bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel (Pt‐Ox)‐(Co‐Oy) Nonbonding Active Structures on Defective Carbon from Oxygen‐Rich Coal Tar Pitch for Efficient HER and ORR
Authors: Zhang Jintao , Wang Mingyong , Wan Tingting , Shi Haotian , Lv Aijing , Xiao Wei , Jiao Shuqiang 
Published: September 2022

AbstractAtomic‐scale utilization and coordination structure of Pt electrocatalyst is extremely crucial to decrease loading mass and maximize activity for hydrogen evolution reactions (HERs) and oxygen reduction reactions (ORRs). A novel atomic‐scale (Pt‐Ox)‐(Co‐Oy) nonbonding active structure is designed and constructed by anchoring Pt single atoms and Co atomic clusters on the defective carbon derived from oxygen‐rich coal tar pitch (CTP). The Pt loading mass is extremely low and only 0.56 wt%. A new nonbonding interaction phenomenon between Pt‐Ox and Co‐Oy is found and confirmed based on X‐ray absorption spectroscopy and density functional theory calculations. Based on the (Pt‐Ox)‐(Co‐Oy) nonbonding active structure, surface chemical field coupling with electrocatalysis for the HER and ORR is confirmed. It is found that the (Pt‐Ox)‐(Co‐Oy) nonbonding active structure exhibits high mass activities of 64.4 A cm−2 mgPt−1 (at an overpotential of 100 mV) and 7.2 A cm−2 mgPt−1 (at 0.8 V vs reversible hydrogen electrode) for the HER and ORR, respectively. The values are 6.5 and 11.6 times as much as those of commercial 20% Pt/C. The work provides innovative insight to design and understand efficient active sites of atomic‐scale Pt on oxygen‐rich CTP‐derived carbon supports for electrocatalysis.
Polarization‐Induced Exciton–Polaron Quenching in Organic Light‐Emitting Devices and Its Control by Dipolar Doping
Authors: Pakhomenko Evgeny , He Siliang , Holmes Russell J. 
Published: September 2022

AbstractMany electron transport layer (ETL) materials employed in organic light‐emitting devices (OLEDs) show a preferred orientation of the molecular permanent dipole moments. This phenomenon is known as spontaneous orientation polarization (SOP) and results in the formation of bound polarization charge. In an OLED, this leads to the accumulation of polarons (typically holes) at the ETL/emissive layer interface to balance this charge. Previous work on phosphorescent OLEDs has found that exciton–polaron quenching due to SOP‐induced hole accumulation can reduce peak efficiency by ≈20%. In this work, the generality of this phenomenon is systematically established by probing polaron accumulation and quenching in phosphorescent OLEDs with varying degrees of SOP. Exciton quenching is quantified by optically probing the photoluminescence of the device emissive layer during operation. It is found that the degree of SOP‐induced luminescence quenching and reduction in device efficiency scale directly with ETL SOP. It is further demonstrated that the degree of polarization and amount of quenching can be tuned by mixing the polar ETL with a nonpolar host (dipolar doping). This work establishes a ubiquitous role for SOP in determining OLED efficiency and demonstrates dipolar doping as a means to tune the underlying exciton–polaron quenching.
Recent Advances and Reliable Assessment of Solid‐State Materials for Hydrogen Storage: A Step Forward toward a Sustainable H2 Economy
Authors: Nazir Ghazanfar , Rehman Adeela , Hussain Sajjad , Aftab Sikandar , Heo Kwang , Ikram Muhammad , Patil Supriya A. , Aizaz Ud Din Muhammad 
Published: September 2022

AbstractThe hydrogen economy is an envisaged system proposed for a sustainable energy future that comprises hydrogen production, storage, transportation, and stationary/mobile applications. Recently, research efforts are devoted to build a H2 economy; however, the reduced hydrogen volumetric density hinders the effective hydrogen storage. To combat this, material‐based hydrogen storage is an emerging trend that has the potential to meet the ongoing goals of the United States Department of Energy. Herein, a critical review is presented on the state‐of‐the‐art material‐based hydrogen storage where nanostructured engineering and nanotechnology have driven a rapid growth in material design from physical sorbents (carbons, metal‐organic frameworks, and organic polymer frameworks) to chemical sorbents (complex and metal nanohydrides). The research trends in physical sorption include tailoring the textural features of porous materials and enhancing the binding energy strength by inducing hydrogen spill‐over effect and functionalization of surfaces. For chemical hydrogen storage, strategies are presented to ameliorate the sorption kinetics and thermodynamics using reactive hydrides, lightweight composites, and nanoconfinement of hydrides. Considering the long‐term hydrogen storage, the concept of para hydrogen storage is also highlighted. Finally, the challenges and their plausible solutions are discussed to attain a sustainable hydrogen economy, in the near future.
Perivascular Stromal Cells Instruct Glioblastoma Invasion, Proliferation, and Therapeutic Response within an Engineered Brain Perivascular Niche Model
Authors: Ngo Mai T. , Sarkaria Jann N. , Harley Brendan A.C. 
Published: September 2022

