bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil moisture and soil properties estimation in the Community Land Model with synthetic brightness temperature observations
Authors: Han Xujun , Franssen Harrie‐Jan Hendricks , Montzka Carsten , Vereecken Harry
Published: July 2014

The Community Land Model (CLM) includes a large variety of parameterizations, also for flow in the unsaturated zone and soil properties. Soil properties introduce uncertainties into land surface model predictions. In this paper, soil moisture and soil properties are updated for the coupled CLM and Community Microwave Emission Model (CMEM) by the Local Ensemble Transform Kalman Filter (LETKF) and the state augmentation method. Soil properties are estimated through the update of soil textural properties and soil organic matter density. These variables are used in CLM for predicting the soil moisture retention characteristic and the unsaturated hydraulic conductivity, and the soil texture is used in CMEM to calculate the soil dielectric constant. The following scenarios were evaluated for the joint state and parameter estimation with help of synthetic L‐band brightness temperature data assimilation: (i) the impact of joint state and parameter estimation; (ii) updating of soil properties in CLM alone, CMEM alone or both CLM and CMEM; (iii) updating of soil properties without soil moisture update; (iv) the observation localization of LETKF. The results show that the characterization of soil properties through the update of textural properties and soil organic matter density can strongly improve with assimilation of brightness temperature data. The optimized soil properties also improve the characterization of soil moisture, soil temperature, actual evapotranspiration, sensible heat flux, and soil heat flux. The best results are obtained if the soil properties are updated only. The coupled CLM and CMEM model is helpful for the parameter estimation. If soil properties are biased, assimilation of soil moisture data with only state updates increases the root mean square error for evapotranspiration, sensible heat flux, and soil heat flux.
Grain‐size sensitive rheology of orthopyroxene
Authors: Bruijn Rolf H.C. , Skemer Philip
Published: July 2014

The grain‐size sensitive rheology of orthopyroxene is investigated using data from rheological and microstructural studies. A deformation mechanism map is constructed assuming that orthopyroxene deforms by two independent mechanisms: dislocation creep and diffusion creep. The field boundary between these mechanisms is defined using two approaches. First, experimental data from Lawlis (1998), which show a deviation from non‐linear power law behavior at low stresses, are used to prescribe the location of the field boundary. Second, a new orthopyroxene grain‐size piezometer is used as a microstructural constraint to the field boundary. At constant temperature, both approaches yield sub‐parallel field boundaries, separated in grain size by a factor of only 2–5. Extrapolating to lithospheric conditions, the deformation mechanism transition occurs at a grain size of ~150–500 µm, consistent with observations from nature. As the transition from dislocation to diffusion creep may promote shear localization, grain‐size reduction of orthopyroxene may play a prominent role in plate‐boundary deformation.
Stationary points in activation energy for heat dissipated with a power law temperature‐dependent viscoelastoplastic rheology
Authors: So B.‐D. , Yuen D. A.
Published: July 2014

We report that there exist a local maximum and minimum in the activation energy Ea describing mechanical heat dissipation of olivine for a given initial temperature and amount of deformation. The stationary point for the minimum dissipation is ~200 kJ/mol lower than that for the maximum. For larger activation energy than the stationary point for maximum dissipation, plastic deformation is sharply weakened and the temperature rise disappears altogether. Higher values of the initial temperature produce a larger local maximum for activation energy. The amount of heat dissipation increases with Ea in a nonlinear manner. Our results have direct ramifications on shear zone, which is governed by the amount of mechanical heat dissipation. We have observed them over a wide range of temperature and deformation boundary conditions. Our two‐dimensional model study can provide valuable insight to enable greater predictive capability for the development of geodynamic shear zone in planetary‐scale plate tectonics.
Climate change and probabilistic scenario of streamflow extremes in an alpine region
Authors: Yang Tao , Wang Xiaoyan , Yu Zhongbo , Krysanova Valentina , Chen Xi , Schwartz Franklin W. , Sudicky Edward A.
Published: July 2014

Future projections of streamflow extremes are of paramount significance in assessing the climate impacts on social and natural systems, particularly for the Himalayan alpine region in the Tibetan Plateau known as the Asian water tower. This study strives to quantify the uncertainties from different sources in simulating future extreme flows and seeks to construct reliable scenarios of future extreme flows for the headwater catchment of the Yellow River Basin in the 21st century. The results can be formulated as follows: (1) The revised snow model based on a daily active temperature method is superior to the commonly used degree‐day method in simulating snowmelt processes. (2) In general, hydrological models contribute more uncertainties than the downscaling methods in high flow and low flow over the cryospheric alpine regions characterized by the snow‐rainfall‐induced runoff processes under most scenarios. Meanwhile, impacts to uncertainty vary with time. (3) The ultimate probability of high flow exhibits a downward trend in future by using an unconditional method, whereas positive changes in the probability of low flow are projected. The method in the work includes a variety of influence from different contributing factors (e.g., downscaling models, hydrological models, model parameters, and their simulation skills) on streamflow projection, therefore can offer more information (i.e., different percentiles of flow and uncertainty ranges) for future water resource planning compared with the purely deterministic approaches. Hence, the results are beneficial to boost our current methodologies of climate impact research in the Himalayan alpine zone.
Advanced Scale Bridging Microstructure Analysis of Single Crystal Ni‐Base Superalloys
Authors: Parsa Alireza B. , Wollgramm Philip , Buck Hinrich , Somsen Christoph , Kostka Aleksander , Povstugar Ivan , Choi Pyuck‐Pa , Raabe Dierk , Dlouhy Antonin , Müller Julian , Spiecker Erdmann , Demtroder Kathrin , Schreuer Jürgen , Neuking Klaus , Eggeler Gunther
Published: July 2014

