bluuebunny/crossref_metadata_2025 huggingface dataset:
Unusually low and density-insensitive thermal conductivity of three-dimensional gyroid graphene
Authors: Jung Gang Seob , Yeo Jingjie , Tian Zhiting , Qin Zhao , Buehler Markus J.
Published: August 2017

The thermal transport properties of three-dimensional gyroid graphene show unique scaling law.
A general and convenient palladium-catalyzed synthesis of benzylideneindolin-3-ones with formic acid as the CO source
Authors: Li Rui , Qi Xinxin , Wu Xiao-Feng
Published: August 2017

A general and convenient palladium-catalyzed carbonylative synthesis of 2-benzylideneindolin-3-ones from 2-iodoanilines and arylacetylenes has been developed.
Carbon dots/Fe3O4 hybrid nanofibers as efficient peroxidase mimics for sensitive detection of H2O2 and ascorbic acid
Authors: Chen Sihui , Chi Maoqiang , Yang Zezhou , Gao Mu , Wang Ce , Lu Xiaofeng
Published: August 2017

Carbon dots/Fe3O4 hybrid nanofibers as efficient peroxidase mimics for sensitive detection of H2O2 and ascorbic acid have been developed.
Dumbbell-like, core–shell and Janus-like configurations in Pd@Au@Pd three-shell nanoalloys: a molecular dynamics study
Authors: Akbarzadeh Hamed , Mehrjouei Esmat , Sherafati Mehdi , Shamkhali Amir Nasser
Published: August 2017

Molecular dynamics simulation was used to investigate the thermal stability and the final stable structure of Pd@Au@Pd three-shell nanoparticles after the melting point.
Suzuki–Miyaura cross-coupling of amides and esters at room temperature: correlation with barriers to rotation around C–N and C–O bonds
Authors: Lei Peng , Meng Guangrong , Shi Shicheng , Ling Yun , An Jie , Szostak Roman , Szostak Michal
Published: August 2017

We report the first general palladium-catalyzed Suzuki–Miyaura cross-coupling of both common amides and aryl esters through the selective cleavage of the C–N and C–O bonds at ambient temperature.
MicroRNA-98 interferes with thrombospondin 1 expression in peripheral B cells of patients with asthma
Authors: Chen Liming , Xu Jianfeng , Chu Xiaoxia , Ju Chenghua
Published: August 2017

Thrombospondin 1 (TSP1)-producing B cells are an important immune regulatory cell fraction in the body, which are compromised in a number of immune diseases. miRs are involved in the immune regulation. The present study aims to elucidate the mechanism by which miR-98 interferes with the expression of TSP1 in B cells of the peripheral blood system. In the present study, peripheral blood samples were collected from patients with allergic asthma. The B cells were isolated from the blood samples to be analyzed for the expression of miR-98 and TSP1. The results showed that the levels of miR-98 were higher, the levels of TSP1 were lower, in B cells isolated from the peripheral blood in patients with asthma. A negative correlation was identified between the data of miR-98 and TSP1 in B cells. Exposure to T helper (Th) 2 (Th2) cytokine, interleukin (IL)-13, increased the expression of miR-98 and suppressed the expression of TSP1 in peripheral B cells, which was abolished by knocking down the miR-98 gene. In conclusion, miR-98 can suppress the expression of TSP1 in the peripheral B cells of patients with allergic asthma.
Inhibitory effect of quercetin on titanium particle induced endoplasmic reticulum stress related apoptosis and in vivo osteolysis
Authors: Zhang Laibo , Tian Zhoubin , Li Wei , Wang Xianquan , Man Zhentao , Sun Shui
Published: August 2017

Wear particle induced periprosthetic osteolysis is the main cause of aseptic loosening of orthopedic implants. The aim of the present study is to determine the protective effect of quercetin (QUE) against titanium (Ti) particle induced endoplasmic reticulum stress (ERS) related apoptosis and osteolysis. In the present study, RAW264.7 cells were pretreated with different concentrations (40, 80, and 160 μmol/l) of QUE for 30 min and then treated with Ti particle (5 mg/ml) for 24 h. Cell viability and apoptosis were determined using MTT assay and Annexin V-FITC Apoptosis Detection Kit, respectively. Protein and mRNA expressions of ERS-related genes were examined by Western blot and real-time PCR, respectively. The release of inflammatory cytokines was detected by ELISA. Then, a mouse calvarial osteolysis model was established. Histological sections of calvaria were stained with Hematoxylin-Eosin (H&E) or tartrate-resistant acid phosphatase (TRAP). The results showed that Ti particle reduced cell viability and induced apoptosis in RAW264.7 macrophages. The cytotoxic effects of Ti particle were dramatically inhibited by QUE pretreatment. Interestingly, we found that QUE also significantly reduced Ti particle induced up-regulation of the expression levels of protein kinase RNA-like ER kinase (PERK), inositol-requiring enzyme-1 (IRE1), glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, and caspase-3 and enhanced the down-regulation of Bcl-2. In addition, QUE decreased Ti particle-induced inflammatory cytokines release from RAW264.7 cells. Moreover, treatment with QUE markedly decreased osteoclast number. In a mouse calvarial osteolysis model, QUE inhibited Ti particle induced osteolysis in vivo by inhibiting osteoclast formation and expressions of ERS-related genes. In conclusion, QUE can protect RAW264.7 cells from Ti particle induced ERS-related apoptosis and suppress calvarial osteolysis in vivo.
Transcriptional mechanisms that control expression of the macrophage colony-stimulating factor receptor locus
Authors: Rojo Rocio , Pridans Clare , Langlais David , Hume David A.
Published: August 2017

