bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multifunctional Inorganic‐Organic U‐MOF Materials with Nitrogen Heterocyclic Carboxylate: Synthesis, Structure and Properties
Authors: Wang Xue‐Meng , Wang Chen , Zhang Nan , Liu Dong‐Qi , Wang Yang , Bai Feng Ying 
Published: July 2020

AbstractTwo uranyl MOF complexes [(UO2)2(TTHA)]⋅[NH2(CH3)2]2⋅(H2O)3 (1) (H6TTHA=1,3,5‐triazine‐2,4,6‐triamine hexa acetic acid) and (UO2)(HL)2(H2O)2 (2) (L=5‐methyl‐1‐(4‐carboxylphenyl)‐1H‐1,2,3‐triazole‐4‐carboxylic acid) were synthesized by the reaction of uranyl acetate as the metal source with H6TTHA and triazole‐carboxylic acid (L) as the ligand, respectively. They were characterized by elemental analysis, IR, UV‐Vis, PXRD, single crystal X‐ray diffraction and thermal gravimetric analysis. The structural analysis showed that complexes 1 and 2 were covalent inorganic‐organic framework structures. The complex 1 exhibited a self‐assembly 3D structure and 2 was a 2D supramolecular structure by the hydrogen bonding interaction. In order to explore their functional properties, their photoluminescence, surface photovoltage and dye adsorption properties have been also studied and discussed initially. The results showed that complexes 1, 2 exhibited some features in dye adsorption.
Recognition of Lanthanide Metal Cations by t‐DSMI@Alkyl‐Substituted Cucurbit[6]uril Probes
Authors: Yang Rui‐Yu , Deng Xin‐Yu , Huang Ying , Zhang Yun‐Qian , Tao Zhu 
Published: July 2020

AbstractThe binding behavior of three different methyl‐substituted cucurbit[6]urils (SQ[6]s), namely hexamethylcucurbit[3,3]uril (Me6Q[3,3]), tri‐hydroxylated symmetrical hexamethylcucurbit[3,3]uril ((OH)3Me6Q[3,3]), and symmetrical tetramethylcucurbit[6]uril (TMeQ[6]) with trans‐4‐[4‐(dimethylamino)styryl]‐1‐methylpyridinium iodide (t‐DSMI) have been investigated. The results showed that the guest t‐DSMI exhibits dramatic fluorescence enhancement upon interacting with the three SQ[6]s to form 1 : 1 inclusion complexes. Upon addition of lanthanide metal cations to the three t‐DSMI@SQ[6] probes, the fluorescence of the guest was quenched to varying degrees. On this basis, it is possible to discriminate lanthanide metal cations with different ionic radii by principal component analysis (PCA).
Nanoscale Properties of the Methylation in GpC Dinucleotide Systems
Authors: Ovando‐Vázquez Cesaré , Salgado‐Blanco Daniel , López‐Urías Florentino 
Published: July 2020

AbstractThe incorporation of a methyl group to DNA nucleotides (methylation) is a well known phenomenon in epigenetic regulation. Methylation can result in gene silencing. Here we investigate the electronic properties of cytosine methylation in different DNA systems using first‐principles density functional theory calculations. Specifically, four systems are investigated consisting of two stacked base pairs, including the deoxyribose‐phosphate backbone. These four systems are the unmethylated GpC‐CpG, the single methylated GpC‐mCpG, the double symmetrical methylated GpCm‐mCpG, and the quadruple symmetrical GpCmm‐mmCpG. Single base‐pair cases are also considered with and without the deoxyribose‐phosphate backbone (with: pG‐pC, pG‐pCm, and pG‐pCmm; without: G−C, G−Cm, and G‐Cmm). These structures are relaxed using the conjugate gradient method. Nanoscale properties, such as the electronic density of states, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) wave functions, charge Mulliken population, hydrogen bond energy, binding energy, and dipole moments between unmethylated and methylated relaxed structures are obtained and compared. These results demonstrate that the deoxyribose‐phosphate backbone plays a crucial role in the spatial distribution of HOMO and LUMO wave functions in the stacked systems modulating reactivity and stability. Cytosine methylation on the GpC‐CpG system results in a stabilization effect. Dipole moment modification in the studied systems could favor specific protein‐DNA interactions due to the methyl group non‐polarity, producing hydrophobic DNA regions. These findings suggest specific rules of interaction between methylated regions and gene silencing elements at the nanoscale level.
Ethanol Guerbet Condensation to n‐Butanol or C4‐C8 Alcohols over Ni/TiO2 Catalyst
Authors: Li Shuaiqi , Zhu Xionghua , An Hualiang , Zhao Xinqiang , Wang Yanji 
Published: July 2020

