bluuebunny/crossref_metadata_2025_split huggingface dataset:
PLGA Spherical Nucleic Acids
Authors: Zhu Shengshuang , Xing Hang , Gordiichuk Pavlo , Park Jungsoo , Mirkin Chad A. 
Published: April 2018

AbstractA new class of polymer spherical nucleic acid (SNA) conjugates comprised of poly(lactic‐co‐glycolic acid) (PLGA) nanoparticle (NP) cores is reported. The nucleic acid shell that defines the PLGA‐SNA exhibits a half‐life of more than 2 h in fetal bovine serum. Importantly, the PLGA‐SNAs can be utilized to encapsulate a hydrophobic model drug, coumarin 6, which can then be released in a polymer composition‐dependent tunable manner, while the dissociation rate of the nucleic acid shell remains relatively constant, regardless of core composition. Like prototypical gold NP conjugate SNAs, PLGA‐SNAs freely enter Raw‐Blue cells and can be used to activate toll‐like receptor 9 in a sequence‐ and dose‐dependent manner. Taken together, the data show that this novel nanoconstruct provides a means for controlling the release kinetics of encapsulated cargos in the context of the SNA platform, which may be useful for developing combination therapeutics.
Ultrafast Single‐Band Upconversion Luminescence in a Liquid‐Quenched Amorphous Matrix
Authors: Moon Byeong‐Seok , Kim Hyoun‐Ee , Kim Dong‐Hwan 
Published: April 2018

AbstractAchieving single‐band upconversion is a challenging but rewarding approach to attain optimal performance in diverse applications, such as multiplexed molecular imaging, security coding, and nonlinear photonic devices. Here, highly efficient single‐band upconversion luminescence in the green spectral regime (16.4 times increase in emission at 525 nm) accomplished by realizing minimal energy loss from two‐photon upconversion in a newly synthesized liquid‐quenched amorphous matrix is reported. In contrast to previously reported single‐band upconversion, this phenomenon originates from the elevated transition probability of the host sensitive transition via changes in the host matrix's microstructure. The elevated transition probability facilitates ultrafast decay of upconversion luminescence with decay times as short as 0.2 µs, the fastest decay ever reported. The material in this study therefore has strong potential for use in photonic devices demanding high upconversion efficiency with a fast response time, which to date has been inaccessible using upconversion materials.
Molecular Cancer Imaging in the Second Near‐Infrared Window Using a Renal‐Excreted NIR‐II Fluorophore‐Peptide Probe
Authors: Wang Weizhi , Ma Zhuoran , Zhu Shoujun , Wan Hao , Yue Jingying , Ma Huilong , Ma Rui , Yang Qinglai , Wang Zihua , Li Qian , Qian Yixia , Yue Chunyan , Wang Yuehua , Fan Linyang , Zhong Yeteng , Zhou Ying , Gao Hongpeng , Ruan Junshan , Hu Zhiyuan , Liang Yongye , Dai Hongjie 
Published: April 2018

AbstractIn vivo molecular imaging of tumors targeting a specific cancer cell marker is a promising strategy for cancer diagnosis and imaging guided surgery and therapy. While targeted imaging often relies on antibody‐modified probes, peptides can afford targeting probes with small sizes, high penetrating ability, and rapid excretion. Recently, in vivo fluorescence imaging in the second near‐infrared window (NIR‐II, 1000–1700 nm) shows promise in reaching sub‐centimeter depth with microscale resolution. Here, a novel peptide (named CP) conjugated NIR‐II fluorescent probe is reported for molecular tumor imaging targeting a tumor stem cell biomarker CD133. The click chemistry derived peptide‐dye (CP‐IRT dye) probe afforded efficient in vivo tumor targeting in mice with a high tumor‐to‐normal tissue signal ratio (T/NT > 8). Importantly, the CP‐IRT probes are rapidly renal excreted (≈87% excretion within 6 h), in stark contrast to accumulation in the liver for typical antibody‐dye probes. Further, with NIR‐II emitting CP‐IRT probes, urethra of mice can be imaged fluorescently for the first time noninvasively through intact tissue. The NIR‐II fluorescent, CD133 targeting imaging probes are potentially useful for human use in the clinic for cancer diagnosis and therapy.
Long‐Term Active Corrosion Protection of Damaged Coated‐AA2024‐T3 by Embedded Electrospun Inhibiting Nanonetworks
Authors: Dieleman Christian D. , Denissen Paul J. , Garcia Santiago J. 
Published: April 2018

