bluuebunny/crossref_metadata_2025 huggingface dataset:
Food mechanical properties and dietary ecology
Authors: Berthaume Michael A.
Published: January 2016

Interdisciplinary research has benefitted the fields of anthropology and engineering for decades: a classic example being the application of material science to the field of feeding biomechanics. However, after decades of research, discordances have developed in how mechanical properties are defined, measured, calculated, and used due to disharmonies between and within fields. This is highlighted by “toughness,” or energy release rate, the comparison of incomparable tests (i.e., the scissors and wedge tests), and the comparison of incomparable metrics (i.e., the stress and displacement‐limited indices). Furthermore, while material scientists report on a myriad of mechanical properties, it is common for feeding biomechanics studies to report on just one (energy release rate) or two (energy release rate and Young's modulus), which may or may not be the most appropriate for understanding feeding mechanics. Here, I review portions of materials science important to feeding biomechanists, discussing some of the basic assumptions, tests, and measurements. Next, I provide an overview of what is mechanically important during feeding, and discuss the application of mechanical property tests to feeding biomechanics. I also explain how 1) toughness measures gathered with the scissors, wedge, razor, and/or punch and die tests on non‐linearly elastic brittle materials are not mechanical properties, 2) scissors and wedge tests are not comparable and 3) the stress and displacement‐limited indices are not comparable. Finally, I discuss what data gathered thus far can be best used for, and discuss the future of the field, urging researchers to challenge underlying assumptions in currently used methods to gain a better understanding between primate masticatory morphology and diet. Am J Phys Anthropol 159:S79–S104, 2016. © 2016 Wiley Periodicals, Inc.
Bone morphologies and histories: Life course approaches in bioarchaeology
Authors: Agarwal Sabrina C.
Published: January 2016

The duality of the skeleton as both a biological and cultural entity has formed the theoretical basis of bioarchaeology. In recent years bioarchaeological studies have stretched the early biocultural concept with the adoption of life course approaches in their study design and analyses, making a significant contribution to how we think about the role of postnatal plasticity. Life course theory is a conceptual framework used in several scientific fields of biology and the social sciences. Studies that emphasize life course approaches in the examination of bone morphology in the past are united in their interrogation of human life as a result of interrelated and cumulative events over not only the timeframe of individuals, but also over generations at the community level. This article provides an overview of the theoretical constructs that utilize the life course concept, and a discussion of the different ways these theories have been applied to thinking about trajectories of bone morphology in the past, specifically highlighting key recent studies that have used life course approaches to understand the influence of growth, stress, diet, activity, and aging on the skeleton. The goal of this article is to demonstrate the scope of contemporary bioarchaeological studies that illuminate the importance of environmental and behavioral influence on bone morphology. Understanding how trajectories of bone growth and morphology can be altered and shaped over the life course is critical not only for bioarchaeologists, but also researchers studying bone morphology in living nonhuman primates and fossil primate skeletons. Am J Phys Anthropol 159:S130–S149, 2016. © 2016 American Association of Physical Anthropologists
Does the primate pattern hold up? Testing the functional significance of infraorbital foramen size variation among marsupials
Authors: Spriggs Amanda N. , Muchlinski Magdalena N. , Gordon Adam D.
Published: January 2016

Objectives

The relative size of the infraorbital foramen (IOF) has been used to infer the ecology of extinct primates for several decades. Primates have relatively smaller IOFs than most other mammals, which may result from the fact that they pre‐process and manipulate food with their hands rather than their muzzles. In primates, relative IOF area co‐varies with diet, where insectivores and folivores have relatively smaller IOFs than frugivores. We wanted to determine whether the observed patterns associated with IOF variation hold across other orders.

Materials and Methods

We examined how relative IOF area differs among marsupials occupying different ecological niches. Marsupials were chosen because they converge with primates in both ecology and morphology, but unlike primates, some marsupials approach and pre‐process foods only with their muzzles. We measured IOF area and cranial lengths from 72 marsupial species, and behavioral feeding data were obtained from a subset of this sample (N = 20).

Results

Relative IOF area did not vary significantly between substrate preferences. However, relative IOF area differed significantly by diet category (P < 0.001). Species that specialize in feeding on non‐grassy leaves have significantly smaller relative IOF areas than species which primarily feed on grasses, insects, vertebrates, or some combination thereof. Behavioral analyses support that folivorous marsupials approach and remove food with the hands more often than marsupials from other dietary groups.

Discussion

Results suggest that relatively small IOF area may reflect increased reliance on the hands while feeding, and that relative IOF size can be used as an indicator of feeding behavior. Am J Phys Anthropol 160:30–40, 2016. © 2016 Wiley Periodicals, Inc.
Antarlides: A New Type of Androgen Receptor (AR) Antagonist that Overcomes Resistance to AR‐Targeted Therapy
Authors: Saito Shun , Fujimaki Takahiro , Panbangred Watanalai , Igarashi Yasuhiro , Imoto Masaya
Published: January 2016

Prostate cancer is treated with androgen receptor (AR) antagonists but most patients experience disease progression after long‐term treatment with these compounds. Therefore, new AR antagonists are required for patient follow‐up treatment. In the course of screening for a new AR antagonist, we isolated the novel compounds antarlides A–E (1–5) from Streptomyces sp. BB47. Antarlides are mutually isomeric with respect to the double bond and have a 22‐membered‐ring macrocyclic structure. The full stereostructure of 1 was established by chemical modifications, including methanolysis, the Trost method, acetonide formation, and the PGME method. 1–5 inhibited the binding of androgen to ARs in vitro. In addition, 2 inhibited the transcriptional activity of not only wild‐type AR but also mutant ARs, which are seen in patients with acquired resistance to clinically used AR antagonists. Therefore, antarlides are a potent new generation of AR antagonists that overcome resistance.
Mechanochromism and Mechanical‐Force‐Triggered Cross‐Linking from a Single Reactive Moiety Incorporated into Polymer Chains
Authors: Zhang Huan , Gao Fei , Cao Xiaodong , Li Yanqun , Xu Yuanze , Weng Wengui , Boulatov Roman
Published: January 2016

