bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantio‐ and Diastereoselective Synthesis of β‐Aryl‐β‐pyrazolyl α‐Amino Acid Esters via Copper‐Catalyzed Reaction of Azomethine Ylides with Benzylidenepyrazolones
Authors: Gong Yan‐Chuan , Wang Yue , Li Er‐Qing , Cui Hao , Duan Zheng
Published: December 2018

A fully stereoselective synthesis of unnatural chiral β‐aryl‐β‐pyrazolyl α‐amino acid esters via copper‐catalyzed addition reactions of azomethine ylides with benzylidenepyrazolones bearing two contiguous stereogenic centers was developed. A 1H‐pyrazol‐5‐ol was introduced by the aromatization of 3H‐pyrazol‐3‐one in the reaction. The transformation operated at room temperature and afforded β‐1H‐pyrazol‐5‐ol‐α‐amino esters in high yields with good to excellent levels of diastereo‐ and enantioselectivity.

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Peptide–siRNA Supramolecular Particles for Neural Cell Transfection
Authors: Hernandez‐Garcia Armando , Álvarez Zaida , Simkin Dina , Madhan Ashwin , Pariset Eloise , Tantakitti Faifan , de J. Vargas‐Dorantes Oscar , Lee Sungsoo S. , Kiskinis Evangelos , Stupp Samuel I.
Published: December 2018

Small interfering ribonucleic acid (siRNA)‐based gene knockdown is an effective tool for gene screening and therapeutics. However, the use of nonviral methods has remained an enormous challenge in neural cells. A strategy is reported to design artificial noncationic modular peptides with amplified affinity for siRNA via supramolecular assembly that shows efficient protein knockdown in neural cells. By solid phase synthesis, a sequence that binds specifically double‐stranded ribonucleic acid (dsRNA) with a self‐assembling peptide for particle formation is integrated. These supramolecular particles can be further functionalized with bioactive sequences without affecting their biophysical properties. The peptide carrier is found to silence efficiently up to 83% of protein expression in primary astroglial and neuronal cell cultures without cytotoxicity. In the case of neurons, a reduction in electrical activity is observed once the presynaptic protein synaptophysin is downregulated by the siRNA–peptide particles. The results demonstrate that the supramolecular particles offer an siRNA delivery platform for efficient nonviral gene screening and discovery of novel therapies for neural cells.
Synergistic Effect of 3D Current Collectors and ALD Surface Modification for High Coulombic Efficiency Lithium Metal Anodes
Authors: Chen Kuan‐Hung , Sanchez Adrian J. , Kazyak Eric , Davis Andrew L. , Dasgupta Neil P.
Published: December 2018

Improving the performance of Li metal anodes is a critical bottleneck to enable next‐generation battery systems beyond Li‐ion. However, stability issues originating from undesirable electrode/electrolyte interactions and Li dendrite formation have impaired long‐term cycling of Li metal anodes. Herein, a bottom‐up fabrication process is demonstrated for a current collector for Li metal electrodeposition and dissolution composed of highly uniform vertically aligned Cu pillars. By rationally controlling geometric parameters of the 3D current collector architecture, including pillar diameter, spacing, and length, the morphology of Li plating/stripping upon cycling can be controlled and optimal cycling performance can be achieved. In addition, it is demonstrated that deposition of an ultrathin layer of ZnO by atomic layer deposition on the current collector surface can facilitate the initial Li nucleation, which dictates the morphology and reversibility of subsequent cycling. This core–shell pillar architecture allows for the effects of geometry and surface chemistry to be decoupled and individually controlled to optimize the electrode performance in a synergistic manner. Using this platform, Li metal anodes are demonstrated with Coulombic efficiency up to 99.5%, providing a pathway toward high‐efficiency and long‐cycle life Li metal batteries with reduced excess Li loading.
Native Vacancy Enhanced Oxygen Redox Reversibility and Structural Robustness
Authors: Li Yejing , Wang Xuefeng , Gao Yurui , Zhang Qinghua , Tan Guoqiang , Kong Qingyu , Bak Seongmin , Lu Gang , Yang Xiao‐Qing , Gu Lin , Lu Jun , Amine Khalil , Wang Zhaoxiang , Chen Liquan
Published: December 2018

Cathode materials with high energy density, long cycle life, and low cost are of top priority for energy storage systems. The Li‐rich transition metal (TM) oxides achieve high specific capacities by redox reactions of both the TM and oxygen ions. However, the poor reversible redox reaction of the anions results in severe fading of the cycling performance. Herein, the vacancy‐containing Na4/7[Mn6/7(◻Mn)1/7]O2 (◻Mn for vacancies in the MnO slab) is presented as a novel cathode material for Na‐ion batteries. The presence of native vacancies endows this material with attractive properties including high structural flexibility and stability upon Na‐ion extraction and insertion and high reversibility of oxygen redox reaction. Synchrotron X‐ray absorption near edge structure and X‐ray photoelectron spectroscopy studies demonstrate that the charge compensation is dominated by the oxygen redox reaction and Mn3+/Mn4+ redox reaction separately. In situ synchrotron X‐ray diffraction exhibits its zero‐strain feature during the cycling. Density functional theory calculations further deepen the understanding of the charge compensation by oxygen and manganese redox reactions and the immobility of the Mn ions in the material. These findings provide new ideas on searching for and designing materials with high capacity and high structural stability for novel energy storage systems.
Perinatal veterinary medicine‐related evaluation in hematological and serum biochemical profiles of experimental beagles throughout pregnancy and parturition
Authors: Kimura Tohru , Kotani Kazuhiko
Published: December 2018

Background

The aims of this study were (a) to ascertain age‐related changes in the reference values in hematological and serum biochemical examinations of beagles, and (b) to clarify the changes in these findings, including acute phase proteins and oxidative stress, throughout pregnancy and after parturition.