In the present work, we show how conventional and advanced mechanical, chemical, and microstructural methods can be used to characterize cast single crystal Ni‐base superalloy (SX) plates across multiple length scales. Two types of microstructural heterogeneities are important, associated with the cast microstructure (dendrites (D) and interdendritic (ID) regions – large scale heterogeneity) and with the well‐known γ/γ′ microstructure (small scale heterogeneity). Using electron probe micro‐analysis (EPMA), we can show that elements such as Re, Co, and Cr partition to the dendrites while ID regions contain more Al, Ta, and Ti. Analytical transmission electron microscopy and atom probe tomography (APT) show that Al, Ta, and Ti partition to the γ′ cubes while γ channels show higher concentrations of Co, Cr, Re, and W. We can combine large scale (EPMA) and small‐scale analytical methods (APT) to obtain reasonable estimates for γ′ volume fractions in the dendrites and in the ID regions. The chemical and mechanical properties of the SX plates studied in the present work are homogeneous, when they are determined from volumes with dimensions, which are significantly larger than the dendrite spacing. For the SX plates (140 mm × 100 mm × 20 mm) studied in the present work this holds for the average chemical composition as well as for elastic behavior and local creep properties. We highlight the potential of HRTEM and APT to contribute to a better understanding of the role of dislocations during coarsening of the γ′ phase and the effect of cooling rates after high temperature exposure on the microstructure.
Atomic layer deposition of polyimide on microporous polyethersulfone membranes for enhanced and tunable performances
Authors: Sheng Ting , Chen He , Xiong Sen , Chen Xiaoqiang , Wang Yong
Published: July 2014

Atomic layer deposition (ALD) of polyimide (PI) is explored to tune the separation properties of microporous polyethersulfone (PES) membranes and also to improve their mechanic and thermal stability. Conformal and uniform thin layers of PI are deposited along the pore wall throughout the entire PES membrane instead of forming a top layer merely on the membrane surface. With increasing ALD cycles, the pore size of the PES membrane is progressively reduced, leading to increased retention. The permeation is correspondingly decreased but its drop is less pronounced than the increase of retention. For example, the retention to 23‐nm silica nanospheres is significantly increased from nearly zero to 60% after 3000 ALD cycles, whereas the water flux is moderately decreased by 54%. Moreover, ALD of PI evidently enhances the mechanical strength and thermal resistance of the PES membrane as PI tightly wraps the skeleton of the membrane. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3614–3622, 2014
The historical Coffin–Lowry syndrome family revisited: Identification of two novel mutations of RPS6KA3 in three male patients
Authors: Nishimoto Hiromi Koso , Ha Kyungsoo , Jones Julie R. , Dwivedi Alka , Cho Hyun‐Min , Layman Lawrence C. , Kim Hyung‐Goo
Published: July 2014

Coffin–Lowry syndrome (CLS) is a rare X‐linked dominant disorder characterized by intellectual disability, craniofacial abnormalities, short stature, tapering fingers, hypotonia, and skeletal malformations. CLS is caused by mutations in the Ribosomal Protein S6 Kinase, 90 kDa, Polypeptide 3 (RPS6KA3) gene located at Xp22.12, which encodes Ribosomal S6 Kinase 2 (RSK2). Here we analyzed RPS6KA3 in three unrelated CLS patients including one from the historical Coffin–Lowry syndrome family and found two novel mutations. To date, over 140 mutations in RPS6KA3 have been reported. However, the etiology of the very first familial case, which was described in 1971 by Lowry with detailed phenotype and coined the term CLS, has remained unknown. More than 40 years after the report, we succeeded in identifying deposited fibroblast cells from one patient of this historic family and found a novel heterozygous 216 bp in‐frame deletion, encompassing exons 15 and 16 of RPS6KA3. Drop episodes in CLS patients were reported to be associated with truncating mutations deleting the C‐terminal kinase domain (KD), and only one missense mutation and one single basepair duplication involving the C‐terminal KD of RSK2 in the patients with drop episode have been reported thus far. Here we report the first in‐frame deletion in C‐terminal KD of RPS6KA3 in a CLS patient with drop episodes. © 2014 Wiley Periodicals, Inc.
Sildenafil does not improve cardiomyopathy in Duchenne/Becker muscular dystrophy
Authors: Leung Doris G. , Herzka Daniel A. , Thompson W. Reid , He Bing , Bibat Genila , Tennekoon Gihan , Russell Stuart D. , Schuleri Karl H. , Lardo Albert C. , Kass David A. , Thompson Richard E. , Judge Daniel P. , Wagner Kathryn R.
Published: July 2014

Objective

Duchenne and Becker muscular dystrophies (DBMD) are allelic disorders caused by mutations in dystrophin. Adults with DBMD develop life‐threatening cardiomyopathy. Inhibition of phosphodiesterase 5 (PDE5) improves cardiac function in mouse models of DBMD. To determine whether the PDE5‐inhibitor sildenafil benefits human dystrophinopathy, we conducted a randomized, double‐blind, placebo‐controlled trial (ClinicalTrials.gov, number NCT01168908).

Methods

Adults with DBMD and cardiomyopathy (ejection fraction ≤ 50%) were randomized to receive sildenafil (20mg 3× daily) or placebo for 6 months. All subjects received an additional 6 months of open‐label sildenafil. The primary endpoint was change in left ventricular end‐systolic volume (LVESV) on cardiac magnetic resonance imaging. Secondary cardiac endpoints, skeletal muscle function, and quality of life were also assessed.

