bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defect termination on crystalline silicon surfaces by hydrogen for improvement in the passivation quality of catalytic chemical vapor-deposited SiNx and SiNx/P catalytic-doped layers
Authors: Thi Trinh Cham , Koyama Koichi , Ohdaira Keisuke , Matsumura Hideki 
Published: January 2016

Abstract
We investigate the role of hydrogen (H) in the improvement in the passivation quality of silicon nitride (SiN
x
) prepared by catalytic chemical vapor deposition (Cat-CVD) and Cat-CVD SiN
x
/phosphorus (P) Cat-doped layers on crystalline silicon (c-Si) by annealing. Both structures show promising passivation capabilities for c-Si with extremely low surface recombination velocity (SRV) on n-type c-Si. Defect termination by H is evaluated on the basis of defect density (N
d) determined by electron spin resonance (ESR) spectroscopy and interface state density (D
it) calculated by the Terman method. The two parameters are found to be drastically decreased by annealing after SiN
x
deposition. The calculated average D
it at midgap (D
it-average) is 2.2 × 1011 eV−1 cm−2 for the SiN
x
/P Cat-doped c-Si sample with a SRV of 2 cm/s, which is equivalent to 3.1 × 1011 eV−1 cm−2 for the SiN
x
/c-Si sample with a SRV of 5 cm/s after annealing. The results indicate that H atoms play a critical role in the reduction in D
it for SiN
x
/c-Si and SiN
x
/P Cat-doped c-Si, resulting in a drastic reduction in SRV by annealing.
Reconstruction of landslide movements by inversion of 4‐D electrical resistivity tomography monitoring data
Authors: Wilkinson Paul , Chambers Jonathan , Uhlemann Sebastian , Meldrum Philip , Smith Alister , Dixon Neil , Loke Meng Heng 
Published: January 2016

AbstractReliable tomographic inversion of geoelectrical monitoring data from unstable slopes relies critically on knowing the electrode positions, which may move over time. We develop and present an innovative inverse method to recover movements in both surface directions from geoelectrical measurements made on a grid of monitoring electrodes. For the first time, we demonstrate this method using field data from an active landslide to recover sequences of movement over timescales of days to years. Comparison with GPS measurements demonstrated an accuracy of within 10% of the electrode spacing, sufficient to correct the majority of artifacts that would occur in subsequent image reconstructions if incorrect positions are used. Over short timescales where the corresponding subsurface resistivity changes were smaller, the constraints could be relaxed and an order‐of‐magnitude better accuracy was achievable. This enabled the onset and acceleration of landslide activity to be detected with a temporal resolution of a few days.
Major softening at brittle‐ductile transition due to interplay between chemical and deformation processes: An insight from evolution of shear bands in the South Armorican Shear Zone
Authors: Bukovská Zita , Jeřábek Petr , Morales Luiz F. G. 
Published: January 2016

AbstractThe formation of S‐C/C′ fabrics in the South Armorican Shear Zone has been evaluated by detailed microstructural study where the focus was given to initiation and early evolution of the C/C′ fabric shear bands. Our observations suggest that the S‐C/C′ fabrics formed at distinct temperature conditions indicating >550°C for the S fabric and 300–350°C at 100–400 MPa for the C/C′ fabric shear bands. The evolving microstructure within shear bands documents switches in deformation mechanisms related to positive feedbacks between deformation and chemical processes and imposes mechanical constraints on the evolution of the brittle‐ductile transition in the continental transform fault domains. Three stages of shear band evolution have been identified. Stage I corresponds to initiation of shear bands via formation of microcracks with possible yielding differential stress of up to 250 MPa. Stage II is associated with subgrain rotation recrystallization and dislocation creep of quartz and coeval dissolution‐precipitation creep of microcline. Recrystallized quartz grains show continual increase in size and decrease in stress and strain rates from 94 MPa to 17–26 MPa and 3.8 × 10−12 s−1–8 × 10−14 s−1 associated with deformation partitioning into weaker microcline layer and shear band widening. The quartz mechanical data allowed us to set some constrains for coeval dissolution‐precipitation of microcline which at our estimated pressure‐temperature conditions suggests creep at 17–26 MPa differential stress and 3.8 × 10−13 s−1 strain rate. Stage III is characterized by localized slip along white mica bands accommodated by dislocation creep at strain rate 3.8 × 10−12 s−1 and stress 9.36 MPa. Our mechanical data point to dynamic evolution of the studied brittle‐ductile transition characterized by major weakening to strengths ~10 MPa. Such nonsteady state evolution may be common in crustal shear zones especially when phase transformations are involved.
Crustal structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for tectonic origins
Authors: Hansen Samantha E. , Kenyon Lindsey M. , Graw Jordan H. , Park Yongcheol , Nyblade Andrew A. 
Published: January 2016

