bluuebunny/crossref_metadata_2025 huggingface dataset:
A Cu(II)–ATP complex efficiently catalyses enantioselective Diels–Alder reactions
Authors: Wang Changhao , Qi Qianqian , Li Wenying , Dang Jingshuang , Hao Min , Lv Shuting , Dong Xingchen , Gu Youkun , Wu Peizhe , Zhang Wenyue , Chen Yashao , Hartig Jörg S.
Published: September 2020

Natural biomolecules have been used extensively as chiral scaffolds that bind/surround metal complexes to achieve stereoselectivity in catalytic reactions. ATP is ubiquitously found in nature as an energy-storing molecule and can complex diverse metal cations. However, in biotic reactions ATP-metal complexes are thought to function mostly as co-substrates undergoing phosphoanhydride bond cleavage reactions rather than participating in catalytic mechanisms. Here, we report that a specific Cu(II)-ATP complex (Cu2+·ATP) efficiently catalyses Diels-Alder reactions with high reactivity and enantioselectivity. We investigate the substrates and stereoselectivity of the reaction, characterise the catalyst by a range of physicochemical experiments and propose the reaction mechanism based on density functional theory (DFT) calculations. It is found that three key residues (N7, β-phosphate and γ-phosphate) in ATP are important for the efficient catalytic activity and stereocontrol via complexation of the Cu(II) ion. In addition to the potential technological uses, these findings could have general implications for the chemical selection of complex mixtures in prebiotic scenarios.
In situ tuning of electronic structure of catalysts using controllable hydrogen spillover for enhanced selectivity
Authors: Xiong Mi , Gao Zhe , Zhao Peng , Wang Guofu , Yan Wenjun , Xing Shuangfeng , Wang Pengfei , Ma Jingyuan , Jiang Zheng , Liu Xingchen , Ma Jiping , Xu Jie , Qin Yong
Published: September 2020

In situ tuning of the electronic structure of active sites is a long-standing challenge. Herein, we propose a strategy by controlling the hydrogen spillover distance to in situ tune the electronic structure. The strategy is demonstrated to be feasible with the assistance of CoOx/Al2O3/Pt catalysts prepared by atomic layer deposition in which CoOx and Pt nanoparticles are separated by hollow Al2O3 nanotubes. The strength of hydrogen spillover from Pt to CoOx can be precisely tailored by varying the Al2O3 thickness. Using CoOx/Al2O3 catalyzed styrene epoxidation as an example, the CoOx/Al2O3/Pt with 7 nm Al2O3 layer exhibits greatly enhanced selectivity (from 74.3% to 94.8%) when H2 is added. The enhanced selectivity is attributed to the introduction of controllable hydrogen spillover, resulting in the reduction of CoOx during the reaction. Our method is also effective for the epoxidation of styrene derivatives. We anticipate this method is a general strategy for other reactions.
Omega-3 index and blood pressure responses to eating foods naturally enriched with omega-3 polyunsaturated fatty acids: a randomized controlled trial
Authors: Stanton Alice V. , James Kirstyn , Brennan Margaret M. , O’Donovan Fiona , Buskandar Fahad , Shortall Kathleen , El-Sayed Thora , Kennedy Jean , Hayes Heather , Fahey Alan G. , Pender Niall , Thom Simon A. M. , Moran Niamh , Williams David J. , Dolan Eamon
Published: September 2020

Diets low in seafood omega-3 polyunsaturated fatty acids (PUFAs) are very prevalent. Such diets have recently been ranked as the sixth most important dietary risk factor—1.5 million deaths and 33 million disability-adjusted life-years worldwide are attributable to this deficiency. Wild oily fish stocks are insufficient to feed the world’s population, and levels of eicosapentaenoic acid and docosahexaenoic acid (DHA) in farmed fish have more than halved in the last 20 years. Here we report on a double-blinded, controlled trial, where 161 healthy normotensive adults were randomly allocated to eat at least three portions/week of omega-3-PUFA enriched (or control) chicken-meat, and to eat at least three omega-3-PUFA enriched (or control) eggs/week, for 6 months. We show that regular consumption of omega-3-PUFA enriched chicken-meat and eggs significantly increased the primary outcome, the red cell omega-3 index (mean difference [98.75% confidence interval] from the group that ate both control foods, 1.7% [0.7, 2.6]). Numbers of subjects with a very high-risk omega-3 index (index < 4%) were more than halved amongst the group that ate both enriched foods. Furthermore, eating the enriched foods resulted in clinically relevant reductions in diastolic blood pressure (− 3.1 mmHg [− 5.8, − 0.3]). We conclude that chicken-meat and eggs, naturally enriched with algae-sourced omega-3-PUFAs, may serve as alternative dietary sources of these essential micronutrients. Unlike many lifestyle interventions, long-term population health benefits do not depend on willingness of individuals to make long-lasting difficult dietary changes, but on the availability of a range of commonly eaten, relatively inexpensive, omega-3-PUFA enriched foods.
Hydrogen-bonded host–guest systems are stable in ionic liquids
Authors: Naranjo Teresa , Álvarez-Asencio Rubén , Pedraz Patricia , Nieto-Ortega Belén , Silva Sara Moreno-Da , Burzurí Enrique , Rutland Mark W. , Pérez Emilio M.
Published: September 2020

We show that H-bonded host–guest systems associate in ionic liquids (ILs), pure salts with melting point below room temperature, in which dipole–dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (Ka) obtained from titrations of four H-bonded host–guest systems in two organic solvents and two ionic liquids yield smaller yet comparable Ka values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy, which confirms that the binding is not solely due to (de)solvation processes. Our results indicate that classic H-bonded host–guest supramolecular chemistry takes place in ILs. This implies that strong H-bonds are only moderately affected by surroundings composed entirely of charges, which can be interpreted as an indication that the balance of Coulombic to covalent forces in strong H-bonds is not tipped towards the former.
Chloroplast development and genomes uncoupled signaling are independent of the RNA-directed DNA methylation pathway
Authors: Wang Liangsheng , Leister Dario , Kleine Tatjana
Published: September 2020

