bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linkage Groups within Thiol–Ene Photoclickable PEG Hydrogels Control In Vivo Stability
Authors: Hunckler Michael D. , Medina Juan D. , Coronel Maria M. , Weaver Jessica D. , Stabler Cherie L. , García Andrés J. 
Published: May 2019

AbstractThiol–norbornene (thiol–ene) photoclickable poly(ethylene glycol) (PEG) hydrogels are a versatile biomaterial for cell encapsulation, drug delivery, and regenerative medicine. Numerous in vitro studies with these 4‐arm ester‐linked PEG‐norbornene (PEG‐4eNB) hydrogels demonstrate robust cytocompatibility and ability to retain long‐term integrity with nondegradable crosslinkers. However, when transplanted in vivo into the subcutaneous or intraperitoneal space, these PEG‐4eNB hydrogels with nondegradable crosslinkers rapidly degrade within 24 h. This characteristic limits the usefulness of PEG‐4eNB hydrogels in biomedical applications. Replacing the ester linkage with an amide linkage (PEG‐4aNB) mitigates this rapid in vivo degradation, and the PEG‐4aNB hydrogels maintain long‐term in vivo stability for months. Furthermore, when compared to PEG‐4eNB, the PEG‐4aNB hydrogels demonstrate equivalent mechanical properties, crosslinking kinetics, and high cytocompatibility with rat islets and human mesenchymal stem cells. Thus, the PEG‐4aNB hydrogels may be a suitable replacement platform without necessitating critical design changes or sacrificing key properties relevant to the well‐established PEG‐4eNB hydrogels.
Interconnected Toroidal Hydrogels for Islet Encapsulation
Authors: Ernst Alexander U. , Wang Long‐Hai , Ma Minglin 
Published: May 2019

AbstractIslet encapsulation and transplantation promises to improve upon current treatments for type 1 diabetes mellitus, though several limitations remain. Macroscale devices have been designed for in vivo transplantation and retrieval, but traditional geometries do not support clinically adequate mass transfer of nutrients to and insulin from the encapsulated tissue. Microcapsule technologies have improved mass transfer properties, but their clinical translation remains challenging as their complete retrieval is difficult, should the graft become a safety concern. Here, the design, characterization and testing of a novel encapsulation structure, comprised of elastomer‐reinforced interconnected toroidal hydrogels is reported. These donut‐shaped hydrogels feature a high surface area, higher than conventional spherical capsules of the same volume, bestowing suitable mass transport conditions, while allowing interconnection and reversible deformation for intraperitoneal implantation and retrieval. Diabetes correction up to 12 weeks and complete retrieval is achieved in a diabetic mouse model, providing a proof‐of‐concept for the potential application as a type 1 diabetes cell replacement therapy.
Multifunctional Nanohybrid of Palladium Nanoparticles Encapsulated by Carbon‐Dots for Exploiting Synergetic Applications
Authors: Dhenadhayalan Namasivayam , Hsin Tzu‐Han , Lin King‐Chuen 
Published: May 2019

AbstractPalladium nanoparticles encapsulated in the carbon dots (Pd/C‐dots) are demonstrated to play a role of multifunctional nanohybrid in the synergetic applications of sensor and catalysis. The photochemical method is applied to synthesize Pd/C‐dots in which Pd nanoparticles (NPs) are dispersedly encapsulated by C‐dots layer. The nanohybrid can function as a fluorescent sensor and reductive catalyst, due to the inherent properties of C‐dots and Pd NPs, respectively. The Pd/C‐dots exhibit a highly selective and sensitive detection toward the nickel (Ni2+) ion with a detection limit of 7.26 × 10−9 m. Moreover, the Ni2+ is detected in MCF‐7 live cells signifying the applicability of nanohybrid as a promising sensor. On the other hand, the Pd/C‐dots show an excellent catalytic performance in the reduction of 4‐nitrophenol and eosin yellow. A plausible mechanism for sensing and catalysis behavior is proposed. The sensor system is designed on the basis of the fluorescence turn‐on when Ni2+ interacts with functional groups of the C‐dots layer. The activities of catalytic reduction are mainly governed by the Pd NPs and further enhanced when the C‐dots layer is incorporated. The Pd/C‐dots can serve as a new paradigm for opening a potential trend in the design of multifunctional materials to diverse applications.
Optical Metasurfaces: Evolving from Passive to Adaptive
Authors: Hail Claudio U. , Michel Ann‐Katrin U. , Poulikakos Dimos , Eghlidi Hadi 
Published: May 2019

