bluuebunny/crossref_metadata_2025 huggingface dataset:
Over 30% External Quantum Efficiency Light‐Emitting Diodes by Engineering Quantum Dot‐Assisted Energy Level Match for Hole Transport Layer
Authors: Song Jiaojiao , Wang Ouyang , Shen Huaibin , Lin Qingli , Li Zhaohan , Wang Lei , Zhang Xintong , Li Lin Song
Published: May 2019

In the study of hybrid quantum dot light‐emitting diodes (QLEDs), even for state‐of‐the‐art achievement, there still exists a long‐standing charge balance problem, i.e., sufficient electron injection versus inefficient hole injection due to the large valence band offset of quantum dots (QDs) with respect to the adjacent carrier transport layer. Here the dedicated design and synthesis of high luminescence Zn1−x
CdxSe/ZnSe/ZnS QDs is reported by precisely controlled shell growth, which have matched energy level with the adjacent hole transport layer in QLEDs. As emitters, such Zn1−xCdxSe‐ based QLEDs exhibit peak external quantum efficiencies (EQE) of up to 30.9%, maximum brightness of over 334 000 cd m−2, very low efficiency roll‐off at high current density (EQE ≈25% @ current density of 150 mA cm−2), and operational lifetime extended to ≈1 800 000 h at 100 cd m−2. These extraordinary performances make this work the best among all solution‐processed QLEDs reported in literature so far by achieving simultaneously high luminescence and balanced charge injection. These major advances are attributed to the combination of an intermediate ZnSe layer with an ultrathin ZnS outer layer as the shell materials and surface modification with 2‐ethylhexane‐1‐thiol, which can dramatically improve hole injection efficiency and thus lead to more balanced charge injection.
Improved Stability and Photodetector Performance of CsPbI3 Perovskite Quantum Dots by Ligand Exchange with Aminoethanethiol
Authors: Bi Chenghao , Kershaw Stephen V. , Rogach Andrey L. , Tian Jianjun
Published: May 2019

A surface engineering strategy aimed at improving the stability of CsPbI3 perovskite quantum dots (QDs) both in solution and as films is demonstrated, by performing partial ligand exchange with a short chain ligand, 2‐aminoethanethiol (AET), in place of the original long chain ligands, oleic acid (OA) and oleylamine (OAm), used in synthesis. This results in the formation of a compact ligand barrier around the particles, which prevents penetration of water molecules and thus degradation of the films and, in addition, at the same time improves carrier mobility. Moreover, the AET ligand can passivate surface traps of the QDs, leading to an enhanced photoluminescence (PL) efficiency. As a result, AET‐CsPbI3 QDs maintain their optical performance both in solution and as films, retaining more than 95% of the initial PL intensity in water after 1 h, and under ultraviolet irradiation for 2 h. Photodetectors based on the AET‐CsPbI3 QD films exhibit remarkable performance, such as high photoresponsivity (105 mA W−1) and detectivity (5 × 1013 Jones at 450 nm and 3 × 1013 Jones at 700 nm) without an external bias. The photodetectors also show excellent stability, retaining more than 95% of the initial responsivity in ambient air for 40 h without any encapsulation.
Chiral Octahydro‐Binaphthol Compound‐Based Thermally Activated Delayed Fluorescence Materials for Circularly Polarized Electroluminescence with Superior EQE of 32.6% and Extremely Low Efficiency Roll‐Off
Authors: Wu Zheng‐Guang , Han Hua‐Bo , Yan Zhi‐Ping , Luo Xu‐Feng , Wang Yi , Zheng You‐Xuan , Zuo Jing‐Lin , Pan Yi
Published: May 2019

Circularly polarized organic light‐emitting diodes (CP‐OLEDs) are particularly favorable for the direct generation of CP light, and they demonstrate a promising application in 3D display. However, up to now, such CP devices have suffered from low brightness, insufficient efficiency, and serious efficiency roll‐off. In this study, a pair of octahydro‐binaphthol (OBN)‐based chiral emitting enantiomers, (R/S)‐OBN‐Cz, are developed by ingeniously merging a chiral source and a luminophore skeleton. These chirality–acceptor–donor (C–A–D)‐type and rod‐like compounds concurrently generate thermally activated delayed fluorescence with a small ΔEST of 0.037 eV, as well as a high photoluminescence quantum yield of 92% and intense circularly polarized photoluminescence with dissymmetry factors (|gPL|) of ≈2.0 × 10−3 in thin films. The CP‐OLEDs based on (R/S)‐OBN‐Cz enantiomers not only display obvious circularly polarized electroluminescence signals with a |gEL| of ≈2.0 × 10−3, but also exhibit superior efficiencies with maximum external quantum efficiency (EQEmax) up to 32.6% and extremely low efficiency roll‐off with an EQE of 30.6% at 5000 cd m−2, which are the best performances among the reported CP devices to date.
Solution‐Processed Transparent Sn4+‐Doped CuI Hybrid Photodetectors with Enhanced Performances
Authors: Li Siyuan , Zhang Yong , Yang Wei , Fang Xiaosheng
Published: May 2019

