bluuebunny/crossref_metadata_2025 huggingface dataset:
Decoding hierarchical control of sequential behavior in oscillatory EEG activity
Authors: Kikumoto Atsushi , Mayr Ulrich
Published: November 2018

Despite strong theoretical reasons for assuming that abstract representations organize complex action sequences in terms of subplans (chunks) and sequential positions, we lack methods to directly track such content-independent, hierarchical representations in humans. We applied time-resolved, multivariate decoding analysis to the pattern of rhythmic EEG activity that was registered while participants planned and executed individual elements from pre-learned, structured sequences. Across three experiments, the theta and alpha-band activity coded basic elements and abstract control representations, in particular, the ordinal position of basic elements, but also the identity and position of chunks. Further, a robust representation of higher level, chunk identity information was only found in individuals with above-median working memory capacity, potentially providing a neural-level explanation for working-memory differences in sequential performance. Our results suggest that by decoding oscillatory activity we can track how the cognitive system traverses through the states of a hierarchical control structure.
Shear-induced damped oscillations in an epithelium depend on actomyosin contraction and E-cadherin cell adhesion
Authors: Sadeghipour Ehsan , Garcia Miguel A , Nelson William James , Pruitt Beth L
Published: November 2018

Shear forces between cells occur during global changes in multicellular organization during morphogenesis and tissue growth, yet how cells sense shear forces and propagate a response across a tissue is unknown. We found that applying exogenous shear at the midline of an epithelium induced a local, short-term deformation near the shear plane, and a long-term collective oscillatory movement across the epithelium that spread from the shear-plane and gradually dampened. Inhibiting actomyosin contraction or E-cadherin trans-cell adhesion blocked oscillations, whereas stabilizing actin filaments prolonged oscillations. Combining these data with a model of epithelium mechanics supports a mechanism involving the generation of a shear-induced mechanical event at the shear plane which is then relayed across the epithelium by actomyosin contraction linked through E-cadherin. This causes an imbalance of forces in the epithelium, which is gradually dissipated through oscillatory cell movements and actin filament turnover to restore the force balance across the epithelium.
Humor of the intimate: Female humor and women policies in Turkey
Authors: Yavuz Görkem Şenay
Published: November 2018

This study focuses on the women policies of the Turkish government and the female humour that is created in response to these policies. A humour magazine is used as the main source since this specific magazine, which is named Bayan Yanı (The Seat Next to a Lady), has the privilege of being the only humour magazine created solely by female caricaturists and writers in Turkey. Six samples of female humour related to intimate matters are selected purposefully from 16 issues of this magazine published between January 2015 and June 2016 and analysed in content, tone, and function. The aim is to develop an understanding on female humour, especially the humour of the intimate, created to lead the public to question the effectiveness of political decisions and practices related to women policies.
Characteristics of the complete mitochondrial genome ofSuhpalacsa longialata(Neuroptera, Ascalaphidae) and its phylogenetic implications
Authors: Gao Xin-Yan , Cai Yin-Yin , Yu Dan-Na , Storey Kenneth B. , Zhang Jia-Yong
Published: November 2018

The owlflies (Family Ascalaphidae) belong to the Neuroptera but are often mistaken as dragonflies because of morphological characters. To date, only three mitochondrial genomes of Ascalaphidae, namelyLibelloides macaronius;Ascaloptynx appendiculatus;Ascalohybris subjacens, are published in GenBank, meaning that they are greatly under-represented in comparison with the 430 described species reported in this family. In this study, we sequenced and described the complete mitochondrial genome ofSuhpalacsa longialata(Neuroptera, Ascalaphidae). The total length of theS. longialatamitogenome was 15,911 bp, which is the longest known to date among the available family members of Ascalaphidae. However, the size of each gene was similar to the other three Ascalaphidae species. TheS. longialatamitogenome included a transposition of tRNACysand tRNATrpgenes and formed an unusual gene arrangement tRNACys-tRNATrp-tRNATyr(CWY). It is likely that the transposition occurred by a duplication of both genes followed by random loss of partial duplicated genes. The nucleotide composition of theS. longialatamitogenome was as follows:A= 41.0%,T= 33.8%,C= 15.5%,G= 9.7%. Both Bayesian inference and ML analyses strongly supportedS. longialataas a sister clade to (Ascalohybris subjacens+L. macaronius), and indicated that Ascalaphidae is not monophyletic.
Intake of supplementary food during pregnancy and lactation and its association with child nutrition in Timor Leste
Authors: Yaya Sanni , Wang Ruoxi , Tang Shangfeng , Ghose Bishwajit
Published: November 2018

There is little evidence on maternal consumption of supplementary food on nutritional status of children. The objectives of this study were to measure the prevalence and determinants of supplementary food intake during pregnancy and lactation, and their association with nutritional status of under-five children in Timor Leste.

Methods

Cross-sectional data from Timor Leste Demographic and Health Survey on 5,993 mother (15–49 years) child dyads (<5 years) were included in the analysis. Self-reported intake of supplementary food intake was the explanatory variable. Child’s nutritional status was assessed by stunting, wasting, and underweight and categorized according to WHO recommendations.

Results

The prevalence of taking supplementary food during pregnancy and lactation was, respectively, 29.1% (95% CI [27.2–31.0]) 31.0% (95% CI [29.1–33.0]), and that of taking iron supplement during pregnancy was close to three-fifths (63.1%, 95% CI [60.9–65.3]). The odds of taking supplementary food during pregnancy and lactation were lower among those in the younger age groups and higher among urban residents. Compared with mothers who had supplementary food during pregnancy and lactation, those did not have had respectively 1.36 (OR = 1.360, 95% CI [1.191–2.072]) and 1.15 times (OR = 1.152, 95% CI [1.019–1.754]) higher odds of having stunted, and 1.30 (OR = 1.307, 95% CI [1.108–1.853]) and 1.43 (OR = 1.426, 95% CI [1.140–1.863]) times higher odds of having underweight children. Those who had none of the supplements had respectively 1.67 (OR = 1.674, 95% CI [1.118–2.087]) and 1.63 (OR = 1.631, 95% CI [1.130–2.144]) times higher odds of having stunted and underweight children.

