bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced Raman Scattering of CuPc Films on Imperfect WSe2 Monolayer Correlated to Exciton and Charge‐Transfer Resonances
Authors: Liu Yanran , Gao Zhibin , Chen Ming , Tan Yang , Chen Feng 
Published: October 2018

AbstractRecently, 2D transition‐metal dichalcogenides (2D TMDCs) are identified as ideal substrates for surface‐enhanced Raman scattering (SERS). However, the effect of enhancement factor (EF) on TMDCs is lower than metal‐based SERS substrates. Here, it is demonstrated that the SERS performance of WSe2 monolayer can be enhanced via tailoring the atomic ratio of WSe2; this correlates to the exciton and charge‐transfer resonances. CuPc molecules are adsorbed onto WSe2 monolayers as the probe molecules, and the atomic ratio (Se:W) of WSe2 is tailored from 2 to 1.92. For an atomic ratio of 1.96, the maximum EF on irradiated WSe2 is more than 120; this is enhanced by more than 40 times compared with pristine WSe2. The amplitude of exciton and charge‐transfer resonances is estimated by femtosecond optical pump‐probe measurement and a bipolar junction transistor (BJT) consisting of CuPc film and 2D materials. It is found that the intensity of resonances in the CuPc–WSe2 system is tailored by the atomic ratio of WSe2. This is closely correlated to the SERS performance of WSe2. This study shows that the SERS performance of WSe2 is enhanced by tuning the atomic ratio of WSe2 and provides qualitative theoretical explanations for the mechanism of enhanced SERS.
A Triboelectric Nanogenerator‐Based Smart Insole for Multifunctional Gait Monitoring
Authors: Lin Zhiming , Wu Zhiyi , Zhang Binbin , Wang Yi‐Cheng , Guo Hengyu , Liu Guanlin , Chen Chaoyu , Chen Yuliang , Yang Jin , Wang Zhong Lin 
Published: October 2018

AbstractAccurately monitoring human gait is critical for health evaluation and/or early diagnosis, especially for elder and injured people's healthcare. The presence of gait abnormalities could be important predictors of the risk of developing diseases. Herein, a triboelectric nanogenerator (TENG)‐based smart insole for real‐time gait monitoring is reported. Due to the novel air‐pressure‐driven structural design, the elastic TENG‐based sensors exhibit compelling features including simple fabrication, fast response time, high durability, and excellent mechanical robustness. The TENG‐based sensors can be easily integrated into the conventional insole so that it can convert the mechanical triggering/impact into electrical output. By analyzing such electrical signals, the smart insole could accurately monitor and distinguish various gait patterns in real time, including jump, step, walk, and run. The smart insole could also be used to monitor the abnormality of gait for rehabilitation assessment. In addition, the smart insole can play another important role in healthcare applications, for example, serving as a fall‐down alert system for elder people or patients. This work not only paves a new way for real‐time and long‐term gait monitoring, but also presents a new perspective for the practical applications of remote clinical biomotion analysis.
Biaxially Stretchable Ultrathin Si Enabled by Serpentine Structures on Prestrained Elastomers
Authors: Sim Kyoseung , Li Yuhang , Song Jizhou , Yu Cunjiang 
Published: October 2018

AbstractBuilding stretchable electronics from inorganic materials is a testified pathway toward devices with high performances for many applications in fields such as optoelectronics, biomedical, etc. Owing to the unstretchable nature of these materials (e.g., brittleness of Si), existing ways to enable stretchabilities mainly involve either bonding thin films on a prestrained elastomer substrate or configuring materials into thin serpentine layouts. It is hypothesized that a combination of prestrain and serpentine will lead to advantages in the: (1) enlarged stretchability at the materials and (2) enhanced areal fill factor of the materials, when compared with existing serpentine structures without using prestrain strategy. This paper reports a biaxially stretchable Si structure and its optoelectronic devices enabled through the combination of serpentine structure designs and prestrain strategy on an elastomer substrate. The detailed device design and fabrication, mechanical analysis, and electrical performance characterization illustrate the key concept and validate the hypothesis. The Si nanomesh can be stretched by 75% biaxially with prestrain of 50% and has an enhanced areal fill factor of 125%. The combined strategy of prestrain and serpentine is applicable to a wide range of materials and devices, and the demonstrated results can be useful for stretchable electronics, optoelectronics, and many others.
Stereoselective Synthesis of 3‐Oxabicyclo[3.3.1]Nonan‐2‐Ones via a Domino Reaction Catalyzed by Modularly Designed Organocatalysts
Authors: Parella Ramarao , Jakkampudi Satish , Arman Hadi , Zhao John C.‐G. 
Published: October 2018

