bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoporous Intermetallic Pd3Bi for Efficient Electrochemical Nitrogen Reduction
Authors: Wang Xuejing , Luo Min , Lan Jiao , Peng Ming , Tan Yongwen 
Published: April 2021

AbstractElectrocatalytic nitrogen reduction at ambient temperature is a green technology for artificial nitrogen fixation but greatly challenging with low yield and poor selectivity. Here, a nanoporous ordered intermetallic Pd3Bi prepared by converting chemically etched nanoporous PdBi2 exhibits efficient electrocatalytic nitrogen reduction under ambient conditions. The resulting nanoporous intermetallic Pd3Bi can achieve high activity and selectivity with an NH3 yield rate of 59.05 ± 2.27 µg h−1 mgcat−1 and a Faradaic efficiency of 21.52 ± 0.71% at −0.2 V versus the reversible hydrogen electrode in 0.05 m H2SO4 electrolyte, outperforming most of the reported catalysts in electrochemical nitrogen reduction reaction (NRR). Operando X‐ray absorption spectroscopy studies combined with density functional theory calculations reveal that strong coupling between the Pd–Bi sites bridges the electron‐transfer channel of intermetallic Pd3Bi, in which the Bi sites can absorb N2 molecules and lower the energy barrier of *N2 for N2 adsorption and activation. Meanwhile, the intermetallic Pd3Bi with bicontinuous nanoporous structure can accelerate the electron transport during the NRR process, thus improving the NRR performance.
Pt Single Atoms Supported on N‐Doped Mesoporous Hollow Carbon Spheres with Enhanced Electrocatalytic H2‐Evolution Activity
Authors: Kuang Panyong , Wang Yaru , Zhu Bicheng , Xia Fanjie , Tung Ching‐Wei , Wu Jinsong , Chen Hao Ming , Yu Jiaguo 
Published: April 2021

AbstractThe electronic metal–support interaction (EMSI) plays a crucial role in catalysis as it can induce electron transfer between metal and support, modulate the electronic state of the supported metal, and optimize the reduction of intermediate species. In this work, the tailoring of electronic structure of Pt single atoms supported on N‐doped mesoporous hollow carbon spheres (Pt1/NMHCS) via strong EMSI engineering is reported. The Pt1/NMHCS composite is much more active and stable than the nanoparticle (PtNP) counterpart and commercial 20 wt% Pt/C for catalyzing the electrocatalytic hydrogen evolution reaction (HER), exhibiting a low overpotential of 40 mV at a current density of 10 mA cm−2, a high mass activity of 2.07 A mg−1Pt at 50 mV overpotential, a large turnover frequency of 20.18 s−1 at 300 mV overpotential, and outstanding durability in acidic electrolyte. Detailed spectroscopic characterizations and theoretical simulations reveal that the strong EMSI effect in a unique N1−Pt1−C2 coordination structure significantly tailors the electronic structure of Pt 5d states, resulting in promoted reduction of adsorbed proton, facilitated H−H coupling, and thus Pt‐like HER activity. This work provides a constructive route for precisely designing single‐Pt‐atom‐based robust electrocatalysts with high HER activity and durability.
Prediction of photosynthetic light‐response curves using traits of the leaf economics spectrum for 75 woody species: effects of leaf habit and sun–shade dichotomy
Authors: Chen Xiaoping , Sun Jun , Lyu Min , Wang Mantang , Hu Dandan , Zhong Quanlin , Cheng Dongliang 
Published: April 2021

PremisePhotosynthetic light‐response (PLR) curves for leaves are important components of models related to carbon fixation in forest ecosystems, linking the Mitscherlich equation and Michaelis–Menten equation to traits of the leaf economics spectrum (LES). However, models do not consider changes in leaf habits (i.e., evergreen and deciduous) and within‐canopy shading variation in these PLR curves.MethodsHere, we measured the PLR curves in sun and shade leaves of 44 evergreen and 31 deciduous species to examine the relationships between variables of the Mitscherlich equation and Michaelis–Menten equation, leaf nitrogen (N) and phosphorus (P) content, and leaf mass per area (LMA).ResultsSmall changes were caused by different leaf habits and shade variations in relationships linking variables of the two equations to leaf N and P content and LMA. Values of the scaling exponents for PLR curve parameters did not differ regardless of canopy position and leaf habit (P> 0.05). The PLR curves in species with different leaf habits (i.e., evergreen and deciduous) at different canopy positions could be predicted using the general allometric relations between leaf traits and PLR parameters in the two equations. For photosynthetic photon flux densities from 0 to 2000 μmol m‐2s‐1, approximately 71% (Mitscherlich equation) and 70% (Michaelis–Menten equation) of the net assimilation rates could be predicted.ConclusionsThese findings indicate that leaf net assimilation rates can be predicted through the large available data for LES traits. Incorporation of values for these traits available in the LES databases into ecosystem models of forest productivity and carbon fixation warrants further investigation.
Range‐wide variations in common milkweed traits and their effect on monarch larvae
Authors: DeLaMater David S. , Couture John J. , Puzey Joshua R. , Dalgleish Harmony J. 
Published: April 2021

