bluuebunny/crossref_metadata_2025 huggingface dataset:
Wafer bonded four‐junction GaInP/GaAs//GaInAsP/GaInAs concentrator solar cells with 44.7% efficiency
Authors: Dimroth Frank , Grave Matthias , Beutel Paul , Fiedeler Ulrich , Karcher Christian , Tibbits Thomas N. D. , Oliva Eduard , Siefer Gerald , Schachtner Michael , Wekkeli Alexander , Bett Andreas W. , Krause Rainer , Piccin Matteo , Blanc Nicolas , Drazek Charlotte , Guiot Eric , Ghyselen Bruno , Salvetat Thierry , Tauzin Aurélie , Signamarcheix Thomas , Dobrich Anja , Hannappel Thomas , Schwarzburg Klaus
Published: January 2014

Triple‐junction solar cells from III–V compound semiconductors have thus far delivered the highest solar‐electric conversion efficiencies. Increasing the number of junctions generally offers the potential to reach even higher efficiencies, but material quality and the choice of bandgap energies turn out to be even more importance than the number of junctions. Several four‐junction solar cell architectures with optimum bandgap combination are found for lattice‐mismatched III–V semiconductors as high bandgap materials predominantly possess smaller lattice constant than low bandgap materials. Direct wafer bonding offers a new opportunity to combine such mismatched materials through a permanent, electrically conductive and optically transparent interface. In this work, a GaAs‐based top tandem solar cell structure was bonded to an InP‐based bottom tandem cell with a difference in lattice constant of 3.7%. The result is a GaInP/GaAs//GaInAsP/GaInAs four‐junction solar cell with a new record efficiency of 44.7% at 297‐times concentration of the AM1.5d (ASTM G173‐03) spectrum. This work demonstrates a successful pathway for reaching highest conversion efficiencies with III–V multi‐junction solar cells having four and in the future even more junctions. Copyright © 2014 John Wiley & Sons, Ltd.
Polymers containing imidazole groups as nanoreactors for hydrolysis of esters
Authors: Giusti Luciano A. , Medeiros Michelle , Ferreira Natasha Londero , Mora José R. , Fiedler Haidi D.
Published: January 2014

A polymer (PAIM) containing the functional groups imidazole and carboxylic acid acts as a nanoreactor to accelerate deacylation and dephosphorylation reactions. The synthesis was designed to position the two functional groups next to each other, allowing cooperativity. The catalytic efficiency of the polymer was evaluated for the hydrolytic cleavage of p‐nitrophenyl acetate (PNPA) and diethyl 2,4‐dinitrophenyl phosphate (DEDNPP). PAIM was both efficient and promiscuous, increasing the rates of all reactions up to 107‐fold. Copyright © 2014 John Wiley & Sons, Ltd.
Degenerate thermal isomerizations of bicyclo[3.1.1]hept‐2‐ene: strategy and analysis
Authors: Baldwin John E. , Hudson Bruce S.
Published: January 2014

Bicyclo[3.1.1]hept‐2‐ene was first prepared and well identified in 1972. In 1974, the degenerate thermal isomerization involving 1‐d‐ and 3‐d‐bicyclo[3.1.1]hept‐2‐ene was approached successfully, as one of the two deuterium‐labeled structures was selected, heated, and equilibrated. There has been no further study of this degenerate isomerization. Here, a detailed outline of reaction trajectories for d2‐labeled bicyclo[3.1.1]hept‐2‐enes is given that will establish the four independent kinetic parameters needed for 20 linking paths between six d2‐species. The use of racemates, eliminating chiral separations and dissections, provides degenerate isomerization paths providing this method with general utility. Copyright © 2014 John Wiley & Sons, Ltd.
Carbon‐Dot‐Decorated Nanodiamonds
Authors: Shenderova Olga , Hens Suzanne , Vlasov Igor , Turner Stuart , Lu Ying‐Gang , Van Tendeloo Gustaaf , Schrand Amanda , Burikov Sergey A. , Dolenko Tatiana A.
Published: January 2014

The synthesis of a new class of fluorescent carbon nanomaterials, carbon‐dot‐decorated nanodiamonds (CDD‐ND), is reported. These CDD‐NDs are produced by specific acid treatment of detonation soot, forming tiny rounded sp2 carbon species (carbon dots), 1–2 atomic layers thick and 1–2 nm in size, covalently attached to the surface of the detonation diamond nanoparticles. A combination of nanodiamonds bonded with a graphitic phase as a starting material and the application of graphite intercalated acids for oxidation of the graphitic carbon is necessary for the successful production of CDD‐ND. The CDD‐ND photoluminescence (PL) is stable, 20 times more intense than the intrinsic PL of well‐purified NDs and can be tailored by changing the oxidation process parameters. Carbon‐dot‐decorated DNDs are shown to be excellent probes for bioimaging applications and inexpensive additives for PL nanocomposites.
Perceived neighborhood safety and asthma morbidity in the School Inner‐City Asthma Study
Authors: Kopel Lianne S. , Gaffin Jonathan M. , Ozonoff Al , Rao Devika R. , Sheehan William J. , Friedlander James L. , Permaul Perdita , Baxi Sachin N. , Fu Chunxia , Subramanian S.V. , Gold Diane R. , Phipatanakul Wanda
Published: January 2014

Aim

The aim of this study was to investigate whether neighborhood safety as perceived by primary caregivers is associated with asthma morbidity outcomes among inner‐city school children with asthma.