AbstractGlioblastoma (GBM) tumor cells are found in the perivascular niche microenvironment and are believed to associate closely with the brain microvasculature. However, it is largely unknown how the resident cells of the perivascular niche, such as endothelial cells, pericytes, and astrocytes, influence GBM tumor cell behavior and disease progression. A 3D in vitro model of the brain perivascular niche developed by encapsulating brain‐derived endothelial cells, pericytes, and astrocytes in a gelatin hydrogel is described. It is shown that brain perivascular stromal cells, namely pericytes and astrocytes, contribute to vascular architecture and maturation. Cocultures of patient‐derived GBM tumor cells with brain microvascular cells are used to identify a role for pericytes and astrocytes in establishing a perivascular niche environment that modulates GBM cell invasion, proliferation, and therapeutic response. Engineered models provide unique insight regarding the spatial patterning of GBM cell phenotypes in response to a multicellular model of the perivascular niche. Critically, it is shown that engineered perivascular models provide an important resource to evaluate mechanisms by which intercellular interactions modulate GBM tumor cell behavior, drug response, and provide a framework to consider patient‐specific disease phenotypes.
Multiplying the Stable Electrostatic Field of Electret Based on the Heterocharge‐Synergy and Superposition Effect
Authors: Lin Shizhe , Xu Zisheng , Wang Shuting , Cao Jianglang , Zhong Junwen , Li Guanglin , Fang Peng 
Published: September 2022

AbstractOwing to magic charge storage behavior, an electret can exhibit an external electrostatic field, which is widely used in numerous domains such as electronics, energy, healthcare, and environment. However, the theory of the charge storage mechanism still needs further development to enhance the performance and stability of the electret. Herein, a stable charge storage model known as the heterocharge‐synergy model (HSM) in electrets is proposed and verified, and the electrostatic field superposition effect of electrets is also proved. Based on the HSM and superposition effect, the stable electrostatic field intensity (average of ≈22.49 kV cm−1 and maximum of ≈29.58 kV cm−1, which is close to the minimum air breakdown field intensity of ≈30 kV cm−1) of the composite electret film is multiplied by simple layer‐by‐layer stacking. Utilizing the multilayer composite electret films and designing a two‐sided electrostatic induction structure, a two‐sided bipolar single‐electrode non‐contact nanogenerator is constructed with transferred charge density up to ≈132.61 µC m−2, which is twice as large as that of the non‐contact nanogenerators with one‐sided electrostatic induction structure. Clearing and utilizing the charge behaviors of the electret can boost the performance and enhance the stability of electret‐based devices in various domains.
Highly Stable Single‐Walled Carbon Nanotube Sorting by Low Molecular Weight Conjugated Polymer with Hydrogen‐Bonded Polyisoprene
Authors: Mburu Maina Moses , Au‐Duong Ai‐Nhan , Li Wei‐Ting , Yu Wen‐Yueh , Lan Yann‐Wen , Chiang Wei‐Hung , Chiu Yu‐Cheng 
Published: September 2022