The proliferation, differentiation, and survival of cells of the macrophage lineage depends upon signals from the macrophage colony-stimulating factor (CSF) receptor (CSF1R). CSF1R is expressed by embryonic macrophages and induced early in adult hematopoiesis, upon commitment of multipotent progenitors to the myeloid lineage. Transcriptional activation of CSF1R requires interaction between members of the E26 transformation-specific family of transcription factors (Ets) (notably PU.1), C/EBP, RUNX, AP-1/ATF, interferon regulatory factor (IRF), STAT, KLF, REL, FUS/TLS (fused in sarcoma/ranslocated in liposarcoma) families, and conserved regulatory elements within the mouse and human CSF1R locus. One element, the Fms-intronic regulatory element (FIRE), within intron 2, is conserved functionally across all the amniotes. Lineage commitment in multipotent progenitors also requires down-regulation of specific transcription factors such as MYB, FLI1, basic leucine zipper transcriptional factor ATF-like (BATF3), GATA-1, and PAX5 that contribute to differentiation of alternative lineages and repress CSF1R transcription. Many of these transcription factors regulate each other, interact at the protein level, and are themselves downstream targets of CSF1R signaling. Control of CSF1R transcription involves feed–forward and feedback signaling in which CSF1R is both a target and a participant; and dysregulation of CSF1R expression and/or function is associated with numerous pathological conditions. In this review, we describe the regulatory network behind CSF1R expression during differentiation and development of cells of the mononuclear phagocyte system.
The Role of Semantic Knowledge in Learning to Read Exception Words
Authors: Dawson Nicola , Ricketts Jessie
Published: August 2017

In research and clinical practice, oral and written language skills have often been treated as separate domains. Yet they do not exist independently. Reading skills are contingent upon earlier acquired oral language skills, and the process of reading fosters growth in oral language. The importance of semantic knowledge for reading comprehension is well-documented, but there is growing evidence that it also plays a significant role in word reading. In English, a distinction can be made between regular words that follow predictable spelling-sound mappings, and exception words that do not. Oral language knowledge may be particularly important for the latter as it functions to supplement partial decoding. For speech- language pathologists (SLPs), it is important to consider how remediation targeted at improving oral language skills may also elicit benefits for reading development, and conversely how reading might be used to support oral language development. Practitioners should be aware of the pattern of literacy impairments that they are likely to encounter in children with developmental language disorder, and how this relates to their oral language profiles. The purpose of this paper is to enable practitioners to generalize their knowledge and skills across the artificial boundaries that have traditionally separated these two domains.
Testing predictors of eruptivity using parametric flux emergence simulations
Authors: Guennou Chloé , Pariat Etienne , Leake James E. , Vilmer Nicole
Published: August 2017

Solar flares and coronal mass ejections (CMEs) are among the most energetic events in the solar system, impacting the near-Earth environment. Flare productivity is empirically known to be correlated with the size and complexity of active regions. Several indicators, based on magnetic field data from active regions, have been tested for flare forecasting in recent years. None of these indicators, or combinations thereof, have yet demonstrated an unambiguous eruption or flare criterion. Furthermore, numerical simulations have been only barely used to test the predictability of these parameters. In this context, we used the 3D parametric magnetohydrodynamic (MHD) numerical simulations of the self-consistent formation of the flux emergence of a twisted flux tube, inducing the formation of stable and unstable magnetic flux ropes of Leake et al. (2013, 2014). We use these numerical simulations to investigate the eruptive signatures observable in various magnetic scalar parameters and provide highlights on data analysis processing. Time series of 2D photospheric-like magnetograms are used from parametric simulations of stable and unstable flux emergence, to compute a list of about 100 different indicators. This list includes parameters previously used for operational forecasting, physical parameters used for the first time, as well as new quantities specifically developed for this purpose. Our results indicate that only parameters measuring the total non-potentiality of active regions associated with magnetic inversion line properties, such as the Falconer parametersLss,WLss,Lsg, andWLsg, as well as the new current integralWLscand lengthLscparameters, present a significant ability to distinguish the eruptive cases of the model from the non-eruptive cases, possibly indicating that they are promising flare and eruption predictors. A preliminary study about the effect of noise on the detection of the eruptive signatures is also proposed.
Recent Advances in the Synthesis of Hydrogenated Azocine-Containing­ Molecules
Authors: Listratova Anna , Voskressensky Leonid
Published: August 2017

This review covers recent advances in synthesis of azocine-containing systems. The most approaches towards azocines are discussed.

1 Introduction

2 Ring-Expansion Reaction

2.1 Ring-Expansion Reaction of Cyclopentane Containing the 1,4-Diketone Moiety with Primary Amines (from 5 to 8)

2.2 Ring-Expansion Reaction of Annulated Tetrahydropyridines under the Action of Activated Alkynes (from 6 to 8)

2.3 Reductive Ring-Expansion Reaction of Cyclic Oximes

2.4 Other Ring-Expansion Reactions

3 Heck Reaction

4 Cycloaddition

5 Ring-Closing Metathesis (RCM)

6 Cyclization

6.1 Metal-Catalyzed Cyclization

6.2 Radical Cyclization

6.3 Friedel–Crafts Cyclization

6.4 Other Examples of Cyclizations

7 Microwave- and Photo-Assisted Reactions

8 Other Methods

8.1 Cascade and Tandem Reactions

8.2 Aldol Condensation

8.3 Thermolysis

8.4 Ring Opening

8.5 Other Methods

9 Conclusion
Can a CT be Omitted in Pediatric Minor Head Trauma?
Authors: Sinzig Maria , Achatz Eveline , Fasching Günter , Arneitz Christoph
Published: August 2017

