bluuebunny/crossref_metadata_2025 huggingface dataset:
A MODELAGEM MATEMÁTICA NOS CURSOS DE LICENCIATURA EM MATEMÁTICA DO ESTADO DO PARANÁ
Authors: Santos Junior Guataçara Dos , Soares Maria Rosana
Published: January 2016

A modelagem matemática como disciplina é essencial para que se contribua com a formação qualificada dos futuros professores de Matemática. Assim, objetivou-se analisar as faculdades/universidades do estado do Paraná que oferecem a disciplina de modelagem matemática inserida na matriz curricular nos cursos de Licenciatura em Matemática. O presente estudo desenvolveu-se à luz da pesquisa qualitativa, no qual a coleta de dados se deu por meio da observação e análise do material obtido nos endereços eletrônicos das instituições de ensino superior cadastradas no “e-mec”[1]. Os resultados apontaram que a maioria dessas faculdades/universidades não insere a modelagem matemática na matriz curricular do curso mencionado. Logo, diversos licenciandos poderão não obter uma preparação para trabalhá-la no ensino e terem dificuldades para reconhecer sua importância no ensino e aprendizagem de Matemática.

 

 
Editorial
Authors: Tomio Daniela
Published: January 2016

Editorial
METODOLOGIA ALTERNATIVA NO PROCESSO DE ENSINO APRENDIZAGEM SOBRE EMBRIOLOGIA E REPRODUÇÃO HUMANA PARA ALUNOS DO ENSINO MÉDIO DAS ESCOLAS DE BLUMENAU
Authors: Prada Radtke Paula , Baratto de Albuquerque Débora , Cim Ribeiro de Souza Ana Luiza , Rigatti Rúbia Tábata , Novello Batzner Clarissa , Bandeira de Andrade Beatriz , Yones Nogara Isabela , Delwing Dal Magro Débora , Almeida Coelho de Albuquerque Cláudia , Barauna Sara Cristiane
Published: January 2016

A inovação das metodologias de ensino durante o período escolar é de extrema importância para melhoria do conhecimento e do interesse por parte dos alunos acerca dos assuntos de embriologia e reprodução humana. No presente estudo foram coletadas informações referentes a idade e sexo de cada aluno participante da palestra. Também foi aplicado um questionário composto por perguntas acerca dos assuntos Embriologia e Reprodução Humana, previamente à palestra e após a mesma. Nas palestras foram utilizados materiais didáticos – maquetes, vídeos, fetos para exposição –, juntamente com a explicação por parte das bolsistas e voluntárias do projeto de extensão, a respeito dos assuntos já citados. Com a utilização de um método expositivo alternativo, comprovou-se uma melhoria no nível de informação sobre os temas Embriologia e Reprodução Humana por parte dos escolares avaliados, o que sugere uma mudança comportamental devido às palestras educativas.
Measurements and modeling of contemporary radiocarbon in the stratosphere
Authors: Kanu A. M. , Comfort L. L. , Guilderson T. P. , Cameron‐Smith P. J. , Bergmann D. J. , Atlas E. L. , Schauffler S. , Boering K. A.
Published: January 2016

Measurements of the 14C content of carbon dioxide in air collected by high‐altitude balloon flights in 2003–2005 reveal the contemporary radiocarbon distribution in the northern midlatitude stratosphere, four decades after the Limited Test Ban Treaty restricted atmospheric testing of nuclear weapons. Comparisons with results from a 3‐D chemical‐transport model show that the 14CO2 distribution is now largely governed by the altitude/latitude dependence of the natural cosmogenic production rate, stratospheric transport, and propagation into the stratosphere of the decreasing radiocarbon trend in tropospheric CO2 due to fossil fuel combustion. From the observed correlation of 14CO2 with N2O mixing ratios, an annual global mean net flux of 14CO2 to the troposphere of 1.6(±0.4) × 1017‰ mol CO2 yr−1 and a global production rate of 2.2(±0.6) × 1026 atoms 14C yr−1 are empirically derived. The results also indicate that contemporary 14CO2 observations provide highly sensitive diagnostics for stratospheric transport and residence times in models.
Dipolarizing flux bundles in the cis‐geosynchronous magnetosphere: Relationship between electric fields and energetic particle injections
Authors: Liu Jiang , Angelopoulos V. , Zhang Xiao‐Jia , Turner D. L. , Gabrielse C. , Runov A. , Li Jinxing , Funsten H. O. , Spence H. E.
Published: January 2016

Dipolarizing flux bundles (DFBs) are small flux tubes (typically <3 RE in XGSM and YGSM) in the nightside magnetosphere that have magnetic field more dipolar than the background. Although DFBs are known to accelerate particles, creating energetic particle injections outside geosynchronous orbit (trans‐GEO), the nature of the acceleration mechanism and the importance of DFBs in generating injections inside geosynchronous orbit (cis‐GEO) are unclear. Our statistical study of cis‐GEO DFBs using data from the Van Allen Probes reveals that just like trans‐GEO DFBs, cis‐GEO DFBs occur most often in the premidnight sector, but their occurrence rate is ~1/3 that of trans‐GEO DFBs. Half the cis‐GEO DFBs are accompanied by an energetic particle injection and have an electric field 3 times stronger than that of the injectionless half. All DFB injections are dispersionless within the temporal resolution considered (11 s). Our findings suggest that these injections are ushered or produced locally by the DFB, and the DFB's strong electric field is an important aspect of the injection generation mechanism.
Reply to comment by E. W. Wolff et al. on “Low time resolution analysis of polar ice cores cannot detect impulsive nitrate events”
Authors: Smart D. F. , Shea M. A. , Melott A. L. , Laird C. M.
Published: January 2016