AbstractThe π–π interaction between the conjugated polymer and single‐walled carbon nanotubes (SWCNTs) is the key to dispersion and selection of semiconducting nanotubes. High molecular weight (Mw > 10 000 Da) conjugated moieties usually form the main chain of the copolymers designed for sorting to ensure strong π–π interaction. However, low Mw conjugated polymers are sorting‐ineffective because they do not interact with SWCNTs. Additionally, sorted nanotubes in solution aggregate during storage or at low temperatures, possibly due to loss of wrapping ability of the dispersant, and stability of the sorted solution is rarely reported. Here, the effectiveness of polyisoprene with hydrogen‐bonding to induce superior sorting and solution stability in a low Mw conjugated polymer is demonstrated. A vinyl‐terminated‐poly(9,9‐dioctylfluorene) (vinyl‐PFO, Mw ≈ 4500) copolymerized with polyisoprene with hydrogen‐bond containing pendant; Poly(2[[(Butylamino) carbonyl]oxy]ethyl‐acrylate, can select large‐diameter semiconducting nanotubes (1.17 nm), and the sorted solution remains stable as observed by UV spectroscopy and thin‐film transistors, for over a year and at low temperatures; 4, −20, and −80 °C. Furthermore, solution can fabricate ambipolar transistors with averaged charge carrier mobility; 48 cm2 V–1 s–1 for p‐type, and 32 cm2 V–1 s–1 for n‐type, with retention stability > 6000 s.
Soybean yield response to sulfur and nitrogen additions across diverse U.S. environments
Authors: Brooks Keren , Mourtzinis Spyridon , Conley Shawn P. , Reiter Mark S. , Gaska John , Holshouser David Lee , Irby Trent , Kleinjan Jonathan , Knott Carrie , Lee Chad , Lindsey Laura , Naeve Seth , Ross Jeremy , Singh Maninder Pal , Vann Rachel , Matcham Emma 
Published: September 2022

AbstractAs soybean [Glycine max (L.) Merr.] yields reach record highs, more nutrients are required to maintain these production levels. This study was conducted to evaluate the effect of S and N on soybean yield in diverse environments across the United States. Data were collected from a total of 52 sites in 10 states over 2 yr (2019 and 2020) for this study. A factorial arrangement of three S rates (11, 22, and 33 kg S ha−1) using two sources (ammonium sulfate [AMS] and calcium sulfate [CaSO4]) were broadcasted by hand at planting. Additionally, to examine the impact of N on soybean yield, urea was applied at 10, 20, and 29 kg N ha−1 to equal that supplied by AMS. A zero‐fertilizer control treatment was also included. Soil samples prior to fertilization as well as grain yield at R8 were collected and analyzed to understand what environmental conditions favor soybean response to S additions. Results indicated that soil and environmental factors are poor indicators of yield response to S and N additions. Yield responses to S and N additions were observed in yield environments averaging >3,643 kg ha−1, but S did not limit yield in most environments (n = 49). Partial profit analysis was conducted at two soybean grain prices (US$0.32 and $0.55 kg ha−1). Yield increases were only profitable at 2 site‐years at the tested soybean grain prices. Overall results suggest that use of N and S fertilizers are rarely justified across diverse growing environments.
Exploring evolutionary adaptations of leaf heteroblasty in subspecific taxa of Hawaiian Chenopodium oahuense
Authors: Bullock Madison R. , Cantley Jason T. 
Published: September 2022

AbstractPremiseChenopodium oahuense is a polymorphic Hawaiian endemic plant inhabiting several xeric habitats. Considerable variability in leaf morphology has made comprehensively describing its diversity difficult. Chenopodium oahuense subsp. ilioense is differentiated from C. oahuense subsp. oahuense by smaller, less‐lobed, succulent leaves, smaller seeds, and prostrate to scandent habit. The lacking quantification of leaf shape, succulence, and previously unknown heteroblastic leaf transition in C. oahuense subsp. ilioense complicates the morphological boundaries separating subspecies.MethodsThis study used landmark analyses, elliptical Fourier descriptors (EFDs), and traditional shape descriptors measured from 1585 greenhouse‐grown plant leaves collected over 18 weeks. Principal component analyses visualized correlations in leaf shape, and linear discriminant analyses predicted classifications, either subspecific or heteroblastic.ResultsIdentity determination and heteroblastic change visualization were limited in landmark analyses. On the basis of EFDs and shape descriptors, C. oahuense subsp. ilioense was determined to be morphologically differentiated from C. oahuense subsp. oahuense with the Pu'u Ka Pele population as intermediate. The EFDs depicted heteroblastic change, predominantly in lobing. All analyses were restricted in correctly attributing a leaf to the week collected. Shape descriptors generally represented significant heteroblastic change over the growth period.ConclusionsThese analyses support significant differentiation between the subspecies, particularly from shape descriptors. Furthermore, we quantified the morphological intermediacy of the Pu'u Ka Pele population. Results suggest this population could be the result of incomplete lineage sorting or a recent hybridization of the two subspecies. Hawaiian Chenopodium is a polymorphic lineage notable for future research in adaptive radiations, phenotypic plasticity, and heteroblasty.
Mendelian segregation for parthenogenetic embryo development at the diploid level in the flowering plant Erigeron
Authors: Noyes Richard D. 
Published: September 2022

