bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unravelling Light‐Induced Degradation of Layered Perovskite Crystals and Design of Efficient Encapsulation for Improved Photostability
Authors: Fang Hong‐Hua , Yang Jie , Tao Shuxia , Adjokatse Sampson , Kamminga Machteld E. , Ye Jianting , Blake Graeme R. , Even Jacky , Loi Maria Antonietta 
Published: April 2018

AbstractLayered halide perovskites have recently shown extraordinary potential for low‐cost solution‐processable optoelectronic applications because of their superior moisture stability over their 3D counterparts. However, few studies have investigated the effect of light on layered hybrid perovskites. Here, the mechanically exfoliated nanoflakes of the 2D perovskite (PEA)2PbI4 (PEA, 2‐phenylethylammonium) are used as a model to investigate their intrinsic photostability. The light‐induced degradation of the flakes is investigated by using in situ techniques including confocal laser scanning microscopy, wide‐field fluorescence microscopy, and atomic force microscopy. Under resonant photoexcitation, (PEA)2PbI4 degrades to PbI2. It is clearly shown that this process is initiated at the crystal edges and from the surface. As a consequence, the photoluminescence of (PEA)2PbI4 is progressively quenched by surface traps. Importantly, the light‐induced degradation can be suppressed by encapsulation using hexagonal boron nitride (hBN) flakes and/or polycarbonates. This report sheds light on a specific mechanism of light‐induced degradation in layered perovskites and proposes a new encapsulation method to improve their photostability.
Highly Secure Plasmonic Encryption Keys Combined with Upconversion Luminescence Nanocrystals
Authors: Park Kisun , Park Minji , Jang Ho Seong , Park Ji Hun , Kim Jaekyun , Cho Younghak , Han Il Ki , Byun Dongjin , Ko Hyungduk 
Published: April 2018

AbstractThis study proposes a novel and highly secure encryption technology based on plasmonic‐enhanced upconversion luminescence (UCL). The technology can be realized by a disordered plasmonic nanostructure composed of a transferred metal nanoparticle–UC nanocrystals (UCNC)–metal (tMUM) film using the graphene transfer process, in which the metal nanoparticles that formed on the graphene layer are transferred using Scotch tape. The plasmonic tMUM film strongly enhances the UCL by a factor of 200 mainly because of the excitation of the gap plasmon polaritons. Meanwhile, the UCNCs in direct contact with the metal film result in luminescence quenching caused by a nonradiative process. Herein, a highly secure anti‐counterfeit film is developed, which is very hard to duplicate and cannot be reused, using two conflicting features (i.e., emission enhancement and quenching phenomena). The UCL is strongly amplified only when the first (i.e., a random metal nanoparticle array) and second (i.e., UCNCs on a Ag film) codes are very precisely overlapped as designed, thereby generating the originally designed final code. Therefore, our novel high‐level security device is expected to be easily applied to protect and identify genuine products.
Identifying Active Sites of Nitrogen‐Doped Carbon Materials for the CO2 Reduction Reaction
Authors: Liu Song , Yang Hongbin , Huang Xiang , Liu Linghui , Cai Weizheng , Gao Jiajian , Li Xuning , Zhang Tao , Huang Yanqiang , Liu Bin 
Published: April 2018

AbstractNitrogen‐doped carbon materials are proposed as promising electrocatalysts for the carbon dioxide reduction reaction (CRR), which is essential for renewable energy conversion and environmental remediation. Unfortunately, the unclear cognition on the CRR active site (or sites) hinders further development of high‐performance electrocatalysts. Herein, a series of 3D nitrogen‐doped graphene nanoribbon networks (N‐GRW) with tunable nitrogen dopants are designed to unravel the site‐dependent CRR activity/selectivity. The N‐GRW catalyst exhibits superior CO2 electrochemical reduction activity, reaching a specific current of 15.4 A gcatalyst−1 with CO Faradaic efficiency of 87.6% at a mild overpotential of 0.49 V. Based on X‐ray photoelectron spectroscopy measurements, it is experimentally demonstrated that the pyridinic N site in N‐GRW serves as the active site for CRR. In addition, the Gibbs free energy calculated by density functional theory further illustrates the pyridinic N as a more favorable site for the CO2 adsorption, *COOH formation, and *CO removal in CO2 reduction.
Lithium Titanate Anode Thin Films for Li‐Ion Solid State Battery Based on Garnets
Authors: Pfenninger Reto , Afyon Semih , Garbayo Iñigo , Struzik Michal , Rupp Jennifer L. M. 
Published: April 2018

