bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors that Limit Continuous‐Wave Lasing in Hybrid Perovskite Semiconductors
Authors: Jia Yufei , Kerner Ross A. , Grede Alex J. , Rand Barry P. , Giebink Noel C. 
Published: November 2019

AbstractMetal halide perovskites are a promising platform for solution‐processed semiconductor lasers but have so far only achieved continuous‐wave (cw) operation at low temperature. Here, the origin of this limitation is investigated in prototypical methylammonium lead iodide (MAPbI3) distributed feedback (DFB) lasers and is found to stem from a combination of pump‐induced heating and the accumulation of photoinduced defects. A temperature rise of more than 30 K in the first few hundred ns following pump turn‐on is observed, which leads to a dynamic increase in threshold owing to the strong temperature dependence of stimulated emission in MAPbI3 thin films. In parallel, it is found that the Shockley–Read–Hall rate coefficient increases by an order of magnitude on a similar timescale, suppressing the carrier density generated by the pump. The combined impact of both effects is understood using a comprehensive model that quantitatively explains the duration of lasing as a function of pump intensity and predicts that the threshold of current DFB lasers must be decreased by an order of magnitude to achieve cw operation at room temperature.
Machine Learning Stability and Bandgaps of Lead‐Free Perovskites for Photovoltaics
Authors: Stanley Jared C. , Mayr Felix , Gagliardi Alessio 
Published: November 2019

AbstractCompositional engineering of perovskites has enabled the precise control of material properties required for their envisioned applications in photovoltaics. However, challenges remain to address efficiency, stability, and toxicity simultaneously. Mixed lead‐free and inorganic perovskites have recently demonstrated potential for resolving such issues but their composition space is gigantic, making it difficult to discover promising candidates even using high‐throughput methods. A machine learning approach employing a generalized element‐agnostic fingerprint is shown to rapidly and accurately predict key properties using a new database of 344 perovskites generated with density functional theory. Bandgap, formation energy, and convex hull distance are predicted using validation subsets to within 146 meV, 15 meV per atom, and 11 meV per atom, respectively. The resulting model is used to predict trends in entirely different chemical spaces, and perform rapid composition and configuration space sampling without the need for expensive ab initio simulations.
Realizing Wafer‐Scale and Low‐Voltage Operation MoS2 Transistors via Electrolyte Gating
Authors: Tang Hongwei , Niu Wei , Liao Fuyou , Zhang Haima , Xu Hu , Deng Jianan , Chen Jing , Qiu Zhijun , Wan Jing , Pu Yong , Bao Wenzhong 
Published: November 2019

AbstractElectrolyte gating, based on the electric double‐layer effect, has been widely used for 2D layered materials (2DLMs), since it is capable of inducing an ultrahigh charge‐carrier density while requiring only a low gate voltage. However, the wafer‐scale fabrication of high‐performance field effect transistors (FETs) based on electrolyte gating remains challenging, due to the lack of an appropriate electrolyte film coating technique. Wafer‐scale MoS2 FETs gated by high‐quality thin electrolyte film are demonstrated. The electrolyte film, formed by spin‐coating method, has a characteristic capacitance in the order of 10 µF cm−2 and shows a great compatible capability in the device fabrication process. Such electrolyte‐based top‐gated FETs arrays are successfully manufactured based on the wafer‐scale MoS2 film thereafter. The resulting MoS2 FETs operate at a low voltage (<1 V) with a current on/off ratio exceeding 104, as well as a small steep subthreshold swing (110 mV dec−1). Moreover, the realization of enhancement mode (E‐mode) MoS2 FET induced by electrolyte gating shows great potential for multistage logic circuits. A resistance‐loaded MoS2 inverter is also demonstrated with an operation frequency up to 500 Hz. The results provide the possibilities for realizing large‐scale electrolyte‐gated logic circuits based on 2DLMs.
Intrinsic Dipole Coupling in 2D van der Waals Ferroelectrics for Gate‐Controlled Switchable Rectifier
Authors: Dai Mingjin , Li Kai , Wang Fakun , Hu Yunxia , Zhang Jia , Zhai Tianyou , Yang Bin , Fu Yongqing , Cao Wenwu , Jia Dechang , Zhou Yu , Hu PingAn 
Published: November 2019

