bluuebunny/crossref_metadata_2025 huggingface dataset:
Restoration of a shrub‐encroached semi‐arid grassland: Implications for structural, hydrologic, and sediment connectivity
Authors: Johnson Justin C. , Williams C. Jason , Guertin D. Phillip , Archer Steven R. , Heilman Philip , Pierson Frederick B. , Wei Haiyan
Published: January 2021

Cross‐scale structural and functional connectivity feedbacks can amplify exogenous forces in dryland environments leading to ecosystem state change (e.g., from grassland to shrubland). Attenuation of these connectivity feedbacks would ostensibly be required to restore transitioned ecosystems to their former state. We compared structural, hydrologic, and sediment connectivity on a shrub‐encroached semi‐arid grassland in south‐eastern Arizona, USA, to that of a nearby site experiencing an increase in non‐native perennial grass (Lehmann lovegrass) abundance 5‐year following treating shrubs with tebuthiuron herbicide. Soil/vegetation attributes were quantified and paired with hydrologic experiments at fine (0.5 m2) to hillslope (50 m2) scales. Fine‐scale rainfall simulations (120 mm·h−1rainfall intensity; 45 min) showed interspaces between shrubs were hydrologically similar on the treated and control sites, whereas herbicided shrub patches were more resource conserving than those within the control (terminal infiltration rates of 105 and 71 mm·h−1, respectively). High structural connectivity of bare ground (basal gap lengths >200 cm) was correlated with increased concentrated flow run‐off and accompanied by greater sediment yields within the untreated site at a coarse scale (~9 m2). Hillslope‐scale modelling suggested a divergence between hydrologic and sediment connectivity: run‐off from high intensity rainfall was similar between sites, while predicted sediment yield was 44% less within the tebuthiuron‐treated site. Our results indicate (i) hydraulic properties of soils between shrubs are unresponsive to herbicide treatment, (ii) disruption of structural connectivity of these interspaces associated with grass cover increases subsequent to herbicide application attenuated run‐off and the energy needed for sediment transport, and (iii) sediment connectivity is reduced by conversion to a novel grassland ecological state.
Combined anti‐PD‐1 and anti‐CTLA‐4 checkpoint blockade: Treatment of melanoma and immune mechanisms of action
Authors: Willsmore Zena N. , Coumbe Ben G. T. , Crescioli Silvia , Reci Sara , Gupta Ayushi , Harris Robert J. , Chenoweth Alicia , Chauhan Jitesh , Bax Heather J. , McCraw Alexa , Cheung Anthony , Osborn Gabriel , Hoffmann Ricarda M. , Nakamura Mano , Laddach Roman , Geh Jenny L. C. , MacKenzie‐Ross Alastair , Healy Ciaran , Tsoka Sophia , Spicer James F. , Josephs Debra H. , Papa Sophie , Lacy Katie E. , Karagiannis Sophia N.
Published: January 2021

Cytotoxic T‐lymphocyte associated protein‐4 (CTLA‐4) and the Programmed Death Receptor 1 (PD‐1) are immune checkpoint molecules that are well‐established targets of antibody immunotherapies for the management of malignant melanoma. The monoclonal antibodies, Ipilimumab, Pembrolizumab, and Nivolumab, designed to interfere with T cell inhibitory signals to activate immune responses against tumors, were originally approved as monotherapy. Treatment with a combination of immune checkpoint inhibitors may improve outcomes compared to monotherapy in certain patient groups and these clinical benefits may be derived from unique immune mechanisms of action. However, treatment with checkpoint inhibitor combinations also present significant clinical challenges and increased rates of immune‐related adverse events. In this review, we discuss the potential mechanisms attributed to single and combined checkpoint inhibitor immunotherapies and clinical experience with their use.
Quaternary Fe‐Cu‐Cr‐Al HT‐WGS Catalysts – Effect of Al Substitution on the Efficiency at Steam‐Lean Process Gas
Authors: Kowalik Paweł , Bicki Robert , Antoniak‐Jurak Katarzyna , Michalska Kamila , Próchniak Wiesław , Mrozek Anna
Published: January 2021

In the present work, we report on Fe–Cu–Cr–Al systems with various Cr/Al substitution as catalysts for high‐temperature water‐gas shift (HT‐WGS) to evaluate the possibility of Cr elimination and usability for carrying out the HT‐WGS process at steam‐lean process gas. The set of Fe–Cu–Cr–Al catalysts with the same Fe/Cu molar ratio and different Cr/Al molar ratio (0/∞) were prepared by the precursors' co‐precipitation and thermal treatment. The catalysts were investigated by XRF, DTG/MS, XRD, N2 sorption, H2‐TPR methods and activity tests. A relationship between Cr/Al ratio and physicochemical parameters and HT‐WGS activity, selectivity and stability of the catalysts have been estimated. Experimental results demonstrated that complete elimination of Cr from the Fe–Cu–Cr–Al catalyst is unfavorable, and it would lead to negative consequences as Cr enhances the catalyst activity and improve its durability.
Guest Modulated Spin States of Metal Complex Assemblies
Authors: Nakaya Manabu , Ohtani Ryo , Hayami Shinya
Published: January 2021

Recently, “host–guest chemistry” aspects of material science have received much attention, particularly in relation to moderating the functions of materials. In particular, magnetic properties involving the “magnetic ordering” and “spin crossover” of host–guest metal complex systems have been actively investigated in terms of their host–guest chemistry. That is, systems in which the magnetic properties are sensitive to perturbation by the uptake of guests (which thus act as chemical stimuli). Such guests (solvents, gases and organic molecules) very often influence the structures of both discrete metallosupramolecular assemblies as well as those of coordination polymers/metal‐organic frameworks (CPs/MOFs), providing a means for fine‐tuning their magnetic behavior, including the switching of their spin states. In this minireview, we report recent progress in the development and investigation of magnetic materials of both the CP and MOF categories as well as of discrete complexes whose properties are modulated by guests.
The Heteroleptic Cu(I) Photosensitizer‐Containing 3,8‐Disubstituted Phenanthroline: Synthesis, Photophysical Properties and Photocatalytic Hydrogen Evolution from Water
Authors: Xu Liang‐Xuan , Wang Tian‐Qi , Liu Xue‐Fen , Chen Hao , Wei Chun‐Jiang , Xu Dan‐Dan , Chen Feng , Li Yang , Luo Shu‐Ping
Published: January 2021