Methods

Clinicopathological parameters were measured in young beagles at 6, 9 and 12 months and in adult beagles aged from 24 to 60 months. Likewise, pregnant beagles were investigated throughout the pregnancy and after parturition.

Results

Apparent age‐related changes were found in erythrocytic parameters during the growth and development of beagles. Most of the parameters (total protein, albumin, blood urea nitrogen, creatinine, urate, alkaline phosphatase (ALP) and creatine kinase (CK) exhibited age‐dependent transitions. White cell count significantly increased after 30 days of pregnancy. The values of erythrocytic parameters moderately decreased during the second half of the pregnancy. Triglycerides, total cholesterol, free cholesterol and phospholipid concentrations increased in the mid‐ and late stages of pregnancy. ALP, lactate dehydrogenase, CK and cholinesterase activities markedly increased during pregnancy and/or after parturition. C‐reactive protein (CRP) concentrations gradually increased and reached a maximum after 30‐40 days of pregnancy. Serum amyloid A (SAA) levels markedly increased at 30 days of pregnancy before subsiding, and then increased again 3 days after parturition. Reactive oxygen metabolites (d‐ROMs) showed significant increases after 30 and 40 days of pregnancy.

Conclusions

Reference values for hematological and serum biochemical examinations should be used for health evaluation of dogs, taking sex, age and the stage of pregnancy into consideration. Measurements of CRP, SAA and d‐ROM levels are also useful for assessing maternal conditions in mid‐pregnancy.
Hydrophobic Shielding of Outer Surface: Enhancing the Chemical Stability of Metal–Organic Polyhedra
Authors: Mollick Samraj , Mukherjee Soumya , Kim Dongwook , Qiao Zhiwei , Desai Aamod V. , Saha Rajat , More Yogeshwar D. , Jiang Jianwen , Lah Myoung Soo , Ghosh Sujit K.
Published: December 2018

Metal–organic polyhedra (MOP) are a promising class of crystalline porous materials with multifarious potential applications. Although MOPs and metal–organic frameworks (MOFs) have similar potential in terms of their intrinsic porosities and physicochemical properties, the exploitation of carboxylate MOPs is still rudimentary because of the lack of systematic development addressing their chemical stability. Herein we describe the fabrication of chemically robust carboxylate MOPs via outer‐surface functionalization as an a priori methodology, to stabilize those MOPs system where metal–ligand bond is not so strong. Fine‐tuning of hydrophobic shielding is key to attaining chemical inertness with retention of the framework integrity over a wide range of pH values, in strong acidic conditions, and in oxidizing and reducing media. These results are further corroborated by molecular modelling studies. Owing to the unprecedented transition from instability to a chemically ultra‐stable regime using a rapid ambient‐temperature gram‐scale synthesis (within seconds), a prototype strategy towards chemically stable MOPs is reported.
Survey on Passivity Based Control of Induction Machine
Authors: Becherif Mohamed
Published: December 2018

Induction machines (IM) constitute a theoretically interesting and practically important class of nonlinear systems. They are frequently used as wind generators for their power/cost ratio. They are described by a fifth‐order nonlinear differential equation with two inputs and only three state variables available for measurement. The control task is further complicated by the fact that IM are subject to unknown (load) disturbances and the parameters can be of great uncertainty. One is then faced with the challenging problem of controlling a highly nonlinear system, with unknown time‐varying parameters, where the regulated output, besides being unmeasurable, is perturbed by an unknown additive signal. Passivity‐based control (PBC) is a well‐established structure‐preserving design methodology which has shown to be very powerful to design robust controllers for physical systems described by Euler‐Lagrange equations of motion. PBCs provide a natural procedure to "shape" the potential energy yielding controllers with a clear physical interpretation in terms of interconnection of the system with its environment and are robust vis á vis to unmodeled dissipative effects. One recent approach of PBC is the Interconnection and Damping Assignment Passivity‐Based Control (IDA‐PBC) which is a very useful technique to control nonlinear systems assigning a desired (Port‐Controlled Hamiltonian) structure to the closed‐loop. The aim of this paper is to give a survey on different PBC of IM. The originality of this work is that the author proves that the well known field oriented control of IM is a particular case of the IDA‐PBC with disturbance.
Clustering the occupant behavior in residential buildings: a method comparison
Authors: Carbonare Nicolás , Pflug Thibault , Wagner Andreas
Published: December 2018

The aim of this paper is to investigate possible patterns of the occupant behavior in residential buildings. Measurements were taken in multi‐family buildings where several occupant‐related variables were recorded. We chose and compared two different clustering methods: whole time series and features clustering (k‐means algorithm). The mentioned methods were performed selecting two variables (window opening and indoor temperature) and tested with supervised learning methods. Results suggest that features clustering can perform better than whole time series. The representation of the occupant behavior through features is meant to be applied in future work regarding the optimization of control strategies in ventilation systems.
Integration von Verbrauchernetzwerken in dynamische Gebäudeenergiemodelle
Authors: Paepcke Anne , Nicolai Andreas , Weiß Dirk
Published: December 2018

