bluuebunny/crossref_metadata_2025 huggingface dataset:
Uranium isotope evidence for an expansion of marine anoxia during the end‐Triassic extinction
Authors: Jost Adam B. , Bachan Aviv , van de Schootbrugge Bas , Lau Kimberly V. , Weaver Karrie L. , Maher Kate , Payne Jonathan L.
Published: July 2017

The end‐Triassic extinction coincided with an increase in marine black shale deposition and biomarkers for photic zone euxinia, suggesting that anoxia played a role in suppressing marine biodiversity. However, global changes in ocean anoxia are difficult to quantify using proxies for local anoxia. Uranium isotopes (δ238U) in CaCO3 sediments deposited under locally well‐oxygenated bottom waters can passively track seawater δ238U, which is sensitive to the global areal extent of seafloor anoxia due to preferential reduction of 238U(VI) relative to 235U(VI) in anoxic marine sediments. We measured δ238U in shallow‐marine limestones from two stratigraphic sections in the Lombardy Basin, northern Italy, spanning over 400 m. We observe a ∼0.7‰ negative excursion in δ238U beginning in the lowermost Jurassic, coeval with the onset of the initial negative δ13C excursion and persisting for the duration of subsequent high δ13C values in the lower‐middle Hettangian stage. The δ238U excursion cannot be realistically explained by local mixing of uranium in primary marine carbonate and reduced authigenic uranium. Based on output from a forward model of the uranium cycle, the excursion is consistent with a 40–100‐fold increase in the extent of anoxic deposition occurring worldwide. Additionally, relatively constant uranium concentrations point toward increased uranium delivery to the oceans from continental weathering, which is consistent with weathering‐induced eutrophication following the rapid increase in pCO2 during emplacement of the Central Atlantic Magmatic Province. The relative timing and duration of the excursion in δ238U implies that anoxia could have delayed biotic recovery well into the Hettangian stage.
Ionospheric annual anomaly—New insights to the physical mechanisms
Authors: Sai Gowtam V. , Tulasi Ram S.
Published: July 2017

The ionospheric annual anomaly or nonseasonal anomaly of the ionosphere is characterized by globally increased ionization in December solstice than in June solstice. Though this phenomenon was reported several decades ago, the causal mechanisms have not been fully understood till today. In this paper, the F2 layer peak electron density (NmF2) data from Formosa satellite 3/Constellation Observing System for Meteorology, Ionosphere, and Climate‐radio occultation observations during the low solar activity year 2009 were systematically analyzed to investigate the physical mechanisms responsible for annual anomaly and its local time, latitudinal, and longitudinal variability. It is found that the annual anomaly is primarily dominant at Southern Hemisphere at all local times, with significant enhancements at equatorial ionization anomaly crest latitudes during noon to afternoon hours and at high latitudes during nighttimes. The annual anomaly in Northern Hemisphere occurs with relatively smaller magnitudes and confined only to morning to early afternoon hours (08–14 LT). This study brings out the important roles of effective neutral winds due to the geomagnetic field configuration and the offset between geomagnetic equator and subsolar point for the enhanced plasma density in the Southern Hemisphere during December that majorly contributes to the ionospheric annual anomaly. These results provide new insights to the responsible mechanisms behind the ionospheric annual anomaly and its local time latitudinal, and longitudinal variation
A corotation electric field model of the Earth derived from Swarm satellite magnetic field measurements
Authors: Maus Stefan
Published: July 2017

Rotation of the Earth in its own geomagnetic field sets up a primary corotation electric field, compensated by a secondary electric field of induced electrical charges. For the geomagnetic field measured by the Swarm constellation of satellites, a derivation of the global corotation electric field inside and outside of the corotation region is provided here, in both inertial and corotating reference frames. The Earth is assumed an electrical conductor, the lower atmosphere an insulator, followed by the corotating ionospheric E region again as a conductor. Outside of the Earth's core, the induced charge is immediately accessible from the spherical harmonic Gauss coefficients of the geomagnetic field. The charge density is positive at high northern and southern latitudes, negative at midlatitudes, and increases strongly toward the Earth's center. Small vertical electric fields of about 0.3 mV/m in the insulating atmospheric gap are caused by the corotation charges located in the ionosphere above and the Earth below. The corotation charges also flow outward into the region of closed magnetic field lines, forcing the plasmasphere to corotate. The electric field of the corotation charges further extends outside of the corotating regions, contributing radial outward electric fields of about 10 mV/m in the northern and southern polar caps. Depending on how the magnetosphere responds to these fields, the Earth may carry a net electric charge.
N′‐(3‐Aminopropyl)‐N′‐dodecylpropan‐1,3‐diamin [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated N‐(3‐aminopropyl)‐N‐dodecylpropane‐1,3‐diamine [
2372‐82‐9
] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available unpublished study reports and publications are described in detail. Critical effects are degeneration of heart muscle cells and lympho‐histiocytic infiltrations in the skeletal muscles of male rats. No NOAEL could be derived for these effects. The LOAEL is 4 mg/kg body weight. A NAEL of 1.3 mg/kg body weight was extrapolated and a MAK value of 0.05 mg/m
3
for the inhalable fraction could be derived. The derivation of the MAK value is conservative because the determined oral absorption is very low and for the inhalative absorption a default value of 100 % is assumed due to a lack of experimental data. N‐(3‐Aminopropyl)‐N‐dodecylpropane‐1,3‐diamine is basic and therefore corrosive to rabbit skin, hence an irritation potential for the respiratory tract has to be assumed. No inhalation studies are available. Compared to several primary, secondary and tertiary amines which have MAK values between 1 and 13 mg/m
3
, the basicity of N‐(3‐aminopropyl)‐N‐dodecylpropane‐1,3‐diamine is almost the same or less. Therefore, a MAK value of 0.05 mg/m
3
should protect against local irritating effects. As the critical effect is systemic, the substance has been classified in Peak Limitation Category II. An excursion factor of 8 is set as the half‐life in blood is at least 28.5 hours. The NOAELs for developmental toxicity in rats and rabbits are 22.5 and 9 mg/kg body weight and day, respectively, which can be scaled to concentrations of 1 and 0.66 mg/m
3
at the workplace. Thus, there is no reason to fear damage to the embryo or foetus when the MAK value is observed and the substance is classified in Pregnancy Risk Group C. N‐(3‐Aminopropyl)‐N‐dodecylpropane‐1,3‐diamine is not genotoxic or carcinogenic. The potential of contact sensitization in humans cannot be definitely assessed because of the corrosive character. The substance is not a contact sensitizer in guinea pigs. Skin contact is not expected to contribute significantly to systemic toxicity
Benzoesäure, und Alkalibenzoate [MAK Value Documentation in German language, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2017

