bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revisiting the Role of Active Sites for Hydrogen Evolution Reaction through Precise Defect Adjusting
Authors: Zhuang Peiyuan , Sun Yangye , Dong Pei , Smith Will , Sun Zhengzong , Ge Yuancai , Pei Yu , Cao Ziyi , Ajayan Pulickel M. , Shen Jianfeng , Ye Mingxin 
Published: June 2019

Abstract2D transition metal dichalcogenides (TMDs) have presented outstanding potential for efficient hydrogen evolution reaction (HER) to replace traditional noble metal catalysts. Here, to achieve enhanced HER performance, specific areas of the few‐layer 1T'‐MoTe2 film are precisely controlled with a focused ion beam to create particular active sites. Electrochemical measurements indicate that the HER performance, although inconspicuous in pristine 1T'‐MoTe2 ultrathin films prepared through the chemical vapor deposition method, can be greatly enhanced after patterning and precisely controlled by the morphologies as well as the amounts of the defects, reaching a small onset potential and a record‐low Tafel slope of 44 mV per decade for few‐layer TMDs. Conductivity tests, visualized copper electrodeposition, and density functional theory calculations also confirm that the enhancement of HER performance comes from the exposed edges by patterning. In this pioneering work, not only is the catalysis mechanism of the edge active sites of 1T'‐MoTe2 unveiled, but also a universal route to study the properties of 2D materials is demonstrated.
Carbon Quantum Dot Assisted Adsorption of Graphene Oxide to the Oil–Water Interface for Copper Sensing Emulsions
Authors: Parks Huw C. W. , McCoy Thomas M. , Tabor Rico F. 
Published: June 2019

AbstractA nanocomplex of graphene oxide (GO) and nitrogen‐doped carbon quantum dots (N‐CQDs) is utilized for effective stabilization of the toluene–water interface in high surface area oil‐in‐water emulsions to assist in detection and extraction of Cu(II) ions. CQDs are nitrogen‐doped to produce a positively charged material that readily adsorbs to GO through charge interactions, forming a surface‐active complex. N‐CQDs serve two key purposes: first, to screen the surface charge of GO and thereby lower the electrostatic barrier to adsorption at the toluene–water interface, and second to detect Cu(II) ions via fluorescence quenching. This combined system is far more effective in lowering the interfacial tension between toluene and water, and thus stabilizing toluene‐in‐water emulsions, than either component alone. The complex comprises cheap and easy to prepare materials, and overcomes the limitations of the individual components through synergistic effects. Additionally, the noncovalent nature and self‐assembly of this system allows for facile use and potential recovery of the materials, and therefore enables utilization in industrial applications such as solvent extraction for mineral processing.
Thermo‐Induced Free‐Radical Cleavage of Enaminone C=C Double Bond for α‐Acyloxyl Ketone Synthesis
Authors: Tian Lihong , Guo Yanhui , Wei Li , Wan Jie‐Ping , Sheng Shouri 
Published: June 2019

AbstractThe cleavage on the C=C double bonds of N,N‐dimethyl enaminones is initiated by a thermo‐induced free‐radical transformation, enabling the chemo‐selective synthesis of α‐acyloxyl ketones. The Mn(II)‐assisted single‐electron transfer (SET) from the free radical intermediate resulting from addition of the carboxyl radical to enaminone is the key process in modulating the expected reaction pathway.
Maternal influence on the development of nut‐cracking skills in the chimpanzees of the Taï forest, Côte d'Ivoire (Pan troglodytes verus)
Authors: Estienne Vittoria , Cohen Heather , Wittig Roman M. , Boesch Christophe 
Published: June 2019