Wärmeübertragung und Wärmeverlustmechanismen von Anlagenkomponenten und ihrer Verteilnetzwerke haben entscheidenden Einfluss auf den Energieverbrauch und die thermische Behaglichkeit eines Gebäudes. Um diese Mechanismen in der befriedigenden Detailtiefe abbilden zu können, müssen geometrische Informationen berücksichtigt werden: die Rohr‐ oder Kanalverlegung im Gebäude, der Schichtaufbau von Rohrwänden und die Position von Verbraucherkomponenten im Raum oder den Raumumgrenzungsflächen. Der Artikel konzentriert sich auf die Integration solcher Modelle in eine dynamische Simulation mit hohem geometrischem Detailgrad. Die Bilanzgleichungen führen dabei auf große schwachbesetzte Systeme, und eine numerisch akkurate und effiziente Lösung der Bilanzgleichungen und der algebraischen Kopplungsgleichungen ist verpflichtend. Geeignete Algorithmen und ihre Umsetzung werden vorgestellt.
BIM‐unterstützte Erstellung interaktiver, immersiver VR‐Szenarien am Beispiel der Brandbekämpfung
Authors: Bittner Timo , Eller Christian , Dombois Marcus , Rüppel Uwe
Published: December 2018

In diesem Beitrag wird die Nutzung von digitalen Gebäudemodellen im Rahmen von Serious Games und Virtual Reality (VR) untersucht. Ziel ist es, unter Verwendung offener Schnittstellen und Formate wie dem Standard der Industry Foundation Classes (IFC) ein interaktives, immersives und zugleich adaptives Szenario zu schaffen, welches es dem Nutzer ermöglicht, verschiedenste Aspekte in der virtuellen Umgebung zu erleben und zu üben. Der Fokus liegt auf der schnellen und unkomplizierten Erstellung einer solchen Anwendung, wobei der Prozess durch BIM‐Methoden unterstützt wird. Das Vorgehen wird anschließend anhand eines Szenarios aus dem Bereich des Digital Civil Safety Engineering validiert.
Special education use in elementary school by children with nonsyndromic orofacial clefts
Authors: Watkins Stephanie E. , Allori Alexander C. , Meyer Robert E. , Aylsworth Arthur S. , Marcus Jeffrey R. , Strauss Ronald P.
Published: December 2018

Background

Children with nonsyndromic orofacial clefts (NS OFCs) may require exceptional children's (EC) services for academic delays. We examined EC service use of children with and without NS OFCs in NC in elementary school.

Methods

We included 559 children with NS OFCs and 6,822 children without birth defects who had NC educational records. We estimated prevalence ratios, trends in enrollment, and characteristics of eligibility classification using descriptive statistics and logistic regression by cleft subtype and race/ethnicity. We estimated the odds of third grade retention by EC enrollment using logistic regression with inverse probability of treatment weights.

Results

Children with NS OFCs were 3.02 (95% CI: 2.50, 3.64) times as likely to receive third grade special education (SE) services compared to unaffected peers. The prevalence odds was highest among children with CL+P (OR: 4.61, 95% CI: 3.49, 6.09) declining by 54% by fifth grade. The prevalence odds of SE for white children was approximately 1.50 times that for African American children in fourth and fifth grades. Approximately 33% of children with NS OFCs within each racial/ethnic group received SE in third grade. African American children were twice as likely to receive services under specific learning disability. Children with NS OFCs receiving EC services were 44% (OR: 0.56; 95% CI: 0.13, 2.38) less likely to be retained in third grade compared to children with NS OFCs who were not receiving services.

Conclusions

Children with NS OFCs are more likely to receive SE services in elementary school compared to their unaffected peers. The eligibility category differed by racial/ethnic group.
Construction of efficient bioelectrochemical devices: Improved electricity production from cyanobacteria (Leptolyngbia sp.) based on π‐conjugated conducting polymer/gold nanoparticle composite interfaces
Authors: Cevik Emre , Buyukharman Mustafa , Yildiz Huseyin Bekir
Published: December 2018

In this study, gold electrodes (GE) were coated with conducting polymers to obtain a high photocurrent using cyanobacteria from a novel bioelectrochemical fuel cell. For this purpose, 4‐(4H‐ditiheno[3,2‐b:2',3'‐d]pyrol‐4‐yl) aniline and 5‐(4H‐dithieno[3,2‐b:2',3'‐d]pyrol‐4‐yl) napthtalane‐1‐amine monomers were coated on GE by performing an electropolymerization process. After that, gold nanoparticles (AuNP) were specifically modified by 2‐mercaptoethane sulfonic acid and p‐aminothiophenol to attach to the electrode surface. The conducting polymers GE coat was modified with functionalized AuNP using a cross‐linker. The resulting electrode structures were characterized by cyclic voltammetry and chronoamperometry under on‐off illumination using a fiber optic light source. Cyanobacteria Leptolyngbia sp. was added to the GE/conducting polymer/AuNP electrode surface and stabilized by using a cellulose membrane. During the illumination, water was oxidized by the photosynthesis, and oxygen was released. The released oxygen was electrocatalytically reduced at the cathode surface and a 25 nA/cm
2 photocurrent was observed in GE/
Leptolyngbia sp. After the electrode modifications, a significant improvement in the photocurrent up to 630 nA/cm
2 was achieved.
Modeling the activity burst in the initial phase of cellulose hydrolysis by the processive cellobiohydrolase Cel7A
Authors: Petrášek Zdeneˇk , Eibinger Manuel , Nidetzky Bernd
Published: December 2018