AbstractSolid state electrolytes, such as Li‐Garnets, are fastest Li‐ionic conductor materials that have attracted attention for safe hybrid and full solid state battery architectures. Turning to oxide‐based low voltage anodes gives opportunities to avoid Li‐dendrite formation and also to reach full thin film microbattery architectures based on garnets as high energy density replacement for supercapacitors. Herein, it is demonstrated that Li4Ti5O12 thin films deposited by pulsed laser deposition can show stable structures and cycling kinetics reaching almost close to theoretical capacity of 175 mAh g−1 when combined to Li6.25Al0.25La3Zr2O12 pellets. Stable operation at room temperature with 90% of theoretical capacity retention at 2.5 mA g−1 over 22 cycles is achieved on bilayer half cell batteries. Rate capability studies show promising charge and discharge capacities and act as a case study for the well‐known Li4Ti5O12 thin film anode, demonstrating its good compatibility with the investigated solid garnet electrolyte. This gives new perspective on the use of oxide‐based low voltage anodes for future strategies avoiding Li‐dendrite formation or safe solid state microbattery thin film assemblies based on Li‐garnets.
An Injectable Supramolecular Polymer Nanocomposite Hydrogel for Prevention of Breast Cancer Recurrence with Theranostic and Mammoplastic Functions
Authors: Wu Yuanhao , Wang Hongbo , Gao Fei , Xu Ziyang , Dai Fengying , Liu Wenguang 
Published: April 2018

AbstractThe high locoregional breast cancer recurrence rate poses a significant risk for patients' survival. Injecting theranostic drugs‐laden soft tissue‐like hydrogels into the resected breast cavity is a promising strategy to achieve both precisely local therapy of breast cancer and reconstructive mammoplasty. In this work, a robust injectable thermoresponsive supramolecular poly(N‐acryloyl glycinamide‐co‐acrylamide) (PNAm) hydrogel bearing polydopamine (PDA) coated‐gold nanoparticles (AuNPs) and doxorubicin (DOX) is fabricated. The supramolecular polymer nanocomposite (SPN) hydrogels exhibit an excellent photothermal effect arising from PDA‐AuNPs that are tightly fixed to the hydrogel matrix via PDA and amide moieties in the network, built‐in near infrared (NIR) light‐triggered gel–sol transition as well as tunable drug delivery. The PNAm‐PDAAu‐DOX sol driven by prior heating is injected into the cavity of resected cancerous breasts of rats where gelation occurred rapidly while the temperature decreased to body temperature, thereby finely serving as a breast filler. During 4 week of implantation, interval NIR light irradiation can mediate photothermal effect and concertedly controllable DOX release, thus collectively preventing the recurrence of breast cancer. Remarkably, this stable remoldable SPN hydrogel facilitates the breast reconstruction and can be tracked by computed tomography (CT) imaging owing to the intrinsic X‐ray attenuation property of the loaded AuNPs.
Advances in Controlling Differentiation of Adult Stem Cells for Peripheral Nerve Regeneration
Authors: Uz Metin , Das Suprem R. , Ding Shaowei , Sakaguchi Donald S. , Claussen Jonathan C. , Mallapragada Surya K. 
Published: April 2018

AbstractAdult stems cells, possessing the ability to grow, migrate, proliferate, and transdifferentiate into various specific phenotypes, constitute a great asset for peripheral nerve regeneration. Adult stem cells' ability to undergo transdifferentiation is sensitive to various cell‐to‐cell interactions and external stimuli involving interactions with physical, mechanical, and chemical cues within their microenvironment. Various studies have employed different techniques for transdifferentiating adult stem cells from distinct sources into specific lineages (e.g., glial cells and neurons). These techniques include chemical and/or electrical induction as well as cell‐to‐cell interactions via co‐culture along with the use of various 3D conduit/scaffold designs. Such scaffolds consist of unique materials that possess controllable physical/mechanical properties mimicking cells' natural extracellular matrix. However, current limitations regarding non‐scalable transdifferentiation protocols, fate commitment of transdifferentiated stem cells, and conduit/scaffold design have required new strategies for effective stem cells transdifferentiation and implantation. In this progress report, a comprehensive review of recent advances in the transdifferentiation of adult stem cells via different approaches along with multifunctional conduit/scaffolds designs is presented for peripheral nerve regeneration. Potential cellular mechanisms and signaling pathways associated with differentiation are also included. The discussion with current challenges in the field and an outlook toward future research directions is concluded.
Metal–Organic Frameworks for Water Harvesting from Air
Authors: Kalmutzki Markus J. , Diercks Christian S. , Yaghi Omar M. 
Published: April 2018