AbstractEthanol Guerbet condensation is an environmentally friendly process for preparing biofuel such as n‐butanol and alcohols with more than 4 carbon atoms. In this work, a multifunctional catalyst Ni/TiO2 was prepared by an excess impregnation method and its catalytic performance for ethanol Guerbet condensation was evaluated. The selectivity of C4‐C8 alcohols reached up to almost 70% (41.4% of n‐butanol) at nearly half conversion of ethanol at 210 °C and 10 h. Based on GC‐MS analysis results, the products in ethanol Guerbet condensation were identified and a reaction network was established. The presence of acetaldehyde and 2‐crotonaldehyde in the reaction products verified that Ni/TiO2‐catalyzed ethanol condensation followed the traditional dehydrogenation‐condensation‐hydrogenation reaction mechanism.
Design, Synthesis, Antibacterial Evaluation and Molecular Docking Study of New 3‐Aminoquinoxaline‐2‐alkynyl Carboxylate Esters
Authors: Abbaspour Sima , Keivanloo Ali , Bakherad Mohammad , Sepehri Saghi 
Published: July 2020

AbstractAntibacterial chemotherapy is the clinical application of the antibiotic drug to treat infectious disease. A new series of 3‐aminoquinoxaline‐2‐alkynyl carboxylate esters have been synthesized through the multi‐component copper‐free Sonogashira coupling reaction. Aromatic and aliphatic carboxylic acids were successfully reacted with 3‐bromoprop‐1‐yne and different amine substituted 3‐chloroquinoxalines in the presence of a Pd‐catalyst to produce the new 3‐(3‐(aminoquinoxalin‐2‐yl)prop‐2‐yn‐1‐yl carboxylates. All the newly synthesized compounds were screened in vitro for their antibacterial activities against the two bacterial strains Micrococcus luteus and Pseudomonas aeruginosa. According to the results obtained, compounds 4 a, 4 d, and 4 e showed the lowest MIC value that was comparable to that for tetracycline with strong inhibition (MIC=62.5 mg/mL) against M. luteus and also compound 4 b exhibited the lowest MIC (62.5 mg/mL) against P. aeruginos. Moreover, the results of the antibacterial activity of the synthesized compounds were investigated using molecular docking calculations. In silico studies showed that the screened molecules could occupy both pterin and p‐aminobenzoic acid binding pockets of the dihydropteroate synthase enzyme. Thus, the active compounds could act using the inhibition of bacterial dihydropteroate synthase.
Transition Metal‐Free, Base‐Induced Arylation of Amino Acids: Synthesis of N‐(para‐Substituted phenyl)amino‐2‐carboxylic acids
Authors: Osinubi Adejoke D. , Izunobi Josephat U. , Asekun Olayinka T. , Familoni Oluwole B. , Bao Xiaoguang 
Published: July 2020

AbstractA metal‐free aryl amination reaction of aryl halides and amino acids; with the amino acid serving as the nucleophilic aminating agent, is reported. The reaction was achieved by the condensation of various aryl halides 1 with cyclic and acyclic amino acids 2, in the presence of a cheap and readily available base, potassium carbonate, in refluxing ethanol/water solution (1 : 1) for 3 h, under simple operating conditions. The products, N‐(p‐substituted phenyl)‐amino‐2‐carboxylic acids 3–12, were obtained in isolated yields of 25–90% and characterized by IR, 1H‐ and 13C‐NMR spectroscopy and high‐resolution mass spectrometry. These arylated amino acids are vital synthons and precursors to many compounds of physiological importance.
Lewis Acid‐Free Ynoate‐Mediated Chemoselective Reduction of Carboxylic Acids to Primary Alcohols
Authors: Sun Feixiang , Feng Huangdi , Huang Liliang , Liu Weiping 
Published: July 2020

AbstractWe present an economical and facile catalytic reduction process of carboxylic acids for the synthesis of alcohols. This pyridine‐catalyzed strategy operates through addition of carboxylic acids with methyl propiolate followed by NaBH4 reduction or unexpected ester exchange, providing the corresponding primary alcohols and esters, respectively. A range of carboxylic acids bearing other reductive groups (e. g., halogen, cyano, nitro, ester and double bond) are accessed with uniformly high chemoselectivity. The use of environmentally benign, convenient and safe procedure also makes this catalytic protocol attractive for practical application.
Coping with Technological Changes: Regional and National Preparedness in Face of Technical Change
Authors: Kaivo-oja Jari , Knudsen Mikkel Stein , Lauraeus Theresa 
Published: July 2020

