bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnosis and treatment of resistant periapical pathoses at the maxillary anterior region
Authors: Pinto Antonione Santos Bezerra , Galvao Neiandro dos Santos , Dias Luis Paulo da Silva , Mendes Jean de Pinho , Lopes Sérgio Lúcio Pereira de Castro , Costa André Luiz Ferreira
Published: February 2017

The objective of this study was to report a clinical case of periapical pathosis at the maxillary anterior region which was resistant to conventional endodontic treatment and discuss the contribution of the magnetic resonance imaging (MRI) to the diagnostic process. Female patient aged 43 years old was referred to specialised dental care following unsuccessful endodontic treatment of tooth #11, which had been carried out after presumptive diagnosis of granuloma or root cyst. For a better evaluation, periapical radiography, cone beam computed tomography and MRI exam were all indicated. By means of these exams, one could observe the presence of another lesion at the region of tooth #13, which was suggestive of residual cyst. On MRI scan, the T2WI of the lesions showed hypersignal areas compatible to inflammatory process. Surgery excision of the lesions and apicoectomy of tooth #11 were the treatments chosen, including further referral for histopathological exam. Final diagnosis of both lesions was non-specific inflammatory process or dental granuloma. Clinical-radiographic control showed area of new bone formation, thus evidencing bone repair process. One can conclude that the diagnosis and treatment of periapical pathoses may be challenging and that MRI contributed by providing important information on the nature and content of these lesions.
Gaining economic profit or losing cultural security: Framing persuasive arguments for two types of conservatives
Authors: Eschert Silke , Diehl Michael , Ziegler René
Published: February 2017

Recent research suggests that different motivational bases underlie economic and cultural conservatism. Different political messages may address these different motivational bases. This article investigates the hypothesis that gain frames and achievement frames are more persuasive for participants high in economic conservatism and for economic conservative political issues, whereas loss and security frames are more persuasive for participants high in cultural conservatism and for cultural conservative political issues. Indeed, differential framing effects were found for economic versus cultural conservative issues across two experimental studies (N = 111 and N = 234). Study 2 could show that these effects were also significantly moderated by individual economic and cultural conservatism. Political arguments were perceived as most persuasive when argument frames matched both the issue at hand and recipient’s individual conservatism. Theoretical implications are discussed with regard to the motivational bases of two dimensions of conservatism along with practical implications for the field of political communication.
Dynamic contribution of recycled components from the subducted Pacific slab: Oxygen isotopic composition of the basalts from 106 Ma to 60 Ma in North China Craton
Authors: Liu Jia , Wang Zi‐Zhen , Yu Hao‐Ran , Xia Qun‐Ke , Deloule Etienne , Feng Min
Published: February 2017

How the materials derived from the stagnant Pacific slab contributed to the mantle sources of the mafic rocks in east China is still in hot debate. In this work, δ18O (Vienna standard mean ocean water) values of clinopyroxene phenocrysts in the oceanic island basalts (OIB)‐type mafic rocks from 106 Ma to 60 Ma in the east North China Craton (NCC) were measured by secondary ion mass spectrometry. Our data show that for all of the samples, the δ18Ocpx are dominantly higher than that of the clinopyroxene from normal mid‐oceanic ridge basalt (5.4–5.8‰), which confirms the role of recycled oceanic crust (ROC) in their mantle sources. Combining the δ18O data of basalts and the lithospheric mantle in the literature, we found that in the southeast NCC, upper and lower ROC components alternately appeared in the mantle sources of basalts, but these ROC components are consistently different from that in the lithospheric mantle, while in the northern NCC, the recycled components in the sources seem to be persistently from upper ROC. These observations suggest that (1) these mafic OIB‐type rocks are most likely derived from the convective asthenosphere and (2) the contribution of components from the Pacific oceanic slab into the NCC upper mantle was dynamic, without a simple temporal trend. This new knowledge calls for the reconsideration of the existing models of the thinning process of the NCC lithospheric mantle, and it warns against simply using the chemical composition of basalts to infer the evolution of lithosphere.
Eocene adakitic porphyries in the central‐northern Qiangtang Block, central Tibet: Partial melting of thickened lower crust and implications for initial surface uplifting of the plateau
Authors: Ou Quan , Wang Qiang , Wyman Derek A. , Zhang Hai‐Xiang , Yang Jin‐Hui , Zeng Ji‐Peng , Hao Lu‐Lu , Chen Yi‐Wei , Liang He , Qi Yue
Published: February 2017

The time and mechanism of crustal thickening and initial surface uplift of the Tibetan Plateau remain highly controversial. Here we report on zircon U‐Pb age, and mineral, element, and Sr‐Nd isotope composition data for Eocene adakitic porphyries in the Laorite Co area of central‐northern Qiangtang Block, central Tibet. Laser ablation‐inductively coupled plasma‐mass spectrometry zircon U‐Pb age dating shows that the porphyries were generated at 42–41 Ma. All samples display adakitic geochemical characteristics, such as high SiO2 and Al2O3, and low Y and Yb contents, and high Sr/Y and La/Yb ratios with positive Sr and negligible Eu anomalies and Nb‐Ta depletion. They also have low magnesium number (Mg #) (16–45) and high K2O (4.0–4.6 wt %) values, as well as high (87Sr/86Sr)i (0.7076–0.7080) and low εNd(t) (−5.9 to −4.4) values. These adakitic rocks were most probably generated by partial melting of thickened lower crust in the stability field of garnet, amphibole, and rutile but with relatively minor plagioclase. Moreover, such a crustal thickening process beneath this block likely occurred no later than the middle Eocene and was most probably caused by the southward subduction of the Songpan‐Ganzi Block in the early Cenozoic. In addition, the occurrences of exposed adakitic porphyries unambiguously indicate that exhumation process occurred after their formation. Thus, these ~42 Ma adakitic porphyries indicate the occurrence of significant exhumation since 42 Ma. Integrated with the thermochronological and paleoelevation data, we suggest that the initial surface uplift of the Qiangtang Block, triggered by crustal thickening, was underway by the middle Eocene (~42 Ma).
Remagnetization of the Paleogene Tibetan Himalayan carbonate rocks in the Gamba area: Implications for reconstructing the lower plate in the India‐Asia collision
Authors: Huang Wentao , Lippert Peter C. , Jackson Michael J. , Dekkers Mark J. , Zhang Yang , Li Juan , Guo Zhaojie , Kapp Paul , van Hinsbergen Douwe J. J.
Published: February 2017