Results

An interim analysis (performed after 15 subjects completed the blinded phase) revealed that 29% (4 of 14) of subjects had a ≥10% increase in LVESV after 6 months of sildenafil compared to 13% (1 of 8) of subjects receiving placebo. Subjects with LVESV > 120ml at baseline were more likely to worsen at 12 months regardless of treatment assignment (p = 0.035). Due to the higher number of subjects worsening on sildenafil, the data and safety monitoring board recommended early termination of the study. There were no statistically significant differences in outcome measures between treatment arms.

Interpretation

Due to the small sample size, comparisons between groups must be interpreted with caution. However, this trial suggests that sildenafil is unlikely to improve cardiac function in adults with DBMD. Ann Neurol 2014;76:541–549
Enantioselective Biomimetic Total Syntheses of Kuwanons I and J and Brosimones A and B
Authors: Han Jianguang , Li Xia , Guan Yong , Zhao Wenjun , Wulff William D. , Lei Xiaoguang
Published: July 2014

The first enantioselective total syntheses of prenylflavonoid Diels–Alder natural products (−)‐kuwanon I, (+)‐kuwanon J, (−)‐brosimone A, and (−)‐brosimone B have been accomplished from a common intermediate based on a concise synthetic strategy. Key elements of the synthesis include a biosynthesis‐inspired asymmetric Diels–Alder cycloaddition mediated by a chiral ligand/boron Lewis acid, as well as a process involving regioselective Schenck ene reaction, reduction, and dehydration to realize a biomimetic dehydrogenation for generation of the required diene precursor. Furthermore, a remarkable tandem inter‐/intramolecular asymmetric Diels–Alder cycloaddition process was applied for the synthesis of (−)‐brosimone A.
Zirconium Allyl Complexes as Participants in Zirconocene‐Catalyzed α‐Olefin Polymerizations
Authors: Babushkin Dmitrii E. , Panchenko Valentina N. , Brintzinger Hans‐Herbert
Published: July 2014

In a search for the hitherto elusive catalyst resting state(s) of zirconocene‐based olefin polymerization catalysts, a combination of UV/Vis and NMR spectrometric methods reveals that polymer‐carrying cationic Zr allyl complexes make up about 90 % of the total catalyst concentration. Other catalyst species that take part in the polymerization process have to be generated from this allyl pool into which they appear to relapse rather frequently.
Efficient cyanation of aryl halide with K4[Fe(CN)6]⋅3H2O catalyzed by a P–O bidentate chelate palladium complex under air
Authors: Fu Leiqing , Li Xiaogang , Zhu Qiming , Chen Sanbao , Kang Yanping , Guo Mengping
Published: July 2014

Cyanation of aryl halide with K4[Fe(CN)6]⋅3H2O has been carried out in the presence of a high‐activity catalyst: an air‐stable P–O bidentate chelate palladium complex. This method is applicable to both activated and deactivated aryl halides, and even a variety of aromatic nitriles are obtained in good yields under aerobic conditions. Copyright © 2014 John Wiley & Sons, Ltd.
Crystalline phase transformation of polytetrafluoroethylene in a fatigue test
Authors: Yang S. B. , Pu X. X. , Huang Z. Y. , Wang Q. Y.
Published: July 2014

In this study, we aimed to characterize the mechanical response of polytetrafluoroethylene (PTFE) laminates under a tension–tension load‐control fatigue test (frequency = 5 Hz, load ratio = 0) and provided an analysis of the failure patterns of the PTFE material with consideration of crystalline phase transformation. In the final results, the evolution of the cyclic creep strain and stress–number of cycles to failure (S–N) curves presented duplex properties accompanying the fatigue life increasing to high cycles (cycle fatigue > 105). A simple phenomenological damage index was defined in this study to describe the cyclic creep process. Additionally, the scanning electronic machine investigation suggested that local fibrosis caused by crystalline phase transformation to phase I led to the initiation of fatigue crack, and the fiber formation and orientation was found to be beneficial to a higher tensile strength and better resistance to crack propagation. The aspect of cyclic‐load‐induced crystallization was observed by the microfocus hard X‐ray diffraction beamline from a new insight. The crystalline phase transformation led to a gradient distribution of crystallinity and lateral crystallite size along the crack propagation direction. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41113.
Dielectric and thermal studies of segmental dynamics in silica/PDMS and silica/titania/PDMS nanocomposites
Authors: Sulym Iryna , Klonos Panagiotis , Borysenko Mykola , Pissis Polycarpos , Gun'ko Vladimir M.
Published: July 2014

Effects of silica and silica/titania nanoparticles on glass transition and segmental dynamics of poly(dimethylsiloxane) (PDMS) were studied for composites of a core–shell type using differential scanning calorimetry, thermally stimulated depolarization current, and dielectric relaxation spectroscopy techniques. Strong interactions between the filler and the polymer suppress crystallinity (Tc, Xc) and affect significantly the evolution of the glass transition in the nanocomposites. The segmental relaxation associated with the glass transition consists of three contributions, arising, in the order of decreasing mobility, from the bulk (unaffected) amorphous polymer fraction (α relaxation), from polymer chains restricted between condensed crystal regions (αc relaxation), and from the semi‐bound polymers in an interfacial layer with strongly reduced mobility due to interactions with surface hydroxyls of silica and silica/titania nanoparticles (α′ relaxation). The evolution of surface affected CH3 groups, as well as the degree of interaction of PDMS molecules with surface hydroxyl groups as a function of treatment temperature, was assessed by Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis. The effectiveness of silica/PDMS and silica/titania/PDMS nanocomposites as hydrophobic coatings was investigated by static contact angle measurements. It was shown that the presence of titania nanoparticles and adsorbed PDMS promotes the hydrophobic properties of the PDMS coating after treatment in the 80–650°C range. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41154.
Regulation of Early Cartilage Destruction in Inflammatory Arthritis by Death Receptor 3
Authors: Wang Eddie C. Y. , Newton Zarabeth , Hayward Olivia A. , Clark Stephen R. , Collins Fraser , Perks William V. , Singh Ravinder K. , Twohig Jason P. , Williams Anwen S.
Published: July 2014

