bluuebunny/crossref_metadata_2025 huggingface dataset:
Interregional differences in MODIS‐derived cloud regimes
Authors: Leinonen Jussi , Lebsock Matthew D. , Oreopoulos Lazaros , Cho Nayeong
Published: September 2016

Cloud regimes based on histogram clustering offer a potentially useful tool for observational analysis of clouds. The utility of the regimes depends on their ability to identify cloud structures that are associated with distinct meteorological conditions. In this study, active remote sensing observations from CloudSat and CALIPSO are binned according to the cloud regimes derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The occurrence of CloudSat radar reflectivity by altitude, as well as CloudSat‐CALIPSO retrievals of cloud cover, precipitation occurrence, cloud radiative effect, and multilayered cloud structure are analyzed for each MODIS cloud regime and for different regions. While the picture of the regimes given by CloudSat and CALIPSO is generally consistent with that derived from MODIS, substantial region‐to‐region variability is found within the regimes. The regimes constrain the shortwave cloud radiative effect well, while the longwave effect and the precipitation occurrence exhibit more variability. The joint distributions of radar reflectivity and altitude also reveal differences in the structure of clouds within each regime. Thus, it appears that there is region‐dependent variability within each regime, resulting from the different meteorological environments. Among the major differences in the cloud structure are cloud top height in convective clouds and the number of distinct cloud layers in boundary layer clouds. Thus, passive optical sensors appear limited in their ability to characterize clouds and assign them to distinct regimes. The differences can be used to estimate the cloud regime inherent variability for studies that use them as a proxy for the climate effects of clouds.
Mars' atmosphere: The sister planet, our statistical twin
Authors: Chen Wilbur , Lovejoy Shaun , Muller Jan‐Peter
Published: September 2016

Satellite‐based Martian reanalyses have allowed unprecedented comparisons between our atmosphere and that of our sister planet, underlining various similarities and differences in their respective dynamics. Yet by focusing on large scale structures and deterministic mechanisms they have improved our understanding of the dynamics only over fairly narrow ranges of (near) planetary scales. However, the Reynolds numbers of the flows on both planets are larger than 1011 and dissipation only occurs at centimetric (Mars) or millimetric scales (Earth) so that over most of their scale ranges, the dynamics are fully turbulent. In this paper, we therefore examine the high‐level, statistical, turbulent laws for the temperature, horizontal wind, and surface pressure, finding that Earth and Mars have virtually identical statistical exponents so that their statistics are very similar over wide ranges. Therefore, it would seem that with the exception of certain aspects of the largest scales (such as the role of dust in atmospheric heating on Mars, or of water in its various phases on Earth), that the nonlinear dynamics are very similar. We argue that this is a prediction of the classical laws of turbulence when extended to planetary scales and that it supports our use of turbulent laws on both planetary atmospheres.
Assigning Electronic States in Carbon Nanodots
Authors: Strauss Volker , Kahnt Axel , Zolnhofer Eva M. , Meyer Karsten , Maid Harald , Placht Christian , Bauer Walter , Nacken Thomas J. , Peukert Wolfgang , Etschel Sebastian H. , Halik Marcus , Guldi Dirk M.
Published: September 2016

Luminescent carbon nanodots exhibit enormous potential to be used as functional building blocks in energy conversion devices. Their intrinsic heterogeneity, however, hinders a thorough characterization and subsequently their applicability. In this work, the spectroscopic and electrochemical properties of prototype carbon nanodots were thoroughly studied in solution. Spectro‐electrochemical experiments revealed information on the spectral features of several oxidized and reduced species of our carbon nanodots. Therefore, these experiments were complemented with pulse radiolysis where the spectral signature of the one‐electron oxidized and reduced forms were identified. Both, electrochemically and radiolytically reduced and oxidized products show high reactivity in solution which correlates with an open‐shell character, detected by paramagnetic resonance spectroscopy. The herein presented studies help to understand the complex nature of carbon nanodots and serve to overcome difficulties in device fabrication.
Local Writing of Exchange Biased Domains in a Heterostructure of Co/Pd Pinned by Magnetoelectric Chromia
Authors: Singh Uday , Echtenkamp W. , Street M. , Binek Ch. , Adenwalla S.
Published: September 2016

The writing of micrometer‐scaled exchange bias domains by local, laser heating of a thin‐film heterostructure consisting of a perpendicular anisotropic ferromagnetic Co/Pd multilayer and a (0001) oriented film of the magnetoelectric antiferromagnet Cr2O3 (chromia) is reported. Exchange coupling between chromia's boundary magnetization and the ferromagnet leads to perpendicular exchange bias. Focused scanning magneto‐optical Kerr measurements are used to measure local hysteresis loops and create a map of the exchange bias distribution as a function of the local boundary magnetization imprinted in the antiferromagnetic pinning layer on field cooling. The robust boundary magnetization of the Cr2O3 fundamentally alters the exchange bias mechanism, enabling the writing of micrometer‐scaled regions of oppositely directed exchange bias using a focused laser beam.
Grafting of Butadiene–Acrylonitrile Copolymer onto High Vinyl Polybutadiene by Copolymerization
Authors: Geng Jieting , Wang Xin , Hua Jing
Published: September 2016

