bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy‐Dispersive,X‐Ray Fluorescence Analysis
Authors: Albertini Valerio Rossi , Paci Barbara , Generosi Amanda
Published: March 2018

Energy‐dispersive X‐ray fluorescence (EDXRF) is an analytical method for qualitative, as well as quantitative, determination of elements in a sample, independent of their chemical form. It is built on the fact that elements that are irradiated with high‐energy X‐rays have a certain probability of emitting characteristic X‐rays, the energies of which are unique for each element. In the energy‐dispersive (ED) systems, the emitted X‐rays are collected, by discriminating them on the basis of their energies. The use of the EDXRF technique has accelerated since the 1960s as a result of the development of liquid nitrogen‐cooled solid‐state detectors, nuclear electronics, and small computers. Nowadays, compact light‐weight electrically cooled detectors are available, which, together with air‐cooled low‐power X‐ray tubes, are perfectly suited for handheld spectrometers. EDXRF is multielemental and nondestructive and can be applied to large, as well as small, samples of different composition and character. If conditions are optimized, the minimum detection limits can be below the nanogram absolute or micrograms per gram concentration level for small laboratory instruments and into the femtogram or nanograms per milliliter region for more advanced instrumentation (total reflection X‐ray fluorescence (TXRF) and synchrotron radiation).

EDXRF spectrometers exist at many degrees of sophistication, ranging from advanced laboratory instruments to small portable instruments for field observations. They can be designed for analysis of bulk materials or for scanning and elemental mapping of small areas. The use of X‐ray optics such as single or polycapillaries and curved mirrors in Kirkpatrick–Baez geometry leads to X‐ray spot sizes of micrometers and below ideally suited for micro‐XRF. Mapping with high spatial resolution is thus possible, opening investigations down to cell dimension.

Typical applications for EDXRF are analysis of agricultural materials, medical samples, archeological and historical objects, painting and fine art objects, and environmental samples such as soil, ores, water, and aerosol particles.
Metal‐Enhanced Fluorescence and Its Applications
Authors: Sugawa Kosuke
Published: March 2018

The fluorescence‐enhancement phenomenon of fluorophores positioned near metal nanostructures (metal‐enhanced fluorescence, MEF) is the result of the interaction between the fluorophores and the localized surface plasmon resonance (LSPR) of the nanostructures. This enhancement phenomenon can contribute to the development of novel sensors based on unprecedented mechanisms, as well as improving the sensitivity of existing biosensors and imaging techniques. In this article, the two main mechanisms for MEF are briefly explained: the light‐harvesting nanoantenna effect and the increase in the radiative decay rate. This is followed by an introduction to metal nanostructures and nanoparticles (substrate‐based platforms and solution‐dispersed colloidal nanoparticle‐based platforms), which can act as MEF platforms. In addition, the efficient suppression of fluorescence blinking and photobleaching induced by the interaction with LSPR are described, as these are secondary advantages for fluorescence‐based sensors. Subsequently, the generation of hot spots, which could be one of the key phenomena for significant fluorescence enhancement, is outlined. An examination of usability of MEF platforms consisting of Al and Cu (metal species other than Au and Ag) to further improve their applicability is also discussed. Finally, some recent applications such as the development of imaging techniques, nanoprobes, and biosensors utilizing the MEF phenomenon are briefly introduced.
Discovery of the Actinide and Transactinide Elements
Authors: Orna Mary Virginia , Fontani Marco
Published: March 2018

When, in 1899, the close friend and colleague of Marie and Pierre Curie, André Louis Debierne, announced the discovery of actinium, he could not imagine that this element would become the first of a group of key elements for understanding atomic structure. A theoretical basis, an initially empirical periodic table, for the systematic study of the atom had been laid down many years earlier by Dmitri Ivanovich Mendeleev in 1869. It turned out to be a tool that could be used to predict what Mendeleev discerned as “missing elements,” elegantly confirmed by the discoveries of gallium in 1875, scandium in 1879, and finally germanium in 1886. Over the course of the following 60 years, a series of discoveries were made that began to reveal the modern picture of the structure of the atom. In chronological order, these were cathode rays, emission spectra, canal rays (protons), X‐rays, radioactivity, the electron, α, β, and γ rays, Planck's law, the photoelectric effect, the atomic nucleus, isotopes, Bohr model of atomic structure, atomic number, and the neutron. It gradually became clear that the number of nuclear protons equaled the nuclear charge and conferred on each atom its unique identity. This allowed scientists to determine how many elements existed in nature, namely 92. It also allowed them to devise experiments to push the envelope beyond 92—to actually create new elements by bombarding and combining the existing atomic nuclei, thus expanding the original periodic table to 118 elements. The impact of these discoveries has changed the course of history. The story of Debierne's discovery, actinium, and the 29 elements that follow it are the subject of this article and this volume.
Design and development of a phantom for tomosynthesis with potential for automated analysis via the cloud
Authors: Goodenough David , Levy Josh , Olafsdottir Hildur , Olafsson Ingvi
Published: March 2018

