bluuebunny/crossref_metadata_2025 huggingface dataset:
Fe–Au Nanoparticle‐Coupling for Ultrasensitive Detections of Circulating Tumor DNA
Authors: Hu Ping , Zhang Shengjian , Wu Tong , Ni Dalong , Fan Wenpei , Zhu Yan , Qian Rong , Shi Jianlin
Published: June 2018

Effectiveness of cancer therapy relies heavily on the efficient early diagnosis. Circulating tumor DNA (ctDNA) detection is one of the most clinically meaningful liquid biopsy approaches for the noninvasive cancer early diagnosis, which, unfortunately, cannot be applied as a routine diagnostic tool till a number of obstacles, for example, unsatisfactory specificity and sensitivity, and extremely high costs, are overcome. Here, the first paradigm of nanomaterial's application in the extremely specific, ultrasensitive, and yet economical ctDNA detections is reported based on a facile nanoparticle‐coupling strategy without amplification, with which polymerase chain reaction (PCR)‐introduced bias and other shortcomings are successfully circumvented. Aiming at seven Kirsten rat sarcoma‐2 virus (KRAS) point mutations, the present strategy exhibits high specificity and an ultrahigh sensitivity of detecting as low as 0.1 pg mL−1 of KRAS point mutation without prior PCR amplification. Discriminating KRAS gene mutations in lung adenocarcinoma patients at an extremely low detection limit equivalent to 0.12% mutation relative to wild‐type gene is successful. It is envisioned that this nanoparticle‐coupling approach could be routinely applied clinically for ultra‐early diagnosis and monitoring of diverse malignant tumors, thus facilitating the fight against cancer.
Roles of Interfacial Tension in Regulating Internal Organization of Low Bandgap Polymer Bulk Heterojunction Solar Cells by Polymer Additives
Authors: Yang Zhenhua , Guo Yichen , Li Hongfei , Zhou Yuchen , Zuo Xianghao , Yu Yingjie , Pan Cheng , Strzalka Joseph , Nam Chang‐Yong , Rafailovich Miriam H.
Published: June 2018

The role of a tertiary polymer‐based additive is investigated in increasing the efficiency of inverted low bandgap polymer:fullerene bulk heterojunction (BHJ) solar cells. Charge separation in polymer BHJ solar cells relies on the phase separation between electron accepting fullerene derivatives and photoactive polymers. Proper distribution of individual phases of suitable crystallinities within the active layer is a key factor for efficient charge transport/extraction and high photovoltaic performance. Here, it is demonstrated that the minor addition of a tertiary amorphous polymer, polystyrene (PS), with optimized molecular weights can increase the overall photovoltaic efficiency of poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)]:phenyl‐C61butyric acid methyl ester (PCDTBT:PCBM) inverted BHJ solar cells, through the interfacial‐tension‐driven increase in crystallinities of photoactive phases and redistribution of PCBM molecules away from the top hole‐collecting anode interface. Complementary studies correlating polymer interfacial tension, blend internal structure, charge transport, and photovoltaic characteristics show that tertiary, high molecular‐weight polymers can serve as effective additives for improving the performance of low bandgap polymer solar cells.
Infrared‐Responsive Colloidal Silver Nanorods for Surface‐Enhanced Infrared Absorption
Authors: Li Nannan , Yin Hang , Zhuo Xiaolu , Yang Baocheng , Zhu Xiao‐Ming , Wang Jianfang
Published: June 2018

Surface‐enhanced infrared absorption (SEIRA) spectroscopy, the enhancement of molecular vibrational signals using resonant metal nanostructures, has recently attracted much attention owing to its potential use in molecular detection in chemistry, biology, and medicine. This study reports on the growth of high‐aspect‐ratio metal nanocrystals and their application for SEIRA. Highly uniform Ag nanorods are synthesized through Au nanobipyramid‐directed Ag overgrowth, and Au nanotubes are further prepared through the galvanic replacement reaction from the Ag nanorods. Both Ag nanorods and Au nanotubes possess narrow distributions in diameter and length and exhibit highly tunable plasmon wavelengths in the near and mid‐infrared regions. The Ag nanorods are employed as plasmonic nanoantennas to enhance the molecular vibration signals of cetyltrimethylammonium bromide molecules that are embedded in a mesostructured silica layer coated on the Ag nanorods. The dimension‐dependent SEIRA performances are carefully investigated both experimentally and numerically. The experimental and simulated SEIRA enhancement factors are in good agreement and both determined to be of the order ≈103. The results point out a promising route to the utilization of chemically synthesized, colloidal metal nanostructures as SEIRA platforms. The synthesis method also provides high‐quality metal nanostructures for exploring various plasmon‐based optical and sensing applications in the infrared region.
Stimuli‐Responsive Prodrug Chemistries for Drug Delivery
Authors: Taresco Vincenzo , Alexander Cameron , Singh Nishant , Pearce Amanda K.
Published: June 2018

