bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of stratospheric warming events during Northern winter
Authors: Maury Pauline , Claud Chantal , Manzini Elisa , Hauchecorne Alain , Keckhut Philippe
Published: April 2016

The strong interest in Sudden Stratospheric Warmings (SSWs) is motivated by their role in the two‐way stratospheric‐tropospheric dynamical coupling. While most studies only investigate major SSWs (vortex breakdown), the minor ones (strong vortex deceleration) are overlooked. This work aims at overcoming this gap by providing a comprehensive description of stratospheric warming events without a priori distinctions between major and minor SSWs, leading to a more complete estimate of the stratospheric variability. Warming events are extracted from reanalysis data sets by means of a midstratospheric polar cap temperature daily index. Events are characterized by a bimodal distribution in amplitude, with a broad peak at small amplitudes (inferior to 5K) and a sharp peak at around 9K. Due to the intrinsic polar vortex dynamics, the warming amplitude presents a distinct seasonal distribution. Small amplitude warmings mainly occur during early and late wintertime by contrast with the larger‐amplitude ones occurring during midwintertime. From mid‐November to mid‐March, the large‐amplitude warmings (i.e., strong warming events, SWEs) include both major and minor SSWs, as well as Canadian and Final warmings. Although major SSWs belong to the tail of the SWEs distribution, there is no clear distinction between the major and minor SSWs according to the considered properties of the events. Such result brings out the idea of “warming continuum.” Furthermore, diagnostics of heat flux reveal that there is no statistical difference between SWEs with regard to their feedbacks on the planetary waves and hence on their potential influence into the troposphere.
Rapidly evolving ultrafine and fine mode biomass smoke physical properties: Comparing laboratory and field results
Authors: Carrico Christian M. , Prenni Anthony J. , Kreidenweis Sonia M. , Levin Ezra J. T. , McCluskey Christina S. , DeMott Paul J. , McMeeking Gavin R. , Nakao Shunsuke , Stockwell Chelsea , Yokelson Robert J.
Published: April 2016

Combining field and laboratory results, we present biomass smoke physical properties. We report sub‐0.56 µm diameter (Dp) particle sizing (fast mobility particle sizer, FMPS) plus light absorption and scattering at 870 nm (photoacoustic extinctiometer). For Dp < 200 nm, the FMPS characterized sizing within ±20% compared to standards. As compared to the traditional scanning mobility particle sizer, the FMPS responded most accurately to single‐mode polydispersions with mean Dp < 200 nm, which characterized the smoke sampled here. Smoke was measured from laboratory fresh emissions (seconds to hours old), the High Park Fire (hours to < 1 day), and from regional biomass burning (several days). During a High Park Fire episode, light extinction rapidly reached a maximum of σep = 569 ± 21 Mm−1 (10 min) with aerosol single scattering albedo peaking at ω = 0.955 ± 0.004. Concurrently, number concentration and size peaked with maximum Dp = 126 nm and a unimodal distribution with σg = 1.5. Long‐range transported smoke was substantially diluted (Ntot factor of 7 lower) and shifted larger (maximum Dp = 143) and wider (σg = 2.2). We compared ambient data to laboratory burns with representative western U.S. forest fuels (coniferous species Ponderosa pine and Alaska black spruce). Smoldering pine produced an aerosol dominated by larger, more strongly light scattering particles (Dp > 100 nm), while flaming combustion produced very high number concentrations of smaller (Dp ~ 50 nm) absorbing particles. Due to smoldering and particle growth processes, Dp approached 100 nm within 3 h after emission. Increased particle cross‐sectional area and Mie scattering efficiency shifted the relative importance of light absorption (flaming maximum) and light scattering (smoldering maximum), increasing ω over time. Measurements showed a consistent picture of smoke properties from emission to aging.
Stability and bistability in a one‐dimensional model of coastal foredune height
Authors: Goldstein Evan B. , Moore Laura J.
Published: April 2016

On sandy coastlines, foredunes provide protection from coastal storms, potentially sheltering low areas—including human habitat—from elevated water level and wave erosion. In this contribution we develop and explore a one‐dimensional model for coastal dune height based on an impulsive differential equation. In the model, coastal foredunes continuously grow in a logistic manner as the result of a biophysical feedback and they are destroyed by recurrent storm events that are discrete in time. Modeled dunes can be in one of two states: a high “resistant‐dune” state or a low “overwash‐flat” state. The number of stable states (equilibrium dune heights) depends on the value of two parameters, the nondimensional storm frequency (the ratio of storm frequency to the intrinsic growth rate of dunes) and nondimensional storm magnitude (the ratio of total water level during storms to the maximum theoretical dune height). Three regions of phase space exist (1) when nondimensional storm frequency is small, a single high resistant‐dune attracting state exists; (2) when both the nondimensional storm frequency and magnitude are large, there is a single overwash‐flat attracting state; (3) within a defined region of phase space model dunes exhibit bistable behavior—both the resistant‐dune and the low overwash‐flat states are stable. Comparisons to observational studies suggest that there is evidence for each state to exist independently, the coexistence of both states (i.e., segments of barrier islands consisting of overwash‐flats and segments of islands having large dunes that resist erosion by storms), as well as transitions between states.
Uncertainty analysis of terrestrial net primary productivity and net biome productivity in China during 1901–2005
Authors: Shao Junjiong , Zhou Xuhui , Luo Yiqi , Zhang Guodong , Yan Wei , Li Jiaxuan , Li Bo , Dan Li , Fisher Joshua B. , Gao Zhiqiang , He Yong , Huntzinger Deborah , Jain Atul K. , Mao Jiafu , Meng Jihua , Michalak Anna M. , Parazoo Nicholas C. , Peng Changhui , Poulter Benjamin , Schwalm Christopher R. , Shi Xiaoying , Sun Rui , Tao Fulu , Tian Hanqin , Wei Yaxing , Zeng Ning , Zhu Qiuan , Zhu Wenquan
Published: April 2016

