bluuebunny/crossref_metadata_2025 huggingface dataset:
The S−S Bridge: A Mixed Experimental‐Computational Estimation of the Equilibrium Structure of Diphenyl Disulfide
Authors: Demaison Jean , Vogt Natalja , Saragi Rizalina Tama , Juanes Marcos , Rudolph Heinz Dieter , Lesarri Alberto
Published: November 2018

The disulfide bridge (−S−S−) is an important structural motif in organic and protein chemistry, but only a few accurate equilibrium structures are documented. We report the results of supersonic‐jet microwave spectroscopy experiments on the rotational spectra of diphenyl disulfide, C6H5−S−S−C6H5 (including all 13C and 34S monosubstituted isotopologues), and the determination of the equilibrium structure by the mixed estimation (ME) method. A single conformation of C2 symmetry was observed in the gas phase. This disulfide is a challenging target since its structure is determined by 34 independent parameters. Additionally, ab initio calculations revealed the presence of three low‐frequency vibrations (<50 cm−1) associated to phenyl torsions which would prevent the calculation of an accurate force field. For this reason, instead of the semiexperimental method, we used the mass‐dependent (rm) method to fit the structural parameters concurrently to moments of inertia and predicate parameters, affected with appropriate uncertainties. The predicates were obtained by high‐level quantum‐chemical computations. A careful analysis of the results of different fits and a comparison with the ab initio optimizations confirms the validity of the used methods, providing detailed structural information on the title compound and the disulfide bridge.
Ionic Liquids as Solvents for SN2 Processes. Demonstration of the Complex Interplay of Interactions Resulting in the Observed Solvent Effects
Authors: Schaffarczyk McHale Karin S. , Haines Ronald S. , Harper Jason B.
Published: November 2018

Bimolecular nucleophilic substitution reactions between triphenylphosphine and benzylic electrophiles have been examined in an ionic liquid to probe interactions with species along the reaction coordinate. Trends in the rate constant were found on both varying the leaving group and the electronic nature of the aromatic ring. In all the cases considered, interactions between the components of the ionic liquid and the transition state were shown to be more significant in determining reaction outcome than previously observed for this class of reaction. This demonstrates the importance of considering interactions of the ionic liquid components with all species along the reaction coordinate when investigating the origin of ionic liquid solvent effects, along with how such effects might be exploited.
Community structure dynamics and carbon stock change of rehabilitated mangrove forests in Sulawesi, Indonesia
Authors: Cameron Clint , Hutley Lindsay B. , Friess Daniel A. , Brown Benjamin
Published: November 2018

To date, discourse associated with the potential application of “blue carbon” within real‐world carbon markets has focused on blue carbon as a mitigation strategy in the context of avoided deforestation (e.g., REDD+). Here, we report structural dynamics and carbon storage gains from mangrove sites that have undergone rehabilitation to ascertain whether reforestation can complement conservation activities and warrant project investment. Replicated sites at two locations with contrasting geomorphic conditions were selected, Tiwoho and Tanakeke on the island of Sulawesi, Indonesia. These locations are representative of high (Tiwoho, deep muds and silty substrates) and low (Tanakeke, shallow, coralline sands) productivity mangrove ecosystems. They share a similar management history of clearing and conversion for aquaculture before restorative activities were undertaken using the practice of Ecological Mangrove Rehabilitation (EMR). Species diversity and mean biomass carbon storage gains after 10 yr of regrowth from the high productivity sites of Tiwoho (49.2 ± 9.1 Mg C·ha−1·yr−1) are already almost of one‐third of mean biomass stocks exhibited by mature forests (167.8 ± 30.3 Mg C·ha−1·yr−1). Tiwoho's EMR sites, on average, will have offset all biomass C that was initially lost through conversion within the next 11 yr, a finding in marked contrast to the minimal carbon gains observed on the low productivity, low diversity, coral atoll EMR sites of Tanakeke (1.1 ± 0.4 Mg C·ha−1·yr−1). These findings highlight the importance of geomorphic and biophysical site selection if the primary purpose of EMR is intended to maximize carbon sequestration gains.
Demographic processes limit upward altitudinal range expansion in a threatened tropical palm
Authors: Souza Aline C. de , Portela Rita C. Q. , de Mattos Eduardo A.
Published: November 2018

Understanding the factors that determine species’ range limits is a key issue in ecology, and is fundamental for biodiversity conservation under widespread global environmental change. Elucidating how altitudinal variation affects demographic processes may provide important clues for understanding the factors limiting current and future species distributions, yet population dynamics at range limits are still poorly understood. Here, we tested the hypothesis that lower abundance at a species’ upper altitudinal range limit is related to lower vital rates. We compared the dynamics of two populations of the tropical palm Euterpe edulis, located near and at the edge of its altitudinal limit of distribution in the Brazilian Atlantic Forest. Data from four annual censuses, from 2012 to 2015, were used. We used matrix population models to estimate asymptotic population growth rates and the elasticity values for the vital rates of the two populations of E. edulis. Life table response experiments were used to compare population performance by measuring the contribution of each vital rate to population growth rates. Population growth rates were not significantly different from one in either population, indicating that both populations were stable during the study period. However, the abundance of all ontogenetic stages was lower at the altitudinal range limit, which was related to decreases in some vital rates, especially fecundity. Additionally, there were higher elasticity values for the survival of immatures and reproductive individuals, compared to all other vital rates, in both populations. Synthesis. Our results show that even a small‐scale environmental variation near range limits is sufficient to drive changes in the demography of this threatened palm. A minor increase in elevation approaching the limit of altitudinal distribution may reduce environmental suitability and affect population vital rates, thus contributing to setting upper altitudinal range limits for plants.
Temperature effects on prey and basal resources exceed that of predators in an experimental community
Authors: Thakur Madhav P. , Griffin John N. , Künne Tom , Dunker Susanne , Fanesi Andrea , Eisenhauer Nico
Published: November 2018

