bluuebunny/crossref_metadata_2025 huggingface dataset:
Intermolecular Charge‐Transfer Transition Emitter Showing Thermally Activated Delayed Fluorescence for Efficient Non‐Doped OLEDs
Authors: Shi Yi‐Zhong , Wang Kai , Li Xing , Dai Gao‐Le , Liu Wei , Ke Ke , Zhang Ming , Tao Si‐Lu , Zheng Cai‐Jun , Ou Xue‐Mei , Zhang Xiao‐Hong
Published: June 2018

A novel molecular model of connecting electron‐donating (D) and electron‐withdrawing (A) moieties via a space‐enough and conjugation‐forbidden linkage (D‐Spacer‐A) is proposed to develop efficient non‐doped thermally activated delayed fluorescence (TADF) emitters. 10‐(4‐(4‐(4,6‐diphenyl‐1,3,5‐triazin‐2‐yl) phenoxy) phenyl)‐9,9‐dimethyl‐9,10‐dihydroacridine (DMAC‐o‐TRZ) was designed and synthesized accordingly. As expected, it exhibits local excited properties in single‐molecule state as D‐Spacer‐A molecular backbone strongly suppress the intramolecular charge‐transfer (CT) transition. And intermolecular CT transition acted as the vital radiation channel for neat DMAC‐o‐TRZ film. As in return, the non‐doped device exhibits a remarkable maximum external quantum efficiency (EQE) of 14.7 %. These results prove the feasibility of D‐Spacer‐A molecules to develop intermolecular CT transition TADF emitters for efficient non‐doped OLEDs.
Ylide‐Functionalized Phosphines: Strong Donor Ligands for Homogeneous Catalysis
Authors: Scherpf Thorsten , Schwarz Christopher , Scharf Lennart T. , Zur Jana‐Alina , Helbig Andreas , Gessner Viktoria H.
Published: June 2018

Phosphines are important ligands in homogenous catalysis and have been crucial for many advances, such as in cross‐coupling, hydrofunctionalization, or hydrogenation reactions. Herein we report the synthesis and application of a novel class of phosphines bearing ylide substituents. These phosphines are easily accessible via different synthetic routes from commercially available starting materials. Owing to the extra donation from the ylide group to the phosphorus center the ligands are unusually electron‐rich and can thus function as strong electron donors. The donor capacity surpasses that of commonly used phosphines and carbenes and can easily be tuned by changing the substitution pattern at the ylidic carbon atom. The huge potential of ylide‐functionalized phosphines in catalysis is demonstrated by their use in gold catalysis. Excellent performance at low catalyst loadings under mild reaction conditions is thus seen in different types of transformations.
Hydrophobicity Control in Adaptive Crystalline Assemblies
Authors: Cohen Erez , Soffer Yahel , Weissman Haim , Bendikov Tatyana , Schilt Yaelle , Raviv Uri , Rybtchinski Boris
Published: June 2018

An amphiphile based on polyethylene glycol (PEG) polymer and two molecular moieties (perylene diimide and C7 fluoroalkyl, PDI and C7F) attached to its termini assembles into crystalline films with long‐range order. The films reversibly switch from crystalline to amorphous above the PEG melting temperature. The adaptive behavior stems from the responsiveness of the PEG domain and the robustness of the PDI and C7F assemblies. The hydrophobicity of the film can be controlled by heating, resulting in switching from highly hydrophobic to superhydrophilic. The long‐range order, reversible crystallinity switching, and the temperature‐controlled wettability demonstrate the potential of block copolymer analogues based on simple polymeric/molecular hybrids.
Palladium‐Catalyzed Asymmetric C(sp3)−H Allylation of 2‐Alkylpyridines
Authors: Murakami Ryo , Sano Kentaro , Iwai Tomohiro , Taniguchi Tohru , Monde Kenji , Sawamura Masaya
Published: June 2018

The palladium‐catalyzed asymmetric side‐chain C(α)‐allylation of 2‐alkylpyridines, without using an external base, was developed. The high linear selectivities and enantioselectivities were achieved using new chiral diamidophosphite monodentate ligands. Given that the reaction conditions do not require an external base, this catalyst system enabled chemoselective C(α)‐allylation of 2‐alkylpyridines containing α‐carbonyl C−H bonds, which are more acidic than α‐pyridyl C−H bonds.
Ceria Nanoparticle Systems for Selective Scavenging of Mitochondrial, Intracellular, and Extracellular Reactive Oxygen Species in Parkinson's Disease
Authors: Kwon Hyek Jin , Kim Dokyoon , Seo Kyungho , Kim Young Geon , Han Sang Ihn , Kang Taegyu , Soh Min , Hyeon Taeghwan
Published: June 2018

Oxidative stress induced by reactive oxygen species (ROS) is one of the critical factors that involves in the pathogenesis and progression of many diseases. However, lack of proper techniques to scavenge ROS depending on their cellular localization limits a thorough understanding of the pathological effects of ROS. Here, we demonstrate the selective scavenging of mitochondrial, intracellular, and extracellular ROS using three different types of ceria nanoparticles (NPs), and its application to treat Parkinson's disease (PD). Our data show that scavenging intracellular or mitochondrial ROS inhibits the microglial activation and lipid peroxidation, while protecting the tyrosine hydroxylase (TH) in the striata of PD model mice. These results indicate the essential roles of intracellular and mitochondrial ROS in the progression of PD. We anticipate that our ceria NP systems will serve as a useful tool for elucidating the functions of various ROS in diseases.
Ruthenium‐Containing Linear Helicates and Mesocates with Tuneable p53‐Selective Cytotoxicity in Colorectal Cancer Cells
Authors: Allison Simon J. , Cooke David , Davidson Francesca S. , Elliott Paul I. P. , Faulkner Robert A. , Griffiths Hollie B. S. , Harper Owen J. , Hussain Omar , Owen‐Lynch P. Jane , Phillips Roger M. , Rice Craig R. , Shepherd Samantha L. , Wheelhouse Richard T.
Published: June 2018