Despite the importance of net primary productivity (NPP) and net biome productivity (NBP), estimates of NPP and NBP for China are highly uncertain. To investigate the main sources of uncertainty, we synthesized model estimates of NPP and NBP for China from published literature and the Multi‐scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP). The literature‐based results showed that total NPP and NBP in China were 3.35 ± 1.25 and 0.14 ± 0.094 Pg C yr−1, respectively. Classification and regression tree analysis based on literature data showed that model type was the primary source of the uncertainty, explaining 36% and 64% of the variance in NPP and NBP, respectively. Spatiotemporal scales, land cover conditions, inclusion of the N cycle, and effects of N addition also contributed to the overall uncertainty. Results based on the MsTMIP data suggested that model structures were overwhelmingly important (>90%) for the overall uncertainty compared to simulations with different combinations of time‐varying global change factors. The interannual pattern of NPP was similar among diverse studies and increased by 0.012 Pg C yr−1 during 1981–2000. In addition, high uncertainty in China's NPP occurred in areas with high productivity, whereas NBP showed the opposite pattern. Our results suggest that to significantly reduce uncertainty in estimated NPP and NBP, model structures should be substantially tested on the basis of empirical results. To this end, coordinated distributed experiments with multiple global change factors might be a practical approach that can validate specific structures of different models.
Revisiting hydraulic hysteresis based on long‐term monitoring of hydraulic states in lysimeters
Authors: Hannes M. , Wollschläger U. , Wöhling T. , Vogel H.‐J.
Published: April 2016

Hysteretic processes have been recognized for decades as an important characteristic of soil hydraulic behavior. Several studies confirmed that wetting and drying periods cannot be described by a simple functional relationship, and that some nonequilibrium of the water retention characteristics has to be taken into account. A large number of models describing the hysteresis of the soil water retention characteristic were successfully tested on soil cores under controlled laboratory conditions. However, its relevance under field conditions under natural forcings has rarely been investigated. In practice, the modeling of field soils usually neglects the hysteretic nature of soil hydraulic properties. In this study, long‐term observations of water content and matric potential in lysimeters of the lysimeter network TERENO‐SoilCan are presented, clearly demonstrating the hysteretic behavior of field soils. We propose a classification into three categories related to different time scales. Based on synthetic and long‐term monitoring data, three different models of hysteresis were applied to data sets showing different degrees of hysteresis. We found no single model to be superior to the others. The model ranking depended on the degree of hysteresis. All models were able to reflect the general structure of hysteresis in most cases but failed to reproduce the detailed trajectories of state variables especially under highly transient conditions. As an important result we found that the temporal dynamics of wetting and drying significantly affects these trajectories which should be accounted for in future model concepts.
The dependence on geomagnetic conditions and solar wind dynamic pressure of the spatial distributions of EMIC waves observed by the Van Allen Probes
Authors: Saikin A. A. , Zhang J.‐C. , Smith C. W. , Spence H. E. , Torbert R. B. , Kletzing C. A.
Published: April 2016

A statistical examination on the spatial distributions of electromagnetic ion cyclotron (EMIC) waves observed by the Van Allen Probes against varying levels of geomagnetic activity (i.e., AE and SYM‐H) and dynamic pressure has been performed. Measurements taken by the Electric and Magnetic Field Instrument Suite and Integrated Science for the first full magnetic local time (MLT) precession of the Van Allen Probes (September 2012–June 2014) are used to identify over 700 EMIC wave events. Spatial distributions of EMIC waves are found to vary depending on the level of geomagnetic activity and solar wind dynamic pressure. EMIC wave events were observed under quiet (AE ≤ 100 nT, 325 wave events), moderate (100 nT < AE ≤ 300 nT, 218 wave events), and disturbed (AE > 300 nT, 228 wave events) geomagnetic conditions and are primarily observed in the prenoon sector (~800 < MLT ≤ ~1100) at L ≈ 5.5 during quiet activity times. As AE increases to disturbed levels, the peak occurrence rates shift to the afternoon sector (1200 < MLT ≤ 1800) between L = 4 and L = 6. A majority of EMIC wave events (~56%) were observed during nonstorm times (defined by SYM‐H). Consistent with the quiet AE levels, nonstorm EMIC waves are observed in the prenoon sector. EMIC waves observed through the duration of a geomagnetic storm are primarily located in the afternoon sector. High solar wind pressure (Pdyn > 3 nPa) correlates to mostly afternoon EMIC wave observations.
The eruptibility of magmas at Tharsis and Syrtis Major on Mars
Authors: Black Benjamin A. , Manga Michael
Published: April 2016

Magnetic and geologic data indicate that the ratio of intrusive to extrusive magmatism (the I/E ratio) is higher in the Tharsis and Syrtis Major volcanic provinces on Mars relative to most volcanic centers on Earth. The fraction of magmas that erupt helps to determine the effects of magmatism on crustal structure and the flux of magmatic gases to the atmosphere and also influences estimates of melt production inferred from the history of surface volcanism. We consider several possible controls on the prevalence of intrusive magmatism at Tharsis and Syrtis Major, including melt production rates, lithospheric properties, regional stresses and strain rates, and magmatic volatile budgets. The Curie temperature is the minimum crustal temperature required for thermal demagnetization, implying that if the primary magnetic mineral is magnetite or hematite, the crust was warm during the intrusive magmatism reflected in Tharsis and Syrtis Major I/E ratios. When wall rocks are warm, thermally activated creep relaxes stresses from magma replenishment and regional tectonics, and eruptibility depends on buoyancy overpressure. We develop a new one‐dimensional model for the development of buoyancy in a viscous regime that accounts for cooling, crystallization, volatile exsolution, bubble coalescence and rise, fluid egress, and compaction of country rock. Under these conditions, we find that initial water and CO2 contents typically <1.5 wt % can explain the observed range of intrusive/extrusive ratios. Our results support the hypothesis that warm crust and a relatively sparse volatile budget encouraged the development of large intrusive complexes beneath Tharsis and Syrtis Major.
Grain size bias in cosmogenic nuclide studies of stream sediment in steep terrain
Authors: Lukens Claire E. , Riebe Clifford S. , Sklar Leonard S. , Shuster David L.
Published: April 2016