Conclusion

A great majority of the mothers in Timor Leste are not taking supplementary food during pregnancy and lactation. We found a positive relationship between supplementary food intake during pregnancy and lactation with stunting and wasting among under-five children.
Implementation of the Management Processes of Mobile Hospital Health Services in the Province of Maguindanao
Authors: Macasayon Mocamad
Published: November 2018

Although agreement about the need for quality improvement in healthcare is almost universal, the means of achieving effective improvement in overall care is not well understood. Mobile hospital health interventions could have beneficial effects on healthcare delivery processes. This study explored the extent of the implementation of the management processes of Mobile Hospital health services. The study used the descriptive correlation method of research. Survey questionnaires were used to collect data from health workers from different municipalities of the province of Maguindanao. The study shows that the management processes of the mobile health services in terms of planning, organizing, staffing, implementation, monitoring, and evaluation were properly implemented. The study implies that the Mobile Hospital health services in the Province of Maguindanao through the application of management processes are effective.
Study the Quran or The Study Quran?
Authors: Fudge Bruce
Published: November 2018

This article discusses issues of scholarship and methodology in Quranic Studies in the context of reviewing The Study Quran, ed. Seyyed Hossein Nasr et al.
Formen und Inhalte althethitischer historischer Literatur. By Amir Gilan
Authors: Pallavidini Marta
Published: November 2018

Formen und Inhalte althethitischer historischer Literatur. By Amir Gilan. Texte der Hethiter, vol. 29.

Heidelberg: Universitätsverlag Winter, 2015. Pp. xii + 404. €45 (paper).
Worldly Gurus and Spiritual Kings: Architecture and Asceticism in Medieval India. By Tamara I. Sears
Authors: Patel Alka
Published: November 2018

Worldly Gurus and Spiritual Kings: Architecture and Asceticism in Medieval India. By Tamara I.

Sears. New Haven: Yale University Press, 2014. Pp. 300, illus. $75.
“. . . für die Wißenschaft, der ich von ganzer Seele lebe.” Otto Böhtlingk (1815–1904): Ein Gelehrten- leben rekonstruiert und beschrieben anhand seiner Briefe; and Otto Böhtlingk an Rudolf Roth: Briefe zum Petersburger Wörterbuch 1852–1885. Index
Authors: Rocher Rosane
Published: November 2018

“. . . für die Wißenschaft, der ich von ganzer Seele lebe.” Otto Böhtlingk (1815–1904): Ein Gelehrten- leben rekonstruiert und beschrieben anhand seiner Briefe. By Agnes Stache-Weiske. Wiesbaden: Harrassowitz. 2017. Pp. xv + 583. €118.

Otto Böhtlingk an Rudolf Roth: Briefe zum Petersburger Wörterbuch 1852–1885. Index. By Agnes Stache-Weiske, Gabriele Zeller, and Frank Köhler. Veröffentlichungen der Helmuth von Glasenapp-Stiftung, vol. 45.2. Wiesbaden: Harrassowitz. 2015. Pp. 188. €59.
Wissenskultur im Alten Orient: Weltanschauung, Wissenschaften, Techniken, Technologien. Edited by Hans Neumann
Authors: Bartash Vitali
Published: November 2018

Wissenskultur im Alten Orient: Weltanschauung, Wissenschaften, Techniken, Technologien. Edited by Hans Neumann. Colloquien der Deutschen Orient-Gesellschaft, vol. 4. Wiesbaden: Harrassowitz Verlag, 2012. Pp. xi + 433, illus. €42.
Back Matter
Authors: Editors
Published: November 2018

Back matter
Resenha: GANS, Herbert . Cultura popular e alta cultura. Uma análise e avaliação do gosto. São Paulo, Edições Sesc, 2014.
Authors: Silva Maurício
Published: November 2018

Resenha do livro:

GANS, Herbert . Cultura popular e alta cultura. Uma análise e avaliação do gosto. São Paulo, Edições Sesc, 2014.
High‐Frequency (Shortwave) Broadcasting
Authors: Elliott Kim Andrew
Published: November 2018

High‐frequency (HF) or shortwave broadcasting has existed since the 1930s both for international and domestic mass communication. It played an important role in World War II and the Cold War. MostHFbroadcasting has been funded and conducted by national governments, but religious and commercial organizations have also participated. Over the years,HFbroadcasting has conveyed a large amount of propaganda, but audiences have tended to tune to shortwave in search of reliable and uncensored news.