The hydrolysis of cellulose by processive cellulases, such as exocellulase TrCel7A from Trichoderma reesei, is typically characterized by an initial burst of high activity followed by a slowdown, often leading to incomplete hydrolysis of the substrate. The origins of these limitations to cellulose hydrolysis are not yet fully understood. Here, we propose a new model for the initial phase of cellulose hydrolysis by processive cellulases, incorporating a bound but inactive enzyme state. The model, based on ordinary differential equations, accurately reproduces the activity burst and the subsequent slowdown of the cellulose hydrolysis and describes the experimental data equally well or better than the previously suggested model. We also derive steady‐state expressions that can be used to describe the pseudo‐steady state reached after the initial activity burst. Importantly, we show that the new model predicts the existence of an optimal enzyme‐substrate affinity at which the pseudo‐steady state hydrolysis rate is maximized. The model further allows the calculation of glucose production rate from the first cut in the processive run and reproduces the second activity burst commonly observed upon new enzyme addition. These results are expected to be applicable also to other processive enzymes.
Simultaneous quantitation of metformin and dapagliflozin in human plasma by LC–MS/MS: Application to a pharmacokinetic study
Authors: Shah Priyanka A. , Shrivastav Pranav S. , Shah Jaivik V. , George Archana
Published: December 2018

A single LC–MS/MS assay has been developed and validated for the simultaneous determination of metformin and dapagliflozin in human plasma using ion‐pair solid‐phase extraction. Chromatographic separation of the analytes and their internal standards was carried out on a reversed‐phase ACE 5CN (150 × 4.6 mm, 5 μm) column using acetonitrile–15 mm ammonium acetate, pH 4.5 (70:30, v/v) as the mobile phase. To achieve higher sensitivity and selectivity for the analytes, mass spectrometric analysis was performed using a polarity switching approach. Ion transitions studied using multiple reaction monitoring mode were m/z 130.1 [M + H]+/60.1 for metformin and m/z 467.1 [M + CH3COO]−/329.1 for dapagliflozin in the positive and negative modes, respectively. The linear calibration range of the assay was established from 1.00 to 2000 ng/mL for metformin and from 0.10 to 200 ng/mL for dapagliflozin to achieve a better assessment of the pharmacokinetics of the drugs. The limit of detection and limit of quantitation for the analytes were 0.39 and 1.0 ng/mL for metformin and 0.03 and 0.1 ng/mL for dapagliflozin, respectively. There was no interference of plasma matrix obtained from different sources, including hemolyzed and lipemic plasma. The method was successfully applied to study the effect of food on the pharmacokinetics of metformin and dapagliflozin in healthy subjects.
Construction of immune‐related risk signature for renal papillary cell carcinoma
Authors: Wang Zhongyu , Song Qian , Yang Zuyi , Chen Jianing , Shang Jun , Ju Wen
Published: December 2018

The kidney renal papillary cell carcinoma (KIRP) is a relatively rare type of kidney cancer. There has been no investigation to find a robust signature to predict the survival outcome of KIRP patients in the aspect of tumor immunology. In this study, 285 KIRP samples from The Cancer Genome Atlas (TCGA) were randomly divided into training and testing set. A total of 1534 immune‐related genes from The Immunology Database and Analysis Portal (ImmPort) were used as candidates to construct the signature. Using univariate Cox analysis, we evaluated the relationship between overall survival and immune‐related genes expression and found 272 immune‐related genes with predicting prognostic ability. In order to construct an efficient predictive model, the Cox proportional hazards model with an elastic‐net penalty was used and identified 23 groups after 1000 iterations. As a result, 15‐genes model showing more stable than other gene groups was chosen to construct our immune‐related risk signature. In line with our expectations, the signature can independently predict the survival outcome of KIRP patients. Patients with high‐immune risk were found correlated with advanced stage. We also found that the high‐immune risk patients with higher PBRM1 and SETD2 mutations, increasing chromosomal instability, together with the gene set enrichment analysis (GSEA) results showing intensive connection of our signature with immune pathways. In conclusion, our study constructs a robust 15‐gene signature for predicting KIRP patients’ survival outcome on the basis of tumor immune environment and may provide possible relationship between prognosis and immune‐related biological function.
Consumer affects when making undesirable purchases to meet the minimum purchase requirement: Decision‐related variables as moderators
Authors: Ku Hsuan‐Hsuan
Published: December 2018

One common type of sales promotion involves a minimum purchase requirement (MinPR), where customers must purchase at least a minimum number of products to enjoy a discount. In the process of making purchases to qualify for the discount, consumers may find their first‐choice product options or have to settle for products that they did not originally prefer. Three between‐subjects experiments examines whether, in various decision situations, counterfactual thinking (CFT) might bias individuals' emotions in response to desirable versus undesirable purchases. Study 1 demonstrates that participants who made undesirable purchases to meet the MinPR felt less satisfied with the purchase outcome precipitated by upward CFT, whereas downward CFT led to feelings of pleasure in participants who could find their first‐choice product options. Studies 2 and 3 find that counterfactual emotions of undesirable purchases were more pronounced when participants experienced a difficult decision process because of a narrow promotion scope or when time pressure, manipulated in terms of explicit deadlines, is heavy rather than light, respectively. On the contrary, participants' responses to desirable purchases did not vary as a function of decision difficulty or time pressure.
Diffusion Profiling of Therapeutic Proteins by Using Solution NMR Spectroscopy
Authors: Falk Bradley T. , Liang Yingkai , McCoy Mark A.
Published: December 2018