Four novel heteroleptic Cu(I) photosensitizers with 3,8‐diaryl‐2,9‐diisopropyl‐1,10‐phenanthroline derivatives as electron‐donating bidentate N‐ligands have been designed and synthesized. The metal copper complexes are studied in light‐driven water reduction system. And the substituent effect at the 3,8‐positions of N‐ligands impacting on photosensitive activity and photoelectric chemical properties are explored and discussed. Surprisingly, with the enhancement of electron‐donating capacity of substituent group at 3,8‐sites of 1,10‐phenanthroline, the photosensitive activity of photosensitizer linearly increases, and photocatalytic performance up to 817 turnover numbers (TON) was reached combining with water reduction catalyst (WRC), Fe3(CO)12. The photocatalytic performance of these photosensitizers dramatically increased compared to 2,9‐diispropyl‐1,10‐phenanthroline complex (TON = 89). Moreover, the introduction of methoxy substituent to copper complexes, which could increase the fluorescence lifetimes (τmax = 209 ns) and promote hydrogen evolution.
Gold‐Loaded Mesoporous Organosilica‐Silica Core‐Shell Nanoparticles as Catalytic Nanoreactors
Authors: Luo Leilei , Bock Lorenz , Liang Yucang , Anwander Reiner
Published: January 2021

Despite immense research efforts in the field of noble metal‐loaded mesoporous silica nanoparticles, the rational design and fabrication of nanosystems with high catalytic efficiency are still a major challenge. The main obstacles are faced when adjusting the size of the implemented metal nanoparticles and when modulating the porosity of nanoreactor arrays. Herein, a series of hierarchically structured core‐shell nanoparticles was synthesized, consisting of a mesoporous siliceous shell and either a thiol‐functionalized mesoporous organosilica core (SH‐MON‐n@MS; n = 1, 2, 3, 4) or an amino‐functionalized variant (NH2‐MON@MS). The distinct core/shell composition enables a selective loading of Au nanoparticles into the core domain affording the hierarchically structured materials Au/SH‐MON‐n@MS (n = 1, 2, 3, 4) and Au/NH2‐MON@MS. The larger shell mesopores facilitate easy access and diffusion of reactants and products, while the inner organosilica pores provide a hydrophobic microenvironment. Due to the superior structural properties, the materials Au/SH‐MON‐n@MS (n = 1, 2, 3, 4) exhibit excellent catalytic performance in the reduction of 4‐nitrophenol to 4‐aminophenol. However, the aerobic oxidation of benzyl alcohol to benzaldehyde is only promoted by Au/SH‐MON‐2@MS, revealing that Au loading and the core pores are main factors to govern the catalytic performance, while the air‐flow rate takes also a key role in the catalytic conversion.
Agostic Hydrogens in 1‐Norbornyl Metal Cyclopentadienyl Structures
Authors: Fan Zhixiang , Hu Yuchen , Li Huidong , Fu Jia , Fan Qunchao , King R. Bruce , Schaefer Henry F.
Published: January 2021

The first‐row transition metal 1‐norbornyl derivatives CpM(nor) Cp = η5‐C5H5; nor = 1‐norbornyl; M = Ti to Cu), including the experimentally known CpNi(nor) reported by Lehmkuhl and Dimitrov, have been examined by density functional theory and benchmarked by the more accurate DLPNO‐CCSD(T) method. The lowest energy CpM(nor) structures for the later first row transition metals from manganese to copper are found to be high‐spin state structures in which the 1‐norbornyl ligand is bonded to the metal only through the M–C σ‐bond to the bridgehead carbon atom. The favored spin states range from doublet for CpCu(nor) to sextet for CpMn(nor). The pattern of favorable structure types changes for the CpM(nor) derivatives of the earlier first row transition metals to the left of manganese since all of their low energy structures have singly or doubly agostic 1‐norbornyl groups. The agostic C–H–M interactions in the CpM(nor) derivatives are characterized by their reduced density gradients and low ν(C–H) frequencies.
Construction of Two Novel Titanium Oxide Clusters: Copper Ion Introducing Enhances Photocatalytic Performance
Authors: Liu Chengdong , Wu Yixin , Meng Xiangyu , Zhao An , Shao Yongliang , Liu Wei , Huang Xin , Pan Fu‐Xing , Liu Weisheng
Published: January 2021

Polyoxometalates (POMs) exhibit excellent properties in many aspects; in addition to their unique geometry and electronic structures, POMs have shown outstanding catalysis, as well as magnetic and redox properties. In contrast, as a new type of polyacid system, many aspects of titanium oxide clusters (TOCs) still remain unexplored. By introducing fluorine‐substituted salicylic acid ligand into the TOCs system, we synthesized [Ti7(µ3‐O)4(LF)4(iPrO)12]·2(CH3CN) (1; LF = 3‐fluorosalicylic acid) with an Anderson‐type related structure, which is already well known for other POMs. Additionally, introducing Cu ions into the same system, we obtained [Ti6Cu2(µ3‐O)2(LF)6(CH3COO)2(CH2CN)2(iPrO)10] with dramatic improvement of the visible‐light photocatalytic performance in both the degradation of dye and the water degradation to release H2.
Phosphorescent Iridium(III) Complexes for Anticancer Applications
Authors: Guan Ruilin , Xie Lina , Ji Liangnian , Chao Hui
Published: January 2021

