bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal Ion‐Terpyridine‐Functionalized L‐Tyrosinamide Aptamers: Nucleoapzymes for Oxygen Insertion into CH Bonds and the Transformation of L‐Tyrosinamide into Amidodopachrome
Authors: Luo Guo‐Feng , Biniuri Yonatan , Vázquez‐González Margarita , Wulf Verena , Fadeev Michael , Lavi Ronit , Willner Itamar
Published: June 2019

A series of metal ion‐terpyridine‐modified L‐tyrosinamide aptamers (Mn+ = Cu2+ or Fe3+) act as enzyme‐mimicking catalysts (nucleoapzymes) for oxygen‐insertion into CH bonds and the transformation of L‐tyrosinamide into amidodopachrome. The reaction proceeds in the presence of H2O2 and coadded L‐ascorbic acid. In one series of experiments, the catalyzed oxidation of L‐tyrosinamide to amidodopachrome by a set of nucleoapzymes consisting of Fe3+‐ or Cu2+‐terpyridine complexes tethered directly or through a 4 × thymidine (4 × T) bridge, to the 5′‐ or 3′‐end of the 49‐mer L‐tyrosinamide aptamer or to a shorter 23‐mer L‐tyrosinamide aptamer is examined. All nucleoapzymes reveal catalytic Michaelis–Menten enzyme‐like activities and the separated Fe3+‐ or Cu2+‐terpyridine and L‐tyrosinamide aptamer units show only minute catalytic properties. The catalytic activities of the nucleoapzymes are attributed to the concentration of the L‐tyrosinamide substrate by the aptamer units in proximity to the catalytic sites (Kd = (14 ± 0.1) × 10−6 m for all 49‐mer catalysts and Kd = (2.5 ± 0.1) × 10−6 m and Kd = (0.8 ± 0.04) × 10−6 m for the 23‐mer catalysts). Electron spin resonance experiments reveal that •OH radicals and ascorbate radicals participate in the transformation of tyrosine derivatives to catechol products. An autocatalytic feedback mechanism for the amplified generation of the two radicals is suggested.
Inherent Photodegradability of Polymethacrylate Hydrogels: Straightforward Access to Biocompatible Soft Microstructures
Authors: Li Lei , Scheiger Johannes M. , Tronser Tina , Long Connor , Demir Konstantin , Wilson Christina L. , Kuzina Mariia A. , Levkin Pavel A.
Published: June 2019

Hydrogels are important functional materials useful for 3D cell culture, tissue engineering, 3D printing, drug delivery, sensors, or soft robotics. The ability to shape hydrogels into defined 3D structures, patterns, or particles is crucial for biomedical applications. Here, the rapid photodegradability of commonly used polymethacrylate hydrogels is demonstrated without the need to incorporate additional photolabile functionalities. Hydrogel degradation depths are quantified with respect to the irradiation time, light intensity, and chemical composition. It can be shown that these parameters can be utilized to control the photodegradation behavior of polymethacrylate hydrogels. The photodegradation kinetics, the change in mechanical properties of polymethacrylate hydrogels upon UV irradiation, as well as the photodegradation products are investigated. This approach is then exploited for microstructuring and patterning of hydrogels including hydrogel gradients as well as for the formation of hydrogel particles and hydrogel arrays of well‐defined shapes. Cell repellent but biocompatible hydrogel microwells are fabricated using this method and used to form arrays of cell spheroids. As this method is based on readily available and commonly used methacrylates and can be conducted using cheap UV light sources, it has vast potential to be applied by laboratories with various backgrounds and for diverse applications.
Plasmonic Self‐Propelled Nanomotors for Explosives Detection via Solution‐Based Surface Enhanced Raman Scattering
Authors: Novotný Filip , Plutnar Jan , Pumera Martin
Published: June 2019

Nanomotors represent a class of artificial machines that span the chasm between molecular motors and bigger micromotors. Their importance lies in the fact that to effectively navigate and perform tasks in a biological environment without alerting the action of the immune system, the maximal size of the object has to be well below 200 nm. Fully nanosized gold/silver core/shell plasmonic nanomotors using the seeded growth wet chemical approach, which allows high scalability of synthesis of the nanomotors compared to planar substrate‐based methods, is presented. Using the nanoparticle tracking analysis, the catalysis driven enhanced diffusion of the plasmonic nanomotors in the presence of low concentrations of fuel is presented and shown that the prepared nanomotors are good candidates for a solution‐based surface‐enhanced Raman spectroscopy detection of picric acid, a typical explosive. In addition to the mentioned effects, ligand‐exchange is performed on the nanomotors to replace the surfactant with its thiolated analog, a combination which is already proven in literature to be stealthy to the immune response of the living organism.
3D Structural Strengthening Urchin‐Like Cu(OH)2‐Based Symmetric Supercapacitors with Adjustable Capacitance
Authors: Chang Peng , Mei Hui , Zhao Yu , Huang Weizhao , Zhou Shixiang , Cheng Laifei
Published: June 2019

