bluuebunny/crossref_metadata_2025 huggingface dataset:
Conductive MXene Nanocomposite Organohydrogel for Flexible, Healable, Low‐Temperature Tolerant Strain Sensors
Authors: Liao Hui , Guo Xuelin , Wan Pengbo , Yu Guihua
Published: July 2019

Conductive hydrogels are attracting tremendous interest in the field of flexible and wearable soft strain sensors because of their great potential in electronic skins, and personalized healthcare monitoring. However, conventional conductive hydrogels using pure water as the dispersion medium will inevitably freeze at subzero temperatures, resulting in the diminishment of their conductivity and mechanical properties; meanwhile, even at room temperature, such hydrogels suffer from the inevitable loss of water due to evaporation, which leads to a poor shelf‐life. Herein, an antifreezing, self‐healing, and conductive MXene nanocomposite organohydrogel (MNOH) is developed by immersing MXene nanocomposite hydrogel (MNH) in ethylene glycol (EG) solution to replace a portion of the water molecules. The MNH is prepared from the incorporation of the conductive MXene nanosheet networks into hydrogel polymer networks. The as‐prepared MNOH exhibits an outstanding antifreezing property (−40 °C), long‐lasting moisture retention (8 d), excellent self‐healing capability, and superior mechanical properties. Furthermore, this MNOH can be assembled as a wearable strain sensor to detect human biologic activities with a relatively broad strain range (up to 350% strain) and a high gauge factor of 44.85 under extremely low temperatures. This work paves the way for potential applications in electronic skins, human−machine interactions, and personalized healthcare monitoring.
Multitargeted Nanoparticles Deliver Synergistic Drugs across the Blood–Brain Barrier to Brain Metastases of Triple Negative Breast Cancer Cells and Tumor‐Associated Macrophages
Authors: Zhang Tian , Lip Hoyin , He Chunsheng , Cai Ping , Wang Zhigao , Henderson Jeffrey T. , Rauth Andrew M. , Wu Xiao Yu
Published: July 2019

Patients with brain metastases of triple negative breast cancer (TNBC) have a poor prognosis owing to the lack of targeted therapies, the aggressive nature of TNBC, and the presence of the blood–brain barrier (BBB) that blocks penetration of most drugs. Additionally, infiltration of tumor‐associated macrophages (TAMs) promotes tumor progression. Here, a terpolymer‐lipid hybrid nanoparticle (TPLN) system is designed with multiple targeting moieties to first undergo synchronized BBB crossing and then actively target TNBC cells and TAMs in microlesions of brain metastases. In vitro and in vivo studies demonstrate that covalently bound polysorbate 80 in the terpolymer enables the low‐density lipoprotein receptor‐mediated BBB crossing and TAM‐targetability of the TPLN. Conjugation of cyclic internalizing peptide (iRGD) enhances cellular uptake, cytotoxicity, and drug delivery to brain metastases of integrin‐overexpressing TNBC cells. iRGD‐TPLN with coloaded doxorubicin (DOX) and mitomycin C (MMC) (iRGD‐DMTPLN) exhibits higher efficacy in reducing metastatic burden and TAMs than nontargeted DMTPLN or a free DOX/MMC combination. iRGD‐DMTPLN treatment reduces metastatic burden by 6‐fold and 19‐fold and increases host median survival by 1.3‐fold and 1.6‐fold compared to DMTPLN or free DOX/MMC treatments, respectively. These findings suggest that iRGD‐DMTPLN is a promising multitargeted drug delivery system for the treatment of integrin‐overexpressing brain metastases of TNBC.
Autoclavable and Injectable Cryogels for Biomedical Applications
Authors: Villard Pierre , Rezaeeyazdi Mahboobeh , Colombani Thibault , Joshi‐Navare Kasturi , Rana Devyesh , Memic Adnan , Bencherif Sidi A.
Published: July 2019

Prior to any clinical application, terminal sterilization of biomaterials is a critical process imposed by the Food and Drug Administration. Of all the methods available for sterilization, high‐pressure steam sterilization such as autoclaving is the most widely used. While autoclave sterilization minimizes pathogen contamination, it can dramatically impact both structural and biological properties of biomaterials. It has recently been reported that injectable cryogels with shape memory properties hold great promises as 3D macroporous biomimetic scaffolds for biomedical applications including tissue engineering. In this study, the impact of autoclave sterilization on properties of a series of cryogels is measured. Unlike conventional hydrogels, cryogels made of natural polymers demonstrate a strong resilience to autoclave sterilization. This process does not alter either their macrostructural or unique physical properties including syringe injectability. The scaffolds' bioactive sites are preserved and autoclaved cryogels retain their excellent cytological compatibility post‐autoclaving. Furthermore, autoclaved cryogels do not trigger a notable activation of primary murine bone marrow‐derived dendritic cells suggesting a minimal risk for biomaterial‐induced inflammation, which is further confirmed by an in vivo histologic analysis. In summary, these results further demonstrate the huge potential of cryogels in the biomedical field and their capacity to be translated into clinical applications.
Thiol–Gelatin–Norbornene Bioink for Laser‐Based High‐Definition Bioprinting
Authors: Dobos Agnes , Van Hoorick Jasper , Steiger Wolfgang , Gruber Peter , Markovic Marica , Andriotis Orestis G. , Rohatschek Andreas , Dubruel Peter , Thurner Philipp J. , Van Vlierberghe Sandra , Baudis Stefan , Ovsianikov Aleksandr
Published: July 2019