The characteristic remanent magnetization (ChRM) isolated from Paleogene carbonate rocks of the Zongpu Formation in Gamba (28.3°N, 88.5°E) of southern Tibet has previously been interpreted to be primary. These data are pertinent for estimating the width of Greater India and dating the initiation of India‐Asia collision. We have reanalyzed the published ChRM directions and completed thorough rock magnetic tests and petrographic observations on specimens collected throughout the previously investigated sections. Negative nonparametric fold tests demonstrate that the ChRM has a synfolding or postfolding origin. Rock magnetic analyses reveal that the dominant magnetic carrier is magnetite. “Wasp‐waisted” hysteresis loops, suppressed Verwey transitions, high frequency‐dependent in‐phase magnetic susceptibility, and evidence that >70% of the ferrimagnetic material is superparamagnetic at room temperature are consistent with the rock‐magnetic fingerprint of remagnetized carbonate rocks. Scanning electron microscopy observations and energy‐dispersive X‐ray spectrometry analysis confirm that magnetite grains are authigenic. In summary, the carbonate rocks of the Zongpu Formation in Gamba have been chemically remagnetized. Thus, the early Paleogene latitude of the Tibetan Himalaya and size of Greater India have yet to be determined and the initiation of collision cannot yet be precisely dated by paleomagnetism. If collision began at 59 ± 1 Ma at ~19°N, as suggested by sedimentary records and paleomagnetic data from the Lhasa terrane, then a huge Greater India, as large as ~3500–3800 km, is required in the early Paleogene. This size, in sharp contrast to the few hundred kilometers estimated for the Early Cretaceous, implies an ever greater need for extension within Greater India during the Cretaceous.
Tracking nitrous oxide emission processes at a suburban site with semicontinuous, in situ measurements of isotopic composition
Authors: Harris Eliza , Henne Stephan , Hüglin Christoph , Zellweger Christoph , Tuzson Béla , Ibraim Erkan , Emmenegger Lukas , Mohn Joachim
Published: February 2017

The isotopic composition of atmospheric nitrous oxide (N2O) was measured semicontinuously, at ∼35 min frequency in intermittent periods of 1–6 days over one and a half years, using preconcentration coupled to a quantum cascade laser spectrometer at the suburban site of Dübendorf, Switzerland. The achieved measurement repeatability was 0.08‰, 0.11‰, and 0.10‰ for δ18O, site preference, and δ15Nbulk respectively, which is better than or equal to standard flask sampling‐based isotope ratio mass spectrometry performance. The observed mean diurnal cycle reflected the buildup of N2O from isotopically light sources on an isotopically heavy tropospheric background. The measurements were used to determine the source isotopic composition, which varied significantly compared to chemical and meteorological parameters monitored at the site. FLEXPART‐COSMO transport modeling in combination with modified Emissions Database for Global Atmospheric Research inventory emissions was used to model N2O mole fractions at the site. Additionally, isotopic signatures were estimated for different source categories using literature data and used to simulate N2O isotopic composition over the measurement period. The model was able to capture variability in N2O mole fraction well, but simulations of isotopic composition showed little agreement with observations. In particular, measured source isotopic composition exhibited one magnitude larger variability than simulated, clearly indicating that the range of isotopic source signatures estimated from literature significantly underestimates true variability of source signatures. Source δ18O signature was found to be the most sensitive tracer for urban/industry versus agricultural N2O. δ15Nbulk and site preference may provide more insight into microbial and chemical emission processes than partitioning of anthropogenic source categories.
Greenhouse gas balance over thaw‐freeze cycles in discontinuous zone permafrost
Authors: Wilson R. M. , Fitzhugh L. , Whiting G. J. , Frolking S. , Harrison M. D. , Dimova N. , Burnett W. C. , Chanton J. P.
Published: February 2017

Peat in the discontinuous permafrost zone contains a globally significant reservoir of carbon that has undergone multiple permafrost‐thaw cycles since the end of the mid‐Holocene (~3700 years before present). Periods of thaw increase C decomposition rates which leads to the release of CO2 and CH4 to the atmosphere creating potential climate feedback. To determine the magnitude and direction of such feedback, we measured CO2 and CH4 emissions and modeled C accumulation rates and radiative fluxes from measurements of two radioactive tracers with differing lifetimes to describe the C balance of the peatland over multiple permafrost‐thaw cycles since the initiation of permafrost at the site. At thaw features, the balance between increased primary production and higher CH4 emission stimulated by warmer temperatures and wetter conditions favors C sequestration and enhanced peat accumulation. Flux measurements suggest that frozen plateaus may intermittently (order of years to decades) act as CO2 sources depending on temperature and net ecosystem respiration rates, but modeling results suggest that—despite brief periods of net C loss to the atmosphere at the initiation of thaw—integrated over millennia, these sites have acted as net C sinks via peat accumulation. In greenhouse gas terms, the transition from frozen permafrost to thawed wetland is accompanied by increasing CO2 uptake that is partially offset by increasing CH4 emissions. In the short‐term (decadal time scale) the net effect of this transition is likely enhanced warming via increased radiative C emissions, while in the long‐term (centuries) net C deposition provides a negative feedback to climate warming.
High‐performance reactive silver‐ion adsorption and reductive performance of poly(N‐methylaniline)
Authors: Jiang Shun‐Hua , Wu Jun‐Xiong , Zhou Jing , Lü Qiu‐Feng
Published: February 2017