High vinyl polybutadiene‐graft‐(hydroxyl‐terminated butadiene–acrylonitrile copolymer) (HVPBR‐g‐HTBN) was successfully synthesized through the copolymerization of butadiene and HTBN using a molybdenum (Mo)‐based catalyst. The results indicated that the grafting coefficient of the product was <1 and the nitrogen content of the product was higher than that of linear HVPBR, demonstrating the grafting during the copolymerization by the Mo‐based catalyst. Upon grafting, the intrinsic viscosity of the product's solution was lower, while the molecular weight was higher than that of linear HVPBR. Moreover, the apparent viscosities of concentrated solutions of grafted products were lower than the linear counterpart, despite their higher molecular weight.
Characterization of the Polycaprolactam‐ or Polycaprolactone‐Grafted Polyurethane and the Grafting Effect on Water Vapor Permeation and Tensile Strength
Authors: Chung Yong‐Chan , Park Ji‐Eun , Kim Ji Som , Chun Byoung Chul
Published: September 2016

Polycaprolactam or polycaprolactone was graft‐polymerized onto polyurethane (PU) to control the water vapor permeation and improve the tensile strength of PU. The tensile strength of the PU sharply increased with the grafting of polycaprolactam or polycaprolactone, without a decrease in the tensile strain. The soft segment melting properties did not significantly change with the increase in the lactam or lactone content. The shape recovery and shape retention of the PU series remained high after the grafting. The water vapor permeability (WVP) was reduced by the grafting of the polycaprolactam, whereas the WVP was increased by the grafting of polycaprolactone.
Molecular Understanding of Fullerene – Electron Donor Interactions in Organic Solar Cells
Authors: Ryno Sean M. , Ravva Mahesh Kumar , Chen Xiankai , Li Haoyuan , Brédas Jean‐Luc
Published: September 2016

Organic solar cells hold promise of providing low‐cost, renewable power generation, with current devices providing up to 13% power conversion efficiency. The rational design of more performant systems requires an in‐depth understanding of the interactions between the electron donating and electron accepting materials within the active layers of these devices. Here, we explore works that give insight into the intermolecular interactions between electron donors and electron acceptors, and the impact of molecular orientations and environment on these interactions. We highlight, from a theoretical standpoint, the effects of intermolecular interactions on the stability of charge carriers at the donor/acceptor interface and in the bulk and how these interactions influence the nature of the charge transfer states as well as the charge separation and charge transport processes.
Transcranial doppler re‐screening of subjects who participated in STOP and STOP II
Authors: Adams Robert J. , Lackland Dan T. , Brown Lynette , Brown David , Voeks Jenifer , Fullerton Heather J. , Kanter Julie , Kwiatkowski Janet L.
Published: September 2016

In children with Sickle Cell Disease, the combination of risk stratification with Transcranial Doppler Ultrasound (TCD) and selective chronic red cell transfusion (CRCT—the STOP Protocol) is one of the most effective stroke prevention strategies in medicine. How fully it is being implemented is unclear.

Nineteen of 26 sites that conducted the two pivotal clinical trials (STOP and STOP II) participated in Post STOP, a comprehensive medical records review assessing protocol implementation in the 10–15 years since the trials ended. Professional abstractors identified medical records in the Post STOP era in 2851 (74%) of the 3,840 children who took part in STOP and/or STOP II, and documented TCD rescreening, maintenance of CRCT in those at risk, and stroke. Among 1,896 children eligible for TCD rescreening (target group), evidence of any rescreening was found in 1,090 (57%). There was wide site variation in TCD rescreening ranging from 18% to 91% of eligible children. Both younger age and having a conditional TCD during STOP/II were associated with a higher likelihood of having a TCD in Post STOP. Sixty eight new abnormal, high risk cases were identified. Despite clear evidence of benefit the STOP protocol is not fully implemented even at experienced sites. Site variation suggests that system improvements might remove barriers to implementation and result in even greater reduction of ischemic stroke in children with SCD. Am. J. Hematol. 91:1191–1194, 2016. © 2016 Wiley Periodicals, Inc.
Clonal hematopoiesis in patients with dyskeratosis congenita
Authors: Perdigones Nieves , Perin Juan C. , Schiano Irene , Nicholas Peter , Biegel Jaclyn A. , Mason Philip J. , Babushok Daria V. , Bessler Monica
Published: September 2016

Dyskeratosis congenita (DC) is a rare inherited telomeropathy most frequently caused by mutations in a number of genes all thought to be involved in telomere maintenance. The main causes of mortality in DC are bone marrow failure as well as malignancies including leukemias and solid tumors. The clinical picture including the degree of bone marrow failure is highly variable and factors that contribute to this variability are poorly understood. Based on the recent finding of frequent clonal hematopoiesis in related bone marrow failure syndromes, we hypothesized that somatic mutations may also occur in DC and may contribute at least in part to the variability in blood production. To evaluate for the presence of clonal hematopoiesis in DC, we used a combination of X‐inactivation, comparative whole exome sequencing (WES) and single nucleotide polymorphism array (SNP‐A) analyses. We found that clonal hematopoiesis in DC is common, as suggested by skewed X‐inactivation in 8 out of 9 female patients compared to 3 out of 10 controls, and by the finding of acquired copy neutral loss‐of‐heterozygosity on SNP‐A analysis. In addition, 3 out of 6 independent DC patients were found to have acquired somatic changes in their bone marrow by WES, including a somatic reversion in DKC1, as well as missense mutations in other protein coding genes. Our results indicate that clonal hematopoiesis is a common feature of DC, and suggest that such somatic changes, though commonly expected to indicate malignancy, may lead to improved blood cell production or stem cell survival. Am. J. Hematol. 91:1227–1233, 2016. © 2016 Wiley Periodicals, Inc.
Nucleoside Diphosphate Sugar Analogues that Target Glycosyltransferases
Authors: Merino Pedro , Delso Ignacio , Tejero Tomás , Ghirardello Mattia , Juste‐Navarro Verónica
Published: September 2016