Objective

To investigate the role of death receptor 3 (DR‐3) and its ligand tumor necrosis factor–like molecule 1A (TL1A) in the early stages of inflammatory arthritis.

Methods

Antigen‐induced arthritis (AIA) was generated in C57BL/6 mice deficient in the DR‐3 gene (DR3−/−) and their DR3+/+ (wild‐type) littermates by priming and intraarticular injection of methylated bovine serum albumin. The joints were sectioned and analyzed histochemically for damage to cartilage and expression of DR3, TL1A, Ly‐6G (a marker for neutrophils), the gelatinase matrix metalloproteinase 9 (MMP‐9), the aggrecanase ADAMTS‐5, and the neutrophil chemoattractant CXCL1. In vitro production of MMP‐9 was measured in cultures from fibroblasts, macrophages, and neutrophils following the addition of TL1A and other proinflammatory stimuli.

Results

DR3 expression was up‐regulated in the joints of wild‐type mice following generation of AIA. DR3−/− mice were protected against cartilage damage compared with wild‐type mice, even at early time points prior to the main accumulation of Teff cells in the joint. Early protection against AIA in vivo correlated with reduced levels of MMP‐9. In vitro, neutrophils were major producers of MMP‐9, while neutrophil numbers were reduced in the joints of DR3−/− mice. However, TL1A neither induced MMP‐9 release nor affected the survival of neutrophils. Instead, reduced levels of CXCL1 were observed in the joints of DR3−/− mice.

Conclusion

DR‐3 drives early cartilage destruction in the AIA model of inflammatory arthritis through the release of CXCL1, maximizing neutrophil recruitment to the joint and leading to enhanced local production of cartilage‐destroying enzymes.
Use of politeness strategies in signed open peer review
Authors: Nobarany Syavash , Booth Kellogg S.
Published: July 2014

Scholarly peer review is a complex collaborative activity that is increasingly supported by web‐based systems, yet little is known about how reviewers and authors interact in such environments, how criticisms are conveyed, or how the systems may affect the interactions and use of language of reviewers and authors. We looked at one aspect of the interactions between reviewers and authors, the use of politeness in reviewers' comments. Drawing on Brown and Levinson's (1987) politeness theory, we analyzed how politeness strategies were employed by reviewers to mitigate their criticisms in an open peer‐review process of a special track of a human‐computer interaction conference. We found evidence of frequent use of politeness strategies and that open peer‐review processes hold unique challenges and opportunities for using politeness strategies. Our findings revealed that less experienced researchers tended to express unmitigated criticism more often than did experienced researchers, and that reviewers tended to use more positive politeness strategies (e.g., compliments) toward less experienced authors. Based on our findings, we discuss implications for research communities and the design of peer‐reviewing processes and the information systems that support them.
Current and future trends in food waste valorization for the production of chemicals, materials and fuels: a global perspective
Authors: Lin Carol Sze Ki , Koutinas Apostolis A. , Stamatelatou Katerina , Mubofu Egid B. , Matharu Avtar S. , Kopsahelis Nikolaos , Pfaltzgraff Lucie A. , Clark James H. , Papanikolaou Seraphim , Kwan Tsz Him , Luque Rafael
Published: July 2014

Food waste is currently generated in significant quantities worldwide. While most of this has generally few uses different from landfilling or composting, advanced valorization alternatives should be developed to maximize the value derived from such an important waste source. This contribution aims to illustrate a series of examples and current valorization strategies proposed in different countries in order to tackle the food waste issue. Proposed processing schemes involve biorefinery approaches based on both chemical and biological technologies. Important legislation aspects in different countries are also presented. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd
Comparing translational population‐PBPK modelling of brain microdialysis with bottom‐up prediction of brain‐to‐plasma distribution in rat and human
Authors: Ball Kathryn , Bouzom François , Scherrmann Jean‐Michel , Walther Bernard , Declèves Xavier
Published: July 2014

The prediction of brain extracellular fluid (ECF) concentrations in human is a potentially valuable asset during drug development as it can provide the pharmacokinetic input for pharmacokinetic–pharmacodynamic models. This study aimed to compare two translational modelling approaches that can be applied at the preclinical stage of development in order to simulate human brain ECF concentrations. A population‐PBPK model of the central nervous system was developed based on brain microdialysis data, and the model parameters were translated to their corresponding human values to simulate ECF and brain tissue concentration profiles. In parallel, the PBPK modelling software Simcyp was used to simulate human brain tissue concentrations, via the bottom‐up prediction of brain tissue distribution using two different sets of mechanistic tissue composition‐based equations. The population‐PBPK and bottom‐up approaches gave similar predictions of total brain concentrations in both rat and human, while only the population‐PBPK model was capable of accurately simulating the rat ECF concentrations. The choice of PBPK model must therefore depend on the purpose of the modelling exercise, the in vitro and in vivo data available and knowledge of the mechanisms governing the membrane permeability and distribution of the drug. Copyright © 2014 John Wiley & Sons, Ltd.
SGLT2 inhibitor lowers serum uric acid through alteration of uric acid transport activity in renal tubule by increased glycosuria
Authors: Chino Yukihiro , Samukawa Yoshishige , Sakai Soichi , Nakai Yasuhiro , Yamaguchi Jun‐ichi , Nakanishi Takeo , Tamai Ikumi
Published: July 2014

Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UEUA) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UEUA, suggesting that SUA decreased as a result of the increase in the UEUA. The increase in UEUA was correlated with an increase in urinary d‐glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UEUA is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and d‐glucose. It was observed that the efflux of [14C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans‐stimulated by 10 mm d‐glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [14C]UA by oocytes was cis‐inhibited by 100 mm d‐glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UEUA could potentially be increased by luseogliflozin‐induced glycosuria, with alterations of UA transport activity because of urinary glucose. © 2014 The Authors. Biopharmaceutics & Drug Disposition. Published by John Wiley & Sons Ltd.
Luminescence properties of red‐emission Mg4Nb2O9:Eu3+ phosphor
Authors: Cao Renping , Cao Chunyan , Yu Xiaoguang , Qiu Jianrong
Published: July 2014

Red‐emitting Mg4Nb2O9:Eu3+ phosphor is synthesized via a solid‐state reaction method in air, and its crystal structure and luminescence are investigated. The phosphor can be excited efficiently by ~ 395 nm light, coupled well with a ~ 395 nm near‐ultraviolet chip and emits red light at ~ 613 nm with sharp spectra due to 5D0 → 7 F2 transition of the Eu3+ ion. Mg4Nb2O9:Eu3+ phosphor sintered at 1350 ºC shows Commission international de I'Eclairage (CIE) chromaticity coordinates of x = 0.6354, y = 0.3592, and is a potential red‐emitting phosphor candidate for white light‐emitting diodes (W‐LEDs) under ~ 395 nm near‐ultraviolet LED chip excitation. Copyright © 2014 John Wiley & Sons, Ltd.
Removal of cleavage slow points from affinity tags used in the IMAC purification of recombinant proteins
Authors: Mooney Jane T. , Fredericks Dale , Christensen Thorkild , Hearn Milton T. W.
Published: July 2014

The complete enzymatic removal of affinity tags from tagged recombinant proteins is often required but can be challenging when slow points for cleavage exist. This study documents a general approach to remove N‐terminal tags from recombinant proteins specifically designed to be efficiently captured by IMAC resins. In particular, site‐directed mutagenesis procedures have been used to modify the amino acid sequence of metal binding tags useful in IMAC purifications of recombinant proteins with the objective to increase cleavage efficiency with the exopeptidase, dipeptidyl aminopeptidase 1. These tags were specifically developed for application with borderline metal ions, such as Ni2+ or Cu2+ ions, chelated to the immobilized ligands, 1,4,7‐triazacyclononane (tacn) and its analogs. Due to the ability to control cleavage site structure and accessibility via site directed mutagenesis methods, these procedures offer considerable scope to obtain recombinant proteins with authentic native N‐termini, thus avoiding any impact on structural stability, humoral and cellular immune responses, or other biological functions. Collectively, these IMAC‐based methods provide a practical alternative to other procedures for the purification of recombinant proteins with tag removal. Overall, this approach is essentially operating as an integrated down‐stream purification capability.
Humanized antibody neutralizing 2009 pandemic H1N1 virus
Authors: Shembekar Nachiket , Mallajosyula Vamsee V Aditya , Chaudhary Piyush , Upadhyay Vaibhav , Varadarajan Raghavan , Gupta Satish Kumar
Published: July 2014

The 2009 pandemic H1N1 S‐OIV (swine origin influenza A virus) caused noticeable morbidity and mortality worldwide. In addition to vaccine and antiviral drug therapy, the use of influenza virus neutralizing monoclonal antibodies (MAbs) for treatment purposes is a viable alternative. We previously reported the isolation of a high affinity, potently neutralizing murine MAb MA2077 against 2009 pandemic H1N1 virus. We describe here the humanization of MA2077 and its expression in a mammalian cell line. Six complementarity‐determining regions (CDRs) of MA2077 were grafted onto the human germline variable regions; along with six and eight back mutations in the framework of heavy and light chains, respectively, pertaining to the vernier zone and interchain packing residues to promote favorable CDR conformation and facilitate antigen binding. The full length humanized antibody, 2077Hu2, expressed in CHO‐K1 cells, showed high affinity to hemagglutinin protein (KD = 0.75 ± 0.32 nM) and potent neutralization of pandemic H1N1 virus (IC50 = 0.17 μg/mL), with marginally higher IC50 as compared to MA2077 (0.08 μg/mL). In addition, 2077Hu2 also retained the epitope specificity for the “Sa” antigenic site on pandemic HA. To the best of our knowledge, this is the first report of a humanized neutralizing antibody against pandemic H1N1 virus.
The Importance of the Diverse Drivers and Types of Environmental Innovation for Firm Performance
Authors: Doran Justin , Ryan Geraldine
Published: July 2014

