bluuebunny/crossref_metadata_2025_split huggingface dataset:
Material‐Based Approaches for the Fabrication of Stretchable Electronics
Authors: Kim Dong Chan , Shim Hyung Joon , Lee Woongchan , Koo Ja Hoon , Kim Dae‐Hyeong 
Published: August 2019

AbstractStretchable electronics are mechanically compatible with a variety of objects, especially with the soft curvilinear contours of the human body, enabling human‐friendly electronics applications that could not be achieved with conventional rigid electronics. Therefore, extensive research effort has been devoted to the development of stretchable electronics, from research on materials and unit device, to fully integrated systems. In particular, material‐processing technologies that encompass the synthesis, assembly, and patterning of intrinsically stretchable electronic materials have been actively investigated and have provided many notable breakthroughs for the advancement of stretchable electronics. Here, the latest studies of such material‐based approaches are reviewed, mainly focusing on intrinsically stretchable electronic nanocomposites that generally consist of conducting/semiconducting filler materials inside or on elastomer backbone matrices. Various approaches for fabricating these intrinsically stretchable electronic materials are presented, including the blending of electronic fillers into elastomer matrices, the formation of bi‐layered heterogeneous electronic‐layer and elastomer support‐layer structures, and modifications to polymeric molecular structures in order to impart stretchability. Detailed descriptions of the various conducting/semiconducting composites prepared by each method are provided, along with their electrical/mechanical properties and examples of device applications. To conclude, a brief future outlook is presented.
Printed Highly Ordered Conductive Polymer Nanowires Doped with Biotinylated Polyelectrolytes for Biosensing Applications
Authors: Xue Qiannan , Wang Qikun , Han Ziyu , Tang Ning , Zhou Cheng , Pan Wenwei , Wang Yanyan , Duan Xuexin 
Published: August 2019

AbstractThe demand for fast and ultratrace biomarkers detection is increasing in bioanalytical chemistry. In this work, highly ordered nanowires array and sensor integration are achieved with nanoscale printing approach. Negatively charged poly(3,4‐ethylenedioxythiophene)–poly(styrenesulfonate) doped with positively charged PEGylated biotin‐derivatized polyelectrolytes results a direct biofunctionalization on the nanowire surface without multiple postmodification steps. It provides homogeneous dispersed biofunctional sites and nonfouling surface on the nanowires. The ordered nanowires array enables the immunosensor to detect biotargets quickly and ultrasensitively. The nanowires impedimetric immunosensor is demonstrated for specific biomarkers detection and achieved a minimum responsive concentration as low as 10 pg mL−1 for protein biomarker and 10 CFU mL−1 for pathogen.
Vibration‐Energy‐Harvesting System: Transduction Mechanisms, Frequency Tuning Techniques, and Biomechanical Applications
Authors: Dong Lin , Closson Andrew B. , Jin Congran , Trase Ian , Chen Zi , Zhang John X. J. 
Published: August 2019

AbstractVibration‐based energy‐harvesting technology, as an alternative power source, represents one of the most promising solutions to the problem of battery capacity limitations in wearable and implantable electronics, in particular implantable biomedical devices. Four primary energy transduction mechanisms are reviewed, namely piezoelectric, electromagnetic, electrostatic, and triboelectric mechanisms for vibration‐based energy harvesters. Through generic modeling and analyses, it is shown that various approaches can be used to tune the operation bandwidth to collect appreciable power. Recent progress in biomechanical energy harvesters is also shown by utilizing various types of motion from bodies and organs of humans and animals. To conclude, perspectives on next‐generation energy‐harvesting systems are given, whereby the ultimate intelligent, autonomous, and tunable energy harvesters will provide a new energy platform for electronics and wearable and implantable medical devices.
Fabrication and Characterization of a Wireless Bioresorbable Pressure Sensor
Authors: Palmroth Aleksi , Salpavaara Timo , Lekkala Jukka , Kellomäki Minna 
Published: August 2019