The Arabidopsis genome is methylated in CG and non-CG (CHG, and CHH in which H stands for A, T, or C) sequence contexts. DNA methylation has been suggested to be critical for seed development, and CHH methylation patterns change during stratification and germination. In plants, CHH methylation occurs mainly through the RNA-directed DNA methylation (RdDM) pathway. To test for an involvement of the RdDM pathway in chloroplast development, we analyzed seedling greening and the maximum quantum yield of photosystem II (Fv/Fm) in Arabidopsis thaliana seedlings perturbed in components of that pathway. Neither seedling greening nor Fv/Fm in seedlings and adult plants were affected in this comprehensive set of mutants, indicating that alterations in the RdDM pathway do not affect chloroplast development. Application of inhibitors like lincomycin or norflurazon inhibits greening of seedlings and represses the expression of photosynthesis-related genes including LIGHT HARVESTING CHLOROPHYLL A/B BINDING PROTEIN1.2 (LHCB1.2) in the nucleus. Our results indicate that the LHCB1.2 promoter is poorly methylated under both control conditions and after inhibitor treatment. Therefore no correlation between LHCB1.2 mRNA transcription and methylation changes of the LHCB1.2 promoter could be established. Moreover, we conclude that perturbations in the RdDM pathway do not interfere with gun signaling.
Dynamic and subtype-specific interactions between tumour burden and prognosis in breast cancer
Authors: Lee S. B. , Kim H.-K. , Choi Y. , Ju Y. W. , Lee H.-B. , Han W. , Noh D.-Y. , Son B. H. , Ahn S. H. , Kim K. S. , Nam S. J. , Kim E.‑K. , Park H. Y. , Park W.-C. , Lee J. W. , Moon H.-G.
Published: September 2020

We investigated the relationship between the prognostic importance of anatomic tumour burden and subtypes of breast cancer using data from the Korean Breast Cancer Registry Database. In HR+/HER2+ and HR−/HER2−tumours, an increase in T stage profoundly increased the hazard of death, while the presence of lymph node metastasis was more important in HR+/HER2+ and HR−/HER2+ tumours among 131,178 patients with stage I–III breast cancer. The patterns of increasing mortality risk and tumour growth (per centimetre) and metastatic nodes (per node) were examined in 67,038 patients with a tumour diameter ≤ 7 cm and < 8 metastatic nodes. HR+/HER2− and HR−/HER2− tumours showed a persistent increase in mortality risk with an increase in tumour diameter, while the effect was modest in HER2+ tumours. Conversely, an increased number of metastatic nodes was accompanied by a persistently increased risk in HR−/HER2+ tumours, while the effect was minimal for HR−/HER2− tumours with > 3 or 4 nodes. The interactions between the prognostic significance of anatomic tumour burden and subtypes were significant. The prognostic relevance of the anatomic tumour burden was non-linear and highly dependent on the subtypes of breast cancer.
Binary symbolic dynamics analysis to detect stress-associated changes of nonstationary heart rate variability
Authors: Spellenberg Conrad , Heusser Peter , Büssing Arndt , Savelsbergh Andreas , Cysarz Dirk
Published: September 2020

Psychological stress may have harmful physiological effects and result in deteriorating health. Acute psychological stress acts also on cardiac autonomic regulation and may lead to nonstationarities in the interbeat interval series. We address the requirement of stationary RR interval series to calculate frequency domain parameters of heart rate variability (HRV) and use binary symbolic dynamics derived from RR interval differences to overcome this obstacle. 24 healthy subjects (12 female, 20–35 years) completed the following procedure: waiting period, Trier Social Stress Test to induce acute psychological stress, recovery period. An electrocardiogram was recorded throughout the procedure and HRV parameters were calculated for nine 5-min periods. Nonstationarities in RR interval series were present in all periods. During acute stress the average RR interval and SDNN decreased compared to rest before and after the stress test. Neither low frequency oscillations (LF), high frequency oscillations (HF) nor LF/HF could unambiguously reflect changes during acute stress in comparison to rest. Pattern categories derived from binary symbolic dynamics clearly identified acute stress and accompanying alterations of cardiac autonomic regulation. Methods based on RR interval differences like binary symbolic dynamics should be preferred to overcome issues related to nonstationarities.
Fueling of a marine-terrestrial ecosystem by a major seabird colony
Authors: Hentati-Sundberg J. , Raymond C. , Sköld M. , Svensson O. , Gustafsson B. , Bonaglia S.
Published: September 2020

Seabirds redistribute nutrients between different ecosystem compartments and over vast geographical areas. This nutrient transfer may impact both local ecosystems on seabird breeding islands and regional biogeochemical cycling, but these processes are seldom considered in local conservation plans or biogeochemical models. The island of Stora Karlsö in the Baltic Sea hosts the largest concentration of piscivorous seabirds in the region, and also hosts a large colony of insectivorous House martins Delichon urbicum adjacent to the breeding seabirds. We show that a previously reported unusually high insectivore abundance was explained by large amounts of chironomids—highly enriched in δ15N—that feed on seabird residues as larvae along rocky shores to eventually emerge as flying adults. Benthic ammonium and phosphate fluxes were up to 163% and 153% higher close to the colony (1,300 m distance) than further away (2,700 m) and the estimated nutrient release from the seabirds at were in the same order of magnitude as the loads from the largest waste-water treatment plants in the region. The trophic cascade impacting insectivorous passerines and the substantial redistribution of nutrients suggest that seabird nutrient transfer should be increasingly considered in local conservation plans and regional nutrient cycling models.
The distinctive geographic patterns of common pigmentation variants at the OCA2 gene
Authors: Kidd Kenneth K. , Pakstis Andrew J. , Donnelly Michael P. , Bulbul Ozlem , Cherni Lotfi , Gurkan Cemal , Kang Longli , Li Hui , Yun Libing , Paschou Peristera , Meiklejohn Kelly A. , Haigh Eva , Speed William C.
Published: September 2020