AbstractChimpanzees’ (Pan troglodytes) nut‐cracking behavior represents one of the most complex forms of tool‐use known among nonhuman animals. Given the close phylogenetic relationship between these apes and humans, investigating how such complex behavior develops in immatures can reveal the evolutionary roots of the cognitive processes that enabled the evolution of outstanding technological skills in our lineage. In this study, we investigated whether maternal behavior directly enhanced nut‐cracking skills in immature individuals. We analyzed the behavior of 11 immatures and their mothers (N = 8) during nut‐cracking activity, spanning over three consecutive nut‐cracking seasons in the Taï National Park, Côte d'Ivoire. We used generalized linear mixed models to (a) obtain values of maternal scaffolding (defined as provision of learning opportunities) and active nut‐sharing behavior of each mother according to the age of their offspring, and their average nut‐cracking efficiency; (b) to test whether these variables enhanced immatures’ nut‐cracking skills; and (c) to test whether immatures’ features (age, sex, and begging behavior) influenced maternal behavior as observed in our videos. Although the predicted values of maternal scaffolding and active nut‐sharing did not obviously affect immatures’ skills, they were positively influenced by the average maternal efficiency and by sharing hammers with their mothers. In addition, our observations showed that mothers were more likely to share nuts with their sons than with their daughters, and the more their offspring begged. Concurrently, male immatures were also found to beg more often than females. Our results add evidence on the ontogenetic pathway leading to the full acquisition of nut‐cracking in wild chimpanzees and on the effect that maternal behavior can have in promoting the acquisition of this complex tool‐use behavior. Moreover, our study strengthens the importance of naturalistic observations to understand complex skill acquisition. Finally, we suggest future avenues for investigating the maternal influence on learning.
Subordination signals improve the quality of social relationships in Verreaux's Sifaka: Implications for the evolution of power structures and social complexity
Authors: Lewis Rebecca J. 
Published: June 2019

AbstractObjectivesUnidirectional dominance‐related signals can be used to communicate submission (an immediate behavioral response) or subordination (the status of an established relationship). Subordination signals are defined as emitted during peaceful interactions and are hypothesized to be critical for the evolution of social complexity and robust power structures because they reduce uncertainty in social relationships. The chatter vocalization in Verreaux's sifaka (Propithecus verreauxi) is a unidirectional submissive signal. I tested the hypothesis that chatter vocalizations can signal subordination and thereby reduce agonism in a dyad.Materials and MethodsI examined 780 chatters from 18 dyads collected over 881 observation hours on four groups of sifaka in Kirindy Forest, Madagascar.ResultsSifaka emitted 63% of chatters in the peaceful context. Peaceful chatters significantly predicted grooming rate, fighting rate, reconciliation, and proportion of wins in a dyad but did not predict time in proximity. Dyad‐type significantly predicted the frequency of peaceful chatters, with intrasexual dyads exhibiting chatters in peaceful contexts more often than intersexual dyads.DiscussionSifaka communicate both submission and subordination with chatter vocalizations. Subordination signaling increased tolerance and affiliation. It reduced conflicts and the probability dominant individuals usurped resources. Moreover, intrasexual power may be more institutionalized than intersexual power in sifaka. The finding of complex and cognitively demanding social communication in a lemur with low levels of cooperation (1) challenges previous assumptions that the evolution of social complexity is dependent on frequent triadic interactions and high levels of cooperation, and (2) highlights the need for taxonomic diversity in studies of social complexity.
Formation of a Pillar[5]arene‐Based Two‐Dimensional Poly‐Pseudo‐Rotaxane: Threading and Crosslinking by the Same Guest Molecules
Authors: Lee Eunji , Park In‐Hyeok , Ju Huiyeong , Kim Seulgi , Jung Jong Hwa , Habata Yoichi , Lee Shim Sung 
Published: June 2019

AbstractA one‐pot reaction of the A1/A2‐thiopyridyl pillar[5]arene L with silver(I) trifluoroacetate in the presence of the linear dinitrile guest C8, [CN(CH2)nCN, n=8], afforded the first example of a two‐dimensional (2D) poly‐pseudo‐rotaxane {[(μ4‐Ag)2(C8@L)2(μ‐C8)](CF3CO2)2}n. Surprisingly, in this structure the C8 guest not only threads into the pillar[5]arene unit but also crosslinks the 1D coordinative polymeric arrays. The formation of the 2D poly‐pseudo‐rotaxane is driven by an adaptive rearrangement of the components that minimizes the steric clashes not only between the threaded guests but also between the threaded and crosslinked guests where crosslinking occurs. A pathway for the formation of the 2D poly‐pseudo‐rotaxane is proposed.
Regioselective Formal [3+2] Cycloadditions of Urea Substrates with Activated and Unactivated Olefins for Intermolecular Olefin Aminooxygenation
Authors: Wu Fan , Alom Nur‐E , Ariyarathna Jeewani P. , Naß Johannes , Li Wei 
Published: June 2019