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated benzoic acid and alkali benzoates [65‐85‐0;532‐32‐1;582‐25‐2] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available study reports and publications are described in detail.

Based on the NOAEC for lung toxicity of 12.6 mg/m3in a 4‐week inhalation study in rats, a MAK value of 0.5 mg/m3for the strongly irritating benzoic acid has been derived. Alkali benzoates are only slightly irritating. In consideration of the systemic NOAEC of 250 mg/m3in another 4‐week inhalation study in rats exposed to benzoic acid, a MAK value for alkali benzoates of 10 mg/m3(inhalable fraction), calculated as benzoate, has been derived. Benzoic acid and alkali benzoates are assigned to Peak Limitation Category II, because systemic effects are critical, and excursion factors of 2 for alkali benzoates and of 4 for benzoic acid are set.

In a developmental toxicity study with sodium benzoate in rats, foetotoxic effects were observed at 1850 mg/kg body weight and day. The NOAEL was 1340 mg/kg body weight and day. In mice, rabbits and hamsters, no developmental toxicity from sodium benzoate was detected in the foetuses of dams treated with up to 175, 250 or 300 mg/kg body weight and day, respectively. The differences between the NOAEL for rats, mice, rabbits and hamsters scaled to an inhalation concentration at the workplace and the MAK value are considered so large that damage to the embryo or foetus is unlikely when the MAK value is observed. Therefore, benzoic acid and alkali benzoates are classified in Pregnancy Risk Group C.

Benzoic acid and alkali benzoates are not regarded as genotoxic. Long‐term studies with sodium benzoate in rats and mice were of limited validity and do not point to a carcinogenic potential. Sensitization is not expected as benzoic acid and alkali benzoates are not contact sensitizers in animal studies. Immediate contact reactions observed in animals and humans are based on a non‐immunologic mechanism. Skin contact is expected to contribute significantly to the systemic toxicity. Therefore, benzoic acid and alkali benzoates are designated with an “H”.
Trypsin and Chymotrypsin [MAK Value Documentation, 2016]
Authors: van Kampen V. , Hartwig A. ,   MAK Commission
Published: July 2017

Trypsin (EC 3.4.21.4) and Chymotrypsin (EC 3.4.21.1) are proteolytic pancreatic enzymes which are secreted as inactive precursors trypsinogen and chymotrypsinogen, respectively. They have several clinical pharmacological as well as laboratory applications and they are used in protein chemistry, especially in the preparation of insulin. Exposure to enzyme dusts has long been known to cause occupational immediate hypersensitivities of the airways. Also trypsin and chymotrypsin are potential inhalable sensitizers; cases of specific airway sensitization caused by trypsin and chymotrypsin containing products could be shown clearly by several studies. Positive skin prick and challenge tests as well as specific IgE antibodies have been described. Since these results and the clinical symptoms usually matched well, an immunological mechanism of action is suggested. There is no clear evidence of allergic cell‐mediated late type eczematous skin reactions. Trypsin and chymotrypsin are designated with “Sa” (for substances causing airway sensitization) but not with “Sh” (for skin‐sensitizing substances).
Renal‐Clearable PEGylated Porphyrin Nanoparticles for Image‐Guided Photodynamic Cancer Therapy
Authors: Cheng Liang , Jiang Dawei , Kamkaew Anyanee , Valdovinos Hector F. , Im Hyung‐Jun , Feng Liangzhu , England Christopher G. , Goel Shreya , Barnhart Todd E. , Liu Zhuang , Cai Weibo
Published: July 2017