AbstractMiniaturization of device elements, such as ferroelectric diodes, depends on the downscaling of ferroelectric film, which is also crucial for developing high‐density information storage technologies of ferroelectric random access memories (FeRAMs). Recently emerged ferroelectric two‐dimensional (2D) van der Waals (vdWs) layered materials bring an additional opportunity to further increase the density of FeRAMs. A lateral, switchable rectifier is designed and fabricated based on atomically thin 2D α‐In2Se3 ferroelectric diodes, thus breaking the thickness limitation of conventional ferroelectric films and achieving an unprecedented level of miniaturization. This is realized through the interrelated coupling between out‐of‐plane and in‐plane dipoles at room temperature; that is, horizontal polarization reversal can be effectively controlled through a vertical electric field. Being further explored as a switchable rectifier, the obtained maximum value of rectification ratio for the α‐In2Se3 based ferroelectric diode can reach up to 2.5 × 103. These results indicate that 2D ferroelectric semiconductors can offer a pathway to develop next‐generation multifunctional electronics.
Growth hormone deficiency in megalencephaly‐capillary malformation syndrome: An association with activating mutations in PIK3CA
Authors: Davis Shanlee , Ware Meredith A. , Zeiger Jordan , Deardorff Matthew A. , Grand Katheryn , Grimberg Adda , Hsu Stephanie , Kelsey Megan , Majidi Shideh , Matthew Revi P. , Napier Melanie , Nokoff Natalie , Prasad Chitra , Riggs Andrew C. , McKinnon Margaret L. , Mirzaa Ghayda 
Published: November 2019

AbstractMegalencephaly‐capillary malformation syndrome (MCAP) is a brain overgrowth disorder characterized by cortical malformations (specifically polymicrogyria), vascular anomalies, and segmental overgrowth secondary to somatic activating mutations in the PI3K‐AKT–MTOR pathway (PIK3CA). Cases of growth failure and hypoglycemia have been reported in patients with MCAP, raising the suspicion for unappreciated growth hormone (GH) deficiency. Here we report an observational multicenter study of children with MCAP and GH deficiency. Eleven participants were confirmed to have GH deficiency, all with very low or undetectable circulating concentrations of insulin‐like growth factor‐1 and insulin‐like growth factor binding protein‐3. Seven underwent GH stimulation testing and all had insufficient responses with a median GH peak of 3.7 ng/ml (range 1.1–8.6). Growth patterns revealed a drastic decline in length z‐scores within the first year of life but then stabilized afterward. Five were treated with GH; one discontinued due to inconsolability. The other four participants continued on GH with improvement in linear growth velocity. Other endocrinopathies were identified in 7 of the 11 participants in this cohort. This study indicates that GH deficiency is associated with MCAP and that children with MCAP and hypoglycemia and/or postnatal growth failure should be evaluated for GH deficiency and other endocrinopathies.
Predictors of long‐term success and failure in primary and revision endoscopic dacryocystorhinostomy
Authors: Lehmann Ashton E. , Scangas George A. , Jafari Aria , Banks Catherine G. , Fullerton Zoe H. , Metson Ralph 
Published: November 2019

BackgroundAlthough endoscopic dacryocystorhinostomy (endo‐DCR) is a common treatment of nasolacrimal duct obstruction, little is known about the determinants of surgical success and failure. The purpose of this study was to identify patient‐ and technique‐specific factors that may influence surgical outcomes of primary and revision endo‐DCR.MethodsA retrospective review was conducted of 596 patients who underwent endo‐DCR over a 30‐year period (1989‐2018). Patients’ demographics and surgical techniques were assessed.ResultsAmong the cohort of patients (n = 478) who underwent primary endo‐DCR, 10% (n = 48) required revision surgery. Patients who failed primary DCR tended to be younger (p = 0.015) and were less likely to have chronic sinonasal inflammation on histopathology (p = 0.047) than the successful surgery group. After adjusting for patient demographics and comorbidities, the occurrence of a postoperative complication was significantly associated with primary DCR failure (odds ratio [OR], 2.2; p = 0.032). Among the cohort of patients (n = 118) who underwent revision endo‐DCR, 8.5% (n = 10) required additional revision surgery. Patients who failed revision DCR tended to be younger (p = 0.022), more likely to have had intraoperative laser usage (p = 0.031), and more likely to have had an intraoperative complication (p = 0.013) than the successful revision surgery group. Endo‐DCR failure was not associated with smoking status, middle turbinate resection, or intraoperative visualization of the internal common punctum (p > 0.05).ConclusionAn understanding of factors associated with primary and revision endo‐DCR failure can help to inform preoperative counseling, intraoperative surgical technique, and postoperative care in the treatment of patients with nasolacrimal duct obstruction.
Efficient Heterogeneous Palladium‐Catalyzed Oxidative Cascade Reactions of Enallenols to Furan and Oxaborole Derivatives
Authors: Li Man‐Bo , Posevins Daniels , Geoffroy Antoine , Zhu Can , Bäckvall Jan‐E. 
Published: November 2019

