bluuebunny/crossref_metadata_2025_split huggingface dataset:
Das 1,3‐Bis(tricyanoboran)imidazolin‐2‐ylidenat‐Anion – Ein ditopischer dianionischer N‐heterocyclischer Carben‐Ligand
Authors: Zapf Ludwig , Radius Udo , Finze Maik 
Published: May 2021

AbstractDas 1,3‐Bis(tricyanoboran)imidazolat‐Anion 1 wurde in hoher Ausbeute ausgehend von Lithiumimidazolat und B(CN)3‐Pyridin‐Addukt erhalten. Das Anion 1 ist chemisch sehr robust, was sich in der Isolierung des H5O2+‐Salzes widerspiegelt. Ferner dient 1 als Startmaterial für das neuartige dianionische N‐heterocyclische Carben (NHC), das 1,3‐Bis(tricyanoboran)imidazolin‐2‐ylidenat‐Anion 3, das mit seinem Carben‐Kohlenstoffatom und den Cyano‐Gruppen an Bor ein ditopischer Ligand ist. Erste Reaktionen des neuen NHC 3 mit Methyliodid, elementarem Selen und [Ni(CO)4] gaben das methylierte Imidazolat‐Ion 4, das dianionische Selen‐Addukt 5 und den dianionischen Nickeltricarbonyl‐Komplex 6. Diese NHC‐Derivate geben erste Einblicke in die elektronischen und sterischen Eigenschaften von 3. Insbesondere die Kombination von Eigenschaften – wie die zweifach negative Ladung, verschiedene Donorzentren, ein großes verdecktes Volumen und gute σ‐Donor‐ und π‐Akzeptor‐Eigenschaften – macht NHC 3 zu einem einzigartigen und vielversprechenden Liganden und Baustein.
Photocatalytic Upgrading of Lignin Oil to Diesel Precursors and Hydrogen
Authors: Dou Zhaolin , Zhang Zhe , Zhou Hongru , Wang Min 
Published: May 2021

AbstractProducing renewable biofuels from biomass is a promising way to meet future energy demand. Here, we demonstrated a lignin to diesel route via dimerization of the lignin oil followed by hydrodeoxygenation. The lignin oil undergoes C−C bond dehydrogenative coupling over Au/CdS photocatalyst under visible light irradiation, co‐generating diesel precursors and hydrogen. The Au nanoparticles loaded on CdS can effectively restrain the recombination of photogenerated electrons and holes, thus improving the efficiency of the dimerization reaction. About 2.4 mmol gcatal−1 h−1 dimers and 1.6 mmol gcatal−1 h−1 H2 were generated over Au/CdS, which is about 12 and 6.5 times over CdS, respectively. The diesel precursors are finally converted into C16–C18 cycloalkanes or aromatics via hydrodeoxygenation reaction using Pd/C or porous CoMoS catalyst, respectively. The conversion of pine sawdust to diesel was performed to demonstrate the feasibility of the lignin‐to‐diesel route.
The Synthesis of Hexaazatrinaphthylene‐Based 2D Conjugated Copper Metal‐Organic Framework for Highly Selective and Stable Electroreduction of CO2 to Methane
Authors: Liu Yanze , Li Shuai , Dai Lu , Li Jiani , Lv Jianning , Zhu Zhejiaji , Yin Anxiang , Li Pengfei , Wang Bo 
Published: May 2021

Abstract2D conjugated MOFs have attracted significant interests in recent years owing to their special structural features and promising physical and chemical properties. These intriguing attributes, to a large extent, stem from the nature of incorporated ligands. The available ligands for the construction of 2D conjugated MOFs are still limited, especially those that have heteroatoms included and exposed to the pores. In this work, we designed and synthesized a highly symmetric hexaazatrinaphthylene (HATNA)‐based ligand with two different coordination sites. Through selective coordination, a highly crystalline and porous 2D conjugated copper metal‐organic framework was constructed. Due to the synergic effects of HATNA and copper catecholate node, this HATNA‐based 2D conjugated MOF can mediate the electrocatalytic reduction of CO2 to methane with high selectivity of 78 % at high current density of 8.2 milliamperes per square centimetre (mA cm−2) for long durability over 12 hours.
Synthesis and Multiple Subsequent Reactivity of Anionic cyclo‐E3 Ligand Complexes (E=P, As)
Authors: Piesch Martin , Reichl Stephan , Seidl Michael , Balázs Gábor , Scheer Manfred 
Published: May 2021