Two‐photon polymerization (2PP) is a lithography‐based 3D printing method allowing the fabrication of 3D structures with sub‐micrometer resolution. This work focuses on the characterization of gelatin–norbornene (Gel–NB) bioinks which enables the embedding of cells via 2PP. The high reactivity of the thiol‐ene system allows 2PP processing of cell‐containing materials at remarkably high scanning speeds (1000 mm s−1) placing this technology in the domain of bioprinting. Atomic force microscopy results demonstrate that the indentation moduli of the produced hydrogel constructs can be adjusted in the 0.2–0.7 kPa range by controlling the 2PP processing parameters. Using this approach gradient 3D constructs are produced and the morphology of the embedded cells is observed in the course of 3 weeks. Furthermore, it is possible to tune the enzymatic degradation of the crosslinked bioink by varying the applied laser power. The 3D printed Gel–NB hydrogel constructs show exceptional biocompatibility, supported cell adhesion, and migration. Furthermore, cells maintain their proliferation capacity demonstrated by Ki‐67 immunostaining. Moreover, the results demonstrate that direct embedding of cells provides uniform distribution and high cell loading independently of the pore size of the scaffold. The investigated photosensitive bioink enables high‐definition bioprinting of well‐defined constructs for long‐term cell culture studies.
Interfacing Manganese Oxide and Cobalt in Porous Graphitic Carbon Polyhedrons Boosts Oxygen Electrocatalysis for Zn–Air Batteries
Authors: Lu Xue Feng , Chen Ye , Wang Sibo , Gao Shuyan , Lou Xiong Wen (David)
Published: July 2019

Rational design and synthesis of highly active and robust bifunctional non‐noble electrocatalysts for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are urgently required for efficient rechargeable metal–air batteries. Herein, abundant MnO/Co heterointerfaces are engineered in porous graphitic carbon (MnO/Co/PGC) polyhedrons via a facile hydrothermal‐calcination route with a bimetal–organic framework as the precursor. The in situ generated Co nanocrystals not only create well‐defined heterointerfaces with high conductivity to overcome the poor OER activity but also promote the formation of robust graphitic carbon. Owing to the desired composition and formation of the heterostructures, the resulting MnO/Co/PGC exhibits superior activity and stability toward both OER and ORR, which makes it an efficient air cathode for the rechargeable Zn–air battery. Importantly, the homemade Zn–air battery is able to deliver excellent performance including a peak power density of 172 mW cm−2 and a specific capacity of 872 mAh g−1, as well as excellent cycling stability (350 cycles), outperforming commercial mixed Pt/C||RuO2 catalysts. This work highlights the synergy from heterointerfaces in oxygen electrocatalysis, thus providing a promising approach for advanced metal–air cathode materials.
Fast Switchable Micro‐Lenticular Lens Arrays Using Highly Transparent Nano‐Polymer Dispersed Liquid Crystals
Authors: Pagidi Srinivas , Manda Ramesh , Bhattacharyya Surjya Sarathi , Lee Sung Guk , Song Seong Min , Lim Young Jin , Lee Joong Hee , Lee Seung Hee
Published: July 2019

A polarization‐dependent micro‐lenticular lens array (MLA) based on phase modulation of the nanostructured polymer dispersed liquid crystal (nano‐PDLC) is proposed. The transparent and optically isotropic composite is formed by photo‐polymerization induced phase separation of the LC and pre‐polymer mixture. The gradient field is generated by interdigitated electrodes and the LCs in nanosized droplets in nano‐PDLC orient along the field direction, resulting in field‐induced birefringence from the optically isotropic phase. Consequently, the MLAs are formed at the focal plane, in which its measured focal length is 22 µm at 50 Vrms. Besides, the position of focused beam in MLA device can be tuned depending on the polarization direction of an incident beam. The MLA device can realize a 3D image when the polarized 2D image arrays encounter the microlens. The proposed MLA device can pave the way toward upcoming fast switchable 2D/3D display device applications with a very fast switching time of 3.8 ms.
Lateral Bilayer MoS2–WS2 Heterostructure Photodetectors with High Responsivity and Detectivity
Authors: Ye Kun , Liu Lixuan , Liu Yujie , Nie Anmin , Zhai Kun , Xiang Jianyong , Wang Bochong , Wen Fusheng , Mu Congpu , Zhao Zhisheng , Gong Yongji , Liu Zhongyuan , Tian Yongjun
Published: July 2019

2D heterostructures combining different layered semiconductors have received great interest due to their intriguing electrical and optical properties. However, the arbitrary growth of layers in a lateral heterostructure remains a challenge. Here, the synthesis of large‐scale lateral bilayer (LBL) WS2–MoS2 heterostructures is reported by a two‐step chemical vapor deposition route. Raman, photoluminescence, and second‐harmonic generation images show the sharp boundaries between WS2 and MoS2 domains in the heterostructure. Atomically resolved scanning transmission electron microscopy further reveals that sharp boundaries are formed by seamless connections via a lateral zigzag epitaxy between WS2 and MoS2. Notably, the photodetector device based on the LBL WS2–MoS2 heterostructure exhibits ultrahigh photoresponsivity and detectivity (6.72 × 103 A W−1 and 3.09 × 1013 Jones for 457 nm laser light, respectively), orders of magnitude higher than those of MoS2 and WS2 monocrystals. These excellent performances render LBL WS2–MoS2 heterostructures as promising candidates for next‐generation optoelectronics.
Mg2+‐Alloyed All‐Inorganic Halide Perovskites for White Light‐Emitting Diodes by 3D‐Printing Method
Authors: Adhikari Gopi Chandra , Thapa Saroj , Zhu Hongyang , Zhu Peifen
Published: July 2019

