bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoliquefiable Ionic Crystals: A Phase Crossover Approach for Photon Energy Storage Materials with Functional Multiplicity
Authors: Ishiba Keita , Morikawa Masa‐aki , Chikara Chie , Yamada Teppei , Iwase Katsunori , Kawakita Mika , Kimizuka Nobuo
Published: December 2014

Ionic crystals (ICs) of the azobenzene derivatives show photoinduced IC–ionic liquid (IL) phase transition (photoliquefaction) upon UV‐irradiation, and the resulting cis‐azobenzene ILs are reversibly photocrystallized by illumination with visible light. The photoliquefaction of ICs is accompanied by a significant increase in ionic conductivity at ambient temperature. The photoliquefaction also brings the azobenzene ICs further significance as photon energy storage materials. The cis‐IL shows thermally induced crystallization to the trans‐IC phase. This transition is accompanied by exothermic peaks with a total ΔH of 97.1 kJ mol−1, which is almost double the conformational energy stored in cis‐azobenzene chromophores. Thus, the integration of photoresponsive ILs and self‐assembly pushes the limit of solar thermal batteries.
Sulfur‐Doped Graphene Derived from Cycled Lithium–Sulfur Batteries as a Metal‐Free Electrocatalyst for the Oxygen Reduction Reaction
Authors: Ma Zhaoling , Dou Shuo , Shen Anli , Tao Li , Dai Liming , Wang Shuangyin
Published: December 2014

Heteroatom‐doped carbon materials have been extensively investigated as metal‐free electrocatalysts to replace commercial Pt/C catalysts in oxygen reduction reactions in fuel cells and Li–air batteries. However, the synthesis of such materials usually involves high temperature or complicated equipment. Graphene‐based sulfur composites have been recently developed to prolong the cycling life of Li–S batteries, one of the most attractive energy‐storage devices. Given the high cost of graphene, there is significant demand to recycle and reuse graphene from Li–S batteries. Herein, we report a green and cost‐effective method to prepare sulfur‐doped graphene, achieved by the continuous charge/discharge cycling of graphene–sulfur composites in Li–S batteries. This material was used as a metal‐free electrocatalyst for the oxygen reduction reaction and shows better electrocatalytic activity than pristine graphene and better methanol tolerance durability than Pt/C.
Hydrogen‐Borrowing and Interrupted‐Hydrogen‐Borrowing Reactions of Ketones and Methanol Catalyzed by Iridium
Authors: Shen Di , Poole Darren L. , Shotton Camilla C. , Kornahrens Anne F. , Healy Mark P. , Donohoe Timothy J.
Published: December 2014

Reported herein is the use of catalytic [{Ir(cod)Cl}2] to facilitate hydrogen‐borrowing reactions of ketone enolates with methanol at 65 °C. An oxygen atmosphere accelerates the process, and when combined with the use of a bulky monodentate phosphine ligand, interrupts the catalytic cycle by preventing enone reduction. Subsequent addition of pro‐nucleophiles to the reaction mixture allowed a one‐pot methylenation/conjugate addition protocol to be developed, which greatly expands the range of products that can be made by this methodology.
Light‐Directing Omnidirectional Circularly Polarized Reflection from Liquid‐Crystal Droplets
Authors: Fan Jing , Li Yannian , Bisoyi Hari Krishna , Zola Rafael S. , Yang Deng‐ke , Bunning Timothy J. , Weitz David A. , Li Quan
Published: December 2014

Constructing and tuning self‐organized three‐dimensional (3D) superstructures with tailored functionality is crucial in the nanofabrication of smart molecular devices. Herein we fabricate a self‐organized, phototunable 3D photonic superstructure from monodisperse droplets of one‐dimensional cholesteric liquid crystal (CLC) containing a photosensitive chiral molecular switch with high helical twisting power. The droplets are obtained by a glass capillary microfluidic technique by dispersing into PVA solution that facilitates planar anchoring of the liquid‐crystal molecules at the droplet surface, as confirmed by the observation of normal incidence selective circular polarized reflection in all directions from the core of individual droplet. Photoirradiation of the droplets furnishes dynamic reflection colors without thermal relaxation, whose wavelength can be tuned reversibly by variation of the irradiation time. The results provided clear evidence on the phototunable reflection in all directions.
The Profound Effect of the Ring Size in the Electrocyclic Opening of Cyclobutene‐Fused Bicyclic Systems
Authors: Ralph Michael J. , Harrowven David C. , Gaulier Steven , Ng Sean , Booker‐Milburn Kevin I.
Published: December 2014

Fused cyclobutenes, prepared by the photocycloaddition of propargyl alcohols to cyclic anhydride chromophores, undergo facile thermochemical ring opening to fused γ‐lactones. The size of the fused ring profoundly influences the temperature that is required to facilitate the ring opening (from 50 °C to 180 °C) and the nature of the product that is formed. Our studies provide new insights into the mechanistic course of these reactions and have been extended to facilitate the preparation of lactams fused to medium‐sized rings.
PyBidine–Cu(OTf)2‐Catalyzed Asymmetric [3+2] Cycloaddition with Imino Esters: Harmony of Cu–Lewis Acid and Imidazolidine‐NH Hydrogen Bonding in Concerto Catalysis
Authors: Arai Takayoshi , Ogawa Hiroki , Awata Atsuko , Sato Makoto , Watabe Megumi , Yamanaka Masahiro
Published: December 2014

A bis(imidazolidine)pyridine (PyBidine)–Cu(OTf)2 complex catalyzing the endo‐selective [3+2] cycloaddition of nitroalkenes with imino esters was applied to the reaction of methyleneindolinones with imino esters to afford spiro[pyrrolidin‐3,3′‐oxindole]s in up to 98 % ee. X‐ray crystallographic analysis of the PyBidine–Cu(OTf)2 complex and DFT calculations suggested that an intermediate Cu enolate of the imino ester reacts with nitroalkenes or methyleneindolinones, which are activated by NH‐hydrogen bonding with the PyBidine–Cu(OTf)2 catalyst.
Fouling control through the hydrophilic surface modification of poly(vinylidene fluoride) membranes
Authors: Jang Hanna , Song Du‐Hyun , Kim In‐Chul , Kwon Young‐Nam
Published: December 2014

