bluuebunny/crossref_metadata_2025_split huggingface dataset:
Series Circuit of Organic Thin‐Film Solar Cells for Conversion of Water into Hydrogen
Authors: Aoki Atsushi , Naruse Mitsuru , Abe Takayuki 
Published: May 2013

AbstractA series circuit of bulk hetero‐junction (BHJ) organic thin‐film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. The BHJ OSCs applied consist of poly(3‐hexylthiophene) as a donor and [6,6]‐phenyl C61 butyric acid methyl ester as an acceptor. A series circuit of six such OSC units has an open circuit voltage (Voc) of 3.4 V, which is enough to electrolyze water. The short circuit current (Jsc), fill factor (FF), and energy conversion efficiency (η) are independent of the number of unit cells. A maximum electric power of 8.86 mW cm−2 is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mW cm−2, AM1.5G), and in one hour 0.65 mL hydrogen is generated.
Versatile Fluorescent Conjugated Polyelectrolyte‐Capped Mesoporous Silica Nanoparticles for Controlled Drug Delivery and Imaging
Authors: Pu Fang , Liu Xia , Yang Xinjian , Liu Zhen , Ren Jinsong , Wang Shu , Qu Xiaogang 
Published: May 2013

AbstractFluorescent conjugated polyelectrolytes (CPEs) with a large extinction coefficient, high quantum efficiency, good photostability, and efficient intramolecular/intermolecular exciton migration have recently received great research attention as a new generation of fluorescent probes. Herein, the unique properties of fluorescent conjugated polyelectrolyte and mesoporous silica nanoparticles (MSNs) are combined to prepare a pH‐sensitive drug delivery and cellular imaging system using a simple and more general method. To the best of our knowledge, this is the first proof‐of‐concept investigation on the use of fluorescent conjugated polyelectrolyte as both the capping agent of MSNs and the cellular imaging probe in parallel. Moreover, the bifunctional nanomaterial exhibits low cytotoxicity and good biocompatibility demonstrated by a cytotoxicity assay against HepG2 cells and a hemolysis assay against human red‐blood cells. It is a promising candidate for simultaneous diagnostics and therapeutics and can also provide a general strategy to develop novel multifunctional nanomedical systems.
Structural Characterization of Anion–Calcium–Humate Complexes in Phosphate‐based Fertilizers
Authors: Baigorri Roberto , Urrutia Oscar , Erro Javier , Mandado Marcos , Pérez‐Juste Ignacio , Garcia‐Mina José María 
Published: May 2013

AbstractFertilizers based on phosphate–metal–humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid31P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the31P NMR peaks. Computational chemistry methods allowed the characterization of phosphate–calcium–humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate–calcium–humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate–metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental31P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the31P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate–calcium interactions within the crystals.
Magnetism in Lithium–Oxygen Discharge Product
Authors: Lu Jun , Jung Hun‐Ji , Lau Kah Chun , Zhang Zhengcheng , Schlueter John A. , Du Peng , Assary Rajeev S. , Greeley Jeffrey , Ferguson Glen A. , Wang Hsien‐Hau , Hassoun Jusef , Iddir Hakim , Zhou Jigang , Zuin Lucia , Hu Yongfeng , Sun Yang‐Kook , Scrosati Bruno , Curtiss Larry A. , Amine Kahlil 
Published: May 2013

AbstractNonaqueous lithium–oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium‐ion batteries, and thus could render long‐range electric vehicles a reality. A molecular‐level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium–oxygen batteries. We demonstrate that the major discharge product formed in the lithium–oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc‐magnetization measurements and a lithium–oxygen cell containing an ether‐based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide‐type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide‐type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.
A Computational Investigation of the Insertion of Carbon Dioxide into Four‐ and Five‐Coordinate Iridium Hydrides
Authors: Bernskoetter Wesley H. , Hazari Nilay 
Published: May 2013