AbstractIn this work, a new concept is introduced for active corrosion protection at damaged sites aiming at overcoming existing limitations of currently proposed strategies based on dispersed inhibitor‐loaded nanocontainers in coatings. The underlying principle is based on the formation of low‐density and/or humidity responsive interconnected paths of inhibitor in the coating, what is called inhibiting nanonetworks. Such an approach allows for (on‐demand) long‐term local supply of corrosion inhibitor at the damage site. For the proof‐of‐concept, water responsive inhibiting nanonetworks based on polyvinyl alcohol and two known efficient corrosion inhibitors for AA2024‐T3 (cerium chloride and lithium carbonate) using electrospinning are developed. The inhibiting nanonetworks are obtained by subsequently embedding the electrospun fiber mats in thermoset epoxy coatings applied on AA2024‐T3. The coated panels are scratched and exposed to NaCl solutions for a month while continuously monitoring the protective properties electrochemically and optically in a hyphenated setup. The effect of the corrosion inhibitor type and the partial crosslinking of the mat on release and protection are analyzed. Protection levels at relatively big damaged sites are obtained for at least a month immersion thereby proving the benefits of high inhibitor quantities continuously released in time.
Chlorotrimethylsilane and Sodium Iodide: A Remarkable Metal‐Free Association for the Desulfurization of Benzylic Dithioketals under Mild Conditions
Authors: Zhao Guangkuan , Yuan Ling‐Zhi , Alami Mouad , Provot Olivier 
Published: April 2018

AbstractA novel metal‐free process allowing the reductive desulfurization of various benzylic dithioketals to afford diarylmethane and benzylester derivatives with good to excellent yields is reported. At room temperature, this mild reduction process requires only the use of TMSCl and NaI in CH2Cl2 and tolerates a large variety of functional groups.magnified image
FeOx‐Based Materials for Electrochemical Energy Storage
Authors: Ma Jingyi , Guo Xiaotian , Yan Yan , Xue Huaiguo , Pang Huan 
Published: April 2018

AbstractIron oxides (FeOx), such as Fe2O3 and Fe3O4 materials, have attracted much attention because of their rich abundance, low cost, and environmental friendliness. However, FeOx, which is similar to most transition metal oxides, possesses a poor rate capability and cycling life. Thus, FeOx‐based materials consisting of FeOx, carbon, and metal‐based materials have been widely explored. This article mainly discusses FeOx‐based materials (Fe2O3 and Fe3O4) for electrochemical energy storage applications, including supercapacitors and rechargeable batteries (e.g., lithium‐ion batteries and sodium‐ion batteries). Furthermore, future perspectives and challenges of FeOx‐based materials for electrochemical energy storage are briefly discussed.
Switching Off Hysteresis in Perovskite Solar Cells by Fine‐Tuning Energy Levels of Extraction Layers
Authors: Guerrero Antonio , Bou Agustín , Matt Gebhard , Almora Osbel , Heumüller Thomas , Garcia‐Belmonte Germà , Bisquert Juan , Hou Yi , Brabec Christoph 
Published: April 2018

