bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrothermal fluid venting in the offshore sector of Campi Flegrei caldera: A geochemical, geophysical, and volcanological study
Authors: Di Napoli R. , Aiuppa A. , Sulli A. , Caliro S. , Chiodini G. , Acocella V. , Ciraolo G. , Di Vito M.A. , Interbartolo F. , Nasello C. , Valenza M. 
Published: October 2016

AbstractThe ongoing unrest at the Campi Flegrei caldera (CFc) in southern Italy is prompting exploration of its poorly studied offshore sector. We report on a multidisciplinary investigation of the Secca delle Fumose (SdF), a submarine relief known since antiquity as the largest degassing structure of the offshore sector of CFc. We combined high‐resolution morphobathymetric and seismostratigraphic data with onshore geological information to propose that the present‐day SdF morphology and structure developed during the initial stages of the last CFc eruption at Monte Nuovo in AD 1538. We suggest that the SdF relief stands on the eastern uplifted border of a N‐S‐trending graben‐like structure formed during the shallow emplacement of the Monte Nuovo feeding dike. We also infer that the high‐angle bordering faults that generated the SdF relief now preferentially allow the ascent of hot brines (with an equilibrium temperature of 179°C), thereby sustaining hydrothermal degassing on the seafloor. Systematic vertical seawater profiling shows that hydrothermal seafloor venting generates a sizeable CO2, pH, and temperature anomaly in the overlying seawater column. Data for the seawater vertical profile can be used to estimate the CO2 and energy (heat) outputs from the SdF area at ∼50 tons/d (∼0.53 kg/s) and ∼80 MW, respectively. In view of the cause‐effect relationship with the Monte Nuovo eruption, and the substantial gas and energy outputs, we consider that the SdF hydrothermal system needs to be included in monitoring programs of the ongoing CFc unrest.
Volcano dome dynamics at Mount St. Helens: Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets
Authors: Salzer Jacqueline T. , Thelen Weston A. , James Mike R. , Walter Thomas R. , Moran Seth , Denlinger Roger 
Published: October 2016

AbstractThe surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity‐ and gas‐driven processes, and the development and distribution of internal dome structures. Here we study short‐term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic monitoring network. We use Digital Image Correlation (DIC) to compute the displacement field between successive images and compare the results to the occurrence and characteristics of seismic events during a 6 week period of dome growth in 2006. The results reveal that dome growth at Mount St. Helens was repeatedly interrupted by short‐term meter‐scale downward displacements at the dome surface, which were associated in time with low‐frequency, large‐magnitude seismic events followed by a tremor‐like signal. The tremor was only recorded by the seismic stations closest to the dome. We find a correlation between the magnitudes of the camera‐derived displacements and the spectral amplitudes of the associated tremor. We use the DIC results from two cameras and a high‐resolution topographic model to derive full 3‐D displacement maps, which reveals internal dome structures and the effect of the seismic activity on daily surface velocities. We postulate that the tremor is recording the gravity‐driven response of the upper dome due to mechanical collapse or depressurization and fault‐controlled slumping. Our results highlight the different scales and structural expressions during growth and disintegration of lava domes and the relationships between seismic and deformation signals.
Polycrystal anelasticity at near‐solidus temperatures
Authors: Yamauchi Hatsuki , Takei Yasuko 
Published: October 2016

AbstractElasticity, anelasticity, and viscosity of polycrystalline aggregates were measured at the near‐solidus temperatures ranging from below to above the solidus temperature (Tm). The result shows that the mechanical effects of the partial melting are twofold; changes just below the solidus temperature in the absence of melt and changes at the solidus temperature due to the onset of partial melting. As homologous temperature (T/Tm) increases from about 0.92 to 1, high‐frequency part of the attenuation spectrum significantly grows. Viscosity of the grain boundary diffusion creep is also reduced in this temperature range. These changes are caused by a solid‐state mechanism and have a large amplitude even for the samples which can generate very small amounts of melt at the solidus temperature. At the onset of melting, further increases in the elastic, anelastic, and viscous compliances occur. These changes are caused by the direct effects of the melt phase and are very small for the samples with very small melt fractions. Mechanical properties of a partially molten aggregate are determined by these twofold changes, and when melt fraction is small, the former changes are dominant. We performed a parameterization of the present experimental results and applied the obtained empirical formula to the seismic tomographic data in the upper mantle. The present model explains well the steep reduction of the seismic shear wave velocity in the oceanic lithosphere just below the solidus temperature.
Evaluation of streamflow simulation results of land surface models in GLDAS on the Tibetan plateau
Authors: Bai Peng , Liu Xiaomang , Yang Tiantian , Liang Kang , Liu Changming 
Published: October 2016