Incorporation of small reactive moieties, the reactivity of which depends on externally imposed load (so‐called mechanophores) into polymer chains offers access to a broad range of stress‐responsive materials. Here, we report that polymers incorporating spirothiopyran (STP) manifest both green mechanochromism and load‐induced addition reactions in solution and solid. Stretching a macromolecule containing colorless STP converts it into green thiomerocyanine (TMC), the mechanically activated thiolate moiety of which undergoes rapid thiol–ene click reactions with certain reactive C=C bonds to form a graft or a cross‐link. The unique dual mechanochemical response of STP makes it of potentially great utility both for the design of new stress‐responsive materials and for fundamental studies in polymer physics, for example, the dynamics of physical and mechanochemical remodeling of loaded materials.
Photoresponsive Formation of an Intermolecular Minimal G‐Quadruplex Motif
Authors: Thevarpadam Julie , Bessi Irene , Binas Oliver , Gonçalves Diana P. N. , Slavov Chavdar , Jonker Hendrik R. A. , Richter Christian , Wachtveitl Josef , Schwalbe Harald , Heckel Alexander
Published: January 2016

The ability of three different bifunctional azobenzene linkers to enable the photoreversible formation of a defined intermolecular two‐tetrad G‐quadruplex upon UV/Vis irradiation was investigated. Circular dichroism and NMR spectroscopic data showed the formation of G‐quadruplexes with K+ ions at room temperature in all three cases with the corresponding azobenzene linker in an E conformation. However, only the para–para‐substituted azobenzene derivative enables photoswitching between a nonpolymorphic, stacked, tetramolecular G‐quadruplex and an unstructured state after E–Z isomerization.
Basenfreie katalytische asymmetrische C‐C‐Kupplung mit terminalen Inamiden als effizienter Zugang zu multifunktionellen Trifluormethylalkoholen
Authors: Cook Andrea M. , Wolf Christian
Published: January 2016

Die asymmetrische Addition terminaler Inamide an Trifluormethylketone mit einem leicht zugänglichem chiralen Zink‐Katalysator ergibt CF3‐substituierte tertiäre Propargylalkohole mit bis zu 99 % Ausbeute und 96 % ee. Der Ausschluss von organischen Zinkadditiven und Basen sowie der Nutzen der Produkte für Synthesen sind besondere Merkmale dieser Reaktion. Der Wert der β‐Hydroxy‐β‐trifluormethylinamide ist exemplarisch mit ausgewählten Umwandlungen zu chiralen Z‐ und E‐Enamiden, einem Amid und N,O‐Ketenacetalen belegt. Die äußerst regioselektive Hydratisierung, stereoselektive Reduktionen und Hydroacyloxylierungen erfolgen mit hohen Ausbeuten und ohne Erosion des ee der verwendeten β‐Hydroxyinamide.
Spurlose Synthese von asymmetrisch modifizierten, bivalenten Nukleosomen
Authors: Lechner Carolin C. , Agashe Ninad D. , Fierz Beat
Published: January 2016

Kombinationen verschiedener posttranslationaler Modifikationen (PTMs) von Histon‐Proteinen haben einen direkten Einfluss auf die epigenetische Genregulation. Obwohl Histone paarweise in Nukleosomen vorliegen, sind die individuellen Histonvarianten nicht zwangsläufig gleich modifiziert, sondern weisen oftmals unterschiedliche PTMs auf (sie sind “asymmetrisch”). Insbesondere in embryonalen Stammzellen (ESCs) existiert eine “bivalente” Chromatinsignatur, gekennzeichnet durch die Koexistenz von H3, entweder trimethyliert an Lysin 4 (H3K4me3) oder 27 (H3K27me3) im gleichen Nukleosom. Wir beschreiben hier ein generell anwendbares und modulares Verfahren zur Herstellung von asymmetrisch modifizierten Nukleosomen. Mittels dieser Methode können wir darlegen, dass die H3K27‐spezifische Lysin‐Methyltransferase (KMT) Polycomb Repressive Complex 2 (PRC2) in bivalenten Nukleosomen durch H3K4me3 inhibiert wird, allerdings nur solange sich die PTM auf demselben H3‐Molekül befindet. Im Gegensatz dazu stimuliert die Anwesenheit von H3K27me3 die Aktivität von PRC2 über das gesamte Nukleosom, und hebt den hemmenden Effekt von H3K4me3 auf. Um in ESCs eine bivalente Chromatinsignatur zu erhalten, muss folglich die Aktivität von PRC2 entweder lokal eingeschränkt oder gar aktiv rückgängig gemacht werden.
Cobalt‐Catalyzed Annulation of Salicylaldehydes and Alkynes to Form Chromones and 4‐Chromanones
Authors: Yang Junfeng , Yoshikai Naohiko
Published: January 2016

A unique cobalt(I)–diphosphine catalytic system has been identified for the coupling of salicylaldehyde (SA) and an internal alkyne affording a dehydrogenative annulation product (chromone) or a reductive annulation product (4‐chromanone) depending on the alkyne substituents. Distinct from related rhodium(I)‐ and rhodium(III)‐catalyzed reactions of SA and alkynes, these annulation reactions feature aldehyde C−H oxidative addition of SA and subsequent hydrometalation of the C=O bond of another SA molecule as common key steps. The reductive annulation to 4‐chromanones also involves the action of Zn as a stoichiometric reductant. In addition to these mechanistic features, the CoI catalysis described herein is complementary to the RhI‐ and RhIII‐catalyzed reactions of SA and internal alkynes, particularly in the context of chromone synthesis.
Stretch‐Induced Drug Delivery from Superhydrophobic Polymer Composites: Use of Crack Propagation Failure Modes for Controlling Release Rates
Authors: Wang Julia , Kaplan Jonah A. , Colson Yolonda L. , Grinstaff Mark W.
Published: January 2016