A hydrophilic fouling‐resistant poly(vinyl alcohol) (PVA) based polymer was synthesized by the etherification of PVA with monochloroacetic acid under alkaline conditions, and the polymer, PVA–OCH2COONa, was subsequently applied to modify a poly(vinylidene fluoride) (PVDF) membrane to both enhance the hydrophilicity and provide fouling resistance. The successful etherification was confirmed by 13C‐NMR and attenuated total reflectance–Fourier transform infrared spectroscopy, whereas the synthesized polymer was shown by differential scanning calorimetry analysis to have an improved thermal stability over PVA. The physicochemical properties of the surfaces of the modified PVDF membranes were investigated with various analytical tools, including field emission scanning electron microscopy, atomic force microscopy, and contact angle analysis. Fouling tests with bovine serum albumin showed the PVA–OCH2COONa modified PVDF membrane to have both a higher pure water flux and a retarded decline in flux over the filtration period compared with the PVA‐coated PVDF membrane. This study demonstrated that the modification of PVDF membranes with PVA–OCH2COONa could be an efficient method for enhancing their fouling resistance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41712.
Influence of the nanofiber dimensions on the properties of nanocellulose/poly(vinyl alcohol) aerogels
Authors: Mueller Silvana , Sapkota Janak , Nicharat Apiradee , Zimmermann Tanja , Tingaut Philippe , Weder Christoph , Foster E. Johan
Published: December 2014

The investigation of aerogels made from cellulose nanofibers and poly(vinyl alcohol) (PVOH) as a polymeric binder is reported. Aerogels based on different nanocellulose types were studied to investigate the influence of the nanocellulose dimensions and their rigidity on the morphology and mechanical properties of the resulting aerogels. Thus, cellulose nanocrystals (CNCs) with low (10), medium (25), and high (80) aspect ratios, isolated from cotton, banana plants, and tunicates, respectively, microfibrillated cellulose (MFC) and microcrystalline cellulose (MCC) were dispersed in aqueous PVOH solutions and aerogels were prepared by freeze‐drying. In addition to the cellulose type, the PVOH‐ and the CNC‐concentration as well as the freeze‐drying conditions were varied, and the materials were optionally cross‐linked by an annealing step or the use of a chemical cross‐linker. The data reveal that at low PVOH content, rigid, high‐aspect ratio CNCs isolated from tunicates afford aerogels that show the least amount of shrinking upon freeze‐drying and display the best mechanical properties. However, with increasing concentration of PVOH or upon introduction of a chemical cross‐linker the differences between materials made from different nanocellulose types decrease. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41740.
Geophysical Investigations on the Viking Period Platform Mound at Aska in Hagebyhöga Parish, Sweden
Authors: Rundkvist Martin , Viberg Andreas
Published: December 2014

Aska hamlet in Hagebyhöga parish, Östergötland (Sweden), is famous among Viking scholars for a rich female burial under a low cairn that was excavated in 1920. The main visible archaeological feature of the site is an enormous barrow, but its contents have not been excavated. As the barrow is oval and has an extensive flat top, it has been hypothesized previously that rather than a grave superstructure, this might be an uncommonly large raised foundation for a long house. We occasionally see this type of feature at elite manorial sites from the period ad 400–1100. We have tested this idea at Aska with ground‐penetrating radar, securing the clear and detailed floor plan of a post‐supported hall building almost 50 m long. Its closest known architectural parallel, also sitting on a similar platform, has been excavated at Old Uppsala, the late first millennium ad political and ceremonial centre of the ancient Swedes. At Aska, it appears that we have found another such real‐world correlate of the Beowulf poem's royal mead‐hall Heorot, but in this case located in a smaller and less powerful polity. This all suggests a petty royal status for the owners of the Aska hall, who enjoyed connections with Scandinavia's top political elite. Copyright © 2014 John Wiley & Sons, Ltd.
Spontaneous Reduction of Mononuclear High‐Spin Iron(III) Complexes to Mononuclear Low‐Spin Iron(II) Complexes in Aqueous Media and Nuclease Activity via Self‐Activation
Authors: Ghosh Kaushik , Tyagi Nidhi , Kumar Dhara Ashish , Singh Udai P.
Published: December 2014

Mononuclear high‐spin [FeIII(Pyimpy)Cl3]⋅2 CH2Cl2 (1⋅2 CH2Cl2) and [FeIII(Me‐Pyimpy)Cl3] (2), as well as low‐spin FeII(Pyimpy)2](ClO4)2 (3) and [FeII(Me‐Pyimpy)2](ClO4)2 (4) complexes of tridentate ligands Pyimpy and Me‐Pyimpy have been synthesized and characterized by analytical techniques, spectral, and X‐ray structural analyses. We observed an important type of conversion and associated spontaneous reduction of mono‐chelated high‐spin FeIII (1⋅2 CH2Cl2 and 2) complexes to low‐spin bis‐chelated FeII complexes 3 and 4, respectively. This process has been explored in detail by UV/Vis, fluorescence, and 1H NMR spectroscopic measurements. The high positive potentials observed in electrochemical studies suggested a better stabilization of FeII centers in 3 and 4. Theoretical studies by density functional theory (DFT) calculations supported an increased stabilization for 3 in polar solvents. Self‐activated nuclease activity of complexes 1⋅2CH2Cl2 and 2 during their spontaneous reduction was examined for the first time and the mechanism of nuclease activity was investigated.
Paracrine signaling mediated at cell–cell contacts
Authors: Roy Sougata , Kornberg Thomas B.
Published: December 2014

Recent findings in several organ systems show that cytoneme‐mediated signaling transports signaling proteins along cellular extensions and targets cell‐to‐cell exchanges to synaptic contacts. This mechanism of paracrine signaling may be a general one that is used by many (or all) cell types in many (or all) organs. We briefly review these findings in this perspective. We also describe the properties of several signaling systems that have previously been interpreted to support a passive diffusion mechanism of signaling protein dispersion, but can now be understood in the context of the cytoneme mechanism.

