvent‐free preparation method was used to synthesize sulphated zirconia catalyst with various amounts of nickel promoter. This research investigated the effect of nickel addition to sulphated zirconia on the catalyst performance in esterification of acetic acid (a bio‐oil model) with n‐butanol. The results show that the addition of nickel contributed to the increase of sulphur content that bonded with nickel, the increase of thermal stability of the catalysts, and the formation of additional sulphate groups, and thus resulted in better catalytic performance compared to sulphated zirconia without nickel. More nickel being added resulted in a significant increase of acetic acid conversion; with 0.05 mol/mol nickel amount, the conversion was 97.93  %. This result represents a dramatic increase of about 2 and 3 times compared to the conversions of non‐nickel sulphated zirconia catalyst and non‐catalyst reactions, respectively.
Optimization of both operating costs and energy efficiency in the alumina evaporation process by a multi‐objective state transition algorithm
Authors: Wang Yalin , He Haiming , Zhou Xiaojun , Yang Chunhua , Xie Yongfang
Published: October 2015

The alumina evaporation process (AEP) is an indispensable step for the reuse of sodium aluminate solution by evaporating excess water contained in the solution. The selection of optimal operating parameters is a complicated task because the process is influenced by many nonlinear factors when both the quality and quantity of the product are concerned. In this paper, we formulate a multi‐objective optimization model to maintain the balance of operating costs and energy efficiency in AEP, and a multi‐objective state transition algorithm (MOSTA) is proposed for solving this problem. With the aim of solving the constrained multi‐objective problem, a search archive strategy of elite populations and a novel infeasible solution replacement mechanism are integrated into STA. Some infeasible solutions with better performances are allowed to be saved and participate randomly in the evolution to select optimal solutions from all possible directions. A mutation operator is introduced into the evolutionary process to enhance the global search ability. Simulation results from some benchmark test problems show that the proposed method tends to converge quickly and effectively to the true Pareto frontier with better distribution. The proposed algorithm is successfully applied to solve the multi‐objective optimization problem arising in AEP. The optimal results show that operating costs and energy loss are considerably reduced, by approximately 13.63 % and 13.39 %, respectively.
The Distribution of Terrestrial Heat Flow and its Structural Control in the Huainan‐Huaibei Coalfield
Authors: Tao PENG , Ji‐Wen WU , Zi‐Qiang REN , Sheng‐Ping XU , Hai‐Chao ZHANG
Published: October 2015

On the basis of the results of the thermal conductivity of 127 rock samples in the tested coal measure strata and combining 59 reliable system temperature measurement data in mine field, we calculated out the heat flow values in Huainan‐Huaibei coalfield and drew the distribution map of terrestrial heat flow. The results show that the heat flow values in Huainan‐Huaibei coalfield range from 29.7 to 83.9 mW·m−2 and the average is 58.3 mW·m−2. There is a certain difference compared to other energy basins and the heat flow value in Huainan coalfield which is 63.7 mW·m−2 is much higher than that in Huaibei coalfield which is 55.2 mW·m−2. Through comprehensive analysis, we come to the conclusion that the difference between the terrestrial heat flow in study area and the one in other basins, and the phenomenon that the heat flow value in Huainan coalfield is higher than the one in Huaibei coalfield are controlled by tectonic evolution and regional geological background. And the reasons of heat flow maldistribution in study area is mainly influence of the geological structure on the geothermal field. Especially, the influence of nappe tectonic on the difference of current heat flow values on upper and lower side is very obvious.
A Stable and Efficient Attenuation Compensation Method based on Inversion
Authors: Ben‐Feng WANG , Xiao‐Hong CHEN , Jing‐Ye LI , Zeng‐Bao CHEN , Guo‐Chang LIU
Published: October 2015

Inverse Q filtering, which can compensate amplitude and correct phase, is an effective method to improve the resolution of seismic data. The conventional inverse Q method is usually based on wavefield continuation, which is unstable or under‐compensation. Based on the forward Q filtering equation in wavefield continuation, this work proposes a new attenuation compensation method, which is stable and accurate, taking advantages of the inverse theory and regularization strategy to obtain compensated seismic data eventually. It is also computationally efficient because only effective frequency components are calculated. Tests on synthetic and real data prove that the proposed method is effective.
Comprehensive Understanding of the Zipingpu Reservoir to the MS8.0 Wenchuan Earthquake
Authors: Hui‐Hong CHENG , Huai ZHANG , Yao‐Lin SHI
Published: October 2015