Self‐assembled poly(N‐methylaniline) (PNMA) microspheres were prepared in a facile way by an unstirred polymerization of N‐methylaniline monomers with ammonium persulfate as an oxidizing agent at different temperatures. The polymers were characterized by FTIR and UV‐vis spectroscopy, SEM, TEM and wide‐angle X‐ray diffraction. Furthermore, adsorption property of PNMA microspheres for silver ions from aqueous solution was investigated by batch experiments. The results revealed that PNMA showed a high‐performance adsorption for silver ions by chelation and redox reaction. The maximum adsorption capacity was up to 2.460 g/g for silver ions on PNMA microspheres prepared at 0°C, at an initial silver ion concentration of 160 mmol/L at 25°C for 48 hr. The adsorption process fits the pseudo‐second‐order kinetics and Freundlich isotherm models. Moreover, the PNMA microspheres exbihit high reductive performances for Au(III) and Pd(II) ions. Therefore, the PNMA microspheres have great potential application in removal and recovery of metal ions from industrial wastewater.
Using Ultralow Dosages of Electron Acceptor to Reveal the Early Stage Donor–Acceptor Electronic Interactions in Bulk Heterojunction Blends
Authors: Ho Carr Hoi Yi , Cheung Sin Hang , Li Ho‐Wa , Chiu Ka Lok , Cheng Yuanhang , Yin Hang , Chan Mau Hing , So Franky , Tsang Sai‐Wing , So Shu Kong
Published: February 2017

Tuning the donor–acceptor (D–A) weight ratio is an essential step to optimize the performance of a bulk heterojunction (BHJ) solar cell. The unoptimized regime with a low acceptor concentration is generally unexplored despite it may reveal the early stage electronic D–A interactions. In this study, PTB7:PC71BM is used to examine factors that limit the device performance in unoptimized regime. The key limiting factor is the creation of traps and localized states originated from fullerene molecules. Photothermal deflection spectroscopy is used to quantify the trap density. Starting with pristine PTB7, addition of small concentration of fullerene increases the electron trap density and lowers the electron mobility. When the D–A weight ratio reaches 1:0.1, fullerene percolation occurs. There is an abrupt drop in trap density and simultaneously a six orders of magnitude increase in the electron mobility. Furthermore, the fill factors of the corresponding photovoltaic devices are found to anticorrelate with the trap density. This study reveals that electron trapping is the key limiting factor for unoptimized BHJ solar cells in low fullerene regime.
Steam‐air blown bubbling fluidized bed biomass gasification (BFBBG): Multi‐scale models and experimental validation
Authors: Bates Richard B. , Ghoniem Ahmed F. , Jablonski Whitney S. , Carpenter Daniel L. , Altantzis Christos , Garg Aaron , Barton John L. , Chen Ran , Field Randall P.
Published: February 2017

During fluidized bed biomass gasification, complex gas‐solid mixing patterns and numerous chemical and physical phenomena make identification of optimal operating conditions challenging. In this work, a parametric experimental campaign was carried out alongside the development of a coupled reactor network model which successfully integrates the individually validated sub‐models to predict steady‐state reactor performance metrics and outputs. The experiments utilized an integrated gasification system consisting of an externally‐heated, bench‐scale, 4‐in., 5 kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer to directly measure tar species. The operating temperature (750–850°C) and air/fuel equivalence ratio (ER = 0–0.157) were independently varied to isolate their effects. Elevating temperature is shown to improve the char gasification rate and reduce tar concentrations. Air strongly impacts the composition of tar, accelerating the conversion of lighter polycyclic‐aromatic hydrocarbons into soot precursors, while also improving the overall carbon conversion. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1543–1565, 2017
Safety of long‐term intranasal budesonide delivered via the mucosal atomization device for chronic rhinosinusitis
Authors: Manji Jamil , Singh Gurkaran , Okpaleke Christopher , Dadgostar Anali , Al‐Asousi Fahad , Amanian Ameen , Macias‐Valle Luis , Finkelstein Andres , Tacey Mark , Thamboo Andrew , Javer Amin
Published: February 2017

Background

Although short‐term use (≤2 months) of atomized topical nasal steroids has been shown to be safe and effective, the long‐term safety has yet to be demonstrated. The aim of this study was to determine the impact of long‐term topical budesonide treatment via the mucosal atomization device (MAD) on the hypothalamic‐pituitary‐adrenal axis (HPAA) and intraocular pressure (IOP).

Methods

A cross‐sectional study of patients with chronic rhinosinusitis (CRS), with or without nasal polyposis, managed with daily nasal budesonide via MAD was conducted at a tertiary rhinology center. Patients using systemic steroids within 3 months of assessment were excluded. HPAA impact was assessed using the cosyntropin stimulation test for adrenal function and a survey of relevant symptomatology. Patients also underwent tonometry to assess for elevated IOP potentially related to corticosteroid use.

Results

A total of 100 CRS patients were recruited with a mean budesonide treatment duration of 23.5 months (range, 6–37 months). Stimulated cortisol response was diminished in 3 patients (3%). No patients with adrenal suppression had relevant symptomatology. IOP was elevated in 6 patients (6%).

