bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Efficient Green Light‐Emitting Diodes from All‐Inorganic Perovskite Nanocrystals Enabled by a New Electron Transport Layer
Authors: Liu Baiquan , Wang Lin , Gu Haoshuang , Sun Handong , Demir Hilmi Volkan 
Published: March 2018

AbstractAdopting proper electron transport layers (ETLs) is essential to high‐performance all‐inorganic perovskite light‐emitting diodes (PeLEDs). However, the effect of ETLs has not been comprehensively investigated in all‐inorganic nanocrystal PeLEDs, while 2,2′,2′′‐(1,3,5‐benzenetriyl) tris‐[1‐phenyl‐1H‐benzimidazole] (TPBi) is the most common ETL. Herein, a novel strategy is proposed to enhance the efficiency of nanocrystal PeLEDs. Tris(8‐hydroxyquinoline) aluminum (Alq3) is incorporated into TPBi to form a new ETL TPBi/Alq3/TPBi, simultaneously enabling charge balance and confinement. The green PeLED with new ETL exhibits a maximum external quantum efficiency (EQE) of 1.43%, current efficiency of 4.69 cd A−1, and power efficiency of 1.84 lm W−1, which are 191%, 192%, and 211% higher than those of PeLEDs with conventional ETL TPBi, respectively. Significantly, the EQE is 36‐fold higher than that of PeLED with high electron mobility ETL. Impressively, the full width at half‐maximum of electroluminescence emission is 16 nm, which is the narrowest among CsPbBr3 PeLEDs. The findings may present a rational strategy to enhance the device engineering of all‐inorganic PeLEDs.
Vertical Organic–Inorganic Hybrid Perovskite Schottky Junction Transistors
Authors: Yu Hyeonggeun , Cheng Yuanhang , Shin Donghun , Tsang Sai‐Wing , So Franky 
Published: March 2018

AbstractWhile organolead halide perovskite materials have attracted considerable attention for high efficiency solar cells, they have shown little potential for use in field‐effect transistors (FETs) due to the limited current modulation at room temperature. Here, by developing a vertically gated methylammonium lead iodide (MAPbI3)/indium‐tin oxide (ITO) Schottky junction, a room temperature‐operable vertical MAPbI3 thin‐film transistor is reported. Due to the injection‐controlled gating mechanism as well as the vertical channel structure, a current modulation ratio up to 104 is achieved. Fabrication of a nanoporous ITO source electrode forming a highly rectifying Schottky junction with the MAPbI3 layer is the key for the large current modulation. It is discovered that the electron transporting layers on top of the MAPbI3 layer play an important role in achieving a large current rectification of 107 at the Schottky junction and hence large current on/off ratios of the resulting transistor.
Metal‐Free Cyclization ofortho‐Nitroaryl Ynamides and Ynamines towards Spiropseudoindoxyls
Authors: Marien Niels , Reddy B. Narendraprasad , De Vleeschouwer Freija , Goderis Steven , Van Hecke Kristof , Verniest Guido 
Published: March 2018

AbstractAn efficient metal‐free cascade reaction between 1‐dibromovinyl‐2‐nitro‐substituted arenes and secondary amines results in the formation of polycyclic pseudoindoxyls in a single step. The reaction mechanism leading to these fused ring systems was investigated, and is believed to involve the initial formation of nitroarylated ynamines/ynamides. These intermediates cycloisomerize towards N‐alkenyl‐tethered 2‐aminoisatogens via a carbene intermediate as demonstrated by QTAIM (quantum theory of atoms in molecules) and ELF (electron localization function) analysis. A subsequent intramolecular dipolar cycloaddition afforded the title compounds.
Big (Bio)Chemical Data Mining Using Chemometric Methods: A Need for Chemists
Authors: Parastar Hadi , Tauler Roma 
Published: March 2018

AbstractThis Review summarizes how big (bio)chemical data (BBCD) can be analyzed with multivariate chemometric methods and highlights some of the important challenges faced by modern analytical researches. Here, the potential of chemometric methods to solve BBCD problems that are being encountered in chromatographic, spectroscopic and hyperspectral imaging measurements will be discussed, with an emphasis on their applications to omics sciences. In addition, insights and perspectives on how to address the analysis of BBCD are provided along with a discussion of the procedures necessary to obtain more reliable qualitative and quantitative results. In this Review, the importance of “big data” and of their relevance to (bio)chemistry are first discussed. Thereafter, analytical tools which can produce BBCD are presented as well as the theoretical background of chemometric methods and their limitations when they are applied to BBCD. Finally, the importance of chemometric methods for the analysis of BBCD in different chemical disciplines is highlighted with some examples. In this work, we have tried to cover many of the current applications of big data analysis in the (bio)chemistry field.
A Telomerase‐Responsive DNA Icosahedron for Precise Delivery of Platinum Nanodrugs to Cisplatin‐Resistant Cancer
Authors: Ma Yi , Wang Zhaohui , Ma Yuxuan , Han Zhihao , Zhang Min , Chen Haiyan , Gu Yueqing 
Published: March 2018

