bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ruthenium Olefin Metathesis Catalysts Bearing a Macrocyclic N‐Heterocyclic Carbene Ligand: Improved Stability and Activity
Authors: Kośnik Wioletta , Lichosyt Dawid , Śnieżek Marcin , Janaszkiewicz Angelika , Woźniak Krzysztof , Malińska Maura , Trzaskowski Bartosz , Kajetanowicz Anna , Grela Karol 
Published: March 2022

AbstractFormation of sterically hindered C−C double bonds via catalytic olefin metathesis is considered a very challenging task for Ru catalysts. This limitation led to the development of specialised catalysts bearing sterically reduced N‐heterocyclic carbene (NHC) ligands that are very active in such transformations, yet significantly less stable as compared to general purpose catalysts. To decrease the small‐size NHC catalysts susceptibility to decomposition, a new NHC ligand was designed, in which two sterically reduced aryl arms were tied together by a C‐8 alkyl chain. The installation of this macrocyclic ligand on the ruthenium centre led to the formation of an olefin metathesis catalyst (trans‐Ru6). Interestingly, this complex undergoes transformation into an isomer bearing two Cl ligands in the cis‐arrangement (cis‐Ru6). These two isomeric complexes exhibit similarly high thermodynamic stability, yet different application profiles in catalysis.
syn‐Selektive Epoxidierung von chiralen, terminalen Allylalkoholen mit einem Titan‐Salalen‐Katalysator und Wasserstoffperoxid
Authors: Severin Fabian , Fusi Giovanni M. , Wartmann Christina , Neudörfl Jörg‐Martin , Berkessel Albrecht 
Published: March 2022

AbstractIn der asymmetrischen Sharpless‐Epoxidierung von chiralen, sekundären Allylalkoholen wird ein Substratenantiomer bevorzugt zum anti‐Epoxyalkohol umgesetzt. In dieser Arbeit stellen wir die erste hoch syn‐selektive Epoxidierung von terminalen Allylalkoholen vor. Mit einem Titan‐Salalen‐Katalysator und H2O2 als Oxidationsmittel werden enantiomerenreine, terminale Allylalkohole mit bis zu 98 % Ausbeute und >99 : 1 dr (syn) zu Epoxyalkoholen umgesetzt. Diese syn‐Selektivität bleibt auch bei niedrigeren Katalysatorbeladungen (bis zu 1 mol‐%) erhalten. Auch die Modifizierung der Allylalkoholfunktion zu einem Ether beeinflusst die Diastereoselektivität nicht [>99 : 1 dr (syn)]. Wird die Katalysatorkonfiguration invertiert, so wird bevorzugt das anti‐Produkt gebildet, allerdings mit niedrigerem dr (ca. 20 : 1). Das Anwendungspotential wird am Beispiel der Synthese eines THF‐Bausteins mit drei Stereozentren im Grammmaßstab demonstriert, in welcher zwei Ti‐Salalen‐katalysierte Epoxidierungen durchlaufen werden.
LiBF4‐Induced Rearrangement and Desymmetrization of a Palladium‐Ligand Assembly
Authors: Sudan Sylvain , Fadaei‐Tirani Farzaneh , Scopelliti Rosario , Ebbert Kristina E. , Clever Guido H. , Severin Kay 
Published: March 2022

AbstractThirteen palladium‐ligand assemblies with different structures and topologies were investigated for the ability to bind lithium ions. In one case, the addition of LiBF4resulted in a profound structural rearrangement, converting a dincluclear [Pd2L4]4+complex into a low‐symmetry [Pd4L8]8+assembly with two binding pockets for solvated LiBF4ion pairs. The rearrangement could only be induced by Li+, indicating highly specific host–guest interactions. A structural analysis of the [Pd4L8]8+receptor revealed a compact structure with multiple intramolecular interactions, reminiscent of what is seen for natural and synthetic foldamers.
Copper‐Catalyzed Dynamic Kinetic C−P Cross‐Coupling/Cyclization for the Concise Asymmetric Synthesis of Six‐, Seven‐ and Eight‐MemberedP‐Stereogenic Phosphorus Heterocycles
Authors: Li Yanli , Jin Xiao , Liu Peng , Zhang Haijuan , Yu Xiuling , Liu Yanjuan , Liu Baixue , Yang Wenqiang 
Published: March 2022