Herein, Sn4+‐doped copper (I) iodide (CuI) is prepared via a facile, cost‐efficient solution process, and the properties of Sn4+‐doped CuI, including morphology, crystalline phase, as well as optical and electrical properties, are investigated by varying the Sn4+ concentration. And by constructing transparent Sn4+‐CuI/ZnO hybrid UV photodetectors, the potential of Sn4+‐CuI as a p‐type material for high‐performance photodetection is investigated. It is found that Sn4+ doping has great effect on the morphology as the formation of Sn4+‐CuI thin sheets is observed, and the resistivity of Sn4+‐CuI could be tuned by controlling Sn4+ addition. The Sn4+‐CuI/ZnO hybrid photodetectors exhibit obviously enhanced photodetecting performance outperforming ZnO film and CuI/ZnO photodetectors by the same preparation method, including significantly improved on/off ratio, spectral responsivity, and shortened responsive time. The enhanced performance of Sn4+‐CuI/ZnO hybrid photodetectors mainly arises from the formation of type‐II p‐Sn4+‐CuI/n‐ZnO heterojunctions, and the better interface contact leads to higher carrier separation efficiency due to the existence of Sn4+‐CuI thin sheets. And the improved performance is also related to the optimized resistivity of Sn4+‐CuI. This study sheds light on the potential of doped CuI toward transparent, high‐performance photodetectors in the future.
Laser‐Induced Graphene Composites for Printed, Stretchable, and Wearable Electronics
Authors: Tehrani Farshad , Beltrán‐Gastélum Mara , Sheth Karan , Karajic Aleksandar , Yin Lu , Kumar Rajan , Soto Fernando , Kim Jayoung , Wang Joshua , Barton Shemaiah , Mueller Michelle , Wang Joseph
Published: May 2019

Graphene‐based composites have received attention as part of the drive towards next‐generation electronic and energy‐storage technologies. However, current graphene synthesis methods are limited by complex, time‐consuming, toxic, costly, and/or often low‐yield procedures. The synthesis of a novel stretchable graphene‐polyurethane‐poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate ink aimed at printing wearable electronics is reported. The procedure is based on low‐cost high‐yield production of high‐performance graphene ink produced by laser induction of polyimide film followed by harvesting the graphene. Screen printing is used to fabricate flexible and intrinsically stretchable micro‐supercapacitors (S‐MSCs) printed on different substrates. The resulting graphene‐based printed S‐MSCs display a remarkably high capacitive performance and attractive mechanical resiliency. High specific areal capacitance, above 23 mF cm−2, is achieved, which is the highest areal capacitance reported for highly stretchable, printed graphene supercapacitors. A repeated (200 cycles) stretchability beyond 100% is obtained while maintaining more than 85% of the S‐MSCs' original capacitance. This unique and highly scalable graphene ink synthesis method holds considerable promise for application in low‐cost graphene‐based chemical formulation, especially in the field of printed and wearable electronics toward multifunctional, energy‐storage systems capable of withstanding severe mechanical deformation while maintaining their optimal electrochemical performance.
Organic Solar Cells on Paper Substrates
Authors: Rawat Madhu , Jayaraman Eswaran , Balasubramanian Sambathkumar , Iyer S. Sundar Kumar
Published: May 2019

The fabrication of organic solar cells on paper substrate is attractive as it paves the way for roll‐to‐roll‐processed modules on more ecologically friendly substrates. A paper‐substrate solar‐cell process is successfully demonstrated. Commercially available paper with coatings from the polyvinyl family of materials is made suitable for electronic‐device fabrication. Smoothing layers of polyvinyl formal (PVF) with a knife‐edge coater give them an acceptable root mean square roughness of around 2.6 ± 0.2 nm. This paper is shown to be compatible with subsequent organic‐solar‐cell device fabrication with a variety of solvents including polar solvents. Top‐illuminated solar cells with blends of either poly(3‐hexylthiophene) and [6,6]‐phenyl C61 butyric acid methyl ester (PCBM), or poly({4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl}{3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl}) and PCBM as photoactive layer having power conversion efficiencies up to 3.37% and 6.44%, respectively, are fabricated. A statistically significant number solar cells with different areas from multiple runs are fabricated and their solar cell parameters are analyzed and discussed. The results show strong promise for solar‐cell fabrication on environmentally friendly paper substrates.
Selective Defect Formation in Hexagonal Boron Nitride
Authors: Abidi Irfan H. , Mendelson Noah , Tran Toan Trong , Tyagi Abhishek , Zhuang Minghao , Weng Lu‐Tao , Özyilmaz Barbaros , Aharonovich Igor , Toth Milos , Luo Zhengtang
Published: May 2019

Luminescent defects in hexagonal boron nitride (hBN) have emerged as promising single photon emitters (SPEs) due to their high brightness and robust operation at room temperature. The ability to create such emitters with well‐defined optical properties is a cornerstone toward their integration into on‐chip photonic architectures. Here, an effective approach is reported to fabricate hBN SPEs with desired emission properties in distinct spectral regions via the manipulation of boron diffusion through copper during atmospheric pressure chemical vapor deposition (CVD)—a process termed gettering. Using the gettering technique the resulting zero‐phonon line is deterministically placed between the regions 550 and 600 nm or from 600 to 650 nm, paving the way for hBN SPEs with tailored emission properties. Additionally, rational control over the observed SPE density in the resulting films is demonstrated. The ability to control defect formation during hBN growth provides a cost effective means to improve the crystallinity of CVD hBN films, and lower defect density making it applicable to hBN growth for a wide‐range of applications. The results are important to understand defect formation of quantum emitters in hBN and deploy them for scalable photonic technologies.
Reduced Local Symmetry in Lithium Compound Li2SrSiO4 Distinguished by an Eu3+ Spectroscopy Probe
Authors: Chen Lei , Cheng Peng , Zhang Zhao , He Liangrui , Jiang Yang , Li Guobao , Jing Xiping , Qin Yan'guang , Yin Min , Chan Ting‐Shan , Hong Bin , Tao Shi , Chu Wangsheng , Zhao Zhi , Ni Haiyong , Kohlmann Holger , Oeckler Oliver
Published: May 2019

Research on lithium compounds has attracted much attention nowadays. However, to elucidate the precise structure of lithium compounds is a challenge, especially when considering the small ions that may be transferred between the interstitial voids. Here, the discovery of reduced local symmetry (symmetry breaking) in small domains of Li2SrSiO4 is reported by employing Eu3+ as a spectroscopic probe, for which X‐ray, neutron, and electron diffraction have confirmed the average long‐range structure with the space group P3121. However, luminescence shows a lower local symmetry, as confirmed by the extended X‐ray absorption fine structure. By considering the reduced symmetry of the local structure, this work opens the door to a new class of understanding of the properties of materials.
New Metallic Ordered Phase of Perovskite CsPbI3 under Pressure
Authors: Liang Yongfu , Huang Xiaoli , Huang Yanping , Wang Xin , Li Fangfei , Wang Youchun , Tian Fubo , Liu Bingbing , Shen Ze Xiang , Cui Tian
Published: May 2019

Pressure‐induced electronic structure transition from insulating phase to metal state is a potential new paradigm for halide perovskites. The metallization based on these materials may afford a novel motif toward realizing new electronic properties even superconductivity phenomenon. Herein, how static compression modulates the crystal and electronic structure of typical perovskite semiconductors cesium lead iodine (CsPbI3) by both experimental and theoretical studies is reported. The comprehensive studies discover the insulator–metal transition of CsPbI3 at 39.3 GPa, and reveal the key information behind the electronic transition. The perovskite's precise structural evolution is tracked upon compression, from orthorhombic Pnma phase to monoclinic C2/m structure before the metallic transition. More interestingly, the C2/m phase has the most distorted octahedra and the shortest Pb–I bond length relative to the average bond length that is ever reported in a halide perovskite structure. The electronic transition stems from the structural changes accompanied by the anomalously self‐distorted octahedra. These studies show that pressure can significantly alter the structural and electronic properties of these technologically important perovskites.
Surgical outcomes of gastroenterological surgery in Japan: Report of the National Clinical Database 2011‐2017
Authors: Hasegawa Hiroshi , Takahashi Arata , Kakeji Yoshihiro , Ueno Hideki , Eguchi Susumu , Endo Itaru , Sasaki Akira , Takiguchi Shuji , Takeuchi Hiroya , Hashimoto Masaji , Horiguchi Akihiko , Masaki Tadahiko , Marubashi Shigeru , Yoshida Kazuhiro , Konno Hiroyuki , Gotoh Mitsukazu , Miyata Hiroaki , Seto Yasuyuki
Published: May 2019

Background

The Japanese National Clinical Database (NCD) is a large‐scale, nationwide, web‐based data entry system that is linked to the surgical board certification system and covers almost all surgical cases carried out in Japan.

Aim

To evaluate outcomes according to the gastroenterological section of the NCD.

Methods

The 115 surgical procedures stipulated by the “Training Curriculum for Board‐Certified Surgeons in Gastroenterology” were registered from 2011 to 2017. The number of surgeries, preoperative comorbidities, and short‐term outcomes were compared between registration periods.

Results

In total, 3 818 414 cases have been registered. More than 70% of all surgeries were carried out at certified institutions. The annual number of cases has been increasing year after year, and the aged population has also been increasing. Although the rates of preoperative comorbidities and postoperative complications have been increasing, the postoperative mortality rate has remained relatively low; in 2017, the 30‐day mortality rate was 1.0% among those who underwent esophagectomy, 0.7% among those who underwent distal gastrectomy, 1.1% among those who underwent total gastrectomy, 1.3% among those who underwent right hemicolectomy, 0.5% among those who underwent low anterior resection, 1.3% among those who underwent hepatectomy, and 1.3% among those who underwent pancreaticoduodenectomy. The annual rate of endoscopic surgery dramatically increased over 7 years between 2011 and 2017, especially for low anterior resection (29.5%‐62.6%) and esophagectomy (31.0%‐56.1%).

Conclusion

This database is expected to ensure the quality of the board‐certification system and surgical outcomes in gastroenterological surgery.
Experimental study of hydrate formation in oil–water systems using a high‐pressure visual autoclave
Authors: Song Guangchun , Li Yuxing , Wang Wuchang , Zhao Pengfei , Jiang Kai , Ye Xiao
Published: May 2019

To investigate the characteristics of hydrate formation in oil–water systems, a high‐pressure visual autoclave equipped with visual windows was used where a series of hydrate formation experiments were performed from natural gas + diesel oil + water systems at different water cuts (30 and 70%), rotation rates (100, 200, 300 r/min) and thermodynamic conditions (temperature, pressure). According to the temperature and pressure profiles in test experiments, the processes of hydrate formation under two kinds of experimental procedures were analyzed first. Then, based on the experimental phenomenon observed through the visual windows, hydrate morphologies and hydrate morphological evolvements throughout the experiments were mainly investigated. In experiments, the growth and annealing of hydrate films on the wall, the agglomeration and deposition of hydrate coated water droplets, flocculent‐like hydrate deposition with water trapped in and the Pickering effect of hydrates were identified. Simultaneously, based on the experimental data of thermodynamic parameters, the kinetics of hydrate formation was studied by calculating the variations of hydrate film area and gas consumption in different experiments. In addition, the influences of temperature, pressure, and rotation rate on hydrate morphologies, hydrate morphological evolvements, and hydrate formation kinetics were also focused on.
Gut microbiota in wild and captive Guizhou snub‐nosed monkeys, Rhinopithecus brelichi
Authors: Hale Vanessa L. , Tan Chia L. , Niu Kefeng , Yang Yeqin , Zhang Qikun , Knight Rob , Amato Katherine R.
Published: May 2019

Many colobine species—including the endangered Guizhou snub‐nosed monkey (Rhinopithecus brelichi) are difficult to maintain in captivity and frequently exhibit gastrointestinal (GI) problems. GI problems are commonly linked to alterations in the gut microbiota, which lead us to examine the gut microbial communities of wild and captive R. brelichi. We used high‐throughput sequencing of the 16S rRNA gene to compare the gut microbiota of wild (N = 7) and captive (N = 8) R. brelichi. Wild monkeys exhibited increased gut microbial diversity based on the Chao1 but not Shannon diversity metric and greater relative abundances of bacteria in the Lachnospiraceae and Ruminococcaceae families. Microbes in these families digest complex plant materials and produce butyrate, a short chain fatty acid critical to colonocyte health. Captive monkeys had greater relative abundances of Prevotella and Bacteroides species, which degrade simple sugars and carbohydrates, like those present in fruits and cornmeal, two staples of the captive R. brelichi diet. Captive monkeys also had a greater abundance of Akkermansia species, a microbe that can thrive in the face of host malnutrition. Taken together, these findings suggest that poor health in captive R. brelichi may be linked to diet and an altered gut microbiota.
Quantum Interface between a Superconducting Qubit and Spin Ensembles
Authors: Zhang Feng‐Yang , Li Wen‐Lin , Yan Wei‐Bin , Yang Chui‐Ping
Published: May 2019

An experimentally feasible strong coupling system between a spin ensemble and a superconducting qubit is studied. The coupling strength can be exponentially enhanced by applying the squeezing transformations to the system. By means of the two spin ensembles commonly coupled to a superconducting qubit, a set of universal nonadiabatic holonomic single‐qubit quantum gates can be realized in a decoherence‐free subspace. Furthermore, this proposal is robust with respect to decay of the system parameters, and it is experimentally feasible with currently available technology.
Rhodium‐Catalyzed Parallel Kinetic Resolution of Racemic Internal Allenes Towards Enantiopure Allylic 1,3‐Diketones
Authors: Hilpert Lukas J. , Breit Bernhard
Published: May 2019

A rare case of a parallel kinetic resolution of racemic 1,3‐disubstituted allenes by means of a rhodium‐catalyzed addition to 1,3‐diketones furnishing enantiopure allylic 1,3‐diketones is described. Mechanistic experiments demonstrate that the different allene enantiomers react in parallel to either the diastereomeric E‐ or Z‐allylic 1,3‐diketones with the same absolute configuration of the newly formed stereogenic center. A broad substrate scope demonstrates the synthetic utility of this new method.
Carnauba Wax Particles: Investigation of Dripping and Cold‐Extrusion Processes
Authors: Paulo Bruna Barbon , Schmiele Marcio , Maximo Guilherme José , Prata Ana Silvia
Published: May 2019

Solid lipids are commonly used as carrier systems for encapsulation processes. However, formulations containing only solid lipids tend to form a highly ordered crystal lattice, which can expel the active compound during long‐term storage, due to the dynamics of polymorphic transitions. Regarding the aspects of particle production, the cooling step of the melted lipid is essential for determining the type of formed crystals. This work aimed to analyze the effects of the crystallization step on the physicochemical properties of lipid particles. Carnauba wax (CW) particles with a relatively high melting point (Tm = 78 °C) were produced by the dripping method, based on melting‐crystallization steps, and by cold extrusion, which uses temperatures lower than the melting point of the lipid. Then, the physical properties, thermal behavior, and X‐ray of CW particles were analyzed. The particles obtained by dripping and extrusion presented mean sizes of 3.7 and 1.5 mm, respectively. All particles presented a similar thermal behavior (Tm = 78 °C; ΔH = 200 J g−1) and crystalline arrangement of the lipids. However, the dripping system presented an operational problem of clogging, requiring efficient thermal insulation, whereas the extrusion is a cost‐effective, time‐saving, and eco‐friendly method.
Effect of ionic radius on soot oxidation activity for ceria‐based binary metal oxides
Authors: Anantharaman Anjana P. , Dasari Hari Prasad , Dasari Harshini , Babu G. Uday Bhaskar
Published: May 2019

CeO2 (C) along with binary metal oxides of Ce0.9M0.1O2‐δ (M = Sn, Hf, Zr, Gd, Sm, and La; CT, CH, CZ CG, CS, and CL) are synthesized using the EDTA–citrate method. Samples having an ionic radius smaller (CT, CH, and CZ) and larger (CG, CS, and CL) than Ce4+ are classified separately, and their soot oxidation activity is analyzed. The incorporation of dopant is confirmed from lattice constant variation in X‐ray diffraction result. The critical descriptors for the activity are dopant nature (ionic radius and oxidation‐state), single‐phase solid solution, lattice strain, reactive (200) and (220) planes, Raman intensity ration (Iov/IF2g), optical bandgap, reducibility ratio, and surface oxygen vacancy. Smaller ionic radius, isovalent dopants (CH and CZ) create a defect site by lowering the optical bandgap along with improved surface oxygen vacancy concentration and thus enhanced soot oxidation activity. Aliovalent dopant with larger ionic radius shows the involvement of lattice oxygen in oxidation reaction by charge compensation mechanism. CL showed the highest activity amongst larger ionic radius samples.
Ultralight nanocomposite aerogels with interpenetrating network structure of bacterial cellulose for oil absorption
Authors: Nie Xiaolin , Lv Pengfei , Stanley Sarah L. , Wang Di , Wu Shuanglin , Wei Qufu
Published: May 2019

Towards the development of novel platforms for oil absorption and environmental remediation, bacterial cellulose aerogels (BCA), a lightweight and highly porous material, were modified with carbon nanotubes (CNT) and carboxylic carbon nanotubes (CCNT), respectively, at both 5 and 10 wt % loading. The resulting nanocomposite materials, termed BCA/CNT and BCA/CCNT, demonstrated improved oil absorption property when tested against liquid paraffin (glycerol), vacuum oil, plant oil, and propanetriol. After a single immersion lasting about 4–119 seconds, BCA/CNT 10% absorbed an average of 120.23 (standard deviation: 1.145) g·g−1of propanetriol. While BCA is known to be fragile, but no destruction was observed before and after oil absorption. The difference between CNT and CCNT is carboxylation, which could reduce hydrophilicity. The samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectrum (FTIR), Brunauer–Emmett–Teller (BET) analysis, contact angle test, and mechanical test. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 48000.
1H‐1,2,3‐Triazole tethered isatin‐moxifloxacin: Design, synthesis and in vitro anti‐mycobacterial evaluation
Authors: Jiang Yu , Qian Ailin , Li Yan
Published: May 2019

A series of novel 1H‐1,2,3‐triazole tethered isatin–moxifloxacin (MXF) hybrids 5a‐l with greater lipophilicity compared with the parent MXF were designed, synthesized and screened for their in vitro antimycobacterial activities against Mycobacterium tuberculosis (MTB) H37Rv and multidrug‐resistant MTB (MDR–MTB) as well as their cytotoxicity on the VERO cell line. All the synthesized hybrids (MIC: 0.025‐0.78 μg/ml) showed considerable activities against MTB H37Rv and MDR–MTB, and the most active conjugate 5c (MIC: 0.025 and 0.06 μg/ml) was 2 to >2048 times more potent in vitro than the three references MXF (MIC: 0.10 and 0.12 μg/ml), rifampicin (MIC: 0.39 and 32 μg/ml) and isoniazid (MIC: 0.05 and >128 μg/ml) against the two tested strains. All hybrids (CC50: 4‐64 μg/ml) were much more cytotoxic than the parent MXF (CC50: 128 μg/ml), but the most active hybrid 5c (CC50: 32 μg/ml) also displayed acceptable cytotoxicity, warranting further investigation.
Unmanned aerial vehicle and structure‐from‐motion photogrammetry for three‐dimensional documentation and digital rubbing of the Zuo River Valley rock paintings
Authors: Wang Shaohua , Wang Yue , Hu Qingwu , Li Jiayuan , Ai Mingyao
Published: May 2019

Three‐dimensional (3D) documenting and rubbing of rock art is aimed to produce descriptive and analytic graphic documentation with metric scale and geospatial information for archaeological analysis. Although the integrated surveying technologies of aerial photogrammetry, close‐range photogrammetry, and laser scanning have been widely used to generate the 3D models of archaeological sites, the implementation of these technologies in complex surroundings with steep terrain, such as riverside cliffs, remains challenging. In this study, we present an unmanned aerial vehicle (UAV)‐based structure‐from‐motion (SfM) photogrammetry approach to obtain the 3D geospatial data of rock paintings. A field data collection approach for high‐resolution multiperspective images using UAV equipped with a high‐resolution camera is implemented together with high accuracy ground control points (GCPs). An appropriate flowchart of multi‐view stereo (MVS) photogrammetry processing is designed including multi‐view dense matching, bundle adjustment (BA) and metric rectification for the orthoimages production of the rock paintings. A digital rubbing approach based on the orthoimages is proposed to obtain the geometry contents, including symbols and characters, of the rock paintings. The Huashan rock paintings, which are located on the vertical faces of the cliffs that line the course of Zuo River, is taken as a case study. Our proposed approach can obtain orthoimages of the Huashan rock paintings with 2 mm resolution. The reality‐based 3D model can reach the absolute accuracy of 5 mm. Clear, exact, and blur‐free metric rubbing images of the Huashan rock paintings are produced, which are useful for the research and preservation of Zhuang culture.
Probing Reaction Mechanism of [1,5]‐Migration in Pyrrolium and Pyrrole Derivatives: Activation of a Stronger Bond in Electropositive Groups Becomes Easier
Authors: Xie Qiong , Zhao Yu , Chen Dandan , Zhu Jun
Published: May 2019

The [1,5]‐migration reaction has attracted considerable attention from experimentalists and theoreticians for decades. Although it has been extensively investigated in various systems, studies on pyrrolium derivatives are underdeveloped. Herein, a theoretical study on the reaction mechanism of [1,5]‐migration in both pyrrolium and pyrrole derivatives is presented. The results reveal lower activation barriers in [1,5]‐migration of electropositive groups (AuPMe3 and SnH3) in pyrrolium derivatives, although the bond dissociation energies of the Au−N bond (98.8 kcal mol−1) and Sn−N bond (81.7 kcal mol−1) are larger than that of the N−F bond (57.6 kcal mol−1). The unexpectedly lower activation barriers (4.5 and 4.9 kcal mol−1 for AuPMe3 and SnH3, respectively) for [1,5]‐migration of electropositive groups, in comparison with the [1,5]‐fluorine shift, can be attributed to aromaticity stabilizing the transition states, as revealed by significantly negative nucleus‐independent chemical shift (NICS) values. Further studies indicate that charge distribution and frontier molecular orbitals also play some roles in [1,5]‐migration of pyrrolium derivatives.
Supramolecular Light‐Harvesting Antennas of Metal‐Coordinated Bis(8‐Hydroxyquinoline)‐Substituted Porphyrin Networks
Authors: Fujimoto Junko , Hayashi Sari , Kainuma Hideyuki , Manseki Kazuhiro , Udagawa Taro , Miyaji Hidekazu
Published: May 2019

Artificial antenna complexes of metal‐coordinated bis(8‐hydroxyquinoline)‐substituted porphyrin networks that mimic antenna chromophores in plants were organized on titanium dioxide electrodes in photoelectrochemical cells. The generated photocurrents can be optimized according to the two ways of porphyrin self‐assembly due to the “antenna effect”: changing the number of assembled porphyrin monolayers and the number of generations of the metal‐coordinated porphyrin networks.
Pd‐Colloids‐Catalyzed/Ag2O‐Oxidized General and Selective Esterification of Benzylic Alcohols
Authors: Sable Vaibhav , Shah Jagrut , Sharma Anuja , Kapdi Anant R.
Published: May 2019

Palladium colloids obtained from the degradation of Hermann–Beller palladacycle proved to be an efficient catalytic system in combination with silver oxide as a selective oxidant for the oxidative esterification of differently substituted benzyl alcohols in MeOH as solvent. Excellent reactivity exhibited by the catalytic system also allowed the alcoholic coupling partner to be changed from MeOH to a wide range of alcohols having diverse functionalities. The mildness of the developed protocol also made it possible to employ propargyl alcohol as the coupling partner without any observation of any interference of the terminal alkyne. Selective oxidative coupling of a primary alcoholic functional group over secondary in the case of glycols and glycerols was also made possible using the developed catalyst system. To test the relevancy of Pd/Ag combined catalysis mixed Pd/Ag colloids were synthesized, characterized by TEM, XRD and XPS and applied to oxidative‐esterification successfully.
Composite active disturbance rejection robust control for a prototype of an active damping artificial ankle prosthesis
Authors: Serrano Hugo Luis , Chairez Isaac , Luviano‐Juárez Alberto
Published: May 2019

The problem of robust control applied to adjust the configuration of an ankle prosthesis based on disturbance estimation has been addressed in this study. Active disturbance rejection control was the paradigm used for controlling the robotic prosthesis by means of a direct active estimation. Based on this active estimation, the robust controller implemented the disturbance cancellation providing a fast converge to the origin of the tracking error. The uncertainties affecting the prosthesis dynamics were identified by a high‐order extended state high gain observer. This identification was used to force the tracking between the actual position and force needed in the ankle prosthesis and some reference values obtained by a biomechanical gait cycle analysis. Therefore, the estimated states were used to implement a robust output feedback controller that was effective to reject actively the perturbations. This rejection implemented within the controller forced the trajectory tracking to a small vicinity of the origin. A strategy based on composite Lyapunov function served to prove that tracking problem for the prosthesis was successfully solved despite the switching nature of the gait cycle. The controller was implemented in numerical simulations for showing the convergence of the tracking error. The convergence of this tracking error to the region around the origin was obtained within the first second of simulation.
Metabolic Engineering of Corynebacterium glutamicum for High‐Level Ectoine Production: Design, Combinatorial Assembly, and Implementation of a Transcriptionally Balanced Heterologous Ectoine Pathway
Authors: Gießelmann Gideon , Dietrich Demian , Jungmann Lukas , Kohlstedt Michael , Jeon Eun J. , Yim Sung S. , Sommer Frederik , Zimmer David , Mühlhaus Timo , Schroda Michael , Jeong Ki J. , Becker Judith , Wittmann Christoph
Published: May 2019

Ectoine is formed in various bacteria as cell protectant against all kinds of stress. Its preservative and protective effects have enabled various applications in medicine, cosmetics, and biotechnology, and ectoine therefore has high commercial value. Industrially, ectoine is produced in a complex high‐salt process, which imposes constraints on the costs, design, and durability of the fermentation system. Here, Corynebacterium glutamicum is upgraded for the heterologous production of ectoine from sugar and molasses. To overcome previous limitations, the ectoine pathway taken from Pseudomonas stutzeri is engineered using transcriptional balancing. An expression library with 185,193 variants is created, randomly combining 19 synthetic promoters and three linker elements. Strain screening discovers several high‐titer mutants with an improvement of almost fivefold over the initial strain. High production thereby particularly relies on a specifically balanced ectoine pathway. In an optimized fermentation process, the new top producer C. glutamicum ectABCopt achieves an ectoine titer of 65 g L−1 and a specific productivity of 120 mg g−1 h−1. This process is the first reported example of a simple fermentation process under low‐salt conditions using well‐established feedstocks to produce ectoine with industrial efficiency. There is a compelling case for more intensive implementation of transcriptional balancing in future metabolic engineering of C. glutamicum.
Light‐Dependent and Aeration‐Independent Gram‐Scale Hydroxylation of Cyclohexane to Cyclohexanol by CYP450 Harboring Synechocystis sp. PCC 6803
Authors: Hoschek Anna , Toepel Jörg , Hochkeppel Adrian , Karande Rohan , Bühler Bruno , Schmid Andreas
Published: May 2019

Oxygenase‐containing cyanobacteria constitute promising whole‐cell biocatalysts for oxyfunctionalization reactions. Photosynthetic water oxidation thereby delivers the required cosubstrates, that is activated reduction equivalents and O2, sustainably. A recombinant Synechocystis sp. PCC 6803 strain showing unprecedentedly high photosynthesis‐driven oxyfunctionalization activities is developed, and its technical applicability is evaluated. The cells functionally synthesize a heterologous cytochrome P450 monooxygenase enabling cyclohexane hydroxylation. The biocatalyst‐specific reaction rate is found to be light‐dependent, reaching 26.3 ± 0.6 U gCDW−1 (U = μmol min−1 and cell dry weight [CDW]) at a light intensity of 150 µmolphotons m−2 s−1. In situ substrate supply via a two‐liquid phase system increases the initial specific activity to 39.2 ± 0.7 U gCDW−1 and stabilizes the biotransformation by preventing cell toxification. This results in a tenfold increased specific product yield of 4.5 gcyclohexanol gCDW−1 as compared to the single aqueous phase system. Subsequently, the biotransformation is scaled from a shake flask to a 3 L stirred‐tank photobioreactor setup. In situ O2 generation via photosynthetic water oxidation allows a nonaerated process operation, thus circumventing substrate evaporation as the most critical factor limiting the process performance and stability. This study for the first time exemplifies the technical applicability of cyanobacteria for aeration‐independent light‐driven oxyfunctionalization reactions involving highly toxic and volatile substrates.
Application of the Quality‐by‐Design (QbD) Approach for Erythropoietin Alpha Purification
Authors: Kim Tae Kyu , Seo Kwang‐Seok , Kwon Sang‐Oh , Little Thomas A. , Kim Mijung , Kim Chan‐Wha
Published: May 2019

This study was aimed at process characterization and improving quality of purification of erythropoietin α, a biopharmaceutical agent. In biopharmaceutical manufacturing, quality should always be targeted to ensure safety and efficacy. Design‐of‐experiments–based approaches have been explored to rapidly and efficiently achieve an optimized yield and an increased understanding of a product and process variables affecting the product's critical quality attributes in the biopharmaceutical industry; this system is known as the quality‐by‐design approach. Changes in three critical process parameters—buffer pH, flow rate, and loading amount—were evaluated. Process characterization was conducted on a scaled‐down model previously validated by comparison with data from a large‐scale production facility. Seven critical quality attributes—relative aggregate content, host cell protein, host cell deoxynucleotides, endotoxin, Z‐value (N‐glycan score), relative content of charge isomers, and step yield—were analyzed. Multivariate regression analysis was performed to establish statistical prediction models for performance indicators and quality attributes; accordingly, we constructed contour plots and conducted a Monte Carlo simulation to clarify the design space. As a result of the optimization analysis of the purification process, it was confirmed that proven acceptance ranges were optimized as follows: loading amount (mg/mL) 0.4–4.0, buffer pH 7.0–8.0, and flow rate (mL/min) 0.5–1.6.
Associations between mindfulness and general change mechanisms in individual therapy: Secondary results of a randomised controlled trial
Authors: D’Errico Louisa , Call Manuela , Blanck Paul , Vonderlin Eva , Bents Hinrich , Mander Johannes
Published: May 2019

Objective

The aim of this study was to investigate the possible effects of the interactions between mindfulness‐based session introductions and general change mechanisms on outcome in cognitive behavioural therapy (CBT).

Method

We investigated the effects of different session introductions on change mechanisms and their prediction of clinical outcome over the course of 25 sessions of training therapy. We compared session introductions with mindfulness (M) elements with progressive muscle relaxation (PMR) and treatment as usual (TAU) in routine CBT sessions conducted by therapists in training. Participants included 162 patients who were diagnosed primarily with either depression or anxiety disorder and 48 therapists. To address the nested data structure, we used multilevel models.

Results

Multilevel modelling (MLM) indicated that the interaction between an increase in several general change mechanisms and treatment condition (TAU + M vs. TAU + PMR) on therapeutic outcome was significant. From the patient perspective, MLM indicated that only the interaction between an increase in one general change mechanism (clarification of meaning) and treatment condition (TAU + M vs. TAU + PMR) turned out significantly. From both perspectives, correlation analyses revealed that general change mechanism effects on outcome were stronger in TAU + M than in TAU + PMR.

Conclusion

Mindfulness has an impact on general change mechanisms, especially for therapists. These associations lead to a significantly higher effect on outcome compared to introductions with PMR.
Technologies for the Storage of Hydrogen. Part 2: Irreversible Conversion and Comparison
Authors: Müller Karsten
Published: May 2019

Generally, hydrogen storage is the storage of a chemical substance. Yet, it is also often proposed and discussed as a form of energy storage. Since many technologies for the storage of hydrogen involve a chemical conversion anyway, it is reasonable to consider skipping the backwards conversion to release hydrogen again. If hydrogen is converted, e.g., by a chemical reaction into a hydrocarbon, it is reasonable to directly combust this hydrocarbon. Such approaches open new routes for the utilization of hydrogen energy. The applied technologies are introduced and a comparison of storage options with recovery of elemental hydrogen is presented.
Strong Binding and Off–On Signaling Functions of Deep‐Red Fluorescent TO‐PRO‐3 for Influenza A Virus RNA Promoter Region
Authors: Sato Yusuke , Aiba Yuri , Yajima Sayaka , Tanabe Takaaki , Higuchi Kei , Nishizawa Seiichi
Published: May 2019

The RNA promoter region of the influenza A virus has recently attracted much attention as an RNA target for the development of anti‐influenza drugs. However, there are very few reports on small RNA‐binding ligands targeting this region. In this work, it is reported that TO‐PRO‐3, a thiazole orange analogue with a trimethine bridge, exhibits strong and selective binding to the internal loop structure of the influenza A virus RNA promoter. This binding accompanies the remarkable light‐up response of TO‐PRO‐3 in the deep‐red spectral region. By virtue of these binding and fluorescence signaling functions, TO‐PRO‐3 can act as a useful indicator for the assessment of the binding capabilities of various test compounds for this RNA region, with a view toward the development of anti‐influenza drug candidates.
Initial low‐dose oral levothyroxine in a child with Down syndrome, myxedema, and cardiogenic shock
Authors: Janson Annika , Hällström Cathrin , Iversen Magnus , Finder Mikael , Elimam Amira , Nergårdh Ricard
Published: May 2019

Myxedema is extremely rare in children, and guidelines are lacking. We treated a 12‐year‐old girl with myxedema and cardiogenic shock with initial low dose (0.3‐2.5 μg/kg body weight/day) of oral levothyroxine and intensive care. Oral administration may safely revert children's myxedema in a dosage resembling that for hypothyroidism.
Blount's disease: The importance of early diagnosis and early treatment
Authors: Delniotis Ioannis , Leidinger Benedikt , Kyriakou Aikaterini , Galanis Nikiforos
Published: May 2019

The purpose of this image is to raise awareness of the early diagnosis and treatment of Blount's disease. Failure to distinguish between physiologic genu varum and early onset of Blount's disease can lead to irreversible outcomes, including progressive deformity with gait deviations, limb‐length discrepancy, and premature arthritis of the knee.
Life Cycle Optimization for Synthetic Rubber Glove Manufacturing
Authors: Poh Gary K. X. , Chew Irene M. L. , Tan Jully
Published: May 2019

Production of synthetic gloves may cause adverse environmental impacts, including global warming, carbon footprint, acidification, photochemical ozone formation, eutrophication, human toxicity, and water footprint. Thus, life cycle assessment is applied as an environmental management tool to evaluate its environmental impacts. Life cycle optimization is implemented to minimize energy consumption and emission of greenhouse gases by proposing five alternative process improvement scenarios. Using electricity generated from biodiesel shows the least environmental impacts as compared to the other alternatives for the production of synthetic gloves. Future economic analysis is needed to evaluate the cost feasibility of these alternatives.
Supported Au Nanoparticles‐Catalyzed Regioselective Dehydrogenative Disilylation of Allenes by Dihydrosilane
Authors: Kidonakis Marios , Kotzabasaki Vasiliki , Vasilikogiannaki Eleni , Stratakis Manolis
Published: May 2019

Supported Au nanoparticles on TiO2 catalyze the unprecedented dehydrogenative disilylation of monosubstituted and 1,1‐disubstituted allenes by Et2SiH2 exclusively on the terminal double bond in a stereoselective manner. Treatment of the disilylation products with H2O, in a one‐pot operation also catalyzed by Au/TiO2, leads to 3‐alkylidene‐1,2,5‐oxadisilolanes, an unknown class of heterocyclic compounds, which are excellent scaffolds for the stereoselective synthesis of alkenes under Hiyama‐type cross‐coupling conditions.
Highly Charged Ruthenium(II) Polypyridyl Complexes as Effective Photosensitizer in Photodynamic Therapy
Authors: Conti Luca , Bencini Andrea , Ferrante Camilla , Gellini Cristina , Paoli Paolo , Parri Matteo , Pietraperzia Giangaetano , Valtancoli Barbara , Giorgi Claudia
Published: May 2019

A comparative study between two novel, highly water soluble, ruthenium(II) polypyridyl complexes, [Ru(phen)2L′] and [Ru(phen)2Cu(II)L′] (L and L‐CuII), containing the polyaazamacrocyclic unit 4,4′‐(2,5,8,11,14‐pentaaza[15])‐2,2′‐bipyridilophane (L′), is herein reported. L and L‐CuII interact with calf‐thymus DNA and efficiently cleave DNA plasmid when light‐activated. They also possess great penetration abilities and photo‐induced biological activities, evaluated on an A375 human melanoma cell line, with L‐CuII being the most effective. Our study highlights the key role of the Fenton active CuII center within the macrocycle framework, that would play a synergistic role with light activation in the formation of cytotoxic ROS species. Based on these results, an optimal design of RuII polypyridyl systems featuring specific CuII‐chelating polyamine units could represent a suitable strategy for the development of novel and effective photosensitizers in photodynamic therapy.
Chemical Modification of the N Termini of Unprotected Peptides for Semisynthesis of Modified Proteins by Utilizing a Hydrophilic Protecting Group
Authors: Chandrashekar Chaitra , Okamoto Ryo , Izumi Masayuki , Kajihara Yasuhiro
Published: May 2019

A simple and efficient strategy for the selective modification of the peptide N terminus with an unnatural amino acid is described. A peptide having a SUMO‐HisTag‐TEV sequence (SUMO: small ubiquitin‐related modifier, TEV: tobacco etch virus) preceding the N terminus of the target peptide was designed. Recombinant expression in E. coli and subsequent SUMO protease cleavage yielded the HisTag‐TEV‐target peptide. Partial protection of the lysine side chains of this peptide with d‐glucopyranosyloxycarbonyl and removal of the HisTag‐TEV sequence by TEV protease yielded the partially protected peptide with a free N‐terminal amine. Coupling of selenocysteine selectively at the N terminus and subsequent acidic deprotection of the carbohydrate protecting groups yielded a modified peptide that can be used for native chemical ligation (NCL). As a proof of concept, the modification of a longer recombinant peptide with selenocysteinylserine (GalNAc) at the N terminus was demonstrated.
Bonds in atomic crystals, energy levels, quantum chemistry and electronegativity visualized by light emitting diodes (LED)
Authors: Koch Klemens
Published: May 2019

Bindungen in gemischten Atomkristallen werden anhand der Elemente N, P und As der Gruppe 15 aus dem Periodensystem in Leuchtdioden (LED) exemplarisch betrachtet. Die Farbe bzw. die Lichtenergie visualisiert die Elektronegativität der Elemente. Eine Kombination von verschiedenfarbigen LEDs als Emitter und Absorber (Detektoren) erlaubt, die Lichtenergien zu vergleichen und das Spektrum nach Energie zu ordnen. Es zeigt sich, dass Elektronen erst ab einer bestimmten Schwelle ins Leitungsband angeregt werden: Das ist der (innere) photoelektrische Effekt, ein Ausdruck der Quantifizierung der Energie bei Bindungen.