bluuebunny/crossref_metadata_2025 huggingface dataset:
BY-PASSING SAND AT SOUTH LAKE WORTH INLET, FLORIDA
Authors: Caldwell Joseph M.
Published: June 2017

This paper describes the installation of and results obtained with the sand pumping plant located on the north jetty of South Lake Worth Inlet, Florida. This pumping plant was installed in order to pump drifting beach sand past the littoral drift barrier formed by the creation of South Lake Worth Inlet with its protecting jetties. It was anticipated that the pumping of the sand would relieve the erosion of the shore south of the inlet and cut down on the rate of shoaling in Lake Worth at the inner end of the inlet channel. A discussion of the results obtained with the installation is also included in the paper.
REFRACTION AND DIFFRACTION DIAGRAMS
Authors: Dunham James W.
Published: June 2017

The use of diagrams to indicate the effects of refraction and diffraction of ordinary wind waves and swell in offshore areas is by no means an innovation in coastal and harbor engineering. Refraction diagrams in particular have been used in various forms by engineers in the United States and in Europe for more than a decade. The principles and procedures for constructing refraction and diffraction diagrams have been developed by academic research and investigation. The purposes of this paper are (1) to review briefly these principles and procedures, and (2) to describe their practical application by the Corps of Engineers, Los Angeles District, Department of the Army.
GENERALIZED WAVE DIFFRACTION DIAGRAMS
Authors: Johnson J. W.
Published: June 2017

Wave diffraction is the phenomenon in which water waves are propagated into a sheltered region formed by a breakwater or similar barrier which interrupts a portion of a regular wave train (Fig. 1). The principles of diffraction have considerable practical application in connection with the design of breakwaters as discussed by Dunham (1951) at the Long Beach Conference. The phenomenon is analogous to the diffraction of light, sound, and electromagnetic waves. Two general types of diffraction problems usually are encountered: one, the passage of waves around the end of a semi-infinite impermeable breakwater (Putnam and Arthur, 1948), and, second, the passage of waves through a gap in a breakwater (Blue and Johnson, 1949t Carr and Stelzriede, 1951). In general, the theoretical solutions have been found to apply with conservative results, that is, the predicted wave heights in the lee of a breakwater are found to be slightly larger than the height of waves that may be expected under actual conditions. The use of the diffraction theory in breakwater design is made convenient when summarized in the form of diagrams with curves of equal values of diffraction coefficients on a coordinate system in which the origin of the Bystem is at the tip of a single breakwater (Figs. 2a-2b, and 3) or at the center of a gap (Figs. 2c, and 4-6). The diffraction coefficient in this instance is defined as the ratio of the diffracted wave height to the incident wave height and usually is designated by the symbol K». The procedure in preparing diffraction diagrams appears elsewhere (Johnson, 1950). The purpose of this paper is to present diffraction diagrams to supplement the material of Dunham (1951). For complete details on the application of diffraction diagrams to typical harbor problems the reader is referred to this latter paper.
CALCULATION OF MAXIMUM WAVE RUN-UP AND EROSION AT VARNA REGIONAL COAST (WESTERN BLACK SEA) USING EMPIRICAL MODELS
Authors: Eftimova Petya , Valchev Nikolay , Andreeva Nataliya , Prodanov Bogdan , Dimitrov Lyubomir
Published: June 2017

European coasts suffer significantly from hazards caused by low-probability and high-impact hydro-meteorological events. The aim of the study is to assess in probabilistic terms the magnitude of stormâ€induced flooding and erosion hazards along Varna regional coast (Bulgaria, western Black Sea). The study is performed employing the Coastal Risk Assessment Framework (CRAF) developed within EU FP7 RISC-KIT project. It constitutes a screening process that allows estimation of relevant hazard intensities and extents within predefined sectors. Since total water level was the chief property considered for determination of coastal flooding hazard, the accurate calculation of maximum wave induced run-up is of utter importance. Therefore, a central part of the study is testing the applicability and validation of three empirical models â€“ from which the Holman model was preferred to be applied on sandy beaches, as well as EurOtop formulation for artificial or rocky slopes. As for erosion hazard, the performance of the convolution model was assessed and subsequently employed for evaluation of shoreline retreat. Quantification of hazard intensities allowed hinterland extent to be roughly delineated. As a final result of the study, hazard indicators were obtained for both flooding and erosion, which were subsequently mapped and used for identification of the most susceptible sectors along the regional coast. It was found that their concentration is highest in Varna Bay.
FIELD OBSERVATION AND NUMERICAL SIMULATION OF BARRIER ISLAND FORMATION AS RESULT OF ELONGATION OF SAND SPIT AND ITS ATTACHMENT TO OPPOSITE SHORE
Authors: Miyahara Shiho , Uda Takaaki , Serizawa Masumi
Published: June 2017

An artificial mound was produced from dredged materials containing sand and gravel in the Nakatsu tidal flat facing the Suo-nada Sea, and this artificial mound served as a supply source of sediment for the development of a barrier island. A sand spit extended from this mound in an extremely shallow sea and attached to the opposite shore, resulting in the formation of a barrier island. The planar changes in the sand spit were investigated using aerial photographs. Observations were compared with the results of a numerical simulation regarding the formation of a barrier island on a sloping bed with a 1/40 slope using the BG model (a model for predicting three-dimensional beach changes based on Bagnoldâ€™s concept). The observed change in the barrier island and the calculated results were in good agreement.
VALIDATION OF A PROBABILISTIC METHOD FOR THE STRUCTURAL
Authors: Buccino Mariano , Dentale Fabio , Salerno Daniela , Contestabile Pasquale
Published: June 2017

