bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abiotic Chemical Fuels for the Operation of Molecular Machines
Authors: Biagini Chiara , Di Stefano Stefano 
Published: January 2020

AbstractNatural molecular machines require a continuous fuel supply to perform motions and/or remain in a functional state. Consequently, the aim of developing artificial devices and materials with life‐type properties has motivated a growing interest in abiotic chemical fuels and in their supply modalities. Many artificial molecular machines have been developed in which the sequential addition of several chemical reagents allows the machine to perform complete cycles of motion. Only recently, examples of molecular machines whose cycles of motion are triggered by a single pulse of fuel have been reported. The latter systems are the object of this Minireview where the abiotic chemical fuels used so far to trigger the complete cycles of motion of molecular machines are described, with particular emphasis on the operation mechanism of the machine/fuel systems.
High shape‐memory effect of hindered phenol/nitrile–butadiene rubber composites by forming hydrogen bonding
Authors: Hu Shi‐Kai , Shou Tao , Chen Si , Zhao Xiu‐Ying , Lu Yong‐Lai , Zhang Li‐Qun 
Published: January 2020

ABSTRACTTo widen the type and scope of use of shape memory polymers (SMPs), we added hindered phenol (AO‐80) to nitrile–butadiene rubber (NBR) to gain a group of AO‐80/NBR rubber composites. The glass transition temperature (Tg), structure, mechanical properties, and shape memory properties of the AO‐80/NBR rubber composites were characterized. It was concluded that the dispersion of AO‐80 in the NBR matrix was homogeneous and intra‐molecular hydrogen bonds were formed between the hydroxyl groups (OH) of AO‐80 and the cyano groups (CN) of NBR molecular chain. The dosage of AO‐80 added could be changed to tune the Tg. AO‐80/NBR rubber composites revealed outstanding shape fixity and shape recovery. The method for tuning the Tg of AO‐80/NBR rubber composites will provide an idea for the fabrication and design of new SMPs. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48911.
Action of silicic acid derived from sodium silicate precursor toward improving performances of porous gelatin membrane
Authors: Zhang Zetian , Liu Jun , Gao Wenwei , Sun Liying , Li Zhengjun 
Published: January 2020

ABSTRACTTo gain an insight into understanding how the silica network generated from hydrolysis and condensation of silicic acid, derived from sodium silicate, enhancing hydrothermal stability and mechanical properties of the leather, and particularly which active groups playing a main role for interaction of silica with collagen protein molecules, herein, effects of incorporated amino or carboxyl groups on the properties of silicic acid modified gelatin (GE) membrane were intensively studied. We found when lots of amino groups were introduced by adding a modified melamine, the thermal denaturation temperature, uniformity of pore diameter distribution and mechanical strength of GE membrane distinctly increased, while incorporating plenty of carboxyl groups by adding low polymerization degree acrylic acid polymer, no obvious change of performances of GE film was discovered. In addition, utilization of γ‐glycidoxypropyltrimethoxysilane had a positive effect on the porosity and flexibility of GE membrane. Importantly, our results indicated that hydrogen bonding probably played the most important role toward improving performances of porous GE film when treated with silicic acid. These findings are greatly beneficial for developing a chrome‐free tanning technology based on silicon containing materials, and are also suggestive for fabricating porous silica‐GE hybrid materials using sodium silicate as a precursor. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2020,137, 48912.
Drawing in 3D: Using 3D printer pens to draw chemical models
Authors: Bernard Paweł , Mendez James D. 
Published: January 2020

AbstractDevelopment of three‐dimensional (3D) printing technology has started a new chapter for in‐classroom modeling of chemical molecules. The technology provides the opportunity to design and produce various types of personalized models. However, using classical 3D printers is time consuming, and it is hard to involve students in the modeling process during traditional class times. One solution can be using hand‐held 3D printers (3D pens) that allow users to instantly draw geometrical structures. Unfortunately, drawing directly in 3D is very difficult, and precise modeling of even small molecules is simply not possible. In this article, a new approach to 3D modeling is described. It is based on 3D templates that enable the drawing of molecular models directly in three dimensions. The modular nature of the templates allows for the creation of a wide variety of structures. The resulting models provide an accurate representation of molecules including correct bond angles and geometry. This approach makes 3D pens a powerful tool for the modeling of chemical structures.
MicroRNA‐221 promotes breast cancer resistance to adriamycin via modulation of PTEN/Akt/mTOR signaling
Authors: Yin Yingchun , Wang Xinmei , Li Tangyue , Ren Qi , Li Liang , Sun Xiaoyu , Zhang Baohua , Wang Xinyun , Han Hongmei , He Yangyang , Cao Zhen , Sun Xiaojie , Zhou Ziqiang 
Published: January 2020

