bluuebunny/crossref_metadata_2025 huggingface dataset:
Buffer layer engineering on graphene via various oxidation methods for atomic layer deposition
Authors: Takahashi Nobuaki , Nagashio Kosuke
Published: October 2016

The integration of a high-k oxide on graphene using atomic layer deposition requires an electrically reliable buffer layer. In this study, Y was selected as the buffer layer due to its highest oxidation ability among the rare-earth elements, and various oxidation methods (atmospheric, and high-pressure O2 and ozone annealing) were applied to the Y metal buffer layer. By optimizing the oxidation conditions of the top-gate insulator, we successfully improved the capacitance of the top gate Y2O3 insulator and demonstrated a large I
on/I
off ratio for bilayer graphene under an external electric field.
Homoepitaxial growth of beta gallium oxide films by mist chemical vapor deposition
Authors: Lee Sam-dong , Kaneko Kentaro , Fujita Shizuo
Published: October 2016

Homoepitaxial single-crystal beta gallium oxide (β-Ga2O3) films were fabricated by the mist chemical vapor deposition method. The crystallinity of the films grown markedly depended on growth temperature, and the optimum growth temperatures were found to be 700–800 °C. Using unintentionally doped β-Ga2O3 films grown on Sn-doped β-Ga2O3(010) substrates, the fabrication of Schottky barrier diodes was demonstrated. Furthermore, we fabricated electrically conductive Sn-doped β-Ga2O3 films on semi-insulating Fe-doped β-Ga2O3(010) substrates. The carrier concentrations were between 1 × 1018 and 5 × 1020 cm−3. The Hall mobility was 45 cm2 V−1 s−1 at the carrier concentration of 1 × 1018 cm−3.
Electron channel mobility in silicon-doped Ga2O3 MOSFETs with a resistive buffer layer
Authors: Wong Man Hoi , Sasaki Kohei , Kuramata Akito , Yamakoshi Shigenobu , Higashiwaki Masataka
Published: October 2016

The electron mobility in depletion-mode lateral β-Ga2O3(010) metal–oxide–semiconductor field-effect transistors (MOSFETs) with an n-channel formed by Si-ion (Si+) implantation doping was extracted using low-field electrical measurements on FET structures. An undoped Ga2O3 buffer layer protected the channel against charge compensation by suppressing outdiffusion of deep Fe acceptors from the semi-insulating substrate. The molecular beam epitaxy growth temperature was identified as a key process parameter for eliminating parasitic conduction at the buffer/substrate growth interface. Devices with a resistive buffer showed room temperature channel mobilities of 90–100 cm2 V−1 s−1 at carrier concentrations of low- to mid-1017 cm−3, with small in-plane mobility anisotropy of 10–15% ascribable to anisotropic carrier scattering.
Refleksjon i barnehagelærerutdanningen
Authors: Moxnes Anna Rigmor
Published: October 2016

Abstract: The purpose of this article is to discuss the use of reflection in both educational- and research literature regarding Early Childhood Teacher Education. When reading the literature, I find that reflection is linked to theory and practice, to change and new knowledge and to ethical and critical reflection. The understanding of reflection as a concept varies, however personal change and new knowledge is a common denominator. My research reveals reflection as a multifaceted and complex concept. A consequence of this complexity is that in order to give reflection importance in teacher education, it will require thorough preparations for reflection and comprehensive monitoring of students.Sammendrag: Hensikten med denne artikkelen er å diskutere hvordan refleksjon anvendes i ulik fag- og forskningslitteratur som omhandler barnehagelærerutdanningen. I studier av tekstene finner jeg at refleksjon knyttes til teori og praksis, refleksjon knyttes til endring og ny erkjennelse og til etisk og kritisk refleksjon. Det varierer hvordan refleksjon forstås, men personlig endring og ny erkjennelse er en fellesnevner. Undersøkelsen viser et mangefasettert og komplekst refleksjonsbegrep. Det framgår også at skal refleksjon ha betydning i barnehagelærerutdanningen, vil det kreve grundige forberedelser og tilrettelegging for refleksjon, og omfattende oppfølging av studenter.
Competition and cooperation with virtual players in an exergame
Authors: Shaw Lindsay A. , Buckley Jude , Corballis Paul M. , Lutteroth Christof , Wuensche Burkhard C.
Published: October 2016

Two cross-sectional studies investigated the effects of competition and cooperation with virtual players on exercise performance in an immersive Virtual reality (VR) cycle exergame. Study 1 examined the effects of: (1) self-competition whereby participants played the exergame while competing against a replay of their previous exergame session (Ghost condition), and (2) playing the exergame with a virtual trainer present (Trainer condition) on distance travelled and calories expended while cycling. Study 2 examined the effects of (1) competition with a virtual trainer system (Competitive condition) and (2) cooperation with a virtual trainer system (Cooperative condition). Post exergame enjoyment and motivation were also assessed.

The results of Study 1 showed that the trainer system elicited a lesser distance travelled than when playing with a ghost or on one’s own. These results also showed that competing against a ghost was more enjoyable than playing on one’s own or with the virtual trainer. There was no significant difference between the participants’ rated enjoyment and motivation and their distance travelled or calories burned. The findings of Study 2 showed that the competitive trainer elicited a greater distance travelled and caloric expenditure, and was rated as more motivating. As in Study 1, enjoyment and motivation were not correlated with distance travelled and calories burned.