Glycosyltransferases (GTs) are enzymes that transfer carbohydrates to a range of substrates and they play a fundamental role in the recognition processes associated with several diseases. The design of glycomimetics of nucleoside diphosphate (NDP) sugars—the natural substrates that act as inhibitors or modulators of GTs—is not only necessary for the development of glycan‐based therapeutic drugs, but is also a crucial tool for understanding their mechanisms of action. Whilst a large number of inhibitors that consist of modifications of the carbohydrate unit and the pyrophosphate linkage have been designed, less attention has been paid to modifications at the ribose moiety and the nucleobase. However, in recent years, promising results have been obtained through such variations, which were prompted by the initial interest in the photolabeling of enzymes to study their structure. In this Focus Review, we survey recent progress in the synthesis of NDP‐sugar analogues that are modified at the ribose moiety or at the heterocyclic base.
Nitrogen dioxide pollution exposure is associated with olfactory dysfunction in older U.S. adults
Authors: Adams Dara R. , Ajmani Gaurav S. , Pun Vivian C. , Wroblewski Kristen E. , Kern David W. , Schumm L. Philip , McClintock Martha K. , Suh Helen H. , Pinto Jayant M.
Published: September 2016

Background

Olfactory dysfunction has profound effects on quality of life, physical and social function, and mortality itself. Nitrogen dioxide (NO2) is a pervasive air pollutant that is associated with respiratory diseases. Given the olfactory nerve's anatomic exposure to airborne pollutants, we investigated the relationship between NO2 exposure and olfactory dysfunction.

Methods

The ability to identify odors was evaluated using a validated test in respondents from the National Social Life, Health, and Aging Project (NSHAP), a representative probability sample of home‐dwelling, older U.S. adults age 57 to 85 years. Exposure to NO2 pollution was assessed using measurements obtained from the U.S. Environmental Protection Agency (EPA) Aerometric Information Retrieval System (AIRS) ambient monitoring site closest to each respondent's home. We tested the association between NO2 exposure and olfactory dysfunction using multivariate logistic regression.

Results

Among older adults in the United States, 22.6% had impaired olfactory function, defined as ≤3 correct (out of 5) on the odor identification test. Median NO2 exposure during the 365 days prior to the interview date was 14.7 ppb (interquartile range [IQR], 10.8 to 19.7 ppb). An IQR increase in NO2 exposure was associated with increased odds of olfactory dysfunction (OR, 1.35; 95% CI, 1.07 to 1.72), adjusting for age, gender, race/ethnicity, education, cognition, comorbidity, smoking, and season of the home interview (n = 1823).

Conclusion

We show for the first time that NO2 exposure is associated with olfactory dysfunction in older U.S. adults. These results suggest an important role for NO2 exposure on olfactory dysfunction, and, potentially, nasal disease more broadly.
Ruthenium‐Catalyzed Modular Synthesis of Cyclic Tertiary Amines from Lactams
Authors: Westhues Stefan , Meuresch Markus , Klankermayer Jürgen
Published: September 2016

Reported is the development of a novel catalytic cascade reaction facilitating the modular synthesis of cyclic tertiary amines from simple lactam substrates and secondary alcohols. Using a single molecular ruthenium‐triphos catalyst in the presence of molecular hydrogen enabled the versatile formation of various amines in high yield with excellent selectivity. Extending the reaction system to using an alcohol as the hydrogen transfer reagent allowed the reduction of lactams without the need for molecular hydrogen.
Direkte Umwandlung eines terminalen Borylen‐ in einen terminalen Phosphinidenkomplex
Authors: Braunschweig Holger , Jimenez‐Halla J. Oscar C. , Radacki Krzysztof , Shang Rong
Published: September 2016

Der erste Manganphosphinidenkomplex wurde quantitativ aus einem terminalen Alkylborylenkomplex erhalten. Dessen Struktur, Bindungssituation sowie der zugrundeliegende Reaktionsmechanismus wurden durch eine Kombination experimenteller und theoretischer Studien untersucht.
Ein Hochdurchsatz‐Fluoreszenz‐Assay zur Bestimmung der Aktivität von Tryptophan‐Halogenasen
Authors: Schnepel Christian , Minges Hannah , Frese Marcel , Sewald Norbert
Published: September 2016

Die Anwendung von Tryptophan‐Halogenasen für die enzymatische Halogenierung hat noch gravierende Limitierungen. Diese könnten mittels gerichteter Evolution überwunden werden, jedoch bedarf die Durchmusterung großer Mutantenbibliotheken eines robusten Hochdurchsatz‐fähigen Testsystems. Im Hinblick darauf wurde eine Suzuki‐Miyaura‐Kreuzkupplung als quantitativer Halogenase‐Assay auf Basis der Bildung eines fluoreszierenden Aryltryptophans entwickelt. Die Methode wurde für die Anwendung im E.‐coli‐Lysat ohne intermediäre Aufarbeitung optimiert und ermöglicht es, halogenierte Tryptophanderivate mit hoher Spezifität in der Mikrotiterplatte quantitativ nachzuweisen. Unter Verwendung dieses Verfahrens wurde eine thermostabile Tryptophan‐6‐Halogenase gefunden, indem mittels fehlerbehafteter PCR eine Mutantenbibliothek erzeugt wurde, die mithilfe der fluorogenen Kreuzkupplung auf erhöhte Thermostabilität durchmustert wurde. Diese Methode lieferte eine verbesserte Enzymvariante mit deutlich gesteigerter Stabilität sowie 2.5‐fach verbesserter Aktivität.
Nanoskopische Bildgebung weicher Materie mittels fluoreszierender Diarylethen‐Photoschalter
Authors: Nevskyi Oleksii , Sysoiev Dmytro , Oppermann Alex , Huhn Thomas , Wöll Dominik
Published: September 2016