AbstractAs a prevalent tumor among women, breast cancer is still an incurable disease due to drug resistance. In this study, we report microRNA‐221 to have a significant effect on breast cancer resistance to adriamycin. The microRNA‐221 is elevated in tumor tissue compared with nearby nontumor samples, as well as in breast cancer cell line with adriamycin resistance (MCF‐7/ADR) compared to its parental line (MCF‐7) and the normal breast epithelial cell line (MCF‐10A). Enforced level of microRNA‐221 promotes cancer resistance to adriamycin, which in turn sustains cell survival and exacerbates malignant formation. Reciprocally, the silence of microRNA‐221 in cancer cells augments the sensitivity to chemotherapy, thereby resulting in enhanced apoptosis of MCF‐7/ADR cells. Mechanistically, we identify PTEN as a direct target of microRNA‐221, which was conversely associated with a microRNA‐221 level in breast tumors. The knock‐down of PTEN partially reversed the stimulatory role of microRNA‐221 in the modulation of the Akt/mTOR signaling. Taken together, these findings suggest microRNA‐221 suppresses PTEN transcription and activates Akt/mTOR pathway, which in turn enhances breast cancer resistance to adriamycin and promotes cancer development. Our data thus illuminate the microRNA‐221/PTEN axis may act as a promising strategy for the treatment of chemotherapy‐resistant breast tumors.
High‐Performance Flexible Asymmetric Supercapacitors Facilitated by N‐doped Porous Vertical Graphene Nanomesh Arrays
Authors: Chi Kai , Zhang Xiangyu , Tian Xin , Zhang Zheye , Wu Zhu , Xiao Fei , Wang Shuai 
Published: January 2020

AbstractInvited for this month's cover picture is the group of Prof. Shuai Wang from Huazhong University of Science and Technology (Wuhan, China). The cover picture shows the fabrication of N‐doped porous vertical graphene nanomesh arrays (NVGMs) on flexible carbon cloth substrate and the decoration of MnO2 nanosheets and polypyrrole films on the NVGMs to develop two types of hierarchical nanohybrid electrodes for flexible asymmetric supercapacitor. Read the full text of the Article at 10.1002/celc.201901499.
AgCoO2−Co3O4/CMC Cloudy Architecture as High Performance Electrodes for Asymmetric Supercapacitors
Authors: Manohara Babu I. , William J. Johnson , Muralidharan G. 
Published: January 2020

AbstractThis work represents the design of superior supercapacitor electrode that comprised of 3D cloud like silver cobalt oxide/cobalt oxide (AgCoO2−Co3O4) and carbon architecture. AgCoO2−Co3O4/C architecture can be fabricated from Co−Ag nitrate precursors with the addition of carboxymethyl cellulose followed by annealing. Mesoporous 3D cloudy architecture provides higher specific capacitance (575 F g−1 at a scan rate of 2 mV s−1) and rate performance (666 F g−1 at a current density of 1 A g−1). The combined effect of AgCoO2 embedded Co3O4 and carboxymethyl cellulose (carbon) highly favors for outstanding cycle life (around 1 % capacitance degradation even after 5000 cycles). Presence of such porous 3D architecture with carbon backbone delivers admirable energy/power density. Also, an advanced asymmetric supercapacitor with an operating range of 1.2 V is designed by utilizing this porous 3D cloudy architecture as positive electrode and activated carbon as negative electrode. The fabricated design shows a robust energy density of 17 W h kg−1 with a high power density of 166 W kg−1 at a current density of 1 A g−1. The findings of the current study underline the potential of AgCoO2−Co3O4/C electrodes for supercapacitor applications.
Catechol Thioesters: Ligands for Hierarchically Formed Lithium‐Bridged Titanium(IV) Helicates and Helicate‐Based Switches
Authors: Kwamen A. Carel N. , de Macedo Gilles S. , Wiederhold Constanze , Oppel Iris M. , Albrecht Markus 
Published: January 2020