Oculocutaneous Albinism type 2 (OCA2) is a gene of great interest because of genetic variation affecting normal pigmentation variation in humans. The diverse geographic patterns for variant frequencies at OCA2 have been evident but have not been systematically investigated, especially outside of Europe. Here we examine population genetic variation in and near the OCA2 gene from a worldwide perspective. The very different patterns of genetic variation found across world regions suggest strong selection effects may have been at work over time. For example, analyses involving the variants that affect pigmentation of the iris argue that the derived allele of the rs1800407 single nucleotide polymorphism, which produces a hypomorphic protein, may have contributed to the previously demonstrated positive selection in Europe for the enhancer variant responsible for light eye color. More study is needed on the relationships of the genetic variation at OCA2 to variation in pigmentation in areas beyond Europe.
Detecting differential ground displacements of civil structures in fast-subsiding metropolises with interferometric SAR and band-pass filtering
Authors: Solano-Rojas Darío , Wdowinski Shimon , Cabral-Cano Enrique , Osmanoğlu Batuhan
Published: September 2020

Ground displacements due to changes in soil conditions represent a threat to the stability of civil structures in many urban areas, worldwide. In fast-subsiding areas, regional subsidence (wavelength ~ 1,000’s m) can be dominantly high and, consequently, mask other signals at local scales (wavelength ~ 10–100’s m). Still, engineering and construction applications require a comprehensive knowledge of local-scale signals, which can threaten the stability of buildings and infrastructure. Here we present a new technique based on band-pass filters for uncovering local-scale signals hidden by regional subsidence as detected by interferometric SAR measurements. We apply our technique to a velocity field calculated from 21 high-resolution COSMO-SkyMed scenes acquired over Mexico City and obtain components of long (> 478 m), intermediate (42–478 m) and short (< 42 m) spatial wavelengths. Our results reveal that long-wavelength velocities exceed − 400 mm/year, whereas intermediate- and short-wavelength velocities are in the order of ± 15 mm/year. We show that intermediate-wavelength velocities are useful for retrieving signals such as uplift along elevated viaducts of Metro lines 4 and B, as well as differential displacements in Pantitlán station’s pedestrian overpass system and across sharp geotechnical boundaries in the piedmont of Sierra de Santa Catarina—where surface faulting occurs.
Early-stage knee OA induced by MIA and MMT compared in the murine model via histological and topographical approaches
Authors: Aüllo-Rasser Gaetan , Dousset Erick , Roffino Sandrine , Zahouani Hassan , Lecurieux-Clerville Roger , Argenson Jean-Noël , Chabrand Patrick
Published: September 2020

Osteoarthritis (OA) is a common degenerative disease whose early management includes promising mechanical treatments. New treatments are initially validated using an animal model in which OA is induced. The MMT (mechanical induction) and MIA (chemical induction) models of OA induction are widespread, but their use to generate early OA is poorly documented. We analyzed and compared early-stage knee OA-induction via these two methods in 16 rats divided into two groups. After 4 weeks of induction, the knees were sampled and studied using both histology (Toluidine Blue and Sirius Red) and surface topology, an innovative technique for characterizing osteoarthritic cartilage. The Mankin-modified score confirms that the two OA-induction models evolved at the same speed. At this early stage, the two models can be differentiated morphologically, although no significant differences were revealed by either cellularity or birefringence analysis. However, the topological analysis generated two forms of quantitative data, the deformation ratio and the cohesion index, that differentiated between the two groups. Thus, the early-stage OA induced by these two models is revealed to differ. The patterns of cartilage damage induced point to MMT as the better choice to assess mechanical approaches to clinical OA treatment.
Divalent cation-induced conformational changes of influenza virus hemagglutinin
Authors: Seok Jong Hyeon , Kim Hyojin , Lee Dan Bi , An Jeong Suk , Kim Eun Jeong , Lee Ji-Hye , Chung Mi Sook , Kim Kyung Hyun
Published: September 2020

Divalent cations Cu2+ and Zn2+ can prevent the viral growth in mammalian cells during influenza infection, and viral titers decrease significantly on a copper surface. The underlying mechanisms include DNA damage by radicals, modulation of viral protease, M1 or neuraminidase, and morphological changes in viral particles. However, the molecular mechanisms underlying divalent cation-mediated antiviral activities are unclear. An unexpected observation of this study was that a Zn2+ ion is bound by Glu68 and His137 residues at the head regions of two neighboring trimers in the crystal structure of hemagglutinin (HA) derived from A/Thailand/CU44/2006. The binding of Zn2+ at high concentrations induced multimerization of HA and decreased its acid stability. The acid-induced conformational change of HA occurred even at neutral pH in the presence of Zn2+. The fusion of viral and host endosomal membranes requires substantial conformational changes in HA upon exposure to acidic pH. Therefore, our results suggest that binding of Zn2+ may facilitate the conformational changes of HA, analogous to that induced by acidic pH.
Neural sources of letter and Vernier acuity
Authors: Barzegaran Elham , Norcia Anthony M.
Published: September 2020