Die In‐situ‐Bildgebung weicher Materie ist grundlegend für ein tieferes Verständnis von Funktionalität auf nanoskopischer Ebene. Während superhochauflösende Fluoreszenzmikroskopiemethoden mit ihren bis dahin unerreichten Möglichkeiten der Bildgebung die Lebenswissenschaften revolutionierten, wurde dieses Potenzial in den Materialwissenschaften bisher kaum ausgeschöpft. Dabei stellt die begrenzte Verfügbarkeit an geeigneten Farbstoffen zur Überwindung des Beugungslimits eines der wesentlichen Hindernisse für einen breiteren Einsatz superhochauflösender Mikroskopieverfahren dar. Hier berichten wir über einen neuartigen Diarylethen‐basierten Photoschalter mit einer stark fluoreszierenden geschlossenen und einer nicht‐fluoreszierenden offenen Form. Seine photophysikalischen Eigenschaften, sein Schaltverhalten und seine hohe Photostabilität machen den Farbstoff zum idealen Kandidaten für photoaktivierte Lokalisationsmikroskopie (PALM). Anhand von aus amphiphilen Blockkopolymeren aufgebauten zylindrischen Mizellen belegen wir, wie damit apolare Strukturen mit einer Auflösung jenseits des Beugungslimits optischen Lichts abgebildet werden können.
A Drying‐Free, Water‐Based Process for Fabricating Mixed‐Matrix Membranes with Outstanding Pervaporation Performance
Authors: Deng Yu‐Heng , Chen Jung‐Tsai , Chang Chia‐Hao , Liao Kuo‐Sung , Tung Kuo‐Lun , Price William E. , Yamauchi Yusuke , Wu Kevin C.‐W.
Published: September 2016

Despite much progress in the development of mixed matrix membranes (MMMs) for many advanced applications, the synthesis of MMMs without particle agglomeration or phase separation at high nanofiller loadings is still challenging. In this work, we synthesized nanoporous zeolitic imidazole framework (ZIF‐8) nanoparticles with a particle size of 60 nm and a pore size of 0.34 nm in water and directly added them into an aqueous solution of the organic polymer poly(vinyl alcohol) (PVA) without an intermediate drying process. This approach led to a high‐quality PVA/ZIF‐8 MMM with enhanced performance in ethanol dehydration by pervaporation. The permeability of this MMM is three times higher than that of pristine PVA, and the separation factor is nearly nine times larger than that of pristine PVA. The significantly improved separation performance was attributed to the increase in the fractional free volume in the membranes.
Insights into the Reaction Mechanism of Ethanol Conversion into Hydrocarbons on H‐ZSM‐5
Authors: Van der Borght Kristof , Batchu Rakesh , Galvita Vladimir V. , Alexopoulos Konstantinos , Reyniers Marie‐Françoise , Thybaut Joris W. , Marin Guy B.
Published: September 2016

Ethanol dehydration to ethene is mechanistically decoupled from the production of higher hydrocarbons due to complete surface coverage by adsorbed ethanol and diethyl ether (DEE). The production of C3+ hydrocarbons was found to be unaffected by water present in the reaction mixture. Three routes for the production of C3+ hydrocarbons are identified: the dimerization of ethene to butene and two routes involving two different types of surface species categorized as aliphatic and aromatic. Evidence for the different types of species involved in the production of higher hydrocarbons is obtained via isotopic labeling, continuous flow and transient experiments complemented by UV/Vis characterization of the catalyst and ab initio microkinetic modeling.
A High‐Throughput Fluorescence Assay to Determine the Activity of Tryptophan Halogenases
Authors: Schnepel Christian , Minges Hannah , Frese Marcel , Sewald Norbert
Published: September 2016

Biocatalytic halogenation with tryptophan halogenases is hampered by severe limitations such as low activity and stability. These drawbacks can be overcome by directed evolution, but for screening large mutant libraries, a facile high‐throughput method is required. Therefore, we developed a quantitative halogenase assay based on a Suzuki–Miyaura cross‐coupling towards the formation of a fluorescent aryltryptophan. The technique was optimized for application in crude E. coli lysate without intermediary purification steps, and was used for quantitatively monitoring the formation of halogenated tryptophans with high specificity by facile fluorescence screening in microtiter plates. This novel screening approach was exploited to engineer a thermostable tryptophan 6‐halogenase. Libraries were constructed by error‐prone PCR and selected for improved thermal resistance simply by fluorogenic cross‐coupling. Our method led to an enzyme variant with substantially increased thermal stability and 2.5‐fold improved activity.
Design, synthesis, characterization and biological studies of copper(II) complexes with 2‐aminobenzimidazole derivatives as biomimetic agents
Authors: Joseph J. , Suman A. , Balakrishnan Nisha
Published: September 2016

Four novel copper(II) complexes of 2‐aminobenzimidazole derivatives (obtained from the Knoevenagel condensation of acetylacetone (obtained from acetylacetone and halogen‐substituted benzaldehydes) and 2‐aminobenzimidazole) were synthesized. They were characterized using elemental analysis, molar conductance measurements, and fast atom bombardment mass, Fourier transform infrared, NMR, UV–visible and electron paramagnetic resonance spectroscopies. On the basis of the spectral studies, a distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their complexes revealed that all the complexes had higher activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes were also studied. The shifts in ΔEp, E1/2, Ipc and Ipa values were explored for the interaction of the complexes with calf thymus DNA using the electrochemical technique.
Optimization of solvent extraction process of some Turkish coals using response surface methodology and production of ash‐free coal
Authors: Sönmez Özgür , Gözmen Belgin , Çevik Turan , Giray Elife Sultan
Published: September 2016