Nanomaterials with renal clearance from the body within a reasonable timescale have shown great promises in the area of nanomedicine recently. However, the integration of theranostic and renal clearance properties into a single ultrasmall nanostructure remains a great challenge. Herein, meso‐tetra(4‐carboxyphenyl)porphyrin (TCPP) structure is utilized as a model, for the first time using noninvasive dynamic positron emission tomography (PET) imaging to investigate the balance of the renal clearance and tumor uptake behaviors of polyethylene glycol (PEG)‐modified porphyrin nanoparticles (TCPP‐PEG) with various molecular weights. This study finds that TCPP‐PEG nanoparticles with larger molecular weight show higher tumor uptake due to the enhanced permeability and retention effect, while the lower ones tend to be better for renal clearance. Based on dynamic PET and fluorescence dual‐modal imaging modalities, the TCPP‐PEG10K nanoparticles seem to be an excellent choice for the balance of renal clearance and tumor retention. In vitro and in vivo photodynamic therapy confirms an excellent therapeutic efficacy. Therefore, this work presents a simplified approach to fabricate and select biocompatible multifunctional TCPP‐PEG‐based theranostic agents with renal clearance behavior, which highlights the clinical application potential of TCPP‐PEG nanoparticles as theranostic probes for imaging‐guided cancer therapy.
A Hollow‐Structured CuS@Cu2S@Au Nanohybrid: Synergistically Enhanced Photothermal Efficiency and Photoswitchable Targeting Effect for Cancer Theranostics
Authors: Deng Xiaoran , Li Kai , Cai Xuechao , Liu Bin , Wei Yi , Deng Kerong , Xie Zhongxi , Wu Zhijian , Ma Ping'an , Hou Zhiyao , Cheng Ziyong , Lin Jun
Published: July 2017

It is of great importance in drug delivery to fabricate multifunctional nanocarriers with intelligent targeting properties, for cancer diagnosis and therapy. Herein, hollow‐structured CuS@Cu2S@Au nanoshell/satellite nanoparticles are designed and synthesized for enhanced photothermal therapy and photoswitchable targeting theranostics. The remarkably improved photothermal conversion efficiency of CuS@Cu2S@Au under 808 nm near‐infrared (NIR) laser irradiation can be explained by the reduced bandgap and more circuit paths for electron transitions for CuS and Cu2S modified with Au nanoparticles, as calculated by the Vienna ab initio simulation package, based on density functional theory. By modification of thermal‐isomerization RGD targeting molecules and thermally sensitive copolymer on the surface of nanoparticles, the transition of the shielded/unshielded mode of RGD (Arg‐Gly‐Asp) targeting molecules and shrinking of the thermally sensitive polymer by NIR photoactivation can realize a photoswitchable targeting effect. After loading an anticancer drug doxorubicin in the cavity of CuS@Cu2S@Au, the antitumor therapy efficacy is greatly enhanced by combining chemo‐ and photothermal therapy. The reported nanohybrid can also act as a photoacoustic imaging agent and an NIR thermal imaging agent for real‐time imaging, which provides a versatile platform for multifunctional theranostics and stimuli‐responsive targeted cancer therapy.
Highly Luminescent 2D‐Type Slab Crystals Based on a Molecular Charge‐Transfer Complex as Promising Organic Light‐Emitting Transistor Materials
Authors: Park Sang Kyu , Kim Jin Hong , Ohto Tatsuhiko , Yamada Ryo , Jones Andrew O. F. , Whang Dong Ryeol , Cho Illhun , Oh Sangyoon , Hong Seung Hwa , Kwon Ji Eon , Kim Jong H. , Olivier Yoann , Fischer Roland , Resel Roland , Gierschner Johannes , Tada Hirokazu , Park Soo Young
Published: July 2017

A new 2:1 donor (D):acceptor (A) mixed‐stacked charge‐transfer (CT) cocrystal comprising isometrically structured dicyanodistyrylbenzene‐based D and A molecules is designed and synthesized. Uniform 2D‐type morphology is manifested by the exquisite interplay of intermolecular interactions. In addition to its appealing structural features, unique optoelectronic properties are unveiled. Exceptionally high photoluminescence quantum yield (ΦF ≈ 60%) is realized by non‐negligible oscillator strength of the S1 transition, and rigidified 2D‐type structure. Moreover, this luminescent 2D‐type CT crystal exhibits balanced ambipolar transport (µh and µe of ≈10−4 cm2 V−1 s−1). As a consequence of such unique optoelectronic characteristics, the first CT electroluminescence is demonstrated in a single active‐layered organic light‐emitting transistor (OLET) device. The external quantum efficiency of this OLET is as high as 1.5% to suggest a promising potential of luminescent mixed‐stacked CT cocrystals in OLET applications.
A Double‐Stimuli‐Responsive Fluorescent Center for Monitoring of Food Spoilage based on Dye Covalently Modified EuMOFs: From Sensory Hydrogels to Logic Devices
Authors: Xu Xiao‐Yu , Lian Xiao , Hao Ji‐Na , Zhang Chi , Yan Bing
Published: July 2017

Unsafe food is a huge threat to human health and the economy, and detecting food spoilage early is an ongoing and imperative need. Herein, a simple and effective strategy combining a fluorescence sensor and one‐to‐two logic operation is designed for monitoring biogenic amines, indicators of food spoilage. Sensors (methyl red@lanthanide metal–organic frameworks (MR@EuMOFs)) are created by covalently modifying MR into NH2‐rich EuMOFs, which have a high quantum yield (48%). A double‐stimuli‐responsive fluorescence center is produced via energy transfer from the ligands to Eu3+ and MR. Portable sensory hydrogels are obtained by dispersing and solidifying MR@EuMOFs in water‐phase sodium salt of carboxy methyl cellulose (CMC‐Na). The hydrogels exhibit a color transition upon “smelling” histamine (HI) vapor. This transition and shift in the MR‐based emission peak are closely related to the HI concentration. Using the HI concentration as the input signal and the two fluorescence emissions as output signals, an advanced analytical device based on a one‐to‐two logic gate is constructed. The four output combinations, NOT (0, 1), YES (1, 0), PASS 1 (1, 1), and PASS 0 (0, 0), allow the direct analysis of HI levels, which can be used for real‐time food‐freshness evaluation. The novel strategy suggested here may be a new application for a molecular logic system in the sensing field.
Synthesis of Dihydrophosphaisocoumarins through a Palladium‐Catalyzed Oxidative Cyclization of Arylphosphonic Acid Monoethyl Esters with 1,3‐Dienes
Authors: Son Jeong‐Yu , Kim Hyunseok , Jeon Woo Hyung , Baek Yonghyeon , Seo Boram , Um Kyusik , Lee Kooyeon , Lee Phil Ho
Published: July 2017