Climate warming alters the structure of ecological communities by modifying species interactions at different trophic levels. Yet, the consequences of warming‐led modifications in biotic interactions at higher trophic levels on lower trophic groups are lesser known. Here, we test the effects of multiple predator species on prey population size and traits and subsequent effects on basal resources along an experimental temperature gradient (12–15°C, 17–20°C, and 22–25°C). We experimentally assembled food web modules with two congeneric predatory mites (Hypoaspis miles and Hypoaspis aculeifer) and two Collembola prey species (Folsomia candida and Proisotoma minuta) on a litter and yeast mixture as the basal resources. We hypothesized that warming would modify interactions within and between predator species, and that these alterations would cascade to basal resources via changes in the density and traits (body size and lipid: protein ratio) of the prey species. The presence of congeners constrained the growth of the predatory species independent of warming despite warming increased predator density in their respective monocultures. We found that warming effects on both prey and basal resources were greater than the effects of predator communities. Our results further showed opposite effects of warming on predator (increase) and prey densities (decrease), indicating a warming‐induced trophic mismatch, which are likely to alter food web structures. We highlight that warmer environments can restructure food webs by its direct effects on lower trophic groups even without modifying top‐down effects.
Ranging patterns, spatial overlap, and association with dolphin morbillivirus exposure in common bottlenose dolphins (Tursiops truncatus) along the Georgia, USA coast
Authors: Balmer Brian , Zolman Eric , Rowles Teri , Smith Cynthia , Townsend Forrest , Fauquier Deborah , George Clay , Goldstein Tracey , Hansen Larry , Quigley Brian , McFee Wayne , Morey Jeanine , Rosel Patricia , Saliki Jerry , Speakman Todd , Schwacke Lori
Published: November 2018

During 2013–2015, an outbreak of dolphin morbillivirus (DMV) occurred in the western North Atlantic, which resulted in the stranding of over 1,600 common bottlenose dolphins (Tursiops truncatus). There are currently five coastal and 10 bay, sound, and estuary dolphin stocks along the U.S. Atlantic coast, yet there is very limited understanding of which stocks were exposed to DMV during the recent outbreak, or how DMV was transmitted across stocks. In order to address these questions, information is needed on spatial overlap and stock interactions. The goals of this project were to determine ranging patterns, prevalence of DMV, and spatial overlap of the South Carolina‐Georgia (SC‐GA) Coastal Stock, and adjacent Southern Georgia Estuarine System (SGES) Stock. During September 2015, a health assessment and telemetry study was conducted in which 19 dolphins were captured, tested for antibodies to DMV, and satellite tagged. Dolphins were classified into one of three ranging patterns (Coastal, Sound, or Estuary) based upon telemetry data. Coastal dolphins (likely members of the SC‐GA Coastal Stock) had a significantly higher prevalence of positive DMV antibody titers (0.67; N = 2/3), than Sound and Estuary dolphins (likely members of the SGES Stock) (0.13; N = 2/16). These results suggest that the SC‐GA Coastal Stock may have experienced greater exposure to DMV as compared to the SGES Stock. However, due to the small size of the SGES Stock and its exposure to high levels of persistent contaminants, this stock may be particularly vulnerable to DMV infection in the future.
Emigration propensity and flight performance are decoupled in a butterfly
Authors: Reim Elisabeth , Baguette Michel , Günter Franziska , Fischer Klaus
Published: November 2018

Dispersal, defined as any movements potentially leading to gene flow, is a major process driving a species’ capacity to cope with human‐induced environmental modifications. However, the dispersal process is multi‐causal, which currently hinders predictions regarding a species’ resilience to global change. We used a multifaceted approach to disentangle the relative importance of a suite of dispersal‐related factors in the butterfly Lycaena tityrus, including condition‐ (morphology and behavior) and context‐ (environmental) dependent factors. Experiments were conducted at an experimental platform dedicated to study dispersal, the Metatron, to record emigration propensity in two‐patch experimental metapopulations under different environmental conditions. The butterflies’ individual condition was subsequently assessed in the laboratory. Individual condition did not generally influence emigration propensity. We detected a significant sex bias in emigration propensity, being generally higher in females than in males, but in a context‐dependent manner. The environmental context affected emigration propensity, which was higher when habitat quality was poor. Our results show that emigration is not random in L. tityrus, but is rather an active process triggered by sex and habitat quality. Our main finding was that individual condition, and particularly flight ability measured by a performance test, was not related to emigration propensity in experimental metapopulations. Our results may have important implications for forecasting future species distributions, as deteriorating environmental contexts are likely to increase emigration whatever the individual condition is.
Delayed spring onset drives declines in abundance and recruitment in a mountain ungulate
Authors: Rattenbury Kumi L. , Schmidt Joshua H. , Swanson David K. , Borg Bridget L. , Mangipane Buck A. , Sousanes Pam J.
Published: November 2018