AbstractOptical metasurfaces are nanoengineered architectures aiming at the functional control of light propagation. In recent years, the performance of metasurfaces has been significantly improved and with the availability of such 2D metamaterials, different optical elements, such as flat achromatic lenses or compact spectrometers have been demonstrated. However, to a large extent, such demonstrations have focused on the realization of entirely passive (nonadaptive) metasurface properties. Adaptivity and active tuning of the optical function of a metasurface after fabrication is highly desirable, because it enables a host of more advanced applications such as beam scanning and dynamic holographic displays. Here, the evolution of the state of the art of metasurfaces toward attaining the adaptivity property and the resulting active control over the wavefront of light is reviewed. Starting from an overview of passive metasurfaces, the different approaches targeting adaptive metasurfaces are discussed, concluding with identifying crucial challenges and opportunities in this future‐oriented field.
Edge Effect on the Population of Free Carriers and Excitons in Single‐Crystal CH3NH3PbBr3 Perovskite Nanomaterials
Authors: Zhang Zhen‐Yu , Yu Kuai , Wang Guo‐Ping 
Published: May 2019

AbstractThe spatial distribution of free carriers and excitons in perovskite micro‐/nanostructures is currently a major topic of debate. They have been reported to coexist with spatial separation in individual perovskite grains and films. It is revealed that free carriers and excitons in single‐crystal CH3NH3PbBr3 perovskite microplatelets can spatially overlap; however, the distribution is such that the edges can be entirely occupied by the former, while the interior is occupied only by the latter. This is further confirmed in single‐crystal CH3NH3PbBr3 perovskite microstrips, in which only free carriers are observed. These results may be attributable to electrostatic potential fluctuations on the edges, which can promote electron–hole separation so that they do not bind to form excitons. Microscopic I–V measurements demonstrate that the microplatelet edges and the microstrips show current densities of more than 260 and 340 A cm−2 in a dark environment under 1.2 V bias voltage, respectively. It is suggested that these findings mean that such microstructures hold promise for the development of novel perovskite micro‐/nanostructure‐based optoelectronic devices with interesting photoconductive properties such as high photoluminescence intensity, longer excited‐state lifetime, high conductivity, large saturation current densities, and suppressed hysteresis effects (smaller open voltages).
Patterned Wettability Surface for Competition‐Driving Large‐Grained Perovskite Solar Cells
Authors: Wang Yang , Li Mingzhu , Li Huizeng , Lan Yangjie , Zhou Xue , Li Chang , Hu Xiaotian , Song Yanlin 
Published: May 2019

AbstractNovel photovoltaic perovskite solar cells (PSCs) with high‐efficient photovoltaic property are largely in thrall to the uncertain perovskite grain size and inevitable defects. Here, inspired by the competitive growth between tree and grass in the forest system, a competitive perovskite grain growth approach via micro‐contact print (MicroCP) method (CD disk as templates) for printing wettability‐patterned substrate is proposed, aiming to achieve large‐grained perovskite and avoid discontinuous perovskite films caused by the low wettability of substrates. A MicroCP process is employed to construct a patterned wettability surface for the perovskite competitive growth mechanism on the electrode surface. This approach modifies the substrates quickly, ensures the uniform coverage of perovskite due to the function of ‐NH2 and Pb2+ bonds, and converts the perovskite films composed of small grains and pinholes into high‐quality perovskite films, free from pinholes and made up of large grains, resulting in efficiencies over 20% for the MicroCP PSCs.
Feedback With Performance Metric Scorecards Improves Resident Satisfaction but Does Not Impact Clinical Performance
Authors: Mamtani Mira , Shofer Frances S. , Sackeim Alexander , Conlon Lauren , Scott Kevin , Mills Angela M. 
Published: May 2019