Cosmogenic nuclides in stream sediment are widely used to quantify catchment‐average erosion rates. A key assumption is that sampled sediment is representative of erosion from the entire catchment. Here we show that the common practice of collecting a narrow range of sizes—typically sand—may not yield a representative sample when the grain size distribution of sediment produced on slopes is spatially variable. A grain size bias arises when some parts of the catchment produce sand more readily than others. To identify catchments that are prone to this bias, we used a forward model of sediment mixing and erosion to explore the effects of catchment relief and area across a range of altitudinal gradients in sediment size and erosion rate. We found that the bias increases with increasing relief, because higher‐relief catchments have a larger fraction of high elevations that are underrepresented in the sampled sand when grain size increases with altitude. The bias also increases with catchment area, because sediment size reduction during transport causes an underrepresentation of more distal, higher elevations within the catchment. Our analysis indicates that grain size bias may be significant at many sites where cosmogenic nuclides have been used to quantify catchment‐average erosion rates. We discuss how to quantify and account for the bias using cosmogenic nuclides and detrital thermochronometry in multiple sediment sizes.
Recent Advances in Breaking Scaling Relations for Effective Electrochemical Conversion of CO2
Authors: Li Yawei , Sun Qiang
Published: April 2016

The increasing concentration of CO2 in the atmosphere, and the resulting environmental problems, call for effective ways to convert CO2 into valuable fuels and chemicals for a sustainable carbon cycle. In such a context, CO2 electrocatalytic reduction has been hotly studied due to the merits of ambient operational conditions and easy control of the reaction process by changing the applied potential. Among the various systems studied, Cu and Au are found to possess the highest Faradaic efficiency toward cathodic electrocatalytic conversion of CO2 to hydrocarbons and CO, respectively. However, both of them suffer from large overpotentials owing to the limitations imposed by the scaling relations between the carbonaceous adsorbates. Therefore, establishing how to break the scaling relations for effective electrochemical conversion of CO2 has become an urgent research topic. The recent advances in breaking the adsorption energy scaling relations to reduce the overpotential, improve the catalytic activity and suppress the side reaction, are summarized. The origin of the scaling relations, their negative effects on CO2 electrocatalysis, and the strategies for breaking the limitations are discussed. Some suggestions for future study are also proposed.
Engineering model for intumescent coating behavior in a pilot‐scale gas‐fired furnace
Authors: Nørgaard Kristian Petersen , Dam‐Johansen Kim , Kiil Søren , Català Pere
Published: April 2016

In the event of a fire, intumescent fire protective coatings expand and form a thermally insulating char that protects the underlying substrate from heat and subsequent structural failure. The intumescence includes several rate phenomena, which have been investigated and quantified in the literature for several decades. However, various challenges still exist. The most important one concerns mathematical model validation under realistic exposure conditions and/or time scales. Another is the simplification of advanced models to overcome the often‐seen lack of a complete set of input and adjustable model parameters for a given coating, thereby providing models for industrial applications. In this work, these two challenges are addressed. Three experimental series, with an intumescent coating inside a 0.65 m3 gas‐fired furnace, heating up according to so‐called cellulosic fire conditions, were conducted and a very good repeatability was evident. The experiments were run for almost 3 h, reaching a final gas temperature of about 1100°C. Measurements include transient temperature developments inside the expanding char, at the steel substrate, and in the mineral wool insulation placed behind the substrate. A mathematical model, describing the intumescent coating behavior and temperatures in the furnace using a single overall reaction was developed and validated against experimental data. By including a decomposition front movement through the char, a good qualitative agreement was obtained. After further validation against experiments with other coating formulations, it has potential to become a practical engineering tool. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3947–3962, 2016
Cytomegalovirus infection does not impact on survival or time to first treatment in patients with chronic lymphocytic leukemia
Authors: Parry Helen Marie , Damery Sarah , Hudson Christopher , Maurer Matthew J. , Cerhan James R. , Pachnio Annette , Begum Jusnara , Slager Susan L. , Fegan Christopher , Man Stephen , Pepper Christopher , Shanafelt Tait D. , Pratt Guy , Moss Paul A. H.
Published: April 2016

Human cytomegalovirus (HCMV) is a widely prevalent herpes virus which establishes a state of chronic infection. The establishment of CMV‐specific immunity controls viral reactivation and leads to the accumulation of very large numbers of virus‐specific T cells which come to dominate the immune repertoire. There is concern that this may reduce the immune response to heterologous infections and HCMV infection has been associated with reduced survival in elderly people. Patients with chronic lymphocytic leukemia (B‐CLL) suffer from a state of immune suppression but have a paradoxical increase in the magnitude of the CMV‐specific T cell and humoral immune response. As such, there is now considerable interest in how CMV infection impacts on the clinical outcome of patients with B‐CLL. Utilizing a large prospective cohort of patients with B‐CLL (n = 347) we evaluated the relationship between HCMV seropositivity and patient outcome. HCMV seropositive patients had significantly worse overall survival than HCMV negative patients in univariate analysis (HR = 2.28, 95% CI: 1.34–3.88; P = 0.002). However, CMV seropositive patients were 4 years older than seronegative donors and this survival difference was lost in multivariate modeling adjusted for age and other validated prognostic markers (P = 0.34). No significant difference was found in multivariate modeling between HCMV positive and negative patients in relation to the time to first treatment (HR = 1.12, 95% CI: 0.68–1.84; P = 0.65). These findings in a second independent cohort of 236 B‐CLL patients were validated. In conclusion no evidence that HCMV impacts on the clinical outcome of patients with B‐CLL was found. Am. J. Hematol. 91:776–781, 2016. © 2016 Wiley Periodicals, Inc.
Shwachman–Diamond syndrome presenting with early ichthyosis, associated dermal and epidermal intracellular lipid droplets, hypoglycemia, and later distinctive clinical SDS phenotype
Authors: Scalais Emmanuel , Connerotte Anne‐Catherine , Despontin Karine , Biver Armand , Ceuterick‐de Groote Chantal , Alders Marielle , Kolivras Athanassios , Hachem Jean‐Pierre , De Meirleir Linda
Published: April 2016