Wolff et al. (2016) comment on Smart et al. (2014) and in doing so concentrate on issues other than the main point. They do not dispute our central assertion, the inadequate resolution of nearly all extant ice cores for detection of impulsive nitrate events (spikes) from any source, including past solar proton events (SPEs). We explain why comparing two short‐length cores from other researchers and analyzed by different methods is insufficient for disputing subannual reproducibility, and call for a multiple, fine‐resolution, replicate core study to resolve this issue. While acknowledging the creation of nitrate by SPEs and the existence of ice core nitrate spikes detected by others, they present several weak arguments, such as alleged scavenging of nitrate by some unnamed and unmeasured aerosol, and why no enhanced nitrate signal for documenting SPE statistics should be distinguishable in the ice. These are not derived from the main points in our Smart et al. (2014) paper. We address these briefly and show that ionization from the February 1956 SPE was sufficient to produce a winter, likely acidic, nitrate spike at Summit, Greenland. While noting some convergence of interpretation, we show why their claim that nitrate spikes cannot be used for deriving SPE statistics is unproven and why rejection of fine resolution core studies as unreliable is premature.
Brewer‐Dobson circulation diagnosed from JRA‐55
Authors: Kobayashi Chiaki , Iwasaki Toshiki
Published: January 2016

We examine the Brewer‐Dobson circulation (BDC) in the lower stratosphere diagnosed from the Japanese 55 year Reanalysis (JRA‐55) data set and compare it with the BDCs diagnosed from the other reanalyses (i.e., ERA‐Interim and JRA‐25), and JRA‐55‐related data sets (i.e., JRA‐55C, created by assimilating only in situ observations, and JRA‐55AMIP, a simulation by a prediction model). The climatological mean seasonal change of the BDC in JRA‐55 is similar to that in ERA‐Interim but considerably different from that in JRA‐25. Dynamical and thermodynamical consistencies among the variables are greatly improved in the JRA‐55 data set. The interannual variations of the annual mean tropical upwellings in JRA‐55 are almost coincident with those in JRA‐55C. It suggests that the weakly increasing trend of the BDC found in JRA‐55 does not have anything to do with changes in the satellite observing system. The climatological mean tropical upwelling diagnosed from JRA‐55 is stronger than that from JRA‐55AMIP. This difference is presumed to partly link to the model's inability to simulate the quasi‐biennial oscillation (QBO). The JRA‐55AMIP data set, a simple simulation performed without data assimilation, does not simulate the QBO, whereas the JRA‐55 data set represents the QBO with the aid of data assimilation. The climatological mean zonal mean states of JRA‐55AMIP considerably deviate from those of JRA‐55 in the lower stratosphere. The deviation of JRA‐55AMIP is similar to the modulation pattern by the QBO in specific phase regions in which the BDC is rather weak. The simulated QBO might enhance the BDC and reduce the model biases in the tropical lower stratosphere.
Emissions and climate forcing from global and Arctic fishing vessels
Authors: McKuin Brandi , Campbell J. Elliott
Published: January 2016

Fishing vessels were recently found to be the largest source of black carbon ship emissions in the Arctic, suggesting that the fishing sector should be a focus for future studies. Here we developed a global and Arctic emissions inventory for fishing vessel emissions of short‐lived and long‐lived climate forcers based on data from a wide range of vessel sizes, fuel sulfur contents, engine types, and operational characteristics. We found that previous work generally underestimated emissions of short‐lived climate forcers due to a failure to account for small fishing vessels as well as variability in emission factors. In particular, global black carbon emissions were underestimated by an order of magnitude. Furthermore, our order of magnitude estimate of the net climate effect from these fishing vessel emissions suggests that short‐lived climate forcing may be particularly important in regions where fuel has a low sulfur content. These results have implications for proposed maritime policies and provide a foundation for future climate simulations to forecast climate change impacts in the Arctic.
Stratospheric polar vortex splits and displacements in the high‐top CMIP5 climate models
Authors: Seviour William J. M. , Gray Lesley J. , Mitchell Daniel M.
Published: January 2016

Sudden stratospheric warming (SSW) events can occur as either a split or a displacement of the stratospheric polar vortex. Recent observational studies have come to different conclusions about the relative impacts of these two types of SSW upon surface climate. A clearer understanding of their tropospheric impact would be beneficial for medium‐range weather forecasts and could improve understanding of the physical mechanism for stratosphere‐troposphere coupling. Here we perform the first multimodel comparison of stratospheric polar vortex splits and displacements, analyzing 13 stratosphere‐resolving models from the fifth Coupled Model Intercomparison Project (CMIP5) ensemble. We find a wide range of biases among models in both the mean state of the vortex and the frequency of vortex splits and displacements, although these biases are closely related. Consistent with observational results, almost all models show vortex splits to occur barotropically throughout the depth of the stratosphere, while vortex displacements are more baroclinic. Vortex splits show a slightly stronger North Atlantic surface signal in the month following onset. However, the most significant difference in the surface response is that vortex displacements show stronger negative pressure anomalies over Siberia. This region is shown to be colocated with differences in tropopause height, suggestive of a localized response to lower stratospheric potential vorticity anomalies.
Flow patterns and morphology of a prograding river delta
Authors: Shaw John B. , Mohrig David , Wagner R. Wayne
Published: January 2016