AbstractA copper‐catalyzed asymmetric aryl C−P cross‐coupling/cyclization reaction was successfully developed via dynamic kinetic asymmetric transformation (DYKAT) under mild conditions. This study provides a general and simple method for the catalytic enantioselective synthesis of stable six‐, seven‐ and eight‐membered P‐stereogenic phosphorus heterocycles with excellent enantioselectivities and moderate to high yields. One‐pot gram‐scale asymmetric synthesis of the P‐stereogenic P‐heterocycle from commercially available materials was also successfully accomplished with excellent enantioselectivity and high yield.
Synthesis, Characterization, and Reactivity of a Hydrido‐ and Imido‐Bridged Dinuclear Ytterbium(III) Complex
Authors: Wen Qingqing , Rajeshkumar Thayalan , Maron Laurent , Leng Xuebing , Chen Yaofeng 
Published: March 2022

AbstractThe trivalent rare‐earth metal hydrido and imido complexes are of versatile reactivity, and many such complexes have been synthesized. However, no example of a rare‐earth metal complex bearing both hydrido‐ and imido‐ligands has been reported. Herein, we report the first rare‐earth metal complex bearing both hydrido‐ and imido‐ligands, namely a hydrido‐ and imido‐bridged dinuclear ytterbium(III) complex. The complex was synthesized via an unprecedented redox reaction of divalent rare‐earth metal hydrido complex with azido compound. DFT calculation indicated that the N2 release from azido compound in the presence of ytterbium(II) is a kinetically facile process because of the cooperative effects of the two metal centers. The reactivity of the hydrido‐ and imido‐bridged dinuclear ytterbium(III) complex was also explored, which showed the redox, addition and σ‐bond metathesis reactivities.
Modular Nitrogen‐Doped Concave Polycyclic Aromatic Hydrocarbons for High‐Performance Organic Light‐Emitting Diodes with Tunable Emission Mechanisms**
Authors: Wagner Jakub , Zimmermann Crocomo Paola , Kochman Michał Andrzej , Kubas Adam , Data Przemysław , Lindner Marcin 
Published: March 2022

AbstractAlthough bowl‐shaped N‐pyrrolic polycyclic aromatic hydrocarbons (PAHs) can achieve excellent electron‐donating ability, their application for optoelectronics is hampered by typically low photoluminescence quantum yields (PLQYs). To address this issue, we report the synthesis and characterization of a series of curved and fully conjugated nitrogen‐doped PAHs. Through structural modifications to the electron‐accepting moiety, we are able to switch the mechanism of luminescence between thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP), and to tune the overall PLQY in the range from 9 % to 86 %. As a proof of concept, we constructed solid‐state organic light‐emitting diode (OLED) devices, which has not been explored to date in the context of concave N‐doped systems being TADF/RTP emitters. The best‐performing dye, possessing a peripheral trifluoromethyl group adjacent to the phenazine acceptor, exhibits yellow to orange emission with a maximum external quantum efficiency (EQE) of 12 %, which is the highest EQE in a curved D‐A embedded N‐PAH to date.
Utility of urinary biomarkers in primary haematuria: Systematic review and meta‐analysis
Authors: Soputro Nicolas Adrianto , Gracias Dylan Neil , Dias Brendan Hermenigildo , Nzenza Tatenda , O'Connell Helen , Sethi Kapil 
Published: March 2022