Research into advanced therapeutic materials is of growing importance worldwide, particularly in the disease areas of infection, neurodegeneration, and oncology. Advances have been made in treating these diverse pathologies but there still remain many challenging areas. Amongst the most difficult are those involving highly potent and/or cytotoxic agents which present the inherent problem of adverse off‐target effects. Of key importance is to widen the therapeutic window for such agents by reducing access to non‐diseased cells and enhancing release at targeted sites. Spatiotemporal controlled release can be achieved by exploiting physical, chemical, or biological stimuli present at the specific diseased area. A crucial strategy involves drug‐carrier linkages able to respond to physiological or biochemical stimuli present in the disease region, and there is now significant literature on (polymeric) prodrugs based on the drug + carrier + cleavable linker philosophy, predominantly for cancer applications. The authors therefore focuse this mini‐review primarily on single/multistimuli‐responsive prodrugs for cancer therapies, covering prominent examples of prodrug chemistries used to endow polymers with controlled and site‐specific drug delivery properties. Additionally, the possibilities for exploiting similar approaches to disease‐associated stimuli present in bacterial and viral infections, inflammatory and immune diseases, and in degenerative disorders are emphasized.
DNA Hydrogel Assemblies: Bridging Synthesis Principles to Biomedical Applications
Authors: Shahbazi Mohammad‐Ali , Bauleth‐Ramos Tomás , Santos Hélder A.
Published: June 2018

DNA is a perfect polymeric molecule for interfacing biology with material science to construct hydrogels that represent fascinating properties for a wide variety of biomedical applications. Tunable multifunctionality, convenient programmability, adequate biocompatibility, biodegradability, capability of precise molecular recognition, and high versatility have made DNA an irreplaceable building block for the construction of novel 3D hydrogels. DNA can be used as the only component of a hydrogel, the backbone or a cross‐linker that connects the main building blocks to form hybrid hydrogels through chemical reactions or physical entanglement. Responsive constructs of DNA with superior mechanical properties are very commonly reported nowadays, which can undergo macroscopic changes induced by various triggers, including alteration in ionic strength, temperature, and pH. These hydrogels can be prepared by various types of DNA building blocks, such as branched double‐stranded DNA, single‐stranded DNA, X‐shaped DNA, or Y‐shaped DNA through intermolecular i‐motif structures, DNA hybridization, enzyme ligation, or enzyme polymerization. These hydrogels are envisioned for a variety of applications, such as drug delivery, sensing, tissue engineering, 3D cell culture, and providing template for nanoparticle synthesis. This review highlights the design of ideal DNA hydrogels from biological and material points of view for future biomedical applications.
Weak effects of common genetic variation in oxytocin and vasopressin receptor genes on rhesus macaque social behavior
Authors: Madlon‐Kay Seth , Montague Michael J. , Brent Lauren J. N. , Ellis Samuel , Zhong Brian , Snyder‐Mackler Noah , Horvath Julie E. , Skene Jesse Haynes Pate , Platt Michael L.
Published: June 2018

The neuropeptides oxytocin (OT) and arginine vasopressin (AVP) influence pair bonding, attachment, and sociality, as well as anxiety and stress responses in humans and other mammals. The effects of these peptides are mediated by genetic variability in their associated receptors, OXTR and the AVPR gene family. However, the role of these genes in regulating social behaviors in non‐human primates is not well understood. To address this question, we examined whether genetic variation in the OT receptor gene OXTR and the AVP receptor genes AVPR1A and AVPR1B influence naturally‐occurring social behavior in free‐ranging rhesus macaques—gregarious primates that share many features of their biology and social behavior with humans. We assessed rates of social behavior across 3,250 hr of observational behavioral data from 201 free‐ranging rhesus macaques on Cayo Santiago island in Puerto Rico, and used genetic sequence data to identify 25 OXTR, AVPR1A, and AVPR1B single‐nucleotide variants (SNVs) in the population. We used an animal model to estimate the effects of 12 SNVs (n = 3 OXTR; n = 5 AVPR1A; n = 4 AVPR1B) on rates of grooming, approaches, passive contact, contact aggression, and non‐contact aggression, given and received. Though we found evidence for modest heritability of these behaviors, estimates of effect sizes of the selected SNVs were close to zero, indicating that common OXTR and AVPR variation contributed little to social behavior in these animals. Our results are consistent with recent findings in human genetics that the effects of individual common genetic variants on complex phenotypes are generally small.
Hypervalent Iodine(III)‐Catalyzed Balz–Schiemann Fluorination under Mild Conditions
Authors: Xing Bo , Ni Chuanfa , Hu Jinbo
Published: June 2018

An unprecedented hypervalent iodine(III) catalyzed Balz–Schiemann reaction is described. In the presence of a hypervalent iodine compound, the fluorination reaction proceeds under mild conditions (25–60 °C), and features a wide substrate scope and good functional‐group compatibility.
Redox‐Triggered Orientational Responses of Liquid Crystals to Chlorine Gas
Authors: Szilvási Tibor , Bao Nanqi , Nayani Karthik , Yu Huaizhe , Rai Prabin , Twieg Robert J. , Mavrikakis Manos , Abbott Nicholas L.
Published: June 2018

Surface‐supported liquid crystals (LCs) that exhibit orientational and thus optical responses upon exposure to ppb concentrations of Cl2 gas are reported. Computations identified Mn cations as candidate surface binding sites that undergo redox‐triggered changes in the strength of binding to nitrogen‐based LCs upon exposure to Cl2 gas. Guided by these predictions, μm‐thick films of nitrile‐ or pyridine‐containing LCs were prepared on surfaces decorated with Mn2+ binding sites as perchlorate salts. Following exposure to Cl2, formation of Mn4+ (in the form of MnO2 microparticles) was confirmed and an accompanying change in the orientation and optical appearance of the supported LC films was measured. In unoptimized systems, the LC orientational transitions provided the sensitivity and response times needed for monitoring human exposure to Cl2 gas. The response was also selective to Cl2 over other oxidizing agents such as air or NO2 and other chemical targets such as organophosphonates.
Übertragung unidirektionaler molekularer Motorrotation auf eine räumlich getrennte Biarylachse
Authors: Uhl Edgar , Thumser Stefan , Mayer Peter , Dube Henry
Published: June 2018