The concept of using crack propagation in polymeric materials to control drug release and its first demonstration are reported. The composite drug delivery system consists of highly‐textured superhydrophobic electrosprayed microparticle coatings, composed of biodegradable and biocompatible polymers poly(caprolactone) and poly(glycerol monostearate carbonate‐co‐caprolactone), and a cellulose/polyester core. The release of entrapped agents is controlled by the magnitude of applied strain, resulting in a graded response from water infiltration through the propagating patterned cracks in the coating. Strain‐dependent delivery of the anticancer agents cisplatin and 7‐ethyl‐10‐hydroxycamptothecin to esophageal cancer cells (OE33) in vitro is observed. Finally the device is integrated with an esophageal stent to demonstrate delivery of fluorescein diacetate, using applied tension, to an ex vivo esophagus.
Nickel‐Catalyzed Activation of Acyl C−O Bonds of Methyl Esters
Authors: Hie Liana , Fine Nathel Noah F. , Hong Xin , Yang Yun‐Fang , Houk Kendall N. , Garg Neil K.
Published: January 2016

We report the first catalytic method for activating the acyl C−O bonds of methyl esters through an oxidative‐addition process. The oxidative‐addition adducts, formed using nickel catalysis, undergo in situ trapping to provide anilide products. DFT calculations are used to support the proposed reaction mechanism, to understand why decarbonylation does not occur competitively, and to elucidate the beneficial role of the substrate structure and the Al(OtBu)3 additive on the kinetics and thermodynamics of the reaction.
Elastic Organic Crystals of a Fluorescent π‐Conjugated Molecule
Authors: Hayashi Shotaro , Koizumi Toshio
Published: January 2016

An elastic organic crystal of a π‐conjugated molecule has been fabricated. A large fluorescent single crystal of 1,4‐bis[2‐(4‐methylthienyl)]‐2,3,5,6‐tetrafluorobenzene (over 1 cm long) exhibited a fibril lamella morphology based on slip‐stacked molecular wires, and it was found to be a remarkably elastic crystalline material. The straight crystal was capable of bending more than 180° under applied stress and then quickly reverted to its original shape upon relaxation. In addition, the fluorescence quantum yield of the crystal was about twice that of the compound in THF solution. Mechanical bending–relaxation resulted in reversible change of the morphology and fluorescence. This research offers a more general approach to flexible crystals as a promising new family of organic semiconducting materials.
Near‐IR Emitting Iridium(III) Complexes with Heteroaromatic β‐Diketonate Ancillary Ligands for Efficient Solution‐Processed OLEDs: Structure–Property Correlations
Authors: Kesarkar Sagar , Mróz Wojciech , Penconi Marta , Pasini Mariacecilia , Destri Silvia , Cazzaniga Marco , Ceresoli Davide , Mussini Patrizia R. , Baldoli Clara , Giovanella Umberto , Bossi Alberto
Published: January 2016

Three NIR‐emitting neutral IrIII complexes [Ir(iqbt)2(dpm)] (1), [Ir(iqbt)2(tta)] (2), and [Ir(iqbt)2(dtdk)] (3) based on the 1‐(benzo[b]thiophen‐2‐yl)‐isoquinolinate (iqtb) were synthesized and characterized (dpm=2,2,6,6‐tetramethyl‐3,5‐heptanedionate; tta=2‐thienoyltrifluoroacetonate; dtdk=1,3‐di(thiophen‐2‐yl)propane‐1,3‐dionate). The compounds emit between λ=680 and 850 nm with high luminescence quantum yields (up to 16 %). By combining electrochemistry, photophysical measurements, and computational modelling, the relationship between the structure, energy levels, and properties were investigated. NIR‐emitting, solution‐processed phosphorescent organic light‐emitting devices (PHOLEDs) were fabricated using the complexes. The devices show remarkable external quantum efficiencies (above 3 % with 1) with negligible efficiency roll‐off values, exceeding the highest reported values for solution‐processible NIR emitters.
Copolymerization of Ethylene and Polar Monomers by Using Ni/IzQO Catalysts
Authors: Tao Wen‐jie , Nakano Ryo , Ito Shingo , Nozaki Kyoko
Published: January 2016

The replacement of precious metals in catalysis by earth‐abundant metals is currently one of the urgent challenges for chemists. Whereas palladium‐catalyzed copolymerization of ethylene and polar monomers is a valuable method for the straightforward synthesis of functionalized polyolefins, the corresponding nickel‐based catalysts have suffered from poor thermal tolerance and low molecular weight of the polymers formed. Herein, we report a series of neutral nickel complexes bearing imidazo[1,5‐a]quinolin‐9‐olate‐1‐ylidene (IzQO) ligands. The Ni/IzQO system can catalyze ethylene polymerization at 50–100 °C with reasonable activity in the absence of any cocatalyst, whereas most known nickel‐based catalysts are deactivated at this temperature range. The Ni/IzQO catalyst was successfully applied to the copolymerization of ethylene with allyl monomers to obtain the corresponding copolymers with the highest molecular weight reported for a Ni‐catalyzed system.
Chromatographic NMR Spectroscopy with Hollow Silica Spheres
Authors: González‐García Tania , Margola Tommaso , Silvagni Adriano , Mancin Fabrizio , Rastrelli Federico
Published: January 2016

