bluuebunny/crossref_metadata_2025_split huggingface dataset:
All‐Solid‐State Oxygen Ion Electrochemical Random‐Access Memory for Neuromorphic Computing
Authors: Nikam Revannath Dnyandeo , Kwak Myonghoon , Hwang Hyunsang 
Published: April 2021

AbstractArtificial synapses based on electrochemical random‐access memory (ECRAM) have emerged as an important component for neuromorphic chips because they are capable to execute simultaneous signal transmission and memory operations. However, existing ECRAM synapse surfers with compatibility and rapid memory loss issue due to highly reactive Li+ and H+ cationic species. Here, all‐solid‐state oxygen ion‐based ECRAM (O‐ECRAM) synapse, which shows linear weight update characteristics through multi‐level nonvolatile analog conductance states is presented. Crucially, an O‐ECRAM device delivering the highly stable, nonvolatile multi‐level conductance states through reversibly controlling the O2– ion tunneling via oxygen vacancies in oxides heterostructure of ionically conducting Y2O3‐stabilized ZrO2 electrolyte (YSZ) and electrically conducting WO3. The kinetic of O2– induced reversible phase transition in WO3 under YSZ electrolyte gating is triggered using X‐ray photoelectron spectroscopy. Ionic conduction of O2– species through oxygen vacancies in YSZ electrolyte is traced by visualizing in situ conductive filament growth. Oxygen vacancy in YSZ electrolyte provides fast oxygen ion conduction, resulting in an analog switching in WO3 with a fast speed of 10 ms, high retention of more than 103 s, and excellent endurance up to 103 pulses. These benefits prove that the O‐ECRAM device can be a potential candidate for developing neuromorphic hardware.
Quantum Dots for Photovoltaics: A Tale of Two Materials
Authors: Duan Leiping , Hu Long , Guan Xinwei , Lin Chun‐Ho , Chu Dewei , Huang Shujuan , Liu Xiaogang , Yuan Jianyu , Wu Tom 
Published: April 2021

AbstractQuantum dot (QD) solar cells, benefiting from unique quantum confinement effects and multiple exciton generation, have attracted great research attention in the past decades. Before 2016, research efforts were mainly devoted to solar cells comprising lead chalcogenide QDs, while lead halide perovskite QDs have recently emerged as a rising star in the field. This review aims to compare similarities and differences between lead chalcogenide and lead halide perovskite QDs for photovoltaic applications. The fundamental physical properties of these two types of nanomaterials and their state‐of‐the‐art photovoltaic devices are summarized, with a focus on ligand and device engineering. Furthermore, a special section is devoted to the stability issue that often hinders photovoltaic technologies. Finally, future development in tandem devices, challenges associated with large‐size cell fabrication and lead toxicity, and potential mitigation solutions are discussed.
Temperature regime influences accessions and effectiveness of germination promoters in the high‐Andean crop maca
Authors: Valqui‐Peña David , Clark Daniel , Gianoli Ernesto , Gonzáles Wilfredo L. 
Published: April 2021

AbstractHigh‐Andean crops are precious resources for low‐income farmers threatened by climate conditions. In the Puna region of the central Peruvian Andes, poor farmers grow maca (Lepidium meyenii Walpers), a root crop endemic to this region, under extreme environmental conditions. The performance ranking of crop accessions may vary with climate variability due to interactions between genotypes and the environment, but this issue has not been addressed for maca crops. Here we used three thermal setups under laboratory conditions and tested the effects of temperature regime, seed accession, and germination promoters on seed germination and seedling performance traits of maca plants. We found significant temperature × accession (T × A) interactions for most response variables, that is, the performance ranking of accessions varied with temperature regimes. The positive effects of promoters (gibberellic acid, GA; sodium hypochlorite, SH) on germination and seedling emergence variables were not additive and showed a clear trend to be greater at lower temperatures. Because available maca accessions still require the Andean Puna´s cold environment to develop their hypocotyls fully, the selection of accessions with better tolerance to higher temperatures should be taken as a long‐term challenge. In the short term, our findings strongly suggest that maca growers might use GA as a promoter to overcome limitations imposed on seed germination and seedling emergence by low temperatures at the crop‐growing areas.
On two‐phase modeling of dewatering pulp suspensions
Authors: Paterson Daniel T. , Eaves Tom S. , Hewitt Duncan R. , Balmforth Neil J. , Martinez D. Mark 
Published: April 2021