AbstractObjectivesThe Emergency Medicine Milestone Project, a framework for assessing competencies, has been used as a method of providing focused resident feedback. However, the emergency medicine milestones do not include specific objective data about resident clinical efficiency and productivity, and studies have shown that milestone‐based feedback does not improve resident satisfaction with the feedback process. We examined whether providing performance metric reports to resident physicians improves their satisfaction with the feedback process and their clinical performance.MethodsWe conducted a three‐phase stepped‐wedge randomized pilot study of emergency medicine residents at a single, urban academic site. In phase 1, all residents received traditional feedback; in phase 2, residents were randomized to receive traditional feedback (control group) or traditional feedback with performance metric reports (intervention group); and in phase 3, all residents received monthly performance metric reports and traditional feedback. To assess resident satisfaction with the feedback process, surveys using 6‐point Likert scales were administered at each study phase and analyzed using two‐sample t‐tests. Analysis of variance in repeated measures was performed to compare impact of feedback on resident clinical performance, specifically patient treatment time (PTT) and patient visits per hour.ResultsForty‐one residents participated in the trial of which 21 were randomized to the intervention group and 20 in the control group. Ninety percent of residents liked receiving the report and 74% believed that it better prepared them for expectations of becoming an attending physician. Additionally, residents randomized to the intervention group reported higher satisfaction (p = 0.01) with the quality of the feedback compared to residents in the control group. However, receiving performance metric reports, regardless of study phase or postgraduate year status, did not affect clinical performance, specifically PTT (183 minutes vs. 177 minutes, p = 0.34) or patients visits per hour (0.99 vs. 1.04, p = 0.46).ConclusionsWhile feedback with performance metric reports did not improve resident clinical performance, resident physicians were more satisfied with the feedback process, and a majority of residents expressed liking the reports and felt that it better prepared them to become attending physicians. Residency training programs could consider augmenting feedback with performance metric reports to aide in the transition from resident to attending physician.
Mechanische Aktivierung beschleunigt die Hydrolyse der Amidbindung drastisch, vergleichbar der Aktivität von Enzymen
Authors: Pill Michael F. , East Allan L. L. , Marx Dominik , Beyer Martin K. , Clausen‐Schaumann Hauke 
Published: May 2019

AbstractPeptidbindungen verbinden Aminosäuren in Proteinen und Polypeptiden. Sie zählen zu den Amidbindungen, die Proteinen und synthetischen Polyamiden ihre enorme Stärke verleihen. Obwohl Proteine und Polyamide in Natur und Technik mechanischen Kräften ausgesetzt sind, ist der Einfluss der Kraft auf die Stabilität der Amid‐ und Peptidbindung noch weitgehend unbekannt. Mittels Einzelmolekülkraftspektroskopie entdeckten wir, dass Kräfte von nur einigen hundert pN die Amidhydrolyse 109‐fach beschleunigen, was bisher nur von proteolytischen Enzymen bekannt war. Die drastische Beschleunigung bei geringer Kraft geht einer moderaten weiteren Beschleunigung bei Kräften im nN‐Bereich voraus. Quantenmechanochemische Ab‐initio‐Rechnungen erklären diese experimentellen Befunde sowohl mechanistisch als auch kinetisch. Unsere Ergebnisse zeigen, dass die Stabilität der Amidbindung entgegen bisherigen Annahmen stark kraftabhängig ist. Sie vermitteln ein grundlegendes Verständnis der Rolle mechanischer Aktivierung bei der Amidhydrolyse und weisen den Weg für mögliche Anwendungen, vom Recycling makromolekularer Reststoffe bis hin zum Design biotechnologisch hergestellter proteolytischer Enzyme.
α‐Arylierung von Carbonylverbindungen mittels oxidativer C‐C‐Bindungsaktivierung
Authors: Li Jing , Bauer Adriano , Di Mauro Giovanni , Maulide Nuno 
Published: May 2019

AbstractEine synthetisch nützliche Methode für die direkte α‐Arylierung von Carbonylverbindungen mittels einer neuartigen, oxidativen C‐C‐Bindungsaktivierung wird vorgestellt. Dieser mechanistisch unübliche Prozess baut auf einer 1,2‐Aryl‐Umlagerung auf, welche zur Bildung von quaternären, vollständig mit Kohlenstoff substituierten Zentren führt. Die Umsetzung weist eine breite Toleranz gegenüber funktionellen Gruppen auf und ist prinzipiell auch in einer asymmetrischen Variante möglich.
Efficient Separation of cis‐ and trans‐1,2‐Dichloroethene Isomers by Adaptive Biphen[3]arene Crystals
Authors: Wang Yiliang , Xu Kaidi , Li Bin , Cui Lei , Li Jian , Jia Xueshun , Zhao Hongbin , Fang Jianhui , Li Chunju 
Published: May 2019