The paper deals with the validation of a wave by wave approach for the calculation of the wave loadings exerted on an overtopping type Wave Energy Converter named Seawave Slot-Cone Generator (SSG). The prediction method, originally developed for regular waves, employs the Iribarren number (Battjes, 1974), the slope parameter (Svendsen, 2006) and the Linear thrust parameter (Buccino et al., 2015) as main predictors. The approach has been tested against five 2-D random wave tests, carried out in view of the design of a new pilot plant to be located along the Norwegian coast.
SAMPLING BIAS IN THE ESTIMATION OF SIGNIFICANT WAVE HEIGHT EXTREME VALUES
Authors: Dentale Fabio , Reale Ferdinando , D'Alessandro Felice , Damiani Leonardo , Di Leo Angela , Pugliese Carratelli Eugenio , Tomasicchio Giuseppe Roberto
Published: June 2017

It has been shown before, and it is intuitively evident, that in a Significant Wave Height (SWH) time series, the longer the sampling interval, the lower is the number of events which are above a given threshold value. As a consequence, the use of data with a low time resolution (such as a 3 h sampling, for instance) causes a considerable undervaluation of the extreme SWH values for a given return time RT. In this paper an example of such a bias is provided, and a method is suggested to estimate it on a regional basis. Results may help to improve the use of historical wave meters data which were often collected with a low time resolution, and may also provide a tool to improve the application of Numerical Meteo-Wave models to the evaluation of extremes.
A NEW STRATEGIC WAVE MEASUREMENT STATION OFF NAPLES PORT MAIN BREAKWATER
Authors: Centurioni Luca , Braasch Lance , Di Lauro Enrico , Contestabile Pasquale , De Leo Francesco , Casotti Raffaella , Franco Leopoldo , Vicinanza Diego
Published: June 2017

The accuracy of directional wave spectra sensors is crucial for obtaining accurate forecasts of ocean and coastal wave conditions for scientific and engineering applications. In this paper, a newly designed, low-cost GPS-based wave buoy, called the Directional Wave Spectra Drifter (DWSD), is presented. A field test campaign was conducted at the Gulf of Naples, Italy with the goal of comparing the directional wave properties obtained with the DWSD and with a nearly co-located bottom-mounted Acoustic Doppler Current Profiler (ADCP) from Teledyne RD-Instruments. The comparison shows a very good agreement between the two methodologies. The reliability of this innovative instrument and its low costs allow a large variety of applications, including the implementation of a global, satellite-linked, real-time open-ocean network of drifting directional wave spectra sensors and monitoring the sea-state in harbors to aid ship transit and for planning coastal and offshore constructions. The DWSD is currently in use to better constrain the wave energy climatology with the goal of optimizing the design of a full-scale prototype Wave Energy Converter (WEC) in the port of Naples, Italy.
THE HISTORY OF A TIDAL LAGOON INLET AND ITS IMPROVEMENT (THE CASE OF AVEIRO, PORTUGAL)
Authors: Abecasis Carlos Krus
Published: June 2017

The described case history is known since the Xth century, and on a scientific level since the end of XVIIIth. Origin and free evolution of the inlet up to 1800, as well as results obtained by artificial improvement attempts subsequently undertaken, are analysed, in order to investigate the main features of local physiography and the way it reacts to human interventions intended to meet ever-increasing navigation requirements. The remarkable success of the projects undertaken, especially of that being executed, seems to legitimate the inference of some principles of general interest as long as tidal lagoon inlets improvement is concerned. Stress is laid upon difference from principles valid in estuaries' amelioration.
A WAVE HEIGHT AND FREQUENCY METER
Authors: Snodgrass Frank E. , Putz Robert R.
Published: June 2017

During World War II a group of Naval officers conducted visual measurements of ocean waves simultaneously with instrumental recordings. A comparison of the visual and instrumental values indicated ".... the natural tendency for the observer .... to record not the average wave height but a wave height based on some kind of average of the highest waves. The general experience is that an observer will give a value for the wave height which represents the average of the highest 20 to 40 per cent of the waves" (SIO, 1944). The average height of the highest one-third of the waves, H1/3, was therefore suggested as the characteristic (or significant) wave height. "Characteristic wave period" was given a corresponding definition as the average period of the highest one-third waves.
FLORIDA COASTAL PROBLEMS
Authors: Bruun Per , Gerritsen F. , Morgan W. H.
Published: June 2017

Florida is at war with coastal problems, Waves and tides threaten to wipe out its priceless heritage of sandy tropical beaches on two seas. Many communities have suffered enormous losses because of beach erosion in the last few years. The annual loss of land is approximately 300 to 500 acres. Man-made fills in bays and waterways are detrimental to inlets and channels. Practically all of these fill operations have been carried out without any previous hydrographic or hydrological surveys. This paper explains the nature and extent of these problems in Florida and gives recommendations for solving them.
EFFECT OF CLAY CONTENT ON STRENGTH OF SOILS
Authors: Trask Parker D. , Close James E. H.
Published: June 2017