AbstractAn experimental study of the dewatering of wood‐pulp fiber suspensions by uniaxial compression is presented, to rationalize their dewatering dynamics within a two‐phase framework. Twenty‐seven pulp suspensions are examined, encompassing materials with different origins, preparation methodologies, and secondary treatments. For each suspension in this library, the network permeability and compressive yield stress are calibrated at low rates of dewatering. Faster compressions are then used to verify that a solid bulk viscosity is essential to match two‐phase model predictions with experimental observations, and to parameterize its magnitude. By comparing the results with a suspension of nylon fibers, we demonstrate that none of the wood‐pulp suspensions behave like an idealized fibrous porous medium. Nevertheless, the properties of pulp fiber networks can be reconciled within a two‐phase framework, and comparisons made between different wood‐pulp suspensions and between wood‐pulp and nylon fibers, by appealing to potential microstructural origins of their macroscopic behavior.
Intravenous high‐dose methotrexate based systemic therapy in the treatment of isolated primary vitreoretinal lymphoma: An LOC network study
Authors: Lam Marion , Touitou Valérie , Choquet Sylvain , Cassoux Nathalie , Ghesquières Hervé , Kodjikian Laurent , Schmitt Anna , Gattoussi Sarra , Tabouret Émeline , Sampo Magali , Blonski Marie , Angioi‐Duprez Karine , Houot Roch , Mouriaux Frédéric , Gyan Emmanuel , Le Lez Marie‐Laure , Moles Marie‐Pierre , Croisé Fabien , Chauchet Adrien , Schwartz Claire , Ahle Guido , Meyer Laurent , Gressin Rémy , Chiquet Christophe , Oberic Lucie , Ollé Priscille , Marolleau Jean‐Pierre , Jany Benjamin , Tempescul Adrian , Cochener Béatrice , Damaj Gandhi , Quintyn Jean‐Claude , Moluçon‐Chabrot Cécile , Rousseau Eve , Franciane Paul , Schneider Christelle , Massé Hélène , Tamburini‐Bonnefoy Jérôme , Brézin Antoine , Fornecker Luc‐Matthieu , Ballonzoli Laurent , Le Garff‐Tavernier Magali , Hoang‐Xuan Khê , Bodaghi Bahram , Soussain Carole , Houillier Caroline 
Published: April 2021

AbstractThe treatment of primary vitreoretinal lymphoma (PVRL) remains controversial regarding the use of local, systemic, or combined treatments. The aim of this study was to analyze the efficacy and toxicity of intravenous high‐dose methotrexate (IV HD‐MTX) based systemic therapy in a uniformly treated population of PVRL patients. From a nationwide French database, we retrospectively selected 59 patients (median age: 70 years, median Karnofsky Performance Status: 90%) with isolated PVRL at diagnosis who received first‐line treatment with HD‐MTX between 2011 and 2018. 8/59 patients also received a local treatment. No deaths or premature discontinuations of MTX due to toxicity were reported. A complete response was obtained in 40/57 patients after chemotherapy. Before treatment, IL‐10 was elevated in the aqueous humor (AH) or in the vitreous in 89% of patients. After treatment, AH IL‐10 was undetectable in 87% of patients with a CR/uCR/PR and detectable in 92% of patients with PD/SD. After a median follow‐up of 61 months, 42/59 (71%) patients had relapsed, including 29 isolated ocular relapses as the first relapse and a total of 22 brain relapses. The median overall survival, progression‐free survival, ocular‐free survival and brain‐free survival were 75, 18, 29 and 73 months, respectively. IV HD‐MTX based systemic therapy as a first‐line treatment for isolated PVRL is feasible, with acceptable toxicity, even in an elderly population. This strategy seems efficient to prevent brain relapse with prolonged overall survival. However, the ocular relapse rate remains high. New approaches are needed to improve local control of this disease, and ocular assessment could be completed by monitoring AH IL‐10.
Occupational risk factors for airway obstruction in a population‐based study in Northern Europe
Authors: Murgia Nicola , Brisman Jonas , Olin Anna‐Carin , Dahlman‐Hoglund Anna , Andersson Eva , Torén Kjell 
Published: April 2021