AbstractWater harvesting from air in passive, adsorption‐based devices holds great potential for delivering drinking water to arid regions of the world. This technology requires adsorbents that can be tailored for a maximum working capacity, temperature response, and the relative pressure range in which reversible adsorption occurs. In this respect, metal–organic frameworks (MOFs) are promising, owing to their structural diversity and the precision of their functionalization for adjusting both pore size and hydrophilicity, thereby facilitating the rational design of their water‐sorption characteristics. Here, chemical and structural factors crucial for the design of hydrolytically stable MOFs for water adsorption are discussed. Prevalent water adsorption mechanisms in micro‐ and mesoporous MOFs alongside strategies for fine‐tuning of their adsorption behavior by means of reticular chemistry are presented. Finally, an approach for the selection of promising MOFs with respect to water harvesting from air is proposed and design concepts for next‐generation MOFs for application in passive adsorption‐based water‐harvesting devices are outlined.
Cephalopod‐Derived Biopolymers for Ionic and Protonic Transistors
Authors: Kautz Rylan , Ordinario David D. , Tyagi Vivek , Patel Priyam , Nguyen Tam N. , Gorodetsky Alon A. 
Published: April 2018

AbstractCephalopods (e.g., squid, octopuses, and cuttlefish) have long fascinated scientists and the general public alike due to their complex behavioral characteristics and remarkable camouflage abilities. As such, these animals are explored as model systems in neuroscience and represent a well‐known commercial resource. Herein, selected literature examples related to the electrical properties of cephalopod‐derived biopolymers (eumelanins, chitosans, and reflectins) and to the use of these materials in voltage‐gated devices (i.e., transistors) are highlighted. Moreover, some potential future directions and challenges in this area are described, with the aim of inspiring additional research effort on ionic and protonic transistors from cephalopod‐derived biopolymers.
Shape‐Controlled Synthesis of Colloidal Metal Nanocrystals by Replicating the Surface Atomic Structure on the Seed
Authors: Gilroy Kyle D. , Yang Xuan , Xie Shuifen , Zhao Ming , Qin Dong , Xia Younan 
Published: April 2018

AbstractControlling the surface structure of metal nanocrystals while maximizing the utilization efficiency of the atoms is a subject of great importance. An emerging strategy that has captured the attention of many research groups involves the conformal deposition of one metal as an ultrathin shell (typically 1–6 atomic layers) onto the surface of a seed made of another metal and covered by a set of well‐defined facets. This approach forces the deposited metal to faithfully replicate the surface atomic structure of the seed while at the same time serving to minimize the usage of the deposited metal. Here, the recent progress in this area is discussed and analyzed by focusing on the synthetic and mechanistic requisites necessary for achieving surface atomic replication of precious metals. Other related methods are discussed, including the one‐pot synthesis, electrochemical deposition, and skin‐layer formation through thermal annealing. To close, some of the synergies that arise when the thickness of the deposited shell is decreased controllably down to a few atomic layers are highlighted, along with how the control of thickness can be used to uncover the optimal physicochemical properties necessary for boosting the performance toward a range of catalytic reactions.
Photocatalytic Hybrid Semiconductor–Metal Nanoparticles; from Synergistic Properties to Emerging Applications
Authors: Waiskopf Nir , Ben‐Shahar Yuval , Banin Uri 
Published: April 2018