Developing advanced three‐dimensional (3D) structural supercapacitors with both high capacity and good mechanical strength remains challenging. Herein, a novel road is reported for fabricating 3D structural strengthening supercapacitors with adjustable capacitance based on urchin‐like Cu(OH)2 lattice electrodes by bridging 3D printing technology with a facile electroless plating and electro‐oxidation method. As revealed by the results, the 3D‐printed octet‐truss lattice electrode features a high volumetric capacitance of 8.46 F cm−3 at 5 mA cm−3 and superior retention capacity of 68% at 1 A cm−3. The assembled symmetric supercapacitor with a 70.2% capacitance retention after 5000 cycles possesses a 12.8 Wh kg−1 energy density at a power density of 2110.2 W kg−1. Additionally, the resulting 3D structural strengthening electrodes can achieve both high compressive strength and toughness of 30 MPa and 264.7 kJ m−3, respectively, demonstrating high mechanical strength and excellent antideformation capacity. With the proposed strategy, the electrochemical and mechanical properties of these novel 3D structural strengthened supercapacitors can be easily tuned by a simple spatial framework design, fulfilling the increasing demand of highly customized power sources in the space‐constrained microelectronics and astronautic electronics industries.
Stretchable Transparent Conductors: from Micro/Macromechanics to Applications
Authors: Chen Zhi Hong , Fang Rui , Li Wei , Guan Jianguo
Published: June 2019

Stretchable transparent conductors (STCs), generally consisting of conducting networks and stretchable transparent elastomers, can maintain stable conductivity and transparency even at large tensile strain, beyond the reach of rigid/flexible transparent conductors. They are essential components in stretchable/wearable electronics for using on irregular 3D conformable surfaces and have attracted tremendous attention in recent years. This review aims to provide systematical correlation of the conducting element–substrate interaction with the structural stability of conducting networks, as well as the properties and device applications of STCs. It starts with the micromechanics for stretching of conducting elements on substrates, including the mechanical mismatch, distribution/level of interfacial shear stress, and the deformation behavior of conducting elements on substrates. The macromechanics for stretching of conducting networks on substrates are then further illustrated from a more statistical point of view, namely sliding/preferred orientation of percolation networks, unfolding of buckled structures, and unit cell distortion/distributed rupture of nanomeshes. The structure‐dependent properties as well as the state‐of‐the‐art applications of STCs are summarized before ending with the conclusions and outlooks for STCs.
Laser Systems and Networks with Organic Nanowires and Nanofibers
Authors: Matino Francesca , Persano Luana , Camposeo Andrea , Pisignano Dario
Published: June 2019

The potentialities of miniaturized laser sources are still far from being fully developed. Unprecedented opportunities are generated in this field by organic nanowires and nanofibers, which can be used as building blocks of micro‐ and nanolasers in which they combine optical gain, waveguiding, and very high versatility to create nanophotonic networks. The progress in laser devices and network architectures based on optically pumped organic light‐emitting nanowires and nanofibers is here presented, with emphasis on developed active materials, fabrication technologies, lasing mechanisms, and cavity geometries, and on achieved device performance in terms of spectral tunability, excitation threshold, and resonator quality factors. Recent examples of optical coupling of different miniaturized lasers, of their application in optical sensing, and of network lasers are presented. Future directions for research are also outlined, which include the exploration of new classes of active organic or hybrid materials within nanowires, the more in‐depth characterization of the fundamental properties of these lasers, and the use of topologically defined organic nanophotonics in network science, computing, and diagnostics.
Perinatal distress in 1p36 deletion syndrome can mimic hypoxic ischemic encephalopathy
Authors: Carter Lauren B. , Battaglia Agatino , Cherry Athena , Manning Melanie A. , Ruzhnikov Maura RZ , Bird Lynne M. , Dowsett Leah , Graham John M. , Alkuraya Fowzan S. , Hashem Mais , Dinulos Mary Beth , Vallee Stephanie , Adam Margaret P. , Glass Ian , Beck Anita E. , Stevens Cathy A. , Zackai Elaine , McDougall Carey , Keena Beth , Peron Angela , Vignoli Aglaia , Seaver Laurie H. , Slavin Thomas P. , Hudgins Louanne
Published: June 2019

1p36 deletion syndrome is a well‐described condition with a recognizable phenotype, including cognitive impairment, seizures, and structural brain anomalies such as periventricular leukomalacia (PVL). In a large series of these individuals by Battaglia et al., “birth history was notable in 50% of the cases for varying degrees of perinatal distress.” Given the potential for perinatal distress, seizures and PVL, we questioned if this disorder has clinical overlap with hypoxic ischemic encephalopathy (HIE). We reviewed the medical records of 69 individuals with 1p36 deletion to clarify the perinatal phenotype of this disorder and determine if there is evidence of perinatal distress and/or hypoxic injury. Our data provides evidence that these babies have signs of perinatal distress. The majority (59% term; 75% preterm) needed resuscitation and approximately 18% had cardiac arrest. Most had abnormal brain imaging (84% term; 73% preterm) with abnormal white matter findings in over half of patients. PVL or suggestion of “hypoxic insult” was present in 18% of term and 45% of preterm patients. In conclusion, individuals with 1p36 deletion have evidence of perinatal distress, white matter changes, and seizures, which can mimic HIE but are likely related to their underlying chromosome disorder.
Elucidating the Doping Effect on the Electronic Structure of Thiolate‐Protected Silver Superatoms by Photoelectron Spectroscopy
Authors: Kim Kuenhee , Hirata Keisuke , Nakamura Katsunosuke , Kitazawa Hirokazu , Hayashi Shun , Koyasu Kiichirou , Tsukuda Tatsuya
Published: June 2019

