bluuebunny/crossref_metadata_2025 huggingface dataset:
A Low‐Cost Neutral Zinc–Iron Flow Battery with High Energy Density for Stationary Energy Storage
Authors: Xie Congxin , Duan Yinqi , Xu Wenbin , Zhang Huamin , Li Xianfeng
Published: October 2017

Flow batteries (FBs) are one of the most promising stationary energy‐storage devices for storing renewable energy. However, commercial progress of FBs is limited by their high cost and low energy density. A neutral zinc–iron FB with very low cost and high energy density is presented. By using highly soluble FeCl2/ZnBr2 species, a charge energy density of 56.30 Wh L−1 can be achieved. DFT calculations demonstrated that glycine can combine with iron to suppress hydrolysis and crossover of Fe3+/Fe2+. The results indicated that an energy efficiency of 86.66 % can be obtained at 40 mA cm−2 and the battery can run stably for more than 100 cycles. Furthermore, a low‐cost porous membrane was employed to lower the capital cost to less than $ 50 per kWh, which was the lowest value that has ever been reported. Combining the features of low cost, high energy density and high energy efficiency, the neutral zinc–iron FB is a promising candidate for stationary energy‐storage applications.
Elucidating the Excited State of Mechanoluminescence in Organic Luminogens with Room‐Temperature Phosphorescence
Authors: Yang Jie , Gao Xuming , Xie Zongliang , Gong Yanbin , Fang Manman , Peng Qian , Chi Zhenguo , Li Zhen
Published: October 2017

Two stable, purely organic luminogens exhibit both mechano‐ (ML) and photoluminescence (PL) with dual fluorescence–phosphorescence emissions at room temperature. Careful analysis of the crystal structures, coupled with theoretical calculations, demonstrate that room‐temperature phosphorescence and ML properties are strongly related to molecular packing. In particular, the formation and fracture of molecular dimers with intermolecular charge‐transfer properties has a significant effect on intersystem crossing, as well as excited triplet state emissions, in both PL and ML processes.
Sorting of C4 Olefins with Interpenetrated Hybrid Ultramicroporous Materials by Combining Molecular Recognition and Size‐Sieving
Authors: Zhang Zhaoqiang , Yang Qiwei , Cui Xili , Yang Lifeng , Bao Zongbi , Ren Qilong , Xing Huabin
Published: October 2017

C4 olefin separations present one of the great challenges in hydrocarbon purifications owing to their similar structures, thus a single separation mechanism often met with limited success. Herein we report a series of anion‐pillared interpenetrated copper coordination for which the cavity and functional site disposition can be varied in 0.2 Å scale increments by altering the anion pillars and organic linkers (GeFSIX‐2‐Cu‐i (ZU‐32), NbFSIX‐2‐Cu‐i (ZU‐52), GeFSIX‐14‐Cu‐i (ZU‐33)), which enable selective recognition of different C4 olefins. In these materials the rotation of the organic linkers is controlled to create a contracted flexible pore window that enables the size‐exclusion of specific C4 olefins, while still adsorbing significant amounts of 1,3‐butadiene (C4H6) or 1‐butene (n‐C4H8). Combining the molecular recognition and size‐sieving effect, these materials unexpectedly realized the sieving of C4H6/n‐C4H8, C4H6/iso‐C4H8, and n‐C4H8/iso‐C4H8 with high capacity.
Oxidative P−P Bond Addition to Cobalt(−I): Formation of a Low‐Spin Cobalt(III) Phosphanido Complex
Authors: Coburger Peter , Demeshko Serhiy , Rödl Christian , Hey‐Hawkins Evamarie , Wolf Robert
Published: October 2017

The first homoleptic cobalt phosphanido complex [K(thf)4][Co{1,2‐(PtBu2)2C2B10H12}2] (1) was prepared by an unprecedented oxidative P−P bond addition of an ortho‐carborane‐substituted 1,2‐diphosphetane to cobalt(−I) in [K(thf)0.2][Co(η4‐cod)2)] (cod=1,5‐cycloctadiene). Compound 1 is a rare distorted tetrahedral 3d6 complex with a low‐spin ground state configuration. Magnetic measurements revealed that the complex is diamagnetic between 2 to 270 K in the solid state and at 298 K in [D8]THF solution. Based on DFT calculations, the unusual singlet ground state is caused by the strong σ‐donor and moderate π‐donor properties of the bis(phosphanido) ligand.
Thermal, mechanical, and shape‐memory properties of nanorubber‐toughened, epoxy‐based shape‐memory nanocomposites
Authors: Wei Hong‐Qiu , Chen Ye , Zhang Tao , Liu Liwu , Qiao Jinliang , Liu Yanju , Leng Jinsong
Published: October 2017

Epoxy‐based shape‐memory polymers (ESMPs) are a type of the most promising engineering smart polymers. However, their inherent brittleness limits their applications. Existing modification approaches are either based on complicated chemical reactions or done at the cost of the thermal properties of the ESMPs. In this study, a simple approach was used to fabricate ESMPs with the aim of improving their overall properties by introducing crosslinked carboxylic nitrile–butadiene nanorubber (CNBNR) into the ESMP network. The results show that the toughness of the CNBNR–ESMP nanocomposites greatly improved at both room temperature and the glass‐transition temperature (Tg) over that of the pure ESMP. Meanwhile, the increase in the toughness did not negatively affect other macroscopic properties. The CNBNR–ESMP nanocomposites presented improved thermal properties with a Tg in a stable range around 100 °C, enhanced thermal stabilities, and superior shape‐memory performance in terms of the shape‐fixing ratio, shape‐recovery ratio, shape‐recovery time, and repeatability of shape‐memory cycles. The combined property improvements and the simplicity of the manufacturing process demonstrated that the CNBNR–ESMP nanocomposites are desirable candidates for large‐scale applications in the engineering field as smart structural materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45780.
Structure and Function in the Lunge Feeding Apparatus: Mechanical Properties of the Fin Whale Mandible
Authors: Shadwick Robert E. , Goldbogen Jeremy A. , Pyenson Nicholas D. , Whale James C.A.
Published: October 2017