AbstractThe thioester moiety is introduced as a lithium binding unit for the hierarchical formation of titanium(IV) catecholate‐based lithium‐bridged helicates. In solution, the coordination compounds show a monomer–dimer equilibrium which —in comparison to the oxo esters— is significantly shifted towards the monomers. In addition, the influence of the thioester side chain on the dimerization behavior is investigated and an expansible/compressible molecular switch is synthesized. In the latter case expansion and compression are performed reversibly in methanol, whereas in DMSO spontaneous expansion occurs.
Enzymatic Synthesis of Methylated Terpene Analogues Using the Plasticity of Bacterial Terpene Synthases
Authors: Hou Anwei , Lauterbach Lukas , Dickschat Jeroen S. 
Published: January 2020

AbstractMethylated analogues of isopentenyl diphosphate were synthesised and enzymatically incorporated into methylated terpenes. A detailed stereochemical analysis of the obtained products is presented. The methylated terpene precursors were also used in conjunction with various isotopic labellings to gain insights into the mechanisms of their enzymatic formation.
Age dependence of modern clinical risk groups for localized prostate cancer—A population‐based study
Authors: Huynh‐Le Minh‐Phuong , Myklebust Tor Åge , Feng Christine H. , Karunamuni Roshan , Johannesen Tom Børge , Dale Anders M. , Andreassen Ole A. , Seibert Tyler M. 
Published: January 2020

BackgroundOptimal prostate cancer (PCa) screening strategies will focus on men likely to have potentially lethal disease. Age‐specific incidence rates (ASIRs) by modern clinical risk groups could inform risk stratification efforts for screening.MethodsThis cross‐sectional population study identified all men diagnosed with PCa in Norway from 2014 to 2017 (n = 20,356). Age, Gleason score (primary plus secondary), and clinical stage were extracted. Patients were assigned to clinical risk groups: low, favorable intermediate, unfavorable intermediate, high, regional, and metastatic. Chi‐square tests analyzed the independence of Gleason scores and modern PCa risk groups with age. ASIRs for each risk group were calculated as the product of Norwegian ASIRs for all PCa and the proportions observed for each risk category.ResultsOlder age was significantly associated with a higher Gleason score and more advanced disease. The percentages of men with Gleason 8 to 10 disease among men aged 55 to 59, 65 to 69, 75 to 79, and 85 to 89 years were 16.5%, 23.4%, 37.2%, and 59.9%, respectively (P < .001); the percentages of men in the same age groups with at least high‐risk disease were 29.3%, 39.1%, 60.4%, and 90.6%, respectively (P < .001). The maximum ASIRs (per 100,000 men) for low‐risk, favorable intermediate‐risk, unfavorable intermediate‐risk, high‐risk, regional, and metastatic disease were 157.1 for those aged 65 to 69 years, 183.8 for those aged 65 to 69 years, 194.8 for those aged 70 to 74 years, 408.3 for those aged 75 to 79 years, 159.7 for those aged ≥85 years, and 314.0 for those aged ≥85 years, respectively. At the ages of 75 to 79 years, the ASIR of high‐risk disease was approximately 6 times greater than the ASIR at 55 to 59 years.ConclusionsThe risk of clinically significant localized PCa increases with age. Healthy older men may benefit from screening.
Can ultrasound systems for risk stratification of thyroid nodules identify follicular carcinoma?
Authors: Castellana Marco , Piccardo Arnoldo , Virili Camilla , Scappaticcio Lorenzo , Grani Giorgio , Durante Cosimo , Giovanella Luca , Trimboli Pierpaolo 
Published: January 2020

BackgroundUltrasound (US) risk stratification systems (RSSs) have been developed to reduce the number of unnecessary fine needle aspirations (FNAs) of thyroid nodules. These systems were designed primarily to identify papillary thyroid carcinomas, thus their performance on follicular thyroid carcinoma (FTC) is debatable. The present study was undertaken to investigate the accuracy of RSSs in selecting FTCs for FNA.MethodsPatients with FTC who underwent US examinations between 2012 and 2018 in 2 institutions were selected. US images were reviewed retrospectively, and FTCs were reclassified according to the American Association of Clinical Endocrinologist/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME), American College of Radiology (ACR‐TIRADS), 2015 American Thyroid Association, British Thyroid Association, European Thyroid Association, Korean Society of Thyroid Radiology and Korean Society of Radiology, and Thyroid Imaging Reporting and Data System (TIRADS). Risk class and indication for FNA were assessed.ResultsForty‐five FTCs from 45 consecutive patients were included in the study. The median tumor diameter was 32 mm (range, 11‐100), and ovoid isoechoic nodule with or without lobulated margins was the most frequent presentation. When FTCs were classified according to RSSs, the most common categories were intermediate and high risk, though 1 case in 3 was not classifiable. FTCs were classified as high risk/high suspicion/malignant in 11% to 74% of cases, with a statistically significant difference among the systems. FNA was indicated in 69% to 100% of cases, with good agreement among AACE/ACE/AME, ACR‐TIRADS, and TIRADS.ConclusionCurrent RSSs show high performance in selecting FTCs for FNA. This result is mainly due to the dimensional RSSs cutoffs indicating FNA. On the contrary, given the reported unsuspicious echo‐structural presentation of FTC and the recognized limitation of cytological assessment to detect it, caution is advised when using US to manage cytologically indeterminate nodules.
Does Pressure Break Mirror‐Image Symmetry? A Perspective and New Insights
Authors: Hochberg David , Cintas Pedro 
Published: January 2020