Visual acuity can be measured in many different ways, including with letters and Vernier offsets. Prior psychophysical work has suggested that the two acuities are strongly linked given that they both depend strongly on retinal eccentricity and both are similarly affected in amblyopia. Here we used high-density EEG recordings to ask whether the underlying neural sources are common as suggested by the psychophysics or distinct. To measure visual acuity for letters, we recorded evoked potentials to 3 Hz alternations between intact and scrambled text comprised of letters of varying size. To measure visual acuity for Vernier offsets, we recorded evoked potentials to 3 Hz alternations between bar gratings with and without a set of Vernier offsets. Both alternation types elicited robust activity at the 3 Hz stimulus frequency that scaled in amplitude with both letter and offset size, starting near threshold. Letter and Vernier offset responses differed in both their scalp topography and temporal dynamics. The earliest evoked responses to letters occurred on lateral occipital visual areas, predominantly over the left hemisphere. Later responses were measured at electrodes over early visual cortex, suggesting that letter structure is first extracted in second-tier extra-striate areas and that responses over early visual areas are due to feedback. Responses to Vernier offsets, by contrast, occurred first at medial occipital electrodes, with responses at later time-points being more broadly distributed—consistent with feedforward pathway mediation. The previously observed commonalities between letter and Vernier acuity may be due to common bottlenecks in early visual cortex but not because the two tasks are subserved by a common network of visual areas.
Parallel model-based and model-free reinforcement learning for card sorting performance
Authors: Steinke Alexander , Lange Florian , Kopp Bruno
Published: September 2020

The Wisconsin Card Sorting Test (WCST) is considered a gold standard for the assessment of cognitive flexibility. On the WCST, repeating a sorting category following negative feedback is typically treated as indicating reduced cognitive flexibility. Therefore such responses are referred to as ‘perseveration’ errors. Recent research suggests that the propensity for perseveration errors is modulated by response demands: They occur less frequently when their commitment repeats the previously executed response. Here, we propose parallel reinforcement-learning models of card sorting performance, which assume that card sorting performance can be conceptualized as resulting from model-free reinforcement learning at the level of responses that occurs in parallel with model-based reinforcement learning at the categorical level. We compared parallel reinforcement-learning models with purely model-based reinforcement learning, and with the state-of-the-art attentional-updating model. We analyzed data from 375 participants who completed a computerized WCST. Parallel reinforcement-learning models showed best predictive accuracies for the majority of participants. Only parallel reinforcement-learning models accounted for the modulation of perseveration propensity by response demands. In conclusion, parallel reinforcement-learning models provide a new theoretical perspective on card sorting and it offers a suitable framework for discerning individual differences in latent processes that subserve behavioral flexibility.
Development and clinical deployment of a smartphone-based visual field deep learning system for glaucoma detection
Authors: Li Fei , Song Diping , Chen Han , Xiong Jian , Li Xingyi , Zhong Hua , Tang Guangxian , Fan Sujie , Lam Dennis S. C. , Pan Weihua , Zheng Yajuan , Li Ying , Qu Guoxiang , He Junjun , Wang Zhe , Jin Ling , Zhou Rouxi , Song Yunhe , Sun Yi , Cheng Weijing , Yang Chunman , Fan Yazhi , Li Yingjie , Zhang Hengli , Yuan Ye , Xu Yang , Xiong Yunfan , Jin Lingfei , Lv Aiguo , Niu Lingzhi , Liu Yuhong , Li Shaoli , Zhang Jiani , Zangwill Linda M. , Frangi Alejandro F. , Aung Tin , Cheng Ching-yu , Qiao Yu , Zhang Xiulan , Ting Daniel S. W.
Published: September 2020

By 2040, ~100 million people will have glaucoma. To date, there are a lack of high-efficiency glaucoma diagnostic tools based on visual fields (VFs). Herein, we develop and evaluate the performance of ‘iGlaucoma’, a smartphone application-based deep learning system (DLS) in detecting glaucomatous VF changes. A total of 1,614,808 data points of 10,784 VFs (5542 patients) from seven centers in China were included in this study, divided over two phases. In Phase I, 1,581,060 data points from 10,135 VFs of 5105 patients were included to train (8424 VFs), validate (598 VFs) and test (3 independent test sets—200, 406, 507 samples) the diagnostic performance of the DLS. In Phase II, using the same DLS, iGlaucoma cloud-based application further tested on 33,748 data points from 649 VFs of 437 patients from three glaucoma clinics. With reference to three experienced expert glaucomatologists, the diagnostic performance (area under curve [AUC], sensitivity and specificity) of the DLS and six ophthalmologists were evaluated in detecting glaucoma. In Phase I, the DLS outperformed all six ophthalmologists in the three test sets (AUC of 0.834–0.877, with a sensitivity of 0.831–0.922 and a specificity of 0.676–0.709). In Phase II, iGlaucoma had 0.99 accuracy in recognizing different patterns in pattern deviation probability plots region, with corresponding AUC, sensitivity and specificity of 0.966 (0.953–0.979), 0.954 (0.930–0.977), and 0.873 (0.838–0.908), respectively. The ‘iGlaucoma’ is a clinically effective glaucoma diagnostic tool to detect glaucoma from humphrey VFs, although the target population will need to be carefully identified with glaucoma expertise input.
H2O2/HOCl-based fluorescent probes for dynamically monitoring pathophysiological processes
Authors: Zhang Dan , Guo Shaobo , Li Le , Shang Kun
Published: September 2020

H2O2/HOCl-based fluorescent probes for dynamically monitoring pathophysiological processesin vivowere described.
Hg2+ detection, pH sensing and cell imaging based on bright blue-fluorescent N-doped carbon dots
Authors: Chang Dan , Li Lin , Shi Lihong , Yang Yongxing
Published: September 2020

A multifunctional sensing platform based on bright blue-fluorescent nitrogen-doped carbon dots (N-CDs) has been ingeniously designed for the sensitive determination of Hg2+ and pH.
Diagnosis of cancer at early stages based on the multiplex detection of tumor markers using metal nanoclusters
Authors: Li Dan , Wang Guannan , Mei Xifan
Published: September 2020