Characterizing changes to structure and behavior is an important aspect of therapeutic protein development. NMR spectroscopy is well suited to study interactions and higher‐order structure that could impact biological function and safety. We used NMR diffusion methods to describe the overall behavior of proteins in solution by defining a “diffusion profile” that captures the complexities in diffusion behavior. Diffusion profiles offer a simple means to interpret protein solution behavior as a distribution of sizes and association states. As a characterization method, diffusion profiling is well suited to complement and augment traditional biophysical and NMR methods to probe the solution behavior of therapeutic proteins.
Results of the combined U.S. multicenter postapproval study of the Nit‐Occlud PDA device for percutaneous closure of patent ductus arteriosus
Authors: Kobayashi Daisuke , Salem Morris M. , Forbes Thomas J. , Gordon Brent M. , Soriano Brian D. , Dimas Vivian , Goldstein Bryan H. , Owada Carl , Javois Alexander , Bass John , Jones Thomas K. , Berman Darren P. , Gillespie Matthew J. , Moore John W. , Levi Daniel S.
Published: December 2018

Objectives

To report the results of the Nit‐Occlud PDA prospective postapproval study (PAS) along with a comparison to the results of the pivotal and continued access trials.

Background

The Nit‐Occlud PDA (PFM Medical, Cologne, Germany), a nitinol coil patent ductus arteriosus (PDA) occluder, was approved by the Food and Drug Administration in 2013.

Methods

The PAS enrolled a total of 184 subjects greater than 6 months of age, weighing at least 5 kg, with PDAs less than 4 mm by angiography at 11 centers. Patients were followed prospectively at 2 months, 12 months, and 24 months postprocedure. These outcomes were compared to the 357 subjects enrolled in the pivotal and continued access protocols. Efficacy and safety data were reported.

Results

Among 184 subjects enrolled for the PAS between 2014 and 2017, 180 (97.8%) had successful device implantation. After 12 months, 98.7% (150/152) had trivial or no residual shunt by echocardiography and two subjects had only small residual shunts. There were three device embolizations that were all retrieved by snare without clinical consequence. Together with the pivotal and continued access study, 97.4% (449/461) had complete echocardiographic closure at 12 months in 541 enrolled subjects. The composite success was 94.4%. There were no mortalities and no serious device‐related adverse events.

Conclusions

The Nit‐Occlud PDA is a safe and effective device for closure of a small to moderate sized PDA. There were no serious device‐related adverse events in a large cohort of three clinical trials.
Angiolymphoid hyperplasia with eosinophilia with clinical pictures of keratoacanthoma: A rare case report
Authors: Santosa Calvin , Wardhana Made , Saputra Herman
Published: December 2018

Key Clinical Message

Angiolymphoid Hyperplasia with Eosinophilia (ALHE) is a benign tumor of the skin which may mimic other benign or malignant lesion of the skin. Practitioners should consider this diagnosis as a differential when encounter such lesion as papule or nodule on the face and scalp area.
Nitrogen, Sulfur Co‐doped Carbon Materials Derived from the Leaf, Stem and Root of Amaranth as Metal‐free Catalysts for Selective Oxidation of Aromatic Hydrocarbons
Authors: Sun Yongbin , Liu Kun , Hou Chao , Liu Jian , Huang Runkun , Cao Changyan , Song Weiguo
Published: December 2018

Development of porous heteroatom‐doped carbon materials from plant biomass is of great significance for various applications in environment, energy conversion and catalysis process. However, the different natures of carbon materials derived from the leaf, stem and root of the same plant biomass are rarely reported. Herein, we synthesized porous carbon materials from the leaf, stem and root of amaranth respectively by pyrolysis without any activation treatment. Detailed characterizations indicated that these three carbon materials all had nitrogen, sulfur doped atoms and similar degree of graphitization, but showed distinct differences in the pore structures and surface compositions. We suggested these differences were contributed by the different contents of ashes, vascular bundles and proteins in different parts. When used as metal‐free carbocatalysts for the oxidation of aromatic hydrocarbons, stem‐derived carbon (SDC‐A) exhibited the highest catalytic performance due to its high surface area, profitable pore volume and rich doped heteroatoms. Moreover, the carbocatalysts derived from the leaf, stem and root of pumpkin vine and coriander showed similar activity differences in oxidation of aromatic alkanes, implying the present results have a certain extent generality, and provide a new guidance for preparing carbon materials from plant biomass.
Computational chemical analysis of Ru(II)‐Pheox–catalyzed highly enantioselective intramolecular cyclopropanation reactions
Authors: Nakagawa Yoko , Nakayama Naofumi , Goto Hitoshi , Fujisawa Ikuhide , Chanthamath Soda , Shibatomi Kazutaka , Iwasa Seiji
Published: December 2018

Computational chemical analysis of Ru(II)‐Pheox–catalyzed highly enantioselective intramolecular cyclopropanation reactions was performed using density functional theory (DFT). In this study, cyclopropane ring–fused γ‐lactones, which are 5.8 kcal/mol more stable than the corresponding minor enantiomer, are obtained as the major product. The results of the calculations suggest that the enantioselectivity of the Ru(II)‐Pheox–catalyzed intramolecular cyclopropanation reaction is affected by the energy differences between the starting structures 5l and 5i. The reaction pathway was found to be a stepwise mechanism that proceeds through the formation of a metallacyclobutane intermediate. This is the first example of a computational chemical analysis of enantioselective control in an intramolecular carbene‐transfer reaction using C1‐symmetric catalysts.
Experimental methods in chemical engineering: Contact angles
Authors: Bruel Charles , Queffeulou Salomé , Darlow Theron , Virgilio Nick , Tavares Jason R. , Patience Gregory S.
Published: December 2018