AbstractA synthetic pathway for the synthesis of novel anionic sandwich complexes with a cyclo‐E3 (E=P, As) ligand as an end deck was developed giving [Cp′′′Co(η3‐E3)]− (Cp′′′=1,2,4‐tri‐tert‐butylcyclopentadienyl, E=P ([5]), As ([6])) in good yields suitable for further reactivity studies. In the reaction with the chlorophosphanes R2PCl (R=Ph, Cy, tBu), neutral complexes with a disubstituted cyclo‐E3P (E=P, As) ligand in [Cp′′′Co(η3‐E3PR2)] (E=P (7 a–c), As (9 a–c)) were obtained. These compounds can be partially or completely converted into complexes with a cyclo‐E3 (E=P, As) ligand with an exocyclic {PR2} unit in [Cp′′′Co(η2:η1‐E3PR2)] (E=P (8 a–c), As (10 a–c)). Additionally, the insertion of the chlorosilylene [LSiCl] (L=(tBuN)2CPh) into the cyclo‐E3 ligand of [5] and [6] was achieved and the novel heteroatomic complexes [Cp′′′Co(η3‐E3SiL)] (E=P (11), As (12)) could be isolated. The reaction pathway was elucidated by DFT calculations.
Pullulan/poly(N‐vinylimidazole) cryogel: An efficient adsorbent for methyl orange
Authors: Hezarkhani Marjan , Ustürk Selma , Özbilenler Cahit , Yilmaz Elvan 
Published: May 2021

AbstractPullulan/poly(N‐vinylimidazole) (PNVI) hybrid cryogels were synthesized under free radical polymerization and chemical crosslinking conditions in an alkaline, aqueous solution of pullulan (PUL), N‐vinylimidazole (NVI), ammonium persulfate and epicholorohydrin (ECH) at −18°C. PUL and PNVI cryogels alone were also synthesized under similar conditions. Optimum cryogel formation conditions were determined by considering product yields and gel fractions of the samples. The products were characterized by elemental analysis, FTIR‐ATR spectrometry, Thermal gravimetric analysis, and scanning electron microscopy (SEM) analyses. It has been found that PUL/PNVI hybrid samples bear improved physicochemical properties compared to ECH crosslinked PUL and PNVI samples alone. They act as hydrogels in aqueous medium reaching equilibrium swelling capacity values of the order of 600%. Dried PUL/PNVI cryogels show higher thermal stability than the dried cryogels of the parent polymers and maintain their physical integrity over a prolonged time period. Macroporous morphology was revealed by SEM analysis. Having 54.2 mg/g maximum equilibrium adsorption capacity in 200 ppm methyl orange solution and maintaining 95% of its adsorption capacity at the end of seven consecutive adsorption/desorption cycles, PUL/PNVI cryogel proved to be an efficient and durable dye adsorbent using methyl orange as the model compound in aqueous solution.
Exploration and reconstruction of a medieval harbour using hydroacoustics, 3‐D shallow seismic and underwater photogrammetry: A case study from Puck, southern Baltic Sea
Authors: Pydyn Andrzej , Popek Mateusz , Kubacka Maria , Janowski Łukasz 
Published: May 2021