AbstractPremiseParthenogenesis is the capacity of organisms to develop embryos from unfertilized eggs. When parthenogenesis is coupled with unreduced gamete formation (apomeiosis), genetically maternal progeny result. Genetic elucidation of this form of reproduction in plants, apomixis, has important agronomic implications. However, genetic characterization of apomeiosis and parthenogenesis has been problematic in part because the traits usually co‐occur and are restricted to polyploids. In this work, the inheritance of parthenogenetic embryo development, by itself, was studied at the diploid level.MethodsProgeny resulting from a cross between a diploid (2n = 18), heterozygous, parthenogenetic pollen donor, and a diploid, wildtype, sexual seed parent were evaluated. Paternity was tested with conserved orthologous sequence (COS) markers, reproductive development of F1s was evaluated with microscopy of cleared ovules, and an amplified fragment length polymorphism (AFLP) marker (Eagc × Macg.615) co‐segregating with parthenogenesis was characterized at the sequence level.ResultsOf 102 diploid biparental progeny, 47 exhibited parthenogenetic embryo and endosperm development, and 55 lacked development of the egg and central cell. This result is consistent with Mendelian inheritance for a single locus (P = 0.43). Isolation and sequencing of the AFLP marker indicates that it is likely a portion of a Ty‐Gypsy retrotransposon. Attempts to develop a sequence‐characterized amplified region marker from the AFLP were unsuccessful.ConclusionsThis work shows that parthenogenesis can be transmitted simply at the diploid level. This advance is key in the development of a tractable system in Erigeron aimed at the identification of the parthenogenesis locus using genetic mapping strategies.
Dual‐Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis
Authors: Losacco Gioacchino Luca , Bennett Raffeal , Ahmad Imad A. Haidar , Barrientos Rodell C. , DaSilva Jimmy O. , Dong Yuyang , Schuppe Alexander W. , Wang Zeshu , Aiken Sheenagh , Mangion Ian , Aggarwal Varinder K. , Regalado Erik L. 
Published: September 2022

AbstractGenerality in analytical chemistry can be manifested in impactful platforms that can streamline modern organic synthesis and biopharmaceutical processes. We herein introduce a hybrid separation technique named Dual‐Gradient Unified Chromatography (DGUC), which is built upon an automated dynamic modulation of CO2, organic modifier, and water blends with various buffers. This concept enables simultaneous multicomponent analysis of both small and large molecules across a wide polarity range in single experimental runs. After a careful investigation of its fundamental aspects, a DGUC‐DAD‐MS screening workflow that combines multiple orthogonal column and mobile phase choices across a far‐reaching universal elution profile is also reported. The power of this framework is demonstrated with new analytical applications guiding academic and industrial laboratories in the development of new (bio)pharmaceutical targets (e.g. synthetic intermediates, nucleosides, cyclic and linear peptides, proteins, antibody drug conjugates).
Hydrogen‐Bond‐Modulated Nucleofugality of SeIII Species to Enable Photoredox‐Catalytic Semipinacol Manifolds
Authors: Park Sooyoung , Dutta Amit K. , Allacher Carina , Abramov Anton , Dullinger Philipp , Kuzmanoska Katerina , Fritsch Daniela , Hitzfeld Patrick , Horinek Dominik , Rehbein Julia , Nuernberger Patrick , Gschwind Ruth M. , Breder Alexander 
Published: September 2022

AbstractChemical bond activations mediated by H‐bond interactions involving highly electronegative elements such as nitrogen and oxygen are powerful tactics in modern catalysis research. On the contrary, kindred catalytic regimes in which heavier, less electronegative elements such as selenium engage in H‐bond interactions to co‐activate C−Se σ‐bonds under oxidative conditions are elusive. Traditional strategies to enhance the nucleofugality of selenium residues predicate on the oxidative addition of electrophiles onto SeII‐centers, which entails the elimination of the resulting SeIV moieties. Catalytic procedures in which SeIV nucleofuges are substituted rather than eliminated are very rare and, so far, not applicable to carbon‐carbon bond formations. In this study, we introduce an unprecedented combination of O−H⋅⋅⋅Se H‐bond interactions and single electron oxidation to catalytically generate SeIII nucleofuges that allow for the formation of new C−C σ‐bonds by means of a type I semipinacol process in high yields and excellent selectivity.
Palladium‐Catalyzed para‐C−H Arylation of Anilines with Aromatic Halides
Authors: Lichte Dominik , Pirkl Nico , Heinrich Gregor , Dutta Sayan , Goebel Jonas F. , Koley Debasis , Gooßen Lukas J. 
Published: September 2022