The transition of flow between laterally confined channels and the unchannelized delta front controls the morphodynamic evolution of river deltas but has rarely been measured at the field scale. We quantify flow patterns and bathymetry that define the evolution of the subaqueous delta front on the Wax Lake Delta, a rapidly prograding delta in coastal Louisiana. A significant portion of flow (∼59%) departs the channel network over lateral channel margins as opposed to the downstream channel tips. Bathymetric surveys and remotely sensed estimates of flow direction allow spatial changes in flow velocity to be quantified and patterns of erosion and deposition to be estimated. Shallowing along channel margins produces spatial acceleration and erosion. Lateral spreading, deceleration, and deposition occur within three to eight channel widths outside of the channel margins. In interdistributary bays, the shape of each flow path is constrained by “nourishment boundaries” that separate the outflows from neighboring channels. Deposit elevation decreases with a basinward slope of 2.4 × 10−4 with distance from a channel margin along any flow path, regardless of the channel or location that flow departed the network. Bathymetric depressions called “interdistributary troughs” form along nourishment boundaries where flow paths are the longest and deposit elevation is correspondingly low. We conclude that the deposit morphology exerts a strong control on bathymetric evolution and that interaction between neighboring channels and even neighboring deltas can influence delta front morphology.
Deviation of permeable coarse‐grained boundary resistance from Nikuradse's observations
Authors: Cheng Nian‐Sheng , Liu Xingnian , Chen Xingwei , Qiao Changkai
Published: January 2016

Nikuradse's (1933) rough pipe study is enormously influential in the understanding of flow resistance over a sediment bed. However, the rough boundary employed in Nikuradse's study differs from permeable sediment beds in rivers. This implies that the results derived from the rough pipe experiments may not be applicable for flows over a permeable coarse‐grained bed. The present study aimed to explore to what extent the flow resistance of a permeable coarse‐grained boundary deviates from the Nikuradse's observations. Experiments were conducted with rough pipes, which were prepared by overlaying the inner wall with one to four layers of spherical beads. The single layer roughness resembles the experimental setup reported in Nikuradse's study, while the multilayer of grains allows significant flow to pass through the porous roughness layer. In addition, the ratio of grain diameter, k, to pipe diameter, d, was chosen to be one to two orders greater than the range (0.001 < k/d < 0.033) adopted in Nikuradse's experiments. The data show that the friction factor deviates significantly from the prediction based on Nikuradse's rough pipe relation. For hydraulically rough pipes, the friction factor is found to be proportional to the squared ratio of the grain diameter to nominal pipe diameter. This result is different from the one‐third power function as implied by Nikuradse's rough pipe relation or the Manning‐Strickler formula but agrees well with laboratory observations of open channel resistance in the presence of large‐scale roughness. The measurements also suggest the existence of a laminar flow regime, in which the friction factor is inversely proportional to the Reynolds number. The observed variations in the flow resistance are attributed to both wall permeability and large‐scale roughness.
Effects of soil spatial variability at the hillslope and catchment scales on characteristics of rainfall‐induced landslides
Authors: Fan Linfeng , Lehmann Peter , Or Dani
Published: January 2016

Spatial variations in soil properties affect key hydrological processes, yet their role in soil mechanical response to hydro‐mechanical loading is rarely considered. This study aims to fill this gap by systematically quantifying effects of spatial variations in soil type and initial water content on rapid rainfall‐induced shallow landslide predictions at the hillslope‐ and catchment‐scales. We employed a physically‐based landslide triggering model that considers mechanical interactions among soil columns governed by strength thresholds. At the hillslope scale, we found that the emergence of weak regions induced by spatial variations of soil type and initial water content resulted in early triggering of landslides with smaller volumes of released mass relative to a homogeneous slope. At the catchment scale, initial water content was linked to a topographic wetness index, whereas soil type varied deterministically with soil depth considering spatially correlated stochastic components. Results indicate that a strong spatial organization of initial water content delays landslide triggering, whereas spatially linked soil type with soil depth promoted landslide initiation. Increasing the standard deviation and correlation length of the stochastic component of soil type increases landslide volume and hastens onset of landslides. The study illustrates that for similar external boundary conditions and mean soil properties, landslide characteristics vary significantly with soil variability, hence it must be considered for improved landslide model predictions.
Characterization of extensional rheological filament stretching with a dual‐mode Giesekus model
Authors: Hallmark Bart , Wilson D. Ian , Pistre Nicolas
Published: January 2016

A new, simple, formulation that describes capillary thinning as predicted by a two‐mode Giesekus model is derived, and its application in analyzing data from extensional rheometry (capillary thinning) experiments is discussed. An algorithm is presented that can be used to fit the expressions obtained from the Giesekus model to extensional rheometry data. Examples of data fitting are given for an idealized data set, for measurements obtained for aqueous solutions of 6 wt % 900,000 molecular weight polyethylene oxide, and for biological fluids obtained from pitchers of Nepenthes Rafflesiana. Good fits to the data were obtained, with coefficients of determination in excess of 0.98. For each data set, it was possible to calculate values of extensional viscosity and relaxation time for each of the two modes, allowing quantitative comparison of different fluids or of the same fluid as it ages. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2188–2199, 2016
Particle‐resolved direct numerical simulation of gas–solid dynamics in experimental fluidized beds
Authors: Luo Kun , Tan Junhua , Wang Zeli , Fan Jianren
Published: January 2016