The use of micrometric hollow silica spheres is described as a strategy to reduce magnetic field inhomogeneities in the context of NMR chromatography. When employed as a stationary phase, hollow silica microspheres allow the use of common solution‐state NMR instruments to measure the diffusion coefficient perturbation induced by the interaction of the analytes with the silica surface.
Breast Cancer Stem Cell Potent Copper(II)–Non‐Steroidal Anti‐Inflammatory Drug Complexes
Authors: Boodram Janine N. , Mcgregor Iain J. , Bruno Peter M. , Cressey Paul B. , Hemann Michael T. , Suntharalingam Kogularamanan
Published: January 2016

The breast cancer stem cell (CSC) potency of a series of copper(II)–phenanthroline complexes containing the nonsteroidal anti‐inflammatory drug (NSAID), indomethacin, is reported. The most effective copper(II) complex in this series, 4, selectivity kills breast CSC‐enriched HMLER‐shEcad cells over breast CSC‐depleted HMLER cells. Furthermore, 4 reduces the formation, size, and viability of mammospheres, to a greater extent than salinomycin, a potassium ionophore known to selectively inhibit CSCs. Mechanistic studies revealed that the CSC‐specificity observed for 4 arises from its ability to generate intracellular reactive oxygen species (ROS) and inhibit cyclooxygenase‐2 (COX‐2), an enzyme that is overexpressed in breast CSCs. The former induces DNA damage, activates JNK and p38 pathways, and leads to apoptosis.
Efficient Access to Multifunctional Trifluoromethyl Alcohols through Base‐Free Catalytic Asymmetric C−C Bond Formation with Terminal Ynamides
Authors: Cook Andrea M. , Wolf Christian
Published: January 2016

The asymmetric addition of terminal ynamides to trifluoromethyl ketones with a readily available chiral zinc catalyst gives CF3‐substituted tertiary propargylic alcohols in up to 99 % yield and 96 % ee. The exclusion of organozinc additives and base as well as the general synthetic utility of the products are key features of this reaction. The value of the β‐hydroxy‐β‐trifluoromethyl ynamides is exemplified by selective transformations to chiral Z‐ and E‐enamides, an amide, and N,O‐ketene acetals. The highly regioselective hydration, stereoselective reduction, and hydroacyloxylation reactions proceed with high yields and without erosion of the ee value of the parent β‐hydroxy ynamides.
A Diradical Approach towards BODIPY‐Based Dyes with Intense Near‐Infrared Absorption around λ=1100 nm
Authors: Ni Yong , Lee Sangsu , Son Minjung , Aratani Naoki , Ishida Masatoshi , Samanta Animesh , Yamada Hiroko , Chang Young‐Tae , Furuta Hiroyuki , Kim Dongho , Wu Jishan
Published: January 2016

A diradical approach to obtain stable organic dyes with intense absorption around λ=1100 nm is reported. The para‐ and meta‐quinodimethane‐bridged BODIPY dimers BD‐1 and BD‐2 were synthesized and were found to have a small amount of diradical character. These molecules exhibited very intense absorption at λ=1088 nm (ɛ=6.65×105 M−1 cm−1) and 1136 nm (ɛ=6.44×105 M−1 cm−1), respectively, together with large two‐photon‐absorption cross‐sections. Structural isomerization induced little variation in their diradical character but distinctive differences in their physical properties. Moreover, the compounds showed a selective fluorescence turn‐on response in the presence of the hydroxyl radical but not with other reactive oxygen species.
Controlling Peptide Self‐Assembly through a Native Chemical Ligation/Desulfurization Strategy
Authors: Rasale Dnyaneshwar B. , Konda Maruthi , Biswas Sagar , Das Apurba K.
Published: January 2016

Self‐assembled peptides were synthesized by using a native chemical ligation (NCL)/desulfurization strategy that maintained the chemical diversity of the self‐assembled peptides. Herein, we employed oxo‐ester‐mediated NCL reactions to incorporate cysteine, a cysteine‐based dipeptide, and a sterically hindered unnatural amino acid (penicillamine) into peptides. Self‐assembly of the peptides resulted in the formation of self‐supporting gels. Microscopy analysis indicated the formation of helical nanofibers, which were responsible for the formation of gel matrices. The self‐assembly of the ligated peptides was governed by covalent and non‐covalent interactions, as confirmed by FTIR, CD, fluorescence spectroscopy, and MS (ESI) analyses. Peptide disassembly was induced by desulfurization reactions with tris(2‐carboxyethyl)phosphine (TCEP) and glutathione at 80 °C. Desulfurization reactions of the ligated peptides converted the Cys and penicillamine functionalities into Ala and Val moieties, respectively. The self‐supporting gels showed significant shear‐thinning and thixotropic properties.
Direct conversion of xylan to butanol by a wild‐type Clostridium species strain G117
Authors: Yan Yu , Basu Anindya , Li Tinggang , He Jianzhong
Published: January 2016

Lignocellulosic biomass has great potential for use as a carbon source for the production of second‐generation biofuels by solventogenic bacteria. Here we describe the production of butanol by a newly discovered wild‐type Clostridium species strain G117 with xylan as the sole carbon source for fermentation. Strain G117 produced 0.86 ± 0.07 g/L butanol and 53.4 ± 0.05 mL hydrogen directly from 60 g/L xylan provided that had undergone no prior enzymatic hydrolysis. After process optimization, the amount of butanol produced from xylan was increased to 1.24 ± 0.37 g/L. In contrast to traditional acetone‐butanol‐ethanol (ABE) solventogenic fermentation, xylan supported fermentation in strain G117 and negligible amount of acetone was produced. The expression of genes normally associated with acetone production (adc and ctfB2) were down‐regulated compared to xylose fed cultures. This lack of acetone production may greatly simplify downstream separation process. Moreover, higher amount of butanol (2.94 g/L) was produced from 16.99 g/L xylo‐oligosaccharides, suggesting a major role for strain G117 in butanol production from xylan and its oligosaccharides. The unique ability of strain G117 to produce a considerable amount of butanol directly from xylan without producing undesirable fermentation byproducts opens the door to the possibility of cost‐effective biofuels production in a single step. Biotechnol. Bioeng. 2016;113: 1702–1710. © 2016 Wiley Periodicals, Inc.
Mortality in individuals with intellectual disabilities in Finland
Authors: Arvio Maria , Salokivi Tommi , Tiitinen Aila , Haataja Leena
Published: January 2016

Objectives

This study aimed at ascertaining the standardized mortality ratios (SMR) for those with an intellectual disability (ID) in Finland.