AbstractA telomerase‐responsive DNA icosahedron was designed to precisely release caged platinum nanodrugs into cisplatin‐resistance tumor cells for effective therapy. This DNA icosahedron was constructed from two pyramidal DNA cages connected with telomerase primers and telomeric repeats, and platinum nanodrugs were then encapsulated into the DNA structure. In the presence of telomerase, the primers are extended, leading to inner‐chain substitution of the DNA icosahedron and subsequent release of the caged nanodrugs. This DNA icosahedron can precisely release caged nanodrugs in response to telomerase in tumor cells, giving enhanced anticancer efficacy in drug‐resistant carcinoma and with reduced toxicity to normal tissues. We speculate that this precisely designed, well controlled DNA cage could be generalized to diverse anticancer drugs.
Kinetic models for the effect of temperature on flavonoid production in liquid submerged fermentation by Phellinus baumii
Authors: Jiang Fu‐Chun , Zhang He‐Nan , Wu Di , Feng Na , Zhang Zhong , Zhang Jing‐Song , Feng Jie , Yang Yan 
Published: March 2018

AbstractKinetic models and temperature control strategy were established to reflect the effect of temperature (22 °C–30 °C) on flavonoid production of Phellinus baumii (P. baumii) in 6‐L fermentor. A modified Logistic equation, Hinshelwood model, and Luedeking Piret equation were used to describe mycelial growth and product formation. The influence of temperature on the estimated kinetic parameters was further studied by regression analysis. Based on kinetic parameters analysis, the new temperature control strategy was proposed. Briefly, at 0–43 H, decreasing temperature (30 °C–28 °C) can shorten the lag phase of mycelial growth, and at 43–90 H, fermentation temperature was reduced gradually from 28 °C to 24 °C to keep high flavonoid productivity. At the fermentation anaphase (90–161 H), temperature was controlled at 24 °C to relieve inhibition of flavonoid and maintain constant production capacity of flavonoid. As a result, the maximum flavonoid yield was reached 4.21 mg/100 mg cell dry weight by temperature control strategy, which was 70.45% higher than that at a constant temperature of 26 °C. Additionally, the establishment of kinetic models based on fermentation temperature, which presented here may provide a scientific basis for further large scales flavonoid production of P. baumii in submerged fermentation.
A Port‐A‐Cath in aorta
Authors: Zoltowska Dominika , Kalavakunta Jagadeesh 
Published: March 2018

Key Clinical MessageTotally implantable venous access ports are valuable invention for oncological patients. Erroneous arterial malposition rate is estimated from 1.1% to 3.7% (Bowen et al. Am. J. Surg., 2014, 208, 937). Early recognition and management are crucial to prevent further complications.
A Linear Trinuclear Oxidodiperoxido‐molybdenum(VI) Complex with Single Triazole Bridges: Catalytic Activity in Epoxidation, Alcoholysis, and Acetalization Reactions
Authors: Antunes Margarida M. , Amarante Tatiana R. , Valente Anabela A. , Almeida Paz Filipe A. , Gonçalves Isabel S. , Pillinger Martyn 
Published: March 2018

AbstractThe complex (Htrz)2[Mo3O6(O2)4(trz)2]⋅H2O (1), isolated from the reaction of MoO3 with H2O2 in the presence of 1,2,4‐triazole (trz), displays singular structural features such as double bridges comprising one oxido and one triazole ligand, and peripheral oxidodiperoxido‐molybdenum(VI) units. A comparative study was performed regarding the catalytic activity and stability of complex 1 and the hybrid material [MoO3(trz)0.5] (2) for the epoxidation of cis‐cyclooctene (Cy8), the alcoholysis of epoxides, and the acetalization of benzaldehyde (PhCHO). Methanol or ethanol were used as solvents and reagents for the latter two reactions. For the substrates Cy8, styrene oxide, and PhCHO, the corresponding epoxide, β‐alkoxy alcohol, and dialkyl acetal were obtained with 100 % selectivity at very high conversions. In general, 1 performed better than 2 for the different catalytic reactions. Under certain oxidant/co‐solvent conditions used for Cy8 epoxidation, 1 was converted to 2 during the reaction.
Manganese N‐Heterocyclic Carbene Complexes for Catalytic Reduction of Ketones with Silanes
Authors: Pinto Mara , Friães Sofia , Franco Federico , Lloret‐Fillol Julio , Royo Beatriz 
Published: March 2018

