bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hunter–gatherer dental pathology: Do historic accounts of Aboriginal Australians correspond to the archeological record of dental disease?
Authors: Littleton Judith 
Published: November 2017

AbstractObjectivesStudies of hunter–gatherer oral pathology, particularly in Australia, often focus upon dental wear and caries or assume that historic studies of Aboriginal people reflect the precontact past. Consequently the range of population variation has been underestimated. In this paper dental pathology from human remains from Roonka are compared with a model of dental pathology derived from historic studies. The aim is to identify aspects of dental pathology indicative of regional or intra‐population diversity.MethodsAdult dentitions (n = 115) dating from the mid to late Holocene were recorded for the following conditions: dental wear, caries, periapical voids, calculus, periodontal disease and antemortem tooth loss. Statistical analysis was used to identify patterns of dental pathology and to identify causal relationships between conditions.ResultsDental wear is marked while dental caries rates are extremely low. Other indications of dental pathology are uncommon (<7% of teeth affected). Temporal heterogeneity is apparent: there are 3 young adults with caries who died in the postcontact period. There is also a small group of middle age to old adults with disproportionate abscessing and pulp exposure who may represent temporal variation or heterogeneity in individual frailty.ConclusionsThe results confirm dental wear as the major cause of dental pathology in this group and that, at a general level, historic accounts do correspond with this archeological sample. However, intra‐sample heterogeneity is apparent while 2 dental conditions, calculus and periodontal disease, along with the pattern of sex differences deviate from expectation, demonstrating that to identify regional variation attention needs to be paid to the dentoalveolar complex as a whole.
Biomimetic Peptide‐Gated Nanoporous Membrane for On‐Demand Molecule Transport
Authors: Xiao Kai , Wu Kai , Chen Lu , Kong Xiang‐Yu , Zhang Yuqi , Wen Liping , Jiang Lei 
Published: November 2017

AbstractThe controllable molecule transport is crucial to realize many highly valuable applications both in vivo and in vitro. Nanoporous membranes, with nanoscopic pores, high porosity, uniform pore dimensions, and controllable surface chemical properties, hold tremendous potential to achieve this function. Herein, we report a nano‐gating system for on‐demand molecule transport based on a peptide‐gated nanoporous membrane. Acting as gatekeeper, the peptides introduced to the nanoporous membrane provide an opportunity to realize on‐demand on–off states via reversible conformational switching of the peptides. This nano‐gating system offers sustained release and can be used as a sophisticated molecule transport platform for localized drug delivery with a feedback function.
Photoinduced Pedalo‐Type Motion in an Azodicarboxamide‐Based Molecular Switch
Authors: Amirjalayer Saeed , Martinez‐Cuezva Alberto , Berna Jose , Woutersen Sander , Buma Wybren Jan 
Published: November 2017

AbstractWell‐defined structural changes of molecular units that can be triggered by light are crucial for the development of photoactive functional materials. Herein, we report on a novel switch that has azodicarboxamide as its photo‐triggerable element. Time‐resolved UV‐pump/IR probe spectroscopy in combination with quantum‐chemical calculations shows that the azodicarboxamide functionality, in contrast to other azo‐based chromophores, does not undergo trans–cis photoisomerization. Instead, a photoinduced pedalo‐type motion occurs, which because of its volume‐conserving properties enables the design of functional molecular systems with controllable motion in a confined space.
Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions
Authors: Ma Yan‐Long , Ke Hua , Valkonen Arto , Rissanen Kari , Jiang Wei 
Published: November 2017

AbstractPositive cooperativity achieved through activating weak non‐covalent interactions is common in biological assemblies but is rarely observed in synthetic complexes. Two new molecular tubes have been synthesized and the syn isomer binds DABCO‐based organic cations with high orientational selectivity. Surprisingly, the ternary complex with two hosts and one guest shows a high cooperativity factor (α=580), which is the highest reported for synthetic systems without involving ion‐pairing interactions. The X‐ray single‐crystal structure revealed that the strong positive cooperativity likely originates from eight C−H⋅⋅⋅O hydrogen bonds between the two head‐to‐head‐arranged syn tube molecules. These relatively weak hydrogen bonds were not observed in the free hosts and only emerged in the complex. Furthermore, this complex was used as a basic motif to construct a robust [2+2] cyclic assembly, thus demonstrating its potential in molecular self‐assembly.
Time‐Resolved Interception of Multiple‐Charge Accumulation in a Sensitizer–Acceptor Dyad
Authors: Mendes Marinho Stéphanie , Ha‐Thi Minh‐Huong , Pham Van‐Thai , Quaranta Annamaria , Pino Thomas , Lefumeux Christophe , Chamaillé Thierry , Leibl Winfried , Aukauloo Ally 
Published: November 2017