Engineers have worked greatly on measuring the strength of soils but relatively little on the fundamental geologic causes of strength. Strength depends principally upon the content of (1) water, (2) clastic materials and (3) plastic materials. Soils are primarily of two types (1) cohesionless soils in which the strength is produced mainly by the friction of clastic particles against one another, and (2) cohesive soils in which the strength, among other things, is influenced by forces between clay particles. The present investigation is a study of the effect of clay content upon the strength of cohesive soils. The strength was measured by a shear vane device working upon synthetic mixtures of clays of known composition. In each mixture strength varies inversely with water content in a straight line relationship when strength is plotted logarithmically and water arithmetically. Mixtures of glycerine with vol-clay (a montmorillonite) give a curvilinear relationship. For given water content the strength increases with respect to type of clay from kaolin through illite, ball clay to montmorillonite. Strength also increases progressively with increasing clay-sand ratio for all types of clay. In clay-sand mixtures of given clay composition strength increases with increasing fineness of grain of the sand mixed with clay. The liquid limit likewise increases regularly with increasing clay concentration and varies with clay type fci the same way as does strength. Strength varies inversely with temperature to a slight extent, changingjess than one percent per degree Centrigrade. Hydrogen kaolin clay, for given water content is several times stronger than sodium clay.
MODEL STUDIES OF THE DYNAMICS OF AN LSM MOORED IN WAVES
Authors: Wiegel R. L. , Beebe K. E. , Dilley R. A.
Published: June 2017

Presented in this report are the results of model tests performed to determine the motions of a moored LSM (Landing Ship Medium) and the associated mooring cable forces when subjected to the action of uniform periodic water waves. Details are given of the design and construction of the 1:60 scale model LSM and the dynamic balancing of the model. Principles of the designs of the model mooring cables and of the meter for measuring the cable forces are also presented. The use of the laboratory equipment, such as the wave-towing tank, the model basin, the photography equipment, and the force and wave height meters are described, and the testing procedure is outlined. The data are presented in terms of the prototype in graphical form. Resonance conditions in the surging and heaving motions and the associated high cable forces, are shown to exist for some initial cable tensions within the range of wave periods normal encountered in many ocean areas. The effect of a roll damping device is shown.
THE DYNAMICS OF A SUBMERGED MOORED SPHERE IN OSCILLATORY WAVES
Authors: Harleman David R.F. , Shapiro William C.
Published: June 2017

The results of an analytical and experimental investigation into the dynamics of a buoyant sphere moored by a single line in shallow water waves are presented. The sphere motion and the mooring line forces are related to the sphere diameter, weight, submergence and the wave frequency, height and water depth. Analytically, the phenomenon is approached as a forced vibration problem. The sphere and its mooring line acts as a spring-mass system driven by the oscillating wave force. The relevant dimensionless parameters are the ratio between the natural frequency of the moored sphere and the wave frequency and the ratio between the dynamic mooring force due to a given wave and the force on the sphere held stationary in the same wave. Experimental values of the frequency and force ratios obtained from tests made at the Massachusetts Institute of Technology Hydrodynamics Laboratory over a range of sphere and wave characteristics are in essential agreement with the analytically determined values. The investigation was supported by the Humble Oil and Refining Company of Houston, Texas.
WAVES ON THE PACIFIC COAST AND ON THE COAST OF ISE BAY CAUSED BY THE ISE-WAN TYPHOON
Authors: Ijima Takeshi , Shato Shoji , Aono Hisashi
Published: June 2017

General aspects of wave characteristics on the Pacific Coast of the main land and on the coast of Ise Bay caused by the Ise-wan Typhoon are studied on the bases of the observed wave data, calculated wave heights by the authors' method of forecasting shallow water wave and the results of the field inspection of damages by the typhoon.
LABORATORY STUDY OF SCALE EFFECTS IN TWO-DIMENSIONAL BEACH PROCESSES
Authors: Iwagaki Yuichi , Noda Hideaki
Published: June 2017

In order to disclose the essential relationship between the beach processes and wave characteristics, two dimensional model tests are often performed for beach profile changes due to incident breaking waves normal to the beach. In applying the results of such experiments to the prototype of beaches, the scale effects of waves and sediments on the beach processes with equilibrium beach profiles should necessarily be considered.

In this paper, as an approach to solve this problem in two dimensional beach studies, the effects of wave height and sediment size on the shore line movement and equilibrium beach profiles are discussed based on the results of experiments made by the authors and other experiments with smaller and larger scales by some researchers. It has been found that the ratio of wave height to sediment diameter is a very significant factor in this problem. In addition, the changes m a character of breaking waves during the time period of wave action from the beach having an initial constant slope to that with an equilibrium profile are presented.
Vertical thermal gradient history in the eastern equatorial Pacific during the early to middle Miocene: Implications for the equatorial thermocline development
Authors: Matsui Hiroki , Nishi Hiroshi , Kuroyanagi Azumi , Hayashi Hiroki , Ikehara Minoru , Takashima Reishi
Published: June 2017

Knowledge of the equatorial thermocline is essential for understanding climate changes in the tropical Pacific. Multispecies planktic foraminiferal analyses provide a way to examine temperature distributions and thus the structure of the thermocline. Although the secular thermocline development has been documented back to the late Miocene, the early to middle Miocene interval has rarely been examined. In addition, relationships with the dynamic Antarctic ice sheets remain unclear. Here we investigate the vertical thermal gradient in the upper water column at Integrated Ocean Drilling Program Site U1337 in the eastern equatorial Pacific (EEP) throughout the early to middle Miocene (23.1 to 11.7 Ma). The gradient increased over the Miocene Climatic Optimum, whereas it decreased during the East Antarctic Ice Sheet Expansion (EAIE). Comparison of the EEP record with its western equatorial Pacific (WEP) counterpart suggests that sea surface temperature was more stable in the WEP than in the EEP. We further estimated equatorial thermocline from two diagonal gradients between the EEP and the WEP: thermocline shoaled from 16.7 to 15.7 Ma and tilt weakened between 16.5 and 13.8 Ma. The onset of the “Monterey Excursion” and the reduced Antarctic ice sheet volume would have affected thermocline depth and tilt, respectively. Thermocline depth was likely much deeper compared to Pliocene‐to‐modern conditions. Furthermore, a 4‐point‐based distribution of isotherms (4DI index) was used as a metric of the evenness or unevenness of the isotherm distributions. The 4DI index considerably reduced at around the EAIE and other Mi‐events, reflecting the evenly distributed isotherms under a more glaciated Antarctica.
Tailoring Differential Moisture Transfer Performance of Nonwoven/Polyacrylonitrile‐SiO2 Nanofiber Composite Membranes
Authors: Babar Aijaz Ahmed , Wang Xianfeng , Iqbal Nousheen , Yu Jianyong , Ding Bin
Published: June 2017