The mandibles of rorqual whales are highly modified to support loads associated with lunge‐feeding, a dynamic filter feeding mechanism that is characterized by rapid changes in gape angle and acceleration. Although these structures are the largest ossified elements in animals and an important part of the rorqual engulfment apparatus, details of internal structure are limited and no direct measurements of mechanical properties exist. Likewise, the forces that are sustained by the mandibles are unknown. Here we report on the structure and mechanical behavior of the mandible of an adult fin whale. A series of transverse sections were cut at locations along the entire length of a 3.6‐m left mandible recovered post‐mortem from a 16‐m fin whale, and CT scanned to make density maps. Cored samples 6–8 mm in diameter were tested in compression to determine the Young's modulus and strength. In addition, wet density, dry density and mineral density were measured. Dense cortical bone occupies only a relatively narrow peripheral layer while much less dense and oil‐filled trabecular bone occupies the rest. Mineral density of both types is strongly correlated with dry density and CT Hounsfield units. Compressive strength is strongly correlated with Young's modulus, while strength and stiffness are both correlated with mineral density. It appears that the superficial compact layer is the main load bearing element, and that the mandible is reinforced against dorso‐vental flexion that would occur during the peak loads while feeding. Anat Rec, 300:1953–1962, 2017. © 2017 Wiley Periodicals, Inc.
Comparative Three‐Dimensional Morphology of Baleen: Cross‐Sectional Profiles and Volume Measurements Using CT Images
Authors: Jensen Megan M. , Saladrigas Amalia H. , Goldbogen Jeremy A.
Published: October 2017

Baleen whales are obligate filter feeders, straining prey‐laden seawater through racks of keratinized baleen plates. Despite the importance of baleen to the ecology and natural history of these animals, relatively little work has been done on baleen morphology, particularly with regard to the three‐dimensional morphology and structure of baleen. We used computed tomography (CT) scanning to take 3D images of six baleen specimens representing five species, including three complete racks. With these images, we described the three‐dimensional shape of the baleen plates using cross‐sectional profiles from within the gum tissue to the tip of the plates. We also measured the percentage of each specimen that was composed of either keratinized plate material or was void space between baleen plates, and thus available for seawater flow. Baleen plates have a complex three‐dimensional structure with curvature that varies across the anterior‐posterior, proximal‐distal, and medial‐lateral (lingual‐labial) axes. These curvatures also vary with location along the baleen rack, and between species. Cross‐sectional profiles resemble backwards‐facing airfoils, and some specimens display S‐shaped, or reflexed, camber. Within a baleen specimen, the intra‐baleen void volume correlates with the average bristle diameter for a species, suggesting that essentially, thinner plates (with more space between them for flow) have thinner bristles. Both plate curvature and the relative proportions of plate and void volumes are likely to have implications for the mechanics of mysticete filtration, and future studies are needed to determine the particular functions of these morphological characters. Anat Rec, 300:1942–1952, 2017. © 2017 The Authors The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists
A “Welcoming” Introduction to a Canadian Northwest Coast Thematic Papers Issue
Authors: Vogl Wayne
Published: October 2017

In this commentary, I provide an introduction to and the context for the four articles in the thematic series published to celebrate the Editorial Board Meeting of the Anatomical Record in Vancouver, British Columbia, Canada in July of 2017. The articles describe various aspects of whale anatomy and the potential for a new generation of digital tags to provide information on functional anatomy of free swimming animals in the wild. The whales described are all native to the northwest coast of North America, as well as being found elsewhere, and the authors are related in some way to the University of British Columbia in Vancouver. Anat Rec, 300:1930–1934, 2017. © 2017 Wiley Periodicals, Inc.
Galaxy overdensities around 3C radio galaxies and quasars at 1 < z < 2.5 revealed by Spitzer 3.6/4.5 µm and Pan‐STARRS
Authors: Ghaffari Z. , Westhues Ch. , Haas M. , Chini R. , Willner S. P. , Ashby M. L. N. , Wilkes B. J.
Published: October 2017

Luminous radio sources are thought to lie in galaxy clusters or proto‐clusters. The complete sample of 64 high‐redshift 3C sources at 1 < z < 2.5 has been mapped with the Spitzer Space Telescope. The IRAC 3.6 and 4.5 µm 5σ detection limit of 4 µJy (22.4 AB mag) allows us to search for the brightest candidate cluster member galaxies associated with the 3C sources. To remove the contamination of foreground stars and galaxies along the lines of sight toward the 3C sources, we apply color cuts: the removed sources satisfy either the IRAC1/2 cut [3.6]–[4.5] < −0.3 or the Pan‐STARRS/IRAC cut i − [4.5] < 0.5 if detected by Pan‐STARRS. For both selection methods, about half of the 3C radio sources show significant overdensities (> 3σ) within 30″ (∼250 kpc) projected distance from the radio source compared to the surrounding galaxy densities measured in the 50–120″ annulus. The Pan‐STARRS/IRAC cut reveals higher average overdensities than the IRAC1/2 cut and also a decline of overdensities at z > 1.4. To infer the nature of the cluster members, we rerun the analysis using a stronger IRAC1/2 cut [3.6]–[4.5] < −0.1, which removes 1 < z < 1.4 passive ellipticals but not star‐forming galaxies. For the strong cut, the overdensities, on average, completely disappear at 1 < z < 1.4. We therefore suggest that the 4.5 µm detected cluster member galaxies are mainly passive ellipticals.
Untersuchung des Bemessungsansatzes der VDI 2719 für den Schallschutz von Fenstern unter Berücksichtigung aktueller Außenlärmspektren des Bahn‐ und Fluglärms
Authors: Kübler Bernhard , Leupoldt Patrick
Published: October 2017