An efficient synthetic method for the selective preparation of dihydrophosphaisocoumarins and their derivatives was developed through a palladium‐catalyzed oxidative cyclization reaction of a wide range of arylphosphonic acid monoethyl esters with activated and unactivated 1,3‐dienes, including 1‐aryl‐substituted 1,3‐dienes and 1‐alkyl‐substituted 1,3‐dienes, thus opening a new avenue for the synthesis of phosphaheterocyclic compounds.

magnified image
A Zinc–Cerium Cell for Energy Storage Using a Sodium‐Ion Exchange Membrane
Authors: Yu Xingwen , Manthiram Arumugam
Published: July 2017

The redox flow battery with a zinc–cerium (Zn–Ce) chemistry has been developed for about 10 years. Under the traditional battery development principle, a Zn–Ce cell has to be operated with an acidic electrolyte to sustain the redox reactions of Ce compounds (Ce(IV) ↔ Ce(III)) at the positive electrode. However, the use of an acidic electrolyte poses a serious corrosion issue on Zn and limits the electrochemical potential of the Zn electrode. Here, a novel Zn–Ce battery is presented with an alkaline electrolyte at the negative electrode side (anolyte) and an acidic electrolyte at the positive electrode side (catholyte). The two different‐pH liquid electrolytes are separated by a sodium‐ion (Na+‐ion) solid‐electrolyte separator. The Na+‐ion, shuttling through the solid electrolyte, is not involved in the redox reactions but rather acts as an ionic mediator to sustain the redox reactions at the negative and positive electrodes. Use of an alkaline anolyte not only eliminates the Zn corrosion problem but also enhances the cell voltage of the Zn–Ce system. In addition, the use of a solid electrolyte prevents the crossover of the liquid electrode materials (Ce(IV) or Ce(III)) and circumvents the concerns of Zn dendrite penetration.
Single Nucleotide Polymorphism Genotyping in Single‐Molecule Electronic Circuits
Authors: He Gen , Li Jie , Qi Chuanmin , Guo Xuefeng
Published: July 2017

Establishing low‐cost, high‐throughput, simple, and accurate single nucleotide polymorphism (SNP) genotyping techniques is beneficial for understanding the intrinsic relationship between individual genetic variations and their biological functions on a genomic scale. Here, a straightforward and reliable single‐molecule approach is demonstrated for precise SNP authentication by directly measuring the fluctuations in electrical signals in an electronic circuit, which is fabricated from a high‐gain field‐effect silicon nanowire decorated with a single hairpin DNA, in the presence of different target DNAs. By simply comparing the proportion difference of a probe‐target duplex structure throughout the process, this study implements allele‐specific and accurate SNP detection. These results are supported by the statistical analyses of different dynamic parameters such as the mean lifetime and the unwinding probability of the duplex conformation. In comparison with conventional polymerase chain reaction and optical methods, this convenient and label‐free method is complementary to existing optical methods and also shows several advantages, such as simple operation and no requirement for fluorescent labeling, thus promising a futuristic route toward the next‐generation genotyping technique.
Safety of union home care aides in Washington State
Authors: Schoenfisch Ashley L. , Lipscomb Hester , Phillips Leslie E.
Published: July 2017

Introduction

A rate‐based understanding of home care aides’ adverse occupational outcomes related to their work location and care tasks is lacking.

Methods

Within a 30‐month, dynamic cohort of 43 394 home care aides in Washington State, injury rates were calculated by aides’ demographic and work characteristics. Injury narratives and focus groups provided contextual detail.

Results

Injury rates were higher for home care aides categorized as female, white, 50 to <65 years old, less experienced, with a primary language of English, and working through an agency (versus individual providers). In addition to direct occupational hazards, variability in workload, income, and supervisory/social support is of concern.

Conclusions

Policies should address the roles and training of home care aides, consumers, and managers/supervisors. Home care aides’ improved access to often‐existing resources to identify, manage, and eliminate occupational hazards is called for to prevent injuries and address concerns related to the vulnerability of this needed workforce.
Selfenergy Effect on the Magnetic Ordering Transition in the Mono‐ and Bilayer Honeycomb Hubbard Model
Authors: Honerkamp Carsten
Published: July 2017

We investigate the impact of electron self‐energy corrections on potential antiferromagnetic ordering instabilities in mono‐ and bilayer graphene, modeled by a Hubbard‐type lattice model with onsite interactions among the electrons, using a self‐consistent random phase approximation (RPA). In qualitative agreement with earlier studies we find that the electronic interactions cause non‐Fermi liquid behavior at low energies. In self‐consistent RPA, the transition scales for antiferromagnetic ordering are renormalized significantly by these self‐energy effects, both for interaction‐driven and temperature‐driven cases.
From Diffusive to Ballistic Transport in Etched Graphene Constrictions and Nanoribbons
Authors: Somanchi Sowmya , Terrés Bernat , Peiro Julian , Staggenborg Maximilian , Watanabe Kenji , Taniguchi Takashi , Beschoten Bernd , Stampfer Christoph
Published: July 2017

