bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potent Pyrimidine and Pyrrolopyrimidine Inhibitors of Testis‐Specific Serine/Threonine Kinase 2 (TSSK2)
Authors: Hawkinson Jon E. , Sinville Rondedrick , Mudaliar Deepti , Shetty Jagathpala , Ward Timothy , Herr John C. , Georg Gunda I. 
Published: September 2017

AbstractTestis‐specific serine/threonine kinase 2 (TSSK2) is an important target for reversible male contraception. A high‐throughput screen of ≈17 000 compounds using a mobility shift assay identified two potent series of inhibitors having a pyrrolopyrimidine or pyrimidine core. The pyrrolopyrimidine 10 (IC50 22 nm; GSK2163632A) and the pyrimidine 17 (IC50 31 nm; ALK inhibitor 1) are the most potent TSSK2 inhibitors in these series, which contain the first sub‐100 nanomolar inhibitors of any TSSK isoform reported, except for the broad kinase inhibitor staurosporine. The novel, potent pyrimidine TSSK2 inhibitor compound 19 (IC50 66 nm; 2‐[[5‐chloro‐2‐[2‐methoxy‐4‐(1‐methylpiperidin‐4‐yl)anilino]pyrimidin‐4‐yl]amino]‐N‐methylbenzenesulfonamide) lacks the potential for metabolic activation. Compound 19 had a potency rank order of TSSK1>TSSK2>TSSK3>TSSK6, indicating that potent dual inhibitors of TSSK1/2 can be identified, which may be required for a complete contraceptive effect. The future availability of a TSSK2 crystal structure will facilitate structure‐based discovery of selective TSSK inhibitors from these pyrrolopyrimidine and pyrimidine scaffolds.
250 MHz passive Q‐modulator for reflection resonators
Authors: Epel Boris , Sundramoorthy Subramanian V. , Halpern Howard J. 
Published: September 2017

AbstractA simple scheme for dynamically switching the quality factor, Q, of a loop‐gap resonator (LGR); working at 250 MHz is presented. The addition of this Q‐modulator resulted in 30% improvement in electron paramagnetic resonance imager signal‐to‐noise ratio. During pulse excitation, this scheme lowered the Q, while higher Q was obtained during signal detection. These conditions favored the image acquisition. The Q‐modulator is passive; the transition between different states was actuated by the radio frequency power itself.
Evaluation of Cyclooctatetraene‐Based Aliphatic Polymers as Battery Materials: Synthesis, Electrochemical, and Thermal Characterization Supported by DFT Calculations
Authors: Speer Martin E. , Sterzenbach Christopher , Esser Birgit 
Published: September 2017

AbstractOrganic electrode materials for rechargeable batteries are becoming a viable alternative for existing technologies. In particular, redox polymers have shown great performances. While many cathode‐active derivatives are known, the development of their anode‐active counterparts, required for the design of full‐organic batteries, lacks behind. Here we present investigation on the suitability of cyclooctatetraene (COT)‐based aliphatic polymers as anode‐active battery materials, inspired by the known reversible reduction chemistry of COT at low electrochemical potential. We found that both synthesized polystyrene derivatives, side‐group functionalized with COT, showed limited electrochemical reversibility of the reduction processes, whereas reductions proceeded reversibly in model compounds of these polymers. Differential scanning calorimetry measurements and density‐functional theory calculations showed that this incomplete reversibility was due to cross‐linking reactions occurring between COT units in the polymers. For the future of COT‐based redox polymers, we propose a molecular design that prevents these cross‐linking reactions.
An oscillatory noise‐shaped quantizer for time‐based continuous‐time sigma‐delta modulators
Authors: Tamaddon Mohsen , Yavari Mohammad 
Published: September 2017

SummaryIn this paper, a new type of an oscillatory noise‐shaped quantizer (NSQ) for time‐based continuous‐time sigma‐delta modulators is presented. The proposed NSQ is composed of an oscillatory voltage‐to‐time converter and a polyphase sampler. Using Tustin's transformation method and through the approximation of the comparator gain, a linearized model of the NSQ is introduced. This way, a novel realization of the first‐ and second‐order NSQ is presented. Its implementation is based on fully passive continuous‐time filters without needing any amplifier or power consuming element. The ploy‐phase sampler inside the NSQ is based on the combination of a time‐to‐digital and a digital‐to‐time converter. The layout of the proposed NSQ is provided in Taiwan Semiconductor Manufacturing Company 0.18 μm complementary metal‐oxide‐semiconductor 1P6M technology. The verification of the proposed NSQ is done via investigating both the system level and postlayout simulation results. Leveraging the proposed NSQ in an Lth‐order time‐based continuous‐time sigma‐delta modulator enhances the noise‐shaping order up to L + 2, confirming its superior effectiveness. This makes it possible to design high performance and wideband continuous‐time SDMs with low power consumption and relaxed design complexity.
Distributed simultaneous wireless information and power transfer in multiuser amplify‐and‐forward ad hoc wireless networks
Authors: Baidas Mohammed W , Afghah Masoud M , Afghah Fatemeh 
Published: September 2017