Gas‐phase photoelectron spectroscopy (PES) was conducted on [XAg24(SPhMe2)18]− (X=Ag, Au) and [YAg24(SPhMe2)18]2− (Y=Pd, Pt), which have a formal superatomic core (X@Ag12)5+ or (Y@Ag12)4+ with icosahedral symmetry. PES results show that superatomic orbitals in the (Au@Ag12)5+ core remain unshifted with respect to those in the (Ag@Ag12)5+ core, whereas the orbitals in the (Y@Ag12)4+ (Y = Pd, Pt) core shift up in energy by about 1.4 eV. The remarkable doping effect of a single Y atom (Y=Pd, Pt) on the electronic structure of the chemically modified (Ag@Ag12)5+ superatom was reproduced by theoretical calculations on simplified model systems and was ascribed to 1) the weaker binding of valence electrons in Y@(Ag+)12 compared to Ag+@(Ag+)12 due to the reduction in formal charge of the core potential, and 2) the upward shift of the apparent vacuum level due to the presence of a repulsive Coulomb barrier between [YAg24(SPhMe2)18]− and electron.
Reversing Chemoselectivity: Simultaneous Positive and Negative Catalysis by Chemically Equivalent Rims of a Cucurbit[7]uril Host
Authors: Rad Nazar , Danylyuk Oksana , Sashuk Volodymyr
Published: June 2019

Enzyme catalysis has always been an inspiration and an unattainable goal for chemists due to features such as high specificity, selectivity, and efficiency. Here, we disclose a feature neither common in enzymes nor ever described for enzyme mimics, but one that could prove crucial for the catalytic performance of the latter, namely the ability to catalyze and inhibit two different reactions at the same time. Remarkably, this can be realized by two identical, spatially resolved catalytic sites. In the future, such a synchronized catalyst action could be used not only for controlling chemoselectivity, as in the present case, but also for regulating other types of chemical reactivity.
Efficient Innate Immune Killing of Cancer Cells Triggered by Cell‐Surface Anchoring of Multivalent Antibody‐Recruiting Polymers
Authors: Uvyn Annemiek , De Coen Ruben , Gruijs Mandy , Tuk Cees W. , De Vrieze Jana , van Egmond Marjolein , De Geest Bruno G.
Published: June 2019

Binding of monoclonal antibodies (mAbs) onto a cell surface triggers antibody‐mediated effector killing by innate immune cells through complement activation. As an alternative to mAbs, synthetic systems that can recruit endogenous antibodies from the blood stream to a cancer cell surface could be of great relevance. Herein, we explore antibody‐recruiting polymers (ARPs) as a novel class of immunotherapy. ARPs consist of a cell‐binding motif linked to a polymer that contains multiple small molecule antibody‐binding motifs along its backbone. As a proof of concept, we employ a lipid anchor that inserts into the phospholipid cell membrane and make use of a polymeric activated ester scaffold onto which we substitute dinitrophenol as an antibody‐binding motif. We demonstrate that ARPs allow for high avidity antibody binding and drive antibody recruitment to treated cells for several days. Furthermore, we show that ARP‐treated cancer cells are prone to antibody‐mediated killing through phagocytosis by macrophages.
Oxygen Vacancies on Layered Niobic Acid That Weaken the Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries
Authors: Xu Lingling , Zhao Hongyang , Sun Mingzi , Huang Bolong , Wang Jianwei , Xia Jiale , Li Na , Yin Dandan , Luo Meng , Luo Feng , Du Yaping , Yan Chunhua
Published: June 2019

Oxygen vacancies are usually considered to be beneficial in catalytic conversion of polysulfides in lithium–sulfur batteries. Now it is demonstrated that the conversion of polysulfides was hindered by oxygen vacancies on ultrathin niobic acid. The inferior performance induced by the oxygen vacancy was mainly attributed to the decreased electric conductivity as well as the weakened adsorption of polysulfides on the catalyst surface. This work shows that the care should be taken when designing a new catalyst for the lithium–sulfur battery using a defect‐engineering strategy.
Ternary CoPtAu Nanoparticles as a General Catalyst for Highly Efficient Electro‐oxidation of Liquid Fuels
Authors: Li Junrui , Jilani Safia Z. , Lin Honghong , Liu Xiaoming , Wei Kecheng , Jia Yukai , Zhang Peng , Chi Miaofang , Tong YuYe J. , Xi Zheng , Sun Shouheng
Published: June 2019

Efficient electro‐oxidation of formic acid, methanol, and ethanol is challenging owing to the multiple chemical reaction steps required to accomplish full oxidation to CO2. Herein, a ternary CoPtAu nanoparticle catalyst system is reported in which Co and Pt form an intermetallic L10‐structure and Au segregates on the surface to alloy with Pt. The L10‐structure stabilizes Co and significantly enhances the catalysis of the PtAu surface towards electro‐oxidation of ethanol, methanol, and formic acid, with mass activities of 1.55 A/mgPt, 1.49 A/mgPt, and 11.97 A/mgPt, respectively in 0.1 m HClO4. The L10‐CoPtAu catalyst is also stable, with negligible degradation in mass activities and no obvious Co/Pt/Au composition changes after 10 000 potential cycles. The in situ surface‐enhanced infrared absorption spectroscopy study indicates that the ternary catalyst activates the C−C bond more efficiently for ethanol oxidation.
Green synthesis of Pd truncated octahedrons using of firmiana simplex leaf extract and their catalytic study for electro‐oxidation of methanol and reduction of p‐nitrophenol
Authors: Peng Xuwen , Bai Xuefeng , Cui Zelin , Liu Xuhui
Published: June 2019

