bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variations in the vertical profile of ozone at four high-latitude Arctic sites from 2005 to 2017
Authors: Bahramvash Shams Shima , Walden Von P. , Petropavlovskikh Irina , Tarasick David , Kivi Rigel , Oltmans Samuel , Johnson Bryan , Cullis Patrick , Sterling Chance W. , Thölix Laura , Errera Quentin 
Published: August 2019

Abstract. Understanding variations in atmospheric ozone in the
Arctic is difficult because there are only a few long-term records of
vertical ozone profiles in this region. We present 12 years of ozone
profiles from February 2005 to February 2017 at four sites: Summit Station,
Greenland; Ny-Ålesund, Svalbard, Norway; and Alert and Eureka, Nunavut, Canada.
These profiles are created by combining ozonesonde measurements with ozone
profile retrievals using data from the Microwave Limb Sounder (MLS). This
combination creates a high-quality dataset with low uncertainty values by relying
on in situ measurements of the maximum altitude of the ozonesondes
(∼30 km) and satellite retrievals in the upper atmosphere (up
to 60 km). For each station, the total column ozone (TCO) and the partial
column ozone (PCO) in four atmospheric layers (troposphere to upper
stratosphere) are analyzed. Overall, the seasonal cycles are similar at
these sites. However, the TCO over Ny-Ålesund starts to decline 2
months later than at the other sites. In summer, the PCO in the upper
stratosphere over Summit Station is slightly higher than at the other sites
and exhibits a higher standard deviation. The decrease in PCO in the middle
and upper stratosphere during fall is also lower over Summit Station. The
maximum value of the lower- and middle-stratospheric PCO is reached earlier
in the year over Eureka. Trend analysis over the 12-year period shows
significant trends in most of the layers over Summit and Ny-Ålesund
during summer and fall. To understand deseasonalized ozone variations, we
identify the most important dynamical drivers of Arctic ozone at each level.
These drivers are chosen based on mutual selected proxies at the four sites
using stepwise multiple regression (SMR) analysis of various dynamical parameters
with deseasonalized data. The final regression model is able to explain more
than 80 % of the TCO and more than 70 % of the PCO in almost all of the
layers. The regression model provides the greatest explanatory value in the
middle stratosphere. The important proxies of the deseasonalized ozone time
series at the four sites are tropopause pressure (TP) and equivalent latitude (EQL) at
370 K in the troposphere, the quasi-biennial oscillation (QBO) in the troposphere
and lower stratosphere, the equivalent latitude at 550 K in the middle and
upper stratosphere, and the eddy heat flux (EHF) and volume of polar stratospheric
clouds throughout the stratosphere.
The 2015–2016 carbon cycle as seen from OCO-2 and the global in situ network
Authors: Crowell Sean , Baker David , Schuh Andrew , Basu Sourish , Jacobson Andrew R. , Chevallier Frederic , Liu Junjie , Deng Feng , Feng Liang , McKain Kathryn , Chatterjee Abhishek , Miller John B. , Stephens Britton B. , Eldering Annmarie , Crisp David , Schimel David , Nassar Ray , O'Dell Christopher W. , Oda Tomohiro , Sweeney Colm , Palmer Paul I. , Jones Dylan B. A. 
Published: August 2019

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques, and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within the ensemble spread, in situ observations, and satellite retrievals constrain a similar global total carbon sink of 3.7±0.5 PgC yr−1, and 1.5±0.6 PgC yr−1 for global land, for the 2015–2016 annual mean. This agreement breaks down in smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.
Past climate and continentality inferred from ice wedges at Batagay megaslump in the Northern Hemisphere's most continental region, Yana Highlands, interior Yakutia
Authors: Opel Thomas , Murton Julian B. , Wetterich Sebastian , Meyer Hanno , Ashastina Kseniia , Günther Frank , Grotheer Hendrik , Mollenhauer Gesine , Danilov Petr P. , Boeskorov Vasily , Savvinov Grigoriy N. , Schirrmeister Lutz 
Published: August 2019

Abstract. Ice wedges in the Yana Highlands of interior Yakutia – the most continental
region of the Northern Hemisphere – were investigated to elucidate changes
in winter climate and continentality that have taken place since the Middle Pleistocene. The
Batagay megaslump exposes ice wedges and composite wedges that were sampled
from three cryostratigraphic units: the lower ice complex of likely
pre-Marine Isotope Stage (MIS) 6 age, the upper ice complex (Yedoma) and the
upper sand unit (both MIS 3 to 2). A terrace of the nearby Adycha River
provides a Late Holocene (MIS 1) ice wedge that serves as a modern reference
for interpretation. The stable-isotope composition of ice wedges in the MIS 3 upper ice complex at Batagay is more depleted (mean δ18O
about −35 ‰) than those from 17 other ice-wedge study
sites across coastal and central Yakutia. This observation points to lower
winter temperatures and therefore higher continentality in the Yana
Highlands during MIS 3. Likewise, more depleted isotope values are found in
Holocene wedge ice (mean δ18O about −29 ‰)
compared to other sites in Yakutia. Ice-wedge isotopic signatures of the
lower ice complex (mean δ18O about −33 ‰)
and of the MIS 3–2 upper sand unit (mean δ18O from about −33 ‰ to
−30 ‰) are less distinctive regionally. The latter unit
preserves traces of fast formation in rapidly accumulating sand sheets and
of post-depositional isotopic fractionation.
Enabling a new method of dynamic field-effect gas sensor operation through lithium-doped tungsten oxide
Authors: Rodner Marius , Bastuck Manuel , Schütze Andreas , Andersson Mike , Huotari Joni , Puustinen Jarkko , Lappalainen Jyrki , Sauerwald Tilman 
Published: August 2019

Abstract. To fulfil today's requirements, gas sensors have to become more and more sensitive and selective. Temperature-cycled operation has long been used to enhance the sensitivity and selectivity of metal-oxide semiconductor gas sensors and, more recently, silicon-carbide-based, gas-sensitive field-effect transistors (SiC-FETs). In this work, we present a novel method to significantly enhance the effect of gate bias on a SiC-FET's response, giving rise to new possibilities for static and transient signal generation and, thus, increased sensitivity and selectivity. A tungsten trioxide (WO3) layer is deposited via pulsed laser deposition as an oxide layer beneath a porous iridium gate, and is doped with 0.1 AT % of lithium cations. Tests with ammonia as a well-characterized model gas show a relaxation effect with a time constant between 20 and 30 s after a gate bias step as well as significantly increased response and sensitivity at +2 V compared to 0 V. We propose an electric field-mediated change in oxygen surface coverage as the cause of this novel effect.
Practical Molecular Testing in a Clinical Genitourinary Service
Authors: Magers Martin J. , Cheng Liang 
Published: August 2019

Context.—Molecular testing is increasingly playing a key role in the diagnosis, prognosis, and treatment of neoplasms of the genitourinary system.Objective.—To provide a general overview of the clinically relevant molecular tests available for neoplasms of the genitourinary tract.Data Sources.—Relevant medical literature indexed on PubMed.Conclusions.—Understanding of the molecular oncology of genitourinary neoplasms is rapidly advancing, and the pathologist must be aware of the practical implications of molecular testing. While many genomic abnormalities are not yet clinically relevant, there is an increasing library of ancillary tests that may guide diagnosis, prognosis, and/or treatment of many neoplasms. Recurrent genomic abnormalities have been identified in many types of renal cell carcinoma, and some types of renal cell carcinoma are specifically defined by the molecular abnormality. Two major routes of developing urothelial carcinoma have been molecularly described. Recurrent translocations involving ETS family genes are found in approximately half of prostate cancer cases. Testicular germ cell tumors typically harbor i(12p). Penile neoplasms are often high-risk human papillomavirus–driven cancers. Nonetheless, even as genitourinary neoplasms are increasingly better understood at the molecular level, further research with eventual clinical validation is needed for optimal diagnosis, prognosis, and treatment of aggressive malignancies in the genitourinary tract.
Breast Cancer Biomarkers: Challenges in Routine Estrogen Receptor, Progesterone Receptor, and HER2/neu Evaluation
Authors: Jorns Julie M. 
Published: August 2019

Context.—Evaluation of estrogen receptor (ER), progesterone receptor (PR), and HER2/neu (HER2) biomarkers is standard of care for all cases of newly diagnosed invasive, recurrent, and metastatic breast cancer. Repeat analysis is also performed in select cases per College of American Pathologists/American Society of Clinical Oncology guidelines and other clinical indications. However, in specific scenarios, preanalytic and analytic variables may pose distinct challenges to testing.Objective.—To provide a review of select challenges in the testing of commonly performed breast cancer biomarkers ER, PR, and HER2 and outline best practices for overcoming these challenges.Data Sources.—Review of College of American Pathologists/American Society of Clinical Oncology recommendations, current literature, and personal experience of the author.Conclusions.—Attention must be given to specimen handling to ensure accurate ER, PR, and HER2 biomarker assessment and appropriate management of breast cancer patients.
Physiological and immunological responses of sea cucumber Apostichopus japonicus during desiccation and subsequent resubmersion
Authors: Hou Shiying , Jin Zewei , Jiang Wenwen , Chi Liang , Xia Bin , Chen Jinghua 
Published: August 2019

Desiccation is one of the extremely stressful situations experienced by aquatic animals, and sea cucumber usually suffers from desiccation stress during transportation without water. The present study was conducted to evaluate the effect of desiccation and subsequent resubmersion on physiological stress, oxidative damage, antioxidant status and non-specific immune response of Apostichopus japonicus, providing valuable information on the health management of sea cucumber culturing. Control and desiccation groups were set up, and each group has three replicates. After 1, 3 and 6 h of desiccation, individuals were resubmersed in aerated seawater for a 24 h recovery in three batches, which were represented as D1, D3 and D6, respectively. The results showed that glucose level in coelomic fluid of sea cucumber significantly decreased after desiccation, whereas lactate, cortisol and osmolality showed remarkable ascending trends. Thereafter, all stress parameters gently recovered towards normal levels as control group during 24 h resubmersion. The prolonged desiccation at D6 treatment induced the significant increases of malondialdehyde (MDA) and reactive oxygen species (ROS) contents, as well as relatively lower superoxide dismutase (SOD) and catalase (CAT) activities. During the period of desiccation and subsequent resubmersion, sea cucumber adjusted antioxidant defense to reduce the concentrations of MDA and ROS as a strategy for protecting against oxidative damage. Desiccation also had significant effects on non-specific immune parameters (total coelomocytes counts, TCC; complement C3; total nitric oxide synthase, T-NOS; lysozyme, LSZ; alkaline phosphatase, AKP) of A. japonicus, which could be recovered to some extent during resubmersion. In conclusion, less than 6 h of desiccation did not induce irreparable damage to sea cucumber, and was recommended for handling and shipping live sea cucumbers.
Bayesian Probability of Success in Clinical Trials
Authors: Liu Guanghan (Frank) , Heyse Joseph 
Published: August 2019

Abstract
Traditionally, power and sample size calculations for clinical trials are based on the assumed parameters that are typically estimated from previous studies. However, the variation of those estimates is not incorporated in the traditional methods. In this article, we provide an overview of Bayesian probability of success (POS), which accounts for the uncertainty of the design parameters in a Bayesian framework. The concepts of assurance or Bayesian POS are reviewed and illustrated with examples including POS for a single study, predictive power at interim analysis, and overall POS for a clinical program with multiple studies. Discussions are provided on how to use POS approach for evaluation of go/no‐go decision‐making and assessing the return on investment (ROI), and on the connection between POS and prediction models for clinical trial outcomes.
Assessment and Interpretation of Surface Wettability Based on Sessile Droplet Contact Angle Measurement: Challenges and Opportunities
Authors: Kung Chun Haow , Sow Pradeep Kumar , Zahiri Beniamin , Mérida Walter 
Published: August 2019

AbstractSurface wettability, a property that governs the interaction between the solid and liquid phases, is central in various biological systems and technological applications. A typical approach to assess the wetting interaction is based on the sessile droplet contact angle. Despite its experimental simplicity, caution is required in the measurement and interpretation of the sessile contact angle as a wettability metric. In this work, the major challenges related to the use of the sessile droplet contact angle for characterizing surface wetting behavior are reviewed. The complexity of interpreting surface wettability using the contact angle value arising from the following factors is discussed: the role of solid–liquid interfacial area and three‐phase contact line, the existence of multiple metastable states with a range of contact angle values, and the droplet size dependence of contact angles. An overview of the emerging alternative wetting evaluation techniques and parameters that can complement the sessile contact angle measurement is outlined.
Silver‐Catalyzed Radical Cascade Cyclization of Unactivated Alkenes towards Cyclopenta[c]quinolines
Authors: Sun Kai , Si Ya‐Feng , Chen Xiao‐Lan , Lv Qi‐Yan , Jiang Nan , Wang Shan‐Shan , Peng Yu‐Yu , Qu Ling‐Bo , Yu Bing 
Published: August 2019

AbstractA convenient radical cascade cyclization of aniline‐linked 1,7‐enynes with 1,3‐dicarbonyl compounds was developed to synthesize cyclopenta[c]quinolines in the presence of AgNO3/K2S2O8. A wide range of cyclopenta[c]quinolines were prepared in moderate to excellent yields.magnified image
What drives farmers’ willingness to adopt e‐commerce in rural China? The role of Internet use
Authors: Ma Wanglin , Zhou Xiaoshi , Liu Min 
Published: August 2019

AbstractThis letter investigates the factors that drive farmers’ willingness to adopt (WTA) e‐commerce, with a focus on the role of Internet use. The recursive bivariate probit model is applied to analyze data collected from rural China. The empirical results reveal that Internet use increases the likelihood of farmers’ WTA e‐commerce by 20%. Further, we show that the WTA effects of Internet use are heterogeneous between male and female household heads and among different regions.
Generierung und Anwendung des Hydroxid‐Trihydrat‐Anions, [OH(OH2)3]−, stabilisiert durch ein schwach koordinierendes Kation
Authors: Weitkamp Robin F. , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold 
Published: August 2019

AbstractDie Reaktion eines stark basischen Phosphazens (Schwesinger‐Base) mit Wasser lieferte das entsprechende metastabile Hydroxid‐Trihydrat‐Anion [OH(OH2)3]−. Dies ist das erste Hydroxid‐Solvat, das nicht mit einem Kation in Kontakt steht. Darüber hinaus stellt es eines der seltenen bekannten wasserstabilisierten Hydroxid‐Anionen dar. Die Thermolyse im Vakuum führt zur Zersetzung des Hydroxidsalzes und zur quantitativen Freisetzung der freien Phosphazenbase. Dieses Verhalten wurde für die Synthese der Schwesinger‐Base aus ihrem Hydrochloridsalz mit einem Anionenaustauscherharz in exzellenten Ausbeuten von über 97 % genutzt. Diese Deprotonierungsmethode kann auch für die phosphazenbasenkatalysierte Synthese des Ruppert‐Prakash‐Reagenzes Me3SiCF3 unter Verwendung von Fluoroform (HCF3) als Trifluormethylbaustein und Natriumhydroxid als formalem Deprotonierungsmittel verwendet werden.
Light‐Driven Intramolecular C−N Cross‐Coupling via a Long‐Lived Photoactive Photoisomer Complex
Authors: Jing Dong , Lu Cong , Chen Zhuo , Jin Songyang , Xie Lijuan , Meng Ziyi , Su Zhishan , Zheng Ke 
Published: August 2019

AbstractReported herein is a visible‐light‐driven intramolecular C−N cross‐coupling reaction under mild reaction conditions (metal‐ and photocatalyst‐free, at room temperature) via a long‐lived photoactive photoisomer complex. This strategy was used to rapidly prepare the N‐substituted polycyclic quinazolinone derivatives with a broad substrate scope (>50 examples) and further exploited to synthesize the natural products tryptanthrin, rutaecarpine, and their analogues. The success of gram‐scale synthesis and solar‐driven transformation, as well as promising tumor‐suppressing biological activity, proves the potential of this strategy for practical applications. Mechanistic investigations, including control experiments, DFT calculations, UV‐vis spectroscopy, EPR, and X‐ray single‐crystal structure of the key intermediate, provides insight into the mechanism.
Near‐Infrared Light‐Initiated Hybridization Chain Reaction for Spatially and Temporally Resolved Signal Amplification
Authors: Chu Hongqian , Zhao Jian , Mi Yongsheng , Zhao Yuliang , Li Lele 
Published: August 2019

AbstractPrecise control over signal amplification provides unparalleled opportunities for diverse applications. However, spatiotemporally controlled amplification has not been realized because of the lack of a design methodology. The aim of this study was thus to develop a conceptual approach for remote control over signal amplification at a chosen time and site in living cells. This system was constructed by re‐engineering the functional units of the hybridization chain reaction (HCR) and combination with upconversion photochemistry, thus resulting in an activatable HCR with the high spatial and temporal precision of near‐infrared (NIR) light. As a proof of concept, we demonstrate the spatially and temporally resolved amplified imaging of messenger RNA (mRNA) with ultrahigh sensitivity in vitro and in vivo. Furthermore, by using a system targeting subcellular sites we have developed a new technique for NIR‐initiated amplified imaging of mRNA exclusively within a specific organelle.
Synthesis and structure–activity relationships of pyrazolo‐[3,4‐b]pyridine derivatives as adenosine 5'‐monophosphate‐activated protein kinase activators
Authors: Zheng Bifeng , Peng Yajun , Wu Weihong , Ma Junlong , Zhang Yuzhao , Guo Yu , Sun Shengjie , Chen Zhuo , Li Qianbin , Hu Gaoyun 
Published: August 2019

AbstractA series of pyrazolo[3,4‐b]pyridine derivatives were designed, synthesized, and evaluated for their activation activity toward adenosine 5'‐monophosphate‐activated protein kinase (AMPK). According to the enzyme activity, the pyrazole N‒H exposure and para substitution on the diphenyl group were proved to be essential for the activation potency. Compound 17f showed equal activation compared with A‐769662. In the molecular modeling study, compound 17f exhibited important hydrogen bond interaction with Lys29, Asp88, and Arg83. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assays on the NRK‐49F cell line showed that potent enzyme activators could effectively inhibit cell proliferation, especially for 17f (EC50 [AMPKα1γ1β1] = 0.42 μM, efficacy = 79%; IC50 [NRK‐49F cell line] = 0.78 μM). These results might provide new insights to explore novel AMPK activators.
Frontiers in Halogen and Chalcogen‐Bond Donor Organocatalysis
Authors: Bamberger Julia , Ostler Florian , Mancheño Olga García 
Published: August 2019

AbstractNon‐covalent molecular interactions on the basis of halogen and chalcogen bonding represent a promising, powerful catalytic activation mode. However, these “unusual” non‐covalent interactions are typically employed in the solid state and scarcely exploited in catalysis. In recent years, an increased interest in halogen and chalcogen bonding has been awaken, as they provide profound characteristics that make them an appealing alternative to the well‐explored hydrogen bonding. Being particularly relevant in the binding of “soft” substrates, the similar strength to hydrogen bonding interactions and its higher directionality allows for solution‐phase applications with halogen and chalcogen bonding as the key interaction. In this mini‐review, the special features, state‐of‐the‐art and key examples of these so‐called σ‐hole interactions in the field of organocatalysis are presented.
Ab Initio Study of the Stepwise versus Concerted Fragmentation Pathways in Microhydrated Thymine Radical Cations
Authors: Semmeq Abderrahmane , Monari Antonio , Badawi Michael , Ouaskit Said 
Published: August 2019

AbstractThymine radiation‐induced fragmentation is characterised by ring opening and the loss of HNCO/NCO. These pathways have been investigated using DFT calculations in the presence of zero, one and two water molecules. In addition to the already characterised stepwise fragmentation mechanism, we propose a novel concerted pathway reported here for the first time. We show that both the stepwise and concerted mechanisms are competitive with activation energies of 2.05 eV and 2.00 eV, respectively, in the gas phase. The effect of microhydration on these mechanisms are examined based on the most stable conformations found by an exploration of the potential energy surface performed by using DFT‐based ab initio molecular dynamics. Microhydration is also accompanied by an increase in the activation energies, with respect to gas phase, amounting to 0.47 eV—an increase that is associated to a stabilising effect of water in agreement with recent experimental studies. However, we also point out that this effect is greatly dependent on the specific water arrangement around thymine and could be limited to only 0.13 eV for some configurations.