AbstractA heterogeneous palladium‐catalyzed oxidative cyclization of enallenols has been developed for the construction of highly substituted furan and oxaborole derivatives. The heterogeneous catalyst (Pd‐AmP‐MCF) exhibits high activity, high site‐ and stereoselectivity, and efficient palladium recyclability in the transformations.
Dodecatwistarene Imides with Zigzag‐Twisted Conformation for Organic Electronics
Authors: Liu Guogang , Xiao Chengyi , Negri Fabrizia , Li Yan , Wang Zhaohui 
Published: November 2019

Abstract1D nonplanar graphene nanoribbons generally have three possible conformers: helical, zigzag, and mixed conformations. Now, a kind of 1D nonplanar graphene nanoribbon, namely dodecatwistarene imides featuring twelve linearly fused benzene rings, was obtained by bottom‐up synthesis of palladium‐catalyzed Stille coupling and C−H activation. Single‐crystal X‐ray diffraction analyses revealed that it displays a zigzag‐twisted conformation caused by steric hindrance between imide groups and neighboring annulated benzene rings with the pendulum angle of 53°. This conformation is very stable and could not convert into other conformations even when heated up to 250 °C for 6 h. Despite of the highly twisted topology, organic field‐effect transistor based on it exhibits electron mobility up to 1.5 cm2 V−1 s−1 after annealing.
Stereospezifische und chemoselektive kupferkatalysierte, deaminierende Silylierung von Benzylammoniumtriflaten
Authors: Scharfbier Jonas , Gross Benjamin M. , Oestreich Martin 
Published: November 2019

AbstractEs wird über eine Methode zur Synthese von Benzylsilanen ausgehend von den entsprechenden Ammoniumtriflaten berichtet. Dafür werden Silylboronsäureester als Siliciumpronukleophile eingesetzt, und die Reaktion wird von Kupfer(I)‐Salzen katalysiert. Enantiomerenangereicherte Benzylammoniumsalze reagieren stereospezifisch über eine SN2‐artige Verdrängung der Ammoniumgruppe, wodurch die α‐chiralen Silane mit Inversion der Konfiguration erzeugt werden. Ein cyclopropylsubstituiertes Substrat geht keine Ringöffnung ein, was einen ionischen Reaktionsmechanismus ohne Beteiligung einer radikalischen Zwischenstufe nahelegt.
Self‐Stabilized and Strongly Adhesive Supramolecular Polymer Protective Layer Enables Ultrahigh‐Rate and Large‐Capacity Lithium‐Metal Anode
Authors: Wang Gang , Chen Chao , Chen Yunhua , Kang Xiongwu , Yang Chenghao , Wang Fei , Liu Yong , Xiong Xunhui 
Published: November 2019

AbstractConstructing a solid electrolyte interface (SEI) is a highly effective approach to overcome the poor reversibility of lithium (Li) metal anodes. Herein, an adhesive and self‐healable supramolecular copolymer, comprising of pendant poly(ethylene oxide) (PEO) segments and ureido‐pyrimidinone (UPy) quadruple‐hydrogen‐bonding moieties, is developed as a protection layer of Li anode by a simple drop‐coating. The protection performance of in‐situ‐formed LiPEO–UPy SEI layer is significantly enhanced owing to the strong binding and improved stability arising from a spontaneous reaction between UPy groups and Li metal. An ultrathin (approximately 70 nm) LiPEO–UPy layer can contribute to stable and dendrite‐free cycling at a high areal capacity of 10 mAh cm−2 at 5 mA cm−2 for 1000 h. This coating together with the promising electrochemical performance offers a new strategy for the development of dendrite‐free metal anodes.
A Light‐Triggerable Nanoparticle Library for the Controlled Release of Non‐Coding RNAs
Authors: Blersch Josephine , Francisco Vitor , Rebelo Catarina , Jiménez‐Balsa Adrian , Antunes Helena , Gonzato Carlo , Pinto Sandra , Simões Susana , Liedl Klaus , Haupt Karsten , Ferreira Lino 
Published: November 2019