Liquid moisture (sweat) transport properties of textile materials play critical role in maintaining the comfort of body which are mainly controlled by surface chemistry, structure, and morphology of substrate. Herein, a dual layer surface treated nonwoven (NW)/electrospun nanofiber membrane with excellent differential liquid moisture transport characteristics is reported. NW is used as inner layer for its high moisture releasing and low moisture absorbing features, and polyacrylonitrile (PAN) as outer layer because of its decent hydrophilic nature. Wettability of NW is tailored by surface treatment with polydopamine, and the wicking characteristics of PAN nanofibers are enhanced by inducing hydrophilic SiO2 nanoparticles (PAN‐SiO2). Performance of resultant surface treated NW (TNW)/PAN‐SiO2 nanofiber composite membranes is thoroughly characterized by moisture management tester (MMT). Subsequent composite membranes offer high wettability gradient which leads to their marvelous MMT performance with an outstanding one‐way transport capacity of 1413%, excellent overall moisture management capacity of 0.99, and a decent water vapor transfer rate of 12.73 kg m−2 d−1, indicating a potential candidate for faster sweat release applications.
Impact of Structural Dynamics on the Optical Properties of Methylammonium Lead Iodide Perovskites
Authors: Panzer Fabian , Li Cheng , Meier Tobias , Köhler Anna , Huettner Sven
Published: June 2017

Organolead halide perovskites have attracted a lot of attention over the recent years mostly due to their bright prospective application in photovoltaic devices. For further development, characterization of their physical properties plays a seminal role in order to gain an in‐depth understanding of these mid‐bandgap ionic semiconductors. Their unique optical and electronic properties are a result of their characteristic electronic structure. Temperature dependent optical spectroscopy, i.e., absorption and photoluminescence (PL) characterization, gives access to their electronic nature that draws strong correlations to their structural properties. Those properties include static and dynamic disorder, and defects or phase transitions, which will be demonstrated in the first part of this research view. The second part focuses on ion migration in these hybrid semiconductors, which can strongly affect the slow dynamics of optical properties. Light‐activated ions result in a number of complex processes that can lead to an increase, but also a decrease of PL intensity, or induce PL intermittency. Parameters like light intensity, crystal quality, and defect density all influence these processes, and ultimately the electronic nature of the hybrid perovskites. We will briefly summarize current achievements and point out challenges for upcoming research.
Longitudinal Optical Fields in Light Scattering from Dielectric Spheres and Anderson Localization of Light
Authors: Escalante Jose M. , Skipetrov Sergey E.
Published: June 2017

Recent research has shown that coupling between point scatterers in a disordered medium by longitudinal electromagnetic fields is harmful for Anderson localization of light. However, it has been unclear if this feature is generic or specific for point scatterers. The present work demonstrates that the intensity of longitudinal field outside a spherical dielectric scatterer illuminated by monochromatic light exhibits a complicated, nonmonotonous dependence on the scatterer size. Moreover, the intensity is reduced for a hollow sphere, whereas one can adjust the parameters of a coated sphere to obtain a relatively low longitudinal field together with a strong resonant scattering efficiency. Therefore, random arrangements of structured (hollow or coated) spheres may be promising three‐dimensional disordered materials for reaching Anderson localization of light.
R. B. Woodward: A Larger‐than‐Life Chemistry Rock Star
Authors: Seeman Jeffrey I.
Published: June 2017

To mark the 100th birthday of R. B. Woodward (April 10, 1917–July 8, 1979), a discussion and analysis of Woodward's persona is given. The fundamental theme is that “Woodward experienced his own exceptionality,” as described by Albert Eschenmoser, Woodward's partner in the vitamin B12 project. Woodward's rock star personality is explored and discussed as one of his legacies in addition to his scientific achievements. Woodward presented himself to his students, colleagues, and fellow chemists with an aura of nobility and romanticism.
Conversion of a Dehalogenase into a Nitroreductase by Swapping its Flavin Cofactor with a 5‐Deazaflavin Analogue
Authors: Su Qi , Boucher Petrina A. , Rokita Steven E.
Published: June 2017

Natural and engineered nitroreductases have rarely supported full reduction of nitroaromatics to their amine products, and more typically, transformations are limited to formation of the hydroxylamine intermediates. Efficient use of these enzymes also requires a regenerating system for NAD(P)H to avoid the costs associated with this natural reductant. Iodotyrosine deiodinase is a member of the same structural superfamily as many nitroreductases but does not directly consume reducing equivalents from NAD(P)H, nor demonstrate nitroreductase activity. However, exchange of its flavin cofactor with a 5‐deazaflavin analogue dramatically suppresses its native deiodinase activity and leads to significant nitroreductase activity that supports full reduction to an amine product in the presence of the convenient and inexpensive NaBH4.
Highly Syndiotactic or Isotactic Polyhydroxyalkanoates by Ligand‐Controlled Yttrium‐Catalyzed Stereoselective Ring‐Opening Polymerization of Functional Racemic β‐Lactones
Authors: Ligny Romain , Hänninen Mikko M. , Guillaume Sophie M. , Carpentier Jean‐François
Published: June 2017