AbstractObjectivesTo evaluate the diagnostic performance of FDA‐approved urinary biomarkers in the evaluation of primary haematuria for investigation of bladder cancer.MethodsThe scientific databases MEDLINE, EMBASE, Pubmed and Web of Science were searched to collect studies. Studies that evaluated the diagnostic performance of FDA‐approved urinary biomarkers in investigating patients with primary haematuria without a prior history of bladder cancer were included. Quality of studies was assessed using the JBI Criteria. Bivariate mixed‐effects regression model was used to calculate pooled sensitivities and specificities for each biomarker.ResultsEighteen studies were included in the analysis. The biomarkers assessed in these studies were CxBladder, AssureMDx, Bladder Tumour Antigen (BTA), NMP22, UroVysion and Immunocyt/uCyt+. Several biomarkers, such as AssureMDx, CxBladder and Immunocyt, were shown to have better diagnostic performance based on their sensitivity, specificity and diagnostic odds ratio, as well as positive and negative likelihood ratios. Across the six biomarkers, sensitivity ranged from 0.659 to 0.973, and the specificity ranged between 0.577 and 0.833.ConclusionDespite certain biomarkers demonstrated better performance, current diagnostic abilities of the FDA‐approved biomarkers remain insufficient for their general application as a rule out test for bladder cancer diagnosis and as a triage test for cystoscopy in patients with primary haematuria. High‐quality prospective studies are required to further analyse this and also analyse the correct scenario in which urinary biomarkers may be best utilised.
Erythrocyte lysis and angle‐resolved light scattering measured by scanning flow cytometry result to 48 indices quantifying a gas exchange function of the human organism
Authors: Yastrebova Ekaterina S. , Nekrasov Vyacheslav M. , Gilev Konstantin V. , Gisich Alla V. , Abubakirova Olga A. , Strokotov Dmitry I. , Chernyshev Andrey V. , Karpenko Andrey A. , Maltsev Valeri P. 
Published: March 2022

AbstractMolecular/cell level of gas exchange function assumes the accurate measurement of erythrocyte characteristics and rate constants concerning to molecules involved into the CO2/O2 transport. Unfortunately, common hematology analyzers provide the measurement of eight indices of erythrocytes only and say little about erythrocyte morphology and nothing about rate constants of cellular function. The aim of this study is to demonstrate the ability of the Scanning Flow Cytometer (SFC) in the complete morphological analysis of mature erythrocytes and characterization of erythrocyte function via measurement of lysing kinetics. With this study we are introducing 48 erythrocyte indices. To provide the usability of application of the SFC in clinical diagnosis, we formed four categories of indices which are as follows: content/concentration (9 indices), morphology (26 indices), age (5 indices), and function (8 indices). The erythrocytes of 39 healthy volunteers were analyzed with the SFC to fix the first‐ever reference intervals for the new indices introduced. The essential measurable reliability of the presented method is expressed in terms of errors of characteristics of single erythrocytes retrieved from the solution of the inverse light‐scattering problem and errors of parameters retrieved from the fitting of the experimental kinetics by molecular‐kinetics model of erythrocyte lysis.
Niche expansion via acquired metabolism facilitates competitive dominance in planktonic communities
Authors: Hsu Veronica , Pfab Ferdinand , Moeller Holly V. 
Published: March 2022

AbstractAcquired phototrophs, organisms that obtain their photosynthetic abilities by hosting endosymbionts or stealing plastids from their prey, are omnipresent in aquatic ecosystems. This acquisition of photosynthetic metabolism allows for niche expansion, and can therefore influence competition outcomes by alleviating competition for shared resources. Here, we test how acquired metabolism alters competitive outcomes by manipulating light availability to control the energetic contribution of photosynthesis to acquired phototrophs. Using freshwater protists that compete for bacterial prey, we demonstrate light‐dependent competition outcomes of acquired phototrophs (Paramecium bursaria) and strict heterotrophs (Colpidium sp.) in laboratory model experiments. We then synthesize these findings using a series of mathematical models, and show that explicitly accounting for resource competition improves model fits. Both empirical and mathematical models predict that the acquired phototroph should increase in competitive dominance with increasing light availability. Our results highlight the importance of acquired metabolism to community dynamics, highlighting the need for more empirical and theoretical studies of this mechanism for niche expansion.
Synthesis of Rigid Macrocyclic Phenols and Their Catalytic Applications in Diels‐Alder Reactions
Authors: Hayashi Tomoya , Ohishi Yuki , Chiba Junya , Inouye Masahiko 
Published: March 2022

AbstractMacrocyclic catalysts having a phenol‐acetylene‐phenol triad were developed as a hydrogen‐bond donor catalyst. The rigid macrocyclic framework suppressed intramolecular hydrogen bonds between neighboring phenolic hydroxy groups. The preorganized phenol‐acetylene‐phenol moiety formed efficient intermolecular hydrogen bonds with carbonyl groups of substrates. The hydrogen‐bond donor catalysts accelerated the Diels‐Alder reaction of methyl vinyl ketone with cyclopentadiene. The catalytic ability was higher than that of an acyclic counterpart.
Engineering Mycolicibacterium neoaurum for the production of antioxidant ergothioneine
Authors: Xiong Liang‐Bin , Xie Zhi‐Yong , Ke Jie , Wang Li , Gao Bei , Tao Xin‐Yi , Zhao Ming , Shen Ya‐Ling , Wei Dong‐Zhi , Wang Feng‐Qing 
Published: March 2022