AbstractThe Global Land Data Assimilation System (GLDAS) project estimates long‐term runoff based on land surface models (LSMs) and provides a potential way to solve the issue of nonexistent streamflow data in gauge‐sparse regions such as the Tibetan Plateau (TP). However, the reliability of GLDAS runoff data must be validated before being practically applied. In this study, the streamflows simulated by four LSMs (CLM, Noah, VIC, and Mosaic) in GLDAS coupled with a river routing model are evaluated against observed streamflows in five river basins on the TP. The evaluation criteria include four aspects: monthly streamflow value, seasonal cycle of streamflow, annual streamflow trend, and streamflow component partitioning. The four LSMs display varying degrees of biases in monthly streamflow simulations: systematic overestimations are found in the Noah (1.74 ≤ bias ≤ 2.75) and CLM (1.22 ≤ bias ≤ 2.53) models, whereas systematic underestimations are observed in the VIC (0.36 ≤ bias ≤ 0.85) and Mosaic (0.34 ≤ bias ≤ 0.66) models. The Noah model shows the best performance in capturing the temporal variation in monthly streamflow and the seasonal cycle of streamflow, while the VIC model performs the best in terms of bias statistics. The Mosaic model provides the best performance in modeling annual runoff trends and runoff component partitioning. The possible reasons for the different performances of the LSMs are discussed in detail. In order to achieve more accurate streamflow simulations from the LSMs in GLDAS, suggestions are made to further improve the accuracy of the forcing data and parameterization schemes in all models.
By‐Product‐Catalyzed Redox‐Neutral Sulfenylation/Deiodination/Aromatization of Cyclic Alkenyl Iodides with Sulfonyl Hydrazides
Authors: Yang Fu‐Lai , Gui Yang , Yu Bang‐Kui , Jin You‐Xiang , Tian Shi‐Kai 
Published: October 2016

AbstractA by‐product‐catalyzed redox‐neutral process has been established through tandem sulfenylation/deiodination/aromatization of cyclic alkenyl iodides with sulfonyl hydrazides. In the absence of external catalysts and additives a range of 4‐iodo‐1,2‐dihydronaphthalenes reacted with sulfonyl hydrazides to give structurally diverse 2‐naphthyl thioethers in good yields. Mechanistic studies showed that at an early stage sulfonyl hydrazides decomposed completely to thiosulfonates and disulfides and at a late stage the resulting thiosulfonates underwent tandem sulfenylation/deiodination/aromatization with 4‐iodo‐1,2‐dihydronaphthalenes involving a [1,5]‐sigmatropic hydrogen shift. Importantly, iodine was generated as a by‐product from 4‐iodo‐1,2‐dihydronaphthalenes upon heating and served as a catalyst for the decomposition of sulfonyl hydrazides and subsequent formation of 2‐naphthyl thioethers.magnified image
Selective Enzymatic Transformation to Aldehydes in vivo by Fungal Carboxylate Reductase from Neurospora crassa
Authors: Schwendenwein Daniel , Fiume Giuseppe , Weber Hansjörg , Rudroff Florian , Winkler Margit 
Published: October 2016

AbstractThe enzymatic reduction of carboxylic acids is in its infancy with only a handful of biocatalysts available to this end. We have increased the spectrum of carboxylate‐reducing enzymes (CARs) with the sequence of a fungal CAR from Neurospora crassa OR74A (NcCAR). NcCAR was efficiently expressed in E. coli using an autoinduction protocol at low temperature. It was purified and characterized in vitro, revealing a broad substrate acceptance, a pH optimum at pH 5.5–6.0, a Tm of 45 °C and inhibition by the co‐product pyrophosphate which can be alleviated by the addition of pyrophosphatase. The synthetic utility of NcCAR was demonstrated in a whole‐cell biotransformation using the Escherichia coli K‐12 MG1655 RARE strain in order to suppress overreduction to undesired alcohol. The fragrance compound piperonal was prepared from piperonylic acid (30 mM) on gram scale in 92 % isolated yield in >98% purity. This corresponds to a productivity of 1.5 g/L/h.magnified image
Study on Vibration Transmission and Interfacial Fusion in Ultrasonic Bonding Process for Thermoplastic Micro Joint
Authors: Sun Yibo , Wang Feng , Li Fang , Yang Xinhua 
Published: October 2016