This study aimed to evaluate the need for radiation exposure in pediatric minor head trauma. Symptomatic patients after minor head trauma were observed for at least 24 hours in a 13-month period. A computed tomography (CT) scan was performed on children with a depressed neurological status. Two hundred fourteen patients with a mean age of 9.3 years were included. An intracranial hemorrhage (ICH) was diagnosed in three (1.4%) patients. The overall CT rate was 10.7%. The study concluded that neuro-observation without initial CT scans is safe in infants and children following minor head trauma. Special pediatric CT protocol can limit radiation exposure.
Deep Inferior Epigastric Perforator Free Flaps for Use in Complicated Groin Wound Repair: A Case Report of Severe Groin Scar Contracture and Review of Pedicled and Free Flaps in Groin Wound Repair
Authors: Sandelin Roger , Klein Richard , Kotick James
Published: August 2017

The use of pedicled and free flaps for tissue transfer and coverage has become a common practice in modern plastic surgery. An area that presents considerable challenge for tissue coverage is the groin. Defects in this area are complicated by issues such as prior surgery; scar contracture; extension of the defect beyond the borders of the groin; radiation damage; high probability of infection; and involvement of vital underlying structures, the genitalia, and perineal and perianal area. Therefore, the choice of donor site and flap usage is often difficult. Multiple methods of tissue transfer closure have been reported in the literature for repair of such defects and are reviewed in the following text. Here the authors present the case of a 30-year-old Caucasian woman born with a congenital giant hairy nevus of her left lower back, buttock, posterior thigh, and flank, who underwent wide local excision and skin grafting as a newborn. After several operations, the closure broke down and was left to heal by secondary intention. She has since developed excessive scar tissue leading to pain with ambulation secondary to scar contracture involving her labia majora. In this report, the wound was repaired with a free DIEP flap with excellent result and resolution of all symptoms.
Testosteronmangel und Demenz
Authors: Dimopoulou Christina , Stalla Günter
Published: August 2017

Was ist neu?

Epidemiologie und Risikofaktoren für Demenz Insgesamt leben in Deutschland gegenwärtig fast 1,6 Mio. Demenzkranke mit Alzheimer als häufigster Ursache. Die Prävalenz der Demenz nimmt mit Alter, weiblichem Geschlecht und niedrigem Bildungsniveau deutlich zu.

Pathophysiologie von Demenz bei Testosteronmangel Neben einem niedrigen Testosteron-Spiegel können auch andere Sexualhormone, metabolisches Syndrom, Diabetes mellitus und Ernährungsgewohnheiten eine Rolle bei schlechter kognitiver Leistung, Demenz und depressiven Symptomen spielen.

Testosteron und Hirnfunktion Ergebnisse aus Zellkultur und Tierversuchen können heutzutage überzeugende Hinweise liefern, dass Testosteron eine protektive Wirkung auf die Hirnfunktion haben könnte. In vivo sind mögliche Effekte einer Testosterontherapie auf die Kognition nach der aktuellen Studienlage umstritten. Weitere multizentrische, randomisierte Studien sind erforderlich, um die Vorteile einer Testosteronsubstitution auf die Kognition älterer Männer zu untersuchen.
Endoskopische Therapie bei gastrointestinalen Neoplasien
Authors: Bruun Sabine , Knabe Mate , Ell Christian
Published: August 2017

Was ist neu?

Endoskopische Resektionstechniken Mit der endoskopischen Submukosadissektion (ESD) können auch größere Läsionen en bloc reseziert werden. Eine Weiterentwicklung der ESD sind Tunnelungstechniken, die bis dato nur in kleineren Pilotserien durchgeführt wurden. Mit der endoskopischen Vollwandresektion können Läsionen, die mit den konventionellen Techniken nicht entfernt werden können, reseziert werden.

Ablative Verfahren Ein neues Verfahren zur Ablation von gastrointestinalen Neoplasien ist die Hybrid-APC, hierbei wird die Argon-Plasma-Koagulation (APC)-Therapie mit einer vorherigen Unterspritzung kombiniert, wodurch die Rate an Strikturen gesenkt werden soll.

Endoskopische Therapie in der Palliation Neue Innovationen in der Palliation sind die endosonografische Gastroenterostomie, die endosonografisch gesteuerte Radiofrequenzablation solider Tumoren und die endoskopisch retrograde Cholangiopankreatografie mit Radiofrequenzablation.
Three modalities on common bile duct exploration
Authors: Zhou Yong , Wu Xu-Dong , Zha Wen-Zhang , Fan Ren-Gen , Zhang Biao , Xu Yong-Hua , Qin Cheng-Lin , Jia Jing
Published: August 2017

Background Choledocholithiasis can be managed by transcystic (TC) and transduct (TD) stone extraction or using cholangioscopy through the left hepatic duct orifice (LHD).

Objective The aim of this study is to evaluate the safety and effectiveness of common bile duct exploration through the TC approach, TD approach, and LHD approach for choledocholithiasis, with a specific emphasis on the TC and LHD approaches versus the TD approach.

Methods Between January 2011 and June 2014, a total of 172 choledocholithiasis patients accompanied by cholecystitis and/or left intrahepatic gallstones were scheduled for laparoscopic or open common bile duct (CBD) exploration using cholangioscopy through the CBD (TD group: n = 72), cystic duct (TC group: n = 63), or LHD orifice (LHD group: n = 37). T-tube insertion was performed in selected patients. Patients were regularly followed up at bimonthly intervals or more frequently in presence of any symptom. Primary outcomes measures included overall operative time, length of hospital stay, and postoperative bile leaks.