Materials and Methods

We used the statistical database of the national insurance institution of Finland and Statistics Finland's mean population figures. We determined the number of individuals who received benefits (disability allowance, disability pension, or care allowance for pensioners) due to an ID diagnosis and the number of those whose benefit had been terminated due to death during the years 1996–2011.

Results

SMR for females with a mild ID (IQ 50–69) was 2.8 (95% CI: 2.60–3.01) and for males 2.0 (95% CI: 1.88–2.14), and for females with a severe ID (IQ <50) 5.2 (95% CI: 4.99–5.50) and for males 2.6 (95% CI: 2.48–2.72).

Conclusion

This significant difference in the SMR figures between males and females with ID warrants further research.
Nanocomposites of Platinum/Metal–Organic Frameworks Coated with Metal–Organic Frameworks with Remarkably Enhanced Chemoselectivity for Cinnamaldehyde Hydrogenation
Authors: Liu Hongli , Chang Lina , Chen Liyu , Li Yingwei
Published: January 2016

The encapsulation of metal nanoparticles (MNPs) within metal–organic frameworks (MOFs) to form core–shell structural nanocomposites is one of the most promising methods to enhance the durability and selectivity of MOF‐supported metal catalysts. However, it is still a challenge to fully encapsulate tiny MNPs inside MOFs. Herein, we report a facile and general strategy to coat MOFs on the surface of Pt/MOFs by direct homoepitaxial growth. The obtained Pt/MOFs@MOFs nanocomposites retained the intrinsic properties (e.g., crystalline structure, pore texture, and surface area) of Pt/MOFs. Strikingly, the MOF‐coated materials exhibited a significantly enhanced chemoselectivity compared to the uncoated materials, for example, in the hydrogenation of cinnamaldehyde, the selectivity to cinnamyl alcohol through C=O hydrogenation was improved from 55 to 96 % at complete conversions of cinnamaldehyde. Moreover, Pt/MOFs@MOFs can be recycled without any remarkable loss in both activity and selectivity. The enhanced catalytic selectivity and stability of MNPs/MOFs could be related to the synergetic effects of the electron donation and nanoconfinement offered by the surrounding MOF networks.
Unique Use of Alkylation for Chemo‐Redox Activity by a PtIV Prodrug
Authors: Pathak Rakesh K. , Dhar Shanta
Published: January 2016

Resistance towards chemotherapeutics displayed by cancer cells is a significant stumbling block against fruitful cisplatin‐based therapy. A unique dual‐acting chemotherapeutic modality, Platin‐B, a prodrug of cisplatin and pipobroman‐mimicking alkylating agent, was constructed to circumvent tumor resistance. Platin‐B exhibited a superior cytotoxicity profile in cisplatin‐resistant cancer cells. Enhanced activity and the ability to overcome cancer‐induced resistance of Platin‐B was related to adduct formation with intracellular glutathione, followed by the activity of Platin‐B on the mitochondria of cells, along with its conventional nuclear activity. Alkylating moieties present on Platin‐B enhanced its cellular and subcellular concentration and protected it from early drug sequestration by biological thiols.
Reactions of 2‐Substituted Pyridines with Titanocenes and Zirconocenes: Coupling versus Dearomatisation
Authors: Reiß Fabian , Altenburger Kai , Becker Lisanne , Schubert Kathleen , Jiao Haijun , Spannenberg Anke , Hollmann Dirk , Arndt Perdita , Rosenthal Uwe
Published: January 2016

Reactions of group 4 metallocene sources with 2‐substituted pyridines were investigated to evaluate their coordination type between innocent and reductive dearomatisation as well as to probe the possibility for couplings. A dependence on the cyclopentadienyl ligands (Cp, Cp*), the metals (Ti, Zr), and the substrates (2‐phenyl‐, 2‐acetyl‐, and 2‐iminopyridine) was observed. While 2‐phenylpyridine is barely reactive, 2‐acetylpyridine reacts vigorously with the Cp‐substituted complexes and selectively with their Cp* analogues. With 2‐iminopyridine, in all cases selective reactions were observed. In the isolated [Cp2Ti], [Cp2Zr], and [Cp*2Zr] compounds the substrate coordinates by its pyridyl ring and the unsaturated side‐chain. Subsequently, the pyridine was dearomatised, which is most pronounced in the [Cp*2Zr] compounds. Using [Cp*2Ti] leads to the unexpected paramagnetic complexes [Cp*2TiIII(N,O‐acpy)] and [Cp*2TiIII(N,N′‐impy)]. This highlights the non‐innocent character of the pyridyl substrates.
Towards the Development of Structure‐Selective G‐Quadruplex‐Binding Indolo[3,2‐b]quinolines
Authors: Funke Andrea , Dickerhoff Jonathan , Weisz Klaus
Published: January 2016