AbstractRNA‐based therapies offer a wide range of therapeutic interventions including the treatment of skin diseases; however, the strategies to efficiently deliver these biomolecules are still limited due to obstacles related to the cellular uptake and cytoplasmic delivery. Herein, we report the synthesis of a triggerable polymeric nanoparticle (NP) library composed of 160 formulations, presenting physico‐chemical diversity and differential responsiveness to light. Six formulations were more efficient (up to 500 %) than commercially available lipofectamine in gene‐knockdown activity. These formulations showed differential internalization by skin cells and the endosomal escape was rapid (minutes range). The NPs were effective in the release of siRNA and miRNA. Acute skin wounds treated with the top hit NP complexed with miRNA‐150‐5p healed faster than wounds treated with scrambled miRNA. Light‐activatable NPs offer a new strategy to topically deliver non‐coding RNAs.
Tandem Cross‐Coupling/Spirocyclization/Mannich‐Type Reactions of 3‐(2‐Isocyanoethyl)indoles with Diazo Compounds toward Polycyclic Spiroindolines
Authors: Chen Guo‐Shu , Chen Shu‐Jie , Luo Jian , Mao Xiang‐Yu , Chan Albert Sun‐Chi , Sun Raymond Wai‐Yin , Liu Yun‐Lin 
Published: November 2019

AbstractTandem reactions of Pd‐catalyzed cross‐coupling of 3‐(2‐isocyanoethyl)indoles with diazoacetates and subsequent spirocyclization/Mannich‐type reaction have been developed to assemble polycyclic spiroindoline skeletons. Formation of spiroindolenines has been proven as the crucial step for the following Mannich‐type cyclization reaction. Accordingly, a novel approach on chiral phosphoric acid catalyzed Mannich‐type cyclization toward the formation of diastereomerically and enantiomerically enriched pentacyclic spiroindolines has been established. Moreover, the products of the reaction are versatile building blocks in synthetic chemistry, as demonstrated by the synthesis of the key framework of aspidosperma and kopsia alkaloids.
Revealing the Nature of Singlet Fission under the Veil of Internal Conversion
Authors: Wang Long , Bai Shuming , Wu Yishi , Liu Yanping , Yao Jiannian , Fu Hongbing 
Published: November 2019

AbstractSinglet fission (SF) holds the potential to boost the maximum power conversion efficiency of photovoltaic devices. Internal conversion (IC) has been considered as one of the major competitive deactivation pathways to transform excitation energy into heat. Now, using time‐resolved spectroscopy and theoretical calculation, it is demonstrated that, instead of a conventional IC pathway, an unexpected intramolecular singlet fission (iSF) process is responsible for excited state deactivation in isoindigo derivatives. The 1TT state could form at ultrafast rate and nearly quantitatively in solution. In solid films, the slipped stacked intermolecular packing of a thiophene‐functionalized derivative leads to efficient triplet pair separation, giving rise to an overall triplet yield of 181 %. This work not only enriches the pool of iSF‐capable materials, but also contributes to a better understanding of the iSF mechanism, which could be relevant for designing new SF sensitizers.
Real‐Time NMR Spectroscopy for Studying Metabolism
Authors: Alshamleh Islam , Krause Nina , Richter Christian , Kurrle Nina , Serve Hubert , Günther Ulrich L. , Schwalbe Harald 
Published: November 2019

AbstractCurrent metabolomics approaches utilize cellular metabolite extracts, are destructive, and require high cell numbers. We introduce here an approach that enables the monitoring of cellular metabolism at lower cell numbers by observing the consumption/production of different metabolites over several kinetic data points of up to 48 hours. Our approach does not influence cellular viability, as we optimized the cellular matrix in comparison to other materials used in a variety of in‐cell NMR spectroscopy experiments. We are able to monitor real‐time metabolism of primary patient cells, which are extremely sensitive to external stress. Measurements are set up in an interleaved manner with short acquisition times (approximately 7 minutes per sample), which allows the monitoring of up to 15 patient samples simultaneously. Further, we implemented our approach for performing tracer‐based assays. Our approach will be important not only in the metabolomics fields, but also in individualized diagnostics.
On‐Surface Synthesis and Characterization of Triply Fused Porphyrin–Graphene Nanoribbon Hybrids
Authors: Mateo Luis M. , Sun Qiang , Liu Shi‐Xia , Bergkamp Jesse J. , Eimre Kristjan , Pignedoli Carlo A. , Ruffieux Pascal , Decurtins Silvio , Bottari Giovanni , Fasel Roman , Torres Tomas 
Published: November 2019