A facile and eco‐friendly biosynthetic route for preparing Pd truncated octahedrons (PdTOs) using firmiana simplex leaf extract was reported without any chemical reducing agents. The information of reducing components, reduction process and time were obtained by ATR‐FTIR imaging, FTIR and UV–Vis spectroscopy, respectively. TEM image revealed that more than 75% of PdNPs were composed of PdTOs with an average diameter of 9.2 nm. HR‐TEM analysis demonstrated that a single PdTO consisted of the mix of {100} and {111} crystal planes. SAED and XRD pattern confirmed the well crystalline nature of fcc structured PdTOs. The model reactions of electro‐oxidation of methanol and reduction of p‐nitrophenol (p‐NP) were adopted to explore the effects of structure and size of PdNPs on the catalytic properties. In the electro‐oxidation of methanol, the forward‐scan peak current density (If) of PdTOs was 10.05 mA cm‐2, 6.3 times and 1.9 times of PdNPs‐0 and PdNPs‐4:1, illustrating its superior electro‐catalytic property to that of spherical PdNPs. In the p‐NP reduction reaction, the apparent rate constant (Ka) over PdTOs was 0.358 min‐1, higher than spherical PdNPs‐0 (0.08 min‐1) with the similar particle size and lower than the same spherical PdNPs‐4:1 (0.562 min‐1) and commercial Pd/C (0.415 min‐1), which all about half the size of PdTOs. It has been demonstrated that electro‐chemical oxidation of methanol was a structure‐sensitive reaction, while the reduction of p‐NP was mainly dependent on the particle size of PdNPs.
Degradation of Perfluorooctane Sulfonamide by Acinetobacter Sp. M and Its Extracellular Enzymes
Authors: Hao Jian , Wang Penghong , Kang Yufei , He Haitao , Luo Huihua , Kim Sarah , Niu Lili , Jiang Haizhen , Ma Kesen
Published: June 2019

The Acinetobacter sp. strain M isolated from a contaminated soil sample in Jiangsu Province of China was found to be able to degrade perfluorooctane sulfonamide (PFOSA) effectively. Fluoride anion (F−) released from PFOSA degradation was detected by ion chromatography, and showed positive correlation to the growth curve of Acinetobacter sp. strain M. The PFOSA degradation efficiency of strain M was approximately 27 %, as assessed by GC analysis. It was shown that enzymes localized outside of cells of Acinetobacter sp. strain M catalyzed the degradation of PFOSA. This further indicates a possibly new (multi‐step/pathway) mechanism for PFOSA degradation. It revealed that the extracellular enzyme of the Acinetobacter strain M preferentially cleaves carbon‐carbon and carbon‐fluorine bonds instead of destroying the carbon‐sulfur bond. The growth condition for Acinetobacter sp. strain M was optimized at 30 °C and pH 7.0 in the presence of 2000 mg L−1 of PFOSA and 0.5 % (v/v) of Tween‐20. The optimal PFOSA degradation time was found to be 12 h, with a degradation efficiency of 76 % by extracellular enzymes in strain M as determined by GC analysis. The result may provide potential applications for biodegradition of perfluoro organic compounds, such as derivatives of perfluorooctane (C8).
Copper Oxide Nanomaterials Derived from Zanthoxylum armatum DC. and Berberis lyciumRoyle Plant Species: Characterization, Assessment of Free Radical Scavenging and Antibacterial Activity
Authors: Mirza Azar Ullah , Khan Mohd Shoeb , Nami Shahab A. A. , Kareem Abdul , Rehman Sumbul , Bhat Shahnawaz Ahmad , Nishat Nahid
Published: June 2019

Copper oxide nanomaterials were synthesized by a facile sustainable biological method using two plant species (Zanthoxylum armatum DC. and Berberis lycium Royle). The formation of materials was confirmed by FT‐IR, ATR, UV‐visible, XRD, TEM, SEM, EDX, TGA and PL. The antibacterial activity was evaluated by agar well diffusion method to ascertain the efficacy of plant species extract and extract derived copper oxide nanomaterials against six Gram‐positive bacteria namely Staphylococcus aureus, Streptococcus mutans, Streptococcus pyogenes, Corynebacterium diphtheriae, Corynebacterium xerosis, Bacillus cereus and four Gram‐negative bacteria such as Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris against the standard drug, Ciprofloxacin for Gram‐positive and Gentamicin for Gram‐negative bacteria, respectively. In both cases, copper oxide nanomaterials were found to be sensitive in all the bacterial species. Sensitivity of copper oxide nanomaterials shows an be higher as compared to plant species extract against different bacteria. Scavenging activity of plant extracts along with nanomaterials have been accessed using previously reported protocols employing ascorbic acid as standard. Scavenging activity of copper oxide nanomaterials shows an increase with increase in concentration. The biological activity (bactericidal and scavenging efficiency) of plant derived copper oxide nanomaterials revealed that these materials can be used as potent antimicrobial agent and DPPH scavengers in industrial as well as pharmacological fields.
Methanol Synthesis from CO2 Hydrogenation
Authors: Bowker Michael
Published: June 2019

In the future we will be phasing out the use of fossil fuels in favour of more sustainable forms of energy, especially solar derived forms such as hydroelectric, wind and photovoltaic. However, due to the variable nature of the latter sources which depend on time of day, and season of the year, we also need to have a way of storing such energy at peak production times for use in times of low production. One way to do this is to convert such energy into chemical energy, and the principal way considered at present is the production of hydrogen. Although this may be achieved directly in the future via photocatalytic water splitting, at present it is electrolytic production which dominates thinking. In turn, it may well be important to store this hydrogen in an energy dense liquid form such as methanol or ammonia. In this brief review it is emphasised that CO2 is the microscopic carbon source for current industrial methanol synthesis, operating through the surface formate intermediate, although when using CO in the feed, it is CO which is hydrogenated at the global scale. However, methanol can be produced from pure CO2 and hydrogen using conventional and novel types of catalysts. Examples of such processes, and of a demonstrator plant in construction, are given, which utilize CO2 (which would otherwise enter the atmosphere directly) and hydrogen which can be produced in a sustainable manner. This is a fast‐evolving area of science and new ideas and processes will be developed in the near future.
Catalytic Alkynylation of Polyfluoroarenes by Amide Base Generated In Situ
Authors: Shigeno Masanori , Okawa Takuya , Imamatsu Masaya , Nozawa‐Kumada Kanako , Kondo Yoshinori
Published: June 2019