The interaction of phenyl‐substituted indolo[3,2‐b]quinolines with DNA G‐quadruplexes of different topology were studied by using a combination of spectroscopic and calorimetric methodologies. N5‐Methylated indoloquinoline derivatives (MePIQ) with an aminoalkyl side chain exhibit high affinities for the parallel‐stranded MYC quadruplex and a (3+1)‐hybrid structure combined with an excellent discrimination against the antiparallel thrombin‐binding aptamer (TBA) and the human telomeric (HT) quadruplexes. Dissociation constants for the binding of the ligand to the MYC quadruplex are in the submicromolar range, being below the corresponding dissociation constants for the antiparallel‐stranded quadruplexes by about one order of magnitude. Competition experiments with double‐helical DNA reveal the impact of indoloquinoline structural features on the selectivity for the parallel quadruplex relative to duplex DNA. Based on a calorimetric analysis binding to MYC is shown to be equally driven by favorable enthalpic and entropic contributions with no significant impact on the type of cation present.
Enantiopure Ferrocene‐Based Planar‐Chiral Iridacycles: Stereospecific Control of Iridium‐Centred Chirality
Authors: Arthurs Ross A. , Ismail Muhammad , Prior Christopher C. , Oganesyan Vasily S. , Horton Peter N. , Coles Simon J. , Richards Christopher J.
Published: January 2016

Reaction of [IrCp*Cl2]2 with ferrocenylimines (Fc=NAr, Ar=Ph, p‐MeOC6H4) results in ferrocene C−H activation and the diastereoselective synthesis of half‐sandwich iridacycles of relative configuration Sp*,RIr*. Extension to (S)‐2‐ferrocenyl‐4‐(1‐methylethyl)oxazoline gave highly diastereoselective control over the new elements of planar chirality and metal‐based pseudo‐tetrahedral chirality, to give both neutral and cationic half‐sandwich iridacycles of absolute configuration Sc,Sp,RIr. Substitution reactions proceed with retention of configuration, with the planar chirality controlling the metal‐centred chirality through an iron–iridium interaction in the coordinatively unsaturated cationic intermediate.
General Assembly of Twisted Trigonal‐Prismatic Nonanuclear Silver(I) Clusters
Authors: Li Xiao‐Yu , Su Hai‐Feng , Zhou Rui‐Qi , Feng Sheng , Tan Yuan‐Zhi , Wang Xing‐Po , Jia Jiong , Kurmoo Mohamedally , Sun Di , Zheng Lan‐Sun
Published: January 2016

A general class of C3‐symmetric Ag9 clusters, [Ag9S(tBuC6H4S)6(dpph)3(CF3SO3)] (1), [Ag9(tBuC6H4S)6(dpph)3(CF3SO3)2]⋅CF3SO3 (2), [Ag9(tBuC6H4S)6(dpph)3(NO3)2] ⋅NO3 (3), and [Ag9(tBuC6H4S)7(dpph)3(Mo2O7)0.5]2⋅2 CF3COO (4) (dpph=1,6‐bis(diphenylphosphino)hexane), with a twisted trigonal‐prism geometry was isolated by the reaction of polymeric {(HNEt3)2[Ag10(tBuC6H4S)12]}n, 1,6‐bis(diphenylphosphino)hexane, and various silver salts under solvothermal conditions. The structures consist of discrete clusters constructed from a girdling Ag9 twisted trigonal prism with the top and bottom trigonal faces capped by diverse anions (i.e., S2− and CF3SO3− for compound 1, 2×CF3SO3− for compound 2, 2×NO3− for compound 3, and tBuC6H4S− and Mo2O72− for compound 4). This trigonal prism is bisected by another shrunken Ag3 trigon at its waist position. Interestingly, two inversion‐related Ag9 trigonal‐prismatic clusters are dimerized by the Mo2O72− ion in compound 4. The twist is amplified by the bulkier thiolate, which also introduces high steric‐hindrance for the capping ligand, that is, the longer dpph ligand. Four more silver–sulfur clusters (namely, compounds 5–8) with their nuclearity ranging from 6–10 were solely characterized by single‐crystal X‐ray diffraction to verify the above‐described synergetic effect of mixed ligands in the construction of Ag9 twisted trigonal prisms. Surprisingly, only cluster 1 emits yellow luminescence at λ=584 nm at room temperature, which may be attributed to a charge transfer from the S 3p orbital to the Ag 5s orbital, or mixed with metal‐centered (MC) d10→d9s1 transitions. Upon cooling from 300 to 80 K, the emission intensity was enhanced along with a hypsochromic shift. The good linear relationship between the maximum emission intensity and the temperature for compound 1 in the range of 180–300 K indicates that this is a promising molecular luminescent thermometer. Furthermore, cyclic voltammetric studies indicated that the diffusion‐ and surface‐controlled redox processes were determined for compounds 1 and 3 as well as compound 4, respectively.
Resolution of Rac‐Bambuterol via Diastereoisomeric Salt Formation with o‐Chloromandelic Acid and Differences in the Enantiomers' Pharmacodynamical Effects in Guinea Pigs and Beagles
Authors: Wu Jie , Liu Fei , Wang Shanping , Wang Hongjun , Liu Qing , Song Xinghan , Li Junxiao , Xu Ling , Tan Wen
Published: January 2016

In this study an enantioseparation method for rac‐bambuterol (5‐(2‐(tert‐butylamino)‐1‐hydroxyethyl)‐1,3‐phenylene bis(dimethylcarbamate)) via diastereoisomeric salt formation with o‐chloromandelic acid was developed. The enantiomeric excess (ee) values and chemical purities of the desired products were confirmed by high‐performance liquid chromatography (HPLC) using chiral stationary phase and reverse‐phase HPLC analyses, respectively. The ee values and the chemical purities both exceeded 99%. Animal experiments showed that (R)‐bambuterol was a potent inhibitor for histamine‐induced asthma reactions. (S)‐bambuterol was ineffective in relaxing the airways. Both enantiomers increased heart rates in beagles. Therefore, replacing rac‐bambuterol with (R)‐bambuterol could be beneficial for asthma patients. Chirality 28:306–312, 2016. © 2016 Wiley Periodicals, Inc.
Application of Site‐Specific Spin Labeling for NMR Detecting Inhibitor‐Induced Conformational Change of HIV‐1 Reverse Transcriptase
Authors: Seetaha Supaporn , Yagi‐Utsumi Maho , Yamaguchi Takumi , Ishii Kentaro , Hannongbua Supa , Choowongkomon Kiattawee , Kato Koichi
Published: January 2016