PremiseLeaf economic spectrum (LES) theory has historically been employed to inform vegetation models of ecosystem processes, but largely neglects intraspecific variation and biotic interactions. We attempt to integrate across environment–plant trait–herbivore interactions within a species at a range‐wide scale.MethodsWe measured traits in 53 populations spanning the range of common milkweed (Asclepias syriaca) and used a common garden to determine the role of environment in driving patterns of intraspecific variation. We used a feeding trial to determine the role of plant traits in monarch (Danaus plexippus) larval development.ResultsTrait–trait relationships largely followed interspecific patterns in LES theory and persisted in a common garden when individual traits change. Common milkweed showed intraspecific variation and biogeographic clines in traits. Clines did not persist in a common garden. Larvae ate more and grew larger when fed plants with more nitrogen. A longitudinal environmental gradient in precipitation corresponded to a resource gradient in plant nitrogen, which produces a gradient in larval performance.ConclusionsBiogeographic patterns in common milkweed traits can sometimes be predicted from LES, are largely driven by environmental conditions, and have consequences for monarch larval performance. Changes to nutrient dynamics of landscapes with common milkweed could potentially influence monarch population dynamics. We show how biogeographic trends in intraspecific variation can influence key ecological interactions, especially in common species with large distributions.
Explaining the boycott behavior: A conceptual model proposal and validation
Authors: Palacios‐Florencio Beatriz , Revilla‐Camacho María‐Ángeles , Garzón Dolores , Prado‐Román Camilo 
Published: April 2021

AbstractThis study proposes a conceptual model with the capacity to substantially explain the boycott behavior. As a first step for the validation of the proposed model, an empirical study has been carried out, focusing on the boycott promoted towards the territory of Catalonia (Spain). Following the postulates of the theory of reasoned action, the effect that the intention to participate in the boycott will have on effective behavior is considered, but social influence, the importance given to brands and the perceived legitimacy of a boycott are also included. Concepts as the attitude towards boycotts as a measure of pressure to change actions and decisions, the perceived usefulness of the boycott and animosity towards the boycott object are included in the model as antecedents to the intention to participate in the boycott. Finally, it is postulated that the legitimacy given to boycott behavior and the ethical ideology based on idealism are explanatory factors for the attitude towards boycott behavior. The relevance of the study is established by the need to respond to boycotts in an appropriate way. This paper can be useful, by pointing out the main factors that cause an individual to take an active part in a boycott.
What We Currently Know about Carbon‐Supported Metal and Metal Oxide Nanomaterials in Electrochemical CO2 Reduction
Authors: Suominen Milla , Kallio Tanja 
Published: April 2021

AbstractElectrochemical reduction of CO2 is considered important in enhancing the circular‐economy design; it can suppress harmful greenhouse‐gas emissions while, combined with intermittent renewable energy sources, it can employ the surplus energy for production of important chemicals and fuels. In the process, electrocatalysts play an important role as the mediators of the highly active and selective conversion of CO2. Transition and post transition metals and their oxides are an important electrocatalyst group. For practical reasons, these metals need to be applied as nanoparticles supported on highly conducting materials enabling fabrication of 3D electrodes. In this minireview, we focus on gathering our current knowledge on the effects which transition and post transition metal and metal oxide nanoparticles supported on different carbons may have on electrochemical reduction of CO2. We focus on literature of studies conducted in aqueous conditions, under as similar conditions as possible, to ensure comparability. This approach enables us to highlight possible support effects and issues that complicate making conclusions on support effects.
Mechanoredox Chemistry as an Emerging Strategy in Synthesis
Authors: Leitch Jamie A. , Browne Duncan L. 
Published: April 2021