AbstractThe ability to cope with technical change is not evenly distributed geographically. It is possible to evaluate and forecast this ability by creating metrics that capture preparedness to face technical change by looking at multiple factors. This chapter presents selected metrics to measure preparedness and discusses how such metrics can be used with other sources of information about the future changes to create a relevant basis for foresight work that helps societies to adopt and to prepare for the age of digitalization and new forms of manufacturing.
Quantifying the Economic Feasibility of Additive Manufacturing: Simulating Production Lifetimes in the Context of Spare Parts Production
Authors: Savolainen Jyrki , Collan Mikael 
Published: July 2020

AbstractIn the literature there is a lot of talk about the economics of additive manufacturing—typically the terminology used is imprecise at best, and attempts to quantify the benefits from additive manufacturing are most often based on single case studies. This chapter sets out to create a more general picture of the overall economics and feasibility of using additive manufacturing by using a simulation model. The simulation optimizes the cost of production and the end result is information on how often and where in the production lifetime additive manufacturing is the cost optimizing choice. This information is compared to literature-based production strategies envisioned for additive manufacturing. The context of this model and the chapter is that of spare parts production, however, the results resonate beyond this context. The results presented are illustrative and widen the understanding of where during the production-cycle additive manufacturing is economically feasible.
Entanglement wedge cross-section in shock wave geometries
Authors: Boruch Jan 
Published: July 2020

Abstract
We consider reflected entropy in a thermofield double state perturbed by a heavy operator insertion. For sufficiently early operator insertions the dual geometry can be described by a localized shock wave geometry. We calculate the entanglement wedge cross-section in this geometry for symmetric intervals and find that it matches precisely with the CFT result for sufficiently late times. Our result exhibits a plateau before going to zero, a behaviour similar to the one observed recently in the context of global quantum quenches. We find that at high temperatures this behaviour is properly captured by the line-tension picture.
Donaldson–Thomas invariants from tropical disks
Authors: Cheung Man-Wai , Mandel Travis 
Published: July 2020

AbstractWe prove that the quantum DT-invariants associated to quivers with genteel potential can be expressed in terms of certain refined counts of tropical disks. This is based on a quantum version of Bridgeland’s description of cluster scattering diagrams in terms of stability conditions, plus a new version of the description of scattering diagrams in terms of tropical disk counts. The weights with which the tropical disks are counted are expressed in terms of motivic integrals of certain quiver flag varieties. We also show via explicit counterexample that Hall algebra broken lines do not result in consistent Hall algebra theta functions, i.e., they violate the extension of a lemma of Carl–Pumperla–Siebert from the classical setting.
Hypoxia and perfusion in breast cancer: simultaneous assessment using PET/MR imaging
Authors: Carmona-Bozo Julia C. , Manavaki Roido , Woitek Ramona , Torheim Turid , Baxter Gabrielle C. , Caracò Corradina , Provenzano Elena , Graves Martin J. , Fryer Tim D. , Patterson Andrew J. , Gilbert Fiona J. 
Published: July 2020

Abstract
Objectives
Hypoxia is associated with poor prognosis and treatment resistance in breast cancer. However, the temporally variant nature of hypoxia can complicate interpretation of imaging findings. We explored the relationship between hypoxia and vascular function in breast tumours through combined 18F-fluoromisonidazole (18 F-FMISO) PET/MRI, with simultaneous assessment circumventing the effect of temporal variation in hypoxia and perfusion.

Methods
Women with histologically confirmed, primary breast cancer underwent a simultaneous 18F-FMISO-PET/MR examination. Tumour hypoxia was assessed using influx rate constant Ki and hypoxic fractions (%HF), while parameters of vascular function (Ktrans, kep, ve, vp) and cellularity (ADC) were derived from dynamic contrast-enhanced (DCE) and diffusion-weighted (DW)-MRI, respectively. Additional correlates included histological subtype, grade and size. Relationships between imaging variables were assessed using Pearson correlation (r).

Results
Twenty-nine women with 32 lesions were assessed. Hypoxic fractions > 1% were observed in 6/32 (19%) cancers, while 18/32 (56%) tumours showed a %HF of zero. The presence of hypoxia in lesions was independent of histological subtype or grade. Mean tumour Ktrans correlated negatively with Ki (r = − 0.38, p = 0.04) and %HF (r = − 0.33, p = 0.04), though parametric maps exhibited intratumoural heterogeneity with hypoxic regions colocalising with both hypo- and hyperperfused areas. No correlation was observed between ADC and DCE-MRI or PET parameters. %HF correlated positively with lesion size (r = 0.63, p = 0.001).