Paramagnetism‐assisted nuclear magnetic resonance (NMR) techniques can provide long‐range structural information complemented with local information derived from chemical‐shift perturbation and nuclear Overhauser effect data. Here, we address the application of paramagnetic relaxation enhancement (PRE) to detect inhibitor‐induced conformational change of a drug target protein using human immunodeficiency virus type 1 reverse transcriptase (HIV‐1 RT) as a model protein. Using a site‐specific spin‐labeled HIV‐1 RT mutant with selective 13C labeling, conformation‐dependent PREs were successfully observed reflecting the stabilization of an open conformation of this enzyme caused by inhibitor binding. This study demonstrates that the paramagnetism‐assisted NMR approach offers an alternative strategy in protein‐based drug screening to identify allosteric inhibitors of a target protein.
Structural and Electrochemical Study of Vanadium‐Doped TiO2 Ramsdellite with Superior Lithium Storage Properties for Lithium‐Ion Batteries
Authors: Pérez‐Flores Juan Carlos , Hoelzel Markus , García‐Alvarado Flaviano , Kuhn Alois
Published: January 2016

Titanium‐oxide‐based materials are considered attractive and safe alternatives to carbonaceous anodes in Li‐ion batteries. In particular, the ramsdellite form TiO2(R) is known for its superior lithium‐storage ability as the bulk material when compared with other titanates. In this work, we prepared V‐doped lithium titanate ramsdellites with the formula Li0.5Ti1−xVxO2 (0≤x≤0.5) by a conventional solid‐state reaction. The lithium‐free Ti1−xVxO2 compounds, in which the ramsdellite framework remains virtually unaltered, are easily obtained by a simple aqueous oxidation/ion‐extraction process. Neutron powder diffraction is used to locate the Li channel site in Li0.5Ti1−xVxO2 compounds and to follow the lithium extraction by difference‐Fourier maps. Previously delithiated Ti1−xVxO2 ramsdellites are able to insert up to 0.8 Li+ per transition‐metal atom. The initial gravimetric capacities of 270 mAh g−1 with good cycle stability under constant current discharge conditions are among the highest reported for bulk TiO2‐related intercalation compounds for the threshold of one e− per formula unit.
Evaluation of a novel automated volumetric flow cytometer for absolute CD4+ T lymphocyte quantitation
Authors: Gossez Morgane , Malcus Christophe , Demaret Julie , Frater John , Poitevin‐Later Françoise , Monneret Guillaume
Published: January 2016

Background

Bead‐based single platform cytometry technology (SPT) is the gold standard when performing CD4 absolute counting. However, it presents drawbacks as precision depends on various critical steps (for example, pipetting methodology, overtime stability of beads, stability of fluidics, regular recalibration…) and thus requires skilled operators. The fully automated volumetric SPT AQUIOS CL (Beckman Coulter) has recently emerged as an alternative with no need of beads. It may help improving results standardisation and fulfilling requirements for certification (ISO 15189). In this study, we assessed SPT AQUIOS CL performances in accordance to requirements for ISO 15189 accreditation.

Methods

We evaluated repeatability and reproducibility (precision), bias (trueness), uncertainty (total error), range limits (linearity, quantification, detection limits), and inter‐reagent/inter‐sample contaminations in enumerating CD4+ T‐cells. Concomitantly, we compared AQUIOS CL CD4+ T‐cell values with the results obtained with our routine bead‐based SPT (that is, FC500 Beckman Coulter, bead‐based SPT), on blood samples from 148 patients representative of clinical laboratory routine workload.

Results

Every result (repeatability, reproducibility, trueness, total error) was below the acceptable thresholds proposed in international recommendations. Contamination results and range limits (linearity, quantification, and detection limits) were all found perfectly suitable to routine analysis. The comparison between AQUIOS CL and FC500 exhibited excellent correlation and agreement (PearsonR = 0.99,P < 0.001; Lin's concordance correlation coefficient: Linρc = 0.991, Cb = 0.999), and Bland‐Altman analysis did not reveal any systematic error.

Conclusions

Our results demonstrate that, upon subsequent validation in more routine conditions, the AQUIOS CL could be a suitable tool for clinical flow cytometry laboratories facing accreditation process. © 2016 International Clinical Cytometry Society
Testosterone and cortisol concentrations vary with reproductive status in wild female red deer
Authors: Pavitt Alyson T. , Pemberton Josephine M. , Kruuk Loeske E. B. , Walling Craig A.
Published: January 2016

Although hormones are key regulators of many fitness and life history traits, the causes of individual level variation in hormones, particularly in wild systems, remain understudied. Whilst we know that androgen and glucocorticoid levels vary within and among individuals in mammalian populations, how this relates to key reproductive processes such as gestation and lactation, and their effects on a female's measurable hormone levels are poorly understood in wild systems. Using fecal samples collected from females in a wild red deer population between 2001 and 2013, we explore how fecal androgen (FAM) and cortisol (FCM) metabolite concentrations change with age and season, and how individual differences relate to variation in reproductive state. Both FAM and FCM levels increase toward parturition, although this only affects FCM levels in older females. FCM levels are also higher when females suckle a male rather than a female calf, possibly due to the higher energetic costs of raising a son. This illustrates the importance of accounting for a female's life history and current reproductive status, as well as temporal variation, when examining individual differences in hormone levels. We discuss these findings in relation to other studies of mammalian systems and in particular to the relatively scarce information on variation in natural levels of hormones in wild populations.
Implications of recurrent disturbance for genetic diversity
Authors: Davies Ian D. , Cary Geoffrey J. , Landguth Erin L. , Lindenmayer David B. , Banks Sam C.
Published: January 2016