Methods

School children with asthma were recruited from 25 inner‐city schools between 2009 and 2012 for the School Inner‐City Asthma Study (N = 219). Primary caregivers completed a baseline questionnaire detailing their perception of neighborhood safety and their children's asthma symptoms, and the children performed baseline pulmonary function tests. In this cross‐sectional analysis, asthma control was compared between children whose caregivers perceived their neighborhood to be unsafe versus safe.

Results

After adjusting for potential confounders, those children whose primary caregivers perceived the neighborhood to be unsafe had twice the odds of having poorly controlled asthma (odds ratio [OR] adjusted = 2.2, 95% confidence interval [CI] = 1.2–3.9, P = 0.009), four times the odds of dyspnea and rescue medication use (OR adjusted = 4.7; 95% CI = 1.7–13.0, P = 0.003, OR adjusted = 4.0; 95% CI = 1.8–8.8, P < 0.001, respectively), three times as much limitation in activity (OR adjusted = 3.2; 95% CI = 1.4–7.7, P = 0.008), and more than twice the odds of night‐time symptoms (OR adjusted = 2.2; 95% CI = 1.3–4.0, P = 0.007) compared to participants living in safe neighborhoods. There was no difference in pulmonary function test results between the two groups.

Conclusions

Primary caregivers' perception of neighborhood safety is associated with childhood asthma morbidity among inner‐city school children with asthma. Further study is needed to elucidate mechanisms behind this association, and future intervention studies to address social disadvantage may be important. Pediatr Pulmonol. 2015; 50:17–24. © 2014 Wiley Periodicals, Inc.
Benchmarking protein–protein interface predictions: Why you should care about protein size
Authors: Martin Juliette
Published: January 2014

A number of predictive methods have been developed to predict protein–protein binding sites. Each new method is traditionally benchmarked using sets of protein structures of various sizes, and global statistics are used to assess the quality of the prediction. Little attention has been paid to the potential bias due to protein size on these statistics. Indeed, small proteins involve proportionally more residues at interfaces than large ones. If a predictive method is biased toward small proteins, this can lead to an over‐estimation of its performance. Here, we investigate the bias due to the size effect when benchmarking protein‐protein interface prediction on the widely used docking benchmark 4.0. First, we simulate random scores that favor small proteins over large ones. Instead of the 0.5 AUC (Area Under the Curve) value expected by chance, these biased scores result in an AUC equal to 0.6 using hypergeometric distributions, and up to 0.65 using constant scores. We then use real prediction results to illustrate how to detect the size bias by shuffling, and subsequently correct it using a simple conversion of the scores into normalized ranks. In addition, we investigate the scores produced by eight published methods and show that they are all affected by the size effect, which can change their relative ranking. The size effect also has an impact on linear combination scores by modifying the relative contributions of each method. In the future, systematic corrections should be applied when benchmarking predictive methods using data sets with mixed protein sizes. Proteins 2014; 82:1444–1452. © 2014 Wiley Periodicals, Inc.
When Relationships Depicted Diagrammatically Conflict With Prior Knowledge: An Investigation of Students’ Interpretations of Evolutionary Trees
Authors: NOVICK LAURA R. , CATLEY KEFYN M.
Published: January 2014

Science is an important domain for investigating students’ responses to information that contradicts their prior knowledge. In previous studies of this topic, this information was communicated verbally. The present research used diagrams, specifically trees (cladograms) depicting evolutionary relationships among taxa. Effects of college students’ and 10th graders’ prior knowledge on their ability to reason from information depicted in cladograms was evaluated in two ways: (1) By keeping the hierarchical branching structure constant while manipulating whether the taxa‐targeted common misconceptions about biological classification or were unfamiliar; and (2) by keeping the targeted misconception constant while manipulating the strength of the evidence countermanding that misconception. Students demonstrated more sophisticated reasoning when (1) the taxa were unfamiliar, so they had to rely on the diagrammatic information presented rather than their incorrect prior knowledge, and (2) stronger evidence contradicting their incorrect prior knowledge was presented. Students’ challenges to correctly interpreting evolutionary trees included lower level of schooling and greater strength of the misconception. College, but not high school, students showed some ability to transfer their better reasoning with cladograms depicting relationships among unfamiliar taxa to cladograms depicting taxon relationships that contradicted their everyday conceptions. Implications for improving biology education and overcoming misconceptions are discussed.
Structural interdependence within top management teams: A key moderator of upper echelons predictions
Authors: Hambrick Donald C. , Humphrey Stephen E. , Gupta Abhinav
Published: January 2014

Studies of the effects of top management team (TMT) composition on organizational outcomes have yielded mixed and confusing results. A possible breakthrough resides in the reality thatTMTs vary in how they are fundamentally structured. Some are structured such that members operate independently of each other, while others are set up such that roles are highly interdependent. We examine the potential for three facets of structural interdependence—horizontal, vertical, and reward interdependence—to resolve ambiguities regarding effects ofTMTheterogeneity. Based on a sample ofTMTs in technology firms, we find that the three facets of structural interdependence are potent moderators of two classic predictions: the positive association betweenTMTheterogeneity and member departures, and betweenTMTheterogeneity and firm performance. Copyright © 2014 John Wiley & Sons, Ltd.
Boron Enolate Chemistry toward the Syntheses of Polyketide Stereotetrads
Authors: Koskinen Ari M. P.
Published: January 2014