AbstractEmbedding sensors into orthopedic devices can enable these implants to monitor the progress of the healing process or detect cues of complications. The simple structure of inductor–capacitor (LC) resonance sensors combined with their wireless readout offers a desirable basis for such sensors. A set of eight bioresorbable inductively coupled pressure sensors is fabricated. The conductors are formed by e‐beam evaporation of magnesium (7 µm) directly onto the substrates, after which two substrates are adhered to a holed spacer to form an LC sensor. All the sensors show a fairly linear pressure response in the physiological pressure range from 0 to 200 mm Hg with an average pressure sensitivity of −6.0 ± 0.5 kHz mm Hg−1. After the pressure response tests, the effects of known error sources are determined. Finally, the sensor performance in vitro in buffer solution at +37 °C is evaluated. The sensors function tolerably for the first 8 h in immersion, after which they are disabled by mechanical changes in the sensor structure. To conclude, a bioresorbable battery‐free wireless pressure sensor architecture with an adequate sensitivity for biomedical applications is described. However, further studies are required to improve the stability of the sensors under physiological conditions.
Full‐Color Chemically Modulated g‐C3N4 for White‐Light‐Emitting Device
Authors: Guo Qianyi , Wei Minchen , Zheng Zekun , Huang Xiongjian , Song Xiaoqian , Qiu Shao‐Bin , Yang Xiao‐bao , Liu Xiaofeng , Qiu Jianrong , Dong Guoping 
Published: August 2019

AbstractPolymeric g‐C3N4 with controllable photoluminescence emission wavelength in the whole visible light range (450–650 nm) is synthesized through the one‐step molecular doping during the thermal condensation process of g‐C3N4 conjugated framework, which opens up its application beyond the conventional catalysis scopes. By adjusting the doped content of hetero‐molecules, the modified g‐C3N4 with the optical properties controlled according to the demand of practical applications can be facilely and largely obtained. It overcomes the limitation of the narrow adjusting range of conventional g‐C3N4 on optical properties and makes it become more promising for applications in solid‐state displays. The corresponding multiple‐color g‐C3N4‐based LED devices and the white‐light LEDs with high quality can be obtained as supported by experiments and theoretical calculations. Moreover, the effect of doped molecule on the π‐conjugated system of g‐C3N4 is systematically studied here, and the tunable luminescence mechanism is proposed.
Palladium‐Catalyzed Selective Synthesis of Dibenzo[c,e]azepin‐5‐ols and Benzo[c]pyrido[2,3‐e]azepin‐5‐ols
Authors: Yao Xinrong , Shao Yinlin , Hu Maolin , Zhang Maosheng , Li Shaotong , Xia Yuanzhi , Cheng Tianxing , Chen Jiuxi 
Published: August 2019

AbstractAn efficient palladium‐catalyzed tandem addition/cyclization of 2′‐formyl‐[1,1′‐biaryl]‐2‐carbonitriles with arylboronic acids is reported. This reaction affords dibenzo[c,e]azepin‐5‐ols and benzo[c]pyrido[2,3‐e]azepin‐5‐ols with excellent selectivity and wide functional group compatibility. The dibenzo[c,e]azepin‐5‐ols show good cell growth inhibitory activity against a triple‐negative breast cancer cell line. Moreover, the proposed mechanistic rationale for this tandem process is supported by theoretical calculations.magnified image
The Psychological Cost of Racial Discrimination: What is the Role of Residential Segregation?
Authors: Woo Bongki , Fan Wen , Tran Thanh , Takeuchi David 
Published: August 2019

AbstractRacial discrimination is known to harm health, but to what extent the health burden of racial discrimination is contingent on residential contexts is understudied. This study examines the moderating role of racial residential segregation in the relationship between racial discrimination and psychological distress. Nationally representative data from the 2002–2003 National Latino and Asian American Study were merged with metropolitan‐level data from the U.S. Census. Logistic regression models were used to test the independent and joint contributions of racial discrimination and residential segregation to psychological distress among Asians and Latinxs, stratified by nativity status. Higher residential segregation (measured by the interaction index) is associated with lower odds of distress among U.S.‐born Asians but not among other groups. As for the moderating effect, residential segregation exacerbates the positive association between discrimination and distress among foreign‐born Asians (measured by the dissimilarity index) and foreign‐born Latinxs (measured by the interaction index), but not among their respective U.S.‐born counterparts. Taken together, the present study highlights that strategies to mitigate the psychological burden of racial discrimination need to move beyond individual‐level efforts to incorporate neighborhood‐based approaches. In particular, results provide empirical support for efforts to reduce residential segregation, particularly among immigrants who are discriminated against.
The promises and challenges of patient‐derived tumor organoids in drug development and precision oncology
Authors: Granat Lauren M. , Kambhampati Ooha , Klosek Stephanie , Niedzwecki Brian , Parsa Kian , Zhang Dong 
Published: August 2019