AbstractBiomimetic models that contain elements of photosynthesis are fundamental in the development of synthetic systems that can use sunlight to produce fuel. The critical task consists of running several rounds of light‐induced charge separation, which is required to accumulate enough redox equivalents at the catalytic sites for the target chemistry to occur. Long‐lived first charge‐separated state and distinct electronic signatures for the sequential charge accumulated species are essential features to be able to track these events on a spectroscopic ground. Herein, we use a double‐excitation nanosecond pump–pump–probe experiment to interrogate two successive rounds of photo‐induced electron transfer on a molecular dyad containing a naphthalene diimide (NDI) linked to a [Ru(bpy)3]2+ (bpy=bipyridine) chromophore by using a reversible electron donor. We report an unprecedented long‐lived two‐electron charge accumulation (t=200 μs).
Hot‐melt adhesives based on co‐polyamide and multiwalled carbon nanotubes
Authors: Latko‐Durałek Paulina , Macutkevic Jan , Kay Christopher , Boczkowska Anna , McNally Tony 
Published: November 2017

ABSTRACTComposites of two hot melt adhesives based on co‐polyamides, one high viscosity (coPA_A), the other low viscosity (coPA_B), and multiwalled carbon nanotubes (MWCNTs) were prepared using twin‐screw extrusion via dilution of masterbatches. Examination of these composites across the length scales confirmed that the MWCNTs were uniformly dispersed and distributed in the polymer matrices, although some micron size agglomerations were also observed. A rheological percolation was determined from oscillatory rheology measurements at a mass fraction of MWCNTs below 0.01 for coPA_B and, between 0.01 and 0.02 for coPA_A. Significant increases in complex viscosity and storage modulus confirmed the “pseudo‐solid” like behavior of the composite materials. Electrical percolation, determined from dielectric spectroscopy was, found to be at 0.03 and 0.01 MWCNT mass fraction for coPA_A and coPA_B based composites, respectively. Addition of MWCNTs resulted in heterogeneous nucleation and altered the crystallization kinetics of both copolymers. Indirect evidence from contact angle measurements and surface energy calculations confirmed that MWCNT addition enhanced the adhesive properties of coPA_B to a level similar to coPA_A. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45999.
Stimuli‐sensitive nanostructured poly(sodium 4‐styrene sulfonate): Synthesis, characterization, and study of metal ion retention properties
Authors: Palencia Manuel , Córdoba Alexander , Arrieta Álvaro 
Published: November 2017

ABSTRACTStimuli‐sensitive polymers are a type of smart polymers having the capability to change their configuration or properties under adequate stimuli as heat, pH, magnetic field, mechanical strength, among other. The aim of this work was to synthesize nanostructured polymers with antibacterial properties capable to change their retention properties of divalent metal ions by external stimuli (pH and ionic strength). For that, a polymerizable nanostructured crosslinker (PNC) based on silver nanoparticles (AgNPs) and acrylic acid was synthesized. Later, NPSS was synthesized by free‐radical polymerization, characterized by different analytical techniques and its retention properties of divalent ions (Cu2+, Fe2+, Mn2+, and Zn2+) were studied at different pHs and ionic strengths (5.0, 7.0, and 9.0; and 0.0, 0.5, and 1.5% NaCl, respectively). It was evidenced that AgNPs can be synthesized using acrylic acid as stabilizing agent, and later, be used for synthesis of NPSS by free‐radical polymerization. For NPSS, metal ion retention decreases as pH is increased; in addition, results suggest that the electrostatic interaction is not the only determining factor in the retention of ions. Other possible factors which would be affecting the retention are: water flow by swelling capacity and water flow by osmotic stress resulting of high salt concentration. NPSS showed antimicrobial activity against Escherichia coli and Staphylococcus aureus which was enhanced by incorporation of PNC based on AgNPs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46001.
Protic NNN and NCN Pincer‐Type Ruthenium Complexes Featuring (Trifluoromethyl)pyrazole Arms: Synthesis and Application to Catalytic Hydrogen Evolution from Formic Acid
Authors: Nakahara Yoshiko , Toda Tatsuro , Matsunami Asuka , Kayaki Yoshihito , Kuwata Shigeki 
Published: November 2017