Great attention has been bestowed upon iridium(III) complexes as anticancer agents in recent years, and a variety of them, in particular, are luminescent. The phosphorescence of these compounds facilitates the visualization and monitoring of their subcellular localization and interactions with other molecules or structures during anticancer therapy, which might help demonstrate the inner pathways and molecular mechanisms of the complexes. In this review, we focus on the development of phosphorescent iridium(III) complexes for anticancer applications in recent five years and intend to highlight some newly reported Ir(III) complexes that are targeting specific organelles, inducing different cell death modes, or photoactivated agents in phototherapies including photodynamic therapy and photoredox catalysis.
Thermally Triggered Isomerization in a Naphthalene‐Based Acylhydrazone with Solid‐State Optical Nonlinearity Response
Authors: Huang Miaoling , Qiu Rongxing , Pan Zhonghua , Tian Dan , Tao Yunwen , Lin Jinqing , Luo Geng‐Geng
Published: January 2021

Under the assistance of the state‐of‐the‐art meta‐dynamics simulations, in this contribution, we report a push‐pull‐type acylhydrazone 4(Z) ([Z)‐2‐(naphthalen‐2‐yloxy)‐N'‐(pyridine‐2‐ylmethylene)acetohydrazide] connecting an electron‐donating naphthalene ether group with an accepting pyridyl unit, which could be thermally converted to its configurational isomer 4(E) ([E)‐2‐(naphthalen‐2‐yloxy)‐N'‐(pyridine‐2‐ylmethylene)acetohydrazide]. The thermally triggered Z‐to‐E configurational isomerization not only involves up to five chemical bonds undergoing 180° rotation in the backbone of acylhydrazone, but changes the crystal packing symmetry from a centrosymmetric space group to a non‐centrosymmetric one. Most impressively, the acentric crystal arrangement of 4(E) exhibits a second‐harmonic generation (SHG) active response, about 2.5 times than that of KH2PO4 (KDP) standard.
Versatile Production of Novel PNP Based Metal Complexes Applicable as Water Reduction Catalysts Showing CH/M as Well as CH/π Interactions
Authors: Pehn Richard , Pann Johann , Ehrmann Katharina , Viertl Wolfgang , Roithmeyer Helena , Bendig Marvin , Strabler Christof , Kopacka Holger , Müller Thomas , Hofer Thomas , Brüggeller Peter
Published: January 2021

Several PNP‐type ligands of the form bis(dianisylphosphanylmethyl)alkylamine, where alkyl is methyl, ethyl, isopropyl, and benzyl (1–4), have been coordinated to Co(II), Ni(II), Pd(II), and Pt(II) (5–26). This series of water reduction catalysts (WRC) has been characterized by single‐crystal X‐ray structure analysis, multinuclear and 2D NMR spectroscopy, mass spectrometry and a computational study. Intramolecular contact approaches show differences depending on hetero‐ or homoleptic complexes. Both solid state and solution structures indicate an enhancement of steric pressure for the latter. As a consequence CH/M as well as CH/π interactions appear in the X‐ray structures and 1H NMR spectra. They can also be clearly identified by quantum mechanical calculations on a B3LYP level. Since these WRC contain proton relays due to the used PNP‐ligands, they are prone to proton coupled electron transfer (PCET) during photocatalysis. The different steric pressure influences their reorganisation energy. Obviously, the observed intramolecular contact approaches should be regarded as a tool for the design of future WRC.
Rational Design of Cycloheptyl‐Fused Bis(arylimino)pyridyl‐cobalt(II) Precatalysts Adorned with Sterically and Electronically Modified N‐Aryls for Enhancing Ethylene Polymerization
Authors: Zada Muhammad , Guo Liwei , Zhang Wenjuan , Ma Yanping , Liang Tongling , Sun Wen‐Hua
Published: January 2021

The sterically and electronically modified cycloheptyl‐fused bis(arylimino)pyridine‐cobalt(II) chloride precatalysts [2,3 : 5,6‐{C4H8C(N‐2,4‐(C15H13)‐6‐R‐C6H2}2C5HN]CoCl2 (R=Me (Co1), Et (Co2), i‐Pr (Co3), Cl (Co4), and F (Co5)) have been prepared via one‐pot synthesis approach. All the precatalysts were characterized by elemental analysis, FT‐IR spectroscopy and the single‐crystal X‐ray diffraction for Co2 confirmed distorted‐square‐pyramidal geometry around the cobalt center. On activation with either MAO (methylaluminoxane) or MMAO (modified methylaluminoxane), all the cobalt precatalysts displayed high catalytic activities for ethylene polymerization with peak performance of 3.47×106 g (PE) mol−1 (Co) h−1 at 50 °C using MAO and 4.53×106 g (PE) mol−1 (Co) h−1 at 30 °C with MMAO. The steric and electronic influence of the ortho‐substitutions (R) displayed significant effect on the catalytic activity and molecular weight of the resultant polyethylene. Notably, the precatalyst Co5 (R=F) exhibited high activity, delivering high‐molecular‐weight (558.17 kg mol−1) polyethylene; highlights the beneficial effect of ortho‐substituents (R) alongside with dibenzocycloheptyl groups. In addition, analysis of the obtained polyethylene showed strictly linear structure with saturated and unsaturated (vinyl) end groups.
Towards the Total Synthesis of Jerangolids – Synthesis of an Advanced Intermediate for the Pharmacophore Substructure
Authors: Lenhof Julian , Hutter Michael , Huch Volker , Jauch Johann
Published: January 2021