Particle‐resolved direct numerical simulations (PR‐DNS) of a simplified experimental shallow fluidized bed and a laboratory bubbling fluidized bed are performed by using immersed boundary method coupled with a soft‐sphere model. Detailed information on gas flow and individual particles’ motion are obtained and analyzed to study the gas–solid dynamics. For the shallow bed, the successful predictions of particle coherent oscillation and bed expansion and contraction indicate all scales of motion in the flow are well captured by the PD‐DNS. For the bubbling bed, the PR‐DNS predicted time averaged particle velocities show a better agreement with experimental measurements than those of the computational fluid dynamics coupled with discrete element models (CFD‐DEM), which further validates the predictive capability of the developed PR‐DNS. Analysis of the PR‐DNS drag force shows that the prevailing CFD‐DEM drag correlations underestimate the particle drag force in fluidized beds. The particle mobility effect on drag correlation needs further investigation. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1917–1932, 2016
CFD–DEM investigation into the scaling up of spout‐fluid beds via two interconnected chambers
Authors: Yang Shiliang , Cahyadi Andy , Sun Yuhao , Wang Jingwei , Chew Jia Wei
Published: January 2016

The hydrodynamics and chamber interaction in a three‐dimensional spout‐fluid bed with two interconnected chambers are investigated via computational fluid dynamics coupled with discrete element method (CFD–DEM), because multiple interconnected chambers are key to scaling up spout‐fluid beds. The overall solid motion, spouting evolution, and spout‐annulus interface is studied, followed by time‐averaged hydrodynamics, particle‐scale information, spout‐annulus interaction, and inter‐chamber interaction. The results show that inter‐chamber interactions lead to unique characteristics distinct from that for a single‐chamber system, including (1) asymmetry of the hydrodynamics within each chamber, (2) alternative spouting behavior in the two chambers, (3) smaller pressure drop in terms of magnitude and fluctuations, (4) two peaks in the solid residence time (SRT) frequency histogram of the annulus, (5) average SRT in the spout is twice that in a single‐chamber, and (6) larger solid dispersion in all three directions. The results provide meaningful understanding for the scale‐up of spout‐fluid beds. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1898–1916, 2016
Novel variants in ZNF34 and other brain‐expressed transcription factors are shared among early‐onset MDD relatives
Authors: Subaran Ryan L. , Odgerel Zagaa , Swaminathan Rajeswari , Glatt Charles E. , Weissman Myrna M.
Published: January 2016

There are no known genetic variants with large effects on susceptibility to major depressive disorder (MDD). Although one proposed study approach is to increase sensitivity by increasing sample sizes, another is to focus on families with multiple affected individuals to identify genes with rare or novel variants with strong effects. Choosing the family‐based approach, we performed whole‐exome analysis on affected individuals (n = 12) across five MDD families, each with at least five affected individuals, early onset, and prepubertal diagnoses. We identified 67 genes where novel deleterious variants were shared among affected relatives. Gene ontology analysis shows that of these 67 genes, 18 encode transcriptional regulators, eight of which are expressed in the human brain, including four KRAB‐A box‐containing Zn2+ finger repressors. One of these, ZNF34, has been reported as being associated with bipolar disorder and as differentially expressed in bipolar disorder patients compared to healthy controls. We found a novel variant—encoding a non‐conservative P17R substitution in the conserved repressor domain of ZNF34 protein—segregating completely with MDD in all available individuals in the family in which it was discovered. Further analysis showed a common ZNF34 coding indel segregating with MDD in a separate family, possibly indicating the presence of an unobserved, linked, rare variant in that particular family. Our results indicate that genes encoding transcription factors expressed in the brain might be an important group of MDD candidate genes and that rare variants in ZNF34 might contribute to susceptibility to MDD and perhaps other affective disorders. © 2016 Wiley Periodicals, Inc.
The ontogeny of nasal shape: An analysis of sexual dimorphism in a longitudinal sample
Authors: Holton Nathan E. , Alsamawi Ammar , Yokley Todd R. , Froehle Andrew W.
Published: January 2016

Objectives

Potential integration between the nasal region and noncranial components of the respiratory system has significant implications for understanding determinants of craniofacial variation. There is increasing evidence that sexual dimorphism in body size and associated male‐female differences in energetically relevant variables influence the development of the nasal region. To better understand this relationship, we examined the ontogeny of sexual dimorphism in nasal shape using a longitudinal series of lateral cephalograms.

Methods

We collected a series of two dimensional coordinate landmark data from n = 20 males and n = 18 females from 3.0 to 20.0+ years of age totaling n = 290 observations across nine age groups. First, we tested whether there are sex differences in the nasal shape related to ontogenetic increases in body size (i.e., sitting height). Additionally, we examined whether there are male‐female differences in patterns of nonallometric variation in nasal shape. Next, we tested whether there are sex differences in the strength of integration between the nasal region and other aspects of the facial skeleton.

Results

Our results indicate that there are a number of similarities in patterns of morphological variation in the nasal region between males and females. However, as sitting height increases males exhibit a disproportionate increase in nasal region height that is not present in the female sample. Moreover, the male nasal region is less integrated with the surrounding facial skeleton when compared to the female sample.