Conclusion
Hypoxia measured by 18F-FMISO-PET correlated negatively with Ktrans from DCE-MRI, supporting the hypothesis of perfusion-driven hypoxia in breast cancer. Intratumoural hypoxia-perfusion relationships were heterogeneous, suggesting that combined assessment may be needed for disease characterisation, which could be achieved using simultaneous multimodality imaging.

Key Points
• At the tumour level, hypoxia measured by 18F-FMISO-PET was negatively correlated with perfusion measured by DCE-MRI, which supports the hypothesis of perfusion-driven hypoxia in breast cancer.
• No associations were observed between 18F-FMISO-PET parameters and tumour histology or grade, but tumour hypoxic fractions increased with lesion size.
• Intratumoural hypoxia-perfusion relationships were heterogeneous, suggesting that the combined hypoxia-perfusion status of tumours may need to be considered for disease characterisation, which can be achieved via simultaneous multimodality imaging as reported here.
A palynological perspective on the impacts of European contact: Historic deforestation, ranching and agriculture surrounding the Cuchumatanes Highlands, Guatemala
Authors: Harvey William J. , Nogué Sandra , Stansell Nathan , Adolf Carole , Long Peter R. , Willis Kathy 
Published: July 2020

AbstractThe Spanish conquest of the Cuchumatanes Highlands (1524–1541ce) led to dramatic land use changes adhering to colonial practices and values, which included the rearing of livestock, agriculture, timber extraction, mining, and the relocation of indigenous populations to new settlements. These changes are often recorded in historical accounts and official records; however, these are sparse, incomplete, and have been lost over the passage of time. Here, we present a high-resolution palaeoenvironmental reconstruction for Cenote Kail (Guatemala) since the Spanish Conquest, to provide additional evidence of land use changes from an integrated multi-proxy perspective. We analysed: (i) fossil pollen; (ii) macroscopic and microscopic charcoal; and (iii) dung fungal spores (Sporormiella) from a lake sediment core extracted from Cenote Kail in the Cuchumatanes highlands, combining these analyses with remotely sensed satellite data. We reconstructed: (i) forest composition and dynamics; (ii) burning, (iii) fauna abundance, and (iv) agricultural activities. High resolution age-depth modelling was conducted using a combination of210Pb and14C dates. The high temporal resolution enabled a novel integrated validation of the charcoal data sets with remotely sensed satellite data and the historical record. Three stages of floral compositional change were discerned from the palynological assemblage data encompassing: (i) the decline of mixed hard wood forests (MHWF), associated with the building of new settlements, agriculture and timber extraction for fuel (1550–1675ce); (ii) pastoral expansions involving the rearing of livestock (1700–1800ce); and (iii) the expansions of urban settlements and increasing management of the land (1821–2015ce). Seed predation is suggested as the dominant factor preventing MHWF from re-establishing in the Cuchumatanes Highlands over the past 500 years. Burning is limited locally and regionally and in line with the modern regime, which suggests that fire has been managed and controlled since European contact.
Involvement of CsERF2 in leaf variegation of Cymbidium sinense ‘Dharma’
Authors: Gao Jie , Liang Di , Xu Qingquan , Yang Fengxi , Zhu Genfa 
Published: July 2020

AbstractMain conclusionCsERF2, an ethylene response factor, plays a role in leaf variegation.AbstractLeaf variegation is a main ornamental characteristic inCymbidium sinense(C.sinense). However, the mechanisms of leaf color variegation remain largely unclear. In the present study, we analyzed the cytological and physiological features, as well as molecular analyses of leaves from wild-type (WT) and leaf variegation mutants ofCymbidium sinense‘Dharma’. Chloroplasts with typical and functional structures were discovered in WT and green sectors of the mutants leaves (MG), but not in yellow sectors of the mutant leaves (MY). The activities of key enzymes involved in chlorophyll (Chl) degradation and their substrate contents were significantly increased in MY. Genes related to Chl degradation also showed a significant up-regulation in MY. Transcriptomic analysis showed that the expression of all identified ethylene response factors (ERFs) was significantly up-regulated, and the 1-aminocyclopropane-1-carboxylic acid (ACC) content in MY was significantly higher compared with MG. QRT-PCR analysis validated that the expression levels of genes related to Chl degradation could be positively affected by ethylene (ETH) treatment. Stable overexpression ofCsERF2inNicotiana tabacum(N. tabacum) led to a decrease in Chl content and abnormal chloroplast. Transcriptomic analysis and qRT-PCR results showed that the KEGG pathway related to chloroplast development and function showed significant change in transgenicN. tabacum. Therefore, the leaf color formation ofC.sinensewas greatly affected by chloroplast development and Chl metabolism.CsERF2played an important role in leaf variegation ofC.sinense.
Technical principles of atmospheric carbon dioxide reduction and conversion: economic considerations for some developing countries
Authors: Roduner Emil , Rohwer Egmont R. 
Published: July 2020