Conclusion

These findings suggest that there is a risk of adrenal suppression and raised IOP associated with the long‐term use of topical nasal budesonide via MAD. Otolaryngologists should consider periodic surveillance for these adverse events in this patient cohort.
Polyhalides as Efficient and Mild Oxidants for Oxidative Carbene Organocatalysis by Radical Processes
Authors: Wu Xingxing , Zhang Yuexia , Wang Yuhuang , Ke Jie , Jeret Martin , Reddi Rambabu N. , Yang Song , Song Bao‐An , Chi Yonggui Robin
Published: February 2017

Simple and inexpensive polyhalides (CCl4 and C2Cl6) have been found to be effective and versatile oxidants in removing electrons from Breslow intermediates under N‐heterocyclic carbene (NHC) catalysis. This oxidative reaction involves multiple single‐electron‐transfer (SET) processes and several radical intermediates. The α, β, and γ‐carbon atoms of aldehydes and enals could be readily functionalized. Given the low cost of the oxidants and the broad applicability of the reactions, this study is expected to greatly enhance the feasibility of oxidative NHC catalysis for large‐scale applications. Also this new SET radical process with polyhalides as single‐electron oxidants will open a new avenue in the development of NHC‐catalyzed radical reactions.
D‐isosorbide and 1,3‐propanediol as plasticizers for starch‐based films: Characterization and aging study
Authors: González Kizkitza , Martin Loli , González Alba , Retegi Aloña , Eceiza Arantxa , Gabilondo Nagore
Published: February 2017

In the present work, D‐isosorbide and 1,3‐propanediol are proposed as alternative plasticizers obtained from renewable resources. Plasticized starch films were prepared by solvent casting method. The influence of using different “green” plasticizers in the final properties of starch‐based films was analyzed. Besides, the characterization of the films was also performed after storage time in order to evaluate the effect of the plasticizer on aging. UV‐spectrophotometry results showed better optical properties for both glycerol and D‐isosorbide films with higher transparency. The thermal and mechanical properties resulted influenced by the nature of the plasticizer. It was demonstrated that water vapor permeability was governed by the starch‐water interactions, whereas the oxygen permeability depended on the plasticizer's nature. The storage time affected the surface, mechanical, and thermal properties of the plasticized starch films. Atomic force microscopy results concluded that the topography of the films changed due to aging. The use of D‐isosorbide as plasticizer reduced the evolution of the mentioned properties and enhanced the reliability of the material. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44793.
Effects of graphene functionalization on the long‐term behavior of epoxy/graphene composites evaluated by dynamic mechanical analysis
Authors: da Silva Luís Carlos Oliveira , Soares Bluma Guenther
Published: February 2017

Graphene oxide (GO) and its reduced version (RGO) were prepared and functionalized with phenyl glycidol chlorophosphate (PGC) to obtain the corresponding GO‐PGC and RGO‐PGC materials. These graphene systems were used to prepare thermosetting composites with a tetrafunctional epoxy resin, 4,4′‐methylenebis(N,N‐diglycidylaniline) (TGMDA) cured with 4,4′‐diamino‐diphenyl‐sulfone (DDS). The systems were evaluated by dynamic mechanical analysis at constant strain and temperature sweeps to estimate the viscoelastic properties and relaxation phenomena at long time, which is important for modeling the mechanical long‐term behavior. The time temperature superposition (TTS) principle was employed for the construction of a master curve. The addition of the graphene‐type fillers shifted the time when the relaxation phenomena start to occur towards higher values, suggesting a better working temperature and durability of the corresponding nanocomposites when compared to the neat epoxy network. This phenomenon is more pronounced for the systems prepared with functionalized graphenes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44816.
KLK4 silencing inhibits the growth of oral squamous cell carcinoma through Wnt/β‐catenin signaling pathway
Authors: Cui Zhi , Cui Ye , Yang Shuting , Luo Gan , Wang Yang , Lou Yixin , Sun Xinhua
Published: February 2017

Oral squamous cell carcinoma (OSCC) is a malignancy that largely impacts the quality of people's daily life. Kallikrein‐related peptidase 4 (KLK4) is highly expressed in OSCC; however, its roles in OSCC cells are unclear. In the present study, the effect of KLK4 silencing on the growth of OSCC cells was investigated. Our study showed that the proliferation and colony formation of OSCC cells was inhibited by KLK4 silencing and their cell cycle was arrested. Additionally, apoptosis of OSCC cells was enhanced by KLK4 silencing, with increased protein levels of cleaved PARP, cleaved caspase‐3, Bax and decreased levels of Bcl‐2. KLK4 silencing inhibited the Wnt/β‐catenin signaling pathway, as evidence by decreased protein levels of Wnt1, β‐catenin, reduced GSK‐3β phosphorylation as well as decreased levels of cyclinD1 and c‐myc proteins. We further showed that Wnt/β‐catenin activator reversed the effects of KLK4 silencing on the proliferation and apoptosis of OSCC cells. We concluded that KLK4 silencing inhibited the growth of OSCC cells through Wnt/β‐catenin signaling pathway, suggesting that KLK4 may become a promising therapeutic target for the treatment of OSCC.
Directly Attached Bisdonor‐BF2 Chelated Azadipyrromethene‐Fullerene Tetrads for Promoting Ground and Excited State Charge Transfer
Authors: Collini Melissa A. , Thomas Michael B. , Bandi Venugopal , Karr Paul A. , D'Souza Francis
Published: February 2017