AbstractA highly stereoselective method for the synthesis of functionalized 3‐oxabicyclo[3.3.1]nonan‐2‐one derivatives with four contiguous stereogenic centers, including one tetrasubstituted stereogenic center, was realized through an organocatalytic domino Michael‐hemiacetalization‐Michael reaction of (E)‐3‐aryl‐2‐nitroprop‐2‐enols and (E)‐7‐aryl‐7‐oxohept‐5‐enals followed by a PCC oxidation. Using the modularly designed organocatalysts (MDOs) self‐assembled from cinchona alkaloid derivatives and amino acids in the reaction media, the title products were obtained in good yields (up to 84%), excellent diastereoselectivities (≥99:1 dr), and high enantioselectivities (up to 96% ee).magnified image
Trapping the Complex Molecular Machinery of Polyketide and Fatty Acid Synthases with Tunable Silylcyanohydrin Crosslinkers
Authors: Konno Sho , La Clair James J. , Burkart Michael D. 
Published: October 2018

AbstractMany families of natural products are synthesized by large multidomain biological machines commonly referred to as megasynthases. While the advance of mechanism‐based tools has opened new windows into the structural features within the protein–protein interfaces guiding carrier protein dependent enzymes, there is an immediate need for tools that can be engaged to link co‐translated domains in a site‐selective manner. Now, the use of silylcyanohydrins is demonstrated in a two‐step, two‐site selective crosslinking for the trapping of carrier–protein interactions within megasynthases. This advance provides a new tool to trap intermediate states within multimodular systems, a key step toward understanding the specificities within fatty acid (FAS) and polyketide (PKS) synthases.
Ionic Janus Liquid Droplets Assembled and Propelled by Electric Field
Authors: Sindoro Melinda , Granick Steve 
Published: October 2018

AbstractTraditional Janus particle approaches to produce active motion are based on using solid particles, but it is interesting to consider liquid droplets instead, because for solid particles, the self‐assembly of synthetic active matter requires moving objects to sit in a near‐planar 2D geometry. Emulsions, cross‐linked polymers, and porous materials have been proposed for 3D self‐assembly but with limitations to propel them. It is now demonstrated that Janus liquid droplets can be used as building block in an active propulsion system. Using an ionic liquid motif, the droplet system can be tuned from core–shell to Janus and multipatches, using facile surfactant‐based methods. The approach was stimulated by the success of electro‐hydrodynamic flow produced by an alternating electric field to produce motion of colloidal particles; its usefulness to also propel ionic liquids is demonstrated.
Regio‐ und stereoselektive allylische Substitutionen chiraler sekundärer Alkylkupferverbindungen: Totalsynthese von (+)‐Lasiol, (+)‐13‐Norfaranal und (+)‐Faranal
Authors: Skotnitzki Juri , Spessert Lukas , Knochel Paul 
Published: October 2018

AbstractChirale sekundäre Alkylkupferverbindungen wurden aus chiralen sekundären Alkyliodiden durch einen I/Li‐Austausch, gefolgt von einer retentiven Transmetallierung mit CuBr⋅P(OEt)3, hergestellt. Durch Wechseln des Lösungsmittels zu THF wird die konfigurative Stabilität der Kupferverbindungen signifikant verbessert und macht diese für regioselektive allylische Substitutionen brauchbar. Diese optisch angereicherten Kupferreagentien gingen SN2‐Substitutionen mit Allylbromiden (bis zu >99 % SN2‐Regioselektivität) ein. Versetzen mit ZnCl2 und die Verwendung von chiralen Allylphosphaten ermöglicht es, die Regioselektivität hin zu SN2′‐Substitutionen zu verschieben (bis zu >99 % SN2′‐Regioselektivität), sowie die Durchführung von äußerst selektiven anti‐SN2′‐Substitutionen mit kompletter Kontrolle von zwei nebeneinanderliegenden Stereozentren. Diese Methode wurde in der Naturstoffsynthese von drei Ameisenpheromonen – (+)‐Lasiol, (+)‐13‐Norfaranal und (+)‐Faranal (dr bis zu 98:2, 99 % ee) – angewendet.
The Complex Coordination Landscape of a Digold(I) U‐Shaped Metalloligand
Authors: Ibáñez Susana , Poyatos Macarena , Peris Eduardo 
Published: October 2018

AbstractA U‐shaped di‐gold metallotweezer with two pyrene‐imidazolylidene edges and a xanthenyl‐bis‐alkynyl connector was prepared. This metallotweezer acts as metalloligand in the presence of Cu+, Tl+, or Ag+, showing three clearly distinct coordination patterns depending on the cation used. The coordination to Cu+ leads to a complex in which the metalloligand is coordinated in a pincer form. The reaction with Tl+ affords a complex in which the ligand is acting as a ϰ2‐(trans)‐chelate ligand. The reaction with Ag+ leads to a self‐assembled structure, with two silver cations encased inside the cavity of a duplex structure formed by two self‐assembled metallotweezers.
Lysosome‐targeted potent half‐sandwich iridium(III) α‐diimine antitumor complexes
Authors: Kong Deliang , Guo Lihua , Tian Meng , Zhang Shumiao , Tian Zhenzhen , Yang Huayun , Tian Ye , Liu Zhe 
Published: October 2018

Fifteen organometallic Ir(III) half‐sandwich complexes (1A–5C) having the general formula [(η5‐Cpx)Ir(N^N)Cl]PF6 (Cpx = Cp*, tetramethyl(phenyl)cyclopentadienyl (Cpxph) or tetramethyl(biphenyl)cyclopentadienyl (Cpxbiph); N^N = diamine) have been synthesized and characterized. The molecular structure of 1A was determined using single‐crystal X‐ray diffraction analysis. The hydrolysis of 1A–5C was monitored using UV–visible spectra. Complexes 3A–3C showed catalytic activity for the oxidation of NADH to NAD+, where 3C showed the highest turnover number of 29.9 within 450 min. Cytotoxicity examination by MTT assay was carried out against two human cancer cell lines (HeLa and A549) after 24 or 48 h drug treatment. The complexes showed high potency, where the most potent complex (3C; IC50 = 3.4 μM) was six times more active than cisplatin against A549 cells after 24 h drug exposure. Cytotoxic potency towards A549 cells increased with phenyl substitution on Cp ring: Cpxbiph > Cpxph > Cp*. In addition, the biological studies showed that 3C caused cell apoptosis and cell cycle arrest at G1 phase in A549 cancer cells. Moreover, 3C increased the level of reactive oxygen species markedly after 24 h, which may provide an important basis for killing cancer cells. Confocal laser scanning microscopy was used to track 3C in A549 cells. The cellular localization experiment showed that 3C targeted lysosomes and caused lysosomal damage.
Ghrelin and NUCB2/Nesfatin‐1 Co‐Localization With Digestive Enzymes in the Intestine of Pejerrey (Odontesthes bonariensis)
Authors: Bertucci Juan Ignacio , Blanco Ayelén Melisa , Sánchez‐Bretaño Aida , Unniappan Suraj , Canosa Luis Fabián 
Published: October 2018

ABSTRACTGhrelin (orexigenic) and nesfatin‐1 (anorexigenic) are two peptides with opposing actions on food intake regulation and are mainly expressed in the hypothalamus and gut of mammals and fish. Both are involved in the regulation of a wide range of physiological processes in vertebrates, including metabolism, growth, and reproduction. However, the anatomical relationship between these peptides and the nutrient assimilation processes are not well understood. Thus, the aim of this work was to determine the localization of ghrelin, nesfatin‐1, and several enzymes involved in the digestive process (lipoprotein lipase, aminopeptidase A, trypsin, and sucrase‐isomaltase) in the intestine of pejerrey (Odontesthes bonariensis), a species with commercial importance in South America. We observed co‐localization of ghrelin and nesfatin‐1 in enteroendocrine cells, absorptive cells, and in cells of the lamina propia. Approximately half of the cells displaying ghrelin‐like immunoreactivity co‐localized the NUCB2/nesfatin‐1‐like signal. In addition, both peptides showed co‐localization with lipoprotein lipase, aminopeptidase A, trypsin, or sucrase‐isomaltase. All digestive enzymes except for aminopeptidase A and trypsin, showed high co‐localization (68–88%) with both ghrelin‐like and NUCB2/nesfatin‐1‐like signals in absorptive, enteroendocrine, and lamina propria cells. Together, our results provide immunohistochemical evidence supporting a role for both ghrelin and NUCB2/nesfatin‐1 in the regulation of nutrient assimilation in fish. Anat Rec, 302:973–982, 2019. © 2018 Wiley Periodicals, Inc.
Description of Tooth Ontogeny and Replacement Patterns in a Juvenile Tarbosaurus bataar (Dinosauria: Theropoda) Using CT‐Scan Data
Authors: Hanai Tomoya , Tsuihiji Takanobu 
Published: October 2018

ABSTRACTTeeth are continually replaced in most of non‐mammalian gnathostomes to maintain their functional dentitions. To clarify the tooth replacement patterns in tyrannosaurid theropod dinosaurs, we examined well‐preserved dentitions (both premaxillae, left maxilla, partial right maxilla, and both dentaries) of a juvenile Tarbosaurus bataar (MPC‐D 107/7) using X‐ray computed tomographic (CT) imaging. Three‐dimensional (3D) rendering of the dentitions and staging of replacement teeth allowed quantitative analyses of the tooth ontogeny and replacement patterns in this specimen. These strategies were validated by comparing the results between MPC‐D 107/7 and extant crocodilians, which are taxa that have previously been studied using non‐CT methods. 3D‐rendered dentitions of MPC‐D 107/7 showed alternate replacement patterns between odd‐ and even‐numbered alveoli. Such patterns were discontinuous at the premaxilla‐maxilla junctions, suggesting the division of replacement patterns between the two dentitions possessing morpho‐functionally different features. The replacement process in the odd‐numbered alveoli of the left maxilla sequentially proceeded from distal alveoli. Meanwhile, in the both dentaries, there were simple alternate patterns in which functional teeth would be simultaneously shed out in every second alveoli. Such a simple alternation had never been reported in the adult tyrannosaurid dentaries. Under this pattern, the half of functional teeth in a single dentition would be shed at the same time, which may hamper foraging functions. We conclude that the simple alternate patterns found in the dentary dentitions of MPC‐D 107/7 represent transient condition in juvenile tyrannosaurids, suggesting ontogenetic changes in tooth replacement patterns in the tyrannosaurid dentary. Anat Rec, 302:1210–1225, 2019. © 2018 Wiley Periodicals, Inc.
The Neuropilin‐1 Ligand, Sema3A, Acts as a Tumor Suppressor in the Pathogenesis of Acute Leukemia
Authors: Yang Zhi‐Gang , Wen Rui‐Ting , Qi Kai , Li Jun , Zheng Gui‐Xian , Wang Yu‐Feng , Hong Yun‐Guang , Zhang Yu‐Ming 
Published: October 2018

ABSTRACTSemaphorin‐3A (Sema3A) and vascular endothelial growth factor (VEGF165) are ligands of neuropilin‐1 (NRP‐1 or CD304) and are related to immunoregulation and tumor angiogenesis, respectively. However, possible interactions between NRP‐1 and Sema3A and VEGF165 in acute leukemia remain unclear, especially whether Sema3A plays a role in acute leukemia. In this study, both of the proportion of regulatory T cells (Tregs) and their expression of NRP‐1 were found to increase in acute leukemia patients compared with healthy controls. In contrast, lower mRNA and plasma levels of Sema3A were detected in the acute leukemia patients. In vitro, the addition of exogenous Sema3A inhibited the expression of NRP‐1 on Tregs and it promoted apoptosis of leukemia cells. However, in the presence of anti‐Sema3A antibody, the effect of rhSema3A on NRP‐1 expression was reversed. These results suggest that Sema3A promotes apoptosis in leukemia cells by inhibiting expression of NRP‐1, and thus, represents a tumor suppressor protein with a role in the pathogenesis of acute leukemia. Consequently, NRP‐1/Sema3A signaling may represent a novel target for the treatment of acute leukemia and should be further studied. Anat Rec, 302:1127–1135, 2019. © 2018 Wiley Periodicals, Inc.
Undergraduate Medical Students' Usage and Perceptions of Anatomical Case‐Based Learning: Comparison of Facilitated Small Group Discussions and eLearning Resources
Authors: Holland Jane C. , Pawlikowska Teresa 
Published: October 2018

AbstractWhile case‐based discussions can empower students to apply knowledge to contextual clinical situations, scheduling these activities is a challenge in crowded curricula. Case‐based eLearning activities, derived from existing cases discussed within anatomy small group tutorials, were created incorporating principles such as interactivity, reinforcement, and feedback. Over half of the students accessed one or more of these online cases, with 18% accessing all eight online cases provided. Access increased as the semester progressed, particularly just before summative examinations, implying students used these primarily as revision aides. Students rated both formats highly, but favored the online format with regard to enjoyment (P = 0.048), learning (P = 0.101), and feedback (P = 0.086). However, more students discussed these cases in small group tutorials within the anatomy dissecting room than completed them online (122 vs. 67) and themes emerging from free text comments included a desire to have more time dedicated to these cases during small group tutorials, and an appreciation for the opportunity for discussion with staff and learning through doing. Additionally, native English speakers rated the anatomy room discussions significantly higher in all aspects than non‐native English speakers, suggesting that non‐native speakers may be hesitant or reluctant to fully participate in front of peers. While online case‐based learning activities are a useful adjunct to anatomy teaching, particularly for revision, assumptions that “digital natives” have an innate preference for digital resources require critical evaluation, as students still place a high value on opportunities for discussion with staff during their studies.
Anxiety among Medical Students when Faced with the Practice of Anatomical Dissection
Authors: Romo Barrientos Carmen , José Criado‐Álvarez Juan , González‐González Jaime , Ubeda‐Bañon Isabel , Saiz‐Sanchez Daniel , Flores‐Cuadrado Alicia , Luis Martín‐Conty José , Viñuela Antonio , Martinez‐Marcos Alino , Mohedano‐Moriano Alicia 
Published: October 2018

Practical training in the dissection of human cadavers is a fundamental and traditional component of human anatomy education in medical schools. This practice, however, can be stressful for students and can generate a certain amount of anxiety. The aim of this study is to explore the attitudes, reactions, and anxiety levels of first‐year medical students when working in the dissecting room, over a period of one year, and to relate these anxiety levels to the results of our educational program. This is a before and after descriptive study of students at the University of Castilla‐La‐Mancha. Questionnaires were distributed among them before and after their dissection practices in order to understand their feelings and emotions and their satisfaction about this activity. State‐Trait Anxiety Inventory questionnaires were used to assess the students’ ‘state anxiety’ (SA), which dropped significantly from 49.1% to 14% by the end of their first year. Female students started with higher levels of SA than their male counterparts but by the end of the year these had dropped to similar levels. Anxiety and fearful thoughts tended to drop (P > 0.05). In contrast, uncertainty levels showed significant changes, falling from 44.4% to 12.3%. Nonetheless, 100% of students would go through the experience again. Indeed, 98.2% considered that dissection practices were useful in reinforcing the theoretical aspects of their education, and 80.7% believed that dissecting was more useful than theoretical models. Although students were satisfied with dissection practices the experience cause stressful responses.
A new multivariate variability control chart based on a covariance matrix combination
Authors: Alfaro Jose Luis , Ortega Juan Fco. 
Published: October 2018

AbstractIn the field of multivariate quality control, there are many control charts related to the process mean but few options addressing process variability. Variability control charts have two main drawbacks: the first relates to the number of parameters to tune and the second relates to how changes in the mean affect the performance of these charts. Thus, in this paper, we propose a new multivariate variability control chart, called the multivariate exponentially weighted covariance matrix combination, which solves these two problems. The results show that this new chart performs well in the detection of changes in variance when the mean does not change and outperforms other charts when the mean does change.
Detecting change points in the stress‐strength reliability P(X < Y)
Authors: Xu Hang , Yu Philip L.H. , Alvo Mayer 
Published: October 2018

AbstractWe address the statistical problem of detecting change points in the stress‐strength reliability R=P(X<Y) in a sequence of paired variables (X,Y). Without specifying their underlying distributions, we embed this nonparametric problem into a parametric framework and apply the maximum likelihood method via a dynamic programming approach to determine the locations of the change points in R. Under some mild conditions, we show the consistency and asymptotic properties of the procedure to locate the change points. Simulation experiments reveal that, in comparison with existing parametric and nonparametric change‐point detection methods, our proposed method performs well in detecting both single and multiple change points in R in terms of the accuracy of the location estimation and the computation time. Applications to real data demonstrate the usefulness of our proposed methodology for detecting the change points in the stress‐strength reliability R. Supplementary materials are available online.