This paper describes Development of a Phantom for Tomosynthesis with Potential for Automated Analysis via the Cloud. Several studies are underway to investigate the effectiveness of Tomosynthesis Mammographic Image Screening, including the large TMIST project as funded by the National Cancer Institute https://www.cancer.gov/about-cancer/treatment/clinical-trials/nci-supported/tmist. The development of the phantom described in this paper follows initiatives from the FDA, the AAPM TG245 task group, and European Reference Organization (EUREF) for Quality Assured Breast Screening and Diagnostic Services Committee report noting, that no formal endorsement nor recommendation for use has been sought, or granted by any of these groups. This paper reports on the possibility of using this newly developed Tomosynthesis Phantom for Quality Assurance, field testing of image performance, including remote monitoring of DBT system performance, e.g., via transmission over the cloud. The phantom includes tests for: phantom positioning and alignment (important for remote analysis), scan geometry (x and y), chest wall offset, scan slice width and Slice Sensitivity Profile (SSP(z)) slice geometry (slice width), scan slice incrementation (z), z axis geometry bead, low contrast detectability using low contrast spheres, spatial resolution via Point Spread Function (PSF), Image uniformity, Signal to Noise Ratio (SNR), and Contrast to Noise Ratio (CNR) via readings over an Aluminum square. The phantom is designed for use with automated analysis via transmission of images over the cloud and the analysis package includes test of positioning accuracy (roll, pitch, and yaw). Data are shown from several commercial Tomosynthesis Scanners including Fuji, GE, Hologic, IMS‐Giotti, and Siemens; however, the focus of this paper is on phantom design, and not in general aimed at direct commercial comparisons, and wherever possible the identity of the data is anonymized. Results of automated analysis of the phantom are shown, and it is demonstrated that reliable analysis of such a phantom can be achieved remotely, including transmission of data through the cloud.
COMP report: CPQR technical quality control guidelines for accelerator‐integrated cone‐beam systems for verification imaging
Authors: Bissonnette Jean‐Pierre
Published: March 2018

The Canadian Organization of Medical Physicists, in close partnership with the Canadian Partnership for Quality Radiotherapy has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet in order to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities. The development process enables rapid review and update to keep the guidelines current with changes in technology. This article presents the quality control guideline accelerator‐integrated cone‐beam systems for verification imaging that has resulted from this process.
Microfluidic Production of Capsules‐in‐Capsules for Programed Release of Multiple Ingredients
Authors: Lee Sangmin , Lee Tae Yong , Amstad Esther , Kim Shin‐Hyun
Published: March 2018

Capsules with thin shells have a high‐loading capacity and are thus well‐suited containers for reagents that must be stored in confined volumes. Capsules contained in larger capsules, so‐called double capsules, allow the encapsulation of distinct reagents within small, defined, well‐separated volumes. Therefore, they offer possibilities to initiate reactions in confined volumes and to release distinct bioactives sequentially while minimizing the risk for cross contaminations. In this study, a new microfluidic capillary device is presented that enables the assembly of water‐oil‐water‐oil‐water (W/O/W/O/W) quadruple‐emulsion drops whose oil layers are ultra thin. These quadruple emulsions can be converted into double capsules with thin membranes through either evaporation‐induced consolidation of biodegradable polymers or photopolymerization of monomers. It is demonstrated that the membrane composition of the inner and outer capsules can be independently selected to enable programed release of distinct encapsulants. For example, biodegradable polymers with two different degradation rates are employed as the membrane materials that enable sequential release of two different encapsulants. In addition, the release of the encapsulants can be triggered by external stimuli such as osmotic pressure. This new class of double capsules provides new opportunities for drug delivery and screening assays that require sequential release of multiple water‐soluble ingredients.
pH‐Regulated Surface Plasmon Absorption from Ultrasmall Luminescent Gold Nanoparticles
Authors: Tan Yue , Liu Lulu , Wang Yaping , Liu Jinbin
Published: March 2018

Luminescent gold nanoparticles (AuNPs) with ultrasmall sizes (2–3 nm) and few free electrons have attracted fundamental science and application research interests due to their robust emission properties, but discoveries on their fantastic plasmonic properties are limited. Herein, controllable surface plasmon resonance (SPR) absorption (>520 nm) is reported from ultrasmall luminescent AuNPs (≈2.0 nm) coated with a small thiolate surface ligand, mercaptoimidazole (MIZ), through pH regulation. The 690 nm emitting MIZ‐AuNPs show SPR absorption and emission with a reversibly pH‐dependent response, i.e., a strong emission with no SPR band at high pH values (e.g., pH 5.0) and strong SPR absorption (570 nm) with weak emission at low pH values (e.g., pH 2.0). The MIZ surface coating, which has a low steric hindrance and high tendency to form intermolecular hydrogen bonds, is shown to play an important role in the creation of strong plasmon coupling and the emergence of plasmonic properties from ultrasmall MIZ‐AuNPs with 44% Au(I) species. The discovery of a plasmonic property in semiconducting luminescent MIZ‐AuNPs opens a new pathway for further understanding the optical properties of AuNPs and designing a new generation of optical AuNPs for various future applications.
Review of Electrolytes in Nonaqueous Lithium–Oxygen Batteries
Authors: Guo Haipeng , Luo Wenbin , Chen Jun , Chou Shulei , Liu Huakun , Wang Jiazhao
Published: March 2018

Based on an inexhaustible and ubiquitous source of oxygen, the lithium–oxygen batteries are currently the subject of much scientific investigation because of their potential for extremely high energy density. The electrocatalytic materials for them have been extensively researched during the past decade. Even though they are a key component in the lithium–oxygen batteries, however, the study of electrolytes is still in its primary stage. Electrolytes have an important influence on the electrochemical performance of lithium–oxygen batteries, especially on their cycling stability and rate capacity. Therefore, it is important to select an ideal electrolyte with excellent stability against attack by reaction intermediates, along with excellent oxygen solubility and diffusivity. In this review, the physicochemical and electrochemical properties of organic electrolytes for lithium–oxygen batteries are discussed and compared. Furthermore, possible research directions are proposed for the development of an ideal electrolyte for enhanced electrochemical performance.
Organic/Inorganic Metal Halide Perovskite Optoelectronic Devices beyond Solar Cells
Authors: Sun Jiachen , Wu Jiang , Tong Xin , Lin Feng , Wang Yanan , Wang Zhiming M.
Published: March 2018