AbstractHybrid semiconductor–metal nanoparticles (HNPs) manifest unique combined and often synergetic properties stemming from the materials combination. These structures exhibit spatial charge separation across the semiconductor–metal junction upon light absorption, enabling their use as photocatalysts. So far, the main impetus of photocatalysis research in HNPs addresses their functionality in solar fuel generation. Recently, it was discovered that HNPs are functional in efficient photocatalytic generation of reactive oxygen species (ROS). This has opened the path for their implementation in diverse biomedical and industrial applications where high spatially temporally resolved ROS formation is essential. Here, the latest studies on the synergistic characteristics of HNPs are summarized, including their optical, electrical, and chemical properties and their photocatalytic function in the field of solar fuel generation is briefly discussed. Recent studies are then focused concerning photocatalytic ROS formation with HNPs under aerobic conditions. The emergent applications of this capacity are then highlighted, including light‐induced modulation of enzymatic activity, photodynamic therapy, antifouling, wound healing, and as novel photoinitiators for 3D‐printing. The superb photophysical and photocatalytic properties of HNPs offer already clear advantages for their utility in scenarios requiring on‐demand light‐induced radical formation and the full potential of HNPs in this context is yet to be revealed.
PD‐1 Blockade Cellular Vesicles for Cancer Immunotherapy
Authors: Zhang Xudong , Wang Chao , Wang Jinqiang , Hu Quanyin , Langworthy Benjamin , Ye Yanqi , Sun Wujin , Lin Jing , Wang Tianfu , Fine Jason , Cheng Hao , Dotti Gianpietro , Huang Peng , Gu Zhen 
Published: April 2018

AbstractCancer cells resist to the host immune antitumor response via multiple suppressive mechanisms, including the overexpression of PD‐L1 that exhausts antigen‐specific CD8+ T cells through PD‐1 receptors. Checkpoint blockade antibodies against PD‐1 or PD‐L1 have shown unprecedented clinical responses. However, limited host response rate underlines the need to develop alternative engineering approaches. Here, engineered cellular nanovesicles (NVs) presenting PD‐1 receptors on their membranes, which enhance antitumor responses by disrupting the PD‐1/PD‐L1 immune inhibitory axis, are reported. PD‐1 NVs exhibit a long circulation and can bind to the PD‐L1 on melanoma cancer cells. Furthermore, 1‐methyl‐tryptophan, an inhibitor of indoleamine 2,3‐dioxygenase can be loaded into the PD‐1 NVs to synergistically disrupt another immune tolerance pathway in the tumor microenvironment. Additionally, PD‐1 NVs remarkably increase the density of CD8+ tumor infiltrating lymphocytes in the tumor margin, which directly drive tumor regression.
Desktop‐Stereolithography 3D‐Printing of a Poly(dimethylsiloxane)‐Based Material with Sylgard‐184 Properties
Authors: Bhattacharjee Nirveek , Parra‐Cabrera Cesar , Kim Yong Tae , Kuo Alexandra P. , Folch Albert 
Published: April 2018

AbstractThe advantageous physiochemical properties of poly(dimethylsiloxane) (PDMS) have made it an extremely useful material for prototyping in various technological, scientific, and clinical areas. However, PDMS molding is a manual procedure and requires tedious assembly steps, especially for 3D designs, thereby limiting its access and usability. On the other hand, automated digital manufacturing processes such as stereolithography (SL) enable true 3D design and fabrication. Here the formulation, characterization, and SL application of a 3D‐printable PDMS resin (3DP‐PDMS) based on commercially available PDMS‐methacrylate macromers, a high‐efficiency photoinitiator and a high‐absorbance photosensitizer, is reported. Using a desktop SL‐printer, optically transparent submillimeter structures and microfluidic channels are demonstrated. An optimized blend of PDMS‐methacrylate macromers is also used to SL‐print structures with mechanical properties similar to conventional thermally cured PDMS (Sylgard‐184). Furthermore, it is shown that SL‐printed 3DP‐PDMS substrates can be rendered suitable for mammalian cell culture. The 3DP‐PDMS resin enables assembly‐free, automated, digital manufacturing of PDMS, which should facilitate the prototyping of devices for microfluidics, organ‐on‐chip platforms, soft robotics, flexible electronics, and sensors, among others.
Localizing Seizure Activity in the Brain Using Implantable Micro‐LEDs with Quantum Dot Downconversion
Authors: Choi Christopher , Colón‐Berríos Aida R. , Hamachi Leslie S. , Owen Jonathan S. , Schwartz Theodore H. , Ma Hongtao , Kymissis Ioannis 
Published: April 2018