AbstractThe Transantarctic Mountains (TAMs) are the largest noncollisional mountain range on Earth. Their origin, as well as the origin of the Wilkes Subglacial Basin (WSB) along the inland side of the TAMs, has been widely debated, and a key constraint to distinguish between competing models is the underlying crustal structure. Previous investigations have examined this structure but have primarily focused on a small region of the central TAMs near Ross Island, providing little along‐strike constraint. In this study, we use data from the new Transantarctic Mountains Northern Network and from five stations operated by the Korea Polar Research Institute to investigate the crustal structure beneath a previously unexplored portion of the TAMs. Using S wave receiver functions and Rayleigh wave phase velocities, crustal thickness and average crustal shear velocity (
) are resolved within ±4 km and ±0.1 km/s, respectively. The crust thickens from ~20 km near the Ross Sea coast to ~46 km beneath the northern TAMs, which is somewhat thicker than that imaged in previous studies beneath the central TAMs. The crust thins to ~41 km beneath the WSB.
ranges from ~3.1–3.9 km/s, with slower velocities near the coast. Our findings are consistent with a flexural origin for the TAMs and WSB, where these features result from broad flexure of the East Antarctic lithosphere and uplift along its western edge due to thermal conduction from hotter mantle beneath West Antarctica. Locally, thicker crust may explain the ~1 km of additional topography in the northern TAMs compared to the central TAMs.
Modeling modern glacier response to climate changes along the Andes Cordillera: A multiscale review
Authors: Fernández Alfonso , Mark Bryan G. 
Published: January 2016

AbstractHere we review the literature preferentially concerned with modern glacier‐climate modeling along the Andes. We find a diverse range of modeling approaches, from empirical/statistical models to relatively complex energy balance procedures. We analyzed these models at three different spatial scales. First, we review global approaches that have included the Andes. Second, we depict and analyze modeling exercises aimed at studying Andean glaciers as a whole. Our revision shows only two studies dealing with glacier modeling at this continental scale. We contend that this regional approach is increasingly necessary because it allows for connecting the “average‐out” tendency of global studies to local observations or models, in order to comprehend scales of variability and heterogeneity. Third, we revise small‐scale modeling, finding that the overwhelming number of studies have targeted glaciers in Patagonia. We also find that most studies use temperature‐index models and that energy balance models are still not widely utilized. However, there is no clear spatial pattern of model complexity. We conclude with a discussion of both the limitations of certain approaches, as for example the use of short calibration periods for long‐term modeling, and also the opportunities for improved understanding afforded by new methods and techniques, such as climatic downscaling. We also propose ways to future developments, in which observations and models can be combined to improve current understanding of volumetric glacier changes and their climate causes.
Development of a Continuous‐Flow Microreactor for Asymmetric Sulfoxidation Using a Biomimetic Manganese Catalyst
Authors: Dai Wen , Mi Yuan , Lv Ying , Chen Bo , Li Guosong , Chen Guangwen , Gao Shuang 
Published: January 2016

AbstractAsymmetric sulfoxidation catalyzed by a biomimetic manganese complex under continuous‐flow microreactor is described. The reaction is conducted in microreactor, it can rapidly (<4 min) oxidize a wide scope of sulfides with high yield (up to 91%) and excellent enantioselectivity (up to 99% ee), and allows shorter reaction times, easier scale‐up and lower catalyst loadings than its batchwise counterpart. Additionally, a convenient numbering‐up strategy for the scale‐up of asymmetric sulfoxidation has been developed which enables a direct scaling of the reaction to 5 g affording the corresponding sulfoxides within 20 min.magnified image
Oxidative Aminoaziridination of 2‐Vinylfuran Derivatives as an Approach to Hexa‐2,5‐diene‐1,4‐dione Monohydrazones
Authors: Sorokina Mariia V. , Pankova Alena S. , Kuznetsov Mikhail A. 
Published: January 2016

