bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wintertime water‐soluble aerosol composition and particle water content in Fresno, California
Authors: Parworth Caroline L. , Young Dominique E. , Kim Hwajin , Zhang Xiaolu , Cappa Christopher D. , Collier Sonya , Zhang Qi 
Published: February 2017

AbstractThe composition and concentrations of water‐soluble gases and ionic aerosol components were measured from January to February 2013 in Fresno, CA, with a particle‐into‐liquid sampler with ion chromatography and annular denuders. The average (±1σ) ionic aerosol mass concentration was 15.0 (±9.4) µg m−3, and dominated by nitrate (61%), followed by ammonium, sulfate, chloride, potassium, nitrite, and sodium. Aerosol‐phase organic acids, including formate and glycolate, and amines including methylaminium, triethanolaminium, ethanolaminium, dimethylaminium, and ethylaminium were also detected. Although the dominant species all came from secondary aerosol formation, there were primary sources of ionic aerosols as well, including biomass burning for potassium and glycolate, sea spray for sodium, chloride, and dimethylamine, and vehicles for formate. Particulate methanesulfonic acid was also detected and mainly associated with terrestrial sources. On average, the molar concentration of ammonia was 49 times greater than nitric acid, indicating that ammonium nitrate formation was limited by nitric acid availability. Particle water was calculated based on the Extended Aerosol Inorganics Model (E‐AIM) thermodynamic prediction of inorganic particle water and κ‐Köhler theory approximation of organic particle water. The average (±1σ) particle water concentration was 19.2 (±18.6) µg m−3, of which 90% was attributed to inorganic species. The fractional contribution of particle water to total fine particle mass averaged at 36% during this study and was greatest during early morning and night and least during the day. Based on aqueous‐phase concentrations of ions calculated by using E‐AIM, the average (±1σ) pH of particles in Fresno during the winter was estimated to be 4.2 (±0.2).
Coarse‐grained debris flow dynamics on erodible beds
Authors: Lanzoni Stefano , Gregoretti Carlo , Stancanelli Laura Maria 
Published: February 2017

AbstractA systematic set of flume experiments is used to investigate the features of velocity profiles within the body of coarse‐grained debris flows and the dependence of the transport sediment concentration on the relevant parameters (runoff discharge, bed slope, grain size, and form). The flows are generated in a 10 m long laboratory flume, initially filled with a layer consisting of loose debris. After saturation, a prescribed water discharge is suddenly supplied over the granular bed, and the runoff triggers a debris flow wave that reaches nearly steady conditions. Three types of material have been used in the tests: gravel with mean grain size of 3 and 5 mm, and 3 mm glass spheres. Measured parameters included: triggering water discharge, volumetric sediment discharge, sediment concentration, flow depth, and velocity profiles. The dynamic similarity with full‐sized debris flows is discussed on the basis of the relevant dimensionless parameters. Concentration data highlight the dependence on the slope angle and the importance of the quasi‐static friction angle. The effects of flow rheology on the shape of velocity profiles are analyzed with attention to the role of different stress‐generating mechanisms. A remarkable collapse of the dimensionless profiles is obtained by scaling the debris flow velocity with the runoff velocity, and a power law characterization is proposed following a heuristic approach. The shape of the profiles suggests a smooth transition between the different rheological regimes (collisional and frictional) that establish in the upper and lower regions of the flow and is compatible with the presence of multiple length scales dictated by the type of contacts (instantaneous or long lasting) between grains.
Outcomes after diagnosis of mild cognitive impairment in a large autopsy series
Authors: Abner Erin L. , Kryscio Richard J. , Schmitt Frederick A. , Fardo David W. , Moga Daniela C. , Ighodaro Eseosa T. , Jicha Gregory A. , Yu Lei , Dodge Hiroko H. , Xiong Chengjie , Woltjer Randall L. , Schneider Julie A. , Cairns Nigel J. , Bennett David A. , Nelson Peter T. 
Published: February 2017