AbstractWell‐defined manganese(I) carbonyl complexes bearing bis‐N‐heterocyclic carbene (NHC) ligands are shown to be effective catalysts for the reduction of carbonyl groups through hydrosilylation reactions. A wide variety of ketones are selectively reduced to the corresponding alcohols by using phenylsilane, and the cheap and readily abundant polymethylhydrosiloxane (PMHS) in the presence of catalytic amounts of MnI organometallic complexes. Interestingly, α,β‐unsaturated ketones and dialkyl ketones are selectively reduced. Mechanistic studies based on radical scavengers suggest the involvement of radical species in the catalytic reaction.
Towards a Mechanistic Understanding of Factors Controlling the Stereoselectivity of Transketolase
Authors: Baierl Anna , Theorell Axel , Mackfeld Ursula , Marquardt Philipp , Hoffmann Friederike , Moers Stephanie , Nöh Katharina , Buchholz Patrick C. F. , Pleiss Jürgen , Pohl Martina 
Published: March 2018

AbstractA structural model for thiamine‐diphosphate (ThDP)‐dependent transketolase (TK) was developed to analyse the effect of amino acid exchanges on the stereoselectivity of this synthetically important class of enzymes. In this study the carboligation of 3‐hydroxypyruvate as a donor and propanal, as well as pentanal, was studied. Based on literature data and additional mutagenesis studies using E. coli TK, a four‐state model was developed to explain the stereoselectivity of TKs by the relative orientation of donor and acceptor substrates in the active site prior to C−C‐bond formation. To enable a functional comparison of relevant amino acids of TKs from different species, a standard numbering scheme was developed. Using this concept, H26, H261, and F434 were identified as the key residues which mediate stereoselectivity, where two main factors influenced the arrangement of ThDP‐bound donor and acceptor prior to carboligation: the relative orientation of the substrate side chains and the orientation of the acceptor carbonyl group towards the donor hydroxy group. This model provides a first framework to understand the structure‐function relationships of TKs with respect to their stereoselectivity.
Nucleoside‐Based Self‐Assembling Drugs for Localized Drug Delivery
Authors: Skilling Kathryn J. , Stocks Michael J. , Kellam Barrie , Ashford Marianne , Bradshaw Tracey D. , Burroughs Laurence , Marlow Maria 
Published: March 2018

AbstractWe have synthesized a range of gelators based on the nucleoside analogues gemcitabine and lamivudine, characterizing representative gels from the series using rheology and transmission electron microscopy. Growth inhibition studies of gemcitabine derivatives confirmed the feasibility of these compounds as novel treatments, indicating the potential of nucleoside‐based gelators for localized drug delivery.
Anticancer Gold(III) Peptidomimetics: From Synthesis to in vitro and ex vivo Biological Evaluations
Authors: Boscutti Giulia , Nardon Chiara , Marchiò Luciano , Crisma Marco , Biondi Barbara , Dalzoppo Daniele , Dalla Via Lisa , Formaggio Fernando , Casini Angela , Fregona Dolores 
Published: March 2018

AbstractFive new AuIII‐peptidodithiocarbamato complexes of the type [AuIIIBr2(dtc‐AA1‐AA2‐OR] (in which AA1=N‐methylglycine (Sar), l/d‐Pro; AA2=l/d‐Ala, α‐aminoisobutyric acid (Aib); R=OtBu, triethylene glycol methyl ether), differing with regard to the amino acid sequence and/or the chiral amino acid configuration, were designed to enhance tumor selectivity and bioavailability. The gold(III)‐based moiety was functionalized to exploit the targeting properties of the peptidomimetic ligand toward two peptide transporters (namely PEPT1 and PEPT2), which are upregulated in several tumor cells. The compounds were synthesized and fully characterized, mainly by means of elemental analysis, one‐ and two‐dimensional NMR spectroscopy, FT‐IR, and UV/Vis spectrophotometry. The crystal structures of three compounds were also solved by X‐ray diffraction. In vitro cytotoxicity studies using a panel of human tumor cell lines (A549 [non‐small‐cell lung carcinoma], MCF‐7 [breast cancer], A2780 [ovarian carcinoma], H1975 [non‐small‐cell lung carcinoma], H460 [large‐cell lung carcinoma], and A431 [human epidermoid carcinoma]) showed the dtc‐Pro‐Aib‐OtBu derivative to be very effective, with GI50 values much lower than those of cisplatin. This complex was thus selected for evaluating stability under physiological conditions and possible interactions with serum albumin, as well in PARP‐1 enzyme inhibition assays and preliminary ex vivo toxicity experiments on healthy rat tissues.
Halogenated Bis(methoxybenzylidene)‐4‐piperidone Curcuminoids with Improved Anticancer Activity
Authors: Schmitt Florian , Subramaniam Dharmalingam , Anant Shrikant , Padhye Subhash , Begemann Gerrit , Schobert Rainer , Biersack Bernhard 
Published: March 2018