All‐inorganic halide perovskites (CsPbX3, X = Cl−, Br−, and I−) are brought to the forefront of research focus in the field of modern lighting technology. However, due to the toxic element (Pb2+), environmentally friendly white‐light emissions are difficult to achieve, thus limiting their practical applications. Herein, high‐quality Mg2+‐alloyed CsPb1−x
Mgx
X3 (up to 20%) nanocrystals (NCs) are synthesized. The structural and optical properties are investigated. The application of these NCs in white‐light‐emitting diodes (LEDs) is also demonstrated. The incorporation of Mg2+ into CsPb1−x
Mgx
X3 NCs results in a lattice contraction without a change in structure and morphology, blue‐shifts in the photoluminescence emission, and increased bandgap. Then, the tunable emission (≈408–650 nm) is obtained by adjusting the compositions of different halides (for 20% Mg2+). Most importantly, for the first time, 3D printed thin color conversion layers for different color emitting NCs (green, yellow, and red) are stacked on top of the blue‐LEDs to achieve high‐quality white light emission. A bright neutral white‐light with a correlated‐color temperature of 5806 K, a high color‐rendering index of 89, CIE coordinates of (0.32, 0.33), a small Duv (<0.003), and high luminous efficacy of radiation of 280 lm W−1 is achieved.
On the Relation between the Open‐Circuit Voltage and Quasi‐Fermi Level Splitting in Efficient Perovskite Solar Cells
Authors: Caprioglio Pietro , Stolterfoht Martin , Wolff Christian M. , Unold Thomas , Rech Bernd , Albrecht Steve , Neher Dieter
Published: July 2019

Today's perovskite solar cells (PSCs) are limited mainly by their open‐circuit voltage (VOC) due to nonradiative recombination. Therefore, a comprehensive understanding of the relevant recombination pathways is needed. Here, intensity‐dependent measurements of the quasi‐Fermi level splitting (QFLS) and of the VOC on the very same devices, including pin‐type PSCs with efficiencies above 20%, are performed. It is found that the QFLS in the perovskite lies significantly below its radiative limit for all intensities but also that the VOC is generally lower than the QFLS, violating one main assumption of the Shockley‐Queisser theory. This has far‐reaching implications for the applicability of some well‐established techniques, which use the VOC as a measure of the carrier densities in the absorber. By performing drift‐diffusion simulations, the intensity dependence of the QFLS, the QFLS‐VOC offset and the ideality factor are consistently explained by trap‐assisted recombination and energetic misalignment at the interfaces. Additionally, it is found that the saturation of the VOC at high intensities is caused by insufficient contact selectivity while heating effects are of minor importance. It is concluded that the analysis of the VOC does not provide reliable conclusions of the recombination pathways and that the knowledge of the QFLS‐VOC relation is of great importance.
Measuring dynamic biased technical change in Lithuanian cereal farms
Authors: Baležentis Tomas , Oude Lansink Alfons
Published: July 2019

Changes in substitutability among inputs and outputs can help farms adapt to economic, technological, or societal changes. However, measurement of technical bias has only been carried out in a static framework, ignoring the confounding effects of technical bias due to adjustment costs. This paper integrates two streams of literature, that is one measuring dynamic inefficiency and the other measuring technical bias, thereby offering non‐parametric measures of technical bias for dynamic production technology. The dynamic framework explains the changes in the extent of output foregone to enable investments. The proposed framework is applied to a panel of data of Lithuanian cereal farms over the period 2004–2014. The results show technical change was, on average, more biased toward increasing output rather than investment. Technical change has been more focused on labor‐usage, relative to land and intermediate consumption in the same period.
Opioid‐related overdose deaths by industry and occupation—Massachusetts, 2011‐2015
Authors: Hawkins Devan , Roelofs Cora , Laing James , Davis Letitia
Published: July 2019

Background

Thousands of people in the United States continue to die from opioid overdoses every year. Work‐related injuries and other factors associated with work may increase exposure to opioids and, subsequently, opioid‐related overdose deaths (OROD). This study sought to determine whether OROD rates differed by industry and occupation and explored work‐related factors that might contribute to these differences.

Methods

We coded industry and occupation information on death certificates for all OROD among Massachusetts residents from 2011 to 2015. We estimated rates of OROD by industry and occupation using Massachusetts employment data. National survey data were used to explore whether work‐related factors known to vary by occupation (occupational injury and illness, job insecurity, and paid sick leave) correlate to observed differences in OROD.

Results

Several industries and occupation groups had rates of OROD that were significantly higher than the rates for other workers. Construction workers and fishing workers stood out for having OROD rates many times higher than the average for all workers. Occupation groups with high rates of occupational injuries and illnesses, high job insecurity, and low availability of paid sick leave had higher rates of OROD.

Conclusions

These findings underscore the need for policy and educational interventions to reduce OROD tailored to the needs of high rate worker populations. Interventions should address workplace hazards that cause injuries for which opioids are prescribed, as well as best practices in medical management and return to work following injury, safer prescribing, enhanced access to treatment for opioid use disorders, and overdose prevention education.
Granulomatous lung disease in two workers making light bulbs
Authors: Ronsmans Steven , Verbeken Eric K , Adams Els , Keirsbilck Stephan , Yserbyt Jonas , Wuyts Wim A , Swennen Rudy , Hoet Peter HM , Nemery Benoit
Published: July 2019

Background

Associations between sarcoidosis or sarcoid‐like granulomatous lung disease and exposure to silica and other inorganic agents have been suggested in several studies.