Conclusions

These results are consistent with the hypothesis that sex differences in nasal development are associated with male‐female differences in energetically relevant variables. Am J Phys Anthropol 160:52–61, 2016. © 2016 Wiley Periodicals, Inc.
Pyridyl Pyrrolide Boron Complexes: The Facile Generation of Thermally Activated Delayed Fluorescence and Preparation of Organic Light‐Emitting Diodes
Authors: Shiu Yi‐Jiun , Cheng Yung‐Chen , Tsai Wei‐Lung , Wu Chung‐Chih , Chao Chun‐Tien , Lu Chin‐Wei , Chi Yun , Chen Yi‐Ting , Liu Shih‐Hung , Chou Pi‐Tai
Published: January 2016

The electron positive boron atom usually does not contribute to the frontier orbitals for several lower‐lying electronic transitions, and thus is ideal to serve as a hub for the spiro linker of light‐emitting molecules, such that the electron donor (HOMO) and acceptor (LUMO) moieties can be spatially separated with orthogonal orientation. On this basis, we prepared a series of novel boron complexes bearing electron deficient pyridyl pyrrolide and electron donating phenylcarbazolyl fragments or triphenylamine. The new boron complexes show strong solvent‐polarity dependent charge‐transfer emission accompanied by a small, non‐negligible normal emission. The slim orbital overlap between HOMO and LUMO and hence the lack of electron correlation lead to a significant reduction of the energy gap between the lowest lying singlet and triplet excited states (ΔET‐S) and thereby the generation of thermally activated delay fluorescence (TADF).
CuSO4/H2O2‐Induced Rapid Deposition of Polydopamine Coatings with High Uniformity and Enhanced Stability
Authors: Zhang Chao , Ou Yang , Lei Wen‐Xi , Wan Ling‐Shu , Ji Jian , Xu Zhi‐Kang
Published: January 2016

Mussel‐inspired polydopamine (PDA) deposition offers a promising route to fabricate multifunctional coatings for various materials. However, PDA deposition is generally a time‐consuming process, and PDA coatings are unstable in acidic and alkaline media, as well as in polar organic solvents. We report a strategy to realize the rapid deposition of PDA by using CuSO4/H2O2 as a trigger. Compared to the conventional processes, our strategy shows the fastest deposition rate reported to date, and the PDA coatings exhibit high uniformity and enhanced stability. Furthermore, the PDA‐coated porous membranes have excellent hydrophilicity, anti‐oxidant properties, and antibacterial performance. This work demonstrates a useful method for the environmentally friendly, cost‐effective, and time‐saving fabrication of PDA coatings.
Phenyltrimethylammonium Salts as Methylation Reagents in the Nickel‐Catalyzed Methylation of C−H Bonds
Authors: Uemura Takeshi , Yamaguchi Mao , Chatani Naoto
Published: January 2016

Methylation of C(sp2)−H bonds was achieved through the NiII‐catalyzed reaction of benzamides with phenyltrimethylammonium bromide or iodide as the source of the methyl group. The reaction has a broad scope and shows high functional‐group compatibility. The reaction is also applicable to the methylation of C(sp3)−H bonds in aliphatic amides.
Esterase‐Sensitive Prodrugs with Tunable Release Rates and Direct Generation of Hydrogen Sulfide
Authors: Zheng Yueqin , Yu Bingchen , Ji Kaili , Pan Zhixiang , Chittavong Vayou , Wang Binghe
Published: January 2016

Prodrugs that release hydrogen sulfide upon esterase‐mediated cleavage of an ester group followed by lactonization are described herein. By modifying the ester group and thus its susceptibility to esterase, and structural features critical to the lactonization rate, H2S release rates can be tuned. Such prodrugs directly release hydrogen sulfide without the involvement of perthiol species, which are commonly encountered with existing H2S donors. Additionally, such prodrugs can easily be conjugated to another non‐steroidal anti‐inflammatory agent, leading to easy synthesis of hybrid prodrugs. As a biological validation of the H2S prodrugs, the anti‐inflammatory effects of one such prodrug were examined by studying its ability to inhibit LPS‐induced TNF‐α production in RAW 264.7 cells. This type of H2S prodrugs shows great potential as both research tools and therapeutic agents.
Highly Efficient Transition Metal Nanoparticle Catalysts in Aqueous Solutions
Authors: Wang Changlong , Ciganda Roberto , Salmon Lionel , Gregurec Danijela , Irigoyen Joseba , Moya Sergio , Ruiz Jaime , Astruc Didier
Published: January 2016

A ligand design is proposed for transition metal nanoparticle (TMNP) catalysts in aqueous solution. Thus, a tris(triazolyl)‐polyethylene glycol (tris‐trz‐PEG) amphiphilic ligand, 2, is used for the synthesis of very small TMNPs with Fe, Co, Ni, Cu, Ru, Pd, Ag, Pt, and Au. These TMNP‐2 catalysts were evaluated and compared for the model 4‐nitrophenol reduction, and proved to be extremely efficient. High catalytic efficiencies involving the use of only a few ppm metal of PdNPs, RuNPs, and CuNPs were also exemplified in Suzuki–Miyaura, transfer hydrogenation, and click reactions, respectively.
Combining Biomimetic Block Copolymer Worms with an Ice‐Inhibiting Polymer for the Solvent‐Free Cryopreservation of Red Blood Cells
Authors: Mitchell Daniel E. , Lovett Joseph R. , Armes Steven P. , Gibson Matthew I.
Published: January 2016