We herein demonstrate that the amide base generated in situ from CsF and N(TMS)3 catalyzes the deprotonative coupling reactions of terminal alkynes with polyfluoroarenes, wherein mono‐ and dialkynylations occur efficiently for penta‐ and hexafluorobenzenes, respectively. Tetraalkynylated products could also be synthesized from dialkynylated compounds.
Inherent Chemotherapeutic Anti‐Cancer Effects of Low‐Dimensional Nanomaterials
Authors: Fu Wen , Zhou Wenhua , Chu Paul K. , Yu Xue‐Feng
Published: June 2019

Low‐dimensional nanomaterials (LDNs) are receiving increasing attention in cancer therapy owing to their unique properties, especially the large surface area‐to‐volume ratio. LDNs such as metallic nanoparticles (NPs), hydroxyapatite NPs, graphene derivatives, and black phosphorus (BP) nanosheets have been proposed for drug delivery, photothermal/photodynamic therapies, and multimodal theranostic treatments. The therapeutic effectiveness is mainly based on the physical characteristics of LDNs, but their inherent bioactivity has not been fully capitalized. In this Minireview, recent advances in the anti‐cancer effects of various types of LDNs with inherent chemotherapeutic bioactivity are described and the bioactivity mechanisms are discussed on the cellular and molecular levels. BP, one of the newest and exciting members of the LDN family, is highlighted owing to the excellent inherent bioactivity, selectivity, and biocompatibility in cancer therapy. LDNs and related derivatives possess inherent bioactivity and selective chemotherapeutic effects suggesting large potential as nanostructured anti‐cancer agents in cancer therapy.
Valence‐Shell Electron‐Pair Repulsion Theory Revisited: An Explanation for Core Polarization
Authors: Munárriz Julen , Calatayud Mónica , Contreras‐García Julia
Published: June 2019

Valence‐shell electron‐pair repulsion (VSEPR) theory constitutes one of the pillars of theoretical predictive chemistry. It was proposed even before the advent of the concept of “spin”, and it is still a very useful tool in chemistry. In this article we propose an extension of VSEPR theory to understand the core structure and predict core polarization in the main‐group elements. We show from first principles (Electron Localization Function analysis) how the inner‐ and outer‐core shells are organized. In particular, electrons in these regions are structured following the shape of the dual polyhedron of the valence shell (3rd period) or the equivalent polyhedron (4th and 5th periods). We interpret these results in terms of “hard” and “soft” core character. All the studied systems follow this trend, providing a framework for predicting electron distribution in the core. We also show that lone pairs behave as “standard ligands” in terms of core polarization. The predictive character of the model was tested by proposing the core polarization in different systems not included in the original set (such as XeF4 and [Fe(CN)6]3−) and checking the hypothesis by means of a posteriori calculations. From the experimental point of view, the extension of VSEPR to the core region has consequences for current crystallography research. In particular, it explains the core polarization revealed by high resolution X‐ray experiments.
Prognostic implication of molecular subtypes and response to neoadjuvant chemotherapy in 760 gastric carcinomas: role of Epstein–Barr virus infection and high‐ and low‐microsatellite instability
Authors: Kohlruss Meike , Grosser Bianca , Krenauer Marie , Slotta‐Huspenina Julia , Jesinghaus Moritz , Blank Susanne , Novotny Alexander , Reiche Magdalena , Schmidt Thomas , Ismani Liridona , Hapfelmeier Alexander , Mathias Daniel , Meyer Petra , Gaida Matthias M , Bauer Lukas , Ott Katja , Weichert Wilko , Keller Gisela
Published: June 2019

Epstein–Barr virus positivity (EBV(+)) and high‐microsatellite instability (MSI‐H) have been identified as molecular subgroups in gastric carcinoma. The aim of our study was to determine the prognostic and predictive relevance of these subgroups in the context of platinum/5‐fluorouracil (5‐FU) based preoperative chemotherapy (CTx). Additionally, we investigated the clinical relevance of the low‐MSI (MSI‐L) phenotype. We analysed 760 adenocarcinomas of the stomach or the gastro‐oesophageal junction encompassing 143 biopsies before CTx and 617 resected tumours (291 without and 326 after CTx). EBV was determined by PCR and in situ hybridisation for selected cases. MSI was analysed by PCR using five microsatellite markers and classified as MSI‐H and MSI‐L. Frequencies of EBV(+), MSI‐H and MSI‐L in the biopsies before CTx were 4.2, 10.5 and 4.9% respectively. EBV(+) or MSI‐H did not correlate with response, but MSI‐L was associated with better response (p = 0.011). In the resected tumours, frequencies of EBV(+), MSI‐H and MSI‐L were 3.9, 9.6 and 4.5% respectively. Overall survival (OS) was significantly different in the non‐CTx group (p = 0.014). Patients with EBV(+) tumours showed the best OS, followed by MSI‐H. MSI‐L was significantly associated with worse OS (hazard ratio [HR], 2.21; 95% confidence interval [CI], 1.21–4.04, p = 0.01). In the resected tumours after CTx, MSI‐H was also associated with increased OS (HR, 0.54; 95% CI, 0.26–1.09, p = 0.085). In multivariable analysis, molecular classification was an independent prognostic factor in the completely resected (R0) non‐CTx group (p = 0.035). In conclusion, MSI‐H and EBV(+) are not predictive of response to neoadjuvant platinum/5‐FU based CTx, but they are indicative of a good prognosis. In particular, MSI‐H indicates a favourable prognosis irrespective of treatment with CTx. MSI‐L predicts good response to CTx and its negative prognostic effect for patients treated with surgery alone suggests that MSI‐L might help to identify patients with potentially high‐benefit from preoperative CTx.
Comparing surgical and nonsurgical larynx‐preserving treatments with total laryngectomy for locally advanced laryngeal cancer
Authors: Patel Sagar A. , Qureshi Muhammad M. , Dyer Michael A. , Jalisi Scharukh , Grillone Gregory , Truong Minh Tam
Published: June 2019