The jerangolids are a class of natural products with a skipped diene substructure isolated from Sorangium cellulosum. Here, we present a new strategy for the total synthesis of these compounds based on a skipped diyne as central building block and a suitably substituted epoxy aldehyde as building block for the dihydropyran substructure. So far, we reached an advanced intermediate which is related to the pharmacophore subunit of the jerangolids as well as of the ambruticins. A key step is a Shi epoxidation with high e.r. to form the epoxy aldehyde. Both building blocks are coupled in a Carreira alkynylation, where additional mechanistic studies based on DFT calculation were realized. The alkynylation is followed by a nucleophilic 6‐endo‐tet epoxide opening to form the pyran structure and a Nicholas reduction to remove a propargylic OH group.
Synthesis of 1,2‐Dicyano‐3‐arylcycl[3.2.2]azines – First 1,2‐Dicarbonitriles Based on Cyclazine Heterocycle
Authors: Starikov Andrei S. , Kalashnikov Valery V. , Tarakanov Pavel A. , Simakov Anton O. , Simonov Sergey V. , Tkachev Valery V. , Yarkov Alexander V. , Kazachenko Vladimir P. , Chernyak Alexander V. , Zhurkin Fedor E. , Tomilova Larisa G. , Pushkarev Victor E.
Published: January 2021

The first 1,2‐dicarbonitriles have been prepared for cyclazine systems. In particular, a synthetic procedure to 1,2‐dicyano‐3‐arylcycl[3.2.2]azines has been developed. Unexpected chlorination of 3‐arylcycl[3.2.2]azine‐1,2‐dicarboxylic acid derivatives by thionyl chloride at 4‐position was found, which according to theoretical considerations can proceed by the electrophilic (SEAr) mechanism. The compounds are blue fluorophores in 450–480 nm region with quantum yields in toluene of ca. 30 % for non‐chlorinated derivatives, which decrease to 3–4 % for chlorinated ones.
Synthesis of Spiro[benzofuran‐2,2'‐benzo[b]thiophene]‐3,3'‐diones via PIDA/CuBr‐Mediated Spirocyclization
Authors: Li Xuemin , Liang Huiyuan , Yang Yaxin O , Wang Xi , Zhang Jingran , Wang Donghua , Sun Fengxia , Du Yunfei
Published: January 2021

A phenyliodine(III) diacetate (PIDA)/CuBr‐mediated construction of the novel 3H,3'H‐spiro[benzofuran‐2,2'‐benzo[b]thiophene]‐3,3'‐dione skeleton was realized from the reaction of (Z)‐3‐hydroxy‐1‐(2‐hydroxyphenyl)‐3‐(2‐halogenphenyl)prop‐2‐en‐1‐ones with potassium ethylxanthate in the presence of 1,10‐phen. The reaction sequence was postulated to encompass a PIDA‐mediated oxidative C–O bond formation followed by a CuBr‐mediated spirocyclization step.
Rhodium Catalysts with a Chiral Cyclopentadienyl Ligand Derived from Natural R‐Myrtenal
Authors: Pototskiy Roman A. , Kolos Andrey V. , Nelyubina Yulia V. , Perekalin Dmitry S.
Published: January 2021

A new chiral cyclopentadiene CpmyrH was synthesized from the natural terpene (R)‐myrtenal in 5 steps and about 40 % total yield. The key step was the reaction of vinyl‐dibromocyclopropane derivative with MeLi which provided the diene CpmyrH via Skattebøl rearrangement. The reaction of CpmyrH with [(cod)Rh(OAc)]2 gave the rhodium(I) complex (Cpmyr)Rh(cod) and subsequent oxidation with halogens X2 gave the rhodium(III) complexes [(Cpmyr)RhX2]2 (X = Br, I). Complex (Cpmyr)Rh(cod) in combination with benzoyl peroxide catalyzed the C–H activation of O‐pivaloyl‐phenylhydroxamic acid and its subsequent annulation with alkenes giving dihydroisoquinolones with high yield (70–90 %) but moderate enantioselectivity (16–36 % ee).
Stereocontrolled Synthesis of Harzialactone A and Its Three Stereoisomers by Use of Standardized Polyketide Building Blocks
Authors: Ballaschk Frederic , Özkaya Yasemin , Kirsch Stefan F.
Published: January 2021

In this paper, we present a short and convenient synthesis of the natural product Harzialactone A and its three stereoisomers. In a three‐step synthesis starting from cheap and commercially available benzaldehyde, we created the small polyketidic compound with full control over its two stereogenic centers. To this end, we employed a chiral building block previously described by us, introducing the first stereogenic center through a Horner–Wittig reaction. The second stereogenic center was installed via stereocontrolled syn‐ or anti‐reduction with the corresponding β‐hydroxy ketone intermediates. Upon ozonolysis followed by oxidation the natural product and its stereovariants were produced with excellent enantio‐ and diastereopurities.
Tetraaryl Cyclopentadienones: Experimental and Theoretical Insights into Negative Solvatochromism and Electrochemistry
Authors: Meitinger Nicolas , Mengele Alexander K. , Witas Kamil , Kupfer Stephan , Rau Sven , Nauroozi Djawed
Published: January 2021

The synthesis of a series of tetraaryl cyclopentadienones comprising different substitution patterns is reported. Their photophysical and electrochemical properties are investigated by UV/Vis spectroscopy and cyclic voltammetry as well as by supporting quantum chemical simulations and reveal a distinct effect of substituents on the redox behavior of the molecules as well as the absorption properties of this class of compounds. While electrochemical data display a shift in reduction potential of up to 200 mV between the differently substituted cyclopentadienones, their photophysical investigations in differently polar solvents suggest a negative solvatochromic effect, although protic solvents induce a bathochromic shift. Crystal structure analyses of some derivatives confirm similarity with related cyclopentadienones while providing insight into intermolecular C–H···O and C–H···π interactions in the solid state.
Visible‐Light Photoredox Alkylation of Heteroaromatic Bases Using Ethyl Acetate as Alkylating Agent
Authors: Győrfi Nándor , Kotschy András , Gyuris Márió
Published: January 2021