AbstractFusion precision is an important factor to be considered for ultrasonic bonding in thermoplastic MEMS. Vibration transmission in ultrasonic bonding process through polymer workpiece was related to the interfacial fusion, which could be used for in situ monitoring. In this article, experimental platform was established to study the vibration transmission. Experiments were carried out to measure the vibration transmitted from horn onto the high‐frequency dynamic force sensor installed in the anvil. According to the peak‐to‐peak value of dynamic force, the whole bonding process could be divided into rising and falling phases. Interfacial fusion corresponding to ultrasonic transmission was also studied. From experimental results, when the peak‐to‐peak value change rate rose to 130%, some area on the surface starts to melt. When it fell down back to 60%, glass transition occurred with the melt spread gradually over the whole interface. When it fell down to 30%, defects of overflow and bubble began to generate as polymer got into viscous flow state. When the change rate reached 10%, the bubbles burst into smaller ones like floccules as the fluidity of polymer was enhanced further under continuous ultrasonic load. The experimental results gave a deep understanding in the formation of interfacial fusion and the generation of defects.
Disparities in precarious workers’ health care access in South Korea
Authors: Min Jin‐Young , Park Shin‐Goo , Hwang Sang Hee , Min Kyoung‐Bok 
Published: October 2016

BackgroundThis study explored whether precarious workers have difficulties in health care access as compared with non‐precarious workers.MethodsThe 2008 Korean Community Health Survey data were used for this study. Information was obtained on 51,322 participants (40,514 non‐precarious workers and 10,808 precarious workers). Precarious workers were defined as part‐time or contingent workers.ResultsPrecarious workers had significantly higher risk of limited access to hospitals (OR = 1.14; 95% CI: 1.06–1.22) and dentists (OR = 1.28; 95% CI: 1.21–1.36) than non‐precarious workers; disparities in doctor contacts among precarious workers were mostly linked to not having enough money. The risk of not receiving preventive care—medical checkups (OR = 0.52; 95% CI: 0.49–0.55) or cancer screenings (OR = 0.82; 95% CI: 0.77–0.86)—was also significantly elevated among precarious workers.ConclusionWe found that precarious workers had more difficulty accessing health care or receiving health checkups or cancer screenings than their non‐precarious counterparts. Am. J. Ind. Med. 59:1136–1144, 2016. © 2016 Wiley Periodicals, Inc.
Revisiting cancer 15 years later: Exploring mortality among agricultural and non‐agricultural workers in the Serrana Region of Rio de Janeiro
Authors: Krawczyk Noa , de Souza Espíndola Santos Aline , Lima Jaime , Meyer Armando 
Published: October 2016

Background Agricultural production has expanded dramatically throughout Brazil. Previous research in the Serrana Region found that from 1979 to 1998, agricultural workers experienced high mortality rates from certain cancers compared to non‐agricultural workers [Meyer et al. (2003): Environ Res 93:264–271].MethodsNew data were obtained for 1999–2013 and Mortality Odds Ratios (MORs) were utilized to compare cancer and other mortality between male agricultural workers in the Serrana Region and non‐agricultural workers in the Serrana Region, Rio de Janeiro, and Porto Alegre, and to compare mortality odds to previous decades.ResultsRespectively, compared to aforementioned reference‐groups, agricultural workers experienced highest MORs for stomach (1.55 [95%CI: 1.13–2.12], 2.30 [95%CI: 1.72–3.08], 2.28 [95%CI: 1.69–3.08]) and esophageal cancers (95%CI: 1.93 [1.38–2.7], 1.93 [95%CI: 1.38–2.71], 3.12 [95%CI: 2.30–4.24]), greater than reported in previous decades. Agricultural workers experienced higher mortality for external‐causes, respiratory, and cardiovascular problems compared to urban reference‐groups.ConclusionAgricultural workers may be at increasing risk for cancer and other mortality. Efforts are needed to investigate distinct risk‐factors among this group. Am. J. Ind. Med. 60:77–86, 2017. © 2016 Wiley Periodicals, Inc.
Visible Light Activation of Boronic Esters Enables Efficient Photoredox C(sp2)–C(sp3) Cross‐Couplings in Flow
Authors: Lima Fabio , Kabeshov Mikhail A. , Tran Duc N. , Battilocchio Claudio , Sedelmeier Joerg , Sedelmeier Gottfried , Schenkel Berthold , Ley Steven V. 
Published: October 2016