The ligands L1 and L2 both form separable dinuclear double‐stranded helicate and mesocate complexes with RuII. In contrast to clinically approved platinates, the helicate isomer of [Ru2(L1)2]4+ was preferentially cytotoxic to isogenic cells (HCT116 p53−/−), which lack the critical tumour suppressor gene. The mesocate isomer shows the reverse selectivity, with the achiral isomer being preferentially cytotoxic towards HCT116 p53+/+. Other structurally similar RuII‐containing dinuclear complexes showed very little cytotoxic activity. This study demonstrates that alterations in ligand or isomer can have profound effects on cytotoxicity towards cancer cells of different p53 status and suggests that selectivity can be “tuned” to either genotype. In the search for compounds that can target difficult‐to‐treat tumours that lack the p53 tumour suppressor gene, [Ru2(L1)2]4+ is a promising compound for further development.
Cp*CoIII‐Catalyzed Efficient Dehydrogenation of Secondary Alcohols
Authors: Gangwar Manoj Kumar , Dahiya Pardeep , Emayavaramban Balakumar , Sundararaju Basker
Published: June 2018

A novel, well‐defined molecular Cp*CoIII complex was isolated and structurally characterized for the first time. The efficiency of this cobalt catalyst was demonstrated in the alcohol dehydrogenation and dehydrative coupling of secondary alcohols under mild conditions into ketones and ethers, respectively.
Spectroscopic and photometric confirmation of chromospheric activity in four stars
Authors: Özdarcan O. , Dal H. A.
Published: June 2018

We present an analysis of medium‐resolution optical spectra and long‐term V band photometry of four cool stars, BD+13 5000, BD+11 3024, TYC 3557‐919‐1, and TYC 5163‐1764‐1. Our spectroscopic analysis demonstrates that the stars are giant or subgiant from K0 or K1 spectral type, and all of them exhibit emission features in their Ca ii H& K lines. These features appear to be modulated with the rotation of the stars. Except for BD+11 3024, we observe that the radial velocities of the target stars are not stable, which suggests that each of them might be a member of a binary system. Global analysis of photometric data indicates a clear cyclic variation for BD+13 5000 and TYC 5163‐1764‐1, with a period of 8.0 ± 0.3 and 5.04 ± 0.04 year, respectively. Besides that, we observe a dramatic increase (∼07) in the mean brightness of BD+11 3024, accompanied with a 2.87 ± 0.12 cyclic variation, embedded into the global brightening trend, which indicates possible multiple cycles on this star.
Learning for democracy: The politics and practice of citizenship education
Authors: Weinberg James , Flinders Matthew
Published: June 2018

It is now two decades since the Advisory Group on Citizenship, commissioned by the newly elected Labour government, recommended the introduction of statutory citizenship education. On the twentieth anniversary of the eponymously named ‘Crick Report’, this article presents the findings of a rigorous mixed‐methods study of citizenship educators in the UK. This research suggests that teachers continue to lack a shared understanding of citizenship, conceptually and pedagogically, and also reveals an emphasis amongst teachers upon individualistic notions of good citizenship that are reflective of national, and increasingly global, political discourse. The findings are analysed using a new conceptual framework—the declarative–procedural paradigm—which is developed here to understand the relationship between political and normatively driven visions of democratic citizenship and classroom pedagogy. In doing so the article adds, theoretically and substantively, to the specific research pool of citizenship studies and broader debates about political disengagement.
CRISPR/dCas9‐Mediated Multiplex Gene Repression in Streptomyces
Authors: Zhao Yawei , Li Lei , Zheng Guosong , Jiang Weihong , Deng Zixin , Wang Zhijun , Lu Yinhua
Published: June 2018

Streptomycetes are Gram‐positive bacteria with the capacity to produce copious bioactive secondary metabolites, which are the main source of medically and industrially relevant drugs. However, genetic manipulation of Streptomyces strains is much more difficult than other model microorganisms like Escherichia coli and Saccharomyces cerevisiae. Recently, CRISPR/Cas9 or dCas9‐mediated genetic manipulation tools have been developed and facilitated Streptomyces genome editing. However, till now, CRISPR/dCas9‐based interference system (CRISPRi) is only designed to repress single gene expression. Herein, the authors developed a novel CRISPRi system for multiplex gene repression in the model strain Streptomyces coelicolor. In this system, the integrative plasmid pSET152 is used as the backbone for the expression of the dCas9/sgRNA complex and both dCas9 and sgRNAs are designed to be under the control of constitutive promoters. Using the integrative CRISPRi system, the authors achieved efficient repression of multiple genes simultaneously; the mRNA levels of four targets are reduced to 2–32% of the control. Furthermore, it is successfully employed for functional gene screening, and an orphan response regulator (RR) (encoded by SCO2013) containing an RNA‐binding ANTAR domain is identified being involved in bacterial growth. Collectively, this integrative CRISPRi system is very effective for multiplex gene repression in S. coelicolor, which could be extended to other Streptomyces strains for functional gene screening as well as for metabolic engineering.
Nomogram to predict lymph node metastasis in patients with early oesophageal squamous cell carcinoma
Authors: Zheng H , Tang H , Wang H , Fang Y , Shen Y , Feng M , Xu S , Fan H , Ge D , Wang Q , Tan L
Published: June 2018

Background

Lymph node status is crucial in determining the prognosis for early oesophageal squamous cell carcinoma (SCC). This study aimed to develop and validate a nomogram for the prediction of lymph node metastasis in patients with early SCC.