Background

The declining 5‐year overall survival (OS) of patients with laryngeal cancer has been associated with increased nonsurgical management of stage III/IV disease. To further assess this hypothesis, the authors evaluated recent OS trends and patterns of use between larynx‐preserving approaches with chemoradiation (CRT) or partial laryngectomy (PL) and total laryngectomy (TL) stratified by tumor and nodal burden.

Methods

The National Cancer Data Base was used to identify 8703 patients with stage III/IV (excluding T1 tumors) laryngeal squamous cell carcinoma treated between 2003 and 2011 with CRT or upfront PL or TL with or without adjuvant therapy. OS was analyzed using the Kaplan‐Meier method and a Cox proportional hazards model.

Results

Among patients with non‐T4, low nodal burden (T2N1 or T3N0‐N1) disease, no survival differences were observed between CRT, PL, and TL. Patients who had non‐T4, high nodal burden (T2‐T3N2‐N3) disease who underwent TL with or without adjuvant treatment had a higher risk of death compared with those who received CRT (hazard ratio, 1.25; 95% CI, 1.04‐1.51; P = .016). For T4N0‐N3 tumors, TL compared with CRT was associated with improved OS (hazard ratio, 0.80; 95% CI, 0.62‐0.92; P = .002). No statistically significant difference in outcome was noted between CRT and PL for all stage groups. The use of CRT has declined and receipt of TL has increased since 2006 for T4 disease, whereas PL rates have remained stably low.

Conclusions

No survival differences were noted between surgical and nonsurgical approaches for patients with non‐T4, low nodal burden laryngeal cancer. Patients with non‐T4, high nodal burden disease may benefit from definitive CRT. Total laryngectomy remains advantageous in patients with T4 disease.
Explicit prognostic disclosure to Asian women with breast cancer: A randomized, scripted video‐vignette study (J‐SUPPORT1601)
Authors: Mori Masanori , Fujimori Maiko , van Vliet Liesbeth M. , Yamaguchi Takuhiro , Shimizu Chikako , Kinoshita Takayuki , Morishita‐Kawahara Miki , Inoue Akira , Inoguchi Hironobu , Matsuoka Yutaka , Bruera Eduardo , Morita Tatsuya , Uchitomi Yosuke
Published: June 2019

Background

Nondisclosure of a poor prognosis to patients with advanced cancer remains a typical practice in Asia. Although the importance of prognostic communication has increasingly been recognized worldwide, little is known about whether explicit prognostic disclosure positively affects Asian patients with advanced cancer. The objective of this study was to examine the effects of explicit prognostic communication on patients with cancer recurrence.

Methods

In this randomized, video‐vignette study, Japanese women with breast cancer who had undergone curative surgery viewed videos of prognostic communication between a patient with recurrent, incurable breast cancer and her oncologist. The videos differed only in the presence or absence of explicit prognostic disclosure. The primary outcome was participants' uncertainty (rated from 0 to 10), and the secondary outcomes included anxiety (measured on the State‐Trait Anxiety Inventory‐State: range, 20‐80), satisfaction (Patient Satisfaction Questionnaire; range 0‐10), self‐efficacy (range, 0‐10), and willingness to discuss advance care planning (range, 1‐4).

Results

In total, 105 women participated (mean ± SD age, 53.8 ± 8.2 years). After viewing the video with more versus less explicit disclosure, participants showed significantly lower uncertainty (mean ± SE scores, 5.3 ±0.2 vs 5.7 ± 0.2, respectively; P = .032) and higher satisfaction (5.6 ± 0.2 vs 5.2 ± 0.2, respectively; P = .010) without increasing anxiety (changes in scores on the State‐Trait Anxiety Inventory‐State: 0.06 ± 0.5 vs 0.6 ± 0.5, respectively; P = .198). No significant differences were observed in self‐efficacy (5.2 ± 0.2 vs 5.0 ± 0.2, respectively; P = .277) or willingness to discuss advance care planning (2.7 ± 0.1 vs 2.7 ± 0.1, respectively; P = .240).

