bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Single‐Molecule and Logic Gate via Optical and Acid–Base Control
Authors: Zhao Wenkai , Zou Dongqing , Sun Zhaopeng , Xu Yuqing , Ji Guomin , Li Xiaoteng , Yang Chuanlu 
Published: September 2020

AbstractSingle‐molecule electronics is a promising solution for electronic device miniaturization. While controllable molecular logic gates are particularly attractive because they are the primary element and can accomplish logical operation reliable and repeatedly for practical application. Here, a brand‐new molecule, which is constructed from a light‐switchable azobenzene unit and proton‐switchable pyrimidine unit, is reported. The electronic transport properties of the molecule are theoretically investigated by density functional theory (DFT) combined with non‐equilibrium Green's function method (NEGF). The calculated current–voltage curves show that the molecule system produces a low resistance only when the ultraviolet (UV) light and acid solution are applied, otherwise, a high resistance will be obtained. Therefore, the molecule system can behave as a single‐molecule AND logic gate which can be controlled by two orthogonal inputs: protonation and light. This work demonstrates a feasible perspective for creating single‐molecule logic gate device.
Controllable and Diversiform Topological Morphologies of Self‐Assembling Supra‐Amphiphiles with Aggregation‐Induced Emission Characteristics for Mimicking Light‐Harvesting Antenna
Authors: Fu Shuang , Su Xiang , Li Meng , Song Shanliang , Wang Lei , Wang Dong , Tang Ben Zhong 
Published: September 2020

AbstractControllable construction of diversiform topological morphologies through supramolecular self‐assembly on the basis of single building block is of vital importance, but still remains a big challenge. Herein, a bola‐type supra‐amphiphile, namely DAdDMA@2β‐CD, is rationally designed and successfully prepared by typical host–guest binding β‐cyclodextrin units with an aggregation‐induced emission (AIE)‐active scaffold DAdDMA. Self‐assembling investigation reveals that several morphologies of self‐assembled DAdDMA@2β‐CD including leaf‐like lamellar structure, nanoribbons, vesicles, nanofibers, helical nanofibers, and toroids, can be straightforwardly fabricated by simply manipulating the self‐assembling solvent proportioning and/or temperature. To the best of knowledge, this presented protocol probably holds the most types of self‐assembling morphology alterations using a single entity. Moreover, the developed leaf‐like lamellar structure performs well in mimicking the light‐harvesting antenna system by incorporating with a Förster resonance energy transfer acceptor, providing up to 94.2% of energy transfer efficiency.
Weather and soil in the US Midwest influence the effectiveness of single‐ and split‐nitrogen applications in corn production
Authors: Clark Jason D. , Fernández Fabián G. , Camberato James J. , Carter Paul R. , Ferguson Richard B. , Franzen David W. , Kitchen Newell R. , Laboski Carrie A. M. , Nafziger Emerson D. , Sawyer John E. , Shanahan John F. 
Published: September 2020

AbstractSplitting the N application into two or more timings may improve corn (Zea mays L.) grain yield and N recovery relative to a single‐N application. A 49 site‐year study across eight U.S. Midwestern states compared the effect of an at‐planting (single‐N application) and two split‐N applications [45 (45+SD) or 90 kg N ha−1 (90+SD) at planting with the remainder of the total rate (180 or 270 kg N ha−1) applied at V9]. For split‐N applications, soil and plant responses were similar between 45+SD and 90+SD 93–98% of the time, indicating the at‐planting N rate of 45 kg N ha−1 may be all that is needed in most cropping scenarios. Splitting the N application compared to a single‐N application changed soil NO3–N at VT and post‐harvest <35% of the time and plant N uptake and grain yield <15% of the time. Split‐N applications had greater grain yield in areas with uniform precipitation around the sidedress timing (Shannon Diversity Index >0.56–0.59) to incorporate N in the root zone, and in coarse‐textured soil (sand content >4–10%) that had greater potential for N loss. Single‐N applications produced greater grain yield in soils with more total N (>2.1–2.4 g kg−1) to support N mineralization and greater cation exchange capacity (CEC) (> 27–31 cmolc kg−1), silt content (>66–74%), or clay content (>24–37%) to improve nutrient and water retention. Decisions on nitrogen application timing should be made based on soil parameters and typical weather conditions around the sidedress timing.
Potassium management over 60 crops: A long‐term study on an Oxisol under no‐till
Authors: Firmano Ruan F. , de Oliveira Junior Adilson , de Castro César , Alleoni Luís R. F. 
Published: September 2020