The efficiency and mechanism of electron‐ and energy‐transfer events occurring in both natural and synthetic donor–acceptor systems depend on their distance, relative orientation, and the nature of the surrounding media. Fundamental knowledge gained from model studies is key to building efficient energy harvesting and optoelectronic devices. Faster charge separation and slower charge recombination in donor–acceptor systems is often sought out. In our continued effort to build donor–acceptor systems using near‐IR sensitizers, in the present study, we report ground and excited‐state charge transfer in newly synthesized, directly linked tetrads featuring bisdonor (donor=phenothiazine and ferrocene), BF2‐chelated azadipyrromethane (azaBODIPY) and C60 entities. The tetrads synthesized using multi‐step synthetic procedure revealed strong charge‐transfer interactions in the ground state involving the donor and azaBODIPY entities. The near‐IR emitting azaBODIPY acted as a photosensitizing electron acceptor along with fullerene whereas the phenothiazine and ferrocene entities acted as electron donors. The triads (bisdonor–azaBODIPY) and tetrads revealed ultrafast photoinduced charge separation leading to D.+–azaBODIPY.−–C60 and D.+–azaBODIPY–C60.− (D=phenothiazine or ferrocene) charge separated states from the femtosecond transient absorption spectral studies in both polar and nonpolar solvent media. The charge‐separated states populated the triplet excited state of azaBODIPY prior returning to the ground state.
Solvatationsforschung ermittelt Rolle des Solvens
Authors: Feresin Emiliano , Havenith Martina
Published: February 2017

Die Frage nach der Rolle des Wassers – und des Lösungsmittels im Allgemeinen – in chemischen Prozessen wurde bis vor kurzem mit makroskopischen und empirischen Ansätzen untersucht, die die Solvenseffekte sehr stark vereinfachen. Daher wurden viele wichtige Vorgänge, z.B. biologische Prozesse und katalytische Reaktionen an Grenzflächen, nicht ausreichend im molekularen Detail untersucht. Der Exzellenzcluster RESOLV nutzt die aktuellsten Fortschritte der experimentellen und theoretischen Methoden und hat damit seit 2012 die Solvatationswissenschaft, Solvation Science, als neues, interdisziplinäres Forschungsfeld etabliert, das einen Bottom‐up‐Ansatz auf der molekularen Ebene verfolgt. Aktuelle Ergebnisse zeigen, dass Solvensmoleküle in die Kontrolle, Vermittlung und Steuerung der allermeisten Prozesse, z.B. die Synthese von enantiomerenreinen Produkten, enzymatische Reaktionen oder die heterogene Katalyse, involviert sind.
Solvatation von Carbenen
Authors: Henkel Stefan
Published: February 2017

Carbene sind wichtige Reaktionsintermediate, deren Reaktivität in Lösung maßgeblich durch den Spinzustand bestimmt wird. Dieser wiederum wird auch durch das Lösungsmittel der Reaktion beeinflusst. So konnte gezeigt werden, dass eine einzelne Wasserstoffbrückenbindung mit Methanol den Spinzustand eines Carbens und damit auch das Reaktionsverhalten ändern kann. Die Aufklärung solcher Solvatationsprozesse ist essenziell für ein grundlegendes Verständnis von Reaktionen in Lösung.
Chemie, völlig für die Katz' C6H10O7Glucuronsäure
Authors: Roth Klaus
Published: February 2017

Moleküle und ihre Beziehung zu uns Menschen sollen in dieser Rubrik vorgestellt werden, die daher auch “Moleküle und Menschen” heißt und den Berliner “Molecule Man” des US‐amerikanischen Bildhauers Jonathan Borofsky (*1942) als Logo trägt. Er selbst sagt über sein Kunstwerk: “Für mich steht diese 30 m hohe Aluminium‐Skulptur von drei, sich im Mittelpunkt treffenden Figuren nicht nur für die Leichtigkeit unserer eigenen massiven Körper, sondern die drei, im Zentrum miteinander verbundenen Figuren stehen für die Vereinigung der Moleküle aller Menschen, um unsere Existenz zu erschaffen.” Unser erstes Molekül ist die Glucuronsäure.
Wie funktioniert eigentlich ein Touchscreen?
Authors: Litzius Kai
Published: February 2017

Touchscreens haben eine enorme Bedeutung für moderne Medien (Abbildung 1). Der prägnanteste Vorteil dieser Technologie ist wohl die Kombination eines intuitiven Ein‐ und Ausgabegerätes in einem kompakten Design, das dem Nutzer erlaubt, durch Wischen, Ziehen und Tippen direkt mit dem System zu interagieren und umgekehrt. Aber wie funktioniert ein solches System, welche Bautypen sind verfügbar und wieso funktionieren einige Touchscreen‐Bauarten mit Fingern, nicht aber mit normalen Stiften? Diese Fragen werden wir hier näher behandeln.
Surfer im Käfergewand
Authors: Tetsch Larissa
Published: February 2017

Bei der Beutejagd fällt der Komma‐Schmalräuber (Stenus comma) manchmal ins Wasser. Um den dort lauernden Feinden zu entkommen, scheidet er am Hinterleib Alkaloide aus, die die Oberflächenspannung des Wassers herabsetzen. Dies induziert einen Oberflächendruck, der den Käfer Richtung Ufer treibt. Zusätzlich erschwert das zähflüssige Verhalten des Alkaloidfilms seine Verfolgung.
Organosiliciumverbindungen leicht gemacht
Authors: Groß Michael
Published: February 2017