The first fully synthetic polymer‐based approach for red‐blood‐cell cryopreservation without the need for any (toxic) organic solvents is reported. Highly hydroxylated block copolymer worms are shown to be a suitable replacement for hydroxyethyl starch as a extracellular matrix for red blood cells. When used alone, the worms are not a particularly effective preservative. However, when combined with poly(vinyl alcohol), a known ice‐recrystallization inhibitor, a remarkable additive cryopreservative effect is observed that matches the performance of hydroxyethyl starch. Moreover, these block copolymer worms enable post‐thaw gelation by simply warming to 20 °C. This approach offers a new solution for both the storage and transport of red blood cells and also a convenient matrix for subsequent 3D cell cultures.
Elemental‐Sulfur‐Mediated Facile Synthesis of a Covalent Triazine Framework for High‐Performance Lithium–Sulfur Batteries
Authors: Talapaneni Siddulu Naidu , Hwang Tae Hoon , Je Sang Hyun , Buyukcakir Onur , Choi Jang Wook , Coskun Ali
Published: January 2016

A covalent triazine framework (CTF) with embedded polymeric sulfur and a high sulfur content of 62 wt % was synthesized under catalyst‐ and solvent‐free reaction conditions from 1,4‐dicyanobenzene and elemental sulfur. Our synthetic approach introduces a new way of preparing CTFs under environmentally benign conditions by the direct utilization of elemental sulfur. The homogeneous sulfur distribution is due to the in situ formation of the framework structure, and chemical sulfur impregnation within the micropores of CTF effectively suppresses the dissolution of polysulfides into the electrolyte. Furthermore, the triazine framework facilitates electron and ion transport, which leads to a high‐performance lithium–sulfur battery.
Scalable Total Synthesis of rac‐Jungermannenones B and C
Authors: Liu Weilong , Li Houhua , Cai Pei‐Jun , Wang Zhen , Yu Zhi‐Xiang , Lei Xiaoguang
Published: January 2016

Reported is the first scalable synthesis of rac‐jungermannenones B and C starting from the commercially available and inexpensive geraniol in 10 and 9 steps, respectively. The unique jungermannenone framework is rapidly assembled by an unprecedented regioselective 1,6‐dienyne reductive cyclization reaction which proceeds through a vinyl radical cyclization/allylic radical isomerization mechanism. DFT calculations explain the high regioselectivity observed in the 1,6‐dienyne reductive radical cyclization.
Rapid Determination of Fast Protein Dynamics from NMR Chemical Exchange Saturation Transfer Data
Authors: Gu Yina , Hansen Alexandar L. , Peng Yu , Brüschweiler Rafael
Published: January 2016

Functional motions of 15N‐labeled proteins can be monitored by solution NMR spin relaxation experiments over a broad range of timescales. These experiments however typically take of the order of several days to a week per protein. Recently, NMR chemical exchange saturation transfer (CEST) experiments have emerged to probe slow millisecond motions complementing R1ρ and CPMG‐type experiments. CEST also simultaneously reports on site‐specific R1 and R2 parameters. It is shown here how CEST‐derived R1 and R2 relaxation parameters can be measured within a few hours at an accuracy comparable to traditional relaxation experiments. Using a “lean” version of the model‐free approach S2 order parameters can be determined that match those from the standard model‐free approach applied to 15N R1, R2, and {1H}‐15N NOE data. The new methodology, which is demonstrated for ubiquitin and arginine kinase (42 kDa), should serve as an effective screening tool of protein dynamics from picosecond‐to‐millisecond timescales.
DNA Nanoparticles for Improved Protein Synthesis In Vitro
Authors: Galinis Robertas , Stonyte Greta , Kiseliovas Vaidotas , Zilionis Rapolas , Studer Sabine , Hilvert Donald , Janulaitis Arvydas , Mazutis Linas
Published: January 2016

The amplification and digital quantification of single DNA molecules are important in biomedicine and diagnostics. Beyond quantifying DNA molecules in a sample, the ability to express proteins from the amplified DNA would open even broader applications in synthetic biology, directed evolution, and proteomics. Herein, a microfluidic approach is reported for the production of condensed DNA nanoparticles that can serve as efficient templates for in vitro protein synthesis. Using phi29 DNA polymerase and a multiple displacement amplification reaction, single DNA molecules were converted into DNA nanoparticles containing up to about 104 clonal gene copies of the starting template. DNA nanoparticle formation was triggered by accumulation of inorganic pyrophosphate (produced during DNA synthesis) and magnesium ions from the buffer. Transcription–translation reactions performed in vitro showed that individual DNA nanoparticles can serve as efficient templates for protein synthesis in vitro.
Enantioselective N‐Heterocyclic Carbene Catalysis by the Umpolung of α,β‐Unsaturated Ketones
Authors: Nakano Yuji , Lupton David W.
Published: January 2016

N‐Heterocyclic carbene‐catalyzed formation of β‐anionic intermediates from enones has been employed in the enantioselective synthesis of 2‐aryl propionates. The reaction was achievable using a homochiral 4‐MeOC6H4 morpholinone catalyst allowing the first example of enantioselective catalysis by umpolung of α,β‐unsaturated ketones. The reaction is high yielding, and shows robustness with reasonable generality. A mechanism is proposed in which the enantiodetermining protonation is achieved using either hexafluoroisopropanol or the formed naphthol product.
Synthesis and characterizations of arsine– and stibine–ligated Schiff base palladacycles and their applications in Suzuki–Miyaura cross‐coupling reactions
Authors: Wang Haozhen , Yang Jin
Published: January 2016