Investigations of organic–inorganic metal halide perovskite materials have attracted extensive attention due to their excellent properties including bandgap tunability, long charge diffusion length, and outstanding optoelectronic merits. Organic–inorganic metal halide perovskites are demonstrated to be promising materials in a variety of optoelectronic applications including photodetection, energy harvesting, and light‐emitting devices. As perovskite solar cells are well studied in literature, here, the recent developments of organic–inorganic metal halide perovskite materials in optoelectronic devices beyond solar cells are summarized. The preparation of organic–inorganic metal halide perovskite films is introduced. Applications of organic–inorganic metal halide perovskite materials in light‐emitting diodes, photodetectors, and lasers are then highlighted. Finally, the recent advances in these optoelectronic applications based on organic–inorganic metal halide materials are summarized and the future perspectives are discussed.
Iron‐Catalyzed Synthesis of Amines and Thioethers Directly from Allylic Alcohols
Authors: Wang Dan‐Yang , Peng Xiao‐Min , Wang Guang‐Zhu , Zhang Ya‐Juan , Guo Tao , Zhang Pan‐Ke
Published: March 2018

A straightforward and efficient approach for the synthesis of allylic amines and thioethers has been developed by an iron‐catalyzed cross‐coupling reaction using diphosphite ligand. The reaction between allylic alcohols and amines/thiols gave allylic amine and thioester. The method is compatible with various functional groups, affording products with high yield and monoallylation selectivity.
An Iron Complex with a Bent, O‐Coordinated CO2 Ligand Discovered by Femtosecond Mid‐Infrared Spectroscopy
Authors: Straub Steffen , Brünker Paul , Lindner Jörg , Vöhringer Peter
Published: March 2018

The activation of carbon dioxide by transition metals is widely recognized as a key step for utilizing this greenhouse gas as a renewable feedstock for the sustainable production of fine chemicals. However, the dynamics of CO2 binding and unbinding to and from the ligand sphere of a metal have never been observed in the time domain. The ferrioxalate anion is used in aqueous solution as a unique model system for these dynamics and femtosecond UV‐pump mid‐infrared‐probe spectroscopy is applied to explore its photoinduced primary processes in a time‐resolved fashion. Following optical excitation, a neutral CO2 molecule is expelled from the complex within about 500 fs to generate a highly intriguing pentacoordinate ferrous dioxalate that carries a bent carbon dioxide radical anion ligand, that is, a reductively activated form of CO2, which is end‐on‐coordinated to the metal center by one of its two oxygen atoms.
Electrochemical C−H Amination by Cobalt Catalysis in a Renewable Solvent
Authors: Sauermann Nicolas , Mei Ruhuai , Ackermann Lutz
Published: March 2018

Syntheses of substituted anilines primarily rely on palladium‐catalyzed coupling chemistry with prefunctionalized aryl electrophiles. While oxidative aminations have emerged as powerful alternatives, they largely produce undesired metal‐containing by‐products in stoichiometric quantities. In contrast, described herein is the unprecedented electrochemical C−H amination by cobalt‐catalyzed C−H activation. The environmentally benign electrocatalysis avoids stoichiometric metal oxidants, can be conducted under ambient air, and employs a biomass‐derived, renewable solvent for sustainable aminations in an atom‐ and step‐economical manner with H2 as the sole byproduct.
Physicochemical Characterization and Fatty Acid Profiling of Different Philippine Pili Nut (Canarium ovatum, Engl.) Varieties
Authors: Millena Cristopher G. , Sagum Rosario S.
Published: March 2018

Canarium ovatum, commonly known as Pili nut, is an endemic crop in the Philippines. This study focused on the assessment of the physical, nutritional, and fatty acid profile of the pulp and kernel of Pili nut varieties. The study included 7 varieties that are cultivated in a single soil condition at the Albay Research and Development Center, Buang, Tabaco City, Philippines. Standard method Association of Official Analytical Chemist for nutritional analysis and DNA barcoding were used in the study. Molecular authentication through DNA barcoding shows that studied Pili nut varieties belong to genus C. ovatum. Split component of the fruit reveals that pulp is the major component (12.6–25.3%) of the fruit, followed by shell (5.97–12.3%), kernel (1.75–3.49%), and testa (0.17–0.34%). Lyophilized Pili nut kernel contains 67.2–74.1% fat, 11.5–13.2% protein, 3.43–9.97% dietary fiber, and 2.93–3.37% ash, and provides 704–749 cal 100 g−1 energy. Pili nut pulp contains 43.4–53.1% dietary fiber, 20.2–31.7% fat, 8.32–10.9% ash, and 4.53–6.32% protein, and provides 361–432 cal 100 g−1 energy. Pili nut pulp is an excellent source of dietary fiber. Prominent fatty acid is oleic acid (C18:1) for all varieties, which is higher in the pulp than in the kernel. Other major fatty acids include palmitic (C16:0), linoleic (C18:2), stearic (C18:0), and linolenic (C18:3) acids. Most of the physical and chemical characteristics measured depend significantly on the variety.
Active Sleep Promotes Functional Connectivity in Developing Sensorimotor Networks
Authors: Del Rio‐Bermudez Carlos , Blumberg Mark S.
Published: March 2018