AbstractPotassium (K) is a typical yield‐limiting nutrient for soybeans [Glycine max (L.) Merr.] in humid tropical regions. The effect of fertilization on K balance over 32 yr of continuous cropping was investigated in a highly weathered Rhodic Hapludox under no‐till. The nutrient balance was calculated based on the amounts of K added via fertilization and on the amounts removed by the crops. Potassium rates interfered with yields over time and modified the final balance of K in the system. Depending on K rates, the balance tended to be positive or negative, and the range of K rates evaluated allowed us to establish conditions of either continuous K depletion, resulting from K removals by harvests, or the accumulation in soil under high rates. In this range, indicators of the efficiency of K fertilizer also varied and made it clear that K fertilizer is not the only source of K for plants.
Evaluating the sensitivity of vegetation and water indices to monitor drought for three Mediterranean crops
Authors: Yildirim Tugba , Zhou Yuting , Flynn K. Colton , Gowda Prasanna H. , Ma Shengfang , Moriasi Daniel N. 
Published: September 2020

AbstractUnderstanding drought effects on vegetative health for crop producing locations, such as the Seferihisar‐Kavakdere region in western Turkey, is vital for water and crop management. This study used Landsat‐derived spectral vegetation indices, specifically normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and land surface water index (LSWI) to evaluate and compare their performance and sensitivity for three major crops (citrus, grape, and olive) under dry (2008), wet (2010), and normal (2015) climatic conditions. Results showed that all three crops were affected by drought despite two (citrus and grape) being irrigated. However, grape and olive were more affected by drought than citrus. Drought conditions were exacerbated during September and October because of lack of precipitation and because irrigation is not a common practice during these months in this region. Therefore, this study aimed to use and compare drought sensitivities of Landsat‐derived spectral vegetation indices. All studied indices were closely related (.48 ≤R2≤ .98) for citrus, grape, and olive. The EVI and LSWI were greater than NDVI when NDVI values were greater than 0.65 for citrus, and LSWI values were larger than NDVI when NDVI values were greater than 0.6 for grape and olive during the wet year. The results showed that different vegetation indices are needed to detect drought from one crop to another under different climatic conditions. Our findings indicate that the irrigation applications in 2008 (drought year) were not sufficient to alleviate the severe drought stress experienced throughout the winter and growing seasons.
A unified framework for adjustable robust optimization with endogenous uncertainty
Authors: Zhang Qi , Feng Wei 
Published: September 2020

AbstractThis work proposes a framework for multistage adjustable robust optimization that unifies the treatment of three different types of endogenous uncertainty, where decisions, respectively, (a) alter the uncertainty set, (b) affect the materialization of uncertain parameters, and (c) determine the time when the true values of uncertain parameters are observed. We provide a systematic analysis of the different types of endogenous uncertainty and highlight the connection between optimization under endogenous uncertainty and active learning. We consider decision‐dependent polyhedral uncertainty sets and propose a decision rule approach that incorporates both continuous and binary recourse, including recourse decisions that affect the uncertainty set. The proposed method enables the modeling of decision‐dependent nonanticipativity and results in a tractable reformulation of the problem. We demonstrate the effectiveness of the approach in computational experiments that cover a wide range of applications. The results show significant benefits from proper modeling of endogenous uncertainty and active learning.
Evaluating life history trade‐offs through the presence of linear enamel hypoplasia at Pueblo Bonito and Hawikku: A biocultural study of early life stress and survival in the Ancestral Pueblo Southwest
Authors: Ham Allison C. , Temple Daniel H. , Klaus Haagen D. , Hunt David R. 
Published: September 2020