Results Successful bile duct clearance was 100 % in the TD group, 93.6 % in the TC group, and 90.9 % in the LHD group. Sixteen cases in the TD group had T-tube placement in contrast to no cases in the TC and LHD groups. There were more bile leaks after TD stone extraction (12.5 %) than TC (3.2 %) and LHD stone extraction (0 %), which prolonged hospitalization in the TD group more than in the TC and LHD groups. For choledocholithiasis patients accompanied by cholecystitis, 2 groups (TC and TD groups) were comparable in operative time. However, for choledocholithiasis patients accompanied by left intrahepatic gallstones, the LHD group had a significantly shorter operative time than the TD group (121.1 ± 16.9 minutes vs. 149.3 ± 42.8 minutes, p < 0.05).

Conclusion The TD group had a higher stone clearance rate but was associated with a higher risk of bile leaks. TC and LHD stone extraction, which seems to be the more effective approach with lower complication rates, is an accessible technique that simplifies the operation procedure by avoiding choledochotomy and subsequent T-tube insertion.
Innere Medizin im G-DRG-System
Authors: Siam Kristina , Roeder Norbert , Fölsch Ulrich , Spies Hans-Friedrich
Published: August 2017

Hintergrund In der Deutschen Gesellschaft für Innere Medizin (DGIM) und dem Berufsverband Deutscher Internisten (BDI) gab es immer wieder Diskussionen zur sachgerechten Abbildung und Vergütung von Leistungen der Inneren Medizin im G-DRG-System.

Methode Insbesondere Fälle mit einer deutlich verlängerten Verweildauer wurden in einem multizentrischen Projekt analysiert. 124 Behandlungsfällen aus 6 Krankenhäusern wurden in der Analyse berücksichtigt.

Ergebnisse Die Ergebnisse zeigten, dass eine beobachtete deutliche Verlängerung der Verweildauer vorrangig auf medizinische Gründe zurückzuführen war.

Diskussion Die Hypothese, dass dabei insbesondere Patienten mit unklarer Symptomatik und umfassend notwendiger Differenzialdiagnostik eine besonders lange Verweildauer aufweisen, konnte zumindest anhand der analysierten Stichprobe nicht bestätigt werden. Vielmehr begründeten Komplikationen während der Behandlung sowie Komorbiditäten die längere Verweildauer. Die Ergebnisse geben auch Hinweise auf verlängerte Hospitalisierungen trotz abgeschlossener akutstationärer Krankenhausbehandlung, da die poststationäre Weiterbehandlung beispielsweise aufgrund fehlender oder vom Kostenträger nicht bewilligter Weiterversorgungsmöglichkeiten wie Rehabilitationsplätze nicht zeitgerecht geklärt ist.
Die Ribeiro-Technik bei Gigantomastie – Review von 294 Reduktionsplastiken in 8 Jahren
Authors: Wolter Andreas , Pluto Naja , Scholz Till , Diedrichson Jens , Arens-Landwehr Andreas , Liebau Jutta
Published: August 2017

Hintergrund Eine Mammareduktionplastik bei Gigantomastie stellt eine Herausforderung in der Mammachirurgie selbst bei sehr erfahrenen
plastischen Chirurgen dar. Extrem lange Mamillenstiele beeinträchtigen die Blutversorgung des Mamillenareolenkomplexes. Der massiv gedehnte
Hautmantel erschwert die Brustformung und effektive Reduktion. Die Ribeiro-Technik stellt einen etablierten Standard zur Mammareduktion in
unserer Klinik dar. Ziel der Studie war ein Review unserer Vorgehensweise bei Gigantomastie im Vergleich mit der aktuellen Literatur.

Patienten und Methoden Im Zeitraum von 01/2009–12/2016 erfolgten in unserer Klinik bei 760 Patientinnen 1247 Mammareduktionsplastiken.
In 294 Reduktionen (23,6 %) war das Einschlusskriterium der Gigantomastie (Resektionsgewicht > 1000 g pro Brust) erfüllt. Die Technik
nach Ribeiro mit superomedialer Mamillenstielung und Bildung eines inferioren dermoglandulären Lappens zur Auffüllung des oberen Brustpols
und Prävention eines bottoming outs wurde als Standard implementiert. Bei Patientinnen mit einem Mamillen-Jugulum-Abstand von > 40 cm
erfolgte eine freie Brustwarzentransplantation. Die Outcome-Parameter Komplikationsrate, Patientenzufriedenheit, Brustwarzensensibilität und
Notwendigkeit einer Korrekturoperation wurden retrospektiv überprüft.

Ergebnisse Bei 174 Patientinnen erfolgten 294 Mammareduktionsplastiken mit mehr als 1000 g pro Brust. Das Resektionsgewicht lag im
Mittel bei 1389,6 g pro Brust (1000–4580 g). Das Durchschnittsalter betrug 43,5 (18–76) Jahre, der durchschnittliche Body-Mass-Index (BMI)
war 29,2 (19–40) kg/m2, der durchschnittliche Mamillen-Jugulum-Abstand war 34,8 (27–52) cm, die durchschnittliche OP-Dauer betrug
117 (72–213) Minuten. Bei 30 Reduktionen erfolgte eine freie Brustwarzentransplantation. Die Komplikationsrate lag bei insgesamt 7,8 %.
Korrekturoperationen erfolgten in 16 %. 93 % der Patientinnen waren „sehr zufrieden“ bis „zufrieden“ mit dem ästhetischen Ergebnis bei in
88 % „sehr gut“ bis „gut“ erhaltener Brustwarzensensibilität.