A series of arsine‐ and stibine‐ligated Schiff base palladacycles were synthesized by the reaction of μ‐Cl‐bridged Schiff base palladacycles [Pd(C6H4CH]NC6H2R)(μ‐Cl)]2 (R = 2,4,6‐trimethyl or 2,6‐diisopropyl) with AsPh3 or SbPh3. The new arsine‐ and stibine‐ligated palladacycles were fully characterized using 1H NMR, 13C NMR and infrared spectroscopies, high‐resolution mass spectrometry, elemental analysis and single‐crystal X‐ray diffraction. Further exploration of the catalytic application of the palladacycles for Suzuki–Miyaura cross‐coupling reactions of aryl bromides with arylboronic acids was carried out. It was found that the new palladacycles are considerably active for these coupling reactions. Copyright © 2016 John Wiley & Sons, Ltd.
Swelling behavior of coal in solvent at elevated temperature and pressure and non‐isothermal kinetic analysis
Authors: Chen Lei , Zhao Longtao , Cao Yi. , Li Yanxun , Lv Hekun , Zhang Hao
Published: January 2016

The swelling ratio of a packed coal bed in a coal liquefaction process derived recycle solvent (REC) and pure tetralin (THN) at elevated temperature and pressure is obtained by a so‐called linear variable differential transformer (LVDT) deformation transducer apparatus. Effects of heating rate and coal rank on the swelling behavior are investigated. A kinetic model based on a pseudopolymolecular reaction is used to model the swelling data up to the maximum swelling ratio. With the increase of the temperature, the thermal motion of solvent molecule and coal macromolecules is enhanced, and the interactions increase between coal macromolecules and solvent molecule. As the temperature is further increased, the swelling ratio of the packed coal bed reduces for the softening and decomposition of coal. For faster heating rates, the maximum swelling ratio shifts to higher temperature and the apparent activation energy and pre‐exponential factor slightly increase with the increase of heating rates. A comparison of coal rank illustrates that the maximum swelling ratio of bituminous coal in REC and THN is more and shows at higher temperature than lignite. The apparent activation energy for coals swelling in REC and THN at elevated temperature and pressure is between 20 and 55 kJ/mol. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Extraction and characterization of holocellulose fibers by microwave‐assisted selective liquefaction of bamboo
Authors: Xie Jiulong , Hse Chung‐Yun , Shupe Todd F. , Pan Hui , Hu Tingxing
Published: January 2016

Microwave‐assisted selective liquefaction was proposed and used as a novel method for the isolation of holocellulose fibers. The results showed that the bamboo lignin component and extractives were almost completely removed by using a liquefaction process at 120 °C for 9 min, and the residual lignin and extractives in the solid residue were as low as 0.65% and 0.49%, respectively. Increasing the reaction temperature or time could decrease the solid yield, but they can also enhance the removal of lignin and extractives from bamboo particles and increase the holocellulose content in the solid residue. The absorbance bands that characterized functional groups of lignin on the Fourier transform infrared spectra of the solid residue weakened or disappeared. The solid residue showed high crystallinity, indicating the removal of noncellulosic material. Small cracks were observed on the SEM images of the residue, which indicated that the fibers from liquefaction may be susceptible to chemical access or enzyme attack. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43394.
Estimation of the mechanical properties of urea–formaldehyde microcapsules by compression tests and finite element analysis
Authors: Ma Wanpeng , Zhang Wei , Zhao Yang , Wang Sijie
Published: January 2016

Information on the mechanical properties of microcapsules is essential to understanding their performance during manufacturing, processing, and applications. The mechanical properties of urea–formaldehyde (UF) microcapsules filled with ethyl phenyl acetate (EPA) were determined by applying single‐microcapsule compression and a finite element model. Microcapsules were prepared by in situ polymerization, and the average wall thickness of microcapsules was 192 ± 12 nm as determined using scanning electron microscopy. The deformation behavior of the microcapsule was measured by a single‐microcapsule compression experiment between two parallel plates. The results show that both burst deformation and burst force were linearly related to microcapsule size. A model for an elastic shell filled with incompressible fluid was used to simulate compression of the microcapsule in ABAQUS. Dimensionless parameters were introduced to the model. The relationship between dimensionless force and dimensionless displacement depended on the ratio of wall thickness to diameter (ε). However, the relationship remained the same when ε was less than 1% and can be fitted well by the mathematical equation. An estimation of Young's modulus can be obtained from the compression data for the dimensionless deformation from 10% to 15%. The average Young's modulus of a UF/EPA microcapsule is estimated to be 2.12 ± 0.45 GPa. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43414.
Case‐control data analysis for randomly pooled biomarkers
Authors: Perkins Neil J. , Mitchell Emily M. , Lyles Robert H. , Schisterman Enrique F.
Published: January 2016

Pooled study designs, where individual biospecimens are combined prior to measurement via a laboratory assay, can reduce lab costs while maintaining statistical efficiency. Analysis of the resulting pooled measurements, however, often requires specialized techniques. Existing methods can effectively estimate the relation between a binary outcome and a continuous pooled exposure when pools are matched on disease status. When pools are of mixed disease status, however, the existing methods may not be applicable. By exploiting characteristics of the gamma distribution, we propose a flexible method for estimating odds ratios from pooled measurements of mixed and matched status. We use simulation studies to compare consistency and efficiency of risk effect estimates from our proposed methods to existing methods. We then demonstrate the efficacy of our method applied to an analysis of pregnancy outcomes and pooled cytokine concentrations. Our proposed approach contributes to the toolkit of available methods for analyzing odds ratios of a pooled exposure, without restricting pools to be matched on a specific outcome.
Novel and sensitive UPLC–MS/MS method for quantification of sofosbuvir in human plasma: application to a bioequivalence study
Authors: Rezk Mamdouh R. , Basalious Emad B. , Amin Mohammed E.
Published: January 2016