Cases

We describe granulomatous lung disease in two workers of a small production unit making metal‐halide lamps. Initially, both were diagnosed with sarcoidosis. However, in both men, birefringent particles were observed in the lung or mediastinal lymph node biopsies. Clipping of glass tubes led to moderate exposure to dust, consisting mainly of amorphous fused silica, with some cristobalite. After removal from exposure, both subjects improved clinically, radiologically, and functionally.

Conclusion

The present cases support the hypothesis that silica might be a trigger for sarcoid‐like granulomatous lung disease. Sarcoidosis should be considered a diagnosis of exclusion and clinicians should carefully collect occupational and environmental exposure histories to identify workplace triggers.
Prevalence of hearing loss among noise‐exposed workers within the Mining and Oil and Gas Extraction sectors, 2006‐2015
Authors: Lawson Sean M. , Masterson Elizabeth A. , Azman Amanda S.
Published: July 2019

Background

The purpose of this study was to estimate the prevalence of hearing loss (HL) among noise‐exposed US workers within the Mining, and Oil and Gas Extraction (OGE) sectors.

Methods

Audiograms of 1.9 million workers across all industries (including 9389 in Mining and 1076 in OGE) from 2006 to 2015 were examined. Prevalence and adjusted risk as compared to a reference industry (Couriers and Messengers) were estimated for all industries combined and the Mining and OGE sectors and subsectors.

Results

The prevalences of HL in Mining and OGE were 24% and 14%, respectively, compared with 16% for all industries combined. Many Mining and one OGE subsector exceeded these prevalences and most had an adjusted risk (prevalence ratio) significantly greater than the reference industry. Some subsectors, particularly in OGE, could not be examined due to low sample size. The prevalences in Construction Sand and Gravel Mining and Natural Gas Liquid Extraction were 36% and 28%, respectively. Workers within Support Activities for Coal Mining had double the risk of HL than workers in the reference industry.

Conclusions

The many subsectors identified with high prevalences and/or worker risks for HL well above risks in the reference industry need critical attention to conserve worker hearing and maintain worker quality of life. Administrative and engineering controls can reduce worker hazardous noise exposures. Noise and ototoxic chemical exposure information is needed for many subsectors, as is audiometric testing results for OGE workers. Additional research is also needed to further characterize exposures and improve hearing conservation measures.
Structural and Computational Analysis of 2‐Halogeno‐Glycosyl Cations in the Presence of a Superacid: An Expansive Platform
Authors: Lebedel Ludivine , Ardá Ana , Martin Amélie , Désiré Jérôme , Mingot Agnès , Aufiero Marialuisa , Aiguabella Font Nuria , Gilmour Ryan , Jiménez‐Barbero Jesus , Blériot Yves , Thibaudeau Sébastien
Published: July 2019

An expansive NMR‐based structural analysis of elusive glycosyl cations derived from natural and non‐natural monosaccharides in superacids is disclosed. For the first time, it has been possible to explore the consequence of deoxygenation and halogen substitution at the C2 position in a series of 2‐halogenoglucosyl, galactosyl, and mannosyl donors in the condensed phase. These cationic intermediates were characterized using low‐temperature in situ NMR experiments supported by DFT calculations. The 2‐bromo derivatives display intramolecular stabilization of the glycosyl cations. Introducing a strongly electron‐withdrawing fluorine atom at C2 exerts considerable influence on the oxocarbenium ion reactivity. In a superacid, these oxocarbenium ions are quenched by weakly coordinating SbF6− anions, thereby demonstrating their highly electrophilic character and their propensity to interact with poor nucleophiles.
Unraveling the Light‐Activated Reaction Mechanism in a Catalytically Competent Key Intermediate of a Multifunctional Molecular Catalyst for Artificial Photosynthesis
Authors: Zedler Linda , Mengele Alexander Klaus , Ziems Karl Michael , Zhang Ying , Wächtler Maria , Gräfe Stefanie , Pascher Torbjörn , Rau Sven , Kupfer Stephan , Dietzek Benjamin
Published: July 2019

Understanding photodriven multielectron reaction pathways requires the identification and spectroscopic characterization of intermediates and their excited‐state dynamics, which is very challenging due to their short lifetimes. To the best of our knowledge, this manuscript reports for the first time on in situ spectroelectrochemistry as an alternative approach to study the excited‐state properties of reactive intermediates of photocatalytic cycles. UV/Vis, resonance‐Raman, and transient‐absorption spectroscopy have been employed to characterize the catalytically competent intermediate [(tbbpy)2RuII(tpphz)RhICp*] of [(tbbpy)2Ru(tpphz)Rh(Cp*)Cl]Cl(PF6)2 (Ru(tpphz)RhCp*), a photocatalyst for the hydrogenation of nicotinamide (NAD‐analogue) and proton reduction, generated by electrochemical and chemical reduction. Electronic transitions shifting electron density from the activated catalytic center to the bridging tpphz ligand significantly reduce the catalytic activity upon visible‐light irradiation.
Bi2O3 Nanosheets Grown on Multi‐Channel Carbon Matrix to Catalyze Efficient CO2 Electroreduction to HCOOH
Authors: Liu Subiao , Lu Xue Feng , Xiao Jing , Wang Xin , Lou Xiong Wen (David)
Published: July 2019