Molekulare Motoren vollführen kontinuierliche direktionale Bewegungen durch Zufuhr externer Energie. Eine große Herausforderung ist die definierte Übertragung direktionaler Motorbewegungen auf räumlich getrennte molekulare Einheiten. Hier wird ein molekulares System präsentiert, in dem die direktionale Rotation einer lichtbetriebenen Motoreinheit über eine Ethylenglycolkette auf eine entfernte Biarylachse übertragen werden kann. Röntgenstrukturanalyse, ECD‐ und NMR‐Experimente sowie umfassende theoretische Studien liefern Beweise für die gekoppelte, schrittweise und direktionale Bewegung beider Moleküleinheiten. Mit dem beschriebenen Moleküldesign können molekulare Motoreinheiten sehr leicht in größere funktionelle Systeme integriert und so komplexe molekulare Maschinen detailliert untersucht werden.
Tandem Payne/Dakin Reaction: A New Strategy for Hydrogen Peroxide Detection and Molecular Imaging
Authors: Ye Sen , Hu Jun Jacob , Yang Dan
Published: June 2018

Hydrogen peroxide (H2O2) has been recognized as one of the most significant ROS (reactive oxygen species) in human health and disease. Because of the intrinsic attributes of H2O2—such as its low reactivity under physiological pH—it is exceedingly challenging to develop small‐molecule fluorescent probes with high selectivity and sensitivity for visualization of H2O2 in an intricate biological milieu. To address this gap, a rationally designed tandem Payne/Dakin reaction is reported that is specific to molecular recognition of H2O2. New H2O2 probes based on this unique chemical strategy can be easily synthesized by a general coupling reaction, and the practical applicability of those probes has been confirmed by the visualization of endogenously produced H2O2 in living cells. In particular, starvation‐induced H2O2 production in mouse macrophages has been detected by the novel probe in both confocal imaging and flow cytometry. This tandem Payne/Dakin reaction provides a basis for developing more sophisticated molecular tools to interrogate H2O2 functions in biological phenomena.
Surgically resected T1‐ and T2‐stage esophageal squamous cell carcinoma: T and N staging performance of EUS and PET/CT
Authors: Jeong Dong Young , Kim Min Yeong , Lee Kyung Soo , Choi Joon Young , Kim Soo Jeong , Chung Myung Jin , Min Yang Won , Kim Hong Kwan , Zo Jae Ill , Shim Young Mog , Sun Jong‐Mu
Published: June 2018

This study aimed to evaluate the frequency of nodal metastases and to disclose the diagnostic performance of endoscopic ultrasonography (EUS) and PET/CT in T and N staging in surgically resected early‐stage esophageal squamous cell carcinomas (eSCCs). Institutional review board approved this retrospective study with waiver of informed consent for reviewing medical record. We included 435 patients with an early T‐stage (Tis or T1a [≤T1a], T1b and T2) eSCC. The rates of metastatic lymphadenopathy were calculated. Then, the performance of EUS and PET/CT in subdividing T and N stages was assessed. 131 ≤ T1a, 234 T1b, and 70 T2 eSCCs were identified. In discriminating ≤T1a from other cancers, the sensitivity, specificity, and accuracy of EUS were 60.3% (79/131), 80.3% (244/304), and 74.3% (323/435) respectively. With ROC curve analysis, cut‐off value of SUVmax 3.05 at PET provided sensitivity 74.8% (98/131), specificity 70.1% (213/304), and accuracy 71.5% (311/435) for differentiating ≤T1a eSCCs from others. Ten (7.6%) of 131 ≤ T1a cancers had nodal metastasis. In discriminating N0 from node‐positive disease, sensitivity, specificity, and accuracy of EUS were 89.6% (267/298), 41.6% (57/137), and 74.5% (324/435), respectively, whereas those of PET/CT were 88.9% (265/298), 38.7% (53/137), and 73.1% (318/435) respectively. In >70% of patients with ≤T1a eSCCs, the tumor stage can be discriminated from higher stage cancers by using EUS or PET/CT. Substantial percentage (7.6%) of ≤T1a eSCC patients have nodal metastases, which are missed in more than half of the patients in clinical staging.
Trends in colorectal cancer incidence among younger adults—Disparities by age, sex, race, ethnicity, and subsite
Authors: Crosbie Amanda B. , Roche Lisa M. , Johnson Linda M. , Pawlish Karen S. , Paddock Lisa E. , Stroup Antoinette M.
Published: June 2018

Millennials (ages 18‐35) are now the largest living generation in the US, making it important to understand and characterize the rising trend of colorectal cancer incidence in this population, as well as other younger generations of Americans. Data from the New Jersey State Cancer Registry (n = 181 909) and Surveillance, Epidemiology, and End Results program (n = 448 714) were used to analyze invasive CRC incidence trends from 1979 to 2014. Age, sex, race, ethnicity, subsite, and stage differences between younger adults (20‐49) and screening age adults (≥50) in New Jersey (NJ) were examined using chi‐square; and, we compared secular trends in NJ to the United States (US). Whites, men, and the youngest adults (ages 20‐39) are experiencing greater APCs in rectal cancer incidence. Rates among younger black adults, overall, were consistently higher in both NJ and the US over time. When compared to older adults, younger adults with CRC in NJ were more likely to be: diagnosed at the late stage, diagnosed with rectal cancer, male, non‐white, and Hispanic. Invasive CRC incidence trends among younger adults were found to vary by age, sex, race, ethnicity, and subsite. Large, case‐level, studies are needed to understand the role of genetics, human papillomavirus (HPV), and cultural and behavioral factors in the rise of CRC among younger adults. Provider and public education about CRC risk factors will also be important for preventing and reversing the increasing CRC trend in younger adults.
Isolated retroperitoneal Castleman's disease: A case report and literature review
Authors: Jhan Jhen‐Hao , Li Ching‐Chia , Wu Wen‐Jeng , Lee Hsiang‐Ying
Published: June 2018