AbstractIn the era of precision medicine, cancer researchers and oncologists are eagerly searching for more realistic, cost effective, and timely tumor models to aid drug development and precision oncology. Tumor models that can faithfully recapitulate the histological and molecular characteristics of various human tumors will be extremely valuable in increasing the successful rate of oncology drug development and discovering the most efficacious treatment regimen for cancer patients. Two‐dimensional (2D) cultured cancer cell lines, genetically engineered mouse tumor (GEMT) models, and patient‐derived tumor xenograft (PDTX) models have been widely used to investigate the biology of various types of cancers and test the efficacy of oncology drug candidates. However, due to either the failure to faithfully recapitulate the complexity of patient tumors in the case of 2D cultured cancer cells, or high cost and untimely for drug screening and testing in the case of GEMT and PDTX, new tumor models are urgently needed. The recently developed patient‐derived tumor organoids (PDTO) offer great potentials in uncovering novel biology of cancer development, accelerating the discovery of oncology drugs, and individualizing the treatment of cancers. In this review, we will summarize the recent progress in utilizing PDTO for oncology drug discovery. In addition, we will discuss the potentials and limitations of the current PDTO tumor models.
Facilitating Gold Redox Catalysis with Electrochemistry: An Efficient Chemical‐Oxidant‐Free Approach
Authors: Ye Xiaohan , Zhao Pengyi , Zhang Shuyao , Zhang Yanbin , Wang Qilin , Shan Chuan , Wojtas Lukasz , Guo Hao , Chen Hao , Shi Xiaodong 
Published: August 2019

AbstractDue to the high oxidation potential between AuI and AuIII, gold redox catalysis requires at least stoichiometric amounts of a strong oxidant. We herein report the first example of an electrochemical approach in promoting gold‐catalyzed oxidative coupling of terminal alkynes. Oxidation of AuI to AuIII was successfully achieved through anode oxidation, which enabled facile access to either symmetrical or unsymmetrical conjugated diynes through homo‐coupling or cross‐coupling. This report extends the reaction scope of this transformation to substrates that are not compatible with strong chemical oxidants and potentiates the versatility of gold redox chemistry through the utilization of electrochemical oxidative conditions.
Chemical Synthesis at Surfaces with Atomic Precision: Taming Complexity and Perfection
Authors: Wang Can , Chi Lifeng , Ciesielski Artur , Samorì Paolo 
Published: August 2019

AbstractScanning probe microscopy (SPM) is a powerful tool to study the structure and dynamics of molecules at surfaces and interfaces as well as to precisely manipulate atoms and molecules by applying an external force, by inelastic electron tunneling, or by means of an electric field. The rapid development of these SPM manipulation modes made it possible to achieve fine‐control over fundamental processes in the physics of interfaces as well as chemical reactivity, such as adsorption, diffusion, bond formation, and bond dissociation with precision at the single atom/molecule level. Their controlled use for the fabrication of atomic‐scale structures and synthesis of new, perhaps uncommon, molecules with programmed properties are reviewed. Opportunities and challenges towards the development of complex chemical systems are discussed, by analyzing potential future impacts in nanoscience and nanotechnology.
Cooperative Self‐Assembly of Pyridine‐2,6‐Diimine‐Linked Macrocycles into Mechanically Robust Nanotubes
Authors: Strauss Michael J. , Asheghali Darya , Evans Austin M. , Li Rebecca L. , Chavez Anton D. , Sun Chao , Becker Matthew L. , Dichtel William R. 
Published: August 2019

AbstractNanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length and mechanical strength of the resultant nanotubes. Imine‐linked macrocycles were recently found to assemble into high‐aspect ratio (>103), lyotropic nanotubes in the presence of excess acid. Yet these harsh conditions are incompatible with many functional groups and processing methods, and lower acid loadings instead catalyze macrocycle degradation. Here we report pyridine‐2,6‐diimine‐linked macrocycles that assemble into high‐aspect ratio nanotubes in the presence of less than 1 equiv of CF3CO2H per macrocycle. Analysis by gel permeation chromatography and fluorescence spectroscopy revealed a cooperative self‐assembly mechanism. The low acid concentrations needed to induce assembly enabled nanofibers to be obtained by touch‐spinning, which exhibit higher Young's moduli (1.33 GPa) than many synthetic polymers and biological filaments. These findings represent a breakthrough in the design of inverse chromonic liquid crystals, as assembly under such mild conditions will enable the design of structurally diverse and mechanically robust nanotubes from synthetically accessible macrocycles.
Ultramicroporous Building Units as a Path to Bi‐microporous Metal–Organic Frameworks with High Acetylene Storage and Separation Performance
Authors: Li Yong‐Peng , Wang Ying , Xue Ying‐Ying , Li Hai‐Peng , Zhai Quan‐Guo , Li Shu‐Ni , Jiang Yu‐Cheng , Hu Man‐Cheng , Bu Xianhui 
Published: August 2019