AbstractWe report herein a new method for the photoredox activation of boronic esters. Using these reagents, an efficient and high‐throughput continuous flow process was developed to perform a dual iridium‐ and nickel‐catalyzed C(sp2)–C(sp3) coupling by circumventing solubility issues associated with potassium trifluoroborate salts. Formation of an adduct with a pyridine‐derived Lewis base was found to be essential for the photoredox activation of the boronic esters. Based on these results we were able to develop a further simplified visible light mediated C(sp2)–C(sp3) coupling method using boronic esters and cyano heteroarenes under flow conditions.
Deactivation of Mcl‐1 by Dual‐Function Small‐Molecule Inhibitors Targeting the Bcl‐2 Homology 3 Domain and Facilitating Mcl‐1 Ubiquitination
Authors: Song Ting , Wang Ziqian , Ji Fangling , Feng Yingang , Fan Yudan , Chai Gaobo , Li Xiangqian , Li Zhiqiang , Zhang Zhichao 
Published: October 2016

AbstractBy means of limited proteolysis assay, three‐dimensional NMR, X‐ray crystallography and alanine mutations, a dynamic region at the Q221R222N223 motif in the Bcl‐2 homology 3 (BH3) domain of Mcl‐1 has been identified as a conformational switch which controls Mcl‐1 ubiquitination. NoxaBH3 binding biases the QRN motif toward a helical conformation, thus leading to an enhanced in vitro ubiquitination of Mcl‐1. In contrast, BimBH3 binding biases the QRN motif toward a nonhelical conformation, thus leading to the inhibition of ubiquitination. A dual function Mcl‐1 inhibitor, which locates at the BH3 domain of Mcl‐1 and forms hydrogen bond with His224 to drive a helical QRN conformation, so that it not only interferes with the pro‐apoptotic partners, but also facilitates Mcl‐1 ubiquitination in living cells, is described. As a result, this inhibitor manifests a more effective apoptosis induction in Mcl‐1‐dependent cancer cells than other inhibitors exhibiting a similar binding affinity with it.
Mechanism‐Guided Design and Synthesis of a Mitochondria‐Targeting Artemisinin Analogue with Enhanced Anticancer Activity
Authors: Zhang Chong‐Jing , Wang Jigang , Zhang Jianbin , Lee Yew Mun , Feng Guangxue , Lim Teck Kwang , Shen Han‐Ming , Lin Qingsong , Liu Bin 
Published: October 2016

AbstractUnderstanding the mechanism of action (MOA) of bioactive natural products will guide endeavor to improve their cellular activities. Artemisinin and its derivatives inhibit cancer cell proliferation, yet with much lower efficiencies than their roles in killing malaria parasites. To improve their efficacies on cancer cells, we studied the MOA of artemisinin using chemical proteomics and found that free heme could directly activate artemisinin. We then designed and synthesized a derivative, ART‐TPP, which is capable of targeting the drug to mitochondria where free heme is synthesized. Remarkably, ART‐TPP exerted more potent inhibition than its parent compound to cancer cells. A clickable probe ART‐TPP‐Alk was also employed to confirm that the attachment of the TPP group could label more mitochondrial proteins than that for the ART derivative without TPP (AP1). This work shows the importance of MOA study, which enables us to optimize the design of natural drug analogues to improve their biological activities.
Molecular Imaging of Growth, Metabolism, and Antibiotic Inhibition in Bacterial Colonies by Laser Ablation Electrospray Ionization Mass Spectrometry
Authors: Li Hang , Balan Pranav , Vertes Akos 
Published: October 2016

AbstractMetabolism in microbial colonies responds to competing species, rapidly evolving genetic makeup, and sometimes dramatic environmental changes. Conventional characterization of the existing and emerging microbial strains and their interactions with antimicrobial agents, e.g., the Kirby–Bauer susceptibility test, relies on time consuming methods with limited ability to discern the molecular mechanism and the minimum inhibitory concentration. Assessing the metabolic adaptation of microbial colonies requires their non‐targeted molecular imaging in a native environment. Laser ablation electrospray ionization (LAESI) is an ambient ionization technique that in combination with mass spectrometry (MS) enables the analysis and imaging of numerous metabolites and lipids. In this contribution, we report on the application of LAESI‐MS imaging to gain deeper molecular insight into microbe–antibiotic interactions, and enhance the quantitative nature of antibiotic susceptibility testing while significantly reducing the required incubation time.
[N⋅⋅⋅I+⋅⋅⋅N] Halogen‐Bonded Dimeric Capsules from Tetrakis(3‐pyridyl)ethylene Cavitands
Authors: Turunen Lotta , Warzok Ulrike , Puttreddy Rakesh , Beyeh Ngong Kodiah , Schalley Christoph A. , Rissanen Kari 
Published: October 2016