Gegenstand dieser Arbeit ist die Untersuchung des Bemessungsansatzes der VDI‐Richtlinie VDI 2719:1987‐08 für den Schallschutz von Fenstern unter Berücksichtigung aktueller Außenlärmpegelspektren des Bahn‐ und Fluglärms. Das Leitmotiv stellt die Problematik der heute in der Praxis festgestellten Fehlbemessung des Schallschutzes bei Verwendung der in VDI 2719 enthaltenen Korrektursummanden dar. Der Ansatz zur Verwendung verschiedener Korrektursummanden in VDI 2719:1987‐08 basiert auf einer 1985 vom Umweltbundesamt in Auftrag gegebenen Forschungsarbeit von Moll und Szabunia. Die K‐Summanden berücksichtigen sowohl die Frequenzabhängigkeit der Fenster‐Schalldämmung als auch der Spektren des Außenlärms, welche sich beide im Laufe der Zeit verändert haben. Mit dieser Arbeit soll eine Basis geschaffen werden, auf der – anhand heute typischer Konstruktionen und Außenlärmsituationen – die erforderliche Schalldämmung der Fenster ohne erhebliche Über‐ oder Unterbemessung des Schallschutzes ermittelt werden kann.
Einfluss des Beschichtungsmaterials auf das Zugtragverhalten von Carbonbeton
Authors: Niederwald Michael
Published: October 2017

In diesem Beitrag werden experimentelle und theoretische Untersuchungen zum Einfluss des Beschichtungsmaterials von textilen Bewehrungen auf das Zugtragverhalten von Carbonbeton beschrieben. Zunächst werden die notwendigen Grundlagen für eine im Anschluss erläuterte Versuchstechnik aus dem Bereich der Luft‐ und Raumfahrttechnik, die als Dynamisch‐Mechanische Analyse (DMA) bezeichnet wird, behandelt. Die DMA dient dazu, das temperatur‐ und frequenzabhängige Materialverhalten textiler Carbonbewehrungen zu erforschen. Die so gewonnenen Versuchsdaten werden verwendet, um Materialparameter für eine Modellierung des mechanischen Verhaltens der Bewehrung im Rahmen der linearen Viskoelastizitätstheorie zu ermitteln. Schließlich werden die Ergebnisse aus Zugversuchen an bewehrten Dehnkörpern unter verschiedenen Belastungsgeschwindigkeiten vorgestellt und mit theoretischen Betrachtungen zum Zugspannungs‐Dehnungs‐Verhalten des Bewehrungsmaterials verglichen.
Haus in Berg am Starnberger See
Authors: di Simone Uta , Heyder Jens , Braml Thomas
Published: October 2017

Durch die zwischen Zusammenarbeit von Architekt und Bauherr ist auf einem Grundstück mit leichter Hanglage am Starnberger See ist ein wahres Prachtstück eines Hauses mit Flachdach und zwei Stockwerken entstanden, wovon eines im Erdboden „versteckt“ ist. Das gesamte Haus besteht aus Sichtbeton. Die Fassade wurde aus Fertigteilen erstellt, sämtliche Innenwände und Decken aus Ortbeton. Raumhohe Fensterflächen befriedigen das Bedürfnis, das Äußere nach innen zu holen. An die Tragwerksplanung stellte der Entwurf hohe Anforderungen in Hinblick auf die Ausarbeitung der Details. So wurden die rahmenlosen Fensterscheiben in die Decken und Wände integriert. Zudem stellte das Konzept der Sichtbetonflächen hohe Anforderungen an die Grenzzustände der Gebrauchstauglichkeit im Stahlbetonbau und auch im Hinblick auf die Ausführung einer WU‐Wanne im Untergeschoss.
Medulloblastoma in children and adolescents: a systematic review of contemporary phase I and II clinical trials and biology update
Authors: Bautista Francisco , Fioravantti Victoria , de Rojas Teresa , Carceller Fernando , Madero Luis , Lassaletta Alvaro , Moreno Lucas
Published: October 2017

Survival rates for patients with medulloblastoma have improved in the last decades but for those who relapse outcome is dismal and new approaches are needed. Emerging drugs have been tested in the last two decades within the context of phase I/II trials. In parallel, advances in genetic profiling have permitted to identify key molecular alterations for which new strategies are being developed. We performed a systematic review focused on the design and outcome of early‐phase trials evaluating new agents in patients with relapsed medulloblastoma. PubMed, clinicaltrials.gov, and references from selected studies were screened to identify phase I/II studies with reported results between 2000 and 2015 including patients with medulloblastoma aged <18 years. A total of 718 studies were reviewed and 78 satisfied eligibility criteria. Of those, 69% were phase I; 31% phase II. Half evaluated conventional chemotherapeutics and 35% targeted agents. Overall, 662 patients with medulloblastoma/primitive neuroectodermal tumors were included. The study designs and the response assessments were heterogeneous, limiting the comparisons among trials and the correct identification of active drugs. Median (range) objective response rate (ORR) for patients with medulloblastoma in phase I/II studies was 0% (0–100) and 6.5% (0–50), respectively. Temozolomide containing regimens had a median ORR of 16.5% (0–100). Smoothened inhibitors trials had a median ORR of 8% (3–8). Novel drugs have shown limited activity against relapsed medulloblastoma. Temozolomide might serve as backbone for new combinations. Novel and more homogenous trial designs might facilitate the development of new drugs.
Racial disparities in pancreatic neuroendocrine tumors survival: a SEER study
Authors: Zhou Huaqiang , Zhang Yuanzhe , Wei Xiaoyue , Yang Kaibin , Tan Wulin , Qiu Zeting , Li Si , Chen Qinchang , Song Yiyan , Gao Shaowei
Published: October 2017