AbstractLead halide perovskites often suffer from a strong hysteretic behavior on their j–V response in photovoltaic devices that has been correlated with slow ion migration. The electron extraction layer has frequently been pointed to as the main culprit for the observed hysteretic behavior. In this work three hole transport layers are studied with well‐defined highest occupied molecular orbital (HOMO) levels and interestingly the hysteretic behavior is markedly different. Here it is shown that an adequate energy level alignment between the HOMO level of the extraction layer and the valence band of the perovskite, not only suppresses the hysteresis, avoiding charge accumulation at the interfaces, but also degradation of the hole transport layer is reduced. Numerical simulation suggests that formation of an injection barrier at the organic/perovskite heterointerface could be one mechanism causing hysteresis. The suppression of such barriers may require novel design rules for interface materials. Overall, this work highlights that both external contacts need to be carefully optimized in order to obtain hysteresis‐free perovskite devices.
Design Strategies, Practical Considerations, and New Solution Processes of Sulfide Solid Electrolytes for All‐Solid‐State Batteries
Authors: Park Kern Ho , Bai Qiang , Kim Dong Hyeon , Oh Dae Yang , Zhu Yizhou , Mo Yifei , Jung Yoon Seok 
Published: April 2018

AbstractOwing to the ever‐increasing safety concerns about conventional lithium‐ion batteries, whose applications have expanded to include electric vehicles and grid‐scale energy storage, batteries with solidified electrolytes that utilize nonflammable inorganic materials are attracting considerable attention. In particular, owing to their superionic conductivities (as high as ≈10−2 S cm−1) and deformability, sulfide materials as the solid electrolytes (SEs) are considered the enabling material for high‐energy bulk‐type all‐solid‐state batteries. Herein the authors provide a brief review on recent progress in sulfide Li‐ and Na‐ion SEs for all‐solid‐state batteries. After the basic principles in designing SEs are considered, the experimental exploration of multicomponent systems and ab initio calculations that accelerate the search for stronger candidates are discussed. Next, other issues and challenges that are critical for practical applications, such as instability in air, electrochemical stability, and compatibility with active materials, are discussed. Then, an emerging progress in liquid‐phase synthesis and solution process of SEs and its relevant prospects in ensuring intimate ionic contacts and fabricating sheet‐type electrodes is highlighted. Finally, an outlook on the future research directions for all‐solid‐state batteries employing sulfide superionic conductors is provided.
Convergent Assembly of Enantioenriched Tetrahydrobenzofuro[2,3‐b]pyrrole Scaffolds by AgI‐Catalyzed Asymmetric Domino Reaction of Isocyanoacetates
Authors: Cheng Hengguang , Zhang Runmei , Wang Min , Zeng Xiaofei , Xie Chunsong 
Published: April 2018

AbstractIn the presence of cinchona‐derived chiral phosphine ligands, enantioenriched tetrahydrobenzofuro[2,3‐b]pyrroles can be efficiently assembled by a mild, convergent and atom‐economic AgI‐catalyzed asymmetric domino reaction of readily available isocyanoacetates and 2‐(2‐hydroxyphenyl)acrylates.
How to perform an ultrasound to diagnose endometriosis
Authors: Leonardi Mathew , Condous George 
Published: April 2018

AbstractUltrasound has become an invaluable tool for the workup and management of patients with symptoms and signs of endometriosis. Until the publication on the systematic approach to ultrasound in patients with suspected endometriosis by the International Deep Endometriosis Analysis (IDEA) group, there was significant heterogeneity in the scientific literature in nomenclature, definitions and components of this particular scan. Despite the concise four steps outlined in their consensus statement, the nature of this ultrasound is advanced, complex and time consuming. Without intending to oversimplify the task, we propose a practical and comprehensive approach on how to perform an ultrasound scan to assess the pelvis of a woman with potential underlying endometriosis.
Enhancing the Anti‐Solvatochromic Two‐Photon Fluorescence for Cirrhosis Imaging by Forming a Hydrogen‐Bond Network
Authors: Ren Tian‐Bing , Xu Wang , Zhang Qian‐Ling , Zhang Xing‐Xing , Wen Si‐Yu , Yi Hai‐Bo , Yuan Lin , Zhang Xiao‐Bing 
Published: April 2018