ObjectiveTo determine clinical and neuropathological outcomes following a clinical diagnosis of mild cognitive impairment (MCI).MethodsData were drawn from a large autopsy series (N = 1,337) of individuals followed longitudinally from normal or MCI status to death, derived from 4 Alzheimer Disease (AD) Centers in the United States.ResultsMean follow‐up was 7.9 years. Of the 874 individuals ever diagnosed with MCI, final clinical diagnoses were varied: 39.2% died with an MCI diagnosis, 46.8% with a dementia diagnosis, and 13.9% with a diagnosis of intact cognition. The latter group had pathological features resembling those with a final clinical diagnosis of MCI. In terms of non‐AD pathologies, both primary age‐related tauopathy (p < 0.05) and brain arteriolosclerosis pathology (p < 0.001) were more severe in MCI than cognitively intact controls. Among the group that remained MCI until death, mixed AD neuropathologic changes (ADNC; ≥1 comorbid pathology) were more frequent than “pure” ADNC pathology (55% vs 22%); suspected non‐Alzheimer pathology comprised the remaining 22% of cases. A majority (74%) of subjects who died with MCI were without “high”‐level ADNC, Lewy body disease, or hippocampal sclerosis pathologies; this group was enriched in cerebrovascular pathologies. Subjects who died with dementia and were without severe neurodegenerative pathologies tended to have cerebrovascular pathology and carry the MCI diagnosis for a longer interval.InterpretationMCI diagnosis usually was associated with comorbid neuropathologies; less than one‐quarter of MCI cases showed “pure” AD at autopsy. Ann Neurol 2017;81:549–559
Two‐Phase Reactions in Microdroplets without the Use of Phase‐Transfer Catalysts
Authors: Yan Xin , Cheng Heyong , Zare Richard N. 
Published: February 2017

AbstractMany important chemical transformations occur in two‐phase reactions, which are widely used in chemical, pharmaceutical, and polymer manufacturing. We present an efficient method for performing two‐phase reactions in microdroplets sheared by sheath gas without using a phase‐transfer catalyst. This avoids disadvantages such as thermal instability, high cost, and, especially, the need to separate and recycle the catalysts. We show that various alcohols can be oxidized to the corresponding aldehydes and ketones within milliseconds in moderate to good yields (50–75 %). The scale‐up of the present method was achieved at an isolated rate of 1.2 mg min−1 for the synthesis of 4‐nitrobenzylaldehyde from 4‐nitrobenzyl alcohol in the presence of sodium hypochlorite. The biphasic nature of this process, which avoids use of a phase‐transfer catalyst, greatly enhances synthetic effectiveness.
Solid‐State 17O NMR Reveals Hydrogen‐Bonding Energetics: Not All Low‐Barrier Hydrogen Bonds Are Strong
Authors: Lu Jiasheng , Hung Ivan , Brinkmann Andreas , Gan Zhehong , Kong Xianqi , Wu Gang 
Published: February 2017

AbstractWhile NMR and IR spectroscopic signatures and structural characteristics of low‐barrier hydrogen bond (LBHB) formation are well documented in the literature, direct measurement of the LBHB energy is difficult. Here, we show that solid‐state 17O NMR spectroscopy can provide unique information about the energy required to break a LBHB. Our solid‐state 17O NMR data show that the HB enthalpy of the O⋅⋅⋅H⋅⋅⋅N LBHB formed in crystalline nicotinic acid is only 7.7±0.5 kcal mol−1, suggesting that not all LBHBs are particularly strong.
An Irreversible Inhibitor of HSP72 that Unexpectedly Targets Lysine‐56
Authors: Pettinger Jonathan , Le Bihan Yann‐Vaï , Widya Marcella , van Montfort Rob L. M. , Jones Keith , Cheeseman Matthew D. 
Published: February 2017

AbstractThe stress‐inducible molecular chaperone, HSP72, is an important therapeutic target in oncology, but inhibiting this protein with small molecules has proven particularly challenging. Validating HSP72 inhibitors in cells is difficult owing to competition with the high affinity and abundance of its endogenous nucleotide substrates. We hypothesized this could be overcome using a cysteine‐targeted irreversible inhibitor. Using rational design, we adapted a validated 8‐N‐benzyladenosine ligand for covalent bond formation and confirmed targeted irreversible inhibition. However, no cysteine in the protein was modified; instead, we demonstrate that lysine‐56 is the key nucleophilic residue. Targeting this lysine could lead to a new design paradigm for HSP72 chemical probes and drugs.
Local mechanical behavior mapping of a biopolymer blend using nanoindentation, finite element computation, and simplex optimization strategy
Authors: Guessasma Sofiane , Zhang Weihong , Zhu Jihong 
Published: February 2017