An efficient room‐temperature visible‐light photoredox α‐acyloxyalkylation reaction of N‐heteroarenes is reported, which relies on the use of ethyl acetate as a cheap and non‐conventional radical source. The direct C(sp2)‐C(sp3) coupling was extended to a diverse set of mono‐, bi‐, and tricyclic of N‐heteroaromatics, and the optimized photoredox protocol was successfully performed on a multigram scale. The scope of the alkylating agent was also explored and a plausible mechanism was proposed, involving photoinduced single‐electron transfer and hydrogen‐atom transfer processes.
Direct Transformation of Alkylarenes into N‐(Pyridine‐2‐yl)amides by C(sp3)–C(sp3) Bond Cleavage
Authors: Zhou Haipin , Liu Yanpeng , Xia Haidong , Xu Jinyi , Wang Tingfang , Xu Shengtao
Published: January 2021

C(sp3)–H bond functionalization and C(sp3)–C(sp3) bond cleavage are very challenging transformations in chemistry. Herein, we report a mild and green methodology for the construction of N‐(pyridine‐2‐yl)amides via tandem C(sp3)–H activation/C–C bond cleavage of alkylarenes. Various N‐heterocyclic amides were directly synthesized from alkylarenes in water in moderate to good yields.
Stereo‐ and Regioselective Construction of Spirooxindoles Having Continuous Spiral Rings via Asymmetric [3+2] Cyclization of 3‐Isothiocyanato Oxindoles with Thioaurone Derivatives
Authors: Gui Hou‐Ze , Meng Zhe , Xiao Zhan‐Shuai , Yang Ze‐Ren , Wei Yin , Shi Min
Published: January 2021

A highly efficient enantioselective [3+2] cyclization of 3‐isothiocyanato oxindoles with thioaurone derivatives was explored for the synthesis of spirooxindoles containing continuous spiral ring structures. Three continuous spiral ring structures and three consecutive chiral centers (including two spiro quaternary stereocenters) were conveniently constructed at a time. In addition, an uncommon sulfur‐containing spirocyclic ring was constructed at the same time. The reaction went smoothly whether the alkenyl moiety of thioaurone derivatives was at 2‐position (up to 99 % yield, up to 99 % ee, up to > 20:1 dr) or at 3‐position (up to 96 % yield, up to 95 % ee, up to 12:1 dr).
Organocatalytic Asymmetric Formal [3+3]‐Cycloaddition to Access 2,3‐Diazaspiro[4.5]deca‐3,6‐dien‐1‐ones
Authors: Krishna A. Vamshi , Reddy G. Surendra , Gorachand B. , Ramachary Dhevalapally B.
Published: January 2021

Medicinally important 2,3‐diazaspiro[4.5]deca‐3,6‐dien‐1‐ones having vicinal quaternary centers were constructed in very good yields with high enantio‐ and diastereoselectivities through an organocatalytic formal [3+3]‐cycloaddition or domino Michael/aldol reactions, which is driven by the double sequence of in situ isoaromatization and dearomatization steps from the α‐arylidene pyrazolinones and (E)‐alkyl 2‐oxo‐4‐arylbut‐3‐enoates.
Optimized and Scalable Synthesis of Carba‐α‐d‐Glucosamine
Authors: Babczyk Alexander , Wingen Lukas M. , Menche Dirk
Published: January 2021

An efficient, high‐yielding synthesis of carba‐α‐d‐glucosamine is reported. Key features of this optimized route include an innovative protecting group strategy and an unusual, stereoconvergent Ferrier carbocyclization of a hindered substrate. The sequence enables the synthesis of larger amounts of this structurally novel antibiotic to allow more detailed biological evaluations of its unique mode of action.
Highly Enantioselective Ring‐Opening of meso‐Epoxides with O‐ and N‐Nucleophiles Catalyzed by a Chiral Sc(III)/bipyridine Complex
Authors: Malatinec Štefan , Bednářová Eva , Tanaka Hiroki , Kotora Martin
Published: January 2021

The ring‐opening of epoxides is a synthetically significant process widely applied in all kinds of chemistry. Herein, we report the catalytic and highly enantioselective variant of this reaction exploiting our recent endeavors to design and synthesize chiral bipyridine type ligands. A Sc‐complex with a newly developed bipyridine ligand exhibited high reactivity and stereocontrol in the desymmetrization of meso‐epoxides with various alcohols. The respective enantiomerically enriched 1,2‐alkoxyalcohols were obtained with e.r. values of up to 99.5:0.5 for various alcohols regardless of their nature (benzyl, alkyl, cycloalkyl, allyl, propargyl, etc.). We attempted ring‐opening of meso‐epoxides with anilines as well; however, it proceeded with lower enantioselectivity and was strongly depended on the electronic effect of substituents attached to the aromatic ring.
Square‐wave Voltammetry and Electrochemical Faradaic Spectroscopy of a Reversible Electrode Reaction: Determination of the Concentration Fraction of the Redox Couple
Authors: Stojanov Leon , Jovanovski Vasko , Mirceski Valentin
Published: January 2021

A comparative study conducted with square‐wave voltammetry (SWV) and electrochemical faradaic spectroscopy (EFS) is presented for a reversible electrode reaction of dissolved redox couple in the presence of both Ox and Red components. In agreement with previous studies, the net peak current ΔΨp of the theoretical SW voltammograms is positioned at the formal potential E0′ and does not depend on the concentration ratio c(Ox)/c(Red). However the forward‐to‐backward peak current ratio is sensitive to the redox state. For very low SW amplitudes, theoretical data imply superior features of EFS over SWV. Theoretical and experimental calibration lines are in good agreement within the interval 0.2≤x(Ox)≤0.8.
Influence of probiotic adjunct cultures on the characteristics of low‐fat Feta cheese
Authors: Ahmed Mahmoud E. , Rathnakumar Kaavya , Awasti Nancy , Elfaruk Mohamed Salem , Hammam Ahmed R. A.
Published: January 2021