AbstractBackgroundAirway obstruction is a key feature of asthma and chronic obstructive pulmonary diseases (COPD). Smoking habits and workplace exposures to vapors, gas, dusts, and fumes (VGDF) could cause or exacerbate airway obstruction. The aim of this study is to evaluate the risk of airway obstruction due to smoking and workplace exposure, and their interaction, in a large population‐based study.MethodsIn this cross‐sectional study, a sample (n = 6153) of the Swedish population aged between 24 and 76 years underwent a questionnaire, clinical examination, blood test, and spirometry to gather information on airway obstruction classified by Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria or American Thoracic Society (ATS)/European Respiratory Society (ERS) criteria, risk factors, and confounders. Occupational exposures to VGDF were rated according to a specific job‐exposure matrix. Adjusted logistic regression models were used to evaluate risk factors for airway obstruction in smokers and nonsmokers.ResultsIn total, 9.8% had airway obstruction by GOLD criteria and 10.3% by ATS/ERS. Smokers with a high likelihood of exposure to VGDF had a higher risk of airway obstruction than those not exposed (odds ratio [OR]: 1.74, 95% confidence interval [CI]: 1.15–2.65 by GOLD; OR: 1.58, 95% CI: 1.06–2.37 by ATS/ERS) especially those >50 years of age. In smokers highly exposed to VGDF, risk estimates were higher than in the whole population, and the interaction between high exposure to VGDF and smoking further increased the risk of airway obstruction.ConclusionsThis study suggests a possible role for interaction between cigarette smoking and VGDF exposure on the risk of airway obstruction.
The prevalence of work‐related suicides varies by reporting source from the National Violent Death Reporting System
Authors: Peek‐Asa Corinne , Zhang Ling , Hamann Cara , Davis Jonathon , Casteel Carri 
Published: April 2021

AbstractIntroductionBoth suicides overall and work‐related suicides are increasing in the United States, and efforts to reduce suicide risk will require an understanding of the frequency and role of work in suicides. This study examines the incidence of occupational suicides using the National Violent Death Reporting System (NVDRS), which identified the role of work in suicides using the traditional death certificate as well as from death investigations.MethodsNVDRS suicides among those aged 16 through 65 from 2013 through 2017 were examined to determine if the death certificate identified the death as work‐related, if the death investigation identified a job problem as a suicide circumstance, and if the death investigation indicated that the job problem was a crisis at the time of the suicide.ResultsOverall, 1.13% of death certificates identified the suicides as work‐related, 2.34% of suicides included a job crisis, and 11.2% a job problem, and proportions did not vary over the years of the study. Overlap between the death certificate and death investigation was very low, with only 0.21% of suicides identified as related to work by both sources. Identification of work‐relatedness varied by source for demographic characteristics, mechanism of suicide, and occupation. For example, the death certificate identified 2.1% of suicides among those working in protective services as work‐related, but death investigations identified 15.2% as having a job problem.ConclusionWork‐related factors may be associated with a far higher proportion of suicides than previously documented.
Mechanistic Support for Intramolecular Migrative Cyclization of Propargyl Sulfones Provided by Catalytic Asymmetric Induction with a Chiral Counter Cation Strategy
Authors: Yamasaki Kohta , Yamauchi Akiho , Inokuma Tsubasa , Miyakawa Yasunori , Wang Yinli , Oriez Raphaël , Yamaoka Yousuke , Takasu Kiyosei , Tanaka Naonobu , Kashiwada Yoshiki , Yamada Ken‐ichi 
Published: April 2021

AbstractWe previously reported an intramolecular migrative cyclization of propargylsufones and sulfonylalkynamides giving oxa‐ and azacycles, respectively. To confirm the postulated reaction mechanism, the reaction was conducted with chiral nucleophiles such as N‐heterocyclic carbenes, phosphines, and pyridines, or with sulfinate anions and chiral cations. As expected, migrative cyclization proceeded to give the enantiomerically enriched products. These results strongly support the postulated mechanism and provide the first example of the asymmetric version of this reaction.
Off‐Set Interactions of Ruthenium–bda Type Catalysts for Promoting Water‐Splitting Performance
Authors: Timmer Brian J. J. , Kravchenko Oleksandr , Liu Tianqi , Zhang Biaobiao , Sun Licheng 
Published: April 2021

AbstractO−O bond formation with Ru(bda)L2‐type catalysts is well‐known to proceed through a bimolecular reaction pathway, limiting the potential application of these catalysts at low concentrations. Herein, we achieved high efficiencies with mononuclear catalysts, with TOFs of 460±32 s−1 at high catalyst loading and 31±3 s−1 at only 1 μM catalyst concentration, by simple structural considerations on the axial ligands. Kinetic and DFT studies show that introduction of an off‐set in the interaction between the two catalytic units reduces the kinetic barrier of the second‐order O−O bond formation, maintaining high catalytic activity even at low catalyst concentrations. The results herein furthermore suggest that π–π interactions may only play a minor role in the observed catalytic activity, and that asymmetry can also rationalize high activity observed for Ru(bda)(isoq)2 type catalysts and offer inspiration to overcome the limitations of 2nd order catalysis.
Synthesis and long‐term stability of acrylic acid and N, N‐methylene‐bis‐acrylamide radiation grafted polypropylene fibers
Authors: Pryhazhayeva Lidziya , Shunkevich Aliaksandr , Polikarpov Aliaksandr , Krul Leonid 
Published: April 2021