AbstractRecent research endeavors have established that the mechanochemical activation of piezoelectric materials can open new avenues in redox chemistry. Impact forces, such as those imparted by a ball mill, have been shown to transform piezoelectric materials such as barium titanate (BaTiO3) into a highly polarized state, which can then donate an electron to a suitable oxidant and receive an electron from a suitable reductant, mimicking established photoredox catalytic cycles. Proof‐of‐concept studies have elucidated that mechanoredox chemistry holds great potential in sustainable and efficient radical‐based synthesis.
A CaO2@Tannic Acid‐FeIII Nanoconjugate for Enhanced Chemodynamic Tumor Therapy
Authors: Chen Fei , Yang Beibei , Xu Lan , Yang Jinfeng , Li Jishan 
Published: April 2021

AbstractChemodynamic therapy (CDT) is an effective tumor treatment strategy in which FeII reacts with hydrogen peroxide (H2O2) in tumor cells to produce highly toxic hydroxyl radical (.OH) through the Fenton reaction. However, the content of endogenous H2O2 in cells is limited, and the reaction between FeIII and H2O2 is inefficient, greatly limiting the efficiency of the Fenton reaction and reducing the effectiveness of tumor treatment. Therefore, in this work, we designed and synthesized a new type of nano‐system (CaO2@TA‐FeIII) for the enhanced CDT of tumors, in which the polyphenolic compound‐ tannic acid (TA) and FeIII formed a TA‐Fe nano‐coating on the surface of calcium peroxide (CaO2) nanospherical aggregates. When the CaO2@TA‐FeIII nanoconjugates reach the tumor site, the CaO2 contained in the nanoconjugates produces H2O2 after disintegration in tumor cells, and the carried TA rapidly reduces FeIII to FeII, solving the two major shortcomings in CDT of (1) insufficient content of H2O2 in cancer cells, and (2) low catalytic efficiency of the Fenton reaction. Additionally, the .OH produced in the Fenton reaction induces oxidative stress for the tumor cells, promoting the occurrence of the “calcium overload” process, and thereby accelerating the death of tumor cells. Experimental results in vitro and in vivo showed that CaO2@TA‐FeIII nanoconjugates can effectively kill cancer cells and display an excellent tumor therapeutic effect. We believe that the CaO2@TA‐FeIII nanoconjugates are a promising new nano‐platform for highly effective tumor treatment.
Continuous Fluidic Techniques for the Precise Synthesis of Metal‐Organic Frameworks
Authors: Tanaka Yoko , Yamada Saki , Tanaka Daisuke 
Published: April 2021

AbstractThe continuous fluidics‐based synthesis of metal‐organic frameworks (MOFs) has attracted considerable attention, resulting in advancements in the reaction efficiency, a continuous production of complex structures, and access to products that are difficult or impossible to attain by bulk synthetic routes. This Minireview discusses the continuous fluidics‐based synthesis of MOFs in terms of reaction process control, and is divided into three chapters dealing with the efficient synthesis of high‐quality MOFs, the confined‐space synthesis of MOF composites with diverse morphologies, and the selective synthesis of metastable products. The products of continuous fluidic synthetic process are introduced (e. g., uniform products, composites, fibers, membranes, and metastable products with advantageous properties that cannot be obtained by bulk synthesis), and their usefulness is demonstrated by referencing representative examples.
Flat, Cα,β‐Didehydroalanine Foldamers with Ferrocene Pendants: Assessing the Role of α‐Peptide Dipolar Moments
Authors: Santi Saverio , Bisello Annalisa , Cardena Roberta , Tomelleri Silvia , Schiesari Renato , Biondi Barbara , Crisma Marco , Formaggio Fernando 
Published: April 2021

AbstractThe foldamer field is continuously expanding as it allows to produce molecules endowed with 3D‐structures and functions never observed in nature. We synthesized flat foldamers based on the natural, but non‐coded, Cα,β‐didehydroalanine α‐amino acid, and covalently linked to them two ferrocene (Fc) moieties, as redox probes. These conjugates retain the flat and extended conformation of the 2.05‐helix, both in solution and in the crystal state (X‐ray diffraction). Cyclic voltammetry measurements agree with the adoption of the 2.05‐helix, characterized by a negligible dipole moment. Thus, elongated α‐peptide stretches of this type are insulators rather than charge conductors, the latter being constituted by peptide α‐helices. Also, our homo‐tetrapeptide has a N‐to‐C length of about 18.2 Å, almost double than that (9.7 Å) of an α‐helical α‐tetrapeptide.
Synthesis of a Highly Fluorescent Bis(1,4‐oxaborine)pentacene
Authors: Lee Johnathan J. C. , Chi Chunyan , Wu Jishan 
Published: April 2021