In order to produce ash‐free coal (AFC) from three Turkish coals, solvent extraction of coals using 1‐methylnaphthalene (1‐MN) at different temperatures were conducted. The extraction yield of coals was found dependent on coal, temperature, and solvent type. When there was usage of 1‐MN as solvent, the extraction yield was low. However, on addition of N‐methyl‐2‐pyryrolidone (NMP) or quinoline (QN) into 1‐MN, the extraction yield increased. Following the extractions, we obtained AFC with less than 0.65% ash content for the three coals used in this study. The response surface methodology (RSM) was employed to investigate the solvent extraction conditions. The factors investigated were extraction temperature and additional polar solvent ratio. The obtained results demonstrated that either excess amount of polar solvent into 1‐MN should be added at low temperatures or extraction should be done at high temperatures using less polar solvent to obtain an increase in extraction efficiency. The sensitivity and validity of results obtained by RSM were confirmed through validation experiments. The results of validation experiments showed a good agreement between the experimental and predicted values (relative error <1.2) and that indicated the robustness of the models. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Including heavy vehicles in a car‐following model: modelling, calibrating and validating
Authors: Aghabayk Kayvan , Sarvi Majid , Young William
Published: September 2016

Heavy vehicles influence general traffic in many different ways compared with passenger vehicles, and this may result in different levels of traffic instability. Increases in the number and proportion of heavy vehicles in the traffic stream will therefore result in different traffic flow conditions. This research initially outlines the different car‐following behaviour of drivers in congested heterogeneous traffic conditions indicating the necessity for developing a car‐following model, which includes these differences. A psychophysical car‐following model, similar in form to Weideman's car‐following model, was developed. Due to the complexity of the developed model, the calibration of the model was undertaken using a particle swarm optimisation algorithm with the data recorded under congested traffic conditions. This was then incorporated into a traffic microsimulation model. The results showed that the car‐following perceptual thresholds and thus action points of drivers differ based on their vehicle and the lead vehicle types. The inclusion of the heavy vehicles in the model showed significant impacts on the traffic dynamic and interactions amongst different vehicles. Copyright © 2016 John Wiley & Sons, Ltd.
Mechanics of neurulation: From classical to current perspectives on the physical mechanics that shape, fold, and form the neural tube
Authors: Vijayraghavan Deepthi S. , Davidson Lance A.
Published: September 2016

Neural tube defects arise from mechanical failures in the process of neurulation. At the most fundamental level, formation of the neural tube relies on coordinated, complex tissue movements that mechanically transform the flat neural epithelium into a lumenized epithelial tube (Davidson, 2012). The nature of this mechanical transformation has mystified embryologists, geneticists, and clinicians for more than 100 years. Early embryologists pondered the physical mechanisms that guide this transformation. Detailed observations of cell and tissue movements as well as experimental embryological manipulations allowed researchers to generate and test elementary hypotheses of the intrinsic and extrinsic forces acting on the neural tissue. Current research has turned toward understanding the molecular mechanisms underlying neurulation. Genetic and molecular perturbation have identified a multitude of subcellular components that correlate with cell behaviors and tissue movements during neural tube formation. In this review, we focus on methods and conceptual frameworks that have been applied to the study of amphibian neurulation that can be used to determine how molecular and physical mechanisms are integrated and responsible for neurulation. We will describe how qualitative descriptions and quantitative measurements of strain, force generation, and tissue material properties as well as simulations can be used to understand how embryos use morphogenetic programs to drive neurulation. Birth Defects Research 109:153–168, 2017. © 2016 Wiley Periodicals, Inc.
Strong green fluorescent hydrogels with Ba2MgSi2O7:Eu2+ phosphor embedded in cellulose
Authors: Zhang Xinguo , Qin Xingzhen , Chen Hailan
Published: September 2016

Non‐cytotoxic and green‐emitting fluorescent hydrogels were constructed from a cellulose solution containing Ba2MgSi2O7:Eu2+ green phosphor in a NaOH/urea aqueous system. The structure, optical properties and cytotoxicity of these hydrogels were studied. The Ba2MgSi2O7:Eu2+ phosphor particles were dispersed evenly in the cellulose hydrogel matrix. Good luminescent properties of Ba2MgSi2O7:Eu2+ phosphor were maintained in the hydrogels, leading to strong green emission under ultraviolet excitation. Fluorescent hydrogels have no obvious cytotoxicity in a 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) proliferation test, and have potential use in in vivo applications like optical imaging and drug delivery.
Defining small vessels and bioresorbable vascular scaffold outcomes
Authors: Velagapudi Poonam , Abbott J. Dawn
Published: September 2016

Key Points

Bioresorbable vascular scaffolds (BVS) are non‐inferior to second generation drug eluting stents (DES) but thrombosis rates for BVS in small vesseles is a concern.

The BVS‐SAVE registry of small vesseles (<2.75 mm) supports safety and efficacy of BVS in this high risk lesion subset.

Definitive recommendation for BVS in small vessels require further trials DES with evaluation of the lower threshold for minimal reference vesseles diameter.
To achieve, or not to achieve complete revascularization
Authors: Belardi Jorge A. , Albertal Mariano
Published: September 2016

Key Points

Prior to minimally invasive valve surgery, a strategy of complete revascularization did not impact overall survival.

Angiographically guided revascularization may have resulted in unnecessary procedures.