ABSTRACTIn this study, we suggest a simple scheme to derive interfacial behavior using combination of nanoindentation and finite element computation. The starting point is the experimental generation of a rectangular grid composed of 32 indentations to measure the exact variation of stiffness across the interface of a bio‐based composite. A finite element simulation of nanoindentation is implemented based on elasto‐plastic material model. An optimization strategy is used to identify the behavior of all phases by matching predicted results to observed mechanical response. Results show that extent of interphase layer has a typical dimension of 8.0 ± 4.9 µm. The optimization strategy based on simplex proves to be efficient to derive the elasto‐plastic behavior of the blend across the interface with a residual value of less than 30 µN. The identification procedure demonstrates that the extent of the interfacial region depends on the measured physical quantity. The contrast across the interface for both Young's and the tangent moduli appear to be more effective than the contrast given by the yield stress. Identified Young's moduli for zein, starch, and interfacial zone are 4.78 ± 0.27, 4.13 ± 0.19, and 3.91 ± 0.17 GPa. Plasticity parameter represented by tangent modulus varies in the same order as 1238 ± 120, 847 ± 108, and 976 ± 94 MPa, respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44891.
Polymers of norbornenyl‐4‐phenol: Dissolution rate characteristics, positive tone photo‐patterning, and polymer properties
Authors: Evans Paul J. , Brick Chad M. , Bell Andrew , Kandanarachchi Pramod , Thoresen Jennifer , Rhodes Larry F. , Onishi Osamu , Ikeda Haruo , Benedikt George M. , Koronich Elaine 
Published: February 2017

ABSTRACTVinyl addition norbornene polymers with phenol pendent groups are obtained by methanolysis of the 4‐acetoxyphenyl norbornene polymer. Thin films of this polymer blended with additives such as norbornene polymers with hexafluoroalcohol pendent groups and diazonaphthoquinone compounds result in linear dissolution in tetramethylammonium hydroxide developer. Good resolution, positive tone patterns are obtained from image‐wise exposure of thin films of blends of the diazonaphthoquinone additives with both phenol pendent norbornene homopolymer and with norbornene copolymers with both phenol and hexafluoroalcohol pendent groups. Properties such as transparency, dielectric constant, chemical, and thermal resistance were determined for cured copolymer compositions containing an epoxy crosslinker. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44952.
Preparation and characterization of binary blends composed of poly(dioctylfluorene‐alt‐hexylsulfonylthiophene) and nonconjugated polymers
Authors: Chiu Hsien‐Tang , Yu Chin‐Yang , Wang Yu‐Hsiang , Wu Szu‐Han 
Published: February 2017

ABSTRACTThe solutions and the thin films of poly[9,9‐dioctyl‐2,7‐fluorene‐alt‐2,5–(3‐hexyl‐sulfonylthiophene)] (PFSO2T) and its binary blends with other nonconjugated polymers such as poly(methyl methacrylate) (PMMA), polycarbonate (PC), and ethylene vinyl acetate copolymer (EVA) can be prepared by different concentrations from a polymer solution. Binary polymer blends can increase the absorbance and photoluminescence intensities in the solid state due to nonconjugated polymers can act as dispersion agents which can reduce the interchain interaction or the aggregation of the conjugated polymers. Photoluminescence intensity of the thin films of fluorescent polymers blending with ethylene vinyl acetate copolymers exhibited six times higher than that of the neat fluorescent polymers. The PFSO2T/EVA binary blends reveal the least extent of optical degradation of around 20% compared to those binary blends in both absorption and emission intensities after the irradiation under the UV‐light for 20 h. The cross‐sectional morphology of fluorescent polymers blending with ethylene vinyl acetate copolymers reveals little aggregation and better phase separation among the other binary polymer blends. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44969.
The adipokinetic hormone of Mantodea in comparison to other Dictyoptera
Authors: Gäde Gerd , Marco Heather G. 
Published: February 2017