Conclusion

Taken together, these results demonstrate that a competitive experience in exergaming is an effective tool to elicit higher levels of exercise from the user, and can be achieved through virtual substitutes for another human player.
Brain-derived neurotrophic factor and schizophrenia
Authors: Gören Jessica L.
Published: October 2016

Schizophrenia is a severe disorder affecting approximately 1% of the population. Historically, alterations of dopaminergic function were considered the primary cause of schizophrenia. However, for many patients, drugs that alter dopaminergic function do not consistently lead to resolution of the symptoms of schizophrenia. Thus, there is an increased interest in pathophysiologic processes that result in altered neurodevelopment and plasticity associated with schizophrenia. Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neurogenesis, synaptic plasticity, cognition, and neurotransmission. Genetic polymorphism, expression, and function of BDNF have been implicated in psychiatric diseases, including schizophrenia. This review discusses BDNF, its role in neurologic processes, and the evidence implicating BDNF in schizophrenia.
Evaluation of the use of low-dose quetiapine and the risk of metabolic consequences: A retrospective review
Authors: Carr Chelsea N. , Lopchuk Shruti , Beckman Mary E. , Baugh Terrence Bradley
Published: October 2016

Introduction:

Quetiapine fumarate is an atypical antipsychotic approved for the treatment of schizophrenia, major depressive disorder, and bipolar disorder. Due to the sedative effects observed at low doses, prescribers use quetiapine to aid patients with sleep disturbances. Current evidence has established that quetiapine can cause negative changes in metabolic parameters, but it is unknown if these consequences also occur at low doses. Due to the use of quetiapine for sleep, the purpose of this study is to identify if metabolic effects are also a risk with the use of low-dose quetiapine.

Methods:

Eligible subjects were identified through the Veterans Affairs electronic medical records as having an active prescription for quetiapine from June 30, 2012, through September 1, 2013. Subjects were then evaluated using inclusion and exclusion criteria for determination of study entrance. Descriptive statistics and t tests were utilized to identify clinical and statistical differences in outcomes.

Results:

A total of 403 subjects were included in the final analysis. The average dose of quetiapine was 116.8 mg and average duration of therapy was 44 months. Increases were observed in systolic blood pressure (+1.95 mmHg; P = .036), diastolic blood pressure (+1.97 mmHg; P = .001), body mass index (+0.52; P = .001), weight (+1.88 kg; P = .002), and fasting blood glucose (+6.71 mg/dL; P = .002). Conversely, a decrease in total cholesterol (−10.06 mg/dL; P < .001) was recognized.

Discussion:

As a result of the findings, there may be negative metabolic consequences with the use of low-dose quetiapine. Routine prescribing of low doses for sleep as a first-line medication should be avoided.
Challenges in planet formation
Authors: Morbidelli Alessandro , Raymond Sean N.
Published: October 2016

Over the past two decades, large strides have been made in the field of planet formation. Yet fundamental questions remain. Here we review our state of understanding of five fundamental bottlenecks in planet formation. These are the following: (1) the structure and evolution of protoplanetary disks; (2) the growth of the first planetesimals; (3) orbital migration driven by interactions between protoplanets and gaseous disk; (4) the origin of the Solar System's orbital architecture; and (5) the relationship between observed super‐Earths and our own terrestrial planets. Given our lack of understanding of these issues, even the most successful formation models remain on shaky ground.
Recent Advances in Soft Materials to Build and Functionalize Hard Structures for Electrochemical Energy Storage and In situ Electrochemical Molecular Biosensing
Authors: Guo Chun Xian , Li Chang Ming
Published: October 2016

Soft materials such as carbon materials, polymers and macromolecules possess rich functional groups and have become an important research filed in material science and engineering but they lack high durability and mechanical rigidity. Hard structures can provide stable and rigid scaffolds as well as hierarchically porous structures for superior physical properties; however, they often suffer from relatively poor surface chemistry. Construction of soft materials functionalized hard structures often generates new composite materials with unique physico‐chemical properties for synergistically boosting high‐efficient energy conversion/storage and biosensing. In this review, starting with introduction of fundamentals and properties of soft materials and hard structures, advances in fabrications and characterizations of the composite materials are discussed. The excellent physico‐chemical and electrochemical properties of the soft materials‐built and functionalized composite materials as well as their applications as electrode materials in solar cells, fuel cells, electrochemical water splitting, lithium‐ion batteries/lithium‐sulfur batteries/supercapacitors, and in situ molecular biosensing for greatly improved performance are surveyed. The performance enhancement mechanisms in these electrochemical systems are discussed to elicit fundamental insights. The challenges and prospects of this research area are also deliberated to inspire future improvements.
Metallic Layered Polyester Fabric Enabled Nickel Selenide Nanostructures as Highly Conductive and Binderless Electrode with Superior Energy Storage Performance
Authors: Nagaraju Goli , Cha Sung Min , Sekhar S. Chandra , Yu Jae Su
Published: October 2016

Highly flexible and conductive fabric (CF)‐supported cauliflower‐like nickel selenide nanostructures (Ni3Se2 NSs) are facilely synthesized by a single‐step chronoamperometry voltage‐assisted electrochemical deposition (ECD) method and used as a positive electrode in supercapacitors (SCs). The CF substrate composed of multi‐layered metallic films on the surface of polyester fibers enables to provide high electrical conductivity as a working electrode in ECD process. Owing to good electrical conductivity, high porosity and intertwined fibrous framework of CF, cauliflower‐like Ni3Se2 NSs are densely integrated onto the entire surface of CF (Ni3Se2 NSs@CF) substrate with reliable adhesion by applying a chronoamperometry voltage of −1.0 V for 240 s. The electrochemical performance of the synthesized cauliflower‐like Ni3Se2 NSs@CF electrode exhibits a maximum specific capacity (CSC) of 119.6 mA h g−1 at a discharge current density of 2 A g−1 in aqueous 1 m KOH electrolyte solution. Remarkably, the specific capacity of the same electrode is greatly enhanced by introducing a small quantity of redox‐additive electrolyte into the aqueous KOH solution, indicating the CSC≈251.82 mA h g−1 at 2 A g−1 with good capacity retention. Furthermore, the assembled textile‐based asymmetric SCs achieve remarkable electrochemical performance such as higher energy and power densities, which are able to light up different colored light‐emitting diodes.
Effect of Photogenerated Dipoles in the Hole Transport Layer on Photovoltaic Performance of Organic–Inorganic Perovskite Solar Cells
Authors: Ahmadi Mahshid , Hsiao Yu‐Che , Wu Ting , Liu Qing , Qin Wei , Hu Bin
Published: October 2016