Since the 12 May 2008 Wenchuan earthquake, whether this massive event was triggered by the impoundment of the nearby Zipingpu reservoir has attracted wide attention in international academic community. In addition to qualitative discussions, many scholars have made calculations on this issue. However, due to the different results, they draw very different conclusions. In this paper, we take the disputes from different teams in the quantitative calculation of Zipingpu reservoir as the starting point. Based on the basic principle of quantitative calculation of the stress changes after the impoundment of the reservoir, we analyze all kinds of influence factors to find out the key factors during the numerical simulation. The results show that the calculation methods, dimension of models, diffusion model, diffusion coefficient and focal mechanism are the main factors that resulted in the differences, especially the diffusion coefficient of the fractured rock mass. The Coulomb failure stress changes of the epicenter of the Wenchuan earthquake attained from the 2D model is about 3 times of that of the 3D model. And it is not reasonable that only considering the fault permeability or homogeneous isotropic rock mass permeability. The different focal mechanisms also could dramatically affect the Coulomb failure stress changes, of which the differences can research 2∼7 times. And the differences of Coulomb failure stress changes can reach several hundred times when selecting different diffusion coefficients. According to existing research that the magnitude of Coulomb failure stress change is about several kPa, we can not rule out the possibility that the Zipingpu reservoir may trigger the Wenchuan earthquake. However, for the background stress is not clear and Coulomb failure stress change is too small, we are not sure there must be a connection between the reservoir and earthquake. In the future work, we should target on the basis of field surveys and indoor experiments, improve the model and develop high‐performance simulation. Based on these calculation methods, we can compare more typical reservoir‐triggered earthquakes with different mechanisms both in China and elsewhere in the world to explore the mechanism of reservoir‐induced earthquakes.
Ambient Noise Tomography in Central‐South Mongolia
Authors: Jia‐Tie PAN , Qing‐Ju WU , Yong‐Hua LI , Da‐Xin YU , Meng‐Tan GAO , Ulziibat M. , Demberel S.
Published: October 2015

Relying on cooperation projects in Mongolia, “Observation and modeling on the geomagnetic, gravitational field and deep structure in the Far East Areas”, we got dense seismic array data in the area for the first time. By using the vertical component of continuous data, recorded by 69 broadband seismic stations from Aug. 2011 to Jul. 2013 in south‐central Mongolia (103.5°E–111.5° E, 43°N–49°N), we calculated the inter‐station Empirical Green functions (EGFs) from cross‐correlation. In addition, a time‐frequency analysis based on a continuous wavelet transform was used to extract the Rayleigh wave phase velocity dispersion curves. Through quality control and manually screening, we finally obtained a total number of 1478 phase velocity dispersion curves at periods ranging from 6 s to 30 s. The Ditmar & Yanovskaya method was utilized to obtain phase velocity maps of the Rayleigh wave at periods of 6∼30 s in the study area. Checkerboard tests showed that the tomographic results had a high resolution of 0.5° ×0.5°. The results revealed that the phase velocity maps of Rayleigh waves have a small perturbation of about ±2%. A phase velocity map with a short period (e. g. 6 s) was imaged with high‐speed anomalies corresponding to the mountain ranges in the north and low‐speed anomalies coinciding with the sedimentary basin and Gobi Desert in the central‐south region. As the period (15 s, 20 s) increased, the imaging still showed a high‐velocity zone (HVZ) in the north and low‐velocity zone (LVZ) in the central‐south. However, the effect of the phase velocity distribution controlled by the surface geological structure was significantly weaker. The phase velocity maps with a long period (e.g. 30 s) showed an HVZ in the north that expanded further to the south than those with shorter periods (e.g., 15 s and 20 s), which is associated with the thinner crust in the south compared to that in the north. On those maps with long periods (e.g., 20 s, 30 s), there were significant differences between the northern and southern sides of Main Mongolian Lineament (MML), indicating that MML was not only a boundary for the topography and tectonics, but also for the crustal structure. The Middle Gobi area always showed an LVZ at periods from 6 s to 30 s, which could have been related to Cenozoic volcanism, while the Hangay‐Hentey basin was always imaged with an HVZ, which could have been associated with the old, stable layers in the north.
The Prognostic Significance of Right Bundle Branch Block: A Meta‐analysis of Prospective Cohort Studies
Authors: Xiong Yunyun , Wang Lian , Liu Wenyan , Hankey Graeme J. , Xu Biao , Wang Shang
Published: October 2015

Background

The prognostic significance of right bundle branch block (RBBB) is inconsistent across studies. We aimed to assess the association between RBBB (in general population and patients with heart disease) and risk of all‐cause mortality, cardiac death, acute myocardial infarction (MI), and heart failure (HF).

Hypothesis

RBBB may be associated with increased risk of death.

Methods

PubMed, EMBASE, and the Cochrane Library up to February 2015 were searched for prospective cohort studies that reported RBBB at baseline and all‐cause mortality, cardiac death, MI, and HF at follow‐up. A meta‐analysis of published data was undertaken primarily by means of fixed‐effects models.