Abstract1,4‐Oxaborines represent an expansion of the current array of heteroborines. Herein, we report a new ladder‐type bis(1,4‐oxaborine)pentacene (BO‐Pen), the backbone of which can be regarded as an isoelectronic structure of pentacene. The synthesis begins with a two‐fold nucleophilic aromatic substitution followed by a ring‐closing reaction. The structure was confirmed by X‐ray crystallographic analysis. Compound BO‐Pen is stable (even after 160 h) under ambient condition and exhibits very different electronic properties as compared to its all‐carbon pentacene analogue (Pen‐M). Particularly, it shows bright photoluminescence (73 % relative quantum yield) in both solution and in solid state.
Meso‐Biphenyl‐Linked, Near‐ and Far‐Infrared Emitting, Chlorin and Bacteriochlorin Dimers: Synthesis, Excitation Transfer, and Singlet Oxygen Production
Authors: Seetharaman Sairaman , Dukh Mykhaylo , Tabaczynski Walter A. , Ou Zhongping , Karr Paul A. , Kadish Karl M. , Pandey Ravindra K. , D'Souza Francis 
Published: April 2021

AbstractA series of meso‐biphenyl linked chlorin and bacteriochlorin dimers, derived from naturally occurring chlorophyll (Chl‐a) and bacteriochlorophyll (BChl‐a) were synthesized in 32 % to 44 % yields and characterized, as photosynthetic antenna mimics, and a new class of singlet oxygen producing agents. The dimers are characterized by absorption, fluorescence, electrochemical, spectroelectrochemical and computational methods to evaluate their physico‐chemical properties, and to identify ground and excited state interactions. Evidence of excited energy exchange among the chromophores in the dimer is derived from femtosecond transient absorption spectral studies. Rate constants for excitation hopping were in the order of 1011 s−1, indicating occurrence of efficient processes. Nanosecond transient absorption studies confirmed relaxation of the singlet excited chlorin and bacteriochlorin dimers to their corresponding triplet states (3Chl* and 3Bchl*). As predicted by the established energy level diagrams, both 3Chl* and 3Bchl* are shown to be capable of producing singlet oxygen with appreciable quantum yields (ϕSO∼0.3).
Effect of Corticosteroids on Mortality in Hospitalized COVID‐19 Patients Not Receiving Invasive Mechanical Ventilation
Authors: Fusina Federica , Albani Filippo , Granato Enza , Meloni Angelo , Rozzini Renzo , Sabatini Tony , Stellini Roberto , Terragnoli Paolo , Rosano Antonio , Abu Hilal Mohammed , Natalini Giuseppe 
Published: April 2021

The most beneficial effect of corticosteroid therapy in COVID‐19 patients has been shown in subjects receiving invasive mechanical ventilation (IMV), corresponding to a score of 6 on the World Health Organization (WHO) COVID‐19 Ordinal Scale for Clinical Improvement (OSCI). The aim of this observational, single‐center, prospective study was to assess the association between corticosteroids and hospital mortality in coronavirus disease 2019 (COVID‐19) patients who did not receive IMV (OSCI 3–5). Included were 1,311 COVID‐19 patients admitted to nonintensive care wards, and they were divided in two cohorts: (i) 480 patients who received corticosteroid therapy and (ii) 831 patients who did not. The median daily dose was of 8 mg of dexamethasone or equivalent, with a mean therapy duration of 5 (3–9) days. The indication to administer or withhold corticosteroids was given by the treating physician. In‐hospital mortality was similar between the two cohorts after adjusting for possible confounders (adjusted odds ratio (ORadj) 1.04, 95% confidence interval (CI), 0.81–1.34, P = 0.74). There was also no difference in Intensive Care Unit (ICU) admission (ORadj 0.81, 95% CI, 0.56–1.17, P = 0.26). COVID‐19 patients with noninvasive mechanical ventilation (NIMV) had a lower risk for ICU admission if they received steroid therapy (ORadj 0.58, 95% CI, 0.35–0.94, P = 0.03). In conclusion, corticosteroids were overall not associated with a difference in hospital mortality for patients with COVID‐19 with OSCI 3–5. In the subgroup of patients with NIMV (OSCI 5), corticosteroids reduced ICU admission, whereas the effect on mortality requires further studies.
Evaluation of the ATN model in a longitudinal memory clinic sample with different underlying disorders
Authors: Eckerström C. , Svensson J. , Kettunen P. , Jonsson M. , Eckerström M. 
Published: April 2021