Judicious choice of transport layer in organic–inorganic halide perovskite solar cells can be one of the essential parameters in photovoltaic design and fabrication techniques. This article reports the effect of optically generated dipoles in transport layer on the photovoltaic actions in active layer in perovskite solar cells with the architecture of indium tin oxide (ITO)/TiO
x
/CH3NH3PbI3–x
Cl
x
/hole transport layer (HTL)/Au. Here, PTB7‐thieno[3,4‐b]thiophene‐alt‐benzodithiophene and P3HT‐poly(3‐hexylthiophene) are separately used as the HTL with significant and negligible photoinduced dipoles, respectively. Electric field‐induced photoluminescence quenching provides the first‐hand evidence to indicate that the photoinduced dipoles are partially aligned in the amorphous PTB7 layer under the influence of device built‐in field. By monitoring the recombination process through magneto‐photocurrent measurements under device operation condition, it is shown that the photoinduced dipoles in PTB7 layer can decrease the recombination of photogenerated carriers in the active layer in perovskite solar cells. Furthermore, the capacitance measurements suggest that the photoinduced dipoles in PTB7 can decrease charge accumulation at the electrode interface. Therefore, the studies indicate the important role of photoinduced dipoles in the HTL on charge recombination dynamics and provide a fundamental insight on how the polarization in transport layer can influence the device performance in perovskite solar cells.
Chemical Bonding and Physical Trapping of Sulfur in Mesoporous Magnéli Ti4O7 Microspheres for High‐Performance Li–S Battery
Authors: Wei Hao , Rodriguez Erwin F. , Best Adam S. , Hollenkamp Anthony F. , Chen Dehong , Caruso Rachel A.
Published: October 2016

Various host materials have been investigated to address the intrinsic drawbacks of lithium sulfur batteries, such as the low electronic conductivity of sulfur and inevitable decay in capacity during cycling. Besides the widely investigated carbonaceous materials, metal oxides have drawn much attention because they form strong chemical bonds with the soluble lithium polysulfides. Here, mesoporous Magnéli Ti4O7 microspheres are prepared via an in situ carbothermal reduction that exhibit interconnected mesopores (20.4 nm), large pore volume (0.39 cm3 g−1), and high surface area (197.2 m2 g−1). When the sulfur cathode is embedded in a matrix of mesoporous Magnéli Ti4O7 microspheres, it exhibits a superior reversible capacity of 1317.6 mA h g−1 at moderate current (C/10) and a low decay in capacity of 12% after 400 cycles at C/5. Strong chemical bonding of the lithium polysulfides to Ti4O7, as well as effective physical trapping in the mesopores and voids in the matrix are considered responsible for the improved electrochemical performance. A mechanism of the physical and chemical interactions between mesoporous Magnéli Ti4O7 microspheres and sulfur is proposed based on systematic investigations.
The Mosaic Structure of Zeolite Crystals
Authors: Qin Zhengxing , Melinte Georgian , Gilson Jean‐Pierre , Jaber Maguy , Bozhilov Krassimir , Boullay Philippe , Mintova Svetlana , Ersen Ovidiu , Valtchev Valentin
Published: October 2016

Zeolites are widely used in many commercial processes, mostly as catalysts or adsorbents. Understanding their intimate structure at the nanoscale is the key to control their properties and design the best materials for their ever increasing uses. Herein, we report a new and controllable fluoride treatment for the non‐discriminate extraction of zeolite framework cations. This sheds new light on the sub‐structure of commercially relevant zeolite crystals: they are segmented along defect zones exposing numerous nanometer‐sized crystalline domains, separated by low‐angle boundaries, in what were apparent single‐crystals. The concentration, morphology, and distribution of such domains analyzed by electron tomography indicate that this is a common phenomenon in zeolites, independent of their structure and chemical composition. This is a milestone to better understand their growth mechanism and rationally design superior catalysts and adsorbents.
High‐Pressure Phase Transformations in TiPO4: A Route to Pentacoordinated Phosphorus
Authors: Bykov Maxim , Bykova Elena , Hanfland Michael , Liermann Hanns‐Peter , Kremer Reinhard K. , Glaum Robert , Dubrovinsky Leonid , van Smaalen Sander
Published: October 2016

Titanium(III) phosphate, TiPO4 , is a typical example of an oxyphosphorus compound containing covalent P−O bonds. Single‐crystal X‐ray diffraction studies of TiPO4 reveal complex and unexpected structural and chemical behavior as a function of pressure at room temperature. A series of phase transitions lead to the high‐pressure phase V, which is stable above 46 GPa and features an unusual oxygen coordination of the phosphorus atoms. TiPO4‐V is the first inorganic phosphorus‐containing compound that exhibits fivefold coordination with oxygen. Up to the highest studied pressure of 56 GPa, TiPO4‐V coexists with TiPO4‐IV, which is less dense and might be kinetically stabilized. Above a pressure of about 6 GPa, TiPO4‐II is found to be an incommensurately modulated phase whereas a lock‐in transition at about 7 GPa leads to TiPO4‐III with a fourfold superstructure compared to the structure of TiPO4‐I at ambient conditions. TiPO4‐II and TiPO4‐III are similar to the corresponding low‐temperature incommensurate and commensurate magnetic phases and reflect the strong pressure dependence of the spin‐Peierls interactions.
The potential of nanoparticles in stem cell differentiation and further therapeutic applications
Authors: Dayem Ahmed Abdal , Choi Hye Yeon , Yang Gwang‐Mo , Kim Kyeongseok , Saha Subbroto Kumar , Kim Jin‐Hoi , Cho Ssang‐Goo
Published: October 2016