AbstractNNN and NCN pincer‐type ruthenium(II) complexes featuring two protic pyrazol‐3‐yl arms with a trifluoromethyl (CF3) group at the 5‐position were synthesized and structurally characterized to evaluate the impact of the substitution on the properties and catalysis. The increased Brønsted acidity by the highly electron‐withdrawing CF3 pendants was demonstrated by protonation–deprotonation experiments. By contrast, the IR spectra of the carbonyl derivatives as well as the cyclic voltammogram indicated that the electron density of the ruthenium atom is negligibly influenced by the CF3 group. Catalysis of these complexes in the decomposition of formic acid to dihydrogen and carbon dioxide was also examined. The NNN pincer‐type complex 1 a with the CF3 group exhibited a higher catalytic activity than the tBu‐substituted analogue 1 b. In addition, the bis(CF3‐pyrazolato) ammine derivative 4 catalyzed the reaction even in the absence of base additives.
Bringing plant cell wall‐degrading enzymes into the lignocellulosic biorefinery concept
Authors: Silva Caio O.G. , Vaz Raissa P. , Filho Edivaldo X.F. 
Published: November 2017

AbstractRecent decades have seen the growth of immense interest in lignocellulosic biomass conversion technologies. This interest is motivated by their huge potential for energy and bioproduct generation and reduced dependency on non‐renewable feedstocks, leading to improved air quality and reduced emission of greenhouse gases. It is in this context that the lignocellulose biorefinery concept arises. Among the lignocellulose conversion technologies available, enzymatic conversion has emerged as a promising candidate, since it represents a biomass management approach that integrates recycling and remediation in an environmentally friendly manner. Although already in existence, biorefineries employing enzymatic conversion of lignocellulose are at an incipient stage. There remain many operational difficulties, resulting in a very costly overall process that is reflected in product price, reducing market competitiveness. Therefore, much research is still needed to improve the operational and financial feasibility of this process. This paper covers general biorefinery concepts, as well as new and associated concepts, such as the circular economy, bioeconomy, and waste biorefinery. Subsequently, the global outlook, including examples of currently existing enzyme‐based lignocellulose biorefineries and their status, is described. The main technical and economic challenges are also discussed, and various potential tools for the optimization of biomass degradation in enzyme‐based biorefineries are presented. Finally, the future perspectives for the sector are considered, and models of the ideal biorefinery and globally integrated biorefinery hubs are proposed. These models may contribute to the future establishment of such biorefineries as competitive industries, consistent with the sustainable bioelectro economy paradigm. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd
H‐likelihood approach for joint modeling of longitudinal outcomes and time‐to‐event data
Authors: Ha Il Do , Noh Maengseok , Lee Youngjo 
Published: November 2017

AbstractIn longitudinal studies, a subject may have different types of outcomes that could be correlated. For example, a response variable of interest would be measured repeatedly over time on the same subject and at the same time, an event time representing a single event or competing‐risks event is also observed. In this paper, we propose a joint modeling framework that accounts for the inherent association between such multiple outcomes via frailties (unobserved random effects). Among outcomes, at least one outcome is an event time that has a type of a single event or competing‐risks event. For inference we use the hierarchical likelihood (h‐likelihood) that provides an unified efficient fitting procedure for the joint models. Numerical studies are provided to show the performance of the proposed method and two data examples are shown.
β‐cyclodextrin encapsulated polyphenols as effective antioxidants
Authors: Roy Pritam , Dinda Amit Kumar , Chaudhury Susmitnarayan , Dasgupta Swagata 
Published: November 2017

AbstractFormation of dityrosine (DT) cross‐linkages in proteins is one of the most widely used markers of oxidative stress. Ribonuclease A (RNase A) has 6 Tyr residues and shows a characteristic DT fluorescence peak upon oxidation in addition to major changes in its secondary structure. DT formation can be prevented by using polyphenols (GA, ECG, and EGCG) which are known to have strong antioxidant activity. However, it has been observed that ECG and EGCG initiate protein oligomerization due to protein‐polyphenol cross‐linkages. To prevent the formation of such cross‐linkages we have used β‐cyclodextrin (β‐CD) to encapsulate the polyphenols and studied its antioxidant properties along with that of free polyphenols. The polyphenol/β‐cyclodextrin (β‐CD) inclusion complexes not only prevent DT formation but also reduce protein oligomerization. This may be attributed to the fact that the quinone forming rings of ECG and EGCG become encapsulated in the cavity of β‐CD and are no longer available for protein cross‐linking.
Patient-reported rates of chronic pain and recurrence after groin hernia repair
Authors: Lundström K-J , Holmberg H , Montgomery A , Nordin P 
Published: November 2017

Abstract

Background
The effectiveness of different procedures in routine surgical practice for hernia repair with respect to chronic postoperative pain and reoperation rates is not clear.