Pancreatic neuroendocrine tumor (pancreatic NETs), is an important cause of cancer‐related death worldwide. No study has rigorously explored the impact of ethnicity on pancreatic NETs. We aimed to demonstrate the relationship between ethnicity and the survival of patients with pancreatic NETs. We used the SEER database to identify patients with pancreatic NETs from 2004 to 2013. Kaplan–Meier methods and Cox proportional hazard models were used to evaluate the impact of race on survival in pancreatic NETs patients. A total of 3850 patients were included: 3357 Non‐Blacks, 493 Blacks. We stratified races as “Black” and “White/Other.” Blacks were more likely to be diagnosed with later stages of tumors (P = 0.021). As for the treatment, the access to surgery seemed to be more limited in Blacks than non‐Black patients (P = 0.012). Compared with non‐Black patients, Black patients have worse overall survival (OS) (HR = 1.17, 95% CI: 1.00–1.37, P = 0.046) and pancreatic neuroendocrine tumors specific survival (PNSS) (HR = 1.22, 95% CI: 1.01–1.48, P = 0.044). Multivariate Cox analysis identified that disease extension at the time of diagnosis and surgical status contributed to the ethnical survival disparity. Black patients whose stages at diagnosis were localized had significantly worse OS (HR = 2.09, 95% CI: 1.18–3.71, P = 0.011) and PNSS (HR = 3.79, 95% CI: 1.62–8.82, P = 0.002). As for the patients who did not receive surgery, Blacks also have a worse OS (HR = 1.18, 95% CI: 1.00–1.41, P = 0.045). The Black patients had both worse OS and PNSS compared to non‐Black patients. The restricted utilization of surgery, and the advanced disease extension at the time of diagnosis are the possible contributors to poorer survival of Blacks with pancreatic NETs.
Intermediate filaments and cellular mechanics
Authors: Goldmann Wolfgang H.
Published: October 2017

Intermediate filaments (IFs) are one of the three types of cytoskeletal polymers that resist tensile and compressive forces in cells. They crosslink each other as well as with actin filaments and microtubules by proteins, which include desmin, filamin C, plectin, and lamin (A/C). Mutations in these proteins can lead to a wide range of pathologies, some of which exhibit mechanical failure of the skin, skeletal, or heart muscle.
GPR120 is not required for ω‐3 PUFAs‐induced cell growth inhibition and apoptosis in breast cancer cells
Authors: Zhu Shenglong , Jiang Xiaowei , Jiang Siyuan , Lin Guangxiao , Gong Jianping , Chen Wei , He Zhao , Chen Yong Q
Published: October 2017

Intake of ω‐3 PUFAs reduces the frequency of breast cancer, and GPR120 receptor transduces ω‐3 PUFAs signaling to increase insulin sensitivity in mice, but whether GPR120 mediates ω‐3 PUFAs signaling to inhibit breast carcinogenesis is currently unknown. In the present study, we found that GPR120 is highly expressed in human breast cancerous tissues but not adjacent normal tissue. Knockdown of GPR120 by siRNA in breast cancer cells significantly reduced cell growth, and dramatically increased ω‐3 FFA‐induced cell growth inhibition and apoptosis. Thus, these observations indicated that GPR120 promotes breast cancer cell growth, whereas ω‐3 PUFA‐induce breast cancer cell apoptosis independently of GPR120.
Enantioselective Brønsted Acid Catalysis as a Tool for the Synthesis of Natural Products and Pharmaceuticals
Authors: Merad Jérémy , Lalli Claudia , Bernadat Guillaume , Maury Julien , Masson Géraldine
Published: October 2017

Synthesis of biologically active molecules (whether at laboratory or industrial scale) remains a highly appealing area of modern organic chemistry. Nowadays, the need to access original bioactive scaffolds goes together with the desire to improve synthetic efficiency, while reducing the environmental footprint of chemical activities. Long neglected in the field of total synthesis, enantioselective organocatalysis has recently emerged as an environmentally friendly and indispensable tool for the construction of relevant bioactive molecules. Notably, enantioselective Brønsted acid catalysis has offered new opportunities in terms of both retrosynthetic disconnections and controlling stereoselectivity. The present report attempts to provide an overview of enantioselective total or formal syntheses designed around Brønsted acid‐catalyzed transformations. To demonstrate the versatility of the reactions promoted and the diversity of the accessible motifs, this Minireview draws a systematic parallel between methods and retrosynthetic analysis. The manuscript is organized according to the main reaction types and the nature of newly‐formed bonds.
Polyoxometalate‐Based Bottom‐Up Fabrication of Graphene Quantum Dot/Manganese Vanadate Composites as Lithium Ion Battery Anodes
Authors: Ji Yuanchun , Hu Jun , Biskupek Johannes , Kaiser Ute , Song Yu‐Fei , Streb Carsten
Published: October 2017