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Targeted purification development enabled by computational biophysical modeling
Authors: Insaidoo Francis K. , Rauscher Michael A. , Smithline Shepard J. , Kaarsholm Niels C. , Feuston Bradley P. , Ortigosa Allison D. , Linden Thomas O. , Roush David J.
Published: December 2014

Chromatographic and non‐chromatographic purification of biopharmaceuticals depend on the interactions between protein molecules and a solid–liquid interface. These interactions are dominated by the protein–surface properties, which are a function of protein sequence, structure, and dynamics. In addition, protein–surface properties are critical for in vivo recognition and activation, thus, purification strategies should strive to preserve structural integrity and retain desired pharmacological efficacy. Other factors such as surface diffusion, pore diffusion, and film mass transfer can impact chromatographic separation and resin design. The key factors that impact non‐chromatographic separations (e.g., solubility, ligand affinity, charges and hydrophobic clusters, and molecular dynamics) are readily amenable to computational modeling and can enhance the understanding of protein chromatographic. Previously published studies have used computational methods such as quantitative structure–activity relationship (QSAR) or quantitative structure–property relationship (QSPR) to identify and rank order affinity ligands based on their potential to effectively bind and separate a desired biopharmaceutical from host cell protein (HCP) and other impurities. The challenge in the application of such an approach is to discern key yet subtle differences in ligands and proteins that influence biologics purification. Using a relatively small molecular weight protein (insulin), this research overcame limitations of previous modeling efforts by utilizing atomic level detail for the modeling of protein–ligand interactions, effectively leveraging and extending previous research on drug target discovery. These principles were applied to the purification of different commercially available insulin variants. The ability of these computational models to correlate directionally with empirical observation is demonstrated for several insulin systems over a range of purification challenges including resolution of subtle product variants (amino acid misincorporations). Broader application of this methodology in bioprocess development may enhance and speed the development of a robust purification platform. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:154–164, 2015
Validation of a modified clinical risk score to predict cancer‐specific survival for stage II colon cancer
Authors: Oliphant Raymond , Horgan Paul G. , Morrison David S. , McMillan Donald C. ,   In collaboration with the West of Scotland Colorectal Cancer Managed Clinical Network
Published: December 2014

Many patients with stage II colon cancer will die of their disease despite curative surgery. Therefore, identification of patients at high risk of poor outcome after surgery for stage II colon cancer is desirable. This study aims to validate a clinical risk score to predict cancer‐specific survival in patients undergoing surgery for stage II colon cancer. Patients undergoing surgery for stage II colon cancer in 16 hospitals in the West of Scotland between 2001 and 2004 were identified from a prospectively maintained regional clinical audit database. Overall and cancer‐specific survival rates up to 5 years were calculated. A total of 871 patients were included. At 5 years, cancer‐specific survival was 81.9% and overall survival was 65.6%. On multivariate analysis, age ≥75 years (hazard ratio (HR) 2.11, 95% confidence intervals (CI) 1.57–2.85; P<0.001) and emergency presentation (HR 1.97, 95% CI 1.43–2.70; P<0.001) were independently associated with cancer‐specific survival. Age and mode of presentation HRs were added to form a clinical risk score of 0–2. The cancer‐specific survival at 5 years for patients with a cumulative score 0 was 88.7%, 1 was 78.2% and 2 was 65.9%. These results validate a modified simple clinical risk score for patients undergoing surgery for stage II colon cancer. The combination of these two universally documented clinical factors provides a solid foundation for the examination of the impact of additional clinicopathological and treatment factors on overall and cancer‐specific survival.
Tenualexin, Other Phytoalexins and Indole Glucosinolates from Wild Cruciferous Species
Authors: Pedras M. Soledade C. , Yaya Estifanos E.
Published: December 2014

In general, the chemodiversity of phytoalexins, elicited metabolites involved in plant defense mechanisms against microbial pathogens, correlates with the biodiversity of their sources. In this work, the phytoalexins produced by four wild cruciferous species (Brassica tournefortii, Crambe abyssinica (crambe), Diplotaxis tenuifolia (sand rocket), and Diplotaxis tenuisiliqua (wall rocket)) were identified and quantified by HPLC with photodioarray and electrospray mass detectors. In addition, the production of indole glucosinolates, biosynthetic precursors of cruciferous phytoalexins, was evaluated. Tenualexin, (=2‐(1,4‐dimethoxy‐1H‐indol‐3‐yl)acetonitrile), the first cruciferous phytoalexin containing two MeO substituents in the indole ring, was isolated from D. tenuisiliqua, synthesized, and evaluated for antifungal activity. The phytoalexins cyclobrassinin and spirobrassinin were detected in B. tournefortii and C. abyssinica, whereas rutalexin and 4‐methoxybrassinin were only found in B. tournefortii. D. tenuifolia, and D. tenuisiliqua produced 2‐(1H‐indol‐3‐yl)acetonitriles as phytoalexins. Because tenualexin appears to be one of the broad‐range antifungals occurring in crucifers, it is suggested that D. tenuisiliqua may have disease resistance traits important to be incorporated in commercial breeding programs.
Essential‐Oil Composition of the Needles Collected from Natural Populations of Macedonian Pine (Pinus peuceGriseb.) from the Scardo‐Pindic Mountain System
Authors: Nikolić Biljana , Ristić Mihailo , Bojović Srdjan , Matevski Vlado , Krivošej Zoran , Marin Petar D.
Published: December 2014