AbstractCurrent methods for high resolution imaging of neural activity, such as functional magnetic resonance imaging and penetrating electrode arrays, are not well suited for chronic patient monitoring in clinical settings. The ability to locally monitor neural activity in the brain would benefit doctors and surgeons treating and diagnosing neurological diseases such as epilepsy. Measurement of the intrinsic optical signal offers a high resolution (better than 100 µm) for the localization of brain activity. The localized detection of seizures in rats using an implantable optical sensor is demonstrated. The implantable optical sensor is fabricated on a 25 µm thick, flexible polyimide substrate and uses micro‐LEDs to measure localized changes in reflectivity due to cerebral blood flow when attached to the surface of the brain. Quantum dot coatings are applied directly to the micro‐LEDs via pneumatic printing for wavelength conversion by photoluminescent re‐emission.
Highly Flexible, Large‐Area, and Facile Textile‐Based Hybrid Nanogenerator with Cascaded Piezoelectric and Triboelectric Units for Mechanical Energy Harvesting
Authors: Song Jian , Yang Bao , Zeng Wei , Peng Zehua , Lin Shuping , Li Jun , Tao Xiaoming 
Published: April 2018

AbstractDespite of the rapid development and demonstrations of wearable energy harvesting devices, their industrial applications are limited by the lack of highly flexible, scalable, and facile fabrication methods. Especially, few studies have combined theoretical analysis with the relevant experimental verification. To this end, a highly flexible and large‐area textile‐based hybrid nanogenerator integrated a net‐shaped nanofiber reinforced piezoelectric unit and a triboelectric unit with a microstructured surface configuration is demonstrated. Electrospinning is used to fabricate an optimized Polyvinylidenefluoride (PVDF)‐carbon nanotube (CNT)‐BaTiO3 nanofiber/particle nonwoven fabric of 18 cm × 27 cm for the piezoelectric unit without further polarization. Then a large‐area freestanding Polydimethylsiloxane (PDMS)‐multiwall CNT‐graphite flexible composite film of 20 cm × 25 cm, optimized for the triboelectric unit is prepared by the doctor‐blading method. The resultant hybrid nanogenerator, 4.5 cm × 5 cm in size, generates a rectified average peak output voltage of 161.66 V, along with the highest peak power output of 2.22 W m−2, directly driving 150 light‐emitting diodes (LEDs). Importantly, an explicit theoretical model for the hybrid nanogenerator is proposed and good agreements are obtained between the theoretical and the corresponding experimental results, which shed new light on the mechanism and predict ways to optimize such hybrid nanogenerators.
Hybridized Nanogenerators for Harvesting Vibrational Energy by Triboelectric–Piezoelectric–Electromagnetic Effects
Authors: Du Xinyu , Zhao Shuyu , Xing Yi , Li Nianwu , Wang Jiaona , Zhang Xiuling , Cao Ran , Liu Yuebo , Yuan Zuqing , Yin Yingying , Wang Zhong Lin , Li Congju 
Published: April 2018

AbstractHarvesting and utilizing the wasted ambient environmental energy can be a feasible solution for continuous operation of distributed sensors that require sustainable power sources. Vibrational mechanical energy is the most ubiquitous energy source in the environment. Therefore, it is important to develop a method to efficiently collect vibrational energy. Here, a hybridized nanogenerator based on triboelectric–piezoelectric–electromagnetic effects for the highly efficient conversion of vibrational mechanical energy into electricity is reported. Integrating with transformers and rectifiers, the hybridized nanogenerator can deliver a power density up to 100 W m−3. Through a power management circuit integrated into the hybridized nanogenerator, a continuous direct current (DC) output is achieved, providing sufficient DC power for driving a radio‐frequency wireless tire‐pressure monitoring system and other conventional electronics. This work takes a significant step toward ubiquitous vibrational energy harvesting and its potential applications in self‐powered wireless sensor networks.
Nanoscale Optical Trapping: A Review
Authors: Bradac Carlo 
Published: April 2018

AbstractOptical trapping is the craft of manipulating objects with light. Decades after its first inception in 1970, the technique has become a powerful tool for ultracold‐atom physics and manipulation of micron‐sized particles. Yet, optical trapping of objects at the intermediate—nanoscale—range is still beyond full grasp. This matters because the nanometric realm is where several promising advances, from mastering single‐molecule experiments in biology, to fabricating hybrid devices for nanoelectronics and photonics, as well as testing fundamental quantum phenomena in optomechanics, are anticipated to produce impactful breakthroughs. After a comprehensive, theoretical introduction to the phenomenon of optical trapping, this review delves into assessing the current state‐of‐the‐art for optical manipulation of objects at the nanoscale. Emphasis is put on presenting the challenges that coalesced into driving the field to its current development, as well as discussing the outstanding barriers, which might lead to future advancements in the field.