A ubiquitous feature of active (REM) sleep in mammals and birds is its relative abundance in early development. In rat pups across the first two postnatal weeks, active sleep promotes the expression of synchronized oscillatory activity within and between cortical and subcortical sensorimotor structures. Sensory feedback from self‐generated myoclonic twitches – which are produced exclusively during active sleep – also triggers neural oscillations in those structures. We have proposed that one of the functions of active sleep in early infancy is to provide a context for synchronizing developing structures. Specifically, neural oscillations contribute to a variety of neurodevelopmental processes, including synapse formation, neuronal differentiation and migration, apoptosis, and the refinement of topographic maps. In addition, synchronized oscillations promote functional connectivity between distant brain areas. Consequently, any condition or manipulation that restricts active sleep can, in turn, deprive the infant animal of substantial sensory experience, resulting in atypical developmental trajectories.
Synthesis of Vinyl Sulfones via I2‐mediated Alkene Sulfonylations with Thiosulfonates
Authors: Hwang Sang Joon , Shyam Pranab K. , Jang Hye‐Young
Published: March 2018

A simple sulfonylation strategy involving I2 and thiosulfonates, as sulfonyl‐group precursors, is reported for the synthesis of vinyl sulfones. Sulfonyl radicals are presumed to be generated from thiosulfonates, which subsequently react with styrene or cinnamic acid derivatives to afford a variety of vinyl sulfones under the described reaction conditions. Detailed conditions, the substrate scope, and mechanistic studies are discussed.
Characterization of brain anatomical patterns by comparing region intensity distributions: Applications to the description of Alzheimer's disease
Authors: Giraldo Diana L. , García‐Arteaga Juan D. , Cárdenas‐Robledo Simón , Romero Eduardo
Published: March 2018

Purpose

This work presents an automatic characterization of the Alzheimer's disease describing the illness as a multidirectional departure from a baseline defining the control state, being these directions determined by a distance between functional‐equivalent anatomical regions.

Methods

After a brain parcellation, a region is described by its histogram of gray levels, and the Earth mover's distance establishes how close or far these regions are. The medoid of the control group is set as the reference and any brain is characterized by its set of distances to this medoid.

Evaluation

This hypothesis was assessed by separating groups of patients with mild Alzheimer's disease and mild cognitive impairment from control subjects, using a subset of the Open Access Series of Imaging Studies (OASIS) database. An additional experiment evaluated the method generalization and consisted in training with the OASIS data and testing with the Minimal Interval Resonance Imaging in Alzheimer's disease (MIRIAD) database.

Results

Classification between controls and patients with AD resulted in an equal error rate of 0.1 (90% of sensitivity and specificity at the same time). The automatic ranking of regions resulting is in strong agreement with those regions described as important in clinical practice. Classification with different databases results in a sensitivity of 85% and a specificity of 91%.

Conclusions

This method automatically finds out a multidimensional expression of the AD, which is directly related to the anatomical changes in specific areas such as the hippocampus, the amygdala, the planum temporale, and thalamus.
Evolving roles of faculty at an emerging hybrid competency‐based transdisciplinary program
Authors: Ashby Iryna , Caskurlu Secil , Exter Marisa
Published: March 2018

Background

Faculty is inseparable from the design and implementation of competency‐based programs. Yet prior research on competency‐based education (CBE) has mainly focused on program design and implementation, paying less attention to the faculty roles and perception of their involvement.

Aims

This paper explores faculty perceptions of their own roles relating to the design and the pilot semester implementation of a new competency‐based transdisciplinary program at a large Midwest research‐intensive university.

Methods

Using a phenomenological approach, we conducted semistructured interviews with faculty involved in the program design and implementation of the pilot semester in this program (n = 7) to gain an understanding of the varied demands and expectations, as well as their perceptions of such roles in the context of the program.

Results

Our findings showed a variety of faculty functions pertaining to their roles within our CBE environment. The faculty interviewed also tended to be actively engaged in terms of student onboarding, motivation, and encouragement, particularly earlier in the semester. Facilitation of students’ learning and competency attainment at the prescribed level of mastery led to the need for ongoing review and feedback of students’ work, and a higher workload than a traditional course. Yet, the faculty had positive responses to the program and their work, which in part may relate to their early buy‐in into the program as part of their collaboration on the program design.

Implications, limitations, and future research are discussed.
Acute interstitial nephritis: a multifaceted disease
Authors: Chamarthi Gajapathiraju , Kamboj Mayanka , Olaoye Olanrewaju A. , Zeng Xu , Koratala Abhilash
Published: March 2018

Key Clinical Message

Drug‐induced acute interstitial nephritis is an important cause of unexplained acute kidney injury in hospitalized patients. It can present with nonspecific clinical features, and renal biopsy should be considered for definitive diagnosis. Removal of the offending agent along with early initiation of corticosteroid therapy is the mainstay of treatment.
Suppurative thyroiditis
Authors: Singla Mandeep , Gaba Saurabh , Bhinder Kanwar
Published: March 2018

Key Clinical Message

Acute bacterial suppurative thyroiditis is an infrequent but life‐threatening medical emergency. It needs to be considered in a patient with painful thyroid enlargement. Therapy consists of appropriate antibiotics and drainage of abscess. The disease may prove fatal if diagnosis and treatment are delayed.
Bile cast nephropathy in a patient with cholangiocarcinoma – a case report
Authors: Kritmetapak Kittrawee , Sathidatekoonchorn Thanatarn , Papanrueng Weerapat
Published: March 2018