In 1976 Mukaiyama published a paper that was to make a major impact on the development of the aldol reaction in the future. Mild enolate formation by treatment of a ketone with dibutylboron triflate in the presence of a tertiary amine generates a relatively stable boron enolate, which can subsequently react with an aldehyde to give the cross‐aldol product in good yields. This reaction has become a reliable tool for the practicing synthetic chemist. Nearly 10000 polyketides are known, and of these about 600 contain the tripropionate unit with a stereotetrad, four contiguous stereocenters with alternating methyl and hydroxyl substituents in the main chain. The versatility of the boron enolate aldol reaction is showcased with selected applications in the synthesis of these structural motifs.
Dicamba affects sex steroid hormone level and mRNA expression of related genes in adult rare minnow (Gobiocypris rarus) at environmentally relevant concentrations
Authors: Zhu Lifei , Li Wei , Zha Jinmiao , Wang Zijian
Published: January 2014

Dicamba is a benzoic acid herbicide that has been detected in surface and ground water. The herbicide has been shown to have cytogeneic and DNA damaging effects and to cause organ damage in mammals; however, little is known about the endocrine disrupting effects of dicamba in fish. In this study, histological changes, plasma vitellogenin (VTG) and sex hormone levels, and mRNA expression of sex steroid hormone‐related genes were determined in adult rare minnow exposed to environmentally relevant concentrations of dicamba (0, 0.05, 0.5, 5, and 50 μg/L) for 40 days. The results showed inhibition of spermatogenesis in male testes and ovarian degeneration in females. Plasma 17β‐estradiol (E2) levels were significantly increased in both genders, and plasma VTG levels were significantly increased in males (p < 0.05). These results indicate that sex hormone homeostasis and normal reproduction of fish could be affected by dicamba. Moreover, the mRNA levels of vtg were significantly upregulated in the livers and gonads of both male and female rare minnows (p < 0.05). The downregulation of cytochrome P450c19a (cyp19a) and steroidogenic acute regulatory protein (star) mRNA levels, and the upregulation of cytochrome P450c17 (cyp17) mRNA levels were observed in the livers and ovaries (p < 0.05). The results of the mRNA analysis suggest that changes in steroid hormone‐related gene expression could serve as a regulatory mechanism to maintain sex hormone homeostasis. Overall, dicamba exposure could result in histological lesions, plasma VTG increases, changes in sex hormone levels, and alterations of hormone‐related gene expression. Therefore, dicamba should be considered to be a potential endocrine disruptor. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 693–703, 2015.
Prenatal and neonatal exposure to perfluorooctane sulfonic acid results in aberrant changes in miRNA expression profile and levels in developing rat livers
Authors: Wang Fan , Liu Wei , Jin Yihe , Wang Faqi , Ma Junsheng
Published: January 2014

Perfluorooctane sulfonate (PFOS) is an animal carcinogen. However, the underlying mechanism in cancer initiation is still largely unknown. Recently identified microRNAs (miRNAs) may play an important role in toxicant exposure and in the process of toxicant‐induced tumorigenesis. We used PFOS to investigate PFOS‐induced changes in miRNA expression in developing rat liver and the potential mechanism of PFOS‐induced toxic action. Dams received 3.2 mg/kg PFOS in their feed from gestational day 1 (GD1) to postnatal day 7 (PND 7). Pups then had free access to treated feed until PND 7. We isolated RNAs from liver tissues on PND 1 and 7 and analyzed the expression profiles of 387 known rat miRNAs using microarray technology. PFOS exposure induced significant changes in miRNA expression profiles. Forty‐six miRNAs had significant expression alterations on PND 1, nine miRNAs on PND 7. Specifically, expression of four miRNAs was up‐regulated on PND 7 but down‐regulated on PND1 (p < 0.05). Many aberrantly expressed miRNAs were related to various cancers. We found oncogenic and tumor‐suppressing miRNAs, which included miR‐19b, miR‐21*, miR‐17‐3p, miR‐125a‐3p, miR‐16, miR‐26a, miR‐1, miR‐200c, and miR‐451. In addition, four miRNAs were simultaneous significantly expressed on both PND 1 and 7. Functional Annotation analysis of the predicted transcript targets revealed that PFOS exposure potentially alters pathways associated with different cancers (cancer, melanoma, pancreatic cancer, colorectal cancer, and glioma), biological processes which include positive regulation of apoptosis and cell proliferation. Results showed PFOS exposure altered the expression of a suite of miRNAs. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 712–723, 2015.
Imaging genetics — towards discovery neuroscience
Authors: Ge Tian , Schumann Gunter , Feng Jianfeng
Published: January 2014

Imaging genetics is an emerging field aimed at identifying and characterizing genetic variants that influence measures derived from anatomical or functional brain images, which are in turn related to brain‐related illnesses or fundamental cognitive, emotional and behavioral processes, and are affected by environmental factors. Here we review the recent evolution of statistical approaches and outstanding challenges in imaging genetics, with a focus on population‐based imaging genetic association studies. We show the trend in imaging genetics from candidate approaches to pure discovery science, and from univariate to multivariate analyses. We also discuss future directions and prospects of imaging genetics for ultimately helping understand the genetic and environmental underpinnings of various neuropsychiatric disorders and turning basic science into clinical strategies.
Structural basis for microtubule recognition by the human kinetochore Ska complex
Authors: Abad Maria Alba , Medina Bethan , Santamaria Anna , Zou Juan , Plasberg-Hill Carla , Madhumalar Arumugam , Jayachandran Uma , Redli Patrick Marc , Rappsilber Juri , Nigg Erich A. , Jeyaprakash A. Arockia
Published: January 2014