Exploring interactions between ecological disturbance, species’ abundances and community composition provides critical insights for ecological dynamics. While disturbance is also potentially an important driver of landscape genetic patterns, the mechanisms by which these patterns may arise by selective and neutral processes are not well‐understood. We used simulation to evaluate the relative importance of disturbance regime components, and their interaction with demographic and dispersal processes, on the distribution of genetic diversity across landscapes. We investigated genetic impacts of variation in key components of disturbance regimes and spatial patterns that are likely to respond to climate change and land management, including disturbance size, frequency, and severity. The influence of disturbance was mediated by dispersal distance and, to a limited extent, by birth rate. Nevertheless, all three disturbance regime components strongly influenced spatial and temporal patterns of genetic diversity within subpopulations, and were associated with changes in genetic structure. Furthermore, disturbance‐induced changes in temporal population dynamics and the spatial distribution of populations across the landscape resulted in disrupted isolation by distance patterns among populations. Our results show that forecast changes in disturbance regimes have the potential to cause major changes to the distribution of genetic diversity within and among populations. We highlight likely scenarios under which future changes to disturbance size, severity, or frequency will have the strongest impacts on population genetic patterns. In addition, our results have implications for the inference of biological processes from genetic data, because the effects of dispersal on genetic patterns were strongly mediated by disturbance regimes.
Fluctuating selection on basal metabolic rate
Authors: Nilsson Johan F. , Nilsson Jan‐Åke
Published: January 2016

BMR (Basal metabolic rate) is an important trait in animal life history as it represents a significant part of animal energy budgets. BMR has also been shown to be positively related to sustainable work rate and maximal thermoregulatory capacity. To this date, most of the studies have focused on the causes of interspecific and intraspecific variation in BMR, and fairly little is known about the fitness consequences of different metabolic strategies. In this study, we show that winter BMR affects local survival in a population of wild blue tits (Cyanistes caeruleus), but that the selection direction differs between years. We argue that this fluctuating selection is probably a consequence of varying winter climate with a positive relation between survival and BMR during cold and harsh conditions, but a negative relation during mild winters. This fluctuating selection can not only explain the pronounced variation in BMR in wild populations, but will also give us new insights into how energy turnover rates can shape the life‐history strategies of animals. Furthermore, the study shows that the process of global warming may cause directional selection for a general reduction in BMR, affecting the general life‐history strategy on the population level.
Morphometric traits capture the climatically driven species turnover of 10 spruce taxa across China
Authors: Li He , Wang GuoHong , Zhang Yun , Zhang WeiKang
Published: January 2016

This study explored the relative roles of climate and phylogenetic background in driving morphometric trait variation in 10 spruce taxa in China. The study further addressed the hypothesis that these variations are consistent with species turnover on climatic gradients. Nine morphometric traits of leaves, seed cones, and seeds for the 10 studied spruce taxa were measured at 504 sites. These data were analyzed in combination with species DNA sequences from NCBI GenBank. We detected the effects of phylogeny and climate through trait‐variation‐based K statistics and phylogenetic eigenvector regression (PVR) analyses. Multivariate analyses were performed to detect trait variation along climatic gradients with species replacement. The estimated K‐values for the nine studied morphometric traits ranged from 0.19 to 0.68, and the studied environmental variables explained 39–83% of the total trait variation. Trait variation tended to be determined largely by a temperature gradient varying from wet‐cool climates to dry‐warm summers and, additionally, by a moisture gradient. As the climate became wetter and cooler, spruce species tended to be replaced by other spruces with smaller needle leaves and seeds but larger cones and seed scales. A regression analysis showed that spruce species tended to be successively replaced by other species, along the gradient, although the trends observed within species were not necessarily consistent with the overall trend. The climatically driven replacement of the spruces in question could be well indicated by the between‐species variation in morphometric traits that carry lower phylogenetic signal. Between‐species variation in these traits is driven primarily by climatic factors. These species demonstrate a narrower ecological amplitude in temperature but wider ranges on the moisture gradient.
Solvent‐Dependent Regio‐ and Stereo­selective Oxidation of [2.2]Para­cyclophane‐Derived Phenols
Authors: Zhuravsky Roman P. , Antonov Dmitrii Yu. , Sergeeva Elena V. , Godovikov Ivan A. , Starikova Zoya A. , Vologzhanina Anna V. , Atman Natalia V.
Published: January 2016

The structure of the products formed upon oxidation of 4‐hydroxy[2.2]paracyclophane and its derivatives with Cu(OH)Cl·TMEDA depends on the solvent used. In MeOH oxidation accompanied with nucleophilic attack of the solvent to furnish predominantly or exclusively ortho‐cyclohexadienones (o‐quinol methyl ethers) of (Rp*,Rp*) relative configuration. Oxidation carried out in CH2Cl2 results in regio‐ and stereoselective formation of para‐cyclohexadienone dimers {variously substituted 7,7′‐bis[2.2]paracyclophan‐4,4′(7H,7′H)‐diones} with (Sp*,Rc*,Rc*,Sp*) relative and (Rp,Sc,Rc,Sp) absolute configurations (two out of six possible diastereomers in each case), whereas oxidation of the enantiomerically pure phenol produced the respective single product. The dimeric cyclohexadienones can suffer aromatization to form the respective dimeric para‐biphenols under the action of KOH in EtOH.