Results

Nineteen cohort studies including 201 437 participants were included with a mean follow‐up period ranging from 1 to 246 months. For general population with RBBB, the pooled adjusted hazard ratio (HR) for all‐cause mortality was 1.17 (95% confidence interval [CI]: 1.03–1.33) compared with no BBB. General population with RBBB had an increased risk of cardiac death (HR: 1.43, 95% CI: 1.17–1.74). For patients with RBBB and acute MI, the pooled risk ratio was 2.31 (95% CI: 2.13–2.49) for in‐hospital mortality, 2.85 (95% CI: 2.46–3.30) for 30‐day mortality, and 1.96 (95% CI: 1.59–2.42) for longer‐term mortality. For acute HF patients, the pooled risk ratio of all‐cause mortality was 1.11 (95% CI: 1.06–1.16), and for chronic HF patients it was 1.75 (95% CI: 1.38–2.22).

Conclusions

Right bundle branch block is associated with an increased risk of mortality in general population and patients with heart disease.
BMO‐Type Norms Related to the Perimeter of Sets
Authors: Ambrosio Luigi , Bourgain Jean , Brezis Haim , Figalli Alessio
Published: October 2015

In this paper we consider an isotropic variant of the BMO‐type norm recently introduced (Bourgain, Brezis, and Mironescu, 2015). We prove that, when considering characteristic functions of sets, this norm is related to the perimeter. A byproduct of our analysis is a new characterization of the perimeter of sets in terms of this norm, independent of the theory of distributions.© 2016 Wiley Periodicals, Inc.
Cancer Cell Imaging Using in Situ Generated Gold Nanoclusters
Authors: Chattoraj Shyamtanu , Amin Md. Asif , Mohapatra Saswat , Ghosh Surajit , Bhattacharyya Kankan
Published: October 2015

In situ generated fluorescent gold nanoclusters (Au‐NCs) are used for bio‐imaging of three human cancer cells, namely, lung (A549), breast (MCF7), and colon (HCT116), by confocal microscopy. The amount of Au‐NCs in non‐cancer cells (WI38 and MCF10A) is 20–40 times less than those in the corresponding cancer cells. The presence of a larger amount of glutathione (GSH) capped Au‐NCs in the cancer cell is ascribed to a higher glutathione level in cancer cells. The Au‐NCs exhibit fluorescence maxima at 490–530 nm inside the cancer cells. The fluorescence maxima and matrix‐assisted laser desorption ionization (MALDI) mass spectrometry suggest that the fluorescent Au‐NCs consist of GSH capped clusters with a core structure (Au8‐13). Time‐resolved confocal microscopy indicates a nanosecond (1–3 ns) lifetime of the Au‐NCs inside the cells. This rules out the formation of aggregated Au–thiolate complexes, which typically exhibit microsecond (≈1000 ns) lifetimes. Fluorescence correlation spectroscopy (FCS) in live cells indicates that the size of the Au‐NCs is ≈1–2 nm. For in situ generation, we used a conjugate consisting of a room‐temperature ionic liquid (RTIL, [pmim][Br]) and HAuCl4. Cytotoxicity studies indicate that the conjugate, [pmim][AuCl4], is non‐toxic for both cancer and non‐cancer cells.
Tuning the Upconversion Luminescence Lifetimes of KYb2F7:Ho3+ Nanocrystals for Optical Multiplexing
Authors: Ding Mingye , Chen Daqin , Ma Danyang , Liu Peng , Song Kaixin , Lu Hongwei , Ji Zhenguo
Published: October 2015

Conventional luminescent color coding is limited by spectral overlap and the interference of background fluorescence, thus restricting the number of distinguishable identities that can be used in practice. Here, we demonstrate the possibility of generating diverse time‐domain codes, specially designed for a single emission band, using lanthanide‐doped upconversion nanocrystals. Based on the knowledge of concentration quenching, the upconversion luminescence kinetics of KYb2F7: Ho3+ nanocrystals can be precisely controlled by modifying the dopant concentration of Ho3+ ions, resulting in a tunable emission lifetime from 75.8 to 1944.5 μs, which suggests the practicality of these time‐domain codes for optical multiplexing.
DIAGNOdent Pen versus tactile sense for detection of subgingival calculus: an in vitro study
Authors: Shakibaie Fardad , Walsh Laurence J
Published: October 2015