AbstractTwo‐photon imaging is an emerging tool for biomedical research and clinical diagnostics. Electron donor–acceptor (D–A) type molecules are the most widely employed two‐photon scaffolds. However, current D–A type fluorophores suffer from solvatochromic quenching in aqueous biological samples. To address this issue, we devised a novel class of D–A type green fluorescent protein (GFP) chromophore analogues that form a hydrogen‐bond network in water to improve the two‐photon efficiency. Our design results in two‐photon chalcone (TPC) dyes with 0.80 quantum yield and large two‐photon action cross section (210 GM) in water. This strategy to form hydrogen bonds can be generalized to design two‐photon materials with anti‐solvatochromic fluorescence. To demonstrate the improved in vivo imaging, we designed a sulfide probe based on TPC dyes and monitored endogenous H2S generation and scavenging in the cirrhotic rat liver for the first time.
The Contribution of Pyroelectricity of AgI Crystals to Ice Nucleation
Authors: Curland Sofia , Meirzadeh Elena , Cohen Hagai , Ehre David , Maier Joachim , Lahav Meir , Lubomirsky Igor 
Published: April 2018

AbstractThe pyroelectricity of AgI crystals strongly affects the icing temperature of super‐cooled water, as disentangled from that of epitaxy. This deduction was achieved by the design of polar crystalline ceramic pellets of AgI, with experimentally determined sense of polarity. These pellets are suitable for measuring both their pyroelectric properties as well as the icing temperature of super‐cooled water, separately on each of the expressed Ag+ and I− hemihedral surfaces. The positive pyroelectric charge at the silver‐enriched side elevates the icing temperature, whereas the negative charge at the iodide side decreases that temperature. Moreover, the effect of pyroelectric charge remains dominant despite the presence of contaminants on both the silver and the iodide‐enriched surfaces. Consequently an electrochemical process for ice nucleation is suggested, which might be of relevance for understanding the role played by electric charges in heterogeneous icing processes in general.
Preparation of Swellable Hydrogel‐Containing Colloidosomes from Aqueous Two‐Phase Pickering Emulsion Droplets
Authors: Douliez Jean‐Paul , Martin Nicolas , Beneyton Thomas , Eloi Jean‐Charles , Chapel Jean‐Paul , Navailles Laurence , Baret Jean‐Christophe , Mann Stephen , Béven Laure 
Published: April 2018

AbstractThe fabrication of stable colloidosomes derived from water‐in‐water Pickering‐like emulsions are described that were produced by addition of fluorescent amine‐modified polystyrene latex beads to an aqueous two‐phase system consisting of dextran‐enriched droplets dispersed in a PEG‐enriched continuous phase. Addition of polyacrylic acid followed by carbodiimide‐induced crosslinking with dextran produces hydrogelled droplets capable of reversible swelling and selective molecular uptake and exclusion. Colloidosomes produced specifically in all‐water systems could offer new opportunities in microencapsulation and the bottom‐up construction of synthetic protocells.
Cu[B2(SO4)4] und Cu[B(SO4)2(HSO4)] – zwei silicatanaloge Borosulfate unterschiedlicher Dimensionalität: Vergleich von Stabilität und Azidität
Authors: Bruns Jörn , Podewitz Maren , Liedl Klaus R. , Janka Oliver , Pöttgen Rainer , Huppertz Hubert 
Published: April 2018

AbstractBorosulfate repräsentieren eine stetig wachsende Verbindungsklasse, deren strukturelle und chemische Vielfalt noch nicht absehbar ist. In dieser Zuschrift berichten wir über die ersten zwei Borosulfate des Kupfers, Cu[B2(SO4)4] und Cu[B(SO4)2(HSO4)]. Diese sind strukturell verwandt, unterscheiden sich aber in der Dimensionalität ihrer anionischen Substruktur. Cu[B2(SO4)4] weist anionische Ketten entsprechend der Formel
[B(SO4)4/2]− auf, die sowohl eine Twist‐ als auch eine einzigartige Sessel‐Konformation der B(SO4)2B‐Einheiten zeigen. In Cu[B(SO4)2(HSO4)] hingegen werden komplexe Oxoanionen der Formel [B2(SO4)4(HSO4)2]4− gefunden, für die ausschließlich eine Twist‐Konformation realisiert wird. Bildhaft kann das komplexe Anion als protonierter Ausschnitt aus der anionischen Kette betrachtet werden. Vergleichende DFT‐Studien, basierend auf magnetochemischen Messungen, ergänzen die experimentellen Ergebnisse. Berechnungen der pKs‐Werte der beiden Konformere des Anions [B2(SO4)4(HSO4)2]4− ergeben, dass diese eher mit denen der Kieselsäure als mit denen der Schwefelsäure vergleichbar sind, was die nahe Verwandtschaft der Borosulfate zu Silicaten unterstreicht.
A Crystalline Diazadiborinine Radical Cation and Its Boron‐Centered Radical Reactivity
Authors: Wang Baolin , Li Yongxin , Ganguly Rakesh , Webster Richard D. , Kinjo Rei 
Published: April 2018