Methods

A prediction model was developed in a derivation cohort of patients with clinicopathologically confirmed early SCC. Patients who underwent oesophagectomy for pT1 SCC between January 2010 and December 2013 were identified from an institutional database. Risk factors for lymph node metastasis were assessed using a binary logistic regression modelling technique. A nomogram for the prediction of lymph node metastasis was constructed using the results of multivariable analyses. For internal validation, bootstraps with 1000 resamples were performed. The predictive performance of the nomogram was measured by Harrell's concordance index (C-index). An independent cohort from the same hospital was used to validate the nomogram. This cohort included consecutive patients with early SCC who underwent oesophagectomy from January 2014 to December 2015.

Results

The derivation cohort included 281 patients. Four variables associated with lymph node metastasis were included in the model: depth of tumour invasion (odds ratio (OR) 4·37, 95 per cent c.i. 1·59 to 12·03; P = 0·004), grade of differentiation (OR 4·47, 1·02 to 19·70; P = 0·048), tumour size (OR 2·52, 1·11 to 5·75; P = 0·028) and lymphovascular invasion (OR 6·58, 2·54 to 17·05; P < 0·001). The C-index was 0·790 (95 per cent c.i. 0·717 to 0·864) in the derivation cohort and 0·789 (0·709 to 0·869) for the validation cohort (198 patients).

Conclusion

A validated nomogram for patients with early oesophageal SCC can predict the risk of lymph node metastasis.
Predictive value of abdominal CT in evaluating internal herniation after bariatric laparoscopic Roux-en-Y gastric bypass
Authors: Ederveen J C , van Berckel M M G , Nienhuijs S W , Weber R J P , Nederend J
Published: June 2018

Background

Internal herniation, a serious complication after bariatric surgery, is challenging to diagnose. The aim of this study was to determine the accuracy of abdominal CT in diagnosing internal herniation.

Methods

The study included consecutive patients who had undergone laparoscopic gastric bypass surgery between 1 January 2011 and 1 January 2015 at a bariatric centre of excellence. To select patients suspected of having internal herniation, reports of abdominal CT and reoperations up to 1 January 2017 were screened. CT was presumed negative for internal herniation if no follow-up CT or reoperation was performed within 90 days after the initial CT, or no internal herniation was found during reoperation. The accuracy of abdominal CT in diagnosing internal herniation was calculated using two-way contingency tables.

Results

A total of 1475 patients were included (84·7 per cent women, mean age 46·5 years, median initial BMI 41·8 kg/m2). CT and/or reoperation was performed in 192 patients (13·0 per cent) in whom internal herniation was suspected. Internal herniation was proven laparoscopically in 37 of these patients. The incidence of internal herniation was 2·5 per cent. An analysis by complaint included a total of 265 episodes, for which 247 CT scans were undertaken. CT was not used to investigate 18 episodes, but internal herniation was encountered in one-third of these during reoperation. Combining the follow-up and intraoperative findings, the accuracy of CT for internal herniation had a sensitivity of 83·8 (95 per cent c.i. 67·3 to 93·2) per cent, a specificity of 87·1 (81·7 to 91·2) per cent, a positive predictive value of 53·4 (40·0 to 66·5) per cent and a negative predictive value of 96·8 (92·9 to 98·7) per cent.

Conclusion

Abdominal CT is an important tool in diagnosing internal herniation, with a high specificity and a high negative predictive value.
Estrogen‐related receptor alpha triggers the proliferation and migration of human non‐small cell lung cancer via interleukin‐6
Authors: Zhang Jing , Guan Xiangqian , Liang Naixin , Li Shanqing
Published: June 2018

Human non‐small cell lung cancer (NSCLC) is one of the leading causes of cancer deaths worldwide. Estrogenic signals have been suggested to be important for the growth and metastasis of NSCLC cells. Our present data showed that estrogen‐related receptor alpha (ERRα), while not ERRβ or ERRγ, was significantly elevated in NSCLC cell lines as compared with that in normal bronchial epithelial cell line BEAS‐2B. The expression of ERRα in clinical NSCLC tissues was significantly greater than that in their matched normal adjacent tissues. Over expression of ERRα can trigger the proliferation, migration, and invasion of NSCLC cells, while si‐ERRα or ERRα inhibitor showed opposite effects. ERRα can increase the mRNA and protein expression of IL‐6, while not IL‐8, IL‐10, IL‐22, VEGF, TGF‐β, or TNF‐α, in NSCLC cells. Silence of IL‐6 attenuated ERRα induced proliferation and cell invasion. Furthermore, our data revealed the inhibition of NF‐κB, while not ERK1/2 or PI3K/Akt, abolished ERRα induced production of IL‐6. This might be due to that overexpression of ERRα can increase the expression and nuclear translocation of p65 in NSCLC cells. Collectively, our data showed that activation of NF‐κB/IL‐6 is involved in ERRα induced migration and invasion of NSCLC cells. It suggested that ERRα might be a potential target for NSCLC treatment.
Bioorthogonally Applicable Fluorescence Deactivation Strategy for Receptor Kinetics Study and Theranostic Pretargeting Approaches
Authors: van der Wal Steffen , de Korne Clarize M. , Sand Laurens G. L. , van Willigen Danny M. , Hogendoorn Pancras C. W. , Szuhai Karoly , van Leeuwen Fijs W. B. , Buckle Tessa
Published: June 2018