AbstractErgothioneine (EGT) represents valuable protective functions for humans, but EGT from the diet cannot meet daily requirements. Although the heterologous synthesis of EGT had been achieved, it is still a challenge to obtain stable and high‐yield EGT‐producing cell factories. Here, after the co‐overexpression of the EGT synthetic gene cluster and hisG, hisC, and allB1 in Mycolicibacterium neoaurum, the natural EGT titer was increased by 7.2‐folds. However, the degradation problem of EGT in large‐scale fermentation needs to be urgently solved. A putative lyase gene Mn_3042 was inactivated, thus inhibiting the product degradation and increasing the EGT titer by 21%. Moreover, the enhancement of S‐adenosyl‐
l‐methionine regeneration further increased EGT titer by 28%. After optimization of fed‐batch fermentation, the yield of EGT was boosted to 1.56 g/L with a productivity of 7.2 mg/L/h. This study provides a systematic engineering strategy for developing EGT‐producing cell factories.
Petrogenesis of the Late Jurassic to Early Cretaceous granites in the Taiping–Huangshan area, north‐eastern Yangtze Block, China
Authors: Zhang Yuanshuo , Xiang Bingquan , Yan Jun , Wang Xiaohai , Li Guofeng , Chen Gang , Tao Shuanglong , Zhang Jiahai , Chen Hui , Chen Fukun 
Published: March 2022

Yanshanian magmatisms are intensive in the eastern Jiangnan orogen and can be divided into early (150–136 Ma) and late (136–120 Ma) stages. About these granitic rocks, the petrogenesis and associated tectonic setting are still hotly debated. The Taiping–Huangshan complex, a representative granitic rock in this region, is selected to perform geochemical studies. Three lithologic units have been identified in the Taiping–Huangshan complex: granodiorite, monzogranite, and alkali‐feldspar granite with zircon U–Pb dating results of 149–144 Ma, 148 Ma, and 135–131 Ma, respectively, belonging to the early stage for the granodiorite and monzogranite, and late stage for the alkali‐feldspar granite. The granodiorite and monzogranite have similar major and trace element characteristics with intermediate‐acidic SiO2 contents ranging from 65.9 to 69.7 wt.%, low Mg# values of 35.8–38.4, enriched LREE, Pb, Th, and U contents, and weak Eu anomalies (δEu = 0.71–0.79). The alkali‐feldspar granite is characterized by high SiO2 contents (73.3–76.6 wt.%), low Mg# (2.6–10.0), enriched Th, U, Ta, Pb, and Nd, depleted high‐field‐strength elements, and pronounced negative Eu anomalies (δEu = 0.01–0.19). The granodiorite and monzogranite have consistent εHf(t) (−5.38 to −9.41) and δ18O (7.18‰ to 11.00‰) values, while the alkali‐feldspar granite has elevated εHf(t) values (−0.96 to −6.48) and δ18O values (6.27‰ to 8.34‰). Integrated geochemical characteristics and batch partial melting modelling constrain that the early stage granitic rocks derived from ca. 8% batch melting of the Neoproterozoic juvenile crust, and the late‐stage granites derived from a similar crust source with a little contribution from mantle. From early to late stage, the tectonic setting translated from post‐orogenic to anorogenic and the later corresponded to a back‐arc extensional setting as increasing of the slab subducted angle of the Palaeo‐Pacific Plate.
Can machine learning accelerate process understanding and decision‐relevant predictions of river water quality?
Authors: Varadharajan Charuleka , Appling Alison P. , Arora Bhavna , Christianson Danielle S. , Hendrix Valerie C. , Kumar Vipin , Lima Aranildo R. , Müller Juliane , Oliver Samantha , Ombadi Mohammed , Perciano Talita , Sadler Jeffrey M , Weierbach Helen , Willard Jared D. , Xu Zexuan , Zwart Jacob 
Published: March 2022