Today, firms are faced with a number of environmental challenges, such as global warming, pollution control and declining natural resources. While there is increasing pressure to deliver environmentally friendly products and services, little is known about what drives the many different types of environmental innovation, or how such pursuits' impact firm performance. Using a sample of 2181 firms, this paper examines the factors that drive nine different types of eco‐innovation in Ireland, and assesses how such innovations impact firm performance. We find that, while demand‐side, supply‐side and regulatory drivers impact on the likelihood of a firm engaging in eco‐innovation, the relative magnitudes of these impacts vary across the types of eco‐innovation considered. Moreover, we find that only two of the nine types of eco‐innovation positively impact firm performance. The results point to regulation and customer pressure as viable mechanisms through which firms can be encouraged to eco‐innovate. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment
Bcl‐2 down‐regulation by small interfering RNA induces Beclin1‐dependent autophagy in human SGC‐7901 cells
Authors: Du Yun , Ji Xiaokun
Published: July 2014

While Bcl‐2 protein is involved in the regulation of apoptosis, recent research showed that Beclin1, described as the essential autophagy effector and haploinsufficient tumor suppressor, was originally isolated as a Bcl‐2 interacting protein. Beclin1 interacts with Bcl‐2 through a BH3 domain; nevertheless, the function of the anti‐apoptotic gene, Bcl‐2, in autophagy is not well understood. We explored the role of Bcl‐2 in autophagy in human SGC‐7901 cells in which Bcl‐2 is overexpressed. Knockdown of Bcl‐2 by small interfering RNA in human SGC‐7901 cells downregulated Bcl‐2 protein levels ∼82% and induced autophagy. Beclin1 protein, the first identified autophagy gene product, was induced by as much as 58%. Transmission electron microscopy and DNA fragmentation assay showed that autophagy was enhanced, but not apoptosis, in Bcl‐2 siRNA treated cells. The results provide evidence that knockout the anti‐apoptotic gene Bcl‐2 induces autophagy in SGC‐7901 cells and Bcl‐2 specific siRNA may be used as a potential therapeutic strategy in gastric cancer cells that overexpress Bcl‐2.
Role of p53 in preadipocyte differentiation
Authors: Huang Qiong , Liu Menglan , Du Xinli , Zhang Rihua , Xue Yi , Zhang Yuanyuan , Zhu Weidong , Li Dong , Zhao Allan , Liu Yun
Published: July 2014

Insulin resistance, diabetes and many kinds of cancers are common in overweight and obese individuals. The tumor suppressor p53 is important in securing genetic stability, but its role in the regulation of metabolic processes and cell differentiation remains unclear. We have investigated the role of p53 in adipocyte differentiation. Using 3T3‐L1 cells, a mouse embryonic fibroblast preadipocyte model and DIO rat model, p53 expression and function during adipocyte differentiation were investigated. p53 expression increased on the second and fourth day of adipocyte differentiation and decreased thereafter. Its overexpression in 3T3‐L1 preadipocytes markedly reduced adipogenesis and marker gene expression. p53 activity was weakened in DIO rat abdominal adipose tissue because of an decreased expression of its activated phosphorylated form. In contrast, p53 knockout enhanced adipogenesis and the expression of marker genes, but significantly reduced insulin‐stimulated Akt phosphorylation. These results indicate that p53 partly suppresses preadipocyte differentiation and adipogenesis by regulating adipocyte gene expression and Akt signaling.
Isobutane Dehydrogenation over Metal (Fe, Co, and Ni) Oxide and Sulfide Catalysts: Reactivity and Reaction Mechanism
Authors: Wang Guowei , Gao Chuancheng , Zhu Xiaolin , Sun Yanan , Li Chunyi , Shan Honghong
Published: July 2014

Silica‐supported metal oxide and sulfide catalysts of Fe, Co, and Ni were evaluated comparatively for the catalytic dehydrogenation of isobutane. The results of the activity test and temperature‐programmed reduction of hydrogen characterization indicate that metal oxides, except Fe2O3, are easily reduced to metal ensembles, which are extremely active for alkane hydrogenolysis and lead to the formation of a considerable amount of methane and coke. However, the dehydrogenation performance was significantly improved after sulfidation treatment. The introduction of sulfur affects the catalysts in two ways: one is the geometric effect, which dilutes the aggregated metallic species and reduces hydrogenolysis activity, and the other is the electronic effect, which facilitates the desorption of olefin and increases the product selectivity. Moreover, the reaction mechanism is explored by using the proposed model of the interaction between isobutane and sulfide catalysts. Finally, sulfur loss and partial coke deposition are determined to be the main reasons for catalyst deactivation.
Synthesis and Solution Studies of Silver(I)‐Assembled Porphyrin Coordination Cages
Authors: Durot Stéphanie , Flamigni Lucia , Taesch Julien , Dang Tung T. , Heitz Valérie , Ventura Barbara
Published: July 2014

The synthesis and the characterization of two porphyrin coordination cages are reported. The design of the cage formation is based on the coordination of silver(I) ions to the pyridyl units of 3‐pyridyl appended porphyrins. 1H/109Ag NMR spectroscopy, and diffusion‐ordered spectroscopy (DOSY) experiments demonstrate that both the free base porphyrin 2H‐TPyP and the Zn‐porphyrin Zn‐TPyP form the closed cages, [Ag4(2H‐TPyP)2]4+ and [Ag4(Zn‐TPyP)2]4+, respectively, upon addition of two equivalents of Ag+. The complexation processes are characterized in details by means of absorption and emission spectroscopy in diluted CH2Cl2 solutions. The data are discussed in the frame of the point‐dipole exciton coupling theory; the two porphyrin monomers, in fact, experience a rigid face‐to‐face geometry in the cages and a weak inter‐porphyrin exciton coupling. An intermediate species is observed, for Zn‐TPyP, in a porphyrin/Ag+ stoichiometric ratio of about 1:0.5 and is tentatively ascribed to an oblique open form. The occurrence of a photoinduced electron‐transfer reaction within the cages is excluded on the basis of the experimental outcomes and thermodynamic evaluations. Photophysical experiments evidence different reactivities of singlet and triplet excited states in the assemblies. A lower fluorescence quantum yield and triplet formation is discussed in relation to the constrained geometry of the complexes. Unusually long triplet excited state lifetimes are measured for the assemblies.
Stereoselective Aminoxylation of Biradical Titanium Enolates with TEMPO
Authors: Gómez‐Palomino Alejandro , Pellicena Miquel , Romo Juan Manuel , Solà Ricard , Romea Pedro , Urpí Fèlix , Font‐Bardia Mercè
Published: July 2014