The ability of kinetochores (KTs) to maintain stable attachments to dynamic microtubule structures (‘straight’ during microtubule polymerization and ‘curved’ during microtubule depolymerization) is an essential requirement for accurate chromosome segregation. Here we show that the kinetochore-associated Ska complex interacts with tubulin monomers via the carboxy-terminal winged-helix domain of Ska1, providing the structural basis for the ability to bind both straight and curved microtubule structures. This contrasts with the Ndc80 complex, which binds straight microtubules by recognizing the dimeric interface of tubulin. The Ska1 microtubule-binding domain interacts with tubulins using multiple contact sites that allow the Ska complex to bind microtubules in multiple modes. Disrupting either the flexibility or the tubulin contact sites of the Ska1 microtubule-binding domain perturbs normal mitotic progression, explaining the critical role of the Ska complex in maintaining a firm grip on dynamic microtubules.
Indigo carmine: An organic crystal as a positive-electrode material for rechargeable sodium batteries
Authors: Yao Masaru , Kuratani Kentaro , Kojima Toshikatsu , Takeichi Nobuhiko , Senoh Hiroshi , Kiyobayashi Tetsu
Published: January 2014

Using sodium, instead of lithium, in rechargeable batteries is a way to circumvent the lithium's resource problem. The challenge is to find an electrode material that can reversibly undergo redox reactions in a sodium-electrolyte at the desired electrochemical potential. We proved that indigo carmine (IC, 5,5′-indigodisulfonic acid sodium salt) can work as a positive-electrode material in not only a lithium-, but also a sodium-electrolyte. The discharge capacity of the IC-electrode was ~100 mAh g−1with a good cycle stability in either the Na or Li electrolyte, in which the average voltage was 1.8 Vvs.Na+/Na and 2.2 Vvs.Li+/Li, respectively. Two Na ions per IC are stored in the electrode during the discharge, testifying to the two-electron redox reaction. An X-ray diffraction analysis revealed a layer structure for the IC powder and the DFT calculation suggested the formation of a band-like structure in the crystal.
Promotion of quality standard of herbal medicine by constituent removing and adding
Authors: Yan Dan , Li Junxian , Xiong Yin , Zhang Congen , Luo Jiaoyang , Han Yumei , Wang Ruiling , Jin Cheng , Qian Hong , Li Jiangyu , Qiu Lingling , Peng Cheng , Lin Yuling , Song Xueai , Xiao Xiaohe
Published: January 2014

To identify major active constituents and measure their levels in a typical medicinal herb–Rhizoma coptidis, we applied the concept of removing and adding, taking inspiration from functional genetic methods. As this herb has bacteriostatic properties and is used to treat bacterial diarrhea, we examined the effects of individual constituents (berberine, palmatine, coptisine, epiberberine, jateorrhizine and columbamine) on the growth of Shigella dysenteriae with microcalorimetry. The removing and adding procedures revealed that berberine and coptisine were the main antibacterial constituents of R. coptidis, with bacteriostatic activities of 54.10% and 39.75%, respectively. The relative levels of berberine and coptisine in R. coptidis were 8.08%–31.92% and 4.05%–14.45%, respectively. On the basis of whole effect, the method of constituents removing and adding, coupled with a bioassay, is a useful strategy to identify the active constituents and measure their levels in herbal medicines, which may provide reference to other natural products.
Quantification of oxymatrine in rat plasma by UPLC-MS/MS to support the pharmacokinetic analyses of oxymatrine-loaded polymersomes
Authors: Yang Jianhong , Dai Guidong , Hou Yanhui , Song Zhihua , Wang Fang , Ji Gangjian , Chen Jianhai
Published: January 2014

We developed a UPLC-MS/MS method that could efficiently extract oxymatrine (OM) from polymersomes and provided for the determination of OM in rat plasma to support pharmacokinetics study of OM-loaded polymersomes.
Synthesis and characterization of functional multicomponent nanosized gallium chelated gold crystals
Authors: Zambre Ajit , Silva Francisco , Upendran Anandhi , Afrasiabi Zahra , Xin Yan , Paulo António , Kannan Raghuraman
Published: January 2014

Multicomponent nanomaterials containing Au, Ga, and a biomolecule have been synthesized. Compositional analysis of these nanoparticles was performed by using STEM-HAADF and EELS spectroscopy.
Aqueous asymmetric cyclopropanation reactions in polymersome membranes
Authors: van Oers Matthijs C. M. , Abdelmohsen Loai K. E. A. , Rutjes Floris P. J. T. , van Hest Jan C. M.
Published: January 2014

Copper-bis(oxazoline) functionalised polymersomes have been developed for asymmetric cyclopropanation reactions in water.
Autocatalytic one pot orchestration for the synthesis of α-arylated, α-amino esters
Authors: Roche Stéphane P. , Samanta Shyam S. , Gosselin Marine M. J.
Published: January 2014

α-Arylated, α-amino esters are synthesized in one pot, using an AcOH/AcCl autocatalytic system, which promotes simultaneous dehydration–activation before Friedel–Crafts functionalization.
Palladium(0)-catalyzed cyclopropanation of benzyl bromides via C(sp3)–H bond activation
Authors: Mao Jiangang , Zhang Shuo-Qing , Shi Bing-Feng , Bao Weiliang
Published: January 2014

A novel Pd(0)-catalyzed domino cyclopropanation reaction was established. The process involves a Heck-type coupling reaction and a C(sp3)–H activation.
Structures of benzoic acids with substituted pyridines and quinolines: salt versus co-crystal formation
Authors: Ramon Gaëlle , Davies Kate , Nassimbeni Luigi R.
Published: January 2014