There are different methods that have been recently applied to develop a process to manufacture low‐fat Feta cheese (LFC) with acceptable flavor and texture. The objective of this study was to produce LFC from skim buffalo's milk (SBM) using Streptococcus thermophilus (ST) and Lactobacillus bulgaricus (LB) as control LFC (T1) incorporated with other probiotic adjunct cultures (PAC), such as Lactobacillus casei (LBC) in T2, Bifidobacterium bifidum (BB) in T3, and Lactococcus lactis subsp. lactis (LL) in T4. The SBM was pasteurized and inoculated with 3% of starter cultures; then, 0.4% of rennet and 3% of salt were added. After coagulation, the cheese was cut, packed, and stored at 4°C. The chemical, microbiological, and sensory characteristics of LFC were monitored during 14 days of storage. The moisture, acidity, total protein (TP), salt, and fat of LFC were approximately 75.0%, 1.0%, 17.0%, 3.0%, and 1.2%, respectively, after 14 days of storage at 4°C. The viability of PAC was high (5–7 log cfu/g) at the end of storage, which makes LFC a functional product with a valuable source of probiotic. Moreover, the adjunct cultures improved (p < .05) the sensory characteristics of LFC, including the texture and flavor.
Comparative study of physicochemical composition and microbial community of Khoormog, Chigee, and Airag, traditionally fermented dairy products from Xilin Gol in China
Authors: Guo Liang , Xu Weiliang , Li Chundong , Guo Yuansheng ,   Yamei , Chagan Irbis
Published: January 2021

Due to their outstanding nutritional and functional properties, the traditionally fermented dairy products (TFDP) from camel, mare, and cow gained universal praise during their long history of production. In this study, the physicochemical composition and microbial communities of Khoormog, Chigee, and Airag, the TFDP from Xilin Gol in China, were investigated and compared. The physicochemical analysis revealed a higher content of total solid content, protein, and fat in Khoormog (12.5 ± 1.6%; 4.6 ± 0.7%; 4.4 ± 1.3%) compared to Chigee (7.8 ± 1.3%; 2.1 ± 0.2%; 0.8 ± 0.2%) and Airag (8.9 ± 0.7%; 3.7 ± 0.4%; 1.4 ± 0.5%). All three types of TFDP shared 41.2% of bacterial and 25.4% of fungal OTUs, and 95.34% of bacterial and 95.52% of fungal sequence reads. The bacterial and fungal community consisted of four phyla and five genera, and three phyla and seven genera, respectively. Lastly, Lactobacillus predominated in Khoormog, Chigee, and Airag at the genus level, while the dominant fungal genera varied among the samples. In conclusion, the microbial community structures of TFDP from camel, mare, and cow were not significantly different in a definite area (Xilingol region), and Khoormog, Chigee, and Airag bred the common “core microbiota”.
Consistent and efficient pricing of SPX and VIX options under multiscale stochastic volatility
Authors: Jeon Jaegi , Kim Geonwoo , Huh Jeonggyu
Published: January 2021

We provide consistent and efficient pricing for both Standard & Poor's 500 Index options and the Chicago Board Options Exchange's Volatility Index options under a multiscale stochastic volatility model. To capture the multiscale, our model adds a fast scale factor to Heston's volatility and we derive approximate analytic formulas for the options under the model. The analytic tractability can greatly improve the efficiency of calibration compared to fitting procedures using a numerical scheme. Our experiment using options data for 3 years shows that the model reduces about 20% of the errors for a single‐scale model.
Bioethics and Addiction
Authors: Kaebnick Gregory E.
Published: January 2021

Bioethicists have sometimes regarded the opioid epidemic as a problem with obvious answers and thus no need for the field's conceptual analysis. Yet, as three essays in the July‐August 2020 issue of the Hastings Center Report demonstrate, the opioid crisis contains a knot of distinctions and puzzles to be sorted out. Travis N. Rieder examines, for example, what is fundamentally driving the crisis—access to the drugs or large societal problems such as poverty and joblessness. The role of choice in addiction, the effects of moral condemnation on approaches to addiction, and what treatment should look like are among the puzzles Hanna Pickard explores, while Daniel S. Goldberg focuses on the common and harmful conflation of the public health problems of substance misuse and pain. These philosophical and bioethical questions point in widely different directions, lying both inside and outside bioethics. They point toward systemic societal factors that determine health and well‐being yet have seemed outside bioethics' largely clinical boundaries. And they point toward a deeper look at the very idea of autonomy—an examination of a topic clearly within bioethics yet occurring at the fringes of its usual constructs.
Listening to Scientists—and Each Other
Authors: Gusmano Michael K.
Published: January 2021

During the past two years, colleagues and I at The Hastings Center have worked on a project, funded by the John S. and James L. Knight Foundation, that seeks to improve the quality of public deliberation, particularly about science. Specifically, we seek to improve the public's capacity for civic learning, which is our term for the ability of people living in a democracy to learn at least the basics of complex policy issues, discuss them, and make civically responsible decisions about them. There are no quick fixes. The forces that have undermined trust in society and that inhibit a mutually respectful deliberation about these issues have built up over centuries.
The Social Risks of Science
Authors: Herington Jonathan , Tanona Scott
Published: January 2021

Many instances of scientific research impose risks, not just on participants and scientists but also on third parties. This class of social risks unifies a range of problems previously treated as distinct phenomena, including so‐called bystander risks, biosafety concerns arising from gain‐of‐function research, the misuse of the results of dual‐use research, and the harm caused by inductive risks. The standard approach to these problems has been to extend two familiar principles from human subjects research regulations—a favorable risk‐benefit ratio and informed consent. We argue, however, that these moral principles will be difficult to satisfy in the context of widely distributed social risks about which affected parties may reasonably disagree. We propose that framing these risks as political rather than moral problems may offer another way. By borrowing lessons from political philosophy, we propose a framework that unifies our discussion of social risks and the possible solutions to them.
Resting‐state magnetoencephalography source magnitude imaging with deep‐learning neural network for classification of symptomatic combat‐related mild traumatic brain injury
Authors: Huang Ming‐Xiong , Huang Charles W. , Harrington Deborah L. , Robb‐Swan Ashley , Angeles‐Quinto Annemarie , Nichols Sharon , Huang Jeffrey W. , Le Lu , Rimmele Carl , Matthews Scott , Drake Angela , Song Tao , Ji Zhengwei , Cheng Chung‐Kuan , Shen Qian , Foote Ericka , Lerman Imanuel , Yurgil Kate A. , Hansen Hayden B. , Naviaux Robert K. , Dynes Robert , Baker Dewleen G. , Lee Roland R.
Published: January 2021