Reported herein is the first stereoselective controlled ROP of a specific family of racemic functional β‐lactones, namely 4‐alkoxymethylene‐β‐propiolactones (BPLORs). This process is catalyzed by an yttrium complex stabilized by a nonchiral tetradentate amino alkoxy bisphenolate ligand {ONOOR′2}2−, which features both a good activity and a high degree of control over the molar masses of the resulting functional poly(3‐hydroxyalkanoate)s. A simple modification of the R′ substituents in ortho and para position on the ligand platform allows for a complete reversal from virtually pure syndioselectivity (Ps up to 0.91 with R′=cumyl) to very high isoselectivity (Pi up to 0.93 with R′=Cl), as supported by DFT insights. This is the first example of a highly isoselective ROP of a racemic chiral β‐lactone.
On the Reaction of Naphthalene Diimides with Fluoride Ions: Acid/Base versus Redox Reactions
Authors: Bélanger‐Chabot Guillaume , Ali Ahmed , Gabbaï François P.
Published: June 2017

The characterization of a naphthalene diimide (NDI) radical anion is presented. Its properties allow a reliable comparison point for other systems involving the NDI radical anion, such as systems claimed to perform the oxidation of the fluoride anion. In addition to reiterating the obvious thermodynamic objections to such an unlikely oxidation, we present several observations that show that the fluoride anion does not act as a one‐electron reducing agent toward the NDI investigated in this work.
Stabilizing Otherwise Unstable Anions with Halogen Bonding
Authors: Zhang Xinxing , Liu Gaoxiang , Ciborowski Sandra , Bowen Kit
Published: June 2017

Both hydrogen bonding (HB) and halogen bonding (XB) are essentially electrostatic interactions, but whereas hydrogen bonding has a well‐documented record of stabilizing unstable anions, little is known about halogen bonding's ability to do so. Herein, we present a combined anion photoelectron spectroscopic and density functional theory study of the halogen bond‐stabilization of the pyrazine (Pz) anion, an unstable anion in isolation due to its neutral counterpart having a negative electron affinity (EA). The halogen bond formed between the σ‐hole on bromobenzene (BrPh) and the lone pair(s) of Pz significantly lowers the energies of the Pz(BrPh)1− and Pz(BrPh)2− anions relative to the neutral molecule, resulting in the emergence of a positive EA for the neutral complexes. As seen through its charge distribution and electrostatic potential analyses, the negative charge on Pz− is diluted due to the XB. Thermodynamics reveals that the low temperature of the supersonic expansion plays a key role in forming these complexes.
A Red‐Light‐Activated Ruthenium‐Caged NAMPT Inhibitor Remains Phototoxic in Hypoxic Cancer Cells
Authors: Lameijer Lucien N. , Ernst Daniël , Hopkins Samantha L. , Meijer Michael S. , Askes Sven H. C. , Le Dévédec Sylvia E. , Bonnet Sylvestre
Published: June 2017

We describe two water‐soluble ruthenium complexes, [1]Cl2 and [2]Cl2, that photodissociate to release a cytotoxic nicotinamide phosphoribosyltransferase (NAMPT) inhibitor with a low dose (21 J cm−2) of red light in an oxygen‐independent manner. Using a specific NAMPT activity assay, up to an 18‐fold increase in inhibition potency was measured upon red‐light activation of [2]Cl2, while [1]Cl2 was thermally unstable. For the first time, the dark and red‐light‐induced cytotoxicity of these photocaged compounds could be tested under hypoxia (1 % O2). In skin (A431) and lung (A549) cancer cells, a 3‐ to 4‐fold increase in cytotoxicity was found upon red‐light irradiation for [2]Cl2, whether the cells were cultured and irradiated with 1 % or 21 % O2. These results demonstrate the potential of photoactivated chemotherapy for hypoxic cancer cells, in which classical photodynamic therapy, which relies on oxygen activation, is poorly efficient.
Diazirines as Potential Molecular Imaging Tags: Probing the Requirements for Efficient and Long‐Lived SABRE‐Induced Hyperpolarization
Authors: Shen Kun , Logan Angus W. J. , Colell Johannes F. P. , Bae Junu , Ortiz Gerardo X. , Theis Thomas , Warren Warren S. , Malcolmson Steven J. , Wang Qiu
Published: June 2017

Diazirines are an attractive class of potential molecular tags for magnetic resonance imaging owing to their biocompatibility and ease of incorporation into a large variety of molecules. As recently reported, 15N2‐diazirine can be hyperpolarized by the SABRE‐SHEATH method, sustaining both singlet and magnetization states, thus offering a path to long‐lived polarization storage. Herein, we show the generality of this approach by illustrating that the diazirine tag alone is sufficient for achieving excellent signal enhancements with long‐lasting polarization. Our investigations reveal the critical role of Lewis basic additives, including water, on achieving SABRE‐promoted hyperpolarization. The application of this strategy to a 15N2‐diazirine‐containing choline derivative demonstrates the potential of 15N2‐diazirines as molecular imaging tags for biomedical applications.
Trifluoroacetic Anhydride Promoted Copper(I)‐Catalyzed Interrupted Click Reaction: From 1,2,3‐Triazoles to 3‐Trifluoromethyl‐Substituted 1,2,4‐Triazinones
Authors: Wu Wei , Wang Junwen , Wang Yukang , Huang Yangjie , Tan Yingfei , Weng Zhiqiang
Published: June 2017