Fazit Bei der Ribeiro-Technik handelt es sich um eine gut etablierte, vielseitig einsetzbare Standardtechnik zur Mammareduktion, die
reproduzierbare, formstabile Ergebnisse in hoher Qualität liefert. Bei Patientinnen mit Gigantomastie stellt dieses Verfahren ebenso eine
effektive komplikationsarme Methode dar, um eine Volumenreduktion mit ästhetisch sehr zufriedenstellenden Ergebnissen zu erreichen.
4.4.19.4 Silyl Sulfides and Selenides (Update 2017)
Authors: Baker A. , Wirth T.
Published: August 2017

This chapter is an update to the earlier Science of Synthesis contribution describing methods for the synthesis of silyl sulfides and silyl selenides. Various efficient synthetic routes to these compounds are shown. The use of disilyl sulfides and disilyl selenides as versatile reagents in synthesis is highlighted.
4.4.7 Product Subclass 7: Silylboron Reagents
Authors: Delvos L. , Oestreich M.
Published: August 2017

This update describes the development of silylboron chemistry since the initial summary in Science of Synthesis by Hemeon and Singer in 2002. In the first part, an overview of the methods to prepare silylboron reagents by nucleophilic substitution, Si-H bond activation, or reductive coupling is provided, and possibilities for further functionalization are presented. The second section comprehensively covers all aspects of the synthetic applications of silylboron compounds, ranging from transition-metal catalysis to transmetalation reactions and Si-B bond activation with Lewis bases. The presented methodologies include silaboration and silylation of unsaturated carbon–carbon bonds, addition and substitution reactions with nucleophilic silicon reagents, silaboration of strained rings under C-C bond cleavage, and Si-B insertion reactions of carbenoids and related compounds.
10.22.4 Product Subclass 4: 1,2-Dihydroazaindol-3-ones
Authors: Mérour J.-Y. , Joseph B.
Published: August 2017

This chapter reviews the synthesis and reactivity of 1,2-dihydroazaindol-3-ones (azaindoxyls) and related 1,2-dihydroazaindol-3-yl acetates. Synthetic preparations are reviewed for all isomers except for 1,2-dihydro-3H-pyrrolo[2,3-c]pyridin-3-ones.
10.22.5 Product Subclass 5: 1H-Azaindole-2,3-diones
Authors: Mérour J.-Y. , Joseph B.
Published: August 2017

This chapter reviews the synthesis and reactivity of 1H-azaindole-2,3-diones (azaisatins). It focuses on the literature published until mid-2014. Synthetic preparations are reviewed for 1H-pyrrolo[3,2-b]pyridine-2,3-diones, 1H-pyrrolo[3,2-c]pyridine-2,3-diones, and 1H-pyrrolo[2,3-b]pyridine-2,3-diones.
10.22.6 Product Subclass 6: Azaindol-2- and Azaindol-3-amines
Authors: Mérour J.-Y. , Joseph B.
Published: August 2017

This chapter presents methods for the preparation of azaindol-2-amines and azaindol-3-amines published in the literature until mid-2014. Synthetic methods are described for each isomer.
21.17 Synthesis of Amides (Including Peptides) in Continuous-Flow Reactors
Authors: Ramesh S. , Cherkupally P. , Govender T. , Kruger H. G. , de la Torre B. G. , Albericio F.
Published: August 2017

Microreactors are powerful tools which present excellent mass- and heat-transfer performance properties for various kinds of chemical reaction. In this chapter, we present a brief introduction to microreactors, followed by an overview of the different microfluidic methods available for the synthesis of amides (including peptides). The range of peptides obtained via microreactor use includes di- to pentapeptides and also some cyclic analogues. Other continuous-flow reactions involving amide-bond formation are also illustrated, including examples of carbonylation, dendrimer preparation, and drug synthesis. The noteworthy features of these microfluidic reactions include shorter reaction times, high yields, and significantly less wastage. They are thus a step toward environmentally friendly, green reactions.
34.1.4.3 Synthesis of Fluoroalkanes by Substitution of Oxygen and Sulfur Functionalities
Authors: Lequeux T. P.
Published: August 2017

This chapter is a revision of the earlier Science of Synthesis contribution describing methods for the synthesis of fluoroalkanes by substitution of oxygen and sulfur functionalities. It now includes the literature published up until 2016. The additional material focuses on new reagents and their applications. For example, the effect of an ionic liquid on the rate of the displacement of sulfonates by cesium fluoride, and expeditious synthesis of nucleoside derivatives are described.
34.3.2 (Fluoromethyl)cyclopropanes (Update 2017)
Authors: Jubault P. , Poisson T. , Pannecoucke X.
Published: August 2017

This chapter is an update to the earlier Science of Synthesis contribution (Section 34.3) describing methods for the synthesis of (fluoromethyl)cyclopropanes. In this review, new methods, published since 2006, by means of direct or two-step fluorodehydroxylation and by rearrangement of fluoroepoxides are described.
34.4.2 Fluorocyclobutanes (Update 2017)
Authors: Poisson T. , Jubault P. , Pannecoucke X.
Published: August 2017

This chapter is an update to the earlier Science of Synthesis contribution (Section 34.4) describing methods for the synthesis of fluorocyclobutanes. In this review, progress made in the field since 2006 is reported. The use of cycloaddition reactions as well as rearrangement reactions to access the fluorocyclobutane motif are significant advances in this area.
35.1.5.1.12 Synthesis of 1-Chloro-n-Heteroatom-Functionalized Alkanes (n ≥2) by Addition across C=C Bonds (Update 2017)
Authors: Wirth T. , Singh F. V.
Published: August 2017