The availability of a receptor for theranostic pretargeting approaches was assessed by use of a new click‐chemistry‐based deactivatable fluorescence‐quenching concept. The efficacy was evaluated in a cell‐based model system featuring both membranous (available) and internalized (unavailable) receptor fractions of the clinically relevant receptor chemokine receptor 4 (CXCR4). Proof of concept was achieved with a deactivatable tracer consisting of a CXCR4‐specific peptide functionalized with a Cy5 dye bearing a chemoselective azide handle (N3‐Cy5‐AcTZ14011). Treatment with a Cy7 quencher dye (Cy7‐DBCO) resulted in optically silent Cy7‐[click]‐Cy5‐AcTZ14011. In situ, a >90 % FRET‐based reduction of the signal intensity of N3‐Cy5‐AcTZ14011 [KD=(222.4±25.2) nm] was seen within minutes after quencher addition. In cells, discrimination between the membranous and the internalized receptor fraction could be achieved through quantitative assessment of quenching/internalization kinetics. Similar evaluation of an activatable tracer variant based on the same targeting moiety (Cy5‐S‐S‐Cy3‐AcTZ14011) was unsuccessful in vitro. As such, using the described deactivatable approach to screen membrane receptors and their applicability in receptor‐(pre‐)targeted theranostics can become straightforward.
Nanoconfined Nitrogen‐Doped Carbon‐Coated Hierarchical TiCoN Composites with Enhanced ORR Performance
Authors: Tang Haibo , Luo Junming , Yu Jinnan , Zhao Weiyue , Song Huiyu , Liao Shijun
Published: June 2018

The high cost of platinum‐based cathode catalysts for the oxygen reduction reaction (ORR) has long hampered the practical application of fuel cells. In‐depth studies have shown titanium nitride (TiN) is an interesting non‐precious‐metal electrocatalysts for replacing Pt, due to their low cost, excellent catalytic properties, and stability. In this study, we report on a three‐dimensional (3D) nitrogen‐doped carbon‐coated hierarchical Ti0.95Co0.05N composite, created using a one‐step impregnation method followed by nitriding. The catalyst exhibited significantly enhanced ORR activity and excellent electrochemical stability. Our optimal catalyst, 20 %C‐Ti0.95Co0.05N, had an ORR performance almost comparable to 20 % Pt/C in an alkaline medium, and a four‐electron pathway was dominant during the ORR reaction. The significantly enhanced ORR performance of this catalyst is attributable to the following factors: the synergic effect of a carbon coating on the nitride nanoparticles (NPs), including the higher surface area and more exposed active‐sites caused by the well‐defined 3D structure resulting from the carbon coating; better mass transfer and electron transfer due to the carbon coating; the contribution of the doped carbon; and enhancement of the nitride's activity by doping with transition metal.
Helicity Control of Supramolecular Gel Fibers Consisting of an Achiral NiII Complex in a Chiral Nematic Solvent
Authors: Maeda Takatoshi , Kuwajima Yuuki , Akita Takuya , Iwai Yosuke , Komiya Naruyoshi , Uchida Yoshiaki , Naota Takeshi
Published: June 2018

The supramolecular chirality of aggregates consisting of achiral trans‐bis(salicylaldiminato)NiII complex 1 bearing long alkyl chains can be generated and controlled precisely in a chiral nematic liquid‐crystalline (LC) solvent, whereas the complex naturally forms achiral gel fibers in achiral nematic LC solvents and crystals in nonmesogenic solvents. The direction and intensity of the helicity of the gel fibers of 1 in the LC gel state can be adjusted by means of the nature of the helical twisting and the concentration of the chiral dopants. Helicity control was precisely detected in the circular dichroism (CD) spectra of LC gels and by direct SEM observation of the dried gel fibers. XRD analysis revealed that the flexibility of the herringbone‐based lamellar alignment of this complex is the key to the LC‐specific gelation and helicity control of the gel fibers.
Recent Advances in the Development of Indazole‐based Anticancer Agents
Authors: Dong Jinyun , Zhang Qijing , Wang Zengtao , Huang Guang , Li Shaoshun
Published: June 2018

Cancer is one of the leading causes of human mortality globally; therefore, intensive efforts have been made to seek new active drugs with improved anticancer efficacy. Indazole‐containing derivatives are endowed with a broad range of biological properties, including anti‐inflammatory, antimicrobial, anti‐HIV, antihypertensive, and anticancer activities. In recent years, the development of anticancer drugs has given rise to a wide range of indazole derivatives, some of which exhibit outstanding activity against various tumor types. The aim of this review is to outline recent developments concerning the anticancer activity of indazole derivatives, as well as to summarize the design strategies and structure–activity relationships of these compounds.
Building a scientific workflow framework to enable real‐time machine learning and visualization
Authors: Li Feng , Song Fengguang
Published: June 2018

Nowadays, we have entered the era of big data. In the area of high performance computing, large‐scale simulations can generate huge amounts of data with potentially critical information. However, these data are usually saved in intermediate files and are not instantly visible until advanced data analytics techniques are applied after reading all simulation data from persistent storages (eg, local disks or a parallel file system). This approach puts users in a situation where they spend long time on waiting for running simulations while not knowing the status of the running job. In this paper, we build a new computational framework to couple scientific simulations with multi‐step machine learning processes and in‐situ data visualizations. We also design a new scalable simulation‐time clustering algorithm to automatically detect fluid flow anomalies. This computational framework is built upon different software components and provides plug‐in data analysis and visualization functions over complex scientific workflows. With this advanced framework, users can monitor and get real‐time notifications of special patterns or anomalies from ongoing extreme‐scale turbulent flow simulations.
Coupling Resonances of Surface Plasmon in Gold Nanorod/Copper Chalcogenide Core−Shell Nanostructures and Their Enhanced Photothermal Effect
Authors: Li Yingying , Pan Guiming , Liu Qiyu , Ma Liang , Xie Ying , Zhou Li , Hao Zhonghua , Wang Ququan
Published: June 2018