AbstractReported here is the highly efficient separation of industrially important cis‐ and trans‐1,2‐dichloroethene (cis‐DCE and trans‐DCE) isomers by activated crystalline 2,2′,4,4′‐tetramethoxyl biphen[3]arene (MeBP3) materials, MeBP3α. MeBP3 can be synthesized in excellent yield (99 %), and a cyclic pentamer is also obtained when using 1,2‐dichloroethane as the solvent. The structure of MeBP3 in the CH3CN@MeBP3 crystal displays a triangle‐shape topology, forming 1D channels through window‐to‐window packing. Desolvated crystalline MeBP3 materials, MeBP3α, preferentially adsorb cis‐DCE vapors over its trans isomer. MeBP3α is able to separate cis‐DCE from a 50:50 (v/v) cis/trans‐isomer mixture, yielding cis‐DCE with a purity of 96.4 % in a single adsorption cycle. Single‐crystal structures and powder X‐ray diffraction patterns indicate that the uptake of cis‐DCE triggers a solid‐state structural transformation of MeBP3, suggesting the adaptivity of MeBP3α materials during the sorption process. Moreover, the separation can be performed over multiple cycles without loss of separation selectivity and capacity.
Mechanical Activation Drastically Accelerates Amide Bond Hydrolysis, Matching Enzyme Activity
Authors: Pill Michael F. , East Allan L. L. , Marx Dominik , Beyer Martin K. , Clausen‐Schaumann Hauke 
Published: May 2019

AbstractAmide bonds, which include peptide bonds connecting amino acids in proteins and polypeptides, give proteins and synthetic polyamides their enormous strength. Although proteins and polyamides sustain mechanical force in nature and technology, how forces affect amide and peptide bond stability is still unknown. Using single‐molecule force spectroscopy, we discover that forces of only a few hundred pN accelerate amide hydrolysis 109‐fold, an acceleration hitherto only known from proteolytic enzymes. The drastic acceleration at low force precedes a moderate additional acceleration at nN forces. Quantum mechanochemical ab initio calculations explain these experimental results mechanistically and kinetically. Our findings reveal that, in contrast to previous belief, amide stability is strongly force dependent. These calculations provide a fundamental understanding of the role of mechanical activation in amide hydrolysis and point the way to potential applications from the recycling of macromolecular waste to the design of bioengineered proteolytic enzymes.
A Safe and Efficient Strategy for the Rapid Elimination of Blood Lead In Vivo Based on a Capture–Fix–Separate Mechanism
Authors: Wan Mi Mi , Xu Ting Ting , Chi Bo , Wang Meng , Huang Yangyang , Wang Qi , Li Ting , Yan Wen Qiang , Chen Huan , Xu Ping , Mao Chun , Zhao Bo , Shen Jian , Xu Hong , Shi Dong Quan 
Published: May 2019

AbstractLead poisoning is an important problem because of its serious effects on human health. Yet a solution is not available due to an incomplete understanding of the state of lead ions in blood. Since most blood lead binds to hemoglobin (Hb) in red blood cells, identifying and capturing lead‐contaminated Hb in RBCs is important. Herein, a magnetic blood lead remover with hyperbranched poly(amidoamine)s (HPAM) as template/co‐adsorbent and core–shell mesoporous structure was synthesized. Lead‐containing Hb was selectively captured and then fixed by mesoporous channels. The magnetic separation technology was used to separate the magnetic remover from blood. A related blood lead clean‐up apparatus was used to remove lead from the blood of a pig in vivo. Results of physical/chemical characterizations, biocompatibility experiments, animal tests, and theoretical simulation verify the safety and efficiency of this removal strategy and the high efficiency of the blood lead clean‐up apparatus.
Nanobody‐Conjugated Nanotubes for Targeted Near‐Infrared In Vivo Imaging and Sensing
Authors: Mann Florian A. , Lv Zhiyi , Großhans Jörg , Opazo Felipe , Kruss Sebastian 
Published: May 2019

AbstractFluorescent nanomaterials such as single‐walled carbon nanotubes (SWCNTs) have many advantages in terms of their photophysics, but it is difficult to target them to specific locations in living systems. In contrast, the green fluorescent protein (GFP) has been genetically fused to proteins in many cells and organisms. Therefore, GFP can be seen not only as a fluorophore but as a universal target/handle. Here, we report the conjugation of GFP‐binding nanobodies to DNA‐wrapped SWCNTs. This approach combines the targeting capabilities of GFP‐binding nanobodies and the nonbleaching near‐infrared fluorescence (850–1700 nm) of SWCNTs. These conjugates allow us to track single Kinesin‐5‐GFP motor proteins in developing embryos of Drosophila melanogaster. Additionally, they are sensitive to the neurotransmitter dopamine and can be used for targeted sensing of dopamine in the nm regime.
Basic properties of proton conductor BaZr0.1Ce0.7Y0.1Yb0.1O3‐δ (BZCYYb) material
Authors: Zhang Yifan , Xie Dong , Chi Bo , Pu Jian , Li Jian , Yan Dong 
Published: May 2019