AbstractSix species of the order Mantodea (praying mantises) are investigated for the presence and sequence of putative adipokinetic hormones (AKHs). The selected species span a wide evolutionary range of various families and subfamilies of the clade Mantodea. The corpora cardiaca of the different species are dissected, methanolic extracts prepared, peptides separated by liquid chromatography, and AKHs detected and sequenced by ion trap mass spectrometry. All six species investigated contain an octapeptide with the primary structure pGlu‐Val‐Asn‐Phe‐Thr‐Pro‐Asn‐Trp amide, which is code‐named Emppe‐AKH and had been found earlier in three other species of Mantodea. Conspecific bioassays with the species Creoboter sp. (family Hymenopodidae) reveal an adipokinetic but not a hypertrehalosemic function of Emppe‐AKH. Comparison with other members of the Dictyoptera (cockroaches, termites) show that Emppe‐AKH is only found in certain termites, which have been recently placed into the Blattaria (cockroaches) as sister group to the family Cryptocercidae. Termites and cockroaches both show biodiversity in the sequence of AKHs, and some cockroach species even contain two AKHs. In contrast, all praying mantises—irrespective of their phylogenetic position—synthesize uniformly only one and the same octapeptide Emppe‐AKH.
Stereoisomerization of Cyclic Silanols
Authors: Endo Hisayuki , Takeda Nobuhiro , Unno Masafumi 
Published: February 2017

AbstractStereoisomerization of readily available all‐cis‐1,3,5,7‐tetrahydroxy‐1,3,5,7‐tetraisobutylcyclotetrasiloxane (1 a) was carried out under acidic conditions to afford cis‐trans‐cis (1 b), all‐trans (1 c), and cis‐cis‐trans (1 d) isomers. The compounds in the reaction mixture could be easily separated into 1 a and a mixture of 1 b, 1 c, and 1 d by the treatment with chloroform. Compounds 1 b, 1 c, and 1 d were further separated and isolated, and each structure was identified. The experimental results indicated that the most plausible mechanism is a substitution reaction at the silicon center via a pentacoordinate intermediate without a cyclic siloxane bond cleavage reaction. The obtained isomer 1 a or 1 b further reacted with dichlorodiphenylsilane in the presence of triethylamine to give syn‐type laddersiloxane (2 a) or anti‐type laddersiloxane (2 b), respectively.
Characteristics of wet and dry spells in the West African monsoon system
Authors: Froidurot Stéphanie , Diedhiou Arona 
Published: February 2017

AbstractUsing 17 years (1998–2014) of daily TRMM 3B42 rainfall data, we provide a climatological characterization of wet and dry spells in West Africa, which should serve to assess the ability of climate model to simulate these high impact events. The study focuses on four subregions (Western and Central Sahel, Sudanian zone and Guinea Coast). Defining wet (dry) spells as sequences of consecutive days with precipitation higher (lower) than 1 mm, we describe the space‐time variability of wet and dry spell occurrence. This climatology stresses the influence of the relief on the number and duration of these spells. The spatio‐temporal variability of the wet and dry spells also appears to be closely related to the spatio‐temporal variability of the West African monsoon. The number of wet spells of all durations and of 2–3 day dry spells have similar features with a maximum occurrence during the local rainy seasons and a spatial pattern similar to the mean annual rainfall with a north–south gradient. In contrast, dry spells lasting more than four days show some singularities such as a low occurrence over the Sahelian band or high occurrence along the Guinea Coast mainly from Ivory Coast to Benin. Moreover, the seasonal cycle of these longer dry spells presents higher occurrences at the beginning and the end of the rainy seasons.
CADASIL: Ultrastructural insights into the morphology of granular osmiophilic material
Authors: Lorenzi Teresa , Ragno Michele , Paolinelli Francesca , Castellucci Clara , Scarpelli Marina , Morroni Manrico 
Published: February 2017

AbstractIntroductionCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary systemic vascular disorder. Granular osmiophilic material (GOM) is its ultrastructural marker. We reviewed tissue biopsies from CADASIL patients to establish whether ultrastructural observations help clarify the pathogenic mechanism of CADASIL. Given the resemblance of the GOM deposits to the immunoglobulin deposits seen in glomerulonephritis and focal segmental glomerulosclerosis (FSGS), their morphologies were investigated and compared.MethodsSkin, skeletal muscle, kidney, and pericardium tissue biopsies from 13 patients with a clinical and molecular diagnosis of CADASIL, and kidney biopsies from five patients with IgA nephropathy and five patients with primary FSGS were subjected to ultrastructural examination.ResultsIn CADASIL patients, several GOM deposits from all sites were partially or totally surrounded by an electron‐lucent halo. The deposits frequently had a more electron‐dense portion with a regular outline on the inner side and a less osmiophilic, looser outer side displaying a less regular profile. The uniformly dense deposits tended to be more osmiophilic if located close to the cell membrane and less osmiophilic if laid farther away from it. The immunoglobulin deposits from the glomerulonephritis and FSGS patients lacked both the granular pattern and the halo.ConclusionsThis study demonstrates that GOM deposits may have a nonuniform morphology and describes in detail an electron‐lucent halo surrounding several of them. It is conceivable that the halo is the morphological evidence and possibly the cause of an aberrant NOTCH3 processing, already suspected to be involved in CADASIL.
Controlling Cellular Uptake and Toxicity of Polyphenylene Dendrimers by Chemical Functionalization
Authors: Hammer Brenton A. G. , Wu Yuzhou , Fischer Stephan , Liu Weina , Weil Tanja , Müllen Klaus 
Published: February 2017