The objective of this study is to compare the performance of the DIAGNOdent laser fluorescence (LF) Pen to conventional periodontal probing for detection of subgingival calculus under defined laboratory conditions. Extracted teeth with various levels of subgingival deposits of calculus were mounted anatomically in stone casts, and an impression material was used to replicate periodontal soft tissues. The casts were examined for the presence of subgingival calculus at eight surfaces per tooth (240 sites) using LF and a periodontal probe. Sites were rescored after 1 and 3 weeks. Direct imaging of the root surfaces under magnification was the gold standard. As a result, for an experienced operator, LF was more accurate than tactile assessment (across all sites, 84.0% vs. 59.8%). The performance difference was greater for multi‐rooted teeth (85.8% vs. 56.9%) than single‐rooted teeth (77.2% vs. 66.7%). The performance of LF in this laboratory trial was influenced strongly by clinician skill and experience. When used by an experienced operator, LF was more sensitive (75.1% vs. 69.2%), specific (92.6% vs. 86.3%), and accurate (84% vs. 77.9%) than for an inexperienced operator. In conclusion, under the defined laboratory conditions used, LF had better performance than tactile examination, particularly for multi‐rooted teeth. This method may have value clinically as an adjunct for detecting subgingival deposits of calculus in clinical practice. The usefulness of the method improves with operator experience.
Multi‐scroll chaotic attractors from a generalized time‐delay sampled‐data system
Authors: Yeniçeri Ramazan , Yalçın Müştak E.
Published: October 2015

In this paper, the first generalization for time‐delay sampled‐data chaotic system in order to generate multi‐scroll attractor is introduced with its circuit implementation. An efficient delay‐line with binary priority encoding, parallel shifting, and binary decoding is also suggested and implemented to overcome the delay line realization drawback in such systems. The proposed system enhances the complexity of chaotic behavior by means of multi‐scroll feature and exemplifies the simplification of chaotic systems for better realizations. Copyright © 2015 John Wiley & Sons, Ltd.
Comparative investigations of DWDM transmission system with PMD for different orthogonally modulated signals at 80 Gb/s
Authors: Bhatia Richa , Sharma Ajay Kumar , Saxena Jyoti
Published: October 2015

Polarization mode dispersion (PMD) has become one of the major limiting factors for high‐bit‐rate optical transmission systems. This paper evaluates the performance of dense wavelength division multiplexed (DWDM) system with PMD at 80 Gb/s in the presence of Kerr‐nonlinear effects. Orthogonally modulated signals have been investigated and compared for tolerance against PMD in a DWDM transmission system with direct detection receivers. The optimized combinations of orthogonal polarization (OP) with carrier‐suppressed return‐to‐zero (CSRZ) and CSRZ differential‐phase‐shift‐keying signals are shown to improve PMD tolerance over high bit rates and long transmission lengths. Improved performance greater than 4 dB is observed for CSRZ modulated signal with OP because of less channel cross talk and reduced power transfer between adjacent bits over different PMD values. The numerical results demonstrate that our proposed orthogonally modulated signals perform better with lesser complex direct detection receivers. Copyright © 2015 John Wiley & Sons, Ltd.
Esco2 regulates cx43 expression during skeletal regeneration in the zebrafish fin
Authors: Banerji Rajeswari , Eble Diane M. , Iovine M. Kathryn , Skibbens Robert V.
Published: October 2015

Background: Roberts syndrome (RBS) is a rare genetic disorder characterized by craniofacial abnormalities, limb malformation, and often severe mental retardation. RBS arises from mutations in ESCO2 that encodes an acetyltransferase and modifies the cohesin subunit SMC3. Mutations in SCC2/NIPBL (encodes a cohesin loader), SMC3 or other cohesin genes (SMC1, RAD21/MCD1) give rise to a related developmental malady termed Cornelia de Lange syndrome (CdLS). RBS and CdLS exhibit overlapping phenotypes, but RBS is thought to arise through mitotic failure and limited progenitor cell proliferation while CdLS arises through transcriptional dysregulation. Here, we use the zebrafish regenerating fin model to test the mechanism through which RBS‐type phenotypes arise. Results: esco2 is up‐regulated during fin regeneration and specifically within the blastema. esco2 knockdown adversely affects both tissue and bone growth in regenerating fins—consistent with a role in skeletal morphogenesis. esco2‐knockdown significantly diminishes cx43/gja1 expression which encodes the gap junction connexin subunit required for cell–cell communication. cx43 mutations cause the short fin (sofb123) phenotype in zebrafish and oculodentodigital dysplasia (ODDD) in humans. Importantly, miR‐133‐dependent cx43 overexpression rescues esco2‐dependent growth defects. Conclusions: These results conceptually link ODDD to cohesinopathies and provide evidence that ESCO2 may play a transcriptional role critical for human development. Developmental Dynamics 245:7–21, 2016. © 2015 Wiley Periodicals, Inc.
Elevated carbon dioxide is predicted to promote coexistence among competing species in a trait‐based model
Authors: Ali Ashehad A. , Medlyn Belinda E. , Aubier Thomas G. , Crous Kristine Y. , Reich Peter B.
Published: October 2015