Dual plasmonic Au@Cu2−xS core−shell nanorods (NRs) have been fabricated by using a hydrothermal method and plasmon‐coupled effect between the Au core and Cu2−xS shell in the near‐infrared (NIR) region. The extinction spectrum of Au@Cu2−xS NRs is dominated by the surface plasmon resonance (SPR) of the Cu2−xS shell, the transverse surface plasmon resonance (TSPR), and the longitudinal surface plasmon resonance (LSPR) of the Au NRs. With the Cu2−xS shell increasing (fixed Au NRs), the TSPR peak slightly redshifts and the LSPR and SPR peaks blueshift, owing to competition between the redshift of the refractive index effect and blueshift from the plasmon coupled effect. Although, for Au@Cu2S NRs, only TSPR and LSPR peaks can be seen and a redshift arises with the increasing Cu2S shell thickness, implying that no plasmonic coupling between Au NRs and Cu2S shell occurred. The extinction spectrum of the Au@Cu2−xS NRs with three coupled resonance peaks is simulated by using the FDTD method, taking into account the electron‐transfer effect. The dispersion properties of the coupling of Au@Cu2−xS NRs with the LSPR of the initial Au core are studied experimentally by changing the length of the Au NRs, which are explained theoretically by the coupled harmonic oscillator model. The calculated coupled coefficients between SPR of the Cu2−xS shell and LSPR of the Au NRs is 180 meV, which is much stronger than that of TSPR of Au NRs of 55 meV. Finally, the enhanced photothermal effect of Au@Cu2−xS NRs has been demonstrated.
Chiral Separation via Molecular Sieving: A Computational Screening of Suitable Functionalizations for Nanoporous Graphene
Authors: Fruehwirth Samuel M. , Meyer Ralf , Hauser Andreas W.
Published: June 2018

In a recent study [Angew. Chem. Int. Ed., 2014, 53, 9957–9960] a new concept of chiral separation has been suggested, which is based on functionalized, nanoporous sheets of graphene. In this follow‐up article we discuss the underlying principle in greater detail and make suggestions for suitable pore functionalizations with respect to a selection of chiral prototype molecules. Considering drug molecules as future targets for a chiral separation via membranes, the necessary pore sizes represent a big challenge for standard methods of computational chemistry. Therefore, we test two common force fields (GAFF, CGenFF) as well as a semiempirical tight‐binding approach recently developed by the Grimme group (GFN‐xTB) against the computationally much more expensive density functional theory. We identify the GFN‐xTB method as the most suitable approach for future simulations of functionalized pores for the given purpose, as it is able to produce reaction pathways in very good agreement with density functional theory, even in cases where force fields tend to an extreme overestimation of barrier heights.
Influence of oral bacteria on adhesion of Streptococcus mutans and Streptococcus sanguinis to dental materials
Authors: Nabert‐Georgi Cindy , Rodloff Arne C. , Jentsch Holger , Reissmann Daniel R. , Schaumann Reiner , Stingu Catalina Suzana
Published: June 2018

In this study, the effect of bacterial multispecies communities on the adhesion of Streptococcus mutans and Streptococcus sanguinis to dental restorative material was investigated. The saliva‐coated specimens of zirconia and composite were incubated with the following combinations: single species, S. mutans or S. sanguinis; two species, single species combined with other oral streptococci; multiple species, combination of Actinomyces naeslundii, Fusobacterium nucleatum, and Prevotella ssp.; and the two‐species combinations. The adherent bacteria were counted after plating of serial dilutions. Effects of material and bacteria on adhesion of S. mutans and S. sanguinis were evaluated with multiple linear regression analyses. No significant differences between the materials regarding the adhesion of S. mutans and S. sanguinis were observed. The adhesion of S. mutans was negatively influenced by the presence of other streptococci. Enhancing effects (610.6%) were seen in the presence of Prevotella intermedia. The adhesion of S. sanguinis decreased in the presence of other bacteria, except F. nucleatum (increase of 717.4%). Significant inhibitory effects were detected in the presence of S. mutans and A. naeslundii (reduction of 95.9% and 78.5%, respectively). The results of this study suggest that adhesion of both types of streptococci to restorative materials is influenced by various bacterial interactions.
Revealing the Relationship between Photocatalytic Properties and Structure Characteristics of TiO2 Reduced by Hydrogen and Carbon Monoxide Treatment
Authors: Liu Yunpeng , Li Yuhang , Yang Siyuan , Lin Yuan , Zuo Jiangliang , Liang Hong , Peng Feng
Published: June 2018