Methods
This was prospective cohort study based on a unique combination of patient-reported outcomes and national registry data. Virtually all patients with a groin hernia repair in Sweden between September 2012 and April 2015 were sent a questionnaire 1 year after surgery. Persistent pain, defined as at least ‘pain present, cannot be ignored, and interferes with concentration on everyday activities’ in the past week was the primary outcome. Reoperation for recurrence recorded in the register was the secondary outcome.

Results
In total, 22 917 patients (response rate 75·5 per cent) who had an elective unilateral groin hernia repair were analysed. Persistent pain present 1 year after hernia repair was reported by 15·2 per cent of patients. The risk was least for endoscopic total extraperitoneal (TEP) repair (adjusted odds ratio (OR) 0·84, 95 per cent c.i. 0·74 to 0·96), compared with open anterior mesh repair. TEP repair had an increased risk of reoperation for recurrence (adjusted OR 2·14, 1·52 to 2·98), as did open preperitoneal mesh repair (adjusted OR 2·34, 1·42 to 3·71) at 2·5-year follow-up. No other methods of repair differed significantly from open anterior mesh repair.

Conclusion
The risk of significant pain 1 year after groin hernia repair in routine surgical practice was 15·2 per cent. This figure was lower in patients who had surgery by an endoscopic technique, but at the price of a significantly higher risk of reoperation for recurrence.
Additive‐Enhanced Crystallization of Solution Process for Planar Perovskite Solar Cells with Efficiency Exceeding 19 %
Authors: You Shuai , Bi Shiqing , Huang Jing , Jia Qiushuang , Yuan Yuhe , Xia Yanjie , Xiao Zhenyu , Sun Zhuzhu , Liu Jiangfeng , Sun Shujie , Zhao Zhiqiang 
Published: November 2017

AbstractTo reduce intrinsic defect density in perovskite films, various additives are often added into the precursor solution. In this paper, a novel solution, in which isopropanol (IPA) was added into the precursor solution, was developed for the preparation of normal planar perovskite solar cells (PSCs). A champion power conversion efficiency (PCE) of 19.70 % was achieved with this approach. By adding IPA into the precursor solution, CH3NH3PbI3 perovskite showed better crystallization and stability, indicating improved film quality. Because of the improved morphology of perovskite crystal, the PCE of PSCs increased. In addition, the unencapsulated PSCs retained high output for up to 40 days in air at room temperature, indicating the stability of PSCs. These results may provide a new avenue for manufacturing high efficiency and high stability PSCs.
A Versatile Strategy to Main Chain Sulfur/Selenium‐Functionalized Polycarbonates by Macro‐Ring Closure of Diols and Subsequent Ring‐Opening Polymerization
Authors: Wei Chao , Zhang Yan , Yan Bingkun , Du Zhengzhen , Lang Meidong 
Published: November 2017

AbstractHerein, a new class of main chain functionalized aliphatic polycarbonates with sulfur/selenium functional groups on the backbone is reported. Sulfur/selenium‐containing cyclic carbonate monomers (MR) are designed and synthesized by enzyme‐catalyzed intermolecular macro‐ring closure of related diols. The proposed synthetic strategy is tolerant of other functionalities such as N‐substituted groups. The ring opening polymerization (ROP) of MR occurs readily as a versatile route to generate a new family of main chain sulfur/selenium substituted aliphatic polycarbonates (PR) with predictable molecular weights (MW), narrow molecular‐weight distribution and controlled copolymer composition. The resultant polymers can be oxidized and/or reduced by treatment with hydrogen peroxide (H2O2) or dithiothreitol (DTT), highlighting their potential for applications in the stimuli‐responsive field and inflammation/cancer targeting. With these desirable results, it is revealed that this versatile technique can provide a broad‐reaching method to the next generation of innovative materials, especially, well‐defined biodegradable chalcogen‐based main chain functional biomaterials.
Three‐Component Synthesis and Photophysical Properties of Novel Coumarin‐Based Merocyanines
Authors: Papadopoulos Julian , Merkens Kay , Müller Thomas J. J. 
Published: November 2017