Changes in climate are driving widespread landscape changes in northern ecosystems, altering the size and distribution of wildlife populations over multi‐decadal time scales. Extreme weather events are also expected to become more common over time, affecting a variety of species, and mountain ungulates may be particularly susceptible because they occupy habitats with particularly harsh winter weather conditions. To explore the impacts of weather conditions and adverse weather events as population drivers, we surveyed Dall's sheep throughout their latitudinal range in Alaska and assessed lamb production and population trend in relation to end of the continuous snow season (CSS) as a measure of spring onset. In 2013, spring onset was extraordinarily late, providing an opportunity to directly assess the impacts of variability in weather on sheep population dynamics. We hypothesized that the timing of the end of the CSS would have greater impacts in arctic areas where conditions are presumably most limiting. We found that lamb production was negatively related to the annual timing of the end of the CSS and was near 0 in arctic areas in 2013. The 2013 event was also associated with ~40–70% declines in overall sheep numbers in arctic areas, indicating adult survival was also impacted. Overall, our results suggest that expected increases in adverse weather events may have direct, lasting impacts on mountain ungulate populations and that these impacts can be expected to be most extreme for populations occurring at northern range limits where growing season conditions are most restricted.
The importance of kelp to an intertidal ecosystem varies by trophic level: insights from amino acid δ13C analysis
Authors: Elliott Smith Emma A. , Harrod Chris , Newsome Seth D.
Published: November 2018

A fundamental question in ecology is understanding how energy and nutrients move through and between food webs, and which sources of production support consumers. In marine ecosystems, these basic questions have been challenging to answer given the limitation of observational methods. Stable isotope analysis of essential amino acids (EAA δ13C) has great potential as a tool to quantify energy and nutrient flow through marine food webs; however, it has been primarily utilized at large spatial scales. Here, we used EAA δ13C analysis to test for connectivity between adjacent subtidal and intertidal components of a nearshore ecosystem in south central Alaska. We measured δ13C of six EAA from four marine producer groups: subtidal kelp (Laminaria sp.), offshore particulate organic matter (POM), and intertidal red (Neorhodomela sp.) and green (Ulva sp.) algae. In addition, we sampled four intertidal invertebrate consumer species spanning a range of trophic/functional groups: Mytilus sp., Strongylocentrotus droebachiensis, Nucella sp., and Pycnopodia helianthoides. Using canonical analysis of principal coordinates (CAP) and isotope mixing models (MixSIAR), we tested for differences among producer EAA δ13C fingerprints and quantified the contribution of producer EAA to consumers. We compared these results to previously published EAA δ13C data on marine producers to examine the generality of this technique. We found the EAA δ13C fingerprints of subtidal kelps (Laminaria), Ulva, and Neorhodomela were highly distinct from one another. Further, our measured EAA δ13C patterns for kelp and red algae matched those previously reported from other localities, suggesting unique and universal EAA δ13C signatures for these groups. However, CAP could not distinguish between microalgae (POM) and Ulva, possibly due to similar biochemical pathways for the synthesis of EAA. Using these producer fingerprints, we found upper trophic‐level invertebrate consumers, Nucella and Pycnopodia, derived more than 60% of their essential amino acids from subtidal kelps. In contrast, the sampled primary consumers in the system, Mytilus and Strongylocentrotus, relied more heavily on Ulva and/or offshore POM. Our results provide evidence for connectivity between two adjacent nearshore ecosystems and exemplify EAA δ13C as a powerful new tool in tracing energy and nutrient flow within and among marine food webs.
Neutron Instruments for Research in Coordination Chemistry
Authors: Xue Zi‐Ling , Ramirez‐Cuesta Anibal J. , Brown Craig M. , Calder Stuart , Cao Huibo , Chakoumakos Bryan C. , Daemen Luke L. , Huq Ashfia , Kolesnikov Alexander I. , Mamontov Eugene , Podlesnyak Andrey A. , Wang Xiaoping
Published: November 2018

Neutron diffraction and spectroscopy offer unique insight into structures and properties of solids and molecular materials. All neutron instruments located at the various neutron sources are distinct, even if their designs are based on similar principles, and thus, they are usually less familiar to the community than commercial X‐ray diffractometers and optical spectrometers. Major neutron instruments in the USA, which are open to scientists around the world, and examples of their use in coordination chemistry research are presented here, along with a list of similar instruments at main neutron facilities in other countries. The reader may easily and quickly find from this minireview an appropriate neutron instrument for research. The instruments include single‐crystal and powder diffractometers to determine structures, inelastic neutron scattering (INS) spectrometers to probe magnetic and vibrational excitations, and quasielastic neutron scattering (QENS) spectrometers to study molecular dynamics such as methyl rotation on ligands. Key and unique features of the diffraction and neutron spectroscopy that are relevant to inorganic chemistry are reviewed.
Regiospecific Remote Pt–H Interactions in Oligomethylene‐Vaulted (N^C^N)‐Pincer PtII Complexes
Authors: Komiya Naruyoshi , Hosokawa Takashi , Adachi Junya , Inoue Ryo , Kawamorita Soichiro , Naota Takeshi
Published: November 2018