AbstractObjectivesDue to the indelible nature of enamel, bioarchaeologists use linear enamel hypoplasia (LEH) to detect early investments in surviving stress and have identified an association between LEH presence and constraints in growth and maintenance as well as an increased susceptibility to future stress events. This study evaluates heterogenous frailty and susceptibility to death in relation to episodes of early life stress, as reflected by LEH presence, in the Ancestral Pueblo Southwest. This study hypothesizes that LEH presence will be associated with decreased survivorship and an increased likelihood of mortality in both samples.Materials and methodsThis study uses two samples, one from Pueblo Bonito (A.D. 800‐1200; n = 28) and the second from Hawikku (A.D. 1300‐1680; n = 103). Kaplan‐Meier survival analysis with a log‐rank test was used to evaluate the effect of LEH presence on survivorship for the two samples.ResultsSurvival analysis reveals statistically significant differences in mortality risk between individuals with and without LEH for the Hawikku sample, but no significant differences for the Pueblo Bonito sample.ConclusionThe results demonstrate differences in the response to early life stress at the Hawikku and Pueblo Bonito sites, likely reflecting context. The Pueblo Bonito sample represents a high‐status group, and survival following LEH may be the result of cultural buffering. Hawikku dates to a period associated with increased levels of disease and malnutrition as well as Spanish colonization. This environment may have exacerbated mortality risk for individuals in the region who survived early life stress and signifies the consequences of European colonialism in the New World.
CHARGE syndrome without colobomas: Ophthalmic findings
Authors: Dosunmu Eniolami O. , Castleberry Katherine M. 
Published: September 2020

AbstractTo report ophthalmic findings of patients without colobomas, and with a clinical and molecular diagnosis of CHARGE Syndrome. Retrospective study of ophthalmic findings in 67 CHARGE patients—clinically confirmed diagnosis with positive CHD7 mutation—seen in the Ophthalmology department of Cincinnati Children's Hospital Medical Center between January 1, 2008 through September 25, 2018. Criteria for inclusion in this study was absence of any form of a coloboma in either eye. In our cohort, all patients had a positive CHD7 mutation, in addition to a clinical diagnosis. 19.4% (13/67) of CHARGE patients did not have a coloboma in either eye. 69.2% (9/13) had strabismus, 76.9% (10/13) had a refractive error that warranted refractive correction, 23.1% (3/13) had amblyopia, 38.5% (5/13) had nasolacrimal duct obstruction, 30.8% (4/13) had dry eye syndrome and exposure keratopathy, 15.4% (2/13) had ptosis, 15.4% (2/13) had blepharitis, 15.4% (2/13) had Cortical Visual Impairment, 7.7% (1/13) of patients had optic nerve drusen, 7.7% (1/13) had Marcus Gunn Jaw Winking, and 7.7% (1/13) with an eyelid nevus. There are numerous ophthalmic findings in individuals with CHARGE Syndrome without colobomas. No study to date has evaluated the ophthalmic findings in CHD7 positive CHARGE patients without colobomas. These findings need to be assessed and treated to ensure optimal vision in the CHARGE patient population. Absence of coloboma does not rule out a diagnosis of CHARGE syndrome, and if there is a clinical suspicion, clinical confirmation then genetic testing would be warranted.
Direct Integration of Phthalazinone and Succinimide Scaffolds via Rh(III)‐Catalyzed C−H Functionalization
Authors: Cho Yong Sun , Kim Hak Do , Kim Euntaek , Han Sang Hoon , Han Soo Bong , Mishra Neeraj Kumar , Jung Young Hoon , Jeong Taejoo , Kim In Su 
Published: September 2020

AbstractThe development of new methods for the direct synthesis of bioactive molecules is a pivotal topic in organic and medicinal chemistry. Herein, we describe the rhodium(III)‐catalyzed C−H functionalization of N‐aryl phthalazinones with maleimides. The complete site‐selectivity and broad functional group tolerance are observed. Notably, this protocol allows the direct integration of phthalazinones and succinimides, which are vital motifs found in bioactive natural products and pharmaceuticals.
Genomics‐Driven Discovery of a Novel Glutarimide Antibiotic from Burkholderia gladioli Reveals an Unusual Polyketide Synthase Chain Release Mechanism
Authors: Nakou Ioanna T. , Jenner Matthew , Dashti Yousef , Romero‐Canelón Isolda , Masschelein Joleen , Mahenthiralingam Eshwar , Challis Gregory L. 
Published: September 2020

AbstractA gene cluster encoding a cryptic trans‐acyl transferase polyketide synthase (PKS) was identified in the genomes of Burkholderia gladioli BCC0238 and BCC1622, both isolated from the lungs of cystic fibrosis patients. Bioinfomatics analyses indicated the PKS assembles a novel member of the glutarimide class of antibiotics, hitherto only isolated from Streptomyces species. Screening of a range of growth parameters led to the identification of gladiostatin, the metabolic product of the PKS. NMR spectroscopic analysis revealed that gladiostatin, which has promising activity against several human cancer cell lines and inhibits tumor cell migration, contains an unusual 2‐acyl‐4‐hydroxy‐3‐methylbutenolide in addition to the glutarimide pharmacophore. An AfsA‐like domain at the C‐terminus of the PKS was shown to catalyze condensation of 3‐ketothioesters with dihydroxyacetone phosphate, thus indicating it plays a key role in polyketide chain release and butenolide formation.
Radical‐Promoted Distal C−H Functionalization of C(sp3) Centers with Fluorinated Moieties
Authors: Nobile Enzo , Castanheiro Thomas , Besset Tatiana 
Published: September 2020