A copper(I)‐catalyzed interrupted click reaction in the presence of trifluoroacetic anhydride has been developed, wherein an N‐trifluoroacetyl group is used to accelerate the ring‐opening of the putative 5‐copper(I) triazolide intermediate. Under the optimized reaction conditions, a broad range of azides and alkynes were found to participate in this transformation, thus affording 3‐trifluoromethyl‐substituted 1,2,4‐triazinones in moderate to excellent yields. The reaction has proven to be compatible with a variety of electron‐withdrawing and electron–donating groups, halogens, and nitrogen‐ and sulfur‐containing heterocycles, as well as pharmaceutically relevant molecules.
People Wait Longer when the Alternative is Risky: The Relation Between Preferences in Risky and Inter‐temporal Choice
Authors: Luckman Ashley , Donkin Chris , Newell Ben R.
Published: June 2017

In two experiments, we demonstrate that despite indicating indifference when probed about risk or delay in isolation, when forced to explicitly trade‐off between the two, participants prefer delayed over risky rewards. This pattern of findings sets a boundary condition for any common utility‐based comparison process involving both risk and delay. Furthermore, this change from indifference‐in‐isolation to delay‐preference‐in‐a‐trade‐off strengthens as reward amount increases. Exploratory modeling results suggest that the shift in preference can be explained by allowing for different discount rates for delay‐only choices compared with when delay is in competition with risk. This explanation is better than one in which probability weighting is different between risk‐only choices and risks considered in the presence of a delay. Together, the empirical and modeling work lays a path for future investigations of why and when people's evaluation of the properties of risky and delayed choices vary as a function of the alternatives on offer. Copyright © 2017 John Wiley & Sons, Ltd.
How Does Explicit Versus Implicit Risk Information Influence Adolescent Risk‐Taking Engagement?
Authors: Osmont Anaïs , Moutier Sylvain , Simon Grégory , Bouhours Lison , Houdé Olivier , Cassotti Mathieu
Published: June 2017

Adolescents have been shown to be more likely to engage in risky behaviors in daily life. Many studies have indicated that adolescents could make advantageous choices when they receive explicit information but could fail to choose advantageously when they are not informed about risks. The current study aimed to examine the influence of explicit risk information (i.e., when risk information is directly available) versus implicit risk information (i.e., when risk information has to be learned from feedback) on risk‐taking engagement, in order to clarify whether the enhanced risk‐taking observed in decision making under ambiguity in adolescents results from either a greater exploration of ambiguous situations (i.e., a higher ambiguity tolerance) or a specific difficulty associated with learning based on previous choices' outcomes. Adolescents and young adults completed a new adaptation of the Balloon Analogue Risk Task. They were required to accumulate as many points as possible by inflating balloons associated with variable break points and avoiding explosions. This adaptation involved a manipulation of the information level with two conditions, an “informed” condition and a “noninformed” condition, in which the participants had to learn the matching of colors with balloons' resistances based on feedback. The results demonstrated that providing explicit risk information allows adolescents to be as efficient as adults at the end of the game. In contrast, adolescents failed to adjust risk‐taking to the balloon resistance in the noninformed condition. These findings critically suggest that this failure reflects a specific impairment of feedback‐based learning ability but not a global excess of risk‐taking during adolescence. Copyright © 2017 John Wiley & Sons, Ltd.
Simple measures to prevent a massive upper gastrointestinal bleed
Authors: Bansal Raghav , Vyas Neil , Companioni Rafael Antonio Ching , Rajnish Ishita , Salehi Ilnaz
Published: June 2017

Key Clinical Message

Nasogastric (NG) tube is frequently used in clinical practice for a variety of indications; however, NG tubes are not without risks, and there are a multitude of gastrointestinal complications that are associated with their use. Simple precautions can help prevent these NG tube‐related injuries.
Cobalt Phosphonates as Precatalysts for Water Oxidation: Role of Pore Size in Catalysis
Authors: Saha Jony , Chowdhury Debarati Roy , Jash Priyajit , Paul Amit
Published: June 2017

We report a simple approach for the synthesis of cobalt phosphonate (CoOP) nanocages with two distinct types of pore diameters by utilizing a novel tetra‐constituent assembly of CoCl2⋅6 H2O, nitrilotris(methylene)triphosphonic acid (NMPA), F127 surfactant, and polyvinyl alcohol (PVA, co‐surfactant). Transmission electron microscopy images revealed the formation of large nanocages in spheres (pore diameter: 20–60 nm) and the existence of narrow micro/mesopores (pore diameter: 1.5–5 nm) on their walls. Brunauer–Emmett–Teller adsorption/desorption experiments led to the observation of dual porosity and indicated that the contribution of micro/mesopores increased gradually with increasing concentration of PVA during synthesis from CoOP‐0 to CoOP‐15 (where the number gives the wt % of PVA used in CoOP synthesis). These materials acted as precatalysts for heterogeneous water oxidation at pH 13.9 (1 m KOH) and electrochemical studies revealed that the reactivity improved remarkably with increasing contribution of narrow micro/mesopores. Among these catalysts, the best catalyst (CoOP‐15) exhibited an overpotential of 380 mV and turnover frequency of 1.6×10−2 s−1. The improvement of reactivity was due to significant enhancement of electrochemically accessible surface area with increasing contribution of narrow micro/mesopores, which facilitated contact between the catalyst and water molecules by improving mass transport inside the nanomaterials. Hence, this study suggests narrow micro/mesopores are beneficial towards enhancement of water oxidation catalysis.
Unearthing [3‐(Dimethylamino)propyl]aluminium(III) Complexes as Novel Atomic Layer Deposition (ALD) Precursors for Al2O3: Synthesis, Characterization and ALD Process Development
Authors: Mai Lukas , Gebhard Maximilian , de los Arcos Teresa , Giner Ignacio , Mitschker Felix , Winter Manuela , Parala Harish , Awakowicz Peter , Grundmeier Guido , Devi Anjana
Published: June 2017