AbstractThis paper is aimed at dissecting and discussing the effect of high pressure on chirogenesis, thus unveiling the role of this universal force in astrochemical and primeval Darwinian scenarios. The first part of this contribution revisits the current status and recent experiments, most dealing with crystalline racemates, for which generation of metastable conglomeratic phases would eventually afford spontaneous resolution and hence enantioenriched mixtures. We then provide an in‐depth thermodynamic analysis, based on previous studies of non‐electrolyte solutions and dense mixtures accounting for the existence of positive excess volume upon mixing, to simulate the mirror symmetry breaking, the evolution of entropy production and dissipation due to enantiomer conversion. Results clearly suggest that mirror symmetry breaking under high pressure may be a genuine phenomenon and that enantioenrichment from initial scalemic mixtures may also take place.
3 D NiO Nanowall Hole‐Transporting Layer for the Passivation of Interfacial Contact in Inverted Perovskite Solar Cells
Authors: Yin Xin , Zhai Jifeng , Du Pingfan , Li Ni , Song Lixin , Xiong Jie , Ko Frank 
Published: January 2020

AbstractNickel oxide (NiO) materials with excellent stability and favorable energy bands are desirable candidates for hole‐selective contact (HSC) of inverted perovskite solar cell (PSC). However, studies that focus on addressing interfacial issues, which are induced by the poor NiO/perovskite contact or other defects, are scarce. In this study, a facile one‐step hydrothermal strategy is demonstrated for the development of a 3 D NiO nanowall (NW) film as a promising HSC. The new NiO NWs HSC exhibits a robust and homogenous mesoporous network structure, which improved the NiO/perovskite interface contact, passivated the interfacial defect and improved the quality of the perovskite film. The optimized interface features enabled a power conversion efficiency (PCE) approaching 18 %. A diethanolamine (DEA) interlayer was introduced to further passivate the intrinsic defect of the NiO surface, resulting in better charge transfer with suppressed recombination loss. As a result, the champion PCE of the NiO NWs/DEA‐based device was increased to 19.16 % with a high open‐circuit voltage (≈1.11 V) and fill factor (>80 %), which is prominent in methylammonium lead iodide‐based inverted PSCs. Furthermore, the device exhibited better stability and lower hysteresis behavior than a conventional solution‐based NiO nanocrystal device.
Heterogeneous Catalyst Design Principles for the Conversion of Lignin into High‐Value Commodity Fuels and Chemicals
Authors: Gale Mark , Cai Charles M. , Gilliard‐Abdul‐Aziz Kandis Leslie 
Published: January 2020

AbstractLignin valorization has risen as a promising pathway to supplant the use of petrochemicals for chemical commodities and fuels. However, the challenges of separating and breaking down lignin from lignocellulosic biomass are the primary barriers to success. Integrated biorefinery systems that incorporate both homo‐ and heterogeneous catalysis for the upgrading of lignin intermediates have emerged as a viable solution. Homogeneous catalysis can perform selected chemistries, such as the hydrolysis and dehydration of ester or ether bonds, that are more suitable for the pretreatment and fractionation of biomass. Heterogeneous catalysis, however, offers a tunable platform for the conversion of extracted lignin into chemicals, fuels, and materials. Tremendous effort has been invested in elucidating the necessary factors for the valorization of lignin by using heterogeneous catalysts, with efforts to explore more robust methods to drive down costs. Current progress in lignin conversion has fostered numerous advances, but understanding the key catalyst design principles is important for advancing the field. This Minireview aims to provide a summary on the fundamental design principles for the selective conversion of lignin by using heterogeneous catalysts, including the pairing of catalyst metals, supports, and solvents. The review puts a particular focus on the use of bimetallic catalysts on porous supports as a strategy for the selective conversion of lignin. Finally, future research on the valorization of lignin is proposed on the basis of recent progress.
A new rank‐order clustering algorithm for prolonging the lifetime of wireless sensor networks
Authors: Mostafavi Seyedakbar , Hakami Vesal 
Published: January 2020