Tissue regeneration could offer therapeutic advantages for individuals experiencing organ or tissue damage. Recently, advances in nanotechnology have provided various nanomaterials, with a wide range of applications, for modulating stem cell behavior and for further therapeutic applications in tissue regeneration. Defects in cell proliferation and differentiation, a low mechanical strength of scaffolds, and inefficient production of factors that are essential for stem cell differentiation are the current challenges in tissue regeneration. This review provides a brief explanation about the link between nanotechnology and tissue engineering, highlighting the current literature about the interaction between nanoparticles (NPs) and stem cells, the promotional effect of NPs on stem cell differentiation into various lineages, and their possible therapeutic applications. We also tried to describe the mechanism through which NPs regulate the spatial‐temporal release and kinetics of vital growth and differentiation factors, enhance stem cell differentiation, and improve culture conditions for in vivo tissue regeneration. The field of nanotechnology is promising and provides novel nanomaterials and methods with valuable clinical applications in the regenerative medicine. Understanding the mechanism, as well as the toxic effects of NPs in stem cell biology will undoubtedly provide valuable insight into their clinical application in the regenerative medicine.
Update on clinical evidence (Part II): A summary of the main post market studies
Authors: Tamburino Corrado , Capranzano Piera , Francaviglia Bruno , Ina Tamburino Claudia , Longo Giovanni , Capodanno Davide
Published: October 2016

Bioresorbable vascular scaffolds (BVS, Absorb, Abbott Vascular, Santa Clara, CA) received the CE mark in October 2011, and were approved by the Food and Drug Administration in July 2016. After their introduction in clinical practice a broad amount of post‐marketing clinical experience with BVS has been generated so far in Europe and outside the United States. The available BVS registries differ in many aspects, including their being single‐center or multicenter, single‐arm or controlled, sponsored or investigator‐initiated, published or presented at a large‐scale international meeting. This article provides an overview of clinical results of the main post‐marketing studies of BVS available. © 2016 Wiley Periodicals, Inc.
Bioresorbable vascular scaffolds: From patient selection to optimal scaffold implantation; tips and tricks to minimize device failure
Authors: Tanaka Akihito , Jabbour Richard J. , Latib Azeem , Colombo Antonio
Published: October 2016

Bioresorbable vascular scaffolds (BVS) have become an attractive option in the field of percutaneous coronary intervention due to the complete resorption process that occurs over a few years. On the other hand, current generation devices have several limitations when compared to metallic drug‐eluting stents including bulky struts and relatively less radial strength, and it has been indicated that an optimized implantation strategy is required. In this article, various tips and tricks to optimize implantation of current generation BVS are discussed. © 2016 Wiley Periodicals, Inc.
Applications of Chiral Thiourea‐Amine/Phosphine Organocatalysts in Catalytic Asymmetric Reactions
Authors: Sun Yao‐Liang , Wei Yin , Shi Min
Published: October 2016

Since the first example of using a thiourea‐amine organocatalyst was reported in 2003, research on thiourea‐based amines and phosphines in asymmetric catalysis has shown the excellent performance of chiral thiourea‐amine/phosphine organocatalysts in a variety of highly enantioselective reactions. In this Minireview, the iconic catalysts and transformations are highlighted and discussed.
Potassium Poly(heptazine imides) from Aminotetrazoles: Shifting Band Gaps of Carbon Nitride‐like Materials for More Efficient Solar Hydrogen and Oxygen Evolution
Authors: Savateev Aleksandr , Pronkin Sergey , Epping Jan Dirk , Willinger Marc Georg , Wolff Christian , Neher Dieter , Antonietti Markus , Dontsova Dariya
Published: October 2016

Potassium poly(heptazine imide) (PHI) is a photocatalytically active carbon nitride material that was recently prepared from substituted 1,2,4‐triazoles. Here, we show that the more acidic precursors, such as commercially available 5‐aminotetrazole, upon pyrolysis in LiCl/KCl salt melt yield PHI with the greatly improved structural order and thermodynamic stability. Tetrazole‐derived PHIs feature long‐range crystallinities and unconventionally small layer stacking distances, leading to the altered electronic band structures as shown by Mott–Schottky analyses. Under the optimized synthesis conditions, visible‐light driven hydrogen evolution rates reach twice the rate provided by the previous gold standard, mesoporous graphitic carbon nitride, which has a much higher surface area. More interestingly, the up to 0.7 V higher valence band potential of crystalline PHI compared with ordinary carbon nitrides makes it an efficient water oxidation photocatalyst, which works even in the absence of any metal‐based co‐catalysts under visible light. To our knowledge, this is the first case of metal‐free oxygen liberation from water.
On the Mechanism of Frustrated Lewis Pair Catalysed Hydrogenation of Carbonyl Compounds
Authors: Das Shubhajit , Pati Swapan K.
Published: October 2016