Acids and bases were crystallized so that their ΔpKa spans the ‘uncertainty’ region for the formation of salt versus co-crystals.
Facile synthesis of single-crystalline NiO nanosheet arrays on Ni foam for high-performance supercapacitors
Authors: Huang Ming , Li Fei , Ji Jun Yi , Zhang Yu Xin , Zhao Xiao Li , Gao Xing
Published: January 2014

Single-crystalline NiO nanosheet arrays on Ni foam as a binder-free electrode for high-performance supercapacitors, fabricated by a facile and cost-effective hydrothermal approach, exhibit a high specific capacitance, good rate capability, and excellent cycling stability.
Comparison of pyridyl and pyridyl N-oxide groups as acceptor in hydrogen bonding with carboxylic acid
Authors: Saraswatula Viswanadha G. , Bhat Mukhtar A. , Gurunathan Pradeep Kumar , Saha Binoy K.
Published: January 2014

The propensity of carboxyl⋯pyridyl synthon is more than carboxyl⋯pyridyl N-oxide synthon, but carboxyl⋯pyridyl N-oxide synthon forms shorter hydrogen bond than carboxyl⋯pyridyl synthon. Carboxyl⋯pyridyl N-oxide synthon containing systems might show better solubility than the corresponding carboxyl⋯pyridyl synthon containing systems.
A copper complex supported by an N2S-tridentate ligand inducing efficient heterolytic O–O bond cleavage of alkylhydroperoxide
Authors: Tano Tetsuro , Mieda Kaoru , Sugimoto Hideki , Ogura Takashi , Itoh Shinobu
Published: January 2014

The sulphur-containing ligand induces efficient O–O bond heterolysis in the reaction of a copper(i) complex and alkylhydroperoxide.
Direct photodegradation of lamotrigine (an antiepileptic) in simulated sunlight – pH influenced rates and products
Authors: Young Robert B. , Chefetz Benny , Liu Aiju , Desyaterik Yury , Borch Thomas
Published: January 2014

In simulated sunlight, pH influenced the direct photodegradation of lamotrigine, an antiepileptic drug recently detected in surface and drinking waters, producing different degradation rates, quantum yields, pathways, and photoproducts.
N-heterocyclic silylene complexes in catalysis: new frontiers in an emerging field
Authors: Blom Burgert , Gallego Daniel , Driess Matthias
Published: January 2014

A review of all existing N-heterocyclic silylene (NHSi) complexes involved in catalysis. Remarkably few examples exist, but already show promise as an emerging new generation of catalysts with the potential to tune catalyst activities and selectivities.
Modulating the copper–sulfur interaction in type 1 blue copper azurin by replacing Cys112 with nonproteinogenic homocysteine
Authors: Clark Kevin M. , Yu Yang , van der Donk Wilfred A. , Blackburn Ninian J. , Lu Yi
Published: January 2014

Replacement of conserved Cys112 in azurin with a nonproteinogenic amino acid homocysteine affords a type-1 copper site with decreased Cu–SCys covalency.
Hierarchical silver mesoparticles with tunable surface topographies for highly sensitive surface-enhanced Raman spectroscopy
Authors: Cheng Lin , Ma Chuansheng , Yang Guang , You Hongjun , Fang Jixiang
Published: January 2014

Using FDTD simulation, the mechanism of the effect of the topographies of hierarchical silver mesoparticles on SERS properties were systematically studied.
Kinetic reconstruction of TiO2 surfaces as visible-light-active crystalline phases with high photocatalytic performance
Authors: Zheng Peng , Hao Ruipeng , Zhao Jianghong , Jia Suping , Cao Baoyue , Zhu Zhenping
Published: January 2014

Visible light responsive TiO2 crystals form on the surfaces of rutile TiO2 nanocrystals during kinetic phase transformation from anatase to rutile. The nanocrystals exhibit excellent photoelectric conversion properties for photocatalytic hydrogen production.
The probiotic Lactobacillus coryniformis CECT5711 reduces the vascular pro-oxidant and pro-inflammatory status in obese mice
Authors: Toral Marta , Gómez-Guzmán Manuel , Jiménez Rosario , Romero Miguel , Sánchez Manuel , Utrilla María Pilar , Garrido-Mesa Natividad , Rodríguez-Cabezas María Elena , Olivares Mónica , Gálvez Julio , Duarte Juan
Published: January 2014

Obesity is associated with intestine dysbiosis and is characterized by a low-grade inflammatory status, which affects vascular function. In the present study, we evaluated the effects of a probiotic with immunomodulatory properties, Lactobacillus coryniformis CECT5711, in obese mice fed on an HFD (high-fat diet). The probiotic treatment was given for 12 weeks, and it did not affect the weight evolution, although it reduced basal glycaemia and insulin resistance. L. coryniformis administration to HFD-induced obese mice induced marked changes in microbiota composition and reduced the metabolic endotoxaemia as it decreased the LPS (lipopolysaccharide) plasma level, which was associated with a significant improvement in gut barrier disruption. Furthermore, it lowered TNFα (tumour necrosis factor α) expression in liver, improving the inflammatory status, and thus the glucose metabolism. Additionally, the probiotic reversed the endothelial dysfunction observed in obese mice when endothelium- and NO (nitric oxide)-dependent vasodilatation induced by acetylcholine in aortic rings was studied. It also restored the increased vessel superoxide levels observed in obese mice, by reducing NADPH oxidase activity and increasing antioxidant enzymes. Moreover, chronic probiotic administration for 2 weeks also improved endothelial dysfunction and vascular oxidative stress induced by in vivo administration of LPS in control mice fed on a standard chow diet. The results of the present study demonstrate an endothelial-protective effect of L. coryniformis CECT5711 in obese mice by increasing NO bioavailability, suggesting the therapeutic potential of this gut microbiota manipulation to prevent vasculopathy in obesity.
Kisspeptin-10 induces endothelial cellular senescence and impaired endothelial cell growth
Authors: Usui Sayaka , Iso Yoshitaka , Sasai Masahiro , Mizukami Takuya , Mori Hiroyoshi , Watanabe Takuya , Shioda Seiji , Suzuki Hiroshi
Published: January 2014