AbstractIntroductionTo evaluate the usefulness of the 2018 NIA‐AA (National Institute on Aging and Alzheimer's Association) research framework in a longitudinal memory clinic study with different clinical outcomes and underlying disorders.MethodsWe included 420 patients with mild cognitive impairment or subjective cognitive impairment. During the follow up, 27% of the patients converted to dementia, with the majority converting to Alzheimer's disease (AD) or mixed dementia. Based on the baseline values of the cerebrospinal fluid biomarkers, the patients were classified into one of the eight possible ATN groups (amyloid beta [Aβ] aggregation [A], tau aggregation reflecting neurofibrillary tangles [T], and neurodegeneration [N]).ResultsThe majority of the patients converting to AD and mixed dementia were in ATN groups positive for A (71%). The A+T+N+ group was highly overrepresented among converters to AD and mixed dementia. Patients converting to dementias other than AD or mixed dementia were evenly distributed across the ATN groupsDiscussionOur findings provide support for the usefulness of the ATN system to detect incipient AD or mixed dementia.
Beyond its anti‐migraine properties, sumatriptan is an anti‐inflammatory agent: A systematic review
Authors: Ala Moein , Ghasemi Mehdi , Mohammad Jafari Razieh , Dehpour Ahmad Reza 
Published: April 2021

AbstractSumatriptan is the first available medication from triptans family that was approved by the U.S. Food and Drug Administration for migraine attacks and cluster headaches in 1991. Most of its action is mediated by selective 5‐HT1B/1D receptor agonism. Recent investigations raised the possibility of repositioning of this drug to other indications beyond migraine, as increasing evidence suggests for an anti‐inflammatory property of sumatriptan. We performed a literature search using PubMed, Web of Science, Scopus, and Google Scholar using “inflammation AND sumatriptan” or “inflammation AND 5HT1B/D” as the keywords. Then, articles were screened for their relevance and those directly discussing the correlation between inflammation and sumatriptan or 5HT1B/D were included. Total references reviewed or inclusion/exclusion were 340 retrieved full‐text articles (n = 340), then based on critical assessment 66 of them were included in this systematic review. Our literature review indicates that at low doses, sumatriptan can reduce inflammatory markers (e.g., interleukin‐1β, tumor necrosis factor‐α, and nuclear factor‐κB), affects caspases and changes cells lifespan. Additionally, nitric oxide synthase and nitric oxide signaling seem to be regulated by this drug. It also inhibits the release of calcitonin gene‐related peptide. Sumatriptan protects against many inflammatory conditions including cardiac and mesenteric ischemia/reperfusion, skin flap, pruritus, peripheral, and central nervous system injuries such as spinal cord injury, testicular torsion‐detorsion, oral mucositis, and other experimental models. Considering the safety and potency of low dose sumatriptan compared to corticosteroids and other immunosuppressive medications, it is worth to take advantage of sumatriptan in inflammatory conditions.
Cardiac rehabilitation with intermittent myocardial ischaemia as a new therapeutic option in refractory angina?
Authors: Corre Jerome , Douard Herve , Ronchard Thibault 
Published: April 2021

AbstractA 72‐year‐old man daily suffered from a refractory angina consecutive to a diffuse coronary artery disease despite optimal medical management. Revascularization could not be performed because of a severe thrombopenia. He was referred to our outpatient cardiac rehabilitation programme where he was candidate for 20 sessions, three times a week, of high‐intensity aerobic interval training involving brief episodes of regressive myocardial ischaemia. After 7 weeks, exercise capacity (+28.5%), VO2 peak (35.7%), and ischaemic threshold increased while clinical status and quality of life improved. No adverse effect was reported. Aerobic interval training with myocardial ischaemia might be a therapeutic alternative in refractory angina.