Shwachman–Diamond syndrome (SDS) is a recessive ribosomopathy, characterized by bone marrow failure and exocrine pancreatic insufficiency (ePI) often associated with neurodevelopmental and skeletal abnormalities. The aim of this report is to describe a SDS patient with early ichthyosis associated with dermal and epidermal intracellular lipid droplets (iLDs), hypoglycemia and later a distinctive clinical SDS phenotype. At 3 months of age, she had ichthyosis, growth retardation, and failure to thrive. She had not cytopenia. Ultrasonography (US) showed pancreatic diffuse high echogenicity. Subsequently fasting hypoketotic hypoglycemia occurred without permanent hepatomegaly or hyperlipidemia. Continuous gavage feeding was followed by clinical improvement including ichthyosis and hypoglycemia. After 14 months of age, she developed persistent neutropenia and ePI consistent with SDS. The ichthyotic skin biopsy, performed at 5 months of age, disclosed iLDs in all epidermal layers, in melanocytes, eccrine sweat glands, Schwann cells and dermal fibroblasts. These iLDs were reminiscent of those described in Dorfman–Chanarin syndrome (DCS) or Wolman's disease. Both LIPA and CGI‐58 analysis did not revealed pathogenic mutation. By sequencing SBDS, a compound heterozygous for a previously reported gene mutation (c.258 + 2T>C) and a novel mutation (c.284T>G) were found. Defective SBDS may hypothetically interfere as in DCS, with neutral lipid metabolism and play a role in the SDS phenotype such as ichthyosis with dermal and epidermal iLDs and hypoglycemia. This interference with neutral lipid metabolism must most likely occur in the cytoplasm compartment as in DCS and not in the lysosomal compartment as in Wolman's disease. © 2016 Wiley Periodicals, Inc.
NIPBL expression levels in CdLS probands as a predictor of mutation type and phenotypic severity
Authors: Kaur Maninder , Mehta Devanshi , Noon Sarah E. , Deardorff Matthew A. , Zhang Zhe , Krantz Ian D.
Published: April 2016

Cornelia de Lange syndrome (CdLS) is a rare, genetically heterogeneous multisystem developmental disorder with a high degree of variability in its clinical presentation. Approximately 65% of probands harbor mutations in genes that encode core components (SMC1A, SMC3, and RAD21) or regulators (NIPBL, HDAC8) of the cohesin complex, of which mutations in NIPBL are the most common. Cohesin plays a canonical role in sister chromatid cohesion during cell division and non‐canonical roles in DNA repair, stem cell maintenance and differentiation, and regulation of gene expression. Disruption of the latter role seems to be the major contributor to the underlying molecular pathogenesis of CdLS. NIPBL is required for loading and unloading the cohesin complex onto chromosomes. The expression levels of NIPBL itself appear to be tightly regulated and highly evolutionarily conserved. Droplet digital PCR was used to quantify NIPBL mRNA expression levels with high precision from a cohort of 37 samples (NIPBL, SMC1A, SMC3, and HDAC8 mutation positive probands and negative control). Probands with severe forms of CdLS or severe mutation types were found to have lower levels of NIPBL in comparison to phenotypically milder patients and controls. Levels of NIPBL also correlated with the presence of mutations in different CdLS‐causing genes. The data suggests that NIPBL levels are closely correlated with the severity of CdLS and with specific causative genes and types of mutations. ddPCR may provide a tool to assist in diagnostic approaches to CdLS, for genetic counseling and prognosis, and for monitoring potential therapeutic modalities in the future. © 2016 Wiley Periodicals, Inc.
Hearing loss, coloboma and left ventricular enlargement in a boy with an interstitial 10q26 deletion
Authors: Ramos Maria , Wilkens Alisha , Krantz Ian D. , Wu Yaning
Published: April 2016

Distal deletion of the long arm of chromosome 10 with breakpoints mapped at 10q26 is a well‐recognized contiguous genomic disorder. A wide spectrum of clinical findings is seen in affected individuals and the common clinical features include craniofacial dysmorphia, developmental delay, intellectual disability, hypotonia, cardiovascular defects, and urogenital malformations. We report herein on a male patient with a 5.5 Mb interstitial deletion of 10q26.11q2613 and compare his clinical presentation to previously reported cases. Apart from characteristic phenotypes seen in 10q26 deletion syndrome, he presents with colobomas and left ventricle enlargement. These are cardiovascular and ophthalmological findings that have not been described in prior cases. © 2016 Wiley Periodicals, Inc.
The osgood criterion and finite‐time cosmological singularities
Authors: Kohli Ikjyot Singh
Published: April 2016