AbstractA new class of intermolecular olefin aminooxygenation reaction is described. This reaction utilizes the classic halonium intermediate as a regio‐ and stereochemical template to accomplish the selective oxyamination of both activated and unactivated alkenes. Notably, urea chemical feedstock can be directly introduced as the N and O source and a simple iodide salt can be utilized as the catalyst. This formal [3+2] cycloaddition process provides a highly modular entry to a range of useful heterocyclic products with excellent selectivity and functional‐group tolerance.
Breaking Parallel Orientation of Rods via a Dendritic Architecture toward Diverse Supramolecular Structures
Authors: Zhang Ruimeng , Feng Xueyan , Zhang Rui , Shan Wenpeng , Su Zebin , Mao Jialin , Wesdemiotis Chrys , Huang Jiahao , Yan Xiao‐Yun , Liu Tong , Li Tao , Huang Mingjun , Lin Zhiwei , Shi An‐Chang , Cheng Stephen Z. D. 
Published: June 2019

AbstractSelf‐assembled nanostructures of rod‐like molecules are commonly limited to nematic or layered smectic structures dominated by the parallel arrangement of the rod‐like components. Distinct self‐assembly behavior of four categories of dendritic rods constructed by placing a tri(hydroxy) group at the apex of dendritic oligo‐fluorenes is observed. Designed hydrogen bonding and dendritic architecture break the parallel arrangement of the rods, resulting in molecules with specific (fan‐like or cone‐like) shapes. While the fan‐shaped molecules tend to form hexagonal packing cylindrical phases, the cone‐shaped molecules could form spherical motifs to pack into various ordered structures, including the Frank–Kasper A15 phase and dodecagonal quasicrystal. This study provides a model system to engineer diverse supramolecular structures by rod‐like molecules and sheds new light into the mechanisms of the formation of unconventional spherical packing structures in soft matter.
Critical Switching of Cyclization Modes of Polyepoxides in Acidic Aqueous Media and Neutral Water: Synthesis and Revised Structure of a Nerolidol‐Type Sesquiterpenoid
Authors: Nishikawa Keisuke , Morita Kengo , Hashimoto Subaru , Hoshino Akihiro , Ikeuchi Takumi , Kumagai Momochika , Morimoto Yoshiki 
Published: June 2019

AbstractBiomimetic epoxide‐opening cascades of polyepoxides enable the efficient and rapid construction of polyether frameworks. Herein, we show that the epoxide‐opening cascade cyclization that affords tetrahydrofuran products in acidic aqueous media produces tetrahydropyran (THP) in neutral water. THP formation proceeded by simply heating polyepoxides in neutral water and followed a different cyclization mode from those observed so far. The novel cascade cyclization in H2O was applied to the synthesis of a new nerolidol‐type sesquiterpenoid, resulting in revision of the proposed structure and determination of the absolute configuration.
The use of Cr (CO)6 as an alternative CO source in Pd‐catalyzed C‐N bond formation: Synthesis of benzamides
Authors: Mozaffari Mozhdeh , Nowrouzi Najmeh , Abbasi Mohammad 
Published: June 2019

An efficient strategy for the synthesis of benzamides from acetamides and aryl iodides using 1 mol% Pd (OAc)2 as catalyst and Cr (CO)6 as CO‐precursor is described. This new synthetic methodology displays high functional group tolerance on both substrates and avoids the need for ligands, reducing agents, or other additives. The corresponding products were obtained in good to excellent yields at atmospheric pressure under mild reaction conditions.
Utility of anthranilic acid and diethylacetylenedicarboxylate for the synthesis of nitrogenous organo/organometallic compounds as urease inhibitors
Authors: El‐Zahabi Heba S. A. , Abdulwahab Hanan G. , Edrees Mastoura M. , Hegab Amany M. 
Published: June 2019

AbstractFumarate diester 3 was synthesized upon reacting anthranilic acid with diethylacetylenedicarboxylate. Compound 3 was reacted with different nucleophiles in mild reaction conditions. Selected reaction routes that afforded products 6, 9, 10, 11, and 12 were explained. The estimated mechanism for the reaction of 3 with ethylenediamine to afford 9 was proved by X‐ray single‐crystal and retro‐synthetic reaction. Acetyl anthranilic acid was utilized with zinc and copper to afford the organometallic compounds 14a and 14b, respectively. Three single crystals were afforded for 3, 9 and the organocopper complex 14b. Target compounds were screened for their inhibitory potential against urease enzyme. Most compounds were more potent than thiourea as standard inhibitor, considering that oxopiperazine 9 exhibited double the activity: IC50 = 8.16 ± 0.65 µM (thiourea IC50 = 20.04 ± 0.33 µM). Docking studies were in agreement with the in vitro enzyme assay.
Gebäudemonitoring bei Anwendung von Innendämmung aus mikroporöser Dämmung und Kalziumsilikat
Authors: Gärtner Gabriele , Meißner Frank , Söhnchen Andreas 
Published: June 2019