Scheme for the multiplex detection of tumor markers based on specific, Chem-nose and label-free sensing.
Rational design of FeTiO3/C hybrid nanotubes: promising lithium ion anode with enhanced capacity and cycling performance
Authors: Tang Yakun , Ma Wenjie , Zhang Yue , Gao Yang , Zeng Xingyan , Liu Lang
Published: September 2020

Porous FeTiO3/C hybrid nanotubes are synthesized by a facile method, and possess excellent electrochemical performances as anodes for lithium ion batteries.
Inflammation-responsive nanocapsules for the dual-release of antibacterial drugs
Authors: Jobdeedamrong Arjaree , Theerasilp Man , Wongsuwan Nattarat , Nasongkla Norased , Crespy Daniel
Published: September 2020

Inflammation-responsive silica nanocapsules allow a programmed release of dual antibiotics at different pH values, corresponding to various stages of wound healing.
Ligand-free copper-catalyzed regio- and stereoselective 1,1-alkylmonofluoroalkylation of terminal alkynes
Authors: Lv Yunhe , Pu Weiya , Wang Xiaoxing
Published: September 2020

A novel copper-catalyzed highly regio- and stereoselective 1,1-alkylmonofluoroalkylation of terminal alkynes without an external ligand has been developed.
One-step surfactant-free controllable synthesis and tunable up-conversion/down-shifting white light emissions of Sr2YF7 crystals doped with Ln3+ ions
Authors: Shen Dingyi , Mao Yini , Yang Jun , Cao Lu , Ning Juntao , Hu Shanshan
Published: September 2020

In this work, uniform and monodisperse Sr2YF7 spheres were successfully synthesized via a facile one-step hydrothermal route without employing any surfactant.
Nanoscale kinetics of amorphous calcium carbonate precipitation in H2O and D2O
Authors: Morris Peter D. , McPherson Ian J. , Meloni Gabriel N. , Unwin Patrick R.
Published: September 2020

Electrophoretic mixing of CaCl2 and NaHCO3 solutions in a nanopipette enables CaCO3 precipitation to be followed at the nanoscale.
Tunable valley polarization, magnetic anisotropy and Dzyaloshinskii–Moriya interaction in two-dimensional intrinsic ferromagnetic Janus 2H-VSeX (X = S, Te) monolayers
Authors: Qi Shengmei , Jiang Jiawei , Mi Wenbo
Published: September 2020

Significant valley polarization and DMI appear in 2D intrinsic ferromagnetic Janus 2H-VSeX (X = S, Te) monolayers.
Localized surface plasmon resonances of a metal nanoring
Authors: Mokkath Junais Habeeb
Published: September 2020

Using the linear combination of atomic orbitals real-time-propagation rt-TDDFT technique and transition contribution maps, we study the optical and plasmonic features of a metal nanoring made up of sodium atoms.
Al(iii)-NTA-fluoride: a simple model system for Al–F binding with interesting thermodynamics
Authors: Hacaperková Eliška , Jaroš Adam , Kotek Jan , Notni Johannes , Straka Michal , Kubíček Vojtěch , Hermann Petr
Published: September 2020

Unsaturated AlIII complex shows a fast exchange of water molecules, hydroxide and fluoride anions in the coordination sphere, highly pH-dependent fluoride binding and release of fluorides at high pH or at high phosphate anion concentrations.
Phytochemicals as modifiers of gut microbial communities
Authors: Dingeo Giulia , Brito Alex , Samouda Hanen , Iddir Mohammed , La Frano Michael R. , Bohn Torsten
Published: September 2020

Phytochemicals effect micribiota via prebiotic effects, antimicrobial properties, tight junction influences, quorum-communication-quenching, among others, influencing host health.
Structure–function relationships of deep eutectic solvents for lignin extraction and chemical transformation
Authors: Hong Si , Shen Xiao-Jun , Xue Zhimin , Sun Zhuohua , Yuan Tong-Qi
Published: September 2020

The effect of the structure and properties of DESs on lignin extraction and chemical transformations.
Photonic hook formation in near-infrared with MXene Ti3C2 nanoparticles
Authors: Spector Marat , Ang Angeleene S. , Minin Oleg V. , Minin Igor V. , Karabchevsky Alina
Published: September 2020

This work investigates the optical forces acting on a titanium carbide nanoparticle with an incident photonic hook field.
Supramolecular assembly of calix[4]resorcinarenes and chitosan for the design of drug nanocontainers with selective effects on diseased cells
Authors: Kashapov Ruslan , Razuvayeva Yuliya , Ziganshina Albina , Sergeeva Tatiana , Kashapova Nadezda , Sapunova Anastasiia , Voloshina Alexandra , Nizameev Irek , Salnikov Vadim , Zakharova Lucia
Published: September 2020

Effective delivery systems for anticancer drugs were prepared through the self-assembly of calix[4]resorcinarenes and chitosan in an aqueous medium.
CuFe2O4 nanoparticles catalyze the reaction of alkynes and nitrones for the synthesis of 2-azetidinones
Authors: Zarei Maaroof
Published: September 2020

The reaction of alkynes and nitrones (Kinugasa reaction) in the presence of magnetically recoverable CuFe2O4 nanoparticles as a highly efficient heterogeneous catalyst under a mild condition for the synthesis of various 2-azetidinones was reported.
Facile synthesis of PdAg nanocatalysts on CeO2/C composite supports as high-performance catalysts toward alkaline ethanol electro-oxidation
Authors: Xie Ayong , Zhang Qing , He Huiqing , Peng Cheng
Published: September 2020

PdAg nanocatalysts on CeO2/C supports were prepared using a facile, environment-friendly method and exhibited superior performance for ethanol electro-oxidation.
First-principles screening of novel ferroelectric MXene phases with a large piezoelectric response and unusual auxeticity
Authors: Zhang Lei , Tang Cheng , Zhang Chunmei , Du Aijun
Published: September 2020