We have explored the reaction mechanism of the metal‐free B(C6F5)3‐catalysed hydrogenation of carbonyl compounds to the corresponding secondary alcohols by density functional theory calculations. Possible reaction routes have been investigated in detail and the results provide solid support for the mechanism proposed on the basis of experimental observations. The critical role of the ethereal solvent, as an active participant in the hydrogenation process, is highlighted with the ether–borane Lewis pair shown to be involved in the heterolytic activation of H2. The feasiblity of an alternative direct hydrogenation route featuring carbonyl–borane‐mediated H2 cleavage has also been examined. We have also investigated the moisture sensitivity of the catalyst and possible decomposition routes. We found that the catalyst shows appreciable water‐tolerance and that even in the presence of moisture the hydrogenation proceeds through the same mechanism as that followed under anhydrous conditions.
Reactivity of [Ge9{Si(SiMe3)3}3]− Towards Transition‐Metal M2+ Cations: Coordination and Redox Chemistry
Authors: Kysliak Oleksandr , Schrenk Claudio , Schnepf Andreas
Published: October 2016

Recently the metalloid cluster compound [Ge9Hyp3]− (1; Hyp=Si(SiMe3)3) was oxidatively coupled by an iron(II) salt to give the largest metalloid Group 14 cluster [Ge18Hyp6]. Such redox chemistry is also possible with different transition metal (TM) salts TM2+ (TM=Fe, Co, Ni) to give the TM+ complexes [Fe(dppe)2][Ge9Hyp3] (3; dppe=1,2‐bis(diphenylphosphino)ethane), [Co(dppe)2][Ge9Hyp3] (4), [Ni(dppe)(Ge9Hyp3)] (5) and [Ni(dppe)2(Ge9Hyp3)]+ (6). Such a redox reaction does not proceed for Mn, for which a salt metathesis gives the first open shell [Hyp3Ge9‐M‐Ge9Hyp3] cluster (2; M=Mn). The bonding of the transition metal atom to 1 is also possible for Ni (e.g., compound 6), in which one or even two nickel atoms can bind to 1. In contrast to this in case of the Fe and Co compounds 3 and 4, respectively, the transition‐metal atom is not bound to the Ge9 core of 1. The synthesis and the experimentally determined structures of 2–6 are presented. Additionally the bonding within 2–6 is analyzed and discussed with the aid of EPR measurements and quantum chemical calculations.
Bifunctional RuII‐Complex‐Catalysed Tandem C−C Bond Formation: Efficient and Atom Economical Strategy for the Utilisation of Alcohols as Alkylating Agents
Authors: Roy Bivas Chandra , Chakrabarti Kaushik , Shee Sujan , Paul Subhadeep , Kundu Sabuj
Published: October 2016

Catalytic activities of a series of functional bipyridine‐based RuII complexes in β‐alkylation of secondary alcohols using primary alcohols were investigated. Bifunctional RuII complex (3 a) bearing 6,6’‐dihydroxy‐2,2’‐bipyridine (6DHBP) ligand exhibited the highest catalytic activity for this reaction. Using significantly lower catalyst loading (0.1 mol %) dehydrogenative carbon−carbon bond formation between numerous aromatic, aliphatic and heteroatom substituted alcohols were achieved with high selectivity. Notably, for the synthesis of β‐alkylated secondary alcohols this protocol is a rare one‐pot strategy using a metal–ligand cooperative RuII system. Remarkably, complex 3 a demonstrated the highest reactivity compared to all the reported transition metal complexes in this reaction.
Palladium‐Catalyzed Carbonylative Multicomponent Reactions
Authors: Shen Chaoren , Wu Xiao‐Feng
Published: October 2016

The achievements on palladium‐catalyzed carbonylative multicomponent reactions (CMCR) have been summarized and discussed according to the type of carbonylation reaction involved.
Synthesis of Quaternary‐Carbon‐Containing β2,2‐Amino Acids by the RhI‐Catalyzed Enantioselective Arylation of α‐Substituted β‐Nitroacrylates
Authors: Fang Jo‐Hsuan , Jian Jia‐Hong , Chang Hao‐Ching , Kuo Ting‐Shen , Lee Way‐Zen , Wu Ping‐Yu , Wu Hsyueh‐Liang
Published: October 2016

An enantioselective RhI‐catalyzed conjugate addition reaction of α‐substituted β‐nitroacrylates with various arylboronic acids by using chiral RhI diene catalysts is described for the first time. The addition reaction proceeds under mild conditions in a range of common organic solvents and additives, and it affords the corresponding quaternary‐carbon‐containing α,α‐disubstituted β‐nitropropionate products in up to 63 % yield and 99 % ee. Reaction of either (E)‐ or (Z)‐β‐nitroacrylates provided the same enantiomer of the product, and a range of esters and aryl groups were tolerated. To demonstrate the utility of the method, ethyl (R)‐1,1‐methyl‐1‐phenyl‐3‐nitropropionate, prepared herein, was converted to the non‐proteinogenic β2,2‐amino acid, (R)‐2‐(aminomethyl)‐2‐phenylpropanoic acid, and to the β2,2‐lactam, (R)‐3‐methyl‐3‐phenylazetidin‐2‐one. In addition, a tripeptide, which comprised l‐phenylalanine, l‐alanine, and β2,2‐amino acid 7, was also synthesized.
Glycerol Dehydration to Acrolein Catalyzed by ZSM‐5 Zeolite in Supercritical Carbon Dioxide Medium
Authors: Zou Bin , Ren Shoujie , Ye X. Philip
Published: October 2016

Supercritical carbon dioxide (SC‐CO2) has been used for the first time as a reaction medium for the dehydration of glycerol to acrolein catalyzed by a solid acid. Unprecedented catalyst stability over 528 hours of time‐on‐stream was achieved and the rate of coke deposition on the zeolite catalyst was the lowest among extensive previous studies, showing potential for industrial application. Coking pathways in SC‐CO2 were also elucidated for future development. The results have potential implications for other dehydration reactions catalyzed by solid acids.
Agroecosystem research with big data and a modified scientific method using machine learning concepts
Authors: Moran M. Susan , Heilman Philip , Peters Debra P. C. , Holifield Collins Chandra
Published: October 2016