Ein nur an drei Positionen verändertes Enzym kann effizient und selektiv Kohlenstoff mit Silicium verknüpfen.
Effectiveness of esophagectomy in patients with thoracic esophageal squamous cell carcinoma receiving definitive radiotherapy or concurrent chemoradiotherapy through intensity‐modulated radiation therapy techniques
Authors: Yen Yu‐Chun , Chang Jer‐Hwa , Lin Wei‐Cheng , Chiou Jeng‐Fong , Chang Yin‐Chun , Chang Chia‐Lun , Hsu Han‐Lin , Chow Jyh‐Ming , Yuan Kevin Sheng‐Po , Wu Alexander T. H. , Wu Szu‐Yuan
Published: February 2017

BACKGROUND

Few large, prospective, randomized studies have investigated the effectiveness of esophagectomy in patients with thoracic esophageal squamous cell carcinoma (TESCC) who receive definitive radiotherapy (RT) or concurrent chemoradiotherapy (CCRT) through modern, intensity modulated‐RT (IMRT) techniques. The therapeutic effects of esophagectomy in patients with TESCC were evaluated using modern clinical staging and RT techniques and suitable RT doses.

METHODS

The authors analyzed data from patients with TESCC from the Taiwan Cancer Registry database. Patients were categorized into the following groups on the basis of treatment modality to compare their outcomes: group 1 received definitive CCRT, group 2 received neoadjuvant RT followed by esophagectomy (total IMRT dose, ≥50 grays [Gy]), and group 3 receiving neoadjuvant CCRT followed by esophagectomy (total IMRT dose, ≥ 50 Gy). The median total RT dose and fraction size were 50.4 Gy and 1.8 Gy per fraction, respectively. Group 1 was used as the control arm for investigating the risk of mortality after treatment.

RESULTS

In total, 3123 patients who had TESCC without distant metastasis were enrolled. Patient ages 65 years and older, Charlson comorbidity index scores ≥3, advanced clinical stages (IIA‐IIIC), alcohol consumption, and cigarette smoking were identified as significant, independent poor prognostic risk factors for overall survival in multivariate Cox regression analyses. In group 3, after adjustment for confounders, the adjusted hazard ratios (95% confidence intervals [CIs]) for overall mortality were 0.62 (95% CI, 0.41‐0.93) for patients with clinical stage IIA disease, 0.61 (95% CI, 0.41‐0.91) for those with clinical stage IIB disease, 0.47 (95% CI, 0.38‐0.55) for those with clinical stage IIIA disease, 0.47 (95% CI, 0.39‐0.56) for those with clinical stage IIIB disease, and 0.46 (95% CI, 0.37‐0.57) for those with clinical stage IIIC disease.

CONCLUSIONS

Esophagectomy can be beneficial in patients with TESCC after definitive CCRT, especially in those who have advanced‐stage disease. Cancer 2017;123:2043–2053. © 2017 American Cancer Society.
5HTR3A‐driven GFP labels immature olfactory sensory neurons
Authors: Finger Thomas E. , Bartel Dianna L. , Shultz Nicole , Goodson Noah B. , Greer Charles A.
Published: February 2017

The ionotropic serotonin receptor, 5‐HT3, is expressed by many developing neurons within the central nervous system. Since the olfactory epithelium continues to generate new olfactory sensory neurons (OSNs) throughout life, we investigated the possibility that 5‐HT3 is expressed in the adult epithelium. Using a transgenic mouse in which the promoter for the 5‐HT3a subunit drives expression of green fluorescent protein (GFP), we assessed the expression of this marker in the olfactory epithelium of adult mice. Both the native 5‐HT3a mRNA and GFP are expressed within globose basal cells of the olfactory and vomeronasal epithelium in adult mice. Whereas the 5‐HT3a mRNA disappears relatively quickly after final cell division, the GFP label persists for about 5 days, thereby labeling immature OSNs in both the main olfactory system and vomeronasal organ. The GFP‐labeled cells include both proliferative globose basal cells as well as immature OSNs exhibiting the hallmarks of ongoing differentiation including GAP43, PGP9.5, but the absence of olfactory marker protein. Some of the GFP‐labeled OSNs show characteristics of more mature yet still developing OSNs including the presence of cilia extending from the apical knob and expression of NaV1.5, a component of the transduction cascade. These findings suggest that 5‐HT3a is indicative of a proliferative or developmental state, regardless of age, and that the 5‐HT3AGFP mice may prove useful for future studies of neurogenesis in the olfactory epithelium. J. Comp. Neurol. 525:1743–1755, 2017. © 2016 Wiley Periodicals, Inc.
Do universal media literacy programs have an effect on weight and shape concern by influencing media internalization?
Authors: Wade Tracey D. , Wilksch Simon M. , Paxton Susan J. , Byrne Susan M. , Austin S. Bryn
Published: February 2017

The current study examined whether media internalization, found to mediate the relationship between selected prevention programs and outcomes, mediated the impact of two universal prevention programs that targeted risk factors for eating disorders and obesity, namely weight concern, and shape concern. Students randomized to a media literacy (Media Smart) program (N = 269, 65% females, mean age 12.97 years) and a healthy lifestyle (Life Smart) program (N = 347, 69% females, mean age 13.07 years) were included in the analyses. There were four waves of data (baseline, end of intervention, 6‐ and 12‐month follow‐up). Latent growth curve modeling was used to explore whether group assignment influenced levels of media internalization, and whether that in turn influenced change over time of our two outcome variables. Being randomly allocated toMedia Smartas opposed toLife Smartresulted in less growth of both outcome variables through the influence on decreasing levels of media internalization. Findings provided support for the suggestion that media literacy programs exert an impact on outcomes related to eating disorder risk through changes to media internalization. Future research should examine whether these mechanisms of change differ between girls and boys.
Immunological consequences of strain variation within the Mycobacterium tuberculosis complex
Authors: Tientcheu Leopold D. , Koch Anastasia , Ndengane Mthawelenga , Andoseh Genevieve , Kampmann Beate , Wilkinson Robert J
Published: February 2017