AbstractDue to their unique properties, fluorinated scaffolds are pivotal compounds in pharmaceuticals, agrochemicals, and materials science. Over the last years, the development of versatile strategies for the selective synthesis of fluorinated molecules by direct C−H bond functionalization has attracted a lot of attention. In particular, the design of novel transformations based on a radical process was a bottleneck for distal C−H functionalization reactions, offering synthetic solutions for the selective introduction of fluorinated groups. This Minireview highlights the major contributions in this blossoming field. The development of new methodologies for the remote functionalization of aliphatic derivatives with various fluorinated groups based on a 1,5‐hydrogen atom transfer process and a β‐fragmentation reaction will be showcased and discussed.
Exploiting the Potential of Meroterpenoid Cyclases to Expand the Chemical Space of Fungal Meroterpenoids
Authors: Mitsuhashi Takaaki , Barra Lena , Powers Zachary , Kojasoy Volga , Cheng Andrea , Yang Feng , Taniguchi Yoshimasa , Kikuchi Takashi , Fujita Makoto , Tantillo Dean J. , Porco John A. , Abe Ikuro 
Published: September 2020

AbstractFungal meroterpenoids are a diverse group of hybrid natural products with impressive structural complexity and high potential as drug candidates. In this work, we evaluate the promiscuity of the early structure diversity‐generating step in fungal meroterpenoid biosynthetic pathways: the multibond‐forming polyene cyclizations catalyzed by the yet poorly understood family of fungal meroterpenoid cyclases. In total, 12 unnatural meroterpenoids were accessed chemoenzymatically using synthetic substrates. Their complex structures were determined by 2D NMR studies as well as crystalline‐sponge‐based X‐ray diffraction analyses. The results obtained revealed a high degree of enzyme promiscuity and experimental results which together with quantum chemical calculations provided a deeper insight into the catalytic activity of this new family of non‐canonical, terpene cyclases. The knowledge obtained paves the way to design and engineer artificial pathways towards second generation meroterpenoids with valuable bioactivities based on combinatorial biosynthetic strategies.
MeSi(CH2SnRO)3 (R=Ph, Me3SiCH2): Bausteine für dreieckförmige Diorganozinnoxidmakrocyclen
Authors: Ayari Jihed , Göb Christian R. , Oppel Iris M. , Lutter Michael , Hiller Wolf , Jurkschat Klaus 
Published: September 2020

AbstractEs wird über die Synthesen der neuartigen siliciumverbrückten tris‐tetraorganozinnverbindungen MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) und ihrer halogensubstituierten Derivative MeSi(CH2SnPh(3−n) In)3 (3, n=1; 4, n=2) und MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) berichtet. Die Reaktion von Verbindung 4 mit Di‐tert‐butylzinnoxid, (t‐Bu2SnO)3 liefert das oktokaideka‐nukleare (18‐nuklear) molekulare Diorganozinnoxid [MeSi(CH2SnPhO)3]6 (7), während aus der Umsetzung von 6 mit Natriumhydroxid, NaOH, das trikonta‐nukleare (30‐nuklear) molekulare Diorganozinnoxid [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2) erhalten wurde. Sowohl 7 und 8 zeigen gürtelartige Leiter‐Typ makrocyclische Strukturen und sind die bei weitem größten bekannten molekularen Diorganozinnoxide. Die Verbindungen wurden mittels Elementaranalysen, Elektrospray‐Massenspektrometrie (ESI‐MS), NMR‐Spektroskopie, 1H‐DOSY‐ NMR‐Spektroskopie (7), IR‐Spektroskopie (7, 8) und Einkristallröntgenstrahlbeugungsanalyse (2, 7, 8) charakterisiert.
Chemistry Evolves, Terms Evolve, but Phenomena Do Not Evolve: From Chalcogen–Chalcogen Interactions to Chalcogen Bonding
Authors: Kolb Simon , Oliver Gwyndaf A. , Werz Daniel B. 
Published: September 2020