AbstractA strategy called ultramicroporous building unit (UBU) is introduced. It allows the creation of hierarchical bi‐porous features that work in tandem to enhance gas uptake capacity and separation. Smaller pores from UBUs promote selectivity, while larger inter‐UBU packing pores increase uptake capacity. The effectiveness of this UBU strategy is shown with a cobalt MOF (denoted SNNU‐45) in which octahedral cages with 4.5 Å pore size serve as UBUs. The C2H2 uptake capacity at 1 atm reaches 193.0 cm3 g−1 (8.6 mmol g−1) at 273 K and 134.0 cm3 g−1 (6.0 mmol g−1) at 298 K. Such high uptake capacity is accompanied by a high C2H2/CO2 selectivity of up to 8.5 at 298 K. Dynamic breakthrough studies at room temperature and 1 atm show a C2H2/CO2 breakthrough time up to 79 min g−1, among top‐performing MOFs. Grand canonical Monte Carlo simulations agree that ultrahigh C2H2/CO2 selectivity is mainly from UBU ultramicropores, while packing pores promote C2H2 uptake capacity.
Zinc chloride/acetamide deep eutectic solvent‐mediated fractionation of lignin produces high‐ and low‐molecular‐weight fillers for phenol‐formaldehyde resins
Authors: Hong Shu , Sun Xiang , Lian Hailan , Pojman John A. , Mota‐Morales Josué D. 
Published: August 2019

ABSTRACTLignin readily dissolves in a deep eutectic solvent (DES) composed of ZnCl2/acetamide 1:3 M ratio in concentrations up to 16.7 wt %, and upon addition of water, two fractions were obtained; one composed of lignin with low‐molecular weight that remained dissolved in the DES/water mixture, whereas the other fraction of lignin with higher molecular weight (regenerated lignin, RL) was regenerated by precipitation. Both the RL fraction and the whole solution of lignin in DES were used to replace part of phenol (20 wt %) in the condensation of phenol and formaldehyde to introduce biomass in the resulting resins. The lignin treatment that produced the higher yield of RL consisted of lignin/DES ratio of 1:10 (w/w) stirred for 4 h at 100 °C. By using 13C NMR spectroscopy, a preferential cleavage of the S unit of lignin during DES treatment was identified. The modified phenol‐formaldehyde resin (RLPF) containing the RL exhibited higher bonding strength (1.28 ± 0.16 MPa) and shorter Sunshine gel time (557 s) than PF (587 s), showing that the RL helps to improve the polycondensation process. The resin modified with the whole solution of lignin in DES exhibited the shortest Sunshine gel time due to the effect of zinc(II) accelerating the curing process. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48385.
Carbonaceous microsphere‐based superabsorbent polymer as filler for coating of NPK fertilizer: Fabrication, properties, swelling, and nitrogen release characteristics
Authors: Ahmed Khan Tanveer , Zakaria Munirah Ezzah Tuan , Kim Hyun‐Joong , Ghazali Suriati , Jamari Saidatul Shima 
Published: August 2019

ABSTRACTRecently, the use of controlled release fertilizers in agriculture has resulted in huge benefits in plant growth and cultivation. Superabsorbent polymer (SAP)‐coated fertilizers have the added advantage in retaining water in soil after irrigation and also reduce the nutrient release rate from soil in a controlled manner. This study aimed to produce a nitrogen–phosphorus–potassium (NPK) fertilizer coated with superabsorbent carbonaceous microspheres polymer (SPC) by inverse suspension polymerization method with water‐retention and controlled release properties. Two sets of experiments were conducted: (1) three different weight percentages and (2) different materials. NPK coated with SPC showed increasing water‐retention ability with respect to carbon microsphere percentages and retains >80% water at the 30th day of experiment compared with pure NPK and NPK coated with SAP. The slow release behavior of all samples was investigated by induced coupled plasma mass spectrometry spectrometry and results showed that NPK coated with SAP and SPC has a low release rate with <50% nutrient release compared with uncoated NPK at the 30th day. The release mechanism kinetics of NPK coated with SAP and SPC were studied based on the Kosmeyer–Peppas model. The mechanisms approached Fickian diffusion‐controlled release as the n value for both samples was less than 0.5. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48396.
Three‐Dimensional Hierarchical Constructs of MOF‐on‐Reduced Graphene Oxide for Lithium–Sulfur Batteries
Authors: Wu Yushan , Jiang Haoqing , Ke Fu‐Sheng , Deng Hexiang 
Published: August 2019