In this paper, we apply Osgood's criterion from the theory of ordinary differential equations to detect finite‐time singularities in a spatially flat FLRW universe in the context of a perfect fluid, a perfect fluid with bulk viscosity, and a Chaplygin and anti‐Chaplygin gas. In particular, we applied Osgood's criterion to demonstrate singularity behaviour for Type 0/big crunch singularities as well as Type II/sudden singularities. We show that in each case the choice of initial conditions is important as a certain number of initial conditions leads to finite‐time, Type 0 singularities, while other precise choices of initial conditions which depend on the cosmological matter parameters and the cosmological constant can avoid such a finite‐time singularity. Osgood's criterion provides a powerful and yet simple way of deducing the existence of these singularities, and also interestingly enough, provides clues of how to eliminate singularities from certain cosmological models.
Isorecticular Synthesis of Dissectible Molecular Bamboo Tubes of Hexarhenium(I) Benzene‐1,2,3,4,5,6‐hexaolate Complexes
Authors: Tseng Tien‐Wen , Luo Tzuoo‐Tsair , Liao Shi‐Hao , Lu Kai‐Hsiang , Lu Kuang‐Lieh
Published: April 2016

A family of bamboo‐like metal–organic nanotubes consisting of in situ synthesized macromolecular blocks (MB) is reported. The MBs are composed of six fac‐(CO)3Re cores, one benzene‐1,2,3,4,5,6‐hexaolate plate, and six pyridine‐derivative pillar ligands, which have a doubly tri‐legged geometry and can be mutually assembled, piece by piece. This entire system is characterized as a simple but precise supramolecular complexation of these macromolecular blocks and further introduces an archetypal approach to systematically constructing a tunable form of dissectible molecular bamboo tubes.
Efficient Palladium‐Assisted One‐Pot Deprotection of (Acetamidomethyl)Cysteine Following Native Chemical Ligation and/or Desulfurization To Expedite Chemical Protein Synthesis
Authors: Maity Suman Kumar , Jbara Muhammad , Laps Shay , Brik Ashraf
Published: April 2016

The acetamidomethyl (Acm) moiety is a widely used cysteine protecting group for the chemical synthesis and semisynthesis of peptide and proteins. However, its removal is not straightforward and requires harsh reaction conditions and additional purification steps before and after the removal step, which extends the synthetic process and reduces the overall yield. To overcome these shortcomings, a method for rapid and efficient Acm removal using PdII complexes in aqueous medium is reported. We show, for the first time, the assembly of three peptide fragments in a one‐pot fashion by native chemical ligation where the Acm moiety was used to protect the N‐terminal Cys of the middle fragment. Importantly, an efficient synthesis of the ubiquitin‐like protein UBL‐5, which contains two native Cys residues, was accomplished through the one‐pot operation of three key steps, namely ligation, desulfurization, and Acm deprotection, highlighting the great utility of the new approach in protein synthesis.
Post‐Synthetic Decoupling of On‐Surface‐Synthesized Covalent Nanostructures from Ag(111)
Authors: Rastgoo‐Lahrood Atena , Björk Jonas , Lischka Matthias , Eichhorn Johanna , Kloft Stephan , Fritton Massimo , Strunskus Thomas , Samanta Debabrata , Schmittel Michael , Heckl Wolfgang M. , Lackinger Markus
Published: April 2016

The on‐surface synthesis of covalent organic nanosheets driven by reactive metal surfaces leads to strongly adsorbed organic nanostructures, which conceals their intrinsic properties. Hence, reducing the electronic coupling between the organic networks and commonly used metal surfaces is an important step towards characterization of the true material. We demonstrate that post‐synthetic exposure to iodine vapor leads to the intercalation of an iodine monolayer between covalent polyphenylene networks and Ag(111) surfaces. The experimentally observed changes from surface‐bound to detached nanosheets are reproduced by DFT simulations. These findings suggest that the intercalation of iodine provides a material that shows geometric and electronic properties substantially closer to those of the freestanding network.
Moisture sorption isotherm characteristics of Hemerocallis Fulva and Cymbopogon
Authors: Ma Chih‐Ming , Chen Hua‐Wei , Hong Gui‐Bing
Published: April 2016

The moisture sorption isotherms of Hemerocallis Fulva and Cymbopogon are measured by the static gravimetric method at 25, 35, and 45 °C over a water activity range of 0.09 to 0.95 using standard saturated salt solutions. The sorption isotherms of H. fulva and Cymbopogon display type III (J‐shaped) and type II (nearly sigmoid shapes) isotherms. In addition, the adsorption and desorption data of H. fulva and Cymbopogon fit well with the White & Eiring model and the Oswin model, respectively. The Brunauer–Emmett–Teller equation is applied to determine the monolayer moisture content, and the surface area of a monolayer was calculated. The values of the net isosteric heat of sorption are found to increase with decreases in the equilibrium moisture content. Moreover, the net isosteric heat of desorption is higher than that of the adsorption heat. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Polyester composite water uptake and organic contaminant release affected by carbon nanofiber reinforcements
Authors: Salehi Maryam , Krishnamurthy Ajay , Forster Aaron M. , Hsiao Kuang–Ting , Whelton Andrew J.
Published: April 2016

The incorporation of carbon nanofiber (CNF) into glass fiber (GF) composites is a potential route to extend polymer composite service‐life and enhance mechanical properties. Under nonstatic conditions, only limited information concerning water uptake and contaminant release properties of nanocomposite materials is currently available. Polyester composites containing GF and oxidized CNF were immersed in water for 30 days under nominal pressure at 23 °C, below the polymer's glass‐transition temperature. Water was analyzed and changed every three days to simulate water chemistry regeneration similar to exposures in flowing systems. Composites with oxidized CNF had greater water sorption capacity and leaching rates than CNF‐free composites. The total mass of organic contaminant released correlated with the amount of water sorbed by each composite (r2 = 0.91), although CNF dispersion was found to vary greatly within composites. The greatest and least contaminant release rates were found for the polyester‐CNF and the polyester‐GF composites, respectively. While volatile aromatic resin solvents and stabilizer compounds were detected, their concentrations declined over the 30 day exposure period. We hypothesize that the hydrophilic nature of the oxidized CNF increased the water sorption capacity of the polyester composites. Additional studies are warranted that examine the impact of this phenomenon on composite mechanical and long‐term durability properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43724.
Ca2Al2SiO7:Ce3+ phosphors for mechanoluminescence dosimetry
Authors: Tiwari Geetanjali , Brahme Nameeta , Sharma Ravi , Bisen D. P. , Sao Sanjay Kumar , Sahu Ishwar Prasad
Published: April 2016