AbstractThe oxidative addition of N‐aminophthalimide to substituted 2‐vinylfurans provides monophthaloylhydrazones of (2Z)‐hexa‐2,5‐diene‐1,4‐dione derivatives instead of 2‐furylaziridines by proceeding through an aziridination of the endocyclic furan C=C bond followed by a regio‐ and stereoselective rearrangement of the bicyclic intermediate. The formation of stable aziridines can then occur through the aziridination of the (E)‐C=C bond of these phthaloylhydrazones. Detailed structure elucidations and mechanistic considerations are provided.
The evolutionary adaptation of the C282Y mutation to culture and climate during the European Neolithic
Authors: Heath Kathleen M. , Axton Jacob H. , McCullough John M. , Harris Nathan 
Published: January 2016

ABSTRACTObjectivesThe C282Y allele is the major cause of hemochromatosis as a result of excessive iron absorption. The mutation arose in continental Europe no earlier than 6,000 years ago, coinciding with the arrival of the Neolithic agricultural revolution. Here we hypothesize that this new Neolithic diet, which originated in the sunny warm and dry climates of the Middle East, was carried by migrating farmers into the chilly and damp environments of Europe where iron is a critical micronutrient for effective thermoregulation. We argue that the C282Y allele was an adaptation to this novel environment.Materials and MethodsTo address our hypothesis, we compiled C282Y allele frequencies, known Neolithic sites in Europe and climatic data on temperature and rainfall for statistical analysis.ResultsOur findings indicate that the geographic cline for C282Y frequency in Europe increases as average temperatures decrease below 16°C, a critical threshold for thermoregulation, with rainy days intensifying the trend.DiscussionThe results indicate that the deleterious C282Y allele, responsible for most cases of hemochromatosis, may have evolved as a selective advantage to culture and climate during the European Neolithic. Am J Phys Anthropol 160:86–101, 2016. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.
Trimerization of the HIV Transmembrane Domain in Lipid Bilayers Modulates Broadly Neutralizing Antibody Binding
Authors: Reichart Timothy M. , Baksh Michael M. , Rhee Jin‐Kyu , Fiedler Jason D. , Sligar Stephen G. , Finn M. G. , Zwick Michael B. , Dawson Philip E. 
Published: January 2016

AbstractThe membrane‐proximal external region (MPER) of HIV gp41 is an established target of antibodies that neutralize a broad range of HIV isolates. To evaluate the role of the transmembrane (TM) domain, synthetic MPER‐derived peptides were incorporated into lipid nanoparticles using natural and designed TM domains, and antibody affinity was measured using immobilized and solution‐based techniques. Peptides incorporating the native HIV TM domain exhibit significantly stronger interactions with neutralizing antibodies than peptides with a monomeric TM domain. Furthermore, a peptide with a trimeric, three‐helix bundle TM domain recapitulates the binding profile of the native sequence. These studies suggest that neutralizing antibodies can bind the MPER when the TM domain is a three‐helix bundle and this presentation could influence the binding of neutralizing antibodies to the virus. Lipid‐bilayer presentation of viral antigens in Nanodiscs is a new platform for evaluating neutralizing antibodies.
Stereoselektive arenbildende Aldolkondensation: Synthese konfigurativ stabiler Oligo‐1,2‐naphthylene
Authors: Lotter Dominik , Neuburger Markus , Rickhaus Michel , Häussinger Daniel , Sparr Christof 
Published: January 2016

AbstractStrukturell wohldefinierte Oligomere sind fundamental wichtig für die Funktionalität natürlicher molekularer Systeme und sind der Schlüssel für synthetische Analoga. Wir berichten hier über eine Strategie für die effiziente Synthese von Oligo‐1,2‐naphthylen‐Stereoisomeren mittels wiederholter Bausteinaddition und anschließender stereoselektiver, arenbildender Aldolkondensation. Die katalysatorkontrollierte atropenantioselektive und die substratkontrollierte atropdiastereoselektive Aldolkondensation ergeben Ter‐ und Quaternaphthalin‐Stereoisomere, die konfigurativ stabile Gegenstücke zu den ansonsten stereodynamischen, helikalen ortho‐Phenylenen darstellen.
Total Synthesis of Ileabethoxazole, Pseudopteroxazole, and seco‐Pseudopteroxazole
Authors: Yang Ming , Yang Xiaowen , Sun Hongbin , Li Ang 
Published: January 2016