Differential species responses to atmospheric CO2 concentration (Ca) could lead to quantitative changes in competition among species and community composition, with flow‐on effects for ecosystem function. However, there has been little theoretical analysis of how elevated Ca (eCa) will affect plant competition, or how composition of plant communities might change. Such theoretical analysis is needed for developing testable hypotheses to frame experimental research. Here, we investigated theoretically how plant competition might change under eCa by implementing two alternative competition theories, resource use theory and resource capture theory, in a plant carbon and nitrogen cycling model. The model makes several novel predictions for the impact of eCa on plant community composition. Using resource use theory, the model predicts that eCa is unlikely to change species dominance in competition, but is likely to increase coexistence among species. Using resource capture theory, the model predicts that eCa may increase community evenness. Collectively, both theories suggest that eCa will favor coexistence and hence that species diversity should increase with eCa. Our theoretical analysis leads to a novel hypothesis for the impact of eCa on plant community composition. This hypothesis has potential to help guide the design and interpretation of eCa experiments.
Effect of Yangtze River on population genetic structure of the relict plantParrotia subaequalisin eastern China
Authors: Geng Qifang , Yao Zhigang , Yang Jie , He Jia , Wang Danbi , Wang Zhongsheng , Liu Hong
Published: October 2015

Parrotia subaequalis(Hamamelidaceae) is a Tertiary relic species endemic in eastern China. We used inter‐simple sequence repeat (ISSR) markers to access genetic diversity and population genetic structure in natural five populations ofP. subaequalis. The levels of genetic diversity were higher at species level (H = 0.2031) but lower at population level (H = 0.1096). The higher genetic diversity at species levels might be attributed to the accumulation of distinctive genotypes which adapted to the different habitats after Quaternary glaciations. Meanwhile, founder effects on the early stage, and subsequent bottleneck of population regeneration due to its biological characteristics, environmental features, and human activities, seemed to explain the low population levels of genetic diversity. The hierarchicalAMOVArevealed high levels (42.60%) of among‐population genetic differentiation, which was in congruence with the high levels of Nei's genetic differentiation index (GST = 0.4629) and limited gene flow (Nm = 0.5801) among the studied populations. Mantel test showed a significant isolation‐by‐distance, indicating that geographic isolation has a significant effect on genetic structure in this species. Unweighted pair‐group method with arithmetic average clustering,PCoA, and Bayesian analyses uniformly recovered groups that matched the geographical distribution of this species. In particular, our results suggest that Yangtze River has served as a natural barrier to gene flow between populations occurred on both riversides. Concerning the management ofP. subaequalis, the high genetic differentiation among populations indicates that preserving all five natural populations in situ and collecting enough individuals from these populations for ex situ conservation are necessary.
Mechanism Involving Hydrogen Sulfite Ions, Chlorite Ions, and Hypochlorous Acid as Key Intermediates of the Autocatalytic Chlorine Dioxide–Thiourea Dioxide Reaction
Authors: Hu Ying , Horváth Attila K. , Duan Sasa , Csekő György , Makarov Sergei V. , Gao Qingyu
Published: October 2015

The kinetics of the chlorine dioxide–thiourea dioxide reaction was investigated by monitoring absorbance–time profiles at λ = 360 nm. Under acidic conditions, the primary carbon‐containing product is cyanamide, not urea as considered previously for many oxidation reactions of thiourea dioxide. Increase of the rate of the reaction by an increase of pH can be readily explained by the slow pH‐dependent formation of a more reactive form of thiourea dioxide (TDO) that is produced steadily and unavoidably as the stock TDO solution ages. We have also found that the absorbance–time profiles of the chlorine dioxide–TDO reaction are sigmoidal with excess TDO. The addition of methionine as a hypochlorous acid scavenging agent inhibits the reaction significantly, whereas the addition of chlorite ions and trace amounts of hydrogen sulfite ions accelerates the decay of chlorine dioxide. On the basis of these experiments, a sixteen‐step kinetic model involving hypochlorous acid, chlorite ions, and hydrogen sulfite ions as key intermediates that provide an autocatalytic cycle is proposed to account for the overall kinetic behavior observed, including the slow rearrangement of TDO.
A Galactose Oxidase Biosensor Based on Graphene Composite Film for the Determination of Galactose and Dihydroxyacetone
Authors: Xie Jia , Chen Chao , Zhou Yuanqing , Fei Junjie , Ding Yonglan , Zhao Jia
Published: October 2015