Identification and synthesis of intramolecularly donor‐stabilized aluminium(III) complexes, which contain a 3‐(dimethylamino)propyl (DMP) ligand, as novel atomic layer deposition (ALD) precursors has enabled the development of new and promising ALD processes for Al2O3 thin films at low temperatures. Key for this promising outcome is the nature of the ligand combination that leads to heteroleptic Al complexes encompassing optimal volatility, thermal stability and reactivity. The first ever example of the application of this family of Al precursors for ALD is reported here. The process shows typical ALD like growth characteristics yielding homogeneous, smooth and high purity Al2O3 thin films that are comparable to Al2O3 layers grown by well‐established, but highly pyrophoric, trimethylaluminium (TMA)‐based ALD processes. This is a significant development based on the fact that these compounds are non‐pyrophoric in nature and therefore should be considered as an alternative to the industrial TMA‐based Al2O3 ALD process used in many technological fields of application.
α‐Unsubstituted Pyrroles by NHC‐Catalyzed Three‐Component Coupling: Direct Synthesis of a Versatile Atorvastatin Derivative
Authors: Fleige Mirco , Glorius Frank
Published: June 2017

A practical one‐pot cascade reaction protocol provides direct access to valuable 1,2,4‐trisubstituted pyrroles. The process involves an N‐heterocyclic carbene (NHC)‐catalyzed Stetter‐type hydroformylation using glycolaldehyde dimer as a novel C1 building‐block, followed by a Paal‐Knorr condensation with primary amines. The reaction makes use of simple and commercially available starting‐materials and catalyst, an important feature regarding applicability and utility. Low catalyst loading under mild reaction conditions afforded a variety of 1,2,4‐substituted pyrroles in a transition‐metal‐free reaction with high step economy and good yields. This methodology is applied in the synthesis of a versatile Atorvastatin precursor, in which a variety of modifications at the pyrrole core structure are possible.
Understanding the relationship between the Centers for Medicare and Medicaid Services' Hospital Compare star rating, surgical case volume, and short‐term outcomes after major cancer surgery
Authors: Kaye Deborah R. , Norton Edward C. , Ellimoottil Chad , Ye Zaojun , Dupree James M. , Herrel Lindsey A. , Miller David C.
Published: June 2017

BACKGROUND

Both the Centers for Medicare and Medicaid Services' (CMS) Hospital Compare star rating and surgical case volume have been publicized as metrics that can help patients to identify high‐quality hospitals for complex care such as cancer surgery. The current study evaluates the relationship between the CMS' star rating, surgical volume, and short‐term outcomes after major cancer surgery.

METHODS

National Medicare data were used to evaluate the relationship between hospital star ratings and cancer surgery volume quintiles. Then, multilevel logistic regression models were fit to examine the association between cancer surgery outcomes and both star rankings and surgical volumes. Lastly, a graphical approach was used to compare how well star ratings and surgical volume predicted cancer surgery outcomes.

RESULTS

This study identified 365,752 patients undergoing major cancer surgery for 1 of 9 cancer types at 2,550 hospitals. Star rating was not associated with surgical volume (P < .001). However, both the star rating and surgical volume were correlated with 4 short‐term cancer surgery outcomes (mortality, complication rate, readmissions, and prolonged length of stay). The adjusted predicted probabilities for 5‐ and 1‐star hospitals were 2.3% and 4.5% for mortality, 39% and 48% for complications, 10% and 15% for readmissions, and 8% and 16% for a prolonged length of stay, respectively. The adjusted predicted probabilities for hospitals with the highest and lowest quintile cancer surgery volumes were 2.7% and 5.8% for mortality, 41% and 55% for complications, 12.2% and 11.6% for readmissions, and 9.4% and 13% for a prolonged length of stay, respectively. Furthermore, surgical volume and the star rating were similarly associated with mortality and complications, whereas the star rating was more highly associated with readmissions and prolonged length of stay.

CONCLUSIONS

In the absence of other information, these findings suggest that the star rating may be useful to patients when they are selecting a hospital for major cancer surgery. However, more research is needed before these ratings can supplant surgical volume as a measure of surgical quality. Cancer 2017;123:4259–4267. © 2017 American Cancer Society.
Ferromagnetism and Half‐Metallicity in Atomically Thin Holey Nitrogenated Graphene Based Systems
Authors: Choudhuri Indrani , Pathak Biswarup
Published: June 2017

Metal‐free half‐metallicity has been the subject of immense research focus in the field of spintronic devices. By using density functional theoretical (DFT) calculations, atomically thin holey nitrogenated graphene (C2N) based systems are studied for possible spintronic applications. Ferromagnetism is observed in all the C‐doped holey nitrogenated graphene. Interestingly, the holey nitrogenated graphene (C2N) based system shows strong half‐metallicity with a Curie temperature of approximately 297 K when a particular C‐doping concentration is reached. It shows a strong half‐metallicity compared with any metal‐free systems studied to date. Thus, such carbon nitride based systems can be used for a 100 % spin polarized current. Furthermore, such C‐doped systems show excellent dynamical, thermal, and mechanical properties. Thus, we predict a metal‐free planar ferromagnetic half‐metallic holey nitrogenated graphene based system for room‐temperature spintronic devices.
Antigen presenting cell‐targeted proinsulin expression converts insulin‐specific CD8+ T‐cell priming to tolerance in autoimmune‐prone NOD mice
Authors: Reeves Peta L. S. , Rudraraju Rajeev , Wong F. Susan , Hamilton‐Williams Emma E. , Steptoe Raymond J.
Published: June 2017