Key Clinical Message

Bile cast nephropathy is characterized by the presence of bile casts associated with renal failure and/or proximal tubulopathy in cases of severe hyperbilirubinemia. The clinician should carefully examine the urine samples for characteristic bile‐stained granular casts in suspected case.
Bilateral ovarian masses with different histopathology in each ovary
Authors: Baradwan Saeed , Alalyani Haneen , Baradwan Amira , Baradwan Afnan , Al‐Ghamdi Maram , Alnemari Jameel , Al‐Jaroudi Dania
Published: March 2018

Key Clinical Message

We document the rare occurrence of multiple primary benign lesions that can occur in bilateral ovarian masses with benign imaging appearances and tumor markers. In addition, this case report contributes important information that may aid physicians in guiding their patients to make optimal clinical decisions together.
A Biomimetic Synthetic Receptor Selectively Recognising Fucose in Water
Authors: Francesconi Oscar , Martinucci Marco , Badii Lorenzo , Nativi Cristina , Roelens Stefano
Published: March 2018

Carbohydrate recognition in water by biomimetic receptors is an attractive, but very challenging goal. Despite advances achieved in glucose recognition, little or no success has been obtained in the recognition of other saccharidic epitopes of paramount importance in biological processes. Herein, the unprecedented recognition of fucose in water by an artificial receptor that shows affinities closely comparable to those of several lectins is reported. The receptor has been constructed by assembling a hydrogen‐bonding element (carbazole), a hydrophobic aromatic moiety (anthracene), and a water‐solubilising function (phosphonate) into a macrocyclic structure to provide the appropriate binding geometry. The described receptor binds fucose with sub‐millimolar affinity in water at physiological pH; this shows that enthalpic binding can be ascribed to hydrogen bonding to saccharidic hydroxy groups and to CH−π interactions between the sugar backbone and aromatic moieties. Experimental NOE contacts coupled to conformational search calculations return a picture of a binding site in which fucose assumes a staggered orientation reminiscent of that shown by fucose when bound to the Ralstonia solanacearum lectin (RSL).
New Possibilities to Design Biogenic Calcite Particles. Influence of Cultivation Parameters and Purification on Coccolith Properties
Authors: Jakob Ioanna , Posten Clemens , Chairopoulou Makrina , Scholl Sarita , Vučak Marijan
Published: March 2018

Coccolithen sind mikrostrukturierte Calcitpartikeln, die von Mikroalgen in der Natur produziert werden. Ihre komplex strukturierte Morphologie und enge Partikelgrößenverteilung unterscheidet sie von synthetischen Partikeln und macht sie interessant für verschiedenste Anwendungsgebiete. Coccolithen können nicht künstlich hergestellt werden und müssen deshalb durch Kultivierung gewonnen werden. In dieser Arbeit wird gezeigt, dass die Eigenschaften von Coccolithen nicht starr sind. Die Variation der Prozessparameter, Medienkomposition und Aufreinigungsstrategie ermöglicht bestimmte Eigenschaften von Coccolithen zu verändern. Dazu gehören die chemische Zusammensetzung, der Anteil von organischem Material und der Oberflächencharakter. Dadurch können Coccolithen zukünftig ihrem potenziellen Einsatzgebiet angepasst werden.
A Versatile C–H Halogenation Strategy for Indole Derivatives under Electrochemical Catalyst‐ and Oxidant‐Free Conditions
Authors: Sun Linhao , Zhang Xing , Li Zilong , Ma Jimei , Zeng Zhen , Jiang Hong
Published: March 2018

Halogenated indoles are essential structural motifs in bioactive natural products. Reported herein is an economical and scalable electrochemical protocol for regioselective 3C–H halogenation of indole derivatives. This strategy provides access to a host of 3‐iodo‐, 3‐bromo‐, 3‐chloro‐, and 3‐thiocyanoindole derivatives under mild conditions using inexpensive (pseudo)halide salts as the sole reagent. The optimized conditions do not require any supplementary electrolyte salts.
Rapid and Sensitive Detection of NADH and Lactate Dehydrogenase Using Thermostable DT‐Diaphorase Immobilized on Electrode
Authors: Kang Juyeon , Shin Jeonghwa , Yang Haesik
Published: March 2018

Rapid and sensitive electrochemical detection of NADH, NADH‐dependent enzymes, and relevant metabolites requires a redox enzyme along with an electron mediator. Preferably, the redox enzyme should be immobilized on electrode rather than dissolved in solution. In this study, to simply immobilize a redox enzyme on electrode and maintain its enzymatic activity for long time, thermostable DT‐diaphorase (DT‐D) is immobilized on an avidin‐modified indium tin oxide (ITO) electrode. Electrochemical‐enzymatic (EN) redox cycling involving ITO electrode, ferrocenemethanol (FcMeOH), DT‐D, and NADH is employed for NADH detection. Electrochemical‐enzymatic‐enzymatic (ENN) redox cycling involving ITO electrode, FcMeOH, DT‐D, NAD+, lactate dehydrogenase (LDH), and lactate is employed for LDH detection. In both cases, a new combination of a redox enzyme and an electron mediator (DT‐D and FcMeOH) is used. The detection limits for NADH and LDH in artificial serum obtained without an incubation period are approximately 0.2 μM and 8 ng/mL, respectively. When an incubation period of 10 min is employed, the detection limit for LDH is approximately 5 ng/mL. Because the ENN redox cycling is very fast, the two detection limits are similar irrespective of incubation period. The enzymatic activity of DT‐D on ITO electrode is maintained for one month without deactivation.
Effect of low thermal pasteurization in combination with carvacrol on color, antioxidant capacity, phenolic and vitamin C contents of fruit juices
Authors: Tchuenchieu Alex , Essia Ngang Jean‐Justin , Servais Marjorie , Dermience Michael , Sado Kamdem Sylvain , Etoa François‐Xavier , Sindic Marianne
Published: March 2018