Bi2O3 nanosheets were grown on a conductive multiple channel carbon matrix (MCCM) for CO2RR. The obtained electrocatalyst shows a desirable partial current density of ca. 17.7 mA cm−2 at a moderate overpotential, and it is highly selective towards HCOOH formation with Faradaic efficiency approaching 90 % in a wide potential window and its maximum value of 93.8 % at −1.256 V. It also exhibits a maximum energy efficiency of 55.3 % at an overpotential of 0.846 V and long‐term stability of 12 h with negligible degradation. The superior performance is attributed to the synergistic contribution of the interwoven MCCM and the hierarchical Bi2O3 nanosheets, where the MCCM provides an accelerated electron transfer, increased CO2 adsorption, and a high ratio of pyrrolic‐N and pyridinic‐N, while ultrathin Bi2O3 nanosheets offer abundant active sites, lowered contact resistance and work function as well as a shortened diffusion pathway for electrolyte.
Elektrochemische Rasterzellmikroskopie einzelner ZIF‐basierter Nanokompositpartikel als Elektrokatalysatoren für die Sauerstoffentwicklung in alkalischen Medien
Authors: Tarnev Tsvetan , Aiyappa Harshitha Barike , Botz Alexander , Erichsen Thomas , Ernst Andrzej , Andronescu Corina , Schuhmann Wolfgang
Published: July 2019

Einzelpartikel‐Messungen (“single entity”) sind essentiell für das Verständnis von Nanopartikel‐Elektrokatalysatoren, ohne Limitierung durch Stofftransport und lokale Änderungen der Eduktkonzentration oder des pH‐Wertes. Wir berichten über die elektrochemische Rasterzellmikroskopie (SECCM) an Kompositpartikeln aus Co/N‐dotiertem Kohlenstoff, abgeleitet aus ZIF‐67, hinsichtlich der Sauerstoffentwicklungsreaktion (OER). Um die inhärenten SECCM Schwierigkeiten der Oberflächenbenetzung in alkalischer Lösung sowie des Potentialdrifts zu überwinden, wurde ein nicht störender Os‐Komplex als frei diffundierender interner Potentialstandard verwendet. Die ermittelte Turnover‐Frequenz (TOF) beträgt 0,25 bis 1,5 s−1 bei Potentialen zwischen 1,7 und 1,8 V vs. RHE und korreliert mit der Anzahl der Co‐Atome in jedem Partikel. Konstante Werte an Orten mit unterschiedlicher Partikelanzahl belegen die OER‐Aktivität ohne den Einfluss makroskopischer Filmeffekte.
Application of palladium nanoparticle‐decorated Artemisia abrotanum extract‐modified graphene oxide for highly active catalytic reduction of methylene blue, methyl orange and rhodamine B
Authors: Hashemi Salehi Mirmehdi , Yousefi Mohammad , Hekmati Malak , Balali Ebrahim
Published: July 2019

A green palladium‐based catalyst supported on Artemisia abrotanum extract‐modified graphene oxide (Pd NPs/RGO‐A. abrotanum) hybrid material has been used as a recoverable and heterogeneous nanocatalyst for the catalytic reduction of various dyes, including methylene blue, methyl orange and rhodamine B, in the presence of NaBH4 as reducing agent in aqueous medium at room temperature. With the help of UV–visible spectroscopy, the catalytic reactions were investigated. According to the results, these reactions followed the pseudo‐first‐order rate equation.
Role of rheology on the formation of Nanofibers from pectin and polyethylene oxide blends
Authors: Akinalan Balik Busra , Argin Sanem
Published: July 2019

Characterizing the parameters critical to the prediction of a successful electrospinning process from solution properties is essential, yet, not easy in the case of biopolymers. In this study, we attempted to present a broad perspective by simultaneously evaluating the effect of eight different parameters, namely zero shear viscosity, tip viscosity, elastic modulus, phase angle, cohesive energy, pH, conductivity, and surface tension, on the formation of smooth pectin nanofibers. Our results showed that (1) the viscosity of the solution is not an indication of jet formation, but once the jet is formed, high zero shear viscosity and high tip viscosity are required to maintain a dominant whipping instability for smooth nanofiber formation and (2) while evaluating the elasticity of the spinning solutions, comparing only the elastic modulus values would be misleading, since low phase angle values are also necessary for pectin solutions to be electrospun into nonbeaded fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48294.
Using low‐cost drones to monitor heterogeneous submerged seaweed habitats: A case study in the Azores
Authors: Kellaris Alexandros , Gil Artur , Faria João , Amaral Ruben , Moreu‐Badia Ignacio , Neto Ana , Yesson Chris
Published: July 2019

Remote sensing is a powerful monitoring tool for seaweeds, providing large‐scale insights into their ecosystem benefits and invasive impacts. Satellites and manned aircraft have been widely used for this purpose, but their spatial resolution is generally insufficient to map heterogeneous seaweed habitats.

In this study, the potential of low‐cost and high‐resolution drone imagery to map heterogeneous seaweed habitats was assessed on Azorean coasts, where an invasive and commercial species, Asparagopsis armata, is present. A Phantom Pro 3 drone equipped with a visible‐light sensor was used to create photomosaics in three sites on São Miguel island, and ground‐truth data for various seaweed groups were collected with exploratory kayak sampling. Support‐vector machine, random forest, and artificial neural network algorithms were used to construct predictive models of seaweed coverage.