Key Clinical Message

Unicentric Castleman's disease (CD) may rarely present as an isolated retroperitoneal tumor. Even experienced surgeons may misdiagnose CD because of its rarity. Surgeons should consider this disease when faced with an isolated retroperitoneal tumor. Unicentric CD is usually cured with surgical resection. In contrast, multicentric CD need numerous systemic therapies.
Short‐term use of oral amiodarone causing torsades de pointes
Authors: Yau Stephen , Chan Patrick , Sapkin Joshua , Hsieh Eric
Published: June 2018

Key Clinical Message

Amiodarone is one of the most commonly used antiarrhythmic drugs. Despite its well‐known side effects, amiodarone is considered to be a relatively safe drug, especially in short‐term usage to prevent life‐threatening ventricular arrhythmias. Our case demonstrates an instance where short‐term usage can yield drug side effect.
Thermochemical Processing of Miscanthus through Fluidized‐Bed Fast Pyrolysis: A Parametric Study
Authors: Wang Wei-Cheng , Lee An-Cheng
Published: June 2018

Thermochemical processing of agriculture waste not only provides surrogates for combustion fuel but also reduces the environmental issues of waste. Miscanthus has been viewed as one of the largest agriculture wastes in Taiwan and a proper process for turning Miscanthus into a valuable product has become a significant subject. Here, fluidized‐bed fast pyrolysis was applied to convert Miscanthus into bio‐oil, bio‐char, and pyrolytic gases as the products. The product distributions were examined depending on various reaction parameters such as reaction temperature, carrier gas flow rate, feedstock feeding rate, and feedstock size. The chemical compositions of the bio‐oil, bio‐char, and product gases were analyzed and the properties of the bio‐oil were also tested via standard methods. So far, bio‐oil derived from Miscanthus is unfavorable for application in combustion engines without further upgrading processes.
Sulfide Surface Dynamics on Cu(100) and Ag(100) Electrodes in the Presence of c(2×2) Halide Adlayers
Authors: Rahn Björn , Magnussen Olaf M.
Published: June 2018

The influence of coadsorbed anions on electrode surface dynamics is studied in situ by direct observation of single adsorbed species via high‐speed scanning tunneling microscopy. Using well‐defined model systems, sulfide adsorbates on Cu(100) and Ag(100) covered by c(2×2) ordered adlayers of chloride or bromide, the influence of halide coadsorbate and the metal substrate on the dynamic behavior is systematically evaluated and quantitatively analyzed. The sulfide tracer diffusion coefficients exhibit a pronounced exponential potential dependence in all systems, caused by the effect of the double layer's electric field on the diffusion barrier. The sulfide mobility in general decreases with potential, with the surprising exemption of the Br‐covered Cu(100) surface where it increases, indicating a different transport mechanism. In contrast to this strong influence of the halide species on the surface diffusion, the sulfide‐sulfide interactions seem to be less affected by the nature of the coadsorbate, but depend more strongly on the type of metal substrate. In addition, the dynamic behavior of clusters on the surface, the formation of grooves, caused by adsorbate‐induced vacancy generation, and the adlayer structure and dynamics at high sulfide coverage is discussed for bromide‐covered surfaces. The data indicate a tendency of bromide to enhance the transfer of sulfide adsorbates to sites within the metal surface layer.
Sequential Alkene Isomerization and Ring‐Closing Metathesis in Production of Macrocyclic Musks from Biomass
Authors: Sytniczuk Adrian , Forcher Gwénaël , Grotjahn Douglas B. , Grela Karol
Published: June 2018

We report successful utilization of sequential alkene isomerization and ring‐closing metathesis of dec‐9‐enoic acid based dienes in synthesis of macrocyclic lactones that possess a strong scent of musk. This catalytic sequence was essential to trim the chain length of starting dienes to yield macrocycles of the right size. Dec‐9‐enoic acid is conveniently obtainable from oleic esters by Ru‐catalysed ethenolysis.
Self‐Priming Enzymatic Fabrication of Multiply Modified DNA
Authors: Whitfield Colette J. , Little Rachel C. , Khan Kasid , Ijiro Kuniharu , Connolly Bernard A. , Tuite Eimer M. , Pike Andrew R.
Published: June 2018

The self‐priming synthesis of multiply modified DNA by the extension of repeating unit duplex “oligoseeds” provides a source of versatile DNA. Sterically‐demanding nucleotides 5‐Br‐dUTP, 7‐deaza‐7‐I‐dATP, 6‐S‐dGTP, 5‐I‐dCTP as well as 5‐(octadiynyl)‐dCTP were incorporated into two extending oligoseeds; [GATC]5/[GATC]5 and [A4G]4/[CT4]4. The products contained modifications on one or both strands of DNA, demonstrating their recognition by the polymerase as both template (reading) and substrate (writing). Nucleobase modifications that lie in the major groove were reliably read and written by the polymerase during the extension reaction, even when bulky or in contiguous sequences. Repeat sequence DNA over 500 bp long, bearing four different modified units was produced by this method. The number, position and type of modification, as well as the overall length of the DNA can be controlled to yield designer DNA that offers sequence‐determined sites for further chemical adaptations, targeted small molecule binding studies, or sensing and sequencing applications.
Mixed‐Phase 2D‐MoS2 as an Effective Photocatalyst for Selective Aerobic Oxidative Coupling of Amines under Visible‐Light Irradiation
Authors: Girish Yarabhally R. , Biswas Rohin , De Mrinmoy
Published: June 2018