AbstractNovel E‐configured coumarin‐based merocyanines were efficiently synthesized by a one‐pot, three‐component Sonogashira coupling–Michael addition starting from triflyl coumarins, terminal alkynes and secondary amines. The photophysical properties of the synthesized yellow to orange merocyanines were studied by UV/Vis and fluorescence spectroscopy and rationalized by Hammett–Taft correlations and DFT and TD‐DFT calculations. Most compounds were only weakly fluorescent in solution; however, two compounds were investigated in more detail with respect to their aggregation behavior. The system for R2=H and NR23=pyrrolidinyl shows aggregation induced emission at a water content of 40–60 % in methanol, while the chromophore with R2=p‐Me2NC6H4 and NR23=morpholinyl displays considerable aggregation induced emission enhancement with a concomitant redshift at increasing water contents in THF.
An oxorhenium complex bearing a chiral cyclohexane‐1‐olato‐2‐thiolato ligand: Synthesis, stereochemistry, and theoretical study of parity violation vibrational frequency shifts
Authors: Saleh Nidal , Bast Radovan , Vanthuyne Nicolas , Roussel Christian , Saue Trond , Darquié Benoît , Crassous Jeanne 
Published: November 2017

AbstractIn our effort towards measuring the parity violation energy difference between two enantiomers, a simple chiral oxorhenium complex 5 bearing enantiopure 2‐mercaptocyclohexan‐1‐ol has been prepared as a potential candidate species. Vibrational circular dichroism revealed a chiral environment surrounding the rhenium atom, even though the rhenium is not a stereogenic center itself, and enabled to assign the (1S,2S)‐(−) and (1R,2R)‐(+) absolute configuration for 5. For both compound 5 and complex 4, previously studied by us and bearing a propane‐2‐olato‐3‐thiolato ligand, relativistic calculations predict parity violating vibrational frequency differences of a few hundreds of millihertz, above the expected sensitivity attainable by a molecular beam Ramsey interferometer that we are constructing.
Biomimetic syntheses of racemic natural products
Authors: Zask Arie , Ellestad George 
Published: November 2017

AbstractRacemic natural products are rarely produced in plants and microorganisms and are thought to be the result of nonenzymatic, spontaneous reactions. These compounds are often highly complex with multiple contiguous chiral centers that present a challenge to organic synthesis. Formation of these racemates often occurs by cyclization reactions that can generate multiple stereocenters from achiral precursors. Biomimetic synthesis of these racemic natural products provides support for their proposed nonenzymatic spontaneous biosynthesis. These elegant syntheses also provide scalable and efficient routes to these complex natural products. Although the number of reported racemic natural products is relatively low, an isolated natural product that has a very small optical rotation has been shown to be a true racemate. Thus, the occurrence of racemic natural products could be more common than thought.
Lipase‐catalyzed enantioselective transesterification of prochiral 1‐((1,3‐dihydroxypropan‐2‐yloxy)methyl)‐5,6,7,8‐tetrahydroquinazoline‐2,4(1H,3H)‐dione in ionic liquids
Authors: Kołodziejska Renata , Studzińska Renata , Pawluk Hanna 
Published: November 2017

AbstractThe application of ionic liquids as solvents for transesterification of prochiral pirymidine acyclonucleoside using lipase (EC 3.1.1.3) Amano PS from Burkholderia cepacia (BCL) is reported. The effect of using medium reaction, acyl group donor, and temperature on the activity and enantioselectivity of BCL was studied. From the investigated ionic solvents, the hydrophobic ionic liquid [BMIM]PF6] was the preferred medium for enzymatic reactions. However, the best result was obtained in the mixture [BMIM][PF6]:TBME (1:1 v/v) at 50°C. Enzyme activity and selectivity in [BMIM][PF6]:TBME (1:1 v/v) was slightly higher in than in conventional organic solvents (for example, TBME), and in this condition, good activity and enantioselectivity were associated with unique properties of ionic liquid such as hydrophobicity and high polarity. Independently of solvents, monester of (R)‐configuration was obtained in excess. Under optimal conditions, desymmetrization of the prochiral compound using different acyl donors was performed. If vinyl butyrate was used as the acylating agent, BCL completely selectively acylated enantiotopic hydroxyl groups.