Invited for the cover of this issue is the group of Naruyoshi Komiya and Takeshi Naota from Osaka University and The Jikei University School of Medicine, Tokyo, Japan. The cover image shows the regiospecific remote activation of inactivated C–H bonds of long alkyl chains in oligomethylene‐vaulted Pt complexes.
Formation and Rearrangement of Reduced Diiminepyridine Complexes of Zr and Hf
Authors: Rahimi Naser , Herbert David E. , Budzelaar Peter H. M.
Published: November 2018

Invited for the cover of this issue is the group of Peter H.àM. Budzelaar, who recently moved from the University of Manitoba (Winnipeg, Canada) to the University of Naples Federico II (Italy). The cover image shows the very different structures of formally divalent Hf and Zr diiminepyridine complexes.
Recent Advances in Intramolecular Metal‐Free Oxidative C–H Bond Aminations Using Hypervalent Iodine(III) Reagents
Authors: Reddy Kandimalla Satheeshkumar , Prathima Parvathaneni Sai , Sabitha Gowravaram , Subba Reddy B. V.
Published: November 2018

Hypervalent iodine chemistry is a rapidly growing area of research with tremendous impact on synthetic chemistry in the past years. A rich and diverse chemistry is now available for reactions using hypervalent iodine reagents, as metal‐free, ecofriendly reagents and the advent of new reactions will be of large benefit to researchers working in the area of selective synthesis. In this review article, we emphasize the usage of hypervalent iodine(III) reagents for metal‐free intramolecular oxidative C–N bond formation/annulation to synthesize wide range of N‐heterocycles in organic synthesis. The functionalization of C–H bonds through the involvement of sp‐, sp2‐, and sp3‐hybridized carbon atoms for cyclizations is discussed in detail.
Redox‐Polysilsesquioxane Film as a New Chloride Storage Electrode for Desalination Batteries
Authors: Silambarasan Krishnamoorthy , Joseph James
Published: November 2018

Desalination battery is an emerging concept used in electrochemical technology to solve the problems in sea water desalination. However, identifying an efficient and reversible chloride (Cl−) storage electrode is a major challenge for the development of desalination batteries. A new membraneless, reversible desalination battery consisting of an efficient, reversible, high‐capacity Cl− storage electrode, ferrocyanide molecule immobilized polysilsesquioxane (redox‐PSQ), in combination with the cation storage material, a nickel hexacyanoferrate film in real sea water, is described. The redox‐PSQ polymer is superior over the other reported Cl− storage electrodes (Ag and Bi electrodes) in terms of cost, stability, reversibility, and Cl− ion removal capacity in real‐time applications. About 164 mg L−1 of Cl− ion is removed from natural sea water per 7.6 × 10−8 mol cm−2 surface concentration of electrode material with 98% coulombic efficiency. During the desalination process, alkali ions move toward nickel hexacyanoferrate and Cl− ions moves toward the redox‐PSQ film from the sea water. During the salination process, the stored ions are recovered from the electrode surface as a result of partial energy recovery. Furthermore, this electrode also removes the sulfate ion present in the sea water by the electrostatic adsorption phenomenon. In addition, a high‐voltage (2.3 V), Mg//redox‐PSQ polymer cell is constructed with a red light‐emitting diode that glows during the salination process.
Preparation of Flexible Self‐Supporting 3D SiOx‐Based Membrane Anodes with Stabilized Electrochemical Performances for Lithium‐Ion Batteries
Authors: Kang Tianxing , Ma Zhen , Zuo Xiaoxi , Xiao Xin , Nan Junmin
Published: November 2018

Three‐dimensional (3D) SiOx‐based membrane anodes with stabilized electrochemical performances for lithium‐ion batteries are fabricated ingeniously using high‐capacity SiOx active material. The flexible self‐supporting substances of poly(vinylidene fluoride) and carbon nanotubes are chosen as the supporting substances, which not only provide the 3D framework for the flexible self‐supporting membrane but also act as a protective layer with enhanced conductive pathway. In particular, this unique 3D structure can prevent the SiOx surface from contacting the electrolyte directly and can buffer the volumetric expansion of SiOx particles. This optimized membrane anode exhibits a high reversible specific capacity of 1436 mAh g−1 and a capacity retention rate of 88% after 100 cycles. In addition, it also demonstrates an outstanding rate performance, a specific capacity of 1245 mAh  g−1 is obtained at 1200 mA g−1, which is about 91% at 100 mA g−1. The stabilized performances of the as‐prepared membrane anodes indicate their promising prospects in the practical applications, and the fabricating method also provides a reference for the preparation of other flexible self‐supporting membrane electrodes.
Synthesis of Metal–Organic Sulfides as Anode Materials for Lithium‐Ion Batteries at Room Temperature
Authors: Chen Tianrui , Mu Deying , Li Ruhong , Liu Jianchao , Ma Quanxin , Ding Fei , Dai Changsong
Published: November 2018