AbstractExploration of the marine environment using underwater remote‐sensing methods is the most reasonable method for investigating submerged archaeological heritage sites, preserving their current condition and maintaining them for future generations. While non‐invasive recognition of heritage sites is one of the main objectives of underwater archaeology, the nearshore environment of the small Polish town of Puck hides one of the biggest medieval harbours in the Baltic Sea. The following research objectives were met in this study: (a) exploration of underwater archaeological heritage harbour in Puck using high‐resolution hydroacoustics, 3‐D shallow seismics and underwater photogrammetry; (b) reconstruction of the submerged Puck medieval port by the combining of hydroacoustics, 3D shallow seismics, underwater photogrammetry and archival documentation; (c) estimation of the rate at which the bottom sediments containing the archaeological objects are being destroyed. The underwater archaeological site of Puck harbour was explored using multiple surveying methods, including multibeam echosounder, parametric sub‐bottom profiler, underwater photogrammetry, aerial photography and comparison with archival documentation. Very high‐resolution bathymetry from a multibeam echosounder allowed seabed features such as piles, stones and horizontal structural elements to be identified, along with other archaeological artefacts, boat wrecks and boat‐building artefacts. The 3‐D shallow seismic datasets allowed us to distinguish, for example, several outcropping structures, a previously unknown buried shipwreck, past excavation trenches, the harbour boundary and a palaeochannel of the Płutnica River. Fusing datasets from multiple sources in the geographic information system (GIS) environment allowed for a combined visualization of the heritage sites, providing a broad archaeological demonstration of the underwater structure. By comparing with archival documentation, we calculated that 43% of biogenic layers containing archaeological objects eroded over 26 years. Our results demonstrated that without any doubt, underwater remote‐sensing methods are the most appropriate for exploration and investigation of underwater heritage sites while maintaining their original value.
A multiproxy approach to studying a large prehistoric enclosure in Ojców, Kraków Upland, Poland
Authors: Leloch Michał , Jakubczak Michał , Przybyła Marcin , Pyżewicz Katarzyna , Szeliga Marcin , Wojenka Michał , Czajka Grzegorz , Kot Małgorzata 
Published: May 2021

AbstractDue to the presence of multiple caves and rock shelters as well as flint outcrops, Ojców Upland is a region with an exceptionally high concentration of prehistoric human settlement traces. It has attracted archaeologists for over 150 years, leading to what was considered to have been a proper prospection of the area. Nonetheless, the analysis of airborne laser scanning has recently brought surprising results. In the very centre of the upland, on the densely forested hill ‘Złota Góra’ (Golden Hill), the remains of an exceptionally large defensive structure in the form of several rows of embankments were found. The use of magnetic methods made it possible to confirm their anthropogenic origin and the likely type of embankment construction. In turn, the layout of embankments combined with the results of a surface survey and the analyses of the acquired artefacts and the settlement context speak in favour of linking this defensive structure with a high degree of probability with the Neolithic or Eneolithic, most likely the Lengyel‐Polgár cycle or Baden culture. The presence of such a large fortification in the immediate vicinity of flint mines could shed new light on the image of the Late Neolithic‐Early/Middle Eneolithic period in this part of Europe.
Bioconversion of waste sheep wool to microbial peptone by Bacillus licheniformisEY2
Authors: Tuysuz Elanur , Ozkan Hakan , Arslan Nazli P. , Adiguzel Ahmet , Baltaci Mustafa O. , Taskin Mesut 
Published: May 2021

AbstractPeptones are among the most expensive culture components used in the cultivation of microorganisms. This study was performed to prepare a protein hydrolysate from sheep wool using a locally isolated keratinolytic bacterium Bacillus licheniformis EY2 (GenBank: MN809476), and to investigate the usability of the prepared hydrolysate as a peptone in a microbial medium. The optimum pH, temperature, and incubation time for wool hydrolysis and keratinolytic activity were determined as 7.0, 55 °C, and 6 days, respectively. Optimum concentrations of KH2PO4, MgSO4, and NaCl were determined as 1.5, 0.5, and 2 g/L, respectively. After the prepared hydrolysate was partially purified, it was converted to wool peptone (WP). The total protein, ash, carbohydrate, and lipid content of WP was found to be 82.7, 7.2, 0.1, and 0.2 g/100 g, respectively. Fourier transform infrared (FTIR) analysis of WP confirmed the formation of sulfoxide bonds (S=O), which indicated the breaking of disulfide bonds. When compared with commercial tryptone peptone (TP), WP was found to be superior for the cell growth performances of Esherichia coli, Bacillus subtilis, Staphylococcus aureus, Lactobacillus plantarum, Pediococcus pentosaceus, Candia albicans and Aspergillus niger. A protein hydrolysate (including wool protein hydrolysate) prepared via microbial hydrolysis was tested for the first time as a peptone source. The cost of WP is much lower than commercial peptones. At the same time, the method developed offers an environmentally friendly approach for the reduction of the amount of unutilized or waste sheep wool. © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd.
Impact of bio‐renewable energy sources on reduction of emission footprint from vehicles
Authors: Puškár Michal , Živčák Jozef , Kočišová Michaela , Šoltésová Marieta , Kopas Melichar 
Published: May 2021