A series of Ce3+ ion single‐doped Ca2Al2SiO7 phosphors was synthesized by a combustion‐assisted method at an initiating temperature of 600 °C. The samples were annealed at 1100 °C for 3 h and their X‐ray diffraction patterns confirmed a tetragonal structure. The phase structure, particle size, surface morphology and elemental analysis were analyzed using X‐ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX) spectroscopy techniques. Thermoluminescence (TL) intensity increased with increase in ultraviolet (UV) light exposure time up to 15 min. With further increase in the UV irradiation time the TL intensity decreases. The increase in TL intensity indicates that trap concentration increased with UV exposure time. A broad peak at 121 °C suggested the existence of a trapping level. The peak of mechanoluminescence (ML) intensity versus time curve increased linearly with increasing impact velocity of the moving piston. Mechanoluminescence intensity increased with increase in UV irradiation time up to 15 min. Under UV‐irradiation excitation, the TL and ML emission spectra of Ca2Al2SiO7:Ce3+ phosphor showed the characteristic emission of Ce3+ peaking at 400 nm (UV–violet) and originating from the Ce3+ transitions of 5d‐4f (2F5/2 and 2F7/2). The photoluminescence (PL) emission spectra for Ca2Al2SiO7:Ce3+ were similar to the ML/TL emission spectra. The mechanism of ML excitation and the suitability of the Ca2Al2SiO7:Ce3+phosphor for radiation dosimetry are discussed. Copyright © 2016 John Wiley & Sons, Ltd.
Modification in hydrophobic packing of HAMP domain induces a destabilization of the auto‐phosphorylation site in the histidine kinase CpxA
Authors: Martinez Marlet , Duclert‐Savatier Nathalie , Betton Jean‐Michel , Alzari Pedro M. , Nilges Michael , Malliavin Thérèse E.
Published: April 2016

The histidine kinases belong to the family of two‐component systems, which serves in bacteria to couple environmental stimuli to adaptive responses. Most of the histidine kinases are homodimers, in which the HAMP and DHp domains assemble into an elongated helical region flanked by two CA domains. Recently, X‐ray crystallographic structures of the cytoplasmic region of the Escherichia coli histidine kinase CpxA were determined and a phosphotransferase‐defective mutant, M228V, located in HAMP, was identified. In the present study, we recorded 1 μs molecular dynamics trajectories to compare the behavior of the WT and M228V protein dimers. The M228V modification locally induces the appearance of larger voids within HAMP as well as a perturbation of the number of voids within DHp, thus destabilizing the HAMP and DHp hydrophobic packing. In addition, a disruption of the stacking interaction between F403 located in the lid of the CA domain involved in the auto‐phosphorylation and R296 located in the interacting DHp region, is more often observed in the presence of the M228V modification. Experimental modifications R296A and R296D of CpxA have been observed to reduce also the CpxA activity. These observations agree with the destabilization of the R296/F403 stacking, and could be the sign of the transmission of a conformational event taking place in HAMP to the auto‐phosphorylation site of histidine kinase. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 670–682, 2016.
The stroke east Saxony pilot project for organized post‐stroke care: a case–control study
Authors: Bodechtel Ulf , Barlinn Kristian , Helbig Uwe , Arnold Katrin , Siepmann Timo , Pallesen Lars‐Peder , Puetz Volker , Reichmann Heinz , Schmitt Jochen , Kepplinger Jessica
Published: April 2016

Background

Low adherence to secondary prevention guidelines in stroke survivors may increase the risk for recurrent stroke and adversely impact quality of life. We aimed to determine the feasibility of a self‐developed standardized post‐stroke pathway and its impact on secondary stroke prevention and long‐term outcome in patients with acute stroke.

Methods

Consecutive patients with acute stroke were prospectively included in a standardized post‐stroke pathway accomplished through a single certified CM (case manager), which comprised educational discussions and quarterly checkups for vascular risk factors and adherence to antithrombotic/anticoagulant medication in addition to usual care. At 12 months, we compared achieved target goals for secondary prevention, functional outcome, stroke recurrence, and vascular death with age‐ and gender‐matched controls that received only usual care after stroke.

Results

We included 45 cases and 45 controls. The following target goals were more frequently achieved in CM‐patients than in controls: blood pressure (100% vs. 46.2%, P < 0.001), cholesterol (100% vs. 74.4%, P < 0.001), and body mass index (67.4% vs. 46.2%, P = 0.052). The CM‐intervention emerged as an independent predictor of favorable functional outcome (mRS ≤ 2) at 12 months after adjusting for stroke severity and systemic thrombolysis (OR: 4.27; 95%CI:1.2–15.21; P = 0.025). Quality of life was rated significantly higher in CM‐patients than in controls (P = 0.049). As opposed to controls, none of the cases experienced a recurrent stroke (0% vs. 13.3%; P = 0.026) or suffered from vascular death (0% vs. 6.7%; P = 0.242).