A larger sample size and greater atherosclerotic burden may be needed to observe an impact with complete revascularization.
The 3 S's of the Sapien balloon expandable valve
Authors: Kornowski Ran
Published: September 2016

Key Points

The Sapien 3 (S3) balloon expandable aortic valve equipped with an outer skirt to minimize paravalvular leakage (PVL) was built upon the predecessor Sapien XT (SXT) valve.

There is scant comparative data of transcatheter aortic valve replacement using S3 versus SXT valve.

The study shows that S3 valve is associated with reduced PVL rate compared with SXT, which is an important clinical advantage.
Promising, but still a matter of debate
Authors: Sotomi Yohei , Serruys Patrick W.
Published: September 2016

Key Points

Several trials failed to demonstrate the efficacy of plaque modification device in patients with severely calcified coronary lesions.

Safety and efficacy of the Diamondback 360® Coronary OAS have been demonstrated by the ORBIT II trial. The 2‐year follow‐up of the ORBIT II trial extends the favorable results previously shown at 30‐day and 1‐year follow‐up.

The single arm, non‐randomized character of the trial with indirect historical comparison may restrict the results to hypothesis generating and entail further prospective randomized trials.
Optimization of the Aromatic/Paraffinic Composition of Synthetic Jet Fuels
Authors: Al‐Nuaimi Ibrahim A. , Bohra Moiz , Selam Muaz , Choudhury Hanif A. , El‐Halwagi Mahmoud M. , Elbashir Nimir O.
Published: September 2016

Aviation fuels derived from the gas‐to‐liquid (GTL) technology may be used as drop‐in alternatives to conventional oil‐derived fuels. Reliable composition‐property relations must be developed based on experimental data to correlate the hydrocarbon compositions of formulated synthetic fuels with their properties to be certified for aviation commercial use. An experimental and property‐integration framework for the design of synthetic jet fuels from GTL‐based kerosene derived by evaluating the role of aromatics on resultant fuel properties is presented. The experimental results were used to develop property‐mixing rules and linear programming for the design of optimum fuel compositions that meet the ASTM specifications. The role of aromatics on critical physical properties for jet fuel certification is revealed. A practical solution for jet fuels blending through optimization of jet fuel formulation based on cost and technically effective manners is provided.
Intensified Distillation‐Based Separation Processes: Recent Developments and Perspectives
Authors: Long Nguyen Van Duc , Minh Le Quang , Ahmad Faizan , Luis Patricia , Lee Moonyong
Published: September 2016

Greater sustainability can be achieved by decreasing the production costs, energy consumption, equipment size, and environmental impact as well as improvement of the raw material yields, remote control, and process flexibility. Process intensification (PI) as the main route for improving the process performance is used widely in heat transfer, reactions, separation, and mixing, which results in plant compactness, cleanliness, and energy efficiency. Some of the main intensified separation processes and improvement mechanisms are reviewed briefly with the main focus on the PI of distillation processes, which are the most important separation methods. In addition to these technologies, the potential and reliability of reactive separation processes are addressed briefly, which will enable higher efficiency and capacity.
Molecular Dimensions and Porous Structure of Activated Carbons for Sorption of Xylene and Isooctane
Authors: Troppová Ivana , Matějová Lenka , Kuboňová Lenka , Strašák Tomáš , Študentová Soňa , Kustrowski Piotr , Obalová Lucie
Published: September 2016

The sorption of xylene and isooctane was measured by the gravimetric flow sorption method on commercial activated carbons (ACs), namely, virgin and reactivated ACs. Nitrogen physisorption, high‐pressure mercury porosimetry, helium pycnometry, iodine number, pH measurement, Raman and X‐ray photoelectron spectroscopies were applied for textural, structural, and surface characterization of ACs. The equilibrium geometries of isooctane and xylene molecules were modeled using density functional theory (DFT) calculations. Their dimensions were estimated to be correlated with textural properties of ACs to reveal the effect of size selectivity. The key factors influencing the adsorption capacity of the chosen ACs for both tested volatile organic compounds (VOCs) were found to be the mesopore surface area and the surface basicity.
Controllability Analysis of Distillation Sequences for the Separation of Bio‐Jet Fuel and Green Diesel Fractions
Authors: Acosta‐Solórzano Angel D. A. , Guerrero‐Farfán Oscar , Ramírez‐Márquez César , Gómez‐Castro Fernando I. , Segovia‐Hernández Juan Gabriel , Hernández Salvador , Gutiérrez‐Antonio Claudia , Briones‐Ramírez Abel
Published: September 2016

The aviation sector is nowadays looking for a biofuel to partially substitute the fossil fuel used for flights, i.e., jet fuel. Among the proposed processes for the production of the renewable jet fuel, the hydrotreating process has, to date, the best performance. At the final stage of the hydrotreating process, a distillation train is required to obtain hydrocarbon fractions useful as fuels. Conventional or thermally coupled distillation sequences can be used in this step, and it can be expected that thermally coupled sequences require less energy to perform the separation. Nevertheless, in the selection of the best sequence for a given separation, it is important to analyze its control properties. A controllability analysis was performed here for different distillation sequences used to obtain biofuels from a hydrocarbon renewable mixture, in order to detect the best sequence in terms of control properties.
Controllable Deposition of Platinum Layers on Oxide Surfaces for the Synthesis of Fuel Cell Catalysts
Authors: Vukmirovic Miomir B. , Kuttiyiel Kurian A. , Meng Hui , Adzic Radoslav R.
Published: September 2016