In 2015, there were an estimated 10.4 million new cases of tuberculosis (TB) globally, making it one of the leading causes of death due to an infectious disease. TB is caused by members of the Mycobacterium tuberculosis complex (MTBC), with human disease resulting from infection by M. tuberculosis sensu stricto and M. africanum. Recent progress in genotyping techniques, in particular the increasing availability of whole genome sequence data, has revealed previously under appreciated levels of genetic diversity within the MTBC. Several studies have shown that this genetic diversity may translate into differences in TB transmission, clinical manifestations of disease, and host immune responses. This suggests the existence of MTBC genotype‐dependent host–pathogen interactions which may influence the outcome of infection and progression of disease. In this review, we highlight the studies demonstrating differences in innate and adaptive immunological outcomes consequent on MTBC genetic diversity, and discuss how these differences in immune response might influence the development of TB vaccines, diagnostics and new therapies.
Trinuclear Complexes Derived from R/S Schiff Bases – Chiral Single‐Molecule Magnets
Authors: Escuer Albert , Mayans Julia , Font‐Bardia Merce , Di Bari Lorenzo , Górecki Marcin
Published: February 2017

Invited for the cover of this issue is the group of Albert Escuer from Universitat de Barcelona, Spain, in collaboration with the group of Lorenzo Di Bari from Università di Pisa, Italy. The cover image shows the space‐filling plots of two enantiomeric MnIII triangles and their electronic circular dichroism (ECD) spectra against a background of an enantiomeric image from the macroscopic world.
First Tandem‐Type One‐Pot Process Combining Asymmetric Organo‐ and Biocatalytic Reactions in Aqueous Media Exemplified for the Enantioselective and Diastereoselective Synthesis of 1,3‐Diols
Authors: Rulli Giuseppe , Duangdee Nongnaphat , Hummel Werner , Berkessel Albrecht , Gröger Harald
Published: February 2017

A suitable “process window” was identified for the combination of an asymmetric organocatalytic aldol reaction and subsequent biocatalytic reduction in aqueous medium, which thus enabled the enantio‐ and diastereoselective synthesis of 1,3‐diols in a tandem‐type, one‐pot process. A key feature of this one‐pot synthesis is the high 500 mm loading of the aldehyde substrate used as a starting material.
Air Starvation Induced Degradation in Polymer Electrolyte Fuel Cells
Authors: Bodner M. , Schenk A. , Salaberger D. , Rami M. , Hochenauer C. , Hacker V.
Published: February 2017

While hydrogen starvation in fuel cells is intensely investigated and strategies for avoidance have been developed, almost no data are available for other unexpected events, such as malfunction of the air supply. In this study we induce oxygen starvation in a manner closer to failure in real systems than commonly applied accelerated stress tests.

By cycling the cathode gas flow, two accelerated stress tests were introduced; simulating short periods of air starvation with duration of either 10 or 60 seconds. Short cathode undersupply does not lead to fuel cell failure. Air starvation results in a voltage drop and hydrogen evolution. This is accompanied by the reduction of platinum oxides in the respective areas, which leads to an improvement of the active catalyst surface area. After extensive cycling, degradation becomes the dominant effect. X‐ray computed tomography is used to visualize the change of the catalyst particle size and distribution in dependence on the location in the fuel cell. Throughout the experiments, a total voltage decay rate of 1.427 mV h−1, a total fluoride emission rate of 0.0031 µmol h−1 cm−2 and severe current and temperature gradients during starvation were observed, leading to an inhomogeneous agglomeration of the platinum electrocatalyst.
Ex vivo humidifying capacity and patient acceptability of stoma cloths in laryngectomized individuals
Authors: Lansaat Liset , van den Boer Cindy , Muller Sara H. , van der Noort Vincent , van den Brekel Michiel W. M. , Hilgers Frans J. M.
Published: February 2017

Background

Heat and moisture exchangers (HMEs) improve respiratory function after laryngectomy, but there is virtually no information on the benefit of traditional stoma cloths or other covers.

Methods

Two sequential studies were performed: (1) an ex vivo test was used to compare the humidifying capacity of stoma cloths to other coverings; and (2) a 4‐week randomized trial was then performed to assess patient acceptability of cloths both alone and with an HME (N = 18).

Results

The humidifying capacity of the coverings tested varied widely. For stoma cloths, a humidifying capacity of 13.7 mg/L was found to decrease to 8.5 mg/L if air‐leaks around the cloth occurred. Patients who used HMEs disliked stoma cloths because they interfered with voicing, they became soiled more easily, and were less effective at reducing coughing and mucus production.

Conclusion

Although less acceptable to patients who use an HME, stoma cloths do provide significant humidifying capacity and should be encouraged when HMEs are unavailable or inappropriate. © 2017 Wiley Periodicals, Inc. Head Neck 39: 921–931, 2017
Niacin intake and risk of skin cancer in US women and men
Authors: Park Sang Min , Li Tricia , Wu Shaowei , Li Wen‐Qing , Weinstock Martin , Qureshi Abrar A. , Cho Eunyoung
Published: February 2017

A recent clinical trial found a protective role of niacinamide, a derivative of niacin, against skin cancer recurrence. However, there is no epidemiologic study to assess the association between niacin intake and risk of skin cancer [basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma]. We prospectively evaluated whether total, dietary and supplemental niacin intake was associated with skin cancer risk based on 72,308 women in the Nurses' Health Study (1984–2010) and 41,808 men in the Health Professionals Follow‐up Study (1986–2010). Niacin intake was assessed every 2 to 4 years during follow‐up and cumulative averaged intake. Cox proportional hazard models were used to compute the hazard ratios (HR) and 95% confidence intervals (CI) and cohort‐specific results were pooled using a random‐effects model. During the follow‐up, we documented 23,256 BCC, 2,530 SCC and 887 melanoma cases. Total niacin intake was inversely associated with SCC risk; the pooled HR for top vs. bottom quintiles was 0.84 (95% CI = 0.74–0.95; ptrend = 0.08). However, there were a marginally positive association between total niacin intake and BCC risk; the pooled HR for top versus bottom quintiles was 1.05 (95% CI = 1.01–1.10; ptrend < 0.01). Higher total niacin intake was also marginally positively associated with melanoma risk in men, but not in women. The results were similar in stratified analyses according to sun exposure related factors and by body location of melanoma and SCC. Our study supports a potential beneficial role of niacin intake in relation to SCC but not of BCC or melanoma.
Novel flexible nerve conduits made of water‐based biodegradable polyurethane for peripheral nerve regeneration
Authors: Hsu Shan‐hui , Chang Wen‐Chi , Yen Chen‐Tung
Published: February 2017

Peripheral nerve conduits were fabricated from biodegradable polyurethane (PU) which was synthesized by a waterborne process. The biodegradable PU was based on poly(ε‐caprolactone) diol and polyethylene butylene adipate diol (2:3 molar ratio) as the soft segment. Conduits formed by the freeze‐drying process had asymmetric microporous structure. The PU nerve conduits were used to bridge a 10‐mm gap in rat sciatic nerve. Nerve regeneration was evaluated by walking track analysis, magnetic resonance imaging (MRI), electrophysiological, and histological analyses. Results demonstrated that after 6 weeks, walking function was recovered by 40%. MR images showed that the transected nerve was reconnected after 3 weeks and the diameter of the regenerated nerve increased from 3 to 6 weeks. The nerve conduction velocity of the regenerated nerve reached 50% of the normal value after 6 weeks. Histological examination revealed that the cross‐sectional area of the regenerated nerve at the midconduit was 0.24 mm2 after 6 weeks. The efficacy of PU nerve conduits based on functional recovery and histology was superior to that of commercial conduits (Neurotube). The PU nerve conduit developed in this study may be a potential candidate for clinical peripheral nerve tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1383–1392, 2017.
Solvent‐ and Metal‐free Oxidative Esterification of Aromatic Aldehydes Using Urea‐2,2‐dihydroperoxypropane as a New Solid Oxidant
Authors: Khosravi Kaveh , Khalaji Kobra , Naserifar Shirin
Published: February 2017

Urea‐2,2‐dihydroperoxypropane as a noble and solid gem‐dihydroperoxide derivative was used to transform various aromatic aldehydes to their corresponding benzoate derivatives in the presence of HBr under mild conditions at room temperature in high yields and short reaction times.
Effectiveness of Brief Abstinence for Modifying Problematic Internet Gaming Cognitions and Behaviors
Authors: King Daniel L. , Kaptsis Dean , Delfabbro Paul H. , Gradisar Michael
Published: February 2017

Objective

This pilot study tested the efficacy of a voluntary 84‐hour abstinence protocol for modifying problematic Internet gaming cognitions and behaviors

Method

Twenty‐four adults from online gaming communities, including 9 individuals who screened positively for Internet gaming disorder (IGD), abstained from Internet games for 84 hours. Surveys were collected at baseline, at daily intervals during abstinence, and at 7‐day and 28‐day follow‐up

Results

Brief voluntary abstinence was successful in reducing hours of gaming, maladaptive gaming cognitions, and IGD symptoms. Abstinence was highly acceptable to participants with total compliance and no study attrition. Clinically significant improvement in IGD symptoms occurred in 75% of the IGD group at 28‐day follow‐up. Reliable improvement in maladaptive gaming cognitions occurred in 63% of the IGD group, whose cognition score reduced by 50% and was comparable to the non‐IGD group at 28‐day follow‐up

Conclusions

Despite limitations of sample size, this study provides promising support for brief abstinence as a simple, practical, and cost‐effective treatment technique for modifying unhelpful gaming cognitions and reducing Internet gaming problems.
Tissue sodium accumulation and peripheral insulin sensitivity in maintenance hemodialysis patients
Authors: Deger Serpil Muge , Wang Ping , Fissell Rachel , Ellis Charles D. , Booker Cindy , Sha Feng , Morse Jennifer L. , Stewart Thomas G. , Gore John C. , Siew Edward D. , Titze Jens , Ikizler Talat Alp
Published: February 2017

Background

Recent data suggest that sodium (Na+) is stored in the muscle and skin without commensurate water retention in maintenance hemodialysis (MHD) patients. In this study, we hypothesized that excessive Na+ accumulation would be associated with abnormalities in peripheral insulin action.

Methods

Eleven MHD patients and eight controls underwent hyperinsulinemic–euglycemic–euaminoacidemic clamp studies to measure glucose (GDR) and leucine disposal rates (LDR), as well as lower left leg 23Na magnetic resonance imaging to measure Na+ concentration in the muscle and skin tissue.

Results

The median GDR and LDR levels were lower, and the median muscle Na+ concentration was higher in MHD patients compared with controls. No significant difference was found regarding skin Na+ concentration between group comparisons. Linear regression revealed inverse relationships between muscle Na+ concentration and GDR and LDR in MHD patients, whereas no relationship was observed in controls. There was no association between skin Na+ content and GDR or LDR in either MHD patients or controls.

Conclusions

These data suggest that excessive muscle Na+ content might be a determinant of IR in MHD patients, although the causality and mechanisms remain to be proven.