Lithium ion battery (LIB) electrodes require a stable connection between a redox‐active metal oxide for charge storage and an electrically conductive (often carbon‐based) material for charge transport. As charge transfer within the metal oxide is often a performance‐limiting factor, one promising concept is the linking of charge transfer and charge storage components on the nanoscale. This would maximize the interfacial contact area and improve charging/discharging behavior. This work presents a one‐step, room‐temperature route giving nanostructured manganese vanadium oxide/graphene quantum dot (GQD) composite electrodes. Manganese vanadium oxide clusters are used as solution‐processable precursors, which are deposited on GQDs using a sonication‐driven conversion leading to electroactive, lightweight composites. Incorporation of the composites as anodes in LIBs shows high electrochemical performance featuring discharge capacities of 970 mAh g−1 over 100 cycles with coulombic efficiencies near 100 %. The study shows how 3d‐metal oxide/GQD nanostructures can be accessed by a scalable sonication route starting from soluble, chemically tunable metal oxide clusters and graphene quantum dots.
Facile Synthesis of Composition‐Controlled Graphene‐Supported PtPd Alloy Nanocatalysts and Their Applications in Methanol Electro‐Oxidation and Lithium‐Oxygen Batteries
Authors: Ye Seong Ji , Bui Hieu Trung , Kim Young Yun , Liao Kin , Cho Kyeong Min , Jung Hee‐Tae , Kang Yongku , Kim Do Youb , Park O Ok
Published: October 2017

A new and simple approach is reported for the synthesis of uniformly dispersed PtPd alloy nanocatalysts supported on graphene nanoplatelets (GNPs) (PtPd‐GNPs) through the introduction of bifunctional materials, which can modify the GNP surface and simultaneously reduce metal ions. With the use of poly(4‐styrenesulfonic acid), poly(vinyl pyrrolidone), poly(diallyldimethylammonium chloride), and poly(vinyl alcohol) as bifunctional materials, PtPd‐GNPs can be produced through a procedure that is far simpler than previously reported methods. The as‐prepared nanocrystals on GNPs clearly exhibit uniform PtPd alloy structures of around 2 nm in size, which are strongly anchored and well distributed on the GNP sheets. The Pt/Pd atomic ratio and loading density of the nanocrystals on the GNPs are controlled easily by changing the metal precursor feed ratio and the mass ratio of GNP to the metal precursor, respectively. As a result of the synergism between Pt and Pd, the as‐prepared PtPd‐GNPs exhibit markedly enhanced electrocatalytic performance during methanol electro‐oxidation compared with monometallic Pt‐GNP or commercially available Pt/C. Furthermore, the PtPd‐GNP nanocatalysts also show greatly enhanced catalytic activity toward the oxygen reduction/evolution reaction in a lithium‐oxygen (Li‐O2) process, resulting in greatly improved cycling stability of a Li‐O2 battery.
Highly Stereoselective Strecker Synthesis Induced by a Slight Modification of Benzhydrylamine from Achiral to Chiral
Authors: Takamatsu Naoya , Aiba Shohei , Yamada Takuya , Tokunaga Yuji , Kawasaki Tsuneomi
Published: October 2017

2‐Methylbenzhydrylamine is a chiral variant of achiral benzhydrylamine; however, the chirality formed from the small difference between the phenyl and o‐tolyl groups is not expected to induce sufficient stereoselectivity in conventional homogeneous reactions. Initiated by the spontaneous formation and asymmetric amplification of the enantioenriched N‐benzhydryl‐α‐aminonitrile forming conglomerate, we here report that (S)‐ and (R)‐configured title amine, upon the Strecker reaction with achiral aldehydes and HCN, afford the corresponding α‐aminonitriles with up to >99.5 % diastereomeric excess, in conjunction with an enhancement of chirality in the solid state. l‐Alanine with 98 % ee was synthesized from the (S)‐amine by using the method discussed here. Achiral aromatic and heteroaromatic aldehydes could also be successfully utilized to afford chiral α‐aminonitriles in a highly stereoselective manner. The stereodivergent synthesis of styrylglycine nitriles has also been accomplished by using racemic and enantioenriched 2‐methylbenzhydrylamine. Thus, accompanied with a small rearrangement of the common substrate from achiral toward chiral, the present reactions induce an enhancement of chirality, and expands the concept of stereoselective synthesis to increase the opportunity to access highly enantioenriched compounds such as α‐amino acids.
Wo Mathematik Wirklichkeit wird
Authors: Neidlinger Andreas
Published: October 2017

Wetter ist heute ein alltägliches Thema und Wettervorhersagen erscheinen uns bereits selbstverständlich (deren Genauigkeit hingegen nicht immer [1,2], wobei die Meteorologie jedoch den meisten als eine wunderliche Mischung aus Wahrsagerei und Wissenschaft erscheint. Hier wollen wir uns heute einmal mit einer tatsächlich sehr überraschenden Kombination auseinandersetzen: Der Demonstration eines mathematischen Satzes am Beispiel des Wetters.
Applications of nanotechnology in oil and gas industry: Progress and perspective
Authors: Peng Baoliang , Tang Juntao , Luo Jianhui , Wang Pingmei , Ding Bin , Tam Kam Chiu
Published: October 2017