AbstractRecently, it has been demonstrated that the insertion of CO2 into iridium hydrides is a crucial step in the catalytic conversion of CO2 and H2 into formic acid. We and others have elucidated the mechanism by which CO2 inserts into six‐coordinate iridium(III) trihydrides supported by pincer ligands; these complexes are very active catalysts for CO2 hydrogenation. However, it has also been demonstrated that five‐coordinate iridium(III) dihydrides can react with CO2 and catalyze both thermal and electrochemical CO2 hydrogenation. In this work, we study the mechanism of CO2 insertion into pincer‐supported five‐coordinate iridium(III) dihydrides and four‐coordinate iridium(I) hydrides using density functional theory. The mechanisms differ slightly between the two cases. Insertion into the five‐coordinate species is a multistep process involving initial CO2 precoordination, whereas insertion into the four‐coordinate species proceeds via a single step with no prior CO2 coordination. Both of these mechanisms are different from the pathway that was recently proposed for CO2 insertion into six‐coordinate iridium(III) trihydrides. In addition, a complete pathway for catalytic CO2 hydrogenation using a five‐coordinate iridium(III) dihydride has been calculated.
Aroma characterization of flaxseed oils using headspace solid‐phase microextraction and gas chromatography‐olfactometry
Authors: Wei Changqing , Xi Wanpeng , Nie Xinyan , Liu Wenyu , Wang Qiang , Yang Beibei , Cao Dong 
Published: May 2013

SummaryFlaxseed oil (FSO) has a distinct flavor among various types of vegetable oil. However, molecular information on FSO volatiles remains limited. In this study, a total of 60 compounds of FSO pressed from three main cultivars in Xinjiang, China, were tentatively identified and then semi‐quantified by the headspace solid phase micro‐extraction gas chromatography‐mass spectrometry (HS‐SPME‐GC‐MS) technique. Thirty of them were previously unknown as volatiles in FSO. These compounds could be categorized into eight groups (with the total numbers and numbers of new compounds per group between brackets): aldehydes (20; 10), ketones (7; 4), alcohols (13; 6), carboxylic acids (8; 3), esters (3; 1), alkanes (3; 3), heterocyclic compounds (4; 2), and other compounds (2; 1). Odor‐specific magnitude estimation (OSME) analysis revealed 53 aroma active compounds in three kinds of FSO in a consensus by using GC‐O, of which (E, E)‐2,4‐pentadienal (green, oily), (E, E)‐2,4‐heptadienal (sweet, hazelnut, woody), 5‐ethyldihydro‐2(3H)‐furanone (cereal‐like), 1‐hexanol (herbaceous, woody, green), acetic acid (sour, pungent, strong), and butyrolactone (sweet, caramel), perceived with high intensity (3.0, OSME values), and are therefore considered as major contributors to the characteristic FSO odor in Xinjiang, China.Practical applications: Volatile compounds, whether major or minor, are crucial to FSO quality. Some of them make no direct contribution to the aroma, could be of important help to understand the formation and degradation of the volatiles with significant contribution to aroma, and they may additionally provide useful quality markers. The flavor of FSO varies widely, depending on fruit variety, degree of fruit ripeness, environmental conditions, growing region, and techniques of processing and storage. Therefore, the present study might be useful to identify purity or blending of FSO and may provide information for the producing conditions and the origin of the basic raw material.
The Disubstitution of Acetals to Prepare δ,δ‐Bis(aryl) β‐Keto Esters
Authors: Priebbenow Daniel L. , Zou Liang‐Hua , Becker Peter , Bolm Carsten 
Published: May 2013

AbstractAn efficient catalytic protocol for the synthesis of δ,δ‐bis(aryl)‐substituted β‐keto esters has been developed. This method involves the Lewis acid catalysed disubstitution reaction of ester‐substituted silyl enol ether acetals with a series of aromatic nucleophiles to afford valuable functionalized β‐keto esters with several sites available for further derivatisation.
Longitudinal and day‐to‐day variability in the ionosphere from lower atmosphere tidal forcing
Authors: Fang Tzu‐Wei , Akmaev Rashid , Fuller‐Rowell Tim , Wu Fei , Maruyama Naomi , Millward George 
Published: May 2013

AbstractSimulations with the global ionosphere plasmasphere model driven by whole atmosphere model winds show significant longitudinal and day‐to‐day variations in the ionospheric parameters. Under fixed solar and geomagnetic activity levels, the contributions of lower atmosphere tides to the longitudinal and day‐to‐day variability in the upper atmosphere are estimated. Larger relative variability is found in the nighttime than in the daytime, which is consistent with observations. The perturbations from the lower atmosphere contribute about half of the observed variability in the ionospheric F2 peak plasma density under moderate solar activity and geomagnetic quiet conditions. The daily variability of the equatorial vertical plasma drifts is primarily driven by the day‐to‐day amplitude changes of the migrating semidiurnal tide, while the wave‐4 and wave‐3 longitudinal variations during September are dominated by the nonmigrating diurnal eastward propagating tides with zonal wave numbers 3 and 2, respectively.
Storage and Processing of Information Using Molecules: The All‐Photonic Approach with Simple and Multi‐Photochromic Switches
Authors: Andréasson Joakim , Pischel Uwe 
Published: May 2013