Chlorination of alkenes is an important synthetic process in organic chemistry. Several approaches for the chlorination of alkenes have been developed, including dichlorination, aminochlorination, halochlorination, oxychlorination, sulfanylchlorination, trihalomethylchlorination, and azidochlorination. Various inorganic and organic chlorides have been used as the source of chlorine, including alkali metal chlorides, tetrabutylammonium chloride, N-chlorosuccinimide, and (dichloroiodo)benzene. In this section, numerous approaches for the chlorination of alkenes using different inorganic and organic chlorides as source of chlorine, to give 1-chloro-n-heteroatom-functionalized alkanes, are discussed.
35.2.2.2 Propargylic Bromides (Update 2017)
Authors: Braun M.
Published: August 2017

This chapter is an update to the earlier Science of Synthesis contribution describing the synthesis of propargylic bromides. The focus in this update is on synthesis by substitution of propargylic alcohols and protected derivatives thereof.
35.2.3.3.3 Synthesis of Benzylic Bromides by Substitution of σ-Bonded Heteroatoms (Update 2017)
Authors: Braun M.
Published: August 2017

This chapter is an update to the earlier Science of Synthesis contribution describing the synthesis of benzylic bromides by substitution of σ-bonded heteroatoms. In this update, the focus is on the substitution of hydroxy groups.
Instrumentation for electrochemical performance characterization of neural electrodes
Authors: Marsh Michael P. , Kruchowski James N. , Hara Seth A. , McIntosh Malcom B. , Forsman Renae M. , Reed Terry L. , Kimble Christopher , Lee Kendall H. , Bennet Kevin E. , Tomshine Jonathan R.
Published: August 2017

In an effort to determine the chronic stability, sensitivity, and thus the potential viability of various neurochemical recording electrode designs and compositions, we have developed a custom device called the Voltammetry Instrument for Neurochemical Applications (VINA). Here, we describe the design of the VINA and initial testing of its functionality for prototype neurochemical sensing electrodes. The VINA consists of multiple electrode fixtures, a flowing electrolyte bath, associated reservoirs, peristaltic pump, voltage waveform generator, data acquisition hardware, and system software written in National Instrument’s LabVIEW. The operation of VINA was demonstrated on a set of boron-doped diamond neurochemical recording electrodes, which were subjected to an applied waveform for a period of eighteen days. Each electrode’s cyclic voltammograms (CVs) were recorded, and sensitivity calibration to dopamine (DA) was performed. Results showed an initial decline with subsequent stabilization in the CV current measured during the voltammetric sweep, corresponding closely with changes in electrode sensitivity to DA. The VINA has demonstrated itself as a useful tool for the characterization of electrode stability and chronic electrochemical performance.
Design of electrical layout of offshore wind farms
Authors: Dhali Shirshak K. , Nandigam Mahidhar
Published: August 2017

The cost and efficiency of offshore wind farms are determined by a variety of factors which include the type of electrical system (AC or DC), transmission length, transmission voltage, rated power, wind turbine type, farm topology, and wind speed. Since the design variable space is large for such problems, computational optimization is necessary to find an optimal solution. This paper discusses a design methodology to determine the optimal values of components to minimize the cost of an offshore wind farm. The cost, loss, reliability models, and the application of geometric programing for optimization of the layout and configuration of an offshore wind farm are presented. The results include how ratings of individual components are influenced by the loss, reliability, and area constraints in order to minimize the cost. Also, the total capacity of the wind farm determines the optimum components to minimize the cost. The cost of energy production and cost per installed kW are comparable well with existing wind farms and other published data.
Algorithmic developments of the kinetic activation-relaxation technique: Accessing long-time kinetics of larger and more complex systems
Authors: Trochet Mickaël , Sauvé-Lacoursière Alecsandre , Mousseau Normand
Published: August 2017

In spite of the considerable computer speed increase of the last decades, long-time atomic simulations remain a challenge and most molecular dynamical simulations are limited to 1 μs at the very best in condensed matter and materials science. There is a need, therefore, for accelerated methods that can bridge the gap between the full dynamical description of molecular dynamics and experimentally relevant time scales. This is the goal of the kinetic Activation-Relaxation Technique (k-ART), an off-lattice kinetic Monte-Carlo method with on-the-fly catalog building capabilities based on the topological tool NAUTY and the open-ended search method Activation-Relaxation Technique (ART nouveau) that has been applied with success to the study of long-time kinetics of complex materials, including grain boundaries, alloys, and amorphous materials. We present a number of recent algorithmic additions, including the use of local force calculation, two-level parallelization, improved topological description, and biased sampling and show how they perform on two applications linked to defect diffusion and relaxation after ion bombardement in Si.
Quaternionic formulation of the two-component Kohn-Sham equations and efficient exploitation of point group symmetry
Authors: Armbruster Markus K.
Published: August 2017

The quaternionic formulation of the time-reversal invariant quasirelativistic Kohn-Sham equations with exact Hartree-Fock exchange leads to hypercomplex one-component equations with half of the dimension compared to the original two-component problem. The combination of the quaternionic equations with point group symmetry exploitation for D2h and its subgroups by construction of corepresentations leads to quaternionic, complex, or real algorithms depending on the structure of the point group. In this work, the quaternionic approach with point group symmetry exploitation of the relativistic four-component Dirac-Hartree-Fock theory by Saue and Jensen [J. Chem. Phys. 111, 6211 (1999)] will be adopted to the quasirelativistic two-component Kohn-Sham scheme for closed-shell systems. The implementation in the program system TURBOMOLE is applied to the large lead cluster Pb56 as a test case.
Cyclic flattened Brazilian disc tests for measuring the tensile fatigue properties of brittle rocks
Authors: Liu Yi , Dai Feng , Xu Nuwen , Zhao Tao
Published: August 2017