Nanotechnology has been successfully implemented in many applications, such as nanoelectronics, nanobiomedicine, and nanodevices. However, this technology has rarely been applied to the oil and gas industry, especially in upstream exploration and production. The oil and gas industry needs to improve oil recovery and exploit unconventional resources. The cost of research and oil production is under immense pressure, and it is becoming more difficult to justify such investment when the crude oil price is weak and depressed. There is a widespread belief that nanotechnology may be exploited to develop novel nanomaterials with enhanced performance to combat these technological barriers. Increasing funding resources from governmental and global oil industry have been allocated to exploration, drilling, production, refining, and wastewater treatment. For example, nanosensors allow for precise measurement of reservoir conditions. Nanofluids prepared using functional nanomaterials may exhibit better performance in oil production processes, and nanocatalysts have improved the efficiency in oil refining and petrochemical processes. Nanomembranes enhance oil, water and gas separation, oil and gas purification, and the removal of impurities from wastewater. Functional nanomaterials can play an important role in the production of smart, reliable, and more durable equipment. In this review paper, we summarize the research progress and prospective applications of nanotechnology and nanomaterials in the oil and gas industry.
Flameless combustion behaviour of preheated pulverized coal
Authors: Ouyang Ziqu , Liu Wen , Zhu Jianguo
Published: October 2017

A method for stable flameless combustion of pulverized coal based on coal preheating was recently proposed. The method involves the initial heating of pulverized coal to a temperature above 800 °C. The heated coal is then transferred into a combustion chamber, where it is mixed with secondary air injected at a high velocity to achieve flameless combustion. The flameless combustion behaviour of the preheated pulverized coal was experimentally investigated in a lab‐scale test apparatus. The results showed that stable flameless combustion of bituminous coal and two different anthracite coals could be achieved. The temperature of the combustion chamber was also observed to be homogeneous. The peak temperature was below 1250 °C, while the average combustion temperature was about 1150 °C. The normalized root mean square temperature fluctuation over the combustion chamber is 7.0 %, 6.7 %, and 6.8 % for the three different coals. The colour of the entire combustion chamber was a faint yellow with no obvious flame front surface observed. Fuel preheating was found to be effective for improving the combustion efficiency, with values of 99.2 %, 98.3 %, and 97.9 % achieved for bituminous coal and two different anthracite coals, respectively. The experimental data further revealed that the NOX emissions for all the considered coals were very low compared to the corresponding cases of traditional combustion, with the values for the different coal types also significantly varying. The NOX emissions were determined to be 232, 187, and 165 mg/Nm3 (6 % O2) for bituminous coal and two different anthracite coals, respectively.
Optimization of commercially available Zika virus antibodies for use in a laboratory‐developed immunohistochemical assay
Authors: Bollweg Brigid C , Silva‐Flannery Luciana , Spivey Pamela , Hale Gillian L
Published: October 2017

Zika virus (ZIKV) infection during pregnancy can cause adverse fetal outcomes and severe irreversible congenital birth defects including microcephaly. Immunohistochemistry (IHC) is a valuable diagnostic tool for detecting ZIKV antigens in tissues from cases of fetal loss in women infected with ZIKV, and for providing insights into disease pathogenesis. As a result, there is increasing demand for commercially available ZIKV antibodies for use in IHC assays. ZIKV antibodies were selected and obtained from commercial sources to include both mouse and rabbit hosts, and a variety of antigenic targets. Pretreatment conditions and antibody concentrations resulting in optimal immunohistochemical staining were determined using ZIKV cell control and polymerase chain reaction (PCR)‐confirmed ZIKV case control material (fetal brain tissue). Cross‐reactivity of the antibodies against other flaviviruses (dengue virus serogroups 1–4, yellow fever virus, Japanese encephalitis virus, West Nile virus) and chikungunya virus was also evaluated. Immunostaining using the commercially available antibodies was compared to a previously validated ZIKV IHC assay used for primary diagnosis. Four antibodies demonstrated optimal staining similar to the previously validated ZIKV IHC assay. Two of the four antibodies cross‐reacted with dengue virus, while the other two antibodies showed no cross‐reactivity with dengue, other flaviviruses, or chikungunya virus. Differences in the cross‐reactivity profiles could not be entirely explained by the antigenic target. Commercially available ZIKV antibodies can be optimized for use in IHC testing to aid in ZIKV diagnostic testing and an evaluation of tissue tropism.
Single‐Assay Profiling of Nucleosome Occupancy and Chromatin Accessibility
Authors: Cook April , Mieczkowski Jakub , Tolstorukov Michael Y.
Published: October 2017

This unit describes a method for determining the accessibility of chromatinized DNA and nucleosome occupancy in the same assay. Enzymatic digestion of chromatin using micrococcal nuclease (MNase) is optimized for liberation, retrieval, and characterization of DNA fragments from chromatin. MNase digestion is performed in a titration series, and the DNA fragments are isolated and sequenced for each individual digest independently. These sequenced fragments are then collectively analyzed in a novel bioinformatics pipeline to produce a metric describing MNase accessibility of chromatin (MACC) and nucleosome occupancy. This approach allows profiling of the entire genome including regions of open and closed chromatin. Moreover, the MACC protocol can be supplemented with a histone immunoprecipitation step to estimate and compare both histone and non‐histone DNA protection components. © 2017 by John Wiley & Sons, Inc.
Cationic Vacancy Defects in Iron Phosphide: A Promising Route toward Efficient and Stable Hydrogen Evolution by Electrochemical Water Splitting
Authors: Kwong Wai Ling , Gracia‐Espino Eduardo , Lee Cheng Choo , Sandström Robin , Wågberg Thomas , Messinger Johannes
Published: October 2017