AbstractEin knapp 150 Jahre altes Bauernhaus im oberbayrischen Landkreis Altötting wurde bereits 2011 in einzelnen Räumen mit einer kapillaraktiven und trotzdem sehr schlanken Innendämmung ausgestattet. Bei dieser Dämmung handelt es sich um einen Hybridbaustoff aus Kalziumsilikat und einer Hochleistungsdämmung (Fa. Evonik). Beide Komponenten sind rein mineralisch und dampfdiffusionsoffen. Bereits im zweiten Jahr nach der Applikation konnte im Rahmen eines angepassten Bauteilmonitorings nachgewiesen werden, dass diese spezielle Form der Dämmung nicht nur ein angenehmes Raumklima unterstützt, sondern auch das Austrocknen der Baufeuchte begünstigt.
Anxiety and depression in patients with suspected carpal tunnel syndrome – A case controlled study
Authors: McCallum Lucy Moira , Damms Nicholas Anthony , Sarrigiannis Ptolemaios Georgios , Zis Panagiotis 
Published: June 2019

AbstractPurposeCarpal tunnel syndrome (CTS) is a common entrapment neuropathy causing significant, and often disabling, pain. We aimed to establish the prevalence of anxiety and depressive symptoms in patients who were referred with suspected CTS and identify potential determinants.MethodsAll patients underwent nerve conduction studies (NCS) and were classified into mild, moderate, severe, and no CTS groups. Volunteers, without symptoms or signs of CTS, formed the control group. Anxiety and depressive symptoms were assessed via the Hospital Anxiety and Depression Scale.ResultsNinety‐one patients and 41 controls were recruited. Following NCS the patients were classified as follows: mild CTS (n = 20), moderate CTS (n = 21), severe CTS (n = 11), and no CTS (n = 31). CTS patients had significantly higher depression scores compared to controls but not anxiety scores. Patients experiencing pain and itchiness had significantly higher anxiety scores compared to those who did not. Patients who reported symptoms suggestive of CTS but did not meet the electrodiagnostic criteria for a diagnosis had significantly higher anxiety and depression scores compared to CTS patients and controls.ConclusionsPatients suffering with CTS may be at an increased risk of depression. Experiencing pain in CTS may further increase the likelihood of experiencing mental health difficulties. Poor mental health can give rise to functional symptoms, similar to those seen in CTS, demonstrating the need for electrophysiological testing before considering surgical intervention.
Video consultations in medication overuse headache. A randomized controlled trial
Authors: Bekkelund Svein I. , Müller Kai I. 
Published: June 2019

AbstractObjectiveTo test the hypothesis that the effect of video consultations is noninferior to traditional consultations in managing patients with overuse headache (MOH).Materials and MethodsPatients were recruited from referrals to a neurological clinic. In a randomized controlled trial (RCT), headache burden measured by headache impact test (HIT‐6) and frequency of headache days <15 per month and visual analogue pain scale (VAS) at baseline, 3 months and 1 year were compared between groups consulted by video‐ (n = 51) and traditional consultations (n = 51) in a post hoc analysis.ResultsThe overall response rate was 74.5%. HIT‐6 changed from 66.3 (SD = 4.7) to 60.0 (SD = 9.1) from baseline to 12 months in participants randomized to video consultations and from 65.8 (SD = 3.7) to 58.4 (SD = 8.3) in the group consulted traditionally (95% CI −2.3 to 6.5, p = 0.44). Frequency of headache days <15 per month at 1‐year follow‐up were 9 (23.1%) respectively 10 (27.0%), p = 0.60. In the video group, VAS improved by 2.3 points compared to 2.4 in the traditional group from baseline to 12 months (95% CI −1.2 to 1.2, p = 0.76). Analyses of repeated measurements comparing HIT‐6 and VAS over two points of time in the two groups were insignificant.ConclusionThe effect of video consultations is noninferior to traditional consultations in managing MOH patients. Using video may be a good alternative in consulting patients with MOH.
Pseudoprogression during treatment with pembrolizumab followed by rechallenge with chemotherapy in metastatic colorectal cancer: A case report
Authors: Trabjerg Natacha Dencker , Rask Christina , Jensen Lars Henrik , Hansen Torben Frøstrup 
Published: June 2019