Long‐term studies of agroecosystems distributed across the North American continent are providing an extraordinary understanding of regional environmental dynamics. The new Long‐Term Agro‐ecosystem Research (LTAR) network (organized in 2012) has designed an explicit cross‐site research program with multiple U.S. Department of Agriculture (USDA) experimental watersheds, ranges, and forests. Here, we report results from studies using a modified scientific method that includes learning through time that was implemented over the past five years with long‐term data from USDA experimental sites in coordination with other networks. The results offer a compelling argument for the LTAR concept of combining site‐based expertise with network‐wide coordination and collaboration to arrive at more accurate scientific conclusions than possible from individual researchers working alone. Simply put, without site‐based expertise and cross‐site communication working in parallel to provide input, feedback, and refinement to each subsequent step, similar to the way machine learning works, the interpretations and conclusions of these studies would have been incomplete, if not incorrect. Further, the up‐front time commitment to data processing and analytics above the time dedicated to place‐based studies increased the productivity of the team and the impact of the research, unlike the common perception that cross‐site research is often less efficient. In turn, this approach supported a non‐traditional system of credit for co‐authors based on citation impact of the journal selected as the publication outlet with less regard for author order. The LTAR network has embraced this modified scientific method in its shared research strategy and common experiment to address the problematic issues of mixed data quality across studies and sites, co‐author credit, research efficiency, and scientific impact on data‐intensive research. This approach can be combined with other types of collaborative and social media approaches, such as crowdsourcing, to take advantage of the wide range of expertise in the agroecological community as well as other disciplines to move science forward in the time of big data.
Economic Analysis and Potential Feed‐in Tariff of Grid‐Connected PV Systems in Nigeria
Authors: Adaramola Muyiwa S. , Paul Samuel S.
Published: October 2016

This study presents a feasibility study of grid‐tied PV system in selected locations across the country with focus on cost of energy produced and incentives such as feed‐in tariff and investment support. Based on the study locations and assumptions used in this study, it was estimated that the annual energy generated by the PV system varies between 2885 kWh in Port‐Harcourt in southern region and 4391 kWh in Isa in northern region. The optimal simulation results reveal that the levelized cost of energy varies from one location to another: highest in very low‐energy site (Port‐Harcourt) and lowest in the very high‐energy (Isa). In addition, it is estimated that the feed‐in tariff varies between N76.54/kWh (or US$0.4556/kWh) in Port‐Harcourt and N50.25/kWh (or US$0.2991/kWh) in Isa. It was further observed that the ratio of levelized cost of energy to current electricity tariff is least at Bauchi with a value of 1.22 and highest in Ikeja with a value of 2.95. Consequently, it would easier to sell solar PV idea to individual in Bauchi than those in Ikeja to invest in solar PV. Some of the benefits and potential challenges of implementing feed‐in tariff in Nigeria were also presented. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 305–314, 2017
Full rate constant matrix contraction method for obtaining branching ratio of unimolecular decomposition
Authors: Sumiya Yosuke , Taketsugu Tetsuya , Maeda Satoshi
Published: October 2016

The branching ratio of unimolecular decomposition can be evaluated by solving the rate equations. Recent advances in automated reaction path search methods have enabled efficient construction of the rate equations based on quantum chemical calculations. However, it is still difficult to solve the rate equations composed of hundreds or more elementary steps. This problem is especially serious when elementary steps that occur in highly different timescales coexist. In this article, we introduce an efficient approach to obtain the branching ratio from a given set of rate equations. It has been derived from a recently proposed rate constant matrix contraction (RCMC) method, and termed full‐RCMC (f‐RCMC). The f‐RCMC gives the branching ratio without solving the rate equations. Its performance was tested numerically for unimolecular decomposition of C3H5 and C4H5. Branching ratios obtained by the f‐RCMC precisely reproduced the values obtained by numerically solving the rate equations. It took about 95 h to solve the rate equations of C4H5 consisting of 234 elementary steps. In contrast, the f‐RCMC gave the branching ratio in less than 1 s. The f‐RCMC would thus be an efficient alternative of the conventional kinetic simulation approach. © 2016 Wiley Periodicals, Inc.
MR‐guided percutaneous sclerotherapy of low‐flow vascular malformations: Clinical experience using a 1.5 tesla MR system
Authors: O'Mara Daniel M. , DiCamillo Paul A. , Gilson Wesley D. , Herzka Daniel A. , Wacker Frank K. , Lewin Jonathan S. , Weiss Clifford R.
Published: October 2016

Purpose

To demonstrate the feasibility, safety, and effectiveness of image‐guided sclerotherapy of low‐flow vascular malformations using a 1.5 Tesla (T) MR scanner with real‐time imaging capability and in‐suite fluoroscopy.

Materials and Methods

Thirty‐three procedures were performed with real‐time 1.5T MR‐guidance on 22 patients with a vascular malformation in the neck (n = 2), chest (n = 6), abdomen and pelvis (n = 15), and extremities (n = 11). Quantitative analysis was performed for changes in (a) planning time, (b) targeting time (interval between needle skin puncture and lesion access), (c) intervention time (interval between needle skin puncture and needle removal), and (d) total procedure time. Qualitative analysis was performed for (a) success of therapy and (b) occurrence of complications.