To relieve the volume effect of metal‐based anode materials for lithium‐ion batteries the size of the active material is reduced to a limit, and organic frameworks are used to provide cushioning for volume expansion. Tin‐based sulfide is designed by 1,3,5‐triazine‐2,4,6‐trithiol trisodium (TMT), and tin dichloride is synthesized at room temperature. TMT like the “solvent” of metal ions has a good electrical conductivity, which makes metal ions disperse in the organic conductive skeleton at the atomic level. A carbon nanotube is introduced to enhance the conductivity among the active particles, and the tin‐based materials deliver a high specific capacity of 713 mAh g−1 at a current density of 500 mA g−1 after 500 cycles. In addition, using Ni2+, Co2+, or Mn2+ instead of Sn2+, the conversion type of the metal‐based anode materials are prepared by the same method, and they also exhibit excellent electrochemical properties.
Hybrid testing with model updating on steel panel damper substructures using a multi‐axial testing system
Authors: Wang Kung‐Juin , Chuang Ming‐Chieh , Tsai Keh‐Chyuan , Li Chao‐Hsien , Chin Pu‐Yuan , Chueh Shen‐Yuo
Published: November 2018

This paper describes a series of hybrid tests performed on a steel panel damper (SPD) specimen by using a multi‐axial testing system. The building under investigation adopted a three‐dimensional six‐story moment resisting frame with four SPDs installed at each story as the main seismic resisting system. The structural model was subjected to bi‐directional ground excitations of three hazard levels. The finite element analysis program “Platform of Inelastic Structural Analysis for 3D Systems” (PISA3D) was used as the analysis kernel for hybrid tests. Relevant programming extensions in PISA3D were created to support geographically distributed hybrid testing in a general‐purpose manner. An external displacement control (EDC) method was developed such that the actual boundary deformation of the specimen fixtures could be continuously measured and immediately compensated during tests. An online model updating (OMU) technique was developed and employed such that the material properties of the specimen could be identified directly from the specimen response during the test. The identified material properties were then immediately used to update those of the other relevant numerical elements to enhance the overall simulation fidelity. Superior flexibility of the underlying software architecture was well demonstrated in this series of hybrid tests since no hardcoding was used to support all the complex test settings. Test results confirmed the effectiveness of the proposed EDC method, as well as the capacity of the proposed OMU technique to satisfactorily and efficiently capture the hysteretic properties of the specimen.
Prognostics of a multistack PEMFC system with multiagent modeling
Authors: Liu Jie , Zio Enrico
Published: November 2018

Current research on prognostics of PEMFC mainly focuses on one stack. However, in practice, the PEMFC stacks are assembled together to provide higher and more reliable power. In this paper, an original multiagent approach is proposed for predicting the remaining useful life‐times of all stacks in a multistack PEMFC system. The predictions are updated dynamically by particle filtering when new stack loads are collected. The major contribution of the paper is not on degradation modeling of a single PEMFC, but on the cooperative prognostics of multiple PEMFC stacks in the same power system. A case study concerning a synthetic combined heat and power system with three PEMFC stacks is considered and the results show the effectiveness of the proposed approach.
Transverse canyon incision and sedimentary basin excavation driven by drainage integration, Aravaipa Creek, AZ, USA
Authors: Jungers Matthew C. , Heimsath Arjun M.
Published: November 2018

Drainage reorganization events have the potential to drive incision and erosion at high rates normally attributed to tectonic or climatic forcing. It can be difficult, however, to isolate the signal of transient events driven by drainage integration from longer term tectonic or climatic forcing. We exploit an ideal field setting in Aravaipa Creek Basin of southeastern Arizona, USA, to isolate just such a signal. Aravaipa Creek Basin underwent a period of transient incision that formed Aravaipa Canyon, evacuating a significant volume of sedimentary basin fill and Tertiary bedrock from the previously internally drained basin. We use digital terrain analyses to reconstruct the pre‐incision landscapes of both Aravaipa Creek Basin and the adjacent Lower San Pedro Basin, which we use to quantify the magnitude of incision and erosion since the drainage basins integrated. Terrestrial cosmogenic nuclide burial dates from 10Be and 26Al concentrations in latest stage basin fill in Aravaipa Creek enable us to calculate long‐term incision and erosion rates from 3 Myr to the present. A 10Be concentration–depth profile from the Lower San Pedro Basin confirms that the San Pedro River incised into its high stand deposits prior to 350 000–400 000 years ago. Combining our landscape reconstructions with these age constraints, we determine that the transient rates of incision that created Aravaipa Canyon were 150 m/Myr or more, but that the background rate of erosion since integration is an order of magnitude lower, between 10 and 20 m/Myr. These results support our growing understanding that tectonic and climatic forcings need not apply for all episodes of rapid, transient incision and erosion during landscape evolution. © 2018 John Wiley & Sons, Ltd.
3D Macroporous Zinc Compound/Silicone Hybrid Foams for Amperometric Sensing of Glucose Oxidase
Authors: Wu Ye , Fu Hao , Xie Weiwei , Lin Yingcheng , Kizilkaya Orhan , Xu Jian
Published: November 2018

A 3D porous matrix makes an intriguing sensing platform, which can integrate functional guest molecules. Here, the first demonstration of a zinc compound/silicone hybrid foam is reported for amperometric sensing of glucose oxidase. The silicone foam is fabricated by a self‐developed solid‐filling‐melting method. Two zinc‐based polymers, Zn‐Compound‐1 and Zn‐Compound‐2, are synthesized. Zn‐Compound‐1 and Zn‐Compound‐2 are characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectroscopy, Raman spectroscopy, and X‐ray absorption nearedge structure spectroscopy of carbon K‐edge, oxygen K‐edge, and zinc L‐edge. Effective amperometric sensing of glucose oxidase is achieved by introducing Zn‐Compound‐1 or Zn‐Compound‐2 into the silicone foam, i.e., an increase of the concentration of the glucose oxidase led to an increase of detected current. This phenomenon can be explained by a possible mechanism of the formation of electron extra bands.
Geochemistry of diverse lava types from the Lau Basin (South West Pacific): Implications for complex back‐arc mantle dynamics
Authors: Zhang Haitao , Yan Quanshu , Li Chuanshun , Zhu Zhiwei , Zhao Renjie , Shi Xuefa
Published: November 2018