AbstractDisease progression during immunotherapy in colorectal cancer does not always indicate treatment failure. A case argues that carcinoembryonic antigen (CEA) may serve as an early marker to distinguish between pseudoprogression and real progression. Presentation of results from reintroduction of chemotherapy after progression on immunotherapy that suggest increased efficiency.
Application of partial least squares as a complementary and preliminary receptor model for source apportionment of ambient aerosol based on molecular organic markers
Authors: Mancilla Yasmany , Mendoza Alberto 
Published: June 2019

AbstractFine particulate matter is of great concern in urban areas because it is one of the most heavily emitted pollutants by numerous emission sources. Several receptor models have been developed to estimate contributions of emission sources to the observed concentrations of air pollutants. Most of these tools require source profiles and uncertainties of the measured concentrations of the pollutants in the atmosphere. In addition, these receptor models have been widely applied using a trace element approach. However, a quick overview of the source contributions and key chemical species is desirable before selecting and applying a robust receptor model. Here, partial least squares (PLS) was applied as a preliminary source apportionment step for particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) attribution based on molecular organic markers. Given that PLS is an unweighted uncertainty model and that the uncertainties for organic species are not easy to quantify, Monte Carlo sampling (MC‐S) was performed as a complement to PLS to assess the variation of source contributions on the total PM2.5. These methods were performed using 43 samples collected during the spring and fall season monitoring campaigns. In general, source contributions obtained from the MC‐S results were not statistically different from the PLS original results, and uncertainties in ambient measurements did not have a significant influence on the source contributions. Finally, the source contributions were compared with those obtained by positive matrix factorization and chemical mass balance showing insignificant differences. The PLS and MC‐S fit well as preliminary and complementary tools for source apportionment based on organic molecular markers.
Circularly Polarized Light Triggers Biosensing Based on Chiral Assemblies
Authors: Hao Changlong , Xu Liguang , Sun Maozhong , Zhang Hongyu , Kuang Hua , Xu Chuanlai 
Published: June 2019

AbstractChiral assemblies have attracted great interest because of their many potential applications, such as in chiral sensing, asymmetric catalysis, and optical devices. Here, by using specific DNAzymes, a chiral core–satellite assembly consisting of a DNAzyme‐driven spiny nanorod dimer core and upconversion nanoparticle (UCNP) satellite was constructed. The chirality of this assembly originates from the geometry chirality. This chiral assembly can be used as a photothermally activated probe for the simultaneous detection of multiple analytes in living cells. Under illumination with 980 nm left circularly polarized (LCP) light, this probe was used to quantify and visualize intracellular metal ions.
Male and female preferences for nest characteristics under paternal care
Authors: Pärssinen Varpu , Kalb Nadine , Vallon Martin , Anthes Nils , Heubel Katja 
Published: June 2019

AbstractNests play a critical role for offspring development across the animal kingdom. Nest quality may contribute to the builder's extended phenotype and serve as an ornament during mate choice. We examined male and female nest choice in the common goby (Pomatoschistus microps), a benthic fish with male‐only parental care where females deposit eggs in male‐built nests. Using prebuilt nest models, we independently manipulated two candidate nest quality traits: (a) nest entrance width with a role in oxygen ventilation, and (b) extent of sand cover with a role in camouflage. In simultaneous choice trials, male gobies exhibited no preference for any nest model type. This suggests that initial characteristics of a nesting substrate have minor importance for males, which usually remodel the nest. Females were given a choice between two males occupying either entrance‐ or cover‐manipulated nests. The same pair of males was then exposed to a second female but now with alternated nest types assigned. Most females were consistent in choosing the same, typically the heavier male of the two regardless of nest properties. However, the females that chose the same nest regardless of the male preferred low over high sand coverage and narrow over wide nest entrance. Our results indicate that females base their mating decision on a combination of male phenotype and nest traits. While we found no indication that females are attracted to highly decorated nests, our study is the first in fishes to disentangle a preference for narrow (and thus more protective) nest entrances independent of nest coverage.