Mild thermal treatment in combination with natural antimicrobials has been described as an alternative to conventional pasteurization to ensure fruit juices safety. However, to the best of our knowledge, no study has been undertaken to evaluate what could be its effect on their color and nutritional value. This study therefore aimed at assessing how a low thermal pasteurization in combination with carvacrol could affect these parameters, with orange, pineapple, and watermelon juices as selected fruit juices. The experimental design used had levels ranging from 50 to 90°C, 0 to 60 μl/L, and 0 to 40 min for temperature, concentration of carvacrol supplemented, and treatment length, respectively. The only supplementation of fruit juices with carvacrol did not affect their color. In comparison with high thermal pasteurization (>70°C), a combined treatment at mild temperatures (50–70°C) better preserved their color, antioxidant capacity (AOC), and vitamin C content, and increased their total phenolic content (TPC). Globally, carvacrol supplementation had a positive impact on the TPC of thermally treated juices and increased the AOC of treated watermelon juice, which was the lowest of the three fruit juices. Mild heat treatment in combination with natural antimicrobials like carvacrol is therefore an alternative to limit the negative effects of conventional pasteurization on fruit juices quality.
Hybodont dentition from the Upper Jurassic of Monte Nerone Pelagic Carbonate Platform (Umbria‐Marche Apennine, Italy) and its ecological implications
Authors: Citton Paolo , Fabbi Simone , Cipriani Angelo , Jansen Maren , Romano Marco
Published: March 2018

Here we describe a number of articulated teeth of a hybodont shark from Upper Jurassic deposits of the Monte Nerone Pelagic Carbonate Platform, in the Umbria‐Marche‐Sabina Palaeogeographic Domain (Northern Apennines, Central Italy). The material has been referred to asAsteracanthuscf.A. magnus, a quite well‐known taxon already reported from Middle to Upper Jurassic deposits of Europe. Teeth indicate an extreme crushing feeding behaviour, suggesting as putative prey both infaunal and epifaunal hard‐shelled invertebrates dwelling the sea‐floor, such as large bivalves, brachiopods, gastropods as well as vagile crustaceans. The finding represents, to date, the first formal report of hybodont shark in the Umbria‐Marche‐Sabina Domain, throwing further light on the ecology within Pelagic Carbonate Platform settings, and on the occurrence ofAsteracanthusin the Late Jurassic of the Western Tethys.
Effect of BMI on pregnancy rates following ovulation induction and assisted conception among women in Qatar experiencing infertility
Authors: Athar Sufia , Hamcho Mohammad A. , Tellisi Amna K. , Puttegowda Rohini , Boama Vincent
Published: March 2018

Body mass index exhibited an inverse relationship with pregnancy rate in patients with infertility.
Formation of new stimulus equivalence classes by exclusion
Authors: Plazas Elberto A. , Villamil Carlos‐Wilcen
Published: March 2018

This study presents three experiments that aimed to show the formation of stimulus equivalence relations among stimuli that had been previously related only by exclusion. In Experiment 1, participants were trained on baseline conditional discriminations to establish two 3‐member equivalence classes. Then, they were exposed to exclusion trials, without feedback, in which undefined stimuli had to be matched by rejecting the defined baseline stimuli. Finally, participants responded to test trials evaluating the emergence of symmetry and transitivity among the undefined stimuli from the exclusion trials. For half of the participants, the stimuli related by exclusion were introduced as S‐ stimuli in the baseline trials, whereas for the other half they were not. Further, half of the participants were assessed for emergent relations with stimuli from all the classes, whereas the other half was assessed for emergent relations with only the stimuli related by exclusion. In Experiment 2, the S‐ comparisons in the emergent relations test trials with stimuli only related by exclusion were stimuli from a null class. In Experiment 3, the number of exclusion trials was doubled. Across experiments, most participants showed emergence of equivalence relations among the stimuli related by exclusion. Some conditions of stimulus control associated with exclusion learning and the emergence of equivalence relations are discussed.
Presence of rare hepatitis C virus subtypes, 2j, 2k, and 2r in Mexico City as identified by sequencing
Authors: Uribe‐Noguez Luis Antonio , Ocaña‐Mondragón Alicia , Mata‐Marín José Antonio , Gómez‐Torres María Elena , Ribas‐Aparicio Rosa María , de la Luz Martínez‐Rodríguez María
Published: March 2018

The HCV 5'UTR, Core/E1, and NS5B regions of samples from fifty patients infected with the hepatitis C virus (HCV) were analyzed. Seventeen patients were identified with genotype (GT) 1b, eleven with GT‐1a, nine with GT‐2b and four with GT‐3a. Two rare subtypes were detected: GT‐2j in two patients and GT‐2r in one patient. Three patients had mixed infections: one with GT‐2k + 2j and two with GT‐1b + 2b. This work identifies HCV GTs, 2j, 2k, and 2r for the first time in Mexico.
High‐throughput multipesticides residue analysis in earthworms by the improvement of purification method: Development and application of magnetic Fe3O4‐SiO2 nanoparticles based dispersive solid‐phase extraction
Authors: Sun Yuhan , Qi Peipei , Cang Tao , Wang Zhiwei , Wang Xiangyun , Yang Xuewei , Wang Lidong , Xu Xiahong , Wang Qiang , Wang Xinquan , Zhao Changshan
Published: March 2018