Type 1 diabetes (T1D) results from autoimmune destruction of insulin‐producing pancreatic β cells. Therapies need to incorporate strategies to overcome the genetic defects that impair induction or maintenance of peripheral T‐cell tolerance and contribute to disease development. We tested whether the enforced expression of an islet autoantigen in antigen‐presenting cells (APC) counteracted peripheral T‐cell tolerance defects in autoimmune‐prone NOD mice. We observed that insulin‐specific CD8+ T cells transferred to mice in which proinsulin was transgenically expressed in APCs underwent several rounds of division and the majority were deleted. Residual insulin‐specific CD8+ T cells were rendered unresponsive and this was associated with TCR downregulation, loss of tetramer binding and expression of a range of co‐inhibitory molecules. Notably, accumulation and effector differentiation of insulin‐specific CD8+ T cells in pancreatic lymph nodes was prominent in non‐transgenic recipients but blocked by transgenic proinsulin expression. This shift from T‐cell priming to T‐cell tolerance exemplifies the tolerogenic capacity of autoantigen expression by APC and the capacity to overcome genetic tolerance defects.
The RMgSn2 Series of Compounds (R = Rare Earth Metal): Synthesis, Crystal Structure, and Magnetic Measurements
Authors: Solokha Pavlo , Minetti Riccardo , De Negri Serena , Pereira Laura Cristina J. , Gonçalves Antonio P. , Saccone Adriana
Published: June 2017

The novel isostructural series of phases RMgSn2 (R = Y, La–Nd, Sm, Gd–Tm, Lu) is presented. They were prepared by direct synthesis in an induction furnace and subsequently annealed at 500 °C. Their crystal structures were determined through single‐crystal X‐ray diffraction analysis of the Ce representative [I42m, tI32‐LaMgSn2, Z = 8, a = 0.82863(3) nm, c = 1.23129(5) nm] and confirmed by powder X‐ray diffraction analysis of the other members of the series. Rietveld refinements were also performed on the homologues with R = Pr, Tm, and Y. The title phases show a unique space distribution of atoms, characterized by the presence of a Sn–Sn dumbbell distanced at around 0.29 nm. Their structures are related to those of a few binary AeTt3 (Ae = alkaline earth; Tt = Si, Ge; I4/mmm, tI32‐YbSi3) compounds that are stable at high pressure, characterized by a more complex 3D covalently bonded Tt network. Compounds CeMgSn2 and TbMgSn2 were magnetically characterized; they show paramagnetic behavior with the presence of ferromagnetic interactions, more pronounced in the case of TbMgSn2, as suggested by the Curie–Weiss temperatures, determined in the high‐temperature range, of 0.96 and 27.6 K for CeMgSn2 and TbMgSn2, respectively.
Ca2+‐Driven Self‐Assembly of POMs into 2D/3D Coordination Polymers
Authors: Buvailo Halyna I. , Makhankova Valeriya G. , Kokozay Vladimir N. , Omelchenko Irina V. , Shishkina Svitlana V. , Zabierowski Piotr , Matoga Dariusz , Jezierska Julia
Published: June 2017

A number of new POM‐based coordination polymers, including two‐dimensional (NH4)4{[Ca(H2O)5][P2Mo5O23]}·3H2O (4) (bpy = 2,2′‐bipyridine), and a rare anion‐based (NH4)5[CoIII(bpy)3]{[Ca(H2O)4]2[Ca(H2O)]6[PMo6O22(PO4)3]2}·17H2O (3), as well as three‐dimensional (NH4)8[CoIII(bpy)3]2{[Ca(H2O)3]2[P2Mo5O23]3}·21H2O (2) have been prepared using a facile wet‐chemistry approach and have been characterized by X‐ray diffraction analysis and a variety of physicochemical methods. The self‐assembly in the above compounds has been rendered by the use of Ca2+ ions as a suitable linker in the network formation. Moreover, Ca2+ ions were also involved in the formation of an extremely rare type of POM anion {[Ca(H2O)]6[PMo6O22(PO4)3]2}12–. The synthesis attempt without the alkaline‐earth metal led, predictably, to the formation of the discrete Strandberg‐based compound (NH4)3[CoIII(bpy)3][P2Mo5O23]·14H2O (1). Thus, the present work reports on a suitable strategy to influence complex POM‐based systems towards self‐organization into multidimensional structures of higher hierarchy. The obtained compounds have been shown to possess electrocatalytic activity towards the reduction of iodates(V).
Near‐Infrared Luminescence Switching in a Spin‐Crossover Polymer Nanocomposite
Authors: Suleimanov Iurii , Molnár Gábor , Salmon Lionel , Bousseksou Azzedine
Published: June 2017

A near‐infrared‐emitting luminescent nanocomposite material was obtained by the association of polyethylenimine, a cyanine dye, and nanoparticles of the [Fe(Htrz)2(trz)](BF4) spin‐crossover complex. The nanocomposite was characterized by electron microscopy, as well as by temperature‐dependent magnetic and fluorescence measurements. An unexpected strong and reversible luminescence intensity drop was observed when switching the spin‐state of the ferrous ions from the high‐spin to the low‐spin state, denoting a switching mechanism, which is not related to the spectral overlap between the dye and the iron complex.