Graphene nanoribbons and constrictions are envisaged as fundamental components of future carbon‐based nanoelectronic and spintronic devices. At nanoscale, electronic effects in these devices depend heavily on the dimensions of the active channel and the nature of edges. Hence, controlling both these parameters is crucial to understand the physics in such systems. This review is about the recent progress in the fabrication of graphene nanoribbons and constrictions in terms of low temperature quantum transport. In particular, recent advancements using encapsulated graphene allowing for quantized conductance and future experiments towards exploring spin effects in these devices are presented. The influence of charge carrier inhomogeneity and the important length scales which play a crucial role for transport in high quality samples are also discussed.
Catalytic Reductive Pinacol‐Type Rearrangement of Unactivated 1,2‐Diols through a Concerted, Stereoinvertive Mechanism
Authors: Drosos Nikolaos , Cheng Gui‐Juan , Ozkal Erhan , Cacherat Bastien , Thiel Walter , Morandi Bill
Published: July 2017

A catalytic pinacol‐type reductive rearrangement reaction of internal 1,2‐diols is reported herein. Several scaffolds not usually amenable to pinacol‐type reactions, such as aliphatic secondary–secondary diols, undergo the transformation well without the need for prefunctionalization. The reaction uses a simple boron catalyst and two silanes and proceeds through a concerted, stereoinvertive mechanism that enables the preparation of highly enantiomerically enriched products. Computational studies have been used to rationalize the preference for migration over direct deoxygenation.
Enantioselective Tandem Cyclization of Alkyne‐Tethered Indoles Using Cooperative Silver(I)/Chiral Phosphoric Acid Catalysis
Authors: Zhu Yugen , He Wei , Wang Wei , Pitsch Chloe E. , Wang Xiaotai , Wang Xiang
Published: July 2017

Reported is the enantioselective synthesis of tetracyclic indolines using silver(I)/chiral phosphoric acid catalysis. A variety of alkyne‐tethered indoles are suitable for this process. Mechanistic studies suggest that the in situ generated silver(I) chiral phosphate activates both the alkyne and the indole nucleophile in the initial cyclization step through an intermolecular hydrogen bond and the phosphate anion promotes proton transfer. In addition, further modifications of the cyclization products enabled stereochemistry–function studies of a series of bioactive indolines.
Enhancing signals from buried Roman structures in Magnetometer data by combining continuous wavelet transform and tensor voting
Authors: Jungmann Matthias , Dolenz Heimo , Clauser Christoph , Berlage Thomas
Published: July 2017

In this paper, a processing chain is proposed for enhancing larger‐scale building structures in magnetometer data using the continuous wavelet transform for extracting the horizontal location, depth, and homogeneity (or shape) of subsurface objects. Even though the values estimated from our data do not clearly describe the archaeological site, they are used as a filter step for removing objects whose depth and homogeneity fall outside a predefined range. This yields a binary map, where valid points represent the horizontal source positions of magnetic anomalies. In a second step, curvilinear subsets of points are identified on a larger scale by the tensor voting framework indicating archaeological relevant structures, such as arcs and lines. Here, a point casts votes on neighbouring points and their values depend on the distance, and relative position of the points. All votes are summed up and the final value discriminates, whether a certain point (and therefore a magnetic source) is part of a salient curve (e.g. arc, line). Thresholding removes points with lower values while keeping those with larger values. Although the result shows many geometric features, it still needs to be combined with other data, e.g. from aerial photography or excavations. In combination, the extracted features continue those structures in the aerial photograph, thus expanding the knowledge about the archaeological site.
Perfluoroalkylated Calix[4]pyrroles: Fluoride Ion Extraction from an Aqueous Medium
Authors: Maji Sinchan , Mandal Debaprasad
Published: July 2017

Octaalkenyl calix[4]pyrrole ((CH2=CH(CH2)2)8C4P) is highly useful for the postfunctionalization of different calix[4]pyrroles with desired functionalities. Functionalization with perfluoroalkyl chains [CF3(CF2)n; Rfn] gave perfluoroalkyl calix[4]pyrroles (Rfn(CH2)4)8C4P; n=6, 8), having >60 % fluorine content, which created a hydrophobic environment inside the calix[4]pyrrole cavity and recognized fluoride and chloride ions in solution as well as in the solid state. The fluoride ion is extracted efficiently from aqueous CsF and TBAF solutions by using (Rf6(CH2)4)8C4P, as droplets. The fluorinated chain generated a hydrophobic environment which broke the hydration shell associated with the anion and separated out fluoride ions as droplets from aqueous medium. Furthermore, the fluoride ions competitively replaced chloride ions from the (Rf6(CH2)4)8C4P cavity.
Quantitative determination of trigonelline in mouse serum by means of hydrophilic interaction liquid chromatography–MS/MS analysis: Application to a pharmacokinetic study
Authors: Szczesny Damian , Bartosińska Ewa , Jacyna Julia , Patejko Małgorzata , Siluk Danuta , Kaliszan Roman
Published: July 2017