A novel and sensitive LC–MS/MS method was developed and validated for determination of sofosbuvir (SF) using eplerenone as an internal standard. The Xevo TQD LC–MS/MS was operated under the multiple‐reaction monitoring mode using electrospray ionization. Extraction with tert‐butyl methyl ether was used in sample preparation. The prepared samples were chromatographed on Acquity UPLC BEH C18 (50 × 2.1 mm, 1.7 μm) column by pumping 0.1% formic acid and acetonitrile in an isocratic mode at a flow rate of 0.35 mL/min. Method validation was performed as per the US Food and Drug Administration guidelines and the standard curves were found to be linear in the range of 0.25–3500 ng/mL for SF. The intra‐ and inter‐day precision and accuracy results were within the acceptable limits. A very short run time of 1 min made it possible to analyze more than 500 human plasma samples per day. A very low quantification limit of SF allowed the applicability of the developed method for determination of SF in a bioequivalence study in human volunteers. Copyright © 2016 John Wiley & Sons, Ltd.
Application of simplex‐based experimental optimization to challenging bioprocess development problems: Case studies in downstream processing
Authors: Konstantinidis Spyridon , Welsh John P. , Roush David J. , Velayudhan Ajoy
Published: January 2016

The identification of feasible operating conditions during the early stages of bioprocess development is implemented frequently through High Throughput (HT) studies. These typically employ techniques based on regression analysis, such as Design of Experiments. In this work, an alternative approach, based on a previously developed variant of the Simplex algorithm, is compared to the conventional regression‐based method for three experimental systems involving polishing chromatography and protein refolding. This Simplex algorithm variant was found to be more effective in identifying superior operating conditions, and in fact it reached the global optimum in most cases involving multiple optima. By contrast, the regression‐based method often failed to reach the global optimum, and in many cases reached poor operating conditions. The Simplex‐based method is further shown to be robust in dealing with noisy experimental data, and requires fewer experiments than regression‐based methods to reach favorable operating conditions. The Simplex‐variant also lends itself to the use of HT analytical methods, when they are available, which can assist in avoiding analytical bottlenecks. It is suggested that this Simplex‐variant is ideally suited to rapid optimization in early‐phase process development. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:404–419, 2016
Assessment of diet and recognition of nutritional deficiencies in paleopathological studies: A review
Authors: Meyer A.
Published: January 2016

An essential part of paleopathology is the study of diet and nutrition as well as inferring aspects of diet and nutrition from the skeletal pathology. Interpretation of nutritional and metabolic disease‐related pathologies often provides additional insight into the daily social and cultural practices of people. However, precise diagnoses of specific vitamin‐related deficiencies in archaeological skeletal remains are still quite problematic and specific diagnoses are rarely possible. This partly stems from the fact that many nutritional or metabolic diseases do not necessarily result in an osteological response and when they do, the comorbidity and analogous osteological responses to vitamin deficiencies may hamper the definite diagnosis of nutrition‐related disease. Clin. Anat. 29:862–869, 2016. © 2016 Wiley Periodicals, Inc.
Electrodeposition of Inorganic Oxide/Nanocarbon Composites: Opportunities and Challenges
Authors: Janáky Csaba , Kecsenovity Egon , Rajeshwar Krishnan
Published: January 2016

The front cover artwork is provided by C. Janáky (University of Szeged, Hungary) and K. Rajeshwar (University of Texas at Arlington, USA). The image shows how electrodeposition can be used to obtain inorganic oxide/nanocarbon hybrid architectures with properties tailored towards specific applications. Read the full text of the Minireview at 10.1002/celc.201500460.
Hollow Zn/Co Zeolitic Imidazolate Framework (ZIF) and Yolk–Shell Metal@Zn/Co ZIF Nanostructures
Authors: Rösler Christoph , Aijaz Arshad , Turner Stuart , Filippousi Maria , Shahabi Azar , Xia Wei , Van Tendeloo Gustaaf , Muhler Martin , Fischer Roland A.
Published: January 2016

Metal–organic frameworks (MOFs) feature a great possibility for a broad spectrum of applications. Hollow MOF structures with tunable porosity and multifunctionality at the nanoscale with beneficial properties are desired as hosts for catalytically active species. Herein, we demonstrate the formation of well‐defined hollow Zn/Co‐based zeolitic imidazolate frameworks (ZIFs) by use of epitaxial growth of Zn‐MOF (ZIF‐8) on preformed Co‐MOF (ZIF‐67) nanocrystals that involve in situ self‐sacrifice/excavation of the Co‐MOF. Moreover, any type of metal nanoparticles can be accommodated in Zn/Co‐ZIF shells to generate yolk–shell metal@ZIF structures. Transmission electron microscopy and tomography studies revealed the inclusion of these nanoparticles within hollow Zn/Co‐ZIF with dominance of the Zn‐MOF as shell. Our findings lead to a generalization of such hollow systems that are working effectively to other types of ZIFs.