AbstractThe total syntheses of ileabethoxazole, pseudopteroxazole, and seco‐pseudopteroxazole, three antituberculosis diterpenoids that had been isolated from Pseudopterogorgia elisabethae, were accomplished in a collective fashion. A cascade alkyne carbopalladation/Stille reaction was exploited to construct a triene precursor with suitable geometry. A fully substituted arene was then assembled through a key 6π electrocyclization/aromatization sequence, and served as an advanced common intermediate. Two radical cyclizations led to the formation of the five‐ and six‐membered rings of ileabethoxazole and pseudopteroxazole, respectively, with the desired stereochemistry, and a straightforward side‐chain elongation delivered seco‐pseudopteroxazole.
Noninvasive Staging of Kidney Dysfunction Enabled by Renal‐Clearable Luminescent Gold Nanoparticles
Authors: Yu Mengxiao , Zhou Jiancheng , Du Bujie , Ning Xuhui , Authement Craig , Gandee Leah , Kapur Payal , Hsieh Jer‐Tsong , Zheng Jie 
Published: January 2016

AbstractAs a “silent killer”, kidney disease is often hardly detected at an early stage but can cause lethal kidney failure later on. Thus, a preclinical imaging technique that can readily differentiate between the stages of kidney dysfunction is highly desired for improving our fundamental understanding of kidney disease progression. Herein, we report that in vivo fluorescence imaging, enabled by renal‐clearable near‐infrared‐emitting gold nanoparticles, can noninvasively detect kidney dysfunction, report on the dysfunctional stages, and even reveal adaptive function in a mouse model of unilateral obstructive nephropathy, which cannot be diagnosed with routine kidney function markers. These results demonstrate that low‐cost fluorescence kidney functional imaging is highly sensitive and useful for the longitudinal, noninvasive monitoring of kidney dysfunction progression in preclinical research.
Chemoproteomik‐vermittelte Entdeckung eines potenten und selektiven Inhibitors des DNA‐Reparaturproteins MGMT
Authors: Wang Chao , Abegg Daniel , Hoch Dominic G. , Adibekian Alexander 
Published: January 2016

AbstractWir präsentieren ein neues chemisches Gerüst für Cystein‐reaktive Inhibitoren. Die Chlormethyltriazole (CMTs) werden in nur zwei chemischen Schritten erhalten, was eine schnelle Optimierung der pharmakologischen Eigenschaften dieser Inhibitoren möglich macht. Wir demonstrieren die Optimierung der CMTs für ein biologisches Target durch die Synthese von AA‐CW236 als ersten, potenten Nicht‐Pseudosubstrat‐Inhibitor der O6‐Methylguanin‐DNA‐Methyltransferase (MGMT), ein Protein von hoher klinischer Bedeutung für die Behandlung mehrerer Krebsarten. Durch die Nutzung quantitativer Proteomiktechniken zeigen wir, dass AA‐CW236 eine hohe Selektivität für MGMT aufweist. Schlussendlich validieren wir die Effektivität unseres MGMT‐Inhibitors in Kombination mit der DNA‐alkylierenden Substanz Temozolomid in Brust‐ und Dickdarmkrebszellinien mithilfe von konfokaler Fluoreszenzmikroskopie und Zellviabilitätsassays. Unsere Ergebnisse könnten zur Entwicklung eines klinisch zugelassenen MGMT‐Inhibitors beitragen.
Elusive Reaction Intermediates in Solution Explored by ESI‐MS: Reverse Periscope for Mechanistic Investigations
Authors: Iacobucci Claudio , Reale Samantha , De Angelis Francesco 
Published: January 2016

AbstractJust as periscopes allow a submarine to visually search for objects above the surface of the sea, in a reversed periscope fashion electrospray mass spectrometry (ESI‐MS) can analyze the compounds at the gas phase/liquid phase interface for chemical entities which may exist in solution. The challenge is the identification and structural characterization of key elusive reaction intermediates in chemical transformations, intermediates which are able to explain how chemical processes occur. This Minireview summarizes recent selected publications on the use of ESI‐MS techniques for studying solution intermediates of homogeneous chemical reactions.
Iron‐Catalyzed Decarboxylative (4+1) Cycloadditions: Exploiting the Reactivity of Ambident Iron‐Stabilized Intermediates
Authors: Wang Qiang , Qi Xiaotian , Lu Liang‐Qiu , Li Tian‐Ren , Yuan Zhi‐Guang , Zhang Kai , Li Bin‐Jie , Lan Yu , Xiao Wen‐Jing 
Published: January 2016