Results

Technical success was achieved in 29 of 33 procedures. The average planning time did not significantly change between the first seven procedures and the last seven procedures (P = 0.447). The average targeting time decreased by 0:24:45 (hours:minutes:seconds) (P = 0.043), the average intervention time decreased by 0:26:58 (P = 0.022), and the average procedure time decreased by 0:28:41 (P = 0.046) when comparing the first seven procedures and the last seven procedures. Overall, there was an improvement in the patients' predominant symptoms following 82% of procedures, including a significant decrease in average pain following therapy (P < 0.001). There was a minor complication rate of 3% with no major complications.

Conclusion

MR‐guided percutaneous sclerotherapy seems to be a safe, effective, and versatile technique for treating low‐flow vascular malformations.

Level of Evidence: 3

J. Magn. Reson. Imaging 2017;45:1154–1162
Can routine office‐based audiometry predict cochlear implant evaluation results?
Authors: Gubbels Samuel P. , Gartrell Brian C. , Ploch Jennifer L. , Hanson Kevin D.
Published: October 2016

Objectives/Hypothesis

Determining cochlear implant candidacy requires a specific sentence‐level testing paradigm in best‐aided conditions. Our objective was to determine if findings on routine audiometry could predict the results of a formal cochlear implant candidacy evaluation. We hypothesize that findings on routine audiometry will accurately predict cochlear implant evaluation results in the majority of candidates.

Study Design

Retrospective, observational, diagnostic study.

Methods

The charts of all adult patients who were evaluated for implant candidacy at a tertiary care center from June 2008 through June 2013 were included. Routine, unaided audiologic measures (pure‐tone hearing thresholds and recorded monosyllabic word recognition testing) were then correlated with best‐aided sentence‐level discrimination testing (using either the Hearing in Noise Test or AzBio sentences test).

Results

The degree of hearing loss at 250 to 4,000 Hz and monosyllabic word recognition scores significantly correlated with sentence‐level word discrimination test results. Extrapolating from this association, we found that 86% of patients with monosyllabic word recognition scores at or below 32% (or 44% for patients with private insurance) would meet candidacy requirements for cochlear implantation.

Conclusions

Routine audiometric findings can be used to identify patients who are likely to meet cochlear implant candidacy upon formal testing. For example, patients with pure‐tone thresholds (250, 500, 1,000 Hz) of ≥75 dB and/or a monosyllabic word recognition test score of ≤40% have a high likelihood of meeting candidacy criteria. Utilization of these predictive patterns during routine audiometric evaluation may assist hearing health professionals in deciding when to refer patients for a formal cochlear implant evaluation.

Level of Evidence

4 Laryngoscope, 127:216–222, 2017
Rapid maxillary expansion for pediatric obstructive sleep apnea: A systematic review and meta‐analysis
Authors: Camacho Macario , Chang Edward T. , Song Sungjin A. , Abdullatif Jose , Zaghi Soroush , Pirelli Paola , Certal Victor , Guilleminault Christian
Published: October 2016

Objectives/Hypothesis

To perform a systematic review with meta‐analysis for sleep study outcomes in children who have undergone rapid maxillary expansion (RME) as treatment for obstructive sleep apnea (OSA).

Data Sources

PubMed/MEDLINE and eight additional databases.

Review Methods

Three authors independently and systematically reviewed the international literature through February 21, 2016.

Results

Seventeen studies reported outcomes for 314 children (7.6 ± 2.0 years old) with high‐arched and/or narrow hard palates (transverse maxillary deficiency) and OSA. Data were analyzed based on follow‐up duration: ≤3 years (314 patients) and >3 years (52 patients). For ≤3‐year follow‐up, the pre‐ and post‐RME apnea–hypopnea index (AHI) decreased from a mean ± standard deviation (M ± SD) of 8.9 ± 7.0/hr to 2.7 ± 3.3/hr (70% reduction). The cure rate (AHI <1/hr) for 90 patients for whom it could be calculated was 25.6%. Random effects modeling for AHI standardized mean difference (SMD) is −1.54 (large effect). Lowest oxygen saturation (LSAT) improved from 87.0 ± 9.1% to 96.0 ± 2.7%. Random effects modeling for LSAT SMD is 1.74 (large effect). AHI improved more in children with previous adenotonsillectomy or small tonsils (73–95% reduction) than in children with large tonsils (61% reduction). For >3‐year follow‐up (range = 6.5–12 years), the AHI was reduced from an M ± SD of 7.1 ± 5.7/hr to 1.5 ± 1.8/hr (79% reduction).

Conclusions

Improvement in AHI and lowest oxygen saturation has consistently been seen in children undergoing RME, especially in the short term (<3‐year follow‐up). Randomized trials and more studies reporting long‐term data (≥3‐year follow‐up) would help determine the effect of growth and spontaneous resolution of OSA. Laryngoscope, 2016 Laryngoscope, 127:1712–1719, 2017
Management of acute complicated mastoiditis at an urban, tertiary care pediatric hospital
Authors: Ghadersohi Saied , Young Nancy M. , Smith‐Bronstein Virginia , Hoff Stephen , Billings Kathleen R.
Published: October 2016

Objectives/Hypothesis

To describe the presentation and management of acute complicated mastoiditis in children.

Study Design

Retrospective case series.

Methods

An analysis of pediatric patients with acute complicated mastoiditis treated at an urban, tertiary care children's hospital from 2007 to 2014 was performed.