Engineering the electronic properties of transition metal phosphides has shown great effectiveness in improving their intrinsic catalytic activity for the hydrogen evolution reaction (HER) in water splitting applications. Herein, we report for the first time, the creation of Fe vacancies as an approach to modulate the electronic structure of iron phosphide (FeP). The Fe vacancies were produced by chemical leaching of Mg that was introduced into FeP as “sacrificial dopant”. The obtained Fevacancy‐rich FeP nanoparticulate films, which were deposited on Ti foil, show excellent HER activity compared to pristine FeP and Mg‐doped FeP, achieving a current density of 10 mA cm−2 at overpotentials of 108 mV in 1 m KOH and 65 mV in 0.5 m H2SO4, with a near‐100 % Faradaic efficiency. Our theoretical and experimental analyses reveal that the improved HER activity originates from the presence of Fe vacancies, which lead to a synergistic modulation of the structural and electronic properties that result in a near‐optimal hydrogen adsorption free energy and enhanced proton trapping. The success in catalytic improvement through the introduction of cationic vacancy defects has not only demonstrated the potential of Fe‐vacancy‐rich FeP as highly efficient, earth abundant HER catalyst, but also opens up an exciting pathway for activating other promising catalysts for electrochemical water splitting.
Cancer‐related mRNA expression analysis using a novel flow cytometry‐based assay
Authors: Depreter Barbara , Philippé Jan , Meul Magali , Denys Barbara , Vandepoele Karl , De Moerloose Barbara , Lammens Tim
Published: October 2017

Background

Cancer‐related gene expression data mostly originate from unfractionated bulk samples, leading to “expression averaging” of heterogeneous populations. Multicolor flow cytometry (FCM) may distinguish heterogeneous populations based on the phenotypic characterization of single‐cells, but is not applicable for RNA targets. Here, we evaluated the PrimeFlow™ RNA assay, a novel FCM‐based assay designed to measure gene expressions, in two cancer entities with high and low RNA target levels.

Methods

Neuroblastoma (NB) cell lines were studied for MYCN gene expression by PrimeFlow™ and compared with the gold standard, RT‐qPCR. Dilution series of NB cells (0.10–11%) were prepared to evaluate performance in small cell populations. Diagnostic material of de novo acute myeloid leukemia (AML) patients was used to measure Wilms' tumor 1 (WT1) expression in bulk leukemic cells and rare subsets, e.g. leukemic stem cells (LSCs). FCM analysis was performed on a FACSCanto II (BD Biosciences) using Infinicyt™ (Cytognos®) for data analysis. mRNA expression was reported by normalized mean fluorescence intensity (MFI) values and staining indices.

Results

MYCN mRNA quantified by PrimeFlow™ significantly correlated with RT‐qPCR and remained detectable in small (0.1%) populations. Using PrimeFlowTM, WT1 levels were shown to be significantly higher in AML patient samples with WT1 overexpression, previously defined by RT‐qPCR. Moreover, WT1 overexpression was distinguishable between heterogeneous cell populations and remained measurable in rare LSCs.

Conclusion

PrimeFlow™ is a sensitive technique to investigate mRNA expressions, with high concordance to RT‐qPCR. High (MYCN) and subtle (WT1) overexpressed mRNA targets can be quantified in heterogeneous and rare subpopulations e.g. LSCs. © 2017 International Clinical Cytometry Society
Bottom‐up control of parasites
Authors: Johnson David Samuel , Heard Richard
Published: October 2017

Parasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free‐living organisms. Bottom‐up theory predicts that resource enhancement will increase the abundance and biomass of free‐living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape‐level experiment in which salt marshes (60,000 m2each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod,Orchestia grillus, and the density and biomass of its trematode parasite,Levinseniella byrdi. Strikingly,L. byrdiprevalence increased over time, up to 13 times higher in nutrient‐enriched marshes (30%) relative to the mean prevalence in reference marshes (2.4%). The biomass density of infected amphipods was, on average, 11 times higher in nutrient‐enriched marshes (1.1 kg/ha) than in reference marshes (0.1 kg/ha), when pooling across all years.Orchestia grillusbiomass comprises 67% of the arthropod community biomass; thus, nutrient enrichment elicits a substantial surge in parasitized biomass in the arthropod community. If our results are typical, they suggest that eutrophication can increase parasite abundance and biomass with chronic resource enhancement. Therefore, minimizing aquatic nutrient pollution may prevent outbreaks of parasites with aquatic hosts.
A parsimonious approach for modeling uncertainty within complex nonlinear relationships
Authors: Strimbu Bogdan M. , Amarioarei Alexandru , Paun Mihaela
Published: October 2017

Advancements in information technology led environmental scientists to the illusion that efforts should be mainly focused on developing models that reduce uncertainty rather than on models adjusted to the existing uncertainty. As a result, environmental relationships are represented by non‐parsimonious and suboptimal models, which in many instances could be even wrong. The objective of this research was to provide scientists focused on modeling ecosystem processes with a procedure that supplies parsimonious correct results. The procedure transforms the response variable to achieve a linear model and the normality of the residuals. After the parameters of the transformed model are estimated, the bias induced by back‐transforming is corrected. We have computed the bias corrections for 11 of the most popular functions from the power, trigonometric, and hyperbolic families by considering the truncated normal distribution, when necessary. Using generated data, we have shown that the proposed procedure supplies unbiased results. We have identified a sample size artifact of data generation such that when the variance increases the truncation of distribution starts altering the corrections of predicted values, sometimes by more than 50% from the actual values. Our results indicate that uncertainty, measured by variance, impacts the analysis in a non‐intuitive way when the defining domain of the response variable is restricted. The subtle way of influencing the development of complex nonlinear models by uncertainty advocates the usage of parsimonious linear models, which are less sensitive to the method of processing data. Finally, ecosystem processes should be modeled with strategies that consider not only processes and computation aspects, but also uncertainty, in particularly reducing variance to levels with no significant impact on the results.
Critical loads of atmospheric N deposition for phytoplankton nutrient limitation shifts in western U.S. mountain lakes
Authors: Williams Jason J. , Lynch Jason A. , Saros Jasmine E. , Labou Stephanie G.
Published: October 2017