AbstractOne‐electron oxidation of 1,4,2,5‐diazadiborinine 1 has been studied. While the reaction of 1 a bearing phenyl groups on the B atoms with AgAl{OC(CF3)3}4 afforded a complex mixture, the same oxidation reaction with 1 b featuring bulky mesityl substituents on the B atoms rendered the corresponding cation radical 2 b as an isolable species. X‐ray diffraction analysis, EPR spectroscopy, and DFT calculations of 2 b revealed the delocalization of the unpaired electron over the entire π‐system of 2 b, as well as a large spin density (0.76 in total) on the two equivalent boron atoms. The chemical trapping reaction of 2 b with p‐benzoquinone and triphenyltin hydride afforded the dicationic species 3 containing two newly formed B−O bonds and the monocationic product 2b‐H containing a B−H bond, respectively, thus confirming the boron‐centered radical reactivity of 2 b.
Aggregation of Giant Cerium–Bismuth Tungstate Clusters into a 3D Porous Framework with High Proton Conductivity
Authors: Liu Jian‐Cai , Han Qing , Chen Li‐Juan , Zhao Jun‐Wei , Streb Carsten , Song Yu‐Fei 
Published: April 2018

AbstractThe exploration of high nuclearity molecular metal oxide clusters and their reactivity is a challenge for chemistry and materials science. Herein, we report an unprecedented giant molecular cerium–bismuth tungstate superstructure formed by self‐assembly from simple metal oxide precursors in aqueous solution. The compound, {[W14CeIV6O61]([W3Bi6CeIII3(H2O)3O14][B‐α‐BiW9O33]3)2}34− was identified by single‐crystal X‐ray diffraction and features 104 metal centers, a relative molar mass of ca. 24 000 and is ca. 3.0×2.0×1.7 nm3 in size. The cluster anion is assembled around a central {Ce6} octahedron which is stabilized by several molecular metal oxide shells. Six trilacunary Keggin anions ([B‐α‐BiW9O33]9−) cap the superstructure and limit its growth. In the crystal lattice, water‐filled channels with diameters of ca. 0.5 nm are observed, and electrochemical impedance spectroscopy shows pronounced proton conductivity even at low temperature.
Berylliumkomplexe mit biologisch relevanten funktionellen Gruppen: Koordinationsgeometrien und Bindungsaffinitäten
Authors: Müller Matthias , Buchner Magnus R. 
Published: April 2018

AbstractSowohl der Koordinationsmodus des Berylliumatoms innerhalb eines Proteins als auch die Bindungsaffinität von Beryllium für Peptide sind unbekannt, da bislang keine koordinationschemischen Untersuchungen zu biologisch relevanten funktionellen Gruppen durchgeführt wurden. Hier werden die ersten umfassenden Untersuchungen zu einzähnigen Carboxylaten, Estern, Aldehyden und Alkoholen vorgestellt. Die Bindungsaffinitäten des Be2+‐Kations für die untersuchten funktionellen Gruppen wurden in Lösung und im Festkörper analysiert und lassen sich wie folgt einordnen: Carboxylat>Alkohol>Aldehyd>Ester. Von allen untersuchten Koordinationsverbindungen wurden Einkristallstrukturen erhalten, auch für das nicht‐basische Berylliumbenzoat, dessen Molekülstruktur aus einem unerwarteten, zwölfkernigen Makrocyclus besteht und welches das bislang erste Beispiel dieser Berylliumcarboxylate darstellt. Die Ergebnisse ermöglichen es, potenzielle Bindungsstellen für Be2+‐Kationen innerhalb eines Proteins zu evaluieren, was für das Verständnis des Mechanismus metallinduzierter Immunreaktionen nötig ist.
Photochemical Generation of Chiral N,B,X‐Heterocycles by Heteroaromatic C−X Bond Scission (X=S, O) and Boron Insertion
Authors: Mellerup Soren K. , Li Cally , Radtke Julian , Wang Xiang , Li Quan‐Song , Wang Suning 
Published: April 2018