Results

Forty‐eight patients presented with a total of 67 complications of acute mastoiditis. Mean age at presentation was 4.8 years (range = 0.1–15.3 years). The most common complications were subperiosteal abscess (n = 22, 45.8%), epidural abscess (n = 16, 33.3%), and sigmoid sinus thrombosis (n = 14, 29.2%). The most common pathogens isolated included Streptococcus pneumoniae (n = 14, 29.2%) and group A streptococcus (n = 10, 20.8%). Multidrug resistance was not associated with complication type. Surgical management included myringotomy ± tympanostomy tube placement in 46 (95.8%) patients (the only surgery in 10), drainage of subperiosteal abscess without mastoidectomy in 18 (37.5%) patients, and mastoidectomy in 21 (43.8%) total patients. Patients presenting with intracranial complications were the most likely to undergo a mastoidectomy. Anticoagulation was used in the management of nine of 14 (64.3%) patients presenting with sigmoid sinus thrombosis. Neurosurgical interventions (n = 7, 14.6% patients) were primarily performed to manage increased intracranial pressure.

Conclusions

Subperiosteal abscess was the most common complication of acute mastoiditis, and when occurring as the sole complication was successfully managed with antibiotics and surgical intervention that did not include mastoidectomy. Epidural abscess and sigmoid sinus thrombosis were more prevalent than reported in prior series and were managed more aggressively. These patients were more likely to need neurosurgical interventions.

Level of Evidence

4. Laryngoscope, 127:2321–2327, 2017
Innovative Technologies in Nanomedicines: From Passive Targeting to Active Targeting/From Controlled Pharmacokinetics to Controlled Intracellular Pharmacokinetics
Authors: Sato Yusuke , Sakurai Yu , Kajimoto Kazuaki , Nakamura Takashi , Yamada Yuma , Akita Hidetaka , Harashima Hideyoshi
Published: October 2016

Nanomedicines promise to extend drug therapy from small molecular compounds to proteins/nucleic acids/genes. Multifunctional envelope‐type nanodevices (MENDs) have been developed for delivering such molecules to the site of action. The YSK‐MEND contains new types of pH‐responsive cationic lipids to efficiently deliver siRNA to hepatocytes via receptor‐mediated endocytosis and use in treating hepatitis C and B in model mice. The RGD ligand is introduced to target tumor endothelial cells (TEC) and RGD‐MEND is able to send siRNA to TEC to regulate the function of tumor microenvironments. The MITO‐Porter is also developed to target mitochondria via membrane fusion. Antisense oligo RNA in the MITO‐Porter permits the knock down of mitochondrial function. Finally, the ssPalms is designed based on a new concept of pH‐dependent protonation in endosomes and cleavage of SS bonds in the reducing conditions in cytosol. These new technologies promise to stimulate the use of Nanomedicines in the future.

image
Profile‐encoding reconstruction for multiple‐acquisition balanced steady‐state free precession imaging
Authors: Ilicak Efe , Senel Lutfi Kerem , Biyik Erdem , Çukur Tolga
Published: October 2016

Purpose

The scan‐efficiency in multiple‐acquisition balanced steady‐state free precession imaging can be maintained by accelerating and reconstructing each phase‐cycled acquisition individually, but this strategy ignores correlated structural information among acquisitions. Here, an improved acceleration framework is proposed that jointly processes undersampled data across N phase cycles.

Methods

Phase‐cycled imaging is cast as a profile‐encoding problem, modeling each image as an artifact‐free image multiplied with a distinct balanced steady‐state free precession profile. A profile‐encoding reconstruction (PE‐SSFP) is employed to recover missing data by enforcing joint sparsity and total‐variation penalties across phase cycles. PE‐SSFP is compared with individual compressed‐sensing and parallel‐imaging (ESPIRiT) reconstructions.

Results

In the brain and the knee, PE‐SSFP yields improved image quality compared to individual compressed‐sensing and other tested methods particularly for higher N values. On average, PE‐SSFP improves peak SNR by 3.8 ± 3.0 dB (mean ± s.e. across N = 2–8) and structural similarity by 1.4 ± 1.2% over individual compressed‐sensing, and peak SNR by 5.6 ± 0.7 dB and structural similarity by 7.1 ± 0.5% over ESPIRiT.

Conclusion

PE‐SSFP attains improved image quality and preservation of high‐spatial‐frequency information at high acceleration factors, compared to conventional reconstructions. PE‐SSFP is a promising technique for scan‐efficient balanced steady‐state free precession imaging with improved reliability against field inhomogeneity. Magn Reson Med 78:1316–1329, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Gradient and shim pre‐emphasis by inversion of a linear time‐invariant system model
Authors: Vannesjo S. Johanna , Duerst Yolanda , Vionnet Laetitia , Dietrich Benjamin E. , Pavan Matteo , Gross Simon , Barmet Christoph , Pruessmann Klaas P.
Published: October 2016

Purpose

The goal of this contribution is to enhance the fidelity and switching speed of gradient and shim fields by advancing pre‐emphasis toward broadband and full cross‐term correction.

Theory and Methods

The proposed approach is based on viewing gradient and shim chains as linear, time‐invariant (LTI) systems. Pre‐emphasis is accomplished by inversion of a broadband digital system model. In the multiple‐channel case, it amounts to a matrix of broadband filters that perform concerted self‐ and cross‐term correction. This approach is demonstrated with gradients and shims up to the third order in a 7 Tesla whole‐body MR system.

Results

Pre‐emphasis by LTI model inversion is first verified by studying settling speeds and response behavior without and with the correction. It is then demonstrated for rapid shim updating, achieving substantially enhanced fidelity of field dynamics and shim settling within approximately 1 ms. In single‐shot echo‐planar imaging (EPI) acquisitions in vivo, this benefit is shown to translate into enhanced geometric fidelity.

Conclusions

The fidelity of gradient and shim dynamics can be greatly enhanced by pre‐emphasis based on inverting a general LTI system model. Permitting shim settling on the millisecond scale, broadband multiple‐channel pre‐emphasis promises to render higher‐order shimming fully versatile at the level of MRI sequence design. Magn Reson Med 78:1607–1622, 2017. © 2016 International Society for Magnetic Resonance in Medicine.