SummaryEnergy efficient resource management is critical for prolonging the lifetime of wireless sensor networks (WSNs). Clustering of sensor nodes with the aim of distributing the traffic loads in the network is a proven approach for balanced energy consumption in WSN. The main body of literature in this topic can be classified as hierarchical and distance‐based clustering techniques in which multi‐hop, multi‐level forwarding, and distance‐based criteria are utilized for categorization of sensor nodes. In this study, we propose the approximate rank‐order wireless sensor networks (ARO‐WSNs) clustering algorithm as a combined hierarchical and distance‐based clustering approach. Different from absolute distance, ARO‐WSN algorithm utilizes a new rank‐order distance measure for agglomerative hierarchical clustering. Specifically, for each sensor node, we generate a ranking order list by sorting all other sensor nodes in the neighborhood by absolute distance. Then, the rank‐order distance of two sensor nodes is computed using their ranking orders. The designed algorithm iteratively group all sensor nodes into a small number of sub‐clusters. The results show that ARO‐WSN outperforms the competitive clustering algorithms in terms of efficiency and precision/recall. The lifetime of the network with the first node death criterion improved relative to LEACH, LEACH‐C, LEACH with fuzzy descriptors, and BPA‐CRP by 60%, 85%, 22%, and 18%, respectively, and with last node death criterion improved relative to K‐means, LEACH, LEACH‐C, and LEACH with fuzzy descriptors by 42%, 67%, 64%, and 24%, respectively.
Fate of cypermethrin in Malaysian oil palm plantation
Authors: Sulaiman Najwa , Chee Beng Yeoh , Ahmad Bustamam Farah Khuwailah , Khairuddin Nik Sasha Khatrina , Muhamad Halimah 
Published: January 2020

AbstractCypermethrin is a pyrethroid insecticide commonly used to control bagworm infestation in oil palm plantations. It is applied through spraying onto the leaves where the bagworms reside. This article reports the fate of cypermethrin used in a Malaysian oil palm plantation during a typical dry season through the analysis of cypermethrin residue in environmental and palm oil samples collected from a supervised field trial. Residues of cypermethrin were not detected in the soil samples collected at different depths, water samples collected at different points in the experimental plots, and oil samples extracted from fresh fruit bunches (FFB) harvested from each plot for both single and double dosages of treatment throughout the study interval. Analysis of leaf samples, however, revealed that cypermethrin residue was detected for both pesticide treatments up to day 2 after cypermethrin application.
Mitogenome evolution in ladybirds: Potential association with dietary adaptation
Authors: Yuan Ming‐Long , Zhang Li‐Jun , Zhang Qi‐Lin , Zhang Li , Li Min , Wang Xiao‐Tong , Feng Run‐Qiu , Tang Pei‐An 
Published: January 2020

AbstractDietary shifts can alter the relative availability of different nutrients and are therefore associated with metabolic adaptation in animals. The Coccinellidae (ladybirds) exhibits three major types of feeding habits and provides a useful model to study the effects of dietary changes on the evolution of mitogenomes, which encode proteins directly involved in energy metabolism. Here, mitogenomes of three coccinellid species were newly sequenced. These data were combined with other ten previously sequenced coccinellid mitogenomes to explore the relationship between mitogenome evolution and diets. Our results indicate that mitogenomic data can be effectively used to resolve phylogenetic relationships of Coccinellidae. Strong codon usage bias in coccinellid mitogenomes was predominantly determined by nucleotide composition. The 13 mitochondrial protein‐coding genes (PCGs) globally evolved under negative constraints, with some PCGs showing a stronger purifying selection. Six PCGs (nad3,nad4L,andnad5from Complex I;cox1andcox3from Complex IV; andatp6from Complex V) displayed signs of positive selection. Of these, adaptive changes incox3were potentially associated with metabolic differences resulting from dietary shifts in Coccinellidae. Our results provide insights into the adaptive evolution of coccinellid mitogenomes in response to both dietary shifts and other life history traits.