The contact angle (CA) formed at equilibrium at the three‐phase line of contact between a liquid, a solid, and a gas may be expressed as a function of both the interfacial and surface tensions. Young first derived this thermodynamic relationship in 1805. In practice, multiple CA values are observed due to kinetic phenomena induced by evaporation, vapour adsorption, or swelling, and thermodynamic ones induced by roughness and surface chemical heterogeneities, even at molecular‐scale. These non‐ideal conditions result into an hysteresis, i.e., a difference between wetting and dewetting behaviours, and Young's equation rarely applies. Three measuring methods stand out for their applicability and reliability. In the sessile drop method, a syringe deposits a liquid drop on a flat surface and the contact angle is measured through optical means based on the drop shape. In the Wilhelmy balance method, the force required to immerse a solid plate in a bath of liquid is indirectly related to the contact angle. In the Washburn capillary rise method, the contact angle is derived from the rate at which a liquid rises by capillarity through a packed bed of powder. Employing probe liquids of various polarities, the free surface energy of the solid may be estimated. Over the last two years, 8600 published articles mentioned “contact angle” in their topic. Their main focus was either to develop the fundamental understanding of wetting science, or to assess the success of surface modification methods for the production of novel surfaces, composites, and membranes with enhanced wetting, adhesive, and filtration properties.
Efficient preparation of nanoscale zero‐valent iron by high gravity technology for enhanced Cr(VI) removal
Authors: Wang Zheng‐Meng , Wang Dan , Zhang Liang‐Liang , Wang Jie‐Xin
Published: December 2018

Owing to its strong reducibility capacity, nanoscale zero‐valent iron (nZVI) can be widely used in the treatment of wastewater. In this study, nZVI particles with an average size of 14 nm were continuously prepared using a rotating packed bed (RPB) reactor with stainless wire mesh packing. The effects of the surfactant type and the rotating speed of the RPB reactor on the particle size of nZVI were investigated. The results indicated that the average particle size could be notably reduced with the proper addition of PVP in the preparation process. Meanwhile, the particle size could be further decreased by increasing the rotating speed of the RPB. Compared to a stirred tank reactor (STR), the RPB reactor had nZVI with a smaller particle size and a much shorter reaction time. The as‐prepared nZVI was further employed to remove Cr(VI) in the simulated sewage. The results indicated that lower pH, higher nZVI dosage, and higher temperature were beneficial to the efficient removal of Cr(VI). The removal process of Cr(VI) well conformed to a pseudo‐first‐order kinetic model. Thermodynamic studies showed that the reduction of Cr(VI) by nZVI was a spontaneous endothermic reaction process with increased entropy. In addition, nZVI prepared in the RPB displayed higher removal efficiency than the counterpart in the STR, and the removal rate was greatly increased by 17.4 times.
Numerical simulation of bubbling fluidization using a local bubble‐structure‐dependent drag model
Authors: Du Shaohua , Liu Lijun
Published: December 2018

The meso‐scale flow structure in gas‐solid bubbling fluidization has significant effects on hydrodynamics and interphase heat and mass transfer. However, traditional homogeneous drag models neglect the meso‐scale structure and fail to yield a reasonable prediction of the hydrodynamics in bubbling fluidization. In this study, the gas‐solid system within a grid cell combines three subsystems in order to take the meso‐scale structure into account. Based on this resolution, a local bubble‐structure‐dependent drag model is established. In addition, a homogeneous interphase drag correlation based on direct numerical simulation is coupled with the novel drag model to describe the interphase interaction when the flow structure is homogeneous. Then, the proposed drag model is incorporated into two fluid models to simulate the hydrodynamics in bubbling fluidization with Geldart A and A/B particles. The predicted profiles of the time‐averaged solid volume fraction are compared with experimental data to validate the effectiveness of the novel drag model. The results show that the average relative error of the solid volume fraction is reduced from over 30 to ∼10 % by replacing homogeneous drag models with the novel drag model.
Slurryability and combustion characteristics of coal‐coking wastewater‐slurry
Authors: Wang Yi , Liu Jian‐Zhong , Chen Cong , Cheng Jun
Published: December 2018

The slurryability, rheological properties, stability, and combustion characteristics of coal water slurry (CWS), made from coking wastewater (CW), deionized water, and Shenhua coal were experimentally studied. Results showed that the solid concentration of coal‐coking wastewater‐slurry (CCWS) could be higher than 60.5 %, which is 0.5–1.5 % lower than that of coal water slurry (CWS). However, the pseudoplastic behaviour of CCWS was greatly evident. The dispersion effects of NNO and NDF were excellent. The stability of CCWS is better than CWS. Moreover, CCWS had lower ignition temperature and burnout temperature, higher combustion characteristic parameters, such as combustion characteristic index S and ignition stability index Rw, and better performance in combustion than CWS. The application of CW for the production of coal water slurry demonstrated the resource utilization of wastewater and improved the combustion characteristic.
Geometrostatic Manifolds of Small ADM Mass
Authors: Sormani Christina , Allen Iva Stavrov
Published: December 2018

We bound the locations of outermost minimal surfaces in geometrostatic manifolds whose ADM mass is small relative to the separation between the black holes and prove the intrinsic flat stability of the positive mass theorem in this setting. © 2018 Wiley Periodicals, Inc.
Simple Estimates for Eutectic Behavior
Authors: Pyykkö Pekka
Published: December 2018