Wind, clouds, and sun glint were the most significant factors affecting drone surveys and images. Exploratory sampling helped locate relatively homogeneous seaweed patches; however, the data were limited and spatially autocorrelated, contributing to overoptimistic model evaluation metrics. Moreover, the models struggled to distinguish seaweeds deeper than 3–4 m.

In conclusion, using drones to monitor heterogeneous seaweed habitats is challenging, especially in oceanic islands where waters are deep and weather is unpredictable. However, this study highlights the potential use of photo‐interpretation to collect modelling data from drone imagery, instead of time‐consuming exploratory ground‐truth sampling. Future studies could assess drones to map seaweeds in less challenging conditions and use photo‐interpretation to improve collection of modelling data.
Output‐feedback‐based sliding mode control for networked control systems subject to packet loss and quantization
Authors: Li Jiarui , Niu Yugang
Published: July 2019

In this paper, observer‐based sliding mode control is considered for networked control systems subject to quantization, in which packet dropout may happen when the measurement output is transmitted from the sensor to the controller. Firstly, a compensating scheme is proposed to deal with the effect of packet loss modelled as a Bernoulli process. Then, by means of available output information and state observer, the desirable sliding mode controller is designed. Furthermore, both the reachability and the stochastic stability of sliding mode dynamics can be attained and the corresponding sufficient conditions are derived. Finally, numerical simulation results are provided to illustrate the proposed control law.
Optical fog‐assisted smart learning framework to enhance students’ employability in engineering education
Authors: Sood Sandeep K. , Singh Kiran Deep
Published: July 2019

In the present scenario, the state of engineering education worldwide is facing a big challenge of the employability of graduates. Cloud computing technology has changed the educational landscape by allowing educators and administrators to shift to the cloud for making actionable decisions. In this paper, a smart learning framework is proposed where universities/colleges can advocate the management of employability enhancement and start skill‐set enhancement courses through e‐learning. This proposed framework monitors the academic/skill data of students to classify their employability at the early stage of graduation. In addition, an algorithm is proposed for skill‐set assessment to find various clusters of students who lack in required skill‐set. The predicted clusters of students can be offered opportunities to improve their required skill‐set through e‐learning. Further, we used the design science research methodology for conducting online courses. Moreover, the prediction of resource usage of the proposed e‐learning framework is calculated to improve its effectiveness. In our experiment, results show that our proposed hybrid classier achieves 96.45% accuracy of classification. The prediction of resource usage offers better opportunities for adaptive resource elasticity. The results depict that by introducing the proposed framework in engineering education; more effective decisions can be made to improve the employability and overall growth of students.
Learning methodology based on weld virtual models in the mechanical engineering classroom
Authors: Rodríguez‐Martín Manuel , Rodríguez‐Gonzálvez Pablo
Published: July 2019

Welding inspection activities within engineering degree programs are usable in practice. The competences acquired through these are usually contextualized in laboratory environments, using for its physical samples of welds, which used to be are scarce and expensive. In this study, a new methodology based on three‐dimensional macro‐photogrammetric models of welds is designed and actively implemented in the classroom, with students of mechanical engineering to evaluate different aspects about the suitability and learning performance of this novel methodology. To obtain the research conclusions, the activities have been chosen to evaluate four important aspects of it: usability, learning, motivation, and scalability. Results demonstrate that the adequate acceptation of the novel methodology studied, making possible new approaches for the acquisition of the competences related the welding inspection in the engineering education context.
A learning analytics tool for the support of the flipped classroom
Authors: Rubio‐Fernández Aarón , Muñoz‐Merino Pedro J. , Delgado Kloos Carlos
Published: July 2019

Nowadays, there are quite a few experiences of the use of the flipped classroom (FC) in engineering education due to their advantages in comparison with the traditional methodology. The possibility of promoting students’ active learning under the FC can lead to improvements in the learning outcomes. Nonetheless, there are several issues that arise when using the FC (such as the students’ need of preparing the face‐to‐face lesson) that must be addressed. To take advantage of the whole potential of the FC, we propose the application of learning analytics (LA) to improve the FC. In particular, we define a methodology that proposes a set of recommended actions to be done to enhance a specific type of flipped classroom through LA. Moreover, we present a LA tool designed and implemented specifically for this methodology. This tool allows teachers to obtain relevant information needed to improve their FC experiences. The information is provided using several visualizations that are analyzed and explained in detail. We illustrate the use of the tool with students from engineering courses.
A randomized phase II trial of nab‐paclitaxel and gemcitabine with tarextumab or placebo in patients with untreated metastatic pancreatic cancer
Authors: Hu Zishuo Ian , Bendell Johanna C. , Bullock Andrea , LoConte Noelle K. , Hatoum Hassan , Ritch Paul , Hool Hugo , Leach Joseph W. , Sanchez James , Sohal Davendra P. S. , Strickler John , Patel Ravindranath , Wang‐Gillam Andrea , Firdaus Irfan , Yu Kenneth H. , Kapoun Ann M. , Holmgren Eric , Zhou Lei , Dupont Jakob , Picozzi Vincent , Sahai Vaibhav , O'Reilly Eileen M.
Published: July 2019

Purpose

Notch signaling dysregulation is implicated in the development of pancreatic adenocarcinoma (PDAC). Tarextumab is a fully human IgG2 antibody that inhibits Notch2/3 receptors.