A novel amperometric biosensor was developed by immobilizing galactose oxidase (GAox) on poly (L‐lactide) stabilized gold nanoparticles (Au@PLLA) modified graphene nano‐composite film (RGO‐Au@PLLA/GAox). The direct electron transfer (DET) of GAox was achieved. Cyclic voltammetry of the GAox in the RGO‐Au@PLLA film revealed a pair of well‐defined and quasireversible peaks at about −0.137 V (vs. SCE), which is characterized of the Cu(II)/Cu(I) redox couple for the galactose oxidase. Amperometric response was measured as a function for the determination of galactose (GA) and dihydroxyacetone (DHA). The constructed biosensor also possesses good stability, reproducibility and anti‐interference ability.
Nephelium lappaceum oil: A low‐cost alternative feedstock for sustainable biodiesel production using magnetic solid acids
Authors: Nguyen Hoang‐Duy , Thi Nguyen Mai‐Huong , Nguyen Trung‐Dzung , Nguyen Phuong‐Tung
Published: October 2015

Waste seed of Nephelium lappaceum or rambutan fruit with high fat content is a promising raw material for low‐cost biodiesel production. Solid acids, such as SiO2‐SO3H/CoFe2O4 and superhydrophobic poly(vinylsulfonic‐co‐divinylbenzene) (PVS‐DVB), were synthesized and characterized via X‐ray diffraction, vibrating sampling magnetometer, field enhanced scanning electron microscopy–energy dispersive X‐ray, and transmission electron microscopy. The magnetic catalysts possessed a mesoporous structure with an average diameter of 100 nm. The transesterification rate could reach 39%, 68%, and 98% when SiO2‐SO3H/CoFe2O4, PVS‐DVB, and H2SO4 acid were used, respectively, at 65°C for 4–10 h. The magnetic acids were readily recovered and reused with negligible activity loss. Fatty acid methyl ester (FAME) was determined through gas chromatography–mass spectrometry. The effects of oil‐to‐methanol molar (O/M) ratio, reaction time, and catalyst amount on FAME conversion were studied to optimize the transesterification conditions. Rambutan oil biodiesel is within the specifications of the American Standard Test Method (ASTM D6751) and European standards (EN 14214). © 2015 American Institute of Chemical Engineers Environ Prog, 35: 603–610, 2016
Gap junction coupling confers isopotentiality on astrocyte syncytium
Authors: Ma Baofeng , Buckalew Richard , Du Yixing , Kiyoshi Conrad M. , Alford Catherine C. , Wang Wei , McTigue Dana M. , Enyeart John J. , Terman David , Zhou Min
Published: October 2015

Astrocytes are extensively coupled through gap junctions into a syncytium. However, the basic role of this major brain network remains largely unknown. Using electrophysiological and computational modeling methods, we demonstrate that the membrane potential (VM) of an individual astrocyte in a hippocampal syncytium, but not in a single, freshly isolated cell preparation, can be well‐maintained at quasi‐physiological levels when recorded with reduced or K+ free pipette solutions that alter the K+ equilibrium potential to non‐physiological voltages. We show that an astrocyte's associated syncytium provides powerful electrical coupling, together with ionic coupling at a lesser extent, that equalizes the astrocyte's VM to levels comparable to its neighbors. Functionally, this minimizes VM depolarization attributable to elevated levels of local extracellular K+ and thereby maintains a sustained driving force for highly efficient K+ uptake. Thus, gap junction coupling functions to achieve isopotentiality in astrocytic networks, whereby a constant extracellular environment can be powerfully maintained for crucial functions of neural circuits. GLIA 2016;64:214–226
Differential senescence capacities in meibomian gland carcinoma and basal cell carcinoma
Authors: Zhang Leilei , Huang Xiaolin , Zhu Xiaowei , Ge Shengfang , Gilson Eric , Jia Renbing , Ye Jing , Fan Xianqun
Published: October 2015

Meibomian gland carcinoma (MGC) and basal cell carcinoma (BCC) are common eyelid carcinomas that exhibit highly dissimilar degrees of proliferation and prognoses. We address here the question of the differential mechanisms between these two eyelid cancers that explain their different outcome. A total of 102 confirmed MGC and 175 diagnosed BCC cases were analyzed. Twenty confirmed MGC and twenty diagnosed BCC cases were collected to determine the telomere length, the presence of senescent cells, and the expression levels of the telomere capping shelterin complex, P53, and the E3 ubiquitin ligase Siah1. Decreased protein levels of the shelterin subunits, shortened telomere length, over‐expressed Ki‐67, and Bcl2 as well as mutations in P53 were detected both in MGC and BCC. It suggests that the decreased protein levels of the shelterin complex and the shortened telomere length contribute to the tumorigenesis of MGC and BCC. However, several parameters distinguish MGC from BCC samples: (i) the mRNA level of the shelterin subunits decreased in MGC but it increased in BCC; (ii) P53 was more highly mutated in MGC; (iii) Siah1 mRNA was over‐expressed in BCC; (iv) BCC samples contain a higher level of senescent cells; (v) Ki‐67 and Bcl2 expression were lower in BCC. These results support a model where a preserved P53 checkpoint in BCC leads to cellular senescence and reduced tumor proliferation as compared to MGC.
Proteomic responses of human intestinal Caco‐2 cells exposed to silver nanoparticles and ionic silver
Authors: Oberemm Axel , Hansen Ulf , Böhmert Linda , Meckert Christine , Braeuning Albert , Thünemann Andreas F. , Lampen Alfonso
Published: October 2015