The needle‐terpene profiles of two natural Pinus peuce populations from the Scardo‐Pindic mountain system (Mt. Ošljak and Mt. Pelister) were analyzed. Among the 90 detected compounds, 87 were identified. The dominant constituents were α‐pinene (45.5%), germacrene D (11.1%), β‐pinene (10.8%), and camphene (10.3%). The following eight additional components were found to be present in medium‐to‐high amounts (0.5–10%): bornyl acetate (5.0%), β‐phellandrene (3.4%), β‐caryophyllene (2.9%), β‐myrcene (0.9%), germacrene D‐4‐ol (0.9%), tricyclene (0.7%), (E)‐hex‐2‐enal (0.7%), and bicyclogermacrene (0.6%). Although the general needle‐terpene profiles of the populations from Mt. Ošljak and Mt. Pelister were found to be similar to those of the populations from Zeletin, Sjekirica, and Mokra Gora (Dinaric Alps), principle component analysis (PCA) of eight terpenes (α‐pinene, β‐myrcene, α‐terpinolene, bornyl acetate, α‐terpinyl acetate, β‐caryophyllene, trans‐β‐farnesene, and germacrene D) in 139 tree samples suggested a divergence between the two population groups, i.e., the samples from the Scardo‐Pindic mountain system and those from the Dinaric Alps. Genetic analysis of the β‐pinene content demonstrated a partial divergence between the two geographical groups. The profiles of both population groups differed from those published for populations from the Balkan‐Rhodope mountains system (literature results), which were characterized by high contents of bornyl acetate and citronellol (Greek populations) or δ‐car‐3‐ene (Bulgarian populations).
Volatile Compounds of Viola odorata Absolutes: Identification of Odorant Active Markers to Distinguish Plants Originating from France and Egypt
Authors: Saint‐Lary Laure , Roy Céline , Paris Jean‐Philippe , Tournayre Pascal , Berdagué Jean‐Louis , Thomas Olivier P. , Fernandez Xavier
Published: December 2014

Absolutes isolated from Viola odorata leaves, valuable materials for the flavor and fragrance industry, were studied. Violets are mainly cultivated in France and Egypt and extracted locally. The absolutes of the two origins showed different olfactory profiles both in top and heart notes, as evidenced by sensory analysis. The aims of this study were i) to characterize the volatile compounds, ii) to determine the odorant‐active ones, and iii) to identify some markers of the plant origin. Two complementary analytical methods were used for these purposes, i.e., headspace solid‐phase microextraction (HS‐SPME) using different fiber coatings followed by GC/MS analysis and gas chromatography – olfactometry/mass spectrometry (GC‐O/MS) applied to violet leaf extracts. From a total of 70 identified compounds, 61 have never been reported so far for this species, 17 compounds were characterized by both techniques (with seven among them known from the literature), 23 compounds were solely identified by HS‐SPME GC/MS (among them only two being already mentioned as components of violet absolutes in the literature), and, finally, 30 compounds were only identified by GC‐O/MS. According to the HS‐SPME GC/MS analyses, ethyl hexanoate and (2E,6Z)‐nona‐2,6‐dienol were specific volatile compounds of the sample with French origin, while (E,E)‐hepta‐2,4‐dienal, hexanoic acid, limonene, tridecane, and eugenol were specific of the samples with Egyptian origin. Additional compounds that were not detected by HS‐SPME GC/MS analysis were revealed by GC‐O analyses, some of them being markers of origin. Pent‐1‐en‐3‐ol, 3‐methylbut‐2‐enal, 2‐methoxy‐3‐(1‐methylethyl)pyrazine, 4‐ethylbenzaldehyde, β‐phenethyl formate, and 2‐methoxy‐3‐(2‐methylpropyl)pyrazine revealed to be odorant markers of the French sample, whereas cis‐rose oxide, trans‐rose oxide, and 3,5,5‐trimethylcyclohex‐2‐enone were odorant markers of the Egyptian samples.
Binding Pockets and Permeation Channels for Dioxygen through Cofactorless 3‐Hydroxy‐2‐methylquinolin‐4‐one 2,4‐Dioxygenase in Association with Its Natural Substrate, 3‐Hydroxy‐2‐methylquinolin‐4(1H)‐one. A Perspective from Molecular Dynamics Simulations
Authors: Pietra Francesco
Published: December 2014

This work describes an investigation of pathways and binging pockets (BPs) for dioxygen (O2) through the cofactorless oxygenase 3‐hydroxy‐2‐methylquinolin‐4‐one 2,4‐dioxygenase in complex with its natural substrate, 3‐hydroxy‐2‐methylquinolin‐4(1H)‐one, in aqueous solution. The investigation tool was random‐acceleration molecular dynamics (RAMD), whereby a tiny, randomly oriented external force is applied to O2 in order to accelerate its movements. In doing that, care was taken that the external force only continues, if O2 moves along a direction for a given period of time, otherwise the force changed direction randomly. Gates for expulsion of O2 from the protein, which can also be taken as gates for O2 uptake, were found throughout almost the whole external surface of the protein, alongside a variety of BPs for O2. The most exploited gates and BPs were not found to correspond to the single gate and BP proposed previously from the examination of the static model from X‐ray diffraction analysis of this system. Therefore, experimental investigations of this system that go beyond the static model are urgently needed.
O‐Methyltransferase Is Shared between the Pentose Phosphate and Shikimate Pathways and Is Essential for Mycosporine‐Like Amino Acid Biosynthesis in Anabaena variabilis ATCC 29413
Authors: Pope Matthew A. , Spence Edward , Seralvo Valentina , Gacesa Ranko , Heidelberger Sibylle , Weston Andrew J. , Dunlap Walter C. , Shick J. Malcolm , Long Paul F.
Published: December 2014

The parent core structure of mycosporine‐like amino acids (MAAs) is 4‐deoxygadusol, which, in cyanobacteria, is derived from conversion of the pentose phosphate pathway intermediate sedoheptulose 7‐phosphate by the enzymes 2‐epi‐5‐epivaliolone synthase (EVS) and O‐methyltransferase (OMT). Yet, deletion of the EVS gene from Anabaena variabilis ATCC 29413 was shown to have little effect on MAA production, thus suggesting that its biosynthesis is not exclusive to the pentose phosphate pathway. Herein, we report how, using pathway‐specific inhibitors, we demonstrated unequivocally that MAA biosynthesis occurs also via the shikimate pathway. In addition, complete in‐frame gene deletion of the OMT gene from A. variabilis ATCC 29413 reveals that, although biochemically distinct, the pentose phosphate and shikimate pathways are inextricably linked to MAA biosynthesis in this cyanobacterium. Furthermore, proteomic data reveal that the shikimate pathway is the predominate route for UV‐induced MAA biosynthesis.
Neuroblastoma SH‐SY5Y cell‐derived exosomes stimulate dendrite‐like outgrowths and modify the differentiation of A375 melanoma cells
Authors: Park Seyeon , Ahn Eun Sook , Kim Yunjoo
Published: December 2014

