bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Intrinsic Hydrophobicity Scale for Amino Acids and Its Application to Fluorinated Compounds
Authors: Hoffmann Waldemar , Langenhan Jennifer , Huhmann Susanne , Moschner Johann , Chang Rayoon , Accorsi Matteo , Seo Jongcheol , Rademann Jörg , Meijer Gerard , Koksch Beate , Bowers Michael T. , von Helden Gert , Pagel Kevin 
Published: April 2019

AbstractMore than 100 hydrophobicity scales have been introduced, with each being based on a distinct condensed‐phase approach. However, a comparison of the hydrophobicity values gained from different techniques, and their relative ranking, is not straightforward, as the interactions between the environment and the amino acid are unique to each method. Here, we overcome this limitation by studying the properties of amino acids in the clean‐room environment of the gas phase. In the gas phase, entropic contributions from the hydrophobic effect are by default absent and only the polarity of the side chain dictates the self‐assembly. This allows for the derivation of a novel hydrophobicity scale, which is based solely on the interaction between individual amino acid units within the cluster and thus more accurately reflects the intrinsic nature of a side chain. This principle can be further applied to classify non‐natural derivatives, as shown here for fluorinated amino acid variants.
Structural Studies Reveal Enantiospecific Recognition of a DNA G‐Quadruplex by a Ruthenium Polypyridyl Complex
Authors: McQuaid Kane , Abell Holly , Gurung Sarah P. , Allan David R. , Winter Graeme , Sorensen Thomas , Cardin David J. , Brazier John A. , Cardin Christine J. , Hall James P. 
Published: April 2019

AbstractBy using X‐ray crystallography, we show that the complexes Λ/Δ‐[Ru(TAP)2(11‐CN‐dppz)]2+ (TAP=1,4,5,8‐tetraazaphenanthrene, dppz=dipyridophenazine) bind DNA G‐quadruplex in an enantiospecific manner that parallels the specificity of these complexes with duplex DNA. The Λ complex crystallises with the normally parallel stranded d(TAGGGTTA) tetraplex to give the first such antiparallel strand assembly in which syn‐guanosine is adjacent to the complex at the 5′ end of the quadruplex core. SRCD measurements confirm that the same conformational switch occurs in solution. The Δ enantiomer, by contrast, is present in the structure but stacked at the ends of the assembly. In addition, we report the structure of Λ‐[Ru(phen)2(11‐CN‐dppz)]2+ bound to d(TCGGCGCCGA), a duplex‐forming sequence, and use both structural models to provide insight into the motif‐specific luminescence response of the isostructural phen analogue enantiomers.
Orthogonal Halogen‐Bonding‐Driven 3D Supramolecular Assembly of Right‐Handed Synthetic Helical Peptides
Authors: Teng Peng , Gray Geoffrey M. , Zheng Mengmeng , Singh Sylvia , Li Xiaopeng , Wojtas Lukasz , van der Vaart Arjan , Cai Jianfeng 
Published: April 2019

AbstractPeptide‐mediated self‐assembly is a prevalent method for creating highly ordered supramolecular architectures. Herein, we report the first example of orthogonal C−X⋅⋅⋅X−C/C−X⋅⋅⋅π halogen bonding and hydrogen bonding driven crystalline architectures based on synthetic helical peptides bearing hybrids of l‐sulfono‐γ‐AApeptides and natural amino acids. The combination of halogen bonding, intra‐/intermolecular hydrogen bonding, and intermolecular hydrophobic interactions enabled novel 3D supramolecular assembly. The orthogonal halogen bonding in the supramolecular architecture exerts a novel mechanism for the self‐assembly of synthetic peptide foldamers and gives new insights into molecular recognition, supramolecular design, and rational design of biomimetic structures.
Syntheses of intrinsically flame‐retardant polyamide 6 fibers and fabrics
Authors: Mourgas Georgios , Giebel Elisabeth , Schneck Tanja , Unold Joerg , Buchmeiser Michael R. 
Published: April 2019