Reducing the amount of Pt, the most costly component of both anode and cathode fuel cell catalysts, has attracted considerable attention from the research community. An approach is reported herein to deposit sub‐monolayer to multilayer amounts of Pt and other noble metals on metal oxides and oxidized carbon materials. The process is exemplified by Pt deposition on RuO2(110). The Pt deposit consists of Pt atoms arranged in a c(2×2) array, that is, a 0.25 monolayer (ML). The deposit has lower catalytic activity for the oxygen reduction reaction (ORR) and similar activity for the hydrogen oxidation reaction compared to Pt(111). These activities are explained by a large calculated upshift of the d‐band center of Pt atoms and larger Pt–Pt interatomic distances than those of Pt(111). A catalyst with Pt coverage larger than 0.25 ML on oxide surfaces and oxidized carbon materials is shown to be active for the ORR as well as for other electrocatalytic reactions. A PtRhSnO2/C catalyst shows high activity for ethanol oxidation as a result of its ability to effectively cleave the C−C bond in ethanol. Pt deposited on reduced graphene oxide shows high Pt mass ORR activity and good stability.
Electrochemical Oxidation of Organotrifluoroborate Compounds
Authors: Suzuki Junji , Tanigawa Masahiro , Inagi Shinsuke , Fuchigami Toshio
Published: September 2016

Electrochemical analyses of various organotrifluoroborates, and the corresponding boronic acids and esters, were comparatively studied by using cyclic voltammetry. The organotrifluoroborates were found to have much lower oxidation potentials compared with the latter two types of compounds. We also found a pronounced β‐effect for allyltrifluoroborate, which was indicated by both experimental and theoretical aspects. Such a β‐effect is similar to that of allyltrimethylsilane. Anodic oxidation of n‐decyltrifluoroborate at a platinum anode gave a radical coupling product in moderate yield, eliminating a boryl moiety. Anodic acetoxylation of phenethyl‐, aryl‐, and styryltrifluoroborates was also successfully carried out at a graphite anode in NaOAc/AcOH to provide the acetoxylated products in good to moderate yields although a large excess of electricity was required.
Engineering the Ionic Self‐Assembly of Polyoxometalates and Facial‐Like Peptides
Authors: Li Jingfang , Li Xiaodong , Xu Jing , Wang Yang , Wu Lixin , Wang Yanqiu , Wang Liyan , Lee Myongsoo , Li Wen
Published: September 2016

The self‐assembly behavior of polyoxometalates (PMs) and facial‐like cationic peptides carrying lysine residues were systematically investigated. Circular dichroism and UV/Vis spectra demonstrated that the multivalent electrostatic attractions between polyanionic PMs and short peptides with protonated lysine residues initiated the conformational transition of peptide molecules from random‐coil to β‐sheet state, and subsequently the co‐assembly. TEM and atomic force microscopy (AFM) measurements showed that uniform nanofibers formed with decreasing size of the PMs or increasing the intermolecular forces of the peptides, such as through hydrogen‐bonding, hydrophobic, and/or π–π interactions. Additionally, the stability of the nanostructures can be improved by rational suppression of the electrostatic repulsion of the shell peptides covering the surface of the nanostructures. These results provide new insight into understanding the ionic self‐assembly of peptides and PMs and controlling their final morphology.
Honeycomb‐like Ordered Assembly of DNA Induced by Flexible Binuclear Ruthenium(II)–Polypyridyl Complexes
Authors: Singh Sushma B. , Kumbhar Avinash S. , Khan Ayesha
Published: September 2016

A series of binuclear ruthenium(II)–polypyridyl complexes of the type [Ru2(N‐N)4(BPIMBp)]4+, in which N‐N is 2,2′‐bipyridine (bpy; 1), 1,10‐phenanthroline (phen; 2), dipyrido[3,2‐d:2′,3‐f] quinoxaline (dpq; 3), dipyrido[3,2‐a:2′,3′‐c] phenanzine (dppz; 4), and 1,4′‐bis[(2‐pyridin‐2‐yl)‐1H‐imidazol‐1‐yl)methyl]‐1,1′‐biphenyl (BPIMBp) is a bridging ligand, have been synthesized and characterized. These complexes are charged (4+) cations and flexible due to the −CH2 group of the bridging ligand and possess terminal ligands with variable intercalative abilities. The interaction of complexes 1–4 with calf thymus DNA (CT‐DNA) was explored by using UV/Vis absorption spectroscopy, steady‐state emission, emission quenching with K4[Fe(CN)6], ethidium bromide displacement assay, Hoechst displacement assay, and viscosity measurements and revealed a groove‐binding mode for all the complexes through a spacer and an intercalative mode for complexes 3 and 4. A decrease in the viscosity of DNA revealed bending and coiling of DNA, an initial step toward aggregation. Interestingly, a distinctive honeycomb‐like ordered assembly of the DNA–complex species was visualized by fluorescence microscopy in the solution state. The use of SEM and AFM confirmed the disordered self‐organization of the DNA–complex adduct on evaporation of the solvent. The small orderly nanosized DNA aggregates were confirmed by means of circular dichroism, dynamic light scattering (DLS), and TEM. These complexes are moderately cytotoxic against three different cell lines, namely, MCF‐7, HeLa, and HL‐60.
Homolytic, Heterolytic, Mesolytic ‐ As You Like It: Steering the Cleavage of a HC(sp3)−C(sp3)H Bond in Bis(1H‐2,1‐benzazaborole) Derivatives
Authors: Hejda Martin , Lyčka Antonín , Mikysek Tomáš , Jambor Roman , Růžička Aleš , Vinklárek Jaromír , Wilfer Claudia , Hoffmann Alexander , Herres‐Pawlis Sonja , Dostál Libor
Published: September 2016