Lavas from back‐arc basins are generally diverse, and their geochemical compositions indicate that they received variable contributions from subduction components during petrogenesis. Obtaining comprehensive geochemistry characteristics for the entire back‐arc basin are helpful in gaining a better understanding of the complexities of back‐arc evolution. In this study, we systematically reviewed the major and trace element compositions of Lau Basin lavas. This data set covered all of the major tectonic units of the basin, for example, the Eastern Lau spreading center (ELSC), the Valu Fa ridge (VFR), the Central Lau spreading center (CLSC), the Northwestern Lau spreading center (NWLSC), the Northeastern Lau spreading center (NELSC), the Mangatolu Triple Junction (MTJ), and the Fonualei Spreading Center (FSC). The lava types from these locations are diverse, including tholeiitic basalts, alkali basalts, basaltic andesites, andesites, dacites, and rhyolites. In addition, the NELSC and FSC contain boninites. In this study, the geochemical compositions of these diverse rock types are used to investigate the spreading dynamics of the Lau Basin back‐arc. We conclude that (a) the subduction components mainly include hydrous fluids released from the subducted slab, and hydrous melt directly from the melting subducted sediment, and the influence of the subducted components on the mantle wedge and the petrogenesis of the central and southern Lau Basin lavas decreases with increasing distance from the Tonga Trench; (b) during the propagation and spreading of the Samoan mantle into the Lau Basin, lavas from the NELSC, NWLSC, MTJ, and even from the northern part of the FSC may receive variable degrees of influence from the Samoan plume; and (c) the migration of Indian MORB‐like mantle southwards into the Pacific mantle is consistent with the opening of the Lau Basin. With the gradual migration of Indian mantle into the Lau Basin, a series of spreading centers were formed, for example, in order, the NWLSC, CLSC, ELSC, and the propagating VFR.
Photobiomodulation improves the frontal cognitive function of older adults
Authors: Chan Agnes S. , Lee Tsz Lok , Yeung Michael K. , Hamblin Michael R.
Published: November 2018

Objectives

The frontal lobe hypothesis of age‐related cognitive decline suggests that the deterioration of the prefrontal cortical regions that occurs with aging leads to executive function deficits. Photobiomodulation (PBM) is a newly developed, noninvasive technique for enhancing brain function, which has shown promising effects on cognitive function in both animals and humans. This randomized, sham‐controlled study sought to examine the effects of PBM on the frontal brain function of older adults.

Methods/designs

Thirty older adults without a neuropsychiatric history performed cognitive tests of frontal function (ie, the Eriksen flanker and category fluency tests) before and after a single 7.5‐minute session of real or sham PBM. The PBM device consisted of three separate light‐emitting diode cluster heads (633 and 870 nm), which were applied to both sides of the forehead and posterior midline, and delivered a total energy of 1349 J.

Results

Significant group (experimental, control) × time (pre‐PBM, post‐PBM) interactions were found for the flanker and category fluency test scores. Specifically, only the older adults who received real PBM exhibited significant improvements in their action selection, inhibition ability, and mental flexibility after vs before PBM.

Conclusions

Our findings support that PBM may enhance the frontal brain functions of older adults in a safe and cost‐effective manner.
Risk perception of a chronic threat of terrorism: Differences based on coping types, gender and exposure
Authors: Cohen‐Louck Keren , Levy Inna
Published: November 2018

High levels of risk perception of terrorism (RPT) may impair an individual's quality of life and welfare. To understand the mechanisms responsible for RPT, this study investigated the association of gender and coping styles with individual differences in two key elements of RPT: perceived control and perceived vulnerability. A convenience sample of 400 Israelis (181 men and 219 women) filled out questionnaires on sociodemographic background, RPT and coping. Employing a multidimensional approach for coping, we divided participants into four coping types: problem‐focused (n = 65), emotion‐focused (n = 70), mixed (n = 122) and minimal (n = 142). The results indicate that problem‐focused coping is associated with higher levels of perceived control than other types of coping and mixed coping is associated with higher levels of perceived vulnerability than other coping strategies. Also, interactions between gender and exposure to terrorism contributed to understanding the differences in perceived control. The discussion addresses gender differences in RPT and coping in the context of traditional gender roles. The study concludes with implications for risk management and therapeutic interventions regarding high levels of fear of terrorism.
Understanding the Bone in Cancer Metastasis
Authors: Fornetti Jaime , Welm Alana L , Stewart Sheila A
Published: November 2018