ABSTRACTIn this study, flame‐retarded polyamide 6 (FR‐PA6) was prepared via the direct co‐condensation of ε‐caprolactam with two different organophosphorus compounds in a typical melt‐polymerization process. Polymer microstructures, especially the incorporation of the phosphorus‐containing comonomers, as well as the thermal and physical properties of the resulting copolyamides have been studied in detail. The phosphorus‐modified PAs have a P‐content of 0.10–0.30 wt %, possess high relative viscosities of 2.2–2.4 and good thermal stability. FR‐PA6 multifilaments were prepared by melt spinning and show tensile strengths up to 40 cN/tex and tenacities up to 0.5 GPa. Knitted fabrics of FR‐PA6 exhibit high limiting oxygen index values around 35%. Due to the very low phosphorus content, there is no impairment of the material properties of PA6. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47829.
A coefficient of determination (R2) for generalized linear mixed models
Authors: Piepho Hans‐Peter 
Published: April 2019

AbstractExtensions of linear models are very commonly used in the analysis of biological data. Whereas goodness of fit measures such as the coefficient of determination (R2) or the adjusted R2 are well established for linear models, it is not obvious how such measures should be defined for generalized linear and mixed models. There are by now several proposals but no consensus has yet emerged as to the best unified approach in these settings. In particular, it is an open question how to best account for heteroscedasticity and for covariance among observations present in residual error or induced by random effects. This paper proposes a new approach that addresses this issue and is universally applicable for arbitrary variance‐covariance structures including spatial models and repeated measures. It is exemplified using three biological examples.
Collagen type I and hyaluronic acid based hybrid scaffolds for heart valve tissue engineering
Authors: Nazir Rabia , Bruyneel Arne , Carr Carolyn , Czernuszka Jan 
Published: April 2019

AbstractTissue engineers have achieved limited success so far in designing an ideal scaffold for aortic valve; scaffolds lack in mechanical compatibility, appropriate degradation rate, and microstructural similarity. This paper, therefore, has demonstrated a carbodiimide‐based sequential crosslinking technique to prepare aortic valve extracellular matrix mimicking (ECM) hybrid scaffolds from collagen type I and hyaluronic acid (HA), the building blocks of heart valve ECM, with tailorable crosslinking densities. Swelling studies revealed that crosslinking densities of parent networks increased with increasing the concentration of the crosslinking agents whereas crosslinking densities of hybrid scaffolds averaged from those of parent collagen and HA networks. Hybrid scaffolds also offered a wide range of pore size (66‐126 μm) which fulfilled the criteria for valvular tissue regeneration. Scanning electron microscopy and images of Alcian blue‐Periodic acid Schiff stained samples suggested that our crosslinking technique yielded an ECM mimicking microstructure with interlaced bands of collagen and HA in the hybrid scaffolds. The mutually reinforcing networks of collagen and HA also resulted in increased bending moduli up to 1660 kPa which spanned the range of natural aortic valves. Cardio sphere‐derived cells (CDCs) from rat hearts showed that crosslinking density affected the available cell attachment sites on the surface of the scaffold. Increased bending moduli of CDCs seeded scaffolds up to two folds (2‐6 kPa) as compared to the non‐seeded scaffolds (1 kPa) suggested that an increase in crosslinking density of the scaffolds could not only increase the in vitro bending modulus but also prevented its disintegration in the cell culture medium.
Development and validation of a sensitive liquid‐chromatography tandem mass spectrometry assay for mycophenolic acid and metabolites in HepaRG cell culture: Characterization of metabolism interactions between p‐cresol and mycophenolic acid
Authors: Rong Yan , Kiang Tony K.L. 
Published: April 2019

AbstractMycophenolic acid (MPA), a frequently used immunosuppressant, exhibits large inter‐patient pharmacokinetic variability. This study (a) developed and validated a sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay for MPA and metabolites [MPA glucuronide (MPAG) and acyl‐glucuronide (AcMPAG)] in the culture medium of HepaRG cells; and (b) characterized the metabolism interaction between MPA and p‐cresol (a common uremic toxin) in this in vitro model as a potential mechanism of pharmacokinetic variability. Chromatographic separation was achieved with a C18 column (4.6 × 250 mm,5 μm) using a gradient elution with water and methanol (with 0.1% formic acid and 2 mm ammonium acetate). A dual ion source ionization mode with positive multiple reaction monitoring was utilized. Multiple reaction monitoring mass transitions (m/z) were: MPA (320.95 → 207.05), MPAG (514.10 → 303.20) and AcMPAG (514.10 → 207.05). MPA‐d3 (323.95 → 210.15) and MPAG‐d3 (517.00 → 306.10) were utilized as internal standards. The calibration curves were linear from 0.00467 to 3.2 μg/mL for MPA/MPAG and from 0.00467 to 0.1 μg/mL for AcMPAG. The assay was validated based on industry standards. p‐Cresol inhibited MPA glucuronidation (IC50 ≈ 55 μm) and increased MPA concentration (up to >2‐fold) at physiologically relevant substrate‐inhibitor concentrations (n = 3). Our findings suggested that fluctuations in p‐cresol concentrations might be in part responsible for the large pharmacokinetic variability observed for MPA in the clinic.
Implementing natural capital credit risk assessment in agricultural lending
Authors: Ascui Francisco , Cojoianu Theodor F. 
Published: April 2019