Reduction is considered to be an effective method to improve the photocatalytic activity of TiO2; however, the underlying relationship between structure and photocatalytic performance has not been adequately unveiled to date. To obtain insights into the effect of structure on photocatalytic activity, two types of reduced TiO2 were prepared from CO (CO‐TiO2) and H2 (H‐TiO2). For H‐TiO2, Ti−H bonds and oxygen vacancies are formed on the surface of H‐TiO2, which results in a more disordered surface lattice. However, for CO‐TiO2, more Ti−OH bonds are formed on the surface and more bulk oxygen vacancies are introduced; the disorder layer of CO‐TiO2 is relatively thin, owing to most surface vacancies being filled by Ti−OH bonds. Under simulated solar irradiation, the photocatalytic H2 evolution rate of CO‐TiO2 reaches 7.17 mmol g−1 h−1, which is 4.14 and 1.50 times those of TiO2 and H‐TiO2, respectively. The photocatalytic degradation rate constant of methyl orange on CO‐TiO2 is 2.45 and 6.39 times those on H‐TiO2 and TiO2. The superior photocatalytic activity of CO‐TiO2 is attributed to the effective separation and transfer of photogenerated electron–hole pairs, due to the synergistic effects of oxygen vacancies and surface Ti−OH bonds. This study reveals the relationship between the photocatalytic properties and structure, and provides a new method to prepare highly active TiO2 for H2 production and environmental treatment.
Implementation of high step‐up DC‐DC converter using voltage‐lift and coupled inductor techniques
Authors: Yang Lung‐Sheng
Published: June 2018

A high step‐up DC‐DC converter using the voltage‐lift and coupled inductor techniques is presented in this paper. Only a single switch is utilized for this converter. The voltage‐lift and coupled inductor techniques are integrated to achieve high voltage gain for the proposed converter. The leakage energy of the coupled inductor is recycled for improving the conversion efficiency. In addition, the operating principles and steady‐state analyses are illustrated for continuous conduction mode. The boundary condition is analyzed in detail. To demonstrate the performance for the proposed converter, a prototype circuit is built in the laboratory.
Novel model coupling approach for resilience analysis of coastal plant communities
Authors: Schibalski Anett , Körner Katrin , Maier Martin , Jeltsch Florian , Schröder Boris
Published: June 2018

Resilience is a major research focus covering a wide range of topics from biodiversity conservation to ecosystem (service) management. Model simulations can assess the resilience of, for example, plant species, measured as the return time to conditions prior to a disturbance. This requires process‐based models (PBM) that implement relevant processes such as regeneration and reproduction and thus successfully reproduce transient dynamics after disturbances. Such models are often complex and thus limited to either short‐term or small‐scale applications, whereas many research questions require species predictions across larger spatial and temporal scales. We suggest a framework to couple a PBM and a statistical species distribution model (SDM), which transfers the results of a resilience analysis by the PBM to SDM predictions. The resulting hybrid model combines the advantages of both approaches: the convenient applicability of SDMs and the relevant process detail of PBMs in abrupt environmental change situations. First, we simulate dynamic responses of species communities to a disturbance event with a PBM. We aggregate the response behavior in two resilience metrics: return time and amplitude of the response peak. These metrics are then used to complement long‐term SDM projections with dynamic short‐term responses to disturbance. To illustrate our framework, we investigate the effect of abrupt short‐term groundwater level and salinity changes on coastal vegetation at the German Baltic Sea. We found two example species to be largely resilient, and, consequently, modifications of SDM predictions consisted mostly of smoothing out peaks in the occurrence probability that were not confirmed by the PBM. Discrepancies between SDM‐ and PBM‐predicted species responses were caused by community dynamics simulated in the PBM and absent from the SDM. Although demonstrated with boosted regression trees (SDM) and an existing individual‐based model, IBC‐grass (PBM), our flexible framework can easily be applied to other PBM and SDM types, as well as other definitions of short‐term disturbances or long‐term trends of environmental change. Thus, our framework allows accounting for biological feedbacks in the response to short‐ and long‐term environmental changes as a major advancement in predictive vegetation modeling.
Reintroducing Azidodifluoromethane: Synthesis, Stability and [3+2] Cycloadditions
Authors: Voltrová Svatava , Putovný Igor , Matoušek Václav , Klepetářová Blanka , Beier Petr
Published: June 2018

Azidodifluoromethane was prepared in 65 % yield from chlorodifluoromethane by a two‐step synthesis using tributyl(difluoromethyl)ammonium chloride as an intermediate. The resulting azide was used in Huisgen azide‐alkyne reactions and ketone [3+2] cycloadditions to access novel N‐difluoromethyl‐1,2,3‐triazoles.
Copper‐Catalyzed Direct C‐3 Benzylation of Quinoxalin‐2(1H)‐ones with Methylarenes under Microwave Irradiation
Authors: Hu Leqian , Yuan Jinwei , Fu Junhao , Zhang Taotao , Gao Lele , Xiao Yongmei , Mao Pu , Qu Lingbo
Published: June 2018

A novel and efficient approach to the C(sp2)–H/C(sp3)–H oxidative coupling of quinoxalin‐2(1H)‐ones with methylarenes by using CuI as catalyst is reported. Various substrates were well tolerated in this methodology and the desired products were given in moderate‐to‐good yields. This reaction features good functional group compatibility and broad substrate scope.
Injecting NMDA and Ro 25‐6981 in insular cortex induce neuroplastic changes and neuropathic pain‐like behaviour
Authors: Yoon M.S. , Koh C.S. , Lee J. , Shin J. , Kong C. , Jung H.H. , Chang J.W.
Published: June 2018

Background

Neuropathic pain is associated with abnormal sensitivity of the central nervous system. Although the mechanism underlying the development of sensitization remains to be fully elucidated, recent studies have reported that neuroplastic changes in the pain circuitry may be involved in hypersensitivity associated with neuropathic pain. However, it is difficult to investigate such phenomena in existing animal pain model. Therefore, in this study, we developed a novel animal model – the circuit plasticity reconstruction (CPR) model – to mimic central sensitization associated with neuroplastic changes.