The number ofHFbroadcast stations and frequency hours has declined in the twenty‐first century as other media, particularly the Internet and satellites, have become more popular among global audiences for the reception of information and entertainment. Nevertheless, as the Internet becomes more subject to censorship,HFbroadcasting may still play a role in providing uncensored news to countries where mass media are controlled.
Atmospheric Ducting and Beyond‐Line‐of‐Sight Communication
Authors: Dinc Ergin , Akan Ozgur B.
Published: November 2018

Atmospheric ducts are caused by rapid decrease in the refractive index of the lower atmosphere, and they significantly alter the near‐surface wave propagation by trapping propagating signals. In this way, atmospheric ducts behave like a waveguide, and trapped signals can even propagate more than 1000 km in the ducting layer. Therefore, communication and radar systems can be adversely affected by the presence of atmospheric ducts. However, atmospheric ducts not only create interference, but also enable an alternative and promising way for communicating to extreme distances, also known as beyond‐Line‐of‐Sight (b‐LoS) communication. In this article, a comprehensive introduction to atmospheric ducts and their effects on near‐surface wave propagation as well as wave propagation modeling and possible utilization of atmospheric ducts for b‐LoS communication systems are presented.
Wind Power Plant Control
Authors: Chen Zhe
Published: November 2018

This article introduces wind turbine technology and presents wind power plant control. In the first part, wind turbine, wind power conversion system, and turbine control are overviewed briefly. The second part details wind power plants. The third part covers the wind power plant control, including the general wind power plant control, as well as more advanced topics, such as the wind power plant as a generator in a power grid, wind power plant optimal operation, and wind power plants in multiple energy systems. The third part also presents grid requirements, performance, interaction with other equipment in the power grid, and use of energy storage in wind power plants. In addition, optimal operation that considers the wake effect, power losses in wind turbines, and collection systems is discussed. A reference list is given for the readers who wish to find more details about these technologies.
Supramolecular Antifouling Additives for Robust and Efficient Functionalization of Elastomeric Materials: Molecular Design Matters
Authors: Ippel Bastiaan D. , Keizer Henk M. , Dankers Patricia Y. W.
Published: November 2018

The ultimate functionality of elastomeric materials can be largely influenced by the molecular design of antifouling additives that interact through directed hydrogen bonding bisurea motifs. Herein, three additives, composed of matching bisurea groups and antifouling oligo(ethylene glycol) (OEG) functionalities, are judiciously designed. The first additive is composed of one bisurea and one OEG, the second additive of one bisurea and two OEGs, and the third additive of two bisurea and one OEG. On solution‐cast films, non‐cell adhesive properties are dependent on the amount of incorporated OEG irrespective of the bisurea design; however, on 3D electrospun scaffolds only the additive that consists of two bisurea moieties connected via an OEG functionality ensures proper non‐cell adhesive properties. Interestingly, robust non‐cell adhesive properties are maintained, both with repeated cell seeding and after partial enzymatic degradation of the scaffold. These results highlight the importance of additive design in supramolecular functionalization and show that translation from simple 2D solution‐cast films to 3D electrospun scaffolds is not trivial with respect to additive presentation and functionality.
PbTiO3 as Electron‐Selective Layer for High‐Efficiency Perovskite Solar Cells: Enhanced Electron Extraction via Tunable Ferroelectric Polarization
Authors: Wang Ming‐Zi , Feng Hong‐Jian , Qian Chong‐Xin , He Jiawei , Feng Jiangshan , Cao Yong‐Hua , Yang Kang , Deng Zun‐Yi , Yang Zhou , Yao Xi , Zhou Jianping , Liu Shengzhong (Frank) , Zeng Xiao Cheng
Published: November 2018

PbTiO3 (PTO) is explored as a versatile and tunable electron‐selective layer (ESL) for perovskite solar cells. To demonstrate effectiveness of PTO for electron–hole separation and charge transfer, perovskite solar cells are designed and fabricated in the laboratory with the PTO as the ESL. The cells achieve a power conversion efficiency (PCE) of ≈12.28% upon preliminary optimization. It is found that the PTO ferroelectric layer can not only increase the PCE, but also tune the photocurrent via tuning PTO's ferroelectric polarization. Moreover, to understand the physical mechanism underlying the carrier transport by the ferroelectric polarization, the electronic structure of PTO/CH3NH3PbI3 heterostructure is computed using the first‐principles methods, for which the triplet state is used to simulate charge transfer in the heterostructure. It is shown that the synergistic effect of type II band alignment and the specific ferroelectric polarization direction provide the effective extraction of electrons from the light absorber, while minimize recombination of photogenerated electron–hole pairs. Overall, the ferroelectric PTO is a promising and tunable ESL for optimizing electron transport in the perovskite solar cells. The design offers a different strategy for altering direction of carrier transport in solar cells.
Polymorph Selectivity of Coccolith‐Associated Polysaccharides from Gephyrocapsa Oceanica on Calcium Carbonate Formation In Vitro
Authors: Walker Jessica M. , Marzec Bartosz , Lee Renee B. Y. , Vodrazkova Kristyna , Day Sarah J. , Tang Chiu C. , Rickaby Rosalind E. M. , Nudelman Fabio
Published: November 2018

Coccolith‐associated polysaccharides (CAPs) are thought to be a key part of the biomineralization process in coccolithophores; however, their role is not fully understood. Two different systems that promote different polymorphs of calcium carbonate are used to show the effect of CAPs on nucleation and polymorph selection in vitro. Using a combination of time‐resolved cryo‐transmission electron microscopy and scanning electron microscopy, the mechanisms of calcite nucleation and growth in the presence of the intracrystalline fraction are examined containing CAPs extracted from coccoliths from Gephyrocapsa oceanica and Emiliania huxleyi, two closely related coccolithophore species. The CAPs extracted from G. oceanica are shown to promote calcite nucleation in vitro, even under conditions favoring the kinetic products of calcium carbonate, vaterite, and aragonite. This is not the case with CAPs extracted from E. huxleyi, suggesting that the functional role of CAPs in vivo may be different between the two species. Additionally, high‐resolution synchrotron powder X‐ray diffraction has revealed that the polysaccharide is located between grain boundaries of both calcite produced in the presence of the CAPs in vitro and biogenic calcite, rather than within the crystal lattice.
Ultrafast Sodium Full Batteries Derived from XFe (X = Co, Ni, Mn) Prussian Blue Analogs
Authors: Ge Peng , Li Sijie , Shuai Honglei , Xu Wei , Tian Ye , Yang Li , Zou Guoqiang , Hou Hongshuai , Ji Xiaobo
Published: November 2018