AbstractAgriculture has critical impacts and dependencies on natural capital, and agricultural lenders are therefore exposed to natural capital credit risk through their loans to farmers. Currently, however, lenders lack any detailed guidance for assessing natural capital credit risk in agriculture and are challenged by the fact that the relevant material risks vary considerably by agricultural sector and geography. This paper develops a natural capital credit risk assessment framework based on a bottom‐up review of the material risks associated with natural capital impacts and dependencies for Australian beef production. It demonstrates that implementing natural capital credit risk assessment is feasible in agricultural lending, using a combination of quantitative and qualitative inputs. Implementation challenges include the complexity and interconnectedness of natural capital processes, data availability and cost, spatial data analytical capacity, and the need for transformational change, both within lending organisations and across the banking sector.
Dynamic Continuum of Molecular Assemblies for Controlling Cell Fates
Authors: Wang Huaimin , Feng Zhaoqianqi , Xu Bing 
Published: April 2019

AbstractBiological systems have evolved to create a structural and dynamic continuum of bio‐macromolecular assemblies for the purpose of optimizing the system′s functions. The formation of these dynamic higher‐order assemblies is precisely controlled by biological cues. However, controlling the self‐assembly of synthetic molecules spatiotemporally in or on live cells is still a big challenge, especially for performing functions. This concept article introduces the use of in situ reactions as a spatiotemporal control to form assemblies of small molecules that induce cell morphogenesis or apoptosis. After briefly introducing a representative example of a natural dynamic continuum of the higher‐order assemblies, we describe enzyme‐instructed self‐assembly (EISA) for constructing dynamic assemblies of small molecules, then discuss the use of EISA for controlling cell morphogenesis and apoptosis. Finally, we provide a brief outlook to discuss the future perspective of this exciting new research direction.
Coordination of Platinum to α‐Synuclein Inhibits Filamentous Aggregation in Solution
Authors: Pan Bin‐Bin , Yang Yin , Liu Hui‐Zhong , Li Yi‐Hua , Su Xun‐Cheng 
Published: April 2019

AbstractAccumulation of filamentous aggregates of α‐synuclein (AS) in Lewy bodies and neurites is characteristic of neurodegenerative diseases such as Parkinson's disease. Inhibition of AS fibrillation is helpful for understanding of AS aggregate structure and for developing chemical therapies. Herein, we report that the PtII‐containing antitumor drug cisplatin suppresses filamentous aggregation of AS in solution. PtII thus contrasts strongly with reported transition‐metal ions such as MnII, FeIII, and CuII, which accelerate AS aggregation. Interaction between PtII and the side chains of methionine and histidine residues was essential for inhibition of AS fibrillation. Binding of PtII to AS did not change the protein′s overall random coil structure, as indicated by solution‐state two‐dimensional NMR and circular dichroism spectroscopy; and a solution of the AS⋅PtII complex remained free of filamentous aggregates. Our results constitute interesting new information about the biological chemistry of metal ions in Parkinson's disease and might open new lines of research into the suppression of filamentous aggregation.
Role of autophagy in inhibiting the proliferation of A549 cells by type III interferon
Authors: Gao Dongmei , Yu Xiaoqin , Zhang Bo , Kong Min , Fang Yong , Cai Yu , Zhu Chengchu , Zhao Jun , Li Jicheng 
Published: April 2019