Conclusions

Explicit prognostic disclosure prompted better outcomes than nondisclosure in Japanese women with breast cancer. When asked about the prognosis by Asian patients with cancer, clinicians may be encouraged to respect their wishes and explicitly discuss the prognosis if deemed appropriate.
Modern Management of Mild Autonomous Cortisol Secretion
Authors: Delivanis Danae A. , Athimulam Shobana , Bancos Irina
Published: June 2019

Incidentally discovered adrenal tumors are reported in ~ 5% of adults undergoing cross‐sectional imaging. Mild autonomous cortisol secretion (MACS) from the adrenal mass is demonstrated in 5–48% of patients with adrenal tumors. The diagnosis of MACS represents a challenge due to limitations of the currently used diagnostic tests, differences in the definitions of the clinically relevant MACS, and heterogeneity in an individual's susceptibility to abnormal cortisol secretion from the adrenal mass. Patients with MACS present with increased risk of cardiovascular risk factors, cardiovascular events, metabolic bone disease, and mortality. Adrenalectomy improves or reverses MACS‐associated comorbidities in selected patients. The current review will address diagnostic and management challenges in the care of patients with MACS, discuss data on emerging biomarkers, and suggest future directions in the field of MACS.
A randomized clinical study to evaluate the effect of denture adhesive application technique on food particle accumulation under dentures
Authors: Atassi Mounir , Milleman Kimberly R. , Burnett Gary R. , Sanyal Susmita , Milleman Jeffery L.
Published: June 2019

Food ingress under dentures is a common problem that may be reduced by denture adhesive use. The objective of this study was to explore the effect of the mode of application of a denture adhesive on reducing accumulation of food particles under dentures. This was a single‐centre, controlled, single‐blind, randomized, three‐treatment, three‐period, crossover study in participants with complete, removable well‐fitting, well‐made upper/lower dentures. Treatments were: 1) experimental denture adhesive application (test adhesive) applied with a precision applicator as continuous strips; 2) marketed denture adhesive (positive control) applied using a flat ribbon nozzle as dabs; 3) no adhesive. Food‐occlusion testing was performed by assessing peanut particle migration under dentures with denture retention/stability evaluated using the Kapur Index (Olshan modification). Differences were assessed using an ANOVA model. Adhesive oozing and perceptions of the adhesives were assessed by questionnaire. All 83 randomized participants completed the study. There were no significant differences between positive control or test adhesives versus no adhesive, or between test adhesive and positive control, for mass of peanut particles recovered from dentures. Both adhesives had significantly higher retention and stability scores compared with no adhesive (all P < .01). Participants reported significantly higher scores for denture comfort, confidence, satisfaction and movement with both adhesives versus no adhesive (all P < .01). No differences in adhesive ooze were reported between adhesives. No adverse events were reported. In conclusion, there was no difference in performance, as measured by peanut particle mass recovered from upper/lower dentures, for the test adhesive, positive control and no adhesive.
Utility of fine‐needle aspiration cytology in the diagnosis of HIV lymphadenopathy
Authors: Suresh Pooja K. , Poojary Shweta , Basavaiah Sridevi Hanganahalli , Kini Jyoti R. , Lobo Flora D. , Sahu Kausalya K.
Published: June 2019

Background

India, being a developing country, harbors the third largest human immunodeficiency virus (HIV)‐infected population in the world, and HIV‐associated lymphadenopathy is commonly encountered. HIV lymphadenopathy is more commonly generalized and pathology ranges from reactive lymphoid hyperplasia to infections like tuberculosis to neoplasms such as lymphoma and Kaposi sarcoma. The study intended to assess the utility of fine‐needle aspiration (FNA) cytology in HIV lymphadenopathy.

Materials and Methods

A retrospective FNA slide review of HIV‐infected cases with lymphadenopathy received over a period of 2 years in the cytopathology department was performed. The clinicopathological characteristics, absolute lymphocyte count (ALC), and CD4 counts were analyzed.

Results

Seventy‐nine lymph node aspirates were received from HIV patients over 2 years. The mean age at presentation was 39 years with a male:female ratio of 2.4:1. Cervical lymph nodes (62%) were more commonly affected. Tuberculous lymphadenitis was the commonest lesion (41.8%), followed by reactive lymphadenitis (24%), nonspecific granulomatous lymphadenitis (14%), suppurative lymphadenitis (8%), cryptococcal lymphadenitis (2%), lymphoma (9%), and metastasis (1%).

Conclusion

Lymph node FNA in HIV/AIDS is not only useful in identifying those cases that require further evaluation, but also aids in categorizing various etiologies such as opportunistic infections, non‐neoplastic, and neoplastic lesions. FNA is a less expensive, expeditious minimally invasive method for an early diagnosis that abets in deciding the treatment strategy, thus curtailing the associated morbidity and mortality.
Impact of hormonal contraceptives on urinary steroid profile in relation to serum hormone changes and CYP17A1 polymorphism
Authors: Ekström Lena , Knutsson Jona Elings , Mullen Jenny , Ericsson Magnus , Hirschberg Angelica Lindén
Published: June 2019

To detect doping with endogenous steroids, six urinary steroids are longitudinally monitored in the athlete biological passport (ABP). These steroids include testosterone, etiocholanolone, androsterone, 5α‐androstane‐3α,17β‐diol, 5β‐androstane‐3α,17β‐diol, and the testosterone isomer epitestosterone. It is known that the intake of hormonal contraceptives may interfere with the ABP biomarkers. A previous study showed that athletes using hormonal contraceptives (HCs) display lower urinary epitestosterone concentrations than non‐using athletes. In this study, we analyzed the urinary steroid profile prior to and three months after administration of an oral HC including levonorgestrel and ethinylestradiol (n = 55). The urinary concentrations of all the ABP metabolites decreased after three months, with epitestosterone showing the largest decline (median 6.78 to 3.04 ng/mL, p˂0.0001) followed by 5α‐androstane‐3α,17β‐diol (median 23.5 to 12.83 ng/mL, p˂0.0001), and testosterone (median 5.32 to 3.66, p˂0.0001). Epitestosterone is included in two of the five ratios in the ABP (T/E and 5αAdiol/E), and consequently these ratios increased 1.7‐fold (range 0.27 to 8.50) and 1.26‐fold (range 0.14 to 5.91), respectively. Some of these changes may mimic the changes seen after administration of endogenous steroids leading to atypical findings. Notably, even though participants used the same contraceptive treatment schedule, the HC‐mediated epitestosterone change varied to a large extent (median 0.43‐fold, range 0.06 to 6.5) and were associated with a functional T˃C promoter polymorphism in CYP17A1. Moreover, the epitestosterone changes correlated with HC‐induced testosterone and gonadotropins changes in serum, indicating that urinary epitestosterone reflects the androgen load in HC‐using women.
Persistent effects of fragmentation on tropical rainforest canopy structure after 20 yr of isolation
Authors: Almeida Danilo R. A. , Stark Scott C. , Schietti Juliana , Camargo Jose L. C. , Amazonas Nino T. , Gorgens Eric B. , Rosa Diogo M. , Smith Marielle N. , Valbuena Ruben , Saleska Scott , Andrade Ana , Mesquita Rita , Laurance Susan G. , Laurance William F. , Lovejoy Thomas E. , Broadbent Eben N. , Shimabukuro Yosio E. , Parker Geoffrey G. , Lefsky Michael , Silva Carlos A. , Brancalion Pedro H. S.
Published: June 2019