A simple formula is derived for the eutectic point of an A–B system in terms of the monomer melting points and melting enthalpies. This estimate is tested on several non‐ionic or ionic systems, with or without common ions, including choline chloride/urea mixtures. The results are compared with the Schröder‐van Laar equation.
Recent Developments in Graphitic Carbon Nitride Based Hydrogels as Photocatalysts
Authors: Hu Chechia , Lin Yan‐Ru , Yang Hung‐Chun
Published: December 2018

Solar‐driven photocatalysis with graphitic carbon nitride (g‐C3N4) is considered to be the most promising approach for the generation of H2 from water, the degradation of organic pollutants, and the reduction of CO2. However, bulk g‐C3N4 exhibits several drawbacks, such as a low specific surface area, high defect density, and fast charge recombination, which result in low photocatalytic performance. The construction of 3D porous hydrogels for g‐C3N4 through nanostructural engineering is a rapid, feasible, and cost‐effective technique to improve the adsorption capability, stability, and separability of the hydrogel composite; to increase the number of active sites; and to create an internal conductive path for facile charge transfer and high photocatalytic activity. This minireview summarizes recent progress in photocatalytic water splitting and dye degradation by using g‐C3N4‐based hydrogels, with respect to state‐of‐the‐art methods for synthesis, preparation, modification, and multicomponent coupling. Furthermore, comprehensive outlooks, future challenges, and concluding remarks regarding the use of g‐C3N4‐based hydrogels as highly efficient photocatalysts are presented.
High genomic diversity and candidate genes under selection associated with range expansion in eastern coyote (Canis latrans) populations
Authors: Heppenheimer Elizabeth , Brzeski Kristin E. , Hinton Joseph W. , Patterson Brent R. , Rutledge Linda Y. , DeCandia Alexandra L. , Wheeldon Tyler , Fain Steven R. , Hohenlohe Paul A. , Kays Roland , White Bradley N. , Chamberlain Michael J. , vonHoldt Bridgett M.
Published: December 2018

Range expansion is a widespread biological process, with well‐described theoretical expectations associated with the colonization of novel ranges. However, comparatively few empirical studies address the genomic outcomes accompanying the genome‐wide consequences associated with the range expansion process, particularly in recent or ongoing expansions. Here, we assess two recent and distinct eastward expansion fronts of a highly mobile carnivore, the coyote (Canis latrans), to investigate patterns of genomic diversity and identify variants that may have been under selection during range expansion. Using a restriction‐associated DNA sequencing (RADseq), we genotyped 394 coyotes at 22,935 SNPs and found that overall population structure corresponded to their 19th century historical range and two distinct populations that expanded during the 20th century. Counter to theoretical expectations for populations to bottleneck during range expansions, we observed minimal evidence for decreased genomic diversity across coyotes sampled along either expansion front, which is likely due to hybridization with other Canis species. Furthermore, we identified 12 SNPs, located either within genes or putative regulatory regions, that were consistently associated with range expansion. Of these 12 genes, three (CACNA1C, ALK, and EPHA6) have putative functions related to dispersal, including habituation to novel environments and spatial learning, consistent with the expectations for traits under selection during range expansion. Although coyote colonization of eastern North America is well‐publicized, this study provides novel insights by identifying genes associated with dispersal capabilities in coyotes on the two eastern expansion fronts.
Trophic cues promote secondary migrations of bivalve recruits in a highly dynamic temperate intertidal system
Authors: Forêt Martin , Barbier Pierrick , Tremblay Réjean , Meziane Tarik , Neumeier Urs , Duvieilbourg Eric , Olivier Frédéric
Published: December 2018

Post‐settlement dispersal is a key process in the recruitment of bivalves. To assess the role of such secondary migrations and to identify potential associated triggers, we conducted an in situ sampling survey during the summer recruitment period on the bivalve assemblages of a coarse‐sediment temperate tidal habitat in the Chausey archipelago (Normandy, France). The dynamics of drifters were studied using three types of settler traps (for example, bedload, pelagic, and sinking transports), and we monitored both the abiotic (hydrological and hydrodynamic conditions) and the trophic (nano‐ and pico‐sized particulate organic matter [POM]; fatty acid composition of POM and sediment organic matter [SOM]) environmental parameters. Such an approach allows the discrimination of passive migration (due to sediment erosion by tidal currents and waves) from active migration (related to recruit behavior). Secondary migrations were observed in 25 bivalve taxa, and these mainly involved decreasing abundances of Mytilidae, Nuculidae, Semelidae, Mactridae, and Lucinidae individuals on the study site, highlighting the crucial role of these processes in highly dynamic coastal benthic assemblages. Surprisingly, the intense post‐settlement dispersal observed at the end of the recruitment season was not synchronized with periods of high hydrodynamic stress but to a change in the structure of phytoplanktonic assemblages, particularly the nanoeukaryotic component. Such a response by bivalve recruits to a trophic pelagic cue—triggering secondary migrations—could result from an increased demand for energy required for active migratory behavior.
Multiple drivers of contrasting diversity–invasibility relationships at fine spatial grains
Authors: Smith Nicola S. , Côté Isabelle M.
Published: December 2018