AbstractInterferons (IFNs) have anti‐viral and anti‐tumour effects. Type III interferon, as a member of the recently discovered interferon family, has been proved to inhibit tumour proliferation and promote the apoptosis of various tumour cells. However, whether type III IFN could inhibit the proliferation of lung cancer was not clear. In this study, we found that interferon λ (IFN λ) could inhibit the proliferation of A549 cells and induce autophagy and apoptosis of A549 cells. IFN λ could promote the expression of autophagy gene Beclin1 and interfere the expression of autophagy gene Beclin1 with small interfering RNA, thus inhibiting the effect of type III interferon on anti‐proliferation and promoting apoptosis of lung cancer cell. These results suggested that IFN λ could inhibit the proliferation of A549 cells by activating autophagy pathway, and IFN λ might be one of the potential therapeutic drugs for lung cancer.
Knockdown of STAT3 targets a subpopulation of invasive melanoma stem‐like cells
Authors: Kulesza Dorota W , Przanowski Piotr , Kaminska Bozena 
Published: April 2019

AbstractTranscription factor signal transducer and activator of transcription 3 (STAT3) is constitutively activated in many cancers, including melanomas. Active, phosphorylated STAT3 contributes to tumor growth and formation of the immunosuppressive tumor microenvironment. Recent evidence suggests an important role of STAT3 in self‐renewal of cancer stem‐like cells (CSCs). In the present study, we aimed to determine the expression and role of active STAT3 in melanoma CSCs. We found the increased levels of phosphorylated (Y705) STAT3 in CSC sphere cultures derived from three human and murine melanoma cells. Knockdown of STAT3 did not affect basal proliferation, but reduced sphere forming capacity of two human melanoma cell lines. Moreover, the level of active STAT3 was elevated in rhodamine 123 negative subpopulations of CSCs sorted from three melanoma cell lines. We found that focal adhesion kinase (FAK) and AKT signaling pathways, implicated in the regulation of cell migration and invasion, were up‐regulated in melanoma CSCs. Moreover, expression of SERPINA3, which regulates melanoma invasion, was increased in melanoma CSCs sphere cultures, which correlated with augmented cell invasion in Matrigel. Our findings show that STAT3 is activated and supports maintenance of melanoma CSCs. It suggests that STAT3 could serve as a potential target to impair tumor progression or recurrence.
Possible role of differentially expressing novel protein markers (ligatin and fibulin‐7) in human aqueous humor and trabecular meshwork tissue in glaucoma progression
Authors: Basu Kaustuv , Maurya Nancy , Kaur Jasbir , Saxena Rohit , Gupta Viney , Sihota Ramanjit , Ghosh Ilora 
Published: April 2019

AbstractThe pathological mechanism underlying glaucoma has always been a complex aspect of this permanently blinding disease but proteomic studies have been helpful in elucidating it to a great extent in several studies. This study was designed to evaluate the expression and to get an idea about the function of two novel markers (ligatin and fibulin‐7) identified in human aqueous humor (hAH) in relation to glaucomatous progression. A significant increase in the protein content of glaucomatous hAH compared to that of non‐glaucomatous controls (NG‐Ctrls) was observed. Ligatin, fibulin‐7, and its proteolysis were revealed in hAH of primary open angle glaucoma (POAG), primary angle closure glaucoma (PACG) and NG‐Ctrls. Quantification confirmed no significant difference in expression of ligatin, whereas fibulin‐7 was significantly (P < 0.05) low in hAH of PACG in comparison to NG‐Ctrls and POAG. Importantly the immunohistochemical assay for both indicated their possible involvement in the maintenance of the appropriate structure of TM in vivo. Since oxidative stress is a major contributor to glaucomatous pathogenesis, in vitro analysis of nuclear and cytoplasmic fractions indicated intracellular changes in localization and expression of ligatin upon oxidative insult of human trabecular meshwork (TM) cells. While no such changes were found for fibulin‐7 expression. This was also corroborated with the immunocytochemical assay. Though a study with a small sample size, this is the first report which confirms the presence of ligatin and fibulin‐7 in hAH, quantified their differential expression, and indicated the possibility of their involvement in the maintenance of the TM structure.
Scope and Limitations of TBA[Fe]‐Catalyzed Carbene Transfer to X−H‐bonds – Indication of a Mechanistic Dichotomy
Authors: Röske Annika , Alt Isabel , Plietker Bernd 
Published: April 2019

AbstractAn in‐depth study of carbene transfer reactions into polar X−H‐bonds catalyzed by the nucleophilic Fe‐complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) is presented. Whereas alcohols are unreactive, thiols and secondary amines are reactive, silanes showed modest activities. Hammett correlations indicate the presence of an X−H‐acidity dependent mechanistic dichotomy.
Activation of Surface Lattice Oxygen in Ceria Supported Pt/Al2O3 Catalyst for Low‐Temperature Propane Oxidation
Authors: Wang Chengxiong , Feng Feng , Du Junchen , Zheng Tingting , Pan Zaifu , Zhao Yunkun 
Published: April 2019