Metal‐semiconductor heterojunctions play a vital role in photocatalysis, yet their preparation can be exceedingly difficult. The heterojunction helps not only to separate the charges and inhibit recombination processes but also to transfer the photogenerated electron/hole to the reacting molecule. Here, we demonstrate 1T (metallic)‐2H (semiconducting) phase boundaries intrinsic to individual sheets of chemically exfoliated 2D‐MoS2 can serve as heterojunctions for enhanced photocatalysis in comparison to only semiconducting phase. Due to the abundance of heterojunctions in these multiphasic materials, chemically exfoliated 2D‐MoS2 provides improved stability and transfer of photogenerated charges to the reactants, giving better yield. We demonstrate that this easy to synthesize material is an effective photocatalyst for the aerobic oxidative coupling of amines to imines under visible light irradiation. Given its broad applications, we believe mixed phase 2D‐MoS2 can be of interest to several industrial synthetic applications related to semiconductor‐based photocatalysis. As an added advantage, this heterogeneous photocatalyst can be recycled for several times up to five cycles without any significant loss in the activity.
Enantioselective Enzymatic Naphthoyl Ring Reduction
Authors: Willistein Max , Haas Julian , Fuchs Jonathan , Estelmann Sebastian , Ferlaino Sascha , Müller Michael , Lüdeke Steffen , Boll Matthias
Published: June 2018

Birch reductions of aromatic hydrocarbons by means of single‐electron‐transfer steps depend on alkali metals, ammonia, and cryogenic reaction conditions. In contrast, 2‐naphthoyl‐coenzyme A (2‐NCoA) and 5,6‐dihydro‐2‐NCoA (5,6‐DHNCoA) reductases catalyze two two‐electron reductions of the naphthoyl‐ring system to tetrahydronaphthoyl‐CoA at ambient temperature. Using a number of substrate analogues, we provide evidence for a Meisenheimer complex‐analogous intermediate during 2‐NCoA reduction, whereas the subsequent reduction of 5,6‐dihydro‐2‐NCoA is suggested to proceed via an unprecedented cationic transition state. Using vibrational circular dichroism (VCD) spectroscopy, we demonstrate that both enzymatic reductions are highly stereoselective in D2O, providing an enantioselective pathway to products inaccessible by Birch reduction. Moreover, we demonstrate the power of VCD spectroscopy to determine the absolute configuration of isotopically engendered alicyclic stereocenters.
Influence of Temperature and Electrolyte Concentration on the Structure and Catalytic Oxygen Evolution Activity of Nickel–Iron Layered Double Hydroxide
Authors: Andronescu Corina , Seisel Sabine , Wilde Patrick , Barwe Stefan , Masa Justus , Chen Yen‐Ting , Ventosa Edgar , Schuhmann Wolfgang
Published: June 2018

NiFe layered double hydroxide (LDH) is inarguably the most active contemporary catalyst for the oxygen evolution reaction under alkaline conditions. However, the ability to sustain unattenuated performance under challenging industrial conditions entailing high corrosivity of the electrolyte (≈30 wt. % KOH), high temperature (>80 °C) and high current densities (>500 mA cm−2) is the ultimate criterion for practical viability. This work evaluates the chemical and structural stability of NiFe LDH at conditions akin to practical electrolysis, in 30 % KOH at 80 °C, however, without electrochemical polarization, and the resulting impact on the OER performance of the catalyst. Post‐analysis of the catalyst by means of XRD, TEM, FT‐IR, and Raman spectroscopy after its immersion into 7.5 m KOH at 80 °C for 60 h revealed a transformation of the structure from NiFe LDH to a mixture of crystalline β‐Ni(OH)2 and discrete predominantly amorphous FeOOH containing minor non‐homogeneously distributed crystalline domains. These structural and compositional changes led to a drastic loss of the OER activity. It is therefore recommended to study catalyst stability at industrially relevant conditions.
„Let's get ready to rumble“ – Elektrochemisch aktive Polymere lassen die (künstlichen) Muskeln spielen!
Authors: Novotny Jana , Wagner Corina , Oetken Marco
Published: June 2018

In diesem Beitrag werden neuartige Experimente zum Themenfeld ‚Intrinsisch leitfähige Polymere – Künstliche Muskeln‘ in Theorie und Praxis vorgestellt. Von der einfachen Abscheidung von Polypyrrol auf einem leitfähigen Rückgrat bis hin zur außerordentlichen Leistungsfähigkeit der Muskeln werden verschiedene Versuche präsentiert. Dieser Artikel beleuchtet zunächst einige theoretische Hintergründe bezüglich der elektrochemisch aktiven Polymere sowie die Leistungsfähigkeit und das Herstellungsverfahren der künstlichen Muskeln, das die Basis aller Versuche darstellt.
A 3D MRI‐based atlas of a lizard brain
Authors: Hoops Daniel , Desfilis Ester , Ullmann Jeremy F. P. , Janke Andrew L. , Stait‐Gardner Timothy , Devenyi Gabriel A. , Price William S. , Medina Loreta , Whiting Martin J. , Keogh J. Scott
Published: June 2018