Patients and Methods

Aphase 2, randomized, placebo‐controlled, multicenter trial evaluated the activity of tarextumab in combination with nab‐paclitaxel and gemcitabine in patients with metastatic PDAC. Patients were stratified based on ECOG performance score and Ca 19‐9 level and randomized 1:1 to nab‐paclitaxel, gemcitabine with either tarextumab or placebo. Based on preclinical and phase Ib results suggesting a positive correlation between Notch3 gene expression and tarextumab anti‐tumor activity, patients were also divided into subgroups of low, intermediate, and high Notch3 gene expression. Primary endpoint was overall survival (OS) in all and in patients with the three Notch3 gene expression subgroups (≥25th, ≥50% and ≥75% percentiles); secondary end points included progression‐free survival (PFS), 12‐month OS, overall response rate (ORR), and safety and biomarker investigation.

Results

Median OS was 6.4 months in the tarextumab group vs 7.9 months in the placebo group (HR = 1.34 [95% CI = 0.95, 1.89], P = .0985). No difference observed in OS in the Notch3 gene expression subgroups. PFS in the tarextumab‐treated group (3.7 months) was significantly shorter compared with the placebo group (5.5 months) (hazard ratio was 1.43 [95% CI = 1.01, 2.01]; P = .04). Grade 3 diarrhea and thrombocytopenia were more common in the tarextumab group.

Conclusions

The addition of tarextumab to nab‐paclitaxel and gemcitabine did not improve OS, PFS, or ORR in first‐line metastatic PDAC, and PFS was specifically statistically worse in the tarextumab‐treated patients.

Clinical trial registry no

NCT01647828.
A linear lesion in a child with atopic dermatitis: Not a coincidence
Authors: Van Gysel Julie , Grimalt Ramon
Published: July 2019

A blaschkolinear lesion in a patient with atopic dermatitis can be a superimposed segmental manifestation of this polygenic disorder. Knowledge of this phenomenon, presence of less severe, disseminated, symmetrically distributed lesions of the same disorder and, if necessary, histology are helpful in the differential diagnosis from other linear inflammatory diseases.
Porous Si@SiOx@N‐Rich Carbon Nanofibers as Anode in Lithium‐Ion Batteries under High Temperature
Authors: Xia Qi , Xu Anding , Huang Chuyun , Yan Yurong , Wu Songping
Published: July 2019

A facile electrospinning technique followed by pre‐oxidation and carbonization treatment is adopted to synthesize silicon anode cladded with SiOx layer and N‐rich carbon nanofibers (Si@SiOx@NCNFs), in which post‐used polyacrylonitrile (PAN) yarn is chosen as single carbon source. As anode in Li‐ion batteries, elaborately designed Si@SiOx@NCNFs renders remarkable reversible capacities of 1045 mA h g−1 at the 500th cycle under a current density of 8 A g−1 at 80°C, and 828 mA h g−1 after subsequent 500 cycles at 15 A g−1, mainly ascribed to the distinct hierarchical structure, N‐rich nature and enhanced pesudocapacitive behavior. When Si@SiOx@NCNFs is matched with commercial cathode LiFePO4, full cell delivers a stable capacity of 140 mA h g−1 at 100 mA g−1, accompanying with an energy density of 455 Wh kg−1 at 50 °C. These conspicuous features undoubtedly enable Si@SiOx@NCNFs to be promising anode materials for high‐power lithium‐ion battery used in harsh conditions.
Negishi's Reagent Versus Rosenthal's Reagent in the Formation of Zirconacyclopentadienes
Authors: Urrego‐Riveros Sara , Ramirez y Medina Isabel‐Maria , Duvinage Daniel , Lork Enno , Sönnichsen Frank D. , Staubitz Anne
Published: July 2019

Zirconacyclopentadienes are versatile precursors for a large number of heteroles, which are accessible by Zr‐element exchange reactions. The vast majority of reports describe their preparation by the use of Negishi′s reagent, which is a species that is formed in situ. The zirconacyclopentadiene is then formed by the addition of one equivalent of a diyne or two equivalents of a monoyne moiety to this Negishi species. Another route involves Rosenthal′s reagent (Cp2Zr(py)Me3SiC≡CSiMe3), which then reacts with a diyne or monoyne moiety. In this work, the efficiency of both routes was compared in terms of reaction time, stability of the product in the reaction mixture, and yield. The synthetic implications of using both routes are evaluated. Novel zirconacyclopentadienes were synthesized, characterized directly from the reaction mixture, and crystal structures could be obtained in most cases.
Continuous Flow Synthesis of a Zr Magnetic Framework Composite for Post‐Combustion CO2 Capture
Authors: He Brandon , Sadiq Muhammad Munir , Batten Michael P. , Suzuki Kiyonori , Rubio‐Martinez Marta , Gardiner James , Hill Matthew R.
Published: July 2019

Metal‐organic frameworks (MOFs) have an unprecedented ability to store gas molecules, however energy efficient regeneration remains challenging. Use of magnetic induction to aid this shows promise, but economical synthesis of the requisite composites is unresolved. Continuous flow chemistry has been reported as a rapid and reliable method of MOF synthesis, delivering step‐change improvements in space time yields (STY). Here the scalable production of nanomaterials suitable for regeneration by magnetic induction is demonstrated. The zirconium MOF composite, MgFe2O4@UiO‐66‐NH2 is prepared using continuous flow chemistry resulting in a material of comparable performance to its batch counterpart. Upscaling using flow chemistry gave STY >25 times that of batch synthesis. Magnetic induced regeneration using this mass produced MFC for carbon capture is then demonstrated.
Tumorigenic effects of TLX overexpression in HEK 293T cells
Authors: Parris Toshima Z. , Vizlin‐Hodzic Dzeneta , Salmela Susanne , Funa Keiko
Published: July 2019

Background

The human orphan receptor TLX (NR2E1) is a key regulator of neurogenesis, adult stem cell maintenance, and tumorigenesis. However, little is known about the genetic and transcriptomic events that occur following TLX overexpression in human cell lines.