AbstractThe use of photochromes for the implementation of molecular logic operations is a very promising approach toward molecular computing. This statement is based on a) the possibility of operating such molecular devices exclusively with photonic signals and b) spatiotemporally and remotely controlled switching, which is characteristic for photochromes. Herein, a brief overview of the application of simple photochromes and multi‐photochromic conjugates for the small‐scale functional integration of complicated logic circuits is given. This complements and extends efforts to design molecular photochromic memories for data storage described by many research groups worldwide.
Beginning to “Unpack” Early Childhood Mental Health Consultation: Types of Consultation Services and Their Impact on Teachers
Authors: Conners‐Burrow Nicola , McKelvey Lorraine , Sockwell Latunja , Harman Ehrentraut Jennifer , Adams Skye , Whiteside‐Mansell Leanne 
Published: May 2013

ABSTRACTThe goal of the current study was to examine the impact of the frequency of two types of early childhood mental health consultation (ECMHC) activities (time spent in the class and time spent meeting with teachers) on teacher–child interactions, use of positive classroom‐management techniques, and the intent to quit the childcare profession. We addressed these questions with a sample of 115 teachers from private childcare settings participating in a midlength (6–8 months) consultation partnership, using pre‐ and posttest data collected from structured classroom observations and teacher surveys. Results suggest that ECMHC time spent in the classroom was associated with less teacher punitiveness, permissiveness, and detachment, and more use of positive classroom‐management strategies at the posttest assessment (controlling for baseline teacher behaviors). The frequency of meetings with teachers did not impact teacher–child interactions; however, in an exploratory analysis, the frequency of meetings with the teacher was associated with a reduction in teachers’ intent to leave the profession of childcare.
Documenting Instructional Practices in a Literacy‐Infused Arts Program
Authors: Brooks Wanda , Smith Michael W. 
Published: May 2013

AbstractThis study examines the instructional practices around literacy that characterized the work of a community based arts program designed for urban adolescents. Two primary sources of data were collected: field notes on approximately 35 hours of instruction spread across seven months and interviews with the program's staff and students. Four distinct instructional episodic structures were observed: explicit instruction, collaborative or individual construction that provided time for students to engage in creative literacy and artistic activity, serial performance in which teachers are on as equal a footing as possible as students, and scaffolded practice that is informed by a belief that all can succeed can foster deep engagement in literate activity.
Towardsin vivointradermal surface enhanced Raman scattering (SERS) measurements: silver coated microneedle based SERS probe
Authors: Yuen Clement , Liu Quan 
Published: May 2013

AbstractWe propose a microneedle coated with silver (Ag) to detect analytes at low concentrations positioned at a depth of more than 700 μm below the surface of a skin phantom with absorbers and scatterers for mimicking the intradermal surface‐enhanced Raman scattering (SERS) measurements. The Ag layer in the Ag‐coated microneedle‐based probe is found to be the key to the effective detection of analytes buried inside the aforesaid phantom. Glucose concentrations ranging from 5 to 150 mM inside phantoms can be estimated with a root mean square error (RMSE) of 3.3 mM. This work shows the potential of using microneedles for simplein vivointradermal SERS measurements of analytes with clinical relevance. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tuning scaffold mechanics by laminating native extracellular matrix membranes and effects on early cellular remodeling
Authors: Amensag Salma , McFetridge Peter S. 
Published: May 2013

AbstractAt approximately 50 µm thin, the human amniotic membrane (hAM) has been shown to be a versatile biomaterial with applications ranging from ocular transplants to skin and nerve regeneration. These investigations describe laminating layers of the hAM into a multilayered, conformation creating a thicker, more robust biomaterial for applications requiring more supportive structures. Amniotic membranes were decellularized using 4 M NaCl and prepared as either flat single‐layered sheets or rolled into concentric five‐layered configurations. Constructs were seeded with human vascular smooth muscle cells and cultured over 40 days to quantify biological and mechanical changes that occurred during early remodeling events. By day 40 single‐layered constructs displayed a decreasing trend in cellular densities and glycosaminoglycan (GAG) concentration, comparative to multilayered constructs with increasing cell densities (from 9.1 to 32 × 106 cells/g) and GAG concentrations (from 6.07 to 17.4 mg/g). Oxygen diffusion was calculated and found to be sufficient to maintain cell populations through the constructs full thickness. Although an overall decrease in the modulus of elasticity was noted, the modulus in the failure range of rolled constructs stabilized at values 25 times higher than single‐layered constructs. Rolled constructs typically displayed an upregulation of contractile and matrix remodeling markers (α‐actin, SM22 and type 1 collagen, MMP‐2 respectively) indicating biological adaptation. Considerable design flexibility can be achieved by varying the number of scaffold layers, allowing the possibility of tuning the constructs physical dimensions, shape and tensile properties to suit specific targeted vascular locations. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1325–1333, 2014.
Preparation and properties of cellulose nanocrystals reinforced collagen composite films
Authors: Li Weichang , Guo Rui , Lan Yong , Zhang Yi , Xue Wei , Zhang Yuanming 
Published: May 2013