SummaryThis paper studies the problem of stable node matching for distributed simultaneous wireless information and power transfer in multiuser amplify‐and‐forward ad hoc wireless networks. Particularly, each source node aims to be paired with another node that takes the role of an amplify‐and‐forward relay to forward its signal to the destination, such that the achievable rate is improved, in return of some payment made to the relaying node. Each relaying node splits its received signal from its respective source into two parts: one for information processing and the other for energy harvesting. In turn, a matching‐theoretic solution based on the one‐to‐one stable marriage matching game is studied, and a distributed polynomial‐time complexity algorithm is proposed to pair each source node with its best potential relaying node based on the power‐splitting ratios, such that their utilities or payments are maximized while achieving network stability. For comparison purposes, an algorithm to enumerate all possible stable matchings is also devised to study the impact of different matchings on the source and relay utilities. Simulation results are presented to validate the proposed matching algorithm and illustrate that it yields sum‐utility and sum‐payment that are closely comparable to those of centralized power allocation and node pairing, with the added merits of low complexity, truth telling, and network stability.
Resource partitioning facilitates coexistence in sympatric cetaceans in the California Current
Authors: Fossette Sabrina , Abrahms Briana , Hazen Elliott L. , Bograd Steven J. , Zilliacus Kelly M. , Calambokidis John , Burrows Julia A. , Goldbogen Jeremy A. , Harvey James T. , Marinovic Baldo , Tershy Bernie , Croll Donald A. 
Published: September 2017

AbstractResource partitioning is an important process driving habitat use and foraging strategies in sympatric species that potentially compete. Differences in foraging behavior are hypothesized to contribute to species coexistence by facilitating resource partitioning, but little is known on the multiple mechanisms for partitioning that may occur simultaneously. Studies are further limited in the marine environment, where the spatial and temporal distribution of resources is highly dynamic and subsequently difficult to quantify. We investigated potential pathways by which foraging behavior may facilitate resource partitioning in two of the largest co‐occurring and closely related species on Earth, blue (Balaenoptera musculus) and humpback (Megaptera novaeangliae) whales. We integrated multiple long‐term datasets (line‐transect surveys, whale‐watching records, net sampling, stable isotope analysis, and remote‐sensing of oceanographic parameters) to compare the diet, phenology, and distribution of the two species during their foraging periods in the highly productive waters of Monterey Bay, California, USA within the California Current Ecosystem. Our long‐term study reveals that blue and humpback whales likely facilitate sympatry by partitioning their foraging along three axes: trophic, temporal, and spatial. Blue whales were specialists foraging on krill, predictably targeting a seasonal peak in krill abundance, were present in the bay for an average of 4.7 months, and were spatially restricted at the continental shelf break. In contrast, humpback whales were generalists apparently feeding on a mixed diet of krill and fishes depending on relative abundances, were present in the bay for a more extended period (average of 6.6 months), and had a broader spatial distribution at the shelf break and inshore. Ultimately, competition for common resources can lead to behavioral, morphological, and physiological character displacement between sympatric species. Understanding the mechanisms for species coexistence is both fundamental to maintaining biodiverse ecosystems, and provides insight into the evolutionary drivers of morphological differences in closely related species.
Effect of Autohydrolysis Pretreatment Conditions on Sugarcane Bagasse Structures and Product Distribution Resulting from Pyrolysis
Authors: Hao Naijia , Lu Kongyu , Ben Haoxi , Adhikari Sushil , Lacerda Tais Bezerra , Ragauskas Arthur J. 
Published: September 2017