AbstractThe front cover artwork for Issue 08/2019 is provided by researchers from Kunming Institute of Precious Metals (China) and Kunming Sino‐platinum Metals Catalysts Co. Ltd. (China). The image shows that oxygen activation at Pt/ceria interfaces promotes propane oxidation at low‐temperature for automotive exhaust purification. See the Communication itself at https://doi.org/10.1002/cctc.201900190.
Lyotropic Liquid Crystal as an Electrolyte Additive for Suppressing Self‐Discharge of Supercapacitors
Authors: Liu Mingyang , Xia Mengyang , Qi Ruijie , Ma Qun , Zhao Man , Zhang Zailei , Lu Xianmao 
Published: April 2019

AbstractSelf‐discharge severely constrains the application of supercapacitors for long‐term energy storage because it causes decay of cell voltage and loss of energy. So far, three pathways have been proposed for the self‐discharge of supercapacitors: i) ohmic leakage, ii) diffusion‐controlled self‐discharge, iii) faradaic reactions. However, solutions for mitigating the self‐discharge of supercapacitors are limited. Here, we choose lyotropic liquid crystal (LLC) as an electrolyte additive to suppress the self‐discharge of supercapacitors through the electrorheological effect of the LLC. The LLC formed by the assembly of a triblock copolymer Pluronic L64 in ion liquid [Bmim]BF4 exhibits dielectric anisotropy and can reorient in an electric field, causing increased viscosity and slower ion diffusion of the electrolyte. It is found that, by adding 5 % (vol%) LLC into TEMABF4/acetonitrile electrolyte, the self‐discharge rate at room temperature can be decreased by 32 % compared to supercapacitors without LLC. Furthermore, the LLC could reduce the self‐discharge rate of supercapacitors even at 50 °C due to its stability in a relatively wide temperature range.
Zwitterionic Copolymer‐Supported Ionogel Electrolytes: Impacts of Varying the Zwitterionic Group and Ionic Liquid Identities
Authors: Rebollar Luis , Panzer Matthew J. 
Published: April 2019

AbstractA series of copolymer scaffolds containing zwitterionic (ZI) functional groups, synthesized in situ in two alkylimidazolium cation‐based ionic liquids, has been created by using two different ZI monomers to yield nonvolatile ionogel electrolytes that exhibit high ionic conductivities and a wide range of elastic moduli. Although all of the examined ionogel formulations consist of 80 mol % ionic liquid, gel properties are observed to depend both on zwitterion content within the copolymer scaffold, as well as the specific ionic liquid/zwitterion pairing. Low zwitterion contents (ca. 1 mol %) generate a notable increase in ionogel room‐temperature ionic conductivity compared to that of their non‐ZI ionogel analogues, whereas higher zwitterion contents (up to 18.5 mol %) yield stiff gels containing a large density of ZI noncovalent cross‐links. This highlights the dual functionality of the ZI groups within zwitterion‐containing copolymer‐supported ionogel electrolytes. All the ionogels synthesized in this study exhibit room‐temperature ionic conductivity values in the range of 3–12 mS cm−1 with compressive elastic modulus values varying between approximately 1–1000 kPa, suggesting their suitability for the design of safer flexible electrochemical devices, including wearable sensors or supercapacitors.
Facile Synthesis of Hierarchical Sulfur Composites for Lithium–Sulfur Batteries
Authors: Cho Chuan‐Sheng , Shih Hsuan‐Ju , Li Chia‐Chen 
Published: April 2019

AbstractA facile approach for the synthesis of core–shell composites composed of a commercial sulfur core and a carbon nanopowder shell with different morphologies and sizes is proposed. When these composites are used to prepare a cathode for lithium−sulfur batteries, their fabricated electrode slurries show better dispersion homogeneity than that prepared through the conventional method of simply mixing sulfur and carbon nanopowders. Hence, the resulting cathodes fabricated by using these composites show superior electronic and ionic conductivity compared to that produced through the conventional method. Electrochemical assessment demonstrates that lithium−sulfur batteries fabricated by using the composites show reduced self‐discharge and improved capacity and maintained 100 % of the columbic efficiency. However, these improvements cannot be achieved if the sulfur crystal of the composite is considerably large, as this negatively affects the dispersion of the electrode constituents.