The bone is the third most common site of metastasis for a wide range of solid tumors including lung, breast, prostate, colorectal, thyroid, gynecologic, and melanoma, with 70% of metastatic prostate and breast cancer patients harboring bone metastasis.1 Unfortunately, once cancer spreads to the bone, it is rarely cured and is associated with a wide range of morbidities including pain, increased risk of fracture, and hypercalcemia. This fact has driven experts in the fields of bone and cancer biology to study the bone, and has revealed that there is a great deal that each can teach the other. The complexity of the bone was first described in 1889 when Stephen Paget proposed that tumor cells have a proclivity for certain organs, where they “seed” into a friendly “soil” and eventually grow into metastatic lesions. Dr. Paget went on to argue that although many study the “seed” it would be paramount to understand the “soil.” Since this original work, significant advances have been made not only in understanding the cell-autonomous mechanisms that drive metastasis, but also alterations which drive changes to the “soil” that allow a tumor cell to thrive. Indeed, it is now clear that the “soil” in different metastatic sites is unique, and thus the mechanisms that allow tumor cells to remain in a dormant or growing state are specific to the organ in question. In the bone, our knowledge of the components that contribute to this fertile “soil” continues to expand, but our understanding of how they impact tumor growth in the bone remains in its infancy. Indeed, we now appreciate that the endosteal niche likely contributes to tumor cell dormancy, and that osteoclasts, osteocytes, and adipocytes can impact tumor cell growth. Here, we discuss the bone microenvironment and how it impacts cancer cell seeding, dormancy, and growth. © 2018 American Society for Bone and Mineral Research.
Efficacy of Chinese herb Cistanche Yishen granules in treatment of tinnitus for patients with chronic nephritis
Authors: Fan Xiaoli , Chen Yue , Li Li , Wang Yang , Zhang Yi , Lu Shan , Zhu Danyang , Sheng Meixiao
Published: November 2018

Objective

This study aimed to investigate the efficacy of Chinese herb Cistanche Yishen granules (CYG) in the treatment of tinnitus for patients with chronic nephritis.

Methods

A total of 89 adult patients were diagnosed with chronic glomerulonephritis from January 2016 to December 2017. All the patients were randomly divided into two groups, such as the control group and the CYG group. The efficacy of tinnitus was determined using tinnitus handicap inventory (THI), Pittsburgh sleep quality index (PSQI), pure tone audiometry (PTA), speech reception threshold (SRT), and visual analog scale (VAS) for tinnitus loudness and annoyance.

Results

In both these two groups of patients, values of THI, PSQI, PTA, SRT, and VAS for tinnitus loudness and annoyance were significantly decreased after the treatment compared with those before treatment. However, all values in CYG group after the treatment were significantly lower than those in the control group.

Conclusion

CYG could apparently release the tinnitus symptoms in the patients with chronic nephritis. This study might give more clinical evidence for Cistanche in the treatment of tinnitus and give a new treatment method for the patients with tinnitus.
Manipulation of molecular pathways and senescence hallmarks by natural compounds in fibroblast cells
Authors: Momtaz Saeideh , Baeeri Maryam , Rahimifard Mahban , Haghi‐Aminjan Hamed , Hassani Shokoufeh , Abdollahi Mohammad
Published: November 2018

Aging contributes to an increased risk of developing a number of neurodegenerative and chronic disorders, predominantly related to oxidative stress (OS) and defects in the antioxidant balance. This study focused on the antisenescence effect of four plant species (Falcaria vulgaris, Ixiolirion tataricum, Ajuga chamaecistus, and Scabiosa flavida) on H2O2‐induced premature senescence in rat NIH3T3 fibroblasts, which were found to be rich in effective phytochemicals with traditional ethnobotanical backgrounds. Plant materials were collected, identified, and extracted. To determine the viability of NIH3T3 cells, an MTT assay was conducted. The levels of OS markers and the senescence‐associated ß‐galactosidase (SA‐ß‐GAL) activity were analyzed by the Elisa reader. The cell cycle pattern was evaluated by flow cytometry. The expression of senescence‐related inflammatory cytokines and the molecules involved in aging signaling pathways were investigated using the real‐time reverse transcription polymerase chain reaction (RT‐PCR). H2O2 treatment decreased cell viability and increased lipid peroxidation (LPO) and the reactive oxygen species (ROS) in NIH3T3s. However, S. flavida exhibited low cytotoxicity, reduced OS and SA‐ß‐GAL activities in NIH3T3 cells compared with the H2O2‐treated group. I. tataricum was the second best plant, although it was more toxic to NIHT3T cells. S. flavida decreased G0/G1 arrest and facilitated the G2/M transition of NIH3T3s, also downregulated the expression of p38, p53, p16, and the related inflammatory mediators. S. flavida potentially modulated senescence‐associated hallmarks in fibroblasts exposed to H2O2, thus it may inhibit the aging process via controlling the OS. Therefore it is a promising candidate for future antiaging explorations.
Identification of NPAC as a novel biomarker and regulator for hepatocellular carcinoma
Authors: Zhang Jiecheng , Sun Nannan , Guo Wenfeng , Wu Xiaojie , Yang Xiaoying , Jin Haiyong , Zhang Yueling , Wu Xiaoting , Zhang Fenglian , Hu Ling , Hu Huiling , Gao Yong
Published: November 2018

Objective

Hepatocellular carcinoma (HCC) has a high morbidity and mortality around the world, yet the effective therapeutic option for HCC is still limited. NPAC, also known as glyoxylate reductase 1 homolog, is a new nuclear protein recently implicated in tumor biology. However, the role of NPAC in HCC remains unclear. The present study aimed to evaluate the clinical significance and potential role of NPAC in HCC.