AbstractPyrolysis has been increasingly perceived as a promising technology to produce biofuel precursors (bio‐oil) from agricultural residuals; however, there is a significant quality gap between a bio‐oil and the fuels used for transportation. In this study, we autohydrolyzed pretreated sugarcane bagasse at three different conditions (180 °C–10 min, 180 °C–40 min, 200 °C–40 min), then we investigated the effect of this pretreatment on a subsequent pyrolysis stage. High‐pressure ion‐exchange chromatography (HPIC) and the 13C cross‐polarization/magic angle spinning (CP/MAS) solid‐state nuclear magnetic resonance (NMR) revealed that the autohydrolysis pretreatment significantly disrupted the hemicellulose fractions in the sugarcane bagasse and caused the breakage of lignin ether linkages in the sugarcane bagasse feedstocks. As the 31P NMR results indicated, the autohydrolysis pretreatment removed carboxylic acid groups up to 66.7 %, which could significantly address the corrosion problem of bio‐oils. Heteronuclear single quantum correlation (HSQC) analysis suggested that the autohydrolysis pretreatment effectively lowered the presence of the oxygenated aromatic compounds in the bio‐oils. Gel permeation chromatography (GPC) analysis of the bio‐oils indicated that the oils from severely pretreated sugarcane bagasse pyrolyzed at a low temperature (i.e., 400 °C) contained lower‐molecular‐weight components similar to those present gasoline products.
Hydrogenation Kinetics of N‐Ethylindole on a Supported Ru Catalyst
Authors: Dong Yuan , Yang Ming , Zhu Ting , Chen Xuedi , Li Chenguang , Ke Hanzhong , Cheng Hansong 
Published: September 2017

AbstractWith its low melting point of −17.8 °C and gravimetric density of 5.23 wt %, N‐ethylindole is a promising candidate for use as a liquid organic hydrogen carrier (LOHC). Here, the influences of reaction temperature and hydrogen pressure on the hydrogen capacity of N‐ethylindole in the liquid phase are studied. It is found that fully hydrogenated N‐ethylindole can be achieved at 190 °C within 80 min. The hydrogenation of N‐ethylindole over 5 wt % Ru/Al2O3 is found to follow first‐order kinetics with an apparent activation energy of 62.4 kJ mol−1; its rate constant is subsequently derived. The initial rate and turn‐over frequency (TOF) at 160 °C–190 °C are also calculated. The structures of the intermediates during hydrogenation of N‐ethylindole are discussed based on the results of density functional theory calculations. Finally, the hydrogenation mechanism for N‐ethylindole is established.
Ammonia Borane Based Nanocomposites as Solid‐State Hydrogen Stores for Portable Power Applications
Authors: Bravo Diaz Laura , Hanlon James M. , Bielewski Marek , Milewska Aleksandra , Gregory Duncan H. 
Published: September 2017

AbstractAmmonia borane (AB) based nanocomposites are studied with the aim of developing a promising solid‐state hydrogen store that complies with the requirements of a modular polymer electrolyte membrane fuel cell (PEM FC) in a portable power pack system. AB‐carbon nanocomposites (prepared via ball milling or solution‐impregnation) demonstrate improved hydrogen release performance compared to AB itself in terms of onset temperature and hydrogen purity, while maintaining a gravimetric density of more than 5 wt. % H2. The most promising of these materials is an AB‐AC (activated carbon) composite, synthesized via solution impregnation with an optimal dehydrogenation temperature of 96 °C. When combined with an external nickel chloride filter downstream, no evolved gaseous by‐products can be detected above 100 ppb. The feasibility of an AB‐AC storage tank is further investigated using simulations in which the reaction rate and the hydrogen flux is found to be nearly constant as the temperature front propagated from the bottom to the top of the tank after initiation.
Fluvial suspended sediment yields over hours to millennia in the High Arctic at proglacial Lake Linnévatnet, Svalbard
Authors: Schiefer Erik , Kaufman Darrell , McKay Nicholas , Retelle Michael , Werner Al , Roof Steve 
Published: September 2017