AbstractNew carboxyl ion‐exchange fibers prepared by acrylic acid (AA) and N, N‐methylene‐bis‐acrylamide (MBAA) monomer grafting to polypropylene (PP) fibers based on the method of γ‐rays pre‐irradiation in air followed by a Mohr's salt redox initiation of grafting reaction were studied. Grafting degree, homopolymer quantity, monomer conversion and grafting efficiency were determined. FTIR spectroscopy was used to establish the nature of the grafted fibers. The thermal stability of the materials was investigated based on DSC analysis in N2/O2 mixture. The long‐term stability during 6–8 years of storage was examined by the measurement of the tensile strength and the elongation at break of the fibers, and the chemical oxygen demand in water extracts as well as in the oxygen uptake experiments. The influence of some factors on the useful life of the grafted fibers was studied: a MBAA cross‐linking, exposure to day light, the Fe (III) residue presence, a grafting reaction temperature. It was found that small amounts of the adsorbed Fe (III) ions increase the deterioration rate of the grafted fibers, while small amounts of MBAA delay this negative process.
Facile and scalable fabrication of bioderived flame retardant based on adenine for enhancing fire safety of fully biodegradable PLA/PBAT/TPS ternary blends
Authors: Qi Juan , Pan Yingtong , Luo Zhonglin , Wang Biaobing 
Published: April 2021

AbstractThe facile fabrication of a bioderived flame retardant (marked as ATMP‐A) via ionic exchange between adenine and amino trimethylene phosphonic acid was reported in the present work. The incorporation of ATMP‐A endows the poly lactic acid (PLA)/poly butylene adipate‐co‐terephthalate (PBAT)/thermoplastic starch (TPS) ternary blends with improved fire safety without negatively affecting the biodegradability. The PLA/PBAT/TPS blend containing 18 wt% ATMP‐A alone achieves a UL‐94 V‐0 rating with a higher LOI value (28%). Meanwhile, its peak of the heat release rate and total heat release are reduced by 60.5% and 34.1% as compared with the PLA/PBAT/TPS ternary blend, respectively. Such excellent flame retardancy is mainly attributed to the formation of the intumescent flame retardant system in which ATMP‐A acts as both acid and gas sources together with TPS as a natural carbon source. Based on the analysis of the volatile gases and the char residues, a possible flame retardant mechanism including gas phase and condensed phase is proposed. This work provides a novel and effective idea for improving the fireproof performance of PLA/PBAT/TPS blends and will broaden its practical application fields, such as, agricultural film and packaging fields.
Cobalt(II)‐dianthracene Frameworks: Assembly, Exfoliation and Properties
Authors: Zou Qian , Bao Song‐Song , Huang Xin‐Da , Wen Ge‐Hua , Jia Jia‐Ge , Wu Lan‐Qing , Zheng Li‐Min 
Published: April 2021

AbstractMetal‐organic frameworks containing responsive organic linkers are attractive for potential applications in sensors and molecular devices. Herein we report three cobalt(II) phosphonates incorporating responsive dianthracene linkers, namely, Co2(amp2H2)2(H2O)4 ⋅ 6H2O (MDAF‐1), Co2(amp2)(H2O)4 ⋅ 2H2O (MDAF‐2) and Co(amp2H2) ⋅ 2H2O ⋅ 0.5DMF (MDAF‐3), where amp2H4 is pre‐photodimerized 9‐anthrylmethylphosphonic acid. MDAF‐1 shows a layer structure in which dinuclear Co2(PO3H)2 units are inter‐connected by dianthracene ligands. In MDAF‐2 and MDAF‐3, inorganic chains of corner‐sharing {CoO4} (or {CoO6}) and {PO3C} are cross‐linked by dianthracene ligands into 3D frameworks. All compounds underwent thermo‐induced phase transitions, first the de‐solvation and then the de‐dimerization of dianthracene (as well as the release of the remaining solvent molecules for MDAF‐2 and ‐3), associated with magnetic changes. MDAF‐1 can be exfoliated into single‐layer nanosheets in water which show light‐triggered luminescent changes.
Utilization of a complex arrangement approach for spectroscopic examination with Eosin Y of various cephalosporins in their pure or pharmaceutical dosage forms, and in human plasma
Authors: Salem Hesham , Omar Mahmoud A. , Mazen Dina Z. , Nour El‐Deen Deena A. M. 
Published: April 2021