The identification of small vesicles released by many cell types as tools of intercellular communication is proposed. Here, we identify SH‐SY5Y neuroblastoma‐derived exosomes comprised of major histocompatibility complex II (MHC II), Hsp90 and flotillin‐1. Our data also suggest that, when applied extracellularly, exosomes released from neuronal cells stimulate dendrite‐like outgrowth and melanogenesis of A375 melanoma cells through the mitogen‐activated protein kinase (MAP kinase), extracellular signal‐regulated kinase 1 (ERK1) activation. These results suggest a modification of differentiation of melanocyte by the treatment of neuronal cell exosomes. Since exosomes from neuronal cells have the capacity to affect melanoma cells, they could be generally implicated in intercellular communication between different types of cells.
Bone marrow mesenchymal stem cells suppressing activation of allogeneic cytokine‐induced killer/natural killer cells either by direct or indirect interaction
Authors: Li Yang , Qu Yu H. , Wu Yan F. , Liu Ling , Lin Xiang H. , Huang Ke , Wei Jing
Published: December 2014

Bone marrow mesenchymal stem cells (MSC) were recently found to be associated with some special immunological characteristics, the immunoregulatory effect of MSC was dose‐dependent. Low amount of MSC was associated with mild immunosuppression or even immune activation, while the high amount of that was associated with significant immunosuppressive effect. In this study, by using a transwell system, we explored the effect of MSC on the cell cycle, apoptosis rate and the expression of CD69, an activation marker, on the allogeneic cord blood derived cytokine‐induced killer(CIK)/natural killer(NK) cells. The results showed that either by transwell or mixed cell‐cell co‐culture, the MSC can effect CIK/NK cells on the cell cycle, such as arrested in the G0/G1 phase, diminished the ratio of cells in S, G2/M phase, and increased the apoptosis of them. MSC can also depress the expression of CD69 on these killer cells, as well as increased the ratio of CD4+CD25+CD127low T regulatory (Treg) cells in the CIK/NK cell culture system. We draw conclusions that either by transwell or mixed co‐culture, the MSC can suppress activation of allogeneic CB‐CIK/NK cells in a dose‐dependent manner.
KGF and BMP‐6 intervene in cellular reprogramming and in mesenchymal‐epithelial transition (MET) of 3T3L1 mouse adipose cells
Authors: Reza Abu M. M. T. , Lee Sungjin , Shiwani Supriya , Singh Naresh K.
Published: December 2014

Mesenchymal‐epithelial transition (MET) is an inevitable process for cellular reprogramming. MET could be induced by suppressing epithelial‐mesenchymal transition (EMT) signaling and activating an epithelial program within the cells. Aiming at MET, we investigated the potential of keratinocyte growth factor (KGF) and bone morphogenetic protein (BMP)‐6 separately for the induction of MET in 3T3L1 mouse adipose cells and to trace the molecular events that probably upregulate during MET induction. KGF successfully induced MET through upregulation of epithelial related genes and transcript expression on 3T3L1 cells. In contrast, BMP‐6 plays completely the reverse role through downregulation of all epithelial related genes and transcript expression. In KGF based treatment, seven genes (K8, K18, EpCAM, K5, K14, SMN1 and α‐SMA) out of a total of eight genes were significantly (P < 0.05/P < 0.01) upregulated. Immunostaining and immunoblotting also revealed significant (P < 0.05/P < 0.01) expression of several epithelial‐specific surface antigens and transcripts. Moreover, Ayoub Shaklar staining (specific to keratin) of KGF treated cells showed formation of keratin (reddish brown color) within cytoplasm of the cells, whereas control and BMP‐6 treated cells did not. Conclusively, KGF was observed to have the potential to enhance MET and these clues could be used in future research into cellular reprogramming and regenerative medicine.
CFD Simulation of the Heat and Mass Transfer Process during Centrifugal Short‐Path Distillation
Authors: Yu Jiang , Chen Lijun , Yuan Xigang , Zeng Aiwu , Ju Ji
Published: December 2014

Numerical simulation was carried out for a centrifugal short‐path distillation arrangement using the computational fluid dynamics technology. Both two phases and interfacial transport were taken into account with an attempt to explore the heat and mass transport in the film body and the interface. The model tried to provide a general method to study the short‐path distillation in various situations. The effects of feed flow rates, feed and heating wall temperature controlling the development of the temperature and concentration along the axial and radial direction were investigated. On the basis of the simulation results, detailed characteristics such as distribution of temperature and concentration, heat and mass transfer coefficient throughout the liquid film can be described.
Delivery of Single Nanoparticles from Nanopipettes under Resistive‐Pulse Control
Authors: Wang Yixian , Cai Huijing , Mirkin Michael V.
Published: December 2014

In this communication we show that the resistive‐pulse setup can be employed to control the delivery of single nanoparticles from a nanopipette. The precise pipette positioning for local delivery of nanoparticles can be attained by using it as a scanning ion‐conductance microscopy (SICM) tip. Experimental SICM approach curves fit the developed theory well.
Platinum Nanoparticles Encapsulated in Nitrogen‐Doped Mesoporous Carbons as Methanol‐Tolerant Oxygen Reduction Electrocatalysts
Authors: Guo Xin , Li Li , Zhang Xiaohua , Chen Jinhua
Published: December 2014