Trigonelline is a pyridine alkaloid found in fenugreek seeds and coffee beans. Most of the previous studies are concerned with the quantification of trigonelline along with other constituents in coffee herbs or beverages. Only a few have focused on its determination in animal or human tissues by applying different modes of HPLC with UV or MS detection. The aim of the study was to develop and validate a fast and simple method for trigonelline determination in serum by the use of hydrophilic interaction liquid chromatography (HILIC) with ESI‐MS/MS detection. Separation of trigonelline was achieved on a Kinetex HILIC column operated at 35°C with acetonitrile–ammonium formate (10 mm, pH = 3) buffer mixture (55:45, v/v) as the mobile phase. The developed method was successfully applied to determine trigonelline concentration in mouse serum after intravenous administration of 10 mg/kg. The developed assay is sensitive (limit of detection = 1.5 ng/mL, limit of quantification = 5.0 ng/mL) and linear in a concentration range from 5.0 to 250.0 ng/mL. Sample preparation is limited to deproteinization, centrifugation and filtration. The application of the HILIC mode of chromatography with MS detection and selection of deuterated trigonelline as internal standard allowed a rapid and precise method of trigonelline quantification to be to developed.
Trabectedin is a promising antitumor agent potentially inducing melanocytic differentiation for clear cell sarcoma
Authors: Nakai Takaaki , Imura Yoshinori , Tamiya Hironari , Yamada Shutaro , Nakai Sho , Yasuda Naohiro , Kaneko Keiko , Outani Hidetatsu , Takenaka Satoshi , Hamada Kenichiro , Myoui Akira , Araki Nobuhito , Ueda Takafumi , Itoh Kazuyuki , Yoshikawa Hideki , Naka Norifumi
Published: July 2017

Clear cell sarcoma is an aggressive soft tissue sarcoma and highly resistant to conventional chemotherapy and radiation therapy. This devastating disease is defined by EWSR1‐ATF1 fusion gene resulting from chromosomal translocation t(12;22)(q13;q12) and characterized by melanocytic differentiation. A marine‐derived antineoplastic agent, trabectedin, inhibits the growth of myxoid liposarcoma and Ewing sarcoma by causing adipogenic differentiation and neural differentiation, respectively. In this study, we examined the antitumor effects and mechanism of action of trabectedin on human clear cell sarcoma cell lines. We showed that trabectedin decreased the cell proliferation of five clear cell sarcoma cell lines in a dose‐dependent manner in vitro and reduced tumor growth of two mouse xenograft models. Flow cytometry and immunoblot analyses in vitro and immunohistochemical analysis in vivo revealed that trabectedin‐induced G2/M cell cycle arrest and apoptosis. Furthermore, trabectedin increased the expression of melanocytic differentiation markers along with downregulation of ERK activity in vitro and the rate of melanin‐positive cells in vivo. These results suggest that trabectedin has potent antitumor activity against clear cell sarcoma cells by inducing cell cycle arrest, apoptosis, and, in part, by promoting melanocytic differentiation through inactivation of ERK signaling. Our present study indicates that trabectedin is a promising differentiation‐inducing agent for clear cell sarcoma.
Transcriptome analysis in primary colorectal cancer tissues from patients with and without liver metastases using next‐generation sequencing
Authors: Wang Sen , Zhang Chuan , Zhang Zhiyuan , Qian Wenwei , Sun Ye , Ji Bing , Zhang Yue , Zhu Chunyan , Ji Dongjian , Wang Qingyuan , Sun Yueming
Published: July 2017

Colorectal cancer (CRC) is the third most common cancer worldwide and liver metastases are the leading cause of death in patients with CRC. In this study, we performed next‐generation sequencing profiling on primary colorectal tumor tissues obtained from three CRC patients with liver metastases and three CRC patients without liver metastases to identify differentially expressed genes (DEGs) that might be responsible for the metastases process. After filtering 2690 DEGs, comprising 996 upregulated and 1694 downregulated RNAs, 22 upregulated and 73 downregulated DEGs were identified. Gene ontology (GO) and pathway analyses were performed to determine the underlying mechanisms. Single‐organism process (biological process), cell (cellular component), and binding (molecular function) were the most related terms in the GO analysis. We selected the top 13 upregulated and top 12 downregulated genes by fold change to verify their differential expression using quantitative real‐time reverse transcription PCR (qRT‐PCR) and immunohistochemistry (IHC). The validation showed that three most significantly upregulated DEGs were HOXD10, UGT2A3, and SLC13A2, whereas the five most significantly downregulated DEGs were SPP1, CXCL8, MMP3, OSM, and CXCL6, respectively. These aberrantly expressed genes may play pivotal roles in promoting or inhibiting metastases. Further studies are required to determine the functions of DEGs to promote the diagnosis of metastases and provide novel chemotherapy targets.
Characterization and Influence of Green Synthesis of Nano‐Sized Zinc Complex with 5‐Aminolevulinic Acid on Bioactive Compounds of Aniseed
Authors: Tavallali Vahid , Rahmati Sadegh , Rowshan Vahid
Published: July 2017

A new water soluble zinc‐aminolevulinic acid nano complex (n[Zn(ALA)2]), which was characterized by TEM, IR, and EDX spectra, has been prepared via sonochemical method under green conditions in water. In the current study, the effectiveness of foliar Zn amendment using synthetic Zn‐ALA nano complex, as a new introduced Zn‐fertilizer here, was evaluated. As the model plant, Pimpinella anisum, the most valuable spice and medicinal plant grown in warm regions, was used. By using zinc nano complex, further twenty compounds were obtained in the essential oil of anise plants. Application of 0.2% (w/v) Zn‐ALA nano complex increased the levels of (E)‐anethole, β‐bisabolene, germacrene D, methyl chavicol, and α‐zingiberene in the essential oil. Nano Zn complex at the rate of 0.2% induced considerable high phenolic compounds and zinc content of shoots and seeds. Chlorogenic acid had the highest level between four detected phenolic compounds. The maximum antioxidant activity was monitored through the application of Zn nano complex. According to the results, nanoscale nutrients can be provided with further decreased doses for medicinal plants. Using Zn‐ALA nano complex is a new and efficient method to improve the pharmaceutical and food properties of anise plants.
Non‐Precious Metal/Metal Oxides and Nitrogen‐Doped Reduced Graphene Oxide based Alkaline Water‐Electrolysis Cell
Authors: Vineesh Thazhe Veettil , Sekar Archana , Rajappa Sivamathini , Pal Shubhadeep , Alwarappan Subbiah , Narayanan Tharangattu N.
Published: July 2017