We propose a cyclic flattened Brazilian disc (FBD) testing method to measure the tensile fatigue properties of brittle rocks. Our method has obvious merits in its specimen preparation and experimental operation. Two parallel flattens are introduced in the disc specimen, which facilitate easily and uniformly loading the specimen without special loading devices required. Moreover, the contact regions between two flattens and loading planes barely change during the entire loading and unloading process, ensuring a consistent contact condition. With certain appropriate loading angles, this method guarantees that the very first breakage of the specimen occurs at the center of the disc, which is the prerequisite of the Brazilian-type indirect tensile tests. To demonstrate our new method, nine cyclic FBD tensile tests are conducted. The fatigue load-deformation characteristics of FBD specimens are revealed. The tensile fatigue lives of tested specimens are observed to increase with the increase in cyclic loading frequency. Our proposed method provides a convenient and reliable approach to indirectly measure the fatigue tensile properties of brittle rocks and other brittle solids subjected to cyclic tensile loadings.
Interfacial colloidal rod dynamics: Coefficients, simulations, and analysis
Authors: Yang Yuguang , Bevan Michael A.
Published: August 2017

Colloidal rod diffusion near a wall is modeled and simulated based on a constrained Stokesian dynamic model of chains-of-spheres. By modeling colloidal rods as chains-of-spheres, complete diffusion tensors are computed for colloidal rods in bulk media and near interfaces, including hydrodynamic interactions, translation-rotation coupling, and all diffusion modes in the particle and lab frames. Simulated trajectories based on the chain-of-spheres diffusion tensor are quantified in terms of typical experimental quantities such as mean squared positional and angular displacements as well as autocorrelation functions. Theoretical expressions are reported to predict measured average diffusivities as well as the crossover from short-time anisotropic translational diffusion along the rod’s major axis to isotropic diffusion. Diffusion modes are quantified in terms of closed form empirical fits to model results to aid their use in interpretation and prediction of experiments involving colloidal rod diffusion in interfacial and confined systems.
Three-dimensional flow with elevated helicity in driven cavity by parallel walls moving in perpendicular directions
Authors: Povitsky Alex
Published: August 2017

The proposed flow in a 3-D cubic cavity is driven by its parallel walls moving in perpendicular directions to create a genuinely three-dimensional highly separated vortical flow, yet having simple single-block cubical geometry of computational domain. The elevated level of helicity is caused by motion of a wall in the direction of axis of primary vortex created by a parallel wall. The velocity vector field is obtained numerically by using second-order upwind scheme and 2003 grid. Helicity, magnitude of normalized helicity, and kinematic vorticity number are evaluated for Reynolds numbers ranging from 100 to 1000. Formation of two primary vortices with their axis oriented perpendicularly and patterns of secondary vortices are discussed. Computational results are compared to the well-known 3-D recirculating cavity flow case where the lid moves in the direction parallel to the cavity side walls. Also results are compared to the diagonally top-driven cavity and to the cavity flow driven by moving top and side walls. The streamlines for the proposed flow show that the particles emerging from top and bottom of the cavity do mix well. Quantitative evaluation of mixing of two fluids in the proposed cavity flow confirms that mixing occurs faster than in the benchmark case.
Source reconstruction for neutron coded-aperture imaging: A sparse method
Authors: Wang Dongming , Hu Huasi , Zhang Fengna , Jia Qinggang
Published: August 2017

Neutron coded-aperture imaging has been developed as an important diagnostic for inertial fusion studies in recent decades. It is used to measure the distribution of neutrons produced in deuterium-tritium plasma. Source reconstruction is an essential part of the coded-aperture imaging. In this paper, we applied a sparse reconstruction method to neutron source reconstruction. This method takes advantage of the sparsity of the source image. Monte Carlo neutron transport simulations were performed to obtain the system response. An interpolation method was used while obtaining the spatially variant point spread functions on each point of the source in order to reduce the number of point spread functions that needs to be calculated by the Monte Carlo method. Source reconstructions from simulated images show that the sparse reconstruction method can result in higher signal-to-noise ratio and less distortion at a relatively high statistical noise level.
Strain-driven diffusion process during silicon oxidation investigated by coupling density functional theory and activation relaxation technique
Authors: Salles N. , Richard N. , Mousseau N. , Hemeryck A.
Published: August 2017

The reaction of oxygen molecules on an oxidized silicon model-substrate is investigated using an efficient potential energy hypersurface exploration that provides a rich picture of the associated energy landscape, energy barriers, and insertion mechanisms. Oxygen molecules are brought in, one by one, onto an oxidized silicon substrate, and accurate pathways for sublayer oxidation are identified through the coupling of density functional theory to the activation relaxation technique nouveau, an open-ended unbiased reaction pathway searching method, allowing full exploration of potential energy surface. We show that strain energy increases with O coverage, driving the kinetics of diffusion at the Si/SiO2 interface in the interfacial layer and deeper into the bulk: at low coverage, interface reconstruction dominates while at high coverage, oxygen diffusion at the interface or even deeper into the bottom layers is favored. A changing trend in energetics is observed that favors atomic diffusions to occur at high coverage while they appear to be unlikely at low coverage. Upon increasing coverage, strain is accumulated at the interface, allowing the oxygen atom to diffuse as the strain becomes large enough. The observed atomic diffusion at the interface releases the accumulated strain, which is consistent with a layer-by-layer oxidation growth.
Insight into the split and asymmetry of charge distribution in biased M-structure superlattice
Authors: Liu Lu , Bi Han , Zhao Yunhao , Zhao Xuebing , Han Xi , Wang Guowei , Xu Yingqiang , Li Yuesheng , Che Renchao
Published: August 2017