Methods

The NPAC expression in HCC tissues and matched adjacent normal tissues was detected by real‐time polymerase chain reaction, immunohistochemistry (IHC), and Western blot analysis. The clinical significance of the expression of NPAC in HCC was assessed by the Kaplan‐Meier survival curve and the Cox regression model. In addition, we established a doxiline‐induced overexpression of the NPAC system. The effects of NPAC on HCC cell proliferation, migration, and apoptosis were checked by CCK‐8 proliferation assays, transwell, and flow cytometry, respectively.

Results

The NPAC expression was significantly downregulated in HCC tissues and HCC cell lines. NPAC reduction was significantly correlated with poorer survival among patients with HCC, and the multivariate analysis confirmed its independent prognostic value. Furthermore, overexpression of NPAC dramatically suppressed the proliferation of HCC cells and promoted HCC cells apoptosis. Besides, the levels of phosphorylation of janus kinase 2 (JAK2) and signal transduction and activator 3 (STAT3) were significantly reduced after overexpression of NPAC in HCC cell lines.

Conclusions

These results suggest that NPAC may play an important role in the development and progression of HCC, and can act as a novel potential prognostic biomarker and therapeutic target for HCC.
Effect of sodium‐glucose cotransporter 2 inhibitor, empagliflozin, and α‐glucosidase inhibitor, voglibose, on hepatic steatosis in an animal model of type 2 diabetes
Authors: Kim Ji‐Won , Lee Ye‐Jee , You Young‐Hye , Moon Min Kyong , Yoon Kun‐Ho , Ahn Yu‐Bae , Ko Seung‐Hyun
Published: November 2018

Objective

We investigated the effects of sodium‐glucose cotransporter 2 inhibitor, empagliflozin, and α‐glucosidase inhibitor, voglibose, on hepatic steatosis in an animal model of type 2 diabetes (T2DM).

Methods

Empagliflozin (OLETF‐EMPA) or voglibose (OLETF‐VOG) was administered to Otsuka Long‐Evans Tokushima fatty (OLETF) rats once daily for 12 weeks. Control Long‐Evans Tokushima Otsuka (LETO) and OLETF (OLETF‐C) rats received saline.

Results

Blood glucose levels were significantly suppressed in OLETF‐EMPA and OLETF‐VOG compared with the OLETF‐C group. The liver fat content was significantly higher in the OLETF‐C group than in the OLETF‐EMPA and OLETF‐VOG. Hepatic gene expressions involved in gluconeogenesis (glucose 6‐phosphatase [G6Pase], fructose‐1,6‐bisphosphatase [FBP1], and phosphoenolpyruvate carboxykinase [PEPCK]) and lipogenesis (acetyl‐CoA carboxylase [ACC], fatty acid synthase [FAS], and sterol regulatory element‐binding transcription factor 1c [SREBP‐1c]) were significantly decreased in the OLETF‐EMPA group compared with other OLETF groups (OLETF‐C and OLETF‐VOG). Sirtuin 1 (SIRT1) expression level and SIRT1 activity were markedly reduced in OLETF‐C rats; however, its expression increased in the OLETF‐EMPA and OLETF‐VOG. AMP‐activated protein kinase (AMPK) phosphorylation level was remarkably increased by empagliflozin treatment in OLETF rats compared with other OLETF groups. Long‐term empagliflozin and voglibose treatment reduced hepatic steatosis with suppression of gluconeogenesis and lipogenesis pathway in OLETF rats.

Conclusion

We suggest that this metabolic improvement might be related to SIRT1 and AMPK pathway in T2DM. But empagliflozin is thought to have more advantage to prevent hepatic steatosis than voglibose in T2DM.
Factors Associated With Cysticidal Treatment Response in Extraparenchymal Neurocysticercosis
Authors: Osorio Rocio , Carrillo‐Mezo Roger , Romo Matthew L. , Toledo Andrea , Matus Carlos , González‐Hernández Iliana , Jung Helgi , Fleury Agnès
Published: November 2018

Extraparenchymal neurocysticercosis is the most severe form of cysticercosis, and response to treatment is suboptimal. We sought to determine how demographic and clinical characteristics and albendazole sulfoxide concentrations were related to cysticidal treatment response. We conducted a longitudinal study of 31 participants with extraparenchymal vesicular parasites who received the same treatment, albendazole 30 mg/kg/day for 10 days with dexamethasone 0.4 mg/kg/day for 13 days, followed by a prednisone taper. Response to treatment was determined by parasite volumes before and 6 months after treatment. Eight participants (25.8%) had a complete treatment response, 16 (51.6%) had a treatment response > 50% but < 100%, and 7 (22.6%) had a treatment response < 50%. Complete treatment response was significantly associated with higher concentrations of albendazole sulfoxide (P = .032), younger age (P = .032), fewer cysts (P = .049) and lower pretreatment parasite volume (P = .037). Higher number of previous cysticidal treatment courses was associated with a noncomplete treatment response (P = .023). Although the large proportion of participants with less than a complete response emphasizes the need to develop more efficacious pharmacologic regimens, the association of albendazole sulfoxide concentrations with treatment response highlights the importance of optimizing existing therapeutic regimens. In addition, the association of treatment response with parasite volume emphasizes the importance of early diagnosis.