As a key representative organism, earthworms can directly illustrate the influence of pesticides on environmental organisms in soil ecosystems. The present work aimed to develop a high‐throughput multipesticides residue analytical method for earthworms using solid–liquid extraction with acetonitrile as the solvent and magnetic material‐based dispersive solid‐phase extraction for purification. Magnetic Fe3O4 nanoparticles were modified with a thin silica layer to form Fe3O4‐SiO2 nanoparticles, which were fully characterized by field‐emission scanning electron microscopy, transmission electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffractometry, and vibrating sample magnetometry. The Fe3O4‐SiO2 nanoparticles were used as the separation media in dispersive solid‐phase extraction with primary secondary amine and ZrO2 as the cleanup adsorbents to eliminate matrix interferences. The amounts of nanoparticles and adsorbents were optimized for the simultaneous determination of 44 pesticides and six metabolites in earthworms by liquid chromatography with tandem mass spectrometry. The method performance was systematically validated with satisfactory results. The limits of quantification were 20 μg/kg for all analytes studied, while the recoveries of the target analytes ranged from 65.1 to 127% with relative standard deviation values lower than 15.0%. The developed method was subsequently utilized to explore the bioaccumulation of bitertanol in earthworms exposed to contaminated soil, verifying its feasibility for real sample analysis.
Association of common candidate variants with vascular malformations and intracranial hemorrhage in hereditary hemorrhagic telangiectasia
Authors: Pawlikowska Ludmila , Nelson Jeffrey , Guo Diana E. , McCulloch Charles E. , Lawton Michael T. , Kim Helen , Faughnan Marie E. ,   the Brain Vascular Malformation Consortium HHT Investigator Group
Published: March 2018

Background

Hereditary hemorrhagic telangiectasia (HHT) is caused by mutations in TGFβ/BMP9 pathway genes and characterized by vascular malformations (VM) including arteriovenous malformations (AVM) in lung, liver, and brain, which lead to severe complications including intracranial hemorrhage (ICH) from brain VM. The clinical heterogeneity of HHT suggests a role for genetic modifier effects. Common variants in loci that modify phenotype severity in Tgfb knockout mice were previously reported as associated with lung AVM in HHT. Common variants in candidate genes were reported as associated with sporadic brain AVM and/or ICH. We investigated whether these variants are associated with HHT organ VM or with ICH from brain VM in 752 Caucasian HHT patients enrolled by the Brian Vascular Malformation Consortium.

Methods

We genotyped 11 candidate variants: four variants reported as associated with lung AVM in HHT (PTPN14 rs2936018, USH2A rs700024, ADAM17 rs12474540, rs10495565), and seven variants reported as associated with sporadic BAVM or ICH (APOE ε2, ANGPTL4 rs11672433, EPHB4 rs314308, IL6 rs1800795, IL1B rs1143627, ITGB8 rs10486391, TNFA rs361525). Association of genotype with any VM, lung AVM, liver VM, brain VM or brain VM ICH was evaluated by multivariate logistic regression adjusted for age, gender, and family clustering.

Results

None of the 11 variants was significantly associated with any phenotype. There was a trend toward association of USH2A rs700024 with ICH (OR = 2.77, 95% CI = 1.13–6.80, p = .026).

Conclusion

We did not replicate previously reported associations with HHT lung AVM and variants in Tgfb modifier loci. We also did not find significant associations between variants reported in sporadic brain AVM and VM or ICH in HHT.
Cherenkov radiation‐based three‐dimensional position‐sensitive PET detector: A Monte Carlo study
Authors: Ota Ryosuke , Yamada Ryoko , Moriya Takahiro , Hasegawa Tomoyuki
Published: March 2018

Purpose

Cherenkov radiation has recently received attention due to its prompt emission phenomenon, which has the potential to improve the timing performance of radiation detectors dedicated to positron emission tomography (PET). In this study, a Cherenkov‐based three‐dimensional (3D) position‐sensitive radiation detector was proposed, which is composed of a monolithic lead fluoride (PbF2) crystal and a photodetector array of which the signals can be readout independently.

Methods

Monte Carlo simulations were performed to estimate the performance of the proposed detector. The position‐ and time resolution were evaluated under various practical conditions. The radiator size and various properties of the photodetector, e.g., readout pitch and single photon timing resolution (SPTR), were parameterized. The single photon time response of the photodetector was assumed to be a single Gaussian for the simplification. The photo detection efficiency of the photodetector was ideally 100% for all wavelengths. Compton scattering was included in simulations, but partly analyzed. To estimate the position at which a γ‐ray interacted in the Cherenkov radiator, the center‐of‐gravity (COG) method was employed. In addition, to estimate the depth‐of‐interaction (DOI) principal component analysis (PCA), which is a multivariate analysis method and has been used to identify the patterns in data, was employed. The time–space distribution of Cherenkov photons was quantified to perform PCA. To evaluate coincidence time resolution (CTR), the time difference of two independent γ‐ray events was calculated. The detection time was defined as the first photon time after the SPTR of the photodetector was taken into account.