AbstractOn‐surface synthesis offers a versatile approach to prepare novel carbon‐based nanostructures that cannot be obtained by conventional solution chemistry. Graphene nanoribbons (GNRs) have potential for a variety of applications. A key issue for their application in molecular electronics is in the fine‐tuning of their electronic properties through structural modifications, such as heteroatom doping or the incorporation of non‐benzenoid rings. In this context, the covalent fusion of GNRs and porphyrins (Pors) is a highly appealing strategy. Herein we present the selective on‐surface synthesis of a Por–GNR hybrid, which consists of two Pors connected by a short GNR segment. The atomically precise structure of the Por–GNR hybrid has been characterized by bond‐resolved scanning tunneling microscopy (STM) and noncontact atomic force microscopy (nc‐AFM). The electronic properties have been investigated by scanning tunneling spectroscopy (STS), in combination with DFT calculations, which reveals a low electronic gap of 0.4 eV.
Microlayer and nanolayer tubing and piping via layer multiplication coextrusion. I. Validation
Authors: Schneider Tyler , Danda Chaitanya , Ling Gerald , Colton Mark F. , McCauley Kevin M. , Maia João 
Published: November 2019

ABSTRACTLayered annular structures produced with layer multiplication coextrusion, utilizing both a standard in‐line “spider” die, and a custom annular die, are compared in structures up to 129 layers. One multilayered system, of a Dow LDPE 5004I was utilized in generating experimental results to validate the custom die design performance. It was found that the custom design demonstrates successful extrusion of high layer number annular structures with substantial benefits over the standard spider die. Moreover, a design method incorporating angular rotation was implemented within the custom die to eliminate weld lines and attain concentric layer structures to further enhance commercial viability and mechanical integrity. Results indicate angular rotation may be utilized to generate idealized annular products with concentric layer structures. Additionally, exploration of flow through the annular die land was conducted with ANSYS Polyflow in under several conditions of angular rotation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48683.
Mechanical and biodegradation properties of bamboo fiber‐reinforced starch/polypropylene biodegradable composites
Authors: Yang Feiwen , Long Haibo , Xie Baojun , Zhou Wuyi , Luo Ying , Zhang Chaoqun , Dong Xianming 
Published: November 2019

ABSTRACTBamboo fiber (BF)‐reinforced starch/polypropylene (PP) composites were prepared by extrusion and injection molding methods. The mechanical and thermal properties and water absorption were evaluated by different methods. Moreover, composite samples were subjected to biodegradation through soil burial test and microbes medium degradation. Different stages of biodegradation were investigated by weight loss, attenuated total reflection Fourier transformed infrared spectroscopy, differential scanning calorimeter, and scanning electron microscope. It was found that contents of BF and starch resin had a significant influence on the properties of the composites. With more content of BF, the composite exhibited a better flexural property and biodegradation. A distinct decrease of weight loss and mechanical properties indicated the degradation caused by the microbes. After biodegradation, thermal stability of the composites decreased while the crystallinity of PP increased. The results prove that the composites more easily tend to be degraded and assimilated by microbes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48694.
Lessons learned from the developmental origins of childhood renal cancer
Authors: Chong Wai Chin , Cain Jason E. 
Published: November 2019

AbstractDespite the rarity of renal tumors in children, many different types of malignant and nonmalignant renal neoplasms have been described. Therefore, the correct diagnosis and clinical management of these patients can represent a challenge. Here we provide a comprehensive review of the commonly diagnosed pediatric renal malignancies, including nephroblastoma (commonly known as Wilms tumor), clear cell sarcoma of the kidney, rhabdoid tumor of the kidney, several subtypes of renal cell tumors (often collectively termed renal cell carcinoma), and congenital mesoblastic nephroma. The epidemiology, pathology, treatments, underlying genetic and molecular mechanisms, and proposed developmental origins are discussed in detail, highlighting differential features and potential improved therapeutic strategies for affected individuals.