Magnetic resonance imaging (MRI) is an established technique for neuroanatomical analysis, being particularly useful in the medical sciences. However, the application of MRI to evolutionary neuroscience is still in its infancy. Few magnetic resonance brain atlases exist outside the standard model organisms in neuroscience and no magnetic resonance atlas has been produced for any reptile brain. A detailed understanding of reptilian brain anatomy is necessary to elucidate the evolutionary origin of enigmatic brain structures such as the cerebral cortex. Here, we present a magnetic resonance atlas for the brain of a representative squamate reptile, the Australian tawny dragon (Agamidae: Ctenophorus decresii), which has been the subject of numerous ecological and behavioral studies. We used a high‐field 11.74T magnet, a paramagnetic contrasting‐enhancing agent and minimum‐deformation modeling of the brains of thirteen adult male individuals. From this, we created a high‐resolution three‐dimensional model of a lizard brain. The 3D‐MRI model can be freely downloaded and allows a better comprehension of brain areas, nuclei, and fiber tracts, facilitating comparison with other species and setting the basis for future comparative evolution imaging studies. The MRI model and atlas of a tawny dragon brain (Ctenophorus decresii) can be viewed online and downloaded using the Wiley Biolucida Server at wiley.biolucida.net.
Dust surface potential in a generalized (r, q)‐distributed multi‐ion dusty plasma
Authors: Ali S. , Abid A.A. , Du J. , Mamun A.A.
Published: June 2018

Potential on the surface of spherical dust is theoretically determined by employing the generalized power law (r, q) distribution function (df) in a multi‐ion dusty plasma. Considering a steady‐state condition, the current balance equation is solved for negatively charged dust particulates and analysed two specific cases, namely, the negative ions as streaming and dynamic non‐thermal particles. It is numerically shown that dust grain (surface) potential is significantly modified by the variation of different plasma parameters, for example, the r and q spectral indices attributed to generalized power law df, the streaming and non‐thermal negative ions, the negative ion‐to‐electron temperature ratio and the density ratio involving the negative‐to‐positive ions. The relevance to low‐temperature laboratory non‐thermal dusty plasma is briefly discussed by incorporating two types of oxygen ion species.
Obesity and diabetes—Not only a simple link between two epidemics
Authors: Chobot Agata , Górowska‐Kowolik Katarzyna , Sokołowska Magdalena , Jarosz‐Chobot Przemysława
Published: June 2018

Diabetes (DM) as well as obesity, due to their increasing incidence, were recognized as epidemic by the World Health Organization. Obesity is involved not only in the aetiopathogenesis of the most common worldwide type of DM—type 2 diabetes—but also in the development of its complications. There is also increasing scientific evidence regarding the role of obesity and overweight in type 1 diabetes. Weight gain may be considered as a complication of insulin treatment but also reveals significant pathophysiological impact on various stages of the disease. Another very important aspect related to DM as well as obesity is the microbiome, which is highly variable. The function of the gut microflora, its interaction with the whole organism, and its role in the development of obesity and type 1 diabetes as well as type 2 diabetes are still not fully understood and subject of ongoing investigations. This review presents a summary of recently published results concerning the relation of obesity/overweight and DM as well as their associations with the microbiome.
Sex‐biased breeding dispersal is predicted by social environment in birds
Authors: Végvári Zsolt , Katona Gergely , Vági Balázs , Freckleton Robert P. , Gaillard Jean‐Michel , Székely Tamás , Liker András
Published: June 2018

Sex‐biased dispersal is common in vertebrates, although the ecological and evolutionary causes of sex differences in dispersal are debated. Here, we investigate sex differences in both natal and breeding dispersal distances using a large dataset on birds including 86 species from 41 families. Using phylogenetic comparative analyses, we investigate whether sex‐biased natal and breeding dispersal are associated with sexual selection, parental sex roles, adult sex ratio (ASR), or adult mortality. We show that neither the intensity of sexual selection, nor the extent of sex bias in parental care was associated with sex‐biased natal or breeding dispersal. However, breeding dispersal was related to the social environment since male‐biased ASRs were associated with female‐biased breeding dispersal. Male‐biased ASRs were associated with female‐biased breeding dispersal. Sex bias in adult mortality was not consistently related to sex‐biased breeding dispersal. These results may indicate that the rare sex has a stronger tendency to disperse in order to find new mating opportunities. Alternatively, higher mortality of the more dispersive sex could account for biased ASRs, although our results do not give a strong support to this explanation. Whichever is the case, our findings improve our understanding of the causes and consequences of sex‐biased dispersal. Since the direction of causality is not yet known, we call for future studies to identify the causal relationships linking mortality, dispersal, and ASR.
Lifetime inbreeding depression in a leaf beetle
Authors: Müller Thorben , Lamprecht Tabea Dagmar , Schrieber Karin
Published: June 2018

Ongoing habitat loss and fragmentation result in rapid population size reductions, which can increase the levels of inbreeding. Consequently, many species are threatened by inbreeding depression, a loss of individual fitness following the mating of close relatives. Here, we investigated inbreeding effects on fitness‐related traits throughout the lifetime of the mustard leaf beetle (Phaedon cochleariae) and mechanisms for the avoidance of inbreeding. Previously, we found that these beetles have family‐specific cuticular hydrocarbon profiles, which are likely not used as recognition cue for precopulatory inbreeding avoidance. Thus, we examined whether adult beetles show postcopulatory inbreeding avoidance instead. For this purpose, we determined the larval hatching rate of eggs laid by females mated sequentially with two nonsiblings, two siblings, a nonsibling, and a sibling or vice versa. The beetles suffered from inbreeding depression throughout their entire ontogeny, as evinced by a prolonged larval development, a decreased larval and adult survival and a decreased reproductive output of inbred compared to outbred individuals. The highest larval hatching rates were detected when females were mated with two nonsiblings or first with a sibling and second with a nonsibling. Significantly lower hatching rates were measured in the treatments with a sibling as second male. Thus, the results do not support the existence of postcopulatory inbreeding avoidance in P. cochleariae, but revealed evidence for second male sperm precedence. Consequently, an alternative strategy to avoid inbreeding costs might exist in this beetle, such as a polyandrous mating system, potentially coupled with a specific dispersal behavior.
Surrounding species diversity improves subtropical seedlings’ carbon dynamics
Authors: Salmon Yann , Li Xuefei , Yang Bo , Ma Keping , Siegwolf Rolf T. W. , Schmid Bernhard
Published: June 2018