Conclusions

Our pilot data suggest that organized post‐stroke care enhances achievement of secondary prevention goals. Its possible effect on stroke recurrence, long‐term disability, and quality of life is currently investigated in a prospective cohort study.
Isolation and characterization of circulating tumor cells using a novel workflow combining the CellSearch® system and the CellCelector™
Authors: Neumann Martin Horst Dieter , Schneck Helen , Decker Yvonne , Schömer Susanne , Franken André , Endris Volker , Pfarr Nicole , Weichert Wilko , Niederacher Dieter , Fehm Tanja , Neubauer Hans
Published: April 2016

Circulating tumor cells (CTC) are rare cells which have left the primary tumor to enter the blood stream. Although only a small CTC subgroup is capable of extravasating, the presence of CTCs is associated with an increased risk of metastasis and a shorter overall survival. Understanding the heterogeneous CTC biology will optimize treatment decisions and will thereby improve patient outcome. For this, robust workflows for detection and isolation of CTCs are urgently required. Here, we present a workflow to characterize CTCs by combining the advantages of both the CellSearch® and the CellCelector™ micromanipulation system. CTCs were isolated from CellSearch® cartridges using the CellCelector™ system and were deposited into PCR tubes for subsequent molecular analysis (whole genome amplification (WGA) and massive parallel multigene sequencing). By a CellCelector™ screen we reidentified 97% of CellSearch® SKBR‐3 cells. Furthermore, we isolated 97% of CellSearch®‐proven patient CTCs using the CellCelector™ system. Therein, we found an almost perfect correlation of R2 = 0.98 (Spearman's rho correlation, n = 20, p < 0.00001) between the CellSearch® CTC count (n = 271) and the CellCelector™ detected CTCs (n = 252). Isolated CTCs were analyzed by WGA and massive parallel multigene sequencing. In total, single nucleotide polymorphisms (SNPs) could be detected in 50 genes in seven CTCs, 12 MCF‐7, and 3 T47D cells, respectively. Taken together, CTC quantification via the CellCelector™ system ensures a comprehensive detection of CTCs preidentified by the CellSearch® system. Moreover, the isolation of CTCs after CellSearch® using the CellCelector™ system guarantees for CTC enrichment without any contaminants enabling subsequent high throughput genomic analyses on single cell level. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:125–132, 2017
Toward intensifying design of experiments in upstream bioprocess development: An industrial Escherichia coli feasibility study
Authors: von Stosch Moritz , Hamelink Jan‐Martijn , Oliveira Rui
Published: April 2016

In this study, step variations in temperature, pH, and carbon substrate feeding rate were performed within five high cell density Escherichia coli fermentations to assess whether intraexperiment step changes, can principally be used to exploit the process operation space in a design of experiment manner. A dynamic process modeling approach was adopted to determine parameter interactions. A bioreactor model was integrated with an artificial neural network that describes biomass and product formation rates as function of varied fed‐batch fermentation conditions for heterologous protein production. A model reliability measure was introduced to assess in which process region the model can be expected to predict process states accurately. It was found that the model could accurately predict process states of multiple fermentations performed at fixed conditions within the determined validity domain. The results suggest that intraexperimental variations of process conditions could be used to reduce the number of experiments by a factor, which in limit would be equivalent to the number of intraexperimental variations per experiment. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1343–1352, 2016
Endophytic Actinobacteria from the Brazilian Medicinal Plant Lychnophora ericoides Mart. and the Biological Potential of Their Secondary Metabolites
Authors: Conti Raphael , Chagas Fernanda Oliveira , Caraballo‐Rodriguez Andrés Mauricio , Melo Weilan Gomes da Paixão , do Nascimento Andréa Mendes , Cavalcanti Bruno Coêlho , de Moraes Manoel Odorico , Pessoa Cláudia , Costa‐Lotufo Letícia Veras , Krogh Renata , Andricopulo Adriano Defini , Lopes Norberto Peporine , Pupo Mônica Tallarico
Published: April 2016

Endophytic actinobacteria from the Brazilian medicinal plant Lychnophora ericoides were isolated for the first time, and the biological potential of their secondary metabolites was evaluated. A phylogenic analysis of isolated actinobacteria was accomplished with 16S rRNA gene sequencing, and the predominance of the genus Streptomyces was observed. All strains were cultured on solid rice medium, and ethanol extracts were evaluated with antimicrobial and cytotoxic assays against cancer cell lines. As a result, 92% of the extracts showed a high or moderate activity against at least one pathogenic microbial strain or cancer cell line. Based on the biological and chemical analyses of crude extracts, three endophytic strains were selected for further investigation of their chemical profiles. Sixteen compounds were isolated, and 3‐hydroxy‐4‐methoxybenzamide (9) and 2,3‐dihydro‐2,2‐dimethyl‐4(1H)‐quinazolinone (15) are reported as natural products for the first time in this study. The biological activity of the pure compounds was also assessed. Compound 15 displayed potent cytotoxic activity against all four tested cancer cell lines. Nocardamine (2) was only moderately active against two cancer cell lines but showed strong activity against Trypanosoma cruzi. Our results show that endophytic actinobacteria from L. ericoides are a promising source of bioactive compounds.
Study of Lanthanum Manganate and Yttrium‐Stabilized Zirconia‐Supported Palladium Dual‐Bed Catalyst System for the Total Oxidation of Methane: A Study by 18O2/16O2 Isotopic Exchange
Authors: Richard Mélissandre , Can Fabien , Gil Sonia , Giroir‐Fendler Anne , Duprez Daniel , Bion Nicolas
Published: April 2016