Three novel ferroelectric MXene phases with out-of-plane and in-plane ferroelectricity, piezoelectricity, and auxeticity are highlighted that can be achieved by surface functionalization.
Ru(ii)-Catalyzed C–H addition and oxidative cyclization of 2-aryl quinazolinones with activated aldehydes
Authors: Choi Jin Ho , Kim Kunyoung , Oh Harin , Han Sangil , Mishra Neeraj Kumar , Kim In Su
Published: September 2020

The ruthenium(ii)-catalyzed cross-coupling reaction between 2-aryl quinazolinones and activated aldehydes under redox-neutral and oxidative conditions is described.
Comment on “Synthesis of cyclic polymers and flaws of the Jacobson–Stockmayer theory” by H. R. Kricheldorf, et al., Polym. Chem., 2020, 11, 2595
Authors: Szymanski Ryszard
Published: September 2020

Ring-opening polymerization combined with simultaneous polycondensation (ROPPOC) does not contradict the Jacobson–Stockmayer cyclization theory.
Single-atom implanted two-dimensional MOFs as efficient electrocatalysts for the oxygen evolution reaction
Authors: Peng Rui-Li , Li Jia-Luo , Wang Xiao-Ning , Zhao Yu-Meng , Li Bao , Xia Bao Yu , Zhou Hong-Cai
Published: September 2020

A facile and controllable synthesis strategy for bimetallic electrocatalysts for the OER from a two-dimensional iron-based metal–organic framework precursor has been reported, in which the Fe/Ni type exhibits the best efficiency and conversion.
A highly stable 8-hydroxyquinolinate-based metal–organic framework as a selective fluorescence sensor for Fe3+, Cr2O72− and nitroaromatic explosives
Authors: Sun Quan , Yang Kun , Ma Wenna , Zhang Liyan , Yuan Guozan
Published: September 2020

A novel 8-hydroxyquinolinate-based metal–organic framework exhibits excellent sensing performance toward Fe3+, Cr2O72− and nitroaromatic explosives.
Palladium bis-pincer complexes with controlled rigidity and inter-metal distance
Authors: Yu Cheng-Han , Zhu Congzhi , Ji Xiaozhou , Hu Wei , Xie Haomiao , Bhuvanesh Nattamai , Fang Lei , Ozerov Oleg V.
Published: September 2020

We report a series of redox-active bis(pincer) Pd(ii) complexes in which the redox active units are based on either a diarylamido or a carbazolide framework.
Controllable construction of core–shell CuCo2S4@polypyrrole nanocomposites as advanced anode materials for high-performance sodium ion half/full batteries
Authors: Li Qun , Jiao Qingze , Zhou Wei , Feng Xueting , Shi Quan , Dai Zheng , Gu Tingting , Zhao Yun , Li Hansheng , Feng Caihong
Published: September 2020

Core–shell CuCo2S4@polypyrrole (CS-CuCo2S4@PPy) nanocomposites, as advanced anode materials for sodium ion batteries with outstanding cycling stability and rate capability, were prepared by a facile solvothermal strategy and subsequent in-situ chemical oxidation polymerization.
Are disulfide bonds resilient to double ionization? Insights from coincidence spectroscopy and ab initio calculations
Authors: Varas Lautaro R. , Fantuzzi Felipe , Coutinho Lúcia Helena , Bernini Rafael B. , Nascimento Marco Antonio Chaer , de Souza G. G. B.
Published: September 2020

Disulfide bonds (–S–S–) are severely damaged as a consequence of sulfur core–shell ionization processes, which is related to their low thermodynamic stability in multiply-charged systems.
Synthesis and characterization of MOFs constructed from 5-(benzimidazole-1-yl)isophthalic acid and highly selective fluorescence detection of Fe(iii) and Cr(vi) in water
Authors: Zhu Bin , Huang Guimei , He Yanni , Xie Jisheng , He Tao , Wang Junli , Zong Ziao
Published: September 2020

In this work, four novel MOFs [Cd(bipa)]n(1), {[Zn2(bipa)2]·2C2H5OH}n(2), {[Co(bipa)]·C2H5OH}n(3), {[Ni(bipa)2]·2DMA}n(4), (H2bipa = 5-(benzimidazole-1-yl)isophthalic acid) were successfully synthesized under solvothermal conditions.
A systematic review on the chemical constituents of the genus Consolida (Ranunculaceae) and their biological activities
Authors: Yin Tianpeng , Cai Le , Ding Zhongtao
Published: September 2020

Multiple constituents from Consolida species showed great research significance for their novel structures and broad bioactivities.
Thermodynamic analysis of dissociation of periodic dislocation dipoles in isotropic crystals
Authors: Zhou X. W.
Published: September 2020

New elastic theory enables dissociation of periodic dislocations to be predicted.
Formation of trisubstituted buta-1,3-dienes and α,β-unsaturated ketones via the reaction of functionalized vinyl phosphates and vinyl phosphordiamidates with organometallic reagents
Authors: Oeser Petr , Koudelka Jakub , Dvořáková Hana , Tobrman Tomáš
Published: September 2020

We studied the reactions of vinyl phosphates and vinyl phosphordiamidates containing an ester functional group with organometallic reagents.
Covalent cucurbit[7]uril–dye conjugates for sensing in aqueous saline media and biofluids
Authors: Hu Changming , Grimm Laura , Prabodh Amrutha , Baksi Ananya , Siennicka Alicja , Levkin Pavel A. , Kappes Manfred M. , Biedermann Frank
Published: September 2020

Unimolecular chemosensor shows superior stability and detection capabilities in biofluids compared to bimolecular reporter pairs.
Controlling cyclization pathways in palladium(ii)-catalyzed intramolecular alkene hydro-functionalization via substrate directivity
Authors: Wang Xin , Li Zi-Qi , Mai Binh Khanh , Gurak John A. , Xu Jessica E. , Tran Van T. , Ni Hui-Qi , Liu Zhen , Liu Zhonglin , Yang Kin S. , Xiang Rong , Liu Peng , Engle Keary M.
Published: September 2020

We report a series of palladium(ii)-catalyzed, intramolecular alkene hydrofunctionalization reactions with carbon, nitrogen, and oxygen nucleophiles to form five- and six-membered carbo- and heterocycles.
Reversible guest-induced gate-opening with multiplex spin crossover responses in two-dimensional Hofmann clathrates
Authors: Turo-Cortés Rubén , Bartual-Murgui Carlos , Castells-Gil Javier , Muñoz M. Carmen , Martí-Gastaldo Carlos , Real José Antonio
Published: September 2020

Layered Hofmann-type iron(ii) coordination polymers functionalised with 5-aminopyrimidine ligands show gate-opening driven guest-exchange accompanied by drastic structural and spin-crossover modulations.
In situ assembled ZIF superstructures via an emulsion-free soft-templating approach
Authors: Singh Namita , Ahmed Sana , Fakim Aliyah , Qutub Somayah , Alahmed Othman , El Tall Omar , Shekhah Osama , Eddaoudi Mohamed , Khashab Niveen M.
Published: September 2020

An emulsion-free approach for the preparation of hollow ZIF-8 superstructures in a single step is established based on metal sulfate hydrates in methanol.
Thionated organic compounds as emerging heavy-atom-free photodynamic therapy agents
Authors: Ortiz-Rodríguez Luis A. , Crespo-Hernández Carlos E.
Published: September 2020

This minireview focuses on recent progress in developing heavy-atom-free photosensitizers based on the thionation of nucleic acid derivatives and other biocompatible organic compounds for prospective applications in photodynamic therapy.
Rubisco lysine acetylation occurs at very low stoichiometry in mature Arabidopsis leaves: implications for regulation of enzyme function
Authors: O'Leary Brendan M. , Scafaro Andrew P. , Fenske Ricarda , Duncan Owen , Ströher Elke , Petereit Jakob , Millar A. Harvey
Published: September 2020

Multiple studies have shown ribulose-1,5-bisphosphate carboxylase/oxygenase (E.C. 4.1.1.39; Rubisco) to be subject to Lys-acetylation at various residues; however, opposing reports exist about the biological significance of these post-translational modifications. One aspect of the Lys-acetylation that has not been addressed in plants generally, or with Rubisco specifically, is the stoichiometry at which these Lys-acetylation events occur. As a method to ascertain which Lys-acetylation sites on Arabidopsis Rubisco might be of regulatory importance to its catalytic function in the Calvin–Benson cycle, we purified Rubisco from leaves in both the day and night-time and performed independent mass spectrometry based methods to determine the stoichiometry of Rubisco Lys-acetylation events. The results indicate that Rubisco is acetylated at most Lys residues, but each acetylation event occurs at very low stoichiometry. Furthermore, in vitro treatments that increased the extent of Lys-acetylation on purified Rubisco had no effect on Rubisco maximal activity. Therefore, we are unable to confirm that Lys-acetylation at low stoichiometries can be a regulatory mechanism controlling Rubisco maximal activity. The results highlight the need for further use of stoichiometry measurements when determining the biological significance of reversible PTMs like acetylation.
Assessment, Diagnosis, and Treatment of Dysphagia in Patients Infected With SARS-CoV-2: A Review of the Literature and International Guidelines
Authors: Vergara José , Skoretz Stacey A. , Brodsky Martin B. , Miles Anna , Langmore Susan E. , Wallace Sarah , Seedat Jaishika , Starmer Heather M. , Bolton Lee , Clavé Pere , Freitas Susana Vaz , Bogaardt Hans , Matsuo Koichiro , de Souza Cinthia Madeira , Mourão Lucia Figueiredo
Published: September 2020

Purpose

Speech-language pathologists are playing a crucial role in the assessment and management of patients infected with severe acute respiratory syndrome coronavirus 2. Our goal was to synthesize peer-reviewed literature and association guidelines from around the world regarding dysphagia assessment and management for this specific population.

Method

A review of publications available in the PubMed database and official guidelines of international groups was performed on May 23, 2020. The information was synthesized and categorized into three content areas for swallowing: clinical evaluation, instrumental assessment, and rehabilitation.

Results

Five publications were identified in the PubMed database. Following title, abstract, and full-text review, only three publications met inclusion criteria: two reviews and one narrative report. Additionally, 19 international guidelines were reviewed. To assess swallowing, a modified clinical evaluation was recommended and only following a risk assessment. Instrumental assessments were often considered aerosol generating, especially transnasal procedures such as endoscopy and manometry. For this reason, many associations recommended that these examinations be performed only when essential and with appropriate personal protective equipment. Guidelines recommended that intervention should focus on compensatory strategies, including bolus modification, maneuvers/postural changes, and therapeutic exercises that can be conducted with physical distancing. Respiratory training devices were not recommended during rehabilitation.

Conclusions

International associations have provided extensive guidance regarding the level of risk related to the management of dysphagia in this population. To date, there are no scientific papers offering disease and/or recovery profiling for patients with dysphagia and coronavirus disease 2019. As a result, research in this area is urgently needed.
Stuttering Practice Self-Assessment by School Speech-Language Practitioners
Authors: Kelly Ellen M. , Singer Cara M. , Henderson Jack K. , Shaw Kenton O.
Published: September 2020

Purpose

The purpose of this study was to survey school speech-language practitioners' self-perceptions of their confidence, knowledge, and need for support for working with school-age students who stutter (SWS).

Method

A total of 120 school-based speech-language practitioners from 27 Nashville, Tennessee, area counties completed an online, 35-item survey examining caseloads, coursework, continuing education, experience, and perceived levels of skill and confidence in service provision to SWS. They also rated their need for consultation from speech-language pathologists who specialize in stuttering to improve their skills with SWS.

Results

Respondents were least confident in and needed most support for providing intervention to SWS. Those who needed most support for intervention rated themselves as less knowledgeable about stuttering theory, assessment, and intervention and were less confident about working with students who only stutter and with SWS who have concomitant communication concerns. Greater practitioner confidence in stuttering intervention skills was positively correlated with the number of SWS on caseloads; continuing education credits in stuttering; and knowledge of stuttering theory, assessment, and intervention. Respondents who completed a graduate course on stuttering had greater confidence in stuttering intervention and were less likely to identify a need for support from specialists.

Conclusions

School speech-language practitioners continue to report needing additional education, practice opportunities, and support, especially with intervention, and desiring specialized guidance to serve SWS. Those with more experience, education, and knowledge about stuttering are more confident and skillful, reflecting the potential positive impact of increased opportunities to learn about and work with SWS. These needs may be addressed through increased availability of specialists in stuttering to consult with school practitioners; opportunities for school-based practitioners to become peer mentors; and provision of readily available, intervention-focused continuing education experiences and resources.
N* Experiments and what they tell us about Strong QCD Physics
Authors: Burkert V. D.
Published: September 2020

I give an overview on experimental studies of the spectrum and the structure of the excited states of the nucleon and what we can learn about their in ternal structure. One focus is on the efforts to obtain a more complete picture of the light-quark baryon exci tation spectrum employing electromagnetic beams that will allow us to draw some conclusions on the symme tries underlying the spectrum. For the higher mass ex citations, the full employment of coupled channel ap proaches is essential when searching for new excited states in the large amounts of data already accumulated in different channels involving a variety of polarization observables. The other focus is on the study of transition form factors and helicity amplitudes and their de pendences on Q2, especially on some of the more promi nent resonances, especially Δ(1232)3/2+, N(1440)1/2+, and negative parity states N(1535)1/2-, and N(1675)5/2-.These were obtained in pion and eta electroproduction experi ments off proton targets and have already led to further insights in the active degrees-of-freedom as a function of the distance scale involved.
Non-strange dibaryons studied in coherent double neutral-meson photoproduction on the deuteron
Authors: Ishikawa Takatsugu , Fujimura Hisako , Fukasawa Hiroshi , Hashimoto Ryo , He Qinghua , Honda Yuki , Iwata Takahiro , Kaida Shun , Kanda Hiroki , Kasagi Jirohta , Kawano Atsushi , Kuwasaki Shuzo , Maeda Kazushige , Masumoto Shin’ichi , Miyabe Manabu , Miyahara Fusashi , Mochizuki Keiichi , Muramatsu Norihito , Nakamura Akihiko , Nawa Ken’ichi , Ogushi Shoei , Okada Yasuyuki , Okamura Ken’yu , Onodera Yoshihito , Ozawa Kyoichiro , Sakamoto Yasunobu , Shimizu Hajime , Sugai Hiroyuki , Suzuki Koutaku , Tajima Yasuhisa , Takahashi Shin’ichiro , Taniguchi Yusuke , Tsuchikawa Yusuke , Yamazaki Hirohito , Yamazaki Ryuji , Yoshida Hiroshi
Published: September 2020

TheB =2 bound/resonance state (dibaryon) is an interesting object, which can be a molecule consisting of two baryons or a spatially compact hexaquark hadron object. Theyd ^ n°n°dreaction has been experimentally investigated at incident energies ranging from 0.58 to 1.15 GeV to study non-strange dibaryons. The angular distributions of deuteron emission in theydcenter-of-mass energy cannot be reproduced by quasi-free production of two neutral pions followed by deuteron coalescence. Additionally a 2.14-GeV peak is observed in the n°d invariant mass distribution. These suggest a sequential process such asyd ^RIS^ n°RIV^ n°n°d with an isoscalar dibaryon RISand an isovector dibaryon RIV. Since the mass of the observed isoscalar dibaryons are close to the sum of the nucleon(N)and nucleon resonance (N*) masses, anS-wave NN* molecule may play a role as a doorway to a dibaryon.
Recent results of charged pion and kaon photoproduction on the proton at SPring-8/LEPS
Authors: Kohri H.
Published: September 2020

We carry out photoproduction experiments by using linearly polarized photon beams with energies of 1.5-3 GeV at SPring-8/LEPS. One of our physics motivations is to understand reaction mechanisms of hadron photoproduction. We study (1) y→p→ π-Δ++, (2) y→p→ π+n, (3) y→p→ K+Λ(K+Σ0), and (4) y→p→ π+Δ0 reactions which produce (1) uu, (2) dd, (3) ss, and (4) dd quark-antiquark pairs in the final state. Differential cross sections and photon beam asymmetries have been measured at forward meson angles of 0.6 < cos θcm <1. Precise comparison between the π-Δ++ and π+Δ0 reactions plays an important role in the study of nucleon resonances. It enables to distinguish between N* and Δ* by taking the cross section ratios of the two reactions. We have measured preliminary cross section ratios dσ(π+Δ0)/dσ(π-Δ++). The ratios are found to be close to 1/3, which is expected from the exchange of isospin=1 in the t channel, for 0.966< cos θcm <1 and all the photon energies. The ratios become larger than 1/3 and close to 1 for larger angles and higher energy regions. The larger ratios might be due to A resonances, giving the ratio 4/3, excited in the intermediate state
Measurement of polarization observables in neutral double pion photoproduction off the proton with the CBELSA/TAPS experiment
Authors: Seifen Tobias
Published: September 2020

Data on the reaction γp → pπ0π0 were taken with the CBELSA/TAPS experiment at ELSA where linearly polarized photons impinged on a transversely polarized butanol target. Target asymmetries and double polarization observables were extracted and entered the BnGa-PWA. Systematic differences in the branching ratios of N* and Δ* resonances hint at the internal structure of these states