AbstractChalcogen bonding is important in numerous aspects of chemistry, both in the solid state and in solution. Surveying the literature, it becomes clear that during its rebranding from chalcogen–chalcogen interactions, some parts of the community have somewhat neglected to recall its discovery and the initial studies referring to it in its previous guise. In this Viewpoint, we trace the path of research into this phenomenon, from its discovery, through its renaming, and to some of the varied and interesting chemistry it has led to so far, ranging from crystal engineering through supramolecular assembly to modern catalysis.
Preparation of antibacterial biocompatible polycaprolactone/keratin nanofibrous mats by electrospinning
Authors: Wang Yang , Wang Yingfeng , Li Lin , Zhang Yan , Ren Xuehong 
Published: September 2020

AbstractKeratin‐based materials are widely used in biomedical applications due to excellent biocompatibility and biodegradability. In this study, keratin was extracted from waste wool fibers and blended with polycaprolactone (PCL) to produce PCL/keratin nanofibrous mats by electrospinning. The electrospun PCL/keratin nanofibrous mats were chlorinated in diluted sodium hypochlorite solution to endow antibacterial properties. The prepared nanofibrous mats were characterized by scanning electron microscopy, X‐ray photoelectron, and Fourier infrared spectroscopy. The effect of the chlorination time on the active chlorine loading of the mats was investigated. The chlorinated PCL/keratin nanofibrous mats with 0.78 ± 0.009 wt% active chlorine displayed potent antibacterial activity against Gram‐positive Staphylococcus aureus (ATCC 6538) and Gram‐negative Escherichia coli O157:H7 (ATCC 43895) with 6.88 and 6.81 log reductions, respectively. It was found that the mats were compatible with mouse fibroblast cells (L929). The chlorinated PCL/keratin nanofibrous mats might find promising applications in the biomedical field.
Polyvinyl alcohol – Zedo gum edible film: Physical, mechanical and thermal properties
Authors: Razmjoo Fatemeh , Sadeghi Ehsan , Rouhi Milad , Mohammadi Reza , Noroozi Razieh , Safajoo Saeede 
Published: September 2020

AbstractThe effects of different percentages of Zedo gum (ZG) (10, 20, and 30 w/w%) on the properties of polyvinyl alcohol (PVA) films by casting method were investigated in this study. Physical, thermal, optical as well as mechanical properties of neat PVA, PVA/ZG and neat ZG films were also characterized. All blend PVA/ZG films produced homogeneous, flexible and transparent films, while neat ZG could not form flexible films and films were opaque. Moreover, Fourier transform infrared (FTIR) spectroscopy and thermal behavior confirmed the formation of hydrogen bonds and subsequently compatibility of the two polymers. In general, reduced moisture content, water solubility and water vapor permeability (WVP) were obtained in the blend films rather than the neat PVA films. However, this reduction tended to increase with a rise in the amount of ZG. Furthermore, films with higher ZG concentration (30%) showed lower mechanical strength than the other blend films but were stronger than neat PVA films. However, low water vapor permeability, high mechanical properties and thermal resistance made this edible film appropriate for packaging different food and non‐food applications.
N‐phosphorylated Iminophosphoranes based on 9,10‐Dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide and their flame‐retardant behavior in epoxy resins
Authors: Weinert Michael , Döring Manfred 
Published: September 2020

AbstractTwo novel N‐phosphorylated iminophosphoranes based on 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) were evaluated as flame retardant (FR) additives. They were incorporated in two different epoxy resin systems (EP) based on diglycidyl ether of bisphenol A (DGEBA) and a novolac glycidyl ether (DEN438) both cured with dicyandiamide/fenuron (D/F). Decomposition temperatures and char yields of the cured EP were evaluated and compared to the corresponding neat EP as well as to structurally related compounds. The flame‐retardant properties were investigated using the UL‐94 V test and further verified with cone calorimetry. The N‐phosphorylated iminophosphoranes with DOPO moieties exhibit distinctive flame‐retardant effects in DGEBA/D/F and DEN438/D/F, depending on the chemical environment around the second phosphorus atom, even with low FR content. If the iminophosphorane is triphenyl phosphite based the mode of action is assigned to act mainly in the condensed phase hence being advantageous in DGEBA/D/F compared to the triphenylphosphine‐based iminophosphorane, which in turn is more active in the gas phase resulting in superiority in DEN438/D/F.