A highly efficient and straightforward aminoxylation of titanium(IV) enolates from (S)‐N‐acyl‐4‐benzyl‐5,5‐dimethyl‐1,3‐oxazolidin‐2‐ones with TEMPO has been developed. A wide array of functional groups on the acyl moiety, including alkyl and aryl substituents, olefins, esters, or α‐cyclopropyl, as well as α‐trifluoromethyl groups, are well tolerated. This transformation can therefore produce the α‐aminoxylated adducts in excellent yields with high diastereomeric ratios (d.r.). In turn, parallel additions to the α,β‐unsaturated N‐acyl counterparts give the corresponding γ‐adducts with complete regioselectivity in moderate to good yields. Removal of the piperidinyl moiety or the chiral auxiliary converts the resultant adducts into enantiomerically pure α‐hydroxy carboxyl derivatives, alcohols, or esters in high yields under mild conditions. Finally, a new mechanistic model based on the biradical character of the titanium(IV) enolates has been proposed.
Semiconductor and Metallic Core–Shell Nanostructures: Synthesis and Applications in Solar Cells and Catalysis
Authors: Kim Mee Rahn , Xu Zhenhe , Chen Guozhu , Ma Dongling
Published: July 2014

Nano‐heterostructures have attracted great attention due to their extraordinary properties beyond those of their single‐component counterparts. This review focuses on a specific type of hybrid structures: core–shell structures. In particular, we present and discuss the recent wet‐chemical synthesis approaches for semiconductor and metallic core–shell nanostructures, and their relevant properties and potential applications in photovoltaics and catalysis, respectively.
Eaton’s Reagent‐Mediated Domino π‐Cationic Arylations of Aromatic Carboxylic Acids to Iasi‐Red Polymethoxylated Polycyclic Aromatic Hydrocarbons: Products with Unprecedented Biological Activities as Tubulin Polymerization Inhibitors
Authors: Ghinet Alina , Gautret Philippe , Hijfte Nathalie Van , Ledé Bertrand , Hénichart Jean‐Pierre , Bîcu Elena , Darbost Ulrich , Rigo Benoît , Daïch Adam
Published: July 2014

A rapid domino π‐cationic arylation of aromatic carboxylic acids, mediated by Eaton’s reagent, has been developed for the synthesis of Iasi‐red polymethoxylated polycyclic aromatic hydrocarbons (PAHs). This route is currently the easiest method to obtain such popular PAH compounds, which bear in addition numerous methoxy groups. The domino process was generalized, the structure of the obtained red products and the mechanism of their formations were elucidated, and some of their photophysical properties were determined. Newly synthesized polymethoxylated‐PAHs were tested for their interaction with tubulin polymerization as well as for their cytotoxicity on a panel of NCI‐60 human cancer cell lines. Interestingly, one of these rubicene derivatives exhibited remarkable cytotoxicity in vitro, including inhibition of leukemia, colon, melanoma, CNS, and ovarian cancer cell lines with GI50 values in the low nanomolar range (GI50<10 nM).
Configuration‐ and Conformation‐Dependent Electronic‐Structure Variations in 1,4‐Disubstituted Cyclohexanes Enabled by a Carbon‐to‐Silicon Exchange
Authors: Emanuelsson Rikard , Löfås Henrik , Wallner Andreas , Nauroozi Djawed , Baumgartner Judith , Marschner Christoph , Ahuja Rajeev , Ott Sascha , Grigoriev Anton , Ottosson Henrik
Published: July 2014

Cyclohexane, with its well‐defined conformers, could be an ideal force‐controlled molecular switch if it were to display substantial differences in electronic and optical properties between its conformers. We utilize σ conjugation in heavier analogues of cyclohexanes (i.e. cyclohexasilanes) and show that 1,4‐disubstituted cyclohexasilanes display configuration‐ and conformation‐dependent variations in these properties. Cis‐ and trans‐1,4‐bis(trimethylsilylethynyl)cyclohexasilanes display a 0.11 V difference in their oxidation potentials (computed 0.11 V) and a 0.34 eV difference in their lowest UV absorption (computed difference between first excitations 0.07 eV). This is in stark contrast to differences in the corresponding properties of analogous all‐carbon cyclohexanes (computed 0.02 V and 0.03 eV, respectively). Moreover, the two chair conformers of the cyclohexasilane trans isomer display large differences in electronic‐structure‐related properties. This enables computational design of a mechanically force‐controlled conductance switch with a calculated single‐molecule ON/OFF ratio of 213 at zero‐bias voltage.
Switching of Single‐Molecule Magnetic Properties of TbIII–Porphyrin Double‐Decker Complexes and Observation of Their Supramolecular Structures on a Carbon Surface
Authors: Inose Tomoko , Tanaka Daisuke , Tanaka Hirofumi , Ivasenko Oleksandr , Nagata Toshi , Ohta Yusuke , De Feyter Steven , Ishikawa Naoto , Ogawa Takuji
Published: July 2014