AbstractControlling regioselectivity in C−H functionalizations is a key challenge in chemical method development. In arenes, functionalizations are most difficult to direct towards the C−H group furthest away from a substituent, in its para position. We herein demonstrate how the para‐C−H arylation of anilines with non‐activated aryl halides, elusive to date, is achieved by a base‐assisted “metalla‐tautomerism” approach. A proton is abstracted from the aniline substrate and replaced by an arylpalladium species, generated from the aryl halide coupling partner. In this step, the palladium is directed away from the N‐ to the tautomeric para‐C−H position by a large phosphine ligand combined with a triphenylmethyl shielding group. The triphenylmethyl group is easily installed and removed, and can be recycled.
Steering the Ultrafast Opening and Closure Dynamics of a Photochromic Coordination Cage by Guest Molecules
Authors: Artmann Kevin , Li Ru‐Jin , Juber Selina , Benchimol Elie , Schäfer Lars V. , Clever Guido H. , Nuernberger Patrick 
Published: September 2022

AbstractPhotochemical studies on supramolecular hosts that can encapsulate small guest molecules commonly focus on three aspects: photoswitching the cage to release or trap the guest, the effect of the confining environment on the guest, and light‐induced exciton or charge transfer within the cage structure. Here, we exploit ultrafast spectroscopy to address how the guest alters the photoswitching characteristics of the cage. For this, the impacts of three disparate guest compounds on ring‐opening or ring‐closure of a dithienylethene (DTE) ligand in a photoswitchable DTE‐based coordination cage are juxtaposed. The guest modulates both outcome and timescale of the cage's photodynamics, by an interplay of structural strain, heavy‐atom effect, and enhancement of charge‐transfer processes exercised by the guest on the photo‐excited cage. The approach might prove beneficial for attuning the applicability of photoswitchable nanocontainers and desired guest compounds.
Simple organic dyes containing multiple anchors as effective co‐sensitizers for DSSCs loaded with Ru (II) complex N‐719
Authors: Aldusi Ameen M. , Fadda Ahmed A. , Ismail Mohamed A. , Elmorsy Mohamed R. 
Published: September 2022

In this work, we report a comprehensive photovoltaic investigation of eight pure organics, structurally simple, and low‐cost 2‐cyano‐N‐thiazolyacrylamide dyes (AM‐1‐8) co‐sensitizers for dye‐sensitized solar cells (DSSCs) with the standard Ru (II) dye (N‐719). A co‐sensitization strategy has been applied for enhancing the performance of DSSCs wherein a Ru (II) metal complex is combined with a simple type of the designed organic metal‐free dyes (AM‐1‐8). The co‐sensitization by the absorption of co‐sensitizers AM‐1‐8 leads to a broader light‐harvesting ability (300–750 nm) and scored photovoltaic efficiency at a range of 6.08%–9.30%. Upon co‐sensitization, the device made of bis(2‐cyanoacetamide) co‐sensitizer AM‐7 system yielded the highest power conversion efficiency (PCE) = 9.30% with JSC = 20.96 mA/cm2, VOC = 0.73 eV, and FF = 60.78 that outperformed the standard dye (N‐719). N‐719 dye only showed PCE of 7.30% with JSC = 18.68 mA/cm2, VOC = 0.64 eV, and FF = 61%. The great enhancement of the effect of the co‐sensitizer AM‐7 on the N‐719 can be related to the enhancement of both short current density (JSC) and open circuit voltage (VOC). The greater JSC value can be attributed to the maximum dye loading value of this dye on the TiO2 surface (3.76 × 10−5/mol cm−2) as a result of the presence of bis‐anchoring function within the dye molecule. The increase in the VOC value can be attributed to its highest recombination resistance because of the multi‐anchoring groups, which was confirmed by electrochemical impedance spectroscopy (EIS). Theoretical density functional theory (DFT) and highest occupied molecular orbital (HOMO)‐ lowest unoccupied molecular orbital (LUMO) energy were performed to study the electron density distribution between donor and acceptor moieties. All the multi‐anchoring functions presented in bis(2‐cyanoacetamide) and 2‐cyanacrylamide co‐sensitizers demonstrate promising co‐sensitizers for excellent photovoltaic performance response on the standard dye (N‐719).