Increasing biodiversity has been linked to higher primary productivity in terrestrial ecosystems. However, the underlying ecophysiological mechanisms remain poorly understood. We investigated the effects of surrounding species richness (monoculture, two‐ and four‐species mixtures) on the ecophysiology of Lithocarpus glaber seedlings in experimental plots in subtropical China. A natural rain event isotopically labelled both the water uptaken by the L. glaber seedlings and the carbon in new photoassimilates through changes of photosynthetic discrimination. We followed the labelled carbon (C) and oxygen (O) in the plant–soil–atmosphere continuum. We measured gas‐exchange variables (C assimilation, transpiration and above‐ and belowground respiration) and δ13C in leaf biomass, phloem, soil microbial biomass, leaf‐ and soil‐respired CO2 as well as δ18O in leaf and xylem water. The 13C signal in phloem and respired CO2 in L. glaber in monoculture lagged behind those in species mixture, showing a slower transport of new photoassimilates to and through the phloem in monoculture. Furthermore, leaf‐water 18O enrichment above the xylem water in L. glaber increased after the rain in lower diversity plots suggesting a lower ability to compensate for increased transpiration. Lithocarpus glaber in monoculture showed higher C assimilation rate and water‐use efficiency. However, these increased C resources did not translate in higher growth of L. glaber in monoculture suggesting the existence of larger nongrowth‐related C sinks in monoculture. These ecophysiological responses of L. glaber, in agreement with current understanding of phloem transport are consistent with a stronger competition for water resources in monoculture than in species mixtures. Therefore, increasing species diversity in the close vicinity of the studied plants appears to alleviate physiological stress induced by water competition and to counterbalance the negative effects of interspecific competition on assimilation rates for L. glaber by allowing a higher fraction of the C assimilated to be allocated to growth in species mixture than in monoculture.
Personality interacts with habitat quality to govern individual mortality and dispersal patterns
Authors: Belgrad Benjamin A. , Griffen Blaine D.
Published: June 2018

Individual phenotypic differences are increasingly recognized as key drivers of ecological processes. However, studies examining the relative importance of these differences in comparison with environmental factors or how individual phenotype interacts across different environmental contexts remain lacking. We performed two field experiments to assess the concurrent roles of personality differences and habitat quality in mediating individual mortality and dispersal. We quantified the predator avoidance response of mud crabs, Panopeus herbstii, collected from low‐ and high‐quality oyster reefs and measured crab loss in a caging experiment. We simultaneously measured the distance crabs traveled as well as the stability of personalities across reef quality in a separate reciprocal transplant experiment. Habitat quality was the primary determinant of crab loss, although the distance crabs traveled was governed by personality which interacted with habitat quality to control the fate of crabs. Here, crabs on low‐quality reefs rapidly emigrated, starting with the boldest individuals, and experienced modest levels of predation regardless of personality. In contrast, both bold and shy crabs would remain on high‐quality reefs for months where bolder individuals experienced higher predation risk. These findings suggest that personalities could produce vastly different population dynamics across habitat quality and govern community responses to habitat degradation.
Sulfinate‐Organocatalyzed (3+2) Annulation Reaction of Propargyl or Allenyl Sulfones with Activated Imines
Authors: Martzel Thomas , Lohier Jean‐François , Gaumont Annie‐Claude , Brière Jean‐François , Perrio Stéphane
Published: June 2018

An operationally simple methodology for the synthesis of 4‐sulfonyl‐3‐pyrrolines is described using a propargylic sulfone and N‐sulfonyl imines as substrates. This annulation process is initiated by an arenesulfinate organocatalyst, which allows a smooth isomerization of the alkynyl precursor into the corresponding allene, followed by the generation of a highly reactive allyl sulfone anion. An asymmetric version involving an unprecedented enantiopure sulfinate–ammonium cooperative ion pair (PhSO2– R4N+*) was investigated. A proof‐of‐concept, with enantiomeric excesses of up to 41 %, was obtained according to a preliminary screening of commercially available chiral phase‐transfer catalysts.
Gold(I)‐Catalyzed Dimerization of 3‐Diazooxindoles towards Isoindigos
Authors: Yao Xinbo , Wang Tao , Zhang Zunting
Published: June 2018

A gold‐catalyzed dimerization of 3‐diazooxindoles was developed, delivering isoindigos as products. The reaction shows broad substrate scope and functional group tolerance by affording various substituted isoindigos. Moreover, the method also exhibited high efficiency on a gram‐scale reaction.
Influence of coal properties on the CO2 adsorption capacity of coal gasification residues
Authors: Sripada Pramod , Khan Md M. , Ramasamy Shanmuganathan , Trivedi Japan , Gupta Rajender
Published: June 2018