The diversity–invasibility hypothesis and ecological theory predict that high‐diversity communities should be less easily invaded than species‐poor communities, but empirical evidence does not consistently support this prediction. While fine‐scale experiments tend to yield the predicted negative association between diversity and invasibility, broad‐scale observational surveys generally report a positive correlation. This conflicting pattern between experiments and observational studies is referred to as the invasion paradox and is thought to arise because different processes control species composition at different spatial scales. Here, we test empirically the extent to which the strength and direction of published diversity–invasibility relationships depend on spatial scale and on the metrics used to measure invasibility. Using a meta‐analytic framework, we explicitly separate the two components of spatial scale: grain and extent, by focusing on fine‐grain studies that vary in extent. We find evidence of multiple drivers of the paradox. When we consider only fine‐grain studies, we still observe conflicting patterns between experiments and observational studies. In contrast, when we examine studies that are conducted at both a fine grain and fine extent, there is broad overlap in effect sizes between experiments and observation, suggesting that comparing studies with similar extents resolves the paradox at local scales. However, we uncover systematic differences in the metrics used to measure invasibility between experiments, which use predominantly invader performance, and observational studies, which use mainly invader richness. When we consider studies with the same metric (i.e., invader performance), the contrasting associations between study types also disappear. It is not possible, at present, to fully disentangle the effect of spatial extent and metric on the paradox because both variables are systematically associated in different directions with study type. There is therefore an urgent need to conduct experiments and observational studies that incorporate the full range of variability in spatial extent and invasibility metric.
Bismuth(III)‐Containing Heteropolytungstates [Bi(XW11O39)2]n– (X = Si, Ge, n = 13; X = P, n = 11) and [Bi(P2W17O61)2]17–
Authors: Ncube Nickolet , Bhattacharya Saurav , Thiam Diarra , Goura Joydeb , Mougharbel Ali S. , Kortz Ulrich
Published: December 2018

We report on the synthesis and structural characterization of four bismuth(III)‐containing sandwich‐type heteropolytungstates with Bi in 8‐coordination. The three isostructural Keggin‐type ions [Bi(α‐XW11O39)2]n– {X = Si (1), Ge (2), n = 13; X = P (3), n = 11} and the Wells–Dawson‐type ion [Bi(α2‐P2W17O61)2]17– (4) were prepared via simple one‐pot synthetic procedures in aqueous medium. The novel polyanions comprise a Bi3+ ion linking two monolacunary {XW11} or {X2W17} units in a sandwich‐type fashion. The Bi3+ ion is coordinated by four oxygens of each monolacunary POM unit, resulting in 8‐coordination with square‐antiprismatic geometry. Such a coordination mode is rare for Bi3+.
Hindered Urea Bond: A Bilaterally Responsive Chemistry to Hydrogen Peroxide
Authors: Ying Hanze , Yang Yingfeng , Cai Kaimin , Cheng Jianjun
Published: December 2018

As a type of safe, clean, and bio‐relevant oxidant, hydrogen peroxide has been widely used as a trigger in the design of stimuli‐responsive materials. Hindered urea bond (HUB) is a type of dynamic covalent bond which can reversibly dissociate into isocyanate and amine. Quenching of isocyanate or amine will shift the equilibrium and facilitate the degradation of HUB bond. Herein, we report that one of the HUB moiety – 1,1‐tert‐butylethylurea (TBEU) can react with hydrogen peroxide (H2O2) resulting in two opposing outcomes. Perhydrolysis of isocyanate and oxidation of amine lead to the bond fracture, while formation of urethane product with an oxygen inserted into the original TBEU structure was also observed giving a stabilized form of linkage. More precise kinetic control of the two distinct pathways are expected to make hydrogen peroxide a trigger to either degrade or fix the HUB based polymeric materials.
Rhodium(III)‐Catalyzed Direct C‐H Alkylation of 2‐Aryl‐1,2,3‐triazole N‐Oxides with Maleimides
Authors: Zhao Juanli , Pi Chao , You Chang , Wang Yong , Cui Xiuling , Wu Yangjie
Published: December 2018

An efficient rhodium(III)‐catalyzed direct C‐H ortho‐alkylation of 2‐aryl‐1,2,3‐triazole N‐oxides has been developed using maleimides as the alkylation reagent. This protocol displays good functional group tolerance, high atom efficiency and avoids the external oxidant. Only mono‐substituted products were obtained. Based on the results of deuterium exchange experiments, the N‐oxide group plays an important role to improve the regioselectivity by increasing the steric hindrance.
Nickel‐Catalyzed Three‐Component Coupling Reaction of Tetrafluoroethylene and Aldehydes with Silanes via Oxa‐Nickelacycles
Authors: Shirataki Hiroshi , Ohashi Masato , Ogoshi Sensuke
Published: December 2018

The nickel‐catalyzed synthesis of a variety of fluorine‐containing silyl ethers from tetrafluoroethylene (TFE) and aldehydes with silanes in a selective manner is disclosed. Stoichiometric reactions revealed that the oxa‐nickelacycle, which is generated upon oxidative cyclization of TFE and an aldehyde with Ni0, is the key intermediate, whose molecular structure was confirmed by single‐crystal X‐ray diffraction analysis. In order to demonstrate the synthetic utility of this procedure, one of the reaction products was transformed into trifluorovinyl and organic silicon compounds via deprotonation with a Lewis base.
Convenient Carbonylative Synthesis of Selenium‐Substituted Vinyl Iodides: (E)‐5‐(Iodomethylene)‐1,3‐selenazolidin‐2‐ones
Authors: Wang Hai , Ying Jun , Ai Han‐Jun , Wu Xiao‐Feng
Published: December 2018

A carbonylative cyclization of propargylic amines with elemental selenium to produce (E)‐5‐(iodomethylene)‐1,3‐selenazolidin‐2‐ones has been developed for the first time. Using DBU as the promoter andn‐C4F9I as the iodide source, various target compounds were produced up to 95 % yields. Notably, benzene‐1,3,5‐triyl triformate (TFBen) was employed as a safe and convenient solid CO source here.