AbstractThe global decline of water quality in rivers and streams has resulted in a pressing need to design new watershed management strategies. Water quality can be affected by multiple stressors including population growth, land use change, global warming, and extreme events, with repercussions on human and ecosystem health. A scientific understanding of factors affecting riverine water quality and predictions at local to regional scales, and at sub‐daily to decadal timescales are needed for optimal management of watersheds and river basins. Here, we discuss how machine learning (ML) can enable development of more accurate, computationally tractable, and scalable models for analysis and predictions of river water quality. We review relevant state‐of‐the art applications of ML for water quality models and discuss opportunities to improve the use of ML with emerging computational and mathematical methods for model selection, hyperparameter optimization, incorporating process knowledge into ML models, improving explainablity, uncertainty quantification, and model‐data integration. We then present considerations for using ML to address water quality problems given their scale and complexity, available data and computational resources, and stakeholder needs. When combined with decades of process understanding, interdisciplinary advances in knowledge‐guided ML, information theory, data integration, and analytics can help address fundamental science questions and enable decision‐relevant predictions of riverine water quality.
Recombinant subunits of SARS‐CoV‐2 spike protein as vaccine candidates to elicit neutralizing antibodies
Authors: Noorabad Ghahroodi Faezeh , Khalili Saeed , Rasaee Mohammad Javad 
Published: March 2022

AbstractObjectivesThe spike protein has been reported as one of the most critical targets for vaccine design strategies against the SARS‐CoV‐2 infection. Hence, we have designed, produced, and evaluated the potential use of three truncated recombinant proteins derived from spike protein as vaccine candidates capable of neutralizing SARS‐CoV‐2 virus.MethodsIn silico tools were used to design spike‐based subunit recombinant proteins (RBD (P1), fusion peptide (P2), and S1/S2 cleavage site (P3)). These proteins were checked for their ability to be identified by the anti‐SARS‐CoV‐2 antibodies by exposing them to COVID‐19 serum samples. The proteins were also injected into mice and rabbit, and the antibody titers were measured for 390 days to assess their neutralization efficiency.ResultsThe antibodies that existed in the serum of COVID‐19 patients were identified by designed proteins. The anti‐spike antibody titer was increased in the animals injected with recombinant proteins. The VNT results revealed that the produced antibodies could neutralize the cultured live virus.ConclusionTruncated subunit vaccines could also be considered as robust tools for effective vaccination against COVID‐19. Using a combination of in silico, in vitro, and in vivo experiments, it was shown that the injection of spike‐based truncated recombinant proteins could stimulate long‐lasting and neutralizing antibody responses.
Spatial–temporal pattern of cultivated land productivity based on net primary productivity and analysis of influencing factors in the Songhua River basin
Authors: Yang Shiliang , Bai Yang , Alatalo Juha M. , Wang Huimin , Tong Jinping , Liu Gang , Zhang Fan , Chen Junyu 
Published: March 2022

AbstractInefficient utilization puts the productivity of cultivated land in a low development state. The key challenge for the efficient utilization of cultivated land is to clarify how various factors affect the spatial differentiation pattern of cultivated land productivity (CLP), to improve food production. However, evaluating the impact of the intensity and direction of CLP on a large‐scale is a difficulty and there is a gap in knowledge. In this study, we used net primary productivity (NPP) to calculate the productivity of cultivated land and reveal its spatial differentiation. Also, this study examined the spatio‐temporal heterogeneity of CLP and determined the effect intensity and the direction of effect of various factors on productivity, using the Songhua River basin (SRB) in China as a research case. We used genetic algorithms to modify and improve a neural network model of factor dimensionality reduction, combined with path analysis, cluster analysis, and regression analysis, to identify the main factors impacting CLP, synergies between these factors, and effect intensity and direction. The results showed that: (1) the area of cultivated land in SRB decreased, but the NPP of cultivated land area increased, during 2000–2020; (2) spatially, NPP was relatively low in the middle of the basin and gradually increased towards the periphery; (3) The main positive factors were the normalized difference vegetation index (NDVI), slope, precipitation, evapotranspiration, and total nitrogen, while the main negative factors were temperature, ratio vegetation index, and total phosphorus. Individual principal factors and the synergy between these factors gave CLP different temporal and spatial heterogeneity. Collaborative management of the threshold range of various influencing factors would improve the CLP. This novel information on spatial–temporal differentiation and factors influencing CLP can be important in formulating science‐based and feasible policies for land protection and for improving CLP.