Double‐decker complexes based on single‐molecule magnets (SMMs) are a class of highly promising molecules for applications in molecular spintronics, wherein control of both the ligand oxidative states and the 2D supramolecular structure on carbon materials is of great importance. This study focuses on the synthesis and study of 2,3,7,8,12,13,17,18‐octaethylporphyrin (OEP)–TbIII double‐decker complexes with different electronic structures comprising protonated, anionic, and radical forms. Magnetic susceptibility measurements revealed that only the anionic and radical forms of the OEP–TbIII double‐decker complexes exhibited SMM properties. The barrier heights for magnetic moment reversal were estimated to be 207 and 215 cm−1 for the anionic and radical forms, respectively. Scanning tunneling microscopy (STM) investigations revealed that these OEP–TbIII complexes form well‐ordered monolayers upon simple dropcasting from dilute dichloromethane solutions. All three complexes form an isomorphic pseudo‐hexagonal 2D pattern, regardless of the differences in the electronic structures of their porphyrin–Tb cores. This finding is of interest for SMM technology as ultrathin films of these materials undergoing chemical transformations will not require any detrimental reorganization. Finally, we demonstrate self‐assembly of the protonated 5,15‐bisdodecylporphyrin (BDP)–TbIII double‐decker complex as an example of successful supramolecular design to achieve controlled alignment of SMM‐active sites.
Outstanding Chiroptical Properties: A Signature of Enantiomerically Pure Alleno–Acetylenic Macrocycles and Monodisperse Acyclic Oligomers
Authors: Donckele Etienne J. , Gidron Ori , Trapp Nils , Diederich Francois
Published: July 2014

A second series of shape‐persistent alleno–acetylenic macrocycles and monodisperse acyclic oligomers with conformationally less flexible backbones were synthesized in enantiomerically pure form by short, high‐yielding routes starting from optically active 1,3‐diethynylallenes. All seven stereoisomers—two pairs of enantiomers and three achiral stereoisomers—in the macrocyclic series were separated and configurationally assigned. The electronic circular dichroism (ECD) spectra of the D2‐symmetric, (P,P,P,P)‐ and (M,M,M,M)‐configured macrocycles display remarkably intense chiroptical responses. A strong amplification of chirality is observed in the acyclic oligomeric series. Their preference for helical secondary structures of one handedness was supported by X‐ray analysis and computational studies. This new set of data provides proof that outstanding ECD responses are a hallmark of alleno–acetylenic macrocyclic and acyclic oligomeric chromophores.
[(p‐Cymene)RuCl2]2: An Efficient Catalyst for Highly Regioselective Allylic Alkylations of Chelated Amino Acid Ester Enolates
Authors: Bayer Anton , Kazmaier Uli
Published: July 2014

Chelated amino acid ester enolates are excellent nucleophiles for ruthenium‐catalyzed allylic alkylations. Although [Cp*Ru(MeCN)3]PF6 was found to be the most reactive catalyst investigated, with the resulting allyl complexes reacting at temperatures as low as −78 °C, unfortunately the process took place with only moderate regio‐ and diastereoselectivity. In contrast, [(p‐cymene)RuCl2]2 allowed allylations to be performed with a high degree of regioretention. Secondary allyl carboxylates with a terminal double bond were found to be the most reactive substrates, giving rise to the branched amino acids with perfect regioretention and chirality transfer. In this case, no isomerization of the Ru–allyl complex formed in situ was observed, in contrast to the analogues palladium complexes. This isomerization‐free protocol can also be used for the synthesis of (Z)‐configured γ,δ‐unsaturated amino acid derivatives, starting from (Z)‐allylic substrates. Here, the more reactive phosphates were found to be superior to the carboxylates, providing the required amino acids in almost quantitative yield with perfect regio‐ and stereoretention. Therefore, the Ru‐catalyzed allylation reactions are well positioned to overcome the drawbacks of Pd‐catalyzed processes.
UV‐Cured, Platinum‐Free, Soft Poly(dimethylsiloxane) Networks
Authors: Goswami K. , Skov A. L , Daugaard A. E.
Published: July 2014

To overcome the drawbacks exhibited by platinum‐catalyzed curing of silicones, photoinitiated thiol–ene cross‐linking of high‐molecular‐weight poly(dimethylsiloxane) (PDMS) prepolymers has been investigated as a pathway to novel soft PDMS networks, based on commercially available starting materials was developed. Through a fast and efficient two‐step cross‐linking reaction highly flexible PDMS elastomers were prepared.
Phosphate‐Triggered Self‐Assembly of N‐[(Uracil‐5‐yl)methyl]urea: A Minimalistic Urea‐Derived Hydrogelator
Authors: Kleinsmann Alexander J. , Weckenmann Nicole M. , Nachtsheim Boris J.
Published: July 2014

N‐[(Uracil‐5‐yl)methyl]urea is reported as a minimalistic low‐molecular‐weight hydrogelator (LMWHG). The unusual phosphate‐induced assembly of this compound has been thoroughly investigated by IR, UV/Vis, and NMR spectroscopy, electron microscopy, and rheological experiments. This rare example of an anion‐triggered urea‐based LMWHG is the first example of a pyrimidine‐ and urea‐containing molecule that can be forced into self‐assembly in aqueous solution without additional aromatic or lipophilic groups. The gelator/phosphate ratio within the hydrogel was successfully determined by 31P MAS NMR spectroscopy. The hydrogel exhibits a very fast and repeatable self‐healing property, and remarkable G′ values. The viscoelastic properties of the hydrogel can easily be tuned by variation of the phosphate ratio.