AbstractThe transport sector generates up to one quarter of greenhouse gas emissions. Transport is also one of the main polluters in urban agglomerations. This has an impact on the quality of the environment and on human health. Road traffic emissions constitute up to 70% of the total emissions of the transport sector. The automotive industry is under growing pressure to reduce emissions significantly and to utilize alternative sources of energy, among which bio‐renewable sources play a very important role. An important task of scientific publications is to analyze the influence of fuels with different bio‐component content on the total emission footprint from vehicles and to evaluate the real contribution of bio‐components to environmental protection. The experiments reported here were conducted during the 13‐regimes testing cycle, which was especially developed for piston combustion engines. The results create a complex view of the generation of gaseous emissions, taking into consideration engine regimes and loading. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd
A new robust Bayesian small area estimation via ‐stable model for estimating the proportion of athletic students in California
Authors: Zarei Shaho , Arima Serena , Jona Lasinio Giovanna 
Published: May 2021

AbstractIn the last few years, diabetes mellitus and obesity revealed to be one of the fastest‐growing chronic diseases in youth in the United States. The number of new diabetes cases is dramatically increasing, and, for the moment, effective therapy does not exist. Experts believe that one of the causes of this increase is the decline in exercise behavior. The California Education Code requires local educational agencies (LEAs) to administer the FITNESSGRAM, the Physical Fitness Test (PFT), to Californian students of public schools. This test evaluates six fitness areas, and experts defined that a passing result on all six areas of the test represents a fitness level that offers some protection against the diseases associated with physical inactivity. We consider 2015–2016 data provided by the California Department of Education (CDE): for each Californian county (), we aim at estimating the county‐level proportion of students with a score equal to six. To account for the heterogeneity of the phenomenon and the presence of outlying counties, we extend the standard area‐level model by specifying the random effects as a symmetric ‐stable (SS) distribution that can accommodate different types of outlying observations. The model can accurately estimate the county‐level proportion of students with a score equal to six. Results highlight some interesting relationships with social and economic situations in each county. The performance of the proposed model is also investigated through an extensive simulation study.
An evaluation of the impact of stimulus mode on acquisition, maintenance, and generalization of tacts of actions
Authors: Mandel Natalie R. , Cividini‐Motta Catia , Schram Jeffrey 
Published: May 2021

AbstractIndividuals with an autism spectrum disorder or communication delay may experience deficits in tacting. Furthermore, children, with and without language impairments, acquire tacts of objects earlier than tacts of actions, suggesting that tacts of actions may be more difficult to learn (e.g., Sheng & McGregor, 2010). One variable that may impact acquisition of tacts of actions is the type of stimulus (e.g., picture of the action; video of the action) used during training. This study compared acquisition of tacts of actions taught using pictures, videos, and in vivo models. Data were also collected on generalization and maintenance of the acquired tacts as well as participant preference towards the stimulus mode used during tact training. All three participants acquired all tacts, independent of the stimulus mode used during training. However, tacts of actions taught using an in vivo model were acquired in fewer sessions and had greater generalization and maintenance outcomes. In addition, preference for a specific stimulus mode was idiosyncratic across participants.
Enhanced production of nonanedioic acid from nonanoic acid by engineered Escherichia coli
Authors: Lee Yongjoo , Sathesh‐Prabu Chandran , Kwak Geun Hwa , Bang Ina , Jung Hyun Wook , Kim Donghyuk , Lee Sung Kuk 
Published: May 2021

AbstractIn this study, whole‐cell biotransformation was conducted to produce nonanedioic acid from nonanoic acid by expressing the alkane hydroxylating system (AlkBGT) from Pseudomonas putida GPo1 in Escherichia coli. Following adaptive laboratory evolution, an efficient E. coli mutant strain, designated as MRE, was successfully obtained, demonstrating the fastest growth (27‐fold higher) on nonanoic acid as the sole carbon source compared to the wild‐type strain. Additionally, the MRE strain was engineered to block nonanoic acid degradation by deleting fadE. The resulting strain exhibited a 12.8‐fold increase in nonanedioic acid production compared to the wild‐type strain. Six mutations in acrR, Pcrp, dppA, PfadD, e14, and yeaR were identified in the mutant MRE strain, which was characterized using genomic modifications and RNA‐sequencing. The acquired mutations were found to be beneficial for rapid growth and nonanedioic acid production.
Lyophilization of premixed COVID‐19 diagnostic RT‐qPCR reactions enables stable long‐term storage at elevated temperature
Authors: Hammerling Michael J. , Warfel Katherine F. , Jewett Michael C. 
Published: May 2021