Exploring high‐rate electrode materials with excellent kinetic properties is imperative for advanced sodium‐storage systems. Herein, novel cubic‐like XFe (X = Co, Ni, Mn) Prussian blue analogs (PBAs), as cathodes materials, are obtained through as‐tuned ionic bonding, delivering improved crystallinity and homogeneous particles size. As expected, Ni‐Fe PBAs show a capacity of 81 mAh g−1 at 1.0 A g−1, mainly resulting from their physical–chemical stability, fast kinetics, and “zero‐strain” insertion characteristics. Considering that the combination of elements incorporated with carbon may increase the rate of ion transfer and improve the lifetime of cycling stability, they are expected to derive binary metal‐selenide/nitrogen‐doped carbon as anodes. Among them, binary Ni0.67Fe0.33Se2 coming from Ni‐Fe PBAs shows obvious core–shell structure in a dual‐carbon matrix, leading to enhanced electron interactions, electrochemical activity, and “metal‐like” conductivity, which could retain an ultralong‐term stability of 375 mAh g−1 after 10 000 loops even at 10.0 A g−1. The corresponding full‐cell Ni‐Fe PBAs versus Ni0.67Fe0.33Se2 deliver a remarkable Na‐storage capacity of 302.2 mAh g−1 at 1.0 A g−1. The rational strategy is anticipated to offer more possibilities for designing advanced electrode materials used in high‐performance sodium‐ion batteries.
Palladium‐Catalyzed Regioselective Synthesis of 1‐Hydroxycarbazoles Under Aerobic Conditions
Authors: Youn So Won , Kim Young Ho , Jo Yoon Hyung
Published: November 2018

A palladium‐catalyzed aerobic C−H amidation of N‐Ts‐2‐amino‐3′‐hydroxylbiaryls has been developed to afford a diverse range of 1‐hydroxycarbazoles with high regioselectivity and efficiency. This protocol benefits from operational simplicity, robustness, and sustainability with the use of ambient air as the sole terminal oxidant. Further elaboration of the products obtained from this process provides facile access to various carbazole alkaloids including carbazolequinones and biscarbazoles. A mechanism involving dual directing group‐assisted regioselective C−H activation at the more sterically hindered C2′‐position of 2‐amino‐3′‐hydroxylbiaryls is proposed.

magnified image
Interfacial Dynamics and Contact Passivation in Perovskite Solar Cells
Authors: De Bastiani Michele , Aydin Erkan , Allen Thomas , Walter Daniel , Fell Andreas , Peng Jun , Gasparini Nicola , Troughton Joel , Baran Derya , Weber Klaus , White Thomas P. , De Wolf Stefaan
Published: November 2018

Charge accumulation at the electron and hole transport layers generates anomalous electrical behavior in perovskite solar cells (PSCs). Hysteresis in the current–voltage characteristic and recombination at the interfaces are the clearest manifestations of this phenomenon, which compromises device performance and stability. Here, the underlying charge‐carrier dynamics of a variety of PSCs are investigated by analyzing their transient photocurrent response. Towards shorter time scales, PSCs often show increasingly severe hysteretic responses. This phenomenon is correlated with the presence of interfacial accumulated charges that hinders the photogenerated carrier extraction process. However, introducing passivating contacts improves the carrier‐injection properties and the devices become completely hysteresis free. These results underline the importance of contact passivation for PSCs and the need to further develop new passivating interlayers that simultaneously eliminate charge‐carrier recombination and provide selective transport for each carrier type at the PSC's contacts.
A cadaveric model for measuring sinonasal continuous positive airway pressure—a proof‐of‐concept study
Authors: Rimmer Ryan A. , Chitguppi Chandala , Garcia Hermes G. , Koszewski Ian J. , Nyquist Gurston G. , Rosen Marc R. , Huntley Colin , Evans James J. , Rabinowitz Mindy R.
Published: November 2018

Background

Obstructive sleep
apnea is a common respiratory disorder that can have negative effects on health and quality of life. Positive pressure therapy (CPAP) is the primary treatment. There is a lack of consensus on the risk of postoperative CPAP after endoscopic sinus or skull base surgery. We present a proof‐of‐concept cadaver model for measuring sinonasal pressure delivered by CPAP.

Methods

Three fresh cadaver heads were prepared by removing the calvaria and brain. Sphenoidotomies were made and sellar bone was removed. Pressure sensors were placed in the midnasal cavity, sphenoid sinus, and sella. CPAP was applied and the delivered pressure was recorded at increasing levels of positive pressure. Paired t tests and intraclass correlation coefficients were used to analyze results.

Results

Increases in positive pressure led to increased pressure recordings for all locations. Nasal cavity pressure was, on average, 81% of delivered CPAP. Pressure was highest in the sphenoid sinus. The effect of middle turbinate medialization on intrasphenoid pressure was not statistically significant in 2 heads. Intrasellar pressure was 80% of delivered CPAP with lateralized turbinates and 84% with medialized turbinates. Pressure recordings demonstrated excellent reliability for all locations. All heads developed non‒sellar‐based cranial base leaks at higher pressures. Cribriform region leaks were successfully sealed with DuraSeal®.

Conclusion

Our proof‐of‐concept cadaver model represents a novel approach to measure pressures delivered to the nasal cavity and anterior skull base by CPAP. With further study, it may have broader clinical application to guide the safe postoperative use of CPAP in this population.
Bioabsorbable steroid‐releasing implants in the frontal sinus ostia: a pooled analysis
Authors: Singh Ameet , Luong Amber U. , Fong Karen J. , Ow Randall A. , Han Joseph K. , Gerencer Roland , Stolovitzky J. Pablo , Stambaugh James W , Raman Aarthi
Published: November 2018

Background

Bioabsorbable steroid‐releasing implants (mometasone furoate, 370 μg) are effective for improving postsurgical outcomes in the frontal sinus ostia (FSO). In this study we evaluated the effect of these implants on frontal outcomes in various patient subgroups with chronic rhinosinusitis (CRS) using pooled data from 2 randomized, controlled trials (RCTs).

Methods

A total of 160 subjects were enrolled in 2 RCTs. After surgery, subjects were randomized to receive an implant in 1 FSO with the contralateral side as control. Data through day 90 from the 2 studies were pooled and subgroup analyses were performed.

Results

At day 30, relative to controls, steroid‐releasing implants significantly reduced the need for postoperative interventions by 46.8% (95% confidence interval [CI], −60.7 to −27.9), for surgical interventions by 51.2% (95% CI, −68.2 to −25.2), and for oral steroid interventions by 37.2% (95% CI, −54.6 to −13.1) in the pooled data set. At day 90, statistically significant reductions (p < 0.05) in the need for postoperative interventions (relative reduction [RR], 30.2%), restenosis/occlusion rate (RR, 31.7%), and inflammation score (absolute difference, −6.0), and increase in estimated FSO diameter (absolute difference, 1 mm), favoring the treated side, were observed. Subgroup analyses of the pooled data showed statistically significant improvements (p < 0.05) at day 90 in restenosis/occlusion rate, and estimated FSO diameter, favoring the treated side across subgroups, with no statistically significant subgroup‐by‐treatment interactions.

Conclusion

Bioabsorbable steroid‐releasing sinus implants improve outcomes of frontal sinus surgery through 90 days, irrespective of asthma status, previous endoscopic sinus surgery, extent of surgery, extent of polyps, or Lund‐Mackay computed tomography stage in the FSO.
The Influence of Non‐Markovian Characters on Quantum Adiabatic Evolution
Authors: Zeng Ye‐Xiong , Gebremariam Tesfay , Ding Ming‐Song , Li Chong
Published: November 2018

The influence of non‐Markovian characters on the adiabatic evolution is investigated. The adiabatic Raman process is simulated in a three‐level system coupled to two independent environments. The results show that the memory effect of environments can restrain the decoherence effect of the system. Even if the system has strong decay rates in the non‐Markovian environments, the adiabatic population transfer can be still completed efficiently. Moreover, the memory effect can reduce the dependence of the adiabatic evolution on the Rabi frequency. Specifically, the two independent non‐Markovian baths can suppress the decoherence more effectively than a single non‐Markovian bath.
Aerobic Toluene Oxidation Catalyzed by Subnano Metal Particles
Authors: Huda Miftakhul , Minamisawa Keigo , Tsukamoto Takamasa , Tanabe Makoto , Yamamoto Kimihisa
Published: November 2018

Subnanocatalysts (SNCs) containing various noble metals (Cu, Ru, Rh, Pd, or Pt) with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template. These materials exhibit high catalytic performance during toluene oxidation without the use of harmful solvents or explosive oxidants, resulting in the formation of valuable organic products, including benzoic acid as the major product. In particular, Pt19 SNC with a narrow particle size distribution exhibits extraordinary catalytic activity, with a turnover frequency of 3238 atom−1 h−1, which is 1700 times greater than that obtained by commercial Pt/C catalysts.
Insights into the Biosynthesis of Cyclic Guanidine Alkaloids from Crambeidae Marine Sponges
Authors: Silva Siguara B. L. , Oberhänsli François , Tribalat Marie‐Aude , Genta‐Jouve Grégory , Teyssié Jean‐Louis , Dechraoui‐Bottein Marie‐Yasmine , Gallard Jean‐François , Evanno Laurent , Poupon Erwan , Thomas Olivier P.
Published: November 2018

Among the outstanding chemical diversity found in marine sponges, cyclic guanidine alkaloids, present in species of the family Crambeidae, are particularly attractive, not only because of their unique chemical features, but also due to a broad range of biological activities. Despite a growing interest in these natural products as therapeutic agents, their metabolic pathway has not been experimentally investigated. Ex situ feeding experiments using radiolabeled precursors performed on the Mediterranean sponge Crambe crambe suggest arginine and fatty acids as precursors in the metabolic pathway of crambescins. A subsequent bio‐inspired approach supported the change of paradigm in the metabolic pathway of cyclic guanidine alkaloids. A large part of the chemical diversity of this family would therefore originate from a tethered Biginelli‐like reaction between C‐2/C‐3 activated fatty acids and a central guanidinylated pyrrolinium.
Auf dem Weg zur Evolution artifizieller Metalloenzyme – aus einem Protein‐Engineering‐Blickwinkel
Authors: Markel Ulrich , Sauer Daniel F. , Schiffels Johannes , Okuda Jun , Schwaneberg Ulrich
Published: November 2018

Durch den Einbau synthetischer metallorganischer Cofaktoren in Proteingerüste wird eine neue Klasse von Katalysatoren generiert, die als Biohybridkatalysatoren oder artifizielle Metalloenzyme bezeichnet werden. Biohybridkatalysatoren können sowohl in der ersten Koordinationssphäre des Metallkomplexes als auch in der zweiten, vom Proteingerüst bereitgestellten Koordinationssphäre chemisch modifiziert werden. Das Reengineering von Proteingerüsten mittels Methoden der gelenkten Evolution stellt Herausforderungen an das Durchmusterungssystem und bedingt eine ausgeklügelte Metall‐Cofaktor‐Konjugation. In diesem Kurzaufsatz fassen wir die Forschungsbemühungen zur Entwicklung von Hochdurchsatz‐Durchmusterungsverfahren für Biohybridkatalysatoren zusammen. Darüber hinaus beleuchten wir das Potenzial solcher Katalysatoren und die Hürden, die überwunden werden müssen, um von Biohybridkatalysatoren zu artifiziellen Metalloproteinen mit den Charakteristika natürlicher Enzyme zu kommen.
DNA Surface Technology: From Gene Sensors to Integrated Systems for Life and Materials Sciences
Authors: Schneider Ann‐Kathrin , Niemeyer Christof M.
Published: November 2018

The evolution of DNA microarray technology has led to sophisticated DNA chips that are being used as routine tools for fundamental and applied genome research such as genotyping and expression profiling. Owing to their capability for highly parallel, site‐directed immobilization of complementary nucleic acids through canonical Watson–Crick base‐pairing, however, DNA‐modified surfaces can also be used for the assembly of complex surface architectures comprised of non‐nucleic acid compounds, such as proteins or colloidal materials. Furthermore, implementation of functional DNA devices and structural DNA nanotechnology can unlock the full potential of DNA surfaces. Based on case studies from diagnostics, sensing, proteome research, cell adhesion, and cell signaling, we show how classical gene sensors have developed into modern integrated systems and platforms for various applications in life sciences and materials research.
Towards the Evolution of Artificial Metalloenzymes—A Protein Engineer's Perspective
Authors: Markel Ulrich , Sauer Daniel F. , Schiffels Johannes , Okuda Jun , Schwaneberg Ulrich
Published: November 2018

Incorporating artificial metal‐cofactors into protein scaffolds results in a new class of catalysts, termed biohybrid catalysts or artificial metalloenzymes. Biohybrid catalysts can be modified chemically at the first coordination sphere of the metal complex, as well as at the second coordination sphere provided by the protein scaffold. Protein‐scaffold reengineering by directed evolution exploits the full power of nature's diversity, but requires validated screening and sophisticated metal cofactor conjugation to evolve biohybrid catalysts. In this Minireview, we summarize the recent efforts in this field to establish high‐throughput screening methods for biohybrid catalysts and we show how non‐chiral catalysts catalyze reactions enantioselectively by highlighting the first successes in this emerging field. Furthermore, we shed light on the potential of this field and challenges that need to be overcome to advance from biohybrid catalysts to true artificial metalloenzymes.
Crystal Structure of Regularly Th‐Symmetric [U(NO3)6]2− Salts with Hydrogen Bond Polymers of Diamide Building Blocks
Authors: Takao Koichiro , Kazama Hiroyuki , Ikeda Yasuhisa , Tsushima Satoru
Published: November 2018

Hexanitratouranate(IV), [U(NO3)6]2−, has been crystallized with anhydrous H+‐involving hydrogen bond polymers connected by selected diamide building blocks. Thanks to the significant moderation of electrostatic interactions between the anions and cations, the molecular structure of [U(NO3)6]2− in these compounds is regularly Th‐symmetric. The f–f transitions stemming from 5f2 configuration of U4+ are strictly forbidden by the Laporte selection rule in such a centrosymmetric system, so that the obtained compounds are nearly colourless in contrast to other UIV species usually coloured in green.
Assessment of Middle Ear Anatomy Teaching Methodologies Using Microscopy versus Endoscopy: A Randomized Comparative Study
Authors: Anschuetz Lukas , Huwendiek Sören , Stricker Daniel , Yacoub Abraam , Wimmer Wilhelm , Caversaccio Marco
Published: November 2018

Teaching methodologies for the anatomy of the middle ear have not been investigated greatly due to the middle ear’s highly complex structure and hidden location inside of the temporal bone. The aim of this randomized study was to quantitatively compare the suitability of using microscope‐ and endoscope‐based methods for teaching the anatomy of the middle ear. We hypothesize that the endoscopic approach will be more efficient compared to the microscopic approach. To answer the study questions, 33 sixth‐year medical students, residents and otorhinolaryngology specialists were randomized either into the endoscopy or the microscopy group. Their anatomical knowledge was assessed using a structured anatomical knowledge test before and after each session. Each participant received tutoring on a human cadaveric specimen using one of the two methods. They then performed a hands‐on dissection. After 2–4 weeks, the same educational curriculum was repeated using the other technique. The mean gains in anatomical knowledge for the specialists, residents, and medical students were +19.0%, +34.6%, and +23.4%, respectively. Multivariate analyses identified a statistically significant increase in performance for the endoscopic method compared to the microscopic technique (P < 0.001). For the recall of anatomical structures during dissection, the endoscopic method outperformed the microscopic technique independently of the randomization or the prior training level of the attendees (P < 0.001). In conclusion, the endoscopic approach to middle ear anatomy education is associated to an improved gain in knowledge as compared to the microscopic approach. The participants subjectively preferred the endoscope for educational purposes.
Fast Turbidimetric Assay for Analyzing the Enzymatic Hydrolysis of Polyethylene Terephthalate Model Substrates
Authors: Belisário‐Ferrari Matheus R. , Wei Ren , Schneider Tobias , Honak Annett , Zimmermann Wolfgang
Published: November 2018

Synthetic plastics such as polyethylene terephthalate (PET) can be cooperatively degraded by microbial polyester hydrolases and carboxylesterases, with the latter hydrolyzing the low‐molecular‐weight degradation intermediates. For the identification of PET‐degrading enzymes, efficient and rapid screening assays are required. Here a novel turbidimetric method in a microplate format for the fast screening of enzyme activities against the PET model substrates with two ester bonds bis‐(2‐hydroxyethyl) terephthalate (BHET) and ethylene glycol bis‐(p‐methylbenzoate) (2PET) is reported. The carboxylesterase TfCa from Thermobifida fusca KW3 is used for validating the method. High correlation and regression coefficients between the experimental and fitted data confirm the accuracy and reproducibility of the method and its feasibility for analyzing the kinetics of the enzymatic hydrolysis of the PET model substrates. A comparison of the hydrolysis of BHET and 2PET by TfCa using a kinetic model for heterogeneous catalysis indicates that the enzyme preferentially hydrolyzes the less bulky molecule BHET. The high‐throughput assay will facilitate the detection of novel enzymes for the biocatalytic modification or degradation of PET.
Screening of Lipopeptide‐Producing Strains of Bacillus sp. Using a New Automated and Sensitive Fluorescence Detection Method
Authors: Heuson Egon , Etchegaray Augusto , Filipe Stephanie L. , Beretta Daniel , Chevalier Mickaël , Phalip Vincent , Coutte François
Published: November 2018

Lipopeptides, such as surfactins are important biosurfactants produced by Bacillus sp. that find applications in many areas (environment, medicine, and food industries). Giving their importance, the use of simple detection methods will facilitate screening and quantification. In the present work, the authors describe a completely automated workflow for the screening of lipopeptide‐producing strains, including quantification. First, isolated colonies from environmental samples are automatically picked and inoculated in 96 wells growth plate. After overnight incubation, surfactin produced in the broth is quantified, using a new sensitive fluorescent method. The method uses fluorescein (FL), which is an anionic dye at neutral to alkaline pH and forms a stable complex with the cationic surfactant cetylpiridinium chloride (CPC), quenching fluorescence. Upon addition of surfactin or other lipopeptides, fluorescein is released from the CPC‐FL complex and quantified. The robustness of this method is assessed by comparing the quantification results to those conventionally measured by RP‐UPLC and the results of strain screening are confirmed by MALDI‐ToF analysis. The authors report for the first time the successful application of this analytical method for high‐throughput screening of novel lipopeptide‐producing strains.
Synthesis of Air‐stable 1T Phase of Molybdenum Disulfide for Efficient Electrocatalytic Hydrogen Evolution
Authors: Jia Wei , Zhou Xu , Huang Yudai , Cao Yali , Sun Ying , Jia Dianzeng
Published: November 2018

Phase engineering of MoS2 from the thermodynamically stable 2H phase to the metastable 1T phase has been demonstrated as an effective way to enhance the electrocatalytic activity for hydrogen evolution reaction (HER). However, the development of highly stable and efficient 1T‐MoS2‐based electrocatalysts toward HER still remains a great challenge. Herein, a facile hydrothermal strategy was introduced for the preparation of stable 1T‐MoS2 via a reduced graphene oxide (RGO)‐assisted process. The optimal catalyst of MoS2/RGO can keep highly stable in air over 90 days without significant activity fading due to Mo−O interactions, which effectively prevent the transformation of 1T phase back to 2H. The catalyst affords superior HER catalytic activity with a low overpotential of 213 mV versus reversible hydrogen electrode (RHE) at a current density of −10 mA cm−2, a small Tafel slope of 43 mV dec−1, a high exchange current density of 0.83 mA cm−2, and excellent durability, which outperforms its corresponding 2H counterpart. The enhanced electrocatalytic activity of the optimal MoS2/RGO sample is associated with the RGO, which can not only facilitate charge transfer along MoS2 nanosheets but also stabilize the 1T‐MoS2 with a high exposure of active sites for HER. This work paves a new pathway for designing highly efficient MoS2‐based electrocatalysts through phase engineering.
Heteromultivalent Glycooligomers as Mimetics of Blood Group Antigens
Authors: Bücher Katharina S. , Konietzny Patrick B. , Snyder Nicole L. , Hartmann Laura
Published: November 2018

Precision glycomacromolecules have proven to be important tools for the investigation of multivalent carbohydrate–lectin interactions by presenting multiple glycan epitopes on a highly‐defined synthetic scaffold. Herein, we present a new strategy for the versatile assembly of heteromultivalent glycomacromolecules that contain different carbohydrate motifs in proximity within the side chains. A new building block suitable for the solid‐phase polymer synthesis of precision glycomacromolecules was developed with a branching point in the side chain that bears a free alkyne and a TIPS‐protected alkyne moiety, which enables the subsequent attachment of different carbohydrate motifs by on‐resin copper‐mediated azide–alkyne cycloaddition reactions. Applying this synthetic strategy, heteromultivalent glycooligomers presenting fragments of histo‐blood group antigens and human milk oligosaccharides were synthesized and tested for their binding behavior towards bacterial lectin LecB.
Deciphering the Multifarious Charge‐Transport Behaviour of Crystalline Propeller‐Shaped Triphenylamine Analogues
Authors: Ambili R. V. , Sasikumar Devika , Hridya P. , Hariharan Mahesh
Published: November 2018

A collection of para‐substituted propeller‐shaped triphenylamine (TPA) derivatives have been computationally investigated for charge‐transport characteristics exhibited by the derivatives by using the Marcus–Hush formalism. The various substituents chosen herein, with features that range from electron withdrawing to electron donating in nature, play a key role in defining the reorganisation energy and electronic coupling properties of the TPA derivatives. The TPA moiety is expected to possess weak electronic coupling on the basis of poor orbital overlap upon aggregation, owing to the restriction imposed by the propeller shape of the TPA core. However, the substituent groups attached to the TPA core can significantly dictate the crystal‐packing motif of the TPA derivatives, wherein the variety of noncovalent intermolecular interactions subsequently generated drive the packing arrangement and influence electronic coupling between the neighbouring orbitals. Intermolecular interactions in the crystalline architecture of TPA derivatives were probed by using Hirshfeld and quantum theory of atoms‐in‐molecules techniques. Furthermore, symmetry‐adapted perturbation theory analysis of the TPA analogues has revealed that a periodic arrangement of energetically stable dimers with significant electronic coupling is essential to contribute high charge‐carrier mobility to the overall crystal.
Complexation and Versatile Reactivity of a Highly Lewis Acidic Cationic Mg Complex with Alkynes and Phosphines
Authors: Pahl Jürgen , Stennett Tom E. , Volland Michel , Guldi Dirk M. , Harder Sjoerd
Published: November 2018

[(BDI)Mg+][B(C6F5)4−] (1; BDI=CH[C(CH3)NDipp]2; Dipp=2,6‐diisopropylphenyl) was prepared by reaction of (BDI)MgnPr with [Ph3C+][B(C6F5)4−]. Addition of 3‐hexyne gave [(BDI)Mg+⋅(EtC≡CEt)][B(C6F5)4−]. Single‐crystal X‐ray analysis, NMR investigations, Raman spectra, and DFT calculations indicate a significant Mg‐alkyne interaction. Addition of the terminal alkynes PhC≡CH or Me3SiC≡CH led to alkyne deprotonation by the BDI ligand to give [(BDI‐H)Mg+(C≡CPh)]2⋅2 [B(C6F5)4−] (2, 70 %) and [(BDI‐H)Mg+(C≡CSiMe3)]2⋅2 [B(C6F5)4−] (3, 63 %). Addition of internal alkynes PhC≡CPh or PhC≡CMe led to [4+2] cycloadditions with the BDI ligand to give {Mg+C(Ph)=C(Ph)C[C(Me)=NDipp]2}2⋅ 2 [B(C6F5)4−] (4, 53 %) and {Mg+C(Ph)=C(Me)C[C(Me)=NDipp]2}2⋅2 [B(C6F5)4−] (5, 73 %), in which the Mg center is N,N,C‐chelated. The (BDI)Mg+ cation can be viewed as an intramolecular frustrated Lewis pair (FLP) with a Lewis acidic site (Mg) and a Lewis (or Brønsted) basic site (BDI). Reaction of [(BDI)Mg+][B(C6F5)4−] (1) with a range of phosphines varying in bulk and donor strength generated [(BDI)Mg+⋅PPh3][B(C6F5)4−] (6), [(BDI)Mg+⋅PCy3][B(C6F5)4−] (7), and [(BDI)Mg+⋅ PtBu3][B(C6F5)4−] (8). The bulkier phosphine PMes3 (Mes=mesityl) did not show any interaction. Combinations of [(BDI)Mg+][B(C6F5)4−] and phosphines did not result in addition to the triple bond in 3‐hexyne, but during the screening process it was discovered that the cationic magnesium complex catalyzes the hydrophosphination of PhC≡CH with HPPh2, for which an FLP‐type mechanism is tentatively proposed.
NMR chiral discrimination of chalcogen containing secondary alcohols
Authors: Marques Naiade B.G. , Jacob Raquel G. , Perin Gelson , Lenardão Eder J. , Alves Diego , Silva Márcio S.
Published: November 2018

Here, we report the general strategies by which NMR spectroscopy can be used to determine the enantiopurity and absolute configuration of chalcogen containing secondary alcohols, including the evaluation of the use of chiral solvating and chiral derivatizing agents. The BINOL/DMAP ternary complex demonstrated a simple and fast protocol for determining enantiopurity. The drug Naproxen afforded a stable, nonhygroscopic, and readily available chiral derivatizing agent (CDA) for NMR chiral discrimination of chalcogen containing secondary alcohols. The chiral recognition by CDA and chiral solvating agent (CSA) was assessed using 1H, 77Se‐{1H}, and 125Te‐{1H} NMR spectroscopy. A simple model for the assignment of the absolute configuration from NMR data is presented.
Impact of co‐flow on the spray flame behaviour applied to nanoparticle synthesis
Authors: Buss Lizoel , Meierhofer Florian , Bianchi Neto Pedro , França Meier Henry , Fritsching Udo , Noriler Dirceu
Published: November 2018

Flame spray pyrolysis (FSP) is an established process to synthesize nanoparticles of various metals and metal oxides. Applying open or enclosed configurations of the FSP reactor is an efficient tool to control the fuel‐oxidizer ratio in the reaction zone and, thus, the temperature distribution and the particle formation and growth process. In the present work, geometrical setups representing an open and an enclosed flame reactor are compared and their influence on the temperature, velocity, and particle characteristics is investigated. In addition, several distinct kinetic mechanisms for the combustion reactions are evaluated and their effects on the local reactor temperature and gas composition distribution are analyzed. An Eulerian‐Lagrangian approach is adopted to describe the multiphase turbulent gas‐droplet flow and a monodisperse approach based on the population balance equation (PBE) model is implemented to predict the particle formation and evolution. From the open reactor results, the air entrainment mass flow rate of gas into the flame is calculated. Several numerical experiments are performed with the enclosed setup. Supplying an appropriate co‐flow rate into the enclosed reactor results in similar flame behaviour as found for the open reactor configuration. By reducing the co‐flow gas, strong recirculation zones and particle deposition on the enclosure walls are observed. In this situation, the local temperature increases considerably, resulting in larger primary nanoparticle diameters.