Results

The position resolution on the photodetector plane could be estimated with high accuracy, by using a small number of Cherenkov photons. Moreover, PCA showed an ability to estimate the DOI. The position resolution heavily depends on the pitch of the photodetector array and the radiator thickness. If the readout pitch were ideally 0 and practically 3 mm, a full‐width at half‐maximum (FWHM) of 0.348 and 1.92 mm was achievable with a 10‐mm‐thick PbF2 crystal, respectively. Furthermore, first‐order correlation could be observed between the primary principal component and the true DOI. To obtain a coincidence timing resolution better than 100‐ps FWHM with a 20‐mm‐thick PbF2 crystal, a photodetector with SPTR of better than σ = 30 ps was necessary.

Conclusions

From these results, the improvement of SPTR allows us to achieve CTR better than 100‐ps FWHM, even in the case where a 20‐mm‐thick radiator is used. Our proposed detector has the potential to estimate the 3D interaction position of γ‐rays in the radiator, using only time and space information of Cherenkov photons.
Muscle echogenicity ratio can indicate severity of carpal tunnel syndrome
Authors: Park Dong Yoon , Kang Seok , Jeong Jin Seok , Yoon Joon Shik
Published: March 2018

Introduction: The purpose of this study was to investigate the usefulness of the echogenicity (EI) ratio of the thenar to hypothenar muscle measured using ultrasonography in assessing the severity of carpal tunnel syndrome (CTS). Methods: Fifty‐nine hands of 30 patients electrodiagnostically confirmed as having CTS were classified into 3 subgroups (mild, moderate, and severe). The EI of the thenar and hypothenar muscles was measured with ultrasonography, and the EI ratio was calculated in the patients and 13 normal participants (26 hands). Results: The average EI ratio was higher in the CTS group than in the control group. We also found a positive correlation between the severity of CTS and a high EI ratio measured with ultrasonography. Discussion: The EI ratio of the thenar to hypothenar muscle is a useful parameter that can indicate the severity of CTS. Muscle Nerve 58: 304–306, 2018
On the p‐median polytope and the odd directed cycle inequalities: Oriented graphs
Authors: Baïou Mourad , Barahona Francisco
Published: March 2018

We study the classical linear programing relaxation of the ‐median problem, together with the so‐called “odd directed cycle inequalities.” We characterize in terms of forbidden subgraphs, the oriented graphs for which this system of inequalities defines an integral polytope. This completes the study started in Baïou and Barahona (2016), where oriented graphs with no triangles were treated.
Thermal Decomposition Kinetics of Nitroguanidine Propellant under Different Pressures
Authors: Zhang Fen , Liu Zhi‐Tao , Du Ping
Published: March 2018

Thermal decomposition of a nitroguanidine‐based propellant at different pressures was investigated under non‐isothermal conditions by high‐pressure differential scanning calorimetry (PDSC). It was found that only one visible exothermic peak appeared in DSC curves at the pressure. With the increase of the environment pressure, the peak temperature decreased, and the decomposition heat increased. Application of elevated pressures changed the mechanism of thermal decomposition of the nitroguanidine propellant as compared with that at 0.1 MPa. The reaction followed the sigmoidal model, where n=0.97 (0.1 MPa), or n=0.96 (high pressures). The mechanism of the process at 0.1 MPa can be classified as chemical reaction, and the kinetic equation can be
; whereas at high pressures, it shifts to nucleation and growth, with
at 2 MPa and
at 4 MPa. Pressure increase lowered the decrease in critical temperature, and lowered entropy of activation (ΔS≠), enthalpy of activation (ΔH≠), free energy of activation (ΔG≠), as well as the thermal safety of the nitroguanidine propellant.
Regeneration mechanisms in Syllidae (Annelida)
Authors: Ribeiro Rannyele P. , Bleidorn Christoph , Aguado M. Teresa
Published: March 2018

Syllidae is one of the most species‐rich groups within Annelida, with a wide variety of reproductive modes and different regenerative processes. Syllids have striking ability to regenerate their body anteriorly and posteriorly, which in many species is redeployed during sexual (schizogamy) and asexual (fission) reproduction. This review summarizes the available data on regeneration in syllids, covering descriptions of regenerative mechanisms in different species as well as regeneration in relation to reproductive modes. Our survey shows that posterior regeneration is widely distributed in syllids, whereas anterior regeneration is limited in most of the species, excepting those reproducing by fission. The latter reproductive mode is well known for a few species belonging to Autolytinae, Eusyllinae, and Syllinae. Patterns of fission areas have been studied in these animals. Deviations of the regular regeneration pattern or aberrant forms such as bifurcated animals or individuals with multiple heads have been reported for several species. Some of these aberrations show a deviation of the bilateral symmetry and antero‐posterior axis, which, interestingly, can also be observed in the regular branching body pattern of some species of syllids.
Substituted Acene Derivatives: Synthesis, Optical Property and Self‐assembly Behavior
Authors: Liang Zhihua , Zhai Guixia , Fan Yanwei , Wang Shifa , Xiao Jinchong
Published: March 2018

A novel twistacene 11,12‐dichloro‐9,14‐diphenyldibenzo [de, qr]tetracene (TPyC) has been synthesized in one pot through classical Diels‐Alder cycloaddition reaction and fully characterized. Its analogues TPyO, TPyS, TPyF and TPyB were re‐prepared through the reported methods. All of them emitted blue fluorescence in toluene solution. The self‐assembly properties based on the as‐prepared molecules were examined in detail by re‐precipitation method, suggesting that the terminal substituents, temperature and solvent could affect the aggregation morphology in large part.