Method

NMDA and Ro 25‐6981 were injected into the right insular cortex of Sprague‐Dawley rats, while electrical stimulation was delivered to the contralateral hind paw. Mechanical allodynia was tested by von Frey test with up–down method, and neuroplastic changes were confirmed by PSA‐NCAM‐positive immunostaining.

Result

The mechanical withdrawal threshold of the left hind paw decreased beginning 1 day after CPR modelling and persisted until day 21 comparing to the modified CPR 1 (mod‐CPR 1) group (CPR: 91.68 ± 1.8%, mod‐CPR 1: 42.71 ± 3.4%, p < 0.001). In contrast, mod‐CPR 2 surgery without electrical stimulation did not induce mechanical allodynia. Immunostaining for PSA‐NCAM also revealed that neuroplastic changes had occurred in the CPR group.

Conclusion

Our results demonstrated that CPR modelling induced neuroplasticity within the insular cortex, leading to alterations in the neural circuitry and central sensitization.

Significance

This article represents that the CPR model can mimic the neuropathic pain derived by neuroplastic changes. Our findings indicate that the CPR model may aid the development of novel therapeutic strategies for neuropathic pain and in elucidating the mechanisms underlying pain induced by central sensitization and neuroplastic changes.
Not all positive categories are alike: Exploring the superiority of the self as a positive source for associative attitude change via intersecting regularities
Authors: Mattavelli Simone , Richetin Juliette , Perugini Marco
Published: June 2018

In associative evaluative learning, attitudes can originate from intersecting regularities between a target and both positive‐ and self‐related stimuli. Liking for a focal target is primarily driven by its reference to one source, but it might be qualified by the reference to a contrast target. This contribution focuses on how the nature of positive and contrast sources affects learning via intersecting regularities. In two studies (N = 199 and N = 185), the self and another positive category lead to increased implicit and explicit liking, regardless of the contrast source's valence. In Study 3 (N = 128), confronting the self and the positive category in the same paradigm yields only implicit preferences for self‐related targets. Both implicitly and explicitly, this preference for self‐ over positive‐related target was moderated by self‐positivity. Our findings confirm the robustness of learning via intersecting regularities and suggest that the self is a special evaluative source.
The Signal Amplification in Electrochemical Detection of Chloramphenicol Using Sulfonated Polyaniline‐chitosan Composite as Redox Capacitor
Authors: Mao Yanjun , Guo Liping , Ning Xiaohui , Li Jian , Zheng Jianbin
Published: June 2018

In this work, a novel redox capacitor was designed for signal amplification in electrochemical detection. It was fabricated by co‐electrodeposition of a conducting polymer, sulfonated polyaniline (SPAN) and chitosan on a glass carbon electrode, and its function was evaluated for being a localized source to transfer electron between FcCOOH (Fc) and Ru(NH3)6Cl3 in solution via redox cycling. Furthermore, the electrochemical detection of chloramphenicol, a broad‐spectrum antibiotic was performed using the redox capacitor in the presence of Fc. A significant amplification in cathodic current response of chloramphenicol was obtained through a continuous redox‐cycling reaction. The performance of the amplifying signal responded linearly to chloramphenicol in a concentration range of 0.05 to 50.0 μmol L−1 with a low detection limit of 0.01 μmol L−1. The proposed approach exhibited good reproducibility and stability, and could be used for detection of chloramphenicol in eye drops by standard addition method with the recoveries from 96.5 % to 103.0 %.
Application of Anodic Stripping Differential Alternative Pulses Voltammetry for Simultaneous Species Quantification
Authors: Zlatev Roumen , Stoytcheva Margarita , Valdez Benjamín
Published: June 2018

The second order voltammetric technique Differential Alternative Pulses Voltammetry (DAPV) was applied in anodic stripping mode for simultaneous quantification of traces of species having close E1/2. The potential‐time waveform and the signal processing allowing the DAPV application in stripping mode are presented. The pulses widths and amplitudes were optimized to obtain maximal sensitivity and resolution at traces of In3+ and Cd2+ (having E1/2 difference of 45 mV) simultaneous quantification in presence of excess of Pb2+. Precise results for both species concentrations were obtained up to In3+ to Cd2+ concentration ratio as high as 1 to 10 without any sample pre‐treatment in purified industrial waste waters using 0.1 mol L−1 HCl as supporting electrolyte.
3D‐FEM Simulation of a MEMS‐Based Electrocaloric Ba(Zr0.2Ti0.8)O3 Thin‐Film Microfluidic Refrigeration Device
Authors: Liebschner Rocco , Gerlach Gerald
Published: June 2018

A microelectromechanical system (MEMS)‐based (4×4×2.5 mm3) active electrocaloric (EC) regenerator (AER) microfluidic system is modeled by a 3D transient thermal and fluid‐dynamic finite‐element (FE) simulation. Special attention is given to the possibility of connecting individual devices to adapt the cooling performance to particular needs. Three different working fluids and three different fluid velocities are considered. A device using silicone oil as the working fluid at a flow rate of 0.1 ms−1 is proven to be the most promising design candidate. The refrigeration capacity for a single EC cell is 0.223 W cm−2 and the coefficient of performance (COP) is 0.52.
The vascular plant flora of Hustai National Park, Mongolia: Composition, life forms, ecological groups and geographical elements
Authors: Tserendulam Tseren‐Ochir , Bayarsaikhan Uudus , Oyuntsetseg Batlai , Wesche Karsten
Published: June 2018