AbstractCollagen films have been widely used in the field of biomedical engineering. However, the poor mechanical properties of collagen have limited its application. Here, rod‐like cellulose nanocrystals (CNCs) were fabricated and used to reinforce collagen films. A series of collagen/CNCs films were prepared by collagen solution with CNCs suspensions homogeneously dispersed at CNCs: collagen weight ratios of 1, 3, 5, 7, and 10. The morphology of the resulting films was analyzed by scanning electron microscopy (SEM), the enhancement of the thermomechanical properties of the collagen/CNCs composites were demonstrated by thermal gravimetric analysis (TGA) and mechanical testing. Among the CNCs contents used, a loading of 7 wt % led to the maximum mechanical properties for the collagen/CNCs composite films. In addition, in vitro cell culture studies revealed that the CNCs have no negative effect on the cell morphology, viability, and proliferation and possess good biocompatibility. We conclude that the incorporation of CNCs is a simple and promising way to reinforce collagen films without impairing biocompatibility. This study demonstrates that the composite films show good potential for use in the field of skin tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1131–1139, 2014.
In vivobiocompatibility and biodegradation of a novel thin and mechanically stable collagen scaffold
Authors: Rahmanian‐Schwarz Afshin , Held Manuel , Knoeller Tabea , Stachon Susanne , Schmidt Timo , Schaller Hans‐Eberhard , Just Lothar 
Published: May 2013

AbstractThe demand for scaffolds comprised of natural materials such as collagen has increased in recent years. However, many scaffolds rely on chemical or physical modifications in order to comply with the necessary requirements for biomedical engineering. We evaluated thein vivobiocompatibility and biodegradation of a novel, thin, mechanically stable, and chemically non‐crosslinked collagen cell carrier (CCC). CCC was implanted subcutaneously into 25 adult Lewis rats and biopsies were taken on days 7, 14, 21, 42, and 84 after surgery. For histological analysis, paraffin sections of implanted skin were immunolabeled for CD68 and stained by hematoxylin–eosin and Masson–Goldner's trichrome method. Macroscopic analysis of skin surface during wound healing process showed a normal physiological reaction. Biodegradation of CCC was completed 42 days after subcutaneous implantation. Histological evaluation revealed no evidence of encapsulation, scar formation, or long‐term vascularization and inflammation. The collagen type I based biomaterial demonstrated a highin vivobiocompatibility, low irritability, complete resorption, and replacement by autologous tissue. Thein vivobiocompatibility and degradation behavior encourage for further evaluation of CCC in surgical applications and regenerative medicine. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1173–1179, 2014.
Comparison of degradation behavior and the associated bone response of ZK60 and PLLA in vivo
Authors: Qi Zheng‐Rong , Zhang Qiang , Tan Li‐Li , Lin Xiao , Yin Yi , Wang Xiu‐Li , Yang Ke , Wang Yan 
Published: May 2013

AbstractThe aim of this study was to investigate whether ZK60, an extruded magnesium alloy, reacts in vivo with an appropriate host response, and to investigate how microarc oxidation treatment influences this in vivo corrosion behavior. Twelve cylinders were machined from as‐extruded ZK60, with six cylinders treated with MAO and six left untreated; poly‐l‐lactic acid pins were used as a control to compare biocompatibility. These cylinders were implanted into the right distal femur of mice along the transepicondylar axis from the medial condyle. Microcomputerized tomography was used to quantitatively analyze corrosion in a nondestructive manner in vivo and the corrosion rate was calculated based on the volume measurements of the residual implants. The physiological response of the rats postimplantation was obtained by clinical observation and blood biochemical analysis. Histological analyses of the soft tissue around the implants were used to assess bone response in relation to the implants. The results obtained clearly indicate that the untreated ZK60 alloy showed high degradation rates in vivo, and that MAO treatment had a significant but unsatisfying effect on protecting the implant from further corrosion. Compared with PLLA, the ZK60 alloy showed good osteoconductivity and osteoinductivity, and, according to biochemical indicators, had good biocompatibility in vivo. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1255–1263, 2014.