Platinum nanoparticles (Pt NPs) encapsulated in nitrogen‐doped mesoporous carbons (NMCs) are prepared by direct carbonization of zeolitic imidazolate framework‐8 (ZIF‐8)‐encapsulated Pt NPs, and used as a methanol‐tolerant oxygen reduction electrocatalyst. ZIF‐8 is used as the carbon and nitrogen precursors and as a matrix for Pt NPs. The obtained Pt NP–NMC hybrids are characterized in detail. The results show that the Pt NP–NMC hybrids possess high surface area (1226 m2 g−1), abundant mesopores with narrow pore size distribution (centered at 3.9 nm), nitrogen doping (5.13 at %), and small and well‐dispersed encapsulated Pt NPs (3.7 nm). Furthermore, the prepared Pt NP–NMC catalyst exhibits high electrocatalytic activity, high stability and excellent methanol tolerance in the oxygen reduction reaction.
Structure–Property Relationship of Supramolecular Ferroelectric [H‐66dmbp][Hca] Accompanied by High Polarization, Competing Structural Phases, and Polymorphs
Authors: Kobayashi Kensuke , Horiuchi Sachio , Ishibashi Shoji , Kagawa Fumitaka , Murakami Youichi , Kumai Reiji
Published: December 2014

Three polymorphic forms of 6,6′‐dimethyl‐2,2′‐bipyridinium chloranilate crystals were characterized to understand the origin of polarization properties and the thermal stability of ferroelectricity. According to the temperature‐dependent permittivity, differential scanning calorimetry, and X‐ray diffraction, structural phase transitions were found in all polymorphs. Notably, the ferroelectric α‐form crystal, which has the longest hydrogen bond (2.95 Å) among the organic acid/base‐type supramolecular ferroelectrics, transformed from a polar structure (space group, P21) into an anti‐polar structure (space group, P21/c) at 378 K. The non‐ferroelectric β‐ and γ‐form crystals also exhibited structural rearrangements around hydrogen bonds. The hydrogen‐bonded geometry and ferroelectric properties were compared with other supramolecular ferroelectrics. A positive relationship between the phase‐transition temperature (TC) and hydrogen‐bond length () was observed, and was attributed to the potential barrier height for proton off‐centering or order/disorder phenomena. The optimized spontaneous polarization (Ps) agreed well with the results of the first‐principles calculations, and could be amplified by separating the two equilibrium positions of protons with increasing . These data consistently demonstrated that stretching  is a promising way to enhance the polarization performance and thermal stability of hydrogen‐bonded organic ferroelectrics.
Phosphorescent Ruthenium Complexes with a Nitroimidazole Unit that Image Oxygen Fluctuation in Tumor Tissue
Authors: Son Aoi , Kawasaki Atsushi , Hara Daiki , Ito Takeo , Tanabe Kazuhito
Published: December 2014

Understanding oxygen fluctuation in a cancerous tumor is important for effective treatment, especially during radiotherapy. In this paper, ruthenium complexes bearing a nitroimidazole group are shown to report the oxygen status in tumor tissue directly. The nitroimidazole group was known to be accumulated in hypoxic tumor tissues. On the other hand, the ruthenium complex showed strong phosphorescence around 600 nm. The emission of ruthenium is quenched instantaneously by molecular oxygen due to energy transfer between triplet states of oxygen and ruthenium complex, but the emission is then recovered by the removal of oxygen. Thus, we could observe oxygen fluctuation in tumor tissue in a real‐time manner by monitoring the phosphorescence of the ruthenium complex. The versatility of the probe is demonstrated by monitoring oxygen fluctuation in living cells and tumor tissue planted in mice. The ruthenium complex promptly penetrated plasma membrane and accumulated in cells to emit its oxygen‐dependent phosphorescence. In vivo experiments revealed that the oxygen level in tumor tissue seems to fluctuate at the sub‐minute timescale.
Hydrothermal Synthesis, Structure, and Optical Properties of Two Nanosized Ln26@CO3 (Ln=Dy and Tb) Cluster‐Based Lanthanide–Transition‐Metal–Organic Frameworks (Ln MOFs)
Authors: Zhang Yu , Huang Lian , Miao Hao , Wan Hong Xiang , Mei Hua , Liu Ying , Xu Yan
Published: December 2014

Two Ln26@CO3 (Ln=Dy and Tb) cluster‐based lanthanide–transition‐metal–organic frameworks (Ln MOFs) formulated as [Dy26Cu3(Nic)24(CH3COO)8(CO3)11(OH)26(H2O)14]Cl ⋅3 H2O (1; HNic=nicotinic acid) and [Tb26NaAg3(Nic)27(CH3COO)6(CO3)11(OH)26Cl(H2O)15]⋅7.5 H2O (2) have been successfully synthesized by hydrothermal methods and characterized by IR, thermogravimetric analysis (TGA), elemental analysis, and single X‐ray diffraction. Compound 1 crystallizes in the monoclinic space group Cc with a=35.775(12) Å, b=33.346(11) Å, c=24.424(8) Å, β=93.993(5)°, V=29065(16) Å3, whereas 2 crystallizes in the triclinic space group P with a=20.4929(19) Å, b=24.671(2) Å, c=29.727(3) Å, α=81.9990(10)°, β=88.0830(10)°, γ=89.9940(10)°, V=14875(2) Å3. Structural analysis indicates the framework of 1 is a 3D perovskite‐like structure constructed out of CO3@Dy26 building units and Cu+ centers by means of nicotinic acid ligand bridging. In 2, however, nanosized CO3@Tb26 units and [Ag3Cl]2+ centers are connected by Nic− bridges to give rise to a 2D structure. It is worth mentioning that this kind of 4d–4f cluster‐based MOF is quite rare as most of the reported analogous compounds are 3d–4f ones. Additionally, the solid‐state emission spectra of pure compound 2 at room temperature suggest an efficient energy transfer from the ligand Nic− to Tb3+ ions, which we called the “antenna effect”. Compound 2 shows a good two‐photon absorption (TPA) with a TPA coefficient of 0.06947 cm GM−1 (1 GM=10−50 cm4 s photon−1), which indicates that compound 2 might be a good choice for third‐order nonlinear optical materials.
Metal Complexes of a Boron‐Dipyrromethene (BODIPY)‐Tagged N‐Heterocyclic Carbene (NHC) as Luminescent Carbon Monoxide Chemodosimeters
Authors: Kos Pavlo , Plenio Herbert
Published: December 2014