Combat‐related mild traumatic brain injury (cmTBI) is a leading cause of sustained physical, cognitive, emotional, and behavioral disabilities in Veterans and active‐duty military personnel. Accurate diagnosis of cmTBI is challenging since the symptom spectrum is broad and conventional neuroimaging techniques are insensitive to the underlying neuropathology. The present study developed a novel deep‐learning neural network method, 3D‐MEGNET, and applied it to resting‐state magnetoencephalography (rs‐MEG) source‐magnitude imaging data from 59 symptomatic cmTBI individuals and 42 combat‐deployed healthy controls (HCs). Analytic models of individual frequency bands and all bands together were tested. The All‐frequency model, which combined delta‐theta (1–7 Hz), alpha (8–12 Hz), beta (15–30 Hz), and gamma (30–80 Hz) frequency bands, outperformed models based on individual bands. The optimized 3D‐MEGNET method distinguished cmTBI individuals from HCs with excellent sensitivity (99.9 ± 0.38%) and specificity (98.9 ± 1.54%). Receiver‐operator‐characteristic curve analysis showed that diagnostic accuracy was 0.99. The gamma and delta‐theta band models outperformed alpha and beta band models. Among cmTBI individuals, but not controls, hyper delta‐theta and gamma‐band activity correlated with lower performance on neuropsychological tests, whereas hypo alpha and beta‐band activity also correlated with lower neuropsychological test performance. This study provides an integrated framework for condensing large source‐imaging variable sets into optimal combinations of regions and frequencies with high diagnostic accuracy and cognitive relevance in cmTBI. The all‐frequency model offered more discriminative power than each frequency‐band model alone. This approach offers an effective path for optimal characterization of behaviorally relevant neuroimaging features in neurological and psychiatric disorders.
The impact of mental health parity laws on birth outcomes
Authors: Carney Monica Harber
Published: January 2021

Prior studies have found that poor mental health during pregnancy is associated with poor birth outcomes, but little is known about the ability of mental health care access and treatment to counteract these effects. I use a difference‐in‐differences strategy exploiting the staggered enactment of state mental health parity laws in 25 states from 1995 to 2002 to identify the impact of mental health care access on the probability of an adverse birth outcome. These state mental health parity laws are insurance mandates requiring coverage of mental health care be equivalent to physical health care. Using birth records, I find that, among the group of mothers most likely to have private insurance, introduction of a mental health parity law in a state decreased the probability of an adverse birth outcome. Furthermore, I find that the parity laws decreased the likelihood that a pregnant woman hospitalized for delivery would receive a mental illness diagnosis.
Computational analysis of the thermal performance of rarefied air flow in V‐shaped microchannels
Authors: Hader Montasir , Al‐Kouz Wael , Kiwan Suhil , Alshare Aiman , Chamkha Ali
Published: January 2021

In this study, a computational fluid analysis of a slip flow developing thermally and hydrodynamically in a triangular microchannel has been considered. The wall of the channel is preserved at a fixed temperature. Temperature jump and velocity slip boundary conditions are imposed on the surfaces. The microchannel is constructed from seven triangular‐shaped channels and the angle of the microchannel (θ) is varied from 0° to 40°. Simulations are carried out for , and the air is used as a working fluid with variable physical properties. The simulation results show that the triangular microchannel can improve heat transfer as compared with plain microchannels. An optimal θ of 20° is found to provide the best heat transfer at moderate frictional losses. Finally, correlations for the average Nusselt number and the average friction coefficient among all parameters are proposed as follows: , .
Forestal Arauco experimental research catchments; daily rainfall‐runoff for 10 catchments with different forest types in Central‐Southern Chile
Authors: Balocchi Francisco , White Don A. , Silberstein Richard P. , Ramírez de Arellano Pablo
Published: January 2021

Forestal Arauco (FA), a global manufacturer of forest products, manages more than 1 million ha of forest plantations and oversees the conservation of more than half a million hectares of native forest and vegetation in Brazil, Argentina and Chile. In 2008, FA responded to local concerns about the effect of plantations on water resources and commenced streamflow monitoring in catchments in the coastal range of central‐southern Chile between 35° and 39° of latitude south. This data note presents an overview of daily streamflow and rainfall records for 10 small catchments (18–112 ha) from 2008 to 2018. The catchments are covered by three different forest types, namely native forest (2), pine plantations of different ages (6) and eucalypt plantations (2). All of these catchments share similar metamorphic geology. A 90° V notch weir was built at each catchment outlet and data collected at 5 min interval using a pressure transducer that was calibrated monthly. The dataset is part of a research programme aiming to improve our understanding about the role of forest plantations on water balance at a stand and catchment level. It also includes the rainfall data from these catchments estimated using a combination of local rain gauges and data from the longer term records of the Chilean Directorate of Water. This dataset can be used in hydrological modelling and in a wide range of research questions and water management issues regarding forest plantations in a Mediterranean climate.
Impact of corporate performance on stock price predictions in the UAE markets: Neuro‐fuzzy model
Authors: Mohamed Elfadil A. , Ahmed Ibrahim Elsiddig , Mehdi Riyadh , Hussain Hanan
Published: January 2021

Predicting stock price remains one of the challenges for investors' investment strategies. This study helps with accurate prediction and the main factors affecting variations in stock prices. It applies an adaptive neuro‐fuzzy model on 58 listed firms from both the Abu Dhabi Securities Exchange and the Dubai Financial Market for the period 2014–2018 to estimate the predictive power of corporate performance measures and their significance. After examining four performance predictors—return on asset (ROA), return on equity (ROE), earning per share (EPS), and profit margin (PM)—the study finds that ROE is the most significant predictor and ROA is the least. EPS is the most influential profitability measure and PM the least.
Dynamic imaging of zebrafish heart with multi‐planar light sheet microscopy
Authors: Huang Zengxin , Gu Panchun , Kuang Dengfeng , Mi Ping , Feng Xizeng
Published: January 2021