Post‐underground coal gasification (UCG) sites hold attractive prospects for geological storage of carbon dioxide. For the successful commercial implementation of UCG with carbon capture and storage (CCS), site‐selection is crucial, and a careful techno‐economic feasibility analysis is essential to systematically assess the site related parameters aside from evaluating the environmental risk. This study is related to one of the important aspects of site selection‐ the coal type. Specifically, this work investigates the influence of coal properties and gasification conditions on the adsorption capacities of CO2 on gasified coal chars. For this purpose, four coals of diverse ranks varying from lignite to bituminous were selected and subjected to CO2 gasification at atmospheric pressure for 10 min at 800, 900, and 1000°C under a low heating rate of 5°C/min. Subsequently, the gasified chars, as well as the raw coals, were tested for their adsorption capacity in a purpose built volumetric adsorption apparatus at 45.5°C and pressures up to 90 bar. Also, complementary coal and char analysis were carried out for determining the surface area, pore size distribution, and surface morphology. The CO2 storage capacity was observed to be a strong function of the coal properties and gasification conditions. Among the samples examined, the highest adsorption capacity was observed for chars of the sub‐bituminous coals. The CO2 adsorption capacity at 80 bar and 45.5°C on the sub‐bituminous char samples was 2.08, 2.43, and 1.95 mmole/g that were prepared at 800, 900, and 1000°C, respectively. The experimental adsorption isotherms were fitted to the Dubinin‐Radushkevic (DR) and the Dubinin‐Astakhov (DA) models.
Joint radio resource and power allocation using Nash bargaining game for H‐CRAN with nonideal fronthaul links
Authors: Esmat H.H. , Elmesalawy Mahmoud M. , Abdelhakam Mostafa M. , Elhattab M.K.
Published: June 2018

Heterogeneous cloud radio access network (H‐CRAN) is introduced as a novel network architecture that takes the full rewards of both heterogeneous cellular network (HCNs) and cloud radio access network (CRAN). In H‐CRAN architecture, the remote radio heads of small cells (SCs) are overlaid within the coverage of macro cell and linked to the baseband unit pool through nonideal fronthaul connections. To improve the spectral efficiency of this network, the SCs are developed to reuse the same resources used by the macro cell. However, this will introduce inter‐tier interference between macro cell and SCs and intra‐tier interference among SCs that need to be efficiently managed. In this paper, the joint problem of radio resource and power allocation in H‐CRAN is formulated using cooperative Nash bargaining game. This optimization problem is designed to maximize the total throughput of SCs, while considering the fairness between user equipments (UEs) in each SC, interference protection requirements for macro UEs, outage probability requirements, and the capacity limitation of nonideal fronthaul connections. Then, by using Lagrangian dual decomposition, the near‐optimal bargaining allocation strategy for radio resources and power of each SC UE is determined. Simulation results illustrate that the performance of the suggested algorithm outperforms the other comparable algorithm in terms of the SCs' achieved throughput and fairness. Moreover, the effect of nonideal fronthaul capacity constraint and the interference protection limit of macro UEs on the performance of the suggested scheme are examined.
Throughput maximization in poisson aerial base station–based networks with coverage probability and power density constraints
Authors: Saeedi Arvin , Azizi Arman , Mokari Nader
Published: June 2018

In this paper, we propose a new scheme called dynamic power‐dynamic density at which our goal is to maximize the throughput of aerial base station–based networks with coverage probability and power density constraints. The corresponding optimization problem is nonconvex and intractable. To tackle this issue, we propose an iterative algorithm based on the well‐known alternative method. In this method, we decompose the optimization problem into two nonconvex subproblems, namely, power allocation and density finding. Then, in order to provide a low complex and high speed algorithm, these subproblems are transformed into geometric programming forms, which can be solved by existing convex tools. Moreover, the convergence of the proposed iterative scheme is proved and it is studied from the computational complexity perspective. To investigate the performance of the proposed algorithm with existing schemes, we consider two other schemes, namely, dynamic power‐fixed density and dynamic density‐fixed power. Based on simulation results, the throughput of aerial base stations in our scheme is approximately 27% more than that of the two existing schemes. Furthermore, the trade‐off between power and density for different network parameters is studied.
Recent admixture between species of the fungal pathogenHistoplasma
Authors: Maxwell Colin S. , Sepulveda Victoria E. , Turissini David A. , Goldman William E. , Matute Daniel R.
Published: June 2018

Hybridization between species of pathogens has the potential to speed evolution of virulence by providing the raw material for adaptation through introgression or by assembling new combinations of virulence traits. Fungal diseases are a source high morbidity, and remain difficult to treat. Yet the frequency of hybridization between fungal species has rarely been explored, and the functional role of introgressed alleles remains largely unknown. Histoplasma mississippiense and H. ohiense are sympatric throughout their range in North America and have distinct virulence strategies, making them an ideal system to examine the role introgression may play in fungal pathogens. We identified introgressed tracts in the genomes of a sample of H. mississippiense and H. ohiense isolates. We found strong evidence in each species for recent admixture, but introgressed alleles were present at low frequencies, suggesting that they were deleterious. Consistent with this, coding and regulatory sequences were strongly depleted within introgressed regions, whereas intergenic regions were enriched, indicating that functional introgressed alleles were frequently deleterious in their new genomic context. Surprisingly, we found only two isolates with substantial admixture: the H. mississippiense and H. ohiense genomic reference strains, WU24 and G217B, respectively. Our results show that recent admixture has occurred, that it is frequently deleterious and that conclusions based on studies of the H. mississippiense and H. ohiense type strains should be revisited with more representative samples from the genus.