The KPs (kisspeptins) are a family of multifunctional peptides with established roles in cancer metastasis, puberty and vasoconstriction. The effects of KPs on endothelial cells have yet to be determined. The aim of the present study was to investigate the effects of KP-10 on endothelial cell growth and the mechanisms underlying those effects. The administration of recombinant KP-10 into the hindlimbs of rats with ischaemia significantly impaired blood flow recovery, as shown by laser Doppler, and capillary growth, as shown using histology, compared with the controls. HUVECs (human umbilical vein endothelial cells) express the KP receptor and were treated with KP-10 in culture studies. KP-10 inhibited endothelial cell tube formation and proliferation in a significant and dose-dependent manner. The HUVECs treated with KP exhibited the senescent phenotype, as determined using a senescence-associated β-galactosidase assay, cell morphology analysis, and decreased Sirt1 (sirtuin 1) expression and increased p53 expression shown by Western blot analysis. Intriguingly, a pharmacological Rho kinase inhibitor, Y-27632, was found to increase the proliferation of HUVECs and to reduce the number of senescent phenotype cells affected by KP-10. In conclusion, KP-10 suppressed endothelial cells growth both in vivo and in vitro in the present study. The adverse effect of KP on endothelial cells was attributable, at least in part, to the induction of cellular senescence.
Design of dual‐band phase offset line with arbitrary phase shift at two operational frequencies
Authors: Li Jiuchao , Liu Yuanan , Li Shulan , Yu Cuiping , Wu Yongle
Published: January 2014

A simple and successful design for an arbitrary phase shift at two operational frequencies by using a T‐section with only a single dual‐band stub‐loaded line is presented, and the design equations are derived analytically. For verification, a proposed dual‐band phase offset line is fabricated and measured at 1618.25 and 2491.75 MHz of the ‘COMPASS’. The results show that there is good agreement between the measured and the electromagnetic simulations.
One‐step fabrication of coaxial nanofibres with core (Ni0.5Zn0.5Fe2O4)/sheath (ZnO) via coaxial electrospinning
Authors: Dai Jianfeng , Jiang Yan , Wang Qing , Li Weixue , Dai Yile
Published: January 2014

One‐dimensional coaxial nanofibres with a core (Ni0.5Zn0.5Fe2O4)/sheath (ZnO) were produced by coaxial electrospinning and calcining. The core/sheath structures were clearly visible by transmission electron microscopy (TEM), because of, respectively, putting chloroform and glycerin into the core and the sheath precursor solutions. Their core/sheath structures, chemical compositions and phase analysis were investigated by means of high‐resolution TEM, scanning electron microscopy and X‐ray diffraction. The results show that its mean diameter is 30 nm; the thickness of the shell is 8 nm; and ZnO promotes the axial growing of Ni0.5Zn0.5Fe2O4.
Nontraumatic Atlantoaxial Rotatory Subluxation: Grisel Syndrome. Case Report and Literature Review
Authors: Barcelos Alécio C. E. S. , Patriota Gustavo C. , Netto Arlindo Ugulino
Published: January 2014

Study Design

Case report and literature review.

Objective

To describe a case of nontraumatic atlantoaxial rotatory subluxation (Grisel syndrome) and to review clinical and radiologic aspects, physiopathology, and treatment of this lesion. There is no well-established protocol in the management of patients without spontaneous reduction. The authors discuss the available strategies to achieve reduction and when to operate on these patients.

Methods

Case presentation of a 7-year-old patient who presented with torticollis ∼1 week after the onset of an upper airway infection. There was no history of head or neck trauma. Computed tomography demonstrated atlantoaxial rotatory subluxation and a normal atlantodental interval.

Results

The patient was treated with nonsteroidal anti-inflammatory drugs and antibiotics and by progressively increasing the soft cervical collar height. Clinical reduction of the subluxation occurred after 48 hours. He wore the rigid collar for 6 weeks. At that moment, the patient was completely asymptomatic and follow-up cervical spine radiograph demonstrated an anatomical C1–C2 relation. The patient was instructed to return to daily life activities in a gradual manner.