AbstractSediment yield can be a sensitive indicator of catchment dynamics and environmental change. For a glacierized catchment in the High Arctic, we compiled and analyzed diverse sediment transfer data, spanning a wide range of temporal scales, to quantify catchment yields and explore landscape response to past and ongoing hydroclimatic variability. The dataset integrates rates of lake sedimentation from correlated varve records and repeated annual and seasonal sediment traps, augmented by multi‐year lake and fluvial monitoring. Consistent spatial patterns of deposition enabled reconstruction of catchment yields from varve‐ and trap‐based fluxes. We used hydroclimatic data and multivariate modeling to examine annual controls of sediment delivery over almost a century, and to examine shorter‐term controls of sediment transfer during peak glacier melt. Particle‐size analyses, especially for annual sediment traps, were used to further infer sediment transfer mechanisms and timing. Through the Medieval Warm Period and Little Ice Age, there were no apparent multi‐century trends in lake sedimentation rates, which were over three times greater than those during the mid‐Holocene when glaciers were diminished. Twentieth‐century sedimentation rates were greater than those of previous millennia, with a mid‐century step increase in mean yield from 240 to 425 Mg km−2 yr−1. Annual yields through the twentieth century showed significant positive relations with spring/summer temperature, rainfall, and peak discharge conditions. This finding is significant for the future of sediment transfer at Linnévatnet, and perhaps more broadly in the Arctic, where continued increases in temperature and rainfall are projected. For 2004–2010, annual yields ranged from 294 to 1330 Mg km−2 yr−1. Sediment trap volumes and particle‐size variations indicate that recent annual yields were largely dominated by spring to early summer transfer of relatively coarse‐grained sediment. Fluvial monitoring showed daily to hourly sediment transfer to be related to current and prior discharge, diurnal hysteresis, air temperature, and precipitation. Copyright © 2017 John Wiley & Sons, Ltd.
Some methods of training radial basis neural networks in solving the Navier‐Stokes equations
Authors: Sinchev Bakhtgerey , Sibanbayeva Saulet Erbulatovna , Mukhanova Axulu Mukhambetkaliyevna , Nurgulzhanova Assel Nurgulzhanovna , Zaurbekov Nurgali Sabyrovich , Imanbayev Kairat Sovetovish , Gagarina Nadezhda Lvovna , Baibolova Lyazzat Kemerbekovna 
Published: September 2017

SummaryThe purpose of this research is to analyze the application of neural networks and specific features of training radial basis functions for solving 2‐dimensional Navier‐Stokes equations.The authors developed an algorithm for solving hydrodynamic equations with representation of their solution by the method of weighted residuals upon the general neural network approximation throughout the entire computational domain. The article deals with testing of the developed algorithm through solving the 2‐dimensional Navier‐Stokes equations.Artificial neural networks are widely used for solving problems of mathematical physics; however, their use for modeling of hydrodynamic problems is very limited. At the same time, the problem of hydrodynamic modeling can be solved through neural network modeling, and our study demonstrates an example of its solution.The choice of neural networks based on radial basis functions is due to the ease of implementation and organization of the training process, the accuracy of the approximations, and smoothness of solutions. Radial basis neural networks in the solution of differential equations in partial derivatives allow obtaining a sufficiently accurate solution with a relatively small size of the neural network model. The authors propose to consider the neural network as an approximation of the unknown solution of the equation. The Gaussian distribution is used as the activation function.
Modeling the potential impacts of CO2 sequestration on shallow groundwater: The fate of trace metals and organic compounds before and after leakage stops
Authors: Zheng Liange , Spycher Nicolas 
Published: September 2017

AbstractLarge‐scale deployment of CO2 geological sequestration requires understanding and assessing the risks of such an operation. One of these risks is the potential contamination of groundwater by CO2/brine leakage into shallow aquifers. Although our understanding of this issue has improved significantly over the last decade, several questions still need to be better addressed, including the fate of organic constituents, the dominant source of trace metals (are they mainly coming from aquifer sediments, or leaking brine), and whether the trace metals released during the leakage phase recover to background levels if the leakage were to be detected and stopped. In this paper, reactive transport simulations that model the behavior of trace metals and organic compounds in response to the leakage of CO2 and brine into a shallow aquifer are presented to address these questions. Model results show that the metals and organic compounds brought by the leaking brine form a plume at the bottom of the aquifer because the density of the brine is higher than that of groundwater. In contrast, metals are mobilized by CO2 over a larger vertical extent because of the spreading of gaseous CO2 by buoyancy. The concentration of organic contaminants is strongly attenuated by adsorption and degradation, with degradation playing the major role in the modeled scenarios. Although the leaking brine is assumed to contain elevated concentrations of As, Pb, Cd, and Ba, it does not contribute significantly to the contamination of the modeled shallow aquifer by these elements. Once the leakage stops, mobilized organic compounds that undergo degradation vanish, while less degradable compounds linger for a longer time; the dissolved concentrations of trace metals decrease significantly, as a result of re‐sorption and reversal of processes leading to Ca‐driven cation exchange. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.
Clinical results of definitive chemoradiotherapy for cervical esophageal cancer: Comparison of failure pattern and toxicities between intensity‐modulated radiotherapy and 3‐dimensional conformal radiotherapy
Authors: Ito Makoto , Kodaira Takeshi , Tachibana Hiroyuki , Tomita Natsuo , Makita Chiyoko , Koide Yutaro , Kato Daiki , Abe Tetsuya , Muro Kei , Tajika Masahiro , Niwa Yasumasa , Hasegawa Yasuhisa 
Published: September 2017

AbstractBackgroundThe efficacy of intensity‐modulated radiotherapy (IMRT) for cervical esophageal cancer has not been determined.MethodsEighty patients with cervical esophageal cancer treated with definitive chemoradiotherapy from 2002 to 2014 were analyzed. Overall survival (OS), failure patterns, and toxicity incidence were compared between the IMRT (N = 32) and 3D conformal radiotherapy (RT; N = 48) groups.ResultsThe median follow‐up was 35.9 months. The 3‐year OS of the IMRT, 3D conformal RT, and total groups was 81.6%, 57.2%, and 66.6%, respectively. Pulmonary toxicity was not observed with IMRT. Six of 62 cases (9.6%) with nodal involvement developed upper cervical node recurrence outside the prophylactic region. Ten patients in the IMRT group were salvaged, and 60% survived without recurrence; 20% of the 3D conformal RT group was salvaged.ConclusionThe IMRT group was comparable with 3D conformal RT group, with a better salvage rate. We recommend extended cervical irradiation for nodal involvement.
Impact of oral hygiene on head and neck cancer risk in a Chinese population
Authors: Kawakita Daisuke , Lee Yuan‐Chin Amy , Li Qian , Chen Yuji , Chen Chien‐Jen , Hsu Wan‐Lun , Lou Pei‐Jen , Zhu Cairong , Pan Jian , Shen Hongbing , Ma Hongxia , Cai Lin , He Baochang , Wang Yu , Zhou Xiaoyan , Ji Qinghai , Zhou Baosen , Wu Wei , Ma Jie , Boffetta Paolo , Zhang Zuo‐Feng , Dai Min , Hashibe Mia 
Published: September 2017

AbstractBackgroundAlthough the impact of oral hygiene on head and neck cancer risk has been investigated, few studies have been conducted among the Asian population.MethodsWe conducted a multicenter case‐control study to investigate this potential association. We performed unconditional multiple logistic regression models adjusted by potential confounders.ResultsWe observed an inverse association of frequency of dental visits with head and neck cancer risk, with an adjusted odds ratio (OR) of 3.70 (95% CI 2.51‐5.45) for never dental visits compared with ≥1 time/year (Ptrend < .001). We also observed a positive association between the number of missing teeth and head and neck cancer risk, with an adjusted OR for ≥5 missing teeth compared with <5 missing teeth of 1.49 (95% CI 1.08‐2.04). Combining multiple oral hygiene indicators, poor oral hygiene scores increased head and neck cancer risk.ConclusionPoor oral hygiene may increase head and neck cancer risk in the Chinese population. Therefore, improving oral hygiene may contribute to reducing the head and neck cancer risk in the Chinese population.
Use of dynamic MRI during swallowing to assess carotid artery invasion by neck metastasis
Authors: Chitose Shun‐ichi , Ono Takeharu , Shin Buichiro , Sato Kiminori , Umeno Hirohito 
Published: September 2017

AbstractBackgroundThe effectiveness of dynamic MRI in evaluating the relationship between metastatic lymph nodes and the carotid artery was investigated.MethodsThirty‐two patients with metastatic lymph nodes, possibly adherent to the carotid artery, were evaluated with dynamic MRI before surgery. Consecutive axial and oblique images were obtained during swallowing. The displacement rate of the target carotid artery to the contralateral carotid artery and the low‐intensity stripe between the metastatic lymph nodes and the carotid artery wall were compared with the surgical findings.ResultsA displacement rate > 50% indicated resectable metastatic lymph nodes. Low‐intensity stripe was present in 65% of patients and indicated no invasion; 82% of patients without low‐intensity stripe had resectable metastatic lymph nodes. The others without low‐intensity stripe required carotid artery resection due to malignant invasion. The accuracy rate, sensitivity, and specificity were 78%, 83%, and 100%, respectively.ConclusionDynamic MRI during swallowing is useful for assessing suspected carotid artery involvement in patients with metastatic lymph nodes to achieve maximal safe resection.