The development of strategies for water‐electrolysis half‐cell‐reaction catalysts without the use of precious metals/metal oxides and the synergistic compilation of catalysts for the full‐cell fabrication are receiving tremendous scientific attention. Here, alkaline water‐electrolysis full cells are developed with novel spongy catalysts for both anode and cathode reactions, such as Co3O4 nitrogen‐doped reduced graphene oxide (Co3O4/NrGO) composite sponge for oxygen evolution reaction (OER) and nickel nitrogen‐doped reduced graphene oxide (NiNrGO) for hydrogen evolution reaction (HER). The performance of the developed OER catalyst, Co3O4/NrGO, is compared with that of the commercial one (IrO2) in alkaline medium with a common benchmark cathode catalyst (Pt) and an augmented full‐cell performance is shown from this novel combination (320 mAcm−2 at an operating voltage of 1.9 V for Co3O4/NrGO, with 199 mA cm−2 for IrO2). A water‐electrolysis full cell is developed without the use of HER catalyst Pt, but rather using a porous spongy catalyst, NiNrGO, having a low operating potential with a high stability (270 mA cm−2 at an operating voltage of 1.9 V with a stability tested for more than 9 h). This work opens up the possibilities of designing lightweight water‐electrolysis cells without the use of commercial benchmark precious‐metal catalysts.
Efficient Conversion of CO2 to Methane Photocatalyzed by Conductive Black Titania
Authors: Yin Guoheng , Bi Qingyuan , Zhao Wei , Xu Jijian , Lin Tianquan , Huang Fuqiang
Published: July 2017

One of the major challenges encountered in CO2 utilization is the development of available and cost‐efficient catalysts with sufficient activity, selectivity, and stability for the generation of useful methane. Here, conductive black titania, TiO2−x, is found to be efficient in photocatalyzing the reduction of CO2 to CH4. This unique material comprises a crystalline core–amorphous shell structure (TiO2@TiO2−x) with numerous surface oxygen vacancies, which facilitates the adsorption and chemical activation of CO2 molecules. Under full solar irradiation, the optimized 500‐TiO2−x material with narrowed band gap and intermediate states below the conduction band tail exhibits a high space‐time yield of CH4 of 14.3 μmol g−1 h−1, with 74 % selectivity and excellent photostability. The present findings can make a significant contribution, not only to develop the surface electron‐modified black TiO2 catalyst to boost photocatalytic efficiency, but also to establish a really viable and convenient CH4 production process for CO2 conversion and renewable solar energy storage.
Homogeneous Gas‐Liquid Distribution for Monolithic Structures via a Needle Distributor
Authors: Meitzner Christine , Hilpmann Gerd , Schäfer Thomas , Haase Stefan , Lange Matthias , Hampel Uwe
Published: July 2017

Structured catalysts are a widely discussed approach for process intensification of chemical multiphase reactors. But equal to common catalyst structures, homogeneous educt distribution along the catalytic surface is mandatory for high reactor performance. Especially monolithic structures require a homogeneous initial fluid distribution. A novel distribution concept for gas‐liquid flow through arbitrary channel matrices is presented. It is based on the injection principle where gas and liquid are inserted directly into the channels. A prototype for different cell densities was built and tested by various measurement techniques: gravimetry, X‐ray tomography, and an optical fiber sensor. Additionally, the flow regime per channel was detected as equal to single‐channel conditions.
An Eulerian‐Eulerian Computational Approach for Simulating Descending Gas‐Liquid Flows in Reactors with Solid Foam Internals
Authors: Subramanian Kumar , Zalucky Johannes , Schubert Markus , Lucas Dirk , Hampel Uwe
Published: July 2017

Chemical reactors with new types of packings, such as metallic and ceramic open‐pore foams, have become subjects of scientific and engineering interest in the past decades. For trickle bed reactors, the new packing types provide favorable conditions, such as high specific surface area and low pressure drop, which are believed to contribute to an intensification of mass and heat transfer. Here, an attempt was made to model and predict the flow pattern and liquid distribution in a trickle bed reactor with solid foams, using computational fluid dynamics. A three‐dimensional model based on the relative permeability approach was adopted, where gas and liquid phases flow co‐currently downwards through a reactor with SiSiC ceramic foams as internals. The influence of both mechanical and capillary dispersion was included and studied in detail for foams of two different pore densities and for different initial distribution patterns.
Urea Decomposition in Selective Catalytic Reduction on V2O5/WO3/TiO2 Catalyst in Diesel Exhaust
Authors: Goldbach Martin , Roppertz Andreas , Langenfeld Philipp , Wackerhagen Mandy , Füger Sven , Kureti Sven
Published: July 2017