Aims

Here, we used cytogenetics and RNA sequencing to investigate the effect of TLX overexpression with an inducible vector system in the HEK 293T cell line.

Methods and results

Conventional spectral karyotyping was used to identify chromosomal abnormalities, followed by fluorescence in situ hybridization (FISH) analysis on chromosome spreads to assess TLX DNA copy number. Illumina paired‐end whole transcriptome sequencing was then performed to characterize recurrent genetic variants (single nucleotide polymorphisms (SNPs) and indels), expressed gene fusions, and gene expression profiles. Lastly, flow cytometry was used to analyze cell cycle distribution. Intriguingly, we show that upon transfection with a vector containing the human TLX gene (eGFP‐hTLX), an isochromosome forms on the long arm of chromosome 6, thereby resulting in DNA gain of the TLX locus (6q21) and upregulation of TLX. Induction of the eGFP‐hTLX vector further increased TLX expression levels, leading to G0‐G1 cell cycle arrest, genetic aberrations, modulation of gene expression patterns, and crosstalk with other nuclear receptors (AR, ESR1, ESR2, NR1H4, and NR3C2). We identified a 49‐gene signature associated with central nervous system (CNS) development and carcinogenesis, in addition to potentially cancer‐driving gene fusions (LARP1‐CNOT8 and NSL1‐ZDBF2) and deleterious genetic variants (frameshift insertions in the CTSH, DBF4, POSTN, and WDR78 genes).

Conclusion

Taken together, these findings illustrate that TLX may play a pivotal role in tumorigenesis via genomic instability and perturbation of cancer‐related processes.
Generating Single Cell–Derived Knockout Clones in Mammalian Cells with CRISPR/Cas9
Authors: Giuliano Christopher J. , Lin Ann , Girish Vishruth , Sheltzer Jason M.
Published: July 2019

CRISPR/Cas9 technology enables the rapid generation of loss‐of‐function mutations in a targeted gene in mammalian cells. A single cell harboring those mutations can be used to establish a new cell line, thereby creating a CRISPR‐induced knockout clone. These clonal cell lines serve as crucial tools for exploring protein function, analyzing the consequences of gene loss, and investigating the specificity of biological reagents. However, the successful derivation of knockout clones can be technically challenging and may be complicated by multiple factors, including incomplete target ablation and interclonal heterogeneity. Here, we describe optimized protocols and plasmids for generating clonal knockouts in mammalian cell lines. We provide strategies for guide RNA design, CRISPR delivery, and knockout validation that facilitate the derivation of true knockout clones and are amenable to multiplexed gene targeting. These protocols will be broadly useful for researchers seeking to apply CRISPR to study gene function in mammalian cells. © 2019 The Authors.
Performance improvement of wireless secret key generation with colored noise for IoT
Authors: Soni Ankit , Upadhyay Raksha , Kumar Abhay
Published: July 2019

Achieving security in the Internet of things (IoT) networks by generating symmetric keys from the wireless channel parameters like received signal strength (RSS) is a promising approach. Despite the easy acquisition of the RSS signal, RSS‐based security is less explored for IoT. In this work, we analyze the performance of RSS‐based wireless physical layer key generation with correlated colored noise components and proposed a low complexity filtering approach to improve the performance for the IoT network. We started with providing a survey of various recent researches related to RSS‐based key generation and also discussed correlated colored noise components with a few of the recent works considering them. Further, we analyze various colored noise components in the time domain by the Allan variance and Ljung‐Box test. Furthermore, we develop a key generation model and proposed a moving window averaging‐based filtering followed by Lloyd max quantization to improve the BDR performance, degraded due to the presence of correlated colored noise components. The simulation results show that the proposed preprocessing technique has a considerable improvement in the BDR performance, and the keys generated have sufficient randomness, which is verified by NIST test.
Peramorphosis, an evolutionary developmental mechanism in neotropical bat skull diversity
Authors: Camacho Jasmin , Heyde Alexander , Bhullar Bhart‐Anjan S. , Haelewaters Danny , Simmons Nancy B. , Abzhanov Arhat
Published: July 2019

Background

The neotropical leaf‐nosed bats (Chiroptera, Phyllostomidae) are an ecologically diverse group of mammals with distinctive morphological adaptations associated with specialized modes of feeding. The dramatic skull shape changes between related species result from changes in the craniofacial development process, which brings into focus the nature of the underlying evolutionary developmental processes.

Results

In this study, we use three‐dimensional geometric morphometrics to describe, quantify, and compare morphological modifications unfolding during evolution and development of phyllostomid bats. We examine how changes in development of the cranium may contribute to the evolution of the bat craniofacial skeleton. Comparisons of ontogenetic trajectories to evolutionary trajectories reveal two separate evolutionary developmental growth processes contributing to modifications in skull morphogenesis: acceleration and hypermorphosis.

Conclusion

These findings are consistent with a role for peramorphosis, a form of heterochrony, in the evolution of bat dietary specialists.