AbstractA series of readily available curcuminoids with a halogenated bis(4‐methoxy/4,5‐dimethoxybenzylidene)‐4‐piperidone structure were prepared and analyzed for their cytotoxic impact on eight human cancer cell lines of five different entities. The known 3,4,5‐trimethoxybenzylidene curcuminoid 2 a and the new bis‐(3‐bromophenyl) and bis‐(3,5‐dibromophenyl) derivatives 3 c and 3 d proved to be more strongly antiproliferative than the known curcuminoid EF24 against six of these cell lines. Compounds 2 a and 3 c caused a distinct increase of reactive oxygen species, which eventually elicited apoptosis in 518A2 melanoma cells. Compound 2 a arrested 518A2 melanoma cells in G1 phase of the cell cycle and had no effect on the expression of pro‐metastatic matrix metalloproteinases MMP‐2 and MMP‐9, whereas 3 c led to an accumulation of 518A2 cells in the G2/M phase and to a downregulation of MMP‐2 expression. In addition, treatment with 2 a and 3 c resulted in significant inhibition of colony formation in HCT116 cells. Both 2 a and 3 c showed antiangiogenic activity, for example, by inhibiting the formation of sub‐intestinal veins (SIV) in zebrafish embryos. Compound 3 c was also well tolerated by mice and inhibited the growth of HCT116 colon cancer xenografts.
Temporal sparse feature auto‐combination deep network for video action recognition
Authors: Wang Qicong , Gong Dingxi , Qi Man , Shen Yehu , Lei Yunqi 
Published: March 2018

SummaryIn order to deal with action recognition for large‐scale video data, we present a spatio‐temporal auto‐combination deep network, which is able to extract deep features from short video segments by making full use of temporal contextual correlation of corresponding pixels among successive video frames. Based on conventional sparse encoding, we further consider the representative features in adjacent nodes of the hidden layers according to activation states similarities. A sparse auto‐combination strategy is applied to multiple input maps in each convolution stage. An information constraint of the representative features of hidden layer nodes is imposed to handle the adaptive sparse encoding of the topology. As a result, the learned features can represent the spatio‐temporal transition relationships better and the number of hidden nodes can be restricted to a certain range. We conduct a series of experiments on two public data sets. The experimental results show that our approach is more effective and robust in video action recognition compared with traditional methods.
Highly Sensitive Luminescence Detection of Photosensitized Singlet Oxygen within Photonic Crystal Fibers
Authors: Williams Gareth O. S. , Euser Tijmen G. , Russell Philip St. J. , MacRobert Alexander J. , Jones Anita C. 
Published: March 2018

AbstractHighly sensitive, quantitative detection of singlet oxygen (1O2) is required for the evaluation of newly developed photosensitizers and the elucidation of the mechanisms of many processes in which singlet oxygen is known or believed to be involved. The direct detection of 1O2 through its intrinsic phosphorescence at 1270 nm is challenging, because of the extremely low intensity of this emission, coupled with the low quantum efficiency of currently available photodetectors at this wavelength. We introduce hollow‐core photonic crystal fibers (HC‐PCF) as a novel optofluidic modality for photosensitization and detection of 1O2. We report the use of this approach to achieve highly sensitive detection of the luminescence decay of 1O2 produced by using two common photosensitizers, Rose Bengal and Hypericin, within the 60‐μm diameter core of a 15 cm length of HC‐PCF. We demonstrate the feasibility of directly detecting sub‐picomole quantities of 1O2 by using this methodology, and identify some aspects of the HC‐PCF technology that can be improved to yield even higher detection sensitivity.
Broad infectivity of Leidynema appendiculatum (Nematoda: Oxyurida: Thelastomatidae) parasite of the smokybrown cockroach Periplaneta fuliginosa (Blattodea: Blattidae)
Authors: Ozawa Sota , Hasegawa Koichi 
Published: March 2018