Several metal complexes with a boron dipyrromethene (BODIPY)‐functionalized N‐heterocyclic carbene (NHC) ligand 4 were synthesized. The fluorescence in [(4)(SIMes)RuCl2(ind)] complex is quenched (Φ=0.003), it is weak in [(4)PdI2(Clpy)] (Φ=0.033), and strong in [(4)AuI] (Φ=0.70). The BODIPY‐tagged complexes can experience pronounced changes in the brightness of the fluorophore upon ligand‐exchange and ligand‐dissociation reactions. Complexes [(4)MX(1,5‐cyclooctadiene)] (M=Rh, Ir; X=Cl, I; Φ=0.008–0.016) are converted into strongly fluorescent complexes [(4)MX(CO)2] (Φ=0.53–0.70) upon reaction with carbon monoxide. The unquenching of the Rh and Ir complexes appears to be a consequence of the decreased electron density at Rh or Ir in the carbonyl complexes. In contrast, the substitution of an iodo ligand in [(4)AuI] by an electron‐rich thiolate decreases the brightness of the BODIPY fluorophore, rendering the BODIPY as a highly sensitive probe for changes in the coordination sphere of the transition metal.
A Bowl‐Shaped Circular Trinuclear Helicate Generated from a TiO4N2 Motif by a Multicomponent Self‐Assembly Approach
Authors: Mobian Pierre , Baradel Nathalie , Kyritsakas Nathalie , Khalil Georges , Henry Marc
Published: December 2014

The synthesis of a bowl‐shaped trinuclear circular titanium‐based helicate is reported. The strategy allowing access to this neutral architecture is based on a multicomponent self‐assembly approach in which the ligands involved in the process are a bis‐biphenol strand and 2,2′‐ bipyrimidine. By reacting the bis‐biphenol ligand and 2,2′‐bipyrimidine with an equimolar amount [Ti(OiPr)4], a bowl‐shaped architecture is obtained through the formation of 18 new coordination bonds. This aggregate built from three octahedral TiO4N2 nodes displays an unusually high stability in solution compared to related species. In addition, by modifying the stoichiometry of the initial components, two assemblies incorporating two titanium centers bridged by a 2,2′‐bipyrimidine ligand are obtained. The crystal structures of these species are reported.
Control over Nanostructures and Associated Mesomorphic Properties of Doped Self‐Assembled Triarylamine Liquid Crystals
Authors: Domoto Yuya , Busseron Eric , Maaloum Mounir , Moulin Emilie , Giuseppone Nicolas
Published: December 2014

We have synthesized a series of triarylamine‐cored molecules equipped with an adjacent amide moiety and dendritic peripheral tails in a variety of modes. We show by 1H NMR and UV/Vis spectroscopy that their supramolecular self‐assembly can be promoted in solution upon light stimulation and radical initiation. In addition, we have probed their molecular arrangements and mesomorphic properties in the bulk by integrated studies on their film state by using differential scanning calorimetry (DSC), variable‐temperature polarizing optical microscopy (VT‐POM), variable‐temperature X‐ray diffraction (VT‐XRD), and atomic force microscopy (AFM). Differences in the number and the disposition of the peripheral tails significantly affect their mesomorphic properties associated with their lamellar‐ or columnar‐packed nanostructures, which are based on segregated stacks of the triphenylamine cores and the lipophilic/lipophobic periphery. Such structural tuning is of interest for implementation of these soft self‐assemblies as electroactive materials from solution to mesophases.
Peptoid‐Ligated Pentadecanuclear Yttrium and Dysprosium Hydroxy Clusters
Authors: Thielemann Dominique T. , Wagner Anna T. , Lan Yanhua , Oña‐Burgos Pascual , Fernández Ignacio , Rösch Esther S. , Kölmel Dominik K. , Powell Annie K. , Bräse Stefan , Roesky Peter W.
Published: December 2014

A new family of pentadecanuclear coordination cluster compounds (from now on simply referred to as clusters) [{Ln15(OH)20(PepCO2)10(DBM)10Cl}Cl4] (PepCO2=2‐[{3‐(((tert‐butoxycarbonyl)amino)methyl)benzyl}amino]acetate, DBM=dibenzoylmethanide) with Ln=Y and Dy was obtained by using the cell‐penetrating peptoid (CPPo) monomer PepCO2H and dibenzoylmethane (DBMH) as supporting ligands. The combination of an inorganic cluster core with an organic cell‐penetrating peptoid in the coordination sphere resulted in a core component {Ln15(μ3‐OH)20Cl}24+ (Ln=Y, Dy), which consists of five vertex‐sharing heterocubane {Ln4(μ3‐OH)4}8+ units that assemble to give a pentagonal cyclic structure with one Cl atom located in the middle of the pentagon. The solid‐state structures of both clusters were established by single‐crystal X‐ray crystallography. MS (ESI) experiments suggest that the cluster core is robust and maintained in solution. Pulsed gradient spin echo (PGSE) NMR diffusion measurements were carried out on the diamagnetic yttrium compound and confirmed the stability of the cluster in its dicationic form [{Y15(μ3‐OH)20(PepCO2)10(DBM)10Cl}Cl2]2+. The investigation of both static (dc) and dynamic (ac) magnetic properties in the dysprosium cluster revealed a slow relaxation of magnetization, indicative of single‐molecule magnet (SMM) behavior below 8 K. Furthermore, the χT product as a function of temperature for the dysprosium cluster gave evidence that this is a ferromagnetically coupled compound below 11 K.
Approach to High Open‐Circuit Voltage in Organic Solar Cells Utilizing a Structural Change of the Oxazolino‐C70 Derivative
Authors: Li Shu‐Hui , Li Zong‐Jun , Nakagawa Takafumi , Ryan James W. , Matsuo Yutaka , Gao Xiang
Published: December 2014