A set of (3,3′)‐bis(1‐Ph‐2‐R‐1H‐2,1‐benzazaborole) compounds, in which R=tBu (Bab‐tBu)2, R=Dipp (Bab‐Dipp)2 or R=tBu and Dipp (Bab‐Dipp)(Bab‐tBu), was synthesized and fully characterized using 1H, 11B, 13C, and 15N NMR spectroscopy as well as single‐crystal X‐ray diffraction analysis. The central HC(sp3)−C(sp3)H bond with restricted rotation at the junction of both 1H‐2,1‐benzazaborole rings displayed an intriguing reactivity. It was demonstrated that this bond is easily mesolytically cleaved using alkali metals to form the respective aromatic 1Ph‐2R‐1H‐2,1‐benzazaborolyl anions M+(THF)n(Bab‐tBu)− (M=Li, Na, K) and K+(THF)n(Bab‐Dipp)−. Furthermore, the central HC(sp3)−C(sp3)H bond of bis(1H‐2,1‐benzazaborole)s is also homolytically cleaved either by heating or photochemical means, giving corresponding 1Ph‐2R‐1H‐2,1‐benzazaborolyl radicals (Bab‐tBu). and (Bab‐Dipp)., which rapidly self‐terminate. Nevertheless, their formation was unambiguously established by NMR analysis of the reaction mixtures containing products of the self‐termination of the radicals after heating or irradiation. (Bab‐Dipp). radical was also characterized using EPR spectroscopy. Importantly, it turned out that the essentially non‐polarized HC(sp3)−C(sp3)H bond in (Bab‐tBu)2 is also cleaved heterolytically with 2 equiv of MeLi, giving the mixture of Li+(SOL)n(Bab‐tBu)− (SOL=THF or Et2O) and lithium methyl‐substituted borate complex Li+(SOL)n(Bab‐tBu‐Me)− in a diastereoselective fashion.
How a Small Structural Difference Can Turn Optical Properties of π‐Extended Coumarins Upside Down: The Role of Non‐Innocent Saturated Rings
Authors: Ventura Barbara , Poronik Yevgen M. , Deperasińska Irena , Gryko Daniel T.
Published: September 2016

The fluorescence properties of two new families of heterocycles possessing either a seven‐ or five‐membered ring attached at the core molecule are entirely different in solution and in the solid state. Crystallization has the effect of inhibiting non‐radiative excited‐state deactivation pathways, operative in solution for the seven‐membered ring compounds, thus leading to significant fluorescence efficiency in the solid state, with quantum yields ranging from 0.10 to 0.36. Conversely, the five‐membered ring derivatives, which display notable emission properties in solution, are almost non‐emissive in the crystalline state, characterized by a long‐range π‐stacked arrangement. When embedded in polymeric films, both series show fluorescence features similar to the solution case, with remarkable fluorescence quantum yields ranging from 0.09 to 0.41. According to quantum chemical calculations, 3H‐chromeno[3,4‐c]pyridine‐4,5‐diones show the specific mechanism of fluorescence quenching. The derivatives bearing the seven‐membered ring undergo, in solution, a significant structural deformation in the excited state, resulting in a large decrease of the energy gap between S1 and S0 and hence to a substantial contribution of the internal conversion in the relaxation process. The fluorescence quenching of the five‐membered ring derivatives is in turn related to the intermolecular interaction between adjacent molecules prevailing to a greater extent in the crystal lattice.
Oxo‐Functionalized Graphene as a Cell Membrane Carrier of Nucleic Acid Probes Controlled by Aging
Authors: Pieper H. , Halbig C. E. , Kovbasyuk L. , Filipovic M. R. , Eigler S. , Mokhir A.
Published: September 2016

We applied a fluorescein‐containing oligonucleotide (ON) to probe surface properties of oxidized graphene (oxo‐G) and observed that graphene‐like patches are formed upon aging of oxo‐G, indicated by enhanced probe binding and by FTIR spectroscopic analysis. By using a recently developed fluorogenic endoperoxide (EP) probe, we confirmed that during the aging process the amount of EPs on the oxo‐G surface is reduced. Furthermore, aging was found to strongly affect cell membrane carrier properties of this material. In particular, freshly prepared oxo‐G does not act as a carrier, whereas oxo‐G aged for 28 days at 4 °C is an excellent carrier. Based on these data we prepared an optimized oxo‐G, which has a low‐defect density, binds ONs, is not toxic, and acts as cell membrane carrier. We successfully applied this material to design fluorogenic probes of representative intracellular nucleic acids 28S rRNA and β‐actin‐mRNA. The results will help to standardize oxidized graphene derivatives for biomedical and bioanalytical applications.
Allosteric and Chelate Cooperativity in Divalent Crown Ether/Ammonium Complexes with Strong Binding Enhancement
Authors: von Krbek Larissa K. S. , Achazi Andreas J. , Solleder Marthe , Weber Marcus , Paulus Beate , Schalley Christoph A.
Published: September 2016

A thorough thermodynamic analysis by isothermal titration calorimetry of allosteric and chelate cooperativity effects in divalent crown ether/ammonium complexes is combined with DFT calculations including implicit solvent on the one hand and large‐scale molecular dynamics simulations with explicit solvent molecules on the other. The complexes studied exhibit binding constants up to 2×106 m−1with large multivalent binding enhancements and thus strong chelate cooperativity effects. Slight structural changes in the spacers, that is, the exchange of two ether oxygen atoms by two isoelectronic methylene groups, cause significantly stronger binding and substantially increased chelate cooperativity. The analysis is complemented by the examination of solvent effects and allosteric cooperativity. Such a detailed understanding of the binding processes will help to efficiently design and construct larger supramolecular architectures with multiple multivalent building blocks.