AbstractA three‐dimensional (3D) hierarchical MOF‐on‐reduced graphene oxide (MOF‐on‐rGO) compartment was successfully synthesized through an in situ reduced and combined process. The unique properties of the MOF‐on‐rGO compartment combining the polarity and porous features of MOFs with the high conductivity of rGO make it an ideal candidate as a sulfur host in lithium–sulfur (Li‐S) batteries. A high initial discharge capacity of 1250 mAh g−1 at a current density of 0.1 C (1.0 C=1675 mAh g−1) was reached using the MOF‐on‐rGO based electrode. At the rate of 1.0 C, a high specific capacity of 601 mAh g−1 was still maintained after 400 discharge–charge cycles, which could be ascribed to the synergistic effect between MOFs and rGO. Both the hierarchical structures of rGO and the polar pore environment of MOF retard the diffusion and migration of soluble polysulfide, contributing to a stable cycling performance. Moreover, the spongy‐layered rGO can buffer the volume expansion and contraction changes, thus supplying stable structures for Li‐S batteries.
Stability of a force‐free Hall equilibrium and release of magnetic energy
Authors: Kitchatinov Leonid 
Published: August 2019

Conservation of magnetic helicity by the Hall drift does not prevent Hall instability of helical fields. This conclusion follows from stability analysis of a force‐free spatially periodic Hall equilibrium. The growth rates of the instability scale as σ ∝ B3/4η1/4 with the field strength B and magnetic diffusivity η and can be large compared to the rate of resistive decay of the background field. The instability deviates the magnetic field from the force‐free configuration. The unstable eigenmodes include a fine spatial structure that evolves into current sheets at the nonlinear stage of the instability. The instability catalyzes the resistive release of magnetic energy. The energy is released in a sequence of spikes, every spike emits several percent of the total energy. A numerically defined scaling for the energy released in a single spike permits an extrapolation to astrophysically relevant values of the Hall number. The instability can be relevant to magnetic energy release in a neutron star crust and, possibly, in stellar coronae.
Acoustic properties of early vocalizations in infants with fragile X syndrome
Authors: Hamrick Lisa R. , Seidl Amanda , Tonnsen Bridgette L. 
Published: August 2019

Fragile X syndrome (FXS) is a neurogenetic syndrome characterized by cognitive impairments and high rates of autism spectrum disorder (ASD). FXS is often highlighted as a model for exploring pathways of symptom expression in ASD due to the high prevalence of ASD symptoms in this population and the known single‐gene cause of FXS. Early vocalization features—including volubility, complexity, duration, and pitch—have shown promise in detecting ASD in idiopathic ASD populations but have yet to be extensively studied in a population with a known genetic cause for ASD such as FXS. Investigating early trajectories of these features in FXS may inform our limited knowledge of potential mechanisms that predict later social communication outcomes. The present study addresses this need by presenting preliminary findings which (a) characterize early vocalization features in FXS relative to low‐risk controls (LRC) and (b) test the specificity of associations between these features and language and ASD outcomes. We coded vocalization features during a standardized child–examiner interaction for 39 nine‐month‐olds (22 FXS, 17 LRC) whose clinical outcomes were assessed at 24 months. Our results provide preliminary evidence that within FXS, associations between vocalization features and 24‐month language outcomes may diverge from those observed in LRC, and that vocalization features may be associated with later ASD symptoms. These findings provide a starting point for more research exploring these features as potential early markers of ASD in FXS, which in turn may lead to improved early identification methods, treatment approaches, and overall well‐being of individuals with ASD. Autism Res2019. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryAlthough vocal features of 9‐month‐olds with FXS did not differ from those of low‐risk controls, several features were associated with later language and ASD outcomes at 24 months in FXS. These preliminary results suggest acoustic data may be related to clinical outcomes in FXS and potentially other high‐risk populations. Further characterizing these associations may facilitate understanding of biological mechanisms and risk factors associated with social communication development and ASD.