Even although quite a number of studies have been performed so far to demonstrate nanoparticle‐specific effects of substances in living systems, clear evidence of these effects is still under debate. The present study was designed as a comparative proteomic analysis of human intestinal cells exposed to a commercial silver nanoparticle reference material and ions from AgNO3. A two‐dimensional gel electrophoresis/MALDI mass spectrometry (MS)‐based proteomic analysis was conducted after 24‐h incubation of differentiated Caco‐2 cells with non‐cytotoxic and low cytotoxic silver concentrations (2.5 and 25 µg ml−1 nanosilver, 0.5 and 5 µg ml−1 AgNO3). Out of an overall number of 316 protein spots differentially expressed at a fold change of ≥ 1.4 or ≤ −1.4 in all treatments, 169 proteins could be identified. In total, 231 spots were specifically deregulated in particle‐treated groups compared with 41 spots, which were limited to AgNO3‐treatments. Forty‐four spots (14 %) were commonly deregulated by both types of treatment. A considerable fraction of the proteins differentially expressed after treatment with nanoparticles is related to protein folding, synthesis or modification of proteins as well as cellular assembly and organization. Overlays of networks obtained for particulate and ionic treatments showed matches, indicating common mechanisms of combined particle and ionic silver exposure and exclusive ionic silver treatment. However, proteomic responses of Caco‐2 cells treated with higher concentrations of silver species also showed some differences, for example regarding proteins related to fatty acid and energy metabolism, suggesting an induction of also some different molecular mechanisms for particle exposure and ionic treatment. Copyright © 2015 John Wiley & Sons, Ltd.
Local co‐delivery of rhBMP‐2 and cathepsin K inhibitor L006235 in poly(d,l‐lactide‐co‐glycolide) nanospheres
Authors: Yu Nicole Y.C. , Fathi Ali , Murphy Ciara M. , Mikulec Kathy , Peacock Lauren , Cantrill Laurence C. , Dehghani Fariba , Little David G. , Schindeler Aaron
Published: October 2015

Cathepsin K inhibitors (CKIs) are an emerging class of drugs that are potent antagonists of osteoclastic activity. We speculated that they may be beneficial in bone tissue engineering, where a stress shielded environment can lead to rapid resorption of new bone. Most CKIs require frequent dosing, so to achieve a sustained release we manufactured polymer nanoparticles encapsulating the CKI L006235 (CKI/nP). CKI/nP and the collagen matrices that were used to deliver them were characterized by electron microscopy and fluorescent confocal microscopy, and data indicated that the particles were evenly distributed throughout the collagen. Elution studies indicated a linear release of the inhibitor from the CKI/nP, with approximately 2% of the drug being released per day. In an in vivo study, mice were implanted with collagen scaffolds containing rhBMP‐2 that were loaded with the CKI/nP. Measurement of bone volume (BV) by microCT showed no significant increase with CKI/nP incorporation, and other parameters similarly showed no statistical differences. Cell culture studies confirmed the activity of the drug, even at low concentrations. These data indicate that polymer nanoparticles are an effective method for sustained drug delivery of a CKI, however, this may not be readily translatable to substantively improved bone tissue engineering outcomes. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 136–144, 2017.
Changes in actin and tubulin expression in osteogenic cells cultured on bioactive glass‐based surfaces
Authors: Martins Carolina Scanavez , Ferraz Emanuela Prado , Castro‐Raucci Larissa Moreira Spinola De , Teixeira Lucas Novaes , Maximiano William Marcatti Amarú , Rosa Adalberto Luiz , De Oliveira Paulo Tambasco
Published: October 2015