Selective catalytic reduction (SCR) of NOx by AdBlue and NH3 on monolithic V2O5/WO3/TiO2 catalyst was studied under flow conditions realistic for diesel exhaust. The tests provided same standard and fast SCR for AdBlue and NH3 from 150 to 350 °C. For standard urea‐SCR, axial concentration profiles were checked by monoliths with different lengths evidencing incomplete conversion of urea and isocyanic acid at low temperatures. But SCR was not clearly affected by under‐stoichiometric NH3 as substantiated by kinetic analysis. However, above 250 °C, SCR was limited by internal mass transport indicated by Weisz‐Prater criterion and lower activation barrier. Formation of deposits was investigated at 175 °C and below showing some urea around the nozzle, whereas cyanuric acid and biuret additionally formed around the catalyst.
Dioxygen Binding to Protonated Heme in the Gas Phase, an Intermediate Between Ferric and Ferrous Heme
Authors: Shafizadeh Niloufar , Soorkia Satchin , Grégoire Gilles , Broquier Michel , Crestoni Maria‐Elisa , Soep Benoît
Published: July 2017

With a view to characterizing the influence of the electronic structure of the Fe atom on the nature of its bond with dioxygen (O2) in heme compounds, a study of the UV/Vis action spectra and binding energies of heme‐O2 molecules has been undertaken in the gas phase. The binding reaction of protonated ferrous heme [FeII‐hemeH]+ with O2 has been studied in the gas phase by determining the equilibrium of complexed [FeII‐hemeH(O2)]+ with uncomplexed protonated heme in an ion trap at controlled temperatures. The binding energy of O2 to the Fe atom of protonated ferrous heme was obtained from a van't Hoff plot. Surprisingly, this energy (1540±170 cm−1, 18.4±2 kJ mol−1) is intermediate between those of ferric heme and ferrous heme. This result is interpreted in terms of a delocalization of the positive charge over the porphyrin cycle, such that the Fe atom bears a fractional positive charge. The resulting electron distribution on the Fe atom differs notably from that of a purely low‐spin ferrous heme [FeII‐heme(O2)] complex, as deduced from its absorption spectrum. It also differs from that of ferric heme [FeIII‐heme(O2)]+, as evidenced by the absorption spectra. Protonated heme creates a specific bond that cannot accommodate strong σ donation.
Assembly of Preformed Gold Nanoparticles onto Thermoresponsive Poly(N‐isopropylacrylamide)‐Based Microgels on the Basis of Au‐thiol Chemistry
Authors: Wang Tao , Song Yanan , Jin Liang , Li Jiaxi , Gao Yu , Shi Shan
Published: July 2017

The assembly of preformed gold nanoparticles (AuNPs) onto the thermoresponsive poly(N‐isopropylacrylamide) (PNIPAM)‐based microgels was achieved on the basis of the driving force of Au‐thiol chemistry. The loading amount of AuNPs can be controlled by varying the ratio of AuNPs relative to PNIPAM‐based microgels. The as‐prepared PNIPAM/Au hybrid microgels showed well‐defined reversible swelling/deswelling transition in response to temperature, which can be employed to tune the plasmonic property of hybrid microgels. As the temperature was increased, the position of localized surface plasmon resonance (LSPR) band red‐shifted to some extent mainly due to the increase in the local refractive index around AuNPs.
Synthesis‐oriented double‐loop feedback model
Authors: van Hartingsveldt Koen , Verhoeven Chris. J. M. , van Roermund Arthur H. M.
Published: July 2017

This paper presents a new feedback model that focuses on the synthesis rather than the analysis of feedback amplifiers. First, a single‐loop synthesis‐oriented feedback model is developed that enables the full synthesis of such amplifiers in a hierarchical and systematic way. This model is subsequently extended to a double‐loop synthesis model, so that also feedback amplifiers with a characteristic input or output impedance—employing two feedback loops—can be synthesized through the same systematic approach. That these new models are suitable for synthesis lies in the fact that they map directly to the circuit level, such that the intended, asymptotic behavior as well as the various individual contributors to the deviation from this intended behavior, like finite loop gain, non‐ideal input and output impedances of the forward gain block, direct feed‐through and attenuations outside the feedback loop(s), are clearly distinguished and can be assigned to the responsible sections of the network. For this purpose, the double‐loop synthesis model makes the transfers of the two feedback networks explicitly visible, so that it gives immediate insight in how to design these networks to get the required signal transfer and characteristic impedance. Copyright © 2017 John Wiley & Sons, Ltd.
A Three‐Year Longitudinal Study of Reading and Spelling Difficulty in Chinese Developmental Dyslexia: The Matter of Morphological Awareness
Authors: Tong Xiuhong , McBride Catherine , Lo Jason Chor Ming , Shu Hua
Published: July 2017

In the present study, we used a three‐time point longitudinal design to investigate the associations of morphological awareness to word reading and spelling in a small group of those with and without dyslexia taken from a larger sample of 164 Hong Kong Chinese children who remained in a longitudinal study across ages 6, 7 and 8. Among those 164 children, 15 had been diagnosed as having dyslexia by professional psychologists, and 15 other children manifested average reading ability and had been randomly selected from the sample for comparison. All children were administered a battery of tasks including Chinese character recognition, word dictation, morphological awareness, phonological awareness and rapid automatized naming. Multivariate analysis of variance and predictive discriminate analysis were performed to examine whether the dyslexic children showed differences in the cognitive‐linguistic tasks in comparison with controls. Results suggested that the dyslexic groups had poorer performance in morphological awareness and RAN across all 3 years. However, phonological awareness was not stable in distinguishing the groups. Findings suggest that morphological awareness is a relatively strong correlate of spelling difficulties in Chinese, but phonological awareness is not. Copyright © 2017 John Wiley & Sons, Ltd.