The present study gives an overview of the flora of Hustai National Park, which hosts southern outposts of boreal forests embedded in a matrix of typical steppes. We address floristic composition, life forms, ecological groups and geographical elements, and compare our data against studies from broadly similar regions. A total of 493 vascular plant species belonging to 246 genera and 65 families were recorded. The biggest plant families are Asteraceae (67 species) followed by Poaceae (56 species), Fabaceae (51 species), and Rosaceae (33 species), while 21 families were represented by only one species each. Mesophytes (32.5%) and xerophytes (25.4%) were the most frequent ecological groups, indicating a typical mountain steppe environment. Most species were hemicryptophytes (56.8%), followed by therophytes (18.7%) and cryptophytes (geophytes 10.5%), while the least frequent life form classes were chamaephytes (5.1%) and helophytes (0.2%). Asian chorological elements constituted 52.3% of the total flora, while Eurasian account for 30%, Holarctic for 14.8%, Asian‐American for 1.4% and Cosmopolitan for 1.4%. The Hustai mountain range thus represents a key example of the transition zone between the relatively moist Taiga forests and the drier steppe grasslands. These climate transitional zones are very sensitive to changing climate and land use.
Germination and juvenile growth of the clonal palm,Acoelorrhaphe wrightii,under different water and light treatments: a mesocosm study
Authors: Edelman Sara , Richards Jennifer H.
Published: June 2018

Clonal growth can vary under different environmental conditions, and differences in clonal growth in the juvenile stage influence adult architecture.Acoelorrhaphe wrightii,a threatened palm in Florida, can occur as solitary or clonal. In order to predict its adult architecture, we determined the effects of water and light on (1) germination and (2) morphology ofA. wrightiiduring juvenile life stages. Germination of wild‐collected seeds exposed to four conditions–subsurface, saturated, low, and high water levels–was monitored every month for a year. Seeds began to germinate after seven months; soils with saturated water levels had highest seed germination. Sixty‐four juveniles were grown in one of four environmental treatments (low water + sun, low water + shade, high water + sun, and high water + shade) and growth was measured every two months for a year. After a year, individuals were harvested to assess the impact of treatments on plant biomass. Low water + sun yielded juveniles with a greater number of leaves, more root mass and more branches. The results of this study suggest thatA. wrightiirequires a dry‐down in order to recruit successfully. Results were used to model the effect of water level on adult vegetative architecture.
Fitness of Jiaozi starter for steamed bread production using a two‐stage procedure
Authors: Wang Shiwei , Li Haifeng , Li Zhijian , Sun Yanmei , Wang Jinshui , Li Meng
Published: June 2018

Steamed bread is a popular staple food in China. Jiaozi shows many advantages as a starter for dough fermentation and is frequently used for steamed bread production. The knowledge about the dough fermentation process using Jiaozi is helpful for production management and quality improvement of the final product. In this study, the applicability of Jiaozi for steamed bread production was investigated. Some important factors involved in dough fermentation were carefully examined and analyzed, including the evolution and diversity of major bacteria and fungi, acidity change, reducing sugar utilization, CO2 production and retention, and different full dough fermentation periods. Combined with the quality evaluation of the final product, the results displayed that traditional Jiaozi was suitable as starter for steamed bread production using a two‐stage procedure with a wide range of full fermentation time and also provided more insights into steamed bread production by Jiaozi.
A practical one‐pot three‐component procedure for preparation of 3a,8a‐dihydroxyindeno[1,2‐d]imidazole derivatives in aqueous ethanol
Authors: Jamaledini Azar , Mohammadizadeh Mohammad Reza
Published: June 2018

The results of our investigations on the preparation of 3a,8a‐dihydroxyindeno[1,2‐d]imidazole derivatives via reaction of thiourea, ninhydrin, and alkyl/benzyl chlorides in aqueous ethanol and under convenient conditions is reported. On the other hand, when guanidinium chloride was used instead of thiourea, the reaction mixtures reached with unexpected products; 2,2‐dialkoxy‐1H‐indene‐1,3(2H)‐diones.
Can a smoking ban save your heart?
Authors: Mazzonna Fabrizio , Salari Paola
Published: June 2018

This paper evaluates the causal effect of environmental tobacco exposure on health by exploiting the time and geographical variation in public‐place smoking bans implemented in Switzerland between 2007 and 2011. We use administrative data on hospitalizations for acute myocardial infarction, which allow to measure the short‐run effects of the policy on an objective metric of health. We show that the incidence of acute myocardial infarction decreases by approximately 8% immediately after implementation of the law with large heterogeneity across regions. Our results indicate that the policy was effective in reducing the negative externality of smoking with potential spillovers on health inequality.
There is no perfect evaluator: An investigation based on prospect theory
Authors: Lee Min Chul , Park Jaehyun
Published: June 2018

Psychophysical measurement has been widely used in various scientific and engineering fields. In the field of human–computer interaction (HCI), many prominent constructs, such as usability, affective satisfaction, user value, and user experience, have been assessed by psychophysical measurement, including Likert, Borg, and 0–100 scales. In spite of considerable empirical evidence that psychophysical measurement is reliable and valid, these measures also have fundamental limitations, such as distortion at both extremes. This study introduced prospect theory, which compensates for decision‐making behavior in uncertain situations, and applied the theory to the transformation of assessed data. In a typical usability assessment study with target selection tasks, this study revealed that psychophysically assessed data might improve reliability and validity. In addition, this study showed that people tend to regard around 75 as judgment criteria on a 0–100 scale. The results of this study can be used and applied to improve the reliability and validity of subjective measurements. This study suggested a method to improve psychological measurements based on prospect theory. The method is expected to be applied to practical engineering experiments, which has been widely conducted in the field of human factors and HCI.