AbstractPolyphenylene dendrimers (PPDs) represent a unique class of macromolecules based on their monodisperse and shape‐persistent nature. These characteristics have enabled the synthesis of a new genre of “patched” surface dendrimers, where their exterior can be functionalized with a variety of polar and nonpolar substituents to yield lipophilic binding sites in a site‐specific way. Although such materials are capable of complexing biologically relevant molecules, show high cellular uptake in various cell lines, and low to no toxicity, there is minimal understanding of the driving forces to these characteristics. We investigated whether it is the specific chemical functionalities, relative quantities of each moiety, or the “patched” surface patterning on the dendrimers that more significantly influences their behavior in biological media.
Looking at the Future of Chemical Production through the European Roadmap on Science and Technology of Catalysis the EU Effort for a Long‐term Vision
Authors: Perathoner Siglinda , Gross Silvia , Hensen Emiel J. M. , Wessel Helge , Chraye Hélène , Centi Gabriele 
Published: February 2017

AbstractThis Essay presents in short the initiative of the European Commission to strengthen the activities in the area of catalysis, a key technology for a sustainable future. In particular, this Essay discusses the thematic European Cluster on Catalysis and its main output: The European Roadmap on Science and Technology of Catalysis. Between the main drivers for the sustainable future of chemical and energy vectors, production of the following aspects have been identified: 1) the change in the energy–chemistry nexus, and the need to move to a new sustainable energy scenario and of enabling long‐distance (world scale) trading of renewable energy, 2) the change to a new vision for refineries, bio‐refineries, and bio‐factories, 3) methanol, as key chemical at the crossover of new energy–chemistry nexus, 4) the new possibilities by exploiting shale‐gas, and bio‐gas‐based chemistry, and 5) solar‐driven chemistry. To address this changing scenario, the Roadmap has identified a series of grand‐challenges for catalysis, discussed in terms of the strategic research agenda and implementation plans: 1) catalysis to address the evolving energy and chemical scenario, 2) catalysis for a cleaner and sustainable future, and 3) addressing catalysis complexity—the latter being divided in three sub‐topics (advanced design of novel catalysts, understanding catalysts from a molecular to a material scale, and expanding catalysis concepts).
Heterogeneous Ketone Hydrodeoxygenation for the Production of Fuels and Feedstocks from Biomass
Authors: Jenkins Rhodri W. , Moore Cameron M. , Semelsberger Troy A. , Sutton Andrew D. 
Published: February 2017

AbstractIn this work, we describe a simple, heterogeneous catalytic system for the hydrodeoxygenation (HDO) of 5‐nonanone and 2,5‐hexanedione, which we use as model compounds for more complex biomass‐derived molecules. We present the stepwise reduction of ketones by using supported metal and solid acid catalysts to identify the intermediates en route to hydrocarbons. Although monoketone HDO can be achieved rapidly using moderate conditions (Ni/SiO2.Al2O3, HZSM‐5, 200 °C, 1.38 MPa H2, 1 h), quantitative γ‐polyketone HDO requires higher pressures and longer reaction times (Pd/Al2O3, HZSM‐5, 2.76 MPa H2, 5 h), although these are more facile conditions than have been reported previously for γ‐polyketone HDO. Stepwise HDO of the γ‐polyketone shows the reaction pathway occurs through ring‐closure to a saturated tetrahydrofuran species intermediate, which requires increased H2 pressure to ring‐open and subsequently to fully HDO. This work allows for further understanding of bio‐derived molecule defunctionalization mechanisms, and ultimately aids in the promotion of biomass as a feedstock for fuels and chemicals.