AbstractThe first example of iron‐catalyzed decarboxylative (4+1) cycloaddition reactions is described in this publication. By using this method, a wide range of functionalized indoline products were prepared from easily available vinyl benzoxazinanones and sulfur ylides in high yields and selectivities. A possible reaction pathway involving an allylic iron intermediate is discussed based on a series of control experiments and density‐functional theory calculations.
Isolation and Versatile Derivatization of an Unsaturated Anionic Silicon Cluster (Siliconoid)
Authors: Willmes Philipp , Leszczyńska Kinga , Heider Yannic , Abersfelder Kai , Zimmer Michael , Huch Volker , Scheschkewitz David 
Published: January 2016

AbstractThe characteristic features of bulk silicon surfaces are echoed in the related partially substituted—and thus unsaturated—neutral silicon clusters (siliconoids). The incorporation of siliconoids into more‐extended frameworks is promising owing to their unique electronic features, but further developments in this regard are limited by the notable absence of functionalized siliconoid derivatives until now. Herein we report the isolation and full characterization of the lithium salt of an anionic R5Si6‐siliconoid, thus providing the missing link between silicon‐based Zintl anions and siliconoid clusters. Proof‐of‐principle for the high potential of this species for the efficient transfer of the intact unsaturated R5Si6 moiety is demonstrated by clean reactions with representative electrophiles of Groups 13, 14, and 15.
Ameliorative Effect of Grape Seed Proanthocyanidin Extract on Cadmium‐Induced Meiosis Inhibition During Oogenesis in Chicken Embryos
Authors: Hou Fuyin , Xiao Min , Li Jian , Cook Devin W. , Zeng Weidong , Zhang Caiqiao , Mi Yuling 
Published: January 2016

ABSTRACTCadmium (Cd) is an environmental endocrine disruptor that has toxic effects on the female reproductive system. Here the ameliorative effect of grape seed proanthocyanidin extract (GSPE) on Cd‐induced meiosis inhibition during oogenesis was explored. As compared with controls, chicken embryos exposed to Cd (3 µg/egg) displayed a changed oocyte morphology, decreased number of meiotic germ cells, and decreased expression of the meiotic marker protein γH2AX. Real time RT‐PCR also revealed a significant down‐regulation in the mRNA expressions of various meiosis‐specific markers (Stra8, Spo11, Scp3, and Dmc1) together with those of Raldh2, a retinoic acid (RA) synthetase, and of the receptors (RARα and RARβ). In addition, exposure to Cd increased the production of H2O2 and malondialdehyde in the ovaries and caused a corresponding reduction in glutathione and superoxide dismutase. Simultaneous supplementation of GSPE (150 µg/egg) markedly alleviated the aforementioned Cd‐induced embryotoxic effects by upregulating meiosis‐related proteins and gene expressions and restoring the antioxidative level. Collectively, the findings provided novel insights into the underlying mechanism of Cd‐induced meiosis inhibition and indicated that GSPE might potentially ameliorate related reproductive disorders. Anat Rec, 299:450–460, 2016. © 2016 Wiley Periodicals, Inc.
Is small‐scale upgrading of landfill gas to biomethane for use as a cellulosic transport biofuel economically viable?
Authors: Czyrnek‐Delêtre Magdalena M , Ahern Eoin P , Murphy Jerry D 
Published: January 2016

AbstractLandfill gas (with methane content of 35–55%) adds significantly to global warming if released to the atmosphere. Under the EU Landfill Directive, all landfill sites are obliged to collect this gas if supplied with biodegradable municipal waste. Landfill gas (LFG) can be (i) flared, (ii) combusted to produce electricity, or (iii) upgraded to biomethane. The last scenario is of special interest. In the USA, LFG is now classified as a cellulosic biofuel; in the EU, there is a mandatory target of 10% share of renewables in transport by 2020. A significant challenge for upgrading LFG to biomethane is the high nitrogen content resulting from negative pressure in the landfill. Cost analyses were conducted to compare three technology solutions for LFG upgrading with accessible LFG flow of 250–500 m3/h. If injection to the transmission grid is considered, then a single‐step pressure swing adsorption (PSA) system may be viable. The optimal solution suggested is an on‐site service station; the cost of this system (including propane addition and service station) was assessed as e0.84/mn3 LFG biomethane. This required a subsidy of e0.55/mn3; this is available in Ireland under the Biofuel Obligation Certificate scheme. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd