bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigations of temporal and spatial distribution of precursors SO2 and NO2 vertical columns in the North China Plain using mobile DOAS
Authors: Wu Fengcheng , Xie Pinhua , Li Ang , Mou Fusheng , Chen Hao , Zhu Yi , Zhu Tong , Liu Jianguo , Liu Wenqing 
Published: February 2018

Abstract. Recently, Chinese cities have suffered severe events of haze air pollution, particularly in the North China Plain (NCP). Investigating the temporal and spatial distribution of pollutants, emissions, and pollution transport is necessary to better understand the effect of various sources on air quality. We report on mobile differential optical absorption spectroscopy (mobile DOAS) observations of precursors SO2 and NO2 vertical columns in the NCP in the summer of 2013 (from 11 June to 7 July) in this study. The different temporal and spatial distributions of SO2 and NO2 vertical column density (VCD) over this area are characterized under various wind fields. The results show that transport from the southern NCP strongly affects air quality in Beijing, and the transport route, particularly SO2 transport on the route of Shijiazhuang–Baoding–Beijing, is identified. In addition, the major contributors to SO2 along the route of Shijiazhuang–Baoding–Beijing are elevated sources compared to low area sources for the route of Dezhou–Cangzhou–Tianjin–Beijing; this is found using the interrelated analysis between in situ and mobile DOAS observations during the measurement periods. Furthermore, the discussions on hot spots near the city of JiNan show that average observed width of polluted air mass is 11.83 and 17.23 km associated with air mass diffusion, which is approximately 60 km away from emission sources based on geometrical estimation. Finally, a reasonable agreement exists between the Ozone Monitoring Instrument (OMI) and mobile DOAS observations, with a correlation coefficient (R2) of 0.65 for NO2 VCDs. Both datasets also have a similar spatial pattern. The fitted slope of 0.55 is significantly less than unity, which can reflect the contamination of local sources, and OMI observations are needed to improve the sensitivities to the near-surface emission sources through improvements of the retrieval algorithm or the resolution of satellites.
Research on Technogene/Anthropocene in Brazil
Authors: França Junior Pedro , Korb Carina Cristiane , Brannstrom Christian 
Published: February 2018

This research aims to present a bibliographical review of the research related to the Technogene /Anthropocene in Brazil. The methodology consisted of bibliographic search in academic Google and in university library sites. The research was categorized according to environment and the geomorphological process: alluvial deposits and accelerated erosion; mining; dam siltation; urban and coastal environments. Of more than 200 publications pertinent to the theme, twenty-nine were selected to be synthesized. The research highlighted the heterogeneity of the knowledge that has already been produced on the Technogene / Anthropocene in Brazil. They corroborate the idea of humans as geological agents, but each study situates the geologic agency of humans in an environment with intrinsic geographic characteristics that provide the technogenic variations in the surface and sub-surface.
Basin of small rivers as an indicator of the environment state
Authors: Mitryasova Olena , Pohrebennyk Volodymyr 
Published: February 2018

Background. Small rivers are an important component of the natural environment. Water resources of small rivers are part of the shared water resources and are often the main and sometimes the only one source of local water. Small rivers are the regulators of the water regime of the landscapes, the factors for maintaining balance and redistribution of moisture. The aim is analysis of interaction between parameters of the quality of the water environment like conductivity and nitrates on the example of natural waters of small rivers. Objects are small rivers Bìst and Rosselle (Saardand lands, Germany) and Mertvovod (Mykolaiv region, Ukraine).
Methods. We used the method of correlative analysis which is effective and efficient for the determination of connections between the parameters of water quality that helps to identify sources of pollution, as well as interpret phenomena, forecast the situation related to the change in the quality of natural waters. The hydrochemical monitoring data were obtained from autonomous automated stations that are located on the rivers Bist, Rossel and Mertvovod. We investigated the following correlation dependencies between such combinations of natural waters quality parameters: nitrates and conductivity. Monitoring data are processed using software MS Excel; correlation dependence was defined using the CORREL.
Results. Correlation value is changed in the range from −1 to + 1 that demonstrates the indirect and direct dependence between the selected parameters. If the value is closer to +1, this means the presence of a strong connection, if closer to 0 – weak. The time periods for the calculation of the correlation between the parameters of natural waters quality is selected: 4, 8, 16 and 24 hours respectively. The following time periods allow the best to trace and predict changes in the natural aquatic environment. Correlation analysis of the concentration of nitrates and conductivity showed that for r. Bìst and r. Rosselle dominates is the positive value of the correlation between the study parameters, which proves their strong interaction. However, at certain concentrations of nitrate-ions observed custom phenomenon of sharp decrease in correlation to the «-1», which is explained by the Onsager equation, namely an excess concentration of nitrates is associated with erosion of different types of fertilizers from the fields as a result of rainfall.
Discussion. Trend analysis of the studied indicators of Mertvovod water quality was conducted on an average value of each indicator (pH, phosphates, nitrates, BOD, soluble oxygen). We used trend analysis for Mertvovod because we did not have enough data in time. Found a significant increase in phosphates with time. This can be explained by the arrival of various surface active substances and, to a lesser extent, the lack of quality sewage treatment facilities. Positive changes are founded in water object that is related to a decrease in the value of BOD.
Evaluating the Influence of Plate Boundary Friction and Mantle Viscosity on Plate Velocities
Authors: Osei Tutu A. , Sobolev S. V. , Steinberger B. , Popov A. A. , Rogozhina I. 
Published: February 2018

AbstractLithospheric plates move over the low‐viscosity asthenosphere balancing several forces, which generate plate motions. We use a global 3‐D lithosphere‐asthenosphere model (SLIM3D) with visco‐elasto‐plastic rheology coupled to a spectral model of mantle flow at 300 km depth to quantify the influence of intra‐plate friction and asthenospheric viscosity on plate velocities. We account for the brittle‐ductile deformation at plate boundaries (yield stress) using a plate boundary friction coefficient to predict the present‐day plate motion and net rotation of the lithospheric plates. Previous modeling studies have suggested that small friction coefficients (
, yield stress
MPa) can lead to plate tectonics in models of mantle convection. Here we show that in order to match the observed present‐day plate motion and net rotation, the frictional parameter must be less than 0.05. We obtain a good fit with the magnitude and orientation of the observed plate velocities (NUVEL‐1A) in a no‐net‐rotation (NNR) reference frame with
and a minimum asthenosphere viscosity of
Pas to 1020 Pas. Our estimates of net rotation (NR) of the lithosphere suggest that amplitudes
(
/Ma), similar to most observation‐based estimates, can be obtained with asthenosphere viscosity cutoff values of
Pas to
Pas and friction coefficients
.
Dynamical Characterization of a Low Oxygen Submesoscale Coherent Vortex in the Eastern North Atlantic Ocean
Authors: Pietri A. , Karstensen J. 
Published: February 2018

AbstractA submesoscale coherent vortex (SCV) with a low oxygen core is characterized from underwater glider and mooring observations from the eastern tropical North Atlantic, north of the Cape Verde Islands. The eddy crossed the mooring with its center and a 1 month time series of the SCV's hydrographic and upper 100 m currents structure was obtained. About 45 days after, and ∼100 km west, the SCV frontal zone was surveyed in high temporal and spatial resolution using an underwater glider. Satellite altimetry showed the SCV was formed about 7 months before at the Mauritanian coast. The SCV was located at 80–100 m depth, its diameter was ∼100 km and its maximum swirl velocity ∼0.4 m s−1. A Burger number of 0.2 and a vortex Rossby number 0.15 indicate a flat lens in geostrophic balance. Mooring and glider data show in general comparable dynamical and thermohaline structures, the glider in high spatial resolution, the mooring in high temporal resolution. Surface maps of chlorophyll concentration suggest high productivity inside and around the SCV. The low potential vorticity (PV) core of the SCV is surrounded by filamentary structures, sloping down at different angles from the mixed layer base and with typical width of 10–20 km and a vertical extent of 50–100 m.
MitochondrialDNARepair and Genome Evolution
Authors: Christensen Alan C. 
Published: February 2018

AbstractIn plants, replicating the mitochondrial genome is probably a very minor expenditure of energy compared to the other costly activities of the cell, including replicating the much larger nuclear genome, transcription, protein synthesis and active transport. This chapter discusses the angiosperm mitochondrial genomes. The mutational burden hypothesis (MBH) explains an inverse correlation between mutation rate and genome size. The types of DNA damage that occur in mitochondria, the available mechanisms of repair, and selection on the repaired DNA products is taken into account in understanding the patterns of plant mitochondrial genome evolution. Analysis of the evolutionary patterns seen in plant mitochondrial genomes led to hypotheses of what mechanisms of DNA repair are available in plant mitochondria. The mechanism of repair ensures accurate inheritance of genes and has the side‐effect of allowing duplications, rearrangements and the accumulation of junk DNA.
A Yolk–Shell Nanoplatform for Gene‐Silencing‐Enhanced Photolytic Ablation of Cancer
Authors: Guo Ranran , Tian Ye , Yang Yueqi , Jiang Qin , Wang Yajun , Yang Wuli 
Published: February 2018

AbstractNoninvasive near‐infrared (NIR) light responsive therapy is a promising cancer treatment modality; however, some inherent drawbacks of conventional phototherapy heavily restrict its application in clinic. Rather than producing heat or reactive oxygen species in conventional NIR treatment, here a multifunctional yolk–shell nanoplatform is proposed that is able to generate microbubbles to destruct cancer cells upon NIR laser irradiation. Besides, the therapeutic effect is highly improved through the coalition of small interfering RNA (siRNA), which is codelivered by the nanoplatform. In vitro experiments demonstrate that siRNA significantly inhibits expression of protective proteins and reduces the tolerance of cancer cells to bubble‐induced environmental damage. In this way, higher cytotoxicity is achieved by utilizing the yolk–shell nanoparticles than treated with the same nanoparticles missing siRNA under NIR laser irradiation. After surface modification with polyethylene glycol and transferrin, the yolk–shell nanoparticles can target tumors selectively, as demonstrated from the photoacoustic and ultrasonic imaging in vivo. The yolk–shell nanoplatform shows outstanding tumor regression with minimal side effects under NIR laser irradiation. Therefore, the multifunctional nanoparticles that combining bubble‐induced mechanical effect with RNA interference are expected to be an effective NIR light responsive oncotherapy.
Gellan Gum Hydrogels with Enzyme‐Sensitive Biodegradation and Endothelial Cell Biorecognition Sites
Authors: da Silva Lucília P. , Jha Amit K. , Correlo Vitor M. , Marques Alexandra P. , Reis Rui L. , Healy Kevin E. 
Published: February 2018

AbstractThe survival of a biomaterial or tissue engineered construct is mainly hampered by the deficient microcirculation in its core, and limited nutrients and oxygen availability to the implanted or colonizing host cells. Aiming to address these issues, we herein propose bioresponsive gellan gum (GG) hydrogels that are biodegradable by metalloproteinase 1 (MMP‐1) and enable endothelial cells adhesion and proliferation. GG is chemically functionalized with divinyl sulfone (DVS) and then biofunctionalized with thiol cell‐adhesive peptides (T1 or C16) to confer GG endothelial cell biorecognition cues. Biodegradable hydrogels are then formed by Michael type addition of GGDVS or/and peptide‐functionalized GGDVS with a dithiol peptide crosslinker sensitive to MMP‐1. The mechanical properties (6 to 5580 Pa), swelling (17 to 11), MMP‐1‐driven degradation (up to 70%), and molecules diffusion coefficients of hydrogels are tuned by increasing the polymer amount and crosslinking density. Human umbilical cord vein endothelial cells depict a polarized elongated morphology when encapsulated within T1‐containing hydrogels, in contrast to the round morphology observed in C16‐containing hydrogels. Cell organization is favored as early as 1 d of cell culture within the T1‐modified hydrogels with higher concentration of peptide, while cell proliferation is higher in T1‐modified hydrogels with higher modulus. In conclusion, biodegradable and bioresponsive GGDVS hydrogels are promising endothelial cell responsive materials that can be used for vascularization strategies.
Advances in Carbon Nanotubes–Hydrogel Hybrids in Nanomedicine for Therapeutics
Authors: Vashist Arti , Kaushik Ajeet , Vashist Atul , Sagar Vidya , Ghosal Anujit , Gupta Y. K. , Ahmad Sharif , Nair Madhavan 
Published: February 2018

AbstractIn spite of significant advancement in hydrogel technology, low mechanical strength and lack of electrical conductivity have limited their next‐level biomedical applications for skeletal muscles, cardiac and neural cells. Host–guest chemistry based hybrid nanocomposites systems have gained attention as they completely overcome these pitfalls and generate bioscaffolds with tunable electrical and mechanical characteristics. In recent years, carbon nanotube (CNT)‐based hybrid hydrogels have emerged as innovative candidates with diverse applications in regenerative medicines, tissue engineering, drug delivery devices, implantable devices, biosensing, and biorobotics. This article is an attempt to recapitulate the advancement in synthesis and characterization of hybrid hydrogels and provide deep insights toward their functioning and success as biomedical devices. The improved comparative performance and biocompatibility of CNT–hydrogels hybrids systems developed for targeted biomedical applications are addressed here. Recent updates toward diverse applications and limitations of CNT hybrid hydrogels is the strength of the review. This will provide a holistic approach toward understanding of CNT‐based hydrogels and their applications in nanotheranostics.
Multimodality Imaging of Silica and Silicon Materials In Vivo
Authors: Karaman Didem Şen , Sarparanta Mirkka P. , Rosenholm Jessica M. , Airaksinen Anu J. 
Published: February 2018

AbstractRecent progress in the development of silica‐ and silicon‐based multimodality imaging nanoprobes has advanced their use in image‐guided drug delivery, and the development of novel systems for nanotheranostic and diagnostic applications. As biocompatible and flexibly tunable materials, silica and silicon provide excellent platforms with high clinical potential in nanotheranostic and diagnostic probes with well‐defined morphology and surface chemistry, yielding multifunctional properties. In vivo imaging is of great value in the exploration of methods for improving site‐specific nanotherapeutic delivery by silica‐ and silicon‐based drug‐delivery systems. Multimodality approaches are essential for understanding the biological interactions of nanotherapeutics in the physiological environment in vivo. The aim here is to describe recent advances in the development of in vivo imaging tools based on nanostructured silica and silicon, and their applications in single and multimodality imaging.
Functionalization of Metal–Organic Frameworks for Photoactive Materials
Authors: Hao Jina , Xu Xiaoyu , Fei Honghan , Li Liangchun , Yan Bing 
Published: February 2018

AbstractMetal–organic frameworks (MOFs) are intriguing platforms with multiple functionalities. Additional functionalization of MOFs generates novel materials for various applications. Here, three main topics are examined regarding the functionalization of MOFs for use as photoactive materials. The first is chemical approaches for postsynthetic modification of the metal clusters and organic linkers in MOFs; that is, sites on pore surfaces and chemical trapping of photoactive moieties within the pores, which create materials with chemical functionalities for water splitting and CO2 reduction by light. The second topic focuses on the functionalization of MOFs for photochemical response and the versatile applications of such materials. State‐of‐the‐art research on functionalizing MOFs through photochemical reactions on the pore surface and within the pores as guests is also summarized. The third topic introduces the functionalization of MOFs for photofunctional materials, including photoluminescent tuning and integration, photoluminescent LED devices and barcodes, and photophysical applications for chemical sensing. Finally, conclusions and perspectives on the fields are given.
Nanosculpting of Atomically Thin 2D Materials for Site‐Specific Photoluminescence Modulation
Authors: Kumar Pawan , Balakrishnan Viswanath 
Published: February 2018

AbstractNanomanufacturing techniques to generate patterned structures of mechanically exfoliated two‐dimensional (2D) materials by lithography, gas phase etching, and electron beam/ion beam irradiation have gained significant interest. Such control over patterning in monolayers of WS2 and MoS2 will aid the development of novel, miniaturized devices for nanoelectronic and nanophotonic applications. In this study a controlled site‐specific nanosculpting of WS2 and MoS2 monolayers grown on SiO2/Si substrate by atmospheric pressure chemical vapor deposition (CVD) is reported. Nanoindentation by sharp diamond Berkovich tip with ≈50 nm radius is used to make periodic arrays of indents to spatially modulate photoluminescence (PL) intensity up to more than an order of changes. To demonstrate systematic strain variation, relatively shallow indentations are also carried out with conical tip of ≈5 µm radius. Raman and PL measurements carried out near the indented region indicate a systematic variation in strain with respect to load and location. Further, nanosculpting to design nonperiodic structures is achieved by performing nanoindentation in close proximity to each other with detailed Raman and PL mapping. The developed approach of indentation‐based site‐specific nanosculpting of 2D materials and modulation of PL intensity provides direct pathways to design a variety of patterned structures and nanoscale devices for photodetector applications.
γ‐Regioselective Functionalization of 3‐Alkenylindoles via 1,6‐Addition to Extended Alkylideneindolenine Intermediates
Authors: Bertuzzi Giulio , Lenti Lucia , Giorgiana Bisag Denisa , Fochi Mariafrancesca , Petrini Marino , Bernardi Luca 
Published: February 2018

AbstractAlkylideneindolenines are widely employed key electrophilic intermediates for the α‐functionalization of the C‐3 side chain of indoles. However, the reactivity of their extended (vinylogous) counterparts has not been carefully explored so far. These intermediates can undergo 1,4‐ or 1,6‐addition with functionalization at α‐ or γ‐position of the side chain, resulting in regioisomeric mixtures of products. This work demonstrates that a complete γ‐regioselectivity can be achieved in the reaction of 3‐indol‐3‐yl allylic alcohols with various nucleophiles. This process is catalysed by just 1 mol% zinc(II) triflate at room temperature and entails the 1,6‐selective addition of the nucleophile to an extended protonated alkylideneindolenine generated in situ. Indoles, pyrroles, anilines and thiols can be efficiently used as nucleophilic partners for this reaction, delivering the corresponding 3‐vinyl substituted, γ‐functionalised indole products in moderate to good yields.magnified image
Direct Observation of an Imidoylnitrene: Photochemical Formation of PhC(=NMe)−N and Me−N from 1‐Methyl‐5‐phenyltetrazole
Authors: Abe Manabu , Bégué Didier , Santos‐Silva Hugo , Dargelos Alain , Wentrup Curt 
Published: February 2018

AbstractThe imidoylnitrene 8, N‐methyl‐C‐phenylimidoylnitrene, has been generated by laser photolysis of 1‐methyl‐5‐phenyltetrazole 6 at 5 K and characterized by its ESR spectrum (|D/hc|=0.9602, |E/hc|=0.0144 cm−1). In addition, the triplet excited states of 6 and of 2‐methyl‐5‐phenyltetrazole 11 were also observed by ESR spectroscopy in the 5 K matrices (6: |D/hc|=0.123 cm−1, E/hc=0.0065 cm−1, 11: |D/hc|=0.126 cm−1, |E/hc|=0.0056 cm−1). The imidoylnitrene 8 is unstable both thermally (disappearing at 80 K) and photochemically (disappearing on continued irradiation at 266 nm). Methyl(phenyl)carbodiimide is the end product of photolysis.
Scalable, Stereocontrolled Formal Syntheses of (+)‐Isoschizandrin and (+)‐Steganone: Development and Applications of Palladium(II)‐Catalyzed Atroposelective C−H Alkynylation
Authors: Liao Gang , Yao Qi‐Jun , Zhang Zhuo‐Zhuo , Wu Yong‐Jie , Huang Dan‐Ying , Shi Bing‐Feng 
Published: February 2018

AbstractDibenzocyclooctadiene lignans are an interesting class of molecules because of their unique structure based on an axially chiral biaryl moiety as well as their significant biological activity. Herein, we describe the development of a palladium‐catalyzed atroposelective C−H alkynylation and its application in gram‐scale, stereocontrolled formal syntheses of (+)‐isoschizandrin and (+)‐steganone. tert‐Leucine was identified as an efficient, catalytic transient chiral auxiliary. A wide range of enantiomerically enriched biaryl compounds were prepared by this approach in good yields (up to 99 %) with excellent enantioselectivity (up to >99 % ee).