Light sheet fluorescence microscopy has become a research hotspot in biomedicine because of low phototoxicity, high speed, and high resolution. However, the conventional methods to acquire three‐dimensional spatial information are mainly based on scanning, which inevitably increases photodamage and is not real‐time. Here, we propose a method to generate controllable multi‐planar illumination with a dielectric isosceles triangular array and a design of multi‐planar light sheet fluorescence microscopy system. We carry out experiments of three‐dimensional illumination beam measurement, volumetric imaging of fluorescent microspheres, and dynamic in vivo imaging of zebrafish heart to evaluate the performance of this system. In addition, we apply this system to study the effects of bisphenol fluorene on the heart shape and heart‐beating rate of zebrafish. Our experiment results indicate that the multi‐planar light sheet microscopy system provides a novel and feasible method for three‐dimensional selected plane imaging and low‐phototoxicity in vivo imaging.
Response of the ENPP1-Deficient Skeletal Phenotype to Oral Phosphate Supplementation and/or Enzyme Replacement Therapy: Comparative Studies in Humans and Mice
Authors: Ferreira Carlos R , Kavanagh Dillon , Oheim Ralf , Zimmerman Kristin , Stürznickel Julian , Li Xiaofeng , Stabach Paul , Rettig R Luke , Calderone Logan , MacKichan Colin , Wang Aaron , Hutchinson Hunter A , Nelson Tracy , Tommasini Steven M , von Kroge Simon , Fiedler Imke AK , Lester Ethan R , Moeckel Gilbert W , Busse Björn , Schinke Thorsten , Carpenter Thomas O , Levine Michael A , Horowitz Mark C , Braddock Demetrios T
Published: January 2021

Inactivating mutations in human ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) may result in early-onset osteoporosis (EOOP) in haploinsufficiency and autosomal recessive hypophosphatemic rickets (ARHR2) in homozygous deficiency. ARHR2 patients are frequently treated with phosphate supplementation to ameliorate the rachitic phenotype, but elevating plasma phosphorus concentrations in ARHR2 patients may increase the risk of ectopic calcification without increasing bone mass. To assess the risks and efficacy of conventional ARHR2 therapy, we performed comprehensive evaluations of ARHR2 patients at two academic medical centers and compared their skeletal and renal phenotypes with ENPP1-deficient Enpp1asj/asj mice on an acceleration diet containing high phosphate treated with recombinant murine Enpp1-Fc. ARHR2 patients treated with conventional therapy demonstrated improvements in rickets, but all adults and one adolescent analyzed continued to exhibit low bone mineral density (BMD). In addition, conventional therapy was associated with the development of medullary nephrocalcinosis in half of the treated patients. Similar to Enpp1asj/asj mice on normal chow and to patients with mono- and biallelic ENPP1 mutations, 5-week-old Enpp1asj/asj mice on the high-phosphate diet exhibited lower trabecular bone mass, reduced cortical bone mass, and greater bone fragility. Treating the Enpp1asj/asj mice with recombinant Enpp1-Fc protein between weeks 2 and 5 normalized trabecular bone mass, normalized or improved bone biomechanical properties, and prevented the development of nephrocalcinosis and renal failure. The data suggest that conventional ARHR2 therapy does not address low BMD inherent in ENPP1 deficiency, and that ENPP1 enzyme replacement may be effective for correcting low bone mass in ARHR2 patients without increasing the risk of nephrocalcinosis. © 2021 American Society for Bone and Mineral Research (ASBMR).
An enhanced psychological mindset intervention to promote adolescent wellbeing within educational settings: A feasibility randomized controlled trial
Authors: Perkins Amorette M. , Bowers Gemma , Cassidy Joseph , Meiser‐Stedman Richard , Pass Laura
Published: January 2021

Objective

This randomized controlled trial feasibility study aimed to investigate a single‐session mindset intervention, incorporating third‐wave constructs, within educational settings as a universal tool to promote emotional wellbeing.

Method

Eighty adolescents (age M = 16.63) were randomized to the 30‐min computer intervention or a usual curriculum waitlist. Outcome measures were administered at baseline, posttreatment, 4‐week, and 8‐week follow‐ups.

Results

Student feedback about the intervention and trial procedure was mainly positive. Participants engaged with the intervention content and data were suggestive of possible small–large intervention effects for targeted mechanisms of personality mindset and psychological flexibility. Between‐group differences over time across wellbeing outcomes of self‐compassion, self‐esteem, low mood, and anxiety also yielded some promising results, though assessments of reliable change were less clear. No harm was reported.

Conclusions

The intervention and study design were deemed feasible, though areas for improvement were noted. A full‐scale trial to determine effectiveness is warranted.
Parental behavior across Nepali schools' parents and children demographic characteristics
Authors: Khadka Jiban
Published: January 2021

This study aims to explore parental behavior with its dimensions: Parental involvement, consistency in disciplinary behavior, monitoring and supervision, and punishing behavior, and also examine the difference across the parents and child demographic characteristics. The data were collected from 644 children of Grade 10 from 20 schools using the Alabama Parenting Questionnaire. Cronbach's alpha was in the range of .7 that would ensure the internal consistency of the questionnaire. From the analysis of data using mean, and SD, t‐test, and analysis of variance or Kruskal–Wallis test, the major findings were that the parents exhibit almost frequently positive parental involvement in their children's study, however, they show inconsistent disciplinary behavior and poor monitoring, and almost rarely use the corporal punishment. The study concludes that parental behavior across parents and children demographic characteristics is imperative for policymakers and practitioners to be realistic while preparing and implementing the educational plans and policies.