Reactions of 2,5‐Bn2C70 (Bn=CH2Ph) with hydroxide and ArCN (Ar=Ph, m‐ClPh) followed by quenching with I2 and BnBr afforded dibenzylated and tetrabenzylated oxazolino[70]fullerenes, respectively. The latter has a novel structural configuration, in which the addends are positioned from the polar to the transequatorial region. A key structural feature of this compound is that the oxygen atom of the oxazoline ring is bound to the equatorial belt region of C70, giving structural change in its reduced state. This enables stabilization of the reduced state, suppressing charge recombination dynamics in organic solar cells to give a high open‐circuit voltage (0.85, 0.93, and 1.11 V in devices using P3HT, PTB7, and DPP(TBFu)2, respectively).
Synthesis of (±)‐Spongiolactone Enabling Discovery of a More Potent Derivative
Authors: Harvey Natalie L. , Krysiak Joanna , Chamni Supakarn , Cho Sung Wook , Sieber Stephan A. , Romo Daniel
Published: December 2014

An eleven‐step synthesis of (±)‐spongiolactone from 1,3‐cyclohexanedione is reported that relies on a diastereoselective, nucleophile‐catalyzed aldol lactonization (NCAL) process with an advanced ketoacid intermediate that installed the anticipated β‐lactone pharmacophore of the natural product. In addition, a stereoselective cyclohexenyl zinc addition to a substituted cyclohexanone simultaneously installed two fully substituted vicinal stereocenters. The reported synthesis enabled preliminary structure–activity studies that revealed a regio‐ and stereoisomeric derivative of spongiolactone with greater antiproliferative activity towards a leukemia (K562) cell line. Furthermore, unusual antiproliferative selectivity of these spongiolactone derivatives toward the K562 cell line was observed with no inhibition of the breast, liver, and lung cancer cell lines tested.
Friedelin aus Kork
Authors: Seupel Raina , Roth Alexander , Steinke Katrin , Sicker Dieter , Siehl Hans‐Ullrich , Zeller Klaus‐Peter , Berger Stefan
Published: December 2014

Der Kork der Korkeiche ist ein faszinierendes Naturmaterial, das seit der Antike genutzt wird. Kork war 1665 auch Namensgeber für die “Zelle” in der Biologie. Friedelin, ein kompliziertes pentacyclisches Triterpenketon, ist ein Korkbestandteil. Wir beschreiben seine Isolierung und berichten über seine Historie. Alle analytischen Spektren sind vollständig entweder im Hauptteil oder in der supporting information wiedergegeben. Die NMR‐ sowie die Massenspektren werden eingehend interpretiert und mit theoretischen Berechnungen der 13C chemischen Verschiebungen verglichen. Das Projekt stellt eine Fortsetzung des Buches “Classics in Spectroscopy” von S. Berger und D. Sicker (Wiley‐VCH 2009) dar.
Die Ostsee atmet auf
Authors: Naumann Michael , Nausch Günther
Published: December 2014

Aktuelle Messdaten zur Umweltüberwachung der Ostsee zeigen einen größeren Einstrom von sauerstoffreichem Salzwasser aus der Nordsee an. Zum ersten Mal seit 2003 wurde das Tiefenwasser der zentralen Ostsee mit größeren Mengen von Sauerstoff versorgt und Schwefelwasserstoff verdrängt. Dieser Effekt wurde durch ein Zusammenwirken mehrerer kleiner Einstromphasen im Winter bis Frühjahr 2013/2014 ausgelöst, die die Wirkung eines in der Fachterminologie als “Major Baltic Inflow” (MBI) bezeichneten Salzwassereinbruchs erzielen. Ende Juli 2014 wurde das Gotlandtief (240 m Wassertiefe, Abbildung 1) von diesen Wassermassen erreicht und die durch langanhaltende Stagnation gekennzeichneten schlechten Umweltbedingungen des Tiefenwassers wurden verbessert.
Phosphatfreie Seife
Authors: Feil Sylvia
Published: December 2014

Silanole haben die gleichen funktionellen Gruppen wie die in der Natur vorkommende Kieselsäue, industriell sind sie Vorläufer für Polysiloxane, also Silicone. Sie kondensieren sehr leicht, sind aber über ihre Verknüpfung gut steuerbar in Richtung Siliconöle oder Siliconharze. Bisher wurde aber wenig untersucht, wie sich gelöste Silanole verhalten. Die Idee, sie als grenzflächenaktiven Stoff zu verwenden, überraschte.
Tunable Nonlinear Optical Property and Photocatalytic Activity on Luminescent Chiral Lanthanide Chains
Authors: Qu Mei , Liu Minmin , Liu Jiang , Zhang Xianming
Published: December 2014

Five chiral (P21) isostructural lanthanide coordination complexes Ln(pic)3 [pic=picolinic acid, Ln=La (1), Gd (2), Nd (3), Sm (4) and Eu (5)] have been hydrothermally generated, featuring one dimensional right‐handed 21 helical chains constructed from LnN3O6 of square antiprism geometry and N,O‐chelated pic− groups, in which 3, 4 and 5 have been reported, but we explore undiscovered properties of their own systematically. In special, 1 undergoes an abnormal transformation of symmetry as the temperature cooling to 100 K. TG‐DSC studies demonstrated that all isologues have good thermal stability with the decomposition temperature up to 400°C. Then, UV‐Vis‐NIR transmission spectroscopy measurements indicated that they possess a short‐wavelength absorption edge onset at 377 nm, corresponding to the optical band gap of 3.29 eV. Meanwhile, powder second harmonic generation (SHG) measurements revealed that the SHG intensity of 1, 2, 4 and 5 may be about 1.2, 2.0, 0.9 and 0.75 times that of KH2PO4, respectively. Interestingly, 1 and 3 exhibit efficient photocatalytic degradation for MB (Methylene Blue) upon UV‐light irradiation. Moreover, both 1 and 2 show strong blue luminescence.