Conclusions

Grisel syndrome should be considered in the differential diagnosis of torticollis, especially in children. The management can be planned according to the classification of Fielding and Hawkins. The initial treatment involves medicines, injury reduction, and cervical spine immobilization. Surgical treatment is indicated only in cases of failure of conservative treatment, recurrences of subluxation, and irreducible subluxations.
The Thermodynamic Properties of the f-Elements and their Compounds. Part 2. The Lanthanide and Actinide Oxides
Authors: Konings Rudy J. M. , Beneš Ondrej , Kovács Attila , Manara Dario , Sedmidubský David , Gorokhov Lev , Iorish Vladimir S. , Yungman Vladimir , Shenyavskaya E. , Osina E.
Published: January 2014

A comprehensive review of the thermodynamic properties of the oxide compounds of the lanthanide and actinide elements is presented. The available literature data for the solid, liquid, and gaseous state have been analysed and recommended values are presented. In case experimental data are missing, estimates have been made based on the trends in the two series, which are extensively discussed.
The application of localized surface plasmons resonance in Ag nanoparticles assisted Si chemical etching
Authors: Ding Ruiqiang , Dai Han , Li Meicheng , Huang Jinjer , Li Yingfeng , Trevor Mwenya , Musselman Kevin P.
Published: January 2014

Localized surface plasmons excited by Ag nanoparticles are introduced in the chemical etching process of silicon. A special crateriform structure with gradually varying radius is achieved by the surface electromagnetic field enhancement effect of localized surface plasmons resonance (LSPR). Theoretical analysis demonstrates that the formation kinetics of the crateriform structures conforms to the local electromagnetic field enhancement and forward scattering induced by LSPR. The LSPR assisted photocatalytic etching offers a potential approach for the preparation of the surface microstructures used in optoelectronic devices.
Design and initial results from a kilojoule level dense plasma focus with hollow anode and cylindrically symmetric gas puff
Authors: Ellsworth J. L. , Falabella S. , Tang V. , Schmidt A. , Guethlein G. , Hawkins S. , Rusnak B.
Published: January 2014

We have designed and built a Dense Plasma Focus (DPF) Z-pinch device using a kJ-level capacitor bank and a hollow anode, and fueled by a cylindrically symmetric gas puff. Using this device, we have measured peak deuteron beam energies of up to 400 keV at 0.8 kJ capacitor bank energy and pinch lengths of ∼6 mm, indicating accelerating fields greater than 50 MV/m. Neutron yields of on the order of 107 per shot were measured during deuterium operation. The cylindrical gas puff system permitted simultaneous operation of DPF with a radiofrequency quadrupole accelerator for beam-into-plasma experiments. This paper describes the machine design, the diagnostic systems, and our first results.
Simultaneous enhancement in thermoelectric power factor and phonon blocking in hierarchical nanostructured β-Zn4Sb3-Cu3SbSe4
Authors: Zou T. H. , Qin X. Y. , Li D. , Sun G. L. , Dou Y. C. , Wang Q. Q. , Ren B. J. , Zhang J. , Xin H. X. , Li Y. Y.
Published: January 2014

In Pb and Te-free β-Zn4Sb3 based composites incorporated with nanophase Cu3SbSe4 (∼200 nm), we concurrently realize ∼30% increase in thermoelectric power factor (PF) through an energy filtering effect caused by carrier scattering at interface barriers, and around twofold reduction in lattice thermal conductivity due to interface scattering allowing the figure of merit (ZT) to reach 1.37 at 648 K in the composite system with 5 vol. % of Cu3SbSe4. Present results demonstrate that simultaneous enhancement of PF and phonon blocking can be achieved via proper design of a material-system and its microstructures, resulting in large increase in ZT of a material-system.
Reversible switching of charge injection barriers at metal/organic-semiconductor contacts modified with structurally disordered molecular monolayers
Authors: Nouchi Ryo , Shigeno Masanori , Yamada Nao , Nishino Tomoaki , Tanigaki Katsumi , Yamaguchi Masahiko
Published: January 2014

Metal/semiconductor interfaces govern the operation of semiconductor devices through the formation of charge injection barriers that can be controlled by tuning the metal work function. However, the controlling ability is typically limited to being static. We show that a dynamic nature can be imparted to the interfaces using electrode surface modification with a structurally disordered molecular monolayer. The barrier height at the interfaces is altered significantly in a reversible way by an external electric field. As a result, a dramatic change in the carrier transport properties through the interfaces is observed, such as a reversible polarity reversion of metal/organic-semiconductor/metal diodes.
Thermal conductivity of ultra-thin chemical vapor deposited hexagonal boron nitride films
Authors: Alam M. T. , Bresnehan M. S. , Robinson J. A. , Haque M. A.
Published: January 2014

Thermal conductivity of freestanding 10 nm and 20 nm thick chemical vapor deposited hexagonal boron nitride films was measured using both steady state and transient techniques. The measured value for both thicknesses, about 100 ± 10 W m−1 K−1, is lower than the bulk basal plane value (390 W m−1 K−1) due to the imperfections in the specimen microstructure. Impressively, this value is still 100 times higher than conventional dielectrics. Considering scalability and ease of integration, hexagonal boron nitride grown over large area is an excellent candidate for thermal management in two dimensional materials-based nanoelectronics.
Selective observation of photo-induced electric fields inside different material components in bulk-heterojunction organic solar cell
Authors: Chen Xiangyu , Taguchi Dai , Manaka Takaaki , Iwamoto Mitsumasa
Published: January 2014

By using electric-field-induced optical second-harmonic generation (EFISHG) measurement at two laser wavelengths of 1000 nm and 860 nm, we investigated carrier behavior inside the pentacene and C60 component of co-deposited pentacene:C60 bulk-heterojunctions (BHJs) organic solar cells (OSCs). The EFISHG experiments verified the presence of two carrier paths for electrons and holes in BHJs OSCs. That is, two kinds of electric fields pointing in opposite directions are identified as a result of the selectively probing of SHG activation from C60 and pentacene. Also, under open-circuit conditions, the transient process of the establishment of open-circuit voltage inside the co-deposited layer has been directly probed, in terms of photovoltaic effect. The EFISHG provides an additional promising method to study carrier path of electrons and holes as well as dissociation of excitons in BHJ OSCs.
Bias-dependent interface roughening and its effect on electric bistability of organic devices
Authors: Zeng Q. , You Y. T. , Ye F. F. , Li W. B. , Chen X. Q. , Yu H. M. , Yang X. J. , Hou X. Y.
Published: January 2014