The charge distribution in real space of an insertion variant based on an InAs/GaSb superlattice for an infrared detector is illustrated by in situ electron microscopy. The localization split of positive charge can be directly observed in the InAs/GaSb/AlSb/GaSb superlattice (M-structure) rather than in the InAs/GaSb superlattice. With the applied bias increasing from 0 to 4.5 V, the double peaks of positive charge density become asymmetrical gradually, with the peak integral ratio ranging from 1.13 to 2.54. Simultaneously, the negative charges move along the direction of the negative electric field. Without inserting the AlSb layer, the charge inversion occurs in both the hole wells and the electron wells of the InAs/GaSb superlattice under high bias. Such a discrepancy between the M-structure superlattice and the traditional superlattice suggests an effective reduction of tunneling probability of the M-structure design. Our result is of great help to understand the carrier immigration mechanism of the superlattice-based infrared detector.
First-principles study of intersite magnetic couplings in NdFe12 and NdFe12X (X = B, C, N, O, F)
Authors: Fukazawa Taro , Akai Hisazumi , Harashima Yosuke , Miyake Takashi
Published: August 2017

We present a first-principles investigation of NdFe12 and NdFe12X (X = B, C, N, O, and F) crystals with the ThMn12 structure. Intersite magnetic couplings in these compounds, the so-called exchange couplings, are estimated by using Liechtenstein's method. It is found that the Nd–Fe couplings are sensitive to the interstitial dopant X, with the Nd–Fe(8j) coupling in particular reduced significantly for X = N. This suggests that magnetocrystalline anisotropy decays quickly with rising temperature in the X = N system although nitrogenation has advantages over other dopants in terms of enhancing low-temperature magnetic properties. The Curie temperature is also calculated from the magnetic couplings by using the mean field approximation. Introduction of X enhances the Curie temperature, with both structural changes and chemical effects found to play important roles in this enhancement.
East coast scientists develop method to optimize offshore wind farms
Authors: Lugo Ryan
Published: August 2017

Using computational analysis, researchers developed a method for wind farm optimization to minimize cost, maximize reliability and minimize electrical loss.
Forecasting on first generation bioethanol production: A comparison of selected linear and non-linear models
Authors: Bayrakdar Ates Ezgi , Barutcu Burak , Karaosmanoglu Filiz
Published: August 2017

Sustainable bioethanol production depends on the continuity of feedstock supply. Thus, an appropriate tool for feedstock supply forecasting is necessary for bioethanol production. This study was aimed at using forecasting models to predict feedstock supply and then estimating how much bioethanol could be produced from the forecasted bioethanol feedstocks as a major investigation in Turkey. It focused on running the linear model as Auto-Regressive (AR) and non-linear models as Auto-Regressive eXogeneous (ARX) and Auto-Regressive Moving Average eXogeneous (ARMAX) to forecast annual potential of wheat, corn, barley, and sugar beet which could be used as feedstock to produce first generation bioethanol. First, model order determination and modeling of feedstock production were studied for long prediction horizons. Model orders were estimated with major model order selection criteria: Akaike Information Criterion (AIC) and Final Prediction Error in the AR model. The same model orders were also used for the ARX model to compare, whereas model orders were determined based on the performance of the ARMAX model. Second, model performances were tested using Root Mean Square, R2, Chi-Square (χ2), and AIC for optimum model orders of each series. Finally, feedstock forecasts were determined to be quantitatively consistent for each model and with legal authority predictions. There were negligible small differences ranging from 0.8% to 2%. It is concluded that barley and wheat supplies have significant potential to produce bioethanol except for their primary use in food, seed, and feed consumption. However, sugar beet and corn are mainly used in Turkey.
Giant nonlinear ion acoustic waves that “phase-lock” in a plasma
Authors: Blaustein Rich
Published: August 2017

Researchers demonstrate that ion acoustic waves in a plasma can be in autoresonance for significant durations and reach extreme nonlinear states.
Sodium bromide additive improved film morphology and performance in perovskite light-emitting diodes
Authors: Li Jinghai , Cai Feilong , Yang Liyan , Ye Fanghao , Zhang Jinghui , Gurney Robert S. , Liu Dan , Wang Tao
Published: August 2017

Organometal halide perovskite is a promising material to fabricate light-emitting diodes (LEDs) via solution processing due to its exceptional optoelectronic properties. However, incomplete precursor conversion and various defect states in the perovskite light-emitting layer lead to low luminance and external quantum efficiency of perovskite LEDs. We show here the addition of an optimum amount of sodium bromide in the methylammonium lead bromide (MAPbBr3) precursor during a one-step perovskite solution casting process can effectively improve the film coverage, enhance the crystallinity, and passivate ionic defects on the surface of MAPbBr3 crystal grains, resulting in LEDs with a reduced turn-on voltage from 2.8 to 2.3 V and an enhanced maximum luminance from 1059 to 6942 Cd/m2 when comparing with the pristine perovskite-based device.
Impact of glacial/interglacial sea level change on the ocean nitrogen cycle
Authors: Ren Haojia , Sigman Daniel M. , Martínez-García Alfredo , Anderson Robert F. , Chen Min-Te , Ravelo Ana Christina , Straub Marietta , Wong George T. F. , Haug Gerald H.
Published: August 2017

Significance

Biologically available nitrogen (fixed N) limits the fertility of much of the ocean. Of the processes that remove fixed N from the ocean, conversion to N
2
in coastal sediments appears to dominate. This work provides the strongest data-based support for the long-standing hypothesis of changes in N loss along the ocean margin due to the cyclic drowning and emergence of the continental shelves. The data also imply strong local coupling of N loss to N
2
fixation, the dominant N input to the ocean, thus suggesting a stable oceanic fixed N reservoir over glacial cycles. Finally, this work points to glacial/interglacial oscillations in the biogeochemical fluxes at and near the ocean margins that would have influenced the evolution of coastal species.