The present study evaluated whether the changes in the labeling pattern of cytoskeletal proteins in osteogenic cells cultured on bioactive glass‐based materials are due to altered mRNA and protein levels. Primary rat‐derived osteogenic cells were plated on Bioglass® 45S5, Biosilicate®, and borosilicate (bioinert control). The following parameters were assayed: (i) qualitative epifluorescence analysis of actin and tubulin; (ii) quantitative mRNA and protein expression for actin and tubulin by real‐time PCR and ELISA, respectively, and (iii) qualitative analysis of cell morphology by scanning electron microscopy (SEM). At days 3 and 7, the cells grown on borosilicate showed typical actin and tubulin labeling patterns, whereas those on the bioactive materials showed roundish areas devoid of fluorescence signals. The cultures grown on bioactive materials showed significant changes in actin and tubulin mRNA expression that were not reflected in the corresponding protein levels. A positive correlation between the mRNA and protein as well as an association between epifluorescence imaging and quantitative data were only detected for the borosilicate. SEM imaging of the cultures on the bioactive surfaces revealed cells partly or totally coated with material aggregates, whose characteristics resembled the substrate topography. The culturing of osteogenic cells on Bioglass® 45S5 and Biosilicate® affect actin and tubulin mRNA expression but not the corresponding protein levels. Changes in the labeling pattern of these proteins should then be attributed, at least in part, to the presence of a physical barrier on the cell surface as a result of the material surface reactions, thus limiting fluorescence signals. Microsc. Res. Tech. 78:1046–1053, 2015. © 2015 Wiley Periodicals, Inc.
Preparation, characterisation and use for antioxidant oligosaccharides of a cellulase from abalone (Haliotis discus hannai) viscera
Authors: Tao Zhi‐Peng , Sun Le‐Chang , Qiu Xu‐Jian , Cai Qiu‐Feng , Liu Guang‐Ming , Su Wen‐Jin , Cao Min‐Jie
Published: October 2015

BACKGROUND

In China, abalone (Haliotis discus hannai) production is growing annually. During industrial processing, the viscera, which are abundant of cellulase, are usually discarded or processed into low‐value feedstuff. Thus, it is of interest to obtain cellulase from abalone viscera and investigate its application for preparation of functional oligosaccharides.

RESULTS

A cellulase was purified from the hepatopancreas of abalone by ammonium sulfate precipitation and two‐steps column chromatography. The molecular weight of the cellulase was 45 kDa on SDS‐PAGE. Peptide mass fingerprinting analysis yielded 103 amino acid residues, which were identical to cellulases from other species of abalone. Substrate specificity analysis indicated that the cellulase is an endo‐1,4‐β‐glucanase. Hydrolysis of seaweed Porphyra haitanensis polysaccharides by the enzyme produced oligosaccharides with degree of polymerisation of two to four, whose monosaccharide composition was 58% galactose, 4% glucose and 38% xylose. The oligosaccharides revealed 2,2′‐diphenyl‐1‐picrylhydrazyl free radical as well as hydrogen peroxide scavenging activity.

CONCLUSION

It is feasible and meaningful to utilise cellulase from the viscera of abalone for preparation of functional oligosaccharides. © 2015 Society of Chemical Industry
Transoral robotic surgery for carcinoma of unknown primary in the head and neck
Authors: Kang Stephen Y. , Dziegielewski Peter T. , Old Matthew O. , Ozer Enver
Published: October 2015

Multiple diagnostic and treatment paradigms exist for the management of carcinoma of unknown primary (CUP) metastatic to cervical lymph nodes. Transoral robotic surgery (TORS) has emerged as a modality for diagnosis and treatment of CUP, optimizing identification and resection of the primary tumor, although also preventing chemotherapy in a subset of patients. This article presents the authors' treatment paradigm and reviews the literature supporting the use of TORS in the management of CUP. J. Surg. Oncol. 2015;112:697–701. © 2015 Wiley Periodicals, Inc.
Endoscopic endonasal greater palatine artery cauterization at the incisive foramen for control of anterior epistaxis
Authors: Butrymowicz Anna , Weisstuch Adam , Zhao Alice , Agarwal Jay , Pinheiro‐Neto Carlos D.
Published: October 2015

Objectives/Hypothesis

To describe the anatomy of the incisive foramen and the transnasal endoscopic approach to the greater palatine artery at this foramen, and to evaluate the importance of the greater palatine artery as a cause of recurrent anterior epistaxis.

Study Design

Anatomical dissection, radiographic study, and prospective case series.

Setting

Academic Medical Center.

Methods

Sixty‐nine computed tomography scans were reviewed, and measurements were made of the incisive foramina's distance to the anterior nasal spine and subnasale. Twenty‐two cadavers had sagittal split craniotomies performed prior to the measurements. The distance from the anterior nasal spine to the incisive foramen was documented. We also present an illustrative case series of patients who underwent endoscopic cautery of the greater palatine artery at the incisive foramen.

Results

Radiographic review of the incisive foramen revealed a mean anterior nasal spine to incisive foramen distance on the right and left of 7.9 and 8.1 mm, respectively. The mean distance from the subnasale to incisive foramen on the right and left were 24.7 and 24.9 mm, respectively.

Conclusions

Endoscopic cauterization of the greater palatine artery at the incisive foramen is a safe and effective method to control recurrent anterior epistaxis. The incisive foramen can be predictively found within 1 cm of the anterior nasal spine. Our case series corroborates the above.

Level of Evidence

4. Laryngoscope, 126:1033–1038, 2016