Atomic force microscopy (AFM), field-emission scanning electron microscopy, and energy dispersive X-Ray spectroscopy are used to study morphological and compositional variations of metal-organic interfaces in organic bistable devices. The results show that bias voltage causes rougher interfaces with new protrusions, and the switching phenomena origins from the evolution of these protrusions under external electric field. In order to exclude other possible factors, three types of bistable devices are designed and examined. In addition, metal-coated AFM probes are utilized to simulate the switching process, which yields similar results and corroborates our conclusion.
Effects of premixed ratio on combustion characteristics of a homogeneous charge compression ignition-direct injection engine fueled with dimethyl ether
Authors: Hou Junxing , Wen Zhenhua , Jiang Zhiqiang , Liu Yuanpeng
Published: January 2014

A two-cylinder, direct injection diesel engine was modified for a homogeneous charge compression ignition-direct injection (HCCI-DI) engine fueled with dimethyl ether. Effects of premixed ratio on HCCI-DI combustion characteristics were experimentally investigated. The results show that in HCCI-DI combustion, as premixed ratio Rp increases, the peak pressure increases and its phase advances gradually; the first peak of pressure rise rate increases and the second peak decreases, and their phase advances gradually. With the increase of Rp, the cool flame peak increases gradually, the peaks of premixed combustion and diffusion combustion decrease gradually. The in-cylinder pressure is decomposed using discrete wavelet transform, the details D1, D2, D3, D4, D5, and D6 are obtained. The relative energy value of pressure at D6, D5, and D4 decreases gradually. The same results are obtained at 0.32 MPa brake mean effective pressure (BMEP), 0.24 MPa BMEP, and 0.16 MPa BMEP. The combustion state plays an important role in determining wavelet relative energy distribution of in-cylinder pressure over details. With increases of Rp, the energy value of in-cylinder pressure at D6 increases gradually, but the energy value at D5 and D4 decreases. It transforms from at D4 and at D5, to at D6 with the increase of Rp.
Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures
Authors: Verma Jai , Islam S. M. , Protasenko Vladimir , Kumar Kandaswamy Prem , (Grace) Xing Huili , Jena Debdeep
Published: January 2014

Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365 nm (3.4 eV, the bulk bandgap) to below 240 nm (>5.2 eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.
Structural Content in Paintings: Artists Overregularize Oriented Content of Paintings Relative to the Typical Natural Scene Bias
Authors: Schweinhart April M , Essock Edward A
Published: January 2014

Natural scenes tend to be biased in both scale (1/ f) and orientation (H > V ≫ O; horizontal > vertical ≫ oblique), and the human visual system has similar biases that serve to partially ‘undo’ (ie whiten) the resultant representation. The present approach to investigating this relationship considers content in works of art—scenes produced for processing by the human visual system. We analyzed the content of images by a method that minimizes errors inherent in some prior analysis methods. In the first experiment museum paintings were considered by comparing the amplitude spectrum of landscape paintings, natural scene photos, portrait paintings, and photos of faces. In the second experiment we obtained photos of paintings at the time they were produced by local artists and compared structural content in matched photos which contained the same scenes that the artists had painted. Results show that artists produce paintings with both the 1/ f bias of scale and the horizontal effect bias of orientation (H > V ≫ O). More importantly, results from both experiments show that artists overregularize the structure in their works: They impose the natural-scene horizontal effect at all structural scales and in all types of subject matter even though, in the real world, the pattern of anisotropy differs considerably across spatial scale and between faces and natural scenes. It appears that artists unconsciously overregularize the oriented structure in their works to make it conform more uniformly to the ‘expected’ canonical ideal.
Does producing more product over a lifetime reduce greenhouse gas emissions and increase profitability in dairy and wool enterprises?
Authors: Browne Natalie A. , Behrendt Ralph , Kingwell Ross S. , Eckard Richard J.
Published: January 2014

Australian agriculture generated 15% of national greenhouse gas emissions (GHGE) in 2011, with CH4 and N2O accounting for 12 and 3% of national emissions, respectively. In 2011, the Australian government introduced a voluntary carbon offset scheme called the Carbon Farming Initiative, which enables farmers to earn carbon credits by lowering GHGE or sequestering carbon. One way of reducing emissions is to decrease the number of replacement animals required on-farm and increase the amount of product that animals produce across their lifetime. This study explores two options for reducing GHGE over an animal’s lifetime: (1) changing from an annual calving system to extended lactation system on dairy farms; and (2) increasing the longevity of ewes on wool enterprises to produce an extra year of wool and offspring. The biophysical models DairyMod and GrassGro were used to simulate the dairy and wool enterprises, respectively, and GHGE were calculated using the Australian National Inventory methodology. Extended lactation produced lower total emissions and emissions intensity (t CO2e/t milk fat plus protein) than annual calving and also resulted in higher operating profits. The GHGE from increasing longevity on sheep enterprises was similar to the baseline scenario, largely as a result of similar stocking rates. Extended lactation had greater potential of reducing emissions than increasing longevity on wool enterprises because there was a larger increase in the production of milk fat plus protein across cows’ lifetimes, as well as greater reductions in the number of replacement animals required on the enterprise. This research demonstrated that the profitability of farm enterprises would be driven more by productivity than claiming carbon offsets from these management changes.