AbstractChiral organoboron compounds with a chelate backbone and mesityl/heterocycle substituents (thienyl, furyl, and derivatives thereof) undergo a quantitative phototransformation that yields rare, chiral N,B,X‐containing heterocycles, such as base‐stabilized 1,2‐thiaborinines and 1,2‐oxaborinines. Boriranes were observed as intermediates in some of these transformations. The oxaborinines display further reactivity, generating 4a,12b‐dihydrobenzo[h][1,2]oxaborinino[4,3‐f]quinolines through a sequential conrotatory electrocyclization and a [1,5]‐H shift. The N,B,X‐containing heterocycles display strong blue‐green to orange‐red emission in the solid state. Combined DFT//CASP2T calculations suggest that a common biradical intermediate is responsible for the formation of these compounds as well as their interconversion.
Universal pH‐Responsive and Metal‐Ion‐Free Self‐Assembly of DNA Nanostructures
Authors: Li Yongfei , Song Lei , Wang Bang , He Jianbo , Li Yulin , Deng Zhaoxiang , Mao Chengde 
Published: April 2018

AbstractpH‐responsiveness has been widely pursued in dynamic DNA nanotechnology, owing to its potential in biosensing, controlled release, and nanomachinery. pH‐triggering systems mostly depend on specific designs of DNA sequences. However, sequence‐independent regulation could provide a more general tool to achieve pH‐responsive DNA assembly, which has yet to be developed. Herein, we propose a mechanism for dynamic DNA assembly by utilizing ethylenediamine (EN) as a reversibly chargeable (via protonation) molecule to overcome electrostatic repulsions. This strategy provides a universal pH‐responsivity for DNA assembly since the regulation originates from externally co‐existing EN rather than specific DNA sequences. Furthermore, it endows structural DNA nanotechnology with the benefits of a metal‐ion‐free environment including nuclease resistance. The concept could in principle be expanded to other organic molecules which may bring unique controls to dynamic DNA assembly.
Cu[B2(SO4)4] and Cu[B(SO4)2(HSO4)]—Two Silicate Analogue Borosulfates Differing in their Dimensionality: A Comparative Study of Stability and Acidity
Authors: Bruns Jörn , Podewitz Maren , Liedl Klaus R. , Janka Oliver , Pöttgen Rainer , Huppertz Hubert 
Published: April 2018

AbstractBorosulfates are an ever‐expanding class of compounds and the extent of their properties is still elusive. Herein, the first two copper borosulfates Cu[B2(SO4)4] and Cu[B(SO4)2(HSO4)] are presented, which are structurally related but show different dimensionalities in their substructure: While Cu[B2(SO4)4] reveals an anionic chain,
[B(SO4)4/2]−, with both a twisted and a unique chair conformation of the B(SO4)2B subunits, Cu[B(SO4)2(HSO4)] reveals isolated [B2(SO4)4(HSO4)2]4− anions showing exclusively a twisted conformation. The complex anion can figuratively be obtained as a cut‐out from the anionic chain by protons. Comparative DFT calculations based on magnetochemical measurements complement the experimental studies. Calculation of the pKa values of the two conformers of the [B2(SO4)4(HSO4)2]4− anion revealed them to be more similar to silicic than to sulfuric acid, highlighting the close relationship to silicates.