Assessing the persistent impacts of fragmentation on aboveground structure of tropical forests is essential to understanding the consequences of land use change for carbon storage and other ecosystem functions. We investigated the influence of edge distance and fragment size on canopy structure, aboveground woody biomass (AGB), and AGB turnover in the Biological Dynamics of Forest Fragments Project (BDFFP) in central Amazon, Brazil, after 22+ yr of fragment isolation, by combining canopy variables collected with portable canopy profiling lidar and airborne laser scanning surveys with long‐term forest inventories. Forest height decreased by 30% at edges of large fragments (>10 ha) and interiors of small fragments (<3 ha). In larger fragments, canopy height was reduced up to 40 m from edges. Leaf area density profiles differed near edges: the density of understory vegetation was higher and midstory vegetation lower, consistent with canopy reorganization via increased regeneration of pioneers following post‐fragmentation mortality of large trees. However, canopy openness and leaf area index remained similar to control plots throughout fragments, while canopy spatial heterogeneity was generally lower at edges. AGB stocks and fluxes were positively related to canopy height and negatively related to spatial heterogeneity. Other forest structure variables typically used to assess the ecological impacts of fragmentation (basal area, density of individuals, and density of pioneer trees) were also related to lidar‐derived canopy surface variables. Canopy reorganization through the replacement of edge‐sensitive species by disturbance‐tolerant ones may have mitigated the biomass loss effects due to fragmentation observed in the earlier years of BDFFP. Lidar technology offered novel insights and observational scales for analysis of the ecological impacts of fragmentation on forest structure and function, specifically aboveground biomass storage.
Spatial patterns of meadow sensitivities to interannual climate variability in the Sierra Nevada
Authors: Albano Christine M. , McClure Meredith L. , Gross Shana E. , Kitlasten Wesley , Soulard Christopher E. , Morton Charles , Huntington Justin
Published: June 2019

Conservation of montane meadows is a high priority for land and water managers given their critical role in buffering the effects of climate variability and their vulnerability to increasing temperatures and evaporative demands. Recent advances in cloud computing have provided new opportunities to examine ecological responses to climate variability over the past few decades and at large spatial scales. In this study, we characterized the sensitivities (magnitude and direction of the slope) of meadow vegetation responses to interannual variations in climate. We calculated sensitivity as the regression slope between a 31‐year (1985–2016) time series of Landsat‐derived vegetation indices characterizing late‐season vegetation vigour and water balance variables from the Basin Characterization Model. We identified April 1 snowpack as the climate variable the majority of meadows were most sensitive to. We assessed how vegetation sensitivities to snowpack varied with hydrogeomorphic context (e.g., climate, geology, soils, watershed geometry, and land cover) across the Sierra Nevada mountain range using factor analysis to reduce the dimensionality of the hydrogeomorphic data and multiple linear regression to model sensitivity responses. We found that meadow sensitivities to snowpack varied with long‐term average meadow climate, indicators of watershed subsurface water storage capacity, and indicators of meadow vegetation composition. Alpine and subalpine meadows with high average annual precipitation but limited catchment subsurface storage exhibited the largest sensitivities. Our results provide a novel regional perspective on spatial patterns of meadow sensitivities to climate variability and the landscape‐scale hydrogeomorphic factors that influence late‐season water availability in meadow ecosystems in the Sierra Nevada.
Analysis of attribute‐based cryptographic techniques and their application to protect cloud services
Authors: Belguith Sana , Kaaniche Nesrine , Hammoudeh Mohammad
Published: June 2019

Recent technological advances such as the internet of things, fog computing, and cloud applications lead to exponential growth in the amount of generated data. Indeed, cloud storage services have experienced unprecedented usage demand. The loss of user control over their cloud stored data introduced several security and privacy concerns. To address these concerns, cryptographic techniques are widely adopted at the user side. Attribute‐based cryptography is commonly used to provide encrypted and/or authenticated access to outsourced data in remote servers. However, the use of these cryptographic mechanisms often increase the storage and computation costs; consequently, the energy consumption in the entire cloud ecosystem. In this paper, we provide a comparative analysis of different attribute‐based cryptographic mechanisms suitable for cloud data sharing services. We also provide a detailed discussion of different reviewed schemes, w.r.t. supported features, namely, security, privacy, and functional requirements. In addition, we explore the limitations of existing attribute‐based cryptographic mechanisms and propose future research directions to better fit the growing needs of this cloud environment in terms of energy savings, processing and storage efficiency, and availability requirements.