AbstractTwo [N⋅⋅⋅I+⋅⋅⋅N] halogen‐bonded dimeric capsules using tetrakis(3‐pyridyl)ethylene cavitands with different lower rim alkyl chains are synthesized and analyzed in solution and the gas phase. These first examples of symmetrical dimeric capsules making use of the iodonium ion (I+) as the main connecting module are characterized by 1H NMR spectroscopy, diffusion ordered NMR spectroscopy (DOSY), electrospray ionization mass spectrometry (ESI‐MS), and ion mobility‐mass spectrometry (TW‐IMS) experiments. The synthesis and effective halogen‐bonded dimerization proceeds through analogous dimeric capsules with [N⋅⋅⋅Ag+⋅⋅⋅N] binding motifs as the intermediates as evidenced by the X‐ray structures of (CH2Cl2)2@[3 a2⋅Ag4⋅(H2O)2⋅OTs4] and (CH2Cl2)2@[3 a2⋅Ag4⋅(H2O)4⋅OTs4], two structurally different capsules.
Mesoporous Amorphous Silicon: A Simple Synthesis of a High‐Rate and Long‐Life Anode Material for Lithium‐Ion Batteries
Authors: Lin Liangdong , Xu Xuena , Chu Chenxiao , Majeed Muhammad K. , Yang Jian 
Published: October 2016

AbstractAmorphous Si (a‐Si) shows potential advantages over crystalline Si (c‐Si) in lithium‐ion batteries, owing to its high lithiation potential and good tolerance to intrinsic strain/stress. Herein, porous a‐Si has been synthesized by a simple process, without the uses of dangerous or expensive reagents, sophisticated equipment, and strong acids that potential cause environment risks. These porous a‐Si particles exhibit excellent electrochemical performances, owing to their porous structure, amorphous nature, and surface modification. They deliver a capacity of 1025 mAh g−1 at 3 A g−1 after 700 cycles. Moreover, the reversible capacity after electrochemical activation, is quite stable throughout the cycling, resulting in a capacity retention about around 88 %. The direct comparison between a‐Si and c‐Si anodes clearly supports the advantages of a‐Si in lithium‐ion batteries.
9‐Silafluorenyl Dichlorides as Chemically Ligating Coupling Agents and Their Application in Peptide Synthesis
Authors: Aspin Samuel J. , Taillemaud Sylvain , Cyr Patrick , Charette André B. 
Published: October 2016

AbstractA fundamentally simple, mild, and practical procedure for peptide bond formation is reported that employs a stoichiometric amount of easy‐to‐access 9‐silafluorenyl dichlorides as the coupling agent. Without initial preactivation or elaboration of the carboxylic acid or amine termini of the amino acids, the developed reagent is proposed to act through an unprecedented chemical ligation mechanism, bringing the two coupling partners together before being subsequently eliminated. The desired amides or peptide bonds are thus furnished in good yields and with low to no epimerization.
Molecularly Designed Stabilized Asymmetric Hollow Fiber Membranes for Aggressive Natural Gas Separation
Authors: Liu Gongping , Li Nanwen , Miller Stephen J. , Kim Danny , Yi Shouliang , Labreche Ying , Koros William J. 
Published: October 2016

AbstractNew rigid polyimides with bulky CF3 groups were synthesized and engineered into high‐performance hollow fiber membranes. The enhanced rotational barrier provided by properly positioned CF3 side groups prohibited fiber transition layer collapse during cross‐linking, thereby greatly improving CO2/CH4 separation performance compared to conventional materials for aggressive natural gas feeds.
Photoisomerization of Arylazopyrazole Photoswitches: Stereospecific Excited‐State Relaxation
Authors: Wang Ya‐Ting , Liu Xiang‐Yang , Cui Ganglong , Fang Wei‐Hai , Thiel Walter 
Published: October 2016

AbstractElectronic structure calculations and nonadiabatic dynamics simulations (more than 2000 trajectories) are used to explore the Z–E photoisomerization mechanism and excited‐state decay dynamics of two arylazopyrazole photoswitches. Two chiral S1/S0 conical intersections with associated enantiomeric S1 relaxation paths that are barrierless and efficient (timescale of ca. 50 fs) were found. For the parent arylazopyrazole (Z8) both paths contribute evenly to the S1 excited‐state decay, whereas for the dimethyl derivative (Z11) each of the two chiral cis minima decays almost exclusively through one specific enantiomeric S1 relaxation path. To our knowledge, the Z11 arylazopyrazole is thus the first example for nearly stereospecific unidirectional excited‐state relaxation.