In many oligotrophic mountain lakes, anthropogenic atmospheric nitrogen (N) deposition has increased concentrations of N, a key limiting nutrient, and thereby shifted phytoplankton biomass growth from N limitation to P limitation. In the western United States, the critical load N deposition rate for these shifts has not been quantified. We synthesized existing mountain lake chemistry, nutrient limitation bioassay, and N deposition data to estimate N critical loads for shifts from N to P limitation of phytoplankton biomass growth. Data from bioassays in 47 mountain lakes were used to define biological (RR‐N/RR‐P = 1) and chemical (NO3, DIN, DIN:TP) thresholds above which biomass P limitation is more likely than N limitation. Logistic regression was used to calculate critical loads as the total N deposition rate with >50% probability of exceeding biological or chemical thresholds, and thus where P limitation is more likely than N limitation. Logistic regression models were developed with N deposition as the only predictor and with both N deposition and watershed characteristics as predictors. Logistic model performance was evaluated by comparing predicted and observed chemical threshold exceedances in 108 mountain lakes. Across models, estimated critical loads ranged from 2.8 to 5.2 kg total N·ha−1·yr−1. The best‐performing model was a univariate logistic model predicting NO3 threshold exceedance, with N deposition as the only predictor. This model yielded a critical load of 4.1 kg total N·ha−1·yr−1 and accurately predicted NO3 threshold exceedance in 69% of lakes. We applied this critical load to an independent sample of 385 mountain lakes with NO3 data to estimate the frequency it would fail to predict a limitation shift—cases where the NO3 threshold for biomass shifts was exceeded, but the critical load was not. The false‐negative rate was 13% across the western United States, but was higher (22%) in the Sierras. Performance analyses suggest a 2.0 kg total N·ha−1·yr−1 critical load may avoid false negatives entirely. Critical loads presented here can be used to assess N deposition impacts on western U.S. mountain lakes, and associated performance information can be used to consider if presented critical loads are adequate for specific management applications.
Disturbance and diversity in a continental archipelago: a mechanistic framework linking area, height, and exposure
Authors: Neufeld Christopher J. , Starko Samuel , Burns Kevin C.
Published: October 2017

Species–area relationships (SARs) are among the most general patterns in nature. Yet, significant variation in species richness often remains after accounting for area, especially for small islands. One factor thought to influence species richness on small islands is disturbance from the combined influence of tides and waves. Here, we derive a quantitative framework for determining how ocean disturbance impacts island communities, which we then test in plant communities in a temperate island archipelago. We do so by applying some well‐developed techniques honed in the marine intertidal zone but rarely applied to studies on land. By estimating and adjusting for the effect of wave exposure on habitable island area, we dramatically improved the fit of the SAR for small islands, nearly doubling the amount of variation in species richness explained (from 37% to 69%). Our predictions of island occupancy also improved using this method. Our approach predicts that small islands (<100,000 m2) are the most affected by ocean‐borne disturbance. Given that many archipelagos are susceptible to wave disturbance, future studies should consider how ocean‐borne disturbances arising from the matrix might interact with sampling area to influence patterns of species richness on small islands.
Composted manure application promotes long‐term invasion of semi‐arid rangeland by Bromus tectorum
Authors: Blumenthal Dana M. , LeCain Daniel R. , Augustine David J.
Published: October 2017

Nutrient‐rich organic waste derived from sewage treatment facilities or livestock manure is often applied to rangelands of western North America to increase soil fertility, forage production, forage quality, and soil carbon storage. This practice can have a number of undesirable side effects, however, including plant invasion. While characteristics of both rangeland ecosystems and invasive plants suggest that organic waste application might often promote invasion, results to date are mixed, perhaps due in part to the paucity of long‐term studies. Here, we describe the long‐term (22 yr) effects of three types of organic waste—composted biosolids, composted cattle manure, and fresh cattle manure—on plant productivity and invasion in native mixed‐grass prairie. Although composted manure and biosolids increased plant productivity and forage quality in the second year of the study, these effects did not persist. In contrast, Bromus tectorum (cheatgrass), which invaded the study site over the course of the experiment, was strongly facilitated by composted manure addition, with particularly large effects observed in years 17 and 22. These results show that nutrient‐rich organic waste can favor invasive species even in the relatively invasion‐resistant grasslands of the western Great Plains. They also demonstrate that effects of organic waste on invasion can become apparent quite gradually and persist for decades following the initial organic waste application. Together, results from experimental additions of organic and inorganic nutrients to native rangelands suggest that the risk of promoting invasive species is significant, and should be considered in programs that apply organic waste to rangelands of western North America.
Private Sector Involvement in the Millennium Ecosystem Assessment: Using a UN platform to promote market‐based instruments for ecosystem services
Authors: Hrabanski Marie
Published: October 2017

The article analyses the implication of private sector representatives in the Millennium Ecosystem Assessment (MEA) (2001–2005). The article shows that, before this international biodiversity assessment, firms were involved in three coalitions: the greenhouse gas pro‐trading coalition, the voluntary private standard coalition and the payment for environmental services coalition. These three coalitions all advocated a particular style of regulation that gave overwhelming emphasis to market‐based policy instruments. Corporate experts from the three coalitions identified were recruited to participate in the MEA. Thanks to the political visibility given to the ecosystem services concept by the MEA, private industry was able to strengthen and legitimize its actions in favour of market‐based environmental governance. At the same time, associating private sector representatives with the MEA process made it easier to disseminate the concept of ecosystem services. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment