bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrasound‐Activated Oxygen and ROS Generation Nanosystem Systematically Modulates Tumor Microenvironment and Sensitizes Sonodynamic Therapy for Hypoxic Solid Tumors
Authors: Fu Jingke , Li Tao , Zhu Yingchun , Hao Yongqiang 
Published: October 2019

AbstractSonodynamic therapy (SDT) is noninvasive and possesses high body‐penetration depth, showing great potential for the treatment of deep‐seated solid tumors. The efficacy of SDT, however, is limited by widespread hypoxia in solid tumors. Given this, an ultrasound‐activated nanosystem is developed by integrating ferrate(VI) and protoporphyrin IX into biodegradable hollow mesoporous organosilica nanoplatforms, followed by assembling a phase‐change material of lauric acid. The ferrate(VI) effectively reacts with water as well as overexpressed hydrogen peroxide and glutathione (GSH) in tumor cells, leading to tumor‐microenvironment‐independent oxygen production and in situ GSH depletion in tumors. More importantly, significant reactive oxygen species (ROS) overproduction is simultaneously achieved by protoporphyrin‐augmented SDT and intracellular Fenton chemistry. Furthermore, the mild hyperthermia induced by ultrasound can trigger the phase change of lauric acid, achieving ultrasound‐responsive control over the release of oxygen and ROS, and the depletion of GSH. The simultaneous oxygen generation, in situ GSH depletion, and ROS overproduction play a synergetic role in sensitizing SDT toward hypoxic solid tumors, which is verified by the remarkable improvement of hypoxic environments and more significant growth inhibition of SDT against osteosarcoma both in vitro and in vivo, showing promising application in hypoxic solid tumor treatment.
Densely Functionalized Cyanographene Bypasses Aqueous Electrolytes and Synthetic Limitations Toward Seamless Graphene/β‐FeOOH Hybrids for Supercapacitors
Authors: Talande Smita V. , Bakandritsos Aristides , Jakubec Petr , Malina Ondřej , Zbořil Radek , Tuček Jiři 
Published: October 2019

AbstractSupercapacitors are a promising energy storage technology owing to their unparalleled power and lifetime. However, to meet the continuously rising demands of energy storage, they must be equipped with higher energy densities. For this purpose, the seamless integration of metal oxides on carbon matrices, such as iron oxides/oxyhydroxides, has been pursued through hydrothermal, atomic layer and electro‐deposition methods directly on current collectors. Nevertheless, such methods present limited compatibility with commercial paste‐coating processes on the current collectors. Furthermore, iron oxides/oxyhydroxides lack conductivity and are hydrophilic, operating with low‐voltage aqueous electrolytes, limiting their power and energy and requiring corrosion‐resistant H2O current collectors. To mitigate these challenges, a seamless and paste‐ready material is successfully developed through a 15 min wet‐chemical method, via the coordination of ultrasmall β‐FeOOH (akaganéite) nanoparticles to the nitrile groups of a covalent graphene derivative. Endowed with graphene‐like impedance response and very high wettability in organic electrolytes, combined high power and energy densities are obtained, with respect to the total mass of both electrode materials and current collectors, overcoming the identified challenges. This offers future prospects for the exploration of alternative molecular handles for improved interfaces and their application in different energy‐storage chemistries.
Freeform, Reconfigurable Embedded Printing of All‐Aqueous 3D Architectures
Authors: Luo Guanyi , Yu Yafeng , Yuan Yuxue , Chen Xue , Liu Zhou , Kong Tiantian 
Published: October 2019

AbstractAqueous microstructures are challenging to create, handle, and preserve since their surfaces tend to shrink into spherical shapes with minimum surface areas. The creation of freeform aqueous architectures will significantly advance the bioprinting of complex tissue‐like constructs, such as arteries, urinary catheters, and tracheae. The generation of complex, freeform, three‐dimensional (3D) all‐liquid architectures using formulated aqueous two‐phase systems (ATPSs) is demonstrated. These all‐liquid microconstructs are formed by printing aqueous bioinks in an immiscible aqueous environment, which functions as a biocompatible support and pregel solution. By exploiting the hydrogen bonding interaction between polymers in ATPS, the printed aqueous‐in‐aqueous reconfigurable 3D architectures can be stabilized for weeks by the noncovalent membrane at the interface. Different cells can be separately combined with compartmentalized bioinks and matrices to obtain tailor‐designed microconstructs with perfusable vascular networks. The freeform, reconfigurable embedded printing of all‐liquid architectures by ATPSs offers unique opportunities and powerful tools since limitless formulations can be designed from among a breadth of natural and synthetic hydrophilic polymers to mimic tissues. This printing approach may be useful to engineer biomimetic, dynamic tissue‐like constructs for potential applications in drug screening, in vitro tissue models, and regenerative medicine.
Bayesian Machine Learning in Metamaterial Design: Fragile Becomes Supercompressible
Authors: Bessa Miguel A. , Glowacki Piotr , Houlder Michael 
Published: October 2019

AbstractDesigning future‐proof materials goes beyond a quest for the best. The next generation of materials needs to be adaptive, multipurpose, and tunable. This is not possible by following the traditional experimentally guided trial‐and‐error process, as this limits the search for untapped regions of the solution space. Here, a computational data‐driven approach is followed for exploring a new metamaterial concept and adapting it to different target properties, choice of base materials, length scales, and manufacturing processes. Guided by Bayesian machine learning, two designs are fabricated at different length scales that transform brittle polymers into lightweight, recoverable, and supercompressible metamaterials. The macroscale design is tuned for maximum compressibility, achieving strains beyond 94% and recoverable strengths around 0.1 kPa, while the microscale design reaches recoverable strengths beyond 100 kPa and strains around 80%. The data‐driven code is available to facilitate future design and analysis of metamaterials and structures (https://github.com/mabessa/F3DAS).
Compositionally Graded Organic–Inorganic Nanocomposites for Enhanced Thermoelectric Performance
Authors: Ou Canlin , Zhang Lu , Jing Qingshen , Narayan Vijay , Kar‐Narayan Sohini 
Published: October 2019

AbstractThermoelectric generators (TEGs) operate in the presence of a temperature gradient, where the constituent thermoelectric (TE) material converts heat into electricity via the Seebeck effect. However, TE materials are characterized by a thermoelectric figure of merit (ZT) and/or power factor (PF), which often has a strong dependence on temperature. Thus, a single TE material spanning a given temperature range is unlikely to have an optimal ZT or PF across the entire range, leading to inefficient TEG performance. Compositionally graded organic–inorganic nanocomposites are demonstrated, where the composition of the TE nanocomposite can be systematically tuned along the length of the TEG, in order to optimize the PF along the applied temperature gradient. The nanocomposite composition is dynamically tuned by an aerosol‐jet printing method with controlled in situ mixing capability, thus enabling the realization of such compositionally graded thermoelectric composites (CG‐TECs). It is shown how CG‐TECs can be realized by varying the loading weight percentage of Bi2Te3 nanoparticles or Sb2Te3 nanoflakes within an organic conducting matrix using bespoke solution‐processable inks. The enhanced energy harvesting capability of these CG‐TECs from low‐grade waste heat (<100 °C) is demonstrated, highlighting the improvement in output power over single‐component TEGs.
Application of NEAT for the simulation of liquid–liquid extraction processes with poorly specified feeds
Authors: Jirasek Fabian , Burger Jakob , Hasse Hans 
Published: October 2019

AbstractThe conceptual design of fluid separation processes is particularly challenging if the considered mixtures are poorly specified, since classical thermodynamic models cannot be applied when the composition is unknown. We have recently developed a method (NEAT) to predict activity coefficients in such mixtures. It combines the thermodynamic group contribution concept with the ability of NMR spectroscopy to quantify chemical groups. In the present work, we describe how NEAT can be applied to equilibrium stage simulations of liquid–liquid extraction processes with poorly specified feeds. Only a single 13C NMR spectrum of the feed is needed for predicting the distribution of a target component for different process parameters, such as temperature or extracting agent. The predictions from several test cases are compared to results that are obtained using the full knowledge on the composition of the feed and surprisingly good agreement is found.
Ecological fragmentation effects in mouse lemurs and small mammals in northwestern Madagascar
Authors: Andriatsitohaina Bertrand , Ramsay Malcolm S. , Kiene Frederik , Lehman Shawn M. , Rasoloharijaona Solofonirina , Rakotondravony Romule , Radespiel Ute 
Published: October 2019

AbstractHabitat loss and fragmentation are major ecological forces threatening animal communities across the globe. These issues are especially true in Madagascar, where forest loss is ongoing. We examined the effects of forest fragmentation on the distribution and abundance of sympatric, endemic gray, and golden‐brown mouse lemurs (Microcebus murinus and Microcebus ravelobensis), the endemic western tuft‐tailed rat (Eliurus myoxinus), and the invasive black rat (Rattus rattus) in two regions in northwestern Madagascar. We used systematic capture procedures in 40 forest fragments and four continuous forest sites which differed in size, shape, and degree of isolation. With a trapping effort of 11,567 trap nights during two dry seasons (2017–2018), we captured 929 individuals (432 M. ravelobensis, 196 M. murinus, 116 E. myoxinus, and 185 R. rattus). We examined the influence of study region, forest type (fragment vs. continuous), forest size, forest shape, the proportion of 50‐m forest edge and distance to continuous forest on the abundance and interaction of the four species. Responses to fragmentation differed strongly between species, but no interaction could be detected between the abundance of the different species. Thus competition within and between native and invasive species may not be regulating abundances in these regions. On the contrary, the abundance of M. ravelobensis and E. myoxinus differed significantly between study regions and was negatively affected by fragmentation. In contrast, there was no evidence of an impact of fragmentation on the abundance of M. murinus. Finally, the invasive R. rattus responded positively to the increasing distance to the continuous forest. In conclusion, the response of small Malagasy mammals to forest fragmentation varies largely between species, and fragmentation effects need to be examined at a species‐specific level to fully understand their ecological dynamics and complexity.
Hypertonic saline and seawater solutions damage sinonasal epithelial cell air‐liquid interface cultures
Authors: Jiao Jian , Yang Jun , Li Jingyun , Li Ying , Zhang Luo 
Published: October 2019

BackgroundNasal irrigation (NI) is commonly used to treat several sinonasal diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP); however, the effects of NI on the sinonasal epithelium are not fully known. The aim of this study was to investigate the effects of commonly used NI solutions on epithelial mucociliary and barrier functionality in primary cultured human nasal epithelial cells (HNECs).MethodsHNECs from control subjects and patients with CRSwNP were established as air‐liquid interface (ALI) cultures. Differentiated cultures were treated with different NI solutions, including isotonic 0.9% and hypertonic 3.0% saline, isotonic and hypertonic seawater, and Ringer lactate solution. The changes in ciliary beat frequency (CBF), numbers of ciliated and goblet cells, and cytotoxicity were measured. Epithelial barrier functionality was assessed by measuring the transepithelial electric resistance (TER), paracellular flux, and expression of tight junction protein zonula occludens‐1 (ZO‐1) and occludin.ResultsIsotonic saline, isotonic seawater, and Ringer lactate solutions did not affect epithelial mucociliary and barrier function in either control or CRSwNP‐derived ALI cultures; however, hypertonic saline induced a significant disruption of these cell functions in both cultures. Hypertonic seawater caused a transient decrease of CBF and TER in CRSwNP‐derived ALI cultures, in contrast to inducing an obvious mucociliary and barrier dysfunction and cytotoxicity in control ALI cultures.ConclusionAlthough isotonic NI solutions appear to not affect epithelial mucociliary and barrier function in control and CRSwNP‐derived ALI cultures, hypertonic saline and seawater solutions damaged sinonasal epithelial cells in ALI cultures. The safety and efficacy of these solutions requires further investigation.
Factors associated with successful rescue intubation attempts in the emergency department: an analysis of multicenter prospective observational study in Japan
Authors: Goto Yukari , Goto Tadahiro , Okamoto Hiroshi , Hagiwara Yusuke , Watase Hiroko , Hasegawa Kohei ,   the Japanese Emergency Medicine Network Investigators
Published: October 2019

AimIt remains unclear whether physicians should change intubation approaches after the failed first attempt. We aimed to determine the rescue intervention approaches associated with a higher success rate at the second attempt in the emergency department (ED).MethodsWe analyzed the data from a prospective, multicenter, observational study – the second Japanese Emergency Airway Network Study. The current analysis included all patients who underwent emergency intubation from February 2012 through November 2017. We defined a rescue intubation attempt as a second intubation attempt with any change in intubation approaches (i.e., change in methods, devices, or intubators) from the failed first attempt. The outcome measure was second‐attempt success.ResultsOf 2,710 patients with a failed first attempt, 43% underwent a second intubation attempt with changes in intubation approach (i.e., rescue intubation). Rescue intubation attempts were associated with a higher second‐attempt success rate compared to non‐rescue intubation attempts (adjusted odds ratio [OR], 1.78; 95% confidence interval [CI], 1.50–2.12). The rescue intubation approaches associated with a higher second‐attempt success were changes from non‐rapid sequence intubation (RSI) to RSI (adjusted OR, 2.04; 95% CI, 1.12–3.75), from non‐emergency medicine (EM) residents to EM residents (adjusted OR, 2.02; 95% CI, 1.44–2.82), and from non‐EM attending physicians to EM attending physicians (adjusted OR, 2.82; 95% CI, 2.14–3.71).ConclusionsIn this large multicenter study, rescue interventions were associated with a higher second‐attempt success rate. The data also support the use of RSI and backup by EM residents or EM attending physicians to improve the airway management performance after a failed attempt in the ED.
Effect of the Quadrupole–Monopole Interaction on Chaos in Compact Binaries
Authors: Li Dan , Wu Xin , Liang Enwei 
Published: October 2019

AbstractThe dynamics of a post‐Newtonian Lagrangian of spinning compact binaries, including the Newtonian, post‐Newtonian, spin‐orbit, spin‐spin, and quadrupole–monopole interaction contributions are investigated herein. According to the Euler–Lagrangian equations, exact and approximate equations of motion can be written. Numerical computations show that the constants of motion can reach satisfactory accuracies in the exact equations but rather poor accuracies in the approximate equations. Similar to the spin–orbit coupling or the spin–spin coupling, the quadrupole–monopole interaction plays a role in some spin effects that lead to the precession of orbits. With the increase in quadrupole–monopole and extension of integration, the orbits precess strongly and the difference in the precession of orbits between the two sets of equations increases. The quadrupole–monopole interaction can also cause the chaoticity of spinning compact binaries. When it increases, chaos is strong under some circumstances in the exact equations but not in the approximate equations.
Characterization of a Citrulline 4‐Hydroxylase from Nonribosomal Peptide GE81112 Biosynthesis and Engineering of Its Substrate Specificity for the Chemoenzymatic Synthesis of Enduracididine
Authors: Zwick Christian R. , Sosa Max B. , Renata Hans 
Published: October 2019

AbstractThe GE81112 tetrapeptides are a small family of unusual nonribosomal peptide congeners with potent inhibitory activity against prokaryotic translation initiation. With the exception of the 3‐hydroxy‐l‐pipecolic acid unit, little is known about the biosynthetic origins of the non‐proteinogenic amino acid monomers of the natural product family. Here, we elucidate the biogenesis of the 4‐hydroxy‐l‐citrulline unit and establish the role of an iron‐ and α‐ketoglutarate‐dependent enzyme (Fe/αKG) in the pathway. Homology modelling and sequence alignment analysis further facilitate the rational engineering of this enzyme to become a specific 4‐arginine hydroxylase. We subsequently demonstrate the utility of this engineered enzyme in the synthesis of a dipeptide fragment of the antibiotic enduracidin. This work highlights the value of applying a bioinformatics‐guided approach in the discovery of novel enzymes and engineering of new catalytic activity into existing ones.
Palladium Single Atoms on TiO2 as a Photocatalytic Sensing Platform for Analyzing the Organophosphorus Pesticide Chlorpyrifos
Authors: Ge Xiaoxiao , Zhou Peng , Zhang Qinghua , Xia Zhonghong , Chen Shulin , Gao Peng , Zhang Zhe , Gu Lin , Guo Shaojun 
Published: October 2019

AbstractTraditional methods for analyzing organophosphorus pesticide chlorpyrifos, usually require the tedious sample pretreatment and sophisticated bio‐interfaces, leading to the difficulty for real‐time analysis. Herein, we use palladium single‐atom (PdSA)/TiO2 as a photocatalytic sensing platform to directly detect chlorpyrifos with high sensitivity and selectivity. PdSA/TiO2, prepared by an in situ photocatalytic reduction of PdCl42− on the TiO2, shows much higher photocatalytic activity (10 mol g−1 h−1) for hydrogen evolution reaction than Pd nanoparticles (1.95 mol g−1 h−1), and excellent stability. In the presence of chlorpyrifos, the photocatalytic activity of PdSA/TiO2 decreases. Through this inhibition effect the platform can realize a detection limit for chlorpyrifos of 0.01 ng mL−1, much lower than the maximum residue limit (10 ppb) permitted by the U.S. Environmental Protection Agency.
Hypergolic Triggers as Co‐crystal Formers: Co‐crystallization for Creating New Hypergolic Materials with Tunable Energy Content
Authors: Titi Hatem M. , Arhangelskis Mihails , Rachiero Giovanni P. , Friščić Tomislav , Rogers Robin D. 
Published: October 2019

AbstractWe demonstrate a co‐crystal‐based strategy to create new solid hypergols, that is, materials exhibiting spontaneous ignition when in contact with an oxidant, from typically non‐hypergolic fuel molecules. In these materials, the energy content and density can be changed without affecting the ignition delay. The use of an imidazole‐substituted decaborane as a hypergolic “trigger” component in combination with energy‐rich but non‐hypergolic nitrobenzene or pyrazine yielded hypergolic co‐crystals that combine improved combustion properties with ultrashort ignition delays as low as 1 ms.
Strain‐Induced Isomerization in One‐Dimensional Metal–Organic Chains
Authors: Telychko Mykola , Su Jie , Gallardo Aurelio , Gu Yanwei , Mendieta‐Moreno Jesús I. , Qi Dongchen , Tadich Anton , Song Shaotang , Lyu Pin , Qiu Zhizhan , Fang Hanyan , Koh Ming Joo , Wu Jishan , Jelínek Pavel , Lu Jiong 
Published: October 2019

AbstractThe ability to use mechanical strain to steer chemical reactions creates completely new opportunities for solution‐ and solid‐phase synthesis of functional molecules and materials. However, this strategy is not readily applied in the bottom‐up on‐surface synthesis of well‐defined nanostructures. We report an internal strain‐induced skeletal rearrangement of one‐dimensional (1D) metal–organic chains (MOCs) via a concurrent atom shift and bond cleavage on Cu(111) at room temperature. The process involves Cu‐catalyzed debromination of organic monomers to generate 1,5‐dimethylnaphthalene diradicals that coordinate to Cu adatoms, forming MOCs with both homochiral and heterochiral naphthalene backbone arrangements. Bond‐resolved non‐contact atomic force microscopy imaging combined with density functional theory calculations showed that the relief of substrate‐induced internal strain drives the skeletal rearrangement of MOCs via 1,3‐H shifts and shift of Cu adatoms that enable migration of the monomer backbone toward an energetically favorable registry with the Cu(111) substrate. Our findings on this strain‐induced structural rearrangement in 1D systems will enrich the toolbox for on‐surface synthesis of novel functional materials and quantum nanostructures.
Late‐Stage Functionalization of Histidine in Unprotected Peptides
Authors: Noisier Anaïs F. M. , Johansson Magnus J. , Knerr Laurent , Hayes Martin A. , Drury William J. , Valeur Eric , Malins Lara R. , Gopalakrishnan Ranganath 
Published: October 2019

AbstractThe late‐stage functionalization (LSF) of peptides represents a valuable strategy for the design of potent peptide pharmaceuticals by enabling rapid exploration of chemical diversity and offering novel opportunities for peptide conjugation. While the C(sp2)−H activation of tryptophan (Trp) is well documented, the resurgence of radical chemistry is opening new avenues for the C−H functionalization of other aromatic side‐chains. Herein, we report the first example of LSF at C2 of histidine (His) utilizing a broad scope of aliphatic sulfinate salts as radical precursors. In this work, the exquisite selectivity for histidine functionalization was demonstrated through the alkylation of complex unprotected peptides in aqueous media. Finally, this methodology was extended for the installation of a ketone handle, providing an unprecedented anchor for selective oxime/hydrazone conjugation at histidine.
Additions to N‐Sulfinylamines as an Approach for the Metal‐free Synthesis of Sulfonimidamides: O‐Benzotriazolyl Sulfonimidates as Activated Intermediates
Authors: Bremerich Maximilian , Conrads Christian M. , Langletz Tim , Bolm Carsten 
Published: October 2019

AbstractSulfonimidamides are obtained in moderate to very good yields from the key intermediates O‐benzotriazolyl sulfonimidates, which are formed by reacting aryldiazonium tetrafluoroborates, N‐tritylsulfinylamine, and N‐hydroxybenzotriazole hydrate in a process mediated by a tertiary amine. The formation of the sulfonimidate proceeds in inexpensive and environmentally benign dimethyl carbonate as the solvent, it does not require anhydrous conditions, and the product yields generally exceed 70 %. The substrate scope is broad, and a wide range of sensitive organic functionalities is well tolerated. The reactions probably proceed via aryl radicals formed from diazonium cations with assistance from both the tertiary amine and the sulfinylamine.