AbstractReverse transcriptase‐quantitative polymerase chain reaction (RT‐qPCR) diagnostic tests for SARS‐CoV‐2 are the cornerstone of the global testing infrastructure. However, these tests require cold‐chain shipping to distribute, and the labor of skilled technicians to assemble reactions and interpret the results. Strategies to reduce shipping and labor costs at the point‐of‐care could aid in diagnostic testing scale‐up and response to the COVID‐19 outbreak, as well as in future outbreaks.In this study we test both lab‐developed and commercial SARS‐CoV‐2 diagnostic RT‐qPCR mixes for the ability to be stabilized against elevated temperature by lyophilization. Fully assembled reactions were lyophilized and stored for up to a month at ambient or elevated temperature and were subsequently assayed for their ability to detect dilutions of synthetic SARS‐CoV‐2 RNA.Of the mixes tested, we show that one commercial mix can maintain activity and sensitivity after storage for at least 30 days at ambient temperature after lyophilization. We also demonstrate that lyoprotectants such as disaccharides can stabilize freeze‐dried diagnostic reactions against elevated temperatures (up to 50°C) for at least 30 days.We anticipate that the incorporation of these methods into SARS‐CoV‐2 diagnostic testing will improve testing pipelines by reducing labor at the testing facility and eliminating the need for cold‐chain shipping.
Directed evolution of unspecific peroxygenase in organic solvents
Authors: Martin‐Diaz Javier , Molina‐Espeja Patricia , Hofrichter Martin , Hollmann Frank , Alcalde Miguel 
Published: May 2021

AbstractFungal unspecific peroxygenases (UPOs) are efficient biocatalysts that insert oxygen atoms into nonactivated C–H bonds with high selectivity. Many oxyfunctionalization reactions catalyzed by UPOs are favored in organic solvents, a milieu in which their enzymatic activity is drastically reduced. Using as departure point the UPO secretion mutant from Agrocybe aegerita (PaDa‐I variant), in the current study we have improved its activity in organic solvents by directed evolution. Mutant libraries constructed by random mutagenesis and in vivo DNA shuffling were screened in the presence of increasing concentrations of organic solvents that differed both in regard to their chemical nature and polarity. In addition, a palette of neutral mutations generated by genetic drift that improved activity in organic solvents was evaluated by site directed recombination in vivo. The final UPO variant of this evolutionary campaign carried nine mutations that enhanced its activity in the presence of 30% acetonitrile (vol/vol) up to 23‐fold over PaDa‐I parental type, and it was also active and stable in aqueous acetone, methanol and dimethyl sulfoxide mixtures. These mutations, which are located at the surface of the protein and in the heme channel, seemingly helped to protect UPO from harmful effects of cosolvents by modifying interactions with surrounding residues and influencing critical loops.
Role of Catalysis in Biofuels Production Process – A Review
Authors: Rehman Ayesha , Noor Tayyaba , Hussain Arshad , Iqbal Naseem , Jahan Zaib 
Published: May 2021

AbstractIn the past few years, biofuels have emerged as renewable alternative to encounter global energy requirements in a greener way. Biomass is a sustainable cost‐effective natural resource with wide diversity for conversion to biofuel such as biodiesel, biogas, bio‐oil, biohydrogen, etc. via various chemical, thermal, or biochemical routes. Catalysis plays a pivotal role to convert biomass to biofuels, but conventional catalysts show a lot of short comings. To address these problems, a novel nanocatalysts approach is considered to be the most promising option. Nanocatalysts offer extremely high surface area, enhanced selectivity, better stability and catalytic activity at an atomic and molecular level in comparison to bulk catalysis. Here an insight about the limitation of traditional catalysts, the importance of nanocatalysts, various types of nanocatalysts, and their application in conversion of biomass to biofuel is given. It emphasizes the state‐of‐the‐art developments in terms of catalysis and catalytic processes that are anticipated to play a crucial role in biomass conversion to fuel are emphasized and the chemistry behind nanocatalyst design for biofuel production and reduction of inhibitory effect is highlighted.