AbstractHost specificity of parasites is important for the understanding of evolutionary strategies of parasitism that would be a basis of predictions of the disease expansion when parasitized hosts invade new environments. The nematode order Oxyurida is an interesting parasite group for studying the evolution of parasitism as it includes parasites of both invertebrates and vertebrates. In our survey, we found that the smokybrown cockroach Periplaneta fuliginosa was primarily infected with only one nematode species Leidynema appendiculatum. In two cases, L. appendiculatum was isolated from two additional cockroach species Pycnoscelus surinamensis, sold in Japan as a reptile food, and Blatta lateralis, captured in the field and cultured in the laboratory. Inoculation of L. appendiculatum into three additional cockroach species P. japonica, Blattella nipponica, and P. surinamensis also resulted in parasitism. Infection prevalence was high, and timing of postembryonic development from hatched nematode larva to mature adult in these hosts was identical with that in P. fuliginosa. While ecological interactions strongly determine the host range, such broad infectivity is still possible in this parasitic nematode.
Origin context of trait data matters for predictions of community performance in a grassland biodiversity experiment
Authors: Roscher Christiane , Schumacher Jens , Gubsch Marlén , Lipowsky Annett , Weigelt Alexandra , Buchmann Nina , Schmid Bernhard , Schulze Ernst‐Detlef 
Published: March 2018

AbstractPlant functional traits may explain the positive relationship between species richness and ecosystem functioning, but species‐level trait variation in response to growth conditions is often ignored in trait‐based predictions of community performance. In a large grassland biodiversity experiment (Jena Experiment), we measured traits on plants grown as solitary individuals, in monocultures or in mixtures. We calculated two measures of community‐level trait composition, i.e., community‐weighted mean traits (CWM) and trait diversity (Rao's quadratic entropy; FD) based on different contexts in which traits were measured (trait origins). CWM and FD values of the different measurement origins were then compared regarding their power to predict community biomass production and biodiversity effects quantified with the additive partitioning method. Irrespective of trait origin, models combining CWM and FD values as predictors best explained community biomass and biodiversity effects. CWM values based on monoculture, mixture‐mean or community‐specific trait data were similarly powerful predictors, but predictions became worse when trait values originated from solitary‐grown individuals. FD values based on monoculture traits were the best predictors of community biomass and net biodiversity effects, while FD values based on community‐specific traits were the best predictors for complementarity and selection effects. Traits chosen as best CWM predictors were not strongly affected by trait origin but traits chosen as best FD predictors varied strongly dependent on trait origin and altered the predictability of community performance. We conclude that by adjusting their functional traits to species richness and even specific community compositions, plants can change community‐level trait compositions, thereby also changing community biomass production and biodiversity effects. Incorporation of these plastic trait adjustments of plants in trait‐based ecology can improve its predictive power in explaining biodiversity–ecosystem functioning relationships.
Negligible effect of competition on coral colony growth
Authors: Álvarez‐Noriega Mariana , Baird Andrew H. , Dornelas Maria , Madin Joshua S. , Connolly Sean R. 
Published: March 2018

AbstractCompetition is an important determinant of assemblage structure and population regulation, often resulting in decreased growth, fecundity or survival. In corals, most studies testing for an effect of competition on demographic traits, such as growth, have been experimental and often impose very high levels of competition upon colonies. To more realistically assess the role of competition on coral traits, multispecies studies in the wild are required. Here, we use 5 yr of data that includes 11 coral species on the reef crest at Lizard Island on the Great Barrier Reef to quantify the effect of competition on growth. Additionally, we test whether species differ in their susceptibility to direct‐contact (overgrowth and digestion) and overtopping competition, and whether species from some morphological groups are more likely to compete with one another than with species from other morphological groups. We also investigate the relationships between competitive ability and three key traits: growth rate, mechanical stability and fecundity. In contrast to most previous work using field manipulations of competition, we found a negligible effect of competition on growth. Acropora species consistently won overtopping encounters but lost in direct‐contact encounters, and these results were consistent among the four Acropora morphological groups. In contrast, the massive Goniastrea spp. were poor at overtopping but generally won direct‐contact encounters. Only tabular colonies were disproportionally more likely to compete against one another than with other morphologies. This propensity increases intraspecific relative to interspecific competition, a phenomenon that can promote coexistence when it is present among dominant competitors. Good competitors grew more quickly and had higher fecundity but were less mechanically stable, implying a tradeoff between performance during disturbance vs. performance in the absence of disturbance. We conclude that competition among adults is less likely to influence community dynamics than previously thought. If competition does have an effect, it is more likely to occur at life‐stages other than adults.