Abstract
Since natural photosynthesis in our biosphere does not have the capacity to cope with the additional atmospheric CO2 due to combustion of fossil fuels, CO2 has to be actively removed. Efficient methods are currently being developed, but the captured gas has to be dumped in safe and permanent storage environments. Alternatively, it has to be purified before it can be recycled catalytically, using renewable energy, to high-value chemicals as feedstock for the synthesis of polymers, fine chemicals, or in large quantities liquid solar fuels. The combustion of solar fuels is carbon-neutral. If produced at locations where renewable energy is cheap, they become an important economic opportunity. The requirement to achieve a carbon-zero energy supply also for air traffic allows planning for an as yet unknown higher price compared to that of fossil fuels. Use of solar fuels in closed cycle applications may also relieve the energy situation in the large number of off-grid households in rural Africa. The availability of energy, in particular of electricity, is essential for advanced living conditions, prevents migration to urban areas, and therefore protects a rich variation of tribal cultural, religious and social traditions.

Graphic abstract
A balancing act: Swedish occupational safety and health inspectors’ reflections on their bureaucratic role when supervising micro-enterprises
Authors: Hagqvist Emma , Vinberg Stig , Toivanen Susanna , Landstad Bodil J. 
Published: July 2020

AbstractThe safety and health of many workers employed in micro-enterprises (with less than 10 employees) is poor, and legal arrangements related to working environments remain a considerable challenge in these enterprises. The aim of this study is to gain a deeper understanding of how Swedish occupational safety and health (OSH) inspectors perceive themselves as inspectors and their role as bureaucratic regulators when meeting micro-enterprises. In the study, 11 Swedish inspectors were interviewed and asked to reflect on their role as inspectors, how they perceive themselves as inspectors and what their role is as bureaucratic regulators when inspecting micro-enterprises. The qualitative content analysis revealed one theme—a balancing act—and three categories: one inspector, many roles; interactions with micro-entrepreneurs; and exercise the profession as an inspector. The results showed that OSH inspectors experience challenges in meeting the requirements of street-level bureaucracy while addressing the needs of micro-enterprises. In conclusion, OSH inspectors need organisational support to develop inspection models and enforcement styles tailored to micro-enterprises, as this could ease their work and contribute to better inspection outcomes. The implications of this study include a need for increased competence about working environment issues in micro-enterprises, development of enforcement styles among the inspectors, emphasis of the importance of specific governmental projects for OSH and development of models in this enterprise group. Additionally, development of micro-enterprise managers’ competence and ability to handle issues related to the working environment and health were also important.
Experimental insights into consolidation rates during one-dimensional loading with special reference to excess pore water pressure
Authors: Olek Bartłomiej Szczepan 
Published: July 2020

AbstractConsolidation rate has significant influence on the settlement of structures founded on soft fine-grained soil. This paper presents the results of a series of small-scale and large-scale Rowe cell consolidation tests with pore water pressure measurements to investigate the factors affecting the consolidation process. Permeability and creep/resistance structure factors were considered as the governing factors. Intact and reconstituted marine clay from the Polish Carpathian Foredeep basin as well as clay–sand mixtures was examined in the present study. The fundamental relationship correlating consolidation degrees based on compression and pore water pressure was assessed to indicate the nonlinear soil behaviour. It was observed that the instantaneous consolidation parameters vary as the process progresses. The instantaneous coefficient of consolidation first drastically increases or decreases with increase in the degree of consolidation and stabilises in the middle stage of the consolidation; it then decreases significantly due to viscoplastic effects occurring in the soil structure. Based on the characteristics of the relationship between coefficient of consolidation and degree of dissipation at the base, the consolidation range that complies with theoretical assumptions was established. Furthermore, the influence of coarser fraction in clay–sand mixtures in controlling the consolidation rates is discussed.