A significant enhancement of the yttrium‐stabilized zirconia‐supported palladium (0.2 wt % Pd/YSZ) catalytic activity for the total oxidation of methane was achieved in a dual‐bed system by the association of LaMnO3+Pd/YSZ materials. The combination with the best performance was 40 wt % LaMnO3+60 wt % Pd/YSZ. Pd/YSZ and LaMnO3 perovskite were characterized by using the 18O2 exchange technique. A Mars–van Krevelen mechanism was demonstrated over Pd/YSZ at 425 °C. Additionally, it was evidenced that LaMnO3 activated the O2 molecule on the YSZ oxygen vacancy sites to result in a significant increase of the oxidation rate characterized by a correlating decrease of the light‐off temperature of 65 °C.
ChemInform Abstract: CORROSION KINETICS IN LOW CONDUCTIVITY MEDIA. I. IRON IN NATURAL WATERS
Authors: MANSFELD F. , KENDIG M. W. , TSAI S.
Published: April 2016

Unter Verwendung von rotierenden F e‐Cylinder‐Elektroden werden potentiodynamische Polarisationskurven mit automatischer Kompensation des Ohmschen Abfalls und Wechselstromimpedanz‐Spektren von Leitungswasser und von korrodierendem Wasser (ASTM) mit Zusätzen von NaClO4 oder NaNOz und frei von Zusätzen aufgenommen.
ChemInform Abstract: CAUSTIC CRACKING OF 9% CHROMIUM‐1% MOLYBDENUM STEEL AT 300°
Authors: POULSON B.
Published: April 2016

Hitzebehandelter 9Cr‐lMo‐Stahl ist in 1‐8 M NaOH‐Lösungen bei 300°C für die Spannungsrißkorrosion bei niedrigen Zuggeschwindigkeiten anfällig.
ChemInform Abstract: REDUCTION OF NITRIC OXIDE BY TIN(II)
Authors: HENDRIKSEN D. E. , POWELL R. E.
Published: April 2016

Die Kinetik der nicht katalysierten Reduktion von NO durch Sn" in wäßriger Lösung zu N2O und N, (als Nebenprodukt) wird untersucht.
ChemInform Abstract: CHIRAL LACTOLS. I. 2,3,3A,4,5,6,7,7A‐OCTAHYDRO‐7,8,8‐TRIMETHYL‐4,7‐METHANOBENZOFURAN‐2‐YL PROTECTIVE GROUP
Authors: NOE C. R.
Published: April 2016

Reduktion der optisch aktiven Camphersäure (I) mit Diboran ‐ erzeugt in situ aus Natriumborhydrid und Bortrifluoridetherat ‐ gefolgt von Tosylierung gibt die Tosylate (II)‐(IV).
ChemInform Abstract: AN IMPROVED PROCEDURE FOR PREPARING AND UTILIZING ALKALI METAL ACETYLIDES
Authors: FISCH A. , COISNE J. M. , FIGEYS H. P.
Published: April 2016

Acetylen (I), das in flüssigem Ammoniak gelöst ist, bildet mit Alkalimetallen wie Natrium oder Lithium rasch die Monoalkaliacetylide (II), die als fein verteiltes Pulver anfallen und mit Carbonylverbindungen (III) Ethinylcarbinole (IV) in guten Ausbeuten ergeben.
ChemInform Abstract: PHOTOCHEMICAL ADDITION OF NITRENES TO VINYLIC ETHERS AND UNSATURATED SUGARS
Authors: KOZLOWSKA‐GRAMSZ E. , DESCOTES G.
Published: April 2016

Die Photolyse der Dihydropyrane (I) in Gegenwart des Azidoformiates (II) als Nitren‐Quelle und der Alkohole (III) liefert über die intermediären Aziridine (IV) und/oder (V) in unterschiedlichen Mengen die Produkte (VI)‐(IX).
ChemInform Abstract: ORGANIC PHOTOCHEMISTRY. PART 58. PHOTOOXYGENATIONS OF 1H‐AZEPINE DERIVATIVES. . ISOLATION AND CHARACTERIZATION OF THE (6+2) CYCLOADDITION PRODUCT
Authors: KUMAGAI T. , TOKIDA A. , KIDOURA K. , SESHIMOTO O. , MUKAI T.
Published: April 2016

Bei der Oxidation mit Singulett‐Sauerstoff, hergestellt durch Bestrahlung in Gegenwart von Tetraphenylporphin erhält man aus den beiden 1H‐Azepin‐carbonsäureestern (Ia) und (Ib) die isomeren Addukte (II) und (III).
ChemInform Abstract: ONE‐STEP SYNTHESES OF BICYCLO(3.1.0)HEX‐3‐EN‐2‐ONE AND METHYL‐SUBSTITUTED DERIVATIVES
Authors: CHILDS R. F. , SHAW G. S. , VARADARAJAN A.
Published: April 2016

Die Photolyse von Phenolen (I) in Trifluormethansulfonsäure, im Falle von (Ia) in Gegenwart von Antimonpentafluorid, ftuhrt unter Isomerisierung zu Bicyclohexenonen (II).
ChemInform Abstract: PROTECTION OF HYDROXY GROUPS BY INTRAMOLECULAR OXIDATIVE FORMATION OF METHOXYBENZYLIDENE ACETALS WITH DDQ
Authors: OIKAWA Y. , YOSHIOKA T. , YONEMITSU O.
Published: April 2016

Bei der Oxidation mit DDQ werden die p‐Methoxybenzyl‐ether von 1,2‐ und 1,3‐Diolen zu p‐Methoxyphenyl‐acetalen kondensiert, die weiter zu Monoestern oxidiert und dann z.B. verseift werden können.
ChemInform Abstract: BIS(IODOMETHYL)MERCURY AS A METHYLENE TRANSFER REAGENT
Authors: SEYFERTH D. , HAAS C. K. , DAGANI D.
Published: April 2016

Die Herstellung von Bis‐(iodmethyl)‐quecksilber (III) wird beschrieben und seine Verwendung als Reagenz zur Addition von Methylengruppen an Olefine (IV) zu Cyclopropanen (V) wird ausführlich untersucht.