AbstractProton conductor BaZr0.1Ce0.7Y0.1Yb0.1O3‐δ (BZCYYb) have a wide range of applications in solid oxide fuel cell due to its resistance to carbon deposition and good protonic conductivity. In this work, several basic properties of BZCYYb perovskite were studied: Structural phase transitions have been investigated with combination of differential scanning calorimeter, dilatometry, and high‐temperature X‐ray diffraction (XRD). Water absorption ability of BZCYYb in the temperature range of 600°C to 800°C was measured by thermogravimetry (TG) in a certain concentration of water vapor; the results showed the best absorption ability of 4.2% weight gain at 600°C, corresponding to a water adsorption of 0.63 mmol/m2. Oxygen stoichiometry of BZCYYb from room temperature to 800°C increased from 0.1296 to 0.386 in air. Besides, we compared the conductivity in different atmospheres (dry and humid N2–H2 [5%] and dry and humid air), which showed the highest total conductivity in humid air and a lower conductivity activation energy in a reducing atmosphere. Finally, CO2 poisoning process of BZCYYb was analyzed by XRD and TG. Compared with the case of pure CO2, lower critical CO2 poisoning temperature and more BaCO3 were found in CO2–H2O, indicating the addition of water could promote the reaction.
Multiple morphologies of a poly(methyl methacrylate)‐block‐poly(N,N‐dimethyl aminoethyl methacrylate) copolymer with pH‐responsiveness and thermoresponsiveness
Authors: Hu Lizhi , Wang Yihan , Yin Qiang , Du Kai , Yin Qinjian 
Published: May 2019

ABSTRACTWe successfully prepared a series of pH‐responsive and thermoresponsive poly(methyl methacrylate) (PMMA)‐block‐poly(N,N‐dimethyl aminoethyl methacrylate (PDMAEMA) copolymers via reversible addition–fragmentation chain‐transfer polymerization with PMMA as a macro chain‐transfer agent. Control over the chain length of PDMAEMA allowed the morphological transformation of PMMA‐b‐PDMAEMA. The critical water content and critical micelle concentration also depended on the length of the PDMAEMA block. UV–visible and fluorescence spectrum analyses indicated that the PMMA‐b‐PDMAEMA copolymer exhibited a lower critical solution temperature type phase transition in water. The particle size of PMMA‐b‐PDMAEMA was dominated by the pH value, as evidenced by dynamic light scattering and transmission electron microscopy. In addition, the PMMA‐b‐PDMAEMA copolymers exhibited good reversible thermoresponsive behavior between 33 and 38°C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47972.
Simultaneous enhancement of electrical conductivity and interlaminar shear strength of CF/EP composites through MWCNTs doped thermoplastic polyurethane film interleaves
Authors: Li Wei , Li Yuntao , Xiang Dong , Zhao Chunxia , Wang Bin , Li Hui , Han Hongchang 
Published: May 2019

ABSTRACTCarbon fiber‐reinforced epoxy (CF/EP) composites have been widely used in aerospace industry, while poor electrical conductivity and interlaminar shear fracture toughness could reduce their safety as structural components in use. In this work, we achieved simultaneous improvement in electrical conductivity and interlaminar shear strength through interleaved multi‐walled carbon nanotubes (MWCNTs) doped thermoplastic polyurethane (TPU) conductive thin films (CTFs), which were prepared by a solution casting method. The experimental results showed that the electrical conductivity of the laminates increased by about 13 and 16 times in the transverse and thickness directions with only about 1 wt % MWCNTs content in the laminates. The end‐notch flexure (ENF) tests showed that the mode II interlaminar fracture toughness (GIIC) of composites with 10 wt % MWCNTs CTF interleaf shows a significant increase of about 106%. The enhancement mechanism was further explored through microscopic morphological observation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47988.
Sampled‐data output feedback stabilization for a class of p‐norm switched stochastic nonlinear systems
Authors: Jiang Yan , Zhai Junyong , Ye Hui 
Published: May 2019

AbstractThis paper addresses the sampled‐data output feedback stabilization problem for a class of p‐norm switched stochastic nonlinear systems with uncontrollable and unobservable linearizations around the origin. With sampled measurements, a reduced‐order observer is constructed to estimate the unmeasurable states. Based on adding a power integrator technique and the homogeneous domination approach, a sampled‐data output feedback controller is designed. Subsequently, by choosing an appropriate Lyapunov‐Krasoviskii functional combined with stochastic analysis techniques, it is shown that the closed‐loop system is globally asymptotically stable in probability under the proposed controller with a proper sampling period. Finally, two examples are presented to illustrate the effectiveness of the proposed scheme.