AbstractApproved, basic, effective and successful spectroscopic strategies (spectrophotometric and spectrofluorimetric) were created to measure seven cephalosporins: cefpiramide (I), cefuroxime (II), cefoxitin (III), ceftazidime (IV), cefpirome (V), ceftobiprole (VI), and ceftriaxone (VII). These strategies used a two‐fold complex arrangement response for the drug amino groups with Eosin Y (EY). The examined drugs were determined spectrophotometrically at 542–550 nm in acetic acid derivative buffer. The examined drugs were determined spectrofluorimetrically by measuring their quenching effect on EY local fluorescence at 545 nm after excitation at 305 nm. The absorbance–intensity plots were rectilinear over the ranges 20–100, 10–130, 20–220, 30–230, 10–210, 20–180 and 10–130 μg ml−1for I, II, III, IV, V, VI, and VII samples, respectively. The fluorescence–intensity plots were rectilinear over the ranges 0.5–1.5, 0.1–0.9, 0.3–1.5, 0.5–2.5, 0.1–0.9, 0.5–2.5 and 0.1–1.0 μg ml−1for I, II, III, IV, V, VI, and VII samples, respectively. The recommended materials were certified as adhering to International Council for Harmonisation (ICH) guidelines and were used to examine the tested drugs in different dosage forms and in human plasma tests. The approved materials matched the reference materials.
Effectiveness of team teaching in biochemistry lectures for undergraduate students
Authors: Govindarajan Sumitra , Rajaragupathy Sujatha , Subramanian Kavitha , Karthikeyan Jayagowri 
Published: April 2021

AbstractTeam teaching is an innovative method to engage the large group and make lectures more interesting. The aim of the study is to evaluate the impact of team teaching in first year biochemistry lecture classes. After obtaining ethical clearance, 150 first year medical undergraduate students participated in the study on a voluntary basis. Topic identified for team teaching was “Protein biosynthesis” in Biochemistry, which was designed to be carried out in 5 h of lecture by three teachers. At the end of the team teaching module and traditional lectures, a structured anonymous feedback was obtained from the students. At the end of each class, students' understanding of the lecture was assessed by an MCQ test comprising 5–6 items, which mainly tested the recollection and understanding levels of Bloom's taxonomy. This was compared with traditional lectures. The mean MCQ test score was significantly higher for team teaching when compared to traditional teaching. The students had increased attention span and were able to answer questions from later part of the class in team lectures. The students had reported that lectures taught by team were more interesting and informative. They also felt that the team was more receptive to the doubts raised, stimulated discussion on the topic and had a better rapport with the class.
Design, Synthesis, and Molecular Docking of Some Novel Tacrine Based Cyclopentapyranopyridine‐ and Tetrahydropyranoquinoline‐Kojic Acid Derivatives as Anti‐Acetylcholinesterase Agents
Authors: Babaee Saeed , Chehardoli Gholamabbas , Akbarzadeh Tahmineh , Zolfigol Mohammad Ali , Mahdavi Mohammad , Rastegari Arezoo , Homayouni Moghadam Farshad , Najafi Zahra 
Published: April 2021

AbstractA novel series of tacrine based cyclopentapyranopyridine‐ and tetrahydropyranoquinoline‐kojic acid derivatives were designed, synthesized, and evaluated as anti‐cholinesterase agents. The chemical structures of all target compounds were characterized by 1H‐NMR, 13C‐NMR, and elemental analyses. The synthesized compounds mostly inhibited acetylcholinesterase enzyme (AChE) with IC50 values of 4.18–48.71 μM rather than butyrylcholinesterase enzyme (BChE) with IC50 values of >100 μM. Among them, cyclopentapyranopyridine‐kojic acid derivatives showed slightly better AChE inhibitory activity compared to tetrahydropyranoquinoline‐kojic acid. The compound 10‐amino‐2‐(hydroxymethyl)‐11‐(4‐isopropylphenyl)‐7,8,9,11‐tetrahydro‐4H‐cyclopenta[b]pyrano[2′,3′ : 5,6]pyrano[3,2‐e]pyridin‐4‐one (6f) bearing 4‐isopropylphenyl moiety and cyclopentane ring exhibited the highest anti‐AChE activity with IC50 value of 4.18 μM. The kinetic study indicated that the compound 6f acts as a mixed inhibitor and the molecular docking studies also illustrated that the compound 6f binds to both the catalytic site (CS) and peripheral anionic site (PAS) of AChE. The compound 6f showed moderate neuroprotective properties against H2O2‐induced cytotoxicity in PC12 cells. The theoretical ADME study also predicted good drug‐likeness for the compound 